Evaluation of the effects of intra-abdominal pressure changesduring laparoscopic abdominal surgeries on optic nerve sheath diameter, cerebral oxygen saturation and cognitive functions

Objective: It was aimed to contribute to the maintenance of cognitive functions at an optimal level and safe surgical practices through investigating the impacts of iatrogenic intra-abdominal pressure elevation generated during laparoscopic abdominal surgery on intracranial pressure, cerebral oxygenation, and early postoperative cognitive function changes. Material and Methods: Fifty patients aged between 20 and 60 years who were scheduled for laparoscopic abdominal surgery under general anesthesia were included in the study. MMSE test was administered before and 24 hours after the procedure in the ward where the patients were hospitalized. In addition to standard anesthesia monitoring, right and left frontal rScO2 monitoring was performed using NIRS, following the patients were taken to the operating room. The ventilator frequency was set to ensure EtCO2 was 33-40 mm Hg throughout the operation. Two ONSD measurements, horizontal and vertical, were performed for each eye. Measurement times were recorded with repeated measurements before induction of general anesthesia (T0), 5 minutes after induction of general anesthesia (T1), 5 minutes after generation of pneumoperitoneum with CO2 (T2), 30 minutes after generation of pneumoperitoneum with CO2 (T3), and 5 minutes after abdominal desufflation (T4). Following the induction of general anesthesia, IAP was measured noninvasively. Results: When ultrasonographic measurements of the ONSD were obtained to assess the intracerebral pressure, it was found out that there was an elevation in ONSD from the onset of the pneumoperitoneum; however, it returned to the baseline value upon the termination of the pneumoperitoneum. Upon evaluating this change in terms of cerebral perfusion through NIRS, a significant decrease was detected in cerebral oximetry values in the 5th minute of pneumoperitoneum, whereas it increased in the following periods. It was determined that the incompatible and inverse change between rScO2 and ONSD continued to increase from the 5th minute after the pneumoperitoneum was created, but there was no significant correlation between the two variables. Although the pneumoperitoneum led to an increase in ONSD, it was found out that cerebral perfusion was stable and there was no correlative change in MMSE scores. Conclusion: Consequently, a decrease was expected in rSO2 values contrary to the increase in ONSD concurrently with IAP levels due to the application of pneumoperitoneum in laparoscopic interventions; however, an increase was observed in rSO2 values. No correlation was determined between MMSE scores and ONSD as well as IAP parameters in terms of POCD.