Effects of neck position and head elevation on intracranial pressure in anaesthetized neurosurgical patients - Preliminary results

This study reports the collective effect of the positions of the operating table, head, and neck on intracranial pressure (ICP) of 15 adult patients s cheduled for elective intracerebral surgery. Patients were anesthetized wit h propofol, fentanyl, and maintained with a propofol infusion and fentanyl. Intracranial pressure was recorded following 20 minutes of stabilization a fter induction at different table positions (neutral, 30 degrees head up, 3 0 degrees head down) with the patient's neck either 1) straight in the axis of the body, 2) flexed, or 3) extended, and in the five following head pos itions: a) head straight, b) head angled at 45 degrees to the right, c) hea d angled at 45 degrees to the left, d) head rotated to the right, or e) hea d rotated the left. For ethical reasons, only patients with ICP 20 mm Hg we re included. Intracranial pressure increased every time the head was in a n onneutral position. The most important and statistically significant increa ses in ICP were recorded when the table was in a 30 degrees Trendelenburg p osition with the head straight or rotated to the right or left, or every ti me the head was flexed and rotated to the right or left-whatever the positi on of the table was. These observations suggest that patients with known co mpromised cerebral compliance would benefit from monitoring ICP during posi tioning, if the use of a lumbar drainage is planed to improve venous return , cerebral blood volume, ICP, and overall operating conditions.