18(3) Jul 05 for PDFs.indd

JULY 2005 221 BUMC PROCEEDINGS 2005;18:220–227 OVERVIEW OF THE DIFFICULT AIRWAY Difficult tracheal intubation using direct laryngoscopy may occur ubiquitously across the spectrum of health care (1–8) and is reported to occur with an incidence of approximately 6% in anesthesiology (9); 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 (10). Laryngoscopic views of the airway frequently associated with difficulty were originally defined by Cormack and Lehane (11) and generally reveal only 1) the epiglottis, 2) the tip of the epiglottis, 3) the posterior cartilages, or 4) soft pharyngeal tissue (Table 1). Failed intubation occurs when the trachea cannot be intubated after multiple attempts. When intubation attempts are repeated beyond three or four times, the incidence of airway trauma and edema can increase and may ultimately create a critical airway event (1, 10) such as “cannot mask ventilate—cannot intubate” (CMVCI). If CMVCI occurs, rapid intervention using a supraglottic ventilation device is usually effective in restoring ventilation and oxygenation (1, 10). A number of supraglottic airways are now available (Table 2); however, an analysis of their individual use is beyond the scope of this report. Supraglottic ventilation devices will generally provide better ventilation and protection from aspiration than that provided by bag-valve-mask ventilation (10). If ventilation cannot be established using a supraglottic airway device, transtracheal jet ventilation (15) or a cricothyrotomy is the standard Recognition and management of the difficult airway with special emphasis on the intubating LMA-Fastrach/ whistle technique: a brief review with case reports