Adding Ketamine in a Multimodal Patient-Controlled Epidural Regimen Reduces Postoperative Pain and Analgesic Consumption

Effect of Combined Epidural Morphine and Midazolam on Postoperative Pain in Patients Undergoing Major Abdominal Cancer Surgery

OBJECTIVE

The objective was to compare analgesic effect of combined epidural morphine-midazolam with either drug alone on postoperative pain in patients undergoing major abdominal cancer surgery.

MATERIALS AND METHODS

Eighty-four patients were allocated in prospective randomized double-blind study to receive epidural analgesia. Patients received 5 mg morphine in morphine (Mor) group, 5 mg midazolam in midazolam (Mid) group, 5 mg morphine + 5 mg midazolam in morphine-midazolam (MM) group, 0.25% bupivacaine was added to injected solution with same volume in all groups. All groups were compared with time of first analgesic request, total analgesic consumption, number of epidural doses, postoperative Visual Analog Scale score, and adverse events.

RESULTS

Time of first analgesic request was 4 to 8 hours in Mid versus 12 to 23 and 14 to 24 hours in Mor and MM groups, respectively, with significant difference between Mid versus Mor ( P <0.001), Mid versus MM ( P <0.001), and Mor versus MM groups ( P <0.031). Analgesic consumption was more in Mid than Mor and MM groups, with significant difference between Mid versus Mor ( P <0.008), Mid versus MM ( P <0.001), with no significant difference between Mor and MM groups ( P <0.6). The number of epidural doses in Mid was 1 to 3 versus 1 to 3, and 1 to 2 in Mor and MM groups, respectively, with significant difference between Mid versus Mor ( P <0.025), Mid versus MM ( P <0.004), with no significant difference between Mor and MM groups ( P =1.0).

CONCLUSIONS

Addition of midazolam to epidural morphine prolonged time of first analgesic request and decreased total analgesic consumption.

Evolving the management of acute perioperative pain towards opioid free protocols: a narrative review

Objective: Identification of pain as the fifth vital sign has resulted in over-prescription and overuse of opioids in the US, with addiction reaching epidemic proportions. In Europe, and more recently in the US, a shift has occurred with the global adoption of multimodal analgesia (MMA), which seeks to minimize perioperative opioid use. Improved functional outcomes and reduced healthcare utilization costs have been demonstrated with MMA, but wide scale use of opioids in pain management protocols continues. As a next step in the pain management evolution, opioid-free analgesia (OFA) MMA strategies have emerged as feasible in many surgical settings.Methods: Articles were limited to clinical studies and meta-analyses focusing on comparisons between opioid-intensive and opioid-free/opioid-sparing strategies published in English.Results: In this review, elimination or substantial reduction in opioid use with OFA strategies for perioperative acute pain are discussed, with an emphasis on improved pain control and patient satisfaction. Improved functional outcomes and patient recovery, as well as reduced healthcare utilization costs, are also discussed, along with challenges facing the implementation of such strategies.Conclusions: Effective MMA strategies have paved the way for OFA approaches to postoperative pain management, with goals to reduce opioid prescriptions, improve patient recovery, and reduce overall healthcare resource utilization and costs. However, institution-wide deployment and adoption of OFA is still in early stages and will require personalization and better management of patient expectations.

WITHDRAWN: Perioperative ketamine for acute postoperative pain

This review has been amended to include further information on Menigaux 2000 pre pre and Menigaux 2000 post included studies.

At July 2014, this review is out of date and has been withdrawn. This review is correct as of the date of publication. The latest version is available in the ‘Other versions’ tab on The Cochrane Library, and may still be useful to readers.

The editorial group responsible for this previously published document have withdrawn it from publication.

Setting up an acute pain management service

Successful implementation of an acute pain management service involves a team approach in which team members have clearly defined roles. Clinical protocols are designed to help address common problems and prevent errors. As the complexity of surgery and patients' diseases continues to increase, current knowledge of new analgesic medications, acute pain literature, and skills in regional anesthesia techniques is imperative. Emphasizing a multimodal approach can improve analgesia and decrease opioid-related side effects.

Evaluation of dexmedetomidine and postoperative pain management in patients with adolescent idiopathic scoliosis: conclusions based on a retrospective study at a tertiary pediatric hospital

OBJECTIVES

This study evaluated the effectiveness of dexmedetomidine in decreasing opioid use in children with adolescent idiopathic scoliosis following posterior spinal fusion surgery at a pediatric tertiary care hospital over the past 10 years.

DESIGN

This was a retrospective chart review. Patients were separated into two groups: those that received opioid via patient-controlled analgesia pain therapy alone and those that received opioid via patient-controlled analgesia pain therapy with dexmedetomidine.

SETTING

A tertiary pediatric free-standing hospital. The study focused on care administered in the perioperative period, including the operating room, ICU, and general hospital floor.

PATIENTS

One hundred sixty-three children with adolescent idiopathic scoliosis.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Measurements included patient demographics, American Society of Anesthesiologists Physical Status Classification System, levels of spinal fusion, length of hospital stay, complications, numeric pain scores, opioid requirement, elastomeric pain pump use, length of time until ambulation, adverse effects, and naloxone use. Data were collected through the first 72 hours of the perioperative period. One hundred six patients received opioids via patient-controlled analgesia therapy with dexmedetomidine and 57 received opioids via patient-controlled analgesia alone. Within the groups, there were 46 patients who received local anesthetic infusions via elastomeric pumps in the patient-controlled analgesia with dexmedetomidine group and 16 patients had pumps in the patient-controlled analgesia-alone group. There was no overall difference in postoperative use of morphine (or equivalents) between the two groups. However, the use of elastomeric pain pumps demonstrated a statistically significant decrease in mean overall opioid consumption (42.6 mg vs 63.1 mg, p < 0.001).

CONCLUSIONS

There was no difference in opioid use related to dexmedetomidine on any postoperative day. The only variable showing a significant opioid sparing effect was the use of local anesthetic infusions via elastomeric pumps. Using continuous local anesthetic infusions instead of dexmedetomidine could eliminate the need for ICU admission, require shorter hospital stays, and reduce costs while still providing safe and effective pain control.

A randomized, controlled trial of a clinical pharmacist intervention in microdiscectomy surgery - Low dose intravenous ketamine as an adjunct to standard therapy

AIM

The hypothesis that postoperative pain would be reduced by using 1 μg/kg/min of ketamine, both intra- and post-operatively, for lumbar microdiscectomy surgery was assessed by measuring morphine consumption. Patient side effects were reported.

METHODS

Forty-five patients undergoing microdiscectomy surgery were randomized under double-blind conditions into three groups: Group1 (G1) received normal saline, Group 2 (G2) ketamine (1 μg/kg/min) intra-operatively and Group 3 (G3) ketamine (1 μg/kg/min) both intra- and post-operatively. Morphine consumption, pain scores, nausea and vomiting, CNS disorders were recorded for 24 h post surgery. This study was conducted by applying the concept of a clinical pharmacist intervention.

RESULTS

The time for the first analgesia demand dose was significantly shorter (P < 0.05) in G117 ± 1.7 min than for G2 and G3. In G3 morphine consumption 6, 12, and 24 h after surgery was 3 ± 2.26, 9.2 ± 2.11 and 26.9 ± 2.71 mg. Total morphine consumption was significantly lower for G3 than for G1 or G2 (P < 0.05). The visual analog scale score (VAS) values were significantly lower in G3 (P < 0.05) than for the other groups during the first 24 h. The rate of nausea and vomiting was significantly higher in G1 vs G3 (P < 0.05). No difference in drug induced CNS disturbances was observed among the groups.

CONCLUSIONS

Using 1 μg/kg/min of ketamine hydrochloride intra- and post-operatively for microdiscectomy surgery could be an adjunct therapy to reduce postoperative morphine consumption minimizing its side effects. Collaborative clinical pharmacy practice on the basis of pharmacology had an effective role in improving the general outcome of microdiscectomy surgery.

Battlefield analgesia: a brief review of current trends and concepts in the treatment of pain in US military casualties from the conflicts in Iraq and Afghanistan

SUMMARY Battlefield analgesia and post-injury pain management is a high priority within the military medical community. The combined military services of the USA have developed a Pain Task Force and clinical practice guidelines to ensure that adequate analgesia is provided to our wounded soldiers as far forward as the point of injury on the battlefield. As a result of this emphasis, novel analgesic techniques and equipment have led to improved pain management. Continuous peripheral nerve blocks, intranasal ketamine, battlefield acupuncture and other adjuncts have all been utilized safely and successfully. The ability to provide rapid analgesia as early in the course of injury as possible not only helps with the immediate pain of the soldier, but potentially minimizes the risk of developing chronic postinjury pain. During the long medical evacuation system the risks of both undertreatment and overtreatment of pain are very real. Future studies and observation will help to delineate best treatment regimens and pave the way for the next generation of medical providers to positively impact a soldier’s recovery. This article is written from the perspective of the USA with a focus on the conflicts in Afghanistan (Operation Enduring Freedom) and Iraq (Operation Iraqi Freedom).

Multimodal therapies for postoperative nausea and vomiting, and pain

Postoperative nausea and vomiting (PONV) and pain are two of the major concerns for patients presenting for surgery. The causes of PONV are multifactorial and can largely be categorized as patient risk factors, anaesthetic technique, and surgical procedure. Antiemetics work on several different receptor sites to prevent or treat PONV. This is probably why numerous studies have now demonstrated that using more than one antiemetic is usually more effective and results in fewer side-effects than simply increasing the dose of a single antiemetic. A multimodal approach to PONV should not be limited to drug therapy alone but should involve a holistic approach starting before operation and continuing intraoperatively with risk reduction strategies to which are added prophylactic antiemetics according to the assessed patient risk for PONV. With the increasing understanding of the pathophysiology of acute pain, especially the occurrence of peripheral and central hypersensitization, it is unlikely that a single drug or intervention is sufficiently broad in its action to be adequately effective, especially with moderate or greater pain. Although morphine and its congeners are usually the foundation of pain management regimens, as their dose increases so does the incidence of side-effects. Thus, the approach for the management of acute postoperative pain is to use multiple drugs or modalities (e.g. regional anaesthesia) to maximize pain relief and reduce side-effects.

Lumbosacral epidural magnesium prolongs ketamine analgesia in conscious sheep

PURPOSE: To determine the analgesic, motor, sedation and systemic effects of lumbosacral epidural magnesium sulphate added to ketamine in the sheep. METHODS: Six healthy adult male mixed-breed sheep; weighing 43 ± 5 kg and aged 20-36 months. Each sheep underwent three treatments, at least 2 weeks apart, via epidural injection: (1) ketamine (KE; 2.5 mg/kg), (2) magnesium sulphate (MG; 100 mg), and (3) KE + MG (KEMG; 2.5 mg/kg + 100 mg, respectively). Epidural injections were administered through the lumbosacral space. Analgesia, motor block, sedation, cardiovascular effects, respiratory rate, skin temperature, and rectal temperature were evaluated before (baseline) and after drug administration as needed. RESULTS: The duration of analgesia with the lumbosacral epidural KEMG combination was 115 ± 17 min (mean ± SD), that is, more than twice that obtained with KE (41 ± 7 min) or MG (29 ± 5 min) alone. KE and KEMG used in this experiment induced severe ataxia. The heart rate and arterial blood pressures changes were no statistical difference in these clinically health sheep. CONCLUSION: The dose of magnesium sulphate to lumbosacral epidural ketamine in sheep is feasible, and can be used in procedures analgesics in sheep.

Role of epidural ketamine for postoperative analgesia after upper abdominal surgery

Ketamine, a N-methyl-D-aspartate receptor antagonist inhibits central sensitization due to peripheral nociception thus potentiating the analgesic effect of morphine. The purpose of our study was to evaluate the effect of adding small-dose ketamine in a multimodal regimen of postoperative patient-controlled epidural analgesia (PCEA). One hundred patients of American Society of Anesthesiologists physical status I-II, undergoing major upper abdominal surgery were randomly allocated to two groups. Group I received PCEA device containing bupivacaine hydrochloride 0.0625% and morphine sulphate (preservative free) 0.05mg/ml. Group II received PCEA device containing bupivacaine hydrochloride 0.0625%, morphine sulphate (preservative free) 0.05 mg/ml and ketamine hydrochloride (preservative free) 0.2 mg/ml. The mean morphine consumption in group I after 1^stand 2^ndpostoperative day was 8.38±2.85 and 7.64±1.95 mg, respectively, compared to 6.81±1.35 and 6.25±1.22 mg (P<0.05) in group II. Although group II consumed significantly less morphine, pain relief at rest and at movement after 6, 12, 24 and 48 hours, postoperatively was significantly better in group II (P<0.05) than in group I. These findings suggest that adding small-dose ketamine to a multimodal PCEA regimen provides better postoperative analgesia and reduces morphine consumption.

Ketamine induces apoptosis via the mitochondrial pathway in human lymphocytes and neuronal cells

BACKGROUND

Ketamine has been shown to have neurotoxic properties, when administered neuraxially. The mechanism of this local toxicity is still unknown. Therefore, we investigated the mechanism of cytotoxicity in different human cell lines in vitro.

METHODS

We incubated the following cell types for 24 h with increasing concentrations of S(+)-ketamine and racemic ketamine: (i) human Jurkat T-lymphoma cells overexpressing the antiapoptotic B-cell lymphoma 2 protein, (ii) cells deficient of caspase-9, caspase-8, or Fas-associated protein with death domain and parental cells, and (iii) neuroblastoma cells (SHEP). N-Methyl-d-aspartate (NMDA) receptors and caspase-3 cleavage were identified by immunoblotting. Cell viability and apoptotic cell death were evaluated flowcytometrically by Annexin V and 7-aminoactinomycin D double staining. Mitochondrial metabolic activity and caspase-3 activation were measured.

RESULTS

Ketamine, in a concentration-dependent manner, induced apoptosis in lymphocytes and neuroblastoma cell lines. Cell lines with alterations of the mitochondrial pathway of apoptosis were protected against ketamine-induced apoptosis, whereas alterations of the death receptor pathway did not reduce apoptosis. S(+)-Ketamine and racemic ketamine induced the same percentage of cell death in Jurkat cells, whereas in neuroblastoma cells, S(+)-ketamine was slightly less toxic.

CONCLUSIONS

Ketamine at millimolar concentrations induces apoptosis via the mitochondrial pathway, independent of death receptor signalling. At higher concentrations necrosis is the predominant mechanism. Less toxicity of S(+)-ketamine was observed in neuroblastoma cells, but this difference was minor and therefore unlikely to be mediated via the NMDA receptor.

Evaluation of the effect of magnesium sulphate vs. clonidine as adjunct to epidural bupivacaine

For treatment of intra and postoperative pain, no drug has yet been identified that specifically inhibits nociception without associated side effects. Magnesium has antinociceptive effects in animal and human models of pain. The current prospective randomised double-blind study was undertaken to establish the effect of addition of magnesium or clonidine, as adjuvant, to epidural bupivacaine in lower abdominal and lower limb surgeries. A total of 90 American Society of Anesthesiology (ASA) grade I and II patients undergoing lower abdominal and lower limb surgeries were enrolled to receive either magnesium sulphate (Group B) or clonidine (Group C) along with epidural bupivacaine for surgical anaesthesia. All patients received 19 ml of epidural bupivacaine 0.5% along with 50 mg magnesium in group B, 150 mcg clonidine in Group C, whereas in control group (Group A), patients received same volume of normal saline. Onset time, heart rate, blood pressure, duration of analgesia, pain assessment by visual analogue score (VAS) and adverse effects were recorded. Onset of anaesthesia was rapid in magnesium group (Group B). In group C there was prolongation of duration of anaesthesia and sedation with lower VAS score, but the incidence of shivering was higher. The groups were similar with respect to haemodynamic variables, nausea and vomiting. The current study establishes magnesium sulphate as a predictable and safe adjunct to epidural bupivacaine for rapid onset of anaesthesia and clonidine for prolonged duration of anaesthesia with sedation.

Effects of perioperative intravenous low dose of ketamine on postoperative analgesia in children

BACKGROUND AND OBJECTIVE

Low dose of ketamine reduces postoperative pain and opioid consumption in adult studies. However, there are only a few data with controversial results in the paediatric population. The aim of this randomized controlled trial was to evaluate the use of low doses of intravenous ketamine on postoperative pain in children after surgery on the lower part of the body.

METHODS

Thirty-seven children with ASA 1 or 2 from 6 to 60 months of age, undergoing scheduled surgery, were prospectively enrolled in a double blind sequential trial using a triangular test, with analysis every 10 patients treated. The children were randomly assigned to intravenously receive saline or 0.15 mg kg(-1) ketamine before surgery, followed by a continuous infusion of 1.4 microg kg(-1) min(-1) over 24 h. After sevoflurane induction and tracheal intubation, a caudal anaesthesia was performed in all children (1 ml kg(-1) of bupivacaine 0.25% with epinephrine). The postoperative analgesic technique was standardized with intravenous paracetamol 15 mg kg(-1) 6 h(-1), rectal morniflumate (20 mg kg(-1) 12 h(-1)) and intravenous nalbuphine infusion 1.2 mg kg(-1) 24 h(-1) for 24 h. The Children's Hospital of Eastern Ontario Pain Scale (CHEOPS) scores, additional bolus of nalbuphine (if CHEOPS >7) and side effects were recorded from eye opening every 2 h over 24 h. The primary endpoint was the CHEOPS area under the curve.

RESULTS

There was no difference in terms of additional bolus of nalbuphine as well as CHEOPS score area under the curve between groups, that is, 76 +/- 10 in the ketamine group versus 74 +/- 7 in the control group. No psychomimetic side effects were noted.

CONCLUSION

The study failed to show any evidence of benefit of ketamine to improve analgesia in children when given in addition to a multimodal analgesic therapy with paracetamol, a NSAID and an opiate.

Effects of preoperative epidural administration of racemic ketamine for analgesia in sheep undergoing surgery

OBJECTIVE

To investigate the effects of preoperative epidural administration of racemic ketamine to provide analgesia in sheep undergoing experimental hind limb orthopedic surgery.

ANIMALS

12 adult sheep (weight range, 51.4 to 67.2 kg).

PROCEDURE

Sheep were anesthetized with guaifenesin, thiopental, and isoflurane; after induction of anesthesia, sheep received a lumbosacral epidural injection of ketamine (1 mg/kg; n = 6) or saline (0.9% NaCl) solution (1 mL/7 kg; 6 [control group]). Respiratory and cardiovascular variables were recorded before and at intervals during and for 6 hours after anesthesia. During that 6-hour postoperative period, analgesia was evaluated subjectively with a numeric ranking scale that included assessments of comfort, posture, movement, and response to wound palpation; buprenorphine was administered when a score > 3 (maximum score, 10) was achieved. Rectal temperature, heart and respiratory rates, and lameness were evaluated daily for 2 weeks after surgery.

RESULTS

At all evaluations, cardiovascular and respiratory variables were comparable between the 2 groups. Compared with control sheep, time to first administration of rescue analgesic was significantly longer and total dose of buprenorphine administered during the 6- hour postoperative period was significantly decreased for ketamine-treated sheep. During the second week following surgery, ketamine-treated sheep had significantly less lameness than control sheep.

CONCLUSIONS AND CLINICAL RELEVANCE

In sheep undergoing hind limb surgery, preoperative epidural administration of ketamine appears to provide analgesia in the immediate postoperative period and has residual analgesic effects, which may contribute to more rapid return of normal function in surgically treated limbs.

Effects of S(+) ketamine added to bupivacaine for spinal anaesthesia for prostate surgery in elderly patients

BACKGROUND AND OBJECTIVE

Intrathecal ketamine as the sole anaesthetic agent has demonstrated a lack of cardiovascular depression that should be of advantage in an elderly population. S(+) ketamine has three-times the analgesic potency of R(-) ketamine and its antinociceptive effects after intrathecal administration in rats are known. We decided to evaluate the effects of intrathecal S(+) ketamine added to a small dose of spinal bupivacaine in elderly patients undergoing transurethral prostate surgery.

METHODS

Forty males over 60 yr old, scheduled for transurethral prostate resection under spinal anaesthesia, were studied in a prospective, double-blinded, randomized way. Patients were allocated to receive either bupivacaine 10 mg or bupivacaine 7.5 mg combined with S(+) ketamine 0.1 mg kg(-1). Spinal block onset time, maximum sensory level, duration of blockade, haemodynamic variables, postoperative analgesic requirements and adverse events were recorded.

RESULTS

Onset times of motor and sensory block were shorter in the bupivacaine plus S(+) ketamine group. Incomplete motor block of the lower extremities was seen in 80% of the patients in bupivacaine plus S(+) ketamine group. Duration of complete motor block and spinal analgesia was shorter in the bupivacaine plus S(+) ketamine group. There was no significant difference in arterial pressure. Heart rate decreased after spinal anaesthesia in the bupivacaine plus S(+) ketamine group and was significantly lower until the end of anaesthesia. The incidence of adverse effects was not different between groups.

CONCLUSIONS

Intrathecal S(+) ketamine administered with a low dose of bupivacaine provides shorter motor and sensory block onset time, shorter duration of action and less motor blockade in elderly males.

Preoperative epidural ketamine in combination with morphine does not have a clinically relevant intra- and postoperative opioid-sparing effect

In this prospective, randomized, and double-blinded clinical trial, we evaluated the efficacy of preincisional administration of epidural ketamine with morphine compared with epidural morphine alone for postoperative pain relief after major upper-abdominal surgery. We studied 50 ASA I and II patients undergoing major upper-abdominal procedures. These patients were randomly allocated to one of the two treatment groups: patients in Group 1 received epidural morphine 50 microg/kg, whereas those in Group 2 received epidural ketamine 1 mg/kg combined with 50 microg/kg of morphine 30 min before incision. Intraoperative analgesia was provided in addition, with IV morphine, and the requirement was noted. A blinded observer using a visual analog scale for pain assessment observed patients for 48 h after surgery. Additional doses of epidural morphine were provided when the visual analog scale score was more than 4. Analgesic requirements and side effects were compared between the two groups. There were no differences between the two groups with respect to age, sex, weight, or duration or type of the surgical procedures. The intraoperative morphine requirement was significantly (P = 0.018) less in Group 2 patients (median, 6.8 mg; range, 3-15 mg) compared with patients in Group 1 (median, 8.3 mg; range, 4.5-15 mg). The time for the first requirement of analgesia was significantly (P = 0.021) longer (median, 17 h; range, 10-48 h) in Group 2 patients than in Group 1 (median, 12 h; range, 4-36 h). The total number of supplemental doses of epidural morphine required in the first 48 h after surgery was comparable (P = 0.1977) in both groups. Sedation scores were similar in both groups. One patient in Group 2 developed hallucinations after study drug administration. None of the patients in either group developed respiratory depression. Other side effects, such as pruritus, nausea, and vomiting, were also similar in both groups. Although the addition of ketamine had synergistic analgesic effects with morphine (reduced intraoperative morphine consumption and prolonged time for first requirement of analgesia), there was no long- lasting preemptive benefit seen with this combination (in terms of reduction in supplemental analgesia) for patients undergoing major upper-abdominal procedures.

IMPLICATIONS

Ketamine added to epidural morphine given before surgery can decrease postoperative pain by its preemptive effect, opioid potentiation, and prevention of acute opioid tolerance. A single epidural bolus of 1 mg/kg of ketamine with morphine given before major upper-abdominal surgery did not result in a clinically relevant reduction in postoperative pain relief.

The Epidural and Intrathecal Administration of Ketamine

An overview of the spinal administration of ketamine is presented. Ketamine acts as a noncompetitive antagonist of the NMDA receptor Ca(++ channel pore. This effect provides interesting possibilities in pain therapy. However, there are still contrasting results that seem to be due to a lack of comparative controlled studies. The presence of systemic and neurotoxic effects presently limits clinical use).