RESUMEN
BACKGROUND: We evaluated if incentive spirometry volume (ISV) and peak expiratory flow rate (PEFR) could predict acute respiratory failure (ARF) in patients with rib fractures. METHODS: Normotensive, co-operative patients were enrolled prospectively. ISV and PEFR were measured on admission, at 24 h and at 48 h by taking the best of three readings each time. The primary outcome, ARF, was defined as requiring invasive or noninvasive positive pressure ventilation. RESULTS: 99 patients were enrolled (median age, 77 years). ARF occurred in 9%. Of the lung function tests, only a low median ISV at admission was associated with ARF (500 ml vs 1250 ml, p = 0.04). Three of 69 patients with ISV of ≥1000 ml versus six of 30 with ISV <1000 ml developed ARF (p = 0.01). Other significant factors were: number of rib fractures, tube thoracostomy, any lower-third rib fracture, flail segment. CONCLUSION: PEFR did not predict ARF. Admission ISV may have value in predicting ARF.