The effect of prolonged steep head-down laparoscopy on the optical nerve sheath diameter

Effect of sevoflurane, propofol and propofol with dexmedetomidine as maintenance agent on intracranial pressure in the Trendelenburg position during laparoscopic surgeries

Background and Aim

Pneumoperitoneum (PP) and the Trendelenburg position (TP) in laparoscopic surgeries are associated with rise in intracranial pressure (ICP). The optic nerve sheath diameter (ONSD) is a surrogate marker of ICP. The study aimed to evaluate the effect of sevoflurane, propofol and propofol with dexmedetomidine as maintenance agent on ICP in TP during laparoscopic surgeries.

Material and Methods

A total of 120 American Society of Anesthesiologists (ASA) physical status I/II patients, aged 18-65 years were randomly allocated into three groups: sevoflurane as group S, propofol as group P, and propofol with dexmedetomidine as group PD. The intra-abdominal pressure (IAP) was kept in the range of 12-14 mmHg and TP varied between 15°- 45° angle. The primary objective was comparison of ICP and secondary objectives were IOP, intraoperative hemodynamic and postoperative recovery characteristics among groups. The ONSD and IOP were measured in both eyes 10 min after endotracheal intubation (T0), 5 min after CO2 insufflation (T1), 5 min after TP (T2) and 5 min after deflation of gas (T3). The data were analyzed by using the Statistical Package for Social Sciences version 23.

Results

ONSD and IOP at T1 and T2 were significantly higher than T0 in all groups, but no significant difference was found among the intergroup groups. Significantly lower heart rate and mean blood pressure were observed in PD group at T1 and T2 compared to group S and group P.

Conclusion

The rise in ICP was comparable among sevoflurane, propofol, and propofol-dexmedetomidine combination as a maintenance agent during laparoscopic surgeries in TP.

Influence of pneumoperitoneum and head-down maneuver on the cerebral microvasculature in rabbits

BACKGROUND

With recent advances in robot-assisted techniques, an increasing number of surgeries are being performed with pneumoperitoneum and head-down maneuver (HDM) that may affect the cerebral microcirculation. For the first time, this study investigated the direct influence of pneumoperitoneum and HDM on the cerebral microvasculature in rabbits.

METHODS

Adult male rabbits were randomly allocated to the following groups (n = 7 each): control, pneumoperitoneum alone (P), and pneumoperitoneum with HDM (P + HDM) for 120 min. A closed cranial window was installed above the parietal bone to visualize the pial microvasculature. Pial arteriolar diameter and hemodynamic and blood gas parameters were measured during the 140-min observation period. Brain edema was assessed by evaluation of the brain water content at the end of the experiment.

RESULTS

Rabbits in the P and P + HDM groups exhibited a similar degree of immediate pial arteriolar dilation following the initiation of both P and P + HDM (P: 1.11 ± 0.03, p = 0.0044 and P + HDM: 1.07 ± 0.02, p = 0.0004, relative changes from the baseline value by defining the baseline as one). In the P + HDM group, pial arteriole diameter returned to the baseline level following the discontinuation of pneumoperitoneum and HDM (1.05 ± 0.03, p = 0.0906, vs. baseline). In contrast, the pial arterioles remained dilated as compared to the baseline level in the P group after discontinuation of pneumoperitoneum. There were no changes in pial arteriole diameter in the animals in the control group. Heart rate, blood gas parameters, and brain water content were not significantly different between the groups.

CONCLUSION

The pial arterioles dilated immediately after pneumoperitoneum with or without HDM. The pial arterioles remained dilated 20 min after discontinuation of pneumoperitoneum alone but constricted upon discontinuation of pneumoperitoneum plus HDM. Pneumoperitoneum and HDM for 2 h did not cause brain edema.

Effects of Increased Optic Nerve Sheath Diameter on Inadequate Emergence from Anesthesia in Patients Undergoing Robot-Assisted Laparoscopic Prostatectomy: A Prospective Observational Study

(1) Background: Robot-assisted laparoscopic prostatectomy (RALP) is preferred over open prostatectomy because it offers superior surgical outcomes and better postoperative recovery. The steep Trendelenburg position and pneumoperitoneum required in Robot-assisted laparoscopic prostatectomy, however, increase intracranial pressure (ICP). The present study aimed to evaluate the effects of elevated ICP on the quality of emergence from anesthesia. (2) Methods: Sixty-seven patients undergoing RALP were enrolled. We measured optic nerve sheath diameter at four timepoints during surgery. Primary outcome was inadequate emergence in the operating room (OR). Secondary outcomes were postoperative neurologic deficits of dizziness, headache, delirium, cognitive dysfunction, and postoperative nausea and vomiting (PONV). (3) Results: A total of 69 patients were screened for eligibility and 67 patients completed the study and were included in the final analysis. After establishing pneumoperitoneum with the Trendelenburg position, ONSD increased compared to baseline by 11.4%. Of the 67 patients, 36 patients showed an increase of 10% or more in optic nerve sheath diameter (ONSD). Patients with ΔONSD ≥ 10% experienced more inadequate emergence in the OR than those with ΔONSD < 10% (47.2% vs. 12.9%, p = 0.003). However, other variables related to the quality of emergence from anesthesia did not different significantly between groups. Similarly, neurologic deficits, and PONV during postoperative day 3 showed no significant differences. (4) Conclusions: ICP elevation detected by ultrasonographic ONSD measurement was associated with a transient, inadequate emergence from anesthesia.