The role of the fiberscope in the critically ill patient.

The role of the fiberscope in the management of difficult and failed intubations has been well established and the importance of learning this valuable skill has been emphasized. Nonetheless, the fiberscope is underutilized in anesthesia and critical care practices because of a high rate of intubation failure. The main cause of failure is lack of expertise in maneuvering the fiberscope. Other technical causes of failure include fogging or clouding of the fiberscope's lens, drifting off the midline, and inability to advance the endotracheal tube or withdraw the fiberscope after completing intubation. Proper selection of the size of the fiberscope in relation to the size of the endotracheal tube, adequate lubrication, and careful passage of the fiberscope through the distal opening of the tracheal tube (not the Murphy eye) prevent difficulties encountered during advancement of the tube or upon withdrawal of the bronchoscope. Patient-related causes include inadequate topical anesthesia, which leads to abrupt movement of the larynx, laryngeal spasm, coughing, and copious secretions; a large floppy epiglottis; and tumor and edema of the upper airway, which also interfere with exposure of the larynx. Various approaches for learning and applying fiberoptic endoscopy have been instituted. The key to increased success involves initial training and practice with an intubation model and tracheobronchial tree. These models enable the learner to develop the eye-hand coordination skills needed to use the fiberscope properly. The fiberscope is best used in patients after learning to perform three simultaneous movements--advancing the fiberscope, coordinated rotation of the insertion cord, and bending the tip of the fiberscope while traversing the airway. After the technical skills of the fiberscope become second nature, the endoscopist can give more attention to patient-related factors to improve the success rate of tracheal intubation. Expert use of the fiberscope can be a life-saving measure through alleviating major airway complications and unnecessary tracheostomies.