27. IMPROVING SURGICAL PAIN pain, coupled with an appropri- MANAGEMENT WITH MULTIDISCIPLINARY ate selection of treatments for each CARE patient. Complex pain cases require multimodal as well as interdisci- INTRODUCTION plinary care. Coordination among healthcare providers before, during, For the last 2 centuries, morphine has been the and after a surgical procedure is single most relied-upon drug for the management of a critical component of successful acute surgical pain. Fortunately, modern advances operative pain management. in anesthesia and analgesia have revolutionized Somatic and visceral pain this pain management approach. Today, multidis- result from stimulation of sensory ciplinary treatment plans have been identified as receptors or nociceptors in response a principal factor in both modern-day pain control to noxious stimuli; they are dis- and optimization of recovery after surgery. Despite tinguished by the location of their numerous medical and technological advances, post- receptors and the nerve fibers surgical pain is often undertreated. An understand- that are stimulated. Somatic pain ing of the physiology and complex, multifaceted receptors are located within the nature of pain is necessary to identifying an optimal skin and respond to environmental treatment plan, which often involves multiple thera- cues such as sharp, focused, painful peutic modalities. This balanced analgesic approach, stimuli. Examples of this type of known as multimodal analgesia, utilizes a combina- pain include incisional or cutaneous tion of opioid and nonopioid analgesics that target burn-related pain. Visceral receptors different sites of the peripheral and central nervous are located in visceral organs system. The aim of multimodal analgesia is to opti- (bladder, ureter, small and large mize postoperative pain control while limiting the bowel, etc) and respond to internal total amount of opioid administered to the patient, cues such as dilation of the bowel thereby minimizing adverse drug effects. This or inflammation from infection. chapter will discuss recent advances in pain man- Visceral fibers are slow-conducting agement and perioperative care that can improve the unmyelinated C fibers that join quality of postoperative recovery and reduce mor- autonomic and somatic nerves bidity after major surgery. Figure 27-1. Transmission of pain signals entering the central nervous system. Visceral pain can either be localized PATHWAYS AND TYPES OF PAIN to the site of tissue damage or be The transduction of noxious stimuli involves horn neurons. Medications used to manage pain act sensed at a distant anatomic region from the source both the peripheral and central nervous systems. It at specific areas along this pathway to reduce the of tissue injury, a phenomenon called “referred begins with peripheral nociceptors, which transmit intensity of the pain experience. pain.” Neuropathic pain is related to the sensory signals along peripheral nerves through the dorsal The different types of pain include somatic, perception of pain associated with peripheral or root ganglia (Figure 27-1). Axons of myelinated A visceral, inflammatory-mediated, and neuropathic central nerves. Nerve injuries caused by stretching, and unmyelinated C fibers synapse in the dorsal pain. Each type responds to different treatment mo- compression, or cancer invasion are often the precur- horn of the spinal cord, and pain signals are trans- dalities; understanding their distinctions will aid sors to neuropathic pain, and may pose formidable mitted to the thalamus and cerebral sensory cortex in developing specific therapeutic interventions to treatment challenges. via the ascending spinothalamic tracts. Descending maximize patient benefit. Optimal pain manage- Inflammatory mediators have been identified modulation of pain is mediated through the dorsal ment requires a careful appraisal of the source of in pain pathways. Substance P, a neurotransmitter 103 27 IMPROVING SURGICAL PAIN WITH MULTIDISCIPLINARY CARE

involved in the perception of pain, is also a mediator TABLE 27-1 time of induction of general anesthesia. in the neuroinflammatory cascade. Interferons and PREOPERATIVE MEASURES TO ASSESS AND The goal of preemptive pain control is to blunt cytokines (interleukin-1, interleukin-6 and tumor CONTROL PAIN the physiologic response to surgery as well as necrosis factor-α) are proinflammatory mediators to decrease the level of overall pain. Specifically, thought to decrease the threshold for pain stimu- effective preemptive analgesia reduces the surgical • History and physical examination lation and increase the intensity of the response. nociceptor input (pain) while simultaneously pre- Interruption of the inflammatory cascade is a o specifics about pain: location, severity, quality of venting an ensuing sensitization of the nervous potential adjunct for achieving optimal pain control. pain, radiation, onset and duration, aggravating and system throughout the perioperative period. The mollifying factors, and associated symptoms efficacy of preemptive multimodal analgesia PREOPERATIVE PATIENT ASSESSMENT o history of chronic pain depends on the interruption of the transduction o medications: opioids, NSAIDs, anxiolytics, gabapentin, of noxious stimuli at multiple sites along the pain An adequate history and physical examination narcotics, antidepressants pathway. Sites targeted by preemptive analgesia are critical to identifying the cause of a patient’s o history of drug use and abuse include peripheral nociceptors, preganglionic pe- pain as well as ensuring that appropriate treatment ripheral nerves, the dorsal horn of the spinal cord, modalities are employed (Table 27-1). Assessment • Patient education and reassurance that pain will be and the sensory cortex and limbic system (see controlled of pain should include several factors: location, Figure 27-1). severity, quality, radiation, duration of onset, ag- • Consider anxiolytics: midazolam (1–5 mg) 10 minutes Adequate arterial perfusion and partial pressure gravating and mollifying events, and associated prior to procedure of oxygen are critical to tissue healing, and vaso- symptoms. The healthcare provider must ascertain • Preemptive pain control constriction is a threat to normal healing. Measures whether or not the patient experiences chronic pain o regional anesthesia with peripheral nerve blocks to control peripheral vasoconstriction should or takes chronic medications such as narcotics, non- be initiated prior to the operation and include steroidal antiinflammatory drugs (NSAIDs), anxi- o neuraxial blockade (spinal, lumbar epidural, and cessation of smoking; controlling fear, pain, and thoracic epidural) olytics, or gabapentin. Patients with chronic pain anxiety; correcting hypertension; maintaining or history of opioid use or drug abuse may have a o systemic medications (NSAIDs, opioids) normal circulating blood volume; and maintaining tolerance of narcotic-based pain medications and normothermia. Preoperative reassurance that pain may require substantially greater doses of narcotics NSAID: nonsteroidal antiinflammatory drugs will be treated aggressively should be a goal of all than opioid-naive patients. Conversely, others members of the operative team. Administration may limit the amount of pain medication they take of an anxiolytic at least 30 minutes before surgery because of fear of drug dependency. PAIN CONTROL AT EACH OPERATIVE STAGE has been shown to decrease both anxiety and post- Acute, severe, and undertreated pain is associ- operative pain throughout the first postoperative ated with many adverse systemic effects including Preoperative. The physiologic response to surgery week in a randomized placebo-controlled trial of increased myocardial oxygen demand, reduced involves a “sympathetic surge,” a profound acti- patients who had outpatient surgery under general functional residual capacity, hypoxemia, and vation of the sympathetic nervous system that is anesthesia. gastrointestinal ileus. Some patients with severe, thought to contribute to afferent pain signals. This The use of perioperative NSAIDs in preemp- poorly controlled operative site pain may develop stress response is a well-established sequence of tive analgesia is preferred over narcotics to limit long-term central sensitization. This condition physiologic and molecular events that include fever, adverse side effects (nausea, vomiting, urinary may serve as the basis for chronic pain syndromes tachycardia, tachypnea, hypertension, gastrointes- retention, cognitive dysfunction, respiratory de- wherein noxious stimuli are accompanied by an tinal ileus, hypercoagulability, protein catabolism, pression). The use of NSAIDs is often combined exaggerated pain response, or hyperalgesia, and and immunosuppression. Circulating cytokines and with infiltration of the wound with a long-acting painless stimuli are perceived as painful, a phe- neuroendocrine mediators are also involved. The local anesthetic (eg, bupivacaine). Continuation nomenon known as allodynia. response lasts approximately 3 to 4 days from the of NSAID analgesia for at least 24 hours after

104 IMPROVING SURGICAL PAIN WITH MULTIDISCIPLINARY CARE 27 surgery is considered essential in order to achieve TABLE 27-2 28 Postsurgical hematomas that form in anatomi- effective postoperative control of peripheral noci- cally confined areas such as the groin continually INTRAOPERATIVE MEASURES BY THE ceptive pain. In addition, NSAIDs may achieve a stimulate peripheral nociceptors, resulting in pain SURGEON TO CONTROL PAIN long-term effect by inhibiting sensitization of the that is difficult to control. Unless it is resorbed over central nervous system. time, a pain hematoma may require reoperation for • Preincision analgesia: subcutaneous injection prior to surical evacuation. Intraoperative. Optimal preemptive pain control operation at incision site, use Blockade of afferent pain signals not only blunts involves measures taken prior to the surgical o bupivacaine (10–30 mL of 0.25%), pain but also reduces the amount of postoperative incision, and continues into the postoperative narcotic required, ultimately improving the quality • Prevention of infection and systemic inflammatory of recovery. Intraperitoneal and intrapleural ad- period (Table 27-2). Injection of medications into cascade, includes the subcutaneous tissue underlying the intended ministration of local anesthetic has been shown to o preoperative antibiotics 60 minutes prior to incision control visceral pain better than systemic medi- incision site reduces postoperative analgesic re- (appropriate to operation) quirements. Long-acting local anesthetics such cation. Recent advances in minimally invasive as bupivacaine are most commonly used, but o expeditious surgery surgery have translated into smaller surgical ketorolac, tramadol, and morphine have also been o gentle tissue handling incisions, reduced stress response and narcotic re- used for preincisional analgesia. quirement, and decreased wound complications, o maintenance of normothermia Operative site infection is an established potent all of which lead to a more rapid postoperative stimulus for proinflammatory cytokines and o adequate tissue perfusion (minimizing peripheral recovery. vasoconstriction) chemokines. Prophylactic antibiotics are adminis- tered within 60 minutes of incision, re-dosed during o adequate tissue oxygen partial pressure Postoperative. Parenteral analgesics are commonly 26 major operations, and continued for 24 hours post- o judicious use of antibiotic irrigation administered postoperatively, because patients operatively. Operations undertaken for infectious are often restricted from oral intake after major o avoidance of fluid overload etiology, such as abscess, cholecystitis, appendicitis, surgery. However, fast-track rehabilitation is chal- and diverticulitis, should focus on control of the o different gloves, instruments, and possibly gowns lenging the surgical dogma that restricts oral pathologic source. Infectious complications can be prior to closure of incision intake for prolonged periods until passage of flatus minimized by expeditious surgery; gentle tissue • Meticulous hemostasis (avoidance of operative site or stool has been achieved. Opioid medications handling; maintenance of normothermia, partial hematoma), prevents (eg, morphine sulfate, fentanyl, Dilaudid [Abbott pressure of oxygen, and perfusion pressures; o visceral irritation Laboratories, Abbott Park, Ill]) are among the most judicious use of antibiotic irrigation; avoidance of common perioperative analgesics administered o hematoma formation. fluid overload; and changing gloves and instru- because of their time-tested efficacy. However, ments before wound closure. Sympatholytic effects • Intraoperative peritoneal or pleural administration of adverse side effects including sedation, nausea, of epidural anesthesia reduce the physiologic stress local anesthetics, use pruritis, and impairment of gastrointestinal motility, response to surgery, improve perfusion, reduce o bupivacaine (15 mL of 0.5% with 1:100,000 make preemptive analgesia an attractive alternative. hypoxemia, limit blood loss (thereby decreasing epinephrine; 2–5 mL per laparoscopic port site) or Multimodal perioperative analgesia using several transfusion requirements), counteract the prothrom- o ropivacaine (20 mL of 7.5 mg/mL; 4 mL per different drug mechanisms of action facilitates botic state of surgery, and optimize pain control and intercostal space) dose reductions in all the pain medications used secondary sensitization. and early discontinuation of narcotic analgesics, Meticulous surgical technique and hemostasis providing better analgesia while minimizing the are fundamental aspects of postoperative pain unwanted side effects of any one drug class. control. Blood within the intraperitoneal cavity The method of narcotic delivery impacts irritates the peritoneum and causes visceral pain. the success of pain control. As needed, 105 27 IMPROVING SURGICAL PAIN WITH MULTIDISCIPLINARY CARE nurse-administered medication may result in unac- SUMMARY Emphasis on multidisciplinary approaches to pain ceptable gaps in postoperative analgesia and fail to management can significantly improve pain care plans establish a therapeutic baseline level of pain control. Comprehensive preoperative assessment by the beyond pharmacologic measures. Coordination among Intravenous patient-controlled anesthesia, which surgeon and anesthesiologist is the key first step to the primary team, anesthesia, acute pain nursing, phar- allows timely patient-directed narcotic administra- optimizing operative outcomes. Many periopera- macy, mental health, physical and rehabilitative medi- tion, has a continuous baseline dosing function to tive measures fundamental to optimizing patient cine, and the family is a vital component of any inpa- limit the peaks of pain intensity in the postopera- outcomes are intuitive: gentle tissue handling, tient pain care activity. For example, although a dense tive period. Multiple studies have documented minimizing blood loss, preventing hypothermia, block of a patient’s upper extremity may provide excel- improved pain outcomes with patient-controlled administering prophylactic antibiotics within 1 hour lent pain relief, if the patient has no motor function in anesthesia as compared to nurse-titrated medica- of incision, judicious antibiotic irrigation of contami- the limb to participate in physical therapy, this modality tion, but no consensus has been reached about nated sites, minimizing peripheral vasoconstriction, may not be in the best interest of the patient’s overall improvements in postoperative complications. limiting use of drains, ensuring high arterial partial recovery and health. Effective acute pain management Transdermal narcotic administration provides more pressure of oxygen, minimizing fluid overload, requires the existence of an acute pain service staffed consistent administration of medication but has a limiting the physiologic stress response to surgery, with motivated professionals dedicated to the effective delayed onset of action. and optimizing control of pain. treatment of pain using a multimodal approach.

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