الفهرس | Only 14 pages are availabe for public view |
Abstract The prone position has been described and developed as a result of requirement for surgical access. In prone position, increased intra-abdominal pressure forced blood from inferior vena cava into extradural venous plexus, resulting in increased bleeding and poor surgical field during spinal surgery. Patient presenting for surgical procedures of the spine present a challenge to the anesthesiologists. The anesthetic management depends on the operative site, spine pathology, surgical approach , the anesthesiologists experience and support system used which influences not only the incidence of complications but also the alterations in cardiovascular and respiratory physiology which occur when a patient is moved from supine to prone position in the operating theatre. Isoflurane exists as a clear, non flammable liquid at a room temperature and has a pungent, ethereal odour . Its intermediate solubility in blood combined with a high potency permits rapid onset and recovery from anesthesia . Total intravenous anesthesia is defined as an anesthetic technique where hypnosis, analgesia and muscle relaxation are provided by intravenously administered drugs without the use of anesthetic vapors or gases with management of airway and adequate alveolar ventilation by oxygen/air. Propofol is an intravenous anesthetic that has been used for both induction and maintenance of general anaesthesia. It is more expensive than thiopentone or methohexitone, but has achieved great popularity because of its favorable recovery characteristics and its antiemetic effect. The objectives of this study was to determine the relative cardiovascular stability, changes in arterial blood gases and pulmonary compliance in the prone position, comparing these changes during inhalation anesthesia with isofluran versus total intravenous anesthesia with propofol. This study was carried out on 80 adult patients of either sex aged 20-50 years old scheduled for spinal surgery in Mansoura University Hospitals. The patients were randomly assigned by closed envelope method to either inhalation anesthesia or TIVA . Patients were turned prone using Wilson frame , monitoring was done using 3-lead ECG, pulse oximetry, capnography and invasive arterial blood pressure . HR, MAP and CVP were recorded 5 minutes following induction of anesthesia and immediately after the patients truned prone, then 10 minutes, 20 minutes, 30 minutes, one hour, 2 hours and at end of surgery. Also arterial blood gases were meassured at 5 minutes following induction of anesthesia and immediately after the patients truned prone, then 30 minutes, one hour, 2 hours and at end of surgery. Dynamic lung compliance was calculated by deviding tidal volume by peak airway pressure at 5 minutes following induction of anesthesia and immediately after the patients truned prone, then 30 minutes, one hour, 2 hours and at end of surgery. |