Mark Wefers Bettink

Monitoring of mitochondrial oxygen tension in the operating theatre 8 155 was used before surgery. Preoperative physical, abdominal, respiratory and cardiac examination were unremarkable. The blood testing results are summarized in table 2. Table 2. Preoperative laboratory assessment Laboratory test (unit) Case A Case B Ref. value Glucose (mg/dL) 185.4 102.6 72.0-109.8 Creatinine (mg/dL) 0.78 0.83 0.74-1.30 Hemoglobin (g/dL) 16.3 14.2 13.9-16.9 Platelets (cells/mm 3 ) 291.000 245.000 150.000-370.000 Leukocytes (cells/mm 3 ) 6.6000 3.5000 3.5000-10.000 An epidural catheter was inserted before induction of anesthesia and epidural analgesia with ropivacaine/sufentanil was given prior to surgery. For induction of anesthesia, an IV bolus of 250 mg propofol, 50 mg rocuronium and infusion of remifentanil 9 mcg/kg/h was used. Anesthesia was maintained by continuous infusion of propofol 8 mg/kg/h and remifentanil 8 mcg/kg/h. Directly after induction, continuous infusion of noradrenalin (0.05-0.19 mcg/kg/min) was necessary to maintain an adequate blood pressure. On top of standard perioperative monitoring consisting of invasive blood pressure measurements, peripheral oxygen saturation, electrocardiography, and temperature measurements, COMET ® was used for mitoPO 2 measurements, and continuous total hemoglobin (SpHb) measurements were performed with a disposable Masimo Rainbow adult adhesive sensor (R2-25a Masimo Corporation, Irvine, USA). Because of a tumor location near the portal vein the procedure was complicated and in a period of 8 hours the patient lost 3750 ml of blood (figure 3). Resuscitation of blood loss was performed using crystalloid (NaCl 0,9% and Sterofundin), colloid solution (Voluven 6%) and vasoactive medication (figure 3). Eventually, intraoperatively there seemed no need for a blood transfusion and intraoperative serum lactate remained low. At the end of surgery fluid balance was 1390 ml positive. During surgery, the mitoPO 2 value gradually declined from 79 mmHg to 5 mmHg. (figure 3). This decrease in mitoPO 2 was accompanied by a decline in hemoglobin from 14.82 g/dL to 9.9 g/dL (determined by a blood gas analyzer). Continuous SpHb measurements were also executed and declined from 11.76 g/dL to 10.63 g/dL. Post- operatively the patient developed increased lactate levels and eventually received blood transfusion.