Risk factors for vital sign deviations in acutely admitted medical patients - an exploratory analysis

In acutely admitted patients, comorbidities, and other patient characteristics known at admission might be risk factors for physiological deterioration during hospitalization. Knowledge of specific risk factors could therefore help clinicians escalate or decrease monitoring practices for selected patient categories. We investigated the association between information obtained at admission and the risk of subsequent severe vital signs deviations in acutely admitted medical patients.

We analyzed data from three clinical trials using continuous monitoring of vital signs in adults during acute medical hospitalizations. The primary exposure variable was number of comorbidities and were obtained from the medical record along with other potential risk factors at the time of admission. The primary outcome was cumulated duration of severe vital sign deviations (SpO2 < 85%, respiratory rate ≤5 min^-1 or > 24 min^-1, heart rate < 30 min^-1 or > 130 min^-1, or systolic blood pressure < 91 mmHg or > 219 mmHg).

We included data from 553 patients (51% female, median age 72 years), of whom 96% were admitted with respiratory symptoms. Patients with two or more comorbidities had severe vital sign deviations lasting 145 minutes/24 hours as compared with 90 minutes/24 hours in patients with none or one comorbidity, p = 0.07. Patients with severe tachypnea upon arrival ( > 30 brpm) had long duration of deviations (241 minutes per 24 hours [IQR 132;421]) as well as patients with increased CRP > 100 mg/L whose durations of deviations were 175 minutes per 24 hours [IQR 60;339].

Comorbidity burden, tachypnea, and increased level of CRP upon arrival were to some extent risk factors for subsequent vital sign deviations. Information obtained at acute admissions can be useful in establishing and escalating patient monitoring level.