EVALUATION OF AIRWAY COMPLICATIONS IN HIGH-RISK PRETERM INFANTS - APPLICATION OF FLEXIBLE FIBEROPTIC AIRWAY ENDOSCOPY

Objectives. We sought to determine factors that would predict the deve lopment of subglottic stenosis (SGS) and tracheomalacia (TM) in preter m infants. The utility of a semiquantitative measurement of airway dim ensions was assessed in relation to signs of airway complications. We also sought to determine from a high-risk population of infants those likely to have abnormal findings identified by bronchoscopic examinati on. Methods. Prospective airway endoscopy was performed for preterm in fants who were intubated for 7 days or more or who demonstrated chroni c oxygen needs beyond 28 days after birth and 36 weeks postconceptiona l age. Subjects were 117 preterm (less than 36 weeks' gestation) infan ts from two level III intensive care nurseries. Endoscopy was used to classify the type and degree of airway injury. Subglottic stenosis was defined subjectively and compared with an objective measurement using subglottic spatial relations described as a trans-subglottic/vocal co rd ratio (TSG/VC). Clinical signs and symptoms and other risk factors were evaluated as significant predictors of SGS and TM, identified by bronchoscopy. Results. Moderate or severe airway abnormalities were id entified in 32 patients (27.3%); 13 with SGS, 17 with TM, and 2 with b oth. All but one infant with TSG/VC less than 0.83 had signs and sympt oms of airway dysfunction. Variables more commonly found in patients w ith SGS included greater number of intubations, use of inappropriately large endotracheal tubes, and longer duration of intubation. Higher a veraged mean airway pressure during the first week after birth and low er gestational age were clinical features associated with TM. Conclusi ons. Flexible bronchoscopic evaluation of a high-risk population demon strated a higher incidence of moderate or severe SGS or TM than previo usly sub suspected, Subglottic stenosis and TM appear to have differen t etiologies based on different factors associated with their developm ent. The TSG/VC ratio correlated well with obstructive symptoms and ma y represent a means to quantitate clinically subglottic narrowing. Inf ants with chronic lung disease who have persistently elevated partial pressure of carbon dioxide, apnea, or phonation abnormalities are most likely to have airway abnormalities identifiable by bronchoscopy.