SummaryThis investigation was undertaken to determine the nature of acute alterations in renal function following the production of hypoxemia, hypercarbia, and acidosis in newborn piglets 6–96 hr of age. After completion of the surgical procedure piglets were allowed to recover from the effects of anesthesia. When respiratory dead space was increased arterial oxygen tension decreased whereas arterial carbon dioxide tension and hydrogen ion concentration increased. There was little change in glomerular filtration rate. Total renal blood flow decreased and renal vascular resistance increased significantly (504 ± 78 mm Hg/liter/mm/m2to 1422 ± 504). There was no change in distribution of intrarenal blood flow. Sodium excretion and urinary flow rate demonstrated significant parallel increases following the increase in dead space. Plasma renin concentration increased from 67 to 110 ng/ml.SpeculationHypoxia, hypercarbia, and acidosis produced changes in renal function in newborn piglets. Therapeutic approaches to the newborn human with respiratory distress must consider the potential for modifications of renal function which may be detrimental to the infant.