persistent vegetative state(redirected from Vegetative states)
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Related to Vegetative states: Persistent vegetative state
condition or situation.
alpha state the state of relaxation and peaceful awakefulness associated with prominent alpha brain wave activity.
anxiety state the condition of experiencing undue anxiety, as in anxiety disorders.
excited state the condition of a nucleus, atom, or molecule produced by the addition of energy to the system as the result of absorption of photons or of inelastic collisions with other particles or systems.
ground state the condition of lowest energy of a nucleus, atom, or molecule.
persistent vegetative state a condition of profound nonresponsiveness in the wakeful state caused by brain damage at whatever level and characterized by a nonfunctioning cerebral cortex, the absence of any discernible adaptive response to the external environment, akinesia, mutism, and inability to signal; the electroencephalogram may be isoelectric or show abnormal activity. Vegetative states raise ethical questions regarding appropriate care, use of resources, and allowing a patient to die.
refractory state a condition of subnormal excitability of muscle and nerve following excitation.
resting state the physiologic condition achieved by complete bed rest for at least 1 hour.
steady state dynamic equilibrium.
persistent vegetative state (PVS),
vegetative state (q.v.) of prolonged duration (defined in different sources as duration of longer than 1 month, 1 year, or 2 years); usually permanent.
See also: vegetative.
See also: vegetative.
persistent vegetative state
a state of wakefulness accompanied by an apparent complete lack of cognitive function, experienced by some patients in an irreversible coma. Vegetative functions and brainstem reflexes are intact, but the cortex is permanently damaged.
persistent vegetative stateChoice in dying A condition caused by injury, disease or illness in which a Pt has suffered a loss of consciousness, with no behavioral evidence of awareness of self or surroundings in a learned manner, other than reflex activity of muscles and nerves for low level conditioned response, and from which to a reasonable degree of medical probability, there can be no recovery; PVS is characterized by a prolonged loss of upper cortical function that may follow acute–eg, infections, toxins, trauma, or vascular events, or chronic–eg, degenerative events; in PVS, Pt is bed-ridden, nutritional support is completely passive, either parenteral or by NG tube; PVS Pts do not require respiratory support or circulatory assistance for survival and are in a state of chronic wakefulness which may be accompanied by spontaneous eye opening, grunts or screams, brief smiles, sporadic movement of facial muscles and limbs; while the eyes blink upon stimulation, they do not do so in response to visual threats; some Pts chew or clamp their teeth; urinary and fecal incontinence is universal; recovery occurs within the 1st month–if at all, recovery is rare beyond the 3rd month. See Advanced directives, DNR, Harvard criteria, Living will, Quinlan. Cf Procurement.
Persistent vegetative state–criteria
1. No evidence of awareness of environment; inability to interact with others
2. No evidence of sustained, reproducible, purposeful, or voluntary behavioral responses to visual, tactile, auditory, or noxious stimuli
3. No evidence of language comprehension or expression
4. Intermittent wakefulness manifested by the presence of sleep-wake cycles
5. Sufficiently preserved hypothalamic and brain-stem autonomic functions to permit survival with medical and nursing care
6. Bowel and bladder incontinence
7. Variably preserved cranial nerve reflexes (pupillary, oculocephalic, corneal, vestibulo-ocular, gag) and spinal reflexes
per·sis·tent ve·ge·ta·tive state(PVS) (pĕr-sis'tĕnt vej'ĕ-tā-tiv stāt)
Vegetative state of prolonged duration (defined in different sources as duration of longer than 1 month, 1 year, or 2 years); usually permanent.
See also: vegetative
See also: vegetative
persistent vegetative stateA condition caused by diffuse lesions of the thalami, the cortical neurons or of the white matter tracts that connect them. The disorder has proved difficult to define because of uncertainties as to the real meaning of ‘consciousness’, ‘awareness’ and ‘wakefulness’. Patients in a persistent vegetative state can breathe without mechanical assistance. Heart, kidney and intestinal functions are normal and the bladder and bowels empty automatically. At times they appear to be awake. They will respond to painful stimuli by opening their eyes, moving their limbs, breathing more quickly, and occasionally grimacing. The type and degree of brain damage indicates, however, that they cannot perform any of the higher neurological or mental functions known to be essential for any mental processes or appreciation of their situation.
per·sis·tent ve·ge·ta·tive state(pĕr-sis'tĕnt vej'ĕ-tā-tiv stāt)
Condition of a patient of prolonged duration (defined in different sources as duration of longer than 1 month, 1 year, or 2 years); usually permanent.