S W Lindow1, D A Davey. 1. Department of Obstetrics and Gynaecology, University of Cape Town Medical School, Groote Schuur Hospital Maternity Centre, Observatory, South Africa.
Abstract
OBJECTIVE: To determine the variability of protein excretion in patients with proteinuric hypertension and the accuracy of either a urinary protein/creatinine ratio or a Multistix examination for the estimation of a 24 h protein excretion. DESIGN: An indwelling urinary catheter was placed for 24 h and successive 8 h specimens examined. SETTING: A tertiary referral hospital in Cape Town, South Africa. SUBJECTS: 22 women with significant proteinuria in pregnancy were studied. MAIN OUTCOME MEASURES: The urine volume, protein excretion and creatinine excretion in eight hourly periods were measured. Multistix examination of each specimen was recorded. RESULTS: A large coefficient of variation in urine volume (41%), amount of protein excreted (44%) and the amount of creatinine excreted (22%) in the eight hourly specimens were noted. The protein creatinine ratio did not accurately predict the 24 h protein excretion. The Multistix examination was less accurate with increasing amounts of proteinuria. The amount of creatinine excreted correlated with the volume of urine passed (r = 0.43). CONCLUSION: The analysis of a 24 h specimen or urine for protein excretion remains the best method of monitoring proteinuria in pregnancy. The amount of creatinine excreted in 24 h cannot be used as an index of completeness of collection of the 24 h specimen.
OBJECTIVE: To determine the variability of protein excretion in patients with proteinuric hypertension and the accuracy of either a urinary protein/creatinine ratio or a Multistix examination for the estimation of a 24 h protein excretion. DESIGN: An indwelling urinary catheter was placed for 24 h and successive 8 h specimens examined. SETTING: A tertiary referral hospital in Cape Town, South Africa. SUBJECTS: 22 women with significant proteinuria in pregnancy were studied. MAIN OUTCOME MEASURES: The urine volume, protein excretion and creatinine excretion in eight hourly periods were measured. Multistix examination of each specimen was recorded. RESULTS: A large coefficient of variation in urine volume (41%), amount of protein excreted (44%) and the amount of creatinine excreted (22%) in the eight hourly specimens were noted. The protein creatinine ratio did not accurately predict the 24 h protein excretion. The Multistix examination was less accurate with increasing amounts of proteinuria. The amount of creatinine excreted correlated with the volume of urine passed (r = 0.43). CONCLUSION: The analysis of a 24 h specimen or urine for protein excretion remains the best method of monitoring proteinuria in pregnancy. The amount of creatinine excreted in 24 h cannot be used as an index of completeness of collection of the 24 h specimen.
Authors: Sofia B Ahmed; Rhonda Bentley-Lewis; Norman K Hollenberg; Steven W Graves; Ellen W Seely Journal: Hypertens Pregnancy Date: 2009 Impact factor: 2.108