The effect of propofol on intrathecal morphine-induced pruritus and its mechanism

Pharmacological agents for prevention of pruritus in women undergoing Caesarean delivery with neuraxial morphine: a systematic review and Bayesian network meta-analysis

BACKGROUND

Neuraxial opioids provide effective analgesia for Caesarean delivery, however, pruritus can be a troubling side-effect. Effective agents to prevent pruritus are needed. Our objective was to perform an updated systematic review and network meta-analysis to provide clinicians with a comparison of relative efficacy of available interventions to reduce the incidence of pruritus, induced by either intrathecal or epidural single-shot morphine, in women undergoing Caesarean delivery.

METHODS

Databases systematically searched (up to January 2022) included PubMed MEDLINE, Web of Science, EBSCO CINAHL, Embase, LILACS, and two Cochrane databases. We included randomised, controlled trials involving adult female patients undergoing Caesarean delivery. We pooled trials comparing interventions used for preventing pruritus after Caesarean delivery and performed a Bayesian model network meta-analysis.

RESULTS

The final primary network included data from comparisons of 14 distinct interventions (including placebo) used to reduce the incidence of pruritus in 6185 participants. We judged five interventions to be 'definitely superior' to placebo: propofol, opioid agonist-antagonists (neuraxial), opioid antagonists, opioid agonist-antagonists (systemic), and serotonin antagonists. For the network evaluating the incidence of severe pruritus (warranting additional therapeutic treatment of pruritus), data were available for 14 interventions (including placebo) in 4489 patients. For this outcome, we judged three interventions to be 'definitely superior' to placebo: dopamine antagonists (neuraxial) and systemic and neuraxial opioid agonist-antagonists.

CONCLUSION

Our analysis found several interventions to be effective in reducing the incidence of pruritus. Although sub-hypnotic doses of propofol appear to have an antipruritic effect, replication of this finding and further investigation of optimal dosing are warranted.

SYSTEMATIC REVIEW PROTOCOL

PROSPERO (CRD42022367058).

The effect of transversus abdominis plane block application on postoperative analgesia quality and patient satisfaction after varicocele surgery: a randomized clinical trial

Background

Postoperative pain management is an important aspect of anesthesia care and multimodal analgesic techniques are generally recommended.

Objective

To compare the effect of spinal anesthesia + transversus abdominis plane (TAP) block application on postoperative analgesia quality and patient satisfaction with spinal anesthesia + intrathecal morphine (ITM) application.

Methods

A total of 70 patients were randomly separated into 2 groups as spinal anesthesia + TAP block (TAP block group, n = 34) and spinal anesthesia + ITM group (ITM group, n = 36). The groups were compared in respect of age, body mass index values, and visual analog scale (VAS) values at 0 h, 2 h, 6 h, 12 h, and 18 h, and patient satisfaction was scored by Quality Improvement in Postoperative Pain Management at 24 h.

Results

The mean age of the patients was 32.52 ± 6.50 years in the TAP block group and 30.11 ± 5.62 years in the ITM group, with no statistically significant difference determined. There was no statistically significant difference in terms of VAS values at 0 h, 2 h, 6 h, 12 h, and 18 h. When the factors affecting postoperative patient satisfaction were evaluated, feeling fatigue after the surgery (r = -0.811, P = 0.001) and postoperative complications such as nausea, vomiting, and itching (r = -0.831, P = 0.001) were found to have a negative effect on patient satisfaction.

Conclusion

Due to low complication rates, TAP block is an effective application for postoperative analgesia management in varicocele operations that increases patient satisfaction postoperatively.

Sub-hypnotic dose of propofol as antiemetic prophylaxis attenuates intrathecal morphine-induced postoperative nausea and vomiting, and pruritus in parturient undergoing cesarean section - a randomized control trial

Background

Postoperative Nausea and Vomiting (PONV) is a dreadful and uncomfortable experience that significantly detracts patients’ quality of life after surgery. This study aimed to examine the antiemetic effect of a single sub-hypnotic dose of propofol as prophylaxis for PONV.

Method

In this prospective, double-blind, randomized control trial, 345 parturients presented for elective cesarean section at the Obstetric unit of Tamale Teaching Hospital were recruited. Each recruited parturient was randomly assigned to one of three groups; Propofol group (n = 115) represented those who received propofol 0.5 mg/kg, Metoclopramide group (n = 115) represented those who received metoclopramide 10 mg and, Control group (n = 115) represented those who received 0.9% saline. Spinal anesthesia with 0.5% hyperbaric bupivacaine 7.5–10 mg, and intrathecal morphine 0.2 mg was employed for the anesthesia.

Results

The data indicate that 108 (93.9%) parturients from the control group, 10 (8.7%) from the propofol group and 8 (7.0%) from the metoclopramide group experienced some incidence of PONV. There was no significant difference in the incidence of PONV (nausea, vomiting, and none) between the propofol and the metoclopramide groups (P = 0.99; 0.31; and 0.35 respectively). Parturients who received antiemetic agents were 105 (97.2%), 1 (10.0%) and 3 (37.5%) from the control, propofol and metoclopramide groups respectively. The data indicated that 98 (85.2%) parturients from the control, 3 (2.6%) from propofol group, and 100 (87.0%) from the metoclopramide group experienced some levels of pruritus. There was a significant difference in the incidence of pruritus (mild, moderate, and no pruritus) between the metoclopramide and propofol groups (P <  0.01; P <  0.01; and P <  0.01 respectively).

Conclusion

A sub-hypnotic dose of propofol is effective as metoclopramide in the prevention of PONV in parturient undergoing cesarean section under spinal anesthesia with intrathecal morphine. Sub-hypnotic dose of propofol significantly reduces the incidence of postoperative pruritus following intrathecal morphine use.

Trial registration

Current control trial, registered at ISRCTN trial registry: ISRCTN15475205. Date registered: 03/04/2019. Retrospectively registered.

Effects of an intrathecal TRPV1 antagonist, SB366791, on morphine-induced itch, body temperature, and antinociception in mice

Purpose

Transient receptor potential vanilloid 1 (TRPV1) not only is activated by multiple stimuli but also is involved with histamine-induced itch. The effects of TRPV1 on morphine-induced itch are unknown. We examined the effects of intrathecal administration of TRPV1 antagonist on morphine-induced itch, body temperature, and antinociception for mice.

Methods

Each C57/BL6j mouse was intrathecally administered with one of the following solutions: morphine, SB366791 (as the TRPV1 antagonist), morphine + SB366791, saline, or vehicle. For each mouse, each instance of observed scratching behavior was counted, the body temperature was measured, and the nociceptive threshold was determined using the tail-immersion test.

Results

SB366791 dose-dependently reduced the scratching behavior induced by the administration of morphine. SB366791 and the morphine + SB366791 groups did not manifest an increase in body temperature. Antinociceptive effects were observed to occur dose-dependently for morphine but not for SB366791. Compared with morphine alone, the administration of morphine + SB366791 did not reduce significant antinociceptive effects.

Conclusion

We propose that an intrathecal TRPV1 antagonist, SB366791, reduced morphine-induced itch without causing hyperthermia and did not suppress morphine-induced antinociception for mice.

A comparison of intrathecal magnesium and ketamine in attenuating remifentanil-induced hyperalgesia in rats

Background

Activation of NMDA receptors play an important role in the development of remifentanil-induced hyperalgesia. We hypothesized that in addition to ketamine, intrathecal MgSO₄ could also relieve thermal and mechanical hyperalgesia in rats.

Methods

Initially, 24 Sprague–Dawley rats were divided into control group, remifentanil group, surgical incision group and remifentanil combined with surgical incision group to create an experimental model. Subsequently, 40 rats were divided into control group, model group, model group plus 100 μg MgSO₄, 300 μg MgSO₄ and 10 μg ketamine respectively. Paw withdrawal mechanical thresholds and paw withdrawal thermal latency tests were performed at −24 h, 2 h, 6 h, 24 h, 48 h, 72 h and 7 day after the surgical procedure. After behavior assessment on the 7th day, remifentanil was given again to ascertain whether or not NMDA antagonists could suppress the re-exposure of remifentanil-induced hyperalgesia.

Results

Remifentanil administration plus surgical incision induced significant postoperative hyperalgesia, as indicated by decreased paw withdrawal mechanical thresholds and paw withdrawal thermal latency to mechanical and thermal stimulation. In addition to ketamine, intrathecal MgSO₄ (100, 300 μg) dose-dependently reduced remifentanil-induced mechanical and thermal hyperalgesia. Ketamine had less mechanical hyperalgesia in 6 h (p = 0.018), 24 h (p = 0.014) and 48 h (p = 0.011) than 300 μg MgSO₄. There was no difference in inhibiting thermal hyperalgesia between the group ketamine and group MgSO₄ (300 μg). The rats were given remifentanil again 7 days later after the first exposure of remifentanil. The hyperalgesic effect induced by re-exposure of remifentanil was not reversed in any groups of MgSO₄ or ketamine.

Conclusions

In addition to ketamine, intrathecal administration of MgSO₄ dose-dependently reduced remifentanil-induced hyperalgesia in a surgical incision mode. Re-exposure to remifentanil 1 week later again produced hyperalgesia, and this was not altered by the prior intrathecal treatments in any 4 groups treated with MgSO₄ or ketamine.

Electronic supplementary material

The online version of this article (doi:10.1186/s12871-016-0235-9) contains supplementary material, which is available to authorized users.

Intrathecal Catheterization and Drug Delivery in Guinea Pigs

Background

Intrathecal infusion of opioids in dogs, sheep, and humans produces local space-occupying masses. To develop a small-animal model, the authors examined effects of intrathecal catheterization and morphine infusion in guinea pigs.

Methods

Under isoflurane, polyethylene or polyurethane catheters were advanced from the cisterna magna to the lumbar enlargement. Drugs were delivered as a bolus through the externalized catheter or continuously by subcutaneous minipumps. Hind paw withdrawal to a thermal stimulus was assessed. Spinal histopathology was systematically assessed in a blinded fashion. To assist in determining catheter placement, ex vivo images were obtained using magnetic resonance imaging in several animals. Canine spinal tissue from previous intrathecal morphine studies was analyzed in parallel.

Results

(1) Polyethylene (n = 30) and polyurethane (n = 25) catheters were implanted in the lumbar intrathecal space. (2) Bolus intrathecal morphine produced a dose-dependent (20 to 40 μg/10 μl) increase in thermal escape latencies. (3) Absent infusion, a catheter-associated distortion of the spinal cord and a fibrotic investment were noted along the catheter tract (polyethylene &gt; polyurethane). (4) Intrathecal morphine infusion (25 mg/ml/0.5 μl/h for 14 days) resulted in intrathecal masses (fibroblasts, interspersed collagen, lymphocytes, and macrophages) arising from meninges proximal to the catheter tip in both polyethylene- and polyurethane-catheterized animals. This closely resembles mass histopathology from intrathecal morphine canine studies.

Conclusions

Continuous intrathecal infusion of morphine leads to pericatheter masses that morphologically resemble those observed in dogs and humans. This small-animal model may be useful for studying spinal drug toxicology in general and the biology of intrathecal granuloma formation in particular.

Endogenous opiates and behavior: 2014

This paper is the thirty-seventh consecutive installment of the annual review of research concerning the endogenous opioid system. It summarizes papers published during 2014 that studied the behavioral effects of molecular, pharmacological and genetic manipulation of opioid peptides, opioid receptors, opioid agonists and opioid antagonists. The particular topics that continue to be covered include the molecular-biochemical effects and neurochemical localization studies of endogenous opioids and their receptors related to behavior (endogenous opioids and receptors), and the roles of these opioid peptides and receptors in pain and analgesia (pain and analgesia); stress and social status (human studies); tolerance and dependence (opioid mediation of other analgesic responses); learning and memory (stress and social status); eating and drinking (stress-induced analgesia); alcohol and drugs of abuse (emotional responses in opioid-mediated behaviors); sexual activity and hormones, pregnancy, development and endocrinology (opioid involvement in stress response regulation); mental illness and mood (tolerance and dependence); seizures and neurologic disorders (learning and memory); electrical-related activity and neurophysiology (opiates and conditioned place preferences (CPP)); general activity and locomotion (eating and drinking); gastrointestinal, renal and hepatic functions (alcohol and drugs of abuse); cardiovascular responses (opiates and ethanol); respiration and thermoregulation (opiates and THC); and immunological responses (opiates and stimulants). This paper is the thirty-seventh consecutive installment of the annual review of research concerning the endogenous opioid system. It summarizes papers published during 2014 that studied the behavioral effects of molecular, pharmacological and genetic manipulation of opioid peptides, opioid receptors, opioid agonists and opioid antagonists. The particular topics that continue to be covered include the molecular-biochemical effects and neurochemical localization studies of endogenous opioids and their receptors related to behavior (endogenous opioids and receptors), and the roles of these opioid peptides and receptors in pain and analgesia (pain and analgesia); stress and social status (human studies); tolerance and dependence (opioid mediation of other analgesic responses); learning and memory (stress and social status); eating and drinking (stress-induced analgesia); alcohol and drugs of abuse (emotional responses in opioid-mediated behaviors); sexual activity and hormones, pregnancy, development and endocrinology (opioid involvement in stress response regulation); mental illness and mood (tolerance and dependence); seizures and neurologic disorders (learning and memory); electrical-related activity and neurophysiology (opiates and conditioned place preferences (CPP)); general activity and locomotion (eating and drinking); gastrointestinal, renal and hepatic functions (alcohol and drugs of abuse); cardiovascular responses (opiates and ethanol); respiration and thermoregulation (opiates and THC); and immunological responses (opiates and stimulants).

Intrathecal morphine for postoperative analgesia: Current trends

The practice of anesthesiology has always been governed by evidence-based medicine. The quick turnover rate of patients in the operating room and patient safety and satisfaction, have also further changed the way we practice anesthesia. The use of intrathecal (IT) opiates as an effective form of postoperative pain relief has been established for many years. Morphine was the first opioid used by IT route. In clinical practice, morphine is regarded as the gold standard, or benchmark, of analgesics used to relieve intense pain. Perhaps for this reason, IT morphine has been used for over 100 years for pain relief. IT morphine is one of the easiest, cost-effective and reliable techniques for postoperative analgesia and technical failures are rare. And yet there is no consensus amongst anesthesiologists regarding the dose of IT morphine. Like all other methods of pain relief, IT morphine also has some side effects and some of them are serious though not very common. This review article looks into some of the key aspects of the use of IT morphine for post-operative analgesia and various doses for different procedures are discussed. This article also describes the side effects of IT morphine and how to treat and prevent them.