Dexmedetomidine reduces sevoflurane EC50 for supraglottic airway device insertion in spontaneously breathing morbidly obese patients

Intraoperative Dexmedetomidine Decreases Postoperative Pain after Gastric Endoscopic Submucosal Dissection: A Prospective Randomized Controlled Trial

BACKGROUND

Postoperative pain is one of the most common complications after gastric endoscopic submucosal dissection (ESD); however, there have been only a few studies assessing the efficacy of interventions on postoperative pain after gastric ESD. This prospective randomized controlled trial was designed to assess the effect of intraoperative dexmedetomidine (DEX) on postoperative pain after gastric ESD.

MATERIALS AND METHODS

A total of 60 patients undergoing elective gastric ESD under general anesthesia were randomly divided into the DEX group receiving DEX with a loading dose of 1 μg/kg, followed by a maintenance dose of 0.6 μg/kg/h until 30 min before the end of the endoscopic procedure, and the control group receiving normal saline. The primary outcome was the visual analog scale (VAS) score of postoperative pain. Secondary outcomes were the dosage of morphine for postoperative pain control, hemodynamic changes during the observable period, the occurrence of adverse events, lengths of postanesthesia care unit (PACU) and hospital stays, and patient satisfaction.

RESULTS

The incidence of postoperative moderate to severe pain was 27% and 53% in the DEX and control groups, respectively, with a significant difference. Compared to the control group, VAS pain scores at 1 h, 2 h, and 4 h postoperatively, the dosage of morphine in the PACU, and the total dosage of morphine within 24 h postoperatively were significantly decreased in the DEX group. Both incidences of hypotension and use of ephedrine in the DEX group were significantly decreased during surgery, but they were significantly increased in the postoperative period. Postoperative nausea and vomiting scores were decreased in the DEX group; however, the length of PACU stay, patient satisfaction, and duration of hospital stay were not significantly different between groups.

CONCLUSION

Intraoperative DEX can significantly decrease postoperative pain level, with a slightly reduced dosage of morphine and a decreased severity of postoperative nausea and vomiting after gastric ESD.

Minimal alveolar concentration of sevoflurane in combination with dexmedetomidine in patients with hysteroscopy: An up-down sequential allocation study

BACKGROUND

Dexmedetomidine is commonly used in hysteroscopy surgery due to its analgesia and sedation without respiratory depression. Many studies have shown that dexmedetomidine can reduce the consumption of sevoflurane. However, the optimal end-tidal concentration of sevoflurane when it is co-administered with dexmedetomidine has not been established. The primary purpose of this study was to investigate the minimal alveolar concentration (MAC) of sevoflurane for cervical dilatation combined with different doses of dexmedetomidine in patients with hysteroscopy surgery.

METHODS

One-hundred patients undergoing hysteroscopy surgery were enrolled in this clinical trial. All the patients were randomly assigned into four groups (C, D₁ , D₂ , D₃ ) and received a loading dose of dexmedetomidine (0, 0.6, 0.8 and 1.0 μg/kg) over 10 min before anaesthesia induction, respectively. Anaesthesia was induced in each patient with 5% sevoflurane in 100% oxygen via a facemask. A laryngeal mask (LMA) was inserted when the patient had lost consciousness and the BIS value decreased below 40. The response to cervical dilatation stimulus (movement vs non-movement) by the insert of hysteroscope was recorded. The MAC of sevoflurane was measured by up and down sequential method of Dixon and Mood and centred isotonic regression analysis.

RESULTS

The calculated MAC of sevoflurane using up-and-down method of Dixon and Mood in patients with hysteroscopy surgery was (1.90 ± 0.13)%, (1.23 ± 0.16)%, (1.03 ± 0.10)% and (0.93 ± 0.08)% in groups C, D₁ , D₂ and D₃ , respectively.

CONCLUSIONS

The administration of dexmedetomidine can significantly decrease the MAC of sevoflurane for hysteroscopy surgery. However, a ceiling effect of the reduction was observed when the dose of dexmedetomidine was higher than 0.8 μg/kg.

Benefits of dexmedetomidine on postoperative analgesia after bariatric surgery: a systematic review and meta-analysis

INTRODUCTION

Anesthetic management of morbidly obese patients is challenging, particularly in those undergoing bariatric surgery. Dexmedetomidine is a α2-adrenergic receptor agonist that is increasingly used in the perioperative setting for its beneficial properties including sedation, anxiolysis, analgesia with opioid-sparing effects, and minimal impact on respiration. The objective of this study was to evaluate the effect of dexmedetomidine on postoperative analgesia and recovery-related outcomes among patients undergoing bariatric surgery.

EVIDENCE ACQUISITION

We conducted a systematic review and meta-analysis of MEDLINE, EMBASE, and CENTRAL databases from conception to September 2021 for randomized controlled trials (RCTs) using dexmedetomidine in bariatric patients on postoperative outcomes. Outcomes were pooled using random effects model and presented as relative risks (RR) or mean differences (MD) with 95% confidence intervals (CI).

EVIDENCE SYNTHESIS

In total, 20 RCTs with 665 patients in the dexmedetomidine group and 671 patients in the control groups were included. Among RCTs, the dexmedetomidine group had significantly lower opioid usage at 24-hours postoperatively (MD: -5.14, 95%CI: -10.18 to -0.10; moderate certainty), reduced pain scores on a 10-point scale at PACU arrival (MD: -1.69, 95%CI: -2.79 to -0.59; moderate certainty) and 6 hours postoperatively (MD: -1.82, 95%CI: - 3.00 to -0.64; low certainty), and fewer instances of nausea (RR: 0.59, 95%CI: 0.45 to 0.75; moderate certainty) and vomiting (RR: 0.25, 95%CI: 0.15 to 0.43; moderate certainty), compared to control groups.

CONCLUSIONS

Dexmedetomidine is an efficacious anesthesia adjunct in patients undergoing bariatric surgery. These benefits of dexmedetomidine may be considered in the multi-modal analgesic management and enhanced recovery pathways in this high-risk population.

Comparison of Low-Dose Sevoflurane Inhalation With Intranasal Ketamine as Rescue Sedation After Intranasal Dexmedetomidine Failure in Outpatient Children Undergoing MRI: A Randomized Control Trial

PURPOSE

The present study aimed to evaluate the effectiveness and safety of low-dose inhalation of sevoflurane through a face mask as a rescue remedy for sedation compared with intranasal ketamine in outpatient children undergoing magnetic resonance imaging (MRI).

DESIGN

A prospective randomized control study. A total of 336 children scheduled for 3.0T MRI but were inadequately sedated after initial intranasal dexmedetomidine (3 μg/kg) were randomly divided into two groups.

METHODS

We used the following protocol for each group: group S, inhalation of low-dose sevoflurane (end-expiratory concentration, 0.4%) through a face mask; group K, intranasal ketamine (2 mg/kg). The success rates were compared between groups as the primary endpoint. The induction time, scan time, recovery time, time to return to baseline functional status, parental and radiologist satisfaction, occurrence of adverse events, and other secondary endpoints were also compared.

FINDINGS

Successful rescue sedation in groups S and K was achieved in 160 (95.2%) and 138 (82.1%) patients, respectively. Compared with group K, group S needed fewer repeat sequences and showed a significantly shorter induction time (5.7 ± 0.5 vs. 10.9 ± 2.7 min; P < 0.001), recovery time (27.4 ± 6.3 vs. 53.8 ± 15.2 min; P < 0.001), and time to return to baseline functional status (3.4 ± 0.6 vs. 6.1 ± 1.1 h; P < 0.001). Radiologist satisfaction, parental satisfaction, and parental desire to repeat the same sedation method were significantly higher in the sevoflurane group.

CONCLUSION

Our results suggest that the inhalation of low-dose sevoflurane through a face mask can provide effective and safe rescue sedation in 1- to 6-year-old outpatient children undergoing MRI, and yields a higher success rate, shorter induction and recovery times, and higher satisfaction than the intranasal ketamine method.

Dexmedetomidine Compared to Remifentanil Infusion as Adjuvant to Sevoflurane Anesthesia during Laparoscopic Sleeve Gastrectomy

Objectives

Evaluation of postoperative (PO) analgesic effects of intraoperative (IO) Dexmedetomidine (DEX) compared to remifentanil (REMI) infusions during sevoflurane anesthesia for laparoscopic gastric sleeve surgery.

Patients and Methods

One hundred and thirty-two patients with body mass index >35 kg.m^-2 and ASA Grades II or III were randomly divided into group R received REMI infusion (6-18 μg.kg^-1.h^-1) and Group D received DEX infusion (0.2-0.5 μg.kg^-1.h^-1) after tracheal intubation till before stoppage of inhalational anesthetic. Heart rate and mean arterial pressure were noninvasively monitored during and after surgery. Emergence time, time until postanesthetic care unit transfer, and total operating room (OR) time was recorded. PO shoulder-tip pain and wound pain scores were recorded and rescue analgesia was provided as 50 mg pethidine intramuscular injection. Occurrence of PO nausea and vomiting (PONV) and frequency of the need for antiemetic therapy were recorded. Primary study outcome was the ability of the study infusions to reduce consumption of PO pethidine down to one dose during 24-hr PO.

Results

IO use of REMI or DEX infusion allowed hemodynamic control to surgical stresses with nonsignificant difference between both infusions. REMI infusion insured significantly rapid recovery and short OR times but required larger volume of sevoflurane during surgery and proper PO follow-up for pain and PONV. DEX infusion significantly improved control of PO pain with a larger number of patient requested rescue analgesia only once, reduced the dose of PO analgesia, reduced the frequency of PONV, and the need for antiemetic therapy.

Conclusion

REMI or DEX infusion as IO adjuvant to general anesthesia is appropriate option to achieve hemodynamic control of surgical stresses and to improve perioperative outcomes. REMI infusion may be preferred for its induced rapid recovery and short OR time, whereas DEX infusion may be chosen for its improved control of PO pain and reduction of PO analgesia and frequency of PONV.