Neuromuscular Blockade Research Articles

Comparison of three different doses of cis-atracurium under isoflurane anesthesia

Aims: In this study; we compared the effects of three different doses of cis-atracurium, a nondepolarizing muscle relaxant agent, on neuromuscular blockade duration, endotracheal intubation quality and hemodynamic parameters under isoflurane anaesthesia.
 Methods: A total of 60 patients (ASA I-II) were included in the study. Patients were premedicated with 10 mg diazepam intramuscularly 45 minutes before the operation. After the patients were transferred to the operating room, they were monitored noninvasively for heart rate and arterial blood pressure. Train of Four (TOF)-GUARD acceleration monitor was used for neuromuscular evaluation. All patients were administered 1 mg/kg fentanyl and 2 mg/kg propofol at induction, and anaesthesia maintenance was provided with 1.5% isoflurane+50% N2O+50% O2. The patients were divided into three groups according to the dose of cisatracurium administered: 0.15 mg/kg was administered to Group 1, 0.20 mg/kg was administered to Group 2, and 0.40 mg/kg cis-atracurium was administered to Group 3. Endotracheal intubation was performed at 120 seconds, and the block time of 99-100% (effect onset time) was recorded.
 Result: Although the endotracheal intubation quality was evaluated as excellent and/or good in all three groups, the intubation quality of Group 3 was statistically higher than the other two groups (p

Effect of Different Doses of Sugammadex on Recovery and Hemodynamic Parameters in Reversing Neuromuscular Blockade in Patients Undergoing Electroconvulsive Therapy.

This retrospective observational study aimed to investigate the effect of different doses of sugammadex used in reversing neuromuscular blockade in electroconvulsive therapy (ECT) procedures on patient recovery and hemodynamic measurements. Anesthesia induction was performed using propofol (1 mg/kg) and rocuronium (0.4 mg/kg). Patients were classified into group 2 (2 mg/kg) and group 3 (3 mg/kg) according to the dose of sugammadex used to reverse neuromuscular blockade. The patient's spontaneous breathing time, eye-opening time, time to comply with voluntary commands, time to reach Modified Aldrete score (MAS) 9, complications, and hemodynamic data were analyzed. In total, 314 ECT sessions were performed on 46 patients. The average age of the patients was 38.3±12.6 years, and 56.6% (n=26) were male. While the average number of ECTs applied to the patients was 6.8±2.8, the average seizure duration was 28.2±12.7 seconds. The most common diagnosis (32.7%) in patients who underwent ECT was bipolar disorder. The average time to recovery of spontaneous breathing, eyeopening time, time to comply with voluntary commands, and time to reach MAS 9 were found to be significantly lower in group 3 (p<0.001, p<0.001, p<0.001, and p=0.002, respectively). Tooth damage was observed in 0.3% (n=1) and tongue abrasion in 0.6% (n=2) of the cases. Hemodynamic measurements were similar between groups (p>0.05). Sugammadex used at a dose of 3 mg/kg in ECT procedures significantly reduces recovery times compared with 2 mg/kg. However, both doses can be safely and cost-effectively used to reverse the neuromuscular blockade provided by 0.4 mg/kg rocuronium.

Comparison of the analgesic effects of different bupivacaine concentrations in continuous femoral block after total knee arthroplasty surgery

Aim: In regional anesthesia practice, anesthesists’ goal must be to use the lowest effective concentration of local anesthetics to provide sufficient pain relief while minimizing side effects and complications. This study was designed to compare the analgesic efficacy of two different concentrations of bupivacaine (0.125% and 0.1%) in continuous femoral block for postoperative analgesia.Method: In this study, fifty patients were enrolled, all of whom underwent femoral nerve block catheterization. The block procedure involved the administration of 30ml of bupivacaine solution at a concentration of 0.25%. Following a thirty-minute interval post-block application, patients underwent knee surgery under general anesthesia. During the closure of subcutaneous tissues, an additional 10ml of bupivacaine solution was injected through the catheter. Two groups were formed based on the concentration of the solution administered: Group(0.125%) received bupivacaine at a concentration of 0.125%, while Group(0.1%) received it at a concentration of 0.1%. Subsequently, upon arrival at the postoperative care unit, infusion through the catheter commenced at a rate of 10ml/h-1, maintaining the same concentrations for both groups. In addition to the nerve block, all patients were provided with intravenous Patient Controlled Analgesia (PCA) devices containing morphine for pain management. Throughout the postoperative period, sensory and motor block levels, Numerical Rating Scale (NRS) values for static and dynamic pain assessment, total morphine consumption, morphine demand, as well as any observed side effects and complications, were meticulously recorded for analysis.Results: Postoperatively the NRSstatic values at 24th and 48th hours and NRSdynamic values at the 24th hour were higher in Group(0.1%) and it was statistically significant(p&lt;0,007). And at 48th hour, morphine consumption was significantly higher in Group(0.1%) (p&lt;0,05).Conclusions: In our study, all patients across both experimental groups initially experienced satisfactory analgesia. However, within the 24-hour postoperative period, Group(0.1%) exhibited a decline in the quality of analgesia, necessitating increased utilization of rescue analgesics. This escalation in rescue analgesic use was associated with a higher incidence of adverse effects and reduced patient comfort levels within this group. Consequently, our findings indicate that the 0.125% concentration of bupivacaine yielded superior efficacy compared to the 0.1% concentration in the context of continuous femoral block administration.

Remifentanil for tracheal intubation without neuromuscular blocking drugs in adult patients: a systematic review and meta-analysis.

There is increasing interest in the use of short-acting opioids such as remifentanil to facilitate tracheal intubation. The aim of this systematic review was to determine the efficacy and safety of remifentanil for tracheal intubation compared with neuromuscular blocking drugs in adult patients. We conducted a systematic search for randomised controlled trials evaluating remifentanil for tracheal intubation. Primary outcomes included tracheal intubation conditions and adverse events. Twenty-one studies evaluating 1945 participants were included in the analysis. Use of remifentanil (1.5-4.0 μg.kg-1 ) showed no evidence of a difference in tracheal intubation success rate compared with neuromuscular blocking drugs (risk ratio (95%CI) 0.97 (0.94-1.01); six studies; 1232 participants; I2 28%; p = 0.16; moderate-certainty evidence). Compared with neuromuscular blocking drugs, the use of remifentanil (2.0-4.0 μg.kg-1 ) makes little to no difference in terms of producing excellent tracheal intubation conditions (risk ratio (95%CI) 1.16 (0.72-1.87); two studies; 121 participants; I2 31%, p = 0.54; moderate-certainty of evidence). There was no evidence of an effect between remifentanil (2.0-4.0 μg.kg-1 ) and neuromuscular blocking drugs for bradycardia (risk ratio (95%CI) 0.44 (0.01-13.90); two studies; 997 participants; I2 81%; p = 0.64) and hypotension (risk ratio (95%CI) 1.05 (0.44-2.49); three studies; 1071 participants; I2 92%; p = 0.92). However, the evidence for these two outcomes was judged to be of very low-certainty. We conclude that remifentanil may be used as an alternative drug for tracheal intubation in cases where neuromuscular blocking drugs are best avoided, but more studies are required to evaluate the haemodynamic adverse events of remifentanil at different doses.

Trapping and reversing neuromuscular blocking agent by anionic pillar[5]arenes: Understanding the structure-affinity-reversal effects

Selective relaxant binding agents (SRBA) have great potential in clinical surgeries for the precise reversal of neuromuscular blockades. Understanding the relationship between the structure-affinity-reversal effects of SRBA and neuromuscular blockade is crucial for the design of new SRBAs, which has rarely been explored. Seven anionic pillar[5]arenes (AP5As) with different aliphatic chains and anionic groups at both edges were designed. Their binding affinities to the neuromuscular blocking agent decamonium bromide (DMBr) were investigated using 1H NMR, isothermal titration calorimetry (ITC), and theoretical calculations. The results indicate that the capture of DMBr by AP5As is primarily driven by electrostatic interactions, ion-dipole interactions and C-H‧‧‧π interactions. The optimal size matching between the carboxylate AP5As and DMBr was ∼0.80. The binding affinity increased with an increase in the charge quantity of AP5As. Further animal experiments indicated that the reversal efficiency increased with increasing binding affinity for carboxylate or phosphonate AP5As. However, phosphonate AP5As exhibited lower reversal efficiencies than carboxylate AP5As, despite having stronger affinities with DMBr. By understanding the structure-affinity-reversal relationships, this study provides valuable insights into the design of innovative SRBAs for reversing neuromuscular blockade.

Effects of Ketamine and Tramadol As Adjuvants to Bupivacaine in Spinal Anesthesia for Unilateral Open Ovarian Cystectomy: A Randomized Controlled Trial.

Spinal anesthesia offers numerous advantages and desirable features. However, it is associated with various side effects related to local anesthetic agents used. Reducing the dose of local anesthetic in spinal anesthesia can help minimize side effects but may lead to a diminished analgesic effect or failure of anesthesia. Therefore, adding an adjuvant may enhance the benefits while mitigating side effects. This study aimed to evaluate the effects of ketamine and tramadol as adjuvants to bupivacaine on the duration of spinal analgesia. The objectives were to compare the three groups and prove their analgesic effects, safety, and superiority.The primary outcomes werethe duration of spinal analgesia, as well as the onset and duration of both sensory and motor blocks. Secondary outcomes included the heart rate, mean arterial pressure, and the incidence of undesired effects such as nausea, vomiting, sedation, shivering, and postoperative headache. In this double-blind randomized controlled trial, 120 female patients undergoing elective open unilateral ovarian cystectomy under spinal anesthesia were studied. The inclusion criteria included patients aged 16-45 years with a physical status classified as American Societyof Anesthesiologists (ASA) class I and II. Patients were randomly allocated into three groups: group B (n=40) received only bupivacaine, group BK (n=40) received bupivacaine mixed with preservative-free ketamine, and group BT (n=40) received bupivacaine mixed with preservative-free tramadol. The mean duration of spinal analgesia, measured in minutes, showed significant differences (P < 0.001) between group BK (165 ± 4) and group B (170 ± 5). There was also a significant difference between group BT (313 ± 8) and group B (170 ± 5) (P < 0.001). Additionally, significant differences were observed between group BK (165 ± 4) and group BT (313 ± 8) (P < 0.001). The administration of 25 mg of ketamine and 25 mg of tramadol as adjuvants to bupivacaine in spinal anesthesia significantly affected the postoperative duration of analgesia. Tramadol prolonged the duration of spinal anesthesia, while ketamine shortened it. The use of both adjuvants did not result in undesired effects.

Sugammadex shortens operation time and improves operation turnover efficacy in video-assisted thoracoscopic surgery.

This study compared sugammadex and neostigmine as agents for routine neuromuscular blockade reversal in video-assisted thoracoscopic surgery (VATS) to determine the optimal choice that achieves a shorter operation time and improved turnover efficiency while enhancing postoperative outcomes and ensuring patient safety during thoracic surgery. This prospective study, conducted from July 2022 to March 2023, compared the effect of sugammadex and neostigmine on operation time and turnover efficiency in VATS, involving 60 participants randomly assigned to either group, with the primary objective of identifying the optimal anesthesia reversal choice for improved outcomes and patient safety during thoracic surgery. In the study, the sugammadex group showed a significantly shorter total operation room occupancy time (130 ± 7 vs 157 ± 7 minutes; p = 0.009) than the neostigmine group. Patients in the neostigmine group had higher mean pulse rates when leaving the operation room (85 ± 3 vs 73 ± 3 beats/min; p = 0.002) and 120 minutes later in the postanesthesia care unit (76 ± 2 vs 68 ± 2; p = 0.016). This study's findings suggest that sugammadex may enhance total operating room occupancy time, operation turnover efficacy, and respiratory recovery outcomes in VATS, potentially improving patient care and anesthesia management.

Anesthetic recommendations for maternal and fetal safety in nonobstetric surgery: a balancing act.

Nonobstetric surgery during pregnancy is associated with maternal and fetal risks. Several physiologic changes create unique challenges for anesthesiologists. This review highlights physiologic changes of pregnancy and presents clinical recommendations based on recent literature to guide anesthetic management for the pregnant patient undergoing nonobstetric surgery. Nearly every anesthetic technique has been safely used in pregnant patients. Although it is difficult to eliminate confounding factors, exposure to anesthetics could endanger fetal brain development. Perioperative fetal monitoring decisions require an obstetric consult based on anticipated maternal and fetal concerns. Given the limitations of fasting guidelines, bedside gastric ultrasound is useful in assessing aspiration risk in pregnant patients. Although there is concern about appropriateness of sugammadex for neuromuscular blockade reversal due its binding to progesterone, preliminary literature supports its safety. These recommendations will equip anesthesiologists to provide safe care for the pregnant patient and fetus undergoing nonobstetric surgery.

Gastrointestinal changes in critical patients with covid-19 receiving enteral nutritional, neuromuscular blockers and/or vasoactive drugs

Objective: The aim of this study was to evaluate the frequency of gastrointestinal alterations (GIA) and possible associated risk factors in critically ill patients with COVID-19 receiving enteral nutrition (EN) concomitantly with vasoactive drug (VAD) and/or neuromuscular blockers (NMB). Methods: Retrospective cohort study, performed in intensive care units (ICU), with individuals over 18 years of age with COVID-19 who received concomitant exclusive EN with at least one VAD and/or one NMB in ≥ 1 day. GIA were: presence of ≥ 1 of the following changes: diarrhea (≥ 3 liquid stools/day), gastric residual volume (GRV), paralysis of the lower gastrointestinal tract (GIT) (absent evacuation for ≥ 3 consecutive days), emesis and gastrointestinal bleeding. A mixed logistic regression was used to assess the association of drugs with GIA and a multivariate logistic regression to assess potential confounders. Results: We evaluated 78 individuals and 774 days of hospitalization. All of them received EN within 48h and 70.5% died. The most frequent GIA were: lower GIT paralysis, 75 patients in 362 days; GRV, 18 patients at 34 days and diarrhea, 13 patients at 22 days. Norepinephrine was associated with GRV (p=0.003) and fentanyl (mcg/min) with the presence of GIA (p=0.029). Conclusions: The NMB showed no relationship with the assessed GIA, as for the VAD we suggest the assessment of norepinephrine as a possible risk factor for GRV.

Median Effective Dose of Ropivacaine for Prophylactic Cervical Cerclage in Chinese Women: A Dose-Finding Study

(Reg Anesth Pain Med. 2023;48:168–172. doi: 10.1136/rapm-2022-104242) Complications in pregnancy leading to preterm labor or miscarriage can occur for a variety of reasons. One reason that represents a significant public health burden is cervical incompetence or insufficiency. Current treatment guidelines focus on cervical cerclage as an effective treatment to prevent or arrest the effects of cervical insufficiency. Performing this procedure requires surgery, and therefore different anesthetic methods can be used to minimize pain and adverse outcomes for the patients, namely general or neuraxial anesthesia. One local anesthetic used for spinal neuraxial blocks in obstetrics is ropivacaine, but research has not explored its effect when used for cervical cerclage. This study from China was designed to find the median effective dose of intrathecal ropivacaine for cervical cerclage placement in 50% of patients (ED50). Secondary to this, the effective dose of intrathecal ropivacaine in 95% of patients (ED95) was also calculated. Other outcome measures included the duration of the sensory and motor blocks.

Peripheral nerve blocks of wrist and finger flexors can increase hand opening in chronic hemiparetic stroke.

Hand opening is reduced by abnormal wrist and finger flexor activity in many individuals with stroke. This flexor activity also limits hand opening produced by functional electrical stimulation (FES) of finger and wrist extensor muscles. Recent advances in electrical nerve block technologies have the potential to mitigate this abnormal flexor behavior, but the actual impact of nerve block on hand opening in stroke has not yet been investigated. In this study, we applied the local anesthetic ropivacaine to the median and ulnar nerve to induce a complete motor block in 9 individuals with stroke and observed the impact of this block on hand opening as measured by hand pentagonal area. Volitional hand opening and FES-driven hand opening were measured, both while the arm was fully supported on a haptic table (Unloaded) and while lifting against gravity (Loaded). Linear mixed effect regression (LMER) modeling was used to determine the effect of Block. The ropivacaine block allowed increased hand opening, both volitional and FES-driven, and for both unloaded and loaded conditions. Notably, only the FES-driven and Loaded condition's improvement in hand opening with the block was statistically significant. Hand opening in the FES and Loaded condition improved following nerve block by nearly 20%. Our results suggest that many individuals with stroke would see improved hand-opening with wrist and finger flexor activity curtailed by nerve block, especially when FES is used to drive the typically paretic finger and wrist extensor muscles. Such a nerve block (potentially produced by aforementioned emerging electrical nerve block technologies) could thus significantly address prior observed shortcomings of FES interventions for individuals with stroke.

Management of Neuromuscular Blocking Agents in Critically Ill Patients with Lung Diseases.

The use of neuromuscular blocking agents (NMBAs) is common in the intensive care unit (ICU). NMBAs have been used in critically ill patients with lung diseases to optimize mechanical ventilation, prevent spontaneous respiratory efforts, reduce the work of breathing and oxygen consumption, and avoid patient-ventilator asynchrony. In patients with acute respiratory distress syndrome (ARDS), NMBAs reduce the risk of barotrauma and improve oxygenation. Nevertheless, current guidelines and evidence are contrasting regarding the routine use of NMBAs. In status asthmaticus and acute exacerbation of chronic obstructive pulmonary disease, NMBAs are used in specific conditions to ameliorate patient-ventilator synchronism and oxygenation, although their routine use is controversial. Indeed, the use of NMBAs has decreased over the last decade due to potential adverse effects, such as immobilization, venous thrombosis, patient awareness during paralysis, development of critical illness myopathy, autonomic interactions, ICU-acquired weakness, and residual paralysis after cessation of NMBAs use. The aim of this review is to highlight current knowledge and synthesize the evidence for the effects of NMBAs for critically ill patients with lung diseases, focusing on patient-ventilator asynchrony, ARDS, status asthmaticus, and chronic obstructive pulmonary disease.

A compressomyograph train of four monitoring device

The monitoring of the neuromuscular blockade is critical for patient's safety during and after surgery. The monitoring of neuromuscular blockade often requires the use of Train of Four (TOF) technique. During a TOF test two electrodes are attached to the ulnar nerve, and a series of four electric pulses are applied. The electrical stimulation causes the thumb to twitch, and the amount of twitch varies depending on the amount of neuromuscular blockade in patient's system. Current medical devices used to assist anesthesiologists to perform TOF monitoring often require free hand movement and do not provide accurate or reliable results. The goal of this work is to design, prototype and test a new medical device that provides reliable TOF results when thumb movement is restricted. A medical device that uses a pressurized catheter balloon to detect the response thumb twitch of the TOF test is created. An analytical model, numerical study, and mechanical finger testing were employed to create an optimum design. The design is tested through a pilot human subjects study. No significant correlation is reported with subjects’ properties, including hand size.

Impact of the combination of abdominal peripheral nerve block and neuromuscular blockade on the surgical space during robot-assisted laparoscopic surgery: a prospective randomized controlled study.

The impact of the combination of abdominal peripheral nerve block (PNB) and the depth of neuromuscular blockade on the surgical field were assessed. Thirty-eight patients undergoing elective robot-assisted laparoscopic radical prostatectomy (RARP) were randomized into two groups: a PNB group (moderate neuromuscular block [train-of-four 1-3 twitches] with abdominal PNB) and a non-PNB group (deep neuromuscular block [post-tetanic count 0-2 twitches] without abdominal PNB). The primary outcome was the change in the depth of the abdominal cavity relaxation assessed by the change in the distance (Δdistance) between the umbilicus port and peritoneum upon pneumoperitoneal pressure increase from 8 to 12mmHg. The secondary outcomes were the CO2 usage for the pneumoperitoneal pressure increase and the subjective differences in the Surgical Rating Score (SRS) during surgery. The Δdistance and the CO2 usage from 8 to 12mmHg did not differ significantly between the non-PNB and PNB groups (1.34 ± 0.65 vs. 1.28 ± 0.61cm, p = 0.763 and 3.64 ± 1.68 vs. 4.34 ± 1.44 L, p = 0.180, respectively). There was also no significant difference in SRS. Comparisons of the Δdistance values for pressure increases from 6 to 8mmHg, 6 to 10mmHg and 6 to 12mmHg between the non-PNB and PNB groups also showed no between-group differences, despite significant intra-group differences (p < 0.001) by pressure increment. Our findings indicate that moderate neuromuscular block with abdominal PNB maintained an adequate surgical space for RARP, with no significant difference from the space achieved by deep neuromuscular block.

Features of Extubation in Obesity Patients

Muscle relaxants are often given during general anesthesia to facilitate endotracheal intubation. However, lingering effects after the end of anesthesia can lead to respiratory failure in the intensive care unit. Strategies to reduce these adverse events include monitoring for neuromuscular blockade, the use of short-acting drugs, and active pharmacological withdrawal before extubation.

Underneath Images and Robots, Looking Deeper into the Pneumoperitoneum: A Narrative Review.

Laparoscopy offers numerous advantages over open procedures, minimizing trauma, reducing pain, accelerating recovery, and shortening hospital stays. Despite other technical advancements, pneumoperitoneum insufflation has received little attention, barely evolving since its inception. We explore the impact of pneumoperitoneum on patient outcomes and advocate for a minimally invasive approach that prioritizes peritoneal homeostasis. The nonlinear relationship between intra-abdominal pressure (IAP) and intra-abdominal volume (IAV) is discussed, emphasizing IAP titration to balance physiological effects and surgical workspace. Maintaining IAP below 10 mmHg is generally recommended, but factors such as patient positioning and surgical complexity must be considered. The depth of neuromuscular blockade (NMB) is explored as another variable affecting laparoscopic conditions. While deep NMB appears favorable for surgical stillness, achieving a balance between IAP and NMB depth is crucial. Temperature and humidity management during pneumoperitoneum are crucial for patient safety and optical field quality. Despite the debate over the significance of temperature drop, humidification and the warming of insufflated gas offer benefits in peritoneal homeostasis and visual clarity. In conclusion, there is potential for a paradigm shift in pneumoperitoneum management, with dynamic IAP adjustments and careful control of insufflated gas temperature and humidity to preserve peritoneal homeostasis and improve patient outcomes in minimally invasive surgery.

Carbon dioxide and cardiac output as major contributors to cerebral oxygenation during apnoeic oxygenation

Apnoeic oxygenation has experienced a resurgence in interest in critical care and perioperative medicine. However, its effect on cerebral oxygenation and factors influencing it, have not yet been investigated in detail. By using near-infrared spectroscopy, we intended to provide further evidence for the safety of apnoeic oxygenation and to increase our understanding of the association between cerebral perfusion, haemodynamic, respiratory and demographic factors. In this secondary analysis of a prospective randomized controlled noninferiority trial, we recruited 125 patients, who underwent surgery under general anaesthesia with neuromuscular blockade. Arterial blood samples were taken every 2 min for a total of 15 min under apnoeic oxygenation with 100% oxygen. Near-infrared spectroscopy and cardiac output were continuously measured. Statistical analysis was performed using uni- and multivariable statistics. Ninety-one complete data sets were analysed. In six patients the SpO2 fell below 92% (predefined study termination criterion). The significant average increase of cerebral oxygenation was 0.5%/min and 2.1 mmHg/min for the arterial pressure of carbon dioxide (paCO2). The median cardiac output increased significantly from 5.0 l/min (IQR 4.5–6.0) to 6.5 l/min (IQR 5.7–7.5). The most significant effect on cerebral oxygenation was exhibited by the variable paCO2 and non-specific patient factors, followed by cardiac output and paO2. Apnoeic oxygenation proves to have a high safety profile while significantly increasing cerebral oxygenation, paCO2 and cardiac output. In reverse, NIRS might act as a reliable clinical surrogate of paCO2 and cardiac output during stable arterial oxygenation.

Comparison of bupivacaine and levobupivacaine in continuous axillary brachial plexus block

Aims: This study compares bupivacaine – lidocaine and levobupivacaine – lidocaine administrations in terms of initiation and duration of motor and sensorial blockage, total number of additional analgesic applications, analgesic amount consumed in 24 hours, side-effects and hemodynamic effects in continuous axillary brachial pleksus block in hand and forearm surgery. Methods: Thirty ASA I &amp; II physical status patients, scheduled hand or forearm surgery were enrolled for of the two groups in a randomized study. Axillary catheter duly placed in both group with appropriate guided techniques. Patients in group B received 0. 5% bupivacaine 20 ml + 2% lidocaine 20 ml and group L received 0. 5% levobupivacaine 20 ml + 2% lidocaine 20 ml through the axillary catheter. Initiation and duration of motor and sensorial block, total number of additional analgesic applications and analgesic amount consumed in postoperative 24 hours were recorded. Pre-block, peri-operative and post-operative blood pressures and heart beat rates were also recorded. Block application duration, operation duration, tourniquet duration and demographic data of patients (age, sex, weight, and length) were recorded. Demanded and applied analgesic doses by the patient controlled analgesia devices, side effects and complications were also recorded. Results: There was no statistically significant difference between two groups in terms of initiation and duration of motor and sensorial block, amount of analgesic consumed in 24 hours, demanded and applied analgesic doses by the patient controlled analgesia devices and hemodynamic data (p&gt;0. 05). There is a mild and positive relation between block application duration and patient weight. (p=0. 014; r=0. 444) Conclusion: Both bupivacaine+lidocaine and levobupivacaine+lidocaine combinations can safely be used in axillary continuous brachial plexus block without any difference in terms of initiation and duration of block, total analgesic amount consumed. Their duration of action and effect on hemodynamic responses are similar.

Molecular Phenotypes of Acute Respiratory Distress Syndrome in the ROSE Trial Have Differential Outcomes and Gene Expression Patterns That Differ at Baseline and Longitudinally over Time.

Rationale: Two molecular phenotypes have been identified in acute respiratory distress syndrome (ARDS). In the ROSE (Reevaluation of Systemic Early Neuromuscular Blockade) trial of cisatracurium in moderate to severe ARDS, we addressed three unanswered questions: 1) Do the same phenotypes emerge in a more severe ARDS cohort with earlier recruitment; 2) Do phenotypes respond differently to neuromuscular blockade? and 3) What biological pathways most differentiate inflammatory phenotypes?Methods: We performed latent class analysis in ROSE using preenrollment clinical and protein biomarkers. In a subset of patients (n = 134), we sequenced whole-blood RNA using enrollment and Day 2 samples and performed differential gene expression and pathway analyses. Informed by the differential gene expression analysis, we measured additional plasma proteins and evaluated their abundance relative to gene expression amounts.Measurements and Main Results: In ROSE, we identified the hypoinflammatory (60.4%) and hyperinflammatory (39.6%) phenotypes with similar biological and clinical characteristics as prior studies, including higher mortality at Day 90 for the hyperinflammatory phenotype (30.3% vs. 61.6%; P < 0.0001). We observed no treatment interaction between the phenotypes and randomized groups for mortality. The hyperinflammatory phenotype was enriched for genes associated with innate immune response, tissue remodeling, and zinc metabolism at Day 0 and collagen synthesis and neutrophil degranulation at Day 2. Longitudinal changes in gene expression patterns differed dependent on survivorship. For most highly expressed genes, we observed correlations with their corresponding plasma proteins' abundance. However, for the class-defining plasma proteins in the latent class analysis, no correlation was observed with their corresponding genes' expression.Conclusions: The hyperinflammatory and hypoinflammatory phenotypes have different clinical, protein, and dynamic transcriptional characteristics. These findings support the clinical and biological potential of molecular phenotypes to advance precision care in ARDS.

Effect of Changing Estimated Glomerular Filtration Rate Formula on Sugammadex Use and Pulmonary Complications for African American and non-African American Patients.

Sugammadex is associated with fewer postoperative pulmonary complications than is neostigmine reversal of neuromuscular blockade. However, the Food and Drug Administration-approved package insert states that its use is "not recommended" in severe renal impairment, separately defined as creatinine clearance <30 mL/min. Recently, the formula for estimating glomerular filtration rate (GFR) was updated to remove the race variable. Compared to the prior formula, the new consensus equation lowers the estimated GFR for African American patients and raises it for everyone else. We sought to determine how this change could differently impact the use of sugammadex, and thus the rate of pulmonary complications, for both African American and non-African American patients. We used Monte Carlo simulation models to estimate the difference in pulmonary complications that would be suffered by patients when the change in creatine clearance calculated from the estimated GFR (using the old race-based and new race-neutral Chronic Kidney Disease Epidemiology Collaboration formulas) crossed the 30 mL/min threshold, which would require a change in sugammadex or neostigmine use. We found that 0.22% (95% confidence interval 0.14%-0.36%) of African American patients' creatinine clearance would drop from above to below 30 mL/min making sugammadex not recommended and 0.19% (0.16%-0.22%) of non-African American patients would have creatinine clearance increase to >30 mL/min making sugammadex now recommended. Based on our model, we estimate that African American patients would suffer (count [95% confidence interval]) 3 [0.4-6] more pulmonary complications per 100,000 African American patients who received rocuronium or vecuronium through the change from sugammadex to neostigmine reversal to comply with labeling recommendations. Conversely, the same change in formulas would reduce the number of non-African American patients suffering pulmonary complications by 3 [2-4] per 100,000. The recent change in GFR formulas may potentially be associated with an increase in postoperative pulmonary complications in African American patients and a decrease in postoperative pulmonary complications in non-African American patients through GFR-driven changes in sugammadex use.