Known Complication Evidence Does Not Require a Special “Risk” Limiting Instruction in Delaware Medical Negligence Trials

Introduction

Deanna McKeehan v. Delaware Neurosurgical Group and Paul T. Boulos, M.D. is a Delaware medical negligence appeal arising from complications following surgical clipping of two unruptured brain aneurysms. After the procedure, McKeehan suffered neurological deficits and was later found to have had a stroke. She sued the neurosurgeon and his practice, alleging that the surgeon deviated from the standard of care by failing to adjust a ligation clip after intraoperative monitoring suggested significantly reduced blood flow, which she contended caused her stroke.

The central appellate issue was not the medical merits, but jury instruction framing: whether the Superior Court was required to give a special limiting instruction telling jurors how to treat expert testimony that stroke is a “known risk” or “known complication” of aneurysm clipping. McKeehan argued the defense’s “known risk” theme could mislead jurors into thinking that if an outcome is a known complication, it cannot also be caused by negligence. The defendants countered that the pattern medical negligence instructions already told the jury that adverse outcomes do not themselves prove negligence, and that the “known complication” testimony went to causation and standard-of-care compliance—not informed consent.

Summary of the Opinion

The Delaware Supreme Court affirmed the defense verdict. It held that the Superior Court did not abuse its discretion by refusing to add McKeehan’s proposed “risk of the procedure” language (or the court’s own contemplated modification) to the pattern instruction defining medical negligence. Read as a whole, the jury charge—covering elements of negligence, burden of proof, the definition of medical negligence, and proximate cause—was “reasonably informative and not misleading.” The Court further concluded that the proposed language was likely to confuse jurors by undermining the instruction that negligence is “never presumed,” thereby risking an impermissible shift in the burden of proof.

Analysis

Precedents Cited

  • Miller v. State, 893 A.2d 937 (Del. 2006)
    Role in the Opinion: The Court relied on Miller for two core propositions: (1) the choice to give a particular instruction is generally within the trial judge’s discretion, and (2) a party does not possess a right to a specific instruction—even a pattern instruction—so long as the jury is correctly instructed overall. In this case, Miller anchored the Court’s conclusion that the pattern negligence instructions, taken together, adequately equipped the jury to decide liability without an extra limiting instruction about “known risks.”
  • State v. Wright, 131 A.3d 310 (Del. 2016) (quoting Charbonneau v. State, 904 A.2d 295 (Del. 2006))
    Role in the Opinion: These cases supplied the operative definition of abuse of discretion—exceeding the bounds of reason and ignoring recognized rules so as to produce injustice. Applying that deferential lens, the Court held the Superior Court’s refusal to modify the pattern charge neither ignored law nor produced injustice.
  • Wright v. State, 953 A.2d 144 (Del. 2008)
    Role in the Opinion: This precedent resolved the standard-of-review dispute. McKeehan argued for de novo review on the theory she sought a “new” instruction. The Court, agreeing with defendants, treated the request as an attempt to change the “form, content or language” of an existing instruction, which under Wright v. State is reviewed for abuse of discretion. This framing was outcome-significant: the Court did not ask whether it would have given the instruction, but whether refusing it was unreasonable.
  • McKenzie v. Blasetto, 686 A.2d 160 (Del. 1996)
    Role in the Opinion: McKenzie supplied the controlling test for instructional adequacy: parties are entitled to a correct statement of the substance of the law, but instructions need only be “reasonably informative and not misleading.” The Court used this standard to validate the trial court’s reliance on pattern medical negligence instructions without supplement.

Legal Reasoning

  1. Risk/complication testimony can be relevant without converting the case into “informed consent.”
    McKeehan argued that defense expert testimony describing stroke as a known complication injected “informed consent” contrary to a pretrial order. The Supreme Court accepted the defendants’ framing: the testimony was consistent with a defense theory that the stroke was an unfortunate consequence of the procedure rather than negligence. In other words, “known complication” evidence may serve as a causation and standard-of-care defense (i.e., a bad outcome can occur absent negligence), even if similar facts might also appear in an informed-consent context.
  2. The pattern instructions already captured the governing negligence principles.
    A key pattern instruction stated: “No presumption of medical negligence arises from the mere fact that the patient's treatment had an undesirable result. Medical negligence is never presumed.” The Court treated this language as a direct antidote to outcome-based liability—precisely the concern raised when a jury hears about known complications. Coupled with separate instructions on elements, burden of proof, and proximate cause, the charge sufficiently directed the jury to decide whether the surgeon breached the standard of care and whether any breach proximately caused the injury.
  3. The proposed supplement risked confusing the jury and shifting the burden.
    The Court identified a specific danger: the proposed sentence (“The fact that a procedure has risks in and of itself does not excuse defendants of liability for any negligence.”) could be read as implicitly directing that once “risk” is shown, negligence becomes easier to infer—or that defendants must “disprove” negligence to avoid liability. That reading would undercut the explicit instruction that negligence is “never presumed,” which safeguards the rule that the plaintiff bears the burden of proving breach and causation by a preponderance of the evidence.
  4. Instructional perfection is not required; holistic adequacy is.
    The Court’s conclusion followed Delaware’s consistent approach: it evaluates the charge as a whole. Even if the requested language accurately stated a general idea (that risk does not immunize negligence), it was not necessary to prevent juror confusion given the existing instruction set, and it posed its own confusion risks.

Impact

This Order clarifies several practical points for Delaware medical negligence litigation:

  • No automatic entitlement to a “known risk” limiting instruction. When the jury is instructed that negligence is never presumed and that injury alone does not establish liability, Delaware trial courts have discretion to decline additional “risk” language even if experts repeatedly describe the injury as a known complication.
  • “Known complication” evidence is not per se an informed-consent issue. Parties may use complication evidence to support a non-negligent causation narrative without necessarily triggering an informed-consent framework—especially where the claim tried is negligence (breach/causation), not disclosure adequacy.
  • Instruction drafting must avoid burden-shift implications. Proposed clarifications that appear plaintiff-friendly may be rejected if they can be construed to dilute the “never presumed” principle or otherwise imply defendants must disprove negligence.
  • Appellate posture matters. By categorizing requested changes as modifications to instruction language rather than omission of an entire legal subject, the Court reaffirmed that review will often be abuse of discretion, making reversals more difficult absent clear instructional error.

Complex Concepts Simplified

Medical negligence / standard of care
Under Delaware law (and reflected in the charge referencing 18 Del. C. § 6801(6)), medical negligence generally means failing to use the degree of skill and care ordinarily employed by reasonably careful providers in the same field under similar circumstances.
Known complication (or “risk of the procedure”)
Some adverse outcomes can occur even when a surgeon acts appropriately. Evidence that a stroke is a known complication can support a defense argument that the injury was an unfortunate but non-negligent outcome. But it does not logically rule out negligence; it simply means the outcome is not, by itself, proof of negligence.
Informed consent
Defined in 18 Del. C. § 6801(5), informed consent concerns what a provider must disclose to a patient about a procedure’s nature, risks, and alternatives. In this appeal, the Court treated “known complication” testimony as going to causation/standard of care rather than to whether disclosures were adequate.
Pattern jury instructions
Standardized instructions used as a baseline. Delaware recognizes they are helpful but not mandatory; the legal requirement is that the instructions given are correct and not misleading.
Abuse of discretion (appellate standard of review)
A deferential review standard. The Supreme Court will not reverse merely because it might have decided differently; it reverses only if the trial judge’s decision was beyond the bounds of reason and produced injustice.
Burden shifting
In negligence cases, the plaintiff must prove breach and causation. An instruction “shifts the burden” if it can be read to require the defendant to disprove negligence or to suggest negligence can be presumed from injury or other facts.

Conclusion

McKeehan v. Delaware Neurosurgical Group reinforces that Delaware trial courts retain broad discretion over the precise wording of jury instructions in medical negligence cases. Where the jury is told that negligence is never presumed, that an undesirable result alone does not establish liability, and where the elements and burden of proof are properly charged, the court may refuse additional “known risk” language—particularly if the proposal could confuse jurors or imply a burden shift. The decision therefore serves as a cautionary precedent: efforts to “neutralize” complication evidence through special instructions must be crafted so they clarify without undermining core negligence principles.