Summarveter was advanced into the abdominal aorta from the right femoral artery. This catheter was used for the determinatioiof This investigation was undertaken to determine the nature of blood pressure and heart rate and for sampling arterial blood. acute alterations in renal function following the production of Radioactive injections were made through a third h~~o x e m i a , h~~e r c a r b i a , and acidosis in newborn piglets 6-96 catheter (PE-90) placed in the ascending aorta by way of the left hr of age* After com~letion of the procedure piglets carotid artery. The urinary bladder was isolated through a small were allowed to recover from the effects of anesthesia. When midline abdominal incision and catheterizedThe posidead space was increased arterial Oxygen tion of all catheters was confirmed by inspection at the end of decreased whereas arterial carbon dioxide tension and hydrogen the experiment. ion concentration increased. There was little change in glomerAfter suturing the skin incisions all wounds were infiltrated ular fdtration rate. Total renal blood flow decreased and renal with lidocaine. Anesthesia was discontinued and the piglets were increased * 78 mm Hg/ placed upright in a supporting sling and allowed to recover from liter/mm/m2 to 1422 * 504). There was no change in distribu-anesthesia for hr. During the surgical procedure and the tion of intrarenal blood flow. Sodium excretion and urinary flow experiment the piglets were maintained at a body temperature rate demonstrated significant parallel increases following the of 380 using a Merco infant Under these conditions the increase in dead space. Plasma renin concentration increased animals remained calm and undisturbed in the sling, often from 67 to 110 ng/ml.sleeping during the experiment. Rectal temperature was continuously monitored using a Yellow Springs thermister. After Speculation completion of the surgical procedure the piglets were intubated Hypoxia, hypercarbia, and acidosis produced changes in renal with a 3.5 mm Portex endotracheal tube. Baseline determinafunction in newborn piglets. Therapeutic approaches to the tions were made and then a dead space 45 cc/ newborn human with respiratory distress must consider the kg) Was added to the tube in order to produce potential for modifications of renal function which may be hypoxia and hypercarbiadetrimental to the infant.Tritiated methoxy inulin (1 pCi/ml) was infused into the femoral vein at a rate of 0.04 ml/min beginning 1 hr before the onset of the experiment. During each clearance period urine The effects of respiratory distress on cardiopulmonary func-collections were made in preweighed flasks under oil. Urine tion in the newborn infant have been extensively studied. flow rate was estimated from the change in weight without However, renal function during this disease process has not ~0"ection for Specific gravity. Urine Was collected for determibeen adequately described. Recent observations have indicated nation of i n~l i n and sodium and potassium concentration. Artethat newbo...