Pain Management of the Breast Cancer Surgery Patient

Prehospital Setting

The initial phase of perioperative pain management begins in the clinic with thorough preoperative assessments and patient education. Preoperative preparation starts with consideration of the patient’s pathology and anticipated surgery, but in order to obtain optimal outcomes should take a comprehensive approach including functional, nutritional, and medical assessments. ERAS protocols implement strategies to get patients back to their functional baselines; hence, it is critical to understand functional deficits or limitations prior to surgery to set appropriate expectations and aid in recovery.

Nutritional optimization is critical for appropriate surgical outcomes and may be implicated in enhanced oncologic outcomes in breast cancer as well. Identification of preoperative malnutrition is paramount to prevent adverse outcomes, as malnutrition has been linked to immunosuppression, delayed wound healing, and higher mortality. Poor wound healing is directly linked to prolonged postoperative pain as well as patient dissatisfaction. From an oncologic standpoint, among patients with metastatic breast cancer, sarcopenic patients have demonstrated higher rates of chemotoxicity and shorter times to progression, highlighting the importance of screening for both calorie and protein malnutrition. In order to mitigate this risk, oncologic guidelines suggest a dietary protein intake target of 1 to 2 g protein/kg/day. In contrast, obesity in breast cancer patients predicts higher rates of surgical complications and increased risk of local recurrence. Beyond assessment of body mass index (BMI), recent changes in weight, reduced dietary intake, or albumin <3.0 g/dL should trigger further nutritional evaluation and possible dietary intervention, per the Perioperative Nutrition Screening (PONS) assessment tool.

In select at-risk patients, further nutritional assessment should be considered and may include preoperative micronutrient and metabolic evaluation ( Fig. 38.1 ). Because of its role as a neuromodulating antioxidant, the potential role of vitamin C has been explored in a number of studies focused on extremity trauma and the orthopedic perioperative setting, and supplementation with vitamin C has shown some success in reducing rates of pain syndromes. This relation has not been established in breast cancer surgery patients but could be considered on a case-by-case basis. Breast cancer patients particularly are at risk for vitamin D deficiency and bone loss. Evaluation of the need for calcium and vitamin D supplementation should be considered to prevent the musculoskeletal complaints associated with their cancer and anticancer treatments. In any operative candidate, particularly those at risk for malnutrition, zinc deficiency should be considered, as this important antioxidant and antiinflammatory factor is critical for wound healing and immunologic modulation. Lastly, medical workup for anemia and iron deficiency is critical in these at-risk patients, and appropriate patient optimization should be tailored with a multidisciplinary team prior to surgery.

Postoperative nausea and vomiting (PONV) is a common and incapacitating complication of perioperative anesthesia, occurring in approximately 30% of adults undergoing general surgical procedures. In the preoperative setting, identifying personal history of PONV, as well as identifiable risk factors such as female gender, nonsmoking status, or history of motion sickness, can facilitate both prevention and management of this phenomenon. A 2018 retrospective trial described a significant benefit in PONV control through the adoption of ERAS protocols in total mastectomy patients; by limiting opioid medications and providing preoperative scopolamine patches to patients identified preoperatively to have a history of PONV, the ERAS group demonstrated a significant reduction in PONV incidence (28% vs. 50%, P < 0.001). The prophylactic use of dronabinol and prochlorperazine together has also demonstrated significant improvements in rates of PONV in breast surgery cohorts. In high-risk populations, we suggest prophylactic use of these medications starting 2 days prior to surgery ( Fig. 38.1 ).

Chronic pain patients represent a particularly challenging population for perioperative pain control. Given their higher baseline pain scores, physicians should avoid routine application of ERAS protocols, and instead use tailored, multimodal pain strategies. Furthermore, chronic pain patients who take opioid medications have higher postoperative pain scores and longer times to pain resolution. Setting realistic expectations, with acknowledgment of the potential risk for a higher than normal postoperative pain experience, is instrumental to achieving patient satisfaction and developing a plan that is appropriate to both the physician and patient. Preoperative pain assessment and planning should be carried out via an interdisciplinary approach using multimodal therapies, though with the understanding that tolerance and dependence in chronic opioid users may curtail complete nonopioid plans. Patient-centered interviewing is an important strategy for setting realistic expectations and developing a reasonable multimodal plan, while minimizing opioid as tolerated by the patient.

Regardless of the type of surgery, preoperative education is essential to promote patients’ understanding and participation in their care. Setting reasonable expectations for the patient’s perioperative course and expected recovery time encourages patient compliance with the ERAS early mobilization and pain control protocols, with the ultimate goal of reducing hospital length of stay and enhancing patient satisfaction. In a randomized controlled trial focused on outpatient surgery, patients who received preoperative education about their perioperative pain plan and narcotic side effects were significantly less likely to fill narcotic prescriptions compared to a cohort of patients who did not receive the same education. Preoperative prophylactic multimodal analgesia has also been shown to significantly reduce postanesthesia care unit (PACU) narcotic use and pain scores. Similar studies utilizing preemptive medication strategies have similarly shown decreased total narcotic requirements, as well as improved postoperative pain and satisfaction scores. In our practice, a multimodal approach with oral acetaminophen and celecoxib is prescribed at the preoperative visit. These regimens are inexpensive and limit narcotic use in an effort to improve pain control, limit PONV, and reduce the contribution to the nation’s opioid crisis ( Fig. 38.1 ).

In order to prevent adverse outcomes, risk factors identified in the patient assessment should be targeted, and detailed counseling should be performed. Active smoking is associated with poor wound healing and increased pulmonary complications, and therefore smoking should be stopped at least 1 month prior to an operation. Evidence-based strategies for perioperative smoking cessation include behavioral support, nicotine replacement therapy, and pharmacotherapy. Similarly, alcohol abuse has been linked to a higher perioperative stress response, poor wound healing, cardiac complications, and prolonged bleeding times. One-month preoperative alcohol abstinence has been associated with a significant reduction postoperative morbidity and should be considered a standard for preoperative counseling. Patients should also be educated about how to prepare for surgery on the day before surgery. The American Society of Anesthesiology recommends 6 hours of fasting from solid foods, allowing a clear liquid diet until 2 hours before surgery. ERAS protocols now often recommend “oral preload,” the concept of consuming carbohydrate-rich fluids the night before and morning of surgery to prevent dehydration and to promote a metabolically fed state. This not only helps reduce the metabolic burden of surgical stressors, but also alleviates patient hunger and anxiety. Postoperative pulmonary complications (PPCs) are leading causes of morbidity and mortality, and postoperative incentive spirometry use promotes deep breathing to prevent PPCs. Preoperative education on proper incentive spirometry use and deep breathing exercises can set up the use of this important tool as an expectation. Lastly, drain placement in breast and axillary surgery is not uncommon. Proper education on drain management prevents postoperative drain-related complications and increases patient satisfaction.

Intraoperative Management

Mindful intraoperative management requires the coordination of the anesthesiologist, surgeon, and entire operative team to promote safe operative conditions and optimize patient conditions for a better postoperative experience. This entails the anesthetic and surgical consideration for tissue injury and expected postoperative inflammation. Consideration of these factors allows for the employment of proper anesthetic techniques to limit pain and PONV. Furthermore, the appropriate management of intraoperative fluid and temperature regulation is critical for perioperative outcomes and postoperative patient experiences. Preoperative premedication is also an important strategy to reduce perioperative pain. As described earlier, acetaminophen and celecoxib provide multimodal analgesia and help reduce perioperative narcotic use. Benzodiazepine premedication prior to general anesthesia is widely used due to its ability to reduce preoperative patient anxiety and produce anterograde amnesia. Preoperative midazolam has also been shown to reduce pain scores at the time of PACU discharge and has the added benefit of reducing intraoperative propofol use without affecting hemodynamic stability.

Most oncologic breast surgeries will be performed under general anesthesia, though sedation can be considered based on tumor and patient factors. Propofol is the most commonly utilized induction agent given its quick onset and rapid clearance. Throughout induction, sensible dosing is key to avoiding hypotension. Unlike opioid medications, propofol is not associated with postoperative nausea. Lidocaine is typically administered to prevent the pain that may be felt with propofol administration. Fentanyl can be used to decrease the hyperdynamic response to tracheal intubation, and B-blocker use can also be considered for laryngoscopy.

During the maintenance phase of anesthesia, it is important to focus on finding an appropriate balance of sedation, analgesia, and mindfulness of side effects. The lowest allowable doses of short-acting agents to prevent lasting effects should be utilized with the goal of emerging from anesthesia calmly, with appropriate analgesia. Short-acting agents such as sevoflurane and desflurane + nitrous oxide are commonly implemented. Total intravenous anesthesia (TIVA) should be considered with patients at high risk of PONV. Typically, TIVA protocols will consist of propofol at 50 to 100 mcg/kg/min. During the operation, anesthesiologists should try to minimize opioid use due to its association with PONV, increased postoperative sedation, bladder and bowel dysfunction, pruritus, respiratory depression, and opioid-induced hyperalgesia (OIH). A number of strategies to minimize intraoperative opioid use including use of intravenous acetaminophen, nonsteroidal antiinflammatory drugs (NSAIDs), dexamethasone, and even B-blockers have been described. Esmolol, a short-acting B1 antagonist, has been demonstrated to be associated with a reduction in intraoperative and postoperative opioid consumption, without significant changes in postoperative pain scores.

Other autonomic blocking agents such as α2-agnoists (dexmedetomidine), calcium antagonists, lidocaine, magnesium, and ketamine have all been shown to reduce opioid use; as a result, opioid-free anesthesia protocols have been described that commonly utilize this combination. Ketamine has hypnotic-sedative as well as analgesic properties and can reduce postoperative pain in some situations. Lidocaine and magnesium decreased pain scores and opioid requirements in the early postoperative period. All these agents are given as bolus doses at the start of anesthesia and then continued at predefined rates. When dexmedetomidine is used, it commonly is bolused prior to induction in order to achieve an appropriate level of sedation and sympathetic block before intubation.

During the emergence phase, the same mindfulness should be used to limit opioid use. In order to prepare for a comfortable emergence, multimodal pain control with acetaminophen and ketorolac is commonly used. Ketorolac is effective for postoperative pain and does not increase postoperative bleeding.

In order to prevent postoperative nausea in all patients, the surgical team should be mindful of all perioperative medications. In order to reduce opioid use, regional anesthesia is critically important in breast surgery. The use of propofol for induction and maintenance also limits PONV, while nitrous oxide and volatile anesthetics tend to increase rates. Furthermore, adequate hydration not only prevents PONV, but also leads to safe practice in the event that nausea and vomiting occur. Patients at risk for PONV should also receive prophylaxis with dexamethasone after induction and ondansetron prior to emergence.

In addition to analgesia, the proper management of intraoperative fluid balance is imperative to avoid a myriad of adverse events. Hypervolemia is linked to peripheral edema limiting postoperative mobility, pulmonary edema contributing to PPCs, postoperative ileus, and electrolyte abnormalities; hypovolemia can result in orthostatic hypotension and decreased cardiac output. In the same way, close attention must be paid to the electrolyte composition of fluids to prevent the sequelae of electrolyte derangements such as arrhythmia, fluid retention, and renal injury. Intraoperative prevention of hypothermia is also critical, as core temperature fluctuations can result in cardiac arrhythmias, hemorrhagic complications, and increased stress responses. The key to successful fluid and temperature maintenance lies in close collaboration between the surgical and anesthesia teams.

In both the intraoperative and postoperative phases, goal-directed fluid therapy (GDFT) encourages the judicious practice of fluid administration based on objective hemodynamic parameters such as cardiac index and stroke volume variation. GDFT aims to optimize hemodynamic status while avoiding the morbidity of over- or under-resuscitation. In a 2011 meta-analysis including 29 studies, GDFT resulted in significantly reduced rates of morbidity and mortality in surgical patients, establishing this as a safe and effective perioperative strategy.