Vasopressor Initiation More Likely as Disease Severity Increases in Patients With Sepsis, Hypotension

The probability of vasopressor initiation increased as overall disease severity increased in patients with sepsis and hypotension, according to findings published in Frontiers in Medicine.

“Sepsis and septic shock represent major public health challenges, contributing to 1 in every 2 to 3 hospital deaths in the United States,” authors said. “Clinically, septic shock is simply defined as a condition of sepsis when vasopressors are required for blood pressure support.”

Researchers created a statistical model to define usual clinical care for vasopressors in patients with hypotension and sepsis. The retrospective analysis involved 589 adult patients who met criteria for severe sepsis and septic shock, admitted to the emergency department between April 1, 2014 and March 31, 2016.

Authors measured vasopressor initiation as well as candidate predictors including routine vital signs, age, gender, race, time elapsed in the emergency department, major pre-existing comorbidities, lab results, common symptoms of infection, and referral for an infectious reason.

Of the full sample, 384 patients were treated with vasopressors at some point in their emergency department visit. The model effectively allowed researchers to distinguish between patients who did not receive vasopressors and patients who were given vasopressors for over 24 hours.

Intravenous fluid volume and several basic vital signs, including SpO₂ and components of the qSOFA sepsis severity score, were predictors for vasopressor administration. Lactate, creatinine, and white blood cell count were absent from the model.

“This implies that, at our medical center, usual care may not be as simple as ‘liberal fluids’ as has been previously described,” authors wrote.

The model also indicated patients who would go on to receive vasopressors for more than 24 hours did not present with clinical parameters typically consistent with vasopressor initiation beforehand. Researchers found only systolic blood pressure measurements significantly changed prior to vasopressor initiation.

Additionally, 25% of patients who received vasopressors initiated treatment earlier than the model predicted. Most of these patients started vasopressors before intravenous fluid. Authors said this suggests there was a documentation error or providers used other clinical cues when deciding to administer immediate treatment.

“Taken together, these findings suggest that, in usual care, the decision to initiate vasopressors is titrated to disease severity: the probability of starting vasopressors at any given time increased as overall disease severity increased,” authors wrote. “Conversely, patients with isolated hypotension in the absence of other signs of organ dysfunction were less likely to have vasopressors initiated.”

Researchers recommended their dynamic care model be used to interpret clinical trial data.

“In short, application of the model was able to identify a sizable minority of vasopressor patients who may have received excess [intravenous fluid], instead of vasopressor initiation, consistent with the institution's usual care,” authors concluded, adding the “model might be able to identify care differences between centers and thereby help provide evidence regarding the use of liberal vs restrictive fluid administration.”

Reference:
Prasad V, Reisner AT, Lynch JC, Filbin MR, Heldt T. Modeling of usual care: vasopressor initiation for sepsis with hypotension. Front Med (Lausanne). 2022;9:715856. doi:10.3389/fmed.2022.715856