Bradycardia during critical care intubation: mechanisms, significance and atropine: Figure 1

Abstract

Bradycardia occurs during the intubation of some critically ill children as a result of vagal stimulation due to hypoxia and/or laryngeal stimulation; such 'stable' bradycardia is accompanied by selective vasoconstriction. Some induction drugs also induce bradycardia which may be accompanied by vasodilatation which is also a feature of certain pathologies, which influence the progression to 'unstable' bradycardia, which does not respond to re-oxygenation and a pause in laryngoscopy. Preintubation atropine diminishes the overall incidence of stable bradycardia during routine anaesthesia. However, clinical studies of critical care intubation show that atropine does not prevent all episodes of bradycardia and specifically cannot affect vasodilatation. As such, there is insufficient evidence to support a recommendation for the indiscriminate use of atropine for intubation during critical care illness, including simple neonatal respiratory distress. Atropine is appropriate during septic or late stage hypovolaemic shock where abnormal vasomotor tone and bradycardia may potentially set up a negative feedback loop of cardiac hypo-oxygenation and hypoperfusion and during premedication when using suxamethonium.

Asystole During Airway Manipulation in Neurosurgical Patient:Causes and Management

“…On the other hand, in certain group of patients, especially pediatric, who have pre-existing higher vagal tone or patients on B-blockers, may manifest bradycardia and even asystole during airway manipulation. Use of repeated doses of suxamethonium has also been linked with bradycardia and mainly reported in pediatric patients [3]. The other factors which may predispose to adverse cardiac events include hypoxemia, hypercarbia, pre-existing cardiac conduction disorders and other cardiac diseases, use of potent opioids, volatile induction and acid-base / electrolytes disturbances [10].…”

“…Airway manipulation during laryngoscopy and intubation may normally produce sympathetic stimulation and in turn cause hypertension and tachycardia [1,2]. However, in certain group of patients (pediatric), these maneuvers may produce bradycardia and other catastrophic consequences [3].…”

Shock séptico en pediatría II: Enfoque actual en el diagnóstico y tratamiento

“…Se aconseja el uso de atropina en el SS, donde el anormal tono vasomotor existente puede transformar una bradicardia estable (respondedora a reoxigenación) en inestable (asociada con compromiso hemodinámico) 47 . Otro fármaco que se puede utilizar es la ketamina, la que ofrece ventajas en el paciente con SS, pues se ha demostrado en modelos experimentales animales, que su administración inhibe las alteraciones hemodinámicas y la respuesta a citoquinas en el shock inducido por endotoxinas 48 , como también mejorar la sobrevida al interferir con la cascada inflamatoria 49 .…”

Shock séptico en pediatría I: Enfoque actual en el diagnóstico y tratamiento

“…Se recomienda el empleo de atropina en el SS, donde el anormal tono vasomotor existente puede transformar una bradicardia estable (respondedora a reoxigenación) en inestable (asociada con inestabilidad hemodinámica) 82 . Circulación: Los accesos vasculares deben ser obtenidos rápidamente.…”