The principles and conduct of anaesthesia for emergency surgery

Abstract

SummaryIn this second article we examine the principles underlying delivery of the components of anaesthesia. Topics considered include anaesthetic technique, management of the airway and lung ventilation, induction and maintenance of anaesthesia, patient monitoring including the place of cardiac output devices. We summarise recent research on the management of shock and sepsis syndromes including goal directed therapy and examine some controversies around intravenous fluid therapy. Finally, we discuss intra-operative awareness and challenges during emergence including perioperative cognitive dysfunction. Choice of anaesthetic techniqueOptimal anaesthetic technique is dependent upon an individualised assessment of patient and surgical requirements. Prospective, randomised, controlled trials of rival anaesthetic techniques, e.g. the GALA trial, are rare [1]. Emergency anaesthesia lacks this evidence base and extrapolations from meta-analyses typically fail to reach clear recommendations for clinicians [2]. The nature of surgery, patient co-morbidities, and urgency will frequently decide the anaesthetic choice but clinicians should remain mindful of the options of local or regional anaesthesia and sedation in appropriate patients, especially when a 'lesser' procedure becomes feasible e.g. percutaneous drainage. Management and protection of the airway including pulmonary aspirationThe fourth National Audit Project (NAP4) of the Royal College of Anaesthetists recorded the epidemiology and management of airway complications in UK practice and is essential reading [3]. It is emphasised that 25% of emergency airway management takes place outside operating theatres and since publication, several resources and recommendations have become available [4][5][6]. In the UK, out-of-theatre tracheal intubation frequently occurs in the absence of essential staff and equipment and capnography was not used in nearly a third of cases in a large observational study [7].Both difficult laryngoscopy and difficult tracheal intubation are more common in emergency patients, often outside the theatre setting [8,9]. One American study of non-theatre emergency tracheal intubation by experienced practitioners identified difficulties in over 10%, with over 4% suffering complications [10]. Predictors of complications included multiple attempts and poor views at laryngoscopy and intubation in a ward or emergency department setting. Human factors are increasingly recognised in airway complications and an unfamiliar environment during airway management is likely to be important [3].

Emergency surgery: the big three – abdominal aortic aneurysm, laparotomy and hip fracture

“…Therefore, anaesthetic management is extrapolated from data on younger patients, adjusted for reduced physiological reserve [51], and includes fluid therapy guided by appropriate monitoring aimed towards treating critically ill patients with signs of sepsis.…”

Propofol protects human cardiac cells against chemical hypoxiainduced injury by regulating the JNK signaling pathways

“…Perioperative acute hypoxic-ischemic cardiac toxicity of anesthetics is one of the most serious complications during surgical procedures, and occurs following the blockade of sodium channels and negative inotropic effect (1)(2)(3)(4). To avoid cardiac toxicity, selection of a suitable drug for the maintenance of anesthesia, especially during cardiac surgery, is crucial (5,6). A combination of epidural and general anesthetics have been commonly applied to reduce the use of general anesthetics, such as combining ropivacaine, a local anesthetic, and propofol, a general anesthetic (7,8).…”

In vivo reversal of general anesthesia by cucurbit[7]uril with zebrafish models

“…2 The recovery from general anesthesia has been a passive process whereby the patients recover from the anesthesia on their own and currently no reversal agents are available to actively induce recovery.…”