Use Of Neuromuscular Blocking Agents Research Articles

Chapter 15. Analgesics, sedatives, and neuromuscular blockade

Chapter 15. Analgesics, sedatives, and neuromuscular blockade

Tracheal Intubation Without the Use of Neuromuscular Blocking Agents

Dear Editor, I read with keen interest the article by Imani et al. (1) in which the authors compare tracheal intubating conditions following intravenous (IV) administration of remifentanil 5 μg/kg or alfentanil 50 μg/kg followed by induction of anesthesia with propofol 2 mg/kg in 100 adult patients premedicated with IV midazolam 1 mg. Intubating conditions were assessed (scoring 1 to 4) by ease of laryngoscopy, patency of vocal cords, jaw relaxation, and limb movement. Airway reaction to tracheal intubation is an important consideration while assessing intubating conditions. Viby-Mogensen et al. (2) describe a qualitative scoring system graded as excellent, good or poor, respectively, comprising of five variables: Laryngoscopy (easy, fair, difficult) Vocal cord position (abducted, intermediate, closed) Vocal cord movement (none, moving, closing) Coughing (none, diaphragmatic, sustained, > 20 s) Movement of the limbs (none, slight, vigorous) Intubating conditions are regarded as excellent (all qualities are excellent), good (all qualities are either excellent or good), and poor (the presence of a single quality listed under poor) (2). They further regard excellent or good intubating conditions as clinically acceptable; and poor intubating conditions as clinically not acceptable. It would be interesting to compare the two narcotic regimens (remifentanil vs. alfentanil) for tracheal intubation without neuromuscular blocking agents (NMBAs) with regard to the incidence of coughing. Tracheal intubation is associated with hemodynamic changes. In this regard, the use of remifentanil 5 μg/kg would be expected to cause significant hypotension and/or bradycardia. It would be useful to know the incidence of hypotension or bradycardia and also if there was need for administration of vasopressors or atropine. I am intrigued by two statements in the article that are in contradistinction: The combination of remifentanil with propofol may also be advantageous in cases of long and difficult intubation, wherein it may not only be possible to inspect the airway with the laryngoscope. Thus, this method is best avoided in patients with high Mallampati grades or airway difficulties. The technique of tracheal intubation without the use of NMBAs enables us to assess the airway by laryngoscopy. This technique may be useful in cases of both predicted and unexpected difficult intubation, in cases where NMBAs are either contraindicated (e.g. myopathies) or not required to facilitate surgical access (3).

What We Know

What We Know

Current Therapeutic Uses, Pharmacology, and Clinical Considerations of Neuromuscular Blocking Agents for Critically III Adults

To summarize literature describing use of neuromuscular blocking agents (NMBAs) for common critical care indications and provide a review of NMBA pharmacology, pharmacokinetics, dosing, drug interactions, monitoring, complications, and reversal. Searches of MEDLINE (1975-May 2011), EMBASE (1980-May 2011), and Cumulative Index to Nursing and Allied Health Literature (1981-May 2011) were conducted to identify observational and interventional studies evaluating the efficacy or safety of NMBAs for management of acute lung injury (ALI)/acute respiratory distress syndrome (ARDS), status asthmaticus, elevated intracranial pressure (ICP), and therapeutic hypothermia. We excluded case reports, animal- or laboratory-based studies, trials describing NMBA use during rapid sequence intubation or in the operating room, and studies published in languages other than English or French. Clinical applications of NMBAs in intensive care include, but are not limited to, immobilizing patients for procedural interventions, decreasing oxygen consumption, facilitating mechanical ventilation, reducing intracranial pressure, preventing shivering, and management of tetanus. Recent data on ARDS demonstrated that early application of NMBAs improved adjusted 90-day survival for patients with severe lung injury. These results may lead to increased use of these drugs. While emerging data support the use of cisatracurium in select patients with ALI/ARDS, current literature does not support the use of one NMBA over another for other critical care indications. Cisatracurium may be kinetically preferred for patients with organ dysfunction. Close monitoring with peripheral nerve stimulation is recommended with sustained use of NMBAs to avoid drug accumulation and minimize the risk for adverse drug events. Reversal of paralysis is achieved by discontinuing therapy or, rarely, the use of anticholinesterases. NMBAs are high-alert medications used to manage critically ill patients. New data are available regarding the use of these agents for treatment of ALI/ARDS and status asthmaticus, management of elevated ICP, and provision of therapeutic hypothermia after cardiac arrest. To improve outcomes and promote patient safety, intensive care unit team members should have a thorough knowledge of this class of medications.

Utilisation des curares en médecine préhospitalière : enquête de pratique dans les Smur de la région Sud-Est

ObjectiveTo evaluate the use of neuromuscular blocking agents (NMBA) in the French adult Prehospital Emergency Medical Services (PEMS). Study designTelephone survey of practices. Materials and methodsA survey was conducted from April to July 2009 in every PEMS of the South-East of France. A PEMS physician by center was interviewed using a standardized quiz including demographic data, methods of anesthetic induction, use of NMBA and succinylcholine. ResultsAll 86 EMS were interviewed. Succinylcholine was used in 98% of cases for rapid sequence induction. Nondepolarizing NMBA were never used by 38%. They were not available in 21% of PEMS. Among the practitioners using them, 79% prescribed them rarely (less than 25% of intubated patients). Nondepolarizing NMBA were prescribed in more than half of cases of patient ventilator asynchrony by 27% of physicians, of ventilator high pressure (23%), of acute status asthmaticus (23%), of suspicion of intracranial hypertension (22%), of refractory hypoxemia (16%), therapeutic hypothermia (10%). Limitations of prescription were essentially little guidance and lack of training. Atracurium and cisatracurium were the most used. The exact dosages were known by only 18% of practitioners. None of the practitioners were performing a monitoring of NMBA. ConclusionThis survey highlights the very frequent use of succinylcholine for rapid sequence induction and low use of nondepolarizing NMBA for selected indications. A training endeavor could be undertaken to improve the use of these anesthetic drugs by prehospital physicians.

Continuous‐Infusion Neuromuscular Blocking Agents in Critically Ill Neonates and Children

Neuromuscular blocking agents (NMBAs) are often administered as a prolonged (> 24 hrs) continuous infusion in infants and children in the intensive care unit for a variety of reasons including facilitation of oxygenation and ventilation. No guidelines on the use of NMBAs in pediatric patients are available yet in the United States; however, pediatric guidelines are available in the United Kingdom. Based on a 2007 U.S. survey, the most commonly used nondepolarizing NMBAs for sustained neuromuscular blockade in critically ill children are pancuronium and vecuronium. Recent national drug shortages involving NMBAs have been reported for atracurium, cisatracurium, pancuronium, rocuronium, and vecuronium. Therefore, to explore alternative options for neuromuscular blockade, we conducted a literature search to identify articles evaluating prolonged use (> 24 hrs) of NMBAs administered by continuous infusion. The search was limited to English-language articles in the MEDLINE (1950-August 2010), EMBASE (1988-August 2010), International Pharmaceutical Abstracts (1970-August 2010), and Cochrane Library (1996-August 2010) databases. Relevant abstracts, reference citations, and manufacturers' product information were also reviewed. A total of 13 reports representing 208 children were included in the analysis. Many of the reports described wide interpatient variability in dosing for the specific NMBAs evaluated. Selection of the most appropriate NMBA should be based on the patient's clinical status, potential adverse effects, and pharmacoeconomics. All patients receiving sustained neuromuscular blockade should be monitored routinely to ensure that dosing is appropriate in order to obtain the desired level of blockade. The goal is to use the lowest dose possible in an effort to limit adverse effects or prolonged blockade.

Neuromuscular Blockers Improves Outcome in Severe and Early Adult Respiratory Distress Syndrome

Synopsis: Early use of neuromuscular-blocking agents in adult respiratory distress syndrome decreases the morbidity and mortality. Source: Papazian L, Forel JM, Gacouin A, et al. Neuromuscular blockers in early acute respiratory distress syndrome. New Engl J Med. 2010;363:1107–1116.

Postoperative Neuromuscular Blocker Use Is Associated With Higher Primary Fascial Closure Rates After Damage Control Laparotomy

Failure to achieve fascial primary closure after damage control laparotomy (DCL) is associated with increased morbidity, higher healthcare expenditures, and a reduction in quality of life. The use of neuromuscular blocking agents (NMBA) to facilitate closure remains controversial and poorly studied. The purpose of this study was to determine whether exposure to NMBA is associated a higher likelihood of primary fascial closure. All adult trauma patients admitted between January 2002 and May 2008 who (1) went directly to the operating room, (2) were managed initially by DCL, and (3) survived to undergo a second laparotomy. Study group (NMBA+): those receiving NMBA in the first 24 hours after DCL. Comparison group (NMBA-): those not receiving NMBA in the first 24 hours after DCL. Primary fascial closure defined as fascia-to-fascia approximation by hospital day 7. One hundred ninety-one patients met inclusion (92 in NMBA+ group, 99 in NMBA- group). Although the NMB+ patients were younger (31 years vs. 37 years, p = 0.009), there were no other differences in demographics, severity of injury, or lengths of stay between the groups. However, NMBA+ patients achieved primary closure faster (5.1 days vs. 3.5 days, p = 0.046) and were more likely to achieve closure by day 7 (93% vs. 83%, p = 0.023). After controlling for age, gender, race, mechanism, and severity of injury, logistic regression identified NMBA use as an independent predictor of achieving primary fascial closure by day 7 (OR, 3.24, CI: 1.15-9.16; p = 0.026). Early NMBA use is associated with faster and more frequent achievement of primary fascial closure in patients initially managed with DCL. Patients exposed to NMBA had a three times higher likelihood of achieving primary fascial closure by hospital day 7.

Impact of sustained neuromuscular blockade on outcome of mechanically ventilated children

Neuromuscular blocking agents (NMBA) are commonly administered to critically ill children in pediatric intensive care units (PICU) in the USA and Europe. Although NMBA are frequently used in PICU patients, their role in the PICU setting has not yet been clearly defined. The aim of this study was to describe the sustained administration of NMBA and its impact on outcome of PICU patients. A 3-year retrospective cohort study was conducted to compare mechanically-ventilated patients who received NMBA for at least 12 h with patients who did not (control group). A total of 317 consecutive patients were ventilated over 3473 days. Patients were similar in age, weight and severity scores. Thirty-four children (10.7%) received NMBA. Compared with controls, the neuromuscular blockade (NMB) group had a longer duration of mechanical ventilation (13.7 vs 5.5 days, P= 0.000), longer PICU stay (20 vs 11 days, P= 0.000) and increased occurrence of ventilator-associated pneumonia (6.6 vs 4.1/1000 ventilator days, P= 0.010). The NMB use was not associated with higher mortality (8.8% vs 17.6%, P= 0.287) or longer hospital stay (30.5 vs 23 days, P= 0.117). Although the use of NMBA was not associated with greater mortality, we found that sustained use of NMBA is associated with prolonged mechanical ventilation, longer PICU stay and higher incidence of ventilator-associated pneumonia when compared with controls. Larger studies are necessary to confirm these findings.

Knowledge of residual curarization: an Italian survey

The use of neuromuscular blocking agents (NMBAs) is widespread in anesthetic practice; little is known about the current use of these drugs in Italy. This survey was conducted to obtain information about the most commonly used clinical tests and the train-of-four (TOF) ratios that are considered as being reliable for assessing recovery from neuromuscular blockade at the end of anesthesia and the estimated occurrence rates of post-operative paralysis in Italian hospitals. The questionnaire was given to Italian anesthesiologists attending the 62nd National Congress of the Italian Society of Anesthesia, Analgesia and Intensive Therapy. Collected data were stratified by age and the total number of surgical procedures performed in the hospitals concerned. Seven hundred and fifty-four correctly compiled questionnaires were collected (response rate 88.7%). Seventy three percent of the respondents only used clinical tests for monitoring the level of neuromuscular blockade. The main clinical tests cited for the evaluation of residual paralysis were keeping the head lifted up for 5 s, protruding the tongue and opening the eyes. TOF was used by 35% of the respondents on a routine basis. Only 24% of the interviewed anesthesiologists reported that before extubation, a TOF ratio of at least 0.9 should be reached. Most Italian anesthetists assess the recovery from neuromuscular blockade only by clinical signs. There is poor awareness about the inability of such techniques to indicate even a significant amount of residual neuromuscular block. A more extensive use of quantitative instrumental monitoring is required for the more rational use of NMBAs.

Avoidance of neuromuscular blocking agents may increase the risk of difficult tracheal intubation: a cohort study of 103 812 consecutive adult patients recorded in the Danish Anaesthesia Database

Previous studies indicate that avoiding neuromuscular blocking agents (NMBAs) may be a risk factor for difficult tracheal intubation (DTI). We investigated whether avoiding NMBA was associated with DTI. A cohort of 103,812 consecutive patients planned for tracheal intubation by direct laryngoscopy was retrieved from the Danish Anaesthesia Database. We used an intubation score based upon the number of attempts, change from direct laryngoscopy to a more advanced technique, or intubation by a different operator. We retrieved data on age, sex, ASA physical status classification, priority of surgery, time of surgery, previous DTI, modified Mallampati score, BMI, and the use of NMBA. Using logistic regression, we assessed whether avoiding NMBA was associated with DTI. The frequency of DTI was 5.1 [95% confidence interval (CI): 5.0-5.3]%. In a univariate analysis, avoiding NMBA was associated with DTI, odds ratio (OR) 1.52 (95% CI: 1.43-1.61)%, P<0.0001. Using multivariate analysis, avoiding NMBA was associated with DTI, OR 1.48 (95% CI: 1.39-1.58), P<0.0001. Among patients intubated using NMBA, a multivariate analysis identified patients anaesthetized with only non-depolarizing NMBA to be more at risk for DTI than those anaesthetized with depolarizing NMBA alone. Avoiding NMBA may increase the risk of DTI. However, confounding by indication may be a problem in this observational study and systematic reviews with meta-analysis or more randomized clinical trials are needed.

TS06 *HEAD INJURY AND OUTCOME – WHAT INFLUENCE DOES PREHOSPITAL INTUBATION HAVE?

Mortality of severe traumatic brain injury (STBI) varies in literature between 23 and 81% depending on pre‐hospital use of neuromuscular blocking agents (NBA) for endotracheal intubation (ETI) (1, 2). In NSW paramedics are not equipped with NBA. Aim of this study was to determine mortality of STBI patients in a NSW Trauma Centre and compare to intentional standards as an initial step to evaluate potential applicability of NBA for ETI in NSW.Methods: A four‐year retrospective study ending December 2008 on consecutive trauma patients admitted to a NSW Level‐1 Trauma Centre with a pre‐hospital Glasgow Coma Score (GCS) &lt; 9 and STBI [Abbreviated Injury Scale (AIS) &gt; 2]. Patients were identified from trauma registry and focused chart review was performed. Primary outcome was mortality. Results are presented as mean ± SD or percentages. Statistical significance was determined at p &lt; 0.05 based on univariate analysis.Results: A total of 124 patients were identified (age 36.4 ± 20, pre‐hospital GCS 4.8 ± 2, ISS 30.6 ± 13, head AIS 4.2 ± 0.7, 28% had systolic blood pressure (SBP) &lt; 90 mmHg). The overall mortality was 34.6%. 27 patients had pre‐hospital ETI with 74.0% mortality. In 5 patients pre‐hospital ETT failed (mortality 20%). 92 patients had ETT on arrival to hospital (mortality 24.4%). Survivors differed from those who died (age &lt;55: 91% vs 52%, ISS: 26.9 ± 10.7 vs 37 ± 16.3, AIS: 4.1 ± 0.6 vs 5.2 ± 2.0, GCS: 5.2 ± 2.0 vs 4.0 ± 1.7, and SBP &lt; 90 mmHg: 15.8% vs 50%). ETI &lt; 30 minutes from injury was more common among non‐survivors (2.7% vs 21.6%).Discussion: Mortality is comparable with trauma systems without pre‐hospital NBA. State‐wide assessment of the STBI outcomes is recommended to determine the potential applicability of pre‐hospital use of NBA.

Neuromuscular blockade, reversal agent use, and operating room time: retrospective analysis of US inpatient surgeries

ABSTRACTPurpose: Reducing operating room (OR) time is of interest to hospital administrators because of high costs of OR utilization. Neuromuscular blocking agents (NMBAs) induce muscle relaxation during surgery. Several acetylcholinesterase inhibitors are used to reverse neuromuscular blockade to shorten recovery time. This study explored the relationship between elapsed OR time and the use of specific NMBAs and reversal agents among patients undergoing selected surgeries based on data from two large hospitals. Specifically, this study sought to test the hypothesis that the application of reversal agents in surgeries using a neuromuscular block would be associated with a decrease in elapsed OR time.Methods: This retrospective cohort study used clinical data from two large hospitals. The authors selected seven types of surgical cases involving thoracic, cardiac, vascular, abdominal, peripheral, urological, and neurological systems. Eligible cases were elective surgeries performed under general anesthesia and using one or more NMBAs (including rocuronium, vecuronium, cisatracurium, and/or pancuronium). Multivariate linear regressions were conducted to examine the relationships among neuromuscular blockade, reversal agent use (including neostigmine, pyridostigmine, and edrophonium), and elapsed OR time by controlling for age, gender, and patient comorbidities.Results: A total of 9670 surgeries were included in this analysis. The mean elapsed OR time across all surgeries was 227 min, and vecuronium was the most commonly used NMBA. Approximately 67% of all surgeries used a reversal agent. After controlling for confounding factors, use of a reversal agent was shown to be associated with the reduction of elapsed OR time in six of seven types of surgery. The magnitude of this effect ranged from 12 to 46 min of OR time saved. The exception was thoracic surgeries, for which use of a reversal agent was shown to be associated with longer OR time (approximately 26 min). Multivariate regression analyses revealed that the type of NMBA used was also a significant predictor of elapsed time for all surgeries (except cardiac).Conclusions: This analysis has shown that use of selected neuromuscular blockade reversal agents may lead to more efficient OR resource use.

Paralytics in critical care: not always the bad guy

The use of neuromuscular blocking agents (NMBAs) in patients with acute respiratory distress syndrome (ARDS) and acute lung injury remains controversial, although frequent. This review analyzes the effects of NMBAs on thoracopulmonary mechanics, gas exchange, patient outcome and their potential adverse effects. NMBAs are used in 25-45% of acute lung injury/ARDS patients for a mean period of 12 days, especially in severe ARDS. Hypoxemia and facilitation of mechanical ventilation are the main indications of NMBAs. Two 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 suggests a beneficial effect on proinflammatory response associated with ARDS and mechanical ventilation. The use of NMBAs in acute lung injury/ARDS patients is not marginal. Recent studies suggest a beneficial effect of early use of NMBAs on oxygenation and inflammation. The role of NMBAs in the occurrence of ICU-acquired neuromyopathies and lung atelectasis in ARDS patients remains largely questioned. The use of NMBAs in the early phase of ARDS could reinforce the beneficial effects of a lung-protective ventilation. In this context, the effect of NMBAs on the outcome of ARDS patients must be evaluated.

Multicenter Prospective Observational Study about the Usage Patterns of Sedatives, Analgesics and Neuromuscular Blocking Agents in the Patients Requiring More Than 72 Hours Mechanical Ventilation in Intensive Care Units of Korea

Background: To investigate the usage patterns of sedatives, analgesics and neuromuscular blocking agents (NMBAs) in patients requiring mechanical ventilation more than 72 hours in intensive care units (ICUs) of Korea. Methods: A total of 536 patients continuing mechanical ventilation more than 72 hours had been enrolled among the twenty-one ICUs of Korea from May 2003 to July 2003. Data about mechanical ventilation, the use of sedatives, analgesics, and NMBAs were prospectively collected for f our weeks. We analyzed the patterns of using these drugs and effects on outcomes. Results: More than half of the patients (50.4%) received sedative drug alone. Most commonly used sedatives and analgesics were midazolam and morphine. NMBAs were administered in 41% of the patients. Volume controlled ventilation mode was associated with more frequent use of NMBAs. There were no significant differences in outcome variables among the usage patterns of sedatives, analgesics and NMBAs. Conclusions: Our investigation shows that analgesics were much less frequently used in the intensive care units of Korea compared with the use of sedatives. And the use of NMB As were quite a common.

Use of sedatives, opioids, and neuromuscular blocking agents in patients with acute lung injury and acute respiratory distress syndrome*

The use of sedatives, opioids, and neuromuscular blocking agents (NMBAs) may delay weaning and prolong intensive care unit length of stay. We hypothesized that in patients on higher positive end-expiratory pressure (PEEP), sedatives, opioids, and NMBAs are used in a higher proportion of patients and in higher doses and that the use of these medications is associated with prolongation of weaning and mortality. Retrospective analysis. The ALVEOLI trial. Five hundred forty-nine patients with acute lung injury/acute respiratory distress syndrome (ALI/ARDS) who were enrolled in the ALVEOLI trial. We analyzed prospectively collected data regarding the impact of sedatives, opioids, and NMBAs in ALI/ARDS patients on duration of mechanical ventilation, time to weaning landmarks, and mortality. Sedatives and opioids were used in >80% of the patients in similar proportion in the two groups. The use of sedatives and opioids, but not the use of NMBAs, was associated with longer time on mechanical ventilation and an increased time to achieve a 2-hr spontaneous breathing trial (p < .0001). Sedatives were also associated with increased time to achieve unassisted breathing. NMBAs were used for a short period of time, in a higher proportion of patients in the lower PEEP group, and for a longer time (0.23 days). Sedatives and opioids use was similar in the higher and lower PEEP groups. The use of sedatives and opioids, but not NMBAs, was associated with a longer time to achieve important weaning landmarks.

Intérêt d'une curarisation systématique précoce de 48 heures sur le pronostic des patients présentant un syndrome de détresse respiratoire aiguë. Étude ACURASYS. Présentation du protocole

Acute respiratory distress syndrome (ARDS) is associated with a mortality of 40% to 60%. Numerous sophisticated treatments have been evaluated. However, the use of neuromuscular blocking agents (NMBA) remains poorly studied in this indication. In a recently published study (Gainnier et al., Crit Care Med 2004), our group reported a persistent oxygenation improvement in ARDS patients paralyzed during the first 48 h after the onset of ARDS as compared with ARDS patients who did not receive NMBA. One plausible explanation would be that tidal volume is much more homogenously distributed when patients are paralyzed. In a very recently published study, we have shown that NMBA use is associated with a significant reduction of pro-inflammatory cytokines in BAL and blood samples (Forel et al., Crit Care Med 2006). When the patients included in these two studies are considered together, we found a significant reduction in the mortality rate. These data have not been published because these two studies were not designed to study the outcome. However, we decided to perform a multicenter double-blind, placebo-controlled prospective trial in order to demonstrate that the early use of a short period of paralysis is associated with a better outcome of ARDS patients. A total of 340 patients need to be included in the twenty ICUs participating in this trial.

Neuromuscular blocking agents decrease inflammatory response in patients presenting with acute respiratory distress syndrome*

To evaluate the effects of neuromuscular blocking agents (NMBAs) on pulmonary and systemic inflammation in patients with acute respiratory distress syndrome ventilated with a lung-protective strategy. Multiple-center, prospective, controlled, and randomized trial. One medical and two medical-surgical intensive care units. A total of 36 patients with acute respiratory distress syndrome (Pao2/Fio2 ratio of < or =200 at a positive end-expiratory pressure of > or =5 cm H2O) were included within 48 hrs of acute respiratory distress syndrome onset. Patients were randomized to receive conventional therapy plus placebo (n = 18) or conventional therapy plus NMBAs (n = 18) for 48 hrs. Both groups were ventilated with a lung-protective strategy (tidal volume between 4 and 8 mL/kg ideal body weight, plateau pressure of < or =30 cm H2O). Bronchoalveolar lavages and blood samples were performed, before randomization and at 48 hrs, to determine the concentrations of tumor necrosis factor-alpha, interleukin (IL)-1beta, IL-6, and IL-8. Pao2/Fio2 ratio was evaluated before randomization and at 24, 48, 72, 96, and 120 hrs. A decrease over time in IL-8 concentrations (p = .034) was observed in the pulmonary compartment of the NMBA group. At 48 hrs after randomization, pulmonary concentrations of IL-1beta (p = .005), IL-6 (p = .038), and IL-8 (p = .017) were lower in the NMBA group as compared with the control group. A decrease over time in IL-6 (p = .05) and IL-8 (p = .003) serum concentrations was observed in the NMBA group. At 48 hrs after randomization, serum concentrations of IL-1beta (p = .037) and IL-6 (p = .041) were lower in the NMBA group as compared with the control group. A sustained improvement in Pao2/Fio2 ratio was observed and was reinforced in the NMBA group (p < .001). Early use of NMBAs decrease the proinflammatory response associated with acute respiratory distress syndrome and mechanical ventilation.

The Effects of Neuromuscular-Blocking Agents on Gas Exchange in Patients With Acute Respiratory Distress Syndrome

In Brief The use of neuromuscular-blocking agents (NMBA) in ventilated patients with acute respiratory distress syndrome (ARDS) is controversial and largely empiric. Few trials looked at their effectiveness on gas exchange or in improving lung mechanics in patients with ARDS. Only one randomized, controlled trial compared the effects of NMBA on gas exchange in patients with ARDS receiving NMBA as compared with patients receiving placebo throughout a period of 48 hours. In this trial, the early use of NMBA in patients with ARDS was associated with a sustained improvement in oxygenation. The muscular paralysis induced by NMBA could reduce the consumption of oxygen linked to the work of breathing. Muscular paralysis could facilitate mechanical ventilation by preventing spontaneous breaths responsible for the dys-synchrony and worsening of gas exchange. Muscular paralysis could increase compliance of the thoracic wall and improve mechanical ventilation during ARDS. However, these hypotheses are controversial. Finally, preliminary data show that the muscular paralysis could provide better adaptation to mechanical ventilation and better satisfaction with the protective criteria for reduction of ventilator-associated lung injuries by homogenizing the distribution of tidal volume and positive end expiratory pressure. The role of new NMBA (benzylisoquinolines) in the occurrence of critical illness neuromyopathy is largely questioned in the recent literature. It is important to design new studies to explain the mechanisms of the improvement in oxygenation associated with NMBA and to evaluate whether the use of NMBA modifies the outcome of patients with ARDS. The administration of neuromuscular-blocking agents (NMBA) in the early phase of acute respiratory distress syndrome is associated with a sustained improvement in oxygenation. Preliminary study shows that NMBA could reinforce the beneficial effects of lung-protective ventilation.

Effets de la curarisation sur les échanges gazeux lors du syndrome de détresse respiratoire aiguë

The use of neuromuscular blocking agents (NMBA) in ventilated patients with acute respiratory distress syndrome (ARDS) is controversial and largely empirical. Few trials looked at their effectiveness on gas exchange or in improving lung mechanics in patients with ARDS. Only one randomized controlled trial compare the effects of NMBA on gas exchange in patients with ARDS receiving NMBA as compared with patients receiving placebo throughout a period of 48 hours. In this trial, the early use of NMBA in patients with ARDS was associated with a sustained improvement in oxygenation. The muscular paralysis induced by NMBA could reduce the consumption of oxygen linked to the work of breathing. Muscular paralysis could facilitate mechanical ventilation by preventing spontaneous breaths responsible for the dyssynchrony and worsening of hematosis. Muscular paralysis could increase compliance of the thoracic wall and improve mechanical ventilation during ARDS. However, these hypotheses are controversial. Finally, preliminary data show that the muscular paralysis could provide better adaptation to mechanical ventilation and better satisfaction with the protective criteria for reduction of ventilator-associated lung injuries by homogenizing the distribution of tidal volume and positive end-expiratory pressure. The role of new neuromuscular blocking agents (benzylisoquinolines) in the occurrence of critical illness neuromyopathy is largely questioned in the recent literature. It is important to design new studies to explain the mechanisms of the improvement in oxygenation associated with NMBA and to evaluate whether the use of NMBA modifies the outcome of patients with ARDS.