Comparison of the effects of remifentanil and alfentanil on cardiovascular response to nasotracheal intubation: A prospective, randomized, double-blind study

Background: Nasotracheal intubation is often necessary in patients undergoing elective or emergency maxillofacial surgery. Previous studies have suggested that the increase in blood pressure after nasotracheai intubation is significantly greater than the increase after orotracheal intubation. Many drugs, including narcotic analgesics, are effective in modifying cardiovascular responses to orotracheal intubation. Objective: The effects of remifentanil and alfentanil on the cardiovascular responses to nasotracheal intubation were compared in healthy patients scheduled to undergo surgery. Methods: This prospective, randomized, double-blind study was conducted at the Department of Anesthesiology and Reanimation, Faculty of Medicine, Dicle University, Diyarbakir, Turkey. Patients aged 16 to 65 years scheduled to undergo elective maxillofacial surgery and who were American Society of Anesthesiologists status I or II were randomly assigned to receive remifentanil 1 mu g/kg in 10 mL, saline over 30 seconds followed by an infusion of 0.5 mu g/kg center dot min, or alfentanil 10 mu g/kg in 10 ml, saline over 30 seconds followed by an infusion of saline. Anesthesia was then induced with propofol, cisatracurium, and 1% isoflurane with 66% nitrous oxide in oxygen. Heart rate (HR) and systolic and diastolic arterial pressures (SAP and DAP, respectively) were measured noninvasively at 2 minutes before general anesthesia induction (baseline); 2 minutes after induction; and 1, 3, and 5 minutes after nasotracheal intubation. Patients were monitored for cardiac changes using electrocardiography. Results: Forty consecutive patients were enrolled in the study. Twenty patients (11 males, 9 females; mean [SD] age, 27.7 [12.6] years) received remifentanil, and 20 patients (12 males, 8 females; mean [SD] age, 31.5 [17.2] years) received alfentanil. Two minutes after anesthesia induction, mean (SD) arterial pressures decreased significantly from baseline in the remifentanil group (changes, 22 [8]/11 [6] mm Hg) and the alfentanil group (changes, 10 [9]/12 [8] mm Hg) (both, P < 0.05). Changes in SAP and DAP followed a similar pattern in both groups, but SAP was significantly lower in the remifentanil group compared with that in the alfentanil group throughout the study period (all, P < 0.05). After 1 minute of intubation, DAP was significantly lower in the remifentanil group compared with that in the alfentanil group (66 [9] mm Hg vs 73 [20] mm Hg; P < 0.05). Compared with baseline, HR was decreased significantly in both groups throughout the study (all, P < 0.05). Except SAP in the alfentanil group, SAP, DAP, and HR were increased I minute after intubation compared with preintubation values. However, SAP, DAP, and HR remained significantly lower compared with baseline values throughout the study period in both groups (all, P < 0.05) except DAP at I minute after intubation in the alfentanil group. Five patients in the remifentanil group and 2 patients in the alfentanil group required treatment of hypotension. None of the patients in either group required treatment of bradycardia. Conclusions: In this study in healthy surgical patients aged 16 to 65 years, remifentanil 1 mu g/kg given over 30 seconds, followed by a remifentanil infusion of 0.5 mu g/kg center dot min, was similarly effective compared with alfentanil 10 mu g/kg in attenuating the pressor response to nasotracheal intubation, but the incidence of hypotension in patients administered remifentanil was high.