Effects of Dexmedetomidine on Blood Glucose and Serum Potassium Levels in Children Undergoing General Anesthesia: A Secondary Analysis of Safety Endpoints During a Randomized Controlled Trial

Dexmedetomidine, an alpha-2 adrenoceptors agonist, provides a neuroprotective effect for dopaminergic neurons in the substantia nigra and attenuates glucose imbalance in the 6-hydroxydopamine animal model of Parkinson's disease

INTRODUCTION

Studies have shown that dexmedetomidine (DEX, an a2-adrenoceptors agonist) provides a neuroprotective effect and influences blood glucose levels. Here, we evaluated the effect of prolonged treatment with low doses of DEX on the survival rate of dopaminergic (DAergic) neurons in the substantia nigra and also serum glucose levels in 6-hydroxydopamine (6-OHDA) - induced Parkinson's disease (PD) in the rat.

MATERIAL AND METHODS

The neurotoxin of 6-OHDA was injected into the medial forebrain bundle by stereotaxic surgery. DEX (25 and 50 µg/kg, i.p) and yohimbine, an a2-adrenoceptor antagonist (1 mg/kg, i.p) were administered before the surgery to the 13 weeks afterward. Apomorphine-induced rotational tests and blood sampling were carried out before the surgery and multiple weeks after that. Thirteen weeks after the surgery, the rats' brain was transcardially perfused to assess the survival rate of DAergic neurons using the tyrosine hydroxylase (TH) immunohistochemistry.

RESULTS

DEX remarkably attenuated the severity of rotational behavior and reversed the progress of the PD. It also increased the number of TH-labeled neurons by up to 60%. The serum glucose levels in 6-OHDA-received rats did not change in the third and seventh weeks after the surgery but decreased significantly in the thirteenth week. Treatment with DEX prevented this decrement in glucose levels. On the other hand, Treatment with yohimbine did not affect PD symptoms and glucose levels.

CONCLUSION

Our data indicate that DEX through neuroprotective activity attenuates the severity of 6-OHDA-induced PD in rats. DEX might also prevent hypoglycemia during the progress of the PD.

Systemic Effects of Perineural Glucocorticoids on Fasting Serum Glucose, Potassium, and White Blood Cell Count in Total Hip Arthroplasty

Purpose

Glucocorticoids are commonly used as regional anesthesia adjuvants to improve blockade quality and duration. There are limited data in the literature regarding the potential systemic effects and safety of perineural glucocorticoids. This study examines the effects of perineural glucocorticoids on serum glucose, potassium, and white blood cell count (WBC) in the immediate postoperative period after primary total hip arthroplasty (THA).

Patients and Methods

A retrospective cohort study was carried out at a tertiary academic medical center utilizing electronic health records of 210 patients who underwent THA, for which patients received either a periarticular local anesthetic injection alone (PAI, N=132) or additional peripheral nerve blocks (PNB, N=78) containing 10 mg dexamethasone and 80 mg methylprednisolone acetate (PAI+PNB). The primary outcome was change in serum glucose from a preoperative baseline on postoperative days (POD) 1, 2, and 3. Secondary outcomes included changes in WBC and serum potassium.

Results

The change in serum glucose from baseline was found to be significantly higher in the PAI+PNB group compared to the PAI group on POD 1 (mean difference 19.87 mg/dL, 95% CI [12.42, 27.32]; P<0.001) and POD 2 (mean difference 17.5 mg/dL, 95% CI [9.66, 25.44], P<0.001). No significant difference was found on POD 3 (mean difference -8.18 mg/dL, 95% CI [-19.07, 2.70], P=0.14). Statistically significant but clinically insignificant differences were detected in serum potassium in the PAI+PNB group compared to the PAI group on POD1 (mean difference 0.16 mEq/L, 95% CI [0.02, 0.30], P=0.03) and WBC on POD 2 (mean difference 3.18 × 1000/mm³, 95% CI [2.14, 4.22], P<0.001).

Conclusion

Patients who underwent THA and received PAI+PNB with glucocorticoid adjuvants demonstrated higher elevations in serum glucose for the first two PODs compared to patients who received PAI alone. These differences resolved by a third POD and are likely to be of no clinical significance.

Effect of intraoperative dexmedetomidine on hepatic ischemia-reperfusion injury in pediatric living-related liver transplantation: A propensity score matching analysis

Background

Hepatic ischemia-reperfusion injury (HIRI) is largely unavoidable during liver transplantation (LT). Dexmedetomidine (DEX), an α2-adrenergic agonist, exerts a variety of organ-protective effects in pediatric populations. However, evidence remains relatively limited about its hepatoprotective effects in pediatric living-related LT.

Methods

A total of 121 pediatric patients undergoing living-related LT from June 2015 to December 2018 in our hospital were enrolled. They were classified into DEX or non-DEX groups according to whether an infusion of DEX was initiated from incision to the end of surgery. Primary outcomes were postoperative liver graft function and the severity of HIRI. Multivariate logistic regression and propensity score matching (PSM) analyses were performed to identify any association.

Results

A 1:1 matching yielded 35 well-balanced pairs. Before matching, no significant difference was found in baseline characteristics between groups except for warm ischemia time, which was longer in the non-DEX group (44 [38–50] vs. 40 [37–44] min, p = 0.017). After matching, the postoperative peak lactic dehydrogenase levels decreased significantly in the DEX group than in the non-DEX group (622 [516–909] vs. 970 [648–1,490] IU/L, p = 0.002). Although there was no statistical significance, a tendency toward a decrease in moderate-to-extreme HIRI rate was noted in the DEX group compared to the non-DEX group (68.6% vs. 82.9%, p = 0.163). Patients in the DEX group also received a significantly larger dosage of epinephrine as postreperfusion syndrome (PRS) treatment (0.28 [0.17–0.32] vs. 0.17 [0.06–0.30] µg/kg, p = 0.010). However, there were no significant differences between groups in PRS and acute kidney injury incidences, mechanical ventilation duration, intensive care unit, and hospital lengths of stay. Multivariate analysis revealed a larger graft-to-recipient weight ratio (odds ratio [OR] 2.657, 95% confidence interval [CI], 1.132–6.239, p = 0.025) and intraoperative DEX administration (OR 0.333, 95% CI, 0.130–0.851, p = 0.022) to be independent predictors of moderate-to-extreme HIRI.

Conclusion

This study demonstrated that intraoperative DEX could potentially decrease the risk of HIRI but was associated with a significant increase in epinephrine requirement for PRS in pediatric living-related LT. Further studies, including randomized controlled studies, are warranted to provide more robust evidence.

Comparisons of α2-Adrenergic Agents, Medetomidine and Xylazine, with Pentobarbital for Anesthesia: Important Pitfalls in Diabetic and Nondiabetic Rats

Purpose: Anesthesia is necessary to conduct rodent electroretinograms (ERGs). We evaluated utility of the α2-agonist medetomidine versus xylazine for ERG studies in nondiabetic and diabetic rats. Pentobarbital was included as a comparator. Methods: Male Sprague-Dawley rats, with and without streptozotocin (STZ)-induced diabetes, were anesthetized with medetomidine (1 mg/kg), xylazine (10 mg/kg) (both with ketamine 75 mg/kg), or pentobarbital (70 mg/kg). The depth of anesthesia was assessed, and if adequate, scotopic ERGs were recorded. Blood glucose was monitored. Results: In nondiabetic rats, all three agents induced satisfactory anesthesia, but with differing durations: medetomidine > pentobarbital > xylazine. ERG responses were similar under medetomidine and xylazine, but relatively reduced under pentobarbital. Both α2-agonists (but not pentobarbital) elicited marked hyperglycemia (peak values 316.1 ± 42.6 and 300.3 ± 29.5 mg/dL, respectively), persisting for 12 h. In diabetic rats, elevated blood glucose concentrations were not affected by any of the agents, but the depth of anesthesia under medetomidine and xylazine was inadequate for ERG recording. Conclusions: In nondiabetic rats, medetomidine and xylazine elicited comparable effects on ERGs that differ from pentobarbital, but both perturbed glucose metabolism, potentially confounding experimental outcomes. In STZ-diabetic rats, neither α2-agent provided adequate anesthesia, while pentobarbital did so. Problems with α2-anesthetic agents, including medetomidine, must be recognized to ensure meaningful interpretation of experimental results.

Effects of dexmedetomidine on glucose-related hormones and lactate in non-diabetic patients under general anesthesia: a randomized controlled trial

BACKGROUND

To explore the effects of dexmedetomidine on glucose-related hormones and lactate levels in non-diabetic patients undergoing malignant gastrointestinal tumor radical resection.

METHODS

Groups D1 and D2 received dexmedetomidine loading dose 1 μg/kg and maintenance dose 0.25 and 0.5 μg/kg/h, respectively. Group C received saline solution. Glucose, lactate, insulin, glucagon, cortisol, epinephrine, norepinephrine and dopamine levels were measured before dexmedetomidine infusion (T1), 1 h after surgery beginning (T2), at surgery ending (T3), and 1 h after transfer to the post-anesthesia care unit (T4).

RESULTS

Compared with group C, glucose levels increased in group D2 at T2 and reduced in groups D1 and D2 at T4. Lactate levels reduced in groups D1 and D2 at T4. A positive correlation between glucose and lactate levels was found in all groups. Compared with group C, insulin level reduced in group D2 at T2; glucagon levels reduced in groups D1 and D2 at T4; cortisol levels reduced in group D1 at T4 and in group D2 at T3 and T4; epinephrine and norepinephrine levels reduced in group D1 at T4 and in group D2 at T2 and T4; and dopamine level reduced in group D2 at T4.

CONCLUSIONS

Dexmedetomidine loading dose 1 μg/kg and maintenance dose 0.25 μg/kg/h produces a stable insulin level and significant postoperative decreases in glucagon, cortisol, epinephrine and norepinephrine secretion with stable maintenance of intraoperative and postoperative blood glucose levels and decreased postoperative lactate levels in non-diabetic patients under general anesthesia.

Opioid-free anesthesia compared to opioid anesthesia for lung cancer patients undergoing video-assisted thoracoscopic surgery: A randomized controlled study

BACKGROUND

Reducing intra-operative opioid consumption benefits patients by decreasing postoperative opioid-related adverse events. We assessed whether opioid-free anesthesia would provide effective analgesia-antinociception monitored by analgesia index in video-assisted thoracoscopic surgery.

METHODS

Patients (ASA Ⅰ-Ⅱ, 18-65 years old, BMI <30 kg m-2) scheduled to undergo video-assisted thoracoscopic surgery under general anesthesia were randomly allocated into two groups to receive opioid-free anesthesia (group OFA) with dexmedetomidine, sevoflurane plus thoracic paravertebral blockade or opioid-based anesthesia (group OA) with remifentanil, sevoflurane, and thoracic paravertebral blockade. The primary outcome variable was pain intensity during the operation, assessed by the depth of analgesia using the pain threshold index with the multifunction combination monitor HXD‑I. Secondary outcomes included depth of sedation monitoring by wavelet index and blood glucose concentration achieved from blood gas.

RESULTS

One hundred patients were randomized; 3 patients were excluded due to discontinued intervention and 97 included in the final analysis. Intraoperative pain threshold index readings were not significantly different between group OFA and group OA from arriving operation room to extubation (P = 0.86), while the brain wavelet index readings in group OFA were notably lower than those in group OA from before general anesthesia induction to recovery of double lungs ventilation (P <0.001). After beginning of operation, the blood glucose levels in group OFA increased compared with baseline blood glucose values (P < 0.001). The recovery time and extubation time in group OFA were significantly longer than those in group OA (P <0.007).

CONCLUSIONS

This study suggested that our OFA regimen achieved equally effective intraoperative pain threshold index compared to OA in video-assisted thoracoscopic surgery. Depth of sedation was significantly deeper and blood glucose levels were higher with OFA. Study's limitations and strict inclusion criteria may limit the external validity of the study, suggesting the need of further randomized trials on the topic. Trial registration: ChiCTR1800019479, Title: "Opioid-free anesthesia in video-assisted thoracoscopic surgery lobectomy".

The effect of dexmedetomidine on intraoperative blood glucose homeostasis: secondary analysis of a randomized controlled trial

Purpose

To investigate the effect of dexmedetomidine on intraoperative blood glucose hemostasis in elderly patients undergoing non-cardiac major surgery.

Methods

This was secondary analysis of a randomized controlled trial. Patients in dexmedetomidine group received a loading dose dexmedetomidine (0.6 μg/kg in 10 min before anaesthesia induction) followed by a continuous infusion (0.5 μg/kg/hr) till 1 h before the end of surgery. Patients in control group received volume-matched normal saline at the same time interval. Primary outcome was the incidence of intraoperative hyperglycemia (blood glucose higher than 10 mmol/L).

Results

303 patients in dexmedetomidine group and 306 patients in control group were analysed. The incidence of intraoperative hyperglycemia showed no statistical significance between dexmedetomidine group and control group (27.4% vs. 22.5%, RR = 1.22, 95%CI 0.92–1.60, P = 0.167). Median value of glycemic variation in dexmedetomidine group (2.5, IQR 1.4–3.7, mmol) was slightly lower than that in control group (2.6, IQR 1.5–4.0, mmol), P = 0.034. In multivariable logistic analysis, history of diabetes (OR 3.007, 95%CI 1.826–4.950, P < 0.001), higher baseline blood glucose (OR 1.353, 95%CI 1.174–1.560, P < 0.001) and prolonged surgery time (OR 1.197, 95%CI 1.083–1.324, P < 0.001) were independent risk factors of hyperglycaemia.

Conclusions

Dexmedetomidine presented no effect on intraoperative hyperglycemia in elderly patients undergoing major non-cardiac surgery.

Trial registration

Present study was registered at Chinese Clinical Trial Registry on December 1, 2015 (www.chictr.org.cn, registration number ChiCTR-IPR-15007654).

Intraoperative dexmedetomidine attenuates norepinephrine levels in patients undergoing transsphenoidal surgery: a randomized, placebo-controlled trial

Background

Dexmedetomidine has sympatholytic effects. We investigated whether dexmedetomidine could attenuate stress responses in patients undergoing endoscopic transnasal transseptal transsphenoidal surgery.

Methods

Forty-six patients were randomized to receive a continuous infusion of 0.9% saline (n = 23) or dexmedetomidine (n = 23). Immediately after general anesthesia induction, the dexmedetomidine group received a loading dose of 1 mcg/kg dexmedetomidine over 10 min, followed by a maintenance dose of 0.2–0.7 mcg/kg/h and the control group received 0.9% saline at the same volume until 30 min before the end of surgery. Serum levels of epinephrine, norepinephrine, and glucose were assessed before surgery (T1) and the end of drug infusion (T2). The primary outcome was the change in norepinephrine levels between the two time points.

Results

Changes (T2-T1 values) in perioperative serum norepinephrine levels were significantly greater in the dexmedetomidine group than in the control group (median difference, 56.9 pg/dL; 95% confidence interval, 20.7 to 83.8 pg/dL; P = 0.002). However, epinephrine level changes did not show significant intergroup differences (P = 0.208). Significantly fewer patients in the dexmedetomidine group than in the control group required rescue analgesics at the recovery area (4.3% vs. 30.4%, P = 0.047).

Conclusions

Intraoperative dexmedetomidine administration reduced norepinephrine release and rescue analgesic requirement. Dexmedetomidine might be used as an anesthetic adjuvant in patients undergoing transnasal transseptal transsphenoidal surgery.

Trial registration

Clinical Trial Registry of Korea, identifier: KCT0003366; registration date: 21/11/2018; presenting author: Ji Seon Jeong.