Contributor: Travis Barlock, MD

Educational Pearls:

What is pulmonary edema?

Pulmonary edema is the accumulation of fluid initially in the interstitium of the lungs, that when severe enough can also accumulate in the alveolar air sacs. It develops when the rate of fluid filtration through the pulmonary vasculature out-paces the lymphatics ability to drain the fluid.

There are 2 theories for what causes pulmonary edema in the setting of naloxone administration: catecholamine surge vs negative pressure/barotrauma

Catecholamine Surge : Naloxone administration precipitates an acute opioid withdrawal in which epinephrine and norepinephrine surge causing marked vasoconstriction on both the heart and the lungs
Negative Pressure/Barotrauma: This mechanism is not directly naloxone related but may be confounded by opioid effects. High dose synthetic opioids can induce sustained laryngospasm that is not mu-opioid mediated (thus not easily reversed by naloxone). With rapid awakening, respiratory muscles induce a negative pressure in the thoracic cavity against a closed glottis. This results in an alveolar barotrauma and a transudative pulmonary edema.

What is the treatment for pulmonary edema secondary to opioid overdose reversal?

Positive pressure ventilation is the mainstay treatment (CPAP/BiPAP) with oxygen supplementation.
Importantly, diuretics are not recommended. The patient is not fluid overloaded like in the case of other pulmonary edemas, and diuresing the patient can worsen kidney injury which is already at an increased risk in opioid overdoses (rhabdomyolysis in particular).

References:

Saari TI, Strang J, Dale O. Clinical Pharmacokinetics and Pharmacodynamics of Naloxone. Clin Pharmacokinet. 2024;63(4):397-422. doi:10.1007/s40262-024-01355-6
DailyMed - NALOXONE HYDROCHLORIDE injection, solution. https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=201fdedf-1736-4e52-9d7d-de14292547fd
Boyer EW. Management of Opioid Analgesic Overdose. New England Journal of Medicine. 2012;367(2):146-155. doi:10.1056/NEJMra1202561
Dezfulian C, Orkin AM, Maron BA, et al. 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. Circulation. 2021;143(16):e836-e870. doi:10.1161/CIR.0000000000000958
Kienbaum P, Thurauf N, Michel M, Scherbaum N, Gastpar M, Peters J. Profound Increase in Epinephrine Concentration in Plasma and Cardiovascular Stimulation after [micro sign]-Opioid Receptor Blockade in Opioid-addicted Patients during Barbiturate-induced Anesthesia for Acute Detoxification Anesthesiology. 1998;88(5):1154-1161. doi:10.1097/00000542-199805000-00004

Summarized by Dan Orbidan, OMS3 | Edited by Dan Orbidan & Ahmed Abdel-Hafiz, NREMT-P