Brazilian Journal of Anesthesiology最新文献

Introduction

This study aimed to assess the learning curves of peribulbar anesthesia and estimate the number of blocks needed to attain proficiency.

Methods

Anonymized records of sequential peribulbar blocks performed by first-year anesthesia residents were analyzed. The block sequential number and the outcomes were extracted from each record. Success was defined as a complete sensory and motor block of the eye, and failure was defined as an incomplete block requiring supplemental local anesthetic injections or general anesthesia. Learning curves using the LC-CUSUM method were constructed, aiming for acceptable and unacceptable failure rates of 10% and 20%, and 10% probability of type I and II errors. Simulations were used to determine the proficiency limit h₀. Residents whose curves reached h₀ were considered proficient. The Sequential Probability Ratio Test Cumulative Sum Method (SPRT-CUSUM) was used for follow-up.

Results

Thirty-nine residents performed 2076 blocks (median = 52 blocks per resident; Interquartile Range (IQR) [range] = 27–78 [4–132]). Thirty residents (77%) achieved proficiency after a median of 13 blocks (13–24 [13–24]).

Conclusions

The LC-CUSUM is a robust method for detecting resident proficiency at peribulbar anesthesia, defined as success rates exceeding 90%. Accordingly, 13 to 24 supervised double-injection peribulbar blocks are needed to attain competence at peribulbar anesthesia.

Background

Anemia is common in the preoperative setting and associated with increased postoperative complications and mortality. However, it is unclear if preoperative anemia optimization reduces postoperative complications. We aimed to assess the association between preoperative anemia optimization and a composite endpoint of major cardiovascular, renal, and pulmonary complications and all-cause mortality within 30 days after noncardiac surgery in adult patients.

Methods

In this retrospective analysis preoperative anemia was defined as hemoglobin concentration below 12.0 g.dl⁻¹ in women and 13.0 g.dl⁻¹ in men within 6 months before surgery. A propensity score-based generalized estimating equation analysis was used to determine the association between preoperative anemia optimization and the primary outcome. Moreover, mediation analysis was conducted to investigate whether intraoperative red blood cell transfusion or duration of intraoperative hypotension were mediators of the relation between anemia optimization and the primary outcome.

Results

Fifty-seven hundred anemia optimized, and 8721 non-optimized patients met study criteria. The proportion of patients having any component of the composite of major complications and all-cause mortality was 21.5% in the anemia-optimized versus 18.0% in the non-optimized, with confounder-adjusted odds ratio estimate of 0.99 (95% CI 0.86‒1.15) for anemia optimization versus non-optimization, p = 0.90. Intraoperative red blood cell transfusion had a minor mediation effect on the relationship between preoperative anemia optimization and the primary outcome, whereas duration of intraoperative hypotension was not found to be a mediator.

Conclusion

Preoperative anemia optimization did not appear to be associated with a composite outcome of major in-hospital postoperative cardiovascular, renal, and pulmonary complications and all-cause in-hospital mortality.

Background

The costoclavicular approach to brachial plexus block may have a more favorable anatomy than the classic infraclavicular approach. However, there are conflicting results in the literature regarding the comparative effectiveness of these two techniques.

Methods

We systematically searched for Randomized Controlled Trials (RCTs) comparing costoclavicular with infraclavicular brachial plexus blocks for upper extremity surgeries on MEDLINE, EMBASE, and Ovid. The outcomes of interest were sensory and motor block onset times, performance times, block failure, and complication rate. We performed statistical analyses using RevMan 5.4 and assessed heterogeneity using the Cochran Q test and I² statistics. We appraised the risk of bias according to Cochrane's Risk of Bias 2 tool.

Results

We included 5 RCTs and 374 patients, of whom 189 (50.5%) were randomized to undergo costoclavicular block. We found no statistically significant differences between the two techniques regarding sensory block onset time in minutes (Mean Difference [MD = -0.39 min]; 95% CI -2.46 to 1.68 min; p = 0.71); motor block onset time in minutes (MD = -0.34 min; 95% CI -0.90 to 0.22 min; p = 0.23); performance time in minutes (MD = -0.12 min; 95% CI -0.89 to 0.64 min; p = 0.75); incidence of block failure (RR = 1.59; 95% CI 0.63 to 3.39; p = 0.63); and incidence of complications (RR = 0.60; 95% CI 0.20 to 1.84; p = 0.37).

Conclusion

This meta-analysis suggests that the CCV block may exhibit similar sensory and motor onset times when compared to the classic ICV approach in adults undergoing distal upper extremity surgery, with comparable rates of block failure and complications.

Perioperative Goal-Directed Therapy (PGDT) has significantly showed to decrease complications and risk of death in high-risk patients according to numerous meta-analyses. The main goal of PGDT is to individualize the therapy with fluids, inotropes, and vasopressors, during and after surgery, according to patients’ needs in order to prevent organic dysfunction development. In this opinion paper we aimed to focus a discussion on possible alternatives to invasive hemodynamic monitoring in low resource settings.

Introduction

Methylene Blue (MB) has been shown to attenuate oxidative, inflammatory, myocardial, and neurological lesions during ischemia-reperfusion and has great potential during cardiac arrest. This study aimed to determine the effects of MB combined with epinephrine during cardiac arrest on myocardial and cerebral lesions.

Method

Thirty-eight male Wistar rats were randomly assigned to four groups: the sham group (SH, n = 5), and three groups subjected to cardiac arrest (n = 11/group) and treated with EPI 20 µg.kg⁻¹ (EPI), EPI 20 µg.kg⁻¹ + MB 2 mg.kg⁻¹ (EPI + MB), or saline 0.9% 0.2 ml (CTL). Ventricular fibrillation was induced by direct electrical stimulation in the right ventricle for 3 minutes, and anoxia was maintained for 5 minutes. Cardiopulmonary Resuscitation (CPR) consisted of medications, ventilation, chest compressions, and defibrillation. After returning to spontaneous circulation, animals were observed for four hours. Blood gas, troponin, oxidative stress, histology, and TUNEL staining measurements were analyzed. Groups were compared using generalized estimating equations.

Results

No differences in the Returning of Spontaneous Circulation (ROSC) rate were observed among the groups (EPI: 63%, EPI + MB: 45%, CTL: 40%, p = 0.672). The mean arterial pressure immediately after ROSC was higher in the EPI+MB group than in the CTRL group (CTL: 30.5 [5.8], EPI: 63 [25.5], EPI+MB: 123 [31] mmHg, p = 0.007). Serum troponin levels were high in the CTL group (CTL: 130.1 [333.8], EPI: 3.70 [36.0], EPI + MB: 43.7 [116.31] ng/mL, p < 0.05).

Conclusion

The coadministration of MB and epinephrine failed to yield enhancements in cardiac or brain lesions in a rodent model of cardiac arrest.

Background

The optimal amount for initial fluid resuscitation is still controversial in sepsis and the contribution of non-resuscitation fluids in fluid balance is unclear. We aimed to investigate the main components of fluid intake and fluid balance in both survivors and non-survivor patients with septic shock within the first 72 hours.

Methods

In this prospective observational study in two intensive care units, we recorded all fluids administered intravenously, orally, or enterally, and losses during specific time intervals from vasopressor initiation: T1 (up to 24 hours), T2 (24 to 48 hours) and T3 (48 to 72 hours). Logistic regression and a mathematical model assessed the association with mortality and the influence of severity of illness.

Results

We included 139 patients. The main components of fluid intake varied across different time intervals, with resuscitation and non-resuscitation fluids such as antimicrobials and maintenance fluids being significant contributors in T1 and nutritional therapy in T2/T3. A positive fluid balance both in T1 and T2 was associated with mortality (p = 0.049; p = 0.003), while nutritional support in T2 was associated with lower mortality (p = 0.040). The association with mortality was not explained by severity of illness scores.

Conclusions

Non-resuscitation fluids are major contributors to a positive fluid balance within the first 48 hours of resuscitation. A positive fluid balance in the first 24 and 48 hours seems to independently increase the risk of death, while higher amount of nutrition seems protective. This data might inform fluid stewardship strategies aiming to improve outcomes and minimize complications in sepsis.

Objective

This trial aimed to identify the Minimum Effective Concentration (MEC₉₀, defined as the concentration which can provide successful block in 90% of patients) of 30 mL ropivacaine for single-shot ultrasound-guided transmuscular Quadratus Lumborum Block (QLB) in patients undergoing Total Hip Arthroplasty (THA).

Methods

A double-blind, randomized dose-finding study using the biased coin design up-and-down sequential method, where the concentration of local anesthetic administered to each patient depended on the response from the previous one. Block success was defined as a Numeric Rating Scale (NRS) score during motion ≤ 3 at 6 hours after arrival in the ward. If the block was successful, the next subject received either a 0.025% smaller dose (probability of 0.11) or the same dose (probability of 0.89); otherwise, the next subject received a 0.025% higher ropivacaine concentration. MEC₉₀, MEC₉₅ and MEC₉₉ were estimated by isotonic regression, and the corresponding 95% Confidence Intervals (95% CIs) were calculated by the bootstrapping method.

Results

Based on the analysis of 52 patients, MEC₉₀, MEC₉₅, and MEC₉₉ of ropivacaine for QLB were estimated to be 0.352% (95% CI 0.334–0.372%), 0.363% (95% CI 0.351–0.383%), and 0.373% (95% CI 0.363–0.386%). The concentration of ropivacaine at 0.352% in a volume of 30 ml can provide a successful block in 90% of patients.

Conclusions

For ultrasound-guided transmuscular QLB in patients undergoing THA, 0.352% ropivacaine in a volume of 30 ml can provide a successful block in 90% of patients. Further dose-finding studies and large sample size are required to verify the concentration.

Background

This randomized and controlled prospective study tested the hypothesis that closed-loop Target-Controlled Infusion (TCI) of propofol would be associated with better system performance when compared with open-loop controlled delivery of propofol.

Methods

Patients scheduled for elective breast surgery were randomly assigned to two groups: a closed-loop group, in which propofol infusion was performed by a closed-loop TCI system that used the Bispectral Index (BIS) as a feedback parameter to titrate the rate of propofol infusion, and an open-loop group, in which propofol infusion was performed manually and guided by the bispectral index.

Results

A total of 156 patients were recruited for this study (closed-loop group n = 79; open-loop group n = 77). The Global Score (GS) of the closed-loop group was lower than that of the open-loop group (34.3 and 42.2) (p = 0.044). The proportions of time with a BIS value between 40 and 60 were almost identical in the closed-loop group and the open-loop group (68.7 ± 10.6% and 66.7 ± 13.3%) (p = 0.318). The individuals in the closed-loop group consumed more propofol compared with those in the open-loop group (7.20 ± 1.65 mg.kg⁻¹.h⁻¹ vs. 6.03 ± 1.31 mg.kg⁻¹.h⁻¹, p < 0.001). No intraoperative recall, somatic events or adverse events occurred. No significant difference in heart rate was observed between the two groups (p = 0.169).

Conclusion

The closed-loop protocol was associated with lower BIS variability and lower out-of-range BIS values, at the cost of a greater consumption of propofol when compared to the open loop group.

Register number

ChiCTR-INR-17010399.