PERIOPERATIVE PAIN MANAGEMENT. IN ANESTHESIA

PERIOPERATIVE PAIN MANAGEMENT

1. PERIOPERATIVE PAIN MANAGEMENT AND ENHANCED RECOVERY AFTER SURGERY MONGER MWAMBA

2. Factors Facilitating Enhanced recovery After Surgery (ERAS) Preadmission counseling No bowel preparation Fluid and CHO-loading/ no fasting No premedication No NG tubes Mid-thoracic epidural anesthesia/analgesia Short-acting anesthetic agent Avoidance of sodium/fluid overload Short incisions, no drains

3. Factors Facilitating ERAS Warm air body heating in operating room Routine mobilization care pathway Nonopiate oral analgesics/NSAIDs Prevention of nausea and vomiting Stimulation of gut motility Early removal of catheters Perioperative oral nutrition Audit of compliance/ outcomes

4. Multimodal interventions to attenuate surgical stress response Surgical stress Pain Catabolism immuno-dysfunction nausea/vomiting Ileus fatigue Surgical stress Impaired pulmonary function increased cardiac demands coagulatory-fibrinolytic dysfunction cerebral dysfunction Fluid homeostasis alteration sleep disturbances

5. Multimodal interventions to attenuate surgical stress response Pharmacological intervention Nonopioid, mulitmodal analgesia Antiemetics Glucocorticoids (antiinflammatory, antiemetic, analgesic) Statins β blockade α2 agonists Insulin (glycemic control/antiinflammatory) anabolic agents (growth hormone, androgens) Nutrition Systemic local anesthetics Afferent neural blockade local infiltration anesthesia Peripheral nerve blocks, epidural/spinal anesthesia/analgesia Other interventions Prevention of intraoperative Hypothermia Pre- and intraoperative fluid Optimization Preoperative carbohydrate Minimally invasive surgery

6. Risk Factors for persistent postsurgical pain Preoperative : Anxiety Catastrophizing Depression Genes Impaired pain modulation Life trauma Other pain states Sleep deprivation Stress

7. Risk Factors for persistent postsurgical pain Intraoperative and postoperative healing period Nerve injury Tissue ischemia Surgical technique Anesthetic technique Pain facilitation or amplification Proinflammatory state Delayed postoperative period Postoperative pain-hyperalgesia Chemotherapy or radiation therapy Repeat surgery Psychosocial factors

8. Anesthetic Management–Related Factors Contributing to Enhanced Recovery a) Preoperative period : Patient education Preoperative risk assessment and optimization of functional status : routine use of β blockers in low risk patients increases risk for stroke perioperative β blockers should be continued in patients already receiving this therapy Perioperative statins decrease postoperative CVS complications and should not be abruptly discontinued

9. Smoking & Alcohol Cessation: Preoperative cessation of smocking reduces pulmonary and wound healing complications by 40% Psychological and pharmacological strategies stop excessive alcohol consumption and reduce the risk of alcohol withdrawal Food and fluid intake : Preoperative fasting and surgical stress induce insulin resistance patients who are not allowed to drink fluids after an overnight fast and patients who receive a bowel preparation experience dehydration, which may increase discomfort and cause drowsiness and orthostatic lightheadedness

10. Hydration and energy supply moderate postoperative insulin resistance. clear fluids up to 2 h prior to induction of anesthesia in patients at low risk for pulmonary aspiration Preoperative carbohydrate drinks (one 100-g night before surgery and a second 50-g dose 2–3 h before induction of anesthesia) : 1. reduce insulin resistance, hunger, fatigue and PONV 2. Positively influences immune status 3. attenuates postoperative nitrogen loss and the loss of skeletal muscle mass

11. b) Intraoperative period Antithrombotic prophylaxis : Reduce perioperative venous thromboembolism Pneumatic compression devices Anticoagulants Antibiotic prophylaxis : ≤ 1h before skin incision to reduce SSI Based on their plasma half-lives, repeat Abx for prolonged surgeries Stop Abx prophylaxis 24h after surgery /48 h after cardiothoracic surgery

12. Strategies to Minimize the Surgical Stress Response: surgical stress response:neuroendocrine, metabolic, and inflammatory changes : Reversible transient insulin resistance :reduced peripheral glucose uptake and increased endogenous glucose production Surgical stress response ∞ intensity of the surgical stimulus; amplified by hypothermia and psychological stress; attenuated by deeper planes of general anesthesia, neural blockade, and reduction in the degree of surgical invasiveness.

13. Strategies to reduce surgical stress response : Minimally invasive surgery Regional anesthesia/analgesic techniques Intravenous lidocaine infusion β- Blockade Therapy Intravenous α 2 -Agonist Therapy

14. a) Minimally Invasive Surgery: Laparascopy :↓ risk of SSI ; ↓length of hospital stay; less morbidity in elderly patients b) Regional Anesthesia/Analgesia Techniques: Neuroaxial blockade blunts metabolic and neuroendocrine stress response to surgery To be effective, blockade must be established before incision and continued postoperatively Thoracic epidural blocked : major thoracic/abdominal surgeries → analgesia, facilitate mobilization and physical therapy, and decrease incidence and severity of ileus Lumber epidural anesthesia : No adequate segmental analgesia for abdominal incision L.L sensory and motor blockade → delay mobilization,↑ risk of falls urinary catheter(UTIs);

15. Opioids sparing epidural block : ↓systemic related S/E → earlier mobilization ; early resumption of oral nutrition; attenuates loss of body mass Neural blockade minimizes postoperative insulin resistance, attenuating postoperative hyperglycemic response and facilitating utilization of exogenous glucose, thereby preventing postoperative loss of amino acids and conserving lean body mass

16. Spinal anesthesia : delayed recovery due to prolonged motor blockade smaller doses of intrathecal L.A ( lidocaine, 30–40 mg; bupivacaine, 3–7 mg; or ropivacaine, 5–10 mg ) with lipophilic intrathecal opioids ( fentanyl, 10–25 mcg, or Sufentanil, 5–10 mcg ) can prolong postoperative analgesia and minimize the motor block without delaying recovery from anesthesia Spinal opioids S/E :nausea, pruritus, urinary retention Intrathecal clonidine : less urinary retention than morphine

17. Continuous peripheral nerve blocks (CPNB): block afferent nociceptive pathways Reduce S/E of opioids CPNB after TKA facilitates earlier discharge and rehabilitation Lumber plexus block + sciatic nerve block → ↓: hospital stay, postoperative urinary retention and ileus TAP block : facilitate postoperative analgesia and early return of bowel function Rectus abdominis block for midline incision L.A wound infusions improve pain control and reduce need for opioids

18. C. Intravenous Lidocaine Infusion bolus of 100 mg or 1.5–2 mg/kg, then Infusion : 1.5–3 mg/kg/h or 2–3 mg/h Has analgesic, antihyperalgesic, and antiinflammatory properties reduce requirements for opioids and general anesthetic agents Provide satisfactory analgesia facilitate early return of bowel function accelerate hospital discharge Indications : colorectal surgery, retropubic prostate surgery

19. D. β- Blockade Therapy Blunt sympathetic response during laryngoscopy and intubation Attenuate the surgical stress-induced increase in circulating catecholamines Prevent perioperative cardiovascular events in at-risk patients undergoing noncardiac surgery Maintain hemodynamic stability during the intraoperative period and during emergence from anesthesia ↓requirements of volatile anesthetics thus ↓MAC May have opioid sparing effect Anticatabolic →↓adrenergic stimulation → ↓energy requirements Positive protein balance when combined with parenteral nutrition in critically ill patients

20. E. Intravenous α 2 -Agonist Therapy clonidine and dexmedetomidine Anesthetic and analgesic properties Clonidine : decreases postoperative pain reduces opioid consumption and opioid-related side effects prolongs neuraxial and peripheral nerve local anesthetic blockade.

21. Use of Short-Acting Intravenous & Inhalation Agents a) Intravenous Anesthetics Propofol: deep sedation general anesthesia induction reduce risk of PONV b) Inhalational agents Desflurane and sevoflurane: shorten anesthesia emergence reduce length of stay in PACU decrease recovery-associated costs Increase risk for PONV

22. Nitrous oxide anesthetic- and analgesic-sparing effects, rapid pharmacokinetic profile, and low cost Frequently administered with other inhalation agents. Increase risk of PONV c) Opioids fentanyl, alfentanil, and remifentanil NB : intraoperative administration of remifentanil to patients who will experience extensive postoperative pain is associated with opioid-induced hyperalgesia, acute opioid tolerance, and increased analgesic requirements during the postoperative period.

23. D. Muscle Relaxants short-acting NMBDs : succinylcholine intermediate-acting NMBDs : rocuronium, atracurium, cisatracurium minimize the risk of unplanned and prolonged muscle relaxation facilitate tracheal intubation while decreasing the risk of residual blockade during anesthesia recovery .

24. Maintenance of Normothermia anesthetic-induced thermoregulatory inhibition, exposure to cold OR environ and intraoperative heat loss predispose to hypothermia Perioperative hypothermia increase sympathetic discharge and inhibit immune cellular response, increasing cardiovascular morbidity and wound infection risk Hypothermia increases risk of bleeding and transfusion Hypothermia decreases metabolism of anesthetics hence increase recovery time

25. Maintenance of Adequate Tissue Oxygenation Surgical stress leads to impaired pulmonary function and peripheral vasoconstriction, resulting in arterial and local tissue hypoxemia Supplemental oxygen Ensuring complete recovery from NMBDs reduces postoperative hypoxemia Intraoperative and postoperative (up to 2h) FiO2 ≥80% increases arterial and subcutaneous O2 tension, ↓rate of wound infection, and lower incidence of PONV R.A techniques decrease SVR improving superficial and deep peripheral tissue perfusion and oxygenation early mobilization and physiotherapy improve postoperative central and peripheral tissue oxygenation.

26. PONV Prophylaxis PONV : delay early feeding and recovery from surgery

27. Goal-Directed Fluid & Hemodynamic Therapy The concept of goal-directed fluid therapy is based on the optimization of hemodynamic measures such as HR,BP,SV, pulse pressure variation, and stroke volume variation Liberal fluid administration and sodium excess lead to fluid overload, increase postoperative morbidity, and prolong hospitalization. Effects of fluid overload : anastomotic leakage pulmonary edema pneumonia wound infection postoperative ileus reduced tissue oxygenation increases body weight by 3–6 kg and may impair postoperative mobilization.

28. Minimizing perioperative extracellular fluid losses: limited preoperative fasting avoidance of mechanical bowel preparation minimally invasive surgical techniques surgery early postoperative enteral nutrition isotonic crystalloid : replace extracellular losses iso-oncotic colloids : replace intravascular volume

29. Physiologically based first-line fluid replacement for goal-directed therapy Physiological Requirement Replace with Amount Extracellular Insensible perspiration Crystalloids Closed abdomen 0.5 mL/kg/h Open abdomen 1 mL/kg/h Urine production Crystalloids Measured output Intravascular Blood loss Colloids Estimated losses Further preload deficit Colloids According to clinical estimation

30. c ) POSTOPERATIVE PERIOD Immediate Postoperative Care Minimize postoperative shivering PONV treatment Multimodal analgesia Strategies to Facilitate Recovery on the Surgical Unit Organization of Multidisciplinary Surgical Care Optimization of Analgesia to Facilitate Functional Recovery Strategies to Minimize Postoperative Ileus

31. c) POSTOPERATIVE PERIOD Immediate Postoperative Care a) Minimizing postoperative shivering Primary cause –hypothermia Effects of postoperative shivering : ↑oxygen consumption ↑catecholamine release ↑ cardiac output heart rate and blood pressure ↑ intracerebral and intraocular pressure ↑morbidity in elderly and ↑stay in PACU

32. efficacy of thermoregulation decreases with aging, and hypoxia can directly inhibit shivering Thus shivering is uncommon in elderly and hypoxic patients Treatment of postoperative shivering : meperidine clonidine tramadol prevention of hypothermia -most efficient strategy .

33. B. PONV Treatment R/O medical and surgical causes of PONV Prompt pharmacological treatment of PONV C. Multimodal Analgesia NSAIDs ( reduce opioid requirement by 30%) increase the risk of gastrointestinal and postoperative bleeding decreases kidney function increase the risk of anastomotic leakage after colorectal surgery impair wound healing. Acetaminophen( analgesic effect 20 – 30% less than NSAIDs ) Efficacy improves when combined with NSAIDs Hepatotoxic

34. Opioids systemic opioids remains a cornerstone in the management of surgical pain patient-controlled analgesia (PCA) provides better pain control, greater patient satisfaction, and fewer opioid side effects Tramadol (partial opioid agonist) : increased incidence of PONV Epidural analgesia excellent analgesia blunts the stress response associated with surgery decreases postoperative morbidity attenuates catabolism accelerates postoperative functional recovery thoracic epidural analgesia provides better static and dynamic pain relief low doses of local anesthetic via thoracic epidural infusion avoids lower extremity motor blockade that may delay postoperative mobilization and recovery.

35. Peripheral nerve block Single-shot /continuous peripheral nerve blocks Accelerate recovery from surgery , improve analgesia and patient satisfaction Opioid sparing effect of nerve blocks minimizes the risk of opioid-related side effects Local anesthetic wound infusion Factors affecting efficacy of L.A wound infusion: Type concentration and dose of local anesthetic type of catheter and catheter placement technique mode of local anesthetic delivery incision location dislodgment of the catheter during patient mobilization.

36. Strategies to Facilitate Recovery on the Surgical Unit Organization of Multidisciplinary Surgical Care Optimization of Analgesia to Facilitate Functional Recovery Strategies to Minimize Postoperative Ileus

37. Organization of Multidisciplinary Surgical Care surgeon, nurse, anesthesiologist, nutritionist, and physiotherapist Comfortable chairs and walkers : to encourage patients to sit, stand, and walk. Encourage patients to sit the evening following surgery, and ambulate starting the next day for a minimum of 4–6 h each day. Encourage physical and deep breathing exercises for bedridden patient

38. B. Optimization of Analgesia to Facilitate Functional Recovery optimal mobilization and dietary intake depend upon adequate analgesia well-organized, well-trained, highly motivated acute pain service (APS) and surgical nursing workforce Utilization of procedure-specific clinical protocols to optimally manage analgesia and related side effects Anesthesiologist and APS, must identify and employ the optimal analgesic techniques tailored to the specific surgical procedure patient must be comfortable ambulating and performing physiotherapy, with minimal side effects such as lightheadedness, sedation, nausea and vomiting, and leg weakness.

39. C. Strategies to Minimize Postoperative Ileus delays enteral feeding, causes patient discomfort, and prolongs postoperative hospital stay . Mechanisms that contribute to ileus : sympathetic inhibitory reflexes local inflammation caused by surgery postoperative opioid analgesia NB: NGTs – do not speed recovery of bowel function ; increase pulmonary morbidity due to increased risk of pulmonary aspiration

40. Excessive perioperative fluid administration commonly causes bowel mucosal edema and delays postoperative return of bowel function. Multimodal nonopioid analgesia shorten duration of postoperative ileus Continuous epidural L.A infusion improve recovery of bowel function by suppressing inhibitory sympathetic spinal cord reflexes Thoracic epidural analgesia (L.A + small doses of opioids ) reduce incidence of ileus and improves pain relief Minimally invasive surgery decreases surgical stress and inflammation, resulting in a faster return of bowel function

41. Laxatives ( milk of magnesia , bisacodyl etc .) reduce postoperative ileus duration Prokinetics (e.g metoclopramide) Neostigmine increases peristalsis ;↑ incidence of PONV Postoperative chewing gum stimulates gastrointestinal reflexes, decreasing ileus duration Peripheral opioid μ- receptor antagonists ( methylnaltrexone and Alvimopan ) minimize adverse effects of opioids on bowel function without antagonizing opioid analgesia