Overviwe:
Sometimes it is assumed that a normal serum creatinine level is associated with a normal creatinine clearance. It may be necessary to directly measure the creatinine clearance in trauma patients with a normal serum creatinine.
Reasons for measuring creatinine clearance in a trauma patient with a normal serum creatinine:
(1) detection of high creatinine clearance > 120 mL per min per 1.73 square m
(2) detection of low creatinine clearance
A patient with a high creatinine clearance will show poor response to medications cleared by the kidneys associated with low serum levels. Similarly a patient with a low creatinine clearance will show accumulation of a renally cleared drug.
Patients at risk for high creatinine clearance with creatinine in the normal reference range:
(1) young males (tend to have a larger muscle mass)
(2) polytrauma or burns
(3) high urine output
Patients at risk for low creatinine clearance with creatinine in the normal reference range:
(1) elderly adult with low muscle mass
(2) low urine output
In these patients a simple estimate of creatinine clearance based on the serum creatinine value may be misleading.
