[The correlation between urine urea nitrogen and total urine nitrogen output in perioperative patients]

Daily urine urea nitrogen (UUN) and total urine nitrogen output (TUNO) concentrations were measured in 19 patients undergoing G-I surgery during the perioperative period of 114 days. The results showed that there was a strong correlation between UUN and TUNO in statistic regression analysis. A formula is worked out TUNO = UUN + 0.7 which is of great value in estimating the nitrogen balance of TPN patients.