Bradycardia during cold ocular irrigation under general anaesthesia: an example of the diving reflex

Abstract

The oculocardiac reflex, well-described in the anaesthesia literature, results from a variety of stimuli including traction on the extraocular muscles, ocular manipulation, pressure or traction on the globe, or pressure applied to an empty orbit. I-5 However, even in the absence of these stimuli, cold ocular irrigation may elicit bradycardia induced by the diving reflex. The oculocardiac reflex is active in awake and anaesthetized subjects and is manifested by a variety of dysrhythmias, which include bradycardia, bigeminy, ectopic beats, nodal rhythm, and asystole. 6-8 The diving reflex may have similar physiological mechanisms and clinical significance. Key wordsHEART: alThythmia; BRADYCARDIA: diving reflex. Accepted for publication 22nd February, 1993.Case report A 60-yr-old woman was scheduled for left scleral buckle. Her past medical history was unremarkable, with no history of cardiovascular, neurological, renal, haematopoetic, endocrinological, or pulmonary disease. She did not smoke or use alcohol or take medications. Previously she had undergone two gynaecological operations during uncomplicated general anaesthesia. Physical examination was normal and there was no syncopal history. The preoperative laboratory results were normal, with haemoglobin and haematocrit 13.7 gin. dl -I and 39.7%, respectively. The preoperative 12-lead electrocardiograph (ECG) showed normal sinus rhythm with no suggestion of ischaemia. The vital signs the day before surgery were blood pressure 140/80 mmHg, pulse 88 beats, min -I and respirations 18 breaths, min -x. She weighed 55.7 kg and was 155 cm tall. Sixty minutes before her operation, the patient received diazepam I0 mg po, and a peripheral /v infusion of lactated Ringer's solution with 5% dextrose.Intraoperative monitoring included a fivedead continuous ECG which displayed limb lead II. After preoxygenation, anaesthesia was induced with thiopentone 275 mg and lidocaine 100 mg /v. Tracheal intubation was facilitated with succinylcholine 80 mg/v, and was easily accomplished. Anaesthesia was maintained with 1% isoflurane and 50% nitrous oxide in oxygen. Ventilation was controlled so that end-tidal carbon dioxide concentration was 36 mmHg. Relaxation was maintained with 5 mg /v vecuronium bromide. Vital signs did not vary by more than 5% during anaesthetic induction and maintenance up to this point.Fifteen minutes after induction, a watertight drape was placed around the left eye and the surgeon began to irrigate the eye liberally with sterile, room-temperature, normal saline. The temperature of the saline was 19.7~ The heart rate promptly decreased from 78 beats, min -1 with normal sinus rhythm to a sinus bradycardia of 30 beats, min-l. The surgeon stopped the irrigation and atropine 0.4 mg was given/v. The heart rate increased to 90 beats-min -I with normal sinus rhythm. The episode CAN J ANAESTH 1993 / 40:6 / pp511-4

Surgical repair of a tibial fracture in a two-week-old grey seal (Halichoerus grypus)

“…It has been suggested by several authors that this reflex might appear inappropriately during anaesthesia, contributing to the death of seals (4,7). This reflex has been reported in humans and dogs when cold water is applied on the cornea, resulting in a period of apnoea and bradycardia which usually does not respond to drugs (8). Atropine sulphate (0.02-0.04 mg/kg) has been used by some authors for premedication and sedation of pinnipeds and it appears to be clinically effective in preventing severe bradycardia (5,9,10).…”

“…The fracture was located 3 cm proximal to the distal tibial growth plate in an immature animal with very soft bone. After local debridement and lavage, a very stable and long-standing fixation was mandatory to manage local infection (5,8,15). The use of the locking plate technology allowed good quality stabilization with a minimum number of implants.…”

Classification of Potential Risk Factors for Trigeminocardiac Reflex in Craniomaxillofacial Surgery

“…21 Anticholinergic agents, such as atropine and glycopyrrolate, are the drugs of first 8 choice in cases of refractory bradycardia or asystole. However, besides the mentioned therapies, recognition of bradycardia is the first step in treatment.…”

Cardiac arrest during cornea transplant surgery

“…This is known as the diving reflex, which manifests as bradycardia when irrigation fluid of 20°C or cooler is applied along the ophthalmic division of the fifth cranial nerve. 10 The bradycardia occurs without hypotension and can be more profound than that seen from the oculocardiac reflex. 11 In the presented case, room temperature balanced salt solution was used to irrigate the ocular surface, but the eye was not irrigated at the time of the onset of the patient's bradycardia and is unlikely to have triggered the oculocardiac reflex in this case.…”