Acute Tubular Necrosis
Patient Presentation
T.T. was a 52yr old female, admitted into the MICU with sepsis. The patient slowly became increasing lethargic to the point that it was difficult for her to stay awake to answer the questions asked. Upon taking her vital signs, her BP was 60/30, RR: 6, and HR: 55. Shortly afterwards, the patient lost her pulse and went into cardiopulmonary arrest. After approximately 30 minutes of resuscitation, the patient was intubated, started on vasopressors, and a pulse was established. The patient was stabilized. A few hours post arrest, the patient’s urine output started to decrease. Normally, her urine output was around 100cc/hr of clear yellow urine; however, post arrest, she was minimally putting out 10-20cc/hr of dark amber urine.
Differential list
Hypovolemia, acute tubular necrosis, sepsis
Diagnosis
The medical team was notified about the decreased urine output. Initially, fluids are started and the patient’s urine output was monitored. 24-48 hours post arrest, the patient continued to be oliguric. Urine sample and blood was taken and sent. Results as shown:
Serum BUN: 34mg/dl, Serum Creatinine: 2.6mg/dl
Urinalysis: positive for casts, kidney tubular cells, and red blood cells
Urine sodium concentration: 50mEq/L, Urine specific gravity: 1.010
In addition, the patient started to develop edema around her legs and ankles. Given the decrease in urine output and the lab results, the medical team diagnosed her with acute tubular necrosis. Within an otherwise healthy patient, patients diagnosed with ATN usually have a good prognosis and typically the acute renal failure is reversible. In sick patients, however, morbidity and mortality is high, often over 50%.
Treatment
After being diagnosed with ATN, the patient was on a fluid restriction. The patient’s electrolytes were followed regularly and she was given diuretics as needed to manage her fluid levels. Eventually, the patient was temporarily placed on CVVHD (central veno-venous hemodialysis) as a result of her minimal amount of urine output, elevated potassium, and elevated BUN. CVVHD allowed the doctors to better manage the patient’s fluid overload, potassium levels, and remove waste and fluids.
Outcome
After a few weeks in the ICU, the patient stabilized. She was titrated off her vasopressors, passed her wean screen, and was extubated. Her kidneys slowly recovered and as her urine output picked up, her CVVHD was discontinued.
Case created by Tina Thieu, 2011.