Effect of Pneumoperitoneum and Patient Positioning on Intracranial Pressures during Laparoscopy: A Prospective Comparative Study.

STUDY OBJECTIVE: To evaluate the effect of pneumoperitoneum and head position during laparoscopic surgery on intracranial pressures (ICPs) using sonographic measurements of optic nerve sheath diameter (ONSD).

DESIGN: Prospective observational study (Canadian Task Force classification II-1).

SETTING: A tertiary-level hospital.

PATIENTS: Sixty-one women aged 15 to 50 years with American Society of Anesthesiologists grade 1 risk and body mass index ≤ 29 kg/m2 were admitted to the hospital between November 2015 and October 2016 for elective laparoscopic surgery and were included in this study.

INTERVENTION: Patients were placed in the Trendelenburg position with head down (group I; n = 33) and reverse Trendelenburg position with head up (group II; n = 28).

MEASUREMENTS AND MAIN RESULTS: ONSD was measured via sonography at 4 time points: at baseline before pneumoperitoneum, after pneumoperitoneum, after patient was placed in respective position, and once pneumoperitoneum was released. Patient demographics were comparable in all respects. ICP as indicated by ONSD showed a significant increase after pneumoperitoneum (p = .0001 in group I and p = .0011 in group II). When patients were placed in either head position, ONSD showed a further increase in ICP. This increase was more pronounced in patients assuming the head-down Trendelenburg position compared with patients in reverse Trendelenburg (head-up) position. Baseline and preoperative ONSD measurements were not reached even after 5 minutes of desufflation.

CONCLUSIONS: Pneumoperitoneum causes an increase in ICP. The patient position, either head up or head down as in gynecologic laparoscopic procedures, further worsens ICP. ONSD does not revert back to baseline until 5 minutes after desufflation.