Clinical Paper, ClinicalContinuous neuromuscular blockade is associated with decreased mortality in post-cardiac arrest patients☆
Introduction
Out-of-hospital cardiac arrest (OHCA) occurs in 400,000 people each year in the United States.1 Survival rates from cardiac arrest (CA) vary widely2 but those who do survive are often functionally limited by the neurologic insult from ischemia–reperfusion injury.3 While there are no specific pharmacologic therapies proven to improve outcomes after cardiac arrest, the use of therapeutic hypothermia has been shown to improve neurologic outcome in this population.4, 5 Side effects of therapeutic hypothermia include an increased risk for arrhythmia, infection or bleeding, and shivering.6
Neuromuscular blockade (NMB) was recently reported to improve outcomes in patients with acute respiratory distress syndrome (ARDS) although this remains controversial.7 The exact mechanism of this effect has yet to be elucidated but may include reduced oxygen consumption by respiratory muscles, increased arterial oxygenation, or a decrease in patient-ventilator dyssyncrony.8, 9 In post-CA patients receiving therapeutic hypothermia, NMB may be used to prevent shivering, yet the evidence evaluating the use of NMB in post-CA populations is limited.10 In the two initial randomized trials showing improved outcome with the use of therapeutic hypothermia, NMB was commonly used in the treatment group but not in the placebo group presenting a possible confounding treatment effect.4, 5 Further, the American Heart Association (AHA) has recommended minimizing the use of NMB in post-CA patients or avoiding it altogether.11 Whether NMB affects outcomes in patients following OHCA is unknown.
Our objective was to evaluate the effect of NMB in OHCA patients following return of spontaneous circulation with the purpose of determining whether there is evidence suggesting a benefit of NMB in this population. Our hypothesis was that NMB in the early post-arrest period would improve overall survival for this population. We utilized data collected in a multi-center prospective observational investigation of adult OHCA to test this hypothesis.
Section snippets
Design and setting
The National Post-Arrest Research Consortium (NPARC) is a clinical research network conducting research in post-cardiac arrest care. The network consists of four urban tertiary care teaching hospitals and was established to evaluate treatment strategies for individuals who are successfully resuscitated after out-of-hospital cardiac arrest. The current investigation is a post hoc analysis of a prospectively conducted NPARC trial evaluating mitochondrial injury in post-cardiac arrest patients
Patients and NMB practice patterns
During the nine-month enrollment period a total of 220 OHCA patients presented to the ED at one of the four NPARC centers; written informed consent was obtained for 111 subjects and were included in this analysis (Fig. 1). The median age was 63 years (IQR: 50–75) and 41% were female. Therapeutic hypothermia was completed in 97% and overall survival was 47%. There were 77 (69%) patients documented to have received NMB at any point within the first 24 h following ROSC. A portion of these patients
Discussion
In this multicenter investigation of adult OHCA we found that NMB in the post-CA period is common as the majority of these patients received NMB at some point in the 24 h following ROSC. However, only a fraction of patients (16%) received NMB for a sustained 24-h period. We found that compared to patients who do not receive early, sustained NMB, patients with 24 h of NMB had improved survival as well as improved lactic acid clearance. These associations remained significant after multivariate
Conclusion
In this population of OHCA, we found that early NMB that is sustained for a 24-h period is associated with an increased probability of survival. Secondarily, we found that early, sustained NMB is associated with improved lactate clearance. The administration of NMB in the early post-CA period may improve outcomes, however, clinical trials are necessary to assess any causal relationship between NMB and outcome from OHCA.
Conflict of interest
Joseph P. Ornato – Co-Chair, NIH-sponsored Resuscitation Outcomes Consortium (ROC), Benjamin S. Abella – Philips Healthcare, NIH, Medtronic Foundation, Doris Duke, HeartSine, Velomedix, David F. Gaieski – Stryker Medical and rest of the authors have no conflict of interest.
Competing interests
The authors state that they have no competing interests.
Acknowledgements
This project was supported by NIH award No. 3UL1RR031990-02S1 and CTSA award No. UL1TR000058 from the National Center for Advancing Translational Sciences.
Additionally, the project described was supported, in part, by Grant Number UL1 RR025758 – Harvard Clinical and Translational Science Center, from the National Center for Research Resources. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Center for Research
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The association between neuromuscular blockade use during target temperature management and neurological outcomes
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2021, Neurologic ClinicsCitation Excerpt :Management of shivering includes surface counter-warming, magnesium sulfate, buspirone, meperidine, sedation, and neuromuscular blockade.34 In a multicenter study of 111 patients with OHCA, the use of early continuous neuromuscular blockade for 24 hours was associated with improved survival (78% vs 41%, P = .005) and lactic acid clearance at 24 hours (1.3 [0.9–2.0] vs 2.9 [1.5–5.5], P<.001) after CA.35 Under normal physiologic conditions, CBF remains constant across a range of mean arterial pressures (MAPs) to ensure that perfusion matches metabolic demands.
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A Spanish translated version of the abstract of this article appears as Appendix in the final online version at http://dx.doi.org/10.1016/j.resuscitation.2013.06.008.
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On behalf the National Post-Arrest Research Consortium.