?-blockade benefits patients following a subarachnoid haemorrhage

Abstract

Previous studies have shown that ECG changes following a subarachnoid haemorrhage are associated with increased catecholamine levels, necrotic myocardial lesions, and a poor prognosis. Furthermore, β-blockade using propranolol reverses some of the ECG changes and prevents necrotic myocardial lesions. This study was established to assess the affects of adrenergic blockade on morbidity and mortality following subarachnoid haemorrhage. Patients were admitted to the randomized double-blind between-patients study if they presented at the neurosurgical unit within 48 hours of a subarachnoid haemorrhage confirmed by lumbar puncture. Of 224 patients, the first 118 received an α-blocker, phentolamine 20 mg three-hourly, and either the β-blocker propranolol 80 mg eight-hourly, or placebo. The last 106 patients received either propranolol or placebo. Treatment was continued for three weeks. Assessment at four weeks revealed significant improvements in the treated group for neurological deficit (p=0.003) and death (p=0.02). More treated patients underwent operation and those that did had a better outcome (p=0.01). Assessment at one year showed that although patients had improved in both groups, patients in the treated group had significantly fewer neurological deficits (p=0.003). There were fewer deaths in the treated group but this difference was not significant (p=0.09). Possible mechanisms for this protective effect of propranolol may include a reduction in plasma renin activity, a reduction in pulmonary oedema, prevention of myocardial infarcts, and a reduction in cerebral oxygen requirements. It is concluded that early β-blockade benefits patients with subarachnoid haemorrhage, in terms of fewer neurological deficits, for up to one year.