Ease of tracheal intubation through the intubating laryngeal mask during manual in‐line head and neck stabilisation

Abstract

SummaryWe have studied core temperature changes occurring during induction of general anaesthesia and surgery in 18 patients undergoing elective aortic aneurysm repair. In the operating theatre, all patients were warmed with a forced-air warmer and a warming mattress, and received warmed (37 ЊC) intravenous fluids. Despite this, mean (SD) [range] core temperatures in the anaesthetic room decreased by 1.5 (0.3)[1.1-2.2] ЊC, while intravascular lines, epidural and urinary catheters were inserted before the introduction of warming methods in theatre. In one-third of patients, the core temperature was still below 36 ЊC at the end of surgery. The overall temperature decrease correlated significantly with the duration of time between induction of general anaesthesia and surgical incision (R 2 0.6912), when the patients were not being warmed. Hypothermia may thus be prevented by minimising the period that the patient is anaesthetised without being warmed. Vascular lines, urinary and epidural catheters should be inserted before the induction of general anaesthesia or, alternatively, warming methods should be introduced in the anaesthetic room. Peri-operative hypothermia is common during major vascular surgery [1], due to factors such as redistribution of blood following induction of general anaesthesia, the abolition of central thermoregulatory mechanisms [2] and the administration of cold intravenous fluids. A patient undergoing aortic surgery is at particular risk of developing hypothermia as the abdomen may be open for a considerable time, there is a period of reduced perfusion of the lower body and fluid losses may be significant. Maintenance of body temperature peri-operatively is desirable as postoperative hypothermia has significant detrimental effects, including coagulopathy and blood loss [3], greater postoperative fluid requirements, increased need for vasopressors and inotropes, increased mortality [4], increased postoperative infection rate [5] and a higher incidence of myocardial ischaemia [6].Several different methods have been used to prevent peri-operative hypothermia [7], including the use of warmed intravenous fluids, forced-air warmers, warming mattresses, radiant heaters and the administration of heated and humidified anaesthetic gases. Of these, the most efficient is the forced-air warmer [8], the use of which has become routine in many institutions.At our hospital, all patients undergoing prolonged (b 2 h) surgery receive prophylactic warming measures in the operating theatre. These include the use of a forced-air warmer, a warming mattress and warmed intravenous fluids wherever possible. Despite this attention to warming techniques, patients undergoing aortic aneurysm repair still become hypothermic by 2 ЊC or more and often do not reach normothermia by the end of surgery, with the result that tracheal extubation may be delayed. We hypothesised that significant heat loss occurs in the anaesthetic room, after induction of anaesthesia and before the introduction of any of these warming methods. We...

Intubating laryngeal mask for fibreoptic intubation — particularly useful during neck stabilization

“…The success rate of fibreoptic tracheal intubation through the intubating laryngeal mask at the first attempt (37 of 42 patients (88%)) in our study was similar to that in previous studies using the intubating laryngeal mask 7,8 and using the conventional laryngeal mask (90% to 95%). 1,13 Previous studies have reported that, when tracheal intubation was attempted blindly through the intubating laryngeal mask the success rate was high (93-100%).…”

“…1,13 Previous studies have reported that, when tracheal intubation was attempted blindly through the intubating laryngeal mask the success rate was high (93-100%). 8,9,14 However, this blind intubation may fail in 50-60% of patients at the first attempt 8,9,14 and might damage the larynx and surrounding tissues, such as impingement of the epiglottis into the laryngeal inlet 15 or perforation of a esophageal pouch. 16 Therefore, caution is required for the blind technique, 17 particularly when there is resistance during the advancement of a tracheal tube or when ventilation via the mask is suboptimal.…”

“…6 The use of the fibrescope should increase the success rate of intubation, but there have been only a few studies of this method 7,8 and none compared the ease of fibreoptic tracheal intubation with and without the use of the intubating laryngeal mask.…”

The FastrachTM Intubating Laryngeal Mask Airway®: an overview and update

“…78 Nileshwar et al found only a non-significant trend toward higher overall intubation success with the Bullard laryngoscope when they compared its use vs blind intubation with the FT-LMA in a simulated setting of an unstable c-spine in 62 patients undergoing general anesthesia with the placement of manual in-line stabilization. 79 Asai et al 80 compared the ease of intubation (measured by a 100 mm VAS) by DL with a gum elastic bougie vs intubation via the FT-LMA using a FOB during manual in-line stabilization of 40 ASA I and II patients with no known upper airway pathology undergoing general anesthesia with muscle relaxant use. The success rate of intubation in the FT-LMA/FOB group was significantly higher than in the DL/bougie group (17/20 vs 9/20, respectively; P \ 0.01).…”

The StyletScope™ is a better intubation tool than a conventional stylet during simulated cervical spine immobilization

“…Sample size was selected to detect a projected difference of 20% between groups for a type I error of 0.05 and a power of 0.8 with respect to intubation success rate in Cormack-Lehane grade 3/4 patients (based on a 60% incidence of grade 3/4 with manualin-line stabilization). 7 Descriptive data were tested using a two-tailed independent t test. Categorical data were tested by Chi-square test.…”