COMPARISION OF EFFECTIVENESS OF DEXMEDETOMIDINE VS ESMOLOL IN BLUNTING OF CARDIOVASCULAR RESPONSE TO LARYNGOSCOPY AND ENDOTRACHEAL INTUBATION IN TREATED HYPERTENSIVES

Hypertension    and     tachycardia     are   frequently   associated   with   direct   laryngoscopy    and   endotracheal   intubation(LETI)   after   induction  of   anaesthesia. Patients  with   hypertension,     both   treated    and     untreated, are  prone to exaggerated   pressor    response    to  LETI  than  are normotensive   patients.The exaggerated  pressor  response to LETI  in  these patients  can  evoke life-threatening   condtions  which include myocardial  ischemia,  pulmonary oedema, cardiac  failure  and cerebral  haemorrhage. Few   studies  have   been   carried out with consideration to attenuate   the   hemodynamic response  to  laryngoscopy  in  the subgroup   of    patients    with   hypertension. Nitroglycerine,  verapamil,diltiazem, esmolol, alfentanil and   remifentanil   have been used of whichesmolol was found to be most effective. Dexmedetomidine, a clonidine-like α2-agonistis a sedative-hypnotic and  analgesic. The mechanism by whichdexmedetomidine produces its actions is mainly through central sympatholysisand decreased circulating levels of catecholamines. Since cardiovascular responseto LETI is sympathetically driven, it can be catastrophic, especially inhypertensives due to their enhanced sensitivity to circulating catecholamines.It is therefore hypothesised that dexmedetomidine can effectively blunt thesympatho-adrenal response to LETI, thereby resulting in decreased morbidity inhypertensive patients. Hence this present study aims to study a new drugdexmedetomidine against the previously established drug esmolol in blunting ofcardiovascular response to LETI.