Continuous thoracic paravertebral infusion of bupivacaine for pain management in patients with multiple fractured ribs

Study objective: To evaluate the efficacy of a continuous thoracic paravertebral infusion of bupivacaine for pain management in patients with unilateral multiple fractured fibs (MFR). Design: Prospective nonrandomized case series. Setting: Multidisciplinary tertiary hospital. Patients: Fifteen patients with unilateral MFR. Interventions: Insertion of a catheter into the thoracic paravertebral space. We administered an initial injection of 0.3 mL/kg (1.5 mg/kg) bupivacaine 0.5% with 1:200,000 epinephrine followed 30 min later by an infusion of bupivacaine 0.25% at 0.1. to 0.2 mL/kg/h for 4 days. Measurements and results: The following parameters were measured during the initial assessment before thoracic paravertebral block (TPVB), 30 min after the initial injection, and during follow-up on day I and day 4 after commencing the infusion of bupivacaine: visual analog pain score at rest and during coughing; respiratory rate; arterial oxygen saturation (Sao(2)); bedside spirometry (ie, FVC, FEV1, FEV1/FVC ratio, and peak expiratory flow rate [PEFR]); arterial blood gas measurements; and O-2 index (ie, Pao(2)/fraction of inspired oxygen ratio). There were significant improvements in pain scores (at rest, p = 0.002; during coughing, p = 0.001), respiratory rate (p < 0.0001), FVC (p = 0.007), PEFR (p = 0.01), Sao(2) (p = 0.04), and 02 index (p = 0.01) 30 min after the initial injection, which were sustained for the 4 days that the thoracic paravertebral infusion was in use (p < 0.05). Paco(2) did not change significantly after the initial injection, but on day 4 it was significantly lower than the post-TPVB value (p = 0.04). One patient had an inadvertent epidural injection, and another developed transient ipsilateral Horner syndrome with sensory changes in the arm. No patient exhibited clinical signs of inadvertent intravascular injection or local anesthetic toxicity. Conclusion: Our results confirmed that continuous thoracic paravertebral infusion of bupivacaine is a simple and effective method of providing continuous pain relief in patients with unilateral MFR. It also produced a sustained improvement in respiratory parameters and oxygenation.