Nitrogen sparing and the catabolic hormones in patients nursed at an elevated ambient temperature following major surgery

• Published in: Intensive care medicine Vol. 16; no. 5; p. 287
• Main Authors: Ryan, D W, Clague, M B
• Format: Journal Article
• Language: English
• Published: United States 01.01.1990
• Subjects: Aged; Beds - standards; Humans; Hydrocortisone - urine; Middle Aged; Nitrogen - urine; Postoperative Care - standards; Proteins - metabolism; Stress, Physiological - metabolism; Stress, Physiological - nursing; Stress, Physiological - urine; Surgical Procedures, Operative; Temperature
• ISSN: 0342-4642
• DOI: 10.1007/BF01706351

Fasted patients managed at an elevated ambient temperature following major surgery have reduced nitrogen excretion and body protein catabolism. To investigate the mechanism behind this three 24 h urine collections were made in 16 patients nursed for 48 h following aortobifemoral surgery on a Clinitron fluidized bed at 32 degrees C and analysed for total urinary nitrogen, cortisol and catecholamine excretion. Results were compared with a similar group of patients nursed throughout on a standard ITU bed at 22 degrees C. Patients managed at the elevated ambient temperature showed a significant reduction in the cumulative total urinary nitrogen (20.73 g +/- 6.42 v 28.95 g +/- 6.44; mean +/- S.D.; p less than 0.002) and cortisol excretion (1238 microg +/- 436 v 2197 microg +/- 844; mean +/- S.D.; p less than 0.001). Catecholamine excretion was also reduced but failed to achieve significance. There were significant correlations between cumulative total nitrogen excretion and both cortisol (r = +0.414; p = 0.02; n = 32) and noradrenaline (r = +0.369; p = 0.05; n = 32). These results confirm that the beneficial effect of an elevated ambient temperature on postoperative protein metabolism is brought about through a reduction in metabolic stress.