Background: Electroencephalogram burst suppression can be associated with postoperative delirium; however, the results of relevant studies are discrepant. This systematic review and meta-analysis aimed to assess the association between intraoperative burst suppression and postoperative delirium in adult surgical patients. Methods: PubMed, MEDLINE, Embase, Google Scholar, and the Cochrane Central Register of Controlled Trials were systematically searched and updated in May 2023. The authors included cohort studies, case–control studies, and randomized controlled studies reporting on postoperative delirium incidence with documented intraoperative burst suppression in adults receiving general anesthesia for any surgery. The primary outcome was the pooled odds ratio for postoperative delirium in cases with intraoperative burst suppression compared to those without burst suppression, calculated using a random-effects model. Two independent investigators extracted the data. The protocol was prospectively registered in the International Prospective Register of Systematic Reviews (registration No. CRD42022326479); the results were reported according to Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines. Results: Fourteen studies (6,435 patients) were included in the analysis. The overall incidence of postoperative delirium was 21.1% (1,358 of 6,435). Patients with intraoperative burst suppression had a higher incidence of postoperative delirium than those without burst suppression (pooled odds ratio, 1.492; 95% CI, 1.022 to 2.178; I² = 44%; 95% CI, 0 to 75%; τ² = 0.110). The intraoperative duration of burst suppression was significantly longer in patients who developed postoperative delirium (standardized mean difference, 0.462; 95% CI, 0.293 to 0.632; I² = 63%; 95% CI, 16 to 84%; τ² = 0.027). The burst suppression ratio was significantly higher in the delirium group (standardized mean difference, 0.150; 95% CI, 0.055 to 0.245; I² = 0%; 95% CI, 0 to 85%; τ² = 0.00). Conclusions: The meta-analysis suggests an association between intraoperative burst suppression and postoperative delirium; however, the quality of evidence was very low. The limited number of studies and substantial heterogeneity across them emphasize the need for further high-quality studies to establish a more robust conclusion.

Background and objectives Epidural analgesia is the gold standard for post-thoracotomy pain management and can be started before or after surgical incision. This systematic review and meta-analysis investigated whether pre-emptive epidural analgesia before thoracotomy incision reduces acute and chronic post-thoracotomy pain in adults compared with epidural analgesia after incision. Methods We searched databases including MEDLINE, Embase, and CENTRAL for randomized controlled trials comparing epidural analgesia initiated before (pre-emptive group) and after (control group) thoracotomy incision in adults. The primary outcomes were the pain intensity during rest and coughing within 72 hours after surgery and the incidence of pain 1 to 6 months after surgery. Data were combined with random-effects meta-analyses. We rated the quality of evidence as high, moderate, low, and very low using the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) method. Results We included 19 trials with 1062 participants involving 529 in the pre-emptive group and 533 in the control group. The pain intensity was significantly lower at rest within 72 hours after surgery (19 studies, n=1062) and during coughing within 48 hours after surgery (11 studies, n=638), and the incidence of pain was significantly lower 1 to 6 months after surgery (6 studies, n=276) in the pre-emptive group than in the control group. The quality of evidence was moderate or low in the primary outcomes. Conclusions Our review provides low-quality evidence that pre-emptive epidural analgesia reduces the intensity of acute pain and the incidence of chronic pain after thoracotomy in adults. Protocol registration number CRD42019131620.

Ultrasonography can be useful to perform a lumbar neuraxial block. It aids in understanding the anatomy of the lumbar spine before the procedure. Pre-procedural ultrasound imaging provides information about the accurate intervertebral level for puncture, optimal needle insertion point, and depth of needle advancement for a successful neuraxial block. The key ultrasonographic views for lumbar neuraxial block include the transverse midline interlaminar and parasagittal oblique views. Ultrasonography can facilitate lumbar neuraxial block in difficult cases, such as the elderly, obese patients, and patients with anatomical abnormality of the lumbar spine. This review elucidates the basics of spinal ultrasonography for lumbar neuraxial block and the current evidence regarding ultrasound-guided neuraxial block in adults.

We sought to investigate the association between intraoperative urine output and postoperative acute kidney injury (AKI) in patients undergoing radical and partial nephrectomy. We retrospectively reviewed data of 742 patients. Postoperative AKI was defined by the Kidney Disease: Improving Global Outcomes criteria. The relationship between intraoperative urine output and the risk of AKI was evaluated by multivariable logistic regression analysis in radical and partial nephrectomy, separately. Minimum P-value approach was used to find the optimal threshold of intraoperative oliguria associated with the risk of AKI. The incidence of AKI was 14.4% (67/466) after partial nephrectomy and 57.6% (159/276) after radical nephrectomy. For partial nephrectomy, multivariable analysis showed that renal ischemic time, operation time, open surgery and intraoperative transfusion were significantly associated with AKI. For radical nephrectomy, history of hypertension, baseline glomerular filtration rate and intraoperative mean urine output were significantly associated with AKI. Intraoperative mean urine output during radical nephrectomy was associated with AKI after radical nephrectomy, while not after partial nephrectomy. Mean urine output <1.0 mL/kg/h was determined to be an optimal cutoff of AKI after radical nephrectomy. Intraoperative oliguria may have different clinical implication for AKI between partial and radical nephrectomy.

Background and objectives The lumbar interlamina space height is an important determinant of successful spinal puncture. We aimed to evaluate the influence of age, laterality, patient position, and spinal level on the height of the interlamina window using ultrasonography. Methods Ultrasonographic examination was performed in 20 adult patients aged under 40 years (group Y) and 20 patients aged over 60 years (group O). We set three primary outcomes: difference in the interlamina height of the ligamentum flavum-dura mater complex (LFD) according to (1) age, (2) laterality, and (3) position. For secondary outcomes, the degree of ultrasonography visualization (poor, intermediate, or good) and the depths from the skin to LFD and to anterior complex were also measured on right and left paramedian sagittal oblique view in both lateral and sitting positions at L3/4, L4/5, and L5/S1 levels. All variables were analyzed in association with age, laterality, patient position, and spinal level. Results The interlamina height of LFD was higher, and the degree of visualization was better in group Y than in group O. It differed depending on laterality in paramedian sagittal oblique view images in the same patients at all spinal levels. The interlamina height of LFD was the largest at L5/S1 level in both groups. Position had little influence on the interlamina height of LFD. Conclusions Scanning both sides and all spinal levels before selecting a puncture site for ultrasound-guided spinal anesthesia is recommended. The L5/S1 spinal level is a good option for spinal puncture in the elderly. Trial registration number NCT03929874.

Introduction Limited non-opioid analgesic options are available for managing postoperative pain after renal transplantation. We aimed to investigate whether the unilateral anterior quadratus lumborum (QL) block would reduce postoperative opioid consumption after living-donor renal transplantation in the context of multimodal analgesia. Methods Eighty-eight adult patients undergoing living-donor renal transplantation were randomly allocated to receive the unilateral anterior QL block (30 mL of ropivacaine 0.375%) or sham block (normal saline) on the operated side before emergence from anesthesia. All patients received standard multimodal analgesia, including the scheduled administration of acetaminophen and fentanyl via intravenous patient-controlled analgesia. The primary outcome was the total opioid consumption during the first 24 hours after transplantation. The secondary outcomes included pain scores, time to first opioid administration, cutaneous distribution of sensory blockade, motor weakness, nausea/vomiting, quality of recovery scores, time to first ambulation, and length of hospital stay. Results The total opioid consumption in the first 24 hours after transplantation did not differ significantly between the intervention and control groups (median (IQR), 160.5 (78–249.8) vs 187.5 (93–309) oral morphine milligram equivalent; median difference (95% CI), −27 (−78 to 24), p=0.29). No differences were observed in the secondary outcomes. Conclusions The anterior QL block did not reduce opioid consumption in patients receiving multimodal analgesia after living-donor renal transplantation. Our findings do not support the routine administration of the anterior QL block in this surgical population. Trial registration number NCT04908761.