摘要
Measurement of renal function is important to optimize drug dosing in critical ly ill pediatric patients and to prevent doserelated toxicities caused by medica tions that are eliminated or metabolized by the kidney. In clinical practice, th e 24-h creatinine clearance (CrCl) is used as a surrogate marker of renal funct ion. However, a 24-h urine collection period delays the availability of the res ult and increases the potential for collection errors. This prospective, observa tional study was performed to determine whether a 12-h CrCl is comparable to th e traditional 24-h CrCl and to assess whether CrCl could be reliably predicted by the Schwartz equation, which mathematically estimates a child’s GFR. A 24-h urine sample was collected in two 12-h aliquots from 60 catheterized criticall y ill children (age 2 d to 18 y). CrCl and Schwartz glomerular filtration rate ( GFR) estimates were determined for each 12-and 24-h period. Agreement between 12-and 24-h CrCl and between CrCl and Schwartz GFR estimates was assessed usin g intraclass correlation coefficients (ICCs). An ICC ≥0.8 was considered to ind icate excellent agreement. The ICC between the first 12-h CrCl and 24-h CrCl w as 0.9605. The ICC between the second 12-h CrCl and 24-h CrCl was 0.9602. The ICC between the 24-h CrCl and Schwartz GFR was only 0.7046. All comparisons of 12-and 24-h CrCl indicated excellent agreement. In summary, the Schwartz equat ion was not a reliable estimate of renal function in critically ill children, an d a 12-h CrCl is just as accurate as the standard 24-h CrCl to assess renal fu nction and guide drug dosing.
Measurement of renal function is important to optimize drug dosing in critical ly ill pediatric patients and to prevent doserelated toxicities caused by medica tions that are eliminated or metabolized by the kidney. In clinical practice, th e 24-h creatinine clearance (CrCl) is used as a surrogate marker of renal funct ion. However, a 24-h urine collection period delays the availability of the res ult and increases the potential for collection errors. This prospective, observa tional study was performed to determine whether a 12-h CrCl is comparable to th e traditional 24-h CrCl and to assess whether CrCl could be reliably predicted by the Schwartz equation, which mathematically estimates a child's GFR. A 24-h urine sample was collected in two 12-h aliquots from 60 catheterized criticall y ill children (age 2 d to 18 y). CrCl and Schwartz glomerular filtration rate ( GFR) estimates were determined for each 12-and 24-h period. Agreement between 12-and 24-h CrCl and between CrCl and Schwartz GFR estimates was assessed usin g intraclass correlation coefficients (ICCs). An ICC ≥0.8 was considered to ind icate excellent agreement. The ICC between the first 12-h CrCl and 24-h CrCl w as 0.9605. The ICC between the second 12-h CrCl and 24-h CrCl was 0.9602. The ICC between the 24-h CrCl and Schwartz GFR was only 0.7046. All comparisons of 12-and 24-h CrCl indicated excellent agreement. In summary, the Schwartz equat ion was not a reliable estimate of renal function in critically ill children, an d a 12-h CrCl is just as accurate as the standard 24-h CrCl to assess renal fu nction and guide drug dosing.
