Estimation of the difference between peritoneal microenvironment and core body temperature during laparoscopic surgery - a prospective observational study.

Maintaining patients' temperature during surgery is beneficial since hypothermia has been linked with perioperative complications. Laparoscopic surgery involves the insufflation of carbon dioxide (CO2) into the peritoneal cavity and has become the standard in many surgical indications since it is associated with better and faster recovery. However, the use of cold and dry CO2 insufflation can lead to perioperative hypothermia. We aimed to assess the difference between intraperitoneal and core temperatures during laparoscopic surgery and evaluate the influence of duration and CO2 insufflation volume by fitting a mixed generalized additive model. In this prospective observational single-center cohort trial, we included patients aged over 17 with American Society of Anesthesiology risk scores I to III undergoing laparoscopic surgery. Anesthesia, ventilation, and analgesia followed standard protocols, while patients received active warming using blankets and warmed fluids. Temperature data, CO2 ventilation parameters, and intraabdominal pressure were collected. We recruited 51 patients. The core temperature was maintained above 36 °C and progressively raised toward 37 °C as pneumoperitoneum time passed. In contrast, the intraperitoneal temperature decreased, thus creating a widening difference from 0.4 [25th-75th percentile: 0.2-0.8] °C at the beginning to 2.3 [2.1-2.3] °C after 240 min. Pneumoperitoneum duration and CO2 insufflation volume significantly increased this temperature difference (P < 0.001 for both parameters). Core vs. intraperitoneal temperature difference increased linearly by 0.01 T °C per minute of pneumoperitoneum time up to 120 min and then 0.05 T °C per minute. Each insufflated liter per unit of time, i.e. every 10 min, increased the temperature difference by approximately 0.009 T °C. Our findings highlight the impact of pneumoperitoneum duration and CO2 insufflation volume on the difference between core and intraperitoneal temperatures. Implementing adequate external warming during laparoscopic surgery effectively maintains core temperature despite the use of dry and unwarmed CO2 gases, but peritoneal hypothermia remains a concern, suggesting the importance of further research into regional effects.Trial registration: Clinicaltrials.gov: NCT04294758.

An Individualized Low-Pneumoperitoneum-Pressure Strategy May Prevent a Reduction in Liver Perfusion during Colorectal Laparoscopic Surgery.

High intra-abdominal pressure (IAP) during laparoscopic surgery is associated with reduced splanchnic blood flow. It is uncertain whether a low IAP prevents this reduction. We assessed the effect of an individualized low-pneumoperitoneum-pressure strategy on liver perfusion. This was a single-center substudy of the multicenter 'Individualized Pneumoperitoneum Pressure in Colorectal Laparoscopic Surgery versus Standard Therapy II study' (IPPCollapse-II), a randomized clinical trial in which patients received an individualized low-pneumoperitoneum strategy (IPP) or a standard pneumoperitoneum strategy (SPP). Liver perfusion was indirectly assessed by the indocyanine green plasma disappearance rate (ICG-PDR) and the secondary endpoint was ICG retention rate after 15 min (R15) using pulse spectrophotometry. Multivariable beta regression was used to assess the association between group assignment and ICG-PDR and ICG-R15. All 29 patients from the participating center were included. Median IAP was 8 (25th-75th percentile: 8-10) versus 12 (12,12) mmHg, in IPP and SPP patients, respectively (p < 0.001). ICG-PDR was higher (OR 1.42, 95%-CI 1.10-1.82; p = 0.006) and PDR-R15 was lower in IPP patients compared with SPP patients (OR 0.46, 95%-CI 0.29-0.73; p = 0.001). During laparoscopic colorectal surgery, an individualized low pneumoperitoneum may prevent a reduction in liver perfusion.

A multifaceted individualized pneumoperitoneum strategy for laparoscopic colorectal surgery: a multicenter observational feasibility study.

BACKGROUND: While guidelines for laparoscopic abdominal surgery advise using the lowest possible intra-abdominal pressure, commonly a standard pressure is used. We evaluated the feasibility of a predefined multifaceted individualized pneumoperitoneum strategy aiming at the lowest possible intra-abdominal pressure during laparoscopic colorectal surgery. METHODS: Multicenter prospective study in patients scheduled for laparoscopic colorectal surgery. The strategy consisted of ventilation with low tidal volume, a modified lithotomy position, deep neuromuscular blockade, pre-stretching of the abdominal wall, and individualized intra-abdominal pressure titration; the effect was blindly evaluated by the surgeon. The primary endpoint was the proportion of surgical procedures completed at each individualized intra-abdominal pressure level. Secondary endpoints were the respiratory system driving pressure, and the estimated volume of insufflated CO2 gas needed to perform the surgical procedure. RESULTS: Ninety-two patients were enrolled in the study. Fourteen cases were converted to open surgery for reasons not related to the strategy. The intervention was feasible in all patients and well-accepted by all surgeons. In 61 out of 78 patients (78%), surgery was performed and completed at the lowest possible IAP, 8 mmHg. In 17 patients, IAP was raised up to 12 mmHg. The relationship between IAP and driving pressure was almost linear. The mean estimated intra-abdominal CO2 volume at which surgery was performed was 3.2 L. CONCLUSION: A multifaceted individualized pneumoperitoneum strategy during laparoscopic colorectal surgery was feasible and resulted in an adequate working space in most patients at lower intra-abdominal pressure and lower respiratory driving pressure. ClinicalTrials.gov (Trial Identifier: NCT03000465).