Recognition and management of the difficult airway with special emphasis on the intubating LMA-Fastrach/whistle technique: a brief review with case reports

James M. Rich, CRNA, MA

Difficult tracheal intubation using direct laryngoscopy may occur ubiquitously across the spectrum of health care and is reported to occur with an incidence of approximately 6% in anesthesiology; nonetheless, most tracheal intubations can be performed using direct laryngoscopy. Difficult intubation occurs when multiple laryngoscopies, maneuvers, and/or blades are used by an experienced airway practitioner. This article describes four patients who after preanesthetic assessment were suspected of having difficult-to-manage airways. Two of the patients were morbidly obese and two were thin. All four patients had an American Society of Anesthesiologists (ASA) physical status =3. The first three patients were receiving anesthesia care for surgical procedures, and the fourth patient was intubated emergently in the emergency department for acute respiratory failure. The three surgical patients had routine ASA monitors applied in the operating room. Patients #1 and #3 were also monitored using a PSA 4000 Patient State Analyzer and direct arterial blood pressure. Capnography was not available in the emergency department for patient #4; however, intubation was confirmed using a colorimetric carbon dioxide detector. All patients received supplemental oxygen, intravenous sedation, and topical local anesthesia of their airways before insertion of the ILMA. A Patil intubation guide (i.e., airway whistle) was used to confirm optimal positioning of the ILMA in each patient and to monitor advancement of the ETT through the ILMA. Three of the patients were intubated through the ILMA using intravenous sedation and topical local anesthesia of the airway. Patient #2 also received general inhalation anesthesia (i.e., sevoflurane) after insertion of the ILMA and prior to tracheal intubation. Tracheal intubation was confirmed in each patient using the presence of end-tidal carbon dioxide and auscultation of bilateral breath sounds.