Spirometry not pain level predicts outcomes in geriatric patients with isolated rib fractures.

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 [ICUs]) based on existing guidelines. Forced vital capacity (FVC) 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 years or older 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, FVC, forced expiratory volume 1 second (FEV1), and negative inspiratory force 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 (SD, 10.2) and 43 (50.0%) were female. Forty-five patients (55.6%) were discharged home, median LOS was 4 days (interquartile range, 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 1 moderately correlated with the LOS. Within each subject, FVC, FEV1, and negative inspiratory force did not change for 3 days despite pain at rest and pain after spirometry improving from day 1 to 3 (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 3 days. After adjustment for confounders, FEV1 remained a significant predictor of discharge home (odds ratio, 1.03; 95% confidence interval, 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: Diagnostic test, level IV.