Anaesthesia in prehospital emergencies and in the emergency room

Abstract

Aims

To review anaesthesia in prehospital emergencies and in the emergency room, and to discuss guidelines for anaesthesia indication; pre-oxygenation; anaesthesia induction and drugs; airway management; anaesthesia maintenance and monitoring; side effects and training.

Methods

A literature search in the PubMed database was performed and 87 articles were included in this non-systematic review.

Conclusions

For pre-oxygenation, high-flow oxygen should be delivered with a tight-fitting face-mask provided with a reservoir. In haemodynamically unstable patients, ketamine may be the induction agent of choice. The rocuronium antagonist sugammadex may have the potential to make rocuronium a first-line neuromuscular blocking agent in emergency induction. An experienced health-care provider may consider prehospital anaesthesia induction. A moderately experienced health-care provider should optimise oxygenation, fasten hospital transfer and only try to intubate a patient in extremis. If intubation fails twice, ventilation should be resumed with an alternative supra-glottic airway or a bag-valve-mask device. A lesser experienced health-care provider should completely refrain from intubation, optimise oxygenation, fasten hospital transfer and only in extremis ventilate with an alternative supra-glottic airway or a bag-valve-mask device. With an expected difficult airway, the patient should be intubated awake. With an unexpected difficult airway, bag-valve-mask ventilation should be resumed and an alternative supra-glottic airway device inserted. Senior help should be called early. In a “can-not-ventilate, can-not-intubate” situation an alternative airway should be tried and if unsuccessful because of severe upper airway pathology, a surgical airway should be performed. Ventilation should be monitored continuously with capnography. Clinical training is important to increase airway management skills.

Introduction

Anaesthesia in prehospital emergencies and in the emergency room may save the life of a critically ill or injured patient. Nevertheless, if not performed properly, anaesthesia may put a patient at an even higher risk of morbidity and mortality.1, 2 There is ongoing controversy whether patients benefit from prehospital anaesthesia.³ For example, emergency tracheal intubation is associated with a relatively high rate of life-threatening oesophageal intubations, and mortality is increased in haemodynamically unstable patients.⁴ Similarly, in a German study the tracheal tube was misplaced bronchially in ∼11% of patients and in ∼7% oesophageally; mortality in patients with tracheal tubes misplaced in the oesophagus was 80%.⁵ Moreover, prehospital intubations may fail more often than in the emergency room.⁶ Additionally, a patient being intubated in the field is at double risk of aspiration when compared to a patient being intubated in the emergency room.⁷ Also, in a prehospital study from the United States 14 out of 15 children with an oesophageally placed or a disconnected tracheal tube died.⁸ In a prehospital study from France, senior emergency physicians encountered intubation difficulties (>2 intubation attempts) only in 2% of patients.⁹ Furthermore, severely head-injured patients being anaesthetised in the emergency room compared to a prehospital setting had only half the mortality.¹⁰ These observations indicate that heterogeneity exists among emergency medical service (EMS) systems worldwide, and the intent to improve patient outcome with prehospital anaesthesia may even increase morbidity and mortality of critically ill or injured patients, at least in some EMS systems.

This review discusses new developments in prehospital and emergency room anaesthesia, especially focusing on airway management and drugs, as these fields have seen impressive scientific advances during the last years.