Haemodynamic Effects During Anorectal Surgery: a Comparison of the Jack -Knife and Lithotomy Position

Background and Goal of Study: Minimal dose of spinal hyperbaric bupivacaine is commonly performed for adult anorectal surgery. This kind of anaesthesia can cause sinus bradycardia and hypotension wich reason is body position, autonomic nervus system reaction, reflex reaction even with low levels of sensory block. However, neither the publication of minimal doses of spinal hyperbaric bupivacaine effects of haemodynamic modifications nor their accuracy was widely discussed. The aim of the study is to make a comparison of the haemodynamic modifications due to minimal dose of spinal hyperbaric bupivacaine for adult anorectal surgery in lithotomy or jack knife position of steering impedance device. Materials and Methods: Patients will be included which are over then 18 years old, who underwent anorectal surgery of the benign pathology, requiring spinal anaesthesia, were admitted in this clinical randomized study, hospitalized in Hospital of Lithuanian University of Health Sciences Kaunas Clinics and agree to participate to this study (written settlement). All patients were implicitly divided in to 4 groups by the position will be operating (lithotomy or jack knife position and by American Society of Anaesthesiologists (ASA) clas I-II and III-IV). Technique of anaesthesia were strictly standardized by protocol. All patients were premedicated with oral diazepam 5mg and diclofenac 100mg 60min before operation. After arrival in the operating theater peripheral vein 18 or 20G catheter was inserted, infusion therapy were started with crystalloid 5-7ml/kg/hour. Standard monitoring was used, including noninvasive arterial blood pressure (BP), electrocardiography (ECG), heart rate, peripheral oxygenation. Circulatory changes were recorded impedance device. 2 single-neck sensors connected vertically on both sides of the neck just below the ears lobe. Another pair of sensors attached on both sides of the chest processus xiphoid axillary line level. Thorax allows a variable electri