T waves”) and other alterations, suggesting subendocardial or myocardial ischemia. There may be a minor elevation of troponin and the myocardial band (MB) of creatine phosphokinase (CPK). In some patients, the cardiac dysfunction is severe enough to seriously reduce the ejection fraction and cause heart failure. There is a tendency to develop hyponatremia (Wijdicks et al); this abnormality and its relationship to intravascular volume depletion play a key role in treatment, as discussed further on. Albuminuria and glycosuria may be present for a few days. Rarely, diabetes insipidus occurs in the acute stages, but water retention or a natriuresis is more frequent. There may be a leukocytosis of 15,000 to 18,000 cells/mm3, but the sedimentation rate and C-reactive protein are usually normal, or any elevation is attributable to another cause.
As regards prognosis of aneurysmal hemorrhage,
McKissock and colleagues decades ago found that the patient’s state of consciousness at the time of arteriography was the single best index of outcome, and this remains largely true today. Their data, representative of the status of aneurysm management in the 1950s and consonant with the natural history before the advent of modern surgical and intensive care techniques, indicated that of every 100 patients reaching a hospital and coming to arteriography, 17 were stuporous or comatose and 83 appeared to be recovering from the ictus. At the end of 6 months, 8 of every 100 patients had died of the original hemorrhage and 59 had a recurrence (with 40 deaths), making a total of 48 deaths and 52 survivors. In regard to recurrence of bleeding, it was found that of 50 patients seen on the first day of the illness, 5 rebled in the first week (all fatal), 8 in the second week (5 fatal), 6 in the third and fourth weeks (4 fatal), and 2 in the next 4 weeks (2 fatal), making a total of 21 recurrences (16 fatal) in 8 weeks.
A comprehensive and still instructive, but now dated, long-term analysis of the natural history of the disease is contained in the report of the Cooperative Study of Intracranial Aneurysms and Subarachnoid Hemorrhage (Sahs et al, 1984). The study was based on long-term observations of 568 patients who sustained an aneurysmal bleed between 1958 and 1965 and were managed only by a conservative medical program. A followup search in 1981 and 1982 disclosed that 378, or two-thirds of the patients, had died; 40 percent of the deaths had occurred within 6 months of the original hemorrhage. For the patients who survived the original hemorrhage for 6 months, the chances of survival during the next two decades were significantly worse than those of a matched normal population. Rebleeding occurred at a rate of 2.2 percent per year during the first decade and 0.86 percent per year during the second, and these were fatal in 78 percent of cases. Although these statistics reflect the outcome prior to the modern era of microsurgery and neurologic intensive care management, current figures are only modestly better. In respect to rebleeding, all series indicate that the risk is greatest in the first day but extends for weeks. The observations of Aoyagi and Hayakawa are representative of other series; they found that rebleeding occurred within 2 weeks in 20 percent of patients, with a peak incidence in the 24 h after the initial episode. Surgical treatment is largely oriented toward reducing this complication.
In a prospective clinical trial conducted by the