A general overview of a broad topic that neuro-intensivists spend years learning about and refining their knowledge and skills on. So I won’t suggest my summary of a summary can do it justice. Some high-yield, interesting points I took away:
- Myocardial “stunning” with depressed ejection fraction and pulmonary edema should be expected, due to a form of tako-tsubo cardiomyopathy, most commonly in subarachnoid hemorrhage. It’s not due to ischemia and gets better over weeks.
- Fever reduction is recommended, although therapeutic cooling and targeted temperature management (induced hypothermia) have not been shown prospectively to improve outcomes. The increased metabolic demand of shivering caused by cooling concerns some experts.
- Regarding prognosis, survival and outcomes data are strongly tainted by self-fulfilling prophecy bias (withdrawal of care in a large percentage of those who seem unlikely to improve based on prognostic signs, leads to indeterminate reliability or truth of those prognostic signs going forward). Do-not-resuscitate status specifically is associated with increased mortality, even when comparing patients with similar illness severity.
- Vasospasm after subarachnoid hemorrhage is common, predictable and can cause cerebral infarction if untreated. Thick blood in the subarachnoid space and bleeding in the lateral ventricles bilaterally signals higher risk for vasospasm. Nimodipine selectively vasodilates cerebral arteries and improves outcomes and should be given to all victims of SAH due to a ruptured aneurysm. A phase III study of pravastatin is also underway.
- There is no standard recommended approach to intracranial pressure monitoring. New devices can measure brain temperature and partial pressure of oxygen, but optimizing these hasn’t been shown to improve outcomes; only optimizing cerebral perfusion pressure (mean arterial pressure minus intracerebral pressure) has.
- Hypertonic saline, given in boluses, is gaining preferred status over mannitol (despite a lack of randomized trials), as mannitol can cause osmotic diuresis and hypovolemia in repeated doses.
- The best approach to blood pressure control is totally unclear. The INTERACT trial is underway to try to answer this.
- Prothrombin complex concentrates may work better than fresh frozen plasma at correcting warfarin coagulopathy. The INCH trial is underway for this question.
- Seizures are bad, and EEG should be obtained for any suspicion. However, anticonvulsants should not be prescribed prophylactically for intraparenchymal hemorrhage — they are associated with worse functional outcomes, and fever, in these patients. Anticonvulsants may be given prophylactically to tenuous SAH patients to prevent seizure-induced rebleeding, but routine use there is also not recommended.
Naidech AM. Intracranial Hemorrhage: Concise Clinical Review. Am J Respir Crit Care Med 2011;184:998-1006.