Prevalence, associations, and risk factors for orthostatic hypotension in medical, surgical, and trauma inpatients: an observational cohort study.

BACKGROUND: Orthostatic hypotension (OH) is prevalent in hospitalized elderly patients. It is defined as a reduction in systolic blood pressure (SBP) of at least 20 mmHg and/or diastolic blood pressure (DBP) of at least 10 mmHg within 3 minutes of standing from a lying position. This observational cohort study describes the prevalence, association with symptoms, and risk factors for OH in medical, surgical, and trauma wards in a tertiary hospital and the differences in hemodynamic behaviors between OH-positive (OHP) and OH-negative (OHN) patients.
METHODS: All 76 patients who were hemodynamically stable and able to stand from 4 hospital wards had noninvasive supine and orthostatic blood pressures (BPs) and pulse rates (PRs) measured over 4 days.
RESULTS: Mean age of the 76 patients included in the study was 67.8 ± 19.6 years. Overall prevalence of OH was 23.7% (95% CI: 14.7%-34.8%) with 21.2% (95% CI: 9.0%-38.9%) in medical, 31.8% (95% CI: 13.9%-54.9%) in surgical, and 19.0% (95% CI: 5.4%-41.9%) in trauma wards. OH had no association with symptoms (P  =  .53). We found no differences in age, number of comorbidities, and medication use between the OHN and OHP groups. The two groups displayed very different hemodynamic responses. The OHN group demonstrated a statistically significant compensatory rise in BP and PR over time to orthostatic challenge, while the OHP group displayed the opposite effect with BP. There was no statistically significant compensatory increase in PR over time to standing in the OHP group.
CONCLUSIONS: OH is common and mostly asymptomatic. Routine measurements are recommended to detect cases in the hospital setting. Our study did not identify any significant risk factors for OH but rather confirmed the previous finding that underlying impairment in autonomic responses in individuals may have instead contributed to the development of OH.