[The oculocardiac reflex during vitrectomy under neuroleptanalgesia]

Oculocardiac reflex (OCR) is a frequently occurring complication in eye operations. It is a trigemino-vagal reflex characterised by the clinical occurrence of bradycardia and other cardiac rhythm disturbances following manipulations on the eye and its surroundings especially after traction of the external eye muscles. In this paper based on an analysis of 402 anaesthesia records, a bradycardia frequency (f = less than 60/min) of 31.8% was noted while other rhythm disturbances occurred in 5.7%. Predisposition facts were identified as age over 50, hypertension and cardiac diseases requiring medication with cardiac drugs. The frequency of OCR is considerably lowered by diabetes mellitus. Examination of 159 traction measurements made at the lateral rectus muscle revealed that the first manipulation made at the rectus bulbi superior muscle resulted in a statistically significantly stronger reflex activity than at the other muscles. In a further series of investigations in which rectus bulbi superior muscle was tested last, this muscle again showed the biggest frequency deviation. Only determination of the percentage heart rate decrease is suitable for characterising reflex activity. The frequency of the reflex occurring in our study was 71.7%, the result being reduced by the high proportion of diabetics, who are relatively reflex insensitive.