The Importance Of The Oculocardiac Reflex During Ocular Surgery [antikvár]

I. INTRODUCTION. Although it is generally accepted that a definite mortality accompanies all forms of anaesthesia, only the percentage varying in different statistics, every effort has to be made to reduce this rate as far as possible. Especially in such branches of surgery as ophthalmology where the operation and the disease themselves are seldom life endangering, unnecessary deaths during anaesthesia are always dreadful experiences. For the most part these accidents occur in children. The oculocardiac reflex which has been known to exist for over fifty years has often been blamed for sudden and unexplained deaths occuring during ocular surgery. Many experimental investigations have shown that it is impossible to cause death in the conscious animal through vagal stimulation with the oculocardiac reflex, as there is always vagal escape after some seconds or at least some tens of seconds of cardiac arrest. During anaesthesia the state of affairs is quite different as anaesthesia and especially hypoxia and hypercapnia sensitize the heart to vagal stimulation. The unanimity of opinions concerning the importance and the incidence of the oculocardiac reflex may be partly due to the above mentioned facts and partly to certain discrepancies between clinical material and experimental works with dogs. During the past few years investigations have been mainly directed to the prevention of the oculocardiac reflex during anaesthesia. Also in this respect opinions vary greatly. As the published series have usually been small and poorly controlled it is not surprising that exact knowledge of the importance of the oculocardiac reflex during anaesthesia and of the hazards of preventive measures is still relatively scanty and warrants further investigation.