L. Niemi et al., EVALUATION OF THE USEFULNESS OF INTRATHECAL BUPIVACAINE INFUSION FOR ANALGESIA AFTER HIP AND KNEE ARTHROPLASTY, British Journal of Anaesthesia, 77(4), 1996, pp. 544-545
Spinal anaesthesia in 47 ASA I-III patients was induced with 0.5% bupi
vacaine 2 ml via a 28-gauge spinal catheter (L3-4 interspace) and 0.5-
ml increments were given if needed before or during hip or knee arthro
plasty. Intrathecal 24-h infusions consisted of 0.5% bupivacaine 0.4 m
l h(-1) (2 mg h(-1)) (n=12), 0.5% bupivacaine 0.2 ml h(-1) (1 mg h(-1)
) (n=12) or saline (n=11) (12 exclusions). Patients received oxycodone
0.1-0.14 mg kg(-1) i.m. for rescue analgesia. Infusion of bupivacaine
2 mg h(-1) provided significantly better postoperative analgesia (19
oxycodone doses per group in 24 h) compared with bupivacaine 1 mg h(-1
) (36 doses of oxycodone per group) and saline (52 doses per group) (P
<0.05). Five patients in the bupivacaine 2-mg h(-1) group and none in
the other groups had measurable sensory block 24 h after the infusion
was started. Three patients in the bupivacaine 2-mg h(-1) group, two w
ith concomitant arterial hypotension, and one patient in the bupivacai
ne 1-mg h(-1) group experienced an increase in block on the ward. The
incidence of nausea and vomiting was similar in all groups. Although a
n effective analgesic, intrathecal infusion of bupivacaine 2 mg h(-1)
cannot be recommended for routine pain relief because of the risk of i
ncreasing spinal block. Technical problems (19%) also reduced the over
all efficacy of the continuous intrathecal analgesic regimen.