The association between intravenous fluid resuscitation and mortality in older emergency department patients with suspected infection.

Objective: Recent studies suggest that hypotension thresholds in current guidelines might be too low for older patients due to arterial stiffening, possibly leading to insufficient fluid resuscitation. We compared intravenous (IV) fluid volumes that older (≥ 70 years) and younger (< 70 years) patients with suspected infection with similar initial systolic blood pressure (SBP) received in the emergency department (ED) and investigated whether this was associated with in-hospital mortality in older patients.

Methods: This was an observational multicenter study using an existing database in which consecutive ED patients hospitalized with suspected infection were prospectively included. We first compared the fluid volumes older and younger ED patients received per initial SBP category. Patients were then stratified into two SBP categories (≤ or > 120 mmHg; 120 has been suggested to be a better threshold) and thereafter into three fluid volume categories: 0-1 L, 1-2 L, or > 2 L. In each SBP and fluid category, case-mix-adjusted in-hospital mortality was compared between older and younger patients, using multivariable logistic regression analysis.

Results: The included 981 (37%) older and 1678 (63%) younger ED patients received similar IV fluid volumes per initial SBP category. Older patients with an initial SBP > 120 mmHg had a higher adjusted OR of 2.06 (95% CI 1.02-4.16), in the 0-1 L category, while this association was not found in the higher fluid categories of 1-2 L or > 2 L. In the SBP ≤ 120 mmHg category, this association was also absent.

Conclusion: This hypothesis-generating study suggests that older patients with suspected infection may need higher fluid volumes than younger patients, when having a seemingly normal initial SBP.