Determination Of The Efficacy And Side-effect Profile Of Lower Doses Of Intrathecal Morphine In Patients Undergoing Total Knee Arthroplasty

The Dose Comparison of Intrathecal Morphine for Postoperative Analgesia in Total Knee Arthroplasty Under Spinal Anesthesia: A Single Institute Retrospective Study

Background and purpose of the study Intrathecal morphine (ITM) provides effective postoperative analgesia in patients undergoing total knee arthroplasty (TKA) under spinal anesthesia. However, the ideal dose at which maximal analgesic effects can be delivered with minimal side effects is not clearly known. This retrospective study is aimed to compare two different doses of ITM with respect to analgesia benefits and side effects. Methods This is a retrospective, descriptive, single-center study approved by the Institutional Review Board (IRB) at the University of Alabama at Birmingham. Three patient groups were selected: a control group receiving continuous adductor canal block (CCACB) under spinal anesthesia, and two experimental groups receiving single-dose adductor canal block (SSACB) under spinal anesthesia with either 100 mcg or 150 mcg of ITM. The sample size included 75 patients (25 per group) who were 18 years and older, American Society of Anesthesiology (ASA) class 1-3 who were undergoing primary TKA. Patients with chronic pain or opioid use exceeding 30 days and those undergoing surgeries other than primary TKA were excluded. Outcome data, including opioid use (from which post-operative oral morphine equivalents (OME) were calculated), antiemetic use, visual analog pain scale (VAS) scores, distance ambulated at 24 hours, and length of hospital stay, were extracted by chart review. Results In the post-anesthesia care unit (PACU), patients in both ITM groups experienced significantly lower opioid consumption and pain scores compared to the control group (p<.001). Furthermore, cumulative OME at 24 hours was significantly less in the ITM groups compared to the control, but there was no difference between ITM doses (p=0.004; mean cumulative OME for control was 77.2 OME vs 43.4 OME for 100 mcg ITM vs 42.6 OME for 150 mcg ITM). Antiemetic usage did not increase in the ITM groups. Although there was no statistically significant difference in ambulation at 24 hours, both ITM groups exhibited a trend toward greater average ambulation distance compared to the control group (p=0.095; mean distance walked for control was 67.6 feet, 76.6 feet for 100 mcg ITM vs 98.8 feet for 150 mcg ITM). Hospital length of stay did not significantly differ between the groups. Conclusion ITM doses of 100 mcg and 150 mcg provide effective analgesia for patients undergoing lower extremity total knee arthroplasty under spinal anesthesia. Patients receiving ITM had better pain scores in the immediate post-operative period and had overall less oral morphine equivalent consumption when compared to control. In addition, the safety and side effect profile for ITM is similar for both doses as there was no incidence of respiratory depression and antiemetic usage did not differ between all study arms. Future studies should explore the use of higher ITM doses and consider a broader patient population to further understand the advantages and potential drawbacks of ITM in TKA surgery.

The use of intrathecal morphine for acute postoperative pain in lower limb arthroplasty surgery: a survey of practice at an academic hospital

BACKGROUND AND PURPOSE OF THE STUDY

Intrathecal morphine (ITM) provides optimal postoperative analgesia in patients who are scheduled for total knee and hip operation with spinal anaesthesia. However, the ideal dose at which maximal analgesic effect occurs with minimal side effects is not known. This study aimed to describe the use of two doses of ITM and side effect profile in patients undergoing elective hip and knee arthroplasty.

METHODS

This was a prospective, descriptive, and contextual study conducted on patients who had total hip and knee replacement at Chris Hani Baragwanath Academic Hospital from 1 September to 30 November 2020. The sample size consisted of 66 patients who were 18 years and older, American Society of Anaesthesiology (ASA) classification 1-3, patients who had received either 100 mcg or 150 mcg ITM dose under spinal anaesthesia and sent to the ward postoperatively. Visual Analogue Scale (VAS) score was used to assess pain in the first 24 h, consumption of rescue analgesia and reported side effects were documented.

RESULTS

There was no relationship between age, weight, ASA classification or type of surgery and VAS score classification groups. Patients who received 100 mcg ITM had a higher median VAS pain score 2 (1-5) compared to those who received 150 mcg ITM 1 (0-2), p = 0.01. The need for rescue analgesia between the two groups was marginally less in the 150 mcg ITM group (p = 0.098). There was no difference in the rate of side effects between the 100 mcg ITM group [12 (41%)] and the 150 mcg ITM group [17 (59%)], p = 0.92. Rescue analgesia was marginally different between groups, p = 0.09. There were no real differences in the VAS pain scores between the total knee and total hip surgeries. None of the patients experienced clinically significant respiratory depression.

CONCLUSION

The 150 mcg ITM dose provided good analgesic effects with longer duration of action and comparable side effect profile to the 100 mcg ITM dose. This dose was not associated with development of respiratory depression and can therefore be administered safely to patients who are discharged to the ward postoperatively in a resource constraint environment.

The Role of Intrathecal Morphine for Postoperative Analgesia in Primary Total Joint Arthroplasty under Spinal Anesthesia: A Systematic Review and Meta-Analysis

OBJECTIVE

To assess the efficacy and safety of intrathecal morphine (ITM) for postoperative analgesia in primary total joint arthroplasty (TJA) under spinal anesthesia and to explore the dose-response relationship for analgesic efficacy or risk of side effects.

METHODS

We searched MEDLINE, EMBASE, Web of Science, Cochrane Central Register of Controlled Trials and ClinicalTrials.gov for any studies meeting the inclusion criteria. All the data were summarized using the random effects model. Subgroup analyses were performed based on the surgical procedure and dose of ITM. Meta-regression was used to explore the dose-response relationship.

RESULTS

Eighteen randomized controlled trials were included. Compared with the placebo or blank control, ITM reduced the postoperative 24-h morphine consumption by 10.07 mg and prolonged the duration of analgesia. However, ITM significantly increased the risk of pruritus by 2.79 fold, with a tendency to increase the risk of postoperative nausea and/or vomiting (P = 0.08). No difference was observed regarding the length of stay (LOS) and incidence of respiratory depression or urinary retention. Furthermore, meta-regression showed a linear dose-response relationship for the postoperative 24-h morphine consumption but no linear dose-response relationship for the risk of side effects.

CONCLUSIONS

Adding morphine to intrathecal anesthetics provides a prolonged and robust analgesic effect without significantly increasing the risk of side effects other than pruritus. Although we found a linear dose-response relationship for the postoperative 24-h morphine consumption, the optimal dose of ITM remains to be further explored in high-quality RCTs with a large sample size.

Randomized Double-Blind Controlled Trial Comparing 0.2 mg, 0.1 mg, and No Intrathecal Morphine Combined With Periarticular Injection for Unilateral Total Knee Arthroplasty

Background

The addition of intrathecal morphine (ITM) to neuraxial anesthesia during total knee arthroplasty (TKA) to achieve postoperative analgesia can elicit opioid-related side effects. The other methods of pain alleviation and side effect reduction, including multimodal analgesia, are challenging. This study aimed to determine the efficacy of various ITM dosages for primary unilateral TKA with periarticular injection (PI).

Methods

This randomized double-blind controlled trial was conducted at Vajira Hospital between April 2018 and March 2019. Patients undergoing TKA were randomized into 3 groups: no ITM (M₀), ITM 0.1 mg (M₁), and ITM 0.2 mg (M₂). All patients received PI. Postoperative pain scores, side effects of ITM, and orthopedic outcomes were compared.

Results

The trial enrolled 102 patients: M₀ (n = 32), M₁ (n = 35), and M₂ (n = 35). The postoperative pain scores and rescue analgesic consumption of groups M₁ and M₂ did not differ significantly within the first 24 hours and were significantly lower than those in group M₀. Nausea and vomiting were observed more frequently 4 hours postoperatively in M₂ than in groups M₁ and M₀ (77%, 51%, and 6%, respectively; P < .05), which required second-line antiemetic administration (29%, 9%, and 13%, respectively; P = .09).

Conclusion

Postoperative pain control achieved with PI combined with ITM 0.1 mg after primary unilateral TKA was comparable to that achieved with ITM 0.2 mg. PI without ITM resulted in higher pain scores and rescue analgesic consumption. The frequency and severity of nausea and vomiting 4 hours postoperatively were also lower in patients administered 0.1 mg of ITM than those in patients administered 0.2 mg of ITM.

Efficacy and safety of local infiltration analgesia for pain management in total knee and hip arthroplasty: A meta-analysis of randomized controlled trial

BACKGROUND

Local infiltration analgesia (LIA) has become popular in postoperative pain relief after total hip arthroplasty (THA) or total knee arthroplasty (TKA). The aim of this meta-analysis was to compare the efficacy and safety of LIA with intrathecal morphine and epidural analgesia after THA and TKA.

METHODS

A systematic article search was performed from PubMed, Embase, and Web of Science databases, up to February 21, 2019. The main outcomes included visual analog scale for assessment of pain, morphine equivalent consumption, length of hospital stay, and adverse events. The data were calculated using weight mean difference (WMD) or risk ratio (RR) with 95% confidence intervals (95% CIs).

RESULTS

Eleven studies with a total of 707 patients met the inclusion criteria and were included in this meta-analysis. LIA provided better pain control than other 2 techniques at 24-hour (WMD = 10.61, 95% CI: 3.36-17.87; P = .004), 48-hour (WMD = 16.0, 95% CI: 8.87-23.13; P < .001), and 72-hour (WMD = 11.31, 95% CI: 3.78-18.83; P < .001). Moreover, LIA had similar morphine consumption and duration of hospital stay with intrathecal morphine and epidural analgesia. There was significantly lower incidence of adverse events with LIA than with the other 2 techniques.

CONCLUSION

LIA provided better postoperative pain control and less adverse events than intrathecal morphine and epidural analgesia after THA and TKA.

Does Intrathecal Morphine in Spinal Anesthesia Have a Role in Modern Multimodal Analgesia for Primary Total Joint Arthroplasty?

BACKGROUND

Intrathecal morphine (ITM) combined with bupivacaine spinal anesthesia can improve postoperative pain, but has potential side effects of postoperative nausea/vomiting (PONV) and pruritus. With the use of multimodal analgesia and regional anesthetic techniques, postoperative pain control has improved significantly to a point where ITM may be avoided in total joint arthroplasty (TJA).

METHODS

We performed a retrospective study of primary TJA patients who underwent a standardized multimodal recovery pathway and received bupivacaine neuraxial anesthesia with ITM vs bupivacaine neuraxial anesthesia alone (control).

RESULTS

In total, 598 patients were identified (131 controls, 467 ITMs) with similar demographics. On postoperative day 0 (POD 0), ITM patients had significantly lower mean visual analog scale scores (1.5 ± 1.6 vs 2.5 ± 1.9, P < .001) and consumed less oral morphine equivalents (10.5 ± 25.4 vs 16.8 ± 27.2, P = .013). ITM patients walked further compared to controls by POD 1 (133.6 ± 159.6 vs 97.3 ± 141 m, P = .028) and were less likely to develop PONV during their entire hospital stay (38.5% vs 48.6%, P = .043). No significant differences were seen for total morphine equivalents consumption, rate of discharge to care facility, length of stay, and 90-day readmission rates.

CONCLUSION

ITM was associated with improved POD 0 pain scores and less initial oral/intravenous opioid consumption, which likely contributes to the subsequent improved mobilization and lower rates of PONV. In the setting of a modern regional anesthesia and multimodal analgesia recovery plan for TJA, ITM can still be considered for its benefits.

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.

The NAPRESSIM trial: the use of low-dose, prophylactic naloxone infusion to prevent respiratory depression with intrathecally administered morphine in elective hepatobiliary surgery: a study protocol and statistical analysis plan for a randomised controlled trial

BACKGROUND

Intrathecally administered morphine is effective as part of a postoperative analgesia regimen following major hepatopancreaticobiliary surgery. However, the potential for postoperative respiratory depression at the doses required for effective analgesia currently limits its clinical use. The use of a low-dose, prophylactic naloxone infusion following intrathecally administered morphine may significantly reduce postoperative respiratory depression. The NAPRESSIM trial aims to answer this question.

METHODS/DESIGN

'The use of low-dose, prophylactic naloxone infusion to prevent respiratory depression with intrathecally administered morphine' trial is an investigator-led, single-centre, randomised, double-blind, placebo-controlled, double-arm comparator study. The trial will recruit 96 patients aged > 18 years, undergoing major open hepatopancreaticobiliary resections, who are receiving intrathecally administered morphine as part of a standard anaesthetic regimen. It aims to investigate whether the prophylactic administration of naloxone via intravenous infusion compared to placebo will reduce the proportion of episodes of respiratory depression in this cohort of patients. Trial patients will receive an infusion of naloxone or placebo, commenced within 1 h of postoperative extubation continued until the first postoperative morning. The primary outcome is the rate of respiratory depression in the intervention group as compared to the placebo group. Secondary outcomes include pain scores, rates of nausea and vomiting, pruritus, sedation scores and adverse outcomes. We will also employ a novel, non-invasive, respiratory minute volume monitor (ExSpiron 1Xi, Respiratory Motion, Inc., 411 Waverley Oaks Road, Building 1, Suite 150, Waltham, MA, USA) to assess the monitor's accuracy for detecting respiratory depression.

DISCUSSION

The trial aims to provide a clear management plan to prevent respiratory depression after the intrathecal administration of morphine, and thereby improve patient safety.

TRIAL REGISTRATION

ClinicalTrials.gov, ID: NCT02885948 . Registered retrospectively on 4 July 2016. Protocol Version 2.0, 3 April 2017. Protocol identification (code or reference number): UCDCRC/15/006 EudraCT registration number: 2015-003504-22. Registered on 5 August 2015.

Comparison of Ramosetron With Ondansetron for Prevention of Intrathecal Morphine-Induced Nausea and Vomiting After Primary Total Knee Arthroplasty: A Randomized Control Trial

BACKGROUND

Spinal anesthesia with intrathecal morphine is a reliable, easy to apply, and cost effective method for controlling pain after total knee arthroplasty (TKA). However, postoperative nausea and vomiting (PONV) is a major concern. 5-Hydroxytryptamine receptor 3 (5-HT₃) antagonists like ondansetron and ramosetron are commonly used for preventing PONV, but the optimal choice remains unclear. We conducted a study to assess the effectiveness of ramosetron and ondansetron, hypothesizing that the longer acting ramosetron may be better than ondansetron in the first 48 hours after TKA, performed with spinal anesthesia and intrathecal morphine.

METHODS

Patients were randomized preoperatively to either intravenous ondansetron (8 mg) or ramosetron (0.3 mg). The primary outcomes were the incidence rates of PONV. Secondary outcomes were the need for a rescue antiemetic (metoclopramide), pain score, patient satisfaction, and adverse drug reactions (ADRs) at 0-6, 6-12, 12-24, and 24-48 hours.

RESULTS

Ninety patients were evaluable; 45 patients/arm. Compared with ondansetron, ramosetron was associated with significantly lower incidence rates of nausea at: (1) 12-18 hours: 3/45 vs 11/45 (P = .016), (2) 18-24 hours: 1/45 vs 9/45 (P = .005), and vomiting at 18-24 hours: 1/45 vs 6/45 (P = .044). There were no significant differences in the use of rescue-antiemetic medicine, pain score, patient satisfaction, and ADRs.

CONCLUSION

Preoperative ramosetron provided more prolonged PONV prophylaxis than ondansetron after TKA in our setting, and had a similar ADR profile. Other trials are needed to confirm our results before ramosetron is adopted widely.

A Randomised Controlled Trial Comparing Three Analgesia Regimens following Total Knee Joint Replacement: Continuous Femoral Nerve Block, Intrathecal Morphine or Both

This randomised controlled trial compared three analgesia regimens following primary unilateral total knee joint replacement: continuous femoral nerve block (CFNB), intrathecal morphine (ITM), and both. The primary outcome was pain ratings over the first 24 hours. Secondary outcomes included morphine consumption, nausea, pruritus and sedation ratings, oxygen saturation (SpO2) ratings, and ability to mobilise postoperatively. All patients received a spinal anaesthetic and a postoperative patient-controlled morphine pump. Patients were randomised to receive CFNB, ITM, or both. In patients with no CFNB, the use of ITM was blinded. Eighty-one patients were randomised and there were no withdrawals. At 24 hours, the ITM-only group had higher pain ratings than either of the other groups ( P=0.04 versus CFNB, P=0.01 versus combination). In the 18 to 24-hour period, the ITM group used more morphine than either of the other groups. There were no statistically significant differences in pain ratings or morphine consumption at earlier time intervals. The ITM group were less likely to be able to sit out of bed on day one. Patients who received ITM were more likely to have pruritus. There were no statistically significant differences in nausea, SpO2 or sedation ratings. This study showed that a CFNB resulted in reduced pain and was also associated with less morphine consumption and improved mobilisation at 24 hours compared to ITM. This study did not show any statistically significant differences between CFNB alone and CFNB+ITM.

The incidence of postoperative urinary retention in patients undergoing elective hip and knee arthroplasty

INTRODUCTION

Postoperative urinary retention requiring urethral catheterisation increases the risk of joint sepsis following arthroplasty. Spinal anaesthesia with opiate administration is used widely in lower limb arthroplasty. We sought to establish whether the choice of opiate agent had any effect on the incidence of postoperative retention and therefore the risk of joint sepsis.

METHODS

A total of 445 consecutive patients who underwent primary elective lower limb arthroplasty were reviewed retrospectively. Patients had general anaesthesia and femoral nerve block (GA+FNB), spinal anaesthesia and intrathecal fentanyl (SA+ITF) or spinal anaesthesia and intrathecal morphine (SA+ITM).

RESULTS

Urinary retention was observed in 14% of male and 2% of female patients with GA+FNB, 9% of male and 3% of female patients with SA+ITF, and 60% of male (p=0.0005) and 5% of female patients with SA+ITM. Men who experienced retention were older (68 vs 64 years, p=0.013) and had longer inpatient stays (6.7 vs 4.6 days, p=0.043). Fewer patients in the SA+ITM group required breakthrough analgesia (28% vs 58%, p=0.004). Concusions: The use of ITM in men significantly increases the incidence of urinary retention requiring urethral catheterisation and subsequently increases the risk of deep joint sepsis. Its use should be rationalised against the intended benefits and alternatives sought where possible.

Intrathecal ketorolac enhances intrathecal morphine analgesia following total knee arthroplasty

Background:

Total knee arthroplasty represents one of the most painful surgeries. The aim of the study was to compare analgesia and adverse effects of intrathecal (IT) ketorolac versus IT morphine, versus the combination of IT ketorolac and morphine.

Materials and Methods:

After ethical approval and patient consent, 80 patients undergoing knee arthroplasty were randomized to one of 4 groups. All groups received 15 mg IT bupivacaine plus IT test drug (2 ml). The control group (CG) received saline as IT test drug. The morphine group (MG) received IT 200 g morphine, the ketorolac group (KG) IT 2 mg ketorolac and the morphine-ketorolac group (MKG) 200 g morphine + 2 mg ketorolac as test drugs. Pain and adverse effects were evaluated. P > 0.05 was considered significant.

Results:

The MG and KG were similar in their times to time to first rescue analgesic (440 ± 38 min and 381 ± 44 min, respectively). Both groups were longer when compared to the CG (170 ± 13 min) (P > 0.01). The MG and KG had lesser ketoprofen consumption compared to the CG (P > 0.05). The time to first rescue analgesic was longer to the MKG (926 ± 222 min) (15 h) compared to CG (P > 0.001) and to the MG and the KG (P > 0.01). MKG displayed lesser ketoprofen consumption compared to MG and KG (P > 0.05) and to the CG (P > 0.02).

Conclusions:

The data suggest a role for spinal ketorolac and morphine in orthopaedic surgery because this combination of agents provided 15 h of analgesia compared to 7 h after each drug alone, with no significant side-effects.

Is pain after TKA better with periarticular injection or intrathecal morphine?

BACKGROUND

Postoperative pain after TKA is a major concern to patients. The best technique to control pain is still controversial. Intrathecal morphine or periarticular multimodal drug injection are both commonly used and both appear to provide better pain control than placebo, but it is unclear whether one or the other provides better pain control.

QUESTIONS/PURPOSES

We asked whether intrathecal morphine or periarticular multimodal drug injection provides better pain control with fewer adverse events.

METHODS

In a prospective, double-blind, randomized controlled trial we randomized 57 patients with osteoarthritic knees who underwent TKAs into two groups. Group M (n = 28) received 0.2 mg intrathecal morphine while Group I (n = 29) received periarticular multimodal drug injection. Postoperative pain was managed with patient-controlled analgesia using ketorolac. The outcomes were pain levels, the amount of analgesic drug used, and drug-related side effects. Patients and evaluators were blinded. All patients were followed up to 3 months.

RESULTS

We found no difference in postoperative pain level, analgesia drug consumption, blood loss in drain, and knee function. More patients in Group M required antiemetic (19 [69%] versus 10 [34%]) and antipruritic drugs (10 [36%] versus three [10%]) than patients in Group I.

CONCLUSIONS

The two techniques provide no different pain control capacity. The periarticular multimodal drug injection was associated with lower rates of vomiting and pruritus.