Use Of Neuromuscular Blocking Agents Research Articles

Effect of administration of neuromuscular blocking agents in children with severe traumatic brain injury on acute complication rates and outcomes: a secondary analysis from a randomized, controlled trial of therapeutic hypothermia.

To evaluate the association between neuromuscular blocking agents and outcome, intracranial pressure, and medical complications in children with severe traumatic brain injury. A secondary analysis of a randomized, controlled trial of therapeutic hypothermia. Seventeen hospitals in the United States, Australia, and New Zealand. Children (< 18 yr) with severe traumatic brain injury. None for this secondary analysis. Children received neuromuscular blocking agent on the majority of days of the study (69.6%), and the modified Pediatric Intensity Level of Therapy scores (modified by removing neuromuscular blocking agent administration from the score) were increased on days when neuromuscular blocking agents were used (9.67 ± 0.21 vs 5.48 ± 0.26; p < 0.001). Children were stratified into groups based on exposure to neuromuscular blocking agents (group 1 received neuromuscular blocking agents each study day; group 2 did not). Group 1 had increased number of daily intracranial pressure readings more than 20 mm Hg (4.4 ± 1.1 vs 2.4 ± 0.5;p = 0.015) and longer ICU and hospital length of stay (p = 0.003 and 0.07, respectively, Kaplan-Meier). The Glasgow Outcome Score-Extended for Pediatrics at hospital discharge and 3, 6, and 12 months after traumatic brain injury and medical complications observed during the acute hospitalization were similar between groups. Administration of neuromuscular blocking agents was ubiquitous and daily administration of neuromuscular blocking agents was associated with intracranial hypertension but not outcomes-likely indicating that increased injury severity prompted their use. Despite this, neuromuscular blocking agent use was not associated with complications. A different study design-perhaps using randomization or methodologies-of a larger cohort will be required to determine if neuromuscular blocking agent use is helpful after severe traumatic brain injury in children.

Neuromuscular blockade improves first-attempt success for intubation in the intensive care unit. A propensity matched analysis.

The use of neuromuscular blocking agents (NMBAs) has been shown to be valuable in improving successful tracheal intubation in the operating room and emergency department. However, data on NMBA use in critically ill intensive care unit (ICU) patients are lacking. Furthermore, there are no data on NMBA use with video laryngoscopy. To evaluate the effect of NMBA use on first-attempt success (FAS) with tracheal intubation in the ICU. Single-center observational study of 709 consecutive patients intubated in the medical ICU of a university medical center from January 1, 2012 to June 30, 2014. Data were collected prospectively through a continuous quality improvement program on all patients intubated in the ICU over the study period. Data relating to patient demographics, intubation, and complications were analyzed. We used propensity score (propensity to use an NMBA) matching to generate 5,000 data sets of cases (failed first intubation attempts) matched to controls (successful first attempts) and conditional logistic regression to analyze the results. There were no significant differences in patient demographics, except median total difficult airway characteristics were higher in the non-NMBA group (2 vs. 1, P < 0.001). There were significant differences in the sedative used between groups and the operator level of training. More patients who were given NMBAs received etomidate (83 vs. 35%) and more patients in the non-NMBA group received ketamine (39 vs. 9%) (P < 0.001). The FAS for NMBA use was 80.9% (401/496) compared with 69.6% (117/168) for non-NMBA use (P = 0.003). The summary odds ratio for FAS when an NMBA was used from the propensity matched analyses was 2.37 (95% confidence interval, 1.36-4.88). In the subgroup of patients intubated with a video laryngoscope, propensity-adjusted odds of FAS with the use of an NMBA was 2.50 (1.43-4.37; P < 0.001). There were no differences in procedurally related complications between groups. After controlling for potential confounders, this propensity-adjusted analysis demonstrates improved odds of FAS at intubation in the ICU with the use of an NMBA. This improvement in FAS is seen even with the use of a video laryngoscope.

Postoperative Residual Neuromuscular Paralysis at an Australian Tertiary Children’s Hospital

Purpose. Residual neuromuscular blockade (RNMB) is known to be a significant but frequently overlooked complication after the use of neuromuscular blocking agents (NMBA). Aim of this prospective audit was to investigate the incidence and severity of RNMB at our Australian tertiary pediatric center. Methods. All children receiving NMBA during anesthesia were included over a 5-week period at the end of 2011 (Mondays to Fridays; 8 a.m.–6 p.m.). At the end of surgery, directly prior to tracheal extubation, the train-of-four (TOF) ratio was assessed quantitatively. Data related to patient postoperative outcome was collected in the postoperative acute care unit. Results. Data of 64 patients were analyzed. Neostigmine was given in 34 cases and sugammadex in 1 patient. The incidence of RNMB was 28.1% overall (without reversal: 19.4%; after neostigmine: 37.5%; n.s.). Severe RNMB (TOF ratio < 0.7) was found in 6.5% after both no reversal and neostigmine, respectively. Complications in the postoperative acute care unit were infrequent, with no differences between reversal and no reversal groups. Conclusions. In this audit, RNMB was frequently observed, particularly in cases where patients were reversed with neostigmine. These findings underline the well-known problems associated with the use of NMBA that are not fully reversed.

Neuromuscular blocking agents in acute respiratory distress syndrome

Neuromuscular blocking agents are widely used in ICU. It is an assistant treatment for nearly 25% to 55% patients with acute respiratory distress syndrome (ARDS). But there is controversy about the use of neuromuscular blocking agents in patients with ARDS. This review aim to discuss the use of neuromuscular blocking agents in patients with ARDS. Key words: Neuromuscular blocking agents; Acute respiratory distress syndrome; Mechanical ventilation

Response to letter regarding article ‘Exploring the link between pholcodine exposure and neuromuscular blocking agent anaphylaxis’

Uyttebroek et al. [1] raise some pertinent questions regarding the utility of various testing modalities in the assessment of neuromuscular blocking agent (NMBA) hypersensitivity. In our cases, clinical history was the major assessment tool for identifying pholcodine as the inciting agent of anaphylaxis [2]. In both patients, the temporal association between pholcodine exposure and clinical reaction was in keeping with drug-induced anaphylaxis and no alternative causes were identified. The positive allergen-specific IgE levels to pholcodine (ImmunoCAP Phadia, Uppsala, Sweden) were used to substantiate the high index of clinical suspicion. As mentioned in the article, skin testing to pholcodine has limited utility because it causes wheal and flare reactions in normal control subjects. While drug provocation challenges are sometimes used to confirm allergy in situations where history and skin/allergen-specific IgE testing are ambiguous, in this circumstance this was not felt appropriate, owing to the severity of systemic reaction in both patients' index events. In one of our cases, a tramadol challenge was performed to give additional options if opiate analgesics were required, and the avoidance of codeine and its active metabolite morphine was recommended. Subsequent evaluation in both our patients was targeted toward the potential for NMBA hypersensitivity given previous studies [3–6], presented in the review, suggesting an association between pholcodine exposure and NMBA anaphylaxis. The recommendations regarding NMBA use in both patients were based on the outcome of skin testing and allergen-specific IgE testing. As Uyttebroek et al. [1] allude to, sensitization to a drug does not always equate with clinically meaningful allergy. However, provocation challenges with various NMBAs, as a means of demonstrating patient tolerance or allergy, are not feasible. Thus, the recommendations were made on the available testing at the time of assessment. The development of basophil activation tests as an adjunct to skin testing and specific IgE testing will no doubt help in the assessment of cases of suspected drug allergy. However, these tests are currently not validated or routinely available in most centres, and sensitivity may be lacking even when cases are carefully phenotyped and selected. The cases presented demonstrate the potential for sensitization to NMBA to occur in the context of pholcodine hypersensitivity. These case studies are reflective, at an individual patient level, of the population-based evidence cited previously [3,5,6]. We agree that consideration of whether the patients are able to tolerate opiates following true pholcodine immediate (IgE) hypersensitivity reactions is an important practical concern, and the specific haptenated products mediating such reactions are unknown. Indeed, codeine is metabolized by the genetically polymorphic isoform CYP2D6 to the active metabolite morphine, adding additional potential variability to potential cross-reactivity and patient tolerance. However, the focus of our article [2] was on the potential association of pholcodine exposure and NMBA allergy, and thus, the presentation of the case studies reflects this. Immunoglobulin E-mediated hypersensitivity reactions to pholcodine and morphine are rare, and this does indeed raise important questions regarding the pathogenesis of pholcodine sensitization and NMBA anaphylaxis. At present, the mechanisms underlying why exposure and sensitization to a substituted ammonium ion in pholcodine can prime NMBA anaphylaxis but not result in allergy to all compounds containing similar substituted ammonium ions remain unresolved.

Neuromuscular blocking agents — what does a nurse need to know?

The need for clarification of what is relevant to nurses is required in order for the veterinary nurse to be able to proceed with involvement of patients using neuromuscular blocking agents (NBAs). Available veterinary literature provides information that nurses do not necessarily require, such as the pharmacological compounds of NBAs and ultimately most do not focus on the nursing side of using NBAs, such as ventilation requirements, heating aids and monitoring equipment required. This article highlights what nurses are required to be aware of when participating in NBA use, providing a condensed nursing perspective.

Predictors of outcome in dogs undergoing thoracic surgery (2002–2011)

ObjectiveTo evaluate mortality in a canine population undergoing thoracic surgery and identify factors which may be associated with outcome. Study designRetrospective cohort study. Animals286 dogs anaesthetized for thoracic surgery at the Royal Veterinary College between June 2002 – June 2011. MethodsVariables examined included: signalment; ASA status; nature of disease; presence of co-morbidities; pre-anaesthetic oxygen requirement; surgical approach; anaesthesia management [anaesthetic agents; requirement for thoracocentesis; central venous pressure measurement; duration of surgery and anaesthesia; use of colloids, blood products, inotropes or neuromuscular blocking agents (NMBA)]. Outcome was defined as either non-survival to 24 hours after surgery or (having survived to 24 hours) to discharge. Univariate and multivariable logistic regressions were performed to identify risk factors associated with non-survival. ResultsOverall non-survival (excluding those euthanased) to discharge was 5.9%. Non-survival was 2.2% at 24 hours and 3.6% at time of discharge. Non-survival to 24 hours was associated with pre-anaesthetic oxygen requirement (odds ratio (OR) 12.2 [95% CI 1.8–84.5]) and NMBA use (OR 9.6 [95% CI 1.6–57.9]). Non-survival to discharge was associated with surgical duration, with surgeries >180 minutes having OR 16.9 [95% CI 2.0–144.0] compared to surgeries ≤90 minutes and blood product use (OR 4.6 [95% CI 1.3–14.6]). No association was found between ASA category and non-survival at 24 hours (OR 1.4 [95% CI 0.2–11.7]) or discharge (OR 4.4 [95% CI 0.6–34.3]). Significant associations were found between NMBA use and ASA category (p = 0.046), surgical duration (p = 0.002), use of colloids (p = 0.011), blood products (p = 0.001) and inotropes and/or vasopressors (p < 0.001). Conclusions and clinical relevanceVariables significantly associated with non-survival from canine thoracic surgery at 24 hours include NMBA use and pre-anaesthetic oxygen requirement. Blood product use and increasing surgical duration were associated with non-survival to hospital discharge. The associations may relate to the need for such products in the most complicated cases.

Therapeutic Range of Spontaneous Breathing during Mechanical Ventilation

In the 4th century before the common era, the Greek philosopher and physician Hippocrates expressed his wisdom on the value of activity to the sick and the healthy by stating that: “The sick will of course profit to a great extent from gymnastics with regard to the restoration of their health and the healthy will profit with regard to its maintenance” (On Regimen in Acute Diseases, 3, 400 BCE). In contemporary critical care medicine, driven by the goal of protecting our patients from self-inflicted injury, pain, and anxiety – and in contrast to Hippoctrates’ suggestions – we have built a culture of immobilizing our patients: we prescribe high doses of opioids, sedatives, anxiolytics, and anti-pychotics, and with the best intentions, place bed-rest and restraints orders. In patients with severe respiratory failure, we frequently use immobilizing ventilator settings such as volume control ventilation. Recent data have been increasingly challenging this tenet in relation to the fields of neuropsychiatry, rehabilitation, and respiratory medicine1–5. In this issue of Anesthesiology, two papers bring new information on why the concept of muscle activity is also relevant to lung biochemistry and regional function. Guldner et al.6 and Bruells et al.7 provide important experimental data on the relationship between the dose of diaphragmatic activity (spontaneous contribution to breathing during mechanical ventilation) and the resulting response in terms of lung mechanical stress, gas exchange, and markers of muscle deconditioning. As the main respiratory muscle, the diaphragm contributes 72% for tidal breathing8 and its role in respiratory mechanics and gas exchange goes well beyond this global number. One of the reasons is its curvature during spontaneous breathing in the supine position, which facilitates expansion of dependent lung regions9, optimizes the regional distribution of lung ventilation, and prevents loss of dependent lung aeration and increase in shunt observed when muscle paralysis is produced10. Accordingly, modes of ventilation proposed since the 1970s tried to explore those advantages in patients with acute respiratory failure. The beneficial effects of maintaining continuous spontaneous breathing during mechanical ventilation of patients with acute respiratory failure have been described by Putensen and coworkers in two well-designed studies11,12. However, in patients with severe respiratory failure, barriers to spontaneous breathing during mechanical ventilation including patient-ventilator asynchrony, high oxygen consumption of the respiratory pump muscles, and the risk of barotrauma, have hindered a clear determination of the value of spontaneous breathing during mechanical ventilation.

Neuromuscular blocking agents in ICU

Neuromuscular blocking agents have been used for a variety of clinical conditions such as emergency intubation, acute respiratory distress syndrome, status asthmaticus, elevated intracranial pressure, etc. Neuromuscular blocking agents should be used and monitored appropriately according to evidence-based guidelines to reduce the adverse events associated with the use of neuromuscular blocking agents. Key words: Intensive care unit; Neuromuscular blockade; Pharmacology

Enquête sur les modalités de la curarisation et la décurarisation au Maroc

ObjectiveTo determine current clinical neuromuscular use in Morocco anesthetic practice. Study designClinical practice survey. MethodsAnesthesiologists were invited to answer anonymously to question about neuromuscular blocking agents (NMBA): pharmacology, monitoring and antagonism drug use. Corrected yates test was used to compare qualitative parameters and variance analysis for quantitative parameters. P<0.05 was considered as significant. ResultsWe had 171 answers, 54% were paramedics (n=93) and 46% (n=78) were physicians (20% global effective in Morocco). Fifty-five percent were seniors. Vecuronium was the most NMBA used in Morocco for 51% of the anesthesiologists. Mean action time of NMBA was underestimate in more than 60% of the staff questioned specially for seniors (24.6%) than juniors (19.2%). Residual neuromuscular blockade was evaluated only by clinical and spirometric parameters in 72%. TOF monitor was used in 18% more in military hospitals (36%) and insurance clinics (40%) than private hospitals (12.5%). Administration of reversal drugs was systematic in 5.8% of anesthesiologists, frequent for 36.3% and rare for 55%. ConclusionsThis study show an underestimation of residual neuromuscular blockade, poor neuromuscular monitor use and lack of knowledge of NMBA specially for senior anesthesiologists and in private hospitals. We should elaborate Moroccan guideline for NMBA use and provide formal training programs for our anesthetic staff.

Abstract 336: Selective Use of Neuromuscular Blockade in Therapeutic Hypothermia Does Not Delay Time to Target Temperature

Background: Optimal management of shivering during Therapeutic Hypothermia(TH) is important to quickly achieve target temperature with a goal of improving neurological outcomes. Interventions (pharmacological and non-pharmacological) to manage shivering vary among institutions. We developed a step-wise guideline approach to: 1) prevent and manage shivering during the different phases of TH, 2) avoid delays to achieving target temperature (TT) and 3) reduce the use of neuromuscular blocking agents (NMBA). Methods: We report a single center experience examining the differences in time to target temperature, medication use and patient outcomes pre-(Jan2009-June2011) and post-(July2011-April2013) implementation of a TH Prevention and Management of Shivering algorithm. Results: A total of 138 patients had TH (62 patients pre vs 76 in the post-guidelines). Fewer patients post-guideline implementation received any NMBA (55.3% vs 83.9%, p=0.001), with a lower total dose of NMBA (59.4± 58.7 vs 99.8 ± 70.3 mg, p=0.001). In patients who received NMBA, the post group received more bolus only (64.3% vs 5.8%); and less infusion only (9.5% vs 48.1%) or infusion + bolus (26.2% vs 46.1% p &lt;0.001) therapy. As expected, propofol use increased in the post- group (3.1 vs 2.5 mg/kg/hr, p=0.02) as did increased use of fentanyl boluses (n=44 [4.1 ± 3] vs n=17 [2.5 ± 1.4] p=0.03). While more shivering was noted in the post group (43.5% vs 27.4%; p=0.04), there was no significant difference between the groups in the ROSC to TT time or ICU days. Survival and neurological outcomes were similar between the two groups. Conclusion: Selective use of NMBA as part of a shivering algorithm does not delay time to TT in TH. The decreased use of NMBA resulted in increased doses of sedation and analgesia without effects on patient survival or neurological outcome. Further research on optimal usage of NMBA in TH is needed.

Impact du sugammadex sur les consommations de curares : étude pharmaco-épidémiologique multicentrique dans les centres hospitalo-universitaires et hôpitaux d’instructions des armées français

IntroductionSeven Neuromuscular Blocking Agents (NMBA) are commercialized in France. Four of them have an intermediate duration of action. Sugammadex required the use of NMBA slightly employed in clinical practice in France. Its introduction in routine practice could have an impact on NMBA use in clinical practice. This study was then conducted to assess and compare NMBA use before and after the commercialization of sugammadex. Materials and methodsA longitudinal, retrospective, observational study was conducted between 2008 and 2011 in French university hospitals and military hospitals. The consumption data for sugammadex and NMBA were collected using a collection grid which was filled by pharmacists or anesthesiologists. Drug use was measured by the number of vials used divided by the annual number of hospitalizations in surgery and obstetrics (HSO). An overall analysis of the annual frequency of NMBA use was firstly performed, then individual data of each hospital were analyzed. Descriptive statistical analysis including mean, standard deviation, median, minimum and maximum was achieved. ResultsThirty-four out of 39 hospitals participated in the study (87%) and analysis was performed on 26 of them (7%). The data of eight institutions were exluded due to missing values or because of the non-admission of sugammadex in their formulary. The NMBA mostly used were non-steroidal NMBA (75% of market share) with an increased use between 2008 and 2011 concerning atracurium (from 41 to 51 vials of 50mg atracurium used per 100 HSO). The overall analysis revealed an increase of the occurrence of rocuronium (between 2008 and 2011: from 1 to 4.8 vials of 50mg rocuronium used per 100 HSO). Individual analyses on each hospital showed a possible effect of sugammadex introduction on NMBA use in nine hospitals. Discussion and conclusionsThe commercialization of sugammadex seems to have induced a discrete increase of steroidal NMBA but non-steroidal NMBA remain the leading agent in France. A long-term follow-up is deserved.

Hemodynamic consequences of ketamine vs etomidate for endotracheal intubation in the air medical setting

ObjectiveRecent drug shortages have required the occasional replacement of etomidate for endotracheal intubation (ETI) by helicopter emergency medical services (HEMS), with ketamine. The purpose of this study was to assess whether there was an association between ketamine vs etomidate use as the main ETI drug, with hemodynamic or clinical (airway) end points. MethodsThis retrospective study used data entered into medical records at the time of HEMS transport. Subjects, 50 ketamine and 50 etomidate, were accrued from 3 US HEMS programs. The study period was from August 2011 through May 2012. Data collection included demographics, diagnostic category, ETI drugs use, ETI success, and complications. Hemodynamic parameters were assessed for up to 2 sets of vital signs before airway management and up to 5 sets of post-ETI vital signs. Significance was defined at the P < .05 level. ResultsPatients on ketamine and etomidate were similar (P > .05) with respect to age, sex, scene/interfacility mission type, trauma vs nontrauma, neuromuscular blocking agent use, and rates of coadministration of fentanyl or midazolam. All patients had successful airway placement. Peri-ETI hypoxemia was seen in 10% of etomidate and 16% of ketamine cases (P = .55). The pre-ETI and post-ETI were similar between the ketamine and etomidate groups with respect to systolic blood pressure and heart rate at every vital signs assessment after ETI. ConclusionInitial assessment of ETI success and complication rates, as well as peri-ETI hemodynamic changes, suggests no concerning complications associated with large-scale replacement of etomidate with ketamine as the major airway management drug for HEMS.

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Introduction: Critical care provider knowledge and perceptions of neuromuscular blocking agents (NMBA) may be insufficient to adopt the recent evidence supporting their use for select patients with acute respiratory distress syndrome (ARDS). Hypothesis: There is suboptimal knowledge and variable use of NMBA for ARDS among ICU providers. Methods: This prospective, single-center survey study was administered in two medical ICUs at Mayo Clinic. The 15-question survey was designed with the Mayo Clinic Survey Research Center and validated in 20 non-included ICU practitioners. For a two-sided alpha of 0.05, 150 providers were necessary to have 8% precision for a dichotomous response. Results: Survey response rate was 53% (166 of 314), including 40 prescribers (intensivists, critical care fellows, nurse practitioners, physician’s assistants), 112 non-prescribers (pharmacists, nurses, respiratory therapists) and 14 unknown respondents. Most respondents correctly identified NMBA as non-analgesic (94%) and non-anxiolytic (89%). Muscle breakdown, foot drop, and corneal abrasion were the most frequently recognized adverse effects of NMBA, whereas consciousness and thromboembolism were infrequently noted (25% and 45%, respectively). Among the prescribers, 50% correctly identified the hepatic clearance of vecuronium, whereas 28% incorrectly identified atracurium as renally eliminated. In all respondents, 9% reported frequent use of continuous infusion NMBA (CI-NMBA) in all-comers with ARDS and 47% in severe ARDS. The prescriber subgroup was similar (5% and 51%, respectively). Pharmacists least often advocated for use of CI-NMBA in severe ARDS (11%). The majority of respondents felt CI-NMBA to be at least somewhat safe and effective (65% and 79%, respectively) for ARDS. Prescribers felt similarly about the efficacy of CI-NMBA for ARDS (72% report they are at least somewhat effective), yet fewer felt they were at least somewhat safe (51%). Conclusions: Provider knowledge of NMBA therapeutics and adverse effects may be insufficient to implement practice change. As evidence of such, frequent use of CI-NMBA, even in severe ARDS, was supported by <50% of providers despite reporting these agents to be somewhat safe and effective.

Intubation-related tracheal ischemic lesions: incidence, risk factors, and outcome

To determine incidence, risk factors and outcome of tracheal ischemic lesions related to intubation. Planned post hoc analysis using patients from a previous randomized controlled study. Fiberoptic tracheoscopy was performed during the 24 h following extubation. In patients with >2 ischemic lesions, ulcer or tracheal rupture, fiberoptic tracheoscopy was repeated 2 weeks after the last extubation. Tracheal ischemic lesions were predefined based on a quantitative score. Ninety-six adult patients were included in this study. Eighty (83 %) patients had at least one tracheal ischemic lesion. Thirty-seven (38 %) patients had a tracheal ischemia score > median score (5; IQ 1, 7). The most common tracheal ischemic lesion was ischemia (68 %), followed by hyperemia (54 %), ulcer (10 %), and tracheal rupture (1 %). Univariate analysis identified duration of neuromuscular-blocking agent use, overinflation of tracheal cuff (>30 cmH2O), percentage of P cuff determination >30 cmH2O, duration of assist-control ventilation, and plateau pressure as risk factors for having a tracheal ischemia score >5. Duration of assist-control mechanical ventilation was the only factor independently associated with tracheal ischemia score >5 [OR (95 % CI) 1.10 per hour (1.02-1.20)]. A fiberoptic tracheoscopy was performed 2 weeks after extubation in 22 patients. This examination was normal in all patients, except the one with tracheal rupture who had marked improvement. Tracheal ischemic lesions are common in intubated, critically ill patients. Duration of assist-control mechanical ventilation through a tracheal tube is the only independent risk factor. These lesions healed in the majority of patients 2 weeks after extubation.

50 Short Term Use of Neuromuscular Blocking Agents in Post Rapid Sequence Intubation Patients Are Not Harmful, and May Be Beneficial

50 Short Term Use of Neuromuscular Blocking Agents in Post Rapid Sequence Intubation Patients Are Not Harmful, and May Be Beneficial

175 Ketamine versus Etomidate for Use in Helicopter Emergency Medical Services Endotracheal Intubation

175 Ketamine versus Etomidate for Use in Helicopter Emergency Medical Services Endotracheal Intubation

The Role of Neuromuscular Blockers in Early ARDS

The use of neuromuscular blocking agents (NMBAs) in patients with acute respiratory distress syndrome (ARDS) and acute lung injury (ALI) remains controversial. However, NMBAs are used in 25% to 45% of ALI/ARDS patients for a mean period of 1±2 days, especially in severe ARDS. Hypoxemia and facilitation of mechanical ventilation are the main indications of NMBAs. Three randomized, controlled trials showed that the systematic early use of NMBAs is associated with a sustained improvement in oxygenation in ARDS patients. The most recent trial reported a decrease in 90-day in-hospital mortality rate when severe ARDS patients received a short course of muscle relaxants. The use of NMBAs in the early phase of ARDS could reinforce the beneficial effects of a lung-protective ventilation strategy. However, the role of prolonged NMBA administration in intensive care unit–acquired paresis in ARDS patients remains largely questioned. This review analyzes the recent findings in the literature concerning the effects of NMBAs on gas exchange and patient outcomes, and their potential adverse effects in ARDS.

Neuromuscular blocking agents in patients with acute respiratory distress syndrome: a summary of the current evidence from three randomized controlled trials

BackgroundAcute respiratory distress syndrome (ARDS) is a potentially fatal disease with high mortality. Our aim was to summarize the current evidence for use of neuromuscular blocking agents (NMBA) in the early phase of ARDS.MethodsSystematic review and meta-analysis of publications between 1966 and 2012. The Medline and CENTRAL databases were searched for studies on NMBA in patients with ARDS. The meta-analysis was limited to: 1) randomized controlled trials; 02) adult human patients with ARDS or acute lung injury; and 03) use of any NMBA in one arm of the study compared with another arm without NMBA. The outcomes assessed were: overall mortality, ventilator-free days, time of mechanical ventilation, adverse events, changes in gas exchange, in ventilator settings, and in respiratory mechanics.ResultsThree randomized controlled trials covering 431 participants were included. Patients treated with NMBA showed less mortality (Risk ratio, 0.71 [95 % CI, 0.55 – 0.90]; number needed to treat, 1 – 7), more ventilator free days at day 28 (p = 0.020), higher PaO2 to FiO2 ratios (p = 0.004), and less barotraumas (p = 0.030). The incidence of critical illness neuromyopathy was similar (p = 0.540).ConclusionsThe use of NMBA in the early phase of ARDS improves outcome.

Critical illness polyneuromyopathy

The clinical characteristics of and treatment approaches for critical illness polyneuromyopathy (CIPNM) are reviewed. CIPNM is an acute axonal sensory-motor polyneuropathy that tends to occur after the development of respiratory insufficiency in patients with systemic inflammatory response syndrome, sepsis, or multiple-organ dysfunction syndrome. Numerous mechanisms have been proposed to explain the pathophysiology of CIPNM, most of which are complex and not fully understood or proven. While the rate of intensive care unit-acquired weakness varies greatly among patients, an estimated 25-85% of critically ill adult patients will develop neuromuscular weakness, most commonly CIPNM, during hospitalization. While no specific pharmacologic treatments exist for CIPNM, the outcome for most patients is related to the severity of the illness and neuromyopathy, as well as early intervention to treat the underlying condition. Electrophysiologic studies, such as electromyography, electroneurography, and muscle and nerve biopsies, are considered the gold standard for aiding in the diagnosis of CIPNM. Preventive measures such as the early provision of appropriate nutrition, glucose control, physical rehabilitation, and the cautious use of medications such as corticosteroids and neuromuscular blocking agents (NMBAs) can help reduce the occurrence of CIPNM. CIPNM is an acute axonal sensory-motor polyneuropathy commonly seen in critically ill patients with sepsis and multiorgan failure. While no specific pharmacologic treatments exist, preventive measures such as the early provision of appropriate nutrition, glucose control, physical rehabilitation, and the cautious use of medications, including corticosteroids and NMBAs, can help reduce the incidence of CIPNM.