Abstract
BACKGROUND:
When deciding whether mechanical ventilation is indicated, physicians integrate their findings on physical examination in a gestalt known as respiratory distress. Despite its importance, this gestalt is poorly understood. This study aims to describe the association between the rating of the severity of respiratory distress and vital signs, severity of illness, use of mechanical ventilation, and death. A prospective observational study with 1,134 consecutive subjects with uncertain triage evaluated by a critical care consult team was carried out in a public inner city teaching hospital.
METHODS:
After the initial evaluation of each patient, a critical care physician rated the level of respiratory distress. We recorded vital signs, diagnosis, and laboratory results and calculated the Acute Physiology and Chronic Health Evaluation (APACHE) II score. We recorded if mechanical ventilation was initiated by 72 h and if the subject died during the hospitalization.
RESULTS:
The most common diagnoses were respiratory illnesses. Higher distress levels were associated with higher breathing frequency (20, 22, 27, and 30 breaths/min, P < .001) and heart rate (96, 101, 109, and 116 beats/min, P < .001) and lower SpO2 (97, 95, 93, and 92%, P < .001). These variables explain only a small portion of the variance of distress. Distress correlated weakly with the APACHE II score (r = 0.22, P = .001). Blood pressure, temperature, Glasgow coma scale score, and laboratory data were unrelated to the levels of distress. However, higher levels of distress correlated with intubation rates (5, 13, 27, and 41%, P < .001). The area under the receiver operating characteristic curve for respiratory distress predicting intubation (0.72) was larger than that for breathing frequency (0.65). Distress was an independent predictor of intubation but not of death.
CONCLUSIONS:
A physician's rating of respiratory distress is independently predictive of intubation in 72 h. Vital signs explain only a small proportion of variance in distress; the other observations contributing to a physician's rating of distress must be determined.
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