Intraoperative Muscle Relaxation Research Articles

One-Stage Orbital Decompression Combined with Intraoperative Muscle Relaxation for TAO: A Randomized Controlled Trial

One-Stage Orbital Decompression Combined with Intraoperative Muscle Relaxation for TAO: A Randomized Controlled Trial

Clinical value of flexion-extension radiographs with bracket support for lumbar stability assessment.

This study proposes a novel standardized technique to evaluate lumbar stability in lumbar lateral flexion-extension radiographs and determine whether the most reliable intraoperative reference level of extension can be attained. A total of 104 patients undergoing surgical treatment for lumbar degenerative disease were included in the study. Radiographs in the conventional extension position (CE) and the extension position with bracket support (CEB) and intraoperative prone fluoroscopic radiographs of patients were included in this study. The slip angle (SA) and slip percentage (SP) were compared for these three radiographic methods. Furthermore, the correlation of differences in the SA and SP were examined among different spinal segments. Among 104 patients (mean age 58 years, 54% women) with a total of 147 operated segments examined, the average SA (10.65°±3.65°) and SP (12.18%±4.91%) with bracket support and SA (10.62°±3.67°) and SP (12.19%±4.90%) during intraoperative muscle relaxation were not significantly different (P=0.54; 0.91). However, the SA and SP in the CEB and intraoperative muscle relaxation conditions were significantly increased compared with the SA (6.46°±3.23°) and SP (7.87%±4.26%) obtained in the CE condition (all P<0.001). Both surgeons demonstrated high reliability, with intraclass correlation coefficient values ranging from 0.8 to 1.0 (P<0.001) for SP and SA measurements. CE radiographs underestimate the degree of displacement of lumbar instability. The CEB position reduces patient back pain and increases the feeling of safety, leading to a greater level of extension. This outcome aligns with the intraoperative muscle relaxation findings.

Factors Affecting the Duration of Surgery in the Management of Condylar Head Fractures.

Prolonged operation times should be avoided due to the associated complications and negative effects on the efficiency of the use of operating room resources. Surgical treatment of mandibular condylar head fractures is a well-established routine procedure at our department, nevertheless, we recognized fluctuating operating times. This study aims to pinpoint the influencing factors, in particular the hypothesis whether the efficiency of intraoperative muscle relaxation may decisively affect the duration of surgery. It analyses 168 mandibular condylar head fractures that were surgically treated in the period from 2007 to 2022 regarding the duration of the surgery and potential factors affecting it. The potential predictors' influence on the dependent variable operation time was mainly calculated as a bivariate analysis or linear regression. Efficiency of relaxation (p ≤ 0.001), fragmentation type (p = 0.031), and fracture age (p = 0.003) could be identified as decisive factors affecting the duration of surgery, as the first surgeon was a constant. In conclusion, surgical intervention should start as soon as possible after a traumatic incident. In addition, a dosage regimen to optimize the efficiency of relaxation should be established in future studies. Fragmentation type and concomitant fractures should also be considered for a more accurate estimation of the operating time.

Effect of intraoperative muscle relaxation reversal on the success rate of motor evoked potential recording in patients undergoing spinal surgery: a randomized controlled trial

BackgroundPartial neuromuscular blockade (NMB) has been applied for some surgeries to reduce bleeding and prevent patient movement for spinal surgery. Sugammadex selectively binds to rocuronium in the plasma and consequently lowers the rocuronium concentration at the neuromuscular junction. In this study, we aimed to observe whether the success rate of transcranial motor-evoked potential (TceMEP) can be increased by sugammadex compared with partial NMB during spinal surgery.MethodsPatients who underwent elective spinal surgery with TceMEP monitoring were randomly assigned to the sugammadex group and control group. Rocuronium was continuously infused to maintain the train of four counts (TOFc) = 2. The sugammadex group discontinued rocuronium infusion at the time of TceMEP monitoring and was infused with 2 mg/kg sugammadex; the control group was infused with the same dose of saline.ResultsA total of 171 patients were included. The success rate of TceMEP monitoring in the sugammadex group was significantly higher than that in the control group. TceMEP amplitudes were greater in the sugammadex group than in the control group at 5 min, 10 min, and 20 min after the start of motor-evoked potential monitoring. The latencies of upper extremity TceMEPs monitoring showed no difference between groups. TOF ratios were greater in the sugammadex group at 5 min, 10 min, and 20 min after the start of motor-evoked potential monitoring. There were no adverse effects caused by sugammadex.ConclusionsSugammadex can improve the success rate of motor-evoked potential monitoring compared with moderate neuromuscular blockade induced by continuous infusion of rocuronium in spinal surgery.Trial registrationThe study was registered on clinicaltrials.gov.cn on 29/10/2020 (trial registration number: NCT04608682).

Effect of intraoperative muscle relaxation reversal on the success rate of motor-evoked potential recording in patients undergoing spinal surgery: study protocol for a randomised controlled trial

IntroductionTranscranial motor-evoked potentials (TceMEPs) is conventionally performed without neuromuscular blockade (NMB) because of its potential interference with neuromuscular junction and signal interpretation. Sugammadex is the first highly selective antagonist that...

Analgesic Effect of Butorphanol during Castration in Donkeys under Total Intravenous Anaesthesia.

Simple SummaryDespite the growing interest in donkey’s welfare, there is little scientific evidence in this species about the analgesic effect of the drugs most used in horses. Total intravenous anaesthesia is a valuable option for field surgery such as castration. Moreover, it is often preferred in small donkeys due to the anatomical features of their proximal airways. The aim of this study was to evaluate the effect of a low dose of butorphanol, in donkeys undergoing castration, after sedation with detomidine before total intravenous anaesthesia with a mixture of guaifenesin, ketamine and detomidine. The addition of butorphanol to detomidine produced more muscle relaxation, and reduced mean heart rate and blood pressure. This resulted in a reduced requirement for rescue analgesia, a more superficial anaesthetic plan and a shorter surgical time. It can be concluded that butorphanol allowed a more stable and superficial anaesthetic plan, probably due to its analgesic effect and synergistic action with detomidine. Due to the low dosages of drugs used and the absence of adverse effects, this protocol can be considered valuable in field conditions and for short surgical procedures, where safety equipment is not available.Pain management is necessary for all surgical procedures. Little scientific evidence about drug efficacy in donkeys is available. The aim of this study was to evaluate the analgesic effect of butorphanol in donkeys undergoing orchiectomy under total intravenous anaesthesia with guaifenesin-ketamine-detomidine. A randomized blinded prospective clinical trial (Protocol n. 2021/0000338), was carried out on 18 clinically healthy donkeys undergoing bilateral orchiectomy. Patients were assigned to Group D (n = 8) or Group DB (n = 10) if receiving intravenous detomidine or detomidine-butorphanol respectively, before induction of general anaesthesia with ketamine-diazepam. Intraoperative muscle relaxation, nystagmus, palpebral reflex, heart and respiratory rate, and non-invasive blood pressure were evaluated every 2 min; time to prepare the patient, duration of surgery and anaesthesia and recovery score were recorded. Group D had significantly longer surgical time, higher heart rate, higher systolic and mean blood pressure (p < 0.05; repeated measure ANOVA), increased muscle rigidity and expression of palpebral reflex (p < 0.05; Mann–Whitney U test) than group DB. Top-ups with thiopental were statistically higher in Group D. Butorphanol and detomidine together produced a more stable anaesthetic plan. The low dosage of opioid and alpha-2-agonists and reduced rescue anaesthesia are responsible for a safer and more superficial anaesthesia, which is mandatory under field conditions.

Hand or foot train-of-four tests and surgical site muscle relaxation assessed with multiple motor evoked potentials: A prospective observational study.

Intra-operative muscle relaxation is often required in orthopaedic surgery and the hand train-of-four (TOF) test is usually used for its quantification. However, even though full muscle relaxation is claimed by anaesthesiologists based on a TOF count of zero, surgeons observe residual muscle activity. The aim of the study was to assess if hand or foot TOF adequately represents intra-operative muscle relaxation compared with multiple motor evoked potentials. Prospective observational study. A single-centre study performed between February 2016 and December 2018 at the Balgrist University Hospital, Zurich, Switzerland. Twenty patients scheduled for elective lumbar spinal fusion were prospectively enrolled in this study after giving written informed consent. To assess neuromuscular blockade (NMB) with the intermediate duration nondepolarising neuromuscular blocking agent rocuronium, hand TOF (adductor pollicis) and foot TOF (flexor hallucis brevis) monitoring, and muscle motor evoked potentials (MMEPs) from the upper and lower extremities were assessed prior to surgery under general anaesthesia. Following baseline measurements, muscle relaxation was performed with rocuronium until the spinal surgeon observed sufficient relaxation for surgical intervention. At this timepoint, NMB was assessed by TOF and MMEP. The primary outcome was to determine the different effect of rocuronium on muscle relaxation comparing hand and foot TOF with the paraspinal musculature assessed by MMEP. Hand TOF was more resistant to NMB and had a shorter recovery time than foot TOF. When comparing MMEPs, muscle relaxation occurred first in the hip abductors, and the paraspinal and deltoid muscles. The most resistant muscle to NMB was the abductor digiti minimi. Direct comparison showed that repetitive MMEPs simultaneously recorded from various muscles at the upper and lower extremities and from paraspinal muscles reflect muscle relaxation similar to TOF testing. Hand TOF is superior to foot TOF in assessing muscle relaxation during spinal surgery. Hand TOF adequately represents the degree of muscle relaxation not only for the paraspinal muscles but also for all orthopaedic surgical sites where NMB is crucial for good surgical conditions. ClinicalTrials.gov (NCT03318718).

Hypobaric Unilateral Spinal Anaesthesia versus General Anaesthesia in Elderly Patients Undergoing Hip Fracture Surgical Repair: A Prospective Randomised Open Trial.

Intraoperative hypotension during hip fracture surgery is frequent in the elderly. No study has compared the haemodynamic effect of hypobaric unilateral spinal anaesthesia (HUSA) and standardised general anaesthesia (GA) in elderly patients undergoing hip fracture surgical repair. We performed a prospective, randomised open study, including 40 patients aged over 75 years, comparing the haemodynamic effects of HUSA (5 mg isobaric bupivacaine with 5 μg sufentanil and 1 mL sterile water) and GA (induction with etomidate/remifentanil and maintenance with desflurane/remifentanil). An incidence of severe hypotension, defined by a decrease in systolic blood pressure of >40% from baseline, was the primary endpoint. The incidence of severe hypotension was lower in the HUSA group compared with that in the GA group (32% vs. 71%, respectively, p=0.03). The median [IQR] ephedrine consumption was lower (p=0.001) in the HUSA group (6 mg, 0-17 mg) compared with that in the GA group (36 mg, 21-57 mg). Intraoperative muscle relaxation and patients' and surgeons' satisfaction were similar between groups. No difference was observed in 5-day complications or 30-day mortality. This study shows that HUSA provides better haemodynamic stability than GA, with lower consumption of ephedrine and similar operating conditions. This new approach of spinal anaesthesia seems to be safe and effective in elderly patients undergoing hip fracture surgery.

Postintubation Sequels: Influence of Fluticasone and Technique of Intra-Operative Muscle Relaxation.

Background:Postintubation sequels (PIS) are a cause of serious concern in the postoperative period.Aim:The aim of this study is to find the influence of preoperative inhaled steroid and technique of muscle relaxation on PIS.Settings and Design:This prospective, exploratory pilot study was conducted on 120 adult American Society of Anesthesiologist physical status Class I and II patients undergoing general anesthesia (GA) with muscle relaxation and cuffed endotracheal tube (ETT) insertion.Patients and Methods:Patients were randomized into four groups as follows: intermittent muscle relaxation with preanesthetic inhalation of either distilled water puffs (Group ID) or fluticasone puffs (Group IF); continuous infusion of muscle relaxant with preanesthetic inhalation of either distilled water puffs (Group CD) or fluticasone puffs (Group CF). After induction of GA, ETT was inserted. The intra-cuff pressure was maintained constant. The trachea was extubated in the light plane in intermittent groups and in the deep plane in continuous groups.Statistical Analysis:Qualitative parameters were compared using the Chi-square test and quantitative parameters using repeated measure ANOVA followed by Tukey's test.Results:Group CF had significantly less incidence of sore throat and hoarseness compared to groups ID and IF. The severity of sore throat was more in groups ID and IF than in groups CF and CD (P < 0.002). The severity of hoarseness was least in group CF (23.3%) and highest in group IF (90%). None of the patients had a cough in group CF. The incidence and severity of dysphagia were significantly less in group CF as compared to other groups (P < 0.005 and P < 0.008, respectively).Conclusion:Continuous infusion of muscle relaxant with extubation in deep plane of anesthesia with preanesthetic inhalation of fluticasone puffs results in lesser incidence and severity of PIS.

Comparison of dexmedetomidine and magnesium sulfate as adjuvants with ropivacaine for spinal anesthesia in infraumbilical surgeries and postoperative analgesia

Introduction:Postoperative pain is a major cause of fear and anxiety in hospitalized patients and so if patients remain pain-free during this period, they can cooperate with the circumstances well, leading to early recovery. Over the last two decades, there has been considerable revival of interest in the use of regional anesthesia techniques for surgery and pain management. As very few studies have been conducted using ropivacaine with dexmedetomidine and magnesium sulfate (MgSO4) as adjuvants, the present study was undertaken with primary aims to compare the hemodynamic stability, onset and duration of sensory and motor block and with secondary aims of the postoperative analgesic effect of dexmedetomidine and MgSO4 along with ropivacaine.Materials and Methods:After getting the Institutional Ethics Committee approval, this study was conducted on fifty patients of the American Society of Anesthesiologists physical Status I and II aged between 20 and 65 years of either sex and scheduled to undergo infraumbilical surgeries under spinal anesthesia. They were divided into two groups of 25 each. Group D patients received 3 ml of 0.75% isobaric ropivacaine hydrochloride with 10 μg of dexmedetomidine whereas Group M patients received 75 mg of MgSO4 in the place of dexmedetomidine. The quality of surgical analgesia and quality of intraoperative muscle relaxation were assessed and graded.Results:We found out that onset of sensory and motor block was earlier in Group D in comparison to Group M. There was a significant reduction in the time to the first rescue analgesia in group receiving intrathecal dexmedetomidine.Conclusion:It is concluded from our study that ropivacaine plus dexmedetomidine group are better than ropivacaine plus MgSO4 in providing early onset of sensory and motor block as well as in providing postoperative analgesia.

Adverse Respiratory Events in a Post-Anesthesia Care Unit

IntroductionAdverse respiratory events (AREs) are leading causes of postoperative morbidity and mortality. This study investigated the incidence and determinants of postoperative ARE. MethodsThis observational prospective study was conducted in a post-anesthesia care unit (PACU). A total of 340 adult subjects were admitted consecutively, and AREs were measured after elective surgery. Population demographics, perioperative parameters, ARE occurrence, and length of stay in the postoperative PACU and in hospital were recorded. Data were analyzed descriptively using the Mann–Whitney U-test and the Chi-square or Fisher's exact test. Multivariate analyses were carried out using logistic binary regression, and the odds ratio (OR) and 95% confidence interval (CI) were calculated. ResultsPostoperative AREs occurred in 67 subjects (19.7%). AREs were more frequent after high-risk procedures (42% vs 24%; P=.003), in patients undergoing major surgery (37% vs 25%; P=.041), those receiving general anesthesia (85% vs 67%; P=.004), and in patients administered intraoperative muscle relaxants (79% vs 55%; P<.001) and neostigmine (69% vs 49%; P=.002). Hypoactive emergence (13% vs 5%; P=.015) and residual neuromuscular blockade (46% vs 11%; P<.001) were more frequent in subjects with postoperative ARE. On multivariate analyses, residual neuromuscular blockade was an independent risk factor for ARE in the PACU (OR 6.4; CI 3.0–13.4; P<.001). ConclusionsARE is an important and common postoperative complication. Residual neuromuscular blockade was an independent risk factor for ARE in the PACU.

Acontecimientos adversos respiratorios en la unidad de cuidados postanestésicos

IntroductionAdverse respiratory events (ARE) are a leading causes of postoperative morbidity and mortality. This study investigated the incidence and determinants of postoperative ARE. MethodsThis observational prospective study was conducted in a post anesthesia care unit (PACU). A total of 340 adult subjects were admitted consecutively, and AREs were measured after elective surgery. Population demographics, perioperative parameters, ARE occurrence, and length of stay in the postoperative PACU and in hospital were recorded. Data were analyzed descriptively using the Mann-Whitney U-test and the Chi-square or Fisher's exact test. Multivariate analyses were carried outusing logistic binary regression, and the odds ratio (OR) and 95% confidence interval (CI) were calculated. ResultsPostoperative AREs occurred in 67 subjects (19.7%). AREs were more frequent after high-risk procedures (42% vs 24%; P=.003), in patients undergoing major surgery (37% vs 25%; P=.041), those receiving general anesthesia (85% vs 67%; P=.004), and in patients administered intraoperative muscle relaxants (79% vs 55%; P<.001) and neostigmine (69% vs 49%; P=.002). Hypoactive emergence (13% vs 5%; P=.015) and residual neuromuscular blockade (46% versus 11%; P<.001) were more frequent in subjects with postoperative ARE. On multivariate analyses, residual neuromuscular blockade was an independent risk factor for ARE in the PACU (OR 6.4; CI 3.0-13.4; P<.001). ConclusionsARE is an important and common postoperative complication. Residual neuromuscular blockade was an independent risk factor for ARE in the PACU.

Homicides Using Muscle Relaxants, Opioids, and Anesthetic Drugs

Homicides Using Muscle Relaxants, Opioids, and Anesthetic Drugs

Intravenous Regional Anaesthesia With Lignocaine, Fentanyl And Pancuronium – Prospective Randomised Controlled Double Blind Study.

Intravenous Regional Anaesthesia (IVRA) is a simple and effective technique for upper limb distal surgery. However, a relatively large dose of LA is required to induce motor and sensory blockade. Lignocaine 3mg/kg as a 0.5% solution is needed to ensure adequate analgesia. Systemic toxic reactions (convulsions, coma, cardiac arrest) can occur when the tourniquet deflates unexpectedly during the procedure or when it deflated intentionally at the end of short surgery.Therefore we conducted this prospective randomized double blind study to compare and evaluate the effects of addition of fentanyl and pancuronium to reduced dose of LA against the standard practice of 0.5% lignocaine.In this study, 75 patients of both sexes in the age group more than 18 years belonging to ASA 1 and 2 undergoing both elective and emergency surgeries of the forearm and hand were divided randomly into group L, group P and group F with 25 patients in each group.In patients belonging to group L, 40 cc of 3mg/kg of 0.5% lignocaine diluted in normal saline was used for administering IVRA, and in patients of group F 40 cc of 1.5mg/kg of 0.25% lignocaine combined with fentanyl 1mg/kg , and in patients of group P 1.5mg/kg of 0.25% lignocaine combined with fentanyl 1mg/kg and pancuronium 0.5mg was used.The time for onset of sensory blockade in group L was 11.76.± 3.08 minutes , group F was 12.96±3.06 minutes , and group P was 10.20±3.52 minutes which was clinically comparable in all the groups. However the time for onset of motor blockade was significantly delayed in group F (21.1±2.7 minutes) as compared to other two groups: group L (12.5±2.6minutes and group P (11.36±3.5 minutes). The patients in group P were showing significantly excellent muscle relaxation and excellent intraoperative analgesia as compared to other two groups. Post operative analgesia in group P (56.4±2.6minutes ) was significantly longer as compared to group F (46.8 ±4.9 minutes) and group L (39 ± 8 minutes). Our results showed that hemodynamic parameters like pulse rate, blood pressure, respiratory rate were well maintained throughout the intra and post operative period in all the patients of all the groups. There were no major untoward side effects were noticed.Thus from the present study, we conclude that the addition of fentanyl 1mg/kg and pancuronium 0.5mg to 0.25% of lignocaine enhances lignocaine action and results in-Adequate sensory and motor block.Excellent intraoperative analgesia.-Excellent intraoperative muscle relaxation. Thus, using this combination the dose of lignocaine for IVRA can be reduced to a non toxic level for the same quality of analgesia and at the same time not offer any post analgesic benefit as all study patients were required supplement of analgesics post operatively after about 50-60 minutes.. INTRODUCTION Intravenous regional anesthesia was first described by August Gustav Bier in 1908. This technique is a simple, easy to administer, effective and reliable method for anesthesia. It involves intravenous injection of local anesthetics into the limb on which surgery is to be performed after the limb is exsanguinated and a tourniquet has been applied proximally. It is the surest way of obtaining a block with a very minimal failure rate, and has gained immense popularity more so for upper limb surgeries. Besides it is extremely useful for emergency surgeries. Being a regional technique it avoids all the complication of general anesthesia, more so in patients coming for emergency surgery as well as patients belonging to ASA class 3 and 4. However the dose of local anesthetic agent required to induce motor and sensory blockade has the potential to cause systemic local anesthetic toxicity. Therefore various methods have been tried to reduce the dose of Local anesthetic used in Intravenous regional anesthesia ,such as alkalization of the local anaesthetic solution, addition of an opioid, muscle relaxant , non steroidal anti-inflammatory drugs, potassium, and Ketamine 9 with various results. We conducted this prospective randomized double blind Intravenous Regional Anaesthesia With Lignocaine, Fentanyl And Pancuronium – Prospective Randomised Controlled Double Blind Study. 2 of 9 study to know the effect of combining fentanyl 1/kg alone and fentanyl1g/kg plus pancuronium 0.5mg with reduced dose of lignocaine( 0.25%) for Intravenous regional anesthesia. AIMS & OBJECTIVES To study the effect of IVRA with lignocaine 0.5% with lignocaine 0.25% plus fentanyl 1/kg and lignocaine 0.25% plus fentanyl1g/kg plus pancuronium 0.5mg with respect to : Time of onset of sensory block. Time of onset of motor block The degree of muscle relaxation Intraoperative analgesia.

Control of perioperative muscle strength during ambulatory surgery

This review describes strategies to control perioperative muscle strength in patients undergoing ambulatory surgery. Although it is impossible to improve muscle relaxation (defined as absence of electrical activity) of intact resting muscle by hypnotics, analgesia is required to prevent pain-evoked muscular contractions during surgery. Regional anesthesia, as well as hypnotics and opioids, promotes intraoperative muscle relaxation. Neuromuscular blocking agents (NMBAs) induce dose-dependent muscle relaxation, but their effects vary widely between individuals, and postoperative residual curarization (PORC) exposes patients to additional risk. Low doses of NMBAs should, therefore, be used, effects be monitored quantitatively by acceleromyography, and residual neuromuscular block be reversed. Acetylcholinesterase inhibitor reversal can cause respiratory side effects, so the lowest efficacious dose should be used: as little as 0.015-0.025 mg kg(-1) of neostigmine is required at a train-of-four count of four with minimal fade. Sugammadex encapsulates steroidal NMBAs. Sugammadex reversal is a viable approach to rapidly antagonize deep levels of neuromuscular block. Optimal muscle relaxation for ambulatory surgery results from a judicious combination of regional anesthesia, opioids, and low doses of NMBAs. The effects of NMBAs should be monitored quantitatively by acceleromyography and reversed appropriately.

Can Spontaneous Adverse Event Reporting Systems Really Be Used to Compare Rates of Adverse Events Between Drugs?

Can Spontaneous Adverse Event Reporting Systems Really Be Used to Compare Rates of Adverse Events Between Drugs?

The Influence of Patient Controlled Analgesia on the Recovery of Muscle Power and Respiratory Function following Intraoperative Muscle Relaxants

Residual muscle paralysis after anesthesia is reduced with the advent of intermediate-acting neuromuscular blocking drugs, yet the incidence is as high as about 10 percent. Opioids in patient-controlled analgesia (PCA) may cause respiratory depression and other problems after anesthesia. The purpose of this study is to evaluate the influence of PCA on the , TOF ratio, head-lift and tongue protrusion during recovery room stay following intraoperative muscle relaxants. Methods: 120 patients aged from 20 to 65 in ASA class I and II were divided into control or PCA groups. All patients received rocuronium (0.9 mg/kg) or atracurium (0.5 mg/kg) for tracheal intubation, and maintenance of relaxation was done with atracurium 0.2 mg/kg/hr during inhalation anesthesia. Reversal of block was done with pyridostigmine 0.15 mg/kg and glycopyrrolate 0.2 mg. SpO2, TOF ratio, 5 sec-head lift, tongue protrusion tests were evaluated in the recovery room. Results: IV-PCA did not influence the incidence of residual block, SPO2, TOF ratio during recovery room stay for 20 minutes, but influenced negatively 5 sec-head lift test, tongue protrusion test only immediately after arrival at the recovery room. Conclusions: Since IV-PCA decreased the ability to perform head-lift and tongue protrusion early postoperatively, it is recommended that patients with IV-PCA should be carefully managed against the risk of aspiration or upper respiratory obstruction during their early recovery room stay.

Colonic anastomotic disruption in the immediate postoperative period

Muscle relaxation is administered to patients undergoing laparotomy for colonic surgery. At the end of the procedure, relaxation needs to be reversed to facilitate extubation. This may be achieved by administering anticholinesterases such as neostigmine. We present a case of colonic anastomotic dehiscence in the immediate postoperative period following the use of neostigmine to reverse intra-operative muscle relaxation. Neostigmine is frequently used to reverse muscle relaxation at the end of colonic surgery. However, the drug should be used with caution as it has been implicated as a cause of early anastomotic disruption.

Awareness during anesthesia: a closed claims analysis.

Awareness during general anesthesia is a frightening experience, which may result in serious emotional injury and post-traumatic stress disorder. We performed an in-depth analysis of cases from the database of the American Society of Anesthesiologists Closed Claims Project to explore the contribution of intraoperative awareness to professional liability in anesthesia. The database of the Closed Claims Project is composed of closed US malpractice claims that have been collected in a standardized manner. All claims for intraoperative awareness were reviewed by the reviewers to identify patterns of causation and standard of care. Logistic regression analysis was used to identify independent patient and anesthetic factors associated with claims for recall during general anesthesia compared to other general anesthesia malpractice claims. Awareness claims accounted for 79 (1.9%) of 4,183 claims in the database, including 18 claims for awake paralysis, i.e., the inadvertent paralysis of an awake patient, and 61 claims for recall during general anesthesia, ie., recall of events while receiving general anesthesia. The majority of awareness claims involved women (77%), younger than 60 yr of age (89%), American Society of Anesthesiologists physical class I-II (68%), who underwent elective surgery (87%). Most (94%) claims for awake paralysis represented substandard care involving errors in labeling and administration, whereas care was substandard in only 43% of the claims for recall during general anesthesia (P < 0.001). Claims for recall during general anesthesia were more likely to involve women (odds ratio [OR] = 3.08, 95% confidence interval [CI] = 1.58, 6.06) and anesthetic techniques using intraoperative opioids (OR = 2.12, 95% CI = 1.20, 3.74), intraoperative muscle relaxants (OR = 2.28, 95% CI = 1.22, 4.25), and no volatile anesthetic (OR = 3.20, 95% CI = 1.88, 5.46). Deficiencies in labeling and vigilance were common causes for awake paralysis. Claims for recall during general anesthesia were more likely in women and with nitrous-narcotic-relaxant techniques.

Electromyographic assessment of ulnar nerve motor block induced by lidocaine

Study Objective: To determine the differences in the onset time and duration of motor block produced by lidocaine 1% and lidocaine 2% via a quantitative and objective method, the measurement of compound muscle action potentials (CMAPs). Study Design: Prospective study. Setting: Main operating rooms of a university hospital. Patients: 20 consecutive patients undergoing surgery not requiring intraoperative muscle relaxation. Interventions: General anesthesia with unilateral ulnar nerve block was administered. In patients’ nondominant (experimental) arms, an insulated block needle was placed adjacent to the ulnar nerve at the wrist while continuous nerve stimulation was delivered to ensure its proper placement. Through this needle, lidocaine 1% or lidocaine 2% was injected. The dominant (control) arm received no injection. Measurements and Main Results: Monitoring of ulnar nerve-evoked CMAPs was performed simultaneously on both arms. Ulnar nerve function was assessed at baseline and then at 10-second intervals by automatically measuring the amplitude of the evoked CMAPs on a two-channel electromyogram. The mean (± SEM) baseline CMAP amplitude prior to injection of lidocaine 1% was 3.10 ± 0.87 mV and 3.06 ± 0.89 mV for the experimental and control ulnar nerves, respectively ( p = NS); for lidocaine 2%, baseline CMAP amplitude was 3.58 ± 1.39 mV and 3.70 ± 1.46 mV, respectively ( p = NS). Over the course of the study, the control CMAP amplitude varied by <12%. At the experimental ulnar nerve, 90% CMAP decrease after injection of lidocaine 1% and lidocaine 2% occurred 7.5 ± 2 minutes and 5 ± 1.5 minutes, respectively ( p = NS), whereas maximal blockade was achieved after 15 ± 3 minutes and 11 ± 5 minutes, respectively ( p = NS). Recovery of CMAP to 90% of baseline occurred 184 ± 31 minutes after injection of lidocaine 1% and 248 ± 30 minutes following lidocaine 2% ( p = NS). Conclusion: The present study describes a technique that can be used in vivo to objectively measure the speed of onset and duration of local anesthetic-induced motor blockade. Although statistically not different, lidocaine 2% demonstrated a faster onset and longer duration of ulnar nerve motor block than lidocaine 1%.