Optimizing the dose of intrathecal morphine in older patients undergoing hip 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.

A double-blind, randomised, placebo-controlled trial comparing intrathecal bupivacaine with bupivacaine plus morphine to reduce delirium in patients with hip fractures-Salmon-Mind trial study protocol

Background

Surgical treatment of proximal femur fractures is complicated by postoperative delirium in about one-third of patients. Pain and opioid consumption are modifiable factors that may influence the incidence of delirium.1 An intrathecal injection of morphine may lead to a reduction in postoperative pain and reduced systemic opioid consumption. In current practice, the addition of morphine to intrathecal anaesthesia is commonly used but depends on the anaesthesiologist's preference. Recently, a retrospective study found that intrathecal morphine was independently associated with a lower incidence of delirium. However, this has to be confirmed in a prospective, randomised study. We hypothesise that using intrathecal morphine reduces postoperative pain and opioid consumption during the first 48 h after surgery and reduces the incidence of delirium during hospital admission. We also seek additional evidence of the association between neuronal injury (delirium) and neurofilament light in serum of patients with proximal femur fractures.

Objective

The primary objective is to compare the incidence of delirium. The secondary objectives are to compare pain scores, systemic opioid consumption, and (opioid-related) side-effects. The tertiary objective is to test the association between intrathecal morphine and neurofilament light as a marker of neuronal injury.

Study design

A double-blind, randomised, placebo-controlled intervention study is proposed.

Study population

All patients with a proximal femur fracture who are scheduled for surgery under spinal anaesthesia.

Intervention

The intervention is the addition of morphine 100 μg to the intrathecal injection for spinal anaesthesia. The intervention group will receive a mixture of bupivacaine 10 mg and morphine 100 μg. The control group will receive bupivacaine 10 mg.

Clinical trial registration

EU Clinical Trials Register: EudraCT number 2020-002143-27.

Intrathecal Morphine versus Morphine-Dexmedetomidine Combination for Postoperative Pain Control After Total Knee Replacement: A Randomized Controlled Trial

Objective

This prospective study aimed to compare the analgesic efficacy and adverse effects of intrathecal morphine, dexmedetomidine, and a combination of both in patients undergoing total knee replacement (TKR).

Patients and Methods

This randomized prospective study was carried out in Tanta university hospital in orthopedic surgery for 6 months on 105 adult patients with American Society of Anesthesiologists Physical Status Class II and III, aged > 50 years, and scheduled for total knee replacement surgery randomly allocated into morphine group received 0.5% heavy bupivacaine plus 0.1 mg of morphine, morphine/ dexmedetomidine group, received 0.5% heavy bupivacaine plus 0.1 mg of morphine and 5 mcg of dexmedetomidine and dexmedetomidine group received 0.5% heavy bupivacaine plus 5 mcg of dexmedetomidine. The time of the first required analgesia, postoperative pain severity, the total dose of morphine, postoperative complication, and the patient's level of sedation were recorded.

Results

About half of the patients in the dexmedetomidine group requested first rescue analgesia 6 hours after the operation, significantly shorter than the other two groups. On the other hand, the other two groups show no significant difference between them regarding the first required analgesia. At rest, the dexmedetomidine group have significantly higher VAS with a significant increase in patients who required morphine as rescue analgesia than the other two groups. While at movement, patients in the dexmedetomidine group felt pain at 4 hrs postoperatively with significantly higher VAS than the other two groups. At the same time, the sedation score was significantly lower in the dexmedetomidine group than in the other two groups. 22.2% of cases in the morphine group developed nausea and vomiting with a significant difference between the three groups.

Conclusion

Despite the absence of substantial side effects, our findings did not suggest enhanced analgesia with the combination of intrathecal morphine and dexmedetomidine.

Effect of different low doses of intrathecal morphine (0.1 and 0.2 mg) on pain and vital functions in patients undergoing total hip arthroplasty: a randomised controlled study

BACKGROUND

Orthopaedic surgeries are among the most painful procedures. By adding low-dose morphine to intrathecal bupivacaine for spinal anaesthesia, the analgesic effect can be improved. The objeсtive of the study was tо compare the efficacy and safety of lоw-dоse (0.1 mg аnd 0.2 mg) intrаtheсаl mоrphine (ITM).

METHODS

А prоspeсtive rаndоmised study was соnduсted at the Hоspitаl оf Trаumаtоlоgy аnd Оrthоpaediсs, Riga, Latvia (February 2020 tо May 2021) and enrolled 90 patients undergoing primary hip arthroplasty. All subjects were randomised intо three study grоups, using the online tool оn www.randomiser.org . Treatment groups were allocated to intrathecal morphine (0.1 mg and 0.2 mg) in addition to bupivacaine (15 to 18 mg). The primary outcome was postoperative pain intensity among the three study groups within 24 hours by NRS. The secondary outcomes: pain at rest 4 h, 7 h, 12 h, 24 h postoperatively, respiratory rate, SpО2, morphine соnsumptiоn, оxygen supply, opioid-related аdverse reасtiоns within 24 hours postoperatively. Dаtа were аnаlysed using R version 4.2.0, applying the Mann-Whitney test, Pearson's chi-squared test, Fisher's exact test, Friedman test, Wilcoxon test.

RESULTS

The primary outcome in the control, ITM 0.1 mg, ITM 0.2 mg groups, respectively: 2.56, 0.87, 0.28 (p < 0.001). The secondary outcomes in the control, ITM 0.1 mg, ITM 0.2 mg group, respectively: pain scores 4h - 1.21, 0.48, 0.17 (p = 0.068); 7 h - 2.62, 1.00, 0.17 (p < 0.001); 12 h - 3.08, 0.65, 0.37 (p < 0.001); 24 h - 2.50, 1.20, 0.41 (p < 0.001); rescue medication requests (incidence, %): 77%, 16.7%, 13.3% (p < 0.001); mean respiratory rate (breath/min) - 15.2; 15.2 (p > 0.05); mean SpO2 (%): 96.7%; 95.7%; 96.07%. Significant adverse effects: pruritus in ITM 0.2 mg group (23% of subjects, p < 0.001).

CONCLUSIONS

Adult patients undergoing THA under spinal anaesthesia with bupivacaine and 0.2 mg morphine had superior analgesia to patients who received spinal analgesia with bupivacaine or bupivacaine and 0.1 mg morphine.

TRIAL REGISTRATION

Study ID ISRCTN37212222; 20/04/2022 (registered retrospectively).

No Benefits of Adding Dexmedetomidine, Ketamine, Dexamethasone and Nerve Blocks to an Established Multimodal Analgesic Regimen after Total Knee Arthroplasty

BACKGROUND.

An optimal opioid-sparing multimodal analgesic regimen to treat severe pain can enhance recovery after total knee arthroplasty. We hypothesized that adding 5 recently described IV and regional interventions to multimodal analgesic regimen can further reduce opioid consumption.

METHODS.

In a double-blinded fashion, seventy-eight patients undergoing elective total knee arthroplasty were randomized to either (1) a control group (n=39) that received spinal anesthesia with intrathecal morphine, periarticular local anesthesia infiltration, IV dexamethasone and a single injection adductor canal block or (2) a study group (n=39) that received the same set of analgesic treatments plus 5 additional interventions - local anesthetic infiltration between the popliteal artery and capsule of the posterior knee, intraoperative IV dexmedetomidine and ketamine, and postoperatively, 1 additional IV dexamethasone bolus, and 2 additional adductor canal block injections. The primary outcome measure was 24-hour cumulative opioid consumption after surgery and secondary outcomes were other analgesic, patient recovery and functional outcomes and adverse events.

RESULTS.

Opioid consumption was not different between groups at 24 hours (oral morphine equivalents, mean ± SD), study: 23.7 ± 18.0 mg vs. control: 29.3 ± 18.7 mg; mean difference [95% CI], -5.6 mg [-2.7, 13.9]; P = 0.189) and all other time points after surgery. There were no major differences in pain scores, quality of recovery, or time to reach rehabilitation milestones. Hypotensive episodes occurred more frequently in the study group (25/39 (64.1%) vs. 13/39 (33.3%), p= 0.010).

CONCLUSIONS.

In the presence of periarticular local anesthesia infiltration, intrathecal morphine, single shot adductor canal block and dexamethasone, the addition of 5 analgesic interventions - local anesthetic infiltration between the popliteal artery and capsule of the posterior knee, IV dexmedetomidine, IV ketamine, an additional IV dexamethasone dose and repeated adductor canal block injections - failed to further reduce opioid consumption, pain scores or improve functional outcomes after total knee arthroplasty.

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.

Ultrasound-Guided Anterior Quadratus Lumborum Block Reduces Postoperative Opioid Consumption and Related Side Effects in Patients Undergoing Total Hip Replacement Arthroplasty: A Propensity Score-Matched Cohort Study

Quadratus lumborum block (QLB) has been shown to be effective for pain relief after hip surgery. This study evaluated the efficacy of ultrasound-guided anterior QLB in pain control after total replacement hip arthroplasty (TRHA). A total of 115 patients receiving anterior QLB were propensity score-matched with 115 patients who did not receive the block. The primary outcome was opioid consumption at 24, 24-48, and 48 postoperative hours. Secondary outcomes included pain scores at the post-anesthesia care unit (PACU), 8, 16, 24, 32, 40, and 48 h length of hospital stay, time to first ambulation, and the incidence of opioid-related side effects. Postoperative opioid consumption 48 h after surgery was significantly lower in the QLB group. Resting, mean, worst, and the difference of resting pain scores compared with preoperative values were significantly lower in the QLB group during the 48 postoperative hours. The length of hospital stay was shorter in the QLB group. The incidence of postoperative nausea and vomiting was significantly lower in the QLB group during the 48 postoperative hours, except at the PACU. This study suggests that anterior QLB provides effective postoperative analgesia for patients undergoing THRA performed using the posterolateral approach.

Efficacy and safety of intrathecal morphine for analgesia after lower joint arthroplasty: a systematic review and meta-analysis with meta-regression and trial sequential analysis

Widespread adoption of intrathecal morphine into clinical practice is hampered by concerns about its potential side‐effects. We undertook a systematic review, meta‐analysis and trial sequential analysis with the primary objective of determining the efficacy and safety of intrathecal morphine. Our secondary objective was to determine the dose associated with greatest efficacy and safety. We also assessed the impact of intrathecal morphine on respiratory depression. We systematically searched the literature for trials comparing intrathecal morphine with a control group in patients undergoing hip or knee arthroplasty under spinal anaesthesia. Our primary efficacy outcome was rest pain score (0–10) at 8–12 hours; our primary safety outcome was the rate of postoperative nausea and vomiting within 24 hours. Twenty‐nine trials including 1814 patients were identified. Rest pain score at 8–12 hours was significantly reduced in the intrathecal morphine group, with a mean difference (95%CI) of −1.7 (−2.0 to −1.3), p < 0.0001 (19 trials; 1420 patients; high‐quality evidence), without sub‐group differences between doses (p = 0.35). Intrathecal morphine increased postoperative nausea and vomiting, with a risk ratio (95%CI) of 1.4 (1.3–1.6), p < 0.0001 (24 trials; 1603 patients; high‐quality evidence). However, a sub‐group analysis by dose revealed that rates of postoperative nausea and vomiting within 24 hours were similar between groups at a dose of 100 µg, while the risk significantly increased with larger doses (p value for sub‐group difference = 0.02). Patients receiving intrathecal morphine were no more likely to have respiratory depression, the risk ratio (95%CI) being 0.9 (0.5–1.7), p = 0.78 (16 trials; 1173 patients; high‐quality evidence). In conclusion, there is good evidence that intrathecal morphine provides effective analgesia after lower limb arthroplasty, without an increased risk of respiratory depression, but at the expense of an increased rate of postoperative nausea and vomiting. A dose of 100 µg is a ‘ceiling’ dose for analgesia and a threshold dose for increased rate of postoperative nausea and vomiting.

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.

Intrathecal Morphine Is Associated with Less Delirium Following Hip Fracture Surgery: A Register Study

Background

Delirium is a common complication after proximal femoral fracture surgery, with pain and opioid consumption as the contributing factors. The administration of intrathecal morphine may decrease these factors postoperatively and potentially reduce delirium.

Objectives

This research aimed to study the association between the use of intrathecal morphine and the occurrence of delirium.

Methods

A retrospective analysis of a prospective register kept in a non-academic hospital in the Netherlands was performed. The register contained data of all patients with proximal femur fractures that were surgically treated with osteosynthesis or prosthesis. Patients receiving spinal anesthesia (SA group) were compared with patients receiving spinal anesthesia with the addition of intrathecal morphine (SIM group). The administration of either SA or SIM was based on the preference of the anesthesiologist. The primary outcome was the incidence of delirium, as defined by the DSM-V classification. The follow-up lasted until hospital discharge. Both univariate and multivariate analyses were performed.

Results

The SA group consisted of 451 patients, and the SIM group included 34 patients. Delirium occurred in 19.7% in the SA group versus 5.9% in the SIM group (P = 0.046). This association remained significant after correction in multivariate analysis (OR of delirium in the SA group, 95% CI: 1.062 - 21.006, P = 0.041). Additionally, multivariate analysis revealed that age, gender, preoperative cognitive impairment, and fracture treatment (osteosynthesis or prosthesis) were independently associated with delirium.

Conclusions

This retrospective study found an independent association between the use of intrathecal morphine and a lower incidence of delirium. This clinically relevant decrease in delirium should be studied in a prospective randomized study.

An Audit of Intrathecal Morphine Analgesia for Non-Obstetric Postsurgical Patients in an Adult Tertiary Hospital

We conducted a retrospective audit of adult non-obstetric patients who had received a single dose of intrathecal morphine for postoperative analgesia. These patients were predominantly admitted to a regular postsurgical ward with strict hourly nursing observations, treatment protocols in place and supervision by an Acute Pain Service for the first 24 hours after intrathecal morphine administration. A total of 409 cases were examined for sedation score, incidence of respiratory depression and other side-effects, admission to the high dependency or intensive care unit and opioidtolerance. Respiratory depression was defined as requiring treatment with naloxone (implying a sedation score of 3 irrespective of respiratory rate), or a sedation score of 2 with a respiratory rate less than six breaths per minute. The patients were predominantly elderly (57.2% were over the age of 70 years) and 84.8% had undergone vascular surgery. Of the total of 409 cases, only one case of respiratory depression was observed. A total of 77 patients were admitted to high dependency or intensive care unit for various reasons including management of postsurgical complications and patient co-morbidities. Our findings suggest that elderly patients who receive intrathecal morphine analgesia can be safely managed in a regular postsurgical ward.

Neuraxial Anesthesia in the Geriatric Patient

Neuraxial anesthesia is recommended as a well-accepted option to minimize the perioperative side effects in the geriatric patients. The available data from the current researches have shifted the focus from the conventional approach to spinal anesthesia to the concept of low dose local anesthetic combined with opioids. What remains clear from all these studies is that hemodynamic stability is much better in patients who received low-doses of intrathecal bupivacaine in combination with opioids, which is possibly result of a potent synergistic nociceptive analgesic effect and their minimal potential effects on sympathetic pathways thus minimizing spinal hypotension. Spinal anesthesia with 5–10 mg of 0.5% heavy bupivacaine, fentanyl 20 mcg and 100 mcg of long-acting morphine added to the perioperative plan decreased the incidence of spinal hypotension and improved perioperative outcomes in the geriatric patients undergoing (low segment) surgical procedures. These findings may be of interest in the gynecologic geriatric surgery also in which area there are very few studies concerning the use of low-dose concept.

Relative Contributions of Adductor Canal Block and Intrathecal Morphine to Analgesia and Functional Recovery After Total Knee Arthroplasty: A Randomized Controlled Trial

BACKGROUND AND OBJECTIVES

Effective postoperative analgesia may enhance early rehabilitation after orthopedic surgery. This randomized double-blind trial investigates the relative contributions of adductor canal block and low-dose intrathecal morphine (ITM) to postoperative analgesia and functional recovery after total knee arthroplasty.

METHODS

Two-hundred one patients undergoing elective unilateral total knee arthroplasty under spinal anesthesia were randomized to 3 groups. All patients received standardized intraoperative local infiltration analgesia and postoperative oral analgesics. Patients in group 1 received a "sham" adductor canal block with 30 mL of normal saline. Patients in group 2 received an adductor canal block with 30 mL of ropivacaine 0.5% with 1:400,000 epinephrine, whereas patients in group 3 received the adductor canal block with the active drug and 100 μg of ITM. The primary outcome measure was the Timed Up and Go (TUG) test on the second postoperative day. Secondary outcomes included postoperative pain scores and opioid requirements, distance walked, time to hospital discharge, and self-reported functional outcomes at 3 months.

RESULTS

All 3 groups had similar values of TUG test on postoperative day (POD) 2 (46 [36-62], 45 [33-61], and 52 [41-69]; P = 0.166) as well as other short-term and 3-month functional outcomes. Patients in group 3 showed a favorable analgesic profile as evidenced by 3 positive secondary outcomes. These positive outcomes were lower pain scores 12 hours postoperatively both at rest (4 [2-6.3], 4 [2.3-6], and 3 [1-4]; P = 0.007) and on movement (6 [4-8], 6 [3-8], and 4 [2-6]; P = 0.002), a lower incidence of "rescue" intravenous patient-controlled analgesia (42%, 34%, and 20%; P = 0.031), and the lowest cumulative opioid requirements for the first 48 hours postoperatively (86 ± 71, 68 ± 46, and 59 ± 39; P < 0.005, group 3 compared with group 1).

CONCLUSIONS

Our data suggest that there is no difference in either the primary outcome of TUG test on POD 2, other immediate functional secondary outcomes, or in global functional outcome at 3 months postoperatively across all 3 groups. Our data also suggest an improved analgesic profile in the first 48 hours postoperatively when both adductor canal block and low-dose ITM (100 μg) are added to local infiltration analgesia as evidenced by several positive secondary outcomes of lower pain scores and opioid requirements.

CLINICAL TRIAL REGISTRATION

This study was registered at ClinicalTrials.gov, identifier NCT02411149.

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.

Comparative Effects of Buprenorphine and Dexmedetomidine as Adjuvants to Bupivacaine Spinal Anaesthesia in Elderly Male Patients Undergoing Transurethral Resection of Prostrate: A Randomized Prospective Study

Background and Aims

Transurethral resection of the prostate is a commonly performed urological procedure in elderly men with spinal anaesthesia being the technique of choice. Use of low-dose spinal anesthetic drug with adjuvants is desirable. This study compares the sensorimotor effects of addition of buprenorphine or dexmedetomidine to low-dose bupivacaine.

Methods

Sixty patients were randomly allocated to three different groups. All received 1.8 mL 0.5% hyperbaric bupivacaine intrathecally. Sterile water (0.2 mL) or buprenorphine (60 μg) or dexmedetomidine (5 μg) was added to control group (Group C), buprenorphine group (Group B), and dexmedetomidine group (Group D), respectively. Time to the first analgesic request was the primary objective, and other objectives included the level of sensory-motor block, time to two-segment regression, time to S₁ sensory regression and time to complete motor recovery. ANOVA and post hoc test were used for statistical analysis. The value of P < 0.05 was considered statistically significant.

Results

All sixty patients completed the study. Postoperative analgesia was not required in the first 24 h in a total of 10 (50%), 12 (60%) and 15 (75%) patients in groups C, B, and D, respectively. Time to S₁ regression was 130 ± 46 min (Group C), 144 ± 51.3 min (Group B) and 164 ± 55.99 min (Group D), P = 0.117. Time to complete motor recovery was 177 ± 56.9 min (Group C), 236 ± 60 min (Group B) and 234 ± 61.71 min (Group D), P < 0.001.

Conclusion

Addition of buprenorphine (60 μg) or dexmedetomidine (5 μg) to intrathecal bupivacaine for transurethral resection prolongs the time to the first analgesic request with comparable recovery profile.

Adjuvants to local anesthetics: Current understanding and future trends

Although beneficial in acute and chronic pain management, the use of local anaesthetics is limited by its duration of action and the dose dependent adverse effects on the cardiac and central nervous system. Adjuvants or additives are often used with local anaesthetics for its synergistic effect by prolonging the duration of sensory-motor block and limiting the cumulative dose requirement of local anaesthetics. The armamentarium of local anesthetic adjuvants have evolved over time from classical opioids to a wide array of drugs spanning several groups and varying mechanisms of action. A large array of opioids ranging from morphine, fentanyl and sufentanyl to hydromorphone, buprenorphine and tramadol has been used with varying success. However, their use has been limited by their adverse effect like respiratory depression, nausea, vomiting and pruritus, especially with its neuraxial use. Epinephrine potentiates the local anesthetics by its antinociceptive properties mediated by alpha-2 adrenoreceptor activation along with its vasoconstrictive properties limiting the systemic absorption of local anesthetics. Alpha 2 adrenoreceptor antagonists like clonidine and dexmedetomidine are one of the most widely used class of local anesthetic adjuvants. Other drugs like steroids (dexamethasone), anti-inflammatory agents (parecoxib and lornoxicam), midazolam, ketamine, magnesium sulfate and neostigmine have also been used with mixed success. The concern regarding the safety profile of these adjuvants is due to its potential neurotoxicity and neurological complications which necessitate further research in this direction. Current research is directed towards a search for agents and techniques which would prolong local anaesthetic action without its deleterious effects. This includes novel approaches like use of charged molecules to produce local anaesthetic action (tonicaine and n butyl tetracaine), new age delivery mechanisms for prolonged bioavailability (liposomal, microspheres and cyclodextrin systems) and further studies with other drugs (adenosine, neuromuscular blockers, dextrans).

Comparison of intrathecal and local infiltration analgesia by morphine for pain management in total knee and hip arthroplasty: A meta-analysis of randomized controlled trial

OBJECTIVE

We performed a meta-analysis from randomized controlled trials to evaluate the efficiency and safety between local infiltration analgesia and intrathecal morphine for pain control in total knee and hip arthroplasty.

METHODS

We systemically searched electronic databases including Embase (1980-2016.7), Medline (1966-2016.7), PubMed (1966-2016.7), ScienceDirect (1985-2016.7), web of science (1950-2016.7) and Cochrane Library for relevant articles. All calculation was carried out by Stata 11.0.

RESULTS

Four randomized controlled trials (RCTs) involving 242 patients met the inclusion criteria. The meta-analysis showed that there were significant differences in terms of postoperative pain scores at 24 h during rest (P = 0.008) and mobilization (P = 0.049) following total knee and hip arthroplasty. Significant difference was found regarding the incidence of nausea (P = 0.030), vomiting (P = 0.005), and pruritus (P = 0.000) between two groups. There was no significant difference between groups in terms of morphine equivalent consumption at postoperative 24 or 48 h.

CONCLUSIONS

Local infiltration analgesia (LIA) provided superior analgesic effects within the first 24 h compared to intrathecal morphine (ITM) following total knee and hip arthroplasty. There were fewer adverse effects in LIA. Doses of morphine consumption were similar in the two groups.

Intrathecal morphine verse femoral nerve block for pain control in total knee arthroplasty: A meta-analysis from randomized control trials

OBJECTIVE

Total knee arthroplasty (TKA) is usually associated with postoperative pain. The objective of this systematic review and meta-analysis was to evaluate the effectiveness and safety of femoral nerve block compared with intrathecal morphine for pain management after TKA.

METHODS

Potentially relevant literature was identified from electronic databases including Medline, PubMed, Embase, ScienceDirect and the Cochrane Library. Gray academic studies were also identified from the reference of included literature. There was no language restriction. Pooling of data was carried out using Stata 11.0.

RESULTS

Four randomized controlled trials (RCTs) involving 185 patients met the inclusion criteria. The meta-analysis indicated that there were no significant differences in terms of Visual Analog Scale (VAS) score at 6 h (standard mean difference (SMD) = -0.09, 95% CI: -1.62 to 1.43, P = 0.903), 12 h (weighted mean difference (WMD) = 1.84, 95% CI: -8.01 to 11.69, P = 0.714) or 24 h (WMD = 1.56, 95% CI: -14.31 to 17.42, P = 0.8474). No significant difference were found regarding morphine consumption at 6 h (WMD = -0.84, 95% CI: -2.52 to 0.85, P = 0.332), 12 h (WMD = 0.031, 95% CI: -3.304 to 0.3366, P = 0.985), 24 h (WMD = 0.21, 95% CI: -7.32 to 7.75, P = 0.956) or incidence of postoperative vomit and nausea (risk difference (RD) = -0.01, 95% CI: -0.15 to 0.12, P = 0.847). There was a significant difference between the groups in terms of the risk of itching postoperatively (RD = 0.41, 95% CI: 0.29 to 0.54, P < 0.001).

CONCLUSIONS

Femoral nerve block provides equal postoperative pain control compared with intrathecal morphine following total knee arthroplasty, although there were fewer side effects in the FNB groups. In contrast, FNB was performed with an additional procedure and required a special apparatus. Both methods are effective at pain control following TKA.

Intrathecal morphine for postoperative pain control after laminoplasty in patients with cervical spondylotic myelopathy

OBJECTIVES

To examine the clinical efficacy of intrathecal morphine as postoperative analgesia for cervical laminoplasty.

SUMMARY OF BACKGROUND DATA

Patients who undergo posterior cervical spinal surgery frequently experience significant postoperative pain. Postoperative pain contributes to patient morbidity because of decreasing early voluntary mobilization and delayed rehabilitation. Intrathecal morphine is known to be a simple and effective analgesia. However, the effectiveness of intrathecal morphine for cervical spinal surgery has not yet been reported.

METHODS

Seventy-eight patients with cervical spondylotic myelopathy were divided into two groups prospectively, a diclofenac suppository (DS) group who received 50 mg diclofenac suppository at the end of the surgery, and an intrathecal morphine (ITM) group who were preoperatively administered 0.3 mg of morphine chloride, intrathecally, via a lumbar puncture. All patients underwent double-door laminoplasty of C3-6 or C3-7 level. Visual analog scale (VAS) of cervical pain, self-rating pain impression, supplemental analgesic usage, and complication rate were evaluated until the seventh postoperative day.

RESULTS

Thirty-one patients in the DS group and 32 patients in the ITM group were finally assessed. No baseline variable differences between the two groups were observed. The VAS was significantly lower in the ITM group at 4 h and 24 h until the seventh postoperative day. Self-rating pain impression was significantly better in the ITM group. No significant difference was observed in complication rate.

CONCLUSIONS

Intrathecal morphine was an effective and safe analgesic method for cervical laminoplasty in patients with cervical spondylotic myelopathy.

High rates of postoperative urinary retention following primary total hip replacement performed under combined general and spinal anaesthesia with intrathecal opiate

BACKGROUND

Postoperative urinary retention (POUR) occurs frequently following hip replacement.

METHODS

94 consecutive primary hip arthroplasty patients were assessed prospectively for POUR. 80 patients followed our anaesthesia protocol with combined general and spinal anaesthesia using bupivacaine and intrathecal diamorphine.

RESULTS

29 instances of POUR with higher rates in men and younger patients (under-50s), independent of either pre-existing renal impairment or opiate strength. POUR was observed to increase length of stay by 1.6 days.

CONCLUSIONS

We report a 36% overall rate of POUR. Males demonstrated a 3-fold increased risk. Patients should be counselled pre-operatively on the risk of urinary retention.

Spinal Anaesthesia with Adjunctive Intrathecal Morphine versus Continuous Lumbar Plexus Blockade: A Randomised Comparison for Analgesia after Hip Replacement

Following elective total hip replacement, both continuous lumbar plexus blockade and spinal anaesthesia (with adjunctive intrathecal morphine) have shown early outcome benefits over opioid analgesia and single-injection nerve block. However, the two techniques have not been compared in a prospective randomised manner. Our study examined 50 patients undergoing elective hip joint replacement who were randomised to receive spinal anaesthesia (with adjunctive intrathecal morphine 0.1 mg) or patient-controlled continuous lumbar plexus blockade. All surgery was conducted under general anaesthesia. Measured outcomes included numerically rated postoperative pain, supplemental opioid consumption and indices of mobilisation together with complications. Results show that block placement time was marginally shorter for the spinal group (5 versus 7 minutes, P=0.01). The primary outcome, worst pain on movement/mobilisation during the first 24 hours, was not statistically significantly different between groups. Patients in the lumbar plexus group were given more intraoperative opioid and rescue morphine in the post-anaesthesia care unit (median = 4 versus 0 mg, P <0.001), with correspondingly higher pain scores (median 5/10 versus 0/10, P <0.001). Pain scores during the subsequent 24 hours were similar between groups, but more patients in the spinal group were given rescue morphine (5 versus 0, P=0.02). Physiotherapy mobilisation indices appeared similar between groups. More spinal group patients reported pruritus (12 versus 5, P=0.01), but antiemetic requirements, episodes of disorientation, arterial oxygen desaturation and falls were all similar between groups. Postoperative symptoms suggestive of neurological irritation or injury did not differ between groups. We found that following elective hip joint replacement, compared to continuous lumbar plexus blockade, spinal anaesthesia incorporating adjunctive intrathecal morphine did not result in a statistically significant difference in worst pain on movement/mobilisation during the first 24 hours, although it was associated with better analgesia in the post-anaesthesia care unit. Subsequently, however, these patients appeared to require more rescue morphine and more of them reported pruritus.

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.

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.

Cardiorespiratory complications of neuraxial opioids in patients with obstructive sleep apnea: a systematic review

We sought to determine the rate of cardiorespiratory complications following neuraxial opioid administration in the setting of obstructive sleep apnea (OSA). This systematic review of the leading biomedical databases originated from a university-affiliated, tertiary-care teaching hospital. A systematic search of Medline, Embase, Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews, and the International Pharmaceutical Abstracts Database (1970 - September 2011) was undertaken. Cardiorespiratory complications were stratified into minor and major based on existing OSA literature. Five studies, including a total of 121 patients, were selected for analysis. All studies comprised low-quality evidence. Six major cardiorespiratory complications were reported among 5 (4.1%) patients and included three deaths, one cardiorespiratory arrest, and two episodes of severe respiratory depression. Five of these complications occurred during continuous fentanyl-containing epidural infusions and without concurrent positive airway pressure treatment. The rate of cardiorespiratory complications following the administration of neuraxial opioids to surgical patients with OSA is difficult to determine.

Postoperative pain relief after total hip arthroplasty: a randomized, double-blind comparison between intrathecal morphine and local infiltration analgesia

BACKGROUND

Postoperative pain after total hip arthroplasty (THA) can delay mobilization. This was assessed after intrathecal morphine (ITM) compared with local infiltration analgesia (LIA) using a non-inferiority design.

METHODS

Eighty patients were recruited in this randomized, double-blind study. ITM 0.1 mg (Group ITM) or periarticular local anaesthetic (ropivacaine 300 mg)+ketorolac 30 mg+ epinephrine 0.5 mg (total volume 151.5 ml) (Group LIA) were compared. After 24 h, 22 ml of saline (Group ITM) or ropivacaine (150 mg)+ketorolac (30 mg)+epinephrine (0.1 mg) (Group LIA) were injected via a catheter. After operation, rescue analgesic consumption, pain intensity, and home-readiness were measured.

RESULTS

Morphine consumption was equivalent, median difference 0 mg (95% confidence interval -4 to 4.5) between the groups at 0-24 h. During 24-48 h, it was lower in Group LIA (3 mg, 0-60 mg, median, range) compared with Group ITM (10 mg, 0-81 mg) (P=0.01). Lower pain scores were recorded at rest at 8 h in Group ITM (P<0.01), but in Group LIA on standing and mobilization, at 24-48 h (P<0.01). Paracetamol and tramadol consumption was lower in Group LIA (P=0.05 and 0.05, respectively) as was pruritus, nausea, and vomiting (P<0.05).

CONCLUSION

Lower pain intensity was recorded early after surgery in ITM group but later, analgesic consumption, pain intensity on mobilization, and side-effects were lower in patients receiving LIA. LIA is a good alternative to ITM in patients undergoing THA.

Spinal opioid bioavailability in postoperative pain

Opioids have been used for spinal analgesia for more than a century, and their injection epidurally and intrathecally has a key role in the control of postoperative pain. Since the discovery of the endogenous opioid system, 3 decades ago, their use has become more generalized in obstetric analgesia, the management of chronic pain, and acute postoperative pain. To use opioids effectively for this type of analgesia, it is important to understand the pharmacokinetics and clinical pharmacology of these drugs, specifically those that produce analgesia by an intrinsic spinal mechanism. Evidence from animal and human experiments indicates that hydrophilic opioids (such as hydromorphone and morphine) bind more strongly to specific receptors within the dorsal horn of the spinal cord than lipophilic opioids (such as alfentanil, fentanyl, and sufentanil). This can be understood by considering the spinal cord selectivity and bioavailability of these opioids. This difference is attributable to differences in the pharmacokinetic and pharmacodynamic properties of the 2 groups. It is more difficult for lipophilic opioids to reach and remain at sufficiently high concentrations at the site of action due to their sequestration in epidural fat and rapid plasma clearance from both epidural and intrathecal spaces, resulting in analgesia with a limited spread and duration, as well as the appearance of early supraspinal side effects. In contrast, morphine has very different properties, including greater spinal bioavailability and therefore administered neuraxially, it is suitable choice for the treatment of acute postoperative pain. However, when using morphine, a greater incidence of adverse effects can be expected, and it requires careful patient selection.

A comparison of epidural magnesium and/or morphine with bupivacaine for postoperative analgesia after cesarean section

BACKGROUND

Magnesium can potentiate the antinociceptive effect of morphine. This prospective randomized double-blinded study was undertaken to establish the analgesic effect of adding magnesium to epidural morphine during cesarean section.

METHODS

Two hundred patients undergoing cesarean section under combined spinal-epidural anesthesia were recruited. After administration of intrathecal bupivacaine 10mg, patients were randomly assigned to receive one of four epidural study solutions: 0.1% bupivacaine 10 mL (Group B); 0.1% bupivacaine 10 mL and morphine 1.5mg (Group B+Mor); 0.1% bupivacaine 10 mL and magnesium 500 mg (Group B+Mg); or 0.1% bupivacaine 10 mL morphine 1.5mg and magnesium 500 mg (Group B+Mor+Mg). The primary outcome was the area under the curve for visual analog scale pain scores during 36 h postoperatively. Secondary outcomes included time to the use of rescue analgesics, patient satisfaction and side effects.

RESULTS

Patients in Group B+Mor+Mg had lower for pain scores and area under the curve pain scores both at rest and on movement, increased time for first analgesic request, and increased satisfaction score at 24h after surgery.

CONCLUSION

Addition of magnesium 500 mg and morphine 1.5mg to epidural 0.1% bupivacaine 10 mL reduced postoperative pain compared with addition of morphine or magnesium alone or no additive.

A clinical approach to neuraxial morphine for the treatment of postoperative pain

Opioids are considered a “gold standard” in clinical practice for the treatment of postoperative pain. The spinal administration of an opioid drug does not guarantee selective action and segmental analgesia in the spine. Evidence from experimental studies in animals indicates that bioavailability in the spinal cord biophase is negatively correlated with liposolubility, and is higher for hydrophilic opioids, such as morphine, than lipophilic opioids, such as fentanyl, sufentanil and alfentanil. Epidural morphine sulphate has proven analgesic efficacy and superiority over systemically administered morphine for improving postoperative pain. However, pain relief after a single epidural injection of morphine could last less than 24 hours. Techniques used to administered and prolong opioid epidural analgesia, can be costly and inconvenient. Moreover, complications can arise from indwelling epidural catheterization, particularly in patients receiving anticoagulants. Clinical trials have shown that epidural morphine in the form of extended-release liposome injections (EREM) gives good analgesia for a period of 48 hours, with no need for epidural catheterisation. Intrathecal morphine produces intense analgesia for up to 24 hours with a single shot, and clinical recommendation is to choose the minimum effective dose and do not exceed 300 μg to prevent the delay respiratory depression.

Retrospective analysis of high-dose intrathecal morphine for analgesia after pelvic surgery

BACKGROUND

The effectiveness of intrathecal opioids (ITOs) for postoperative analgesia has been limited by reduced opioid dosing because of opioid-related side effects, most importantly respiratory depression. To overcome these limitations, high-dose intrathecal morphine was combined with a continuous intravenous (IV) postoperative naloxone infusion. The aim of the present chart analysis was to investigate the safety and efficacy of high-dose ITOs combined with IV naloxone compared with IV opioid analgesia alone.

METHODS

A retrospective chart analysis was performed on 121 female patients requiring major pelvic surgery. Ninety-eight patients received a single injection of high-dose ITOs before administration of typical general anesthesia, followed by an IV naloxone infusion at 5 µg⁄kg⁄h started post-ITO and continued for 22 h postoperatively. Twenty-three patients were given IV morphine (IVM) for postoperative analgesia and served as a reference group. Postoperative pain relief, analgesic consumption and ability to ambulate were assessed for 48 h postoperatively. Treatment safety was assessed by monitoring opioid-related side effects and vital signs. Data are presented as mean ± SD.

RESULTS

Mean ITOs given were morphine 1.1±0.2 mg combined with fentanyl 49 ± 6 µg. The mean worst pain visual analogue scale score in the first 12 h postoperatively was 0.2 ± 0.90 in the ITO group versus 4.3 ± 3.0 in the IVM group (P<0.05). On postoperative day 2, the mean worst pain visual analogue scale score was only 1 ± 1.8 in the ITO group versus 4.1 ± 2.6 in the IVM group (P<0.05). Analgesic requirements were reduced in the ITO group. In the first 24 h, the ITO group used 6.8±10.2 morphine equivalents (mg IV) versus 76.1 ± 44.4 in the IVM group (P<0.05). All patients in the ITO group were able to ambulate in the first 12 h postoperatively compared with 17⁄23 in the IVM group. There was a higher incidence of opioid-related sedation in the IVM group. Other opioid-related side effects were infrequent and minor in both groups.

CONCLUSIONS

High-dose ITOs combined with a postoperative IV naloxone infusion provided excellent analgesia for major pelvic surgery. The IV naloxone infusion combined with high-dose ITOs appeared to control opioid side effects without affecting analgesia.

Intrathecal opioid versus ultrasound guided fascia iliaca plane block for analgesia after primary hip arthroplasty: study protocol for a randomised, blinded, noninferiority controlled trial

BACKGROUND

Hip replacement surgery is increasingly common due to an ageing population, and rising levels of obesity. The provision of excellent pain relief with minimal side effects is important in order to facilitate patient mobilisation and rehabilitation.Spinal opioids provide excellent analgesia but are associated with adverse effects. The fascia-iliaca block is an alternative technique which provides analgesia to the nerves innervating the hip. The success of fascia iliaca blocks has been demonstrated to be superior when using ultrasound compared to landmark techniques. However, the clinical benefit of this improvement has yet to be investigated.The aim of this study is to compare the efficacy and safety of ultrasound guided fascia iliaca block with spinal morphine for hip replacement surgery.

METHODS/DESIGN

This study is a randomised, blinded, placebo-controlled, noninferiority trial. Patients scheduled to undergo unilateral primary hip arthroplasty will receive a study information sheet and consent will be obtained in keeping with the Declaration of Helsinki. Patients will be randomised to receive either; (i) Ultrasound guided fascia iliaca block using levobupivacaine, plus spinal anaesthesia with hyperbaric bupivacaine containing no morphine, or (ii) sham ultrasound guided fascia iliaca block performed with sterile saline, and spinal anaesthesia containing hyperbaric bupivacaine and 0.1 mg of spinal morphine.A total of 108 patients will be recruited. Primary outcome is post-operative morphine consumption in a 24 hour period. Secondary outcomes include; pain scores at 3, 6, 12, 24, 36 and 48 hours, episodes of respiratory depression, hypotension, nausea and vomiting, pruritus, sedation, time to first mobilisation and patient satisfaction.

CONCLUSIONS

There are no studies to date comparing ultrasound guided fascia iliaca block with spinal morphine for pain control after hip arthroplasty. If the ultrasound guided fascia iliaca block provides pain relief which is not inferior to spinal morphine, then morphine could be removed from the spinal injection. This could reduce side effects and improve patient safety.

TRIAL REGISTRATION

This study has been approved by the West of Scotland Research Ethics Committee 4 (reference no. 10/S0704/43) and is registered with ClinicalTrials.gov (reference no. NCT01217294).

Prevalence and management of obstructive sleep apnea in patients undergoing total joint arthroplasty

Obstructive sleep apnea (OSA) may be a risk factor for complications after total joint arthroplasty (TJA). We sought to determine the prevalence of OSA in patients undergoing TJA, and the safety and effectiveness of intrathecal narcotic (IN) in these patients. We retrospectively reviewed 1255 consecutive patients undergoing 1463 TJA at one hospital. All patients underwent routine screening for OSA and IN anesthesia, with 109 patients (134 TJA) identified with OSA (8.7%). Compared with 127 randomly selected patients (141 TJA) without OSA, OSA patients were significantly heavier and had higher American Society of Anesthesiologists scores, more comorbidities, longer length of stay, more transient hypoxia, more transfusions, and more medical variances. Despite more minor variances, with appropriate screening and management, OSA patients did not have a higher rate of significant or major complications. Length of stay, although longer, was only 2.3 days in OSA patients, demonstrating the safety and efficacy of IN anesthesia in these patients.

Local anaesthetic adjuvants: neuraxial versus peripheral nerve block

PURPOSE OF REVIEW

To present a review of the literature on the importance and the clinical characteristics relevant to adjuvants added to local anaesthetics in neuraxial and peripheral nerve blocks.

RECENT FINDINGS

In neuraxial anaesthesia, both opioids and alpha-2 receptor agonists have beneficial effects. Intrathecally, fentanyl and sufentanil not only improve the postoperative analgesia but also make it possible to allow a decrease in the local anaesthetic dose. When clonidine or dexmedetomidine was added to intrathecal local anaesthetics, the regression of sensory, motor block increased dose-dependently and postoperative analgesia was prolonged. The potency of intrathecal clonidine: dexmedetomidine seems to be 10: 1. In peripheral nerve block, when opioid was combined with local anaesthetics, no increased improvement in analgesia was reported in comparison with systemic controls in most of the studies, except buprenorphine. Also clonidine is controversial as an analgesic adjuvant. Special factors, such as type of local anaesthetics, block of upper or lower limb, are important for its the beneficial effect. Other adjuvants, except neuraxial low-dose neostigmine, are of minor importance.

SUMMARY

Opioids and alpha-2 receptor agonists are important as neuraxial adjuvants to improve the quality of peroperative and postoperative analgesia in high-risk patients and in ambulatory procedures. In peripheral nerve blocks, however, some benefit is found only when clonidine is added to local anaesthetics under certain circumstances.

The effective duration of analgesia after intrathecal morphine in patients without additional opioid analgesia: a randomized double-blind multicentre study on orthopaedic patients

BACKGROUND AND OBJECTIVE

To know whether the application of patient-controlled analgesia devices could be avoided if intrathecal morphine is given in combination with spinal anaesthesia.

METHODS

In a randomized, double-blind multicentre study, 188 orthopaedic patients were randomized to receive intrathecally placebo, 0.1 mg morphine or 0.2 mg morphine in addition to 15 mg bupivacaine. The primary outcome parameter was the number of patients without any additional request for opioid during a period of 72 h after surgery.

RESULTS

Patients with 0.1 or 0.2 mg morphine showed a significant reduction in opioid requests compared with placebo during 72 h after surgery (P = 0.0001). At 24 h after surgery, the rate of patients who required additional opioid analgesia was 71% in the placebo group, 51% in the 0.1 mg morphine group and 31% of the patients in the 0.2 mg morphine group. After 0.2 mg morphine, systemic opioid requirements at 24 h were significantly lower than those in patients with 0.1 mg morphine (P < 0.05). Intrathecal morphine was not associated with an increased frequency of respiratory depression. Forty per cent of patients with intrathecal morphine did not ask for systemic opioids.

CONCLUSION

Intrathecal morphine in a dose of 0.1 and 0.2 mg provides effective analgesia for up to 48 h without any need for systemic opioids at all in many patients.

Risks and side-effects of intrathecal morphine combined with spinal anaesthesia: a meta-analysis

Intrathecal morphine is often used for postoperative analgesia after surgery. We performed a meta-analysis to obtain more detailed information on the frequency of side-effects in patients receiving intrathecal morphine in combination with spinal anaesthesia compared with placebo treated patients. We clustered the analysis to patients receiving placebo, less than morphine 0.3 mg (M < 0.3), or equal to or more than morphine 0.3 mg (M > or = 0.3) and calculated the risk ratios of morphine vs placebo. Twenty-eight studies investigating 46 morphine groups vs placebo were included. A total of 790 patients with intrathecal morphine and 524 patients who received placebo were analysed. Compared with placebo the lower dose of morphine resulted in an increase of nausea (RR 1.4, 95% CI 1.1-1.7), vomiting (RR 3.1, 95% CI 1.5-6.4) and pruritus (RR 1.8, 95% CI 1.4-2.2). The higher dose resulted in an increased risk ratio for pruritus (RR 5.0, 95% CI 2.9-8.6), but not nausea (RR 1.2, 95% CI 0.9-1.6) or vomiting (RR 1.3, 95% CI 0.9-1.9). Overall, intrathecal morphine did not increase respiratory depression. However, the higher dose of intrathecal morphine was associated with more episodes of respiratory depression (7/80) compared with the lower dose (2/247). Intrathecal morphine is associated with a mild increase in side-effects. With a dose < 0.3 mg we found there were no more episodes of respiratory depression than in placebo patients who received systemic opioid analgesia.

Intraoperative Ketamine may Influence Persistent Pain following Knee Arthroplasty under Combined General and Spinal Anaesthesia: A Pilot Study

We report the findings of a randomised controlled triple-blind pilot study of intraoperative ketamine infusion combined with spinal anaesthesia on the prevalence of persisting post surgical pain following total knee arthroplasty surgery. Twelve patients were randomised to receive either ketamine or placebo in association with spinal anaesthesia for total knee arthroplasty. All patients also received general anaesthesia. More patients were pain-free at six months in the ketamine group (three of five) compared to the control group (two of seven). Perioperative data collected during the study suggested that the addition of intraoperative ketamine might also improve the quality of recovery. Although no statistical analysis was undertaken due to the small numbers, these preliminary findings suggest that the use of intraoperative systemic ketamine in association with spinal anaesthesia for the reduction of persisting post surgical pain deserves further study.

Optimizing the dose of intrathecal morphine when combined with continuous 3-in-1 nerve block after total knee replacement

BACKGROUND

Continuous femoral 3-in-1 block alone is insufficient for the treatment of severe pain after total knee replacement (TKR). Intrathecal (IT) morphine provides effective postoperative analgesia but may result in many side effects. The optimal dose of spinal morphine when combined with continuous 3-in-1 block after TKR is not known.

METHODS

Patients were randomized to receive IT morphine in five groups (n = 20 per group): 1) 0.0 mg, 2) 0.05 mg, 3) 0.1 mg, 4) 0.15 mg, and 5) 0.2 mg. All patients received continuous 3-in-1 block performed with 20 ml of 0.25% bupivacaine, followed by a continuous infusion of 0.125% bupivacaine at the rate of 2 ml/h plus PCA boluses of 1 ml with a lockout of 10 minutes. The intensity of pain at rest and on movement of the knee was assessed by using a visual analog scale for the first two postoperative days.

RESULTS

All treatment groups produced effective pain relief and decreased cumulative femoral PCA bolus use of 0.125% bupivacaine compared with control, respectively (P < 0.05); however, there were no significant differences among the treatment groups. The incidence of vomiting was significantly more frequent with 0.1-0.2 mg IT morphine groups compared with control, respectively (P < 0.05). The rate of administration of antipruritic medication was increased as IT morphine dose increased (P < 0.05).

CONCLUSIONS

Use of 0.05 mg IT morphine would appear to provide the optimal balance between pain relief and adverse effects following TKR.