Small-dose naloxone combined with epinephrine improves the resuscitation of cardiopulmonary arrest

Outcomes of Out-of-Hospital Cardiac Arrest Patients Who Received Naloxone in an Emergency Medical Services System With a High Prevalence Of Opioid Overdose

BACKGROUND

Opioid-associated out-of-hospital cardiac arrest (OA-OHCA) is a subset of cardiac arrests that could benefit from measures outside of standard Advanced Cardiac Life Support (ACLS), such as naloxone.

STUDY OBJECTIVES

In this study, we sought to examine whether OHCA patients chosen for naloxone therapy by emergency medical services (EMS) clinicians in a system with high rates of opioid overdose would have increased rates of return of spontaneous circulation (ROSC) and survival to hospital discharge.

METHODS

The study took place in an urban EMS system with a high prevalence of opioid overdose. Paramedics could administer naloxone in cardiac arrest in addition to ACLS. It was often administered based on clinical gestalt for suspected OA-OHCA. The outcomes of OHCA patients who received naloxone were compared against those who received usual care in both an adjusted and unadjusted fashion. Lastly, we created a logistic regression model to test for an independent association of naloxone administration on ROSC and survival to hospital discharge.

RESULTS

A consecutive sample of 769 OHCA patients was obtained, of which 175 (23%) received naloxone. On average, patients who received naloxone had significantly fewer comorbidities and were younger. There was no difference in ROSC, survival to hospital discharge, or modified Rankin Scores. Using logistic regression modeling, there was no statistically significant effect of naloxone administration on these outcomes.

CONCLUSION

OHCA patients who received naloxone, despite being younger and having fewer comorbidities, had similar outcomes compared to those who received usual care. The difference in baseline characteristics suggests that paramedic gestalt reasonably selected for OA-OHCA.

Opioid-Associated Out-of-Hospital Cardiac Arrest: Distinctive Clinical Features and Implications for Health Care and Public Responses: A Scientific Statement From the American Heart Association

Opioid overdose is the leading cause of death for Americans 25 to 64 years of age, and opioid use disorder affects >2 million Americans. The epidemiology of opioid-associated out-of-hospital cardiac arrest in the United States is changing rapidly, with exponential increases in death resulting from synthetic opioids and linear increases in heroin deaths more than offsetting modest reductions in deaths from prescription opioids. The pathophysiology of polysubstance toxidromes involving opioids, asphyxial death, and prolonged hypoxemia leading to global ischemia (cardiac arrest) differs from that of sudden cardiac arrest. People who use opioids may also develop bacteremia, central nervous system vasculitis and leukoencephalopathy, torsades de pointes, pulmonary vasculopathy, and pulmonary edema. Emergency management of opioid poisoning requires recognition by the lay public or emergency dispatchers, prompt emergency response, and effective ventilation coupled to compressions in the setting of opioid-associated out-of-hospital cardiac arrest. Effective ventilation is challenging to teach, whereas naloxone, an opioid antagonist, can be administered by emergency medical personnel, trained laypeople, and the general public with dispatcher instruction to prevent cardiac arrest. Opioid education and naloxone distributions programs have been developed to teach people who are likely to encounter a person with opioid poisoning how to administer naloxone, deliver high-quality compressions, and perform rescue breathing. Current American Heart Association recommendations call for laypeople and others who cannot reliably establish the presence of a pulse to initiate cardiopulmonary resuscitation in any individual who is unconscious and not breathing normally; if opioid overdose is suspected, naloxone should also be administered. Secondary prevention, including counseling, opioid overdose education with take-home naloxone, and medication for opioid use disorder, is important to prevent recurrent opioid overdose.

Effects of terlipressin and naloxone compared with epinephrine in a rat model of asphyxia-induced cardiac arrest

OBJECTIVE

To evaluate the hemodynamic and metabolic effects of terlipressin and naloxone in cardiac arrest.

METHODS

Cardiac arrest in rats was induced by asphyxia and maintained for 3.5 minutes. Animals were then resuscitated and randomized into one of six groups: placebo (n = 7), epinephrine (0.02 mg/kg; n = 7), naloxone (1 mg/kg; n = 7) or terlipressin, of which three different doses were tested: 50 µg/kg (TP50; n = 7), 100 µg/kg (TP100; n = 7) and 150 µg/kg (TP150; n = 7). Hemodynamic variables were measured at baseline and at 10 (T10), 20 (T20), 30 (T30), 45 (T45) and 60 (T60) minutes after cardiac arrest. Arterial blood samples were collected at T10, T30 and T60.

RESULTS

The mean arterial pressure values in the TP50 group were higher than those in the epinephrine group at T10 (165 vs. 112 mmHg), T20 (160 vs. 82 mmHg), T30 (143 vs. 66 mmHg), T45 (119 vs. 67 mmHg) and T60 (96 vs. 66.8 mmHg). The blood lactate level was lower in the naloxone group than in the epinephrine group at T10 (5.15 vs. 10.5 mmol/L), T30 (2.57 vs. 5.24 mmol/L) and T60 (2.1 vs. 4.1 mmol/L).

CONCLUSIONS

In this rat model of asphyxia-induced cardiac arrest, terlipressin and naloxone were effective vasopressors in cardiopulmonary resuscitation and presented better metabolic profiles than epinephrine. Terlipressin provided better hemodynamic stability than epinephrine.