OBJECTIVE: Continuous bupivacaine paravertebral nerve
block after thoracotomy has been shown to reduce postoperative
pain. This study was designed to determine whether paravertebral
nerve block using bupivacaine infused through a catheter placed
intraoperatively, can reduce postoperative pain, and analgesia
requirements after loin incision.
METHODS: Thirty-four patients undergoing renal surgery
through loin incision at Jordan University Hospital, Amman,
Jordan, from October 2001 to March 2003, were randomized either
to receive bupivacaine 0.5% or normal saline through a catheter
positioned intraoperatively against the costovertebral joints in
the paravertebral space. The infusions were continued until the
evening of the third postoperative day. Patients had access on
request to intramuscular Morphine sulphate 5-15 mg, or
Diclofenac sodium 50-100 mg, or both depending on body weight.
Pain after operation was assessed at rest using linear visual
analogue scale. Patient scores were recorded in the recovery
room, at 4 hours, 8 hours, and at 9 am, and 5 pm.
RESULTS: The analgesia requirements for each patient were
recorded. Pain scores in the recovery room were significantly
lower in the bupivacaine group (mean 4.5 versus 8.0, p=0.001).
At 4 hours, the pain score was lower in the bupivacaine group
though not significant (mean 3.5 versus 4.37, p=0.393).
Thereafter, the pain scores were significantly lower in the
bupivacaine group. Mean morphine requirement in the bupivacaine
group was 13.3 mg (ranges 0-50), while in the saline group 40.13
mg (range 10-112.5), p<0.001. Morphine requirements in the first
and second postoperative days were significantly less in the
bupivacaine group (p=0.015 and p=0.03).
CONCLUSION: Paravertebral blockade using bupivacaine is
an effective and safe method for pain relief following renal
surgery through loin incision.
Institution
Department of Urology, Jordan University Hospital, Amman,
Jordan. zawwad@yahoo.com |