A 53-year old man (height, 175 cm; weight, 87 kg) was scheduled to undergo subtotal stomach-preserving pancreatoduodenectomy with portal vein reconstruction for pancreatic cancer after receiving neoadjuvant chemotherapy with gemcitabine and nab-paclitaxel. Laparoscopic left nephrectomy for renal cell carcinoma was performed 1 year prior; therefore, harvesting the left internal jugular vein for portal vein reconstruction was planned because the left renal vein was too short. Preoperative serum creatinine level and potassium level were 1.39 mg/dL and 4.1 mEq/L, respectively.
General anesthesia was induced rapidly with propofol, rocuronium, fentanyl, and remifentanil and maintained with desflurane. The patient’s vital signs remained stable while resection of the distal stomach, gallbladder, distal common bile duct, and pancreatic head was performed. Bleeding from the first jejunal vein (J1V) occurred during adhesion detachment around the superior mesenteric vein (SMV), and clamping of the J1V was required to control the bleeding. Immediately after J1V clamping, bowel congestion progressed because the patient’s intestinal blood flow had been bypassed from the SMV to the inferior pancreaticoduodenal vein through J1V due to complete obstruction of the portal vein by the tumor. Therefore, a heparin-coated bypass tube (ANTHRON™ bypass tube, TORAY MEDICAL Co., Tokyo, Japan) was inserted from the SMV to the right great saphenous vein to relieve the bowel congestion. Several minutes after insertion of the ANTHRON™ bypass tube, blood potassium level rose from 4.7 mEq/L to 6.0 mEq/L, and pulseless ventricular tachycardia occurred. Chest compression was promptly performed by surgeons, and anesthesiologists attempted direct current defibrillation several times; epinephrine, magnesium sulphate, bicarbonate, lidocaine, and amiodarone were also administered. In addition to resuscitation, anesthesiologists inserted a blood-access catheter to the right internal jugular vein and started continuous renal replacement therapy to prevent elevation of blood potassium level. Spontaneous circulation was recovered after 30 min. The surgical team decided to discontinue the surgery, and the patient was transferred to the intensive care unit (ICU) after packing gauze into the abdomen and with the ANTHRON™ bypass tube left inserted. Total blood loss was 5620 mL, and total fluid balance was + 6115 mL. The operation time was 10 h 30 min.
Two days after the first operation, the patient was scheduled to undergo tumor resection and portal vein reconstruction with REIV. The surgical team abandoned using the left internal jugular vein for portal vein reconstruction because of concerns that brain congestion after harvesting the jugular vein could affect brain function recovery. Anesthesia was maintained with dexmedetomidine, fentanyl, rocuronium, and remifentanil. Continuous hemodiafiltration had been performed in the ICU due to persistent anuria and continued during the operation to prevent hyperkalemia. Both legs were compressed with a pneumatic compression device throughout the operation to prevent deep venous thrombosis formation. A section of the REIV 5 cm in length was harvested intraperitoneally with a surgical stapler, and the REIV distal end was closed with a 4-0 polypropylene running suture. The inferior epigastric vein, pubic branch of the obturator vein, and the deep circumflex iliac vein were preserved. A surgical nurse noticed swelling of the patient’s right leg 2 h after harvesting; the surgical team ensured careful observation throughout the surgery because a transient change by congestion of the right leg was suspected. Blood potassium level was slightly elevated after REIV resection, but ventricular arrhythmia was absent. Surgery was completed as scheduled (operation time, 7 h 3 min), and the patient was transferred to the ICU again. Total blood loss and total fluid balance were 2485 mL and + 2587 mL, respectively.
On ICU admission, distention and fullness of the right leg worsened. An orthopedist diagnosed the patient with acute compartment syndrome, and right leg elevation to lower the intracompartmental pressure was initiated. Blood potassium level was rapidly elevated immediately after leg elevation (Fig. ), which caused sustained ventricular tachycardia despite efforts to lower blood potassium level such as the administration of bicarbonate, glucose-insulin, and continuous hemodialysis with potassium-free dialysate. Chest compressions were initiated immediately. Ventricular tachycardia was prolonged; therefore, veno-arterial extracorporeal membrane oxygenation (V-A ECMO) was induced, and spontaneous circulation was recovered after resolution of hyperkalemia (Fig. , Table ). Emergent fasciotomy was performed by orthopedists 1 h after induction of V-A ECMO because the intracompartmental tissue pressure of the anterior compartment was 70 mmHg.
V-A ECMO was withdrawn 2 days later, and the patient was extubated 10 days after portal vein reconstruction. He had no apparent neural deficits; however, paralysis and paresthesia of the right leg persisted after discharge from the ICU 17 days post-operatively.
The formula for computing Cockcroft-Gault is given by CrCl = ((140 - age) * adjusted weight * (gender_coefficient)) / (serum creatinine * 72), where the gender_coefficient is 1 if male, and 0.85 if female. The serum creatinine concentration is in mg/dL.
The patient's gender is male, which means that the gender coefficient is 1.
The patient is 53 years old. 
The concentration of creatinine is 1.39 mg/dL. 
The formula for computing the patient's BMI is (weight)/(height * height), where weight is the patient's weight in kg and height is the patient's height in m.
The patient's height is 175.0 cm, which is 175.0 cm * 1 m / 100 cm = 1.75 m. The patient's weight is 87.0 kg. The patient's bmi is therefore 87.0 kg / (1.75 m * 1.75 m) = 28.408 kg/m^2.The patient's BMI is 28.4, indicating they are overweight/obese.
Because the patient is overweight/obese, we use the adjusted body weight formula to get the adjusted weight used for Cockroft-Gault Equation. Shown below is the computation for IBW (ideal body weight).
The patient's gender is Male.
The patient's height is 175.0 cm, which is 175.0 cm * 0.393701 in/cm = 68.898 in. 
For males, the ideal body weight (IBW) is calculated as follows:
IBW = 50 kg + 2.3 kg * (height (in inches) - 60)
Plugging in the values gives us 50 kg + 2.3 kg * (68.898 (in inches) - 60) = 70.465 kg.
Hence, the patient's IBW is 70.465 kg.Shown below is the computation for ABW (adjusted body weight).
To compute the ABW value, apply the following formula: ABW = IBW + 0.4 * (weight (in kg) - IBW (in kg)). ABW = 70.465 kg + 0.4 * (87.0 kg  - 70.465 kg) = 77.079 kg. The patient's adjusted body weight is 77.079 kg.

Using the Cockcroft-Gault equation:
CrCl = ((140 - age) * adjusted weight * gender_coefficient) / (serum creatinine * 72).
Plugging the patient's values gives us ((140 - 53) * 77.079 * 1) / (1.39 * 72) = 67.005 mL/min. Hence, the patient's creatinine clearance is 67.005 mL/min.