Low-dose intravenous dexmedetomidine reduces shivering following cesarean delivery: a randomized controlled trial

Intravenous Bolus of Dexmedetomidine for Treatment of Severe Shivering After Caesarean Delivery Under Combined Spinal-Epidural Anaesthesia: A Randomized Dose-Response Study

Purpose

Shivering occurs frequently after caesarean delivery. The present study aimed to investigate the ED50 and ED95 of an intravenous (i.v.) bolus of dexmedetomidine for treating severe shivering after caesarean delivery under combined spinal-epidural anaesthesia.

Patients and methods

Seventy-five parturients with severe shivering after caesarean delivery were randomized into one of the five groups to receive an i.v. bolus of 0.2 (Group D1), 0.25 (Group D2), 0.3 (Group D3), 0.35 (Group D4) or 0.4 (Group D5) μg/kg of dexmedetomidine. Effectiveness of shivering treatment was defined as a standardized shivering score decreasing to ≤1 within 10 min of dexmedetomidine injection. The ED50 and ED95 were determined by probit regression. Adverse effects were also compared among the groups.

Results

The ED50 and ED95 of i.v. dexmedetomidine to treat severe shivering were 0.23 (95% CI, 0.16-0.26) μg/kg and 0.39 (95% CI, 0.34-0.52) μg/kg, respectively. No difference in the incidence of adverse effects was found between groups.

Conclusion

An i.v. bolus of 0.39 μg/kg of dexmedetomidine will treat 95% of parturients experiencing severe shivering after caesarean delivery.

Pain during cesarean delivery: A patient-related prospective observational study assessing the incidence and risk factors for intraoperative pain and intravenous medication administration

INTRODUCTION

The incidence of pain during cesarean delivery (PDCD) remains unclear. Most studies evaluated PDCD using interventions suggesting inadequate analgesia: neuraxial replacement, unplanned intravenous medication (IVM), or conversion to general anesthesia. Few assess self-reported pain. This study evaluates the incidence of and risk factors for self-reported PDCD and IVM administration.

METHODS

Between May and September 2022, English-speaking women undergoing cesarean delivery under neuraxial anesthesia were approached within the first 48 h. Participants answered a 16-question survey about intraoperative anesthesia care. Clinical characteristics were extracted from electronic medical records. The primary outcome was PDCD. Secondary outcomes were analgesic IVM (opioids alone or in combination with ketamine, midazolam, or dexmedetomidine) and conversion to general anesthesia. Risk factors for PDCD and analgesic IVM were identified using multivariable logistic regression models.

RESULTS

Pain was reported by 46/399 (11.5%; 95% CI: 8.6, 15.1) participants. Analgesic IVM was administered to 16 (34.8%) women with PDCD and 45 (12.6%) without. Conversion to general anesthesia occurred in 3 (6.5%) women with and 4 (1.1%) without PDCD. Risk factors associated with PDCD were substance use disorder and intrapartum epidural extension. Risk factors associated with analgesic IVM were PDCD, intrapartum epidural extension when ≥2 epidural top-ups were given for labor analgesia, and longer surgical duration.

DISCUSSION

In our cohort of scheduled and unplanned cesarean deliveries, the incidence of PDCD was 11.5%. A significant proportion of women (15.1%) received analgesic IVM, of which some but not all reported pain, which requires further evaluation to identify triggers for IVM administration and strategies optimizing shared decision-making.

A comprehensive overview of clinical research on dexmedetomidine in the past 2 decades: A bibliometric analysis

Introduction: Dexmedetomidine is a potent, highly selective α-2 adrenoceptor agonist with sedative, analgesic, anxiolytic, and opioid-sparing properties. A large number of dexmedetomidine-related publications have sprung out in the last 2 decades. However, no bibliometric analysis for clinical research on dexmedetomidine has been published to analyze hot spots, trends, and frontiers in this field. Methods: The clinical articles and reviews related to dexmedetomidine, published from 2002 to 2021 in the Web of Science Core Collection, were retrieved on 19 May 2022, using relevant search terms. VOSviewer and CiteSpace were used to conduct this bibliometric study. Results: The results showed that a total of 2,299 publications were retrieved from 656 academic journals with 48,549 co-cited references by 2,335 institutions from 65 countries/regions. The United States had the most publications among all the countries (n = 870, 37.8%) and the Harvard University contributed the most among all institutions (n = 57, 2.48%). The most productive academic journal on dexmedetomidine was Pediatric Anesthesia and the first co-cited journal was Anesthesiology. Mika Scheinin is the most productive author and Pratik P Pandharipande is the most co-cited author. Co-cited reference analysis and keyword analysis illustrated hot spots in the dexmedetomidine field including pharmacokinetics and pharmacodynamics, intensive care unit sedation and outcome, pain management and nerve block, and premedication and use in children. The effect of dexmedetomidine sedation on the outcomes of critically ill patients, the analgesic effect of dexmedetomidine, and its organ protective property are the frontiers in future research. Conclusion: This bibliometric analysis provided us with concise information about the development trend and provided an important reference for researchers to guide future research.

Risk factors for dexmedetomidine-associated bradycardia during spinal anesthesia: A retrospective study

Sedation with dexmedetomidine is needed for patients undergoing spinal anesthesia. However, dexmedetomidine sedation increases the incidence of bradycardia. We aimed to identify and to evaluate risk factors for bradycardia in patients undergoing spinal anesthesia with dexmedetomidine sedation. The records of 91 patients who underwent spinal anesthesia with sedation using dexmedetomidine were reviewed retrospectively. For this study, we identified 15 characteristics of included patients from this group who underwent lower leg surgery and had an estimated blood loss of <300 mL. We collected details on potential risk factors for bradycardia from their clinical records. These factors included age, American Society of Anesthesiologists classification, height, weight, sensory level of spinal anesthesia, history of hypertension, diabetes mellitus, loading, and maintenance dose of dexmedetomidine, tourniquet time, initial diastolic and systolic blood pressure, initial heart rate (HR), and anesthesia and surgery duration. The primary endpoint of this study was the occurrence of bradycardia. We identified potential risk factors using logistic regression analysis. The incidence of bradycardia was obtained in 23 (25%) of 91 patients. Initial HR and tourniquet time were significant individual predictive factors for the occurrence of bradycardia. Logistic regression analysis showed that adjusted baseline HR and duration of tourniquet use were risk factors for bradycardia. Patients should be monitored when undergoing spinal anesthesia with sedation using dexmedetomidine for bradycardia when they have a long tourniquet time. A low initial HR could also be a predictive factor for bradycardia.

Dexmedetomidine infusion for emergence coughing prevention in patients undergoing an endovascular interventional procedure: A randomized dose-finding trial

OBJECTIVE

Dexmedetomidine has been introduced in emergence coughing, agitation, and shivering prevention. This study aimed to investigate the optimal dose of dexmedetomidine for emergence cough prophylaxis.

METHODS

In this randomized, double-blinded, and prospective trial, 356 patients scheduled for an endovascular interventional procedure were randomly assigned to 0.3 (D 0.3), 0.4 (D 0.4), 0.5 (D 0.5), and 0.6 (D 0.6) μg·kg^-1·h^-1 dexmedetomidine rate, or saline control (C), from anesthesia induction until the end of surgery. The primary outcomes measured were cough grade and frequency. Additionally, groups were compared according to mean arterial pressure (MAP), heart rate, agitation, shivering, postoperative nausea and vomiting (PONV), extubation time, sedation scores, and postoperative first night sleep quality (secondary outcomes).

RESULTS

A total of 351 patients were included in the analysis. The respective incidences of D 0.3, D 0.4, and D 0.5 versus C group were: 78.6%, 68.6%, 53.4% and 42.9% vs 89.7% for cough (p = 0.002, p < 0.001, and p < 0.001 between group D 0.4, D 0.5 and D 0.6 vs C, respectively); 30%, 27.1%, 20.5%, 15.7% vs 44.1% for agitation (p = 0.04, p = 0.003, and p < 0.001 between group D 0.4, D 0.5 and D 0.6 vs C, respectively); 8.6%, 7.1%, 6.8%, 5.7% vs 22.1% for shivering (p = 0.027, p = 0.013, p = 0.01, and p = 0.01 between D 0.3, D 0.4, D 0.5 and D 0.6 vs C, respectively); and 52.9%, 57.1%, 42.5%, 44.3% vs 61.8% for poor sleep quality (p = 0.02 and p = 0.04 between group D 0.5 and D 0.6 vs C, respectively). D 0.4, D 0.5 and D 0.6 showed lower MAP during extubation, compared with the C group. Also, D 0.5 and D 0.6 presented a slight delay in extubation (3.1 and 3.3 min longer than C; p = 0.002 and p < 0.001, respectively). Meanwhile, the frequency of atropine, vasopressor administration, PONV and dizziness were similar to the control.

CONCLUSIONS

Both 0.5 and 0.6 μg·kg^-1·h^-1 dexmedetomidine infusion rates effectively mitigated emergence coughing with prolonged extubation time, besides sleep disturbance. D 0.4, D 0.5, and D 0.6 reduced agitation and sustained hemodynamic stability. Finally, the four doses applied were effective in shivering attenuation.