To evaluate the efficacy of Serenno Medical Automatic Urine Output measuring device in patients with indwelling urinary catheter hospitalized in the cardiac surgery intensive care unit.

In order to evaluate the efficacy of Serenno Medical Automatic Urine Output measuring device we will perform a non inferiority of study device in compare with Urinometer (with acceptance of 3% standard deviation), in patients hospitalized in the intensive care unit after cardiac surgery.

Secondary endpoints are to attribute and Identify urine output changes prior to early stage acute renal failure, and identifying urine output changes prior to fluid overload or dehydration.

Inclusion Criteria:

• Subjects, aged >18 years
• Patients hospitalized in the intensive care unit requiring an indwelling urinary catheter for urine output monitoring for at least 24 hours.

Exclusion Criteria:

• Known urological pathology including but not limited to nephrolithiasis, polycystic kidney disease, congenital abnormalities of the kidneys and or urinary tract, history of obstructive uropathy, advanced chronic kidney disease (stage 4) of any cause.
• Known pregnancy or lactating women.
• Cognitive and/or psychiatric impairment which may not allow cognitive signing on the informed consent unless patient has a legal representative that was appointed prior to patient enrollment.