It is crucial to predict and prevent re-bleeding from ruptured intracranial aneurysms in patients with subarachnoid hemorrhage (SAH). During the prehospital period and on arrival to the hospital, blood glucose and serum potassium levels, as well as changes in levels of consciousness were assessed in patients in the acute stage of spontaneous subarachnoid hemorrhage. These assessments were analyzed as possible risk factors for re-bleeding and as potential contributors to the prevention of re-bleeding, both in prehospital care and after hospital admission.

Upon the arrival of 202 patients with spontaneous subarachnoid hemorrhage, the following indications were examined retrospectively: (1) presence/absence of re-bleeding; (2) time interval between the onset of SAH and re-bleeding; (3) level of consciousness using the Glasgow Coma Scale (GCS) score before and on arrival; (4) amount and distribution of subarachnoid blood using Fisher's Computerized Tomography Classification; (5) blood pressure; (6) blood glucose concentration; and (7) serum potassium concentration. The patients were hospitalized in the Yokohama City University Critical Care and Emergency Center (Yokohama, Japan) between January 1991 and December 2000. The re-bleeding rate was analyzed using the chi-square ([X]2 test, and the averages and standard deviations of hematological data were compared using the Mann-Whitney U-test. The level of statistical significance was set at p <0.05.

The overall re-bleeding rate was 20.8%. Among 119 patients with a GCS score of 3–7 before arrival, 42 (35.3%) had re-bleeding, but none of the 83 patients with a GCS score of 8–15 before arrival had re-bleeding. Of 105 patients with a GCS score of 13–15 on arrival, 14 (51.8%) of 27 patients whose consciousness level was a GCS score of 3–7 before arrival experienced re-bleeding. The re-bleeding rate of this group was high. Moreover, this rebleeding group had a significantly higher blood glucose concentration than did the patients whose GCS score was 13–15 both before and on arrival. Between the patients with or without re-bleeding, there was no significant difference in the blood pressure on arrival or in distribution according to Fisher's Computerized Tomography Classification

Since the re-bleeding rate is high in patients who have hyperglycemia and a history of a level of consciousness as low as a GCS score of 3–7, a detailed assessment of level of consciousness and blood glucose tests performed on arrival provide important information that will contribute to predicting and preventing re-bleeding. This may be extended to the prehospital phase, because blood glucose tests are simple and safe when performed by paramedics.