Anaesthesia
-
A 31-year-old female with no risk factors for cardiac disease suffered a peri-operative myocardial infarction during an elective gynaecological procedure under spinal anaesthesia. The timing and nature of cardiac symptoms suggest that the myocardial infarction was caused by coronary artery vasospasm secondary to ephedrine and/or metaraminol, which were administered to treat spinal-induced hypotension. We review the recent literature and case reports on myocardial infarction attributed to sympathomimetic drugs, and recommend the use of sublingual or intravenous nitrates when signs or symptoms of coronary arterial vasospasm become evident during their use.
-
In rapid sequence induction of anaesthesia in the emergency setting in shocked or hypotensive patients (e.g. ruptured abdominal aortic aneurysm, polytrauma or septic shock), prior resuscitation is often suboptimal and comorbidities (particularly cardiovascular) may be extensive. The induction agents with the most favourable pharmacological properties conferring haemodynamic stability appear to be ketamine and etomidate. ⋯ Ketamine has been traditionally contra-indicated in the presence of brain injury, but we argue in this review that any adverse effects of the drug on intracranial pressure or cerebral blood flow are in fact attenuated or reversed by controlled ventilation, subsequent anaesthesia and the greater general haemodynamic stability conferred by the drug. Ketamine represents a very rational choice for rapid sequence induction in haemodynamically compromised patients.
-
Randomized Controlled Trial Comparative Study
Tracheal intubation and alternative airway management devices used by healthcare professionals with different level of pre-existing skills: a manikin study.
The classic Laryngeal Mask Airway (cLMA), ProSeal Laryngeal Mask Airway (PLMA), Intubating Laryngeal Mask Airway (ILMA), Combitube (CT), Laryngeal Tube (LT) and tracheal intubation (TI) were compared in a manikin study. Nurses, anaesthetic nurses, paramedics, physicians and anaesthetists inserted the devices three times in a randomised sequence. Time taken for successful insertion, success rates and ease of insertion were evaluated. ⋯ All non-anaesthetists were able to insert the cLMA, PLMA and LT within two attempts with a > 90% success rate on the first attempt. The ILMA and TI were the only devices where more than one subject experienced some difficulty in insertion. The cLMA, PLMA and LT should be evaluated for use in situations where only limited airway training is possible.
-
Hyperinflation of the laryngeal mask airway cuff may exert high pressure on pharyngeal and laryngeal structures. In vitro data show that high intra cuff pressures may occur when inflated to only 30% of the manufacturer's recommended maximum inflation volume. We prospectively assessed the pressure volume curves of paediatric sized laryngeal mask airways (size 1-3) in 240 consecutive children (0-15 years). ⋯ Approximately half the maximum volume produced a cuff pressure > or = 60 cmH(2)O. This occurred in all brands and all sizes studied. We recommend that cuff manometers should be used to guide inflation in paediatric laryngeal mask airways.