Effects of targeted mild hypercapnia versus normocapnia on cerebral oxygen saturation in patients undergoing laparoscopic hepatectomy under low central venous pressure: a prospective, randomized controlled study.

BACKGROUND: Laparoscopic hepatectomy under low central venous pressure (LCVP) is associated with intraoperative organ hypoperfusion, including cerebral hypoperfusion. We hypothesized that a ventilation strategy designed to achieve targeted mild hypercapnia (TMH) (end-tidal carbon dioxide partial pressure [PetCO2] of 45 ± 5 mmHg) rather than targeted normocapnia (TN) (PetCO2 of 30 ± 5 mmHg) would increase regional cerebral oxygen saturation (rSO2) during laparoscopic hepatectomy under LCVP. METHODS: Eighty patients undergoing laparoscopic hepatectomy under LCVP were randomly divided into the TMH group (n = 40) and the TN group (n = 40). Mechanical ventilation was adjusted to maintain the PetCO2 within the relevant range. Cerebral oxygenation was monitored continuously using the FORE-SIGHT system before anesthetic induction until the patient left the operating room. Patient and surgical characteristics, rSO2, intraoperative hemodynamic parameters (CVP, mean artery blood pressure [MAP], and heart rate), PetCO2, intraoperative blood gas analysis results, and postoperative complications were recorded. RESULTS: No significant differences were observed in CVP, MAP, and heart rate between the two groups during surgery. The rSO2 was significantly lower in the TN group on both the left and right sides during the intraoperative period (P < 0.05), while the TMH group had a stable rSO2. In the TN group, the mean rSO2 decreased most during liver parenchymal transection when compared with the baseline value (P < 0.05). The mean (standard deviation) percentage change in rSO2 from baseline to parenchymal transection was - 7.5% (4.8%) on the left and - 7.1% (4.6%) on the right. The two groups had a similar incidence of postoperative complications (P > 0.05). CONCLUSION: Our findings demonstrate that rSO2 is better maintained during laparoscopic hepatectomy under LCVP when patients are ventilated to a PetCO2 of 45 ± 5 mmHg (TMH) than a PetCO2 of 30 ± 5 mmHg (TN). TRIAL REGISTRATION: ChiCTR2100051130(14/9/2021).

Comparison of adjuvant pharmaceuticals for caudal block in pediatric lower abdominal and urological surgeries: A network meta-analysis.

STUDY OBJECTIVE: Caudal block helps relieve pain after sub-umbilical surgery in pediatric patients; however, the duration for which it exerts its analgesic effect is limited. The addition of certain adjuvant agents to local anesthetics (LAs) that are used to administer caudal block can prolong postoperative analgesia. Therefore, we aimed to compare the efficiencies and side effects of caudal adjuvants in the settings of pediatric lower abdominal and urological surgeries. DESIGN: A network meta-analysis (NMA). PATIENTS: One hundred and twelve randomized controlled trials (RCTs) involving 6800 pediatric patients were included in the final analysis. INTERVENTIONS: Different adjuvant agents, namely clonidine, dexamethasone, dexmedetomidine, fentanyl, ketamine, magnesium, midazolam, morphine, neostigmine, and tramadol. MEASUREMENTS: The primary outcome was the duration of analgesia. The secondary outcomes included the requirement for additional analgesia, analgesic consumption, and postoperative complications. The effects and rankings were evaluated using NMA and the surface under the cumulative ranking curve scores, respectively. RESULTS: Neostigmine, dexmedetomidine, and dexamethasone were found to be the three most effective adjuvants that prolong the duration of analgesia for caudal block, and these adjuvants extended this duration by 8.9 h (95% confidence interval [CI], 7.1-10.7), 7.3 h (95% CI, 6.0-8.6), and 5.9 h (95% CI, 4.0-7.7), respectively. Caudal neostigmine was associated with an increase in the incidence of postoperative nausea and vomiting, whereas dexmedetomidine and dexamethasone showed no postoperative complications. CONCLUSIONS: This NMA provided evidence and suggested that dexmedetomidine and dexamethasone may be the most beneficial adjuvant pharmaceutics adding to LAs for caudal block in children. However, given the off-label status of caudal dexmedetomidine and dexamethasone, further high-quality RCTs are still warranted, especially to determine whether delayed neurological complications will occur.