Attenuation of the pressor responses to laryngoscopy and endotracheal intubation with intravenous dexmedetomidine versus magnesium sulphate under bispectral index-controlled anaesthesia: A placebo-controlled prospective randomised trial

Abstract

Background and Aims:Laryngoscopy and intubation cause sympathetic stimulation and arousal reactions. We evaluated the role of dexmedetomidine and magnesium sulphate on pressor responses to laryngoscopy and intubation as compared to placebo, when depth of anaesthesia was maintained at a constant bispectral index (BIS) range 40-50 (±5).Methods:One hundred and twenty patients were randomised to receive either dexmedetomidine 1 μg/kg (Group DS), magnesium sulphate 30 mg/kg diluted in 100 ml saline (Group MS) or 100 ml normal saline (Group NS) 15 min before induction of anaesthesia in a double blind manner. After achieving BIS 40–50 (±5), laryngoscopy and intubation were performed. Heart rate (HR), systolic blood pressure (SBP) and diastolic blood pressure (DBP) were recorded pre-drug, after drug, at intubation, at intervals of 1 min till 5 min, then every 2 min till 10 min and every 10 min for 30 min. Statistical analysis was done using Chi-square test and one way analysis of variance.Results:SBP, DBP and HR fell in the DS and MS groups. No significant changes in BP were seen in the NS group at induction and after intubation. HR rose in the NS group (P < 0.001) at induction from 86.35 ± 9.05 to 95.35 ± 11.60 at 2 min. Patients in DS and MS groups had significantly lower HR, SBP and DBP at laryngoscopy and intubation.Conclusion:At BIS levels 40-50 (±5) there was no pressor response to intubation in the NS Group. Dexmedetomidine and magnesium sulphate significantly reduced the heart rate and blood pressure from baseline.

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

“…Various studies have investigated the effects of intravenous dexmedetomidine on the hemodynamic response to laryngoscopy and intubation [ 11 – 15 , 23 – 26 ]. While doses of 1–2 µg/kg have been found to be effective in attenuating this hemodynamic response, they are associated with significant side effects, such as bradycardia, hypotension, or respiratory depression [ 24 , 25 ]. Lawrence and De Lange [ 24 ], found that a single dose of 2 µg/kg dexmedetomidine caused a higher incidence of bradycardia and hypotension compared with the placebo treatment.…”

Evaluation of nebulised dexmedetomidine in blunting haemodynamic response to intubation: A prospective randomised study

“…[ 1 ] The consequences of laryngoscopy and intubation may precipitate ischaemia, arrhythmias, cerebrovascular stroke, pulmonary oedema, increase in intracranial pressure in the vulnerable group. [ 2 ] Till date, numerous drugs and various routes have been tried to attenuate this stress response such as opioids, vasodilators, beta-blockers, calcium channel blockers, intravenous lignocaine, topical sprays, volatile agents, α2 agonists but none of the agents proved to be ideal. [ 3 ]…”

Comparative evaluation of oral melatonin and oral clonidine for the attenuation of haemodynamic response to laryngoscopy and tracheal intubation—A prospective randomised double blind study

“…[ 3 ] Various methods to attenuate the sympathetic response to laryngoscopy and achieve smoother manipulation of airway have been evaluated like topical anaesthesia of pharynx, superior laryngeal nerve block, intravenous lidocaine, beta blockers, opioids, calcium channel blockers, benzodiazepines, barbiturates, propofol, pregabalin, magnesium sulphate, nitroglycerin (intranasal and intravenous) and alpha2 adrenoceptor agonists like clonidine and dexmedetomidine (intravenous and intranasal). [ 4 5 6 ] However, the use of these agents is associated with the respective adverse effects like respiratory depression, hypotension, tachycardia, bradycardia, rebound hypertension or allergic reactions; hence, the quest for a better agent is always on.…”