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Outcome of coma in ICU (for hypoxic cerebral injury) 05 November 2004 Outcome
of coma in ICU 1.
abnormal brainstem response (abnormal pupil, corneal, oculocephalic) 2.
no withdrawal to pain 3.
no verbal response 4.
creatinine >132.6 umol/l 5.
> 70 years coma persisting for more than 3 days with 4/5 factors has poor outcome (5% probability of survival at 2 mths)
The
role of EEG in prognosis of anoxic cerebral injury. Grade
1. “Near normal” Excellent
prognosis unless “locked
in”or alpha pattern coma Grade
2. Theta dominant If
reactive the prognosis is very good If
nonreactive survival is usually accompanied by neurological sequelae Grade
3. Delta dominant If
reactive the prognosis can be good If
non-reactive the prognosis is grave provided drugs and hypothermia excluded. Grade
4. Burst suppression & continuous bilateral periodic sharp waves Prognosis
grave if drugs and hypothermia excluded Often
associated with clinical myoclonus. Grade
5. Isoelectric Prognosis
grave if drugs and hypothermia excluded. Alpha
pattern coma Anterior
predominance Unreactive
alpha frequency activity. Rare
survivors but only if brain stem reflexes intact Theta
pattern coma Usually
elderly 5
Hz theta with low amplitude burst suppression morphology Grave
prognosis Spindle
coma Usually
head injury, rarely anoxic injury resembles
stage II sleep prognostically
benign. The
role of EEG in coma prognosis in anoxic injury The
difficult group are grade II nonreactives and grade III. These are also the most
common groups. SEPs are useful to further define the prognosis in these groups The
role of SEPs in anoxic cerebral injury and severe head injury The
bilateral absent of the “thalamo-cortical” wave forms (N19, N20,
N1)signifies that the patient will not recover to better than PVS (persistent
vegetative state)………….100% specificity However
sensitivity is low (20-30 %). Hence
the interest in the N70 N70 •
Madl et al “Of
113 patients with a bilateral N70 peak latency >130 msec or absent all but
one had a poor outcome” Sensitivity
of 94% and specificity of 97% •
Sherman et al Using
a bilateral N70 peak latency > 176 msec all had a poor outcome Sensitivity
78% and specificity of 100% SSEP,
CSF CK-BB & awakening after cardiac arrest (Sherman
et al. Neurology 2000;
54(4):889-94) awakening
defined as following commands or comprehensible speech
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