[Methods of measuring respiratory volume and minute ventilation in children in the youngest age groups].

Three modes of measuring tidal volume, minute ventilation and respiration rate in children of the youngest age groups are presented. Differences of the methods as applied in the given age groups are pointed out as well as factors which adversely affect the objectivity of the results. The method using open system spirometer during physiological sleep was found to have the lowest accuracy as the contact of the mask with the naso-oral region of the child's face affects the respiratory center (the child hyperventilates). The plethysmographic method requires the most demanding equipment, yet its great advantage is that the child is not in direct contact with the scanner during recording of data. For routine examinations the most advantageous method is by means of open system spirometer at sleep induced by chloral hydrate, which substantially eliminates the effect of the contact with the mask on the respiration of the child.