Dexmedetomidine infusion as an anesthetic adjuvant to general anesthesia for appropriate surgical field visibility during modified radical mastectomy with i-gel®: a randomized control study

The Effect of Dexmedetomidine on Postanesthesia Care Unit Discharge and Recovery: A Systematic Review and Meta-Analysis

BACKGROUND

Current evidence on the effect of dexmedetomidine in early postoperative recovery is limited. We conducted a systematic review to evaluate the effect of dexmedetomidine on the length of stay (LOS) and recovery profile in postanesthesia care unit (PACU) patients.

METHODS

The study protocol is registered on International Prospective Register of Systematic Reviews (PROSPERO; CRD42021240559). No specific funding or support was received. We conducted searches in MEDLINE, Embase, PubMed, and Cochrane Library to March 31, 2021 for peer-reviewed randomized controlled studies comparing adult patients who received intravenous dexmedetomidine and placebo undergoing noncardiac, nonneurosurgical procedures under general anesthesia. All studies reporting statistics relating to the duration of stay in the recovery ward or PACU, the primary outcome, were included. We performed individual random-effect meta-analysis on the primary and secondary outcomes (time to extubation, emergence agitation, cough, pain, postoperative nausea and vomiting, shivering, residual sedation, bradycardia, and hypotension) using Stata version 17.0. Evidence was synthesized as mean difference (MD) and risk ratio (RR) for continuous and dichotomous variables, respectively. The quality of evidence was assessed using the revised Cochrane risk-of-bias tool for randomized trials (RoB 2) tool and Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach.

RESULTS

Thirty-three studies including 2676 patients were eligible for analysis. All studies had low risk or some concerns of overall bias and provided low-to-high certainty evidence for all studied outcomes. Dexmedetomidine was not associated with a significantly increased PACU LOS (MD, 0.69 minute; 95% confidence interval [CI], -1.42 to 2.81 minutes). It was associated with a statistically but not clinically significant prolonged time to extubation (MD, 1 minute; 95% CI, 0.32-1.68 minutes). Dexmedetomidine was associated with significantly reduced incidence of emergence agitation (RR, 0.38; 95% CI, 0.29-0.52), cough (RR, 0.69; 95% CI, 0.61-0.79), pain (RR, 0.50; 95% CI, 0.32-0.80), postoperative nausea and vomiting (RR, 0.54; 95% CI, 0.33-0.86), and shivering (RR, 0.24; 95% CI, 0.12-0.49) in PACU. There was an increased incidence of hypotension (RR, 5.39; 95% CI, 1.12-5.89) but not residual sedation (RR, 1.23; 95% CI, 0.20-7.56) or bradycardia (RR, 5.13; 95% CI, 0.96-27.47) in the dexmedetomidine group.

CONCLUSIONS

The use of dexmedetomidine did not increase the duration of PACU LOS but was associated with reduced emergence agitation, cough, pain, postoperative nausea and vomiting, and shivering in PACU. There was an increased incidence of hypotension but not residual sedation or bradycardia in PACU.

Effect and Mechanism of Lidocaine Pretreatment Combined with Dexmedetomidine on Oxidative Stress in Patients with Intracranial Aneurysm Clipping

This study aimed to explore the effect and mechanism of lidocaine pretreatment combined with dexmedetomidine on oxidative stress in patients with intracranial aneurysm clipping. Many studies have used various drugs such as lidocaine to explore the effect and mechanism of lidocaine pretreatment. A total of 80 patients with intracranial aneurysm clipping surgery were randomly divided into 4 groups: the single lidocaine group, single dexmedetomidine group, lidocaine combined with dexmedetomidine group, and control group. The thread embolism method was used to establish a stable intracranial aneurysm model of Hashimoto rats. Fifty adult rats were randomly divided into a sham operation group, ligation of the left common carotid artery and bilateral posterior branch of renal artery, lidocaine group, dexmedetomidine group, and lidocaine combined with dexmedetomidine group. The colorimetric method was used to determine the oxidative stress indicators in brain tissue: MDA content, SOD activity, and T-AOC content. The western blot method characterized the protein levels related to oxidative stress: nNOS, iNOS, and NADPH oxidase subunits p22phox, gp91phox, and p47phox. The differences in each index between the groups were statistically significant (P < 0.05). Animal experiment results revealed that the content of MDA in the brain tissue of rats in the LD group was significantly lower than that in the single-drug group and sham group. The T-AOC and SOD concentrations in the LD group were significantly higher than those in the single-drug group and sham group, and the differences between the groups were statistically significant (P < 0.05). The protein expression of the LD group was significantly lower than that of the drug-alone group and model group, and the difference between groups was statistically significant (P < 0.05). To sum up, lidocaine pretreatment combined with dexmedetomidine can effectively maintain the hemodynamic stability of patients with intracranial aneurysm clipping and reduce postoperative oxidative stress response. Its mechanism of action may be related to the inhibition of oxidative stress damage mediated by nNOS, iNOS, and p22phox, gp91phox, and p47phox in the hippocampus. Our study has significant and applicable medical aspects in lidocaine pretreatment combined with dexmedetomidine on oxidative stress in patients.

Conditions for laryngeal mask airway placement in terms of oropharyngeal leak pressure: a comparison between blind insertion and laryngoscope-guided insertion

Background

Insertion under laryngoscopic guidance has been used to achieve ideal positioning of the laryngeal mask airway (LMA). However, to date, the efficacy of this technique has been evaluated only using fiberoptic evaluation, and the results have been conflicting. Other reliable tests to evaluate the efficacy of this technique have not been established. Recently, it has been suggested that the accuracy of LMA placement can be determined by clinical signs such as oropharyngeal leak pressure (OPLP). The aim of this study was to assess the efficacy of LMA insertion under laryngoscopic guidance using OPLP as an indicator.

Methods

After approved by the institutional ethics committee, a prospective comparison of 100 patients divided into 2 groups (50 with blind technique and 50 with the laryngoscope technique) were evaluated. An LMA (LarySeal™, Flexicare medical Ltd., UK) was inserted using the blind approach in the blind insertion group and using laryngoscopy in the laryngoscope-guided insertion group. The OPLP, fiberoptic position score, whether the first attempt at LMA insertion was successful, time taken for insertion, ease of LMA insertion, and adverse airway events were recorded.

Results

Data were presented as mean ± standard deviation. The OPLP was higher in the laryngoscope-guided insertion group than in the blind insertion group (21.4 ± 8.6 cmH₂O vs. 18.1 ± 6.1 cmH₂O, p = 0.031). The fiberoptic position score, rate of success in the first attempt, ease of insertion, and pharyngolaryngeal adverse events were similar between both groups. The time taken for insertion of the LMA was significantly longer in the laryngoscope-guided insertion group, compared to blind insertion group (35.9 ± 9.5 s vs. 28.7 ± 9.5 s, p < 0.0001).

Conclusion

Laryngoscope-guided insertion of LMA improves the airway seal pressure compared to blind insertion. Our result suggests that it may be a useful technique for LMA insertion.

Trial registration

cris.nih.go.kr, identifier: KCT0001945 (2016-06-17).

The Effect of Intravenous Infusion of Dexmedetomidine to Prevent Bleeding During Functional Endoscopic Sinus Surgery: A Clinical Trial

Background

Bleeding during surgery can lead to serious complications. Methods and drugs to control bleeding are always important both for the surgeon and anesthesiologist, especially in endoscopic procedures. A lot of efforts are made to optimize the surgical conditions for functional endoscopic sinus surgery. Induced hypotension is widely advocated to prevent bleeding and consequently to improve the quality of an operation . Amongst the pharmacological agents, dexmedetomidine is the most recently introduced drug to provide hypotensive anesthesia during functional endoscopic sinus surgery.

Objectives

The current study aimed at investigating the effects of intravenous infusion of dexmedetomidine on bleeding, nausea, awakening time, and other intravenous anesthetic doses during functional endoscopic sinus surgery.

Methods

Sixty patients aged 16 to 60 years with American society of anesthesiologists (ASA) class I or II in Imam Khomeini hospital of Ahvaz, Iran, who were the candidate for the elective functional endoscopic sinus surgery were enrolled in the current double-blind clinical trial. They were randomly divided into 2 groups: group D (receiving dexmedetomidine), and group N (receiving normal saline). Sampling was based on the block randomization method. In group D, a 1-μg/kg dexmedetomidine was injected during 10 minutes just before the induction. Then, 0.5 µg/ kg/ hour infusion was started. Both groups had the same induction and maintenance method as well as the drugs administered for general anesthesia induction. For maintenance, the patients received O₂ 50%: N₂O 50% and 100 μg/kg/minute of propofol and 0.2 μg/kg/minute of remifentanil. In group N, instead of dexmedetomidine in bolus and maintenance, normal saline was used with the same volume. Mean arterial pressure was maintained between 65 to 75 mmHg. The incidence of bleeding, nausea and vomiting after surgery, the amount of maintenance drugs, and awakening time were recorded in a checklist.

Results

The intravenous use of dexmedetomidine significantly reduced the amount of bleeding (P < 0.0001); in addition, the need for opioids (P < 0.0001) and intravenous anesthetics significantly decreased (P = 0.001). Awakening time was significantly longer (P = 0.001), but its effect on postoperative nausea and vomiting was not significant (P = 0.052).

Conclusions

The current study showed that although propofol and remifentanil compounds can control hemodynamic state, but intravenous infusion of dexmedetomidine during the functional endoscopic sinus surgery reduced the amount of bleeding more significantly. It also reduced the dosage of maintenance drugs.