Abstract
The loss of nitrogen after surgery is said to be related to body size as well as to the magnitude of the metabolic effects of surgery. Urine nitrogen should be ‘corrected’ for body size before it can be taken as a guide to the severity of surgery in the individual. Twenty-three patients were studied after elective abdominal surgery of moderate severity, when they were having only 3 litres of dextrose saline daily. The 24-hr urine nitrogen excretion (mean of days 3 and 4) was correlated with 3 indices of body size, body weight (r=0·614), fat-free mass (r=0·743) and 24-hr creatinine excretion (r=0·780).
Nitrogen excretion was corrected for body size by calculating the ratio of nitrogen to each index. For each index the s.d. of this corrected nitrogen excretion at the mean value of the index was less than the s.d. of the uncorrected data. The nitrogen: creatinine ratio in an untimed urine sample was closely related to the ration in the 24-hr urine (r=0·914). These results demonstrate that nitrogen excretion after surgery is related to body size and can be corrected for body size by calculating the nitrogen: creatinine ratio in an untimed urine.
Full text
PDF
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Blackburn G. L., Flatt J. P., Clowes G. H., Jr, O'Donnell T. F., Hensle T. E. Protein sparing therapy during periods of starvation with sepsis of trauma. Ann Surg. 1973 May;177(5):588–594. doi: 10.1097/00000658-197305000-00012. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Border J. R. Metabolic response to short-term starvation, sepsis, and trauma. Surg Annu. 1970;2(0):11–34. [PubMed] [Google Scholar]
- Craig R. P., Tweedle D., Davidson H. A., Johnston I. D. Intravenous glucose, aminoacids, and fat in the postoperative period. A controlled evaluation of each substrate. Lancet. 1977 Jul 2;2(8027):8–11. doi: 10.1016/s0140-6736(77)90004-6. [DOI] [PubMed] [Google Scholar]
- Duke J. H., Jr, Jørgensen S. B., Broell J. R., Long C. L., Kinney J. M. Contribution of protein to caloric expenditure following injury. Surgery. 1970 Jul;68(1):168–174. [PubMed] [Google Scholar]
- Durnin J. V., Womersley J. Body fat assessed from total body density and its estimation from skinfold thickness: measurements on 481 men and women aged from 16 to 72 years. Br J Nutr. 1974 Jul;32(1):77–97. doi: 10.1079/bjn19740060. [DOI] [PubMed] [Google Scholar]
- Forbes G. B., Bruining G. J. Urinary creatinine excretion and lean body mass. Am J Clin Nutr. 1976 Dec;29(12):1359–1366. doi: 10.1093/ajcn/29.12.1359. [DOI] [PubMed] [Google Scholar]
- Kinney J. M. The effect of injury on metabolism. Br J Surg. 1967;54(Suppl):435–437. doi: 10.1002/bjs.1800541310. [DOI] [PubMed] [Google Scholar]