Nebulized sodium cromoglycate in preterm infants--protection against water challenge-induced bronchoconstriction.

Nebulized water is an effective bronchoprovocative agent in asthmatic adults and children. The aim of this study was to assess the bronchoconstrictor effect of this agent in preterm infants studied at follow-up and if their response to it was altered by pre-treatment with nebulized sodium cromoglycate. Lung function, thoracic gas volume and airway resistance, was measured by whole body plethysmography and specific conductance (SGAW) calculated. Measurements were made before and after nebulized saline, nebulized water (first water challenge), nebulized sodium cromoglycate and again nebulized water (second water challenge). There was no significant change in SGAW following either normal saline or sodium cromoglycate. In nine infants SGAW deteriorated by more than 16% (twice the coefficient of variation of the measurement) after the first water challenge but only in one after the second water challenge (P < 0.01). We conclude that nebulized water is an effective bronchoconstrictor in preterm infants and that sodium cromoglycate can protect against this challenge.