RT Journal
A1 Rosenberg RN
T1 COnsciousness, coma, and brain death—2009
JF JAMA
JO JAMA
YR 2009
FD March 18
VO 301
IS 11
SP 1172
OP 1174
DO 10.1001/jama.2009.224
UL http://dx.doi.org/10.1001/jama.2009.224
AB 
Coma must be differentiated from the stuporous state in which the patient is unresponsive but with stimuli shows some evoked activity.1 It must be distinguished from the persistent vegetative state (PVS),2 a syndrome with several causes in which the patient has sustained severe brain damage, and in which coma has advanced to a state of wakefulness without detectable awareness. In addition, the minimal conscious state3 has been described in which the patient exhibits definite responsiveness that is cognitively driven, rather than unconscious reflexive responses. There may be a progressive improving continuum from coma to PVS and then to minimal conscious state. The continuum can also proceed in an adverse manner with deterioration from coma to brain death, an irreversible clinical condition in which, by neurological examination, the patient has lost all brain stem reflexes, including any respiratory response to hypercapnea exceeding an arterial PaCO2 of 60 mm Hg; and hasnormal routine clinical chemistry results, negative toxicology screen, normal body temperature, and absence of brain blood flow by diagnostic imaging procedures.4