Rescue Neuromuscular Blockade in Acute Respiratory Distress Syndrome Should Not Be Flat Dose

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.

Personalized medicine targeting different ARDS phenotypes: The future of pharmacotherapy for ARDS?

INTRODUCTION

Acute respiratory distress syndrome (ARDS) still represents a major challenge with high mortality rates and altered quality of life. Many well-designed studies have failed to improve ARDS outcomes. Heterogeneity of etiologies, mechanisms of lung damage, different lung mechanics, and different treatment approaches may explain these failures. At the era of personalized medicine, ARDS phenotyping is not only a field of research, but a bedside consideration when implementing therapy. ARDS has moved from being a simple syndrome to a more complex area of subgrouping. Intensivists must understand these phenotypes and therapies associated with a better outcome.

AREAS COVERED

After a brief sum-up of the different type of ARDS phenotypes, we will present some relevant therapy that may be impacted by phenotyping. A focus on pharmacotherapy will be realized before a section on non-pharmaceutical strategies. Eventually, we will highlight the limits of our knowledge of phenotyping and the pitfalls of personalized medicine.

EXPERT OPINION

Biological and morphological ARDS phenotypes are now well studied. The future of ARDS therapy will go through phenotyping that allows a personalized medication for each patient. However, a better assessment of these phenotypes is required, and clinical trials should be conducted with an ad-hoc phenotyping before randomization.

Comparison of three cisatracurium dosing strategies in acute respiratory distress syndrome: A focus on drug utilization and improvement in oxygenation

Purpose

Three continuous dosing strategies of cisatracurium (CIS) for acute respiratory distress syndrome (ARDS) have been described in the literature. After implementation of a ventilator synchrony protocol (VSP), we sought to determine which continuous CIS dosing strategy utilized the least amount of drug without compromising efficacy.

Methods

We retrospectively reviewed patients with ARDS receiving continuous CIS from January 1, 2013 to December 31, 2018. We categorized patients into one of three dosing strategies: fixed dose (FD), titration based solely on train-of-four (TOF), or the VSP. We documented drug consumption and determined efficacy by comparing the change in PaO₂/FiO₂ ratio (P/F) and oxygenation index (OI) from baseline up to 48 h.

Results

A total of 1047 patients were screened, and 189 met inclusion criteria (VSP = 69, TOF = 99, FD = 21). Drug consumption (mg) was significantly lower in the VSP arm: 415 [IQR 318–528] compared to both the TOF: 665 [IQR 472–927] and the FD arms: 1730 [IQR 1695–1800], p < 0.001 for each. The change in P/F and OI from baseline were statistically equivalent at all time points.

Conclusion

Without impacting efficacy of gas exchange, a protocol using ventilator synchrony for CIS titration required significantly less drug compared to TOF-based titration and a fixed dosing regimen.

Comparison of fixed dose versus train-of-four titration of cisatracurium in acute respiratory distress syndrome

PURPOSE

To compare the ventilatory and clinical outcomes associated with a fixed-dose cisatracurium infusion versus a titrated infusion strategy in patients with Acute Respiratory Distress Syndrome (ARDS).

MATERIALS AND METHODS

Single-center, retrospective, cohort study in a medical ICU of a tertiary care academic medical center. Adult patients ≥18 years old with a continuous infusion of cisatracurium for ≥12 h for treatment of ARDS were included. The primary outcome was the PaO2 /FiO2 ratio assessed at 24 and 48 h following cisatracurium initiation. Secondary outcomes included amount of average dose of drug administered, 28-day ventilator-free days, LOS, and hospital mortality.

RESULTS

167 patients were included; median baseline PaO2/FiO2 was 97 (76-146), median SOFA score of 9 (7-11), and ICU mortality was 71/167 (43%). In a mixed-effects model, fixed dose and titrated cisatracurium associated with similar changes in PaO2/FiO2 assessed at 24 and 48 h (p = 0.316). Fixed-dose was associated with a >3-fold increase in drug exposure (average dose 6.4 (5.4-8.0) vs. 2.0 (1.5-2.8) mcg/kg/min; p < 0.001, respectively). No differences were observed in secondary clinical endpoints.

CONCLUSION

Fixed-dose cisatracurium was associated with similar ventilatory and clinical outcomes compared to titrated strategy, yet it was associated with a 3-fold increase in dose administered.

Dosing of neuromuscular blocking agents in patients with obesity: A narrative review

There is no consensus on which weight clinicians should use for weight-based dosing of neuromuscular blocking agents (NMBAs), as exemplified by differing or absent recommendations in clinical practice guidelines. The purpose of this paper is to review studies that evaluated various size descriptors for weight-based dosing of succinylcholine and non-depolarising NMBAs, and to provide recommendations for the descriptors of choice for the weight-based dosing of these agents in patients with obesity. All of the studies conducted to date involving depolarising and non-depolarising NMBAs in patients with obesity have assessed single doses or short-term infusions conducted in perioperative settings. Recognising that any final dosing regimen must take into account patient-specific considerations, the available evidence suggests that actual body weight is the size descriptor of choice for weight-based dosing of succinylcholine and that ideal body weight, or an adjusted (or lean) body weight, is the size descriptor of choice for weight-based dosing of non-depolarising NMBAs.

An Evaluation of Continuous Infusion Rocuronium for Sustained Neuromuscular Blockade in Critically Ill Adults

BACKGROUND

Recent medication shortages of the neuromuscular blocking agent (NMBA) cisatracurium have forced the prescribing of aminosteroidal agents such as rocuronium. There are limited data on the use and dosing of continuous infusion (CI) rocuronium in critically ill patients outside of the operating room.

OBJECTIVE

We sought to describe the use of CI rocuronium for sustained neuromuscular blockade in intensive care unit (ICU) patients by characterizing the dosing, utilization, and safety profile in patients with multiple organ failure (MOF) and non-MOF.

METHODS

This was a retrospective review of patients in mixed ICUs from 2 tertiary medical centers who received CI rocuronium between January 2018 and July 2019.

RESULTS

A total of 46 unique rocuronium infusions were utilized for 40 patients during the evaluation period. Of these, 37% had MOF, and 41% had at least 1 organ fail during the rocuronium infusion. The median starting and maximum dose was 8 µg/kg/min. Overall, 64% of train of 4 (TOF) measurements were a TOF 0 (T0) or TOF 1 (T1), with a higher percentage of T0 or T1 in the MOF group compared with the non-MOF group (75% vs 50%). The median time to recovery was more than twice as long for the MOF compared with the non-MOF group (10 vs 4.6 hours). ICU-acquired weakness was diagnosed in 27% of survivors.

CONCLUSION AND RELEVANCE

In ICU patients with MOF, continuous rocuronium infusions were associated with deep levels of paralysis and prolonged recovery times. If neuromuscular blockade is required for critically ill patients, alternative strategies could be considered.

Sedation, Analgesia, and Paralysis in COVID-19 Patients in the Setting of Drug Shortages

The rapid spread of the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) has led to a global pandemic. The 2019 coronavirus disease (COVID-19) presents with a spectrum of symptoms ranging from mild to critical illness requiring intensive care unit (ICU) admission. Acute respiratory distress syndrome is a major complication in patients with severe COVID-19 disease. Currently, there are no recognized pharmacological therapies for COVID-19. However, a large number of COVID-19 patients require respiratory support, with a high percentage requiring invasive ventilation. The rapid spread of the infection has led to a surge in the rate of hospitalizations and ICU admissions, which created a challenge to public health, research, and medical communities. The high demand for several therapies, including sedatives, analgesics, and paralytics, that are often utilized in the care of COVID-19 patients requiring mechanical ventilation, has created pressure on the supply chain resulting in shortages in these critical medications. This has led clinicians to develop conservation strategies and explore alternative therapies for sedation, analgesia, and paralysis in COVID-19 patients. Several of these alternative approaches have demonstrated acceptable levels of sedation, analgesia, and paralysis in different settings but they are not commonly used in the ICU. Additionally, they have unique pharmaceutical properties, limitations, and adverse effects. This narrative review summarizes the literature on alternative drug therapies for the management of sedation, analgesia, and paralysis in COVID-19 patients. Also, this document serves as a resource for clinicians in current and future respiratory illness pandemics in the setting of drug shortages.