The minimum effective concentration (MEC90) of ropivacaine for ultrasound-guided quadratus lumborum block for analgesia after cesarean delivery: a dose finding study.

BACKGROUND: Quadratus lumborum block was recently proposed as an alternative technique for post-cesarean delivery analgesia. However, there is not a definite optimum concentration of local anesthetics. A biased coin design up-and-down method was used to explore the minimum effective concentration of ropivacaine in quadratus lumborum block for satisfactory analgesia after cesarean delivery. METHODS: Fifty-six patients weighing 60-80 kg after cesarean section and with ages between 18 and 40 years were recruited. For the posterior quadratus lumborum block, a volume of 25 ml of the assigned concentration of ropivacaine was injected bilaterally. The concentration administered to each patient depended on the response to the previous dose. The first patient received 0.25%. If a successful block was observed, the next patient was randomized to receive the same ropivacaine concentration (with a probability of 0.89) or 0.025% less (with a probability of 0.11). After any block failure, the concentration was always increased by 0.025% for the next. The study ended when 45 successful blocks were obtained. We defined effective quadratus lumborum block as a resting visual analog score ≤ 3 and the absence of a need for rescue anesthetics. RESULTS: The 90% minimum effective concentration of ropivacaine was 0.335% (95% CI 0.306 to 0.375%), and the 99% minimum effective concentration was 0.371% (95% CI 0.355 to 0.375%). The sufentanil consumption was 11 (11,13) and 24 (22,27) µg at 12 and 24 hours after quadratus lumborum block, respectively. CONCLUSIONS: The optimum dosage of ropivacaine is a 25 ml volume of 0.335% for quadratus lumborum block after cesarean delivery. TRIAL REGISTRATION: The study was registered in the Chinese Clinical Trial Registry (No. ChiCTR2000040415 ).

Analysis of risk factors for unplanned reoperation following primary repair of gastrointestinal disorders in neonates.

BACKGROUND: The aim of our study was to identify the factors associated with unplanned reoperations among neonates who had undergone primary repair of gastrointestinal disorders. METHODS: A retrospective chart review was conducted for neonates who underwent primary gastrointestinal surgery between July 2018 and September 2020. The neonates were divided into two cohort, depending on whether they had an unplanned reoperation. The primary outcome was the occurrence of unplanned reoperation. The risk factors that associated the occurrence of unplanned reoperation were examined. MAIN RESULTS: Two hundred ninety-six neonates fulfilled the eligibility criteria. The incidence of unplanned reoperation was 9.8%. Analyses of all patients with respect of developing unplanned reoperation showed that the length of operative time was an independent risk factor [Odds Ratio 1.02; 95% confidence interval 1.00, 1.04; p = 0.03]. Patients with unplanned reoperation had a longer postoperative hospital length-of-stay [19.9 ± 14.7 vs. 44.1 ± 32.1 days; p<0.01]. CONCLUSION: The current study is the first analysis of risk factors associated with an unplanned reoperation in neonates undergoing primary repair of gastrointestinal disorders. The length of operative time is the only risk factor for an unplanned reoperation, and the unplanned reoperation can directly prolong the postoperative hospital length-of-stay. TRIAL REGISTRATION: This study was registered at http://www.chictr.org.cn/index.aspx with No. ChiCTR2000040260 .

The low fresh gas flow anesthesia and hypothermia in neonates undergoing digestive surgeries: a retrospective before-after study.

BACKGROUND: Based on the previous investigation in our institution, the incidence of intraoperative hypothermia in neonates was high. Since September 1st, 2019, the recommendation had been launched to utilize ≤1 L/min fresh gas flow during the neonates' surgical procedure. We therefore intended to evaluate the association between low fresh gas flow anesthesia and the occurrence of hypothermia in neonates undergoing digestive surgeries. METHODS: A retrospective chart review, before-after study was conducted for neonates who underwent digestive surgeries. The primary outcomes were the incidence of hypothermia. The secondary outcomes included hospital mortality, the value of lowest temperature, blood loss, mean body temperature during the surgery, the length of hypothermia during the surgery and postoperative hospital length-of- stay (PLOS). RESULTS: 249 neonates fulfilled the eligibility criteria. The overall incidence of intraoperative hypothermia was 81.9%. The low fresh gas flow anesthesia significantly reduced the odds of hypothermia [routine group: 149 (87.6%) versus low flow group: 55 (69.6%); p < 0.01]. Moreover, the low fresh gas flow anesthesia could reduce the length of hypothermia [routine group: 104 mins (50, 156) versus low flow group: 30 mins (0,100); p < 0.01], as well as elevate the value of lowest temperature for neonates [routine group: 35.1 °C (34.5, 35.7) versus low flow group: 35.7 °C (35.3, 36); p < 0.01]. After adjustment for confounding, low fresh gas flow anesthesia and the length of surgical time were independently associated with intraoperative hypothermia. CONCLUSIONS: Low fresh gas flow anesthesia is an effective way to alleviate hypothermia in neonates undergoing open digestive surgery.

Evaluation of neonatal acute kidney injury (AKI) after emergency gastrointestinal surgery.

BACKGROUND: The overall incidence of acute kidney injury (AKI) in neonates undergoing emergency gastrointestinal surgery is yet to be determined. The study aims are to analyze our experience in emergency gastrointestinal surgery for neonates and to evaluate the incidence of AKI. METHODS: We conducted a retrospective study of neonates undergoing emergency gastrointestinal surgery between June 31, 2018 and May 10, 2022 (N = 329). The primary outcome was the overall incidence of AKI. The diagnostic AKI was based on the Modified Kidney Disease: Improving Global Outcomes (KDIGO) definition of neonatal AKI. The secondary outcomes, including the postoperative length of hospital stay (PLOS), 24-h mortality, in-hospital mortality, and total in-hospital cost, were analyzed. The risk factors associated with the development of postoperative AKI were also analyzed. RESULTS: The incidence of postoperative AKI was 9.1% (30/329). No significant differences were detected in the 24-h mortality and in-hospital mortality between the two cohorts. In the final model, patients undergoing mechanical ventilation before surgery, vasopressor support, surgical duration, intraoperative oliguria and preoperative lowest serum creatinine (SCr), were independently associated with AKI. CONCLUSION: Our study found that patients undergoing mechanical ventilation before surgery, vasopressor support, surgical duration, intraoperative oliguria and preoperative lowest SCr were independently associated with postoperative AKI in neonates who accepted emergency gastrointestinal surgeries.

Inadvertent hypothermia and acute kidney injury (AKI) in neonates undergoing gastrointestinal surgeries: a retrospective study.

OBJECTIVE: The purpose of our study was to evaluate the association between intraoperative hypothermia and AKI in neonates undergoing gastrointestinal surgeries. STUDY DESIGN: This retrospective study was conducted for neonates who underwent gastrointestinal surgeries from June 2018 to August 2020. Neonates with a minimum of two documented creatinine values before and after surgical procedures within 48 h were included. According to the mean intraoperative temperature, the eligible neonates were divided into three groups. The primary outcome was the incidence of AKI (as defined by the modified KDIGO criteria). The association between variables and AKI or hospital mortality was also examined. RESULTS: A total of 295 neonates fulfilled the eligibility criteria. AKI was more common in patients with lower intraoperative temperature compared to the normothermia group. Intraoperative mean temperature was independently associated with AKI. Patients developing AKI had a higher hospital mortality. AKI and gestational age were independently associated with hospital mortality. CONCLUSIONS: Inadvertent intraoperative hypothermia was associated with developing postoperative AKI.