Optimal reverse trendelenburg position in patients undergoing craniotomy for cerebral tumors.

Object: To the authors' knowledge, repeated measurements of intracranial pressure (ICP), cerebral perfusion pressure (CPP), and the degree of dural tension during different positions on the operating table (reverse Trendelenburg position [rTp]) have not been studied in patients undergoing craniotomy.

Methods: In the present study 53 patients with supratentorial cerebral tumors who underwent craniotomy in the supine position were included. Subdural ICP, mean arterial blood pressure (MABP), CPP, and jugular bulb (JB) pressure were recorded, and the degree of dural tension was analyzed while patients were in the neutral operating position and at 5, 10, and 15 degrees rTp. The optimal operating position was defined as the one at which subdural ICP was as low as possible, and CPP was greater than or equal to 60 mm Hg or as high as possible. Subdural ICP, MABP, and JB pressure decreased significantly after each 5 degrres change in rTp compared with the preceding position. Dural tension decreased significantly up to 10 degrees rTp, but was unchanged at 15 degrees rTp. At 5 degrees rTp CPP remained unchanged, but it decreased significantly during 10 and 15 degrees rTp. The optimal position in the majority of patients was determined to be 15 degrees rTp.

Conclusions: Before opening the dura mater for craniotomy, repeated measurements of ICP and CPP, in the neutral position and at 5, 10, and 15 degrees rTp, provide valuable information regarding the optimal level of ICP and CPP.