[Dosage of atrial natriuretic peptide in pediatric patients submitted to mechanical ventilation]

The aims of this article are to verify if there is any alteration in the secretion of natriuretic atrial factor (NAF) in children submitted to mechanical pulmonary ventilation and if these possible alterations would lead to modification in the urinary volume and in the urinary sodium excretion.

A prospective study in a tertiary pediatric intensive care unit, nine children submitted to mechanical pulmonary ventilation for recuperation from anesthetics, except one who suffered a not surgical cranioencephalic trauma. The period of the study was from September 1995 to March 1996. Patients with renal pathology, pulmonary pathology, in use of diuretics until 24 hours before the collection of laboratory dosages, hemodynamic instability in need of vasoactive and inothropic agents, and patients with alterations of sodium blood levels were excluded from this work. In order to have an adequate alveolar recruitment at least 3 hours were taken. After this period a blood sample was collected for dosage of natriuretic atrial factor, arterial gas analysis, glucose analysis, creatinine and electrolytes dosage. Urine was collected in a 6 hours interval during the patient's period under mechanical pulmonary ventilation in order to verify the urinary volume and urinary sodium excretion. Fifteen to thirty minutes after extubation, blood an urine were collected for the same dosages done before. Urine was collected in a 6 hour period. A statistical comparison was done by the non parametric test of Wilcoxon signed rank, with a significance level of 0,05.

The natriuretic atrial factor showed tendency to increase when mechanical pulmonary ventilation was taken away (p=0,0547). The urinary volume and natriuresis were not altered by mechanical pulmonary ventilation.