PULMONARY-FUNCTION AFTER ONE-LUNG VENTILATION IN NEWBORNS - THE BASISFOR NEONATAL THORACOSCOPY

Background. To maintain good exposure during major video-assisted thor acic surgery it is necessary to deflate completely the ipsilateral lun g. However, little is known about the effects of one-lung ventilation (OLV) on pulmonary function in newborn patients. Methods. Ten neonatal domestic pigs with a mean age of 6 +/- 0.6 days were intubated and ve ntilated in pressure-controlled mode (inspired oxygen fraction = 1.0). One-lung ventilation was maintained for 120 minutes. Serial measureme nts of hemodynamics and gas exchange were done before, during, and unt il 90 minutes after OLV. Pulmonary function testing was performed befo re and after OLV for each lung separately. Results. With the inspired oxygen fraction set at 1.0, arterial oxygen saturation remained stable at 100% during OLV. Venous admixture and alveolar-arterial oxygen ten sion gradient increased slightly from the baseline value of 2.6% +/- 0 .3% to 3.8% +/- 0.3% during OLV (mean +/- standard error of the mean; p = 0.02), and from 358 +/- 28 to 407 +/- 18 mm Hg (not significant), respectively. Both values returned to baseline during the subsequent v entilation of both lungs. Static compliance and resistance of the vent ilated lung did not change. Compliance of the collapsed lung decreased after reexpansion from 0.42 +/- 0.07 to 0.29 +/- 0.06 mt cm H2O-1 kg( -1), p = 0.008. Resistance remained unchanged (0.22 +/- 0.02 versus 0. 25 +/- 0.05 cm H2O . L-1 . s(-1); not significant). Conclusions. There were only minor effects on pulmonary function during and after OLV in the neonatal piglet. Alterations in gas exchange during OLV were mini mal. Prolonged collapse of the lung with subsequent reexpansion was as sociated with a slight decrease in compliance, indicating some mild lu ng injury. (C) 1998 by The Society of Thoracic Surgeons.