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

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. Key words: Rib fractures; Analgesia; Ultrasound guided; Thoracic paravertebral block; Pulmonary function