Effect of ultrasound guided patient-controlled paravertebral block on pulmonary function in patients with multiple fractured ribs

Abstract

Objective: To investigated the effects of patient controlled intravenous analgesia and ultrasound guided patient-controlled paravertebral block on pulmonary function in patients with multiple fractured ribs. Methods: From May 2015 to March 2016, 60 patients with multiple rib fractures in Ningbo NO.6 Hospital with American Society of Anesthesiologists Ⅱ-Ⅲ underwent internal fixation, including 30 males and 30 females aged from 16 to 70 years(mean age (54.6±15.2) years). All patients were randomly divided into 2 groups (n=30 each): patient controlled intravenous analgesia(PCIA) group and patient controlled thoracic paravertebral block(PCPB) group.PCIA solution contained sufentanil 2 μg/kg in 100 ml of normal saline.The PCIA pump was set up to deliver a 2 ml bolus dose with 15 minutes lockout interval and background infusion at 2 ml/hour.In PCPB group, the patients received paravertebral injection of 0.2% ropivocaine 15 ml on the corresponding area of fractured side under ultrasound guidance at the end of operation, and then received PCPB.PCPB solution contained 0.75% ropivacaine 67 ml in 250 ml of normal saline, and the pump was set up to deliver a 5 ml bolus dose, with 15 minutes lock out interval and background infusion at 5 ml/hour. Both analgesia lasted to 72 hours after operation.Before the operation, at 30 minutes, 60 minutes, 1 day, 2 days, 3 days after analgesia, arterial blood samples were collected to test the levels of pH, PaO2, PaCO2, PaO2/FiO2 and PA-aDO2. The pulmonary function was also examined before and 3 days after the operation through FEV1 and FEV1%. Results: Compared with PCIA group at 30 minutes, 60 minutes, 1 day, 2 days, 3 days after analgesia, the level of PaO2 ((85.1±9.7)mmHg vs.(72.4±12.3)mmHg, (90.3±12.4)mmHg vs.(73.5±7.8)mmHg, (94.2±8.2)mmHg vs.(86.1±5.6)mmHg, (98.5±7.0)mmHg vs. (88.8±7.5)mmHg, (99.6±9.8)mmHg vs. (91.3±8.6)mmHg, P<0.05)) and PaO2/FiO2 were significantly increased ((405.1±46.0)mmHg vs. (340.1±58.9)mmHg, (430.5±59.1)mmHg vs. (344.0±65.4)mmHg, (448.3±39.1)mmHg vs. (410.1±26.7)mmHg, (460.1±33.5)mmHg vs. (423.2±36.5)mmHg, (465.1±28.2)mmHg vs. (435.1±40.8)mmHg, P<0.05)), the level of PA-aDO2 was decreased ((22.9±4.6)mmHg vs. (36.6±5.1)mmHg, (17.7±4.7)mmHg vs. (34.5±2.9)mmHg, (13.8±4.1)mmHg vs. (21.9±3.2)mmHg, (13.5±4.6)mmHg vs. (19.2±3.8)mmHg, (12.4±2.0)mmHg vs. (17.7±2.4)mmHg, P<0.05)), and FEV1, FEV1% were significantly increased at 3 days after operation in PCPB group ((2.9±0.4)mmHg vs.(2.2±0.5)mmHg, (78.1±4.7)mmHg vs.(64.8±4.3)mmHg; P<0.01)). Conclusion: Ultrasound guided patient-controlled paravertebral block improves the arterial oxygenation function and accelerates the recovery of pulmonary function in patients with multiple-fractured ribs after internal fixation operation.