Neurocritical Care

31. Approach to Organ Donation

A 51-year-old man with poorly controlled hypertension and severe congestive heart failure was admitted with a devastating ganglionic hemorrhage. Soon after arrival he was intubated in the emergency department. About 2 hours after the onset of signs the patient had his eyes closed with no opening to temporomandibular pressure, fixed midsize pupils, absent corneal reflexes, minimal oculovestibular responses, but a good cough response after tracheal suctioning. He also had spontaneous extensor posturing and triple flexion responses with Babinski signs. The CT scan showed a large destructive ganglionic hemorrhage starting in the putamen and extending into the frontal lobe and diencephalon. There was trapping of the third ventricle and acute hydrocephalus. In a desperate and likely ineffective attempt to improve the neurologic condition, a ventriculostomy was placed, but the consulted neurosurgeon felt there was no benefit in removing the large hematoma with so many brainstem reflexes lost. Over the next hours more brainstem reflexes disappeared, and only a faint cough reflex and a breathing drive remained, as evidenced by triggering of the ventilator.

The family understood very well that there was no chance to salvage him and they were told that he might progress further and become brain-dead within several hours. The family brought up his previously expressed strong desire for organ donation if something major would happen to him. However, 24 hours after admission to the neurological intensive care unit, the neurologic examination has remained unchanged. The family would still like to donate his organs after withdrawal of support.

What do you do now?

Catastrophic neurologic injury is often quite obvious even within hours after presentation. In such extreme cases, acute neurosurgical intervention or other measures to reduce increased intracranial pressure are futile. In these acute circumstances with rapid onset of coma, neurologists and neurosurgeons try to identify “a point of no return,” and that is mostly defined by the degree of destruction, by the involvement of crucial structures maintaining awareness (i.e., the diencephalon), and by persistent upper brainstem dysfunction. Clinically this translates into no pupillary light responses, no corneal responses, and no oculocephalic responses. The lower part of the brainstem (lower pons and medulla oblongata) is often still functioning, as made clear by the presence of a motor response to a noxious stimulus, a cough response to tracheal suctioning, and the patients’ preserved ability to trigger a ventilator.

In these situations when there is no hope for recovery, withdrawal of intensive care support will rapidly come up during a family conference, and often the decision is to provide palliative care after extubation.

It is easy to see that something good may come out of such a deep distress, and we should agree with the family, that if feasible, organ donation should be explored. Two clinical scenarios are expected. First, a considerable proportion of these patients will eventually progress to loss of all brainstem function and can be officially declared brain-dead and be therefore legally deceased. Organ donation can then be discussed, and the procedures are well established. But, if the patient does not meet the clinical criteria for brain death, the patient could potentially become a candidate for donation after withdrawal of life support. This procedure is known as donation after cardiac death protocol (abbreviated “DCD protocol”). It requires two important decisions: to establish with certainty the presence of a hopeless situation and when to withdraw life-support measures. Proponents of a DCD protocol have claimed a significant increase in donation rates, but the increase has still been less conspicuous than hoped for.

A DCD procurement protocol is more complicated and restricted than a brain death procurement protocol. Important differences between the two protocols are shown in Table 31.1.

TABLE 31.1 Differences between a Donation after Cardiac Death (DCD) and Donation after Brain Death (DBD) Protocols

Variables

DCD

DBD

Preconditions

No confounders and irremediable cause

No confounders and irremediable cause

Clinical findings

Devastating neurologic injury and often loss of upper brainstem function.

Coma, absent brainstem reflexes, no motor response and apnea

Eligibility Determination

Preferably an independent physician

Attending physician (may need confirmation by another physician)

Organ recovery

5 minutes circulatory arrest after patient extubation in the operating room

Immediately after arrival

Organ/tissue

All those consented except heart (lungs rarely procured)

All those consented

Triage

May return to ICU for palliative care if patient breathes after extubation

Morgue

Many hospitals in the United States—in order to maintain accreditation—are now required to have a DCD protocol in place; however, few physicians are fully aware of their responsibilities within these protocols. The utilization of DCD protocols worldwide is more variable, with marked differences in utilization between Asian and European countries. Most notable is the absence of DCD protocols in Germany.

In brief, the DCD protocol is based on organ retrieval after circulatory arrest. After withdrawal of life support has been decided, the patient may become a candidate for a DCD protocol. The eligibility is decided by an organ procurement coordinator and it requires a detailed conversation with the family, a signed informed consent, a determination of organ suitability, and a match with a recipient. A detailed medical and social history is obtained from the family. Contraindications to organ donation may include infectious diseases (notably HIV and hepatitis C), potentially transmissible malignancies (possibly including primary brain tumors manipulated by biopsy or ventriculostomy), and, most commonly, unsuitable organs. Blood (or tissue) samples are sent to a laboratory designated by the organ procurement organization for serological testing and tissue typing. The family should be made aware that the entire DCD procedure may take about 24 to 36 hours to complete. During this time the patient is examined regularly because progression to brain death may still occur. This transition is dependent on the time from the injury, but such progression is not common if no neurologic deterioration has been observed for 2 days. The family should also be made aware that the patient goes still intubated to an operating room. Extubation takes place in the operating room, but after extubation the patient may breathe, and the heart may not stop. If circulatory arrest does not happen within a predefined time interval (up to 60 minutes) the DCD procedure is aborted, and the patient may have to return to the intensive care unit and later the ward for further palliative care.

So what can be expected if the family decides to go ahead? After all appropriate preparations, the patient is transferred to the operating room and prepared for organ retrieval. In the operating bed, the patient is fully draped with the thorax and abdomen sterilized. Instruments are prepared and placed on a tray. Coming to the operating room for family members is a major event and a new and likely a difficult experience. (We had nurses that had a visceral response after witnessing such a procedure and prefer not to go there anymore.) In the dimly lit serene operating room the family would sit close to the patients’ head behind a sterile drape. Usually only the attending physician, an anesthesiologist, and an operating nurse and the organ procurement coordinator are present. The surgical team is out of the operating room and out of sight.

The patient is extubated. After the patient is extubated the patient will often gasp for several minutes, becoming deeply cyanotic until breathing stops. It may take several minutes for a circulatory arrest to occur (asystole is not a criterion although both often go together). The determination of circulatory arrest involves palpating the carotid artery, next to appearance of a zero reading of the invasive arterial pressure tracing. At that very moment the family is told the patient has died and is escorted out the operating room. After circulatory arrest is determined and documented, a 5-minute “death watch” begins with monitoring for any change. After 5 minutes have passed, the surgical team enters the operating room and proceeds quickly with a large splitting thoracoabdominal incision followed by rapid cooling, emptying large buckets of ice in the abdominal cavity, cannulation of major arteries, and infusion of preservation fluids and mobilization of transplantable organs. The transplant surgeon may determine on inspection that certain organs are unsuitable for organ donation. The deceased patient then goes to the morgue.

However, organ harvesting cannot take place if respiratory and circulatory arrest do not occur within one hour of extubation. In such cases, the patient is transported back to the ICU or to a regular room to receive palliative measures. These failed DCD attempts are not only costly but also can be distressing to families and discouraging to the medical team.

Respiratory and circulatory arrest in the operating room after extubation has been very difficult to predict, and most studies show about a 50/50 chance of respiratory/circulatory arrest within the 60-minute allotted observation time. Available predictive scores are not adapted for neurological patients. In one study of critically ill neurological patients the combination of absent corneal reflex, absent cough reflex, and extensor or absent motor responses predicted respiratory/circulatory arrest within 60 minutes of extubation in 85% of cases. When combined with an abnormal oxygenation index (> 4.2) the prediction increased to 93%. (Each factor alone predicted respiratory-circulatory arrest about two thirds of the time.)

The organ procurement coordinator often also will try to do a “mini apnea test” in the ICU, which is basically placing the patient on a CPAP of 5 cm of H2O and watching for respiratory deterioration. With no evidence of respiratory deterioration, the chance that the patient will develop a respiratory arrest after extubation in operating room later is smaller, and some organ procurement officers will call the procedure off and have the patient not go to the operating room. Clearly, more accurate predictors for cardiac arrest are necessary in patients with a catastrophic neurologic injury when life support is withdrawn.

DCD protocols create an important opportunity to donate tissue and organs, but the decisions—starting with the determination to withdraw support—are far more complicated and ethically challenging than in cases of donation after brain death. With an expected increase in DCD donors—still about 20% of all donors—physicians should be aware of the procedures.

KEY POINTS TO REMEMBER REGARDING APPROACH TO ORGAN DONATION

· Patients who do not fulfill brain death criteria may still be candidates for a DCD protocol.

· Some patients started in the process of a DCD protocol become brain-dead, and a switch to brain death organ donation protocol is possible. It, therefore, remains important to repeatedly examine the patient’s neurological status until the time comes to go to the operating room.

· The DCD procedure involves many steps, is time-consuming, and requires close communication with an organ procurement coordinator.

· Patients may have to return to the ICU if respiratory and circulatory arrest does not occur shortly after extubation in the operating room.

Further Reading

Bernat JL, Capron AM, Bleck TP et al. The circulatory-respiratory determination of death in organ donation. Crit Care Med 2010; 38:963–670.

Dominguez-Gil G, Haase-Kromwijk B,Van Leiden H et al. Current situation of donation after circulatory death in European countries. Transplant Int. 2011 April 19, Ahead of print.

Frontera JA. How I manage the adult potential organ donor: donation after cardiac death (part 2). Neurocrit Care 2010; 12:111–116.

Frontera JA, Kalb T. How I manage the adult potential organ donor: donation after neurological death (part 1). Neurocrit Care 2010; 12:103–110.

Fugate JE, Rabinstein AA, Wijdicks EFM. Variability in DCD protocols: a national survey. Transplantation 2011; 91:386–389.

Reich DJ, Mulligan DC, Abt PL et al. ASTS recommended practice guidelines for controlled donation after cardiac death organ procurement and transplantation. Am.J Transplant 2009;9: 2004–2011.

Wijdicks EFM. Brain Death (2ed) Oxford University Press, New York, 2011.

Yee AH, Rabinstein AA, Thapa P, Mandrekar J, Wijdicks EFM. Factors influencing time to death after withdrawal of life support in neurocritical patients. Neurology 2010; 74:1380–1385.


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