Effect of Oral Pregabalin as Preemptive Analgesic in Patients Undergoing Lower Limb Orthopedic Surgeries under Spinal Anaesthesia

OPIOID FREE GENERAL ANESTHESIA IN CLINICAL PRACTICE - A REVIEW ARTICLE

Currently, enhanced recovery after surgery (ERAS) protocols are multimodal perioperative care pathways with the goal to achieve early patient recovery after surgery with minimal postoperative complications. According to studies, opioid free general anesthesia has many perioperative benefits and should be part of the ERAS protocols in specific surgical and patient indications. Opioid free general anesthesia is a multimodal balanced technique that is based on the concept that opioids are not used preoperatively or intraoperatively until the patient has aroused. The basic concept of opioid free general anesthesia is intravenous administration of several nonopioid drugs that operate at different pharmacological sites blocking surgical stress and sympathetic activation response. Moreover, current studies have shown that opioid free anesthesia is a technique which satisfactorily controls postoperative pain as the fifth vital sign, and has minimal side effects and better patient recovery with the same surgical conditions as general multimodal balanced anesthesia. However, further research is needed.

Effect of Preemptive Multimodal Analgesia Regimen on Post-operative Epidural Demand Boluses in Lower Limb Orthopaedic Surgeries

Introduction Excruciating pain is associated with lower limb orthopaedic surgeries involving femoral shaft fractures. Postoperative pain management is still ineffective in low-resource settings where the use of epidural and opioid-free analgesia is impractical. Literature is scarce with respect to the effect of a preemptive multimodal analgesia regimen on the requirement of postoperative epidural demand boluses. Hence, the present study aimed to evaluate the effect of pre-emptive multimodal analgesia in reducing the requirement of epidural demand boluses postoperatively, and to find out the time required to receive the first epidural bolus. Material and methods This double-blinded randomized control study included 48 subjects. Patients aged 18-60 years with lower limb fractures requiring surgery under combined spinal-epidural anesthesia were included. Patients were divided into two groups through random allocation. Group A: Preemptive multimodal group received intravenous paracetamol 1 g, IV diclofenac 75 mg diluted in 100ml NS, IV tramadol 50 mg diluted in 100ml NS and tab pregabalin 75 mg orally, 30 mins before surgery. Group B: Placebo group received 3 pints of 100ml NS IV and tab ranitidine 150 mg, 30 mins before surgery. Intraoperatively, combined spinal-epidural anaesthesia was administered taking all the aseptic precautions. Visual analogue scale (VAS) was recorded immediately on shifting to a postoperative room, and then at 1, 4, 8, 12, and 24 hr for both groups. Epidural boluses (10 ml of 0.125% bupivacaine with 2 μg/ml of fentanyl) were given whenever the patient's visual analogue scale was more than 4. The time at which the first epidural bolus was required by the patient was recorded. The total number of epidural boluses given over 24 hours based on VAS was recorded for both, the preemptive and placebo groups. If the patient still complained of pain, IV diclofenac 75 mg was given if the VAS was more than 4, while IV diclofenac 75 mg along with IV tramadol 50 mg was given if the VAS was more than 6. Patient satisfaction with anesthesia care, in general, was assessed 24 hrs postoperatively. Results A total of 48 subjects were included in the study. During the immediate-postoperative period, and at 8, 12 and 24 hr, the median VAS was significantly low in group A as compared to group B. A significant increase in the demand for epidural bolus immediate-postoperatively was observed in group B (70.83%) compared to group A (4.17%) (p-value of <0.001). At 8 hr, 12hr, and 24hr, patients in group A found a significantly less need for epidural boluses compared to Group B. The mean total number of epidural boluses taken in group A was significantly less compared to group B (1.79 ± 0.41 VS 3.33 ± 0.48, p-Value <0.001). In group A, all patients reported no requirement for diclofenac and tramadol. In group B, 8.33% required diclofenac 75 mg, while the remaining 91.66% had no requirement for diclofenac and tramadol. The difference in patient satisfaction with anaesthesia care in general between the two study groups was found to be significant with a p-value of 0.027. Patients in Group A were very satisfied compared with those in group B. Conclusions The study found that the pre-emptive multimodal analgesia group had better postoperative pain control because they required fewer epidural boluses and no extra analgesics postoperatively. This group was more satisfied with the anaesthesia care in general.

A Randomized, Double-Blind, Prospective Study to Evaluate the Effect of Oral Pregabalin in Upper Limb Surgeries Under Brachial Plexus Block

Context

The oral pregabalin administration preoperatively has been reported to reduce acute postoperative pain and prolong the duration of anesthesia produced by single-injection peripheral nerve blockade.

Aim

To study the effect of single dose pregabalin on duration of brachial plexus block

Settings and design

Prospective, randomised, double blind, comparative study

Material and methods

Patients were divided into two groups (groups A and B), with each group having 50 patients. In group A, the patient received a pregabalin capsule of 300 mg orally two hours before surgery with a sip of water. Group B received a placebo (vitamin B complex capsule) orally two hours before surgery. Brachial plexus block was performed, and data was collected.

Statistical analysis

Data analysis was done using SPSS version 21.0 statistical analysis software. Demographic data and clinical variables were compared using the student's t-test, chi-square test, and Mann-Whitney U test.

Results

The requirement of the first dose of analgesia was significantly earlier in group B as compared to group A (4:56±0:20 vs. 8:01±0:30 hours). Group B patients, as compared to group A patients, had significantly higher levels of pain after two hours of surgery (0.32±0.47 vs. 0.00±0.00) and at four hours of surgery (2.42±0.50 vs. 0.34±0.59).

Conclusions

Oral pregabalin prolongs analgesia from brachial plexus block without significant effect on the motor block. In addition, premedication with oral pregabalin increases the sensory block of brachial plexus block.

The effects of pregabalin and adductor canal block on postoperative pain in arthroscopic anterior cruciate ligament reconstruction

Background/aim

To determine the effectiveness of pregabalin and adductor canal block on opioid consumption, postoperative pain, and fast-tracking.

Materials and methods

A total of 51 American Society of Anaesthesiologists (ASA) classification I–II patients aged 18–70 years who were scheduled to undergo elective anterior cruciate ligament reconstruction were included in the study. Patients were randomized into groups P, A, and C. Patients in group P (n = 16), received 150 mg of preoperative oral pregabalin, patients in group A (n = 17) received postoperative adductor canal blockade, and patients in group C (n = 18) received neither adductor canal block nor pregabalin. Surgeries were performed under spinal anaesthesia with hyperbaric bupivacaine following monitorization. Demographic data along with block features, hemodynamic data, mean opioid consumption, numerical rating scale score, White’s fast-track score, and postoperative adverse effects were recorded.

Results

Fifty-seven patients were enrolled in the study, and 6 patients were excluded from the study; the data of 51 patients were included in the final analyses. Demographic characteristics and hemodynamic data were similar between the 3groups. Postoperative opioid consumption was significantly lower in groups A and P compared with group C (group P = 178.75 mg, group C = 318.61 mg, group A = 236.47 mg; P < 0.05). The regression of sensory block was significantly slower in group P (P < 0.05). The first analgesic requirement was earlier in group C than in groups P and A (P < 0.05). Patients in group P had higher fast-track scores at 8 h and 12 h compared with group C (P < 0.05); however, group A fast-track scores were similar to those of the other 2groups (P > 0.05). The rate of postoperative adverse effects was similar between the groups (P > 0.05).

Conclusion

Preoperative pregabalin (150 mg) reduced postoperative opioid consumption as much as adductor canal block in patients undergoing anterior cruciate ligament reconstruction. The first analgesic requirement was earlier in group C than in groups P and A. In addition, pregabalin can prolong the duration of spinal sensory block and shorten the time required to achieve high fast-tracking scores. We recommend the use of both methods as a part of multimodal analgesia.

Effects of a single dose of preoperative pregabalin and gabapentin for acute postoperative pain: a network meta-analysis of randomized controlled trials

Background

Pregabalin (PGB) and gabapentin (GBP) are current and emerging drugs in the field of pre-emptive preoperative analgesia. However, the role of PGB or GBP in acute postoperative pain management still remains elusive.

Materials and methods

We conducted a comprehensive literature search of articles published by December 3, 2017. A total of 79 randomized controlled trials with 6,201 patients receiving single-dose premedication were included. Through a network meta-analysis (NMA), we validated the analgesic effect and incidence of adverse events by using various doses of PGB or GBP administration.

Results

NMA results suggested that the analgesic effect may be dose related. For 24-hour opioid consumption, a consistent decrease was found with the increase in the dose of PGB or GBP. For 24-hour pain score at rest, a high dose (≥150 mg) of PGB was more effective in decreasing pain score than a dose of 75 mg, and a high dose (≥900 mg) of GBP reduced pain intensity than doses of 300 or 600 mg. Moreover, the incidence of adverse reactions varied with varying doses of PGB or GBP.

Conclusion

A dose-response relationship was detected in opioid consumption and postoperative pain for a single-dose preoperative administration of PGB and GBP. Making reasonable choice of drugs and dosage may prevent the occurrence of adverse reactions.

An Updated Overview on Therapeutic Drug Monitoring of Recent Antiepileptic Drugs

Given the distinctive characteristics of both epilepsy and antiepileptic drugs (AEDs), therapeutic drug monitoring (TDM) can make a significant contribution to the field of epilepsy. The measurement and interpretation of serum drug concentrations can be of benefit in the treatment of uncontrollable seizures and in cases of clinical toxicity; it can aid in the individualization of therapy and in adjusting for variable or nonlinear pharmacokinetics; and can be useful in special populations such as pregnancy. This review examines the potential for TDM of newer AEDs such as eslicarbazepine acetate, felbamate, gabapentin, lacosamide, lamotrigine, levetiracetam, perampanel, pregabalin, rufinamide, retigabine, stiripentol, tiagabine, topiramate, vigabatrin, and zonisamide. We describe the relationships between serum drug concentration, clinical effect, and adverse drug reactions for each AED as well as the different analytical methods used for serum drug quantification. We discuss retrospective studies and prospective data on the serum drug concentration-efficacy of these drugs and present the pharmacokinetic parameters, oral bioavailability, reference concentration range, and active metabolites of newer AEDs. Limited data are available for recent AEDs, and we discuss the connection between drug concentrations in terms of clinical efficacy and nonresponse. Although we do not propose routine TDM, serum drug measurement can play a beneficial role in patient management and treatment individualization. Standardized studies designed to assess, in particular, concentration-efficacy-toxicity relationships for recent AEDs are urgently required.

Injury to skeletal muscle of mice following acute and sub-acute pregabalin exposure

Objective(s):

Pregabalin (PGB) is a new antiepileptic drug that has received FDA approval for patient who suffers from central neuropathic pain, partial seizures, generalized anxiety disorder, fibromyalgia and sleep disorders. This study was undertaken to evaluate the possible adverse effects of PGB on the muscular system of mice.

Materials and Methods:

To evaluate the effect of PGB on skeletal muscle, the animals were exposed to a single dose of 1, 2 or 5 g /kg or daily doses of 20, 40 or 80 mg/kg for 21 days, intraperitoneally (IP). Twaenty-four hr after the last drug administration, all animals were sacrificed. The level of fast-twitch skeletal muscle troponin I and CK-MM activity were evaluated in blood as an indicator of muscle injury. Skeletal muscle pathological findings were also reported as scores ranging from 1 to 3 based on the observed lesion.

Results:

In the acute and sub-acute toxicity assay IP injection of PGB significantly increased the activity and levels of CK-MM and fsTnI compared to the control group. Sub-acute exposure to PGB caused damages that include muscle atrophy, infiltration of inflammatory cells and cell degeneration.

Conclusion:

PGB administration especially in long term care causes muscle atrophy with infiltration of inflammatory cells and cell degeneration. The fsTnI and CK-MM are reliable markers in PGB-related muscle injury. The exact mechanisms behind the muscular damage are unclear and necessitate further investigations.