Clinical trial NCT00478907: Prevention of Complications of Eye Surgery
Official title: phase2 Study of Prevention of Complications of Strabismus Surgery
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: PHASE2
Conditions: Strabismus
Keywords: oculocardiac reflex; strabismus surgery;
Lead sponsor: Isfahan University of Medical Sciences
Sponsor class: OTHER
First posted: 2007-05-25
Enrollment: 300
Sex: ALL
Minimum age (years): 2
Maximum age (years): 18
Standard ages: CHILD
ADULT
Accepts healthy volunteers: no
Allocation: RANDOMIZED
Intervention model: PARALLEL
Primary purpose: PREVENTION

Brief summary: This study was designed to investigate pre-operatively measured parameters of various anaesthetic regimes, iris color, sex, age, surgical time, severity of Marcus-Gunn Pupil (MGP), type of mechanical stimulation of eye, and number of extraocular muscle (EOM) under tension as predictors of significant OCR in pediatric strabismus surgery.

Detailed description: Objectives: Despite various proposed maneuver, successfully predicting an oculocardiac reflex (OCR) is difficult to achieve. This study was designed to investigate pre-operatively measured parameters of various anaesthetic regimes, iris color, sex, age, surgical time, severity of Marcus-Gunn Pupil (MGP), type of mechanical stimulation of eye, and number of extraocular muscle (EOM) under tension as predictors of significant OCR in pediatric strabismus surgery.

Methods: Three hundred patients were randomized to one of three anesthetic regimes: group P: propofol (2 mg/kg), alfentanil 0.02 mg/kg, and atracurium 0.5 mg/kg at induction; group K: ketamine (2mg/kg), alfentanil 0.02 mg/kg, and atracurium 0.5 mg/kg at induction; group T: thiopental (5mg/kg), alfentanil 0.02 mg/kg, and atracurium 0.5 mg/kg at induction. OCR was defined as a 10% change in heart rate induced by traction.

Results: Incidence of OCR was significantly lower in patients in group k compared with patients in group T or P. Chi-square test results showed that the occurrence of OCR was significantly associated with difference of iris color (P=0.01). The occurrence of the OCR did not correlate with sex, age, duration of surgery, iris color, severity of MGP, number of EOM under tension, and type of mechanical stimulation of eye. Type of mechanical stimulation of eye or number of EOM under tension increased risk of developing OCR by 0.81 (95% CI, 0.66-0.98) and 1.29 (95% CI; 1.12-1.63) respectively.

Conclusions: Induction of anesthesia with ketamine is associated with least hemodynamic changes induced by OCR during strabismus surgery. The prediction of oculocardiac reflex propensity remains elusive.

Eligibility criteria: Inclusion Criteria:

* 300 ASA physical status I or II patients, aged 2-18 years, who candidate for elective strabismus surgery

Exclusion Criteria:

* trauma to eye, ASA III or IV, who had contraindication for using thiopental, ketamine, or propofol, had cardiovascular diseases or had taken cardiovascular drugs

Primary outcomes:
measure: incidence of OCR
timeFrame: TWO YEARS
Secondary outcomes:
measure: TYPE OF DRUG PREVENTING OCR
timeFrame: 2 YEARS
Other outcomes:
Locations:
city: Tehran
country: Iran, Islamic Republic of
facility: Feiz Hospital
state: Isfahan
Study officials:
affiliation: isfahan committee of research
name: mohammad safavi, phd
role: STUDY_CHAIR
affiliation: feiz hospital
name: hasan soltani, phd
role: PRINCIPAL_INVESTIGATOR
References:
citation: Apivor D, Ravi PK. Ketamine and the oculocardiac reflex. Dysrhythmia in pediatric strabismus surgery: the role of intravenous atropine. Anaesthesia. 1976 Jan-Feb;31(1):18-22. doi: 10.1111/j.1365-2044.1976.tb11740.x.