Send to

Choose Destination
Anesth Analg. 1998 Mar;86(3):658-61.

Small-dose fentanyl: optimal time of injection for blunting the circulatory responses to tracheal intubation.

Author information

Department of Anesthesiology and Institute of Cardiovascular Research, Chonbuk National University Medical School, Chonju, Republic of Korea.


This study was designed to examine the optimal time of injection of a small dose of fentanyl during anesthetic induction to attenuate circulatory responses to laryngoscopy and tracheal intubation. One hundred seventy patients were randomly assigned to one of five groups. In Groups II, III, IV, and V, patients received fentanyl (2 microg/kg) 1, 3, 5, or 10 min before tracheal intubation, respectively. Group I patients did not receive fentanyl and served as the control group. In Groups III and IV, blood pressures were not increased, except diastolic pressure in Group III, significantly postintubation compared with preinduction values; but Groups I, II, and V showed a significant increase (P < 0.05). The 1-min postintubation values of systolic, diastolic, and mean arterial pressure in Groups III and IV were less than those in the control group (P < 0.05). Increases of heart rate in Group IV were less (P < 0.05) than those in the control group, but significant differences were not observed in Groups II, III, and V. The number of patients with tachycardia and dysrhythmia was significantly smaller in Group IV than in the control group (P < 0.05). We conclude that the most effective time to administer fentanyl to protect circulatory responses to laryngoscopy and tracheal intubation is 5 min before tracheal intubation.


Fentanyl is often used to reduce the hemodynamic response to tracheal intubation. However, large doses may cause unwanted side effects. Administration of fentanyl at the optimal time reduces the dose required. Our results indicate that optimal injection time of fentanyl for intubation is 5 min before intubation.

[Indexed for MEDLINE]

Supplemental Content

Full text links

Icon for Wolters Kluwer
Loading ...
Support Center