Strange Harvest. Lesley A. Sharp
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patient with a known irreversible massive brain lesion and no contributing metabolic derangements” (2002: 1). Embedded within Wijdick's statement is the understanding that brain death is detected through the systematic application of diagnostic procedures (Wijdicks 2001). (I will return to this issue later.) Among the more confusing aspects of brain death for the clinically uninitiated is precisely how much or what part of the brain is in fact irreversibly damaged. During fifteen years of field research I have received a range of answers to the question, What is brain death? when speaking with OPO educational and clinical staff, as well as internists, transplant surgeons, and neurologists. OPO staff typically underscore what it is not: brain death is neither a coma nor a vegetative state. OPO staff are especially averse to these terms (even when either condition is described as “irreversible”) because they evoke within the lay public images of injury followed by spontaneous recovery. Other interviewees (especially those who are clinically trained) sometimes describe brain death as “full” or “total” brain failure.15 Neurologists whom I interviewed in 2004 preferred to speak of brain stem failure (cf. Hill 1999; Matta 2000; P. Young and Matta 2000). As Dr. Needler, who regularly diagnoses brain death in patients, explained, “During my clinical training I learned what any physician learns—we learn about the hierarchical organization of the brain—if the brain stem has ceased to function, then the upper brain's capabilities will fail, too. This is why we speak of [the] brain stem in reference to brain death.” Another neurologist, Dr. Valentine, underscored that the damage sustained from this form of head trauma is irreversible and, further, that the brain may begin to “liquefy” or “grow necrotic” even as procurement staff are in the process of assessing a donor's status. All that is left is perhaps some residual spinal activity, nothing more.
Diagnosis by a physician is a relatively straightforward procedure that requires few specialized tools, but from a lay perspective brain death is a truly confounding medical category. Oddly, too, whereas several professional organizations—such as the American Academy of Neurology and the American Academy of Pediatrics—have published diagnostic guidelines, brain death criteria have yet to be standardized either within this country or internationally (AAP 1987; Gelb and Robertson 1990; J. Lynch and Eldadah 1992; University of North Dakota 1998; Wijdicks 1995a). Within the United States specifically, mandated diagnostic criteria vary from one state to another, among OPOs, and even among hospitals located within the same city. Dr. Lazarre, a neurointensivist who described himself as one who has “diagnosed literally hundreds of brain dead patients,” stressed that “brain death is a clinical diagnosis. You don't need special tools or tests to do it. It only takes me about four minutes—it's very quick. It is not difficult for me [to recognize]—diagnosis is not [a] difficult [task].”
Regardless of protocols, in the end, the purpose of diagnostic criteria is to confirm the absence of brain activity. The systematic assessment is generally conducted by a neurologist, although any trained physician is capable of the task. (Sometimes, though rarely, a nurse may assume this duty.) In-house protocols almost always require that the assessment be administered twice and by two separate physicians, although the period of time between the two varies significantly from one institution to another. Dr. Lazarre, who proudly stated that he had “streamlined” his unit's protocol, put it thus:
| DR. LAZARRE: | I…got rid of the observation period. |
| L. S.: | But don't two separate doctors still evaluate the patient? |
| DR. LAZARRE: | You still need two different doctors. Some places they [conduct separate observations] six, twelve, twenty-four hours apart. I got rid of this. You don't need it. I can do the [tests] two minutes apart with two people [and that's all it takes]. If you really understand brain death—[after all] you can't become un-brain-dead. [He then describes the function of the hypothalamus.] You will [then] have cardiac death. We [might be able to] keep you alive for two to three days. There are those who write [about] people who can be brain dead for two to three months—but the body [falls apart eventually]. I find it hard to believe [that maintaining someone this long] is realistic or happens [very often at all]. |
Drawing from the literature and my field interviews, I offer the following review of brain death assessment in adult patients.16 First, the patients must be deeply comatose and artificially ventilated, their CAT scan and spinal fluid tests generating abnormal results. Before proceeding with diagnostic tests for brain death, the physician must also know the origin of injury, so that he or she can exclude other causes that can mimic brain death. These include hypothermia, endocrine crisis, severe acid-base abnormalities, intoxication, the presence of barbiturates and other sedatives (self-or hospital-administered), as well as neuromuscular blocking agents.
Once these are ruled out as probable causes, the physician tests systemically for brain stem activity in response to excessive noxious stimuli. The physician exerts pressure on the nail beds of the hands and feet and on the sternum (located in the upper central region of the chest). Throughout such tests the physician watches for such reflexes as eye opening, facial grimaces, head movements, and reflex movements of the limbs. The purpose of these tests is to make certain that the patient's condition results not merely from a damaged cerebral cortex but specifically from brain stem failure. For instance, the pupils can be any shape, but they should exhibit no response to bright light. There should be no evidence of normal eye closure as the corneas are stroked, or eye movements when the head is moved briskly or when the interior of each ear is flushed with cold water. Also, brain dead patients do not gag or cough in response to a throat swab or tongue blade, or when the physician wiggles the ventilator tube within the trachea. A range of more sophisticated (and technologically mediated) diagnostics, referred to as “confirmatory tests,” might then be applied. (Although required in Europe, they do not define a mandatory component of U.S. protocols.) They include cerebral angiography, electroencephalogram, transcranial doppler, and other brain imaging techniques.
In the United States the single required confirmatory technique is the apnea test, whose purpose is to document that the patient is incapable of breathing spontaneously when disconnected from the ventilator. (This ability is marked by such responses as coughing or gasping.) As recently as the mid-1990s, the apnea test was considered highly controversial within those OPOs where I conducted research. A widespread fear was that cessation of ventilation could induce cardiac arrest or other forms of trauma, circumstances that threatened the viability of organs for later transplantation (Wi-jdicks 1995b). The apnea test has since evolved into a normative practice, in part because of a range of more recent techniques designed to prepare and stabilize the patient before and during the procedure. Common precautions include using a warming blanket to increase the core temperature of the body and administering vasopressors to counteract low blood pressure, as well as other medications to control fluid levels. Prior to the test patients are also typically oxygenated; once the patient is disconnected from the ventilator, the physician must document blood gas levels (paying particular attention to carbon dioxide [CO2] readings) for several minutes. Depending on the hospital, the apnea test may last anywhere from three to eight minutes. As Dr. Lazarre explained, “This is the biggest stimulus to the brain [to start breathing]. You look, watching with your own eyes for no breathing movements. In the end you…document that there's evidence that the blood is [saturated] with CO2 and not oxygen…. you draw arterial blood and then document the CO2 [level this way].” In some instances the apnea test is repeated, although staff whom I interviewed (drawn from OPOs of a range of sizes) all reported that this was strictly optional in locations where they worked.
Today the administration of diagnostic tests defines a ritualized form of witnessing for patients' kin in some hospitals. As a neurologist, Dr. Needler prefers to have family members present when she tests for brain death because this helps her to explain more clearly what is wrong with the patient. A troublesome element here is that brain dead patients sometimes manifest what clinicians refer to as a “Lazarus sign”: that is, their bodies may move as a result of residual spinal activity. Wijdicks stresses that such movements frequently occur following an apnea test, and he thus offers these cautionary words: “It should tell you that the family members should never be present during this procedure [because] it might be very difficult to discuss organ donation after this occurs” (University of North Dakota 1998). Nevertheless, some OPOs have taken the radical step of encouraging the kin of prospective donors to be present during the apnea test. Dora Tucker-man, who