Aha! This is actually the correct answer this time. But why? The strongest predictors of a poor neurologic prognosis are 1) absent pupillary light reflexes at ≥ 72 hours from ROSC, and 2) absent N20s on SSEPs bilaterally at ≥ 48-72 hours from ROSC. For this patient, the former doesn't apply, so we should proceed towards testing for the latter. Interestingly, the usual sedation used in ICUs shouldn't affect the results. (If you think about it, SSEPs are a standard intraoperative monitoring tool during neurosurgical procedures, and those patients are definitely on agents such as propofol. Volatile anesthetics do interfere with the results, though.) If the patient has excessive myogenic activity (e.g. shivering or myoclonus), it's reasonable to use neuromuscular blockade for SSEP acquisition to minimize artifact and ensure a high-quality test. Absent N20s bilaterally indicates that the patient has a poor neurologic prognosis-- defined as having severe disability, a minimally conscious state, or a state of unresponsive wakefulness. Any finding other than this is simply indeterminate-- not indicative of a good nor poor prognosis-- and would necessitate to moving onto the moderate predictors of a poor prognosis.
This patient unfortunately has sustained a cervical cord injury, acute no less. Thus, we cannot reliably perform SSEPs for this patient, as the electrical signal might not be able to reach the cortex. So, we have to move on to the moderate predictors of a poor prognosis. If we're able to get it, an MRI of his brain would be a helpful next test.
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