Olfactory Disturbance in Pediatric Tracheotomy

Several studies have described hyposmia after laryngectomy. The most common mechanism invoked is a reduction in nasal airflow, leading to elevated olfactory detection thresholds. Children with nasal obstruction have been shown to also have elevated olfactory detection thresholds linked to reduced nasal airflow. A child with a tracheotomy is in some degree similar to a laryngectomee. These patients will have variable amounts of nasal airflow reduction proportional to the degree of suprastomal obstruction. Our concern was that this alteration in nasal airflow may cause hyposmia. Furthermore, if the olfactory system requires adequate early stimulation for normal development (as is the case with vision and hearing), tracheotomy would be suspected to cause persistent hyposmia even after decannulation. Thus decreased olfactory sensitivity, delayed olfactory experience, or both could interfere with a child's ability to recognize and identify odor stimuli. We studied children aged 4 to 16 years with upper airway obstruction requiring tracheotomy and compared their abilities to identify familiar odorants with those of a large group of normal control children. None of the children had intrinsic mucosal or olfactory pathology. Statistical analysis of the early data shows a significant reduction in olfactory identification scores in the patients with tracheotomies, both by Student's t test and by the Wilcoxon rank sum test. Analysis of covariance confirmed age as an independent prognostic variable for identification ability. We therefore conclude that tracheotomy can reduce a child's ability to identify familiar odorants.