Lower Driving Pressure and Neuromuscular Blocker Use Are Associated With Decreased Mortality in Patients With COVID-19 ARDS

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

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

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.

Predicting factors associated with prolonged intensive care unit stay of patients with COVID-19

BACKGROUND

Predicting the length of stay (LOS) for coronavirus disease 2019 (COVID-19) patients in the intensive care unit (ICU) is essential for efficient use of ICU resources. We analyzed the clinical characteristics of patients with severe COVID-19 based on their clinical care and determined the predictive factors associated with prolonged LOS.

METHODS

We included 96 COVID-19 patients who received oxygen therapy at a high-flow nasal cannula level or above after ICU admission during March 2021 to February 2022. The demographic characteristics at the time of ICU admission and results of severity analysis (Sequential Organ Failure Assessment [SOFA], Acute Physiology and Chronic Health Evaluation [APACHE] II), blood tests, and ICU treatments were analyzed using a logistic regression model. Additionally, blood tests (C-reactive protein, D-dimer, and the PaO2 to FiO2 ratio [P/F ratio]) were performed on days 3 and 5 of ICU admission to identify factors associated with prolonged LOS.

RESULTS

Univariable analyses showed statistically significant results for SOFA score at the time of ICU admission, C-reactive protein level, high-dose steroids, mechanical ventilation (MV) care, continuous renal replacement therapy, extracorporeal membrane oxygenation, and prone position. Multivariable analysis showed that MV care and P/F ratio on hospital day 5 were independent factors for prolonged ICU LOS. For D-dimer, no significant variation was observed at admission; however, after days 3 and 5 days of admission, significant between-group variation was detected.

CONCLUSIONS

MV care and P/F ratio on hospital day 5 are independent factors that can predict prolonged LOS for COVID-19 patients.

Physicians' attitudes and perceptions of neuromuscular blocker infusions in ARDS

PURPOSE

The perceptions and practices of ICU physicians regarding initiating neuromuscular blocker infusions (NMBI) in acute respiratory distress syndrome (ARDS) may not be evidence-based amidst the surge of severe ARDS during the SARS-CoV-2 pandemic and new practice guidelines. We identified ICU physicians' perspectives and practices regarding NMBI use in adults with moderate-severe ARDS.

MATERIALS AND METHODS

After extensive development and testing, an electronic survey was distributed to 342 ICU physicians from three geographically-diverse U.S. health systems(n = 12 hospitals).

RESULTS

The 173/342 (50.5%) respondents (75% medical) somewhat/strongly agreed a NMBI should be reserved until: after a trial of deep sedation (142, 82%) or proning (59, 34%) and be dose-titrated based on train-of-four monitoring (107, 62%). Of 14 potential NMBI risks, 2 were frequently reported to be of high/very high concern: prolonged muscle weakness with steroid use (135, 79%) and paralysis awareness due to inadequate sedation (114, 67%). Absence of dyssychrony (93, 56%) and use ≥48 h (87, 53%) were preferred NMBI stopping criteria. COVID-19 + ARDS patients were twice as likely to receive a NMBI (56 ± 37 vs. 28 ± 19%, p < 0.01).

CONCLUSIONS

Most intensivists agreed NMBI in ARDS should be reserved until after a deep sedation trial. Stopping criteria remain poorly defined. Unique considerations exist regarding the role of paralysis in COVID-19+ ARDS.

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.

Neuromuscular blocking agents in the intensive care unit

Neuromuscular blocking agents (NMBA) are a controversial therapeutic option in the approach to the critically ill patient. They are not innocuous, and the available evidence does not support their routine use in the intensive care unit. If necessary, monitoring protocols should be established to avoid residual relaxation, adverse effects, and associated complications. This narrative review discusses the current indications for the use of NMBA and the different tools for monitoring blockade in the intensive care unit. However, expanding the use of NMBA in critical settings merits the development of prospective studies.

Early spontaneous breathing for acute respiratory distress syndrome in individuals with COVID-19

BACKGROUND

Acute respiratory distress syndrome (ARDS) represents the most severe course of COVID-19 (caused by the SARS-CoV-2 virus), usually resulting in a prolonged stay in an intensive care unit (ICU) and high mortality rates. Despite the fact that most affected individuals need invasive mechanical ventilation (IMV), evidence on specific ventilation strategies for ARDS caused by COVID-19 is scarce. Spontaneous breathing during IMV is part of a therapeutic concept comprising light levels of sedation and the avoidance of neuromuscular blocking agents (NMBA). This approach is potentially associated with both advantages (e.g. a preserved diaphragmatic motility and an optimised ventilation-perfusion ratio of the ventilated lung), as well as risks (e.g. a higher rate of ventilator-induced lung injury or a worsening of pulmonary oedema due to increases in transpulmonary pressure). As a consequence, spontaneous breathing in people with COVID-19-ARDS who are receiving IMV is subject to an ongoing debate amongst intensivists.

OBJECTIVES

To assess the benefits and harms of early spontaneous breathing activity in invasively ventilated people with COVID-19 with ARDS compared to ventilation strategies that avoid spontaneous breathing.

SEARCH METHODS

We searched the Cochrane COVID-19 Study Register (which includes CENTRAL, PubMed, Embase, Clinical Trials.gov WHO ICTRP, and medRxiv) and the WHO COVID-19 Global literature on coronavirus disease to identify completed and ongoing studies from their inception to 2 March 2022.

SELECTION CRITERIA

Eligible study designs comprised randomised controlled trials (RCTs) that evaluated spontaneous breathing in participants with COVID-19-related ARDS compared to ventilation strategies that avoided spontaneous breathing (e.g. using NMBA or deep sedation levels). Additionally, we considered controlled before-after studies, interrupted time series with comparison group, prospective cohort studies and retrospective cohort studies. For these non-RCT studies, we considered a minimum total number of 50 participants to be compared as necessary for inclusion. Prioritised outcomes were all-cause mortality, clinical improvement or worsening, quality of life, rate of (serious) adverse events and rate of pneumothorax. Additional outcomes were need for tracheostomy, duration of ICU length of stay and duration of hospitalisation.

DATA COLLECTION AND ANALYSIS

We followed the methods outlined in the Cochrane Handbook for Systematic Reviews of Interventions. Two review authors independently screened all studies at the title/abstract and full-text screening stage. We also planned to conduct data extraction and risk of bias assessment in duplicate. We planned to conduct meta-analysis for each prioritised outcome, as well as subgroup analyses of mortality regarding severity of oxygenation impairment and duration of ARDS. In addition, we planned to perform sensitivity analyses for studies at high risk of bias, studies using NMBA in addition to deep sedation level to avoid spontaneous breathing and a comparison of preprints versus peer-reviewed articles. We planned to assess the certainty of evidence using the GRADE approach.

MAIN RESULTS

We identified no eligible studies for this review.

AUTHORS' CONCLUSIONS

We found no direct evidence on whether early spontaneous breathing in SARS-CoV-2-induced ARDS is beneficial or detrimental to this particular group of patients.  RCTs comparing early spontaneous breathing with ventilatory strategies not allowing for spontaneous breathing in SARS-CoV-2-induced ARDS are necessary to determine its value within the treatment of severely ill people with COVID-19. Additionally, studies should aim to clarify whether treatment effects differ between people with SARS-CoV-2-induced ARDS and people with non-SARS-CoV-2-induced ARDS.