Background: Whether individualized positive end-expiratory pressure (PEEP) improves intraoperative oxygenation and reduces postoperative pulmonary complications (PPCs) remains unclear. This systematic review and meta-analysis examined whether individualized PEEP is associated with improved intraoperative oxygenation and reduced PPCs for patients needing pneumoperitoneum with the Trendelenburg position during surgery. Methods: Medline, Embase, the Cochrane Library, and www.clinicaltrials.gov were searched for randomized controlled trials evaluating the effects of individualized PEEP on intraoperative oxygenation and PPCs in patients who required Trendelenburg positioning with pneumoperitoneum. The primary outcome was the oxygenation (PaO ₂ /FiO ₂ ) during the procedure. Secondary outcomes included PPCs, intraoperative respiratory mechanics (driving pressure, compliance), and vasopressor consumption. DerSimonian–Laird random effects models were used to calculate mean differences (MDs) and log risk ratios (log RRs) with 95% confidence intervals (CIs). The Cochrane Risk-of-Bias tool 2.0 was applied to assess the risk of bias in included studies. The protocol of this meta-analysis has been registered in PROSPERO. Results: We included 14 studies (1121 patients) that employed different individualized PEEP strategies. Compared with control groups, individualized PEEP groups exhibited a significantly improved intraoperative PaO ₂ /FiO ₂ (MD=56.52 mmHg, 95% CI: [33.98–79.06], P <0.001) and reduced incidence of PPCs (log RR=−0.50, 95% CI: [−0.84 to −0.16], P =0.004). Individualized PEEP reduced driving pressure while improving respiratory compliance. Intraoperative vasopressor consumption was similar between both groups. The weighted mean PEEP in the individual PEEP groups was 13.2 cmH ₂ O [95% CI, 11.7–14.6]. No evidence indicated that one individualized PEEP strategy is superior to others. Conclusions: Individualized PEEP seems to work positively for lung protection in the Trendelenburg position and pneumoperitoneum in patients undergoing general anesthesia.

This study aims to identify the risk factors for postoperative pulmonary complications (PPCs) in elderly patients undergoing major abdominal surgery and to investigate the relationship between patient-controlled analgesia (PCA) and PPCs. A retrospective study. Clinical data and demographic information of elderly patients (aged ≥ 60 years) who underwent upper abdominal surgery at the First Affiliated Hospital of Sun Yat-sen University from 2017 to 2019 were retrospectively collected. Patients with PPCs were identified using the Melbourne Group Scale Version 2 scoring system. A directed acyclic graph was used to identify the potential confounders, and multivariable logistic regression analyses were conducted to identify independent risk factors for PPCs. Propensity score matching was utilized to compare PPC rates between patients with and without PCA, as well as between intravenous PCA (PCIA) and epidural PCA (PCEA) groups. A total of 1,467 patients were included, with a PPC rate of 8.7%. Multivariable analysis revealed that PCA was an independent protective factor for PPCs in elderly patients undergoing major abdominal surgery (odds ratio = 0.208, 95% confidence interval = 0.121 to 0.358; P < 0.001). After matching, patients receiving PCA demonstrated a significantly lower overall incidence of PPCs (8.6% vs. 26.3%, P < 0.001), unplanned transfer to the intensive care unit (1.1% vs. 8.4%, P = 0.001), and in-hospital mortality (0.7% vs. 5.3%, P = 0.021) compared to those not receiving PCA. No significant difference in outcomes was observed between patients receiving PCIA or PCEA after matching. Patient-controlled analgesia, whether administered intravenously or epidurally, is associated with a reduced risk of PPCs in elderly patients undergoing major upper abdominal surgery.

Opioid consumption for analgesia in burn patients is enormous. Non-opioid analgesics for burn pain management may result in opioid sparing, reducing opioid-related adverse reactions and drug tolerance or addiction. A dual-center, randomized controlled trial assessed Esketamine for the perioperative period in patients with severe [20-50 % total body surface area (TBSA)] and extensive (≥ 50 % TBSA) burns, comparing analgesia with standard anesthesia. Sixty patients were randomly allocated (1:1 ratio) to two arms. In the Treatment Arm, patients received intra-operative Esketamine and postoperative intravenous primary intelligent analgesia pump with Esketamine. Patients in the Control Arm received the same intervention as Treatment Arm without Esketamine. The primary endpoint was subjective analgesic efficacy (SAE) evaluated on Day 28 or the day before hospital discharge. Secondary outcomes included the postoperative Numeric Pain Rating (NPR) Scale at rest (NPRr) and during movement (NPRm) and opioid consumption. Gastrointestinal dysfunction Scores (GIDS) and serum markers of intestinal injury [intestinal fatty acid-binding protein 2 (iFabp2) and apolipoproteinA2 (ApoA2)] were measured in the 1st and 4th post-injury weeks. Depression and sleep quality were assessed by relevant questionnaires. Fifty-five patients were included in the analysis. Esketamine-treated Arm recorded a better analgesic efficacy than the Control Arm (proportion of patients with Grade 1 or 2 SAE scores, 67.9 % vs. 40.7 %, p = 0.022). Esketamine-treated patients had lower NPRm values (p = 0.033) and lower daily opioid consumption (p = 0.033) when compared with Controls. Esketamine-treated patients showed comparable gastrointestinal recovery to those in the Control Arm. The overall sleep quality might be improved in the Treatment Arm. Esketamine use is safe for perioperative primary intelligent analgesia of severe burns, resulting in improved resting pain control and lower opioid requirements. The trial was registered at the Chinese Clinical Trial Registry (www.chictr.org.cn/) (ChiCTR2000034069).

Background: Myocardial injury after noncardiac surgery (MINS) is one of the most common complications associated with postoperative adverse cardiovascular outcomes and mortality. However, MINS often fails to be timely diagnosed due to the absence of clinical symptoms and limited diagnostic methods. The metabolomic analysis might be an efficient way to discover new biomarkers of MINS. Characterizing the metabolomic features of MINS patients may provide new insight into the diagnosis of MINS. Methods: In this study, serum samples from 20 matched patients with or without MINS (n = 10 per group) were subjected to untargeted metabolomics analysis to investigate comprehensive metabolic information. Differential metabolites were identified, and the enriched metabolic pathway was determined based on the Kyoto Encyclopedia of Genes and Genomes (KEGG) database. Results: A comprehensive analysis revealed 124 distinct metabolites, predominantly encompassing lipids, amino acids and other compounds. The observed modifications in metabolic pathways in patients with or without MINS showed significant clustering in cholesterol metabolism, aldosterone synthesis and secretion, primary bile acid biosynthesis, as well as cysteine and methionine metabolism. Four specific metabolites (taurocholic acid, L-pyroglutamic acid, taurochenodeoxycholic acid, and pyridoxamine) exhibited promising potential as biomarkers for prognosticating MINS. Conclusions: This study contributes valuable insights into the metabolomic features of MINS and the discovery of potential biomarkers which may help the early diagnosis of MINS. The identified metabolites and altered pathways offer valuable insights into the molecular underpinnings of MINS, paving the way for improved diagnostic approaches and potential intervention strategies.

Background: While propofol is widely used for gastrointestinal endoscopic sedation, its cardiovascular and respiratory side effects and lack of analgesia can compromise safety and comfort. Esketamine provides both sedation and analgesia with minimal hemodynamic or respiratory impact. Combining esketamine with propofol may miti-gate propofol’s adverse effects while enhancing sedation quality. However, the com-bination’s overall safety and efficacy remain inconclusive. Methods: This systematic review and meta-analysis compared propofol-based sedation with versus without intravenous esketamine in gastrointestinal endoscopy, synthesizing evidence from randomized controlled trials. The primary outcome was the incidence of hypotension. Secondary outcomes included intraoperative adverse respiratory events, propofol consumption, involuntary movement, hypertension, arrhythmias, PONV recovery times, and dizziness. Results: Eighteen trials were included in the analysis. Additional esketamine significantly reduced the incidence of hypotension (risk ratio [RR]: 0.32; 95% confidence interval [CI]: 0.24 to 0.43; P < 0.01; I ² = 44.4%; moderate quality). The addition of esketamine to propofol can reduce the incidence of adverse respiratory events (RR: 0.57, 95% CI: 0.38 to 0.86; P < 0.01; I ² = 67.8%; moderate quality). Esketamine added to propofol decreased involuntary movement (RR: 0.61, 95% CI: 0.42 to 0.92; P = 0.02; I ² = 77.2%; low quality) and reduced the propofol consumption (mean difference [MD]: −0.94, 95% CI: −1.53 to −0.35 mg/kg; P < 0.01; I ² = 96.2%; low quality). No significant differences were found for hypertension, arrhythmias, PONV, recovery time or dizziness. Conclusion: Supplementing propofol-based sedation with esketamine reduced the risk of hypotension and adverse respiratory events, without increasing cardiovascular complications, or extending recovery-time. Systematic Review Registration: https://www.crd.york.ac.uk/PROSPERO/ , identifier CRD420251030940.

Postoperative pulmonary complications (PPCs) are common following abdominal surgery, contributing significantly to perioperative morbidity and mortality, p