الفهرس 
INTRODUCTIONOnly 14 pages are availabe for public view
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Abstract
The pain following thoracotomy is one of the most intense pains ever described by the patients as the surgery involves muscle-dividing incision of the chest wall, which moves during respiration. Normal and deep breathing results in stretching of the skin incision. This stretching during deep inspiration and active exhalation results in severe pain and it results in reduced lung volume and capacities and failure to cough resulting in retention of secretion, airway closure leading to atelectasis and pneumonia. It also can lead to hypoxaemia, hypercapnia and respiratory failure, especially in patients with pre-existing lung disease. Thus proper control of post thoracotomy pain in addition to providing comfort for the patient facilitates chest physiotherapy, effective expectoration and early ambulation.
Also acute pain causes increased sympathetic tone accompanied by increased myocardial oxygen demand, increased afterload, myocardial dysfunction and arrhythmias. Poor analgesia may also result in a delay in patients’ mobilization with increased incidence of deep venous thrombosis and pulmonary embolism, longer intensive care unit and overall hospital stay.
Although currently various methods of post thoracotomy pain relief are available none has matched the requirement of an ideal pain relief technique. Regional techniques have received much attention because they are associated with less sedation and early ambulation.
Epidural analgesia has emerged as the analgesic technique of choice for postoperative thoracotomy pain management. In addition to improved pain control, epidural analgesia can improve patient outcome by attenuating detrimental perioperative physiology.
The aim of this work was to compare the effect of different doses of epidural ketamine combined with bupivacaine as regard the analgesic efficacy, duration and side effects in patients undergoing thoracotomy.
The present study was carried out in Department of Anaesthesia, Cardiothoracic surgery department in Alexandria Main University Hospitals on forty five adult patients of both sexes, classified as ASA physical status II or III, scheduled for elective thoracotomy.
Exclusion criteria
1. Any contraindication for epidural analgesia.
2. Cardiac diseases.
3. Metabolic diseases (as hepatic, renal, diabetic, endocrinal).
Patients were randomly categorized into three equal groups (fifteen patients in each group) after approval of Local Ethical Committee and with written informed consent from patients:
Patients in the first group (group I): received a thoracic epidural injection of 0.25% bupivacaine 25 mg (total volume of injection is 10 ml of 0.25% bupivacaine).
Patients in the second group (group II): received a thoracic epidural injection of 0.25% bupivacaine 25 mg with ketamine 0.3 mg/kg (total volume of injection is 10ml of 0.25% bupivacaine and ketamine 0.3 mg/kg).
Patients in the third group (group III): received a thoracic epidural injection of 0.25% bupivacaine 25mg with ketamine 0.5mg/kg (total volume of injection is 10ml of 0.25% bupivacaine and ketamine 0.5mg/kg).
Preoperative evaluation will be carried out through proper history taking and clinical examination. Routine laboratory investigations was performed including complete blood count, coagulation profile, fasting blood sugar, renal and liver function tests, pulmonary function tests and plain X-ray chest. Moreover all patients were taught how to express pain intensity postoperatively using visual analogue score.
On the day of the surgery, all patients were premedicated with 7.5 mg midazolam orally one and half hour before induction.
Before induction of general anaesthesia, identification of epidural space was performed while the patient was in the sitting position, then a 3ml of 2% lidocaine was injected as local infiltration under complete aseptic technique. Epidural catheter was inserted using 17-gauge Touhy needle at thoracic interspaces (T7-T8).
All patients were then subjected to general anaesthesia using fentanyl 1µg/kg; propofol 2.5mg/kg and tracheal intubation was facilitated by rocuronium 0.6mg/kg. Anaesthesia was maintained by inhalation of isoflurane 1-1.5%, incremental doses of rocuronium and intravenous fentanyl 1µg/kg was titrated according to hemodynamic changes. By the end of surgery, general anaesthesia was terminated by discontinuing the inhalational anaesthetic and neuromuscular blockade was reversed using neostigmine and atropine and guided by nerve stimulator.