Journal of Anesthesia最新文献

Background: In Japan, labor neuraxial analgesia (LNA) is frequently administered by obstetricians rather than board-certified anesthesiologists, particularly in smaller facilities. Although awareness of maternal safety has increased in recent years, the extent of anesthesiologist involvement in obstetric anesthesia remains unclear.

Methods: This nationwide cross-sectional study analyzed data from Birth-Navi, a public registry of childbirth facilities maintained by Ministry of Health, Labour and Welfare of Japan. As of August 2024, facilities offering LNA were categorized into two groups: those listing a board-certified anesthesiologist (Group A) and an obstetrician-gynecologist (Group O) as a responsible physician. Institutional characteristics and analgesia practices were compared between groups using chi-square tests.

Results: Among 2063 registered facilities, 837 (40.6%) provided LNA, of which 771 met the inclusion criteria. Only 27.2% facilities listed a board-certified anesthesiologist as the responsible physician. Group A facilities were more likely to be hospitals (86.8% vs. 30.4%, p < 0.001) and more likely to utilize combined spinal-epidural techniques (23.7% vs. 14.0%, p = 0.002). However, 24 h analgesia availability was significantly lower in Group A than in Group O (25.9% vs. 47.1%, p < 0.05). Notably, only 284 facilities (13.8%) provided round-the-clock analgesia upon maternal request.

Conclusion: It is important to note that anesthesiologist-led LNA remains limited in Japan. While associated with more advanced techniques, 24 h availability is uncommon. To improve both access and safety, system-level strategies-such as redistribution of personnel and the implementation of collaborative tele-anesthesia networks-should be considered.

Purpose: Kidneys are relatively resistant to ischemia. Few studies have examined the effects of short ischemic time in living-donor kidney transplantation. This retrospective study investigated the effects of ischemic time on renal function in living-donor kidney transplantation.

Methods: Patients who have undergone kidney transplantation in Kyushu University Hospital between January 2017 and December 2021 were divided into two groups based on the median ischemic time (< 170 min and ≥ 170 min), after propensity score matching. A multivariate analysis was performed to determine the risk factors for renal dysfunction.

Results: Each group contained 89 patients. Shorter ischemic time (< 170 min) was associated with higher postoperative glomerular filtration rates during the first-seventh postoperative days (POD7, 48.8 ± 18.9 vs. 42.8 ± 20.5; p = 0.04). Donor sex (female, odds ratio [OR]: 2.53, 95% confidence interval [CI] 1.11-5.82, p = 0.028), donor age (≥ 50 years, OR: 18.7, 95% CI 8.51-41.1, p < 0.001), diabetes (OR: 3.01, 95% CI 1.17-7.77, p = 0.023), and acute rejection within 1 year (OR: 17.3, 95% CI 2.02-148.2, p = 0.009) significantly increased renal dysfunction risk at 1 year. Ischemic time was not related to renal dysfunction 1 year after kidney transplantation (ischemic time ≥ 170 min, OR 1.06, 95% CI [0.52-2.14]; p = 0.88). The OR for an ischemic time ≥ 170 min was 0.69 (95% CI 0.27-1.75) in donors aged < 50 and 1.70 (95% CI: 0.63-4.60) in those aged ≥ 50 years (interaction p = 0.13).

Conclusions: Longer ischemic time was correlated with early postoperative renal dysfunction, although the effect on renal function at 1 year was minimal with short ischemic times. Adverse effects of ischemic time on renal function after 1 year should be considered with older donors.

Background: Postoperative delirium is a common complication associated with prolonged hospitalization, cognitive decline, and increased mortality. Intraoperative hypotension (IOH) is a potential modifiable risk factor for postoperative delirium, but previous studies have shown inconsistent results due to methodological limitations. High-risk surgical patients, particularly those with comorbidities or advanced age, may be especially vulnerable. We evaluated the association between IOH and postoperative ICU delirium within 48 h.

Methods: We conducted a single-center retrospective study of high-risk adult patients who underwent surgery under general anesthesia without cardiopulmonary bypass and were admitted to the ICU between 2017 and 2024. IOH exposure was quantified using the cumulative area where mean arterial pressure (MAP) was below 65 mmHg (hypotension area) and total time under this threshold (hypotension time). Multivariable logistic regression was used to assess the association between IOH and postoperative ICU delirium, adjusting for preoperative comorbidities, intraoperative medications, and anesthetic depth. Subgroup and interaction analyses explored effect modifiers.

Results: Among 4798 patients, both hypotension area (OR 1.16, 95% CI 1.05-1.29, P = 0.003) and hypotension time (OR 3.42, 95% CI 1.21-9.65, P = 0.02) were significantly associated with postoperative ICU delirium within 48 h. Subgroup analyses suggested stronger associations in patients with advanced age, higher ASA-PS, inhalational anesthesia, neurosurgery, and intubation at ICU admission.

Conclusions: IOH was significantly associated with postoperative ICU delirium. These findings underscore the importance of vigilant blood pressure management during surgery, particularly in high-risk patients. Interventional studies are needed to confirm these results and guide preventive strategies.

Purpose: To compare the effects of propofol and remimazolam on peri-operative oxygen supply-demand balance.

Methods: This prospective quasi-randomized controlled trial was carried out in a single tertiary care university hospital between January and October 2022, with patients (n = 50) aged 18-85 years undergoing major abdominal surgery. General anesthesia was induced and maintained with propofol or remimazolam. The primary endpoints were peri-operative oxygen consumption (VO₂) and carbon dioxide production (VCO₂). The secondary endpoints were oxygen delivery (DO₂) and the respiratory quotient (RQ). These were measured using indirect calorimetry and arterial pressure waveform analysis for cardiac output monitoring. Time-series changes in these parameters were analyzed to compare the effects of the anesthetics on oxygen supply-demand balance. The associations among the choice of anesthetic agent, patient characteristics, and VCO₂ levels were investigated.

Results: Anesthesia induction significantly decreased VO₂, VCO₂, DO₂, and RQ. The reduction in VO₂, VCO₂, DO₂, and RQ in the propofol and remimazolam groups was 17.6% [IQR: -0.55-27.8] vs 17.4% [10.3-31.6] (P = 0.47), 26.1% [5.2-40.5] vs 31.2% [16.2-42.6] (P = 0.59), 24.4% [1.0-35.2] vs 20.7% [15.4-32.8] (P = 0.93), and 10.3% [4.4-16.7] vs 10.4% [-4.7-21.6] (P = 0.71), respectively. A weak association between anesthesia choice and VCO₂ concentrations was observed. Patients with higher VCO₂ were younger, with better cardiac function than those with lower VCO₂.

Conclusions: Anesthesia induction suppressed metabolism. However, the choice of general anesthetic for scheduled major abdominal procedures did not significantly affect the oxygen supply-demand balance.

Trial registration: University Hospital Medical Information Network Clinical Trials Registry identifier: UMIN000046531.

Acute kidney injury (AKI) is a common and serious perioperative complication with several diverse etiologies. Elderly surgical patients are particularly vulnerable, experiencing higher rates of AKI and suffering worse outcomes, including multiorgan dysfunction, elevated mortality rates, and a heightened risk of developing chronic kidney disease (CKD) or end-stage renal disease (ESRD). AKI also imposes a significant economic burden, increasing healthcare costs due to prolonged hospitalizations and increased resource utilization. Given the limited treatment options for AKI, prevention is paramount. This involves identifying and optimizing modifiable patient, surgical, and anesthetic risk factors, implementing evidence-based care bundles in high-risk patients, avoiding potential causes of kidney insult, and employing novel preventive strategies such as remote-ischemic preconditioning. Early diagnosis is crucial when prevention fails, allowing timely intervention before irreversible kidney damage occurs. Novel diagnostic tools show promise in improving the accuracy and timeliness of AKI detection, facilitating prompt management. While renal-replacement therapy (RRT) remains the only definitive treatment for AKI, more refined criteria for its initiation are needed to enhance its delivery and improve patient outcomes.

Purpose: Postoperative bleeding is a major concern in pediatric cardiac surgery under cardiopulmonary bypass (CPB). The comparative utility of viscoelastic testing and central laboratory assays for predicting bleeding risk remains unclear. This study aimed to (1) compare the predictive value of thromboelastography parameters-maximum amplitude of citrated functional fibrinogen (CFF-MA) and citrated rapid thromboelastography (CRT-MA)-with central laboratory tests (serum fibrinogen and platelet count) for early postoperative bleeding, and (2) identify clinical factors influencing the correlation between CFF-MA and fibrinogen.

Methods: A retrospective analysis was performed on 357 pediatric patients (< 18 years) undergoing congenital heart surgery with CPB at a single pediatric center in Japan between April 2022 and January 2025. Parameters measured after protamine administration included CFF-MA, CRT-MA, serum fibrinogen, and platelet count. Early postoperative bleeding was defined as chest/pericardial drain output > 10% of estimated blood volume within 6 h post-PICU admission. Predictive ability was assessed using receiver operating characteristic (ROC) curve analysis, and clinical factors were evaluated by multivariable linear regression.

Results: CRT-MA and platelet count demonstrated the highest predictive ability for early postoperative bleeding (area under the curve [AUC] 0.74, 95% CI 0.69-0.79). CFF-MA outperformed serum fibrinogen (AUC 0.72 vs. 0.42, p < 0.001). The correlation between CFF-MA and fibrinogen was notably weaker in infants after protamine administration. Only 3.9% of patients had fibrinogen < 150 mg/dL.

Conclusions: CRT-MA and platelet demonstrated relatively high predictive ability for early postoperative bleeding in pediatric cardiac surgery. The predictive value of CFF-MA and fibrinogen may diverge, especially in younger age groups.

Purpose: Hemorrhage may suppress the amplitude of transcranial motor evoked potentials (TcMEPs). We compared the effects of hemorrhage, subsequent fluid resuscitation, and transient anesthetic deepening on the recently developed transesophageal motor evoked potentials (TeMEPs) with those on conventional TcMEPs.

Methods: Twelve swine (26.0 ± 0.5 kg) were anesthetized with 8-13% desflurane during preparation and then switched to propofol and remifentanil anesthesia. After baseline measurements, 700 mL of blood was withdrawn over 30 min to induce hypovolemia. Hypovolemia was then treated with 700 mL of hydroxyethyl starch for 30 min (fluid resuscitation). Subsequently, 5 mg of remimazolam was administered, followed by 50 mg of propofol after the effects of remimazolam had reversed. TcMEPs and TeMEPs were recorded at the end of each condition and immediately before and after the administration of remimazolam or propofol.

Results: In all conditions and in all limbs, TeMEPs' amplitudes were greater than those of TcMEPs. Massive hemorrhage reduced the amplitudes of both TeMEPs and TcMEPs in the bilateral lower limbs and this reduction was not reversed by fluid resuscitation. Following bolus administration of remimazolam or propofol, TcMEPs were markedly suppressed, whereas TeMEPs remained unchanged.

Conclusions: Similar to TcMEPs, TeMEPs amplitudes may decrease after hemorrhage, and this suppression is not reversed by fluid resuscitation. However, unlike TcMEPs, TeMEPs are resistant to transient anesthetic deepening, suggesting that the observed suppression may be attributable to reduced oxygen delivery to the spinal cord rather than to anesthetic deepening.