Journal of Clinical Anesthesia最新文献

Background: Remimazolam, an ultra-short-acting benzodiazepine, has similar clinical effects to propofol for sedation in general anaesthesia. However, it remains uncertain whether remimazolam could increase postoperative delirium (POD) compared with propofol.

Objectives: The purpose of our study was to compare the incidence of POD between remimazolam and propofol as sedative agents in general anaesthesia.

Study design: Systematic review and meta-analysis of randomised controlled trials (RCTs).

Methods: PubMed, Embase, Cochrane Library, and Web of Science databases were searched for prospective RCTs published through September 16, 2024. RCTs reporting the incidence of POD and comparing remimazolam with propofol for general anaesthesia were included. Odds ratio (ORs) were calculated using a random-effects model. The primary outcome was the incidence of POD. The secondary outcomes included time to extubation, awakening time, and adverse events such as intraoperative hypotension.

Results: A total of six RCTs involving 1107 patients were included in this meta-analysis. For the primary outcome, the incidence of POD did not differ between the remimazolam and propofol groups (OR, 0.92; 95 % confidence interval [CI], 0.58-1.44). Regarding the secondary outcomes, remimazolam was associated with a lower incidence of intraoperative hypotension compared with propofol (OR, 0.31; 95 % CI, 0.21-0.46). There were no significant differences in other secondary outcomes. In the sensitivity analysis on three RCTs including only older patients (≥60 years old), there was no significant difference in the incidence of POD (OR, 1.00; 95 % CI, 0.52-1.93).

Conclusion: Perioperative remimazolam administration did not increase POD and reduced the risk of intraoperative hypotension compared to propofol. Further large-scale RCTs are warranted to explore the association of remimazolam and POD. Systematic review protocol: PROSPERO CRD42024544122.

Study objective: To evaluate the impact of positive end-expiratory pressure (PEEP) with or without pressure support ventilation (PSV) on the lung volume and the ventilation distribution during inhalational induction of anesthesia in children.

Design: Prospective observational clinical pilot-study.

Setting: University Children's Hospital of Lyon, France.

Patients: Children without significant comorbidity (ASA 1 or 2) undergoing planned or unplanned surgery with inhalational induction of anesthesia.

Intervention: After the beginning of Guedel's stage 3 of anesthesia, several settings were applied for 60 s in the following systematic order: spontaneous breathing when applying a facemask (SB-Mask), then PEEP 4 cmH₂O, PSV 4 cmH2O above PEEP 4 cmH₂O, and PSV 4 to 7 cmH₂O above PEEP 4 cmH₂O, at the anesthesiologist's discretion.

Measurements: Children were monitored using Electrical Impedance Tomography (EIT; Pulmovista 500, Dräger, France). Tidal volume (TV), dorsal fraction of the ventilation, and end-expiratory lung impedance (EELI) were assessed with the ventilator and EIT.

Main results: Twenty-two patients were included (20 analyzed), their median [IQR] age was 21 [14-36] months. TV did not significantly differ between the settings. The increase in EELI was greater with PSV (+0.60 [0.48-0.91] arbitrary units) than with PEEP 4 cmH₂O alone (+0.39 [0.20-0.06] arbitrary units, p = 0.005), and did not change with increased level of PSV (+0.66 [0.40-1.22] arbitrary units). The dorsal fraction of lung ventilation decreased using PSV, from 56 % [45-63] with SB-mask to 53 % [43-56] with PSV 4cmH₂O (p = 0.002) and 47 % [40-55] with PSV 7cmH₂O (p = 0.001).

Conclusion: The ventilator settings used during inhalational induction of anesthesia in children have an impact on lung ventilation. PSV during inhalational induction of anesthesia in children may restore the end-expiratory lung volume independently from the increase in TV.

Background: Frailty, a syndrome of decreased resilience to physiologic stress, has been associated with increased postoperative length of stay (LOS) for specific procedures. Yet, the literature lacks large-scale analyses examining the relationship between frailty and LOS across surgical procedure.

Study design: We conducted a retrospective cohort study of patients aged 65+ undergoing inpatient surgery including emergency procedures between 2015 and 2019 using American College of Surgeons National Surgical Quality Improvement Program (ACS NSQIP®) data. Frailty, measured by the modified 5-item frailty index (mFI-5), was categorized as non-frail (mFI-5 < 2) or frail (mFI-5 ≥ 2). We modeled LOS, adjusting for demographic variables, comorbidities, and surgical factors, and conducted a subgroup analysis based on emergency surgery status and surgical procedure type.

Main results: Among 1,254,809 patients, 29.0 % were frail. A higher proportion of frail patients were Black (10 % vs. 5.5 %), Hispanic (6.1 % vs. 3.8 %), of ASA class IV/V (23.3 % vs. 9.1 %), malnourished (2.7 % vs. 1.9 %), and underwent vascular surgery (16.5 % vs. 8.3 %). They experienced longer median LOS across all surgical procedures, except bariatric surgery. Unadjusted analysis revealed that mFI-5 scores of 4 and 5 were associated with increased median LOS by 3.5 days (95 % CI 3.36-3.64) and 4.64 days (95 % CI 3.96-5.32), respectively, compared to mFI-5 scores of 0. In adjusted analysis, frailty remained a significant risk factor for increased median LOS, with an mFI-5 score of 5 associated with a 3-day longer increase (95 % CI 2.79-3.22) compared to an mFI-5 score of 0. Subgroup analysis showed that each one-point increase in mFI-5 score had the strongest association with increased median LOS in emergency surgery (0.5 days, 95 % CI 0.48-0.52) and lower extremity bypass surgery (0.53 days, 95 % CI 0.47-0.59).

Conclusions: Frailty is an independent risk factor for prolonged postoperative LOS among older surgical patients, even after adjustment for patient and procedure covariates. Other independent risk factors for increased LOS include emergent surgery, malnutrition, and higher ASA class.

Backgrounds: The cerebral oximetry index (CO_x) uses near-infrared spectroscopy to estimate cerebral autoregulation during cardiac surgery. However, the relationship between intraoperative loss of cerebral autoregulation and postoperative delirium or stroke remains unclear in patients recovering from carotid endarterectomy (CEA).

Methods: Our prospective observational cohort study enrolled patients scheduled for CEA. CO_x was estimated as the coefficient of a continuous, moving Spearman correlation between mean arterial pressure and cerebral oxygen saturation. A receiver operating characteristics curve with Youden's index identified the optimal CO_x threshold for predicting a composite of postoperative delirium or new-onset overt stroke.

Results: One hundred and forty patients scheduled for CEA were enrolled. The incidence of delirium was 10.7 % (15/140) and the incidence of stroke was 3.6 % (5/140), including 1 patient who had both. The cumulative anesthesia time when CO_x exceeded 0.3 was longer in patients with complications than those without. When CO_x > 0.6, the corresponding predictive ability was AUC = 0.69, Youden index = 0.61, P = 0.0003, with a positive predictive value of 100 %. In the post hoc subgroup analyses, before clamping, the greatest increase in the risk was observed when CO_x > 0.7 for 20 min (Odds ratio = 3.10, 95 % CI 2.20, 3.78). In contrast, CO_x was not predictive during clamping. After clamping, the optimal CO_x threshold was 0.4 (AUC = 0.85, Youden index = 0.82, P < 0.0001), with the positive predictive value being 100 %.

Conclusions: CO_x is a promising metric for predicting postoperative delirium or new-onset overt stroke in patients having CEA. The optimal CO_x threshold was 0.7 in the pre-clamping phase and 0.4 in the post-clamping phase.

Study objective: To determine whether individualized fraction of inspired oxygen (iFiO₂) improves pulmonary atelectasis after elective laparoscopic colorectal surgery relative to 60 % FiO₂.

Design: This was a single-center, prospective, randomized study.

Setting: This study was conducted in a single tertiary care hospital in China.

Patients: A total of 84 eligible inpatients who underwent elective laparoscopic colorectal surgery between August 2021 and May 2022 were included in the study.

Interventions: The patients were randomly assigned to receive either a fixed fraction of inspiration oxygen (fFiO₂ group) or individualized FiO₂ based on physiological SpO₂ (iFiO₂ group).

Measurements: The primary outcome was the lung ultrasound score (LUS) at 30 min after extubation. Secondary outcomes included the length of hospital stay, admission to the intensive care unit, the length of post-anesthetic care unit stay, the ratio of lung capacity on the third day after surgery compared with before surgery, the incidence of nausea and vomiting, and surgical site infections after surgery. Additionally, the airway plate pressure, airway peak pressure, pulmonary dynamic compliance, PaO₂, oxygenation index, alveolar-arterial oxygen tension gradient (A-aDO₂), and pulmonary shunt fraction (Qs/Qt) were considered.

Main results: The LUS was significantly lowered in the iFiO₂ group (5 [4, 7]) compared with the fFiO₂ group (8 [4, 10]) (P = 0.03). Based on the criterion for determining atelectasis, 25 patients (62.5 %) in the fFiO₂ group experienced significant atelectasis compared with 15 patients (37.5 %) in the iFiO₂ group (P = 0.025). At the end of surgery, PaO₂, A-aDO₂, and Qs/Qt were significantly reduced in patients in the iFiO₂ group compared with those in the fFiO₂ group.

Conclusions: The use of iFiO₂ during operation significantly reduces the LUS and pulmonary atelectasis in patients undergoing laparoscopic colorectal surgery under general anesthesia.

Clinical trial registration: ChiCTRT2100049615.