| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
Correspondence |
G B Pant Hospital, New Delhi, India, E-mail: drrajivchawla{at}gmail.com
To the Editor:
We read with interest the recently published article by Yamazaki et al.1 The authors describe the role of landiolol, a new ß1 selective antagonist in attenuating tachycardia in response to tracheal intubation. The authors conclude that landiolol [0.1 mg·kg–1 (L1 group) and 0.3 mg·kg–1 (L3 group)] prevents tachycardia without affecting blood pressure. However, the results indicate that there was no difference in heart rate (HR) values between the control group and L1 group. We believe that this may be related to the anesthetic induction technique, which comprised propofol (2 mg·kg–1) and succinylcholine (1 mg·kg–1). It is well known that propofol2 as well as succinylcholine3 are associated with a decrease in HR. Further, it is unclear as to when vecuronium was administered during the induction-intubation sequence: as this may have presented an additional confounding factor. Thus, it appears that a dose of 0.1 mg·kg–1 of landiolol was unable to attenuate the tachycardia in response to tracheal intubation independently from the effects of the anesthetic agents. Further, the mean HR values ranged between 70 to 90 beats·min–1 (SD ± 10) in all the groups at all stages. Although the increase in HR was statistically significant, the magnitude of change was clinically insignificant, barring perhaps one minute after intubation.
Therefore, it seems that the conclusions drawn by the authors should be revised. The study does not demonstrate that a dose of 0.1 mg·kg–1 of landiolol produced any significant change in HR as compared with the control group. Perhaps the drug should be evaluated in combination with other anesthetic techniques. Although the authors suggest that studies should be performed in patients with heart disease to demonstrate beneficial effects of landiolol, most patients with coronary artery disease are usually receiving beta blockers preoperatively. Long acting drugs such as atenolol may confer an antiischemic benefit during the entire perioperative period4 (up to one week after surgery) and not just following tracheal intubation. Thus, it seems that the utility of landiolol may be limited to those patients in whom the effect is required for brief periods without causing a decrease in arterial pressure.
Footnotes
Accepted for publication September 21, 2005.
References
1 Yamazaki A, Kinoshita H, Shimogai M, et al.. Landiolol attenuates tachycardia in response to endo-tracheal intubation without affecting blood pressure. Can J Anesth 2005; 52: 254–7.
2 Tramer MR, Moore RA, McQuay HJ. Propofol and bradycardia: causation, frequency and severity. Br J Anaesth 1997; 78: 642–51.
3 Mirakhur RK, Donati F. Neuromuscular blocking agents and their antagonists. In: Healy TE, Knight PR (Eds). Wylie and Churchill-Davidson’s A Practice of Anesthesia, 7th ed. London: Arnold Publications; 2003: 583–98.
4 Wallace A, Layug B, Tateo I, et al. Prophylactic atenolol reduces postoperative myocardial ischemia. Anesthesiology 1998; 88: 7–17.[Medline]
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
