Intrathecal morphine administration reduces postoperative pain and peripheral endocannabinoid levels in total knee arthroplasty patients: a randomized clinical trial

Background

The primary goal of this study was to determine whether administration of intrathecal morphine reduces postoperative pain. The secondary goal was to determine the effect of intrathecal morphine upon circulating levels of the weakly analgesic endocannabinoids, anandamide (AEA) and 2-arachidonoylglycerol (2-AG), and the related lipids palmitoylethanolamide (PEA) and oleoylethanolamide (OEA).

Methods

Forty two total knee arthroplasty (TKA) patients were enrolled in a prospective, double-blinded, randomized study. The intervention consisted of intrathecal morphine (200 μg) or placebo administered at the time of the spinal anesthesia. Postoperative pain was measured during the first 4 h after surgery while serum levels of AEA, 2-AG, PEA, OEA, and cortisol were measured at baseline and 4 h after surgery.

Results

Administration of intrathecal morphine reduced postoperative pain 4 h after TKA surgery compared to placebo (p = 0.005) and reduced postoperative systemic opioid consumption (p = 0.001). At baseline, intrathecal morphine led to a significant reduction in AEA, 2-AG, and OEA levels but did not affect PEA or cortisol levels. In patients administered intrathecal placebo, 2-AG levels were elevated 4 h after surgery; whereas patients receiving intrathecal morphine showed reductions in AEA, PEA, and OEA when compared to placebo. At 4 h after TKA surgery cortisol levels were significantly elevated in the placebo group and reduced in those receiving morphine.

Conclusions

These results indicate that intrathecal morphine reduces postoperative pain in TKA patients. Furthermore, activation of central opioid receptors negatively modulates the endocannabinoid tone, suggesting that potent analgesics may reduce the stimulus for production of peripheral endocannabinoids. This study is the first to document the existence of rapid communication between the central opioid and peripheral endocannabinoid systems in humans.

Trial registration

This trial was registered retrospectively. Trial registry: NCT02620631. Study to Examine Pain Relief With Supplemental Intrathecal Morphine in TKA Patients, NCT02620631, 12/03/2015.

Randomized trial of acupressure to improve patient satisfaction and quality of recovery in hospitalized patients: study protocol for a randomized controlled trial

Background

Acupressure therapy may be potentially beneficial in improving postoperative symptoms like postoperative nausea and vomiting (PONV), pain and sleep disorder and improving postoperative quality of recovery. The primary aim of this study is to investigate the efficacy of acupressure therapy on postoperative patient satisfaction and quality of recovery in hospitalized patients after surgical treatment.

Methods/design

This three-group, parallel, superiority, blinded, randomized controlled trial will test the hypothesis that a combination of PC6, LI4 and HT7 acupressure is superior to sham or no intervention for improving postoperative quality of recovery in hospitalized patients. A minimum of 150 patients will be randomly allocated to one of the three experimental groups: control (no visit), light touch (sham acupressure) or active acupressure therapy in a 1:1:1 ratio. Interventions will be performed three times a day for 2 days. Patient satisfaction, quality of recovery, PONV and pain will be measured during the 3 days following randomization. The study protocol was approved by the Stony Brook University Institutional Review Board on 21 March 2016. Written informed consent will be recorded from every consented patient.

Discussion

This study has the potential to improve the recovery of hospitalized patients by adding knowledge on the efficacy of acupressure therapy in this setting. A multipoint acupressure protocol will be compared to both a no intervention group and a light touch group, providing insight into different aspects of the placebo effect.

Trial registration

ClinicalTrial.gov, NCT02762435. Registered on 14 April 2016.

Electronic supplementary material

The online version of this article (doi:10.1186/s13063-017-1839-1) contains supplementary material, which is available to authorized users.

Retrograde Epidural Catheter Relieves Intractable Sacral Pain

Pain caused by tumor infiltration of the sacral area remains a major clinical challenge. Patients with poor pain control despite comprehensive medical management may be treated with neuraxial techniques such as continuous epidural or spinal anesthetic. We report a case in which a patient with metastatic breast cancer experienced inadequate pain relief after multiple intravenous pain management regimens as well as intrathecal (IT) drug delivery. The concentration of local anesthetics delivered via the IT catheter was limited due to the patient's baseline motor weakness which would be exacerbated with higher concentrations of local anesthetics. Thus, a decision was made to insert an epidural catheter via a retrograde technique to provide the patient with a "band of anesthesia" which would provide profound sensory blockade without concomitant motor weakness. Pain refractory to other modalities of pain control was successfully treated with the epidural technique.