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                                                      - 332 -
                             Nebraska Court of Appeals Advance Sheets
                                  28 Nebraska Appellate Reports
                                         CHRISTENSEN v. SHERBECK
                                           Cite as 28 Neb. App. 332




                     Michael T. and Cathy D. Christensen, individually
                       and as the parents and next friends of Chad
                       M. Christensen, and as the Coguardians and
                         Coconservators of Chad M. Christensen,
                        a protected person, appellants, v. Beverly
                          L. Sherbeck, Personal Representative
                           of the Estate of Albert F. Sherbeck,
                            deceased, and Beverly L. Sherbeck,
                                  individually, appellees.
                                                  ___ N.W.2d ___

                                        Filed May 12, 2020.     No. A-19-124.

                 1. Expert Witnesses: Appeal and Error. Abuse of discretion is the
                    proper standard of review of a district court’s evidentiary ruling on
                    the admission of expert testimony under Daubert v. Merrell Dow
                    Pharmaceuticals, Inc., 509 U.S. 579, 113 S. Ct. 2786, 125 L. Ed. 2d
                    469 (1993).
                 2. Judges: Words and Phrases. A judicial abuse of discretion exists when
                    a judge, within the effective limits of authorized judicial power, elects
                    to act or refrain from acting, but the selected option results in a deci-
                    sion which is untenable and unfairly deprives a litigant of a substantial
                    right or a just result in matters submitted for disposition through a judi-
                    cial system.
                 3. Trial: Evidence: Appeal and Error. To constitute reversible error in a
                    civil case, the admission or exclusion of evidence must unfairly preju-
                    dice a substantial right of a litigant complaining about evidence admitted
                    or excluded.
                 4. Jury Instructions: Appeal and Error. In reviewing a claim of preju-
                    dice from jury instructions given or refused, the instructions must be
                    read together, and if, taken as a whole, they correctly state the law, are
                    not misleading, and adequately cover the issues supported by the plead-
                    ings and evidence, there is no prejudicial error.
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          Nebraska Court of Appeals Advance Sheets
               28 Nebraska Appellate Reports
                        CHRISTENSEN v. SHERBECK
                          Cite as 28 Neb. App. 332

 5. Jury Instructions: Judgments: Appeal and Error. Whether a jury
    instruction given by a trial court is correct is a question of law. When
    reviewing questions of law, an appellate court has an obligation to
    resolve the question independently of the conclusion reached by the
    trial court.
 6. Words and Phrases. An unavoidable accident has been defined as an
    unexpected catastrophe which occurs without any of the parties thereto
    being to blame for it.
 7. Negligence: Proof. A loss of consciousness constitutes an unavoidable
    accident and thereby a defense to an action based upon negligence; such
    a defense is an affirmative defense, and where the plaintiff has estab-
    lished a prima facie case of negligence, the burden of proof shifts to the
    defendant to establish the loss of consciousness defense.
 8. ____: ____. Where a sudden loss of consciousness is an affirmative
    defense, a defendant’s burden is twofold: First, the defendant must
    present sufficient evidence to establish that he suffered a sudden loss
    of consciousness prior to the accident, and second, the defendant must
    prove that the loss of consciousness was not foreseeable.
 9. Trial: Negligence: Motor Vehicles: Evidence. When the evidence is
    conflicting as to whether the accident was caused by the driver’s sudden
    loss of consciousness and whether the loss of consciousness was unfore-
    seen, it is a question of fact to be determined by the jury; however, if
    the evidence points to only one reasonable conclusion, it is a question of
    law for the court.
10. Jury Instructions: Appeal and Error. It is error to give an unavoidable
    accident, or loss of consciousness, jury instruction where there is no evi-
    dence in the record to give legal support to the defense that the accident
    was unavoidable.
11. Evidence: Circumstantial Evidence: Proof. Any fact can be proved by
    direct or circumstantial evidence.
12. Negligence: Motor Vehicles: Notice: Proof. In establishing the loss of
    consciousness defense, the issue of foreseeability is crucial. The defense
    is not available where a driver was put on notice of facts sufficient to
    cause an ordinary and reasonable person to anticipate that his or her
    driving might likely lead to injury to others.

  Appeal from the District Court for Custer County: Karin L.
Noakes, Judge. Affirmed.
  David S. Houghton and Keith A. Harvat, of Houghton,
Bradford & Whitted, P.C., L.L.O., and John O. Sennett and
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        Nebraska Court of Appeals Advance Sheets
             28 Nebraska Appellate Reports
                  CHRISTENSEN v. SHERBECK
                    Cite as 28 Neb. App. 332

James V. Duncan, of Sennett, Duncan, Jenkins & Wickham,
P.C., L.L.O., for appellants.

  Daniel M. Placzek and Jared J. Krejci, of Smith, Johnson,
Baack, Placzek, Allen, Connick & Hansen, for appellees.

  Moore, Chief Judge, and Arterburn and Welch, Judges.

   Arterburn, Judge.
                    I. INTRODUCTION
   Michael T. and Cathy D. Christensen appeal from a judg-
ment entered by the district court for Custer County which
found in favor of Beverly L. Sherbeck and against the
Christensens on the Christensens’ claim for damages arising
out of a motor vehicle accident involving their son, Chad
M. Christensen, and Beverly’s husband, Albert F. Sherbeck.
Based on the jury’s verdict that Albert suffered a sudden
loss of consciousness prior to the collision, no damages were
awarded to the Christensens. For the reasons set forth herein,
we affirm.

                      II. BACKGROUND
   This action arises out of a motor vehicle accident that
occurred in Custer County, Nebraska, on June 1, 2012. The
following facts are not disputed: On the day of the accident,
Albert was operating a pickup truck owned by himself and
Beverly. He was driving toward his home and was headed
eastbound on Highway 2 when he drove left of center and col-
lided head on with a 10-passenger van traveling westbound.
The van was transporting eight students from Broken Bow
High School who were returning from a basketball clinic
held in Kearney, Nebraska. The van was being driven by a
basketball coach for the high school. As a result of the col-
lision, Albert, the basketball coach, and the front seat pas-
senger of the van, who was also a basketball coach for the
high school, died at the scene. One of the students, Chad, was
seriously injured.
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        Nebraska Court of Appeals Advance Sheets
             28 Nebraska Appellate Reports
                   CHRISTENSEN v. SHERBECK
                     Cite as 28 Neb. App. 332

                         1. Pleadings
   In March 2013, the Christensens filed an amended com-
plaint against Beverly, both in her individual capacity and in
her capacity as the personal representative of Albert’s estate.
The amended complaint alleged that Albert was negligent in
operating his vehicle and that Beverly was negligent in failing
to prevent Albert from driving the vehicle or, in the alterna-
tive, was vicariously liable for Albert’s negligence because he
was operating the vehicle in order to further a family purpose.
The Christensens sought general damages for Chad’s “perma-
nent[] disab[ility]” and future medical expenses for Chad’s
ongoing care. The Christensens filed a separate lawsuit against
Broken Bow Public Schools.
   In her second amended answer, Beverly asserted numer-
ous affirmative defenses to the allegations contained in the
complaint, including that “[t]he accident alleged in [the
Christensens’] Amended Complaint occurred after Albert . . .
suffered a sudden loss of consciousness that was not foresee-
able.” Beverly also filed a third-party complaint alleging that
Broken Bow Public Schools was negligent in its operation
of the van prior to the accident and that such negligence was
a proximate cause of the injuries to Chad. We note that the
claims against Broken Bow Public Schools are not discussed
in this appeal.
           2. The Christensens’ Motion in Limine
   Prior to trial, the Christensens filed a motion in limine
seeking to exclude Beverly’s proposed medical expert wit-
nesses who were to testify that Albert suffered sudden car-
diac death prior to the collision and was not conscious at the
time of impact. In the motion, the Christensens alleged that
the expert opinions should be excluded pursuant to the prin-
ciples outlined in Daubert v. Merrell Dow Pharmaceuticals,
Inc., 509 U.S. 579, 113 S. Ct. 2786, 125 L. Ed. 2d 469
(1993), and Schafersman v. Agland Coop, 268 Neb. 138,
681 N.W.2d 47 (2004). A hearing was held on the motion in
limine. At the hearing, the Christensens offered into evidence
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        Nebraska Court of Appeals Advance Sheets
             28 Nebraska Appellate Reports
                    CHRISTENSEN v. SHERBECK
                      Cite as 28 Neb. App. 332

numerous exhibits, including an accident report completed by
the Nebraska State Patrol, depositions from witnesses to the
collision, and depositions of four different medical experts.
                (a) Evidence Offered at Motion
                       in Limine Hearing
   The accident report, which was authored by Dion Neumiller,
a trooper with the Nebraska State Patrol, detailed the results
of the accident reconstruction analysis. The report indicated
that Albert’s pickup truck, which was facing eastbound, “had
come to final rest” with its front axle in the westbound lane
of Highway 2 and its rear axle on the westbound paved shoul-
der. The truck had “severe contact damage to the front of the
vehicle[, which had] fold[ed] the hood rearward.” The school
van, which was facing westbound, “had come to final rest”
also in the westbound lane. While the rear of the van was
angled toward the shoulder, it still remained entirely within
the westbound lane. The van “also had severe contact damage
to the front, [which had] fold[ed] the hood rearward into the
windshield.” In his deposition, Neumiller explained that the
accident resulted in a “nearly . . . head-on collision” such that
the vehicles were lined up “license plate to license plate” when
they came to a stop.
   The accident report revealed that the airbag control module
from the school van indicated that in the 5 seconds lead-
ing up to the collision, the van was slowing down. In fact,
the antilock brakes on the van were engaged half a second
prior to the collision. To the contrary, the airbag control
module from Albert’s pickup truck indicated that the truck
continued at a consistent speed of 63 miles per hour in the 5
seconds leading up to the collision. Neumiller testified that
there was no indication that the pickup truck’s brakes were
deployed at any point in the seconds leading up to the colli-
sion. Another trooper testified in his deposition that it is likely
the pickup truck had its cruise control engaged at the time of
impact. No preimpact or postimpact marks were located on
the roadway.
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        Nebraska Court of Appeals Advance Sheets
             28 Nebraska Appellate Reports
                   CHRISTENSEN v. SHERBECK
                     Cite as 28 Neb. App. 332

   The steering wheel of Albert’s pickup truck was “fixed and
rotated” to the right at approximately 20 degrees. Neumiller
explained that this could indicate that “the last steering input
made by the driver may have been to the right.” However,
Neumiller also indicated that there could be other reasons for
the steering wheel to have been slightly rotated during or after
the collision.
   Although Albert did not have his seatbelt on, he was sitting
upright in the driver’s seat of the pickup truck at the time of
the collision. His airbag was deployed and had “no significant
blood” on it. Neumiller opined that the minimal amount of
blood on the airbag could indicate that Albert was deceased
prior to the collision.
   Approximately 10 minutes prior to the collision, Albert ini-
tiated a telephone call using his cellular telephone. He spoke
to a member of his church and inquired what songs the choir
would be singing that Sunday. The telephone call lasted just
over 5 minutes, and the recipient of the call later reported
that Albert sounded “fine.” After the collision, Albert’s cel-
lular telephone was located in his left shirt pocket. Albert’s
family, who spent the day with him prior to the collision, also
indicated that Albert seemed fine, although he had mentioned
feeling tired.
   There were two witnesses to the collision, John Scott and
Lavera Scott, who were in a vehicle which was traveling
directly behind Albert’s pickup truck. Both John and Lavera
provided deposition testimony regarding their observations.
   John testified that on the afternoon of the accident, he
and his wife, Lavera, were driving eastbound on Highway 2,
which was a two-lane highway. While he was driving, John
observed a pickup truck approximately two blocks ahead of
him on the highway. John estimated that the pickup truck
must have been traveling between 55 and 60 miles per hour
because John had his cruise control set at 60 miles per hour
and “was beginning to gain a little on [the pickup truck].”
John indicated that he could not see inside the pickup truck
from his vantage point two blocks behind it.
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        Nebraska Court of Appeals Advance Sheets
             28 Nebraska Appellate Reports
                   CHRISTENSEN v. SHERBECK
                     Cite as 28 Neb. App. 332

   Prior to the collision, John did not observe the pickup truck
swerve either onto the shoulder or into the oncoming traffic
lane. In fact, John indicated that he did not observe anything
unusual about the pickup truck prior to the collision. John did
observe the collision. He testified that the pickup truck sud-
denly “jumped over” in front of the van. He described the
movement of the truck as not “slow,” but “fast” and “[s]udden.”
John testified that the pickup truck moved directly over into
the oncoming traffic lane. John indicated that he never saw the
pickup truck’s brake lights engage.
   Although John did not know who was driving the pickup
truck prior to the collision, when he approached the pickup
truck after the collision, he learned that the driver was Albert.
John testified that Albert was slumped down to the left after
the collision. John was familiar with Albert and knew that
some of Albert’s farmland was adjacent to where the acci-
dent occurred.
   Lavera testified similarly to John’s testimony. She testified
that she and her husband were driving “a couple of blocks”
behind the pickup truck on the highway. From her vantage
point, she could see that there was just one person in the
pickup truck, but she was unable to observe specific move-
ments of the sole occupant. Prior to the accident, she did
not observe any unusual movement by the pickup truck. The
pickup truck did not swerve onto the shoulder, did not move
into the oncoming traffic lane, and did not swerve within its
own lane. Lavera observed the collision. She described that
“suddenly the pickup was there and then it wasn’t there.” The
pickup truck had “almost jumped” into the oncoming lane of
traffic. Lavera testified that the pickup truck’s movement in
this regard was “sudden.” Lavera did not see the pickup truck’s
brake lights engage.
   Lavera testified that since the date of the accident, she had
been diagnosed with macular degeneration, which had some-
what affected her vision. However, she also testified that she
had no trouble viewing the collision.
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        Nebraska Court of Appeals Advance Sheets
             28 Nebraska Appellate Reports
                   CHRISTENSEN v. SHERBECK
                     Cite as 28 Neb. App. 332

   At the motion in limine hearing, the Christensens offered
into evidence the deposition of one of the high school students
who was riding in the school van at the time of the collision
and who remembered the moments leading up to the accident.
The student testified that immediately prior to the collision,
he remembered the van’s driver telling everyone in the van
to “hold on.” The student then looked up and observed a
pickup truck “drifting into our lane.” He described the motion
of the pickup truck as seeming slow. The student also testi-
fied that he believed that the van’s driver was attempting to
avoid the impending collision by applying the brakes and
trying to steer onto the shoulder of the road. We note that the
Christensens also offered the deposition testimony of Chad.
However, Chad is unable to recall any of the events surrounding
the collision.
   The remaining evidence offered by the Christensens at the
motion in limine hearing was composed of deposition tes-
timony from four medical experts. Two of the experts, Drs.
Daniel McGowan and Jeffrey Mahoney, were retained by
Beverly. The other two experts, Drs. Jeffrey Rubinstein and
George Riley Nichols II, were retained by the Christensens.
   McGowan is an interventional cardiologist who treated
Albert for symptoms related to coronary disease beginning in
February 2009. On February 27, McGowan diagnosed Albert
as suffering from a 99-percent stenosis of the left circumflex
artery. As a result of this diagnosis, McGowan placed a stent
in that artery to improve blood flow. McGowan then pre-
scribed beta-blocking medication for Albert in order to slow
down his heart rate and treat both the blockage found in the
left circumflex artery and Albert’s ongoing coronary artery
disease. McGowan was unsure if Albert continued to take this
medication at the time of the collision.
   McGowan also diagnosed Albert as suffering from a 75- to
80-percent stenosis in the right coronary artery. McGowan
placed a stent in the right coronary artery in April 2009 and
later, in January 2010, further repaired that artery with an
atherectomy procedure.
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        Nebraska Court of Appeals Advance Sheets
             28 Nebraska Appellate Reports
                    CHRISTENSEN v. SHERBECK
                      Cite as 28 Neb. App. 332

   In May 2009, Albert was diagnosed as suffering from reno-
vascular hypertension after testing revealed a 60- to 70-percent
stenosis of his right renal artery. McGowan believed that the
stenosis of the right renal artery caused Albert to suffer from
high blood pressure. McGowan indicated that Albert’s high
blood pressure was controlled with medication.
   In February 2011, McGowan diagnosed Albert as suffering
from mild left ventricular dysfunction. He described this con-
dition as systolic dysfunction, which relates to how the heart
contracts. Subsequent stress testing of Albert’s heart revealed
an “ejection fraction” of 50 percent, which is slightly below
a normal ejection fraction of 55 percent or more. McGowan
indicated that Albert’s below normal ejection fraction was a
residual effect of left ventricular heart damage, which was con-
sistent with Albert’s having suffered a prior heart attack.
   On September 2, 2011, Albert returned to McGowan com-
plaining of increased fatigue and shortness of breath during
exertion. He also reported having felt heart palpitations a few
weeks prior to this visit, which McGowan believed could indi-
cate that Albert was experiencing an abnormal heart rhythm.
Testing revealed that Albert was suffering from atrial fibrilla-
tion, a fast heart rhythm causing a lack of effective contraction.
McGowan prescribed three different medications to treat this
condition. After the September 2011 visit, Albert did not return
to see McGowan prior to his death in June 2012.
   After Albert’s death, McGowan reviewed the autopsy report.
Based on his review, McGowan believed that sometime after
Albert’s last office visit and before the day of his death, he
suffered a heart attack which went untreated and which caused
a “large scar” in the wall of his heart. McGowan stated that
“the extent of the infarct on the autopsy was much more than
what I saw on the imaging modalities that I used.” McGowan
did not, however, believe that Albert suffered a heart attack
immediately prior to the collision because there were no
observable signs of such a cardiac event in the autopsy. Rather,
McGowan opined that Albert was at a high risk of suffering
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        Nebraska Court of Appeals Advance Sheets
             28 Nebraska Appellate Reports
                    CHRISTENSEN v. SHERBECK
                      Cite as 28 Neb. App. 332

a sudden cardiac death at the time of the collision and had,
in fact, suffered sudden cardiac death immediately prior to
the collision.
   McGowan explained that sudden cardiac death “is when
the heart goes into a rhythm that’s very fast. Typically in that
situation, the two rhythm disorders are ventricular fibrillation,
ventricular tachycardia, where the heart’s beating over 300
times a minute, cannot fill full of blood, and the patient will
decompensate, pass out and die.” McGowan further explained
that there are no observable indications which can be found
on an autopsy which would demonstrate that a person suffered
sudden cardiac death. Rather, his opinion that Albert suffered
sudden cardiac death prior to the collision was based upon
      the medical records from the time that [McGowan began]
      car[ing] for [Albert], which would include the extent of
      his coronary disease; his risk factors for sudden cardiac
      death, including, [age, male sex, atrial fibrillation, history
      of a coronary vascular disease event in the past year]; the
      autopsy findings of [an extensive infarct in the posterior-
      lateral distribution]; and also the cardiomyopathy or car-
      diomegaly that they found on autopsy.
   McGowan essentially opined that while Albert was driving,
he suffered from sudden cardiac death which made him pass
out within a few seconds. Due to Albert’s unconsciousness,
he drove into the oncoming traffic lane and collided with the
school van. McGowan indicated that he did not disagree with
the official cause of Albert’s death listed on his death certifi-
cate, which was multiple blunt force trauma to his head, neck,
and trunk. McGowan simply opined that the collision was a
result of Albert’s suffering from sudden cardiac death.
   Mahoney concurred with McGowan’s opinions that Albert
was at a high risk for sudden cardiac death and, in fact, suf-
fered sudden cardiac death prior to the collision. Mahoney is a
cardiologist who specializes in electrophysiology. Specifically,
Mahoney specializes in diagnosing and treating conditions
that may lead to sudden cardiac death, ventricular fibrillation,
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        Nebraska Court of Appeals Advance Sheets
             28 Nebraska Appellate Reports
                    CHRISTENSEN v. SHERBECK
                      Cite as 28 Neb. App. 332

or ventricular tachycardia. In forming his opinions, Mahoney
reviewed Albert’s medical records, the autopsy report, and
various witness statements.
   Based upon Mahoney’s review of these documents, he
opined that immediately prior to the collision, Albert suffered
a sudden life-threatening abnormal heart rhythm that caused
him to suddenly and abruptly lose consciousness, which in
turn caused him to abruptly swerve into the oncoming lane
and collide with the school van. Mahoney conceded that there
was nothing specific observed during Albert’s autopsy which
definitively demonstrated that Albert suffered from sudden
cardiac death; however, certain findings from the autopsy
demonstrated that Albert was at a high risk for suffering from
sudden cardiac death. These findings included “extensive coro-
nary artery disease, a large posterolateral myocardial infarc-
tion, a large scar in the heart which . . . undoubtedly affect[ed]
his pumping function of his heart.”
   Mahoney testified that the results of the autopsy revealed
that sometime after May 2011 (the day of Albert’s last stress
test with McGowan) but before the day of the collision, Albert
suffered a “silent[, but significant,] heart attack[]” which left
a large scar in his heart. Mahoney opined that when consider-
ing Albert’s history of heart-related problems together with
the large scar from a significant heart attack observed dur-
ing the autopsy, Albert’s risk of sudden cardiac death in any
given 5-year period was approximately 12 to 15 percent. He
explained that research has demonstrated that 80 percent of
patients who experience sudden cardiac death have suffered
from coronary artery disease. Seventy-five percent of patients
who experience sudden cardiac death have suffered a prior
heart attack. Albert had both of those risk factors.
   Mahoney ultimately opined that it is more likely than not
that Albert died of a sudden cardiac death or an abnormal heart
rhythm. He further explained that the “vast majority” of people
who have sudden cardiac death have no prior symptoms: “They
are perfect one second, the next second they collapse.”
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        Nebraska Court of Appeals Advance Sheets
             28 Nebraska Appellate Reports
                    CHRISTENSEN v. SHERBECK
                      Cite as 28 Neb. App. 332

   Rubinstein is a cardiologist who was retained by the
Christensens to provide an opinion regarding whether Albert
suffered sudden cardiac death prior to the collision. In reach-
ing his opinion, Rubinstein reviewed Albert’s medical records,
the autopsy report, the death certificate, photographs, and
witness statements. Rubinstein agreed with the opinions of
McGowan and Mahoney that Albert was at risk for sudden
cardiac death due to his coronary artery disease and some scar-
ring in his heart. However, Rubinstein did not agree that Albert
suffered sudden cardiac death prior to the collision. He opined
that such an event was “highly unlikely,” or at least no more
likely than that Albert fell asleep prior to the collision or was
distracted prior to the collision. Rubinstein indicated that there
was no more than a 20-percent likelihood that Albert suffered
a sudden cardiac event just prior to the collision.
   Ultimately, Rubinstein asserted that any theory that Albert
died, or suffered from, sudden cardiac death prior to the colli-
sion was “nothing more than pure speculation” because there
is no way to definitively prove what happened in the moments
leading up to the collision.
   Nichols is a forensic pathologist who was retained by the
Christensens to provide a further opinion regarding whether
Albert suffered sudden cardiac death prior to the collision.
In reaching his opinion, Nichols reviewed the autopsy report,
the accident report, and some of Albert’s medical records.
Nichols opined that Albert did not suffer from sudden cardiac
death prior to the collision. Nichols found evidence of “car-
diac output” for “at least . . . a little while” after the accident,
including the amount of blood in Albert’s chest and abdomi-
nal cavities and surrounding his brain during the autopsy.
He explained that such bleeding indicates that Albert’s heart
continued to work for some amount of time after the collision.
In addition, Nichols pointed to the lack of any “acute finding
in [Albert’s] coronary arteries [to definitively demonstrate]
sudden cardiac death.” Although, Nichols conceded that it is
impossible to view a fatal, irregular heart rhythm during an
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        Nebraska Court of Appeals Advance Sheets
             28 Nebraska Appellate Reports
                    CHRISTENSEN v. SHERBECK
                      Cite as 28 Neb. App. 332

autopsy. He also testified that Albert’s heart showed irregulari-
ties, including evidence of a “large previous heart attack” and
severe coronary artery disease.
   Nichols also found evidence that Albert was seated upright
in the driver’s seat at the time of the collision because “a mark
very similar to a steering wheel mark [was present] on his
chest.” Nichols opined that if Albert suffered sudden cardiac
death prior to the accident and lost consciousness, his hands
would have dropped from the steering wheel and he would
have slumped over.
   Finally, Nichols opined that any opinion that Albert suf-
fered or died from a sudden cardiac event is nothing more
than speculation. Nichols indicated that there is simply no
way to determine whether Albert suffered from sudden car-
diac death, because he was not wearing a heart monitor
and no one was in the pickup truck with him to report what
Albert experienced.

                (b) District Court Decision on the
                 Christensens’ Motion in Limine
   After the hearing on the Christensens’ motion in limine,
the district court entered a detailed order denying, in part,
and granting, in part, the motion. Specifically, the district
court explained that Beverly’s medical experts, McGowan and
Mahoney, could testify as to two opinions if allowed by the
court. First, they could testify that Albert was at a high risk
of suffering a severe cardiac event, like sudden cardiac death.
Second, they could testify that Albert did, in fact, suffer a car-
diac event immediately prior to the collision which rendered
him unconscious. The court noted, “Both opinions are relevant
and would assist the trier of fact in determining the cause of
the collision and whether the sudden loss of consciousness
defense has been proven.” However, that conclusion did not
end the court’s inquiry. The court then analyzed whether each
opinion met “the additional requirements outlined in Daubert
and Schafersman.”
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        Nebraska Court of Appeals Advance Sheets
             28 Nebraska Appellate Reports
                    CHRISTENSEN v. SHERBECK
                      Cite as 28 Neb. App. 332

   The district court found that McGowan’s and Mahoney’s
opinion that Albert was at a high risk of suffering a severe
cardiac event was admissible. The court indicated that both
doctors are qualified to testify as experts regarding diseases
of the heart and that the methodology and reasoning underly-
ing each of their opinions about Albert’s risk of suffering a
severe cardiac event is scientifically valid and reliable. The
court also indicated, “The factfinder should be allowed to
weigh this evidence against the other possible causes to make
[its] factual determination.” Finally, the court found that the
opinion was not substantially outweighed by the danger of
unfair prejudice.
   The district court found that McGowan’s and Mahoney’s
opinion that Albert did, in fact, suffer a cardiac event imme-
diately prior to the collision which rendered him unconscious
was not admissible. The court pointed to the testimony of both
doctors that there was no medical evidence to prove that Albert
suffered a sudden cardiac event on the date of the collision
and, as a result, found that the facts supporting the doctors’
opinions are “lacking.” The court also found that the reasoning
and methodology the doctors used in arriving at each of their
opinions that Albert suffered a sudden cardiac event just prior
to the collision is not supported by the scientific tests and stud-
ies presented. The court indicated that the doctors could not
give an opinion based upon inferences.
   After the district court entered its order, the Christensens
filed a supplemental motion in limine. In the motion, the
Christensens renewed their argument that “any evidence relat-
ing to [Albert’s] medical condition and the presence of risk fac-
tors immediately before the accident on June 1, 2012, includ-
ing the testimony of . . . McGowan and . . . Mahoney,” should
be excluded. The court denied this supplemental motion. The
court explained:
         The evidence is relevant. The jury is charged with
      determining the cause of the accident. [Beverly has] raised
      sudden loss of consciousness as a defense. [Albert’s]
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        Nebraska Court of Appeals Advance Sheets
             28 Nebraska Appellate Reports
                   CHRISTENSEN v. SHERBECK
                     Cite as 28 Neb. App. 332

     medical condition is relevant to that determination. It is
     also relevant to determine whether any possible loss of
     consciousness was foreseeable.
        The admission of this evidence does not permit the jury
     to improperly speculate as to causation. [Albert’s] medi-
     cal condition is one of many facts and inferences the jury
     is allowed to consider when determining causation. The
     doctor[s’] testimony regarding his medical condition prior
     to the accident is not speculative. It is based on informa-
     tion these experts had direct knowledge of, is reliable and
     can be presented as circumstantial evidence by [Beverly]
     to prove loss of consciousness.
        The court agrees that the causal link between [Albert’s]
     medical condition and causation must be established
     through expert testimony. This is consistent with the
     court’s prior ruling.
                             3. Trial
   At trial, the parties presented voluminous evidence, some
of which was previously offered during the hearing on the
Christensens’ motion in limine. Given the issues presented
by this appeal, we limit our recitation of the evidence pre-
sented at trial to evidence that is relevant to Beverly’s defense
that Albert suffered a sudden loss of consciousness prior to
the collision.
   During the trial, the Christensens called Neumiller to testify
regarding the results of his accident reconstruction investiga-
tion. Neumiller detailed the way the vehicles were situated
after the impact and provided his opinion that the collision
was “a near head-on collision with license plate almost to
license plate.” He also relayed the information gained from
the airbag control modules of both vehicles, including that
although the school van’s brakes were engaged prior to the
impact, Albert never engaged his pickup truck’s brakes or
even slowed down.
   Neumiller indicated that Albert was likely seated in the
driver’s seat at the time of the collision. Neumiller testified
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that the driver’s side airbag did deploy in Albert’s pickup
truck and that it did have some blood on it which was con-
sistent with Albert’s facial injuries. In addition, the damage to
the steering wheel was consistent with someone having been
seated in the driver’s seat. Neumiller did indicate, however,
that there was not enough information to definitively deter-
mine whether Albert was seated upright or was slumped over
the steering wheel at the time of the collision. Additionally,
Neumiller noted that the airbag did not have “significant”
amounts of blood on it which could indicate that Albert’s heart
had stopped pumping by the time of the collision. A sheriff’s
deputy, who was the first law enforcement officer to arrive at
the scene of the collision, noted that although Albert’s legs
were in the driver’s seat, the rest of his body “was laid over
towards the passenger seat.”
   Neumiller testified that the steering wheel in Albert’s
pickup truck was rotated 20 degrees. Neumiller explained that
rotation could be due to a number of reasons, including that
Albert turned the wheel just prior to impact, that the force of
Albert’s body changed the position of the steering wheel dur-
ing the collision, or that the steering wheel linkage was dam-
aged during the impact.
   Finally, Neumiller testified that although Albert used his cel-
lular telephone to place a call approximately 10 to 12 minutes
prior to the collision, there is no evidence to suggest he was
using his cellular telephone at the time of the collision because
it was found in his shirt pocket during the autopsy.
   The Christensens next called Beverly to testify regarding
Albert’s activities on the day of the collision. Beverly testified
that on June 1, 2012, she and Albert spent much of the day
helping their son and daughter-in-law with a garage sale at the
local fairground. In fact, the two had spent a “long and tiring
day” the day before helping with the garage sale.
   On the morning of June 1, 2012, Albert complained that his
back was hurting, so he stayed behind at home while Beverly
left to assist with the garage sale. Albert then arrived at the
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sale at approximately 10:30 a.m. and began visiting with cus-
tomers and accepting payments for the garage sale items. After
lunch, Albert accompanied his son to deliver a table and chairs
that had been purchased by a customer at the garage sale.
When they returned to the sale, Albert resumed his place at the
“money table” and continued to visit with customers. Beverly
testified that Albert seemed “fine.”
   At approximately 3:30 p.m. that day, Albert indicated that
the garage sale was no longer busy and that he was “kind of
tired” so he was going to return home. Beverly testified that,
at the time, she believed that Albert was more bored than he
was tired.
   Beverly testified that the collision occurred approximately
three-fourths of a mile from the road which led to their home
and 1 mile from their home. Directly adjacent to the collision
site were fields which she and Albert owned, but which they
rented out to others for farming. While Beverly explained that
sometimes she and Albert would take a drive to check on the
crops at the rented fields, Albert would always stop the vehi-
cle to observe the fields, rather than just drive by. However,
Beverly believed that at the time of the collision, the crops
were not even up yet, so there would have been nothing to
see in the fields. Beverly indicated that Albert would get tired
while driving “[m]aybe once in a while.”
   By the time of the trial, the two witnesses to the collision,
John and Lavera, were deceased. As a result, the Christensens
read into evidence each of their deposition testimonies. The
specifics of their depositions are detailed above in our recita-
tion of the evidence offered at the hearing on the Christensens’
motion in limine.
   After the Christensens rested, Beverly offered into evidence
the videotaped trial depositions of McGowan and Mahoney.
The Christensens objected to this evidence, arguing that it was
not relevant. Those objections were overruled.
   McGowan testified that he is a board-certified interven-
tional cardiologist. He explained that a cardiologist is a doctor
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who cares for patients that have cardiovascular diseases. An
interventional cardiologist cares for patients that have coro-
nary disease, by implanting “stents [and] balloons” in both
coronary arteries located within the heart and other arteries
located throughout the body.
   McGowan treated Albert from February 2009 through
September 2011 for cardiovascular problems. In his trial
deposition, McGowan explained the specific treatment he pro-
vided to Albert during this time period. This testimony is very
similar to the testimony we detailed above in our recitation
of the evidence offered at the hearing on the Christensens’
motion in limine. As such, we do not reiterate the particu-
lars of this testimony here, other than to note that during his
trial deposition, McGowan provided further details regard-
ing stress testing completed on Albert from February 2009
through September 2011. Such testing indicated that Albert’s
ejection fraction was normal after the stents were placed in
the left and right sides of his heart. However, by May 2011,
Albert’s ejection fraction had dropped to “[l]ow normal.” The
last time that Albert saw McGowan in September 2011, he
complained of fatigue, shortness of breath, and intermittent
heart palpitations. Testing revealed that Albert was suffering
from episodes of atrial fibrillations, indicating that the top
chamber of his heart was not staying in rhythm and was not
contracting effectively. McGowan prescribed a medication to
try to normalize Albert’s heart rhythm and another to thin his
blood to reduce the risk of a stroke.
   After Albert’s death, McGowan reviewed the autopsy report.
McGowan explained that many of the autopsy findings, as
they related to Albert’s heart, were “significant.” The autopsy
revealed that Albert’s heart was enlarged and that he “had
extensive coronary artery disease involving the left main
artery. Two branches of the LAD called diagonals, as well as
the right coronary artery, further show that he had an extensive
infarct involving the left ventricular myocardicum.” McGowan
explained that an infarct is a heart attack. He opined that
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Albert had suffered a heart attack sometime between September
2011, when McGowan last examined Albert, and June 2012,
prior to the collision. As a result of the heart attack, Albert
had “extensive scarring” which placed him “at a much higher
risk of abnormal heart rhythms and also sudden cardiac death.”
Sudden cardiac death is when a person’s heart beats abnor-
mally with no effective contraction. McGowan stated, “Those
patients have complete hemodynamic collapse, will pass out,
and will pass away” within seconds.
   McGowan explained that an autopsy cannot show whether
a person suffered sudden cardiac death, because an autopsy
does not show how a person’s heart was beating prior to
death. However, McGowan opined that on the day of the col-
lision, Albert was “at considerable increased risk for sudden
cardiac death” based upon his clinical risk factors. Those fac-
tors included Albert’s gender, the large size of his heart, and
“his age, his established coronary disease, the extent of his
coronary disease on autopsy, as well as his monitor showing
PVCs, at times ventricular begeminy, as well as the extensive
infarct report on the path sections.” McGowan testified that
patients do not typically have any warning that they are about
to experience sudden cardiac death. McGowan testified that he
never advised Albert to stop driving.
   Mahoney testified that he is a board-certified cardiolo-
gist who specializes in electrophysiology. He explained that,
essentially, he specializes in abnormal heart rhythms, including
implanting pacemakers, defibrillators, and other heart fail-
ure devices. Mahoney reviewed Albert’s medical records and
the autopsy report. Based on his review of this information,
he opined that Albert was at extremely high risk for suffer-
ing from sudden cardiac death on the day of the collision.
Mahoney explained that when a person suffers from sudden
cardiac death, they will “abruptly collapse.”
   Mahoney based his opinion on multiple factors. First, he
found evidence in the autopsy report that Albert had suffered a
heart attack sometime between his last stress test in May 2011
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and approximately 6 weeks prior to the collision on June 1,
2012. This heart attack had caused “extensive scarring” within
the heart which had left the heart wall muscle weak. Mahoney
noted that Albert had never reported having such a heart attack
to medical professionals. Mahoney did not believe Albert’s
lack of report to be unusual, as people have “silent” heart
attacks all the time.
   Second, Mahoney believed that the size of Albert’s heart
was a risk factor for sudden cardiac death. Mahoney stated,
“[A]n enlarged heart would potentially put you at higher risk
of sudden cardiac death in the general population.” Other risk
factors included Albert’s suffering from significant coronary
artery disease, from atherosclerotic heart disease, and from
premature ventricular contraction. Mahoney further stated that
75 percent of patients who experience sudden cardiac arrest
have a history of having a heart attack. Eighty percent of
patients who experience sudden cardiac death have significant
coronary artery disease.
   Mahoney testified that there is no pathologic findings that
can be observed during an autopsy to demonstrate that some-
one suffered from sudden cardiac death. Rather, an autopsy
can demonstrate that someone was at significant risk for
such an episode. Mahoney opined that Albert may not have
had any warning that he was about to experience sudden car-
diac death.
   After Beverly rested her case, the Christensens read into
evidence portions of Mahoney’s discovery deposition, Nichols’
discovery deposition, and Rubinstein’s discovery deposition as
rebuttal evidence. Beverly objected to this rebuttal evidence,
but the objections were overruled.
   The portion of Mahoney’s discovery deposition that was read
into evidence included his explanation of “typical” symptoms
suffered during a “massive” heart attack. Mahoney explained
that typical symptoms include crushing substernal chest pain,
heaviness, shortness of breath, sweating, nausea, and vomit-
ing. Mahoney indicated that there was no evidence that Albert
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had ever presented to a medical professional complaining of
those symptoms.
   The portion of Nichols’ discovery deposition that was read
into evidence included his opinion that any theory that Albert
either suffered or died as a result of any sudden cardiac event
prior to the collision can be nothing more than pure specula-
tion. Nichols explained this opinion as follows:
      If it’s a cardiac event, you must have a monitor of some
      type on the person to be able to prove it, or an observer in
      the car with them to be able to make — make the obser-
      vation. There’s no witness in — in the pickup truck. I’m
      unaware of a monitor being placed upon him leading up
      to — to his — to the collision.
   The portion of Rubinstein’s discovery deposition that was
read into evidence included his opinion that any theory that
Albert either suffered or died as the result of a sudden cardiac
death prior to the collision can be nothing more than pure
speculation. Rubinstein explained, “He could’ve had multiple
reasons to have driven into the other car.” Rubinstein also indi-
cated that there was no medical evidence to prove that Albert
suffered a sudden cardiac event prior to the collision.
   At the close of the evidence, the district court gave the jury
an instruction on the loss of consciousness defense raised by
Beverly, over the Christensens’ objections. Jury instruction No.
2 read, in pertinent part:
                     DEFENDANTS[’] DEFENSE
                                ISSUES
         In defense to plaintiff’s claims, Defendant Beverly
      Sherbeck, Personal Representative of the Estate of Albert
      Sherbeck, deceased[,] and Beverly Sherbeck claim that
      Albert Sherbeck suffered a sudden loss of consciousness
      prior to the collision.
                         BURDEN OF PROOF
         In connection with their claim that Albert Sherbeck
      suffered a sudden loss of [c]onsciousness, the burden is
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      on defendant to prove by the greater weight of the evi-
      dence both of the following:
         1. That Albert Sherbeck suffered a sudden loss of con-
      sciousness prior to the accident; and
         2. The loss of consciousness was not foreseeable.
                       EFFECT OF FINDINGS
         If the defendant has met her burden of proving her
      defense, the[n] your verdict must be for Beverly Sherbeck,
      Personal Representative of the Estate of Albert Sherbeck,
      deceased, on this claim . . . .
   Ultimately, the jury returned a verdict in favor of Beverly,
both in her personal capacity and in her capacity as the per-
sonal representative of Albert’s estate. Specifically, the jury
found that although the Christensens had sufficiently proved
their negligence claims, Beverly had also sufficiently proved
that Albert suffered a sudden loss of consciousness prior to
the collision.
   The Christensens filed a motion for new trial alleging that
the district court erred in instructing the jury on the loss of
consciousness defense because there was not sufficient, com-
petent evidence presented during the trial to prove that Albert
had, in fact, lost consciousness prior to the collision. The
Christensens stated that “the Court’s instruction to the jury on
sudden loss of consciousness materially affected the substan-
tial rights of the [Christensens], is not sustained by sufficient
evidence and is contrary to law.” After a hearing, the district
court denied the motion for new trial.
   The Christensens appeal from the verdict entered against
them and in favor of Beverly.
                III. ASSIGNMENTS OF ERROR
   On appeal, the Christensens allege, renumbered and consoli-
dated, that the district court erred in (1) admitting into evidence
the expert medical opinions of McGowan and Mahoney and
(2) instructing the jury on the sudden loss of consciousness
defense where there was not sufficient evidence presented at
trial to support such a defense.
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                  IV. STANDARD OF REVIEW
   [1-3] Abuse of discretion is the proper standard of review of
a district court’s evidentiary ruling on the admission of expert
testimony under Daubert v. Merrell Dow Pharmaceuticals,
Inc., 509 U.S. 579, 113 S. Ct. 2786, 125 L. Ed. 2d 469 (1993).
Gonzales v. Nebraska Pediatric Practice, 26 Neb. App. 764,
923 N.W.2d 445 (2019). A judicial abuse of discretion exists
when a judge, within the effective limits of authorized judicial
power, elects to act or refrain from acting, but the selected
option results in a decision which is untenable and unfairly
deprives a litigant of a substantial right or a just result in mat-
ters submitted for disposition through a judicial system. Id.
To constitute reversible error in a civil case, the admission
or exclusion of evidence must unfairly prejudice a substantial
right of a litigant complaining about evidence admitted or
excluded. Id.
   [4,5] In reviewing a claim of prejudice from jury instruc-
tions given or refused, the instructions must be read together,
and if, taken as a whole, they correctly state the law, are not
misleading, and adequately cover the issues supported by the
pleadings and evidence, there is no prejudicial error. Jay v.
Moog Automotive, 264 Neb. 875, 652 N.W.2d 872 (2002).
Whether a jury instruction given by a trial court is correct is a
question of law. When reviewing questions of law, an appellate
court has an obligation to resolve the question independently
of the conclusion reached by the trial court. Id.

                         V. ANALYSIS
            1. Admissibility of Expert Testimony
              on Loss of Consciousness Defense
   On appeal, the Christensens assert that the district court
erred in permitting McGowan and Mahoney to testify that
Albert was at a high risk of suffering from sudden car-
diac death. Although the Christensens broadly asserted in the
district court that this expert medical testimony should be
excluded pursuant to the principles outlined in Daubert v.
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Merrell Dow Pharmaceuticals, Inc., supra, and Schafersman
v. Agland Coop, 268 Neb. 138, 681 N.W.2d 47 (2004), on
appeal, the Christensens narrowed the focus of their argu-
ment to whether the expert opinions were relevant to the
issue of the cause of the collision. Upon our review, we
agree with the district court that McGowan’s and Mahoney’s
opinion that Albert was at a high risk of suffering from sud-
den cardiac death was relevant in determining the cause of
the collision.
   In this case, the main issue in contention at trial was the
cause of the collision. More specifically, the jury was asked
to decide why Albert’s pickup truck veered into the oncom-
ing traffic lane and struck the school van. The Christensens
offered the jury multiple theories to support their belief that
Albert was negligent, including that Albert fell asleep while
driving, that he became distracted by observing the status of
the farmland he rented out, or that he intentionally caused
the collision. Beverly offered the jury one theory: that Albert
suddenly lost consciousness while driving after suffering from
sudden cardiac death.
   In order to support her theory of causation, Beverly offered
expert medical testimony from McGowan and Mahoney that
Albert was at a high risk for suffering from sudden cardiac
death. The doctors also opined that if Albert had suffered
from sudden cardiac death in the moments prior to the col-
lision, he would have been rendered unconscious almost
immediately. As the district court found, this expert medical
testimony was relevant to the jury’s determination of why
Albert’s pickup truck veered into the oncoming traffic lane.
“Relevant evidence” is defined as that evidence which has
any tendency to make the existence of any fact that is of
consequence to the determination of an action more probable
or less probable than it would be without the evidence. Neb.
Evid. R. 401, Neb. Rev. Stat. § 27-401 (Reissue 2016); City of
Omaha v. Savard-Henson, 9 Neb. App. 561, 615 N.W.2d 497
(2000). Expert medical evidence that Albert was at a high risk
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for suffering from sudden cardiac death makes it more prob-
able that Albert did, in fact, suffer from such a cardiac event
prior to the collision. In addition, evidence that Albert was at
a high risk for suffering from sudden cardiac death makes it
more probable that he lost consciousness prior to the collision
with the school van. The expert medical evidence is also rel-
evant to a determination of whether any loss of consciousness
was foreseeable.
   Moreover, it is clear from the testimonies of both McGowan
and Mahoney that their opinions that Albert was at a high risk
for suffering from sudden cardiac death were not speculative.
Instead, the expert opinions were based upon both doctors’
extensive knowledge in the area of heart-related conditions and
the doctors’ review of both Albert’s medical records and the
autopsy report. In fact, in the case of McGowan, his opinion
was also based upon his direct treatment of Albert in the years
prior to his death.
   We find that the district court did not err in permitting
McGowan and Mahoney to offer their expert medical opinions
that Albert was at a high risk of suffering from sudden cardiac
death at the time of the collision. The opinions were reliable
and were relevant to the jury’s determination of the ultimate
cause of the collision.

               2. Jury Instruction on Loss of
                    Consciousness Defense
   On appeal, the Christensens also renew the argument they
raised multiple times before the district court that Beverly
failed to meet her burden to establish the requisite elements
of an unavoidable accident defense and that, as a result,
the district court should not have instructed the jury regard-
ing such a defense. Specifically, the Christensens assert that
Beverly did not present sufficient, competent evidence to prove
that Albert did, in fact, lose consciousness prior to the col-
lision with the school van. The Christensens also assert that
even if Beverly did sufficiently demonstrate Albert’s loss of
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consciousness, she failed to demonstrate the loss of conscious-
ness was not foreseeable.
   [6,7] An unavoidable accident has been defined by the
Nebraska Supreme Court as an unexpected catastrophe which
occurs without any of the parties thereto being to blame for it.
Storjohn v. Fay, 246 Neb. 454, 519 N.W.2d 521 (1994). See
Owen, Administrator v. Moore, 166 Neb. 226, 88 N.W.2d 759
(1958). A loss of consciousness constitutes an unavoidable
accident and thereby a defense to an action based upon negli-
gence. Storjohn v. Fay, supra. Such a defense is an affirmative
defense, and where the plaintiff has established a prima facie
case of negligence, the burden of proof shifts to the defendant
to establish the loss of consciousness defense. See id.
   [8-10] Where a sudden loss of consciousness is an affirma-
tive defense, a defendant’s burden is twofold: First, the defend­
ant must present sufficient evidence to establish that he suf-
fered a sudden loss of consciousness prior to the accident, and
second, the defendant must prove that the loss of consciousness
was not foreseeable. Id. When the evidence is conflicting as
to whether the accident was caused by the driver’s sudden
loss of consciousness and whether the loss of consciousness
was unforeseen, it is a question of fact to be determined by
the jury. Id. However, if the evidence points to only one rea-
sonable conclusion, it is a question of law for the court. Id.
Accordingly, it is error to give an unavoidable accident, or loss
of consciousness, jury instruction where there is no evidence in
the record to give legal support to the defense that the accident
was unavoidable. See id.
   Albert died in the collision, so no light can be shed on his
own experience immediately before the collision. In addition,
there is no eyewitness who can directly confirm that Albert
suddenly and actually lost consciousness prior to the collision,
and no postaccident evidence exists that can directly confirm
that Albert suddenly and actually lost consciousness prior to
the collision. However, there is relevant evidence support-
ing each parties’ position on the possibility that Albert lost
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consciousness prior to his truck’s entering the oncoming traffic
lane and colliding with the school van.
   The Christensens point to the lack of eyewitness testimony
which would definitively demonstrate that Albert lost con-
sciousness and slumped over prior to veering into the oncom-
ing lane of traffic. Instead, the Christensens rely on evidence
that Albert was seated upright in the driver’s seat of his truck
at the time of the collision, including evidence of Albert’s
blood on the driver’s side airbag and his position immediately
after the collision. The Christensens assert that, presumably,
had Albert lost consciousness prior to the collision, he would
not have remained seated upright, especially since he was not
wearing his seatbelt. The Christensens also rely on the lack of
any tangible, medical evidence that Albert suffered a heart-
related incident prior to the collision.
   To the contrary, Beverly offered evidence which suggests
that Albert had lost consciousness prior to the collision. This
evidence includes the expert testimonies of both McGowan
and Mahoney that Albert was at a very high risk of suffer-
ing from sudden cardiac death, which would have caused him
to lose consciousness in a matter of seconds. Both doctors
also indicated that sudden cardiac death could not be readily
identifiable during an autopsy. The deposition testimonies of
John and Lavera indicate that Albert was driving his pickup
truck straight down the road at a steady speed in the minutes
prior to the collision until it “suddenly” “jumped over” into
the oncoming lane of traffic and in front of the school van.
Beverly suggests that this evidence indicates that something
sudden and catastrophic happened in the moments leading up
to the collision. Finally, Beverly points to evidence from the
accident report which indicated that Albert failed to apply his
truck’s brakes or take any evasive action to avoid the colli-
sion in the seconds leading up to the accident. In fact, Albert’s
truck continued at a constant rate of speed in the seconds lead-
ing up to the collision. Neumiller, the author of the accident
report, testified that there was a lack of any “significant” blood
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on the driver’s side airbag in Albert’s truck. Neumiller opined
that the lack of blood could indicate that Albert’s heart had
stopped pumping prior to the collision.
   In their brief on appeal, the Christensens highlight that
Beverly’s assertion that Albert had lost consciousness prior to
the collision is based upon circumstantial, rather than direct,
evidence. The Christensens argue that a sudden loss of con-
sciousness defense should only be available where there is
direct evidence of a loss of consciousness, such as eyewitness
testimony. They further assert that evidence that Albert lost
consciousness prior to the collision “simply invited the jury to
speculate.” Brief for appellant at 30.
   [11] The Christensens’ argument that Albert’s loss of con-
sciousness had to be proved by direct evidence is not consist­
ent with precedent from the Supreme Court which specifically
recognizes that any fact can be proved by direct or circumstan-
tial evidence. See, e.g., Jacobs Engr. Group v. ConAgra Foods,
301 Neb. 38, 65, 917 N.W.2d 435, 458 (2018) (“[c]ircum-
stantial evidence is not inherently less probative than direct
evidence, and a fact proved by circumstantial evidence is
nonetheless a proven fact”), citing State v. Pierce, 248 Neb.
536, 537 N.W.2d 323 (1995); Carpenter v. Cullan, 254 Neb.
925, 937, 581 N.W.2d 72, 80 (1998) (“‘“[n]egligence, like any
other fact, may be proved by circumstantial evidence . . .”’”),
quoting McVaney v. Baird, Holm, McEachen, 237 Neb. 451,
466 N.W.2d 499 (1991).
   Moreover, we agree with the district court that evidence
of Albert’s loss of consciousness did not invite the jury to
speculate:
         The admission of this evidence does not permit the
      jury to improperly speculate as to causation. [Albert’s]
      medical condition is one of many facts and inferences the
      jury is allowed to consider when determining causation.
      The doctor’s testimony regarding his medical condition
      prior to the accident is not speculative. It is based on
      information these experts had direct knowledge of, is
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       reliable and can be presented as circumstantial evidence
       by [Beverly] to prove loss of consciousness.
   Although the evidence presented by Beverly that Albert had
lost consciousness prior to his truck’s entering the oncoming
traffic lane and colliding with the school van was circumstan-
tial, we find that based upon all of the evidence presented at
trial, a jury could reasonably find that the collision was the
direct result of Albert’s loss of consciousness. We now turn
to our analysis of whether Albert’s loss of consciousness
was foreseeable.
   [12] Even assuming that Albert suffered a sudden loss of
consciousness prior to the accident, we must examine the
record to determine whether such a loss was foreseeable. In
establishing the loss of consciousness defense, the issue of
foreseeability is crucial. The defense is not available where a
driver was put on notice of facts sufficient to cause an ordi-
nary and reasonable person to anticipate that his or her driving
might likely lead to injury to others. Storjohn v. Fay, 246 Neb.
454, 519 N.W.2d 521 (1994).
   In this case, both McGowan and Mahoney testified that the
majority of people who suffer from sudden cardiac death have
no prior symptoms and no prior warning of their impending
heart condition. Mahoney explained that most people who suf-
fer from sudden cardiac death are “perfect one second” and
then “the next second they collapse.” In addition, McGowan
testified that given his understanding of Albert’s heart prob-
lems prior to the collision, he never advised Albert not to
drive a vehicle. The Christensens did not offer any evidence
to directly counter the expert testimony that Albert’s sudden
loss of consciousness was not foreseeable. However, on appeal,
they point to Albert’s extensive heart problems in the years
prior to the collision in arguing that Albert must have known
that he could experience another heart problem while driv-
ing. There is nothing in the record, however, to suggest that
Albert’s known heart problems had ever affected his ability to
drive or had ever caused him to lose consciousness. Rather,
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        Nebraska Court of Appeals Advance Sheets
             28 Nebraska Appellate Reports
                    CHRISTENSEN v. SHERBECK
                      Cite as 28 Neb. App. 332

Albert described his principal symptoms as fatigue and short-
ness of breath.
   Given all of the evidence presented at the trial, we cannot
say that the district court erred in instructing the jury on the
loss of consciousness defense. Beverly presented sufficient
evidence for a reasonable jury to conclude that Albert lost
consciousness prior to the collision, including expert medical
testimony, eyewitness testimony from John and Lavera, and
the results of the accident investigation. In addition, Beverly
presented sufficient evidence for a reasonable jury to conclude
that Albert’s sudden loss of consciousness was not foreseeable.
The decision of the district court in this regard is affirmed. The
jury instruction regarding the loss of consciousness defense
correctly stated the law and was adequately supported by the
pleadings and the evidence.
                     VI. CONCLUSION
   We conclude that the district court did not err in permit-
ting expert medical testimony that Albert was at a high risk
of suffering from sudden cardiac death or in instructing the
jury on the sudden loss of consciousness defense. Accordingly,
we affirm.
                                                  Affirmed.
