The costoclavicular block is a proximal approach for blocking the brachial plexus in the infraclavicular fossa. Whether the costoclavicular block offers advantages over lateral paracoracoid approaches has been debated. However, diaphragm-sparing anesthesia for shoulder surgery has recently reignited interest in the costoclavicular space. In this review, we examine the costoclavicular block as an alternative to the interscalene block for shoulder surgery, focusing on minimizing involvement of the phrenic nerve. We conducted a systematic search of MEDLINE, EMBASE, and Google Scholar databases using the search terms “costoclavicular block” and “shoulder surgery,” to identify relevant studies published up to April 2025. Only randomized trials meeting rigorous inclusion criteria, i.e., those that were prospectively registered, used blinded assessment, and provided sample size justification, were included. The findings of these studies suggested that local anesthetic deposition in the costoclavicular space can reliably anesthetize the brachial plexus cords, achieving a high rate of suprascapular nerve blockade, while sparing the diaphragm. The effectiveness of the anesthesia and analgesia provided by this block depends on use of the appropriate local anesthetic volume and concentration. Further research is needed to validate these findings. Nevertheless, the evidence to date indicates that the costoclavicular block is a promising alternative for patients at risk of respiratory insufficiency secondary to hemidiaphragmatic paralysis.

Background
One-lung ventilation (OLV) during thoracoscopic surgery can impair oxygenation due to increased intrapulmonary shunts. Remimazolam has gained attention for its hemodynamic stability and rapid recovery profile; however, its effects on arterial oxygenation during OLV remain unclear. This study aimed to compare the effects of remimazolam and sevoflurane on arterial oxygenation during OLV.
Methods
In this prospective, randomized controlled trial, 58 adult patients undergoing thoracoscopic surgery were assigned to receive either sevoflurane or remimazolam for anesthesia maintenance. Arterial blood gas analysis and hemodynamic parameters were measured at four time points: 10 min after lateral positioning during two-lung ventilation (TLV10) and 15, 30, and 60 min after initiating OLV (OLV15, OLV30, and OLV60). The primary outcome was arterial partial pressure of oxygen (PaO2) at OLV30. Secondary outcomes included time-dependent changes in PaO2, hemodynamic variables, and serum lactate levels.
Results
No significant difference in PaO2 at OLV30 was observed between groups (108.9 ± 37.9 vs. 107.0 ± 37.8 mmHg, 95% CI [−21.8 to 18.0], P = 0.815). In within-group analysis, PaO2 at OLV60 increased significantly from TLV10 in the remimazolam group (95% CI [0.3–36.8], P = 0.044), while no such improvement was observed in the sevoflurane group. Serum lactate levels exhibited a significant time-by-group interaction with a greater reduction in the remimazolam group (P = 0.021).
Conclusions
Remimazolam provided arterial oxygenation and hemodynamic stability comparable to sevoflurane during OLV. The greater reduction in serum lactate levels with remimazolam suggests its potential metabolic or immunomodulatory advantages that warrant further investigation.

Background
We conducted a multicenter cohort study to evaluate whether preoperative acute hyperglycemia is associated with postoperative adverse cardiac events.
Methods
Data from 10 hospitals were converted to the Observational Medical Outcomes Partnership Common Data Model and analyzed. We extracted the records of 318 119 adult patients who underwent non-cardiac surgery and had available blood glucose measurements less than 24 h before surgery. We defined acute hyperglycemia as at least one fasting blood glucose measurement > 140 mg/dl or random blood glucose level measurement > 180 mg/dl < 24 h before surgery. Risk of adverse cardiac events during the first year after surgery was analyzed.
Results
After 1:2 propensity score matching (PSM), 40 340 patients with acute hyperglycemia and 70 770 patients without hyperglycemia were enrolled. Acute hyperglycemia was associated with an increased risk of adverse cardiac events (hazard ratio [HR], 1.26; 95% CI, 1.16–1.36; P < 0.001). In the subgroup analyses, the young age group (≤ 65 years) had a significantly higher risk (HR, 1.61; 95% CI, 1.40–1.85) than the older age group (HR, 1.13; 95% CI, 1.03–1.25; P for interaction < 0.001). A greater adverse cardiac events risk was observed in patients without hypertension (HR, 1.37; 95% CI, 1.24–1.52) but not in those with hypertension (HR, 1.09; 95% CI, 0.96–1.22; P for interaction = 0.003).
Conclusions
Preoperative acute hyperglycemia was associated with adverse cardiac events during one year of follow up. Further investigation is warranted to determine whether acute glycemic control before non-cardiac surgery could prevent perioperative cardiac complications.

Background
This study aimed to determine the association between frailty, as measured by the five-item modified frailty index (mFI-5), and postoperative pulmonary complications (PPCs) in older patients undergoing major abdominal surgery and to explore the predictive value of frailty beyond traditional PPC risk factors.
Methods
In this retrospective cohort study, we collected baseline and perioperative data of older patients (aged ≥ 65 years) undergoing major abdominal surgery in a tertiary hospital. The association between the mFI-5 score and PPCs was examined using multivariate logistic regression analysis. Additionally, the predictive value of the mFI-5 beyond the four basic PPC risk models was estimated using discrimination (areas under receiver operating characteristic curve [AUROCs]; DeLong’s test), calibration (Hosmer–Lemeshow test), goodness of fit (likelihood ratio χ2 test), explained variance (Nagelkerke R2), and reclassification (categorical and continuous net reclassification improvement and integrated discrimination improvement).
Results
A total of 3298 patients were included, of whom 351 (10.6%) developed PPCs. After adjusting for confounding factors, higher mFI-5 scores were independently associated with an increased risk of PPCs compared with a score of 0 (all P < 0.05). Incorporating the mFI-5 score into the basic PPC risk models significantly improved the AUROC, goodness of fit, and risk reclassification (all P < 0.001); enhanced or maintained calibration (all P > 0.05); and increased explained variance.
Conclusions
Frailty, measured using the mFI-5, was independently associated with an increased risk of PPCs and improved the predictive performance of conventional risk factors for PPCs in older patients undergoing major abdominal surgery.

Background
Non-anemic iron deficiency (ID) may be harmful during cardiac surgery with cardiopulmonary bypass. However, its impact on off-pump coronary artery bypass (OPCAB) remains unclear. This study examined the association between non-anemic ID and outcomes following OPCAB.
Methods
This single-center retrospective study included non-anemic patients who underwent OPCAB between November 2016 and May 2023. Patients were classified by preoperative ID status, defined as serum ferritin < 100 μg/L or 100–300 μg/L with C-reactive protein > 5 mg/L or transferrin saturation < 20%. The risk of primary outcome, defined as the composite of acute kidney injury, permanent stroke, deep sternal wound infection, hemostatic reoperation, prolonged mechanical ventilation, delirium, myocardial infarction, and 30-day mortality, was compared using multivariable logistic regression. Mediation analysis was performed to determine the indirect effects of non-anemic ID via perioperative red blood cell (RBC) transfusion.
Results
Of the 433 non-anemic patients, 229 (52.9%) had ID. The incidence of composite outcome was similar between patients with and without ID (30.1% vs. 22.5%, P = 0.075). ID was not significantly associated with the composite outcome, whereas perioperative transfusion (odds ratio: 2.10, 95% CI [1.17–3.78], P = 0.013) showed significant associations. Perioperative RBC transfusion was more common in patients with ID (25.8% vs. 10.8%, P < 0.001). Mediation analysis suggested that RBC transfusion partially mediated the effect of ID on the composite outcome.
Conclusions
Preoperative ID was not associated with adverse outcomes in non-anemic patients who had undergone OPCAB. However, its indirect impact via RBC transfusion warrants further investigation.

Background
The sex-specific association between serum uric acid (SUA) levels and postoperative outcomes in elective non-cardiac surgery remains unclear. This study aimed to identify sex-specific SUA thresholds and their impact on short- and long-term outcomes.
Methods
A retrospective analysis of 295 267 patients (2012–2021) undergoing non-cardiac surgery was conducted. Patients were stratified by preoperative SUA levels: for males (< 4 to ≥ 9 mg/dl) and females (< 3 to ≥ 8 mg/dl), with mid-range levels as reference. Mortality (30-day to overall) and complications were assessed using Cox and logistic regression. Cubic splines evaluated nonlinear trends, with subgroup analyses by age and surgical risk.
Results
SUA levels exhibited a nonlinear, sex-specific association with postoperative outcomes. The estimated lower-risk SUA range was 5.08–7.63 mg/dl in males and 3.34–5.35 mg/dl in females. In Cox and spline analyses, a U-shaped association between SUA and mortality was observed in both sexes, with significant risks at both low (< 4 mg/dl) and high (≥ 9 mg/dl) levels in males, and predominantly at low levels (< 3 mg/dl) in females. The types of complications varied subtly between sexes. Within SUA ranges of 4–6 mg/dl (males) and 3–4 mg/dl (females), composite and specific complication risks were lower than at either extreme, showing a protective effect, with reduced risk of acute kidney injury in males and pneumonia in females. Additionally, extreme SUA levels were significantly associated with increased mortality and complications, particularly in low-risk surgical patients.
Conclusions
Preoperative SUA levels show a nonlinear, sex-specific association with postoperative outcomes, highlighting the need for sex- and risk-based perioperative stratification.

Background
The interpectoral and pectoserratus plane (PECs) blocks have been reported to provide favorable postoperative analgesia after mastectomy. However, studies have reported controversial data regarding its effect on the quality of recovery (QoR). We aimed to evaluate the effect of the PECs block in light of baseline psychological factors and pain sensitivity.
Methods
Patients undergoing partial mastectomy were randomly assigned to receive either a PECs block (PECs group, n = 69) or no block (Control group, n = 70). We assessed the preoperative psychosocial factors and pain recognition using the Hospital Anxiety Depression Scale (HADS), Pain Catastrophizing Scale, Breast Cancer Pain Questionnaire, temporal pain summation (TPS), and pressure pain threshold and tolerance; we then conducted the interaction test to evaluate the moderating role of these factors on the efficacy of the PECs block.
Results
The global QoR-15 score 1 day after surgery did not differ between the groups (136.50 [124.00, 144.00] vs. 141.00 [127.00, 148.00], P = 0.061); however, the score was enhanced in patients who were depressed, did not ruminate pain aberrantly, and did not have pre-existing pain. The pain Verbal Numeric Rating Scale 1 day after surgery was not different between the groups; however, the TPS score showed an interaction, indicating that the PECs block could reduce pain intensity in patients with high pain sensitivity.
Conclusions
The PECs block did not enhance the QoR-15 score or pain intensity after mastectomy, but its efficacy was pronounced in patients with several specific emotional traits and pain perception.

Background
Injectate distribution patterns in the pterygopalatine fossa may differ based on the drug administration approach used. This study primarily aimed to assess and compare injectate distribution following the posterior infrazygomatic and transoral approaches. The secondary aim was to evaluate the safety of both approaches.
Methods
Injectate distribution patterns were evaluated in 13 cadaveric head specimens. The vessels were perfused with a gelatin-based solution containing an iodinated contrast agent. The ultrasound-guided posterior infrazygomatic approach and transoral approach were performed on contralateral sides, and needle placement was confirmed using computed tomography (CT). A methylene blue and iodinated contrast agent solution was administered following successful needle placement. Injectate distribution and injuries were assessed via CT and anatomical dissection.
Results
With the posterior infrazygomatic approach, methylene blue consistently stained the maxillary artery and nerve, sphenopalatine ganglion, and lateral pterygoid muscle, whereas with the transoral approach, it most frequently surrounded the maxillary artery and structures within the greater palatine canal. The iodinated contrast agent was distributed predominantly along the needle trajectories for both approaches. Injuries to the maxillary artery and facial nerve were documented following the posterior infrazygomatic approach, whereas injury to the lateral pterygoid plate was observed following the transoral approach.
Conclusions
With the posterior infrazygomatic approach, contrast agent encompassed the entire pterygopalatine fossa, whereas the transoral approach yielded a more localized distribution, primarily within the inferior portion and greater palatine canal. These differences in distribution patterns should guide the selection of the most appropriate approach based on the specific clinical indication.