Analgesia in patients undergoing thoracotomy: epidural versus paravertebral technique. A randomized, double-blind, prospective study.

BACKGROUND

Pain control after thoracotomy prevents postsurgical complications and improves respiratory function. The gold standard for post-thoracotomy analgesia is the epidural catheter. The aim of this study was to compare it with a new technique that involves placement of a catheter in the paravertebral space at the end of surgery under a surgeon's direct vision.

METHODS

From November 2011 to June 2012, 52 patients were randomized into 2 groups depending on catheter placement: an epidural catheter for group A and a paravertebral catheter for group B. At 12, 24, 48, and 72 hours after surgery, the following parameters were recorded: (1) pain control using the patient's completion of a visual analog scale module, (2) respiratory function using forced expiratory volume in 1 second and ambient air saturation, and (3) blood cortisol values as an index of systemic reaction to pain.

RESULTS

Statistically significant differences (P < .05) were found in favor of group B for both cough and rest pain control (P = .002 and .002, respectively) and respiratory function in terms of forced expiratory volume in 1 second and ambient air saturation levels (P = .023 and .001, respectively). No statistically significant differences were found in blood cortisol trends between the 2 groups (P > .05). Collateral effects such as vomiting, nausea, low pressure, or urinary retention were observed only in group A. No collateral effects were recorded in the paravertebral group.

CONCLUSIONS

According to our data, drugs administered through a paravertebral catheter are very effective. Moreover, it does not present contraindications to its positioning or collateral effects. More studies are necessary to confirm data we collected.