Influence of dexmedetomidine and lidocaine on perioperative opioid consumption in laparoscopic intestine resection: a randomized controlled clinical trial

Effects of intravenous lidocaine on postoperative pain and gastrointestinal function recovery following gastrointestinal surgery: a meta-analysis

INTRODUCTION

The full extent of intravenous lidocaine's effectiveness in alleviating postoperative pain and enhancing gastrointestinal function recovery remains uncertain.

EVIDENCE ACQUISITION

We conducted an exhaustive search of databases to identify randomized controlled trials that compared intravenous lidocaine infusion's efficacy to that of a placebo or routine care in patients undergoing gastrointestinal surgery. The primary outcome measure was resting pain scores 24 h postoperatively. We utilized a random-effects model based on the intention-to-treat principle for the overall results.

EVIDENCE SYNTHESIS

This study included twenty-four trials with 1533 patients. Intravenous lidocaine significantly reduced resting pain scores 24 h after gastrointestinal surgery (twenty trials, SMD -0.67, 95% CI -1.09 to -0.24, P=0.002, I2 = 90%). This finding was consistent in subgroup analyses and sensitivity analyses. The benefit was also observed at other resting and moving time points (1, 2, 4, and 12 h) postoperatively. Intravenous lidocaine significantly decreased opioid consumption within 24 h after surgery (eleven trials, SMD: -1.19; 95% CI: -1.99 to -0.39; P=0.003). Intravenous lidocaine also shortened the time to bowel sound (MD: -8.51; 95% CI: -14.59 to -2.44; P=0.006), time to first flatus (MD: -6.00; 95% CI: -9.87 to -2.13; P=0.002), and time to first defecation (MD: -9.77; 95% CI: -17.19 to -2.36; P=0.01).

CONCLUSIONS

Perioperative intravenous lidocaine can alleviate acute pain and expedite gastrointestinal function recovery in patients undergoing gastrointestinal surgery. However, the results should be interpreted with caution due to substantial heterogeneity. Further large-scale studies are necessary to validate these findings.

PROcedure-SPECific postoperative pain management guideline for laparoscopic colorectal surgery: A systematic review with recommendations for postoperative pain management

Colorectal cancer is the second most common cancer diagnosed in women and third most common in men. Laparoscopic resection has become the standard surgical technique worldwide given its notable benefits, mainly the shorter length of stay and less postoperative pain. The aim of this systematic review was to evaluate the current literature on postoperative pain management following laparoscopic colorectal surgery and update previous procedure-specific pain management recommendations. The primary outcomes were postoperative pain scores and opioid requirements. We also considered study quality, clinical relevance of trial design, and a comprehensive risk-benefit assessment of the analgesic intervention. We performed a literature search to identify randomised controlled studies (RCTs) published before January 2022. Seventy-two studies were included in the present analysis. Through the established PROSPECT process, we recommend basic analgesia (paracetamol for rectal surgery, and paracetamol with either a nonsteroidal anti-inflammatory drug or cyclo-oxygenase-2-specific inhibitor for colonic surgery) and wound infiltration as first-line interventions. No consensus could be achieved either for the use of intrathecal morphine or intravenous lidocaine; no recommendation can be made for these interventions. However, intravenous lidocaine may be considered when basic analgesia cannot be provided.

The effect of dexmedetomidine on expression of neuronal nitric oxide synthase in spinal dorsal cord in a rat model with chronic neuropathic pain

BACKGROUND

Neuropathic pain typically refers to the pain caused by somatosensory system injury or diseases, which is usually characterized by ambulatory pain, allodynia, and hyperalgesia. Nitric oxide produced by neuronal nitric oxide synthase (nNOS) in the spinal dorsal cord might serve a predominant role in regulating the algesia of neuropathic pain. The high efficacy and safety, as well as the plausible ability in providing comfort, entitle dexmedetomidine (DEX) to an effective anesthetic adjuvant. The aim of this study was to investigate the effect of DEX on the expression of nNOS in spinal dorsal cord in a rat model with chronic neuropathic pain.

METHODS

Male Sprague Dawley (SD) rats were randomly assigned into three groups: sham operation group (sham), (of the sciatic nerve) operation (CCI) group, and dexmedetomidine (DEX) group. Chronic neuropathic pain models in the CCI and DEX groups were established by sciatic nerve ligation. The thermal withdrawal latency (TWL) was measured on day 1 before operation and on day 1, 3, 7 and 14 after operation. Six animals were sacrificed after TWL measurement on day 7, and 14 days after operation, in each group, the L4-6 segment of the spinal cords was extracted for determination of nNOS expression by immunohistochemistry.

RESULTS

Compared with the sham group, the TWL threshold was significantly decreased and the expression of nNOS was up-regulated after operation in the CCI and DEX groups. Compared with the CCI grou[, the TWL threshold was significantly increased and the expression of nNOS was significantly down-regulated on day 7 and 14 days after operation in the DEX group.

CONCLUSION

Down-regulated nNOS in the spinal dorsal cord is involved in the attenuation of neuropathic pain by DEX.

Appropriate Duration of Perioperative Intravenous Administration of Lidocaine to Provide Satisfactory Analgesia for Adult Patients Undergoing Colorectal Surgery: A Meta-Analysis of Randomized Controlled Trials

BACKGROUND

Perioperative lidocaine infusion has been reported to alleviate pain intensity after colorectal surgery. However, there is no consensus on whether prolonged lidocaine infusion is more effective than short lidocaine infusion. This meta-analysis aimed to determine an appropriate duration of lidocaine infusion in patients undergoing colorectal surgery.

METHODS

We searched the PubMed, EMBASE, Web of Science, and Cochrane Library databases to identify articles published before December 17, 2021. Randomized controlled trials comparing intravenous lidocaine with placebo for pain relief in patients undergoing colorectal surgery were included. The primary outcome was pain scores (visual analog scale [VAS], 0-10 cm) at 24 hours postoperatively at rest and on movement. Secondary outcomes included pain scores at 12, 48, and 72 hours postoperatively, analgesic consumption (mg), gastrointestinal function return (hour), length of hospital stay (days), and incidence of complications. According to the duration of lidocaine infusion, studies were grouped into infusion for at least 24 hours (prolonged lidocaine infusion) and less than 24 hours (short lidocaine infusion) to assess the impact of lidocaine infusion duration on the outcomes of interests. Quantitative analyses were performed using a random effects model.

RESULTS

Eleven studies with 548 patients were included. Five studies used prolonged lidocaine infusion, while 6 studies used short lidocaine infusion. Prolonged lidocaine infusion reduced postoperative pain scores versus placebo at 24 hours at rest (mean difference [MD], -0.91 cm; 95% confidence interval [CI], -1.54 to -0.28; P = .02) and on movement (MD, -1.69 cm; 95% CI, -2.15 to -1.22; P < .001), while short lidocaine infusion showed no benefit. Compared with placebo, prolonged lidocaine infusion reduced pain scores at 12 hours at rest and at 12 and 48 hours on movement, but short lidocaine infusion did not. However, there was no significant difference in pain scores between the prolonged and short lidocaine infusion groups at these time points. Compared with placebo, prolonged lidocaine infusion shortened the length of hospital stay (MD, -1.30 days; 95% CI, -1.72 to -0.88; P < .001) and time to first postoperative defecation (MD, -12.51 hours; 95% CI, -22.67 to -2.34; P = .02). There were no differences between groups regarding the other outcomes.

CONCLUSIONS

The analgesic effect of intravenous lidocaine may depend on the duration of infusion, and our results suggest that lidocaine infusion should be administered for at least 24 hours after colorectal surgery. Since overall evidence quality was low, further high-quality, large-sample trials are needed to explore an optimal lidocaine infusion strategy in patients undergoing colorectal surgery.

A Multimodal Analgesic Protocol with Gabapentin-dexmedetomidine for Post-operative Pain Management after Modified Radical Mastectomy Surgery: A Randomized Placebo-Controlled Study

Background and Aim: Modified radical mastectomy (MRM) is accompanied by severe acute postoperative pain. This study evaluated the safety and efficacy of oral gabapentin plus dexmedetomidine infusion as an analgesic multimodal protocol in patients undergoing MRM. Methods: This prospective randomized, double-blind placebo-controlled study included 30 females scheduled for MRM from June 2021 to December 2021. They were randomly divided into two groups. GD Group (n=15) received oral gabapentin 400 mg and IV infusion of Dexmedetomidine 0.4 µg/kg/h over 10 min after a bolus of 0.5 µg/kg before induction of general anesthesia. Placebo Group (n=15) received a placebo capsule and saline infusion identical to the GD Group. The primary outcome measure was total morphine consumption, and secondary outcomes were pain and sedation scores and intraoperative fentanyl consumption. Results: Pain score was significantly lower in the GD Group than the Placebo group, starting immediately postoperative up to 24 hours except after 18 hours. The total intraoperative fentanyl consumption and postoperative morphine consumption were significantly lower in the GD Group. The sedation score was significantly higher in the GD Group compared to the Placebo group immediately postoperative and after 2 hours. The heart rate and mean arterial pressure were within the clinically accepted ranges intra- and postoperatively in the two groups. Conclusion: Preemptive oral gabapentin plus dexmedetomidine IV infusion is a safe and effective analgesic alternative for patients undergoing MRM.

The effect of perioperative dexmedetomidine on postoperative bowel function recovery in adult patients receiving general anaesthesia: a systematic review and meta-analysis of randomised controlled trials

INTRODUCTION

Dexmedetomidine has opioid sparing actions but its effect on bowel recovery is controversial. Primary aim of this review was to evaluate the effect of perioperative dexmedetomidine on postoperative bowel recovery. Secondary aim was to evaluate the effect of dexmedetomidine on hospital discharge.

EVIDENCE ACQUISITION

Randomised controlled trials in English language reporting any or all of the following parameters of bowel recovery; time to first bowel sounds, first flatus, first faeces, or time to oral diet were included.

EVIDENCE SYNTHESIS

Twelve hundred and thirty-five patients from 13 studies were analysed. There were insufficient studies evaluating bowel sounds. Perioperative dexmedetomidine usage significantly reduced the time to first flatus [MD -5.61 hours (95% CI -8.61 to -2.60); P = 0.0003; I2 = 95%], first faeces [MD -12.70 hours (95% CI -19.11 to -6.29); P = 0.0001; I2 = 76%] and the composite outcome of bowel recovery (flatus, faeces, oral diet) [MD -7.44 hours (95% CI -10.31 to -4.57); P < 0.00001; I2 = 96%]. No difference was seen in the time to oral diet [MD -6.29 hours (95% CI -13.48 to 0.91); P = 0.09; I2 = 88%] or hospital discharge [MD -0.47 days (95% CI -1.27 to 0.33); P = 0.25; I2 = 86%].

CONCLUSIONS

Perioperative dexmedetomidine usage significantly shortens the time to first flatus, faeces and composite bowel recovery but does not result in a shorter time to oral diet or earlier hospital discharge in adult patients receiving general anaesthesia. Strength of evidence is however very low for the effect of dexmedetomidine on bowel recovery.

Comparison of Respiratory Effects between Dexmedetomidine and Propofol Sedation for Ultrasound-Guided Radiofrequency Ablation of Hepatic Neoplasm: A Randomized Controlled Trial

Patient’s cooperation and respiration is necessary in percutaneous radiofrequency ablation (RFA) for hepatocellular carcinoma (HCC). We compared the respiratory patterns of dexmedetomidine and propofol sedation during this procedure. Participants were randomly allocated into two groups: the continuous infusions of dexmedetomidine-remifentanil (DR group) or the propofol-remifentanil (PR group). We measured the tidal volume for each patient’s respiration during one-minute intervals at five points and compared the standard deviation of the tidal volumes (SDvt) between the groups. Sixty-two patients completed the study. SDvt at 10 min was not different between the groups (DR group, 108.58 vs. PR group, 149.06, p = 0.451). However, SDvt and end-tidal carbon dioxide (EtCO₂) level of PR group were significantly increased over time compared to DR group (p = 0.004, p = 0.021; ß = 0.14, ß = −0.91, respectively). Heart rate was significantly decreased during sedation in DR group (p < 0.001, ß = −2.32). Radiologist satisfaction was significantly higher, and the incidence of apnea was lower in DR group (p = 0.010, p = 0.009, respectively). Compared with propofol-remifentanil, sedation using dexmedetomidine-remifentanil provided a lower increase of the standard deviation of tidal volume and EtCO₂, and also showed less apnea during RFA of HCC.

Endogenous opiates and behavior: 2019

This paper is the forty-second consecutive installment of the annual anthological review of research concerning the endogenous opioid system, summarizing articles published during 2019 that studied the behavioral effects of molecular, pharmacological and genetic manipulation of opioid peptides and receptors as well as effects of opioid/opiate agonists and antagonists. The review is subdivided into the following specific topics: molecular-biochemical effects and neurochemical localization studies of endogenous opioids and their receptors (1), the roles of these opioid peptides and receptors in pain and analgesia in animals (2) and humans (3), opioid-sensitive and opioid-insensitive effects of nonopioid analgesics (4), opioid peptide and receptor involvement in tolerance and dependence (5), stress and social status (6), learning and memory (7), eating and drinking (8), drug abuse and alcohol (9), sexual activity and hormones, pregnancy, development and endocrinology (10), mental illness and mood (11), seizures and neurologic disorders (12), electrical-related activity and neurophysiology (13), general activity and locomotion (14), gastrointestinal, renal and hepatic functions (15), cardiovascular responses (16), respiration and thermoregulation (17), and immunological responses (18).

Comparative effectiveness of pharmacological interventions to prevent postoperative delirium: a network meta-analysis

Many pharmacologic agents were investigated for the effect to prevent delirium. We aimed to comprehensively compare the effect of the pharmacological interventions to prevent postoperative delirium. A Bayesian network meta-analysis of randomized trials was performed using random effects model. PubMed, the Cochrane Central Register of Controlled Trials, and Embase were searched on 20 January 2021. Randomized trials comparing the effect of a drug to prevent postoperative delirium with another drug or placebo in adult patients undergoing any kind of surgery were included. Primary outcome was the postoperative incidence of delirium. Eighty-six trials with 26,992 participants were included. Dexmedetomidine, haloperidol, and atypical antipsychotics significantly decreased the incidence of delirium than placebo [dexmedetomidine: odds ratio 0.51, 95% credible interval (CrI) 0.40-0.66, moderate quality of evidence (QOE); haloperidol: odds ratio 0.59, 95% CrI 0.37-0.95, moderate QOE; atypical antipsychotics: odds ratio 0.27, 95% CrI 0.14-0.51, moderate QOE]. Dexmedetomidine and atypical antipsychotics had the highest-ranking probabilities to be the best. However, significant heterogeneity regarding diagnostic time window as well as small study effects precludes firm conclusion.

Which idea is better with regard to immune response? Opioid anesthesia or opioid free anesthesia

The stress of surgery is characterized by an inflammatory response with immune suppression resulting from many factors, including the type of surgery and the kind of anesthesia, linked with the drugs that are used and the underlying disease of the patient. The trauma of surgery triggers a cascade of reactions involving the immune response and nociception. As strong analgesics, opioids provide the analgesic component of general anesthesia with bi-directional effect on the immune system. Opioids influence almost all aspects of the immune response in regards to leukocytes, macrophages, mast cells, lymphocytes, and NK cells. The suppressive effect of opioids on the immune system is limiting their use, especially in patients with impaired immune response, so the possibility of using multimodal anesthesia without opioids, known as opioid-free anesthesia (OFA), is gaining more and more sympathizers. The idea of OFA is to eliminate opioid analgesia in the treatment of acute pain and to replace it with drugs from other groups that are assumed to have a comparable analgesic effect without affecting the immune system. Here, we present a review on the impact of anesthesia, with and without the use of opioids, on the immune response to surgical stress.

Mechanisms of Dexmedetomidine in Neuropathic Pain

Dexmedetomidin is a new-generation, highly selective α2 adrenergic receptor agonist with a large number of advantages, including its sedative and analgesic properties, its ability to inhibit sympathetic nerves, its reduced anesthetic dosage, its hemodynamic stability, its mild respiratory depression abilities, and its ability to improve postoperative recognition. Its safety and effectiveness, as well as its ability to provide a certain degree of comfort to patients, make it a useful anesthetic adjuvant for a wide range of clinical applications. For example, dexmedetomidine is commonly used in patients undergoing general anesthesia, and it also exerts sedative effects during tracheal intubation or mechanical ventilation in intensive care unit patients. In recent years, with the deepening of clinical research on dexmedetomidine, the drug is still applied in the treatment of spastic pain, myofascial pain, neuropathic pain, complex pain syndrome, and chronic headache, as well as for multimodal analgesia. However, we must note that the appropriateness of patient and dose selection should be given attention when using this drug; furthermore, patients should be observed for adverse reactions such as hypotension and bradycardia. Therefore, the safety and effectiveness of this drug for long-term use remain to be studied. In addition, basic experimental studies have also found that dexmedetomidine can protect important organs, such as the brain, heart, kidney, liver, and lung, through various mechanisms, such as antisympathetic effects, the inhibition of apoptosis and oxidative stress, and a reduction in the inflammatory response. Moreover, the neuroprotective properties of dexmedetomidine have received the most attention from scholars. Hence, in this review, we mainly focus on the characteristics and clinical applications of dexmedetomidine, especially the role of dexmedetomidine in the nervous system and the use of dexmedetomidine in the relief of neuropathic pain.

The effects of intravenous lidocaine on wound pain and gastrointestinal function recovery after laparoscopic colorectal surgery

To evaluate the efficacy of intravenous lidocaine in relieving postoperative pain and promoting rehabilitation in laparoscopic colorectal surgery, we conducted this meta-analysis. The systematic search strategy was performed on PubMed, EMBASE, Chinese databases, and Cochrane Library before September 2019. As a result, 10 randomised clinical trials were included in this meta-analysis (n = 527 patients). Intravenous lidocaine significantly reduced pain scores at 2, 4, 12, 24, and 48 hours on movement and 2, 4, and 12 hours on resting-state and reduced opioid requirement in first 24 hours postoperatively (weighted mean difference [WMD] = -5.02 [-9.34, -0.70]; P = .02). It also decreased the first flatus time (WMD: -10.15 [-11.20, -9.10]; P < .00001), first defecation time (WMD: -10.27 [-17.62, -2.92]; P = .006), length of hospital stay (WMD: -1.05 [-1.89, -0.21]; P = .01), and reduced the incidence of postoperative nausea and vomiting (risk ratio: 0.53 [0.30, 0.93]; P = .03) when compared with control group. However, it had no effect on pain scores at 24 and 48 hours at rest, the normal dietary time, and the level of serum C-reactive protein. In summary, perioperative intravenous lidocaine could alleviate acute pain, reduce postoperative analgesic requirements, and accelerate recovery of gastrointestinal function in patients undergoing laparoscopic colorectal surgery.