Pain management in plastic surgery

Introduction

Postoperative pain management in plastic surgery remains a topic of increasing interest amidst heightened awareness of the opioid epidemic. Pain is defined as the sensory and emotional reaction to actual or perceived tissue injury. Nociceptive pain is due to stimulation of peripheral pain receptors at suprathreshold levels from damage to non-neural tissue. Inflammatory pain is due to peripheral pain sensitization from activation of the immune system via chemical mediators. Surgery results in nociceptive and inflammatory pain from tissue injury. Pathological pain results from dysfunction of the nervous system without tissue damage; this is maladaptive and serves no biological function.

Uncontrolled postsurgical pain has been associated with worse surgical outcomes. This includes increased risk of poor pulmonary function, myocardial ischemia, ileus, thromboembolism, and impaired immune function. It has been associated with increased post-anesthesia care unit stays, prolonged admissions and increased readmission rates; this may affect reimbursement and patient satisfaction. Uncontrolled postsurgical pain has also been implicated in the development of persistent postsurgical pain (PPSP) as a result of maladaptive neuronal plasticity. PPSP is estimated to affect 20%–25% of mastectomy patients, 50%–85% of amputation patients, and 5%–35% of hernia repair patients. PPSP may have implications for long-term opiate use among patients affected.

In the era of the American opioid epidemic, surgeons play a crucial role in optimizing postoperative pain and minimizing narcotic use. Enhanced Recovery After Surgery (ERAS) protocols were pioneered in the early 2000s by Ljungqvist and Fearson based on the work by Kehlet. These protocols are designed to enhance recovery after surgery through perioperative interventions focused on nutrition, pain control, and early mobilization. Non-pharmacologic pain management strategies such as mindfulness, massage, and acupuncture have been found to be effective pain management strategies and should be utilized. This chapter reviews pain management strategies available to plastic surgeons based on therapeutic class of medication and provides a framework for pain management based on ERAS protocols.

Opioid epidemic

The opioid epidemic within the US was declared a public health crisis by the Surgeon General in November 2016. The US accounts for 4.4% of the world’s population but consumes 80% of the world’s opiates. The opiate epidemic has claimed nearly 500,000 lives from 1999 to 2019 due to prescription and illicit opioids. It has been estimated to cost the US economy $100 billion per year in direct healthcare costs, lost productivity, and law enforcement support. The Centers for Disease Control and Prevention (CDC) divides the opioid epidemic into three phases: the first phase began in the 1990s with overdose deaths largely due to prescription drugs, the second phase began in 2010 with overdose deaths largely due to heroin, and the third phase began in 2013 with the rapid rise of overdose deaths linked to synthetic opiates (largely involving fentanyl).

Opiate prescribing began to decrease in 2011 due to advocacy, legislation, and clinical practice guidelines. Despite this, overdose deaths continued to increase largely due to non-prescription opiates. Contrary to the national trend of decreasing opiate prescribing, surgical, dental, and emergency medicine specialties saw an increase in opiate prescribing from 2010 to 2016; surgery patients saw an increase of 70% in average total morphine equivalents during this period. Additionally, when analyzing the types of opiates prescribed to surgery patients, Larach et al . found that surgery patients were more likely to receive oxycodone and hydrocodone – more potent opiate formulations – than dental and emergency department patients. This trend is particularly worrisome as a systematic review into prescribing practices found that as many as 92% of surgery patients reported that 70% of their prescribed opiates went unused. Among plastic surgeons, Chu et al . reported that, on average, 52% of all opiate pills prescribed for patients undergoing plastic and reconstructive surgery procedures went unused; this amounted to an average of 13 unused opiate pills per patient. This trend in opiate prescribing practices among surgeons is particularly troubling as new persistent use (defined as continued opiate prescription refills 3 months after the index procedure) is as high as 6.6% for patients undergoing general plastic surgery reconstructive procedures, 6.1% for patients undergoing body contouring, and 13% for patients undergoing hand surgery.

Opioids

Opioids are pervasive in today’s healthcare system. This class of analgesics primarily act on mu (μ) opioid receptors in the central nervous system. Opioids modify afferent pain signals by binding to opiate receptors, thereby decreasing the perception of pain. The mu opiate receptor not only has analgesic properties but also results in euphoria, sedation, anorexia, and respiratory depression; this explains the adverse effects associated with opiate use. The addictive potential of opioids has been well established and cannot be overstated, with estimates of postoperative chronic opiate use in previously opiate naïve patients ranging from 5% to 13%.

Opioids are administered parenterally or orally. Intravenous administration has predictable peak plasma concentration with rapid time of onset and offset. Intravenous formulations of opioids allow for an effective method of analgesia in patients without enteral absorptive capacity, such as in patients with postoperative ileus. Patient-controlled analgesia (PCA) devices allow for repeated low doses of opioids to be administered by the patient. PCAs have gained popularity as they decrease time burden on nursing staff; however, PCAs have been shown to increase side effects such as nausea, vomiting, and pruritus. Oral administration of opioids has slower time of onset due to first pass metabolism through the liver; however, this slower enteral absorption allows for more steady and longer-lasting analgesic effects.

Opioids should be used with caution in geriatric patients, patients with obstructive sleep apnea (OSA), and those with abuse history or potential. Surgeons must exercise caution in prescribing opioids to patients who use other sedative medications, such as benzodiazepines, antihistamines, or sleep aids, as these can have additive effects and cause respiratory depression. Opiates should also be used with caution in anyone with a history of excess alcohol consumption.

We recommend minimizing opiate use postoperatively by employing a multimodal analgesic (MMA) approach to ambulatory and inpatient surgery patients. For patients who require opioids for acute postsurgical pain, we recommend the use of opioids without added acetaminophen to decrease risk of acetaminophen toxicity (maximum dose 4000 mg in 24 hours).

Acetaminophen, nonsteroidal anti-inflammatory drugs, and selective COX-2 inhibitors