Thoracic epidural analgesia for off-pump coronary artery bypass surgery in patients with chronic obstructive pulmonary disease.

ABSTRACT

The benefits of thoracic epidural analgesia in patients undergoing coronary artery bypass grafting are well documented. However, the literature available on the role of high thoracic epidural analgesia (HTEA) in patients with chronic obstructive pulmonary disease undergoing off-pump coronary artery bypass graft (OPCAB) surgery is scarce. We conducted a randomized clinical trial to establish whether HTEA is beneficial in patients with chronic obstructive pulmonary disease undergoing elective OPCAB surgery. After institutional ethics board approval and informed consent, 62 chronic obstructive pulmonary disease patients undergoing elective OPCAB were randomly grouped into two (n = 31 each). Both groups received general anesthesia (GA), but in the HTEA group patients, TEA was also administered. Standardized surgical and anesthetic techniques were used for both the groups. Pulmonary function tests were performed pre-operatively, 6 h and 24 h post-extubation and on days 2, 3, 4 and 5 along with arterial blood gas analysis (ABG) analysis. Time for extubation (h) and time for oxygen withdrawal (h) were recorded. Pain score was assessed by the 10-cm visual analogue scale. All hemodynamic/oxygenation parameters were noted. Any complications related to the TEA were also recorded. Patients in the HTEA group were extubated earlier (10.8 h vs. 13.5 h, P < 0.01) and their oxygen withdrawal time was also significantly lower (26.26 h vs. 29.87 h, P < 0.01). The VAS score, both at rest and on coughing, was significantly lower in the HTEA group at all times, post-operatively (P < 0.01). The forced vital capacity improved significantly at 6 h post-operatively in the HTEA group (P = 0.026) and remained significantly higher thereafter. A similar trend was observed in forced expiratory volume in the first second on day 2 in the HTEA group (P = 0.024). We did not observe any significant side-effects/mortality in either group. In chronic obstructive pulmonary disease patients undergoing elective OPCAB surgery, HTEA is a good adjunct to GA for early extubation, faster recovery of pulmonary function and better analgesia.