Perioperative Effect of Desflurane Versus Total Intravenous Anesthesia With Propofol on Hemostasis Guided by Thromboelastometry in Splenectomy With Liver Cirrhosis.

After obtaining approval from the Institutional Research Ethics Committee and informed written consent, thirty adult patients aged 25- 55 years of either sex, American Society of Anesthesiologists (ASA) class II- III (Child A) suffering from cytopenia scheduled for elective splenectomy will be recruited. Pancytopenia is defined as anemia (hemoglobin < 13.5 g/dL-male; <12 g/dL-female); leucopenia (total leukocyte count < 4,000/mm3) and thrombocytopenia (platelet count < 150,000/mm3). Child B and C, Hb < 10 g/dL platelet count < 50,000/mm3, White Blood Cells (WBCs) < 2,000/mm3, prothrombin time [PT] > 16 s and INR > 1.7, extremes of age, obese patients (body mass index >35 kg m-2), and those using oral anticoagulants, other antithrombotic drugs, or oral contraceptives, will be excluded from the study.

All patients will be premedicated with 0.05 mg kg-1 i.v midazolam half an hour before operation. In the operating room, continuous pulse oximetry, electrocardiogram, non-invasive arterial blood pressure, PECO2, end-tidal anesthetic agent, neuromuscular monitoring, core temperature (Infinity Kappa, Dräger, Lübeck, Germany) and hourly urine output will be monitored throughout the operation. Depth of anesthesia will be monitored by using Bispectral index (BIS). All IV fluids will be warmed, and a warm air blanket (Bair Hugger) will be applied to every patient.

Thirty eligible patients will be allocated randomly to one of two equal groups (15 patients each) according to a computer generated randomization list: group D; maintenance of anesthesia with inhaled desflurane at 1 minimum alveolar concentration (MAC); group P, maintenance of anesthesia with target-controlled infusion (TCI) propofol with a target plasma concentration of propofol between 2 and 5 µg ml-1. The concentration of volatile anesthetics or the rate of infusion of injected anesthetics will be titrated to maintain the BIS numerical value between 40-50.

Anesthesia will be induced in both groups using i.v. fentanyl 1.5- 2 µg kg-1 and propofol 2- 2.5 mg kg-1. Atracurium 0.5 mg kg-1 will be administered for neuromuscular block and continued according to the response to train-of-four peripheral nerve stimulation. After intubation, patients will be mechanically ventilated with 30% oxygen in air throughout surgery using a low flow system (1L min-1) to adjust an end-tidal carbon dioxide (PECO2) between 30- 35 mmHg. Acetated Ringer's solution will be given as a preload and maintenance at a rate of 5-7 ml kg-1 h-1. Patients' systolic arterial pressures will be maintained at 100 mmHg or 70% of the preoperative value, whichever is higher. Hypotension will be treated with i.v. crystalloid fluid loading or intravenous boluses of ephedrine as appropriate. No colloid transfusion will be allowed. Transfusions of red blood cells will be used to maintain hemoglobin levels equal to or above 8 g dl-1. Platelets or fresh frozen plasma will be infused only when indicated by ROTEM. At the end of surgery, neuromuscular blockade will be antagonized with 0.05 mg kg-1 neostigmine and 0.02 mg kg-1 atropine. Postoperative analgesia was provided by intravenous infusion of 1 gm acetaminophen and IV meperidine 1 mg kg-1 every 12 hours. Patients are given an anti-emetic ondansetron 4 mg postoperatively.

Blood Sampling: