23, 28
Amplitude carries information that presence-or-absence discards, and evoked potentials are the one instrument that works early in both directions. On ECMO their value depends entirely on technical adequacy - insist on an explicit adequacy statement in the report and treat its absence as an uninterpretable study, not a negative one.
Other early prognostic indices, for both good and poor outcome
[VERIFICATION REQUIRED] - DOI/PMID not confirmed
Somatosensory evoked potentials including amplitude, latency and the middle-latency N70 component
65 patients, single cohort, no ECMO patients, and a narrative review describes evoked potentials as unreliable on a circuit without quantifying it. Structured abstract only. [VERIFICATION REQUIRED]
Bilaterally absent cortical responses: 100% specificity (89-100) with 67% sensitivity (48-82). Adding low-amplitude (under 1.2 µV) prolonged (over 10 ms) responses without an N70 raised sensitivity to 93% (79-99) without loss of specificity. A high-amplitude (over 3 µV) response with a preserved N70 predicted good outcome with 94% sensitivity (79-99) and 100% specificity (89-100). Evoked potentials outperformed every other early index in both directions.
65 comatose adults after cardiac arrest, assessed within six hours