An Observational Study of the Efficacy of Cisatracurium Compared with Vecuronium in Patients with or at Risk for Acute Respiratory Distress Syndrome

Analgesia and Sedation Use During Noninvasive Ventilation for Acute Respiratory Failure

OBJECTIVES

To describe U.S. practice regarding administration of sedation and analgesia to patients on noninvasive ventilation (NIV) for acute respiratory failure (ARF) and to determine the association of this practice with odds of intubation or death.

DESIGN

A retrospective multicenter cohort study.

SETTING

A total of 1017 hospitals contributed data between January 2010 and September 2020 to the Premier Healthcare Database, a nationally representative healthcare database in the United States.

PATIENTS

Adult (≥ 18 yr) patients admitted to U.S. hospitals requiring NIV for ARF.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

We identified 433,357 patients on NIV of whom (26.7% [95% CI] 26.3%-27.0%) received sedation or analgesia. A total of 50,589 patients (11.7%) received opioids only, 40,646 (9.4%) received benzodiazepines only, 20,146 (4.6%) received opioids and benzodiazepines, 1.573 (0.4%) received dexmedetomidine only, and 2,639 (0.6%) received dexmedetomidine in addition to opioid and/or benzodiazepine. Of 433,357 patients receiving NIV, 50,413 (11.6%; 95% CI, 11.5-11.7%) patients underwent invasive mechanical ventilation on hospital days 2-5 or died on hospital days 2-30. Intubation was used in 32,301 patients (7.4%; 95% CI, 7.3-7.6%). Further, death occurred in 24,140 (5.6%; 95% CI, 5.5-5.7%). In multivariable analysis adjusting for relevant covariates, receipt of any medication studied was associated with increased odds of intubation or death. In inverse probability weighting, receipt of any study medication was also associated with increased odds of intubation or death (average treatment effect odds ratio 1.38; 95% CI, 1.35-1.40).

CONCLUSIONS

The use of sedation and analgesia during NIV is common. Medication exposure was associated with increased odds of intubation or death. Further investigation is needed to confirm this finding and determine whether any subpopulations are especially harmed by this practice.

Current Practice Review in the Management of Acute Respiratory Distress Syndrome

Acute respiratory distress syndrome (ARDS) presents as an acute inflammatory lung injury characterized by refractory hypoxemia and non-cardiac pulmonary edema. An estimated 10% of patients in the intensive care unit and 25% of those who are mechanically ventilated are diagnosed with ARDS. Increased awareness is warranted as mortality rates remain high and delays in diagnosing ARDS are common. The COVID-19 pandemic highlights the importance of understanding ARDS management. Treatment of ARDS can be challenging due to the complexity of the disease state and conflicting existing evidence. Therefore, it is imperative that pharmacists understand both pharmacologic and non-pharmacologic treatment strategies to optimize patient care. This narrative review provides a critical evaluation of current literature describing management practices for ARDS. A review of treatment modalities and supportive care strategies will be presented.

Critical Care Pharmacist Attitudes and Perceptions of Neuromuscular Blocker Infusions in ARDS

BACKGROUND

Current critical care pharmacist (CCP) practices and perceptions related to neuromuscular infusion (NMBI) use for acute respiratory distress syndrome (ARDS) maybe different with the COVID-19 pandemic and the publication of 2020 NMBI practice guidelines.

OBJECTIVE

To evaluate CCP practices and perceptions regarding NMBI use for patients with moderate-severe ARDS.

METHODS

We developed, tested, and electronically administered a questionnaire (7 parent-, 42 sub-questions) to 409 American College of Clinical Pharmacy (ACCP) Critical Care Practice and Research Network members in 12 geographically diverse states. The questionnaire focused on adults with moderate-severe ARDS (PaO2:FiO2<150) whose causes of dyssynchrony were addressed. Two reminders were sent at 10-day intervals.

RESULTS

Respondents [131/409 (32%)] primarily worked in a medical intensive care unit (ICU) 102 (78%). Compared to COVID-negative(-) ARDS patients, COVID positive(+) ARDS patients were twice as likely to receive a NMBI (34 ± 18 vs.16 ± 17%; P < 0.01). Respondents somewhat/strongly agreed a NMBI should be reserved until after trials of deep sedation (112, 86%) or proning (92, 81%) and that NMBI reduced barotrauma (88, 67%), dyssynchrony (87, 66%), and plateau pressure (79, 60%). Few respondents somewhat/strongly agreed that a NMBI should be initiated at ARDS onset (23, 18%) or that NMBI reduced 90-day mortality (12, 10%). Only 2/14 potential NMBI risks [paralysis awareness (101, 82%) and prolonged muscle weakness (84, 68%)] were frequently reported to be of high/very high concern. Multiple NMBI titration targets were assessed as very/extremely important including arterial pH (109, 88%), dyssynchrony (107, 86%), and PaO2: FiO2 ratio (82, 66%). Train-of-four (55, 44%) and BIS monitoring (36, 29%) were deemed less important. Preferred NMBI discontinuation criteria included absence of dysschrony (84, 69%) and use ≥48 hour (72, 59%).

CONCLUSIONS AND RELEVANCE

Current critical care pharmacists believe NMBI for ARDS patients are best reserved until after trials of deep sedation or proning; unique considerations exist in COVID+ patients. Our results should be considered when ICU NMBI protocols are being developed and bedside decisions regarding NMBI use in ARDS are being formulated.

Association between Substance Misuse and Outcomes in Critically III Patients with Pneumonia

Rationale: In patients with pneumonia requiring intensive care unit (ICU) admission, alcohol misuse is associated with increased mortality, but the relationship between other commonly misused substances and mortality is unknown. Objectives: We sought to establish whether alcohol misuse, cannabis misuse, opioid misuse, stimulant misuse, or misuse of more than one of these substances was associated with differences in mortality among ICU patients with pneumonia. Methods: This was a retrospective cohort study of hospitals participating in the Premier Healthcare Database between 2010 and 2017. Patients were included if they had a primary or secondary diagnosis of pneumonia and received antibiotics or antivirals within 1 day of admission. Substance misuse related to alcohol, cannabis, stimulants, and opioids, or more than one substance, were identified from the International Classification of Diseases (Ninth and Tenth Editions). The associations between substance misuse and in-hospital mortality were the primary outcomes of interest. Secondary outcomes included the measured associations between substance misuse disorders and mechanical ventilation, as well as vasopressor and continuous paralytic administration. Analyses were conducted with multivariable mixed-effects logistic regression modeling adjusting for age, comorbidities, and hospital characteristics. Results: A total of 167,095 ICU patients met inclusion criteria for pneumonia. Misuse of alcohol was present in 5.0%, cannabis misuse in 0.6%, opioid misuse in 1.5%, stimulant misuse in 0.6%, and misuse of more than one substance in 1.2%. No evidence of substance misuse was found in 91.1% of patients. In unadjusted analyses, alcohol misuse was associated with increased in-hospital mortality (odds ratio [OR], 1.12; 95% confidence interval [CI], 1.06-1.19), whereas opioid misuse was associated with decreased in-hospital mortality (OR, 0.46; 95% CI, 0.39-0.53) compared with no substance misuse. These findings persisted in adjusted analyses. Although cannabis, stimulant, and more than one substance misuse (a majority of which were alcohol in combination with another substance) were associated with lower odds for in-hospital mortality in unadjusted analyses, these relationships were not consistently present after adjustment. Conclusions: In this study of ICU patients hospitalized with severe pneumonia, substance misuse subtypes were associated with different effects on mortality. Although administrative data can provide epidemiologic insight regarding substance misuse and pneumonia outcomes, biases inherent to these data should be considered when interpreting results.

Sedation for adult ICU patients: A narrative review including a retrospective study of our own data

The optimization of patients' treatment in the intensive care unit (ICU) needs a lot of information and literature analysis. Many changes have been made in the last years to help evaluate sedated patients by scores to help take care of them. Patients were completely sedated and had continuous intravenous analgesia and neuromuscular blockades. These three drug classes were the main drugs used for intubated patients in the ICU. During these last 20 years, ICU management went from fully sedated to awake, calm, and nonagitated patients, using less sedatives and choosing other drugs to decrease the risks of delirium during or after the ICU stay. Thus, the usefulness of these three drug classes has been challenged. The analgesic drugs used were primarily opioids but the use of other drugs instead is increasing to lessen or wean the use of opioids. In severe acute respiratory distress syndrome patients, neuromuscular blocking agents have been used frequently to block spontaneous respiration for 48 hours or more; however, this has recently been abolished. Optimizing a patient's comfort during hemodynamic or respiratory extracorporeal support is essential to reduce toxicity and secondary complications.

Physiological and clinical variables identify ARDS classes and therapeutic heterogeneity to glucocorticoids: a retrospective study

OBJECTIVE

We aimed to identify new classes in acute respiratory distress syndrome (ARDS) using physiological and clinical variables and to explore heterogeneity in the effects of glucocorticoid therapy between classes.

METHODS

Using the Medical Information Mart for Intensive Care-IV database, we identified patients with ARDS. Potential profile analysis was used to identify classes with physiological and clinical data as delineating variables. Baseline characteristics and clinical outcomes were compared between classes. The effect of glucocorticoid treatment was explored by stratifying by class and glucocorticoid treatment.

RESULTS

From 2008 to 2019, 1104 patients with ARDS were enrolled in the study. The 2-class potential analysis model had the best fit (P < 0.0001), with 78% of patients falling into class 1 and 22% into class 2. Additional classes did not improve the model fit. Patients in class 2 had higher anion gap, lactate, creatinine, and glucose levels and lower residual base, blood pressure, and bicarbonate compared with class 1. In-hospital mortality and 28-day mortality were significantly higher among patients in class 2 than those in class 1 (P < 0.001). Heterogeneity of glucocorticoid treatment was observed, stratified by class and treatment, with no significant effect in class 1 (P = 0.496), increased mortality in class 2 (P = 0.001), and a significant interaction (P = 0.0381). In class 2, 28-day survival was significantly lower with glucocorticoid treatment compared with no hormone treatment (P = 0.001).

CONCLUSION

We used clinical and physiological variables to identify two classes of non-COVID-19-associated ARDS with different baseline characteristics and clinical outcomes. The response to glucocorticoid therapy varied among different classes of patients.

Efficacy and Safety of Cisatracurium Compared to Vecuronium for Neuromuscular Blockade in Acute Respiratory Distress Syndrome

PURPOSE

Previous studies analyzing neuromuscular blocking agents (NMBAs) in acute respiratory distress syndrome (ARDS) have evaluated the benefit of cisatracurium with conflicting results, and data evaluating other NMBAs remains limited. The objective of this study was to compare the efficacy and safety of cisatracurium to vecuronium in ARDS.

MATERIALS AND METHODS

A single-center, retrospective, propensity matched review of patients who received cisatracurium or vecuronium continuous infusions between October 1, 2017 and June 30, 2020 for ARDS was conducted. The primary endpoint was duration of mechanical ventilation. Secondary endpoints included change in PaO₂/FiO₂ ratio at 48 h, intensive care unit (ICU) and hospital mortality, and ICU and hospital length of stay (LOS). Safety endpoints included newly developed myopathy, presence of bradycardia or hypotension, and newly developed barotrauma or volutrauma.

RESULTS

Twenty-nine patients were included in each group. There was no statistically significant difference in the primary endpoint of ventilator days between cisatracurium and vecuronium groups (mean 15.9 vs. 20.5 days respectively; p = .2). No statistically significant differences were found in secondary endpoints of ICU mortality (51.7% vs. 51.7%) or length of stay (18.7 vs. 23.9 days, p = .19), hospital mortality (51.7% vs. 55.2%, p = .79) or length of stay (22 vs. 30.6 days, p = .08), or mean change in PaO₂/FiO₂ (29.8 vs. 36.6; p = .74). Statistically significant differences were not observed in safety endpoints of myopathy (37.9% vs. 37.9%), barotrauma or volutrauma (13.8% vs. 3.5%; p = .16), bradycardia (31% vs. 13.8%; p = .12), or hypotension (96.6% vs. 82.8%; p = .08).

CONCLUSIONS

No significant differences were seen in efficacy or safety endpoints between cisatracurium or vecuronium groups, suggesting that vecuronium may be a safe alternative agent for neuromuscular blockade in ARDS. Results of this analysis warrant confirmation in a larger, randomized study.

Extracorporeal Membrane Oxygenation for Refractory Asthma Exacerbations With Respiratory Failure

BACKGROUND

Asthma exacerbations with respiratory failure (AERF) are associated with hospital mortality of 7% to 15%. Extracorporeal membrane oxygenation (ECMO) has been used as a salvage therapy for refractory AERF, but controlled studies showing its association with mortality have not been performed.

RESEARCH QUESTION

Is treatment with ECMO associated with lower mortality in refractory AERF compared with standard care?

STUDY DESIGN AND METHODS

This is a retrospective, epidemiologic, observational cohort study using a national, administrative data set from 2010 to 2020 that includes 25% of US hospitalizations. People were included if they were admitted to an ECMO-capable hospital with an asthma exacerbation, and were treated with short-acting bronchodilators, systemic corticosteroids, and invasive ventilation. People were excluded for age < 18 years, no ICU stay, nonasthma chronic lung disease, COVID-19, or multiple admissions. The main exposure was ECMO vs No ECMO. The primary outcome was hospital mortality. Key secondary outcomes were ICU length of stay (LOS), hospital LOS, time receiving invasive ventilation, and total hospital costs.

RESULTS

The study analyzed 13,714 patients with AERF, including 127 with ECMO and 13,587 with No ECMO. ECMO was associated with reduced mortality in the covariate-adjusted (OR, 0.33; 95% CI, 0.17-0.64; P = .001), propensity score-adjusted (OR, 0.36; 95% CI, 0.16-0.81; P = .01), and propensity score-matched models (OR, 0.48; 95% CI, 0.24-0.98; P = .04) vs No ECMO. Sensitivity analyses showed that mortality reduction related to ECMO ranged from OR 0.34 to 0.61. ECMO was also associated with increased hospital costs in all three models (P < .0001 for all) vs No ECMO, but not with decreased ICU LOS, hospital LOS, or time receiving invasive ventilation.

INTERPRETATION

ECMO was associated with lower mortality and higher hospital costs, suggesting that it may be an important salvage therapy for refractory AERF following confirmatory clinical trials.

Highly Water-Soluble Cucurbit[8]uril Derivative as a Broad-Spectrum Neuromuscular Block Reversal Agent

Broad-spectrum agents for the reversal of residual curarization induced by neuromuscular blocking agents are of great significance. Here, we report a highly water-soluble cucurbit[8]uril (CB[8]) derivative as a broad-spectrum neuromuscular block reversal agent induced by both benzylisquinolinium and aminosteroid neuromuscular block agents by the supramolecular sequestration strategy. The UV/Vis competition titration assays suggest the high binding affinity of the CB[8] derivative toward both benzylisquinolinium-type cisatracurium besylate and aminosteroid-type rocuronium, vecuronium, and pancuronium, at the level of 10⁷ M^-1. In vivo studies demonstrate that the administration of the CB[8] derivative could significantly accelerate the recovery time compared to the placebo or neostigmine groups. The reversal activity of the CB[8] derivative is comparable to or higher than that of clinically approved sugammadex. Acute toxicity evaluations reveal that the CB[8]-derivative displays outstanding biocompatibility, with the maximum tolerance dose as high as 960 mg kg^-1.

Neuromuscular Blockade in the Pre- and COVID-19 ARDS Patients

Acute respiratory distress syndrome (ARDS) accounts for a quarter of mechanically ventilated patients, while during the pandemic, it overwhelmed the capacity of intensive care units (ICUs). Lung protective ventilation (low tidal volume, positive-end expiratory pressure titrated to lung mechanics and oxygenation, permissive hypercapnia) is a non-pharmacological approach that is the gold standard of management. Among the pharmacological treatments, the use of neuromuscular blocking agents (NMBAs), although extensively studied, has not yet been well clarified. The rationale is to minimize the risk for lung damage progression, in the already-injured pulmonary parenchyma. By abolishing rigorous spontaneous efforts, NMBAs may decrease the generation of high transpulmonary pressures that could aggravate patients’ self-inflicted lung injury. Moreover, NMBAs can harmonize the patient–ventilator interaction. Recent randomized controlled trials reported contradictory results and changed the clinical practice in a bidirectional way. NMBAs have not been documented to improve long-term survival; thus, the current guidance suggests their use only in patients in whom a lung protective ventilation protocol cannot be applied, due to asynchrony or increased respiratory efforts. In the present review, we discuss the published data and additionally the clinical practice in the “war” conditions of the COVID-19 pandemic, concerning NMBA use in the management of patients with ARDS.

Early short course of neuromuscular blocking agents in patients with COVID-19 ARDS: a propensity score analysis

BACKGROUND

The role of neuromuscular blocking agents (NMBAs) in coronavirus disease 2019 (COVID-19) acute respiratory distress syndrome (ARDS) is not fully elucidated. Therefore, we aimed to investigate in COVID-19 patients with moderate-to-severe ARDS the impact of early use of NMBAs on 90-day mortality, through propensity score (PS) matching analysis.

METHODS

We analyzed a convenience sample of patients with COVID-19 and moderate-to-severe ARDS, admitted to 244 intensive care units within the COVID-19 Critical Care Consortium, from February 1, 2020, through October 31, 2021. Patients undergoing at least 2 days and up to 3 consecutive days of NMBAs (NMBA treatment), within 48 h from commencement of IMV were compared with subjects who did not receive NMBAs or only upon commencement of IMV (control). The primary objective in the PS-matched cohort was comparison between groups in 90-day in-hospital mortality, assessed through Cox proportional hazard modeling. Secondary objectives were comparisons in the numbers of ventilator-free days (VFD) between day 1 and day 28 and between day 1 and 90 through competing risk regression.

RESULTS

Data from 1953 patients were included. After propensity score matching, 210 cases from each group were well matched. In the PS-matched cohort, mean (± SD) age was 60.3 ± 13.2 years and 296 (70.5%) were male and the most common comorbidities were hypertension (56.9%), obesity (41.1%), and diabetes (30.0%). The unadjusted hazard ratio (HR) for death at 90 days in the NMBA treatment vs control group was 1.12 (95% CI 0.79, 1.59, p = 0.534). After adjustment for smoking habit and critical therapeutic covariates, the HR was 1.07 (95% CI 0.72, 1.61, p = 0.729). At 28 days, VFD were 16 (IQR 0-25) and 25 (IQR 7-26) in the NMBA treatment and control groups, respectively (sub-hazard ratio 0.82, 95% CI 0.67, 1.00, p = 0.055). At 90 days, VFD were 77 (IQR 0-87) and 87 (IQR 0-88) (sub-hazard ratio 0.86 (95% CI 0.69, 1.07; p = 0.177).

CONCLUSIONS

In patients with COVID-19 and moderate-to-severe ARDS, short course of NMBA treatment, applied early, did not significantly improve 90-day mortality and VFD. In the absence of definitive data from clinical trials, NMBAs should be indicated cautiously in this setting.

Continuously protracted infusion of cisatracurium besilate in patients with ARDS

Background

Acute respiratory distress syndrome (ARDS) is still associated with significant mortality, especially the elderly and those with comorbidities are at highest risk of death. Neuromuscular blocking agents (NMBAs) are used in a large but highly variable proportion of patients with ARDS.

Case presentation

We describe the case of one critically ill patient with serious ARDS, because of virus pneumonia. In spite of the reduced tidal volume to 4–6 mL/kg of predicted body weight (PBW) and prone position were applied timely, the irresistible progress of disease leaded to an amazing prolonged application of deep sedation and analgesia, as well as NMBA, for the purpose of lung-protective mechanical ventilation.

Result

The clinical and biochemical parameters guided us toward the recognition that cisatracurium, bolus of 0.1 mg/kg followed by a median infusion rate of 1.91 (1.43–9.52) μg/kg.min, combined with continuous infusion of midazolam 3.43 (2.06–6.17) mg/kg.d and remifentanil 3.79 (3.43–8.57) μg/kg.h is efficacious and suitable for continuous muscle paralysis.

Conclusion

The intensive care unit (ICU)-acquired weakness (ICU-AW) was inevitable. Besides, an increased demand on drug concentration with the extension of medication time was observed as well.

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The continuous infusion of cisatracurium is safety and efficacy.

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The drug concentration of cisatracurium is time-dependent.

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ICU-acquired weakness (ICU-AW) is inevitable for the critical illness.

Pharmacologic Treatments for Acute Respiratory Distress Syndrome

Acute respiratory distress syndrome is a heterogenous syndrome with many etiologies for which there are no definitive pharmacologic treatments, despite decades of research. We explore some adjunctive pharmacologic therapies, including neuromuscular blockade, corticosteroids, and inhaled pulmonary vasodilators. Additionally, we explore some investigative therapies, including Vitamin C, beta-agonists, statins, mesenchymal stromal cells, and granulocyte-macrophage colony stimulating factor. We do discuss the potential role of steroids in acute respiratory distress syndrome with severe acute respiratory syndrome coronavirus 2 as a trigger. The standard of care, however, remains supportive care.

[Simultaneous determination of three quaternary ammonium muscle relaxants in blood by high performance liquid chromatography-tandem mass spectrometry]

Vecuronium, rocuronium, and pancuronium are widely used as non-depolarizing muscle relaxants. There have been occasional cases of allergic reactions and even death when using such muscle relaxants. Rapid determination of the concentration of these muscle relaxants in blood can provide valuable information for early clinical diagnosis. As quaternary ammonium compounds, these muscle relaxants are highly polar. Hence, they cannot be retained effectively on reversed-phase chromatographic columns with conventional mobile phases. These quaternary ammonium muscle relaxants are mainly separated by ion-pair chromatography. Using an ion-pairing reagent can help improve the retention capabilities of quaternary ammonium muscle relaxants. Nevertheless, the sensitivity of MS detection is significantly decreased because of ionic inhibition caused by the ion-pairing reagent in the mobile phase. Furthermore, ion-pairing reagents can pollute the MS system. A method based on high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) was established for the simultaneous determination of the three quaternary ammonium muscle relaxants in blood. The blood samples were diluted and subjected to high-speed centrifugation. The supernatant was purified on a Bond Elut AL-N solid phase extraction column and then filtered through a 0.45 μm microporous membrane. The quaternary ammonium muscle relaxants were separated on a ZIC-cHILIC analytical column (50 mm×2.1 mm, 3.0 μm) with gradient elution. Acetonitrile and 0.1% formic acid aqueous solution were used as mobile phases. The separated compounds were analyzed by tandem MS with an electrospray ionization (ESI) source in positive and multiple reaction monitoring (MRM) modes. The matrix effects of vecuronium, rocuronium, and pancuronium in blood were 88.1% to 95.4%. The calibration curves for vecuronium, rocuronium, and pancuronium showed good linear relationships in each range, and all correlation coefficients (R2) were > 0.996. The limits of detection of vecuronium, rocuronium, and pancuronium were 0.2-0.8 ng/mL, with the corresponding limits of quantification being 0.5-2.0 ng/mL. The recoveries of vecuronium, rocuronium, and pancuronium were 92.8% to 110.6%, with relative standard deviations (RSDs) of 3.2%-9.4%. This method is sensitive, accurate, and easy to operate, and it can be used to rapidly determine vecuronium, rocuronium, and pancuronium in blood.

Comparative Efficacy of Fentanyl and Morphine in Patients with or At Risk for Acute Respiratory Distress Syndrome: A Propensity Score-Matched Cohort Study

Introduction

Opioids are potent painkillers but can have severe adverse effects in the intensive care unit (ICU). The aim of this study was to compare the outcomes of fentanyl and morphine use among patients at risk for and with acute respiratory distress syndrome (ARDS).

Methods

We developed a dataset of real-world data to enable the comparison of the effectiveness and safety of opioids and the associated outcomes from the Multiparameter Intelligent Monitoring in Intensive Care (MIMIC)-III database and the eICU Collaborative Research Database. Patients who were admitted to the ICU with a diagnosis of or at risk for ARDS and received mechanical ventilation for at least 12 h were included. Patients were enrolled sequentially into one of six groups in three cohorts: treated with fentanyl or not; treated with morphine or not; and treated with fentanyl or morphine. Propensity score matching and multivariable analyses were performed.

Results

Fentanyl was associated with higher in-hospital mortality in the propensity score-matched model but not in the linear regression model. The use of morphine was associated with a higher in-hospital mortality in both models. Both fentanyl and morphine were associated with longer duration of mechanical ventilation, ICU stay, and hospitalization and a decreased likelihood of being discharged home in both models. Notably, compared with morphine, fentanyl was associated with a lower mortality and an increased likelihood of being discharged home.

Conclusions

Both fentanyl and morphine were independent risk factors for worse outcomes in patients with or at risk for ARDS. Compared with morphine, fentanyl may be preferred in these patients.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40268-021-00338-3.

Comparative Effectiveness of Midazolam, Propofol, and Dexmedetomidine in Patients With or at Risk for Acute Respiratory Distress Syndrome: A Propensity Score-Matched Cohort Study

Background: Sedatives are commonly used in patients with or at risk for acute respiratory distress syndrome (ARDS) during mechanical ventilation. To systematically compare the outcomes of sedation with midazolam, propofol, and dexmedetomidine in patients with or at risk for ARDS.

Methods: We developed a dataset of real-world data to enable the comparison of the effectiveness and safety of sedatives and the associated outcomes from the MIMIC-III database and the eICU Collaborative Research database. We performed a systematic study with six cohorts to estimate the relative risks of outcomes among patients administered different sedatives. Propensity score matching was performed to generate a balanced 1:1 matched cohort and to identify potential prognostic factors. The outcomes included hospital mortality, duration of mechanical ventilation, length of intensive care unit stay, length of hospitalization, and likelihood of being discharged home.

Results: We performed 60 calibrated analyses among all groups and outcomes with 17,410 eligible patients. Sedation with dexmedetomidine was associated with a lower in-hospital mortality rate than sedation with midazolam and propofol or sedation without dexmedetomidine (p < 0.001). When compared with no sedation, the use of midazolam, propofol or dexmedetomidine was associated with a longer ICU stay and longer hospitalization duration (p < 0.01). Patients treated with midazolam were relatively less likely to be discharged home (p < 0.05).

Conclusion: Patients treated with dexmedetomidine had a reduced risk of mortality. These data suggest that dexmedetomidine may be the preferred sedative in patients with or at risk for ARDS.

Noninvasive Ventilation Use in Critically Ill Patients with Acute Asthma Exacerbations

Rationale: Noninvasive ventilation decreases the need for invasive mechanical ventilation and mortality among patients with chronic obstructive pulmonary disease but has not been well studied in asthma.Objectives: To assess the association between noninvasive ventilation and subsequent need for invasive mechanical ventilation and in-hospital mortality among patients admitted with asthma exacerbation to the ICU.Methods: We performed a retrospective cohort study using administrative data collected during 2010-2017 from 682 hospitals in the United States. Outcomes included receipt of invasive mechanical ventilation and in-hospital mortality. Generalized estimating equations, propensity-matched models, and marginal structural models were used to assess the association between noninvasive ventilation and outcomes.Measurements and Main Results: The study population included 53,654 participants with asthma exacerbation. During the study period, 13,540 patients received noninvasive ventilation (25.2%; 95% confidence interval [CI], 24.9-25.6%), 14,498 underwent invasive mechanical ventilation (27.0%; 95% CI, 26.7-27.4%), and 1,291 died (2.4%; 95% CI, 2.3-2.5%). Among those receiving noninvasive ventilation, 3,013 patients (22.3%; 95% CI, 21.6-23.0%) required invasive mechanical ventilation after first receiving noninvasive ventilation, 136 of whom died (4.5%; 95% CI, 3.8-5.3%). Across all models, the use of noninvasive ventilation was associated with a lower odds of receiving invasive mechanical ventilation (adjusted generalized estimating equation odds ratio, 0.36; 95% CI, 0.32-0.40) and in-hospital mortality (odds ratio, 0.48; 95% CI 0.40-0.58). Those who received noninvasive ventilation before invasive mechanical ventilation were more likely to have comorbid pneumonia and severe sepsis.Conclusions: Noninvasive ventilation use during asthma exacerbation was associated with improved outcomes but should be used cautiously with acute comorbid conditions.

Reducing the dose of neuromuscular blocking agents with adjuncts: a systematic review and meta-analysis

BACKGROUND

Acute global shortages of neuromuscular blocking agents (NMBA) threaten to impact adversely on perioperative and critical care. The use of pharmacological adjuncts may reduce NMBA dose. However, the magnitude of any putative effects remains unclear.

METHODS

We conducted a systematic review and meta-analysis of RCTs. We searched Medline, Embase, Web of Science, and Cochrane Database (1970-2020) for RCTs comparing use of pharmacological adjuncts for NMBAs. We excluded RCTs not reporting perioperative NMBA dose. The primary outcome was total NMBA dose used to achieve a clinically acceptable depth of neuromuscular block. We assessed the quality of evidence using the GRADE (Grades of Recommendation, Assessment, Development, and Evaluation) criteria. Data are presented as the standardised mean difference (SMD); I² indicates percentage of variance attributable to heterogeneity.

RESULTS

From 3082 records, the full texts of 159 trials were retrieved. Thirty-one perioperative RCTs met the inclusion criteria for meta-analysis (n=1962). No studies were conducted in critically ill patients. Reduction in NMBA dose was associated with use of magnesium (SMD: -1.10 [-1.44 to -0.76], P<0.001; I²=85%; GRADE=moderate), dexmedetomidine (SMD: -0.89 [-1.55 to -0.22]; P=0.009; I²=87%; GRADE=low), and clonidine (SMD: -0.67 [-1.13 to -0.22]; P=0.004; I²=0%; GRADE=low) but not lidocaine (SMD: -0.46 [-1.01 to -0.09]; P=0.10; I²=68%; GRADE=moderate). Meta-analyses for nicardipine, diltiazem, and dexamethasone were not possible owing to the low numbers of studies. We estimated that 30-50 mg kg^-1 magnesium preoperatively (8-15 mg kg h^-1 intraoperatively) reduces rocuronium dose by 25.5% (inter-quartile range, 14.7-31).

CONCLUSIONS

Magnesium, dexmedetomidine, and clonidine may confer a clinically relevant sparing effect on the required dose of neuromuscular block ing drugs in the perioperative setting.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO: CRD42020183969.

Myorelaxants in ARDS patients

Neuromuscular blocking agents (NMBAs) inhibit patient-initiated active breath and the risk of high tidal volumes and consequent high transpulmonary pressure swings, and minimize patient/ ventilator asynchrony in acute respiratory distress syndrome (ARDS). Minimization of volutrauma and ventilator-induced lung injury (VILI) results in a lower incidence of barotrauma, improved oxygenation and a decrease in circulating proinflammatory markers. Recent randomized clinical trials did not reveal harmful muscular effects during a short course of NMBAs. The use of NMBAs should be considered during the early phase of severe ARDS for patients to facilitate lung protective ventilation or prone positioning only after optimising mechanical ventilation and sedation. The use of NMBAs should be integrated in a global strategy including the reduction of tidal volume, the rational use of PEEP, prone positioning and the use of a ventilatory mode allowing spontaneous ventilation as soon as possible. Partial neuromuscular blockade should be evaluated in future trials.

Neuromuscular blocking agents in acute respiratory distress syndrome: updated systematic review and meta-analysis of randomized trials

Purpose

Existing clinical practice guidelines support the use of neuromuscular blocking agents (NMBA) in acute respiratory distress syndrome (ARDS); however, a recent large randomized clinical trial (RCT) has questioned this practice. Therefore, we updated a previous systematic review to determine the efficacy and safety of NMBAs in ARDS.

Methods

We searched MEDLINE, EMBASE (October 2012 to July 2019), the Cochrane (Central) database, and clinical trial registries (ClinicalTrials.gov, ISRCTN Register, and WHO ICTRP) for RCTs comparing the effects of NMBA as a continuous infusion versus placebo or no NMBA infusion (but allowing intermittent NMBA boluses) on patient-important outcomes for adults with ARDS. Two independent reviewers assessed the methodologic quality of the primary studies and abstracted data.

Results

Seven RCTs, including four new RCTs, met eligibility criteria for this review. These trials enrolled 1598 patients with moderate to severe ARDS at centers in the USA, France, and China. All trials assessed short-term continuous infusions of cisatracurium or vecuronium. The pooled estimate for mortality outcomes showed significant statistical heterogeneity, which was only explained by a subgroup analysis by depth of sedation in the control arm. A continuous NMBA infusion did not improve mortality when compared to a light sedation strategy with no NMBA infusion (relative risk [RR] 0.99; 95% CI 0.86–1.15; moderate certainty; P = 0.93). On the other hand, continuous NMBA infusion reduced mortality when compared to deep sedation with as needed NMBA boluses (RR 0.71; 95% CI 0.57–0.89; low certainty; P = 0.003). Continuous NMBA infusion reduced the rate of barotrauma (RR 0.55; 95% CI 0.35–0.85, moderate certainty; P = 0.008) across eligible trials, but the effect on ventilator-free days, duration of mechanical ventilation, and ICU-acquired weakness was uncertain.

Conclusions

Inconsistency in study methods and findings precluded the pooling of all trials for mortality. In a pre-planned sensitivity analysis, the impact of NMBA infusion on mortality depends on the strategy used in the control arm, showing reduced mortality when compared to deep sedation, but no effect on mortality when compared to lighter sedation. In both situations, a continuous NMBA infusion may reduce the risk of barotrauma, but the effects on other patient-important outcomes remain unclear. Future research, including an individual patient data meta-analysis, could help clarify some of the observed findings in this updated systematic review.

Ventilator dyssynchrony - Detection, pathophysiology, and clinical relevance: A Narrative review

Mortality associated with the acute respiratory distress syndrome remains unacceptably high due in part to ventilator-induced lung injury (VILI). Ventilator dyssynchrony is defined as the inappropriate timing and delivery of a mechanical breath in response to patient effort and may cause VILI. Such deleterious patient–ventilator interactions have recently been termed patient self-inflicted lung injury. This narrative review outlines the detection and frequency of several different types of ventilator dyssynchrony, delineates the different mechanisms by which ventilator dyssynchrony may propagate VILI, and reviews the potential clinical impact of ventilator dyssynchrony. Until recently, identifying ventilator dyssynchrony required the manual interpretation of ventilator pressure and flow waveforms. However, computerized interpretation of ventilator waive forms can detect ventilator dyssynchrony with an area under the receiver operating curve of >0.80. Using such algorithms, ventilator dyssynchrony occurs in 3%–34% of all breaths, depending on the patient population. Moreover, two types of ventilator dyssynchrony, double-triggered and flow-limited breaths, are associated with the more frequent delivery of large tidal volumes >10 mL/kg when compared with synchronous breaths (54% [95% confidence interval (CI), 47%–61%] and 11% [95% CI, 7%–15%]) compared with 0.9% (95% CI, 0.0%–1.9%), suggesting a role in propagating VILI. Finally, a recent study associated frequent dyssynchrony-defined as >10% of all breaths-with an increase in hospital mortality (67 vs. 23%, P = 0.04). However, the clinical significance of ventilator dyssynchrony remains an area of active investigation and more research is needed to guide optimal ventilator dyssynchrony management.

Early Neuromuscular Blockade in Children with Pediatric Acute Respiratory Distress Syndrome

Pediatric acute respiratory distress syndrome (PARDS) is a challenging problem with high mortality. Role of neuromuscular blockade in the management of ARDS to date has been controversial, and this study was done to study the role of neuromuscular blockade in children having PARDS and development of associated complications, if any. This was a prospective, case-control study conducted in the pediatric intensive care unit (PICU) of a tertiary care teaching hospital, over a period of 24 months. Patients of age 1 to 18 years who presented with or developed PARDS during their course of hospitalization were included after written informed consent was obtained from their parents and/or guardians. Patients with PARDS requiring invasive mechanical ventilation were partitioned into a case group and a control group. Case group patients were sedated and paralyzed using midazolam (1 µg/kg/min) and vecuronium (1 µg/kg/min), respectively, along with institution of definitive management. Control group patients were given definitive and supportive therapy, but no neuromuscular blocking agents (NMBAs). All patients were followed up for signs and symptoms of myopathy or neuropathy during the entire duration of hospital stay and up to 3 months after discharge. During the study period, 613 patients were admitted to the PICU of which 91 patients qualified as having PARDS. Sepsis was the main etiology in 67 of the 91 patients (73.6%) with PARDS. Fifty-nine patients were included in the study, of which 29 patients were included in the case group and 30 patients were included in the control group. Among the 29 case group patients, 25 patients (86.2%) were successfully extubated. Four patients from the case group expired, while 14 out of 30 control group patients (46.7%) expired. Hypotension was present in 26 case group patients (89.6%), of which all showed resolution within 48 hours of definitive treatment. The mean time to resolution of hypotension was 41.6 hours (standard deviation [SD]: 5.759; range: 24-48) for case group patients, significantly lower ( p  < 0.0001) than the mean time to resolution of 103 hours (SD: 18.995; range: 90-126) for the 10 control group patients with hypotension that survived. Mean oxygenation index (OI) following 48 hours of vecuronium therapy was significantly lower ( p  < 0.0001; 95% confidence interval: 5.9129-9.9671) than mean OI at admission for case group patients. None of the patients receiving vecuronium exhibited neuromuscular deficit during their hospital stay, at time of discharge, or at follow-up evaluation up to 3 months after discharge. In this study, pediatric cases diagnosed with PARDS and managed with mechanical ventilation and vecuronium therapy had improved mean OI following 48 hours of NMBA therapy and a lower mortality when compared with matched control group patients. Incidence of NMBA-related weakness was not commonly observed in these patients.

Supportive Management and Interventions for Respiratory Failure Due to SARS-CoV-2

Severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) infection can vary from asymptomatic to severe symptoms. It can lead to respiratory failure and acute respiratory distress syndrome requiring intubation and mechanical ventilation. Triaging patients is key to prevent spread, conserving medical resources, and providing appropriate care. The treatment of these patients remains supportive. Respiratory failure due to the virus should be managed by providing supplemental oxygen and early intubation. Some patients develop acute respiratory distress syndrome and refractory hypoxemia. In this article, we review the 2 phenotypes of respiratory failure, mechanical ventilation and the management of refractory hypoxemia.

Neuromuscular blockade management in the critically Ill patient

Neuromuscular blocking agents (NMBAs) can be an effective modality to address challenges that arise daily in the intensive care unit (ICU). These medications are often used to optimize mechanical ventilation, facilitate endotracheal intubation, stop overt shivering during therapeutic hypothermia following cardiac arrest, and may have a role in the management of life-threatening conditions such as elevated intracranial pressure and status asthmaticus (when deep sedation fails or is not tolerated). However, current NMBA use has decreased during the last decade due to concerns of potential adverse effects such as venous thrombosis, patient awareness during paralysis, development of critical illness myopathy, autonomic interactions, and even residual paralysis following cessation of NMBA use.

It is therefore essential for clinicians to be familiar with evidence-based practices regarding appropriate NMBA use in order to select appropriate indications for their use and avoid complications. We believe that selecting the right NMBA, administering concomitant sedation and analgesic therapy, and using appropriate monitoring techniques mitigate these risks for critically ill patients. Therefore, we review the indications of NMBA use in the critical care setting and discuss the most appropriate use of NMBAs in the intensive care setting based on their structure, mechanism of action, side effects, and recognized clinical indications. Lastly, we highlight the available pharmacologic antagonists, strategies for sedation, newer neuromuscular monitoring techniques, and potential complications related to the use of NMBAs in the ICU setting.

To Block or Not: Updates in Neuromuscular Blockade in Acute Respiratory Distress Syndrome

Objective: To review and evaluate neuromuscular blocking agents (NMBAs) in critically ill patients with acute respiratory distress syndrome (ARDS). Data Sources: A literature search utilizing PubMed was performed (January 1991 to January 2020) using the following search terms: ( neuromuscular blocking agents OR neuromuscular blockade OR cisatracurium OR rocuronium OR vecuronium OR pancuronium OR atracurium) AND * acute respiratory distress syndrome OR acute lung injury). Publications in English were evaluated. Study Selection and Data Extraction: Relevant clinical studies in humans were considered. Data Synthesis: Although NMBAs have been used for decades in the setting of ARDS, questions regarding mortality benefit remain. Early NMBA, within 48 hours of lung injury, have been historically used in critically ill patients with ARDS to aid in increasing alveolar recruitment, improving patient-ventilator synchrony, and promoting oxygenation by the prevention of contraction of respiratory muscles. Until recently, the literature showed an improvement in 90-day adjusted mortality. However, recent literature has demonstrated the lack of a mortality benefit. The continued receipt of NMBAs, with no clear benefit, could potentially lead to increased costs, skin breakdown, corneal abrasions, venous thromboembolisms, intensive care unit acquired weakness, and awareness with inappropriate sedation. Relevance to Patient Care and Clinical Practice: This review aims at discussing the preferred NMBA based on mechanism of action and reviews specific clinical trial data for the use of NMBAs in ARDS, clinical implications of these trial data, complications for the use of NMBAs, and needed future directions. Conclusions: The mortality benefit of NMBAs in ARDS has contradicting evidence with potentially serious adverse effects and notable controversies.

Neuromuscular blockers in the acute respiratory distress syndrome: A meta-analysis

Background

The effects of neuromuscular blocking agents (NMBAs) on adult patients with acute respiratory distress syndrome (ARDS) remain unclear. We performed a meta-analysis of randomized controlled trials (RCTs) to evaluate its effect on mortality.

Methods

We searched the Cochrane (Central) database, Medline, Embase, the Chinese Biomedical Literature Database (SinoMed), WanFang data and ClinicalTrials from inception to June 2019, with language restriction to English and Chinese. We included published RCTs and eligible clinical trials from ClinicalTrials.gov that compared NMBAs with placebo or usual treatment in adults with ARDS. We pooled data using random-effects models. The primary outcome was mortality. The secondary outcomes were the ratio of the partial pressure of arterial oxygen to the fraction of inspired oxygen (PaO₂/FIO₂), total positive end expiratory pressure (PEEP), plateau pressure (Pplat), days free of ventilator at day 28, barotrauma and ICU-acquired weakness.

Results

We included 6 RCTs (n = 1557). Compared with placebo or usual treatment, NMBAs were associated with lower 21 to 28-day mortality (RR 0.72, 95% CI 0.53–0.97, I2 = 59%). NMBAs significantly improved oxygenation (Pao2:Fio2 ratios) at 48 hours (MD 27.26 mm Hg, 95% CI 1.67, 52.84, I2 = 92%) and reduced the incidence of barotrauma (RR 0.55, 95% CI 0.35, 0.85, I2 = 0). However, NMBAs had no effect on oxygenation (Pao2:Fio2 ratios) (MD 18.41 mm Hg, 95% CI -0.33, 37.14, I2 = 72%) at 24 hours. We also found NMBAs did not affect total PEEP, plateau pressure, days free of ventilation at day 28 and ICU-acquired weakness.

Conclusions

In patients with moderate-to-severe ARDS, the administration of NMBAs could reduce 21 to 28-day mortality and barotrauma, and improve oxygenation at 48 hours, but have no significant effects on 90-day/ICU mortality, days free of ventilation at day 28 and the risk of ICU-acquired weakness. Further large-scale, high-quality RCTs are needed to confirm our findings. Registration: PROSPERO (ID: CRD 42019139656).

Neuromuscular blocking agents for acute respiratory distress syndrome: an updated meta-analysis of randomized controlled trials

Backgrounds

The aim of this study is investigating the benefits and harms of neuromuscular blocking agents (NMBAs) in patients with acute respiratory distress syndrome (ARDS).

Methods

We comprehensively searched PubMed, EMBASE, and Cochrane library for randomized controlled trials comparing NMBAs to any other comparator. We pooled data using relative risk (RR) for dichotomous outcomes and weighted mean difference (WMD) for continuous outcomes, with 95% confidence intervals. We assessed the quality of included studies using the Cochrane tool and levels of evidence using the GRADE method.

Results

Finally, six RCTs (n = 1557 patients) were eligible for analysis. The results showed NMBAs use was not associated with reduced 28 days mortality (RR 0.78; 95% CI, 0.58 to 1.06; P = 0.11), 90 days mortality (RR, 0.92; 95% CI, 0.81 to 1.04; P = 0.16), and intensive care unit (ICU) mortality (RR, 0.90; 95% CI, 0.79 to 1.03; P = 0.13) in patients with ARDS. However, 21–28 days mortality was slightly lower in patients received NMBAs (RR 0.73; 95% CI, 0.54 to 0.99; P = 0.04; I² = 53%). Besides, NMBAs use could improve the PaO₂/FiO₂ ratio at 48 and 72 h, decrease plateau pressure and PEEP at 72 h. Additionally, NMBAs had no significant effects on days free of ventilation at day 28 (WMD, 0.55; 95% CI, − 0.46 to 1.57; P = 0.29), days not in ICU at day 28 (WMD, 0.12; 95% CI, − 0.85 to 1.08; P = 0.82), ICU-acquired weakness (RR, 1.23; 95% CI, 0.99 to 1.93; P = 0.06). Finally, NMBAs use was associated with a lower risk of barotrauma (RR, 0.55; 95% CI, 0.35 to 0.85; P = 0.007).

Conclusion

In patients with respiratory distress syndrome, NMBAs may be beneficial in reverse refractory hypoxemia and may be associated with reduced short-term mortality and incidence of barotrauma. However, there is no significant effects of NMBAs on mid-term and long-term mortality, and further studies are required.

Neuromuscular blocking agents for adult patients with acute respiratory distress syndrome: A meta-analysis of randomized controlled trials

BACKGROUND

To explore the effect of neuromuscular blocking agents (NMBAs) on adult patients with acute respiratory distress syndrome (ARDS) by meta-analysis.

METHODS

Three databases including Cochrane central register of controlled trials, PubMed, and Wanfang Data were searched to find relevant articles. We included randomized controlled trials that evaluated NMBAs compared with placebo or usual treatment in adult patients with ARDS.

RESULTS

Five trials totaling 551 patients were identified eligible for inclusion. All the five trials were protective ventilation strategies based. All patients (the ratio of partial pressure of arterial oxygen/fraction of inspired oxygen ≤ 200 mm Hg) met American-European Consensus Conference or the Berlin definition oxygenation criteria for ARDS. Neuromuscular blocking agents significantly reduced intensive care unit mortality (relative risk, 0.73; 95% confidence intervals [CI], 0.58-0.93; p = 0.009; I = 0.0%; 4 trials, 455 patients) and 21- to 28-day mortality (relative risk, 0.63; 95% CI, 0.49-0.82; p = 0.001; I = 0.0%; 4 trials, 527 patients). At 48 hours, NMBAs improved oxygenation (weighted mean differences [WMD], 27.98; 95% CI, 7.45-48.51; p = 0.008; I = 44.2%; 4 trials, 212 patients). However, NMBAs have no effect on reduction of oxygenation at 24 hours (WMD, 26.83; 95% CI, -5.89 to 59.55; p = 0.108; I = 82.4%; 4 trials, 447 patients), and plateau pressure (WMD, 0.43; 95% CI, -0.46 to 1.31; p = 0.345; 4 trials, 455 patients) as well as positive end expiratory pressure (WMD, 0.10; 95% CI, -0.47 to 0.67; p = 0.73; 4 trials, 455 patients) at 48 hours.

CONCLUSION

Protective ventilation strategies based NMBAs treatment reduces mortality in patients with moderate to severe ARDS.

LEVEL OF EVIDENCE

Systematic reviews & meta-analysis, level III.

Formal guidelines: management of acute respiratory distress syndrome

Fifteen recommendations and a therapeutic algorithm regarding the management of acute respiratory distress syndrome (ARDS) at the early phase in adults are proposed. The Grade of Recommendation Assessment, Development and Evaluation (GRADE) methodology has been followed. Four recommendations (low tidal volume, plateau pressure limitation, no oscillatory ventilation, and prone position) had a high level of proof (GRADE 1 + or 1 -); four (high positive end-expiratory pressure [PEEP] in moderate and severe ARDS, muscle relaxants, recruitment maneuvers, and venovenous extracorporeal membrane oxygenation [ECMO]) a low level of proof (GRADE 2 + or 2 -); seven (surveillance, tidal volume for non ARDS mechanically ventilated patients, tidal volume limitation in the presence of low plateau pressure, PEEP > 5 cmH2O, high PEEP in the absence of deleterious effect, pressure mode allowing spontaneous ventilation after the acute phase, and nitric oxide) corresponded to a level of proof that did not allow use of the GRADE classification and were expert opinions. Lastly, for three aspects of ARDS management (driving pressure, early spontaneous ventilation, and extracorporeal carbon dioxide removal), the experts concluded that no sound recommendation was possible given current knowledge. The recommendations and the therapeutic algorithm were approved by the experts with strong agreement.

Formal guidelines: management of acute respiratory distress syndrome

Fifteen recommendations and a therapeutic algorithm regarding the management of acute respiratory distress syndrome (ARDS) at the early phase in adults are proposed. The Grade of Recommendation Assessment, Development and Evaluation (GRADE) methodology has been followed. Four recommendations (low tidal volume, plateau pressure limitation, no oscillatory ventilation, and prone position) had a high level of proof (GRADE 1 + or 1 −); four (high positive end-expiratory pressure [PEEP] in moderate and severe ARDS, muscle relaxants, recruitment maneuvers, and venovenous extracorporeal membrane oxygenation [ECMO]) a low level of proof (GRADE 2 + or 2 −); seven (surveillance, tidal volume for non ARDS mechanically ventilated patients, tidal volume limitation in the presence of low plateau pressure, PEEP > 5 cmH2O, high PEEP in the absence of deleterious effect, pressure mode allowing spontaneous ventilation after the acute phase, and nitric oxide) corresponded to a level of proof that did not allow use of the GRADE classification and were expert opinions. Lastly, for three aspects of ARDS management (driving pressure, early spontaneous ventilation, and extracorporeal carbon dioxide removal), the experts concluded that no sound recommendation was possible given current knowledge. The recommendations and the therapeutic algorithm were approved by the experts with strong agreement.

Evaluation of Prophylactic Heparin Dosage Strategies and Risk Factors for Venous Thromboembolism in the Critically Ill Patient

BACKGROUND

Venous thromboembolism (VTE) occurs frequently in critically ill patients without heparin prophylaxis. Although heparin prevents VTE, VTEs occur frequently despite prophylaxis. A higher heparin dosage may be more effective for preventing VTE.

METHODS

A retrospective study was conducted using the Premier Incorporated Perspective Database to evaluate comparatively the effects of different heparin prophylaxis dosing strategies in the critically ill patient. Critically ill adult patients who were mechanically ventilated for at least 1 day and had an intensive care unit (ICU) length of stay of at least 2 days were included. Patients received 5000 units of heparin either twice/day or 3 times/day. The primary outcome was development of a new VTE. Key secondary outcomes included clinically important bleeding, thrombocytopenia, and mortality. Patients were propensity matched to control for confounding. Multivariable analysis was conducted for VTE risk factors.

RESULTS

The study included 30,800 patients from 374 hospitals who were propensity matched by heparin dosage. New VTE occurred in 6.16% of patients treated with 3 times/day heparin versus 6.23% with twice/day heparin (p=0.8). No significant differences in the incidence of pulmonary embolism (0.91% vs 0.8%, p=0.29) or deep vein thrombosis (5.56% vs 5.70% p=0.59) were observed between the two types of heparin dosing. No differences were observed between the two types of heparin dosing in in-hospital mortality (15.8% vs 15.15%), bleeding (0.23% vs 0.33%), or thrombocytopenia (5.19% vs 5.34%, p>0.08 for all), respectively. Risk factors associated with VTE included intraabdominal and urinary tract infections, loop diuretics, malnutrition, obesity, thrombocytopenia, paralytics, vasopressors, female sex, peripheral vascular disease, sepsis, neutropenia, and end-stage renal disease. Antiplatelet therapy, heart failure, diabetes, and substance abuse were associated with reduced VTE (p<0.05 for all).

CONCLUSIONS

In critically ill patients, prophylactic dosing of heparin 3 times/day versus twice/day was not associated with differences in new VTE or safety outcomes. Several modifiable VTE risk factors were identified.

Impact of Macrolide Antibiotics on Hospital Readmissions and Other Clinically Important Outcomes in Critically Ill Patients with Acute Exacerbations of Chronic Obstructive Pulmonary Disease: A Propensity Score-Matched Cohort Study

STUDY OBJECTIVE

To assess whether a macrolide-based antibiotic treatment strategy reduces in-hospital mortality, decreases hospital readmissions, or improves other clinically important outcomes compared with a non-macrolide antibiotic treatment strategy in critically ill patients with acute exacerbations of chronic obstructive pulmonary disease (AECOPD).

DESIGN

Propensity score-matched pharmacoepidemiologic cohort study.

DATA SOURCE

Premier's Perspective Hospital Database.

PATIENTS

A total of 28,700 adults aged 40 years or older who were admitted to one of 566 United States intensive care units and had the primary diagnosis of AECOPD between January 2010 and December 2014 and received antibiotic treatment within 2 days of hospital admission were included. Patients were divided into macrolide (11,602 patients [40%]) or non-macrolide (17,098 patients [60%]) antibiotic treatment groups. Propensity score analysis successfully matched 8660 patients in each treatment group.

MEASUREMENTS AND MAIN RESULTS

In the matched cohort, the macrolide treatment group was not associated with decreased hospital mortality after day 2 (3.0% vs 3.3%, p=0.28), intensive care unit length of stay (2 days vs 2 days, p=0.12), hospital length of stay (6 days vs 6 days, p=0.86), or length of assisted ventilation (3 days vs 3 days, p=0.71), compared with the non-macrolide treatment group. However, a macrolide-based antibiotic regimen was associated with an overall reduction in 30-day hospital readmissions (7.3% vs 8.8%, p<0.01), increased time to next all-cause (159 vs 130 days, p<0.01) or AECOPD (200 vs 175 days, p=0.03) readmission, and decreased hospital costs ($32,730 vs $34,021, p<0.01).

CONCLUSION

The results of this study suggest that inclusion of a macrolide antibiotic in the treatment regimen may have both acute and sustained benefits in critically ill patients admitted to the intensive care unit with an AECOPD, including reductions in hospital readmissions and improvements in time to next readmission.

Moderate to Severe Acute Respiratory Distress Syndrome Management Strategies: A Narrative Review

Acute respiratory distress syndrome (ARDS) remains a common complication associated with significant negative outcomes in critically ill patients. Lung-protective mechanical ventilation strategies remain the cornerstone in the management of ARDS. Several therapeutic options are currently available including fluid management, neuromuscular blocking agents, prone positioning, extracorporeal membrane oxygenation, corticosteroids, and inhaled pulmonary vasodilating agents (prostacyclins and nitric oxide). Unfortunately, an evidence-based, standard-of-care approach in managing ARDS beyond lung-protective ventilation remains elusive, contributing to significant variability in clinical practice. Although the optimal therapeutic strategy for managing moderate to severe ARDS remains extremely controversial, therapies supported with more robust clinical evidence should be considered first. The purpose of this narrative review is to discuss the published clinical evidence for both pharmacologic and nonpharmacologic management strategies in adult patients with moderate to severe ARDS as well as to discuss practical considerations for implementation.

Neuromuscular blocking agents for acute respiratory distress syndrome

Acute respiratory distress syndrome (ARDS) is an acute inflammatory process that impairs the ability of the lungs to oxygenate thereby resulting in respiratory failure. Treatment of ARDS is often a multimodal approach using both nonpharmacologic and pharmacologic treatment strategies in addition to trying to reverse the underlying cause of ARDS. Neuromuscular blocking agents (NMBAs) have been prescribed to patients with ARDS as they are thought to decrease inflammation, oxygen consumption, and cardiac output and help facilitate ventilator synchrony. NMBAs have only been evaluated in patients with early, severe ARDS in three multicenter, randomized, controlled trials (n = 432), but have resulted in decreased inflammation and improved oxygenation, ventilator-free days, and mortality. Despite reports of NMBAs being associated with adverse effects like postparalytic quadriparesis, myopathy, and prolonged recovery, these effects have not been seen in patients receiving short courses of NMBAs for ARDS. A large multicenter, prospective, randomized, placebo-controlled trial is ongoing to confirm benefit of NMBAs in early, severe ARDS when adjusting for limitations of the previous studies. The current available literature suggests that 48 h of NMBA therapy in patients with early, severe ARDS improves mortality, without resulting in additional patient harm.

Evaluation of unfractionated heparin versus low-molecular-weight heparin and fondaparinux for pharmacologic venous thromboembolic prophylaxis in critically ill patients with cancer

Essentials Critically ill cancer patients require pharmacologic prophylaxis for venous thromboembolism (VTE). Patients from 566 hospitals in the United States between 2010 and 2014 were included. Low-molecular-weight heparin (LMWH) prophylaxis was not associated in a reduction of VTE rates. LMWH prophylaxis was associated with a reduction in bleeding and heparin induced thrombocytopenia. SUMMARY: Background Critically ill patients with cancer are at increased risk of venous thromboembolism (VTE) from physical and cellular factors, requiring pharmacologic prophylaxis to reduce the risk of VTE. Objectives To assess whether low-molecular-weight heparin (LMWH) prophylaxis reduces in-hospital rates of VTE or improves clinical outcomes compared with unfractionated heparin (UFH) prophylaxis in critically ill patients with cancer. Methods We used a propensity-matched comparative-effectiveness cohort from the Premier Database. Patients aged 18 years or older with a primary diagnosis of cancer, intensive care unit admission and VTE prophylaxis within 2 days of admission between 1 January 2010 and 31 December 2014 were included. Patients were divided into LMWH or UFH prophylaxis groups. Results A total of 103 798 patients were included; 75 321 (72.6%) patients received LMWH and 28 477 (27.4%) patients received UFH. Propensity analysis matched (2 : 1) 42 343 LMWH patients and 21 218 UFH patients. Overall, LMWH was not associated with a decreased incidence of VTE (5.32% vs. 5.50%). LMWH prophylaxis was associated with a reduction in pulmonary embolism (0.70% vs. 0.99%), significant bleeding (13.3% vs. 14.8%) and heparin-induced thrombocytopenia (HIT) (0.06% vs. 0.19%). In non-metastatic solid disease, LMWH was associated with decreased VTE (4.27% vs. 4.84%) and PE (0.47% vs. 0.95%). Conclusions The use of an LMWH for VTE prophylaxis was not associated with a reduction in the incidence of in-hospital VTE as compared with UFH, but was associated with significant reductions in PE, clinically important bleeding events, and incidence of HIT in critically ill patients with cancer.