Reflections of difficult decannulation.

A new approach is suggested for the problem of difficult decannulation in tracheostomized infants and children in whom no evident obstruction can be found. The so-called "decannulation panic" is probably insufficient to explain the dyspnea alone. Other factors which may be involved include some effects of normal and pathological laryngeal and tracheal anatomy and physiology, Bernoulli's law, and larynx closure. The later may result from overshooting homeostatic mechanism, fear, hyperventilation, lesion of parathyroid glands and recurrent laryngeal nerves, disuse, and retardation of laryngeal growth. The possible interaction of these factors is discussed, and the conclusion is drawn that the problem may be more complex than hitherto has been recognized. Some questions are reviewed, the answers of which might lead towards its solution.