Chapter 13: Pain Management In Plastic Surgery

Acute pain is physiologically useful to protect individuals from injury and allow healing to occur. It can be either nociceptive and/or inflammatory and limit activities that may predispose to poor outcomes after surgery. In contrast, chronic pain is maladaptive and exceeds beyond the period of healing. This can be a real problem for patients with 1 in 10 adults being newly diagnosed with this annually in the US. Chronic pain is therefore is not to protect tissues while healing, even in the later stages. The focus of postoperative pain management should be not only to minimize physiologic consequences of untreated pain, but also to minimize adverse effects of analgesic medications. In this way, effective pain control can help patient recovery and optimize outcomes following surgery through the rehabilitation phase. Even where there is severe pain, side effects of medication must be considered and there must be a compromise or balance reached between the positive analgesic effects and the unwanted side effects of any regimen.1

All doctors and prescribing nurse practitioners owe a duty of care to their patients to take responsibility for safe and value based prescribing. The mainstay of postoperative medication should be nonopioid based as these medications are generally sufficiently effective for pain management and carry reduced adverse effects and risk for addiction. For example, acetaminophen and nonsteroidal anti-inflammatory drugs (NSAIDs) are often effective without the addition of opioids. Patients can become opioid dependent even after minor surgery where medications are unnecessarily prescribed, so their prescription is discouraged. Indeed, development of postsurgical opioid dependency would be considered a surgical complication.1–5 According to a systematic review in 2015, acetaminophen efficacy is similar whether IV or oral delivery is undertaken in spite of the increased bioavailability of the former. Therefore, in patients who are able to take oral medication, acetaminophen should be preferentially prescribed orally.6

Respiratory depression is a significant risk for patients who have been given an excess of opioids. In the extreme they can lose consciousness and control of their airway. On the other hand, anxiety and depression, poor wound healing, myocardial ischemia and infarction, and chronic persistent surgical pain are sequelae each associated with failure to adequately manage pain postoperatively. Other potential problems of excess opioid use include impaired pulmonary function, ileus, and failure to progress. These can collectively lead to an increased hospital stay, and readmission to hospital.1–3

The term “new persistent use of opioid medications” means that previously opioid naïve patients undergoing surgery who are prescribed opioids postoperatively will continue to use them for more than 90 days post surgery. For the vast majority of surgical procedures performed in plastic surgery, this would not be justified. Furthermore, this would be considered an avoidable postsurgical complication. As prescribers, it is the surgeon’s responsibility to minimize opioid prescription and instead provide alternative solutions such as long-acting local and regional nerve blocks, in combination with appropriate splints or dressings, followed by multimodal therapy with nonopioid medications.1,2 Surgeons are responsible for around 10% of total opioid prescriptions in the US so it has a significant impact on their use and may play a role in propagating the current addiction crisis.3

It is important to consider risk factors for patients undergoing surgery of developing reliance on analgesia following treatment. There are a number of predictable risk factors for patients developing reliance on opioids. These include a history of previous substance abuse including alcohol, prescription and nonprescription medications as well as smoking. Other risk factors include male sex (not female), low socioeconomic status (not high), and previous psychiatric comorbidities. Patients who already have established substance abuse disorders should ideally have surgery postponed until these have been resolved, unless it is a surgical emergency or really cannot be safely avoided.1,2

6. Jibril F, Sharaby S, Mohamed A, Wilby KJ. Intravenous versus oral acetaminophen for pain: systematic review of current evidence to support clinical decision-making. Can J Hosp Pharm 2015;68(3):238–247

Opioid wastage through over-prescription can be either where the medication is simply not used by anyone and ends up in cupboards stored for longer term or flushed down the toilet, or misused by individuals for whom it was never prescribed. Diversion is the term used for the transfer of prescription medications from their intended use to an illicit alternative. Doctors and patients can both help to minimize waste through education and common sense. Reducing prescriptions and exchanging opioid medications for less addictive but effective alternatives is the first step in this process. The second step is patient education to ensure that unused medications are returned or safely disposed of.1

Most people with prescription opioid abuse disorder get their medications from friends and family and this is termed diversion. Diversion broadly means that the “wrong” or unintended person receives the prescribed medication. Diversion does not mean that money has changed hands in the exchange. Unfortunately, a vast majority of medications are not safely stored. Figures suggest that up to 90% of medications are not safely stored in a locked location.1,2 Most patients are not educated on proper storage or disposal of medications, which will also contribute to diversion. Unused medications should either be taken back to the pharmacy or flushed down the toilet based on FDA guidance for each individual medication. Surgeons’ contribution to opioid prescription is estimated to be at least 10% (not just 1%).3

The main aim of the enhanced recovery program is to decrease patient recovery time after surgery. There has been much support for this in recent years as there are many knock-on effects of successfully reducing recovery times. First, there are financial benefits. These include shorter hospital stay and quicker time to full function and working life or social independence where appropriate. If recovery is enhanced, there may be a secondary benefit on overall better outcomes, reduced complications, and better pain control. Taking further steps, there has been emphasis on preoperative conditioning of patients such that they enter their surgical pathway in the best shape they can. Factors include optimization of cardiovascular performance, BMI, smoking cessation, and blood glucose control. Sometimes this process is termed “prehabilitation,” i.e., preoperative rehabilitation. Things we can alter to enhance recovery include early ambulation, improved pain control, and early access to diet and fluids.1–3

There is a recognized ERAS protocol for breast reconstruction patients. There are three phases to the protocol advice: preoperative factors, intraoperative factors, and postoperative factors. The main preoperative factors include carbohydrate loading 2 hours before surgery, smoking cessation 1 month before surgery, a target BMI of <30 kg/m2, adequate hydration with clear fluids up to 2 hours before surgery, and venous thromboembolism (VTE) prophylaxis according to risk stratification. This may involve chemoprophylaxis and/or compression stockings.1,2

There is a recognized ERAS protocol for breast reconstruction patients. There are three phases to the protocol advice: preoperative factors, intraoperative factors, and postoperative factors. Within the intraoperative phase, a preference is given to total IV anesthesia where possible as this has many perceived advantages over inhalational anesthesia. Surgical site infection is minimized by using chlorhexidine skin preparation in alcohol base, IV antibiotics are given 30–60 minutes before surgery not at induction, maintenance of core body temperature should be at least 36° C (not 37° C), and use of vasopressors as required even in the setting of free tissue transfer.1,2

There is a recognized ERAS protocol for breast reconstruction patients. There are three phases to the protocol advice: preoperative factors, intraoperative factors, and postoperative factors. Postoperatively it is vital to ensure adequate pain relief to optimize rehabilitation and minimize adverse effects of uncontrolled pain such as myocardial ischemia, venous thromboembolism, anxiety, and depression. Therefore, a multimodal approach to pain relief is advocated. Other factors that need consideration include early diet and fluids, early mobilization, and supportive physiotherapy programs prior to and beyond hospital discharge.1,2

Ketamine is an example of an N-methyl-D-aspartate (NMDA) receptor antagonist that can be a useful component of multimodal analgesic therapy. The NMDA receptor is activated in response to intense and sustained painful stimuli so is implicated in both acute and chronic pain. Ketamine uniquely preserves respiratory drive and hemodynamic stability under anesthesia and is often used as an anesthetic adjunct in a multimodal pain management approach because it reduces opioid requirements and enhances analgesia. It is limited by its potential neuropsychiatric side effects, which include dysphoria, hallucinations, vivid unpleasant dreams, catatonia, or psychoses. Furthermore, it can have addictive qualities and is involved in substance misuse. Nonsteroidal anti-inflammatory medications such as naproxen and ibuprofen play an important role in multimodal pain therapy. They inhibit cyclooxygenase enzymes, either COX-2 selectively or both COX-1 and COX-2 nonselectively, which in turn inhibits the synthesis of prostaglandins and thromboxanes. Not only do they have analgesic qualities, but also have antipyretic and anti-inflammatory qualities as well. Unfortunately, they can cause gastrointestinal irritation and bleeding. They are contraindicated in patients with a history of coronary artery disease (CAD) or renal failure and may be contraindicated in asthmatics. Celecoxib is an example of a COX- 2-specific inhibitor. It is better tolerated in terms of gastrointestinal side effects than nonselective nonsteroidal anti-inflammatory drugs (NSAIDs), but still should be avoided in patients with a history of CAD or renal failure. Acetaminophen is a very useful medication that has both analgesic and antipyretic qualities. The specific mechanism of action is unknown though it is thought it may also function as a COX inhibitor. It is contraindicated in patients with liver disease and those who have excessive alcohol intake. Both oral and intravenous preparations are available and efficacy is similar between the two in patients able to take their medications orally. Intravenous acetaminophen can be helpful in the anesthetized patient and in the recovery room. Gabapentin and its derivative pregabalin are examples of alpha-2-agonists. They bind to calcium channels causing the release of glutamate, norepinephrine, and substance P. These activate pathways in the dorsal horn that regulate pain. They can be very helpful in managing nerve pain but have side effects of somnolence and dizziness. They are contraindicated in patients on continuous positive airway pressure (CPAP) therapy as they can exacerbate obstructive sleep apnea. They should be used with caution in elderly patients. Multimodal analgesia (MMA) with a selective COX-2 inhibitor and gabapentin decreases postanesthesia care opioid use and pain scores in outpatient breast plastic surgery by 40%.1 Nonopioid regimens with a selective COX-2 inhibitor and gabapentin decrease rescue opioid, rescue anti-emetic, and postanesthesia care unit (PACU) length-of-stay in aesthetic surgery.2 The addition of a COX-2 inhibitor decreases pain scores, decreases opioid consumption, expedites return of bowel function and activities of daily living, and improves patient satisfaction in core plastic surgery procedures.3