The effectiveness of intramuscular dexmedetomidine on hemodynamic responses during tracheal intubation and anesthesia induction of hypertensive patients: a randomized, double-blind, placebo-controlled study

Nebulized Versus Intravenously Administered Dexmedetomidine for Obtunding Hemodynamic Responses to Laryngoscopy and Tracheal Intubation: A Randomized Double-Blind Comparative Study

Introduction Intravenous dexmedetomidine is known to cause major adverse effects such as bradycardia, hypotension, cardiac arrhythmias, and heart block when used as premedication for attenuation of the laryngoscopy and intubation response, limiting its routine use. Thus, it is important to study other routes of administration of dexmedetomidine. Objectives To compare the hemodynamic response and sedation score between intravenous and nebulized dexmedetomidine as premedication for the attenuation of the laryngoscopy and intubation response. Materials and methods In this study, 60 patients fulfilling inclusion criteria undergoing surgeries under general anesthesia (ASA Grade I and II) were randomly allocated into two groups of 30 patients each. Group IV received intravenous 1 mcg/kg dexmedetomidine in 100 mL normal saline, and Group IN received nebulization with 1 mcg/kg dexmedetomidine diluted to a total volume of 5 cc of normal saline, 30 minutes prior to the induction of general anesthesia. Sedation scores were calculated using the Ramsay sedation score at 20 minutes after the administration of the drug; patients were induced by the standard protocol, and laryngoscopy was performed. Vitals were recorded before the administration of the drug and after intubation at stipulated time intervals. Results The median heart rate becomes significantly lower at 15 minutes (70 vs. 76.5) and 20 minutes (66 vs. 76) after induction among Group IV as compared to Group IN. The median systolic blood pressure was significantly lower at 20 minutes in Group IV (110 mmHg) than in Group IN (119 mmHg). The median diastolic blood pressure was significantly lower at 10 minutes (76 vs. 79), 15 minutes (70 vs. 77), and 20 minutes (69 vs. 78.5) in Group IV than in Group IN. The median of mean arterial pressure was significantly lower at 15 minutes (84.8 vs. 91.5) and 20 minutes (83 vs. 92) in Group IV than in Group IN. A comparison of vitals after induction shows that the median heart rate, systolic blood pressure, diastolic blood pressure, and mean arterial pressure were significantly lower statistically among Group IV as compared to Group IN at 0, 1, 3, 5, 10, 15, and 30 minutes after induction (except for systolic blood pressure at 3 minutes). The median sedation score was lower in Group IN (0) than in Group IV (1); this difference is statistically significant. Conclusion The obtundation of hemodynamic responses following laryngoscopy and maintaining hemodynamics intraoperatively is statistically better with nebulized dexmedetomidine compared to intravenous dexmedetomidine.

Nebulized dexmedetomidine for attenuating hemodynamic response to laryngoscopy and endotracheal intubation in adult patients undergoing surgeries under general anaesthesia: a systematic review and meta-analysis of randomized controlled trials

BACKGROUND

Sympathetic stimulation associated with laryngoscopy and endotracheal intubation (ETI) may lead to adverse cardio-/cerebro-vascular events in susceptible patients. Nebulization is a novel route for dexmedetomidine administration providing a large surface area for absorption while avoiding bradycardia and hypotension associated with intravenous route. We aimed to evaluate the efficacy and safety of dexmedetomidine nebulization for attenuating hemodynamic response to ETI in adult patients undergoing surgery under general anaesthesia.

METHODS

This systematic review was registered prospectively in the International Prospective Register of Systematic Reviews (CRD42023403624). PubMed, Embase (OvidSP), Cochrane library, Scopus (Elsevier), Web of Science (Clarivate) and Google Scholar were systematically searched from database inception until March 31, 2023. Two reviewers independently screened titles, abstracts and then full text against pre-specified eligibility criteria. Randomized controlled trials (RCTs) assessing effect of dexmedetomidine nebulization on hemodynamic response to ETI in adult patients undergoing surgeries under general anaesthesia were included. All studies reporting heart rate and systolic blood pressure at baseline and various time points after ETI were included. A pre-piloted data extraction form, Cochrane revised risk-of-bias tool (ROB 2) tool, GRADE approach and RevMan 5.4.1 (Cochrane Collaboration, Copenhagen, Denmark) were used for data extraction, risk of bias assessment, rating certainty of evidence and data synthesis respectively. Mean difference and relative risk with 95% Confidence Interval (CI) were used for continuous and dichotomous variables respectively.

RESULTS

Six RCTs randomized 480 patients with ASA I/II patients aged < 60 years of age and undergoing elective surgeries to receive either dexmedetomidine (n = 240) or saline nebulization (n = 240). Except for one RCT which used 2 μg/kg, all other RCTs used dexmedetomidine dose of 1 μg /kg. Heart rate, systolic, diastolic and mean blood pressure were significantly lower in the dexmedetomidine group at all the measured time points after laryngoscopy and ETI with the only exception being systolic blood pressure at 3 min [mean difference -13.86 (95% CI -30.01 to 2.99), p = 0.09]. Bradycardia and hypotension as adverse effects were absent across the included studies. However, only one-third of the included studies had a low risk of bias and strength of evidence was very low according to the GRADE assessment.

CONCLUSIONS

Compared to placebo, premedication with dexmedetomidine nebulization was associated with lower HR and BP following ETI without any risk of bradycardia and hypotension. However, the strength of evidence was very poor and came from just one country. Future well designed and conducted studies in different populations are warranted.

TRIAL REGISTRATION

PROSPERO Registration number: CRD42023403624.

Evaluation of Nebulised Dexmedetomidine Given Pre-operatively to Attenuate Hemodynamic Response to Laryngoscopy and Endotracheal Intubation: A Randomised Control Trial

Background and aim

A variety of medications have been studied to reduce the hemodynamic response to laryngoscopy and intubation. Dexmedetomidine has been used intravenously in many studies to reduce the hemodynamic response to laryngoscopy and intubation. In high-risk patients, this pressor response can increase morbidity and mortality. As dexmedetomidine has a good bioavailability via the nebulisation route, we formulated this study to evaluate the effect of nebulised dexmedetomidine on the hemodynamic response to laryngoscopy and endotracheal intubation.

Methods

This is a prospective, randomised controlled trial conducted on 100 patients with the American Society of Anesthesiologists grade I and II. The primary objective of the study was to see if nebulised dexmedetomidine at a dose of 1 microgram/kg could reduce the stress reaction to laryngoscopy and intubation. The secondary objective was to study the dose sparing effect of nebulised dexmedetomidine on the amount of propofol used during induction of general anaesthesia. The study population was randomly divided into two groups: group A (n = 50) included patients nebulised with dexmedetomidine 1 microgram/kg and group B (n = 50) included patients nebulised with 5 ml saline 30 minutes before induction of anaesthesia in a sitting position.

Results

The demographics were similar in both groups. Following laryngoscopy and intubation, the systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial pressure (MAP), and heart rate showed a significant increase in the control group B as compared to the treatment group A. In group A, there was attenuation in SBP (one minute = 113.2 ± 14.503, P < 0.001; five minutes = 109.86 ± 8.342, P < 0.001; 10 minutes = 114.24 ± 7.797, P = 0.010), DBP (one minute = 73.72 ± 10.986, P = 0.011; five minutes = 71.62 ± 9.934, P = 0.005; 10 minutes = 76.1 ± 8.006, P = 0.009), MAP (one minute = 86.80 ± 11.86, P = 0.001; five minutes = 84.44 ± 8.97, P = 0.006; 10 minutes = 88.72 ± 7.44, P = 0.018), and heart rate (one minute = 83.34 ± 12.325, P = 0.001; five minutes = 81.56 ± 13.33, P = 0.003; 10 minutes = 80.16 ± 14.086, P = 0.013) following laryngoscopy and intubation. Induction dose of propofol was significantly lower in the dexmedetomidine group (73 ± 19.509, P < 0.001).

Conclusion

Nebulised dexmedetomidine effectively blunts the hemodynamic response to laryngoscopy and intubation and also has a dose sparing effect on the induction dose of propofol.

Effect of preoperative dexmedetomidine nebulization on the hemodynamic response to laryngoscopy and intubation: a randomized control trial

Background

Dexmedetomidine, an alpha-2 agonist, has been used for attenuation of hemodynamic response to laryngoscopy but not through the nebulized route. We evaluated the effects of preoperative dexmedetomidine nebulization on the hemodynamic response to laryngoscopy and intubation and examined the intraoperative anesthetic-analgesic requirements and recovery outcomes.

Methods

Overall, 120 American Society of Anesthesiologists I & II adult patients (of either gender) undergoing elective surgeries and requiring tracheal intubation, were randomized to receive nebulized dexmedetomidine (1 µg/kg in 3–4 ml of 0.9% saline) or 0.9% saline (3–4 ml), 30 min before anesthesia induction. Heart rate (HR) and non-invasive systolic blood pressure (SBP) were monitored for 10 min following laryngoscopy.

Results

After laryngoscopy, linear mixed effect modelling showed significantly lower trend of increase in HR in the dexmedetomidine group versus saline (P = 0.012); however, there was no difference in the SBP changes between the two groups (P = 0.904). Induction dose of propofol (P < 0.001), intraoperative fentanyl consumption (P = 0.007), and isoflurane requirements (P = 0.013) were significantly lower in the dexmedetomidine group. There was no difference in the 2 h incidence of postoperative nausea and vomiting (PONV) (P = 0.612) or sore-throat (P = 0.741).

Conclusions

Nebulized dexmedetomidine at 1 µg/kg attenuated the increase in HR but not SBP following laryngoscopy and reduced the intraoperative anesthetic and analgesic consumption. There was no effect on early PONV, sore-throat, or increase in incidence of adverse effects. Nebulized dexmedetomidine may represent a favorable alternative to the intravenous route in short duration surgeries.

Comparision of Vital Surgical Parameters, after Administration of Midazolam and Dexmedetomidine for Conscious Sedation in Minor Oral Surgery

Aim:

The aim of this study is to compare the efficacy between midazolam and dexmedetomidine in relation to vital parameters, sedation score, pain score, cognitive judgment, and postoperative amnesia to the event in conscious sedation for minor oral surgical procedure.

Materials and Methods:

A sample size of 30 patients were selected in each group: Group M (midazolam) and Group D (dexmedetomidine).

Results:

The mean heart rate (HR) and systolic and diastolic blood pressure measurements were significantly higher in Group M after the 20^th min when compared to Group D. The visual analog scale (VAS) scores of pain were not statistically significant between the two groups during the procedure, but at the time of discharge, statistically significant VAS scores were found between the two groups. Nine (30%) patients in Group D and 21 (70%) patients in Group M showed cognitive judgment impairment with the Stroop Color and Word Test at the 30^th min.

Conclusion:

The dexmedetomidine group of patients had reduced blood pressure and HR. No significant differences were noted in oxygen saturation or in respiratory rate between the two drugs. Patients had better sedation, analgesia, lesser cognitive impairment, and amnesia in the dexmedetomidine group.

Propofol Versus Thiopental for Rapid-Sequence Induction in Isolated Systolic Hypertensive Patients: A Factorial Randomized Double-Blind Clinical Trial

Objective

We investigated the effects of four different anaesthesia induction protocols on the haemodynamic response to laryngoscopy and tracheal intubation during rapid-sequence induction (RSI) in systolic hypertensive patients.

Methods

One hundred and twenty hypertensive adult patients (systolic pressure >140 mmHg and diastolic pressure <90 mmHg), classified according to the American Association of Anesthesiologists as Class II and III were randomized into four groups. After pre-oxygenation for 3 minutes, induction and tracheal intubation were performed by blinded investigators, who also scored the intubation. Study groups composed of 30 patients each received lidocaine 1 mg kg^-1+thiopental 5 mg kg^-1 or remifentanil 1 μg kg^-1+thiopental 5 mg kg^-1 or lidocaine 1 mg kg^-1+propofol 2 mg kg^-1 or remifentanil 1 μg kg^-1+propofol 2 mg kg^-1. Succinylcholine was the muscle relaxant. Haemodynamic data were obtained before (baseline) and after induction, at intubation, and at 1, 3, 5 and 10 minutes after intubation. A rise or drop in the arterial blood pressure and heart rate >20% were considered to be significant.

Results

Patients receiving remifentanil+propofol had a reduction in the systolic and mean blood pressure >20% when compared to patients receiving remifentanil and thiopental: systolic values were 125±27 mmHg in the remifentanil+propofol group versus 153±35 mmHg in the remifentanil+thiopental group 1 minute after intubation (p<0.01); the mean arterial pressure values were 87±18 mmHg in the remifentanil+propofol group versus 105±25 mmHg in the remifentanil+thiopental group 1 minute after intubation (p<0.05).

Conclusion

Propofol was not superior to thiopental for the attenuation of the response to laryngoscopy and intubation during RSI in systolic hypertensive patients, whereas propofol+remifentanil combination appears to be so in terms of the heart rate stability.

Dexmedetomidine for acute baclofen withdrawal

BACKGROUND

Intrathecal baclofen is widely accepted as a treatment option for severe spasticity through its γ-Aminobutyric acid-B (GABAB ) agonist properties. Abrupt cessation can lead to severe and life-threatening withdrawal characterized by altered mental status, autonomic dysreflexia, rigidity, and seizures. This symptomatic presentation is similar to alcohol withdrawal, which is mediated by modification of GABAA expression. Use of the α2-adrenergic agonist dexmedetomidine for the treatment of ethanol withdrawal has been widely reported, raising the question of its potential role in baclofen withdrawal. We present a case of the successful treatment of acute severe baclofen withdrawal with a dexmedetomidine infusion.

METHODS

A 15-year-old patient with spastic quadriparesis and cerebral palsy underwent unexpected removal of his baclofen pump due to an infection that was encountered during a planned pump revision. Following removal, he was placed on high dose enteral baclofen every 6 h. Despite further benzodiazepine supplementation, he had progressive hemodynamic instability, severe rebound spasticity, and intermittent spontaneous clonus consistent with baclofen withdrawal. A dexmedetomidine infusion was titrated to a peak dose of 16 mcg per hour with successful treatment of withdrawal symptoms.

RESULTS

The patient became normotensive without tachycardia. Tone and agitation improved.

CONCLUSION

Dexmedetomidine is to our knowledge a previously unreported option for treatment of acute severe baclofen withdrawal. We report a case of safe and efficacious use in a patient with spastic quadriparesis on chronic intrathecal baclofen. Scientifically rigorous comparison with other options remains to be performed.

Comparative analysis of efficacy of lignocaine 1.5 mg/kg and two different doses of dexmedetomidine (0.5 μg/kg and 1 μg/kg) in attenuating the hemodynamic pressure response to laryngoscopy and intubation

CONTEXT

Laryngoscopy and intubation cause an intense reflex increase in heart rate, blood pressure, due to an increased sympathoadrenal pressor response. Lignoocaine has shown blunting of pressor response to intubation. Dexmedetomidine has sympatholytic effects.

AIMS

To the best of our knowledge there is no study comparing the efficacy of lignocaine with two different doses of dexmedetomidine for attenuating the pressor response. With this idea, we planned to conduct the present study.

MATERIALS AND METHODS

After approval by the Hospital Ethics committee, 90 consenting adults aged 18-65 years of age of either sex of non-hypertensive ASA Grade I or II were randomly allocated into three groups. Group D1- IV Dexmedetomidine 0.5μg/kg over 10 minutes Group D2- IV Dexmedetomidine 1μg/kg over 10 minutes Group X- IV Lignocaine 1.5mg/kg in 10 ml normal saline.

STATISTICAL ANALYSIS USED

ANOVA and Student's t test used for analysis.

RESULTS

Dexmedetomidine 1µg/kg was more effective than 0.5µg/kg and lignocaine 1.5mg/kg in attenuating the pressor response.

CONCLUSIONS

We conclude that dexmedetomidine 1μg/kg adequately attenuates the hemodynamic response to laryngoscopy and endotracheal intubation when compared with dexmedetomidine 0.5μg/kg and lignocaine 1.5mg/kg.

The effect of prophylactic dexmedetomidine on hemodynamic disturbances to double-lumen endotracheal intubation: a prospective, randomized, double-blind, and placebo-controlled trial

The purpose of this study was to determine the effect of dexmedetomidine on hemodynamic responses to DLT intubation compared to placebo and to assess the adverse effects related to dexmedetomidine. Sixty patients were randomly allocated to receive 0.7 μg/kg dexmedetomidine (n = 30) or normal saline (n = 30) 10 minutes before general anesthesia. Systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial pressure (MAP), heart rate (HR), and rate pressure product (RPP) between groups were recorded. During intubation and 10 minutes afterward (T1-T10), the mean SBP, DBP, MAP, HR, and RPP in the control group were significantly higher than those in the dexmedetomidine group throughout the study period except at T1. The mean differences of SBP, DBP, MAP, HR, and RPP were significantly higher in the control group, with the value of 15.2 mmHg, 10.5 mmHg, 14 mmHg, 10.5 beats per minute, and 2,462.8 mmHg min⁻¹. Four patients in the dexmedetomidine group and 1 patient in the control group developed hypotension, while 2 patients in the dexmedetomidine group had bradycardia. Prophylactic dexmedetomidine can attenuate the hemodynamic responses to laryngoscopy and DLT intubation with minimal adverse effects. This trial is registered with ClinicalTrials.gov NCT01289769.