Factors influencing preoperative stress response in coronary artery bypass graft patients

Abstract

BackgroundIn many studies investigating measures to attenuate the hemodynamic and humoral stress response during induction of anaesthesia, primary attention was paid to the period of endotracheal intubation since it has been shown that even short-lasting sympathetic cardiovascular stimulation may have detrimental effects on patients with coronary artery disease. The aim of this analysis was, however, to identify the influencing factors on high catecholamine levels before induction of anaesthesia.MethodsVarious potential risk factors that could impact the humoral stress response before induction of anaesthesia were recorded in 84 males undergoing coronary aortic bypass surgery, and were entered into a stepwise linear regression analysis. The plasma level of norepinephrine measured immediately after radial artery canulation was chosen as a surrogate marker for the humoral stress response, and it was used as the dependent variable in the regression model. Accordingly, the mean arterial blood pressure, heart rate and the calculated pressure-rate product were taken as parameters of the hemodynamic situation.ResultsStepwise regression analysis revealed that the oral administration of low-dose clonidine (mean dose 1.75 μg·kg-1) on the morning of surgery was the only significant predictor (p = 0.004) of the high variation in preoperative norepinephrine plasma levels. This intervention decreased norepinephrine levels by more than 40% compared to no clonidine administration, from 1.26 to 0.75 nmol·l-1. There was no evidence for dose-responsiveness of clonidine. All other potential predictors were removed from the model as insignificant (p > 0.05). The use of beta-blocker, ace-inhibitors, ejection fraction, and body mass index were significant determinants for the hemodynamic situation (heart rate, mean arterial pressure, pressure rate product) of the patient during the pre-induction period.ConclusionThe oral administration of clonidine is the only significant predictor for the observed variation of norepinephrine levels during the preoperative period. Lack of significant dose responsiveness suggests that even a low dose of the drug can attenuate the preoperative stress response and thus is recommended in cardiovascular high risk patients.

Effect of Dexmedetomidine on Dose Requirement of Propofol and Thiopentone Induction in Patients Under General Endotracheal Anesthesia

“…The increase in sympathetic and sympathoadrenal activity results in pressor response [1,2], as substantiated by the fact that plasma catecholamines concentration increased in patients undergoing surgery under general anesthesia [3]. Dexmedetomidine, the pharmacologically active d-isomer of medetomidine imidazole is a highly specific and selective α2 adrenoreceptor agonist [4][5][6].…”

A Prospective Randomized Study of Efficacy of Clonidine in Attenuating Haemodynamic Response to Laryngoscopy and Tracheal Intubation

“…But it may be hazardous to those with hypertension, myocardial insufficiency or cerebrovascular diseases. [2] Name & Address of Corresponding Author Dr. Narayan Acharya Assoc. Prof, Department of Anaesthesiology, MKCG Medical College, Berhampur, Odisha.…”

Clonidina subaracnoidea y respuesta al trauma en cirugías cardíacas con circulación extracorpórea

“…Además de eso, la clonidina ha revelado una capacidad moduladora de la respuesta al estrés quirúrgico y la aplicación significativa en el tratamiento del dolor crónico [10][11][12][13] . Algunos estudios también sugieren que la clonidina actúa en la reducción de la morbimortalidad perioperatoria de pacientes de riesgo para coronariopatía 14,15 .…”