Laryngoscopy and intubation often provoke hypertension and tachycardia due to the stimulation both sympathetic and sympathoadrenal activities. While the adverse hemodynamic effects of laryngoscopy and endotracheal intubation can precipitate myocardial ischemia, even in patients without hypertension, the responses are exaggerated in patients with hypertension . In the previous studies , many drugs, including opioids and beta-blockers, have been used to modify the hemodynamic response associated with laryngoscopy and tracheal intubation. To seek the correlation of Fentanyl given time, we will analysis the data collected from vital signs monitoring machine.~All patients were premedicated with Midazolam 0.1mg/kg , Lidocaine 0.5mg/kg (L), Propofol 2mg/kg (P), Rocuronium 1mg/kg (R) before induction of general anesthesia. Laryngoscopy lasting a maximum of 30 s was attempted 3 min after administration of the induction agents. Fentanyl 2mcg/kg was given at different time before intubation.
Opioids have been used to modify the hemodynamic response associated with laryngoscopy and tracheal intubation. To seek the correlation of Fentanyl given time, we will analysis the data collected from vital signs monitoring machine. Patients'details will be recorded too.