OLFACTORY DISTURBANCE IN PEDIATRIC TRACHEOTOMY

Several studies have described hyposmia after laryngectomy. The most c ommon mechanism invoked is a reduction in nasal airflow leading to ele vated olfactory detection thresholds. Children with nasal obstruction have been shown to also have elevated olfactory detection thresholds l inked to reduced nasal airflow. A child with a tracheotomy is in some degree similar to a laryngectomee. These patients will have variable a mounts of nasal airflow reduction proportional to the degree of supras tomal obstruction. Our concern was that this alteration in nasal airfl ow may cause hyposmia. Furthermore, if the olfactory system requires a dequate early stimulation for normal development (as is the case with vision and hearing), tracheotomy would be suspected to cause persisten t hyposmia even after decannulation. Thus decreased olfactory sensitiv ity, delayed olfactory experience, or both could interfere with a chil d's ability to recognize and identify odor stimuli. We studied childre n aged 4 to 16 years with upper airway obstruction requiring tracheoto my and compared their abilities to identify familiar odorants with tho se of a large group of normal control children. None of the children h ad intrinsic mucosal or olfactory pathology. Statistical analysis of t he early data shows a significant reduction in olfactory identificatio n scores in the patients with tracheotomies, both by Student's t test and by the Wilcoxon rank sum test. Analysis of covariance confirmed ag e as an independent prognostic variable for identification ability. We therefore conclude that tracheotomy can reduce a child's ability to i dentify familiar odorants.