Can Pediatricians Define and Apply the Concept of Brain Death?

DISCUSSION

This study represents an attempt to quantify the ability of pediatric residents and academic attending physicians to define and apply the concept of death by brain criteria, while recording their self-rated confidence at discussing this diagnosis with a patient's family. The questionnaire format is artificial and does not reflect the knowledge, judgment, and skill of physicians confronted by actual patients and clinical scenarios. Although our questions are narrow and do not do justice to the richness of a real case, we suspect that the additional nuances of a critically ill patient may add confusion, not clarification, to most physicians' thinking.

In our study, pediatric residents and attendings had difficulty correctly recognizing the definition of brain death. Death by brain criteria is not so new or so complex that physicians should not have a clear understanding of this concept. In part, the explanation may be that many physicians do not believe that patients without whole brain function are “really dead.”⁴ Many physicians may find the cardiorespiratory or “higher brain” standards of death to be more conceptually appealing.

In addition there are physiologic inconsistencies in the determination of death by brain criteria. Many brain dead patients still have some brain function, usually neurohumoral.¹¹ In one study, less than half of brain dead children have diabetes insipidus.¹² Some patients who fulfill physical examination criteria still have some minimal electrical activity on their electroencephalogram.¹³ Death is a clinical, not a pathologic, diagnosis. As Truog said, “the criterion of whole-brain death is only an approximation”.¹¹ This approximation may contribute to cognitive dissonance and clinical confusion.

New arguments question the necessity of adhering to a strict whole brain definition of brain.^{11 ,14} Some scholars have suggested that defining brain death as irreversible loss of all cortical and brainstem function is too restrictive. A cortical or higher brain definition of brain death (that is irreversible loss of higher brain function but not necessarily brainstem function), reflects the opinion that such patients have lost identity as a person, and therefore should be considered dead. The higher brain definition also would allow many patients from whom support is withdrawn to donate organs¹¹ and thus could substantially increase the number of donor organs. It may be that the conceptual challenges of the whole brain standard of death illustrated in this debate are reflected in physicians' limited grasp of this important concept.

Our clinical scenario involves decision-making around the withdrawal of support, now the most common mode of death in the PICU.⁵We have noted in our clinical practice that distinguishing between a brain dead and severely brain injured patient can be confusing to residents and attending pediatricians. Patients who are dead by brain criteria are either maintained on mechanical ventilation to preserve their potential as an organ donor or support is discontinued. Respiratory effort, even in the absence of other neurologic function, disqualifies a patient as an organ donor unless there is a nonheart beating donor program at the institution in question.¹⁵

Pediatric residents and attendings had difficulty interpreting the clinical scenario. Pediatric residents and attendings who correctly defined brain death were no more likely to correctly interpret the clinical scenario than their peers who did not. We believe this lack of concordance represents poor internalization of the concept of brain death.

Brain death may be diagnosed by two neurologic exams, including apnea testing, separated in time. To diagnose brain death, the patient must have a diagnosis compatible with the clinical situation and may not be hypotensive, hypothermic, or sedated. Just over half of the residents and faculty recognized that confirmatory testing beyond the physical examination is not a legal necessity.

More than one task force and many individual hospitals have proposed guidelines for the mechanics of diagnosing brain death in children.^{8 ,9 ,10} Recommendations regarding the necessity, timing, and choice of confirmatory tests varies from guideline to guideline. Clinically, physicians diagnose brain death in a variety of ways.¹⁶ Most states have adopted the Uniform Determination of Death Act, which recognizes neurologic criteria for death but does not stipulate how a physician should make this determination. Although many institutions have guidelines for diagnosing brain death that include confirmatory testing, no state has legislation that demands confirmatory testing. Published guidelines and local institutional rules undoubtedly add to physician confusion regarding the legal necessity of confirmatory testing.

We found that increasing resident seniority (level of training) did not improve performance at defining brain death, interpreting the clinical scenario, or understanding whether confirmatory testing is necessary. This suggests that effective teaching is not occurring as residents progress through their training programs. We found that resident pediatricians' inability to correctly define brain death or interpret the clinical scenario was not associated with a lower level of confidence in discussing brain death with a patient's family.

Fortunately, attendings who were able to correctly define brain death and interpret the clinical scenario were more confident than their peers who could not. Concordance between confidence and objective knowledge about brain death improved with experience and responsibility. Overconfidence in knowledge or ability is a source of problems in medicine.

Issues surrounding the end of life often are included in medical ethics curricula. Self-reported ethics education was associated only with improved resident performance at interpreting the clinical scenario. If ethics education is an appropriate forum to teach about brain death, more effective educational strategies need to be identified and used.

The training program was not associated with improved resident or attending performance. This is of particular interest as no two training programs or academic faculties are identical in their clinical or educational emphasis. Similar results from programs that differ in terms of size and geography, suggest that confusion regarding brain death is common.

Most clinical decisions regarding brain death are made in the PICU. The pediatric intensivists' responses were consistent and correct. Surprisingly, less than half of the pediatric neurologists correctly defined brain death. As pediatric medicine becomes increasingly subspecialized, clinical knowledge and experience may be increasingly partitioned. Nonintensivists confront issues surrounding brain death infrequently. A primary care physician's involvement in the care of a critically ill child provides comfort to the family and longitudinal perspective to the critical care specialist. It is incumbent on subspecialists to communicate effectively with primary care providers about the determination of death, to facilitate their effective involvement in clinical decision-making.

A clear understanding of brain death is imperative when providing comprehensive pediatric intensive care. Rational and consistent decision-making regarding organ donation, organ procurement, and withdrawal of support all depend on the ability to define and apply the concept of brain death. Inappropriate or unnecessary interventions may be minimized by enhanced education regarding death by brain criteria, ensuring that critical decisions are made by knowledgeable physicians and well-informed families.