Tracheal Intubation with the Macintosh Laryngoscope versus Intubating Laryngeal Mask Airway in Adults with Normal Airways

Abstract

We tested the hypothesis that haemodynamic changes to intubation and postoperative pharyngolaryngeal morbidity are similar for blind intubating laryngeal mask (ILM)-guided compared with laryngoscope-guided tracheal intubation in adults with normal airways. We also compared intubation success rates and airway complications. One-hundred and fifty paralysed, anaesthetized adult patients undergoing elective surgery were randomly assigned to one of three equal-sized groups: 1. blind intubation via the ILM using a straight, silicone tube; 2. intubation with a Macintosh laryngoscope using a straight silicone tube and 3. intubation with a Macintosh laryngoscope using a polyvinyl chloride tube (controls). A standard sequence of adjusting manoeuvres was followed if intubation was difficult. The number of adjusting manoeuvres and intubation attempts, time to intubation, intubation success rate (first attempt and within 3 min), haemodynamic changes (pre-induction, post-induction, post-intubation), oesophageal intubation, mucosal trauma (blood detected), hypoxia (SpO 2 <95%) and postoperative pharyngolaryngeal morbidity (double-blinded) were documented. Time to successful intubation was longer (57 vs 35s), and more intubation attempts were required in the ILM group (P<0.0001). The intubation success rate was 100% (all first attempt) for the laryngoscope groups and 94% (56% first attempt) for the ILM group. There were no significant differences in heart rate or blood pressure among groups. Oesophageal intubation (26 v 0%) and mucosal trauma (19 v 2%) were more common in the ILM group. Hypoxia and postoperative pharyngolaryngeal morbidity were similar among groups. Blind intubation through the ILM offers no advantages over the Macintosh laryngoscope for adult patients requiring intubation for elective surgery with normal airways, but it is a feasible alternative.

Airway Scope: early clinical experience in 405 patients

“…In the current series, we collected data on intubation from the fi rst experience to the 405th experience at our institution; 60 of the 74 operators had performed tracheal intubations less than ten times. Insuffi cient experience with the AWS might explain the difference between our results and those of previous studies [8,9]. With respect to the 14 residents who had experienced intubation more than ten times, the shortest mean time was 24.7 ± 4.6 s. This duration may be similar to that required for anesthesia residents performing tracheal intubation with a Macintosh laryngoscope.…”

“…Of these, 344 (92%) tracheal intubations were completed within 1 min. The overall time needed to secure the airway was 42.4 ± 19.7 s. This duration, however, seems longer than that reported in the literature when the Macintosh laryngoscope was used for tracheal intubation [8,9]. In the current series, we collected data on intubation from the fi rst experience to the 405th experience at our institution; 60 of the 74 operators had performed tracheal intubations less than ten times.…”

Intubating condition, hemodynamic parameters and upper airway morbidity: A comparison of intubating laryngeal mask airway with standard direct laryngoscopy

“…In previous studies, success rate of intubation through ILMA varied from 76 to 99.3%. [3810141516] However, in most studies, it varied from 93 to 97%; there was a potential difference at the first attempt, ranging from 56 to 87%. It is difficult to compare the studies due to inter-study differences in type of tracheal tube, anesthesia techniques, different size, selection criteria and sequences of adjusting maneuvers.…”

“…However, another study by Kihara and associates[8] concluded that blind intubation through ILMA offers no advantages over the Macintosh laryngoscope for patients requiring intubation for elective surgery with normal airways, though it is a feasible alternative.…”

Paramedic Tracheal Intubation Using the Intubating Laryngeal Mask Airway

“…5−7 The intubating laryngeal mask airway, Fastrach (ILMA) (Laryngeal Mask Airway Company Ltd), is stated to be easier to use 8 and in specific situations provides advantages over the standard laryngeal mask airway, 9,10 Blind tracheal intubation through the ILMA has been evaluated, in controlled settings, as an acceptable and safe alternative to laryngoscopic intubation. 11 A number of pilot trials have suggested the intubating laryngeal mask airway might be successfully used in the out-of-hospital environment. 5 It is not known if the broad implementation of the intubating laryngeal mask airway into an ambulance paramedic system will support this theory.…”