Global Hypoxia-Ischemia and critical care Seizures

Seizures after cardiopulmonary arrest are a common problem in the intensive care unit, occurring in as many as one-third of these patients during hospitalization. The etiology, treatment, and prognostic importance of seizures in this setting have not been well delineated in the literature. Whether seizures exacerbate global hypoxic-ischemic brain injury in humans remains unclear, which raises uncertainty about how aggressively they should be treated. Some pathological data suggest that anoxic brain injury is worsened by generalized tonic-clonic (GTC) status epilepticus. When the prognosis remains uncertain, GTC status epilepticus should be treated in the conventional manner described elsewhere in this book. Partial seizures and simple myoclonus are unlikely to exacerbate neuronal damage, and treatment should probably be reserved for those seizures that are traumatic to family members or interfere with mechanical ventilation. Status myoclonus in hypoxic-ischemic coma is particularly troublesome because it can be highly refractory to conventional anticonvulsants and appears to portend an extremely poor prognosis, regardless of its management. Care should be taken to distinguish true SM from postanoxic action myoclonus (Lance-Adams Syndrome), which does not carry the same prognostic significance. It is also important to distinguish SM occurring after pure respiratory arrest from cardiac arrest, as there are several case reports of patients making good neurological recoveries after respiratory arrest despite SM. The decision to use anesthetic agents and paralytics in the setting of SM must be individualized.