Perioperative risk factors in obese patients for bariatric surgery: a Singapore experience.

INTRODUCTION: Morbid obesity and obstructive sleep apnoea (OSA) are increasingly encountered in anaesthetic practice today. Difficult intubation may be seen more frequently in our practice. This high-risk group may also be more prone to complications in the postoperative period. METHODS: We reviewed a consecutive series of patients who had undergone laparoscopic gastric banding at our institution from 2001 to 2006. The incidence of difficult intubation, early postoperative complications and its attendant risk factors were studied. RESULTS: Severe OSA and neck circumference greater than 44 cm were factors associated with difficult intubation in morbidly obese patients who presented for bariatric surgery. Asthma and increasing age may be associated risk factors for adverse events in the postoperative period. CONCLUSION: It is important to anticipate and prepare for a difficult intubation scenario in patients with severe OSA and a larger neck circumference. Close monitoring is recommended for patients with respiratory comorbidities and advanced age.

Comparison between use of neuromuscular blocking agent and placebo with the intubating laryngeal mask airway.

INTRODUCTION: The intubating laryngeal mask airway (ILMA) is a specially-designed airway device that can be used for endotracheal intubation without direct laryngoscopy. The advantage of this device is that it allows blind endotracheal intubation with a predictably high success rate. The use of neuromuscular blocking agents in facilitating the use of the ILMA has been investigated in the Western population with a quoted successful intubation rate of 88-96 percent. This randomised, double-blind study aimed to see if the use of neuromuscular blocking agent is necessary for successful intubations. METHODS: A total of 150 patients, rated categories 1 and 2 on the American Society of Anesthesiology Physical Status Classification System, were induced with propofol 2.5 mg/kg and fentanyl 2 microg/kg. After insertion of the ILMA, the patients received either saline or 0.6 mg/kg of rocuronium. After 90 seconds, tracheal intubation was attempted using the specially-designed silicon endotracheal tube. In addition to the success rate of intubation, the incidence of complications was also recorded. RESULTS: The success rate for tracheal intubation within three attempts was 93.3 percent for the saline group and 92.0 percent for the rocuronium group; this was statistically insignificant. The time to securing the airway was 11.5 seconds for the saline group, compared to 10.0 seconds in the rocuronium group, but this was statistically insignificant. The incidence of coughing during insertion of the endotracheal tube was 42.7 percent in the saline group as compared to 1.3 percent in the rocuronium group (p-value is less than 0.001). 12 percent of the patients in the saline group moved during intubation, while none was reported to move in the rocuronium group (p-value is 0.003). These results compared favourably with rates quoted in studies conducted on Western populations. CONCLUSION: The intubating laryngeal mask airway-assisted intubation yields a high success rate, which was similar between the paralysed and non-paralysed patients, with no statistical significance. However, the non-paralysed patients were prone to coughing and movements during intubation, requiring supplemental propofol.