Neuromuscular blockade requirement is associated with good neurologic outcome in cardiac arrest survivors treated with targeted temperature management

Neuromuscular blocking agents during targeted temperature management for out-of-hospital cardiac arrest patients

BACKGROUND

Neuromuscular blocking agents (NMBAs) can control shivering during targeted temperature management (TTM) of patients with cardiac arrest. However, the effectiveness of NMBA use during TTM on neurologic outcomes remains unclear. We aimed to evaluate the association between NMBA use during TTM and favorable neurologic outcomes after out-of-hospital cardiac arrest (OHCA).

MATERIALS AND METHODS

A multicenter, prospective, observational cohort study from 2019 to 2021. It included OHCA patients who received TTM after hospitalization. We conducted overlap weight propensity-score analyses after multiple imputation to evaluate the effect of NMBAs during TTM. The primary outcome was a favorable neurological outcome, defined as a cerebral performance category of 1 or 2 at discharge. Subgroup analyses were conducted based on initial monitored rhythm and brain computed tomography findings.

RESULTS

Of the 516 eligible patients, 337 received NMBAs during TTM. In crude analysis, the proportion of patients with favorable neurological outcome was significantly higher in the NMBA group (38.3% vs. 16.8%; risk difference (RD): 21.5%; 95% confidence interval (CI): 14.0% to 29.1%). In weighted analysis, a significantly higher proportion of patients in the NMBA group had a favorable neurological outcome compared to the non-NMBA group (32.7% vs. 20.9%; RD: 11.8%; 95% CI: 1.2% to 22.3%). In the subgroup with an initial shockable rhythm and no hypoxic encephalopathy, the NMBA group showed significantly higher proportions of favorable neurological outcomes.

CONCLUSIONS

The use of NMBAs during TTM was significantly associated with favorable neurologic outcomes at discharge for OHCA patients. NMBAs may have benefits in selected patients with initial shockable rhythm and without poor prognostic computed tomography findings.

Association between neuromuscular blocking agent use and outcomes among out-of-hospital cardiac arrest patients treated with extracorporeal cardiopulmonary resuscitation and target temperature management: A secondary analysis of the SAVE-J II study

Background

Neuromuscular blocking agents are used to control shivering in cardiac arrest patients treated with target temperature management. However, their effect on outcomes in patients treated with extracorporeal cardiopulmonary resuscitation is unclear.

Methods

This study was a secondary analysis of the SAVE-J II study, a retrospective multicenter study of 2175 out-of-hospital cardiac arrest patients treated with extracorporeal cardiopulmonary resuscitation in Japan. We classified patients into those who received neuromuscular blocking agents and those who did not and compared in-hospital mortality and incidence rates of favorable neurological outcome and in-hospital pneumonia between the groups using multivariable regression models and stabilized inverse probability weighting with propensity scores.

Results

Six hundred sixty patients from the SAVE-J II registry were analyzed. Neuromuscular blocking agents were used in 451 patients (68.3%). After adjusting for potential confounders, neuromuscular blocking agents use was not significantly associated with in-hospital mortality (aHR 0.88; 95% CI, 0.67-1.14), favorable neurological outcome (aOR 0.85; 95% CI, 0.60-1.11), or pneumonia (aOR 1.52; 95% CI, 0.85-2.71). The results for in-hospital mortality (aHR 0.89; 95% CI, 0.64-1.25), favorable neurological outcome (aOR 0.94; 95% CI, 0.59-1.48) and pneumonia (aOR 1.59; 95% CI, 0.74-3.41) were similar after weighting was performed.

Conclusions

Although data on the rationale for using neuromuscular blocking agents were unavailable, their use was not significantly associated with outcomes in out-of-hospital cardiac arrest patients treated with extracorporeal cardiopulmonary resuscitation and targeted temperature management. Neuromuscular blocking agents should be used based on individual clinical indications.

General Critical Care, Temperature Control, and End-of-Life Decision Making in Patients Resuscitated from Cardiac Arrest

Cardiac arrest affects millions of people per year worldwide. Although advances in cardiopulmonary resuscitation and intensive care have improved outcomes over time, neurologic impairment and multiple organ dysfunction continue to be associated with a high mortality rate. The pathophysiologic mechanisms underlying the post-resuscitation disease are complex, and a coordinated, evidence-based approach to post-resuscitation care has significant potential to improve survival. Critical care management of patients resuscitated from cardiac arrest focuses on the identification and treatment of the underlying cause(s), hemodynamic and respiratory support, organ protection, and active temperature control. This review provides a state-of-the-art appraisal of critical care management of the post-cardiac arrest patient.

Neuromuscular Blockade for Cardiac Arrest Patients Treated With Targeted Temperature Management: A Systematic Review and Meta-Analysis

Background: Neuromuscular-blocking agents (NMBA) are often administered to control shivering in comatose cardiac arrest (CA) survivors during targeted temperature management (TTM) management. Thus, we performed a systematic review and meta-analysis to investigate the effectiveness and safety of NMBA in such a patient population. Methods: We searched for relevant studies in PubMed, Embase, and the Cochrane Library until 15 Jul 2021. Studies were included if they reported data on any of the predefined outcomes in adult comatose CA survivors managed with any NMBA regimens. The primary outcomes were mortality and neurological outcome. Results were expressed as odds ratio (OR) or mean difference (MD) with an accompanying 95% confidence interval (CI). Heterogeneity, sensitivity analysis, and publication bias were also investigated to test the robustness of the primary outcome. Data Synthesis: We included 12 studies (3 randomized controlled trials and nine observational studies) enrolling 11,317 patients. These studies used NMBA in three strategies: prophylactic NMBA, bolus NMBA if demanded, or managed without NMBA. Pooled analysis showed that CA survivors with prophylactic NMBA significantly improved both outcomes of mortality (OR 0.74; 95% CI 0.64-0.86; I 2 = 41%; p < 0.0001) and neurological outcome (OR 0.53; 95% CI 0.37-0.78; I 2 = 59%; p = 0.001) than those managed without NMBA. These results were confirmed by the sensitivity analyses and subgroup analyses. Only a few studies compared CA survivors receiving continuous versus bolus NMBA if demanded strategies and the pooled results showed no benefit in the primary outcomes between the two groups. Conclusion: Our results showed that using prophylactic NMBA strategy compared to the absence of NMBA was associated with improved mortality and neurologic outcome in CA patients undergoing TTM. However, more high-quality randomized controlled trials are needed to confirm our results.

The association between neuromuscular blockade use during target temperature management and neurological outcomes

BACKGROUND

To date, no study has comprehensively analyzed the association between neuromuscular blockade (NMB) during target temperature management (TTM) and the neurological outcomes after out-of-hospital cardiac arrest (OHCA) using a multicenter dataset. We aimed to examine the association between NMB during TTM after cardiac arrest and neurological outcomes after OHCA.

METHODS

This study was a secondary analysis of the Japanese Population-based Utstein-style study with defibrillation and basic/advanced Life Support Education and implementation-Hypothermia (J-PULSE-HYPO) study registry. The exposure of the current study was the use of NMB during TTM. The primary outcome was favorable neurological outcome, i.e., a cerebral performance category of 1-2, at hospital discharge.

RESULTS

Of the 452 patients with OHCA enrolled in the J-PULSE-HYPO study, 431 were analyzed. NMB was used in 353 patients (81.9%). Multivariable logistic regression analysis revealed that NMB use was not independently associated with favorable outcomes [odds ratio (OR), 0.96; 95% confidence interval (CI), 0.42-2.18; p = .918)] or survival at discharge (OR, 0.83; 95% CI, 0.31-2.02; p = .688). After adjusting the covariates, the predicted probabilities did not reveal significant differences between NMB use and non-NMB use in the respective mean (95% CI) values for favorable neurological outcomes [53.6 (50.2-57.0) % vs. 58.0 (50.4-65.6) %, p = .304], and survival rates [77.1 (74.7-79.5) % vs. 75.8 (70.5-81.0) %, p = .647].

CONCLUSIONS

The NMB use during TTM was not associated with favorable neurological outcomes and survival rate in patients with OHCA.

Association Between Target Temperature Variability and Neurologic Outcomes for Patients Receiving Targeted Temperature Management at 36°C After Cardiac Arrest: A Retrospective Cohort Study

Maintaining strict temperature control during the maintenance phase of targeted temperature management (TTM) after cardiac arrest may be an important component of clinical care. Temperature variability outside of the goal temperature range may lessen the benefit of TTM and worsen neurologic outcomes. The purpose of this retrospective study of 186 adult patients (70.4% males, mean age 53.8 ± 15.7 years) was to investigate the relationship between body temperature variability (at least one body temperature measurement outside of 36°C ± 0.5°C) during the maintenance phase of TTM at 36°C after cardiac arrest and neurologic outcome at hospital discharge. Patients with temperature variability (n = 124 [66.7%]) did not have significantly higher odds of poor neurologic outcome compared with those with no temperature variability (odds ratio [OR] = 1.01, 95% confidence interval [CI] = 0.36-2.82). Use of neuromuscular blocking agents (NMBAs) and having an initial shockable rhythm were associated with both higher odds of good neurologic outcome (shockable rhythm: OR = 10.77, 95% CI = 4.30-26.98; NMBA use: OR = 4.54, 95% CI = 1.34-15.40) and survival to hospital discharge (shockable rhythm: OR = 5.90, 95% CI = 2.65-13.13; NMBA use: OR = 3.03, 95% CI = 1.16-7.90). In this cohort of postcardiac arrest comatose survivors undergoing TTM at 36°C, having temperature variability during maintenance phase did not significantly impact neurologic outcome or survival.

Postresuscitation Care after Out-of-hospital Cardiac Arrest: Clinical Update and Focus on Targeted Temperature Management

Out-of-hospital cardiac arrest is a major cause of mortality and morbidity worldwide. With the introduction of targeted temperature management more than a decade ago, postresuscitation care has attracted increased attention. In the present review, we discuss best practice hospital management of unconscious out-of-hospital cardiac arrest patients with a special focus on targeted temperature management. What is termed post-cardiac arrest syndrome strikes all organs and mandates access to specialized intensive care. All patients need a secured airway, and most patients need hemodynamic support with fluids and/or vasopressors. Furthermore, immediate coronary angiography and percutaneous coronary intervention, when indicated, has become an essential part of the postresuscitation treatment. Targeted temperature management with controlled sedation and mechanical ventilation is the most important neuroprotective strategy to take. Targeted temperature management should be initiated as quickly as possible, and according to international guidelines, it should be maintained at 32° to 36°C for at least 24 h, whereas rewarming should not increase more than 0.5°C per hour. However, uncertainty remains regarding targeted temperature management components, warranting further research into the optimal cooling rate, target temperature, duration of cooling, and the rewarming rate. Moreover, targeted temperature management is linked to some adverse effects. The risk of infection and bleeding is moderately increased, as is the risk of hypokalemia and magnesemia. Circulation needs to be monitored invasively and any deviances corrected in a timely fashion. Outcome prediction in the individual patient is challenging, and a self-fulfilling prophecy poses a real threat to early prognostication based on clinical assessment alone. Therefore, delayed and multimodal prognostication is now considered a key element of postresuscitation care. Finally, modern postresuscitation care can produce good outcomes in the majority of patients but requires major diagnostic and therapeutic resources and specific training. Hence, recent international guidelines strongly recommend the implementation of regional prehospital resuscitation systems with integrated and specialized cardiac arrest centers.

Variation in Sedation and Neuromuscular Blockade Regimens on Outcome After Cardiac Arrest

OBJECTIVES

Sedation and neuromuscular blockade protocols in patients undergoing targeted temperature management after cardiac arrest address patient discomfort and manage shivering. These protocols vary widely between centers and may affect outcomes.

DESIGN

Consecutive patients admitted to 20 centers after resuscitation from cardiac arrest were prospectively entered into the International Cardiac Arrest Registry between 2006 and 2016. Additional data about each center's sedation and shivering management practice were obtained via survey. Sedation and shivering practices were categorized as escalating doses of sedation and minimal or no neuromuscular blockade (sedation and shivering practice 1), sedation with continuous or scheduled neuromuscular blockade (sedation and shivering practice 2), or sedation with as-needed neuromuscular blockade (sedation and shivering practice 3). Good outcome was defined as Cerebral Performance Category score of 1 or 2. A logistic regression hierarchical model was created with two levels (patient-level data with standard confounders at level 1 and hospitals at level 2) and sedation and shivering practices as a fixed effect at the hospital level. The primary outcome was dichotomized Cerebral Performance Category at 6 months.

SETTING

Cardiac arrest receiving centers in Europe and the United states from 2006 to 2016 PATIENTS:: Four-thousand two-hundred sixty-seven cardiac arrest patients 18 years old or older enrolled in the International Cardiac Arrest Registry.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

The mean age was 62 ± 15 years, 36% were female, 77% out-of-hospital arrests, and mean ischemic time was 24 (± 18) minutes. Adjusted odds ratio (for age, return of spontaneous circulation, location of arrest, witnessed, initial rhythm, bystander cardiopulmonary resuscitation, defibrillation, medical history, country, and size of hospital) was 1.13 (0.74-1.73; p = 0.56) and 1.45 (1.00-2.13; p = 0.046) for sedation and shivering practice 2 and sedation and shivering practice 3, respectively, referenced to sedation and shivering practice 1.

CONCLUSION

Cardiac arrest patients treated at centers using as-needed neuromuscular blockade had increased odds of good outcomes compared with centers using escalating sedation doses and avoidance of neuromuscular blockade, after adjusting for potential confounders. These findings should be further investigated in prospective studies.