Monitoring Renal Oxygen Supply in Critically-Ill Patients Using Urinary Oxygen Tension

• Published in: Anesthesia and analgesia Vol. 97; no. 6; pp. 1764 - 1768
• Main Authors: Morelli, Andrea, Rocco, Monica, Conti, Giorgio, Orecchioni, Alessandra, Alberto De Blasi, Roberto, Coluzzi, Flaminia, Pietropaoli, Paolo
• Format: Journal Article
• Language: English
• Published: Hagerstown, MD International Anesthesia Research Society 01.12.2003; Lippincott
• Subjects: Adolescent; Anesthesia. Intensive care medicine. Transfusions. Cell therapy and gene therapy; Biological and medical sciences; Blood Urea Nitrogen; Child; Creatinine - blood; Critical Illness; Diuresis - drug effects; Dopamine Agonists - pharmacology; Electrodes, Implanted; Emergency and intensive care: techniques, logistics; Female; Fenoldopam - pharmacology; Hemodynamics - physiology; Humans; Intensive care medicine; Kidney - drug effects; Kidney - metabolism; Male; Medical sciences; Monitoring; Monitoring, Physiologic; Natriuresis - drug effects; Oxygen - urine; Oxygen Consumption - drug effects; Oxygen Consumption - physiology; Potassium - urine; Urinary Bladder - physiology; Urodynamics - physiology; Human; Urine; Biological fluid; Agonist; Oxygen; Intensive care; Vasodilator agent; Critically ill; D1 Dopamine receptor; Pressure; Kidney; Fenoldopam; Diuretic; Hypotensive drug; Chemotherapy; Treatment; Dopamine agonist; Antihypertensive agent; Oxygenation; Monitoring
• ISSN: 0003-2999; 1526-7598
• DOI: 10.1213/01.ANE.0000087037.41342.4F

Critically-ill patients are at risk of developing renal disorders as a consequence of systemic hypoperfusion. Ischemic acute tubular necrosis and resulting acute renal failure are caused by hypotension or therapeutic management. In this study, we tested the change of O2 availability induced by fenoldopam mesylate using the continuous measurement of urinary oxygen tension (Puo2), a relatively noninvasive technique that could provide potentially important real-time data regarding renal oxygenation in intensive care unit patients. Fenoldopam was administered at different doses (0.03, 0.06, and 0.09 μg · kg · min) to 50 stable critically-ill patients. Urine output was collected every hour to assess volume and urinary electrolytes. Heart rate, mean arterial blood pressure, cardiac output, pulmonary artery occlusion pressure, arterial oxygen delivery index, and oxygen consumption index were analyzed after fenoldopam dose modifications and at infusion end. Pao2 and Puo2 continuous measurements were obtained through two sensors inserted in the radial artery and in the bladder. After a fenoldopam dose increase, Puo2 significantly increased (P < 0.05), whereas Pao2 remained unchanged. During the study, heart rate, mean arterial blood pressure, cardiac output, central venous pressure, pulmonary artery occlusion pressure, arterial oxygen delivery index, and oxygen consumption remained unchanged. Dose-dependent Puo2 increases, unrelated to indexes of systemic perfusion and cardiac function, demonstrate that fenoldopam affects the balance between renal oxygen supply and demand in stable critically-ill patients.