
393 S.E.2d 321 (1990)
99 N.C. App. 563
Eleanor Kay LABARRE, Plaintiff,
v.
DUKE UNIVERSITY and Private Diagnostic Clinic, Defendants.
No. 8914SC1044.
Court of Appeals of North Carolina.
July 17, 1990.
*323 Grover C. McCain, Jr., and Ada F. Most, Chapel Hill, for plaintiff, appellant.
Womble Carlyle Sandridge & Rice by Charles F. Vance, Jr., Guy F. Driver, Jr., and David A. Shirlen, Winston-Salem, for defendant, appellee Duke University.
Smith, Anderson, Blount, Dorsett, Mitchell & Jernigan by Samuel G. Thompson, and William H. Moss, Raleigh, for defendant, appellee Private Diagnostic Clinic.
HEDRICK, Chief Judge.
In her only assignment of error, plaintiff contends the trial court erred by allowing defendants' summary judgment motions with respect to her claims for breach of contract and for negligence. She argues that genuine issues of material fact exist, and defendants were therefore not entitled to judgment as a matter of law. We disagree.

A. BREACH OF CONTRACT
Summary judgment is a drastic remedy which should be used with caution. Bradshaw v. McElroy, 62 N.C.App. 515, 302 S.E.2d 908 (1983). Nevertheless, summary judgment is appropriate if the moving party meets the burden of proving that an essential element of the nonmoving party's claim is nonexistent. Anderson v. Canipe, 69 N.C.App. 534, 317 S.E.2d 44 (1984). It is well established that in an action for breach of contract, defendant's promise must be supported by consideration for it to be enforceable. Investment Properties v. Norburn, 281 N.C. 191, 188 S.E.2d 342 (1972). This rule also applies where plaintiff attempts to modify an existing contractual agreement. Any new promise by defendant must also be supported by additional consideration. Lee v. Paragon Group Contractors, 78 N.C.App. 334, 337 S.E.2d 132 (1985), disc. rev. denied, 316 N.C. 195, 345 S.E.2d 383 (1986).
In the present case, plaintiff claims to have requested and received Dr. Redick's assurance that if an epidural anesthetic became necessary during her delivery, only he or another fully-trained faculty anesthesiologist would administer it. This promise, however, was not supported by consideration. It was merely gratuitous and, consequently, unenforceable. We therefore conclude that the trial judge properly allowed summary judgment on the issue of breach of contract.

B. NEGLIGENCE
Plaintiff also claims the trial court erred by allowing defendants' motions for summary judgment as to the issue of medical negligence. Although plaintiff does not contend the resident physician who placed the catheter was negligent, she does argue that Dr. Redick's alleged failure to keep a promise as to who would administer the anesthetic was a breach of his duty of care owed to plaintiff. Such breach, according to plaintiff, was the proximate cause of her injuries.
*324 This court has previously stated that "an action in tort must [ordinarily] be grounded on a violation of a duty imposed by operation of law, and the right invaded must be one that the law provides without regard to the contractual relationship of the parties, rather than one based on an agreement between the parties." Asheville Contracting Co. v. City of Wilson, 62 N.C.App. 329, 342, 303 S.E.2d 365, 373 (1983). Moreover, "[a] tort action does not lie against a promisor `for his simple failure to perform his contract, even though such failure was due to negligence or lack of skill.'" Holland v. Edgerton, 85 N.C. App. 567, 572, 355 S.E.2d 514, 518 (1987) (quoting Ports Authority v. Roofing Co., 294 N.C. 73, 83, 240 S.E.2d 345, 351 (1978)).
Dr. Redick's alleged failure to keep his promise to plaintiff and her husband did not violate any duty of care imposed on him by law. Only Dr. Parham, the senior resident who placed the catheter, owed her a duty of care with respect to administering the anesthesia. Clearly, the only right arguably infringed as a result of Dr. Redick's alleged breach of promise was a contractual one. Even this right, however, was unenforceable due to a lack of consideration as previously discussed. Because North Carolina does not provide a remedy in tort where a promisor negligently fails to keep a contractual promise, a cause of action for medical negligence is not available to plaintiff. Thus, the trial court properly allowed defendants' motions for summary judgment as to plaintiff's negligence claim.
For the reasons stated herein, the judgment of the trial court is affirmed.
Affirmed.
SARAH ELIZABETH PARKER and COZORT, JJ., concur.
