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Study finds administering IV fluids during emergency tracheal intubation does not lower cardiac arrest risk

Jun. 20, 2022, 9:39 AM

by Nancy Humphrey

Rapidly administering IV fluids to critically ill adults undergoing emergency tracheal intubation does not significantly decrease chances of hypotension (low blood pressure) and cardiac arrest, a Vanderbilt University Medical Center-led study shows.

The results of the PREventing cardiovascular collaPse with Administration of fluid REsuscitation during Induction and Intubation (PREPARE II) trial, published in the Journal of the American Medical Association (JAMA), were presented June 16 at the 2022 Critical Care Reviews Conference in Belfast, Ireland.

Current international guidelines recommend preventive IV fluids prior to emergency tracheal intubation. A fluid bolus is administered during approximately 40-50% of tracheal intubations in current clinical practice, said Matthew Semler, MD, MSCI, assistant professor of Medicine in the Division of Allergy, Pulmonary and Critical Care Medicine and senior author of the study. The belief has been that the fluid bolus will transiently increase intravascular volume and prevent dangerously low blood pressures.

“From 2014 to 2018, approximately 2 million critically ill adults underwent tracheal intubation each year in the United States,” Semler said. “For critically ill adults undergoing tracheal intubation, one in five will experience severe hypotension, which can lead to death. It’s very common.”

Although patients are also intubated during scheduled surgeries in the operating room, severe hypotension occurs much less commonly in that setting, Semler said. “Patients coming to the operating room for elective procedures have been at home and been doing relatively well, and their surgery can be delayed or canceled if they appear unwell. In an emergency department or intensive care unit, patients are usually being intubated because they are unwell — they’re bleeding or have a bad infection. Those groups of critically ill patients are at a much higher risk for all complications, including severe hypotension.”

The randomized clinical trial included 1,065 critically ill adults at 11 intensive care units in the United States between Feb. 1, 2019, and May 24, 2021. The incidence of cardiovascular collapse was 21% with administration of a fluid bolus and 18.2% without, a difference that was not statistically significant.

Semler said a previous trial looked at whether a fluid bolus prevented hypotension in tracheal intubation patients, but it was halted early and wasn’t definitive. This follow-up study is very definitive. It closes the door.”

The study was led by the Pragmatic Critical Care Research Group, led by Semler and Jonathan Casey, MD, MSCI, assistant professor of Medicine in the Division of Allergy, Pulmonary and Critical Care Medicine and co-first author of the study.

Semler said that because hypotension is common during emergency tracheal intubation and a fluid bolus has been definitively shown to be ineffective at preventing hypotension during intubation, future studies will need to focus on other potential causes like the sedative medication used to induce loss of consciousness at the time of intubation.

Casey is leading another study, funded by the National Heart Lung and Blood Institute (NHLBI) to compare the most commonly used sedatives during emergency tracheal intubation to see if one is better for patients.

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