Study on the Efficacy and Safety of Gelaspan

Inclusion: * Male or female patients ≥ 18 years of age and ≤ 80 years of age. * Patients scheduled to undergo open elective abdominal or pelvic surgery. * Anticipated intraoperative volume requirement for gelatine solution is at least 15 mL/kg body weight * Negative pregnancy test (urine dipsticks) in women of child bearing potential. * Provision of voluntary consent to participate in the study, following a full explanation of the nature and purpose of the study, by signing the informed consent form approved by the regulatory authorities of the Russian Federation and Local Ethics Committee (LEC) prior to all evaluations. Exclusion: * Patients of ASA-class \> III. * Known hypersensitivity to gelatine or to any of the constituents of the solution. * Patients treated with other colloid solutions and / or blood products 24 hours prior to surgery. * Patients on hemodialysis. * Patients suffering from: * Decompensated renal function (i.e. serum creatinine \> 3.0 mg/dL) * Hypervolemia; * Severe heart failure; * Moderate lung edema; * Hyperhydration; * Severe blood coagulation disorders (aPTT \>2.5 x ULN or fibrinogen \< 0.5 x LLN or INR \>2.5 x ULN); * Hypernatremia (serum Na+ \> 150 mmol/L); * Hyperchloremia (serum Cl- \> 110 mmol/L); * Hypercalcemia (serum ionized Ca++ \> 1.5 mmol/L); * Metabolic alkalosis; * Severe generalized edema; * Intracranial haemorrhage; * Hyperkalemia (serum K+ \> 5.5 mmol/L). * Pregnancy and/or nursing. * Hypertension with the Systolic Blood Pressure \> 180 mm Hg and Diastolic Blood Pressure \> 110 mm Hg identified at screening. * Patients who in the investigator's opinion couldn't take part in the study. * Simultaneous participation in another clinical trial. * Emergencies.