Free water clearance of -1.3 ml/min signifies
No secretion of vasopressin
Urine is hypotonic to plasma
Urine is hypeonic to plasma
Urine is isosmotic to plasma
In the physiology of the kidney, free water clearance (CH2O) is the volume of blood plasma that is cleared of solute-free water per unit time. If an individual is producing urine more dilute than the plasma, there is a positive value for free water clearance, meaning pure water is lost in the urine in addition to a theoretical isoosmotic filtrate. If the urine is more concentrated than the plasma, then free water is being extracted from the urine, giving a negative value for free water clearance.Ref: Ganong&;s review of medical physiology; 23rd edition; page no; 657
Renal physiology