Evaluation of the analgesic effect of ketamine as an additive to intrathecal bupivacaine in patients undergoing cesarean section. ACTA ACUST UNITED AC. 2013;51:155-160. [PMID: 24529671 DOI: 10.1016/j.aat.2013.12.004]

Efficacy and safety of ketamine as an adjuvant to regional anesthesia: A systematic review and meta-analysis of randomized controlled trials

STUDY OBJECTIVE

To identify whether adding ketamine to the local anesthetics (LA) in the regional anesthesia could prolong the duration of analgesia.

DESIGN

A Systematic review and meta-analysis of randomized controlled trials.

SETTING

The major dates were obtained in the operating room and the postoperative recovery ward.

PATIENTS

A total of 1011 patients at ASA physical status I and II were included in the analysis. Procedure performed including cesarean section, orthopedic, radical mastectomy, urological or lower abdominal surgery and intracavitary brachytherapy implants insertion.

INTERVENTIONS

After an extensive search of the electronic database, patients received regional anesthesia combined or not combined general anesthesia and with or without adding ketamine to LA were included in the analysis. The regional anesthesia includes spinal anesthesia, brachial plexus block, pectoral nerve block, transversus abdominis plane block and femoral and sciatic nerve block.

MEASUREMENT

The primary outcome was the duration of analgesia. Secondary outcomes were the duration and onset time of motor and sensory block as well as the ketamine-related adverse effect. Data are expressed in mean differences in continuous data and odds ratios (OR) for dichotomous data with 95% confidence intervals. The risk of bias of the included studies was evaluated using the revised Cochrane risk of bias tool for randomized trials. The quality of evidence for each outcome was rated according to the Grading of Recommendations, Assessment, Development and Evaluations (GRADE) Working Group system.

MAIN RESULT

Twenty randomized controlled trials were included in the analysis. When ketamine was used as an adjuvant to LA, the duration of analgesia could be prolonged(172.21 min, 95% CI, 118.20 to 226.22; P<0.00001, I2 = 98%), especially in the peripheral nerve block(366.96 min, 95% CI, 154.19 to 579.74; P = 0.0007, I2 = 98%). Secondary outcomes showed ketamine could prolong the duration of sensory block(29.12 min, 95% CI, 10.22 to 48.01; P = 0.003, I2 = 96%) but no effect on the motor block(6.94 min, 95% CI,-2.65 to 16.53;P = 0.16, I2 = 84%), the onset time of motor and sensory block (motor onset time, -1.17 min, 95% CI, -2.67 to 0.34; P = 0.13, I2 = 100%; sensory onset time, -0.33 min, 95% CI,-0.87 to 0.20; P = 0.23, I2 = 96%) as well as the ketamine-related adverse effect(OR, 1.97, 95% CI,0.93 to 4.17;P = 0.08, I2 = 57%).

CONCLUSION

This study indicates that ketamine could be an ideal adjuvant to local anesthetics regardless of the types of anesthesia. Overall, the quality of the evidence is low.

Effects of Ketamine and Tramadol As Adjuvants to Bupivacaine in Spinal Anesthesia for Unilateral Open Ovarian Cystectomy: A Randomized Controlled Trial

BACKGROUND

Spinal anesthesia offers numerous advantages and desirable features. However, it is associated with various side effects related to local anesthetic agents used. Reducing the dose of local anesthetic in spinal anesthesia can help minimize side effects but may lead to a diminished analgesic effect or failure of anesthesia. Therefore, adding an adjuvant may enhance the benefits while mitigating side effects.

OBJECTIVE

This study aimed to evaluate the effects of ketamine and tramadol as adjuvants to bupivacaine on the duration of spinal analgesia. The objectives were to compare the three groups and prove their analgesic effects, safety, and superiority. The primary outcomes were the duration of spinal analgesia, as well as the onset and duration of both sensory and motor blocks. Secondary outcomes included the heart rate, mean arterial pressure, and the incidence of undesired effects such as nausea, vomiting, sedation, shivering, and postoperative headache.

METHODS

In this double-blind randomized controlled trial, 120 female patients undergoing elective open unilateral ovarian cystectomy under spinal anesthesia were studied. The inclusion criteria included patients aged 16-45 years with a physical status classified as American Society of Anesthesiologists (ASA) class I and II. Patients were randomly allocated into three groups: group B (n=40) received only bupivacaine, group BK (n=40) received bupivacaine mixed with preservative-free ketamine, and group BT (n=40) received bupivacaine mixed with preservative-free tramadol.

RESULTS

The mean duration of spinal analgesia, measured in minutes, showed significant differences (P < 0.001) between group BK (165 ± 4) and group B (170 ± 5). There was also a significant difference between group BT (313 ± 8) and group B (170 ± 5) (P < 0.001). Additionally, significant differences were observed between group BK (165 ± 4) and group BT (313 ± 8) (P < 0.001).

CONCLUSION

The administration of 25 mg of ketamine and 25 mg of tramadol as adjuvants to bupivacaine in spinal anesthesia significantly affected the postoperative duration of analgesia. Tramadol prolonged the duration of spinal anesthesia, while ketamine shortened it. The use of both adjuvants did not result in undesired effects.

Low-dose spinal and opioid-free anesthesia in patient with Severe Aortic Stenosis and SARS-CoV-2 infection: Case report

The best anesthesiologic approach to severe AS patient has not been adequately studied in literature. Although the current guidelines have a cautious attitude in this regard, Combined Spinal-Epidural Anesthesia (CSEA) has proved to be a safe technique. Therefore, we would like to provide our experience with a severe AS and COVID-19 patient.

Single dose perioperative intrathecal ketamine as an adjuvant to intrathecal bupivacaine: A systematic review and meta-analysis of adult human randomized controlled trials

STUDY OBJECTIVE

To identify whether adding intrathecal ketamine to intrathecal bupivacaine prolongs the time to first analgesic request in adult humans.

DESIGN

A meta-analysis of randomized controlled trials in humans.

SETTING

The majority of data was obtained in an operating room and postoperative recovery area.

PATIENTS

A total of 750 ASA physical status I and II patients were included in the study. Procedures performed include: cesarean section, lower abdominal surgery, lower limb surgery, and urologic surgery.

INTERVENTIONS

Databases including PubMed, Embase, Web of Science, and Cochrane were searched. Google Scholar was also queried. Multiple reviewers screened the papers for inclusion.

MEASUREMENTS

The primary outcome assessed was time to first analgesic request. Secondary outcomes included onset of sensory blockade, onset of motor blockade, duration of sensory blockade, and duration of motor blockade. Data were extracted to include means, 95% confidence intervals, tests for heterogeneity, and use of the Cochrane Collaboration guidelines to assess for publication bias.

MAIN RESULTS

Eleven randomized controlled trials met inclusion criteria. When comparing intrathecal bupivacaine plus ketamine to intrathecal bupivacaine alone, the time to first analgesic request was prolonged (effect size = 58.23 min (95% CI 37.36 to 79.10) p < 0.0001). Secondary outcomes showed the onset time of sensory blockade was shortened (effect size = -0.87 min (95% CI -1.361 to 0.378) p = 0.0005), the onset time of motor blockade was reduced (effect size = -0.88 min (95% CI -1.77 to 0.013) p = 0.05), the duration of sensory blockade was prolonged (effect size = 39.73 min (95% CI 15.97 to 63.50) p = 0.001), and the duration of motor blockade was prolonged (effect size = 4.02 min (95% CI 3.27 to 4.78) p < 0.0001). Studies were shown to have high heterogeneity. Egger tests for all outcomes were non-significant and funnel plots assessing publication bias were all asymmetrical.

CONCLUSIONS

The studies analyzed suggest there may be a benefit to using intrathecal ketamine as an adjunct to bupivacaine. Additional studies are warranted to optimize dosing, clarify the safety and efficacy of this intrathecal drug combination, and examine the various ketamine formulations as intrathecal bupivacaine adjuvants.

To compare the analgesic efficacy of two different doses of epidural ketamine in chronic low back-pain patients: A randomised double-blind study

Background and Aims:

Ketamine, an adjunct to epidural steroid injections (ESI) for chronic back-pain provides better quality and prolonged duration of analgesia. The present study aims to evaluate the analgesic efficacy in terms of pain scores, duration of pain-free period, patient satisfaction score (PSS) and number of repeat injections with 25 mg versus 50 mg ketamine as adjuvants to ESI.

Methods:

In a prospective, randomised, double-blind trial at a tertiary care hospital, 60 patients of chronic low back-pain of either sex, aged 18–65 years, received preservative free 25 mg ketamine in Group I and 50 mg ketamine in Group II as adjunct to 40 mg triamcinolone in total 6 ml volume given epidurally. Baseline data along with follow-ups at 2, 4, 8 and 12 weeks post-procedure included assessment of pain using Visual Analogue Scale (VAS), duration, number of repeat blocks using PSS, Quality of Life (QoL) and side-effects. Categorical data analysed using the Chi-Square test, and continuous data using paired t-test.

Results:

Pain evaluation within the groups over time showed significant improvement from baseline (P = 0.000), and between the groups showed comparable VAS scores at 12 weeks (P = 0.392). The PSS, pain-free duration and number of repeat injections were also statistically comparable. However, the QoL improved more in Group II vs Group I (P = 0.024). The short-lasting side effects were more in Group II, but no features of neurotoxicity were observed in any patient.

Conclusion:

The analgesic efficacy of adjuvant therapy with 50 mg ketamine appeared comparable to 25 mg ketamine. Although, there was a better quality of life and longer pain-free interval with 50 mg ketamine, the side effects were more.

Intrathecal Nalbuphine versus Ketamine with Hyperbaric Bupivacaine in Lower Abdominal Surgeries

Background

Spinal anesthesia is an effective method of anesthesia with fewer side effects. The main limitations include the shorter duration of action and shorter postoperative analgesia when performed only with local anesthetics.

Aim

The aim of this study is to compare adjuvants nalbuphine and ketamine to hyperbaric bupivacaine in spinal anesthesia with respect to the duration of analgesia, sensory and motor onset, hemodynamic status, and side effects.

Settings and Design

This was a prospective, randomized, double-blind study.

Materials and Methods

After ethical committee's clearance and informed consent, 90 patients of the American Society of Anesthesiologists physical status I and II were randomly allocated in three groups N, K, and B who received 3 ml hyperbaric bupivacaine with 0.8 mg nalbuphine, 3 ml hyperbaric bupivacaine with 25 mg ketamine (preservative free), and 3 ml hyperbaric bupivacaine with 0.5 ml normal saline, respectively.

Statistical Analysis

Data were analyzed using paired t-test. Results were analyzed and compared to previous studies. SPSS-22 version of software was used, released 2013, IBM Corp., Armonk, NY, USA.

Results

Mean duration of analgesia in Group N, K, and B was 290 ± 6.09, 220 ± 5.03, and 154 ± 6.04 min, respectively. Mean time of sensory onset in Group N, K, and B was 2.08 ± 0.34, 3.5 ± 0.25, and 4.5 ± 0.37 min, respectively. Time of motor onset was 7.60 ± 0.58, 7.79 ± 0.37, and 7.82 ± 0.53 min in Group N, K, and B, respectively.

Conclusion

Nalbuphine is an effective adjuvant in spinal anesthesia with respect to sensory onset, duration of analgesia, and hemodynamic stability.

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).

Evaluation of the effects of ketamine on spinal anesthesia with levobupivacaine or ropivacaine

Spinal anesthesia or regional anesthesia is a potent anesthetic procedure. Additional modalities have been sought to increase the duration of block in spinal anesthesia. Ketamine is an N-methyl-D-aspartate (NMDA) receptor blocker that has an anesthetic effect when injected intrathecally and has a synergic effect with bupivacaine. Ketamine also has potent analgesic properties. The present study investigated the effect of intrathecally administered ketamine on spinal anesthesia with levobupivacaine or ropivacaine. Sprague-Dawley rats at post-natal day 21 were exposed to spinal anesthesia with 0.5% levobupivacaine or 0.5% ropivacaine. Separate groups of rats were treated with intrathecal ketamine at a 5 or 10 mg/kg bodyweight dose along with ropivacaine or levobupivacaine. The thermal and mechanical withdrawal latencies of the animals were determined using hot plate and von Frey filaments, respectively. A rotarod apparatus was employed to assess the capacity of the rats to rotate the spindle at 24 h following anesthesia. The gait of the rat pups was also assessed. Intrathecal administration of ketamine resulted in dense blocks and extended the duration of spinal blocks as evidenced by thermal latencies and responses to von Frey filaments. The latency to fall was shorter in rats exposed to ketamine along with ropivacaine or levobupivacaine spinal anesthesia. The gait parameters were also more disturbed upon ketamine administration. In conclusion, ketamine administration with ropivacaine or levobupivacaine increased the intensity and duration of spinal blockade, thereby increasing the anesthetic effects.

Intrathecal Sufentanil Does Not Reduce Shivering During Neuraxial Anesthesia: A Meta-Analysis

BACKGROUND

We performed this meta-analysis to evaluate the efficacy of intrathecal sufentanil in preventing shivering during neuraxial anesthesia.

MATERIAL/METHODS

We searched the Cochrane Library, PubMed, and Embase for all randomized controlled trials (RCT) on use of intrathecal sufentanil for preventing shivering during neuraxial anesthesia. References of retrieved articles were also screened. The quality of the studies was evaluated by the method recommended by the Cochrane Collaboration. Meta-analysis was conducted using the Cochrane Collaboration's RevMan 5.3 software. The primary outcome was incidence and severity of shivering, and the secondary outcomes were drug-related complications of pruritus, nausea, vomiting, hypotension, and bradycardia.

RESULTS

Eight original RCTs investigating a total of 1032 patients, of whom 599 received sufentanil and 473 received placebo, met the inclusion criteria. Compared to the placebo group, sufentanil did not reduce incidence of shivering (OR, 0.60; 95% CI, 0.35 to 1.01; P=0.06), but it increased the incidence of pruritus (OR, 12.52; 95% CI, 5.07 to 30.91; P<0.00001). Compared to the placebo group, sufentanil did not increase the incidence of nausea (OR, 0.69; 95% CI, 0.41 to 1.16; P=0.16), hypotension (OR, 0.93; 95% CI, 0.62 to 1.41; P=0.74), or bradycardia (OR, 0.86; 95% CI, 0.41 to 1.82; P=0.70). In addition, sufentanil reduced the incidence of vomiting during neuraxial anesthesia (OR, 0.45; 95% CI, 0.22 to 0.92; P=0.03).

CONCLUSIONS

Neither epidural nor subarachnoid intrathecal sufentanil reduced shivering during neuraxial anesthesia, but it did increase the incidence of pruritus.

Intrathecal magnesium sulfate as a spinal adjuvant in two different doses, combined with 0.5% heavy bupivacaine for infraumbilical surgeries

The spinal anesthesia has the definitive advantage that profound nerve block can be produced in a large part of the body by the relatively simple injection of a small amount of local anesthetic.

Effect of Two Different Doses of Dexmedetomidine as Adjuvant in Bupivacaine Induced Subarachnoid Block for Elective Abdominal Hysterectomy Operations: A Prospective, Double-blind, Randomized Controlled Study

OBJECTIVES

Improvements in perioperative pain management for lower abdominal operations has been shown to reduce morbidity, induce early ambulation, and improve patients' long-term outcomes. Dexmedetomidine, a selective alpha-2 agonist, has recently been used intrathecally as adjuvant to spinal anesthesia to prolong its efficacy. We compared two different doses of dexmedetomidine added to hyperbaric bupivacaine for spinal anesthesia. The primary endpoints were the onset and duration of sensory and motor block, and duration of analgesia.  .

METHODS

A total of 100 patients, aged 35-60 years old, assigned to have elective abdominal hysterectomy under spinal anesthesia were divided into two equally sized groups (D5 and D10) in a randomized, double-blind fashion. The D5 group was intrathecally administered 3ml 0.5% hyperbaric bupivacaine with 5µg dexmedetomidine in 0.5ml of normal saline and the D10 group 3ml 0.5% bupivacaine with 10µg dexmedetomidine in 0.5ml of normal saline. For each patient, sensory and motor block onset times, block durations, time to first analgesic use, total analgesic need, postoperative visual analogue scale (VAS) scores, hemodynamics, and side effects were recorded.  .

RESULTS

Although both groups had a similar demographic profile, sensory and motor block in the D10 group (p<0.050) was earlier than the D5 group. Sensory and motor block duration and time to first analgesic use were significantly longer and the need for rescue analgesics was lower in the D10 group than the D5 group. The 24-hour VAS score was significantly lower in the D10 group (p<0.050). Intergroup hemodynamics were comparable (p>0.050) without any appreciable side effects.  .

CONCLUSION

Spinal dexmedetomidine increases the sensory and motor block duration and time to first analgesic use, and decreases analgesic consumption in a dose-dependent manner.

Novel polymeric bioerodable microparticles for prolonged-release intrathecal delivery of analgesic agents for relief of intractable cancer-related pain

Intractable cancer-related pain complicated by a neuropathic component due to nerve impingement is poorly alleviated even by escalating doses of a strong opioid analgesic. To address this unmet medical need, we developed sustained-release, bioerodable, hydromorphone (potent strong opioid)- and ketamine (analgesic adjuvant)-loaded microparticles for intrathecal (i.t.) coadministration. Drug-loaded poly(lactic-co-glycolic acid) (PLGA) microparticles were prepared using a water-in-oil-in-water method with evaporation. Encapsulation efficiency of hydromorphone and ketamine in PLGA (50:50) microparticles was 26% and 56%, respectively. Microparticles had the desired size range (20-60 μm) and in vitro release was prolonged at ≥28 days. Microparticles were stable for ≥6 months when stored refrigerated protected from light in a desiccator. Desirably, i.t. injected fluorescent dye-labeled PLGA microparticles in rats remained in the lumbar region for ≥7 days. In a rat model of neuropathic pain, i.t. coinjection of hydromorphone- and ketamine-loaded microparticles (each 1 mg) produced analgesia for 8 h only. Possible explanations include inadequate release of ketamine and/or hydromorphone into the spinal fluid, and/or insufficient ketamine loading to prevent development of analgesic tolerance to the released hydromorphone. As sub-analgesic doses of i.t. ketamine at 24-48 h intervals restored analgesia on each occasion, insufficient ketamine loading appears problematic. We will investigate these issues in future work.

Effect of different doses of dexmedetomidine as adjuvant in bupivacaine -induced subarachnoid block for traumatized lower limb orthopaedic surgery: a prospective, double-blinded and randomized controlled study

BACKGROUND AND AIMS

Improved pain management for blunt trauma to the lower extremity has shown to reduce morbidity, induce early ambulation and improve long-term outcomes. Dexmedetomidine; a selective α-2 agonist; has recently been used intrathecally in different doses to prolong spinal anaesthesia. We evaluated the effect of adding two different doses of dexmedetomidine to hyperbaric bupivacaine for spinal anaesthesia. The primary endpoints were the onset and duration of sensory, motor block and duration of analgesia.

MATERIALS AND METHODS

Eighty patients, (20-60yrs) posted for elective lower limb orthopedic surgery of traumatic origin under spinal anaesthesia were divided into 2 equal groups (Group D5&D10) in a randomized, double-blind fashion. In this prospective parallel group study, group D5(n=40) 3ml 0.5% hyperbaric bupivacaine+5μg dexmedetomidine in 0.5 ml of normal saline and group D10 (n=40) 3ml 0.5% bupivacaine+10μg dexmedetomidine in 0.5 ml of normal saline were administered intrathecally. Sensory and motor block onset times and block durations, time to first analgesic use, total analgesic need, postoperative VAS, hemodynamics and side effects were recorded for each patient.

RESULTS

Though with similar demographic profile in both groups, sensory and motor block in group D10(p<0.05) was earlier than group D5. Sensory, motor block duration and time to first analgesic use were significantly longer and the need for rescue analgesics was lower in group D10(p<0.05) than D5. 24 h VAS score was significantly lower in group D10(p<0.05). Intergroup hemodynamics was comparable (p>0.05) without any appreciable side effects.

CONCLUSION

Spinal dexmedetomidine increases the sensory, motor block duration and time to first analgesic use, and decreases analgesic consumption in a dose-dependent manner.