A patient who has had a cardiac arrest may develop post-anoxic coma. Bassetti et al identified prognostic factors associated with a bad outcome in these patients. The authors are from University Hospital Bern in Switzerland.
A bad outcome was defined as the persistent vegetative state or death (Glasgow Outcome Scores 1 or 2).
Parameters:
(1) Glasgow Coma Score (GCS)
(2) EEG
(3) somatosensory evoked potentials (SEPs)
|
EEG |
Grade |
|
dominant normally distributed alpha activity |
I |
|
dominant theta-delta activity, reactive |
II |
|
delta-theta activity without alpha activity, reactive or non-reactive |
III |
|
"alpha or theta coma", non-reactive |
IV* |
|
burst suppression activity |
IV |
|
low voltage delta activity, non-reactive |
IV |
|
periodic general phenomenon with isoelectric intervals |
IV |
|
very low voltage EEG |
V |
|
isoelectric EEG |
V |
|
Somatosensory Evoked Potentials |
Grade |
|
normal N20/P25 responses bilaterally |
I |
|
abnormal N20/P25 unilaterally |
II |
|
abnormal N20/P25 bilaterally |
II |
|
absent N20/P25 bilaterally |
III |
where:
• An abnormal N20/P25 involves an amplitude reduction > 50% or CCT > 7.2 milliseconds or both.
• I am uncertain about how a unilateral absence of N20/P25 should be coded. Based on the above table I would assume it is Grade II.
The risk of a bad outcome based on multivariate analysis:
|
Glasgow Coma Score at 48 Hours |
SEP |
Risk of Bad Outcome |
95% CI |
|
> 8 |
normal (Grade I) |
12% |
2-46% |
|
< 8 or |
or abnormal or absent (Grade II or III) |
68% |
47-84% |
|
< 8 and |
and abnormal or absent (Grade II or III) |
97% |
86-99% |
In these findings are inconclusive, the presence of an unfavorable EEG (Grade IV or V) will support the prediction of poor outcome.
Specialty: Cardiology
ICD-10: ,
