Effects of adding Dexmedetomidine to 4 Percent Lignocaine nebulization on hemodynamic stress response to laryngoscopy and intubation : A Randomized Control Trial

Laryngoscopy and endotracheal intubation often trigger significant hemodynamic responses (HDR), such as increased heart rate and blood pressure, lasting at least 10 minutes. These responses are due to sympathoadrenal activation from stretching pharyngeal and laryngeal tissues. While manageable in healthy individuals, HDR can be risky for those with compromised cardiac function. Various anesthetic techniques and medications aim to mitigate these responses.Dexmedetomidine, an alpha-2 adrenoceptor agonist, helps manage haemodynamic response by providing sedation, analgesia, and reducing sympathetic activity, which lowers heart rate and blood pressure. Dexmedetomidine selectively binds to alpha-2A receptors, which affects all three types of alpha-2 receptors. This binding inhibits adenyl cyclase, lowering adenosine monophosphate levels and causing hyperpolarization of noradrenergic neurons. As a result, nerve conduction is suppressed by blocking calcium entry needed for neurotransmitter release, leading to reduced sympathetic activity, lower heart rate, and blood pressure . It can be administered intravenously, intramuscularly, intranasally, buccally, or via nebulization. Lignocaine, a local anesthetic, is used to numb tissues and manage cough during procedures like bronchoscopy and laryngoscopy. Lignocaine is used to manage cough in various clinical scenarios. It has been tested as a spray or gel to suppress acute cough during procedures like bronchoscopy and laryngoscopy. It also helps alleviate postoperative sore throat, cough, and hoarseness, and can be administered via nebulizer for severe cough in terminal patients. As an amide local anesthetic, lignocaine reduces hemodynamic responses to tracheal intubation by acting as a myocardial depressant and having central stimulant effects. Hence the purpose of this study is  to compare the effectiveness of using dexmedetomidine and lignocaine nebulization  together versus each drug alone in attenuating the haemodynamic stress responses to laryngoscopy and endotracheal intubation .