Effect of Different Surgical Positions on the Changes in Cerebral Venous Drainage (CVD) and Intracranial Pressure (ICP) in Patients Undergoing Elective Neurosurgery

Background: Various positions employed to facilitate neurosurgical procedures can compromise the cerebral venous return and can cause increase in ICP. There are no direct indices of CVD. We aimed to use ultrasound (USG) and Doppler indices to assess the changes in CVD during positioning (supine, prone, and lateral) of patients undergoing neurosurgical procedures.

Materials and Methods: After IEC approval, consented ASA I/II patients with GCS 14 to 15 undergoing elective primary brain tumor resection surgery were included. Internal jugular vein (IJV) cross-sectional areas and peak Doppler velocities were recorded on both sides with USG at three different time intervals (before induction of anesthesia (T0), 10 minutes after induction (T1), and 10 minutes after final positioning (T2)). In addition, optic nerve sheath diameter (ONSD) was measured as an estimate of ICP at T1 and T2. Forty-five patients were included in all three groups, that is, supine, lateral, and prone (15 each).

Results: We found a significant change in flow from supine 0 to 30 degrees head tilt. In prone position, in spite of increase in IJV cross-sectional area, flow did not change. In lateral, the dependent side showed a severe decrease in IJV flow (p < 0.05). The maximum increase in ONSD was found in lateral position. The right IJV was dominant in 88% patients.

Conclusion Decrease in IJV flow was seen after final positioning, more significantly in dependent side of lateral position and supine with head tilt. This warrants careful positioning during neurosurgical procedures to prevent iatrogenic increase in ICP which can lead to brain bulge and increased bleeding.

Publication History

Article published online:
25 March 2020