The laryngeal lift: a method to facilitate endotracheal intubation

Cricoid Pressure Controversies

Since cricoid pressure was introduced into clinical practice, controversial issues have arisen, including necessity, effectiveness in preventing aspiration, quantifying the cricoid force, and its reliability in certain clinical entities and in the presence of gastric tubes. Cricoid pressure–associated complications have also been alleged, such as airway obstruction leading to interference with manual ventilation, laryngeal visualization, tracheal intubation, placement of supraglottic devices, and relaxation of the lower esophageal sphincter. This review synthesizes available information to identify, address, and attempt to resolve the controversies related to cricoid pressure. The effective use of cricoid pressure requires that the applied force is sufficient to occlude the esophageal entrance while avoiding airway-related complications. Most of these complications are caused by excessive or inadequate force or by misapplication of cricoid pressure. Because a simple-to-use and reliable cricoid pressure device is not commercially available, regular training of personnel, using technology-enhanced cricoid pressure simulation, is required. The current status of cricoid pressure and objectives for future cricoid pressure–related research are also discussed.

Improvement in Cormack and Lehane grading with laparoscopic assistance during tracheal intubation

BACKGROUND

To use laparoscope as an easily available and easy to use alternative option to videolaryngoscope.

AIMS

The aim of the study was to assess the improvement in the glottic view using a conventional direct laryngoscope (DL) assisted by a laparoscope with its endovision system along with the time taken for tracheal intubation.

SETTINGS AND DESIGN

A prospective, double blind, randomized, controlled study was conducted in a tertiary care centre.

METHODS

Sixty patients with American Society of Anesthesiologists (ASA) physical status I and II requiring general anaesthesia and tracheal intubation for elective surgery were included in the study. The patients were anaesthetized, paralysed, DL was performed and Cormack and Lehane grade (C and L) noted, followed by the introduction of the laparoscope alongside the flange of the Macintosh laryngoscope and a further C and L grading done as seen on monitor. Demographic data, ASA physical status, airway assessment, mouth opening, modified Mallampatti class, jaw protrusion, thyromental and sternomental distances, optimal external laryngeal manipulation, time taken for intubation, pulse oximetry, blood on; tracheal tube, lip, dentition or mucosal trauma, sore throat, hoarseness of voice, excessive secretions and regurgitation were recorded.

STATISTICAL ANALYSIS

Statistical analysis was done using statistics package for social sciences software (17.0 version). A P-value less than 0.05 was considered statistically significant.

RESULTS

Eighty-three percent of the patients showed improvement in glottic view after laparoscopic assistance. Eighty-one and 85% of the patients with C and L grade II and III respectively on DL had an improved glottic view with this technique. The mean time to intubate was 37 seconds.

CONCLUSIONS

Laparoscopic assistance provided a better glottic view than DL in most patients (83%). It has a potential advantage over standard DL in difficult intubation.

Strategies for airway management

Airway management is a critical part of anaesthesia practice. Management includes mask ventilation, laryngoscopy, endotracheal intubation and extubation of the patient. Difficulty can be encountered at any of these stages, potentially resulting in significant complications. Thorough preoperative assessment, as well as careful planning and preparation, can reduce the potential for complications. The American Association of Anesthesiologists (ASA) developed and recently revised guidelines for the management of the difficult airway. These guidelines focus on strategies for intubation as well as alternative airway techniques that can be used when a patient with a difficult airway is encountered.

A difficult airway is not more prevalent in patients suffering from spasmodic torticollis: a case series

PURPOSE

We designed this retrospective study to assess the frequency of difficult airway and difficult intubation in patients with spasmodic torticollis and compare it to that of the general population.

METHODS

After Institutional Review Board approval, data were collected from the charts of all the patients with spasmodic torticollis who underwent selective peripheral denervation at our institution between 1988 and 2001. The intubation grade was determined using the Cormack and Lehane laryngoscopic classification. The best laryngeal view was recorded.

RESULTS

Data from 342 patients were available for analysis. Fourteen patients had a difficult airway. In two patients, intubation was difficult with three attempts at laryngoscopy in one patient and use of fibreoptic bronchoscopy in the other. Twelve (3.5%) patients presented with laryngoscopic grades of III or IV. The combined prevalence of laryngoscopic view grade III and IV and difficult intubation was 4.4%.

CONCLUSIONS

This study assesses the frequency of difficult intubation in patients suffering from spasmodic torticollis. When compared to the general population, these patients do not appear to have a higher frequency of difficult airway or difficult intubation.

The efficacy of the "BURP" maneuver during a difficult laryngoscopy

The displacement of the larynx in the three specific directions (a) posteriorly against the cervical vertebrae, (b) superiorly as possible, and (c) slightly laterally to the right have been reported and named the "BURP" maneuver. We evaluated the efficacy of the BURP maneuver in improving visualization of the larynx. Six hundred thirty patients without obvious malformation of the head and neck participated in this study. We divided the degree of visualization of the larynx using laryngoscopy into five grades and compared the visualization of the larynx using the BURP maneuver with that of laryngoscopy with and without simple laryngeal pressure ("Back"). The maneuver of Back and BURP significantly improved the laryngoscopic visualization from initial inspection. The BURP maneuver also significantly improved the visualization compared with the Back maneuver. We concluded that the BURP maneuver improved the visualization of the larynx more easily than simple back pressure on the larynx.

Quantitative improvement in laryngoscopic view by optimal external laryngeal manipulation

STUDY OBJECTIVE

To determine the improvement in laryngoscopic view obtained using both the Macintosh and Miller blades by applying optimal external laryngeal manipulation (OELM).

DESIGN

Prospective, with each patient serving as his or her own control.

SETTING

Inpatient operating rooms of a University Medical Center.

PATIENTS

181 informed and consenting adult nonpregnant patients requiring general anesthesia and tracheal intubation. The only exclusion criteria was the need to apply cricoid pressure to prevent aspiration of gastric contents.

INTERVENTIONS

Anesthetized, paralyzed patients underwent laryngoscopy without external laryngeal manipulation and the laryngoscopic view was graded ("A") according to visualized structures [1.0-1.9 = all (1.0) or part of the vocal cords (90% = 1.1 and 10% = 1.9); 2 = just the arytenoids; 3 = just the epiglottis; 4 = just the soft palate]. The larynx was then quickly manipulated by the thumb and index and middle fingers of the laryngoscopist's right hand in both cephalad and posterior directions over the hyoid, thyroid, and cricoid cartilages until it was determined which vector and spot produced the optimal laryngoscopic view ("B").

MEASUREMENTS AND MAIN RESULTS

It was found that in every patient with a "A" greater than 1.0, OELM improved the view; i.e., "B" decreased relative to "A." For both the Macintosh blade patients and Miller blade patients with an "A" equal to 2, "B" decreased by one whole laryngoscopic grade in all patients. For both the Macintosh and Miller blade patients with an "A" equal to 3, "B" decreased by at least one whole laryngoscopic grade in all patients and by two laryngoscopic grades in most patients. No patient had an "A" equal to 4. The distribution of optimal-external-laryngeal-manipulation (OELM) spots for all patients was 1%, 40%, 48%, and 11% for the hyoid, high thyroid, low thyroid, and cricoid cartilages, respectively, and the distribution was not significantly different for either the Macintosh and Miller blade groups or for the "A" and "B" subgroups (i.e., "A" < 1.9, = 2 or = 3).

CONCLUSIONS

We conclude that OELM can improve the laryngoscopic view by at least one whole grade, that the best way to determine OELM for an individual patient is on an empirical basis by manipulation of the larynx with the laryngoscopist's right hand, and that OELM should be an instinctive and reflex response to any "A" of 2, 3, or 4.