Korean J Anesthesiol.  2001 Oct;41(4):450-454. 10.4097/kjae.2001.41.4.450.

Correlation between Respiratory Rates and the Degree of Bradycardia in Strabismus Surgery in Children

• Kang JM
• Kim HS
• Kim CS
• Yum MK

• KMID: 2240012
• DOI: http://doi.org/10.4097/kjae.2001.41.4.450

Abstract

BACKGROUND
Strabismus surgery is frequent in pediatric ophthalmic surgery. Traction on the extra ocular muscles can trigger an oculocardiac reflex. We investigated the correlation between respiratoy rates and the degree of bradycardia to find another management for preventing oculocardiac reflex.
METHODS
No premedications were administered. They were induced with thiopental and vecuronium and maintained with O2-enflurane-N2O. The tidal volume was 10 ml/kg. Respiratory rate of group 1 (n = 18) was fixed at 24 bpm, group 2 (n = 18) at 20 bpm, and group 3 (n = 19) at 16 bpm. We measured the mean heart rate from intubation to the beginning of surgery and defined this as the basal heart rate. We defined the lowest heart rate after traction of the extraocular muscles as the minimal heart rate. We calculated the correlation coefficient between the respiratory rate and basal heart rate, minimal heart rate, the change of heart rates and EtCO2.
RESULTS
There was a positive correlation between the respiratory rate and the basal heart rate, and minimal heart rate. There was no correlation between the respiratory rate and the change of heart rate. There was no difference in EtCO2 among the 3 groups.
CONCLUSIONS
Can be increased both basal heart rate in anesthetized patients and minimal heart rate induced by oculocardiac reflex by making the respiratory rate more rapid if there is no significant difference of EtCO2. The oculocardiac reflex may be reduced by making respiratory rate more rapid if there is no significant influence on minute ventilation.

Keyword

pediatric; respiratory rate; oculocardiac reflex

MeSH Terms

Bradycardia*
Child*
Heart Rate
Humans
Intubation
Muscles
Premedication
Reflex, Oculocardiac
Respiratory Rate*
Strabismus*
Thiopental
Tidal Volume
Traction
Vecuronium Bromide
Ventilation
Thiopental
Vecuronium Bromide