Intracranial pressure monitoring after elective intracranial surgery. A retrospective study of 514 consecutive patients.

A retrospective study of 514 consecutive patients whose intracranial pressure (ICP) was monitored after elective supratentorial or infratentorial surgery is reported. Of the 412 patients operated on in the supratentorial region, 76 (18.4%) had a postoperative sustained ICP elevation exceeding 20 torr. Abnormally high ICP occurred after 13 (12.7%) of the 102 infratentorial operations. Risk factors for postoperative ICP elevation were: resection of glioblastoma in 27.2% of cases, repeat surgery in 42.9% of cases, and protracted surgery (greater than 6 hours) in 41.7% of cases. Of the 89 patients with elevated ICP, 47 (52.8%) had an associated clinical deterioration. In 19 of these, the rise in ICP occurred before this deterioration was noticed, leading as a rule to quick diagnostic and management response. In eight patients clinical deterioration was noticed before the rise in ICP, and in 20 it happened simultaneously. The higher the level of ICP elevation, the greater were the chances of associated deterioration. The most common findings on computerized tomography scanning in 35 of 89 patients with elevated ICP were brain edema (19 cases) and bleeding in the tumor bed (15 cases). Mannitol, thiopental, additional hyperventilation, and reintubation (in patients who were previously extubated) were used to reduce ICP, in addition to surgical decompression whenever indicated. Thirteen patients with raised ICP and clinical deterioration underwent reoperation. The postoperative infection rate was 1.2% (six cases). In only one patient could infection be attributed to ICP monitoring. It was concluded that ICP monitoring is advantageous in the immediate postoperative management after elective intracranial surgery and is almost risk-free. It should therefore be used liberally, especially when risk factors for ICP elevation can be identified prior to the end of surgery.