Teresa Marie Schiavo died on March 31, 2005, 15 years after sustaining a cardiac arrest and entering a persistent vegetative state (PVS). Her saga ignited national debates over the rights of the incapacitated, the outcomes of patients in persistent vegetative states, the basic requirements for human life, the distinction between nutrition and other medical treatments, and the involvement of the courts and politicians in our most private affairs. Sadly, Terri’s plight is not unique, and such a tragic predicament poses special challenges for hospitalists. The goals of this article are to review the definition and prognosis of PVS, and to outline the ethical argument for deciding to withdraw or withhold treatment from patients in PVS.
Clinical Features of the Persistent Vegetative State
Comatose patients may experience one of three general outcomes: recovery (partial or complete), death, or a prolonged or irreversible period of unconsciousness. As life support measures improved throughout the 1960s, this latter group represented an increasingly large yet ill-defined subgroup. In an attempt to characterize this population of severely brain-damaged patients who progress from coma to a state of wakefulness without awareness, Jennett and Plum coined the term “vegetative state” in 1972 (1). An estimated 10,000 to 25,000 adults in the United States exist in this manner for at least 1 month and are said to be in a persistent vegetative state.
In 1991, the Multi-Society Task Force on PVS was established and identified several key components of the condition (Table 1) (2). Hospitalists encounter patients who transition into PVS after an acute injury due to head trauma, or following nontraumatic diffuse bilateral cortical insult from prolonged hypoxic-ischemic periods. Less commonly, PVS is diagnosed in the hospital as an end-stage manifestation of a neurodegenerative illness. The cornerstone of PVS is diffuse cortical damage with relative preservation of brainstem and hypothalamic functions. Lacking cortical function, patients in PVS remain unaware of themselves or their environment, and are not thought to suffer. Many autonomic functions remain intact, however. PVS patients exhibit sleep-wake patterns, thermoregulate, maintain stable hemodynamics, respond with reflexive movements, and often live independent of a ventilator.
Several conditions have been confused with PVS (2). Coma is often applied inappropriately to patients in PVS. A lack of self-awareness characterizes both conditions; however, comatose patients (eyes closed, unresponsive) do not have recognizable sleep-wake cycles, whereas PVS patients exhibit wakefulness with open eyes. Key points of distinction between PVS, coma, brain death, and the locked-in syndrome are listed in Table 2.
Physical movements have traditionally been a source of confusion in PVS, and Terri Schiavo’s case was no exception. Politicians with medical backgrounds pointed to publicized video footage as evidence of her potential for recovery, or as an indication that a diagnosis of PVS had been made erroneously. In fact, PVS patients frequently exhibit truncal and limb movement, and they may smile, grimace, grunt, moan, or even cry on occasion. Some demonstrate a startle myoclonus and have preserved gag and cough reflexes. However, PVS patients do not exhibit sustained visual pursuit, visual fixation, or reproducible responses to threatening gestures. Because their ability to coordinate swallowing is impaired, most rely on alternative means to oral feeding and hydration for sustenance.