The median local analgesic dose of intrathecal bupivacaine with hydromorphone for labour: a double-blind randomized controlled trial

Abstract

Purpose Neuraxial hydromorphone has been reported to provide rapid onset of labour analgesia, effective segmental pain relief, and a longer duration of action than commonly used lipophilic opioids. This study was conducted to test the hypothesis that intrathecal hydromorphone reduces the dose requirement for intrathecal bupivacaine to induce rapid analgesia for women in the first stage of labour. Methods In this double-blind randomized controlled sequential allocation trial, 88 labouring parturients received combined spinal-epidural analgesia at 2-6 cm cervical dilation. Participants received intrathecal bupivacaine alone or bupivacaine plus hydromorphone 100 lg with the bupivacaine dose determined using updown sequential allocation. An effective dose was defined as a visual analogue pain score of B10 mm (on a 100-mm pain scale) reported within 20 min of injection. The median effective doses were calculated using the formula of Dixon and Massey and verified using isotonic regression. Results A decrease was observed in the median local analgesic doses (effective dose [ED50]) estimated according to the formulas of Dixon and Massey, with a between-group difference of -0.45 mg. The precision of the estimate was wide-ranging (95% confidence interval -1.23 to 0.33), so no definitive conclusion can be drawn. Conclusion Further research is needed to determine whether or not intrathecal hydromorphone 100 lg changes the dose of intrathecal bupivacaine required to induce labour analgesia within 20 min. Trial registration The trial was conducted in 2007 prior to widespread acceptance of the standard for clinical trial registration. RésuméObjectif Il a été décrit que l'hydromorphone administrée par voie neuraxiale favorisait l'installation rapide de

Preemptive analgesia for postoperative pain relief in thoracolumbosacral spine operations: a double-blind, placebo-controlled randomized trial

“…21 The use of epidural hydromorphone alone or hydromorphone with bupivacaine has been used with good results in joint arthroplasty, 12 scoliosis surgery, 10 and labor. 16 Both our study groups had significantly higher percentages of patients who did not require opioid rescue in the PACU. For both groups, if patients did require opioid rescue in the PACU, it was at a much later time.…”

Determination of ED50 and time to effectiveness for intrathecal hydromorphone in laboring patients using Dixon’s up-and-down sequential allocation method

“…Mhyre and colleagues were unable to conclude that 100 μg intrathecal hydromorphone significantly reduced intrathecal bupivacaine requirement for labor analgesia [ 8 ]. That group measured effective reduction in pain scores within 20 min but conceded that the 20 min window may have been too short.…”

“…In the United States, intrathecal use of hydromorphone is off-label per licensing by the United States Food and Drug Administration. We and others have discussed concerns about lack of demonstrated safety of intrathecal hydromorphone, specifically as it relates to neurotoxicity [ 8 , 12 , 16 – 18 ]. However, given the long track record of safety of other opioids (sufentanil, fentanyl, morphine, and meperidine), we are reasonably reassured with respect to hydromorphone [ 19 ].…”

“…Morphine has been found to be efficacious for postoperative analgesia following Caesarean delivery, but it has been found to have a limited role in labor analgesia because of its slow onset due to its relative lipid insolubility [ 6 , 7 ]. One recently published study has questioned the value of hydromorphone as an effective adjunct to intrathecal bupivacaine for labor analgesia [ 8 ]. The study had limitations, however, because the authors chose 20 min as their endpoint when maximal analgesia may not be achieved until later.…”