Spirometry Not Pain Level Predicts Outcomes in Geriatric Patients with Isolated Rib Fractures

J Trauma Acute Care Surg. 2020 May 26. doi: 10.1097/TA.0000000000002795. Online ahead of print.

Abstract

Background: Geriatric patients with rib fractures are at risk for developing complications and are often admitted to a higher level of care (intensive care units, ICU) based on existing guidelines. Forced vital capacity has been shown to correlate with outcomes in patients with rib fractures. Complete spirometry may quantify pulmonary capacity, predict outcome and potentially assist with admission triage decisions.

Methods: We prospectively enrolled 86 patients, 60 and over with three or more isolated rib fractures presenting after injury. After informed consent patients were assessed with respect to: pain (visual-analog scale), grip strength, forced vital capacity (FVC), forced expiratory volume 1 second (FEV1), and negative inspiratory force (NIF) on hospital days 1, 2, and 3. Outcomes included discharge disposition, length of stay (LOS), pneumonia, intubation, and unplanned ICU admission.

Results: Mean age was 77.4 (±10.2) and 43 (50.0%) were female. Forty-five patients (55.6%) were discharged home, median LOS was 4 days (IQR 3, 7). Pneumonias (2), unplanned ICU admissions (3) and intubation (1) were infrequent. Spirometry measures including FVC, FEV1, and grip strength predicted discharge to home and FEV1 and pain level on day one moderately correlated with the LOS. Within each subject FVC, FEV1 and NIF did not change over three days despite pain at rest and pain after spirometry improving from day one to three (p=0.002, p<0.001 respectively). Change in pain also did not predict outcomes and pain level was not associated with respiratory volumes on any of the three days. After adjustment for confounders FEV1 remained a significant predictor of discharge home (OR 1.03 95% CI [1.01-1.06]) and LOS, p=0.001.

Conclusion: Spirometry measurements early in the hospital stay predict ultimate discharge home and this may allow immediate or early discharge. The impact of pain control on pulmonary function requires further study.

Level of evidence: Level IV, diagnostic test.