Prognosis in PVS
After 1 month has elapsed and a diagnosis of PVS is firmly established, attention focuses on prognosis. The Multi-Society Task Force reviewed the outcomes of 603 adults in PVS from traumatic and nontraumatic causes. Although PVS following trauma has a better prognosis than PVS following nontraumatic injury, the outcomes of both are poor (Table 3). Irreversibility is implied the longer a person remains in a vegetative state (3).
When does PVS become permanent?
In their comprehensive review, the Task Force defined durations of PVS after which meaningful recovery is near impossible: 12 months following trauma and 3 months after nontraumatic injury (Figure) (3).
Twenty-four percent of patients who entered PVS following trauma improved to a point of moderate disability. However, once the duration of PVS exceeded 12 months, only 7 of 434 patients recovered. In all 7 cases, recovery was noted between 23 and 36 months after traumatic injury, but the patients’ functional status remained quite poor: 5 remained severely disabled, 1 was moderately disabled, and the status of the 7th could not be determined.
PVS following acute nontraumatic injury portends an even worse prognosis. Among 169 PVS patients in this category, 15% regained consciousness, and only 1 patient experienced a good recovery. After 3 months, the probability of recovery was less than 1%.
Based on the dismal outcomes after several months, how do we account for the occasional media reports of recovery after many years in vegetative states? The Task Force reviewed all such accounts and identified 5 patients with verified recovery after prolonged PVS, ranging in age from 18 to 61; all but 1 remained severely disabled. Following nontraumatic anoxic injury, the longest duration of PVS prior to regaining consciousness was 22 months (3). Given the prevalence of PVS, late recovery after PVS appears to be exceptionally rare. Following her anoxic injury, Terri Schiavo remained in PVS for 15 years—well beyond the 3-month cut-off for potential reversibility.
The Ethical Basis for Withdrawing Support in Patients with PVS
Life-sustaining treatment (LST) is most commonly withdrawn or withheld when this is known to be the patient’s preference either because of advance directives or through a surrogate representing the best interests of the patient. Conflicts arise when physicians recommend withdrawal of LST over the objections of surrogates. Faced with this dilemma, physicians caring for patients in PVS may cede to the wishes of the family. Alternatively, they may pursue withdrawal of LST based on 1 of the following 3 arguments:
- The perceived futility of ongoing LST;
- The presumption that patients in PVS have very poor quality of life and would opt for withdrawal if they could communicate their wishes; and
- The belief that patients in PVS no longer possess the minimal requirements for human existence and therefore have no interests to advance.
Is life-sustaining treatment futile for patients in PVS?
In its narrowest sense, futility implies the inability to achieve a particular physiologic goal because the treatment has no pathophysiologic basis, because the treatment has already been tried and failed in a patient, or because maximal therapy is failing (4). Invoking futility as a reason to withhold or withdraw care unilaterally in PVS is problematic. Because patients in PVS can remain alive for months to years with supportive measures, interventions (such as antibiotics or nutrition) are not futile, because the goal of prolonging life can be achieved, though at a markedly diminished level of quality.