Airway resistance of the posterior nasal pathways in sudden infant death victims.

In order to test the hypothesis that infectious swelling of parts of the inner nose causes airway obstruction and is of aetiological significance for sudden infant death (SID), we measured the airway resistances of the prepared posterior nasal pathways of 55 SID victims and 7 infants who died of other causes. About 25% of the SID victims but none of the control cases had strongly elevated nasal resistances; over 4000 kPa.s.m-3 up to unmeasurable values. A histological survey showed that about 50% of the SID cases and only 1 of the control cases exhibited distinct to severe signs of inflammation of the nasal mucous membranes. No correlation was found between nasal resistance and age, sex, body weight, body length, head circumference, or histological findings. We conclude that an elevated nasal resistance plays a role in some SID cases and that SID is rather the result of different processes than a monocausal disease.