Dexmedetomidine,Ketamine and Their Combination to Bupivicaine on Thoracic Epidural Analgesia

Breast cancer is the most common cancer diagnosed in Egyptian women. Many modalities are used in the treatment of breast cancer including chemotherapy, radiotherapy or surgical intervention. Nowadays, surgical intervention is more conservative.Modified radical mastectomy (MRM) is the standard surgical procedure of choice in these patients. MRM is usually performed under general anesthesia, almost always combining intravenous and inhalational agents.The drawback of general anesthesia includes inadequate pain control due to lack of analgesia, high incidence of nausea and vomiting, stress of anesthesia and surgery, and increasing the length of hospital stay.Post mastectomy pain is a pain which occur following breast cancer procedures, particularly those operations that remove tissues in upper outer quadrant of breast and/or axilla. This pain can be severe enough to cause long term disabilities and interfere with sleep, performance of daily activities. Also, it can seriously affect the patient mood, and social functions.

Thoracic epidural analgesia (TEA) faces growing interest as adjuvant anesthetic and post-operative analgesic regimen. the use of adjuvant drug with local anesthetic is essential as it prolongs the duration of action, gives better success rate and increases patient satisfaction.

Ketamine, an N-methyl-D-aspartate (NMDA) antagonist, not only abolishes peripheral afferent noxious stimulation, but it can also prevent the central sensitization of nociceptors. When added to epidural local anesthetics, ketamine appears to have adjuvant effects. Dexmedetomedine is a selective, α2-adrenoceptor agonist with analgesic potency, sedative properties, and minimal respiratory depression when used as an adjuvant to regional anesthesia.

Inclusion criteria

• Patients scheduled for modified radical mastectomy.
• ASA Physical status I, II and III.

Exclusion criteria

• Patients' refusal.
• Uncooperative patients & severe psychiatric illness (cannot evaluate their own pain intensity using visual analogue scale (VAS).
• Patients with history of drug allergy.
• severe renal or liver impairment, unstable ischemic heart disease
• Any contraindications to epidural analgesia (coagulopathy, recent -less than 1 week-treatment with thrombolytic or potent antiplatelet drugs as clopidogrel, and local infection).