A 44-year-old woman with a history of ex-smoking, hypertension, type 2 DM, morbid obesity (BMI 59.19 kg/m2), cholecystectomy, appendectomy, umbilical herniorrhaphy and caesarean section. She was referred to General Surgery for bariatric surgery using the Larrad technique. She attended the emergency department two months after the operation, reporting repeated postprandial vomiting since discharge and a syncopal episode. Physical examination revealed poor general condition, signs of hydrosaline depletion, BP 66/48 and PVC 4 cc H2O. Blood tests: urea 284 mg/dl, Cr 6.98 mg/dl, Na 119 mmol/l, K 2.4 mmol/l, Cl 65 mmol/l, CRP 4.8 mg/dl, lactate 4.7 mmol/l, osmolarity 333 mOsm/kg; haemogram: Hb 14.2 g/dl, HV 42%; leucocytes 19000/ul; platelets 251000/ul; venous blood gases: pH 7.49, bicarbonate 25.9 mmol/l, pCO2 34 mmHg; urine renal function: EF Na 0.11%, urea 276 mg/dl, Cr 274.8 mg/dl, Na 5 mmol/l, K 15.4 mmol/l. The patient was admitted to the nephrology department with a diagnosis of pre-renal ARF secondary to volume depletion, hyponatraemia and hypokalaemia. Hydrosaline replacement and progressive electrolyte correction was started with improvement in renal function until normalisation. During her admission, the patient presented respiratory failure and septic shock secondary to respiratory infection. She was transferred to the intensive care unit and died after two months of hospitalisation.