A Retrospective Examination of the Efficacy of Paravertebral Block for Patients Requiring Intraoperative High-Dose Unfractionated Heparin Administration During Thoracoabdominal Aortic Aneurysm Repair

Abstract

Objective: Postoperative respiratory complications are serious and frequently observed among patients who undergo thoracoabdominal aortic aneurysm (TAAA) repair. Paravertebral block (PVB) can provide effective analgesia for relief of postoperative thoracotomy pain and may reduce respiratory complications. However, the impact of PVB on postoperative pain and respiratory function in patients who undergo TAAA repair requiring intraoperative high-dose heparin administration is unknown. This study examined the efficacy of PVB on postoperative pain and respiratory function after TAAA repairs.

Design: Retrospective, observational cohort study.

Setting: Single center in Japan.

Participants: Fifty-eight consecutive patients who underwent TAAA repair from March 2013 to October 2014.

Interventions: Application of thoracic PVB.

Measurement and main results: A total of 56 patients were analyzed. Two patients were excluded because 1 patient was dead within 24 hours after surgery and 1 patient was 9 years old. Patients with PVB were defined as group P (n = 17), and patients without PVB as group C (n = 39). There was no significant difference in baseline characteristics between the 2 groups. Both postoperative pain at rest and postoperative pain while coughing were assessed using a numeric rating scale (NRS); the incidence of reintubation and noninvasive positive-pressure ventilation (NPPV) also were compared between the 2 groups. The NRS score of postoperative pain at rest was significantly lower in group P (group P: Median 2, interquartile range 1 to 3; group C: Median 6, interquartile range 5 to 7; p = 0.000), and the NRS score of postoperative pain while coughing was significantly lower in group P (group P: Median 5, interquartile range 3.5 to 6.5; group C: Median 8, interquartile range 7 to 10; p = 0.000). Reintubation rate was significantly lower in group P (group P: 0%, group C: 23%, p = 0.045); the incidences of NPPV (group P: 12%, group C: 46%, p = 0.016) and postoperative pneumonia were significantly lower in group P (group P: 0%, group C: 28%, p = 0.024).

Conclusions: PVB significantly reduced postoperative pain at rest and while coughing and significantly reduced the reintubation rate, the rate of NPPV use, and postoperative pneumonia without complications. PVB could be a safe and an effective analgesic method that reduces postoperative respiratory exacerbation in patients who undergo TAAA repair.

Keywords: analgesia; anticoagulation; paravertebral block; pulmonary complications; thoracoabdominal aortic aneurysm repair; unfractionated heparin.