Analgesia Nociception Index-Guided Remifentanil versus Standard Care during Propofol Anesthesia: A Randomized Controlled Trial

The clinical benefits to be expected from intraoperative nociception monitors are currently under investigation. Among these devices, the Analgesia Nociception-Index (ANI) has shown promising results under sevoflurane anesthesia. Our study investigated ANI-guided remifentanil administration under propofol anesthesia. We hypothesized that ANI guidance would result in reduced remifentanil consumption compared with standard management. This prospective, randomized, controlled, single-blinded, bi-centric study included women undergoing elective gynecologic surgery under target-controlled infusion of propofol and remifentanil. Patients were randomly assigned to an ANI or Standard group. In the ANI group, remifentanil target concentration was adjusted by 0.5 ng mL−1 steps every 5 min according to the ANI value. In the Standard group, remifentanil was managed according to standard practice. Our primary objective was to compare remifentanil consumption between the groups. Our secondary objectives were to compare the quality of anesthesia, postoperative analgesia and the incidence of chronic pain. Eighty patients were included. Remifentanil consumption was lower in the ANI group: 4.4 (3.3; 5.7) vs. 5.8 (4.9; 7.1) µg kg−1 h−1 (difference = −1.4 (95% CI, −2.6 to −0.2), p = 0.0026). Propofol consumption was not different between the groups. Postoperative pain scores were low in both groups. There was no difference in morphine consumption 24 h after surgery. The proportion of patients reporting pain 3 months after surgery was 18.8% in the ANI group and 30.8% in the Standard group (difference = −12.0 (95% CI, −32.2 to 9.2)). ANI guidance resulted in lower remifentanil consumption compared with standard practice under propofol anesthesia. There was no difference in short- or long-term postoperative analgesia.

Cardiac Arrest due to Carbon Dioxide Embolism During Laparoscopic Gynecologic Surgery of a Patient with Previous Abdominal Surgery: A Case Report

Catastrophic carbon dioxide (CO2) embolism is a rare, but potentially life-threatening, the complication of laparoscopic gynecologic surgery. We report the case of a healthy 53-year-old woman who developed CO2 embolism and cardiac arrest during laparoscopic surgery. She had a history of two cesarean sections and had extensive peritoneal adhesions. After placement of the trocar and insufflation of CO2, end-tidal CO2 dropped from 35 to 15 mm Hg, and the patient had a cardiovascular collapse. In this patient, CO2 embolism was diagnosed on the basis of a sudden decrease in end-tidal CO2, hypotension, and hypoxemia. The patient was managed quickly and aggressively. The patient recovered completely following the treatment for CO2 embolism, with no cardiopulmonary or neurological sequelae. There is an increased risk of catastrophic CO2 embolism during laparoscopic gynecologic surgery in patients with previous abdominal surgery. Therefore, the surgeon and anesthesiologist should remain vigilant to promote early detection of CO2 embolism.

The Effect of Ultrasound-Guided Lung Recruitment Maneuvers On Atelectasis In Lung-Healthy Patients Undergoing Laparoscopic Gynecologic Surgery: a Randomized Controlled Trial

BackgroundAtelectasis is a major cause of hypoxemia during general anesthesia and postoperative pulmonary complications (PPCs).Some previous reported that the combined use of lung recruitment procedures (LRMs) and positive end-expiratory pressure (PEEP) in mechanical ventilation mode contributes to the avoidance of PPCs in patients after general anesthesia, while others suggest that the use of LRMs makes patients more susceptible to hemodynamic disturbances and lung injury, and is of limited potential to decrease the incidence of PPCs. From this perspective, controversy exists as to whether LRMs should be routinely applied to surgical patients. More importantly, corresponding clinical studies are also lacking. Therefore, this trial was conducted with the aim of solving the above problem.MethodsIn current clinical trial, patients undergoing laparoscopic gynecologic surgery with healthy lungs were randomized to the recruitment maneuvers group (RM group; 6 cm H2O PEEP and RMs) and the control group (C group; 6 cm H2O PEEP and no RMs). Lung ultrasound was performed on patients at five separate time points. During mechanical ventilation, patients in the RM group received ultrasound-guided pulmonary resuscitation when atelectasis was detected, while the C group did not intervene. Lung ultrasound scores were used to evaluate the incidence and severity of atelectasis.ResultsAfter LRMs, the incidence of atelectasis was significantly lower in the RM group (40%) than in the C group (80%) 15 minutes after arrival in the post-anesthesia care unit (PACU), and this difference did not persist for 24 hours after surgery. Meanwhile, postoperative pulmonary complications showed no difference between the two groups.ConclusionsThe combination of LRMs and PEEP decreased the incidence of atelectasis 15 minutes after admission to the PACU, but did not improve PPCs in adults with healthy lungs. Hence, for lung-healthy patients undergoing gynecological laparoscopic surgery, we do not recommend routine recruitment maneuvers. Trial registration: (prospectively registered): ChiCTR2000033529. Registered on 6/4/2020.