Acute Kidney Injury Clinical Case Scenario • 69-year old woman with chronic compensated hypertension and type 2 diabetes mellitus. • She was febrile, with cough, diarrhea and vomitting for 4 days. These symptoms worsened despite treatment with cefuroxime. Vomiting with low oral intake progressed. Peroral antidiabetics (metformin and glimepiride) were discontinued. • After another 2 days somnolence and anuria appeared. She was admitted to the ER of the University Hospital. Her vital signs at admission were: • respiratory rate 25/min, SpO2 86% on room air • BP 60/40 mm Hg, HR 50/min • prolonged capillary refill time. • somnolence • Oxygen via face mask with reservoir bag was administered • peripheral line and urinary catheter were inserted • 1 liter of crystalloid was rapidly infused • blood cultures and labs were taken. Laboratory results • B(a)pH < 6,8 • B(a)pCO2 3.2 kPa • B(a)pO2 19.2 kPa • B(a)HCO3 2.6 mmol/l • B(a)BD- -35 mmol/l • B(a)sO2c 0.888 • Glykémie 30.5 mmol/l • Leukocyty 37.6 10^9/l • Erytrocyty 4.31 10^12 • Hemoglobin 130 g/l • Trombocyty 164 10^9/l • Urea 30.3 mmol/l • Kreat. 974 umol/l • Na 133 mmol/l • K 6.4 mmol/l • Cl 86 mmol/l • Ca 2.35 mmol/l • Bi-celk. 6.2 umol/l • AMS 11.07 ukat/l • CRP 16.7 mg/l • Prokalc. 47.66 ng/ml • Laktát 18.2 mmol/l • During the subsequent hour, patient remained anuric. • Mental alteration and bradycardia with hypotension progressed • bradypoea with severe hyposaturation developed rapidly. • Rapid sequence intubation was performed, central venous catheter, arterial line, dialysis catheter and nasogastric tube were inserted. • Sodium bicarbonate was administered repetitively, infusion of norepinephrine was started, crystalloids and colloids (4% albumin) were given. • Cultures (urine, sputum) were taken, broadspectrum antibiotic (piperacillin/tazobactam) was commenced. Diagnosis • Septic shock with multiple organ failure MOF/MODS (respiratory, circulatory, CNS, renal) • Probable origin – urosepsis • Severe lactic acidosis – shock induced plus metformin associated • Decompensated diabetes mellitus • Other chronic illnesses… AKI - epidemiology • 5-7% patients in hospital • 50% AKI on ICU due to sepsis Mechanism: - Prerenal 40-70% - Renal 10-50% - Postrenal 10% AKI - patophysiology Prerenal: • decreased renal blood flow - hypovolemia, hypotension • drugs (NSAIDs, aminoglycosides, ACEi, etc) Renal: • Pathophysiology is very complex and is closely related to MODS/MOF (tissue damage by inflammation..) Postrenal: • obstruction that affects the flow of urine out of both kidneys (acute) – BPH, stones, tumor AKI – laboratory and clinical signs • retention of fluids • low (oliguria) or no urine output (anuria) • small molecules disturbance (hyperkalemia, hyperphosphatemia) • retention of BUN (blood urea nitrogen), creatinine • metabolic acidosis Renal Replacement Therapy Elimination techniques • Intermittent methods – Intermittent hemodialysis (IHD) • Continuous methods – Continuous Renal Replacement Therapy (CRRT) • Slow (Sustained) low-efficiency dialysis (SLED) CVVH – Continuous Veno-Venous Hemofiltration Technical Aspects • Catheter for HD • Blood pump • Exctracorporeal circuit • Filter • Anticoagulation • Substitution Anticoagulation Systemic anticoagulation: • UFH • LMWH Regional anticoagulation: • Na citrate • UHF/protamin • Extracorporeal cooling system Without anticoagulation CRRT - pro • more hemodynamic stability • advantages with nutrition • slow fluid removal • precise control of homeostasis CRRT - con • higher risk of bleeding (if systemic anticoagulation used) • more expensive • longer contact of blood with arteficial surfaces • technical difficulties • Renal replacement therapy was instituted : intermittent hemodialysis with subsequent continuous veno-venous hemofiltration. • Regional anticoagulation with citrate was maintained during CRRT. • Initially on high doses of norepinephrine, stress-dose of hydrocortisone was added, volumotherapy with invasive hemodynamic monitoring was performed • After 2 days, hemodynamic stability was achieved • After 3 days, the the therapy was switched to IHD with ultrafiltration. • Diuresis was resumed, ongoing IHD therapy every 2 days. • Sedation was stopped, consciousness was resumed with transient delirium. • Weaning with daily spontaneous breathing trials was started. • After 14 days of mechanical ventilation, patient was successfully extubated. • After another 3 days, she was transferred to HDU with intermittent hemodialysis facility.