INTRODUCTION: The purpose of this study is to assess whether the newly-developed VBM (Medizintechnik GmbH, Sulz, Germany) laryngeal tube (LT) is able to provide adequate ventilation and oxygenation to patients with an unstable neck and require airway management. The haemodynamic responses to insertion between the two devices were also studied. We compared the LT to the laryngeal mask airway (LMA) as an alternative airway management tool in adult patients with unstable neck and who underwent intubation with manual in-line neck stabilisation.
METHODS: A randomised single-blinded prospective study was conducted involving a total of 40 American Society of Anesthesiology I and II pre-medicated patients who were divided into two groups, LT or LMA, for airway management during elective surgery. There were 20 patients for each group. After pre-oxygenation, anaesthesia was induced using intravenous (i.v.) fentanyl and i.v. propofol. The neuromuscular blockade was produced with either i.v. vecuronium or i.v. atracurium. The LT or LMA was inserted after neuromuscular blockade was confirmed using a peripheral nerve stimulator (train-of-four 1). A size 3, 4 or 5 LT or a size 3 or 4 LMA was inserted while the patient's head and neck were being stabilised by an assistant who held the sides of the neck and the mastoid processes (manual in-line stabilisation). If it was not possible to ventilate the lungs, or if end-tidal carbon dioxide and/or chest movement did not indicate a patent airway, the LT or LMA was removed. After three failed attempts, the study was terminated and the airway was secured in the most suitable manner determined by the anaesthetist. After successful placement of LT or LMA, anaesthesia was maintained with 66 percent nitrous oxide in oxygen and 2 minimum alveolar concentration sevoflurane. All patients received standard anaesthesia monitoring. The ease of insertion, the number of attempts needed to successfully secure the airway, episodes of desaturation (less than 95 percent) and end-tidal carbon dioxide at various time intervals were studied. The haemodynamic parameters such as systolic blood pressure, diastolic blood pressure, mean arterial pressure and heart rate at different time intervals were also studied.
RESULTS: The study showed a statistically significant difference in time required for successful insertion between the groups; time required for LT was 24.8 +/- 7.7 seconds and LMA was 36.1 +/- 17.3 seconds (p-value equals 0.01). Both groups had no statistical differences (p-value is greater than 0.05) in number of attempts needed to achieve a patent airway, and the successful insertion rate was 100 percent for both groups. There were also no statistical differences in the haemodynamic response to insertion and the end-tidal carbon dioxide in this study.
CONCLUSION: We conclude that, under anaesthesia, the LT was a valuable and better alternative to LMA for ventilation and airway management when the patient's head and neck are stabilised by the manual in-line method.
Abdominal aortic aneurysm (AAA) repairs represent a significant workload in vascular surgery in Asia. This study aimed to audit AAA surgery and evaluate the application of the Portsmouth Physiological and Operative Severity Score for the Enumeration of Mortality and Morbidity (P-POSSUM) in an Asian vascular unit for standard of care. Eighty-five consecutive surgical patients with AAA from a prospective vascular database from July 1996 to December 2001 in Sarawak were available for analysis. Comparisons between predicted deaths by P-POSSUM and observed deaths in both urgency of surgery categories (elective, urgent, emergency ruptures) and risk range groups (0-5%, >5-15%, >15-50%, >50-100%) were made. No significant difference was found between the predicted and observed rates of death for elective, urgent and emergency AAA repairs. The observed mortality rates were 5%, 18% and 30%, respectively. The observed rates of death were also comparable to P-POSSUM predicted rates of death in the various risk range groups. The POSSUM score used with the P-POSSUM mortality equation is easy to use and applicable as a comparative vascular auditing tool in Asia.
The quality of laryngoscopy and tracheal intubation with propofol augmented by alfentanil was investigated as an alternative technique for rapid tracheal intubation. 119 patients aged between 18 and 60 years (ASA 1 and 2) undergoing elective surgery were prospectively studied in a randomized double-blind controlled fashion. Tracheal intubation facilitated by suxamethonium 1.0 mg/kg alfentanil 15 mu g/kg alfentanil 30 mu g/kg or saline control was compared after propofol induction. The quality of laryngoscopy and intubation were graded according to jaw relaxation, ease of insertion of the endotracheal tube and coughing on intubation. Failure to intubate occurred in 4% and 17% with alfentanil 15 mu g/kg and saline control respectively Tracheal intubation was successful in all patients with alfentanil 30 mu g/kg and suxamethonium 1.0 mg/kg. Alfentanil 15 mu g/kg was not statistically significantly different from saline (P = 0.112). Alfentanil 30 mu g/kg provided similar overall intubating conditions (P = 0.5) to suxamethonium 1.0 mg/kg. Alfentanil in both dosages effectively attenuated the haemodynamic responses to laryngoscopy and tracheal intubation.