الفهرس | Only 14 pages are availabe for public view |
Abstract Pain control is the primary concern of patients scheduled for surgery to obtain an optimal outcome after surgery. The stress response consists of complex neurohumoral , immune response to injury and associated with hormonal / metabolic response. Stress response saves the body from lifethreatening injury, but it may need to be controlled with medications or other techniques to keep it from causing new illnesses or complications. Pre-emptive analgesia involves the introduction of an analgesic regimen before the onset of noxious stimuli, with the goal of preventing sensitization of the nervous system to subsequent stimuli that could amplify pain. It works by through reducing the nociceptive input (Minimally invasive surgery, LA, NSAIDS, Opioids), attenuating transmission (Blocks, Spinal, Epidural) and modulate mechanisms that underlie sensitization (NMDA blockade, Opioids). Patient controlled analgesia (PCA) offers potential unique benefits (reliable analgesic effect,improved patient autonomy,flexible adjustment to individual needs, etc) whether or not they truly offer significant clinical advantages as the overall effectiveness of any analgesic technique depends on Summary 103 both the degree of pain relief that can be achieved and the incidence of side effects or complications. Pain neurobiology is a complex of dynamic interrelated systems and unimodal analgesia cannot be sufficient to provide optimal pain management so multiple modes should improve outcome by its additive & synergistic effects of actions. Multimodal pain management principles through action on multiple sites, multiple mechanisms, avoid opioid dominance, multimodal lower doses of used drugs to reduce adverse effects, prevent toxicity of drugs . Epidural analgesia is considered as the gold standard analgesic technique for major surgery. It has the potential to provide suitable patients with complete dynamic analgesia for as long as the epidural is continued. Spinal analgesia and nerve blocks offer simplicity, yet efficacy remain an issue (work best supplementing other analgesic techniques). IV opioids form the cornerstone of perioperative analgesia with excellent results. However, IV opioids may cause pruritis, nausea and vomiting, urinary retention and respiratory depression. Nonsteroidal anti-inflammatory drugs (NSAIDS) and cyclooxygenase (COX) inhibitors were initially promising, yet serious questions persist regarding safety (alteration in gastric Summary 104 mucosal barrier and renal tubular function, inhibition of platelet aggregation, wound infection and thromboembolic complications). Alpha adrenergic agonists may enhance postoperative analgesia and hemodynamic stability (potentially decreasing myocardial ischemia) yet may cause excessive postoperative sedation and aggravate postoperative hemodynamic instability via bradycardia or decreased systemic vascular resistance. Other potentially useful adjuvants used as apart of perioperative multimodal analgesia including benzodiazepines, propofol, N-methyle –D-aspartate receptor antagonist, corticosteroids, anticonvulsant drugs,antidepressant drugs and local anesthetic infiltration . Perioperative analgesia is very important to improve patient comfort, decrease somatic & autonomic responses to airway manipulation, improve hemodynamic stability, lower requirements for inhaled anesthetics, decrease postsurgical organ dysfunction & complication, early recovery and decrease hospital stay |