Abstract □ 5

Introduction: Disturbances of cardiorespiratory patterns (CRP) have been implicated as a possible cause of apparent life threatening event (ALTE) in an infant but it's degree of risk for sudden unexplained death during infancy (SUDI) is still questionable. Anyhow CRP remained the most widely used procedure for evaluation of risk of ALTE infants. On the other hand simple procedures based on scoring systems of exact parents' history (so called taxonomy profiles) have been widely used for possible risk evaluation. Aim of the study: to verify the hypothesis about the existance of a statistically significant correlation between the degree of severity of an event determined by taxonomy profile and an abnormality of CRP obtained by standard cardiorespiratory technique. We also aimed to determine the percentage of presumably explained ALTE cases just by using taxonomy profile. Methods: Adapted taxonomy profile proposed by Fleming DG (Ped Pulmol 1995; 20: 336) was used while CRP were obtained by 6-hourly Edentec recording. The study included 72 infants with history of an ALTE (38 male and 34 female infants; mean age 1.92 ± 1.79 months). The severity of an ALTE was based on parents' history and defined according to the grade of intensity (grade 1 to 4) of four ALTE signs (respiration, skin color, motor activity and intervention used by parents). The severity of ALTE has been scored as low risk (1-8), moderate risk (9-12) and high risk (13-16). For statistical purposes rank-sum technique of Wilcoxon was used. Results: Statistically significant degree of correlation (p<0.05) was found between the severity of an unexplained ALTE obtained by taxonomy profile and the abnormality of the CRP. We found that in 44.4% of our ALTE infant cases the event could already be explained just by simple taxonomy and was later confirmed by appropriate evaluation. The most frequent causes in our series were gastroesophageal reflux, neurological disorder and upper airway tract infection. Conclusions: In those ALTE infants where no treatable cause was found, important information regarding risk for further CRP abnormalities and possible SUDI could be obtained by accurately fulfilled taxonomy profile. In our group of ALTE infants 55.6% of the cases remained unexplained. This fact should perhaps imply the notion that whenever we are dealing with an ALTE infant for the first time there exist roughly the same percentage of possibility that the event will remain unexplained regardless to the extent of historical data and/or the scope of various diagnostic procedures.