Learning Objectives/Outcomes: After completing this 2-part CME/NCPD activity, the provider will be able to:
1. Describe the risks of pain assessment strategies that emphasize severity.
2. Identify screening tools for patients at high risk of postsurgical pain.
3. Recommend appropriate preoperative nonpharmacologic pain management.
This article is the second of a 2-part series. The first part, in the January 2021 issue of Topics in Pain Management (Vol. 36, No. 6), provided an overview of chronic postsurgical pain (CPSP), with context including the global opioid crisis.
In this part 2, we focus on CPSP and explore diverse means to assess and mitigate the development of chronic pain.
The global opioid crisis and the widespread acknowledgement of the great difficulty in managing patients with chronic pain have emphasized the importance of mitigating the risk of CPSP and pharmaceutical opioid use disorder (OUD) and their sequelae.
Personalized multidimensional treatment for chronic pain, including CPSP, should prioritize nonpharmacologic interventions, incorporate nonopioid pharmacologic interventions when appropriate, and add opioid analgesia to a management strategy of nonpharmacologic care only if the anticipated benefits for function and pain outweigh the risks.
Although estimates from epidemiologic studies vary, a great deal of data now show that CPSP occurs in 10% to 30% of all surgical patients (reporting pain persisting 1 year after surgery) and that 5% of all surgical patients report that their CPSP is severe enough that it is disabling.1-3
CPSP usually begins as pain in the acute postoperative phase that responds poorly to analgesia. Shortly afterward, it transitions into a neuropathic pain condition that responds poorly to opioids.4 By this time, patients have been inadvertently conditioned by a lengthy stepwise approach to passive pain management. This approach shifts the patient's locus of control externally and decreases the sense of self-efficacy, while increasing the patient's expectation that another passive intervention, such as interventional pain management or another surgical procedure, will cure the pain.
Epidemiologists and public health experts have announced the emergence of a global syndemic created by the conjunction of the opioid and COVID-19 pandemics.5 This comes with the recognition of the increased risk that comes with using narcotics, whether illicit or prescribed, while living in relative social isolation for a protracted period. Early data from the beginning of the COVID-19 syndemic suggest the US opioid death rate is continuing to rise.
Chronic Postsurgical Pain
The definition of CPSP included in the International Classification of Diseases (ICD-11) is pain that persists for a minimum of 3 months after an acute postoperative episode of pain and that:
* Is localized to the surgical site or a referred area;
* Develops or increases in intensity after a surgery;
* Causes a significant negative impact on quality of life;
* May develop after an asymptomatic period; and
* Is not better explained by another cause (eg, infection, malignancy, or a preexisting pain condition).6,7
CPSP is known to correlate with poorer surgical outcomes, poorer rehabilitation outcomes, decreased functional ability, increased psychologic trauma, increased health care costs, and decreased quality of life.4,8-13 Acute and chronic pain after surgery both have adverse effects on patient outcomes and warrant clinical management, but postoperative pain management has historically been dominated by opioids and other pharmaceutical products, in addition to interventional pain management procedures that are often ineffective.
Pain Assessment
Pain-specific patient-reported outcome measures (PROMs) are considered the gold standard of pain assessment. This is a broad category of measures that investigate intensity (numeric rating scale, Visual Analog Scale, Faces); location (Ransford pain diagram); description (verbal descriptor scales); questionnaires; and pain diaries. However, many of these focus on a unidimensional aspect of a person's pain experience.
Growth in the awareness of the multidimensional nature of pain suggests that clinicians should use several PROMs to capture each dimension of a patient's pain experience. The Orebro Musculoskeletal Pain Questionnaire and other multidimensional measurement tools incorporate key items from earlier unidimensional PROMs and capture a broader picture of the patient's pain experience than merely pain intensity.14
In patients with a primary symptom of pain, it may be useful to consider 2 fundamental questions: Who are the people who choose to become patients? More than 116 million US adults suffer from common chronic pain conditions,15 but most of these people do not seek medical care. The next question to consider is: What is it about a person's pain experience that leads him or her to seek guidance or solutions from a health professional?
Risk Factors for CPSP
Many of the risk factors for acute postsurgical pain can be identified before surgery, and several of these are also risk factors for CPSP (Table 1). Risk factors for CPSP can be patient-specific or surgery-specific.19,20 In total, clinical factors are estimated to predict more than 70% of CPSP risk.27 These factors include type of surgical procedure, age, physical health, mental health, preoperative pain in the surgical field, and preoperative pain in another area.
The intensity of acute postsurgical pain is a prominent predictor of CPSP for a wide variety of procedures investigated.12,13,20,27 It is of great consequence to understand that the overall (median) intensity of pain over the first 7 postoperative days is a better predictor of CPSP than is the maximum pain score.21,28 The duration of severe pain in the acute postoperative period seems to be a more important predictor of CPSP than peak intensity of pain.
Roughly 8% of people who never took opioids for preoperative pain management report continuing to take them 1 year after undergoing low-risk surgery.29 There is evidence that the use of regional anesthesia or substituting nonopioid anesthesia can be a protective factor against acute and chronic postsurgical pain,30,31 suggesting that opioid-based anesthesia may also be a risk factor in the development of chronic pain and OUD after surgery. Opioid-free anesthesia approaches are becoming increasingly popular among anesthesiology providers.
Postoperative bleeding, infection, and the need for reoperation all seem to increase the risk of persistent postsurgical pain.20 Pain intensity is greater for joint arthroplasty than for gynecologic or other visceral operations. Some orthopedic surgeries are associated with a greater CPSP risk than others, with hip arthroplasty showing 10% risk but knee arthroplasty showing a 20% risk.11
Although surgery-specific risk factors are usually within the control of the surgeon, most CPSP risk factors are patient-specific and are beyond that control. Avoiding elective surgery for these patients may be justifiable, as they are more likely to be poor candidates and merit extremely careful consideration of the risk-benefit analysis. The inability of the surgeon to control these factors underscores the importance of thorough presurgical screening. Keep in mind that the development of persistent postsurgical pain does not necessarily suggest an iatrogenic surgical event.32
There is evidence that several of the patient characteristics for CPSP are modifiable, including coping, self-efficacy, fear avoidance beliefs, and pain catastrophizing. Findings show that a large proportion of the disability in people with low back pain can be attributed to variables such as depression and self-efficacy,23-25 neither of which is a central focus of usual presurgical screening methods. Before a patient becomes a candidate for surgery, patient screening should be performed with a recognition of the breadth and multidimensional nature of pain. A standard history and review of systems related to preexisting pain should include known risk factors, including previous surgeries, interventional pain management procedures, and preoperative use of narcotics, whether illicit or prescribed.22,33
Even after multidimensional screening, patients may still develop CPSP. Rather than merely obtaining informed consent to surgery, clinicians should discuss with patients the full variety of risk factors, in addition to intraoperative risk factors, to allow patients to make an informed choice between all reasonable options. This approach fully respects patient autonomy.
System-Level Problem: Pitfalls of the Stepped Care Pain Management Approach
The stepwise pain management approach commonly taught in US medical schools recommends initial care options that are noninvasive and low-cost unless clinical findings justify more aggressive care.34 Then, if this approach is unsatisfactory, care should escalate to more aggressive treatment.
Nonpharmacologic pain management approaches that focus on empowering the patient, such as lifestyle management, self-care, independent exercise, and physical therapy, typically are not included in this model-even though these approaches are all less invasive and costly relative to surgery. This produces a limited stepped care approach giving the illusion that safer options have been exhausted. Regrettably, this fosters an overconfidence bias toward a more aggressive course of treatment, often leading to opioids and medical interventions that carry greater risk, all of which are passive interventions that focus on correcting an impairment rather than empowering the person.
Socioeconomic Risk Factors
Socioeconomic risk factors significantly impact access to care. For patients who present with painful musculoskeletal conditions, the lack of access to potentially risky care can play a protective role in decreasing the likelihood of the iatrogenic effects of surgery or opioids, if their conditions pose little risk of escalation. Insurance coverage with high annual deductibles and copayments are likely to steer patients away from provider-based pain management approaches that require recurring visits such as physical therapy, chiropractic therapy, massage therapy, or acupuncture, and toward prescription opioid medication, as it incurs a lower copayment under most plans.
Since March 2020, a peak of more than 22 million jobs were lost in the United States due to the upheaval caused by the COVID-19 pandemic. This resulted in the loss of employment-based health insurance for a great many of those workers. However, before this pandemic, more Americans were covered by health insurance coverage than at any time in US history. Despite such broad health coverage, many Americans still could not afford to use health services due to the high deductibles associated with many employer-provided health plans. Meanwhile, copayments for common pharmaceuticals, including opioids, are often significantly lower than copayments for nonpharmacologic care. These financial burdens increase the risk of OUD by incentivizing patients to select opioids over safer nonpharmacologic options.
Prescribers may avoid offering their patients a referral to a physical therapist, chiropractor, or acupuncturist due to knowledge of the patient's inability to afford the cost of coinsurance or copayments. Existing price points for insurance copayments disincentivize nonpharmacologic pain management, leaving many less-affluent patients with opioids as their only reasonably priced option.
Enhanced Preoperative Screening to Mitigate the Risk of Postoperative Pain
Postoperative pain may be related to intraoperative events. However, there is a great deal of evidence that preoperative and postoperative considerations play a significant role that, in many cases, has a much greater impact on the development of CPSP than do intraoperative events. Preoperative screening using validated patient-reported outcome measures to identify those who are at heightened risk for developing CPSP could mitigate this risk by facilitating appropriate candidate selection and safe patient management.
Chronic preoperative pain is a predictor of postoperative pain, and some of these patients may have developed OUD even before surgery. Preoperative prescription opioid use increases the likelihood of CPSP with a relative risk twice that of not using opioids preoperatively (95% confidence interval, 1.2-3.3).35 CPSP occurs in 10% to 30% of surgical patients. Many of these patients opted for surgery due to reasons of pain and now have more pain after surgery. Severe postsurgical pain is not uncommon with a large observational study reporting that 2.2% of postoperative patients still had severe CPSP 1 year after surgery with a Numeric Rating Scale score of greater than 6.21 These apparently poor surgical outcomes often do not seem to match surgical estimations of postsurgical success, because surgical success is often defined by biomechanical factors, such as the structural integrity of a spinal fusion, rather than functional outcomes and patient satisfaction.
Substance Use Disorder
Substance use disorder (SUD) is a group of mental, emotional, intellectual, behavioral, and physical symptoms that imply that a patient has continued using a substance despite significant substance-related complications. Characteristic of an SUD is an impulse-control problem resulting in an inability to stop using the substance despite knowledge that continued use is harmful and/or is causing problems for the individual. The diagnosis is based on a compulsive pattern of behaviors that can be attributed to the use of the substance.
This means that, contrary to popular belief, people with SUDs do not use to get high, as seen in recreational substance use. People who have SUD commonly feel that they need the substance to avoid the negative effects of withdrawal that they often do not recognize as withdrawal.
Medication-related risk factors for OUD and overdose include higher dosage of prescription opioids, long duration of opioid use, a history of previous opioid use, and the use of extended-release opioid medication.36 This is thought to be due to the higher total dosage of medication consumed by the patient.
Screening for SUD can be performed by a variety of health professionals quickly and easily, using a patient-reported outcome measure such as the Alcohol Use Disorders Identification Test (AUDIT) for alcohol use or the CAGE-AID Questionnaire that is designed for alcohol and drug use.
It is now more widely recognized that a number of factors associated with depressed breathing, such as sleep apnea, asthma, or coprescribing opioids with antidepressants or benzodiazepines, can compound the risk for unintentional opioid overdose death. The Risk Index for Overdose or Serious Opioid-Induced Respiratory Depression (RIOSORD) is a questionnaire with weighted items that has been validated using a case-control analysis of more than 18 million medical users of prescription opioids. It has excellent predictive accuracy and is broadly generalizable.37
Mental Disorders and Locus of Control
Conditions within the category of mental disorders may impact patient choices regarding pain management even when those disorders are mild. As such, they should be given serious consideration during clinical decision making. Preoperative anxiety correlates strongly with postoperative pain.
A poor sense of self-efficacy is associated with an external locus of control and an increase in the likelihood that a patient will choose surgery, interventional pain procedures, opioids, or another passive intervention.
Each year for the past 20 years, the top 3 causes of years lived with disability for American males from 15 to 49 years of age have been mental disorders, musculoskeletal disorders, and SUDs, in that order (Figure 1).38 In light of the prevalence of these traits, patient screening using validated self-efficacy scales may help identify those who are more likely to seek passive pain management approaches.
Adverse Childhood Experiences
An adverse childhood experience (ACE) can profoundly affect an individual's health outcomes even decades after resolution of the experience, but this is substantially more likely when someone has multiple ACEs in his or her health history and closely associated with the most serious and costly health conditions in the United States (Table 2). Close to 1 in 4 children in the United States has experienced 3 or more ACEs, placing him or her in a high-risk category for poor health outcomes that show a statistical correlation with mental health disorders, SUDs, and poor spinal surgery success rate. These links have been noted in published scientific research since the early 1990s.
Many patients may fail to disclose ACEs to health care professionals simply because they are unaware of a possible link to health outcomes. Other patients may be unwilling to disclose ACEs in their medical history for a variety of personal reasons, making this risk factor a challenge to discern (Table 3).
The use of ACE questionnaires to collect this information has facilitated disclosure in psychologic and psychiatric practice for many years.40 However, as the use of patient-reported outcome measures for ACEs is relatively new in family medical and surgical practice, there is no consensus on a framework for evaluating these tools in these settings. The Centers for Disease Control and Prevention (CDC) has been conducting telephone surveys regarding the prevalence of ACEs since 1984 and collecting these data on its Behavioral Risk Factor Surveillance System.
Presurgical Management
Early clinical decisions regarding patient management can have an exceptional influence on the overall course of care, suggesting that presurgical management may have a profoundly protective effect and mitigate the risk of CPSP.
The form of pain management a patient pursues throughout his or her entire course of care is often dictated by the treating clinician initially encountered by the patient at his or her point of entry into the health care system. Data from a large, private insurer suggest that, when a patient's first point of contact for pain treatment is a physical therapist, chiropractor, or acupuncturist, the odds of early and long-term exposure to opiates are markedly reduced by 75% to 90%, relative to providers who have medication-prescribing privileges.41
Early nonpharmacologic pain management has been found to be safe and cost-effective, while decreasing opioid exposure.42 Preventing pain not only has the potential to eliminate an unnecessary elective procedure, it also reduces the likelihood of developing an OUD. However, for some, acute pain may still transition to chronic pain. Even in these cases, according to the CDC, opioids are not first-line or routine therapy for chronic pain.43
More importantly, managing pain without opioids eliminates one of the major risk factors for CPSP, should the patient still ultimately undergo surgery.
Nonpharmacologic Pain Management Approaches
Traditional approaches to medical pain management emphasize pathoanatomical and pathophysiologic aspects of the patient's condition while underemphasizing the psychosocial nature of a patient's presenting symptoms. Many hospitals have developed an acute pain service (APS) to ensure safe and effective postsurgical pain management that is still directed by health professionals who prescribe pharmacologic treatment.
Increasingly, decision-making authority is shared within APS teams, and prescribers are not the chief decision makers. In many of these teams, health professionals who provide nonpharmacologic pain management approaches have equal standing with all other members. Management approaches are often multimodal, centered on physical activity, and have been shown to decrease total opioid intake. In some cases, these approaches supplant pharmacologic pain management. This can be fortuitous, as oral medications have no demonstrated ability to cure musculoskeletal injuries or correct underlying biomechanical causes of chronic musculoskeletal conditions.
According to the CDC, nonpharmacologic therapies and nonopioid medications are preferred for chronic pain. If opioids are used at all, they should be used together with nonpharmacologic therapies and nonopioid medications, as appropriate. Prescribers should consider prescribing opioids only if the anticipated benefits for function and pain are expected to outweigh the risks. When pain is chronic, the CDC does not recommend prescribing opioids for the management of pain alone.43
Active nonpharmacologic pain management approaches include:
* Active self-management;
* Independent exercise; and
* Physical therapy.
It has been broadly recognized that people who exercise regularly have less pain,44 and the vast majority of evidence-based guidelines for the management of painful chronic conditions already recommend exercise therapies over passive care such as pharmacologic management and surgery. This suggests that self-care approaches emphasizing physical activity are a reasonable, lowest cost, first-line approach.
For those patients requiring guidance with exercise, stepped care pain management should include guided physical rehabilitation early, if not first. When patients with back pain are managed using this strategy, it requires fewer opioids and high-cost services.45 Abruptly terminating opioids may be dangerous, but keeping new patients opioid-naive when appropriate may prevent years lost to disability due to OUD and could even prevent deaths due to opioid overdose.
There is a wide variety of nonpharmacologic pain management techniques that do not involve physical activity. These include but are not limited to:
* Acupuncture;
* Aromatherapy;
* Chiropractic;
* Cognitive behavioral therapy;
* Counseling and supportive communication;
* Education about what the patient should expect at each phase of recovery;
* Hypnosis;
* Massage therapy;
* Mindfulness; and
* Music therapy.
Passive modalities include heat/cold therapy and transcutaneous electrical nerve stimulation.
Cognitive Behavioral Therapy
Cognitive behavioral therapy (CBT) is a form of psychologic intervention that has been demonstrated to be effective for a range of problems, including anxiety disorder, depression, marital problems, eating disorders, and SUDs-in addition to persistent pain conditions. It is best thought of as a family of therapies that make up a broad category of psychobehavioral techniques that are designed to address patient problems with a practical, short-term, goal-oriented approach. These goals focus on behavioral modification by centering on the thoughts, beliefs, and attitudes that drive the problematic behavior, which exacerbates the patient's problem.
CBT is based on several core principles among which are that psychologic problems are based, to some extent, on unhelpful ways of thinking and on learned patterns of unhelpful behavior. In guiding patients to find more helpful coping strategies, the therapist typically attempts to reframe thought patterns. These strategies might include:
* Reevaluating thought patterns;
* Examining the impact of behavior;
* Problem-solving to manage challenging situations;
* Developing a greater sense of confidence in one's own abilities;
* Confronting one's fears; and
* Quieting one's mind.
The patient and the therapist collaborate to obtain an understanding of the problem and to develop a treatment strategy. Based upon these discussions, most types of CBT will focus on few of these strategies to, ultimately, help patients learn to respond differently and negotiate challenging episodes independently. As responses to current episodes are often rooted in patterns of behavior caused by emotional reactions, therapists emphasize current challenges in the patient's life, rather than issues that preceded these problems. As such, the emphasis is primarily on making forward progress to develop more effective ways of coping with life, rather than perseverating on the perceived cause of their problems.
Stratifying Risk for Back Pain
It is well established that it is clinically effective to screen people who are at risk for progressing from acute back pain to chronic back pain. The STarT Back Screening Tool (Subgroups for Targeted Treatment) is a brief, validated, 9-item, multidimensional pain assessment questionnaire designed to stratify primary care patients with low back pain into 1 of 3 evidence-based matched treatment pathways based on prognostic indicators for risk of progressing to chronic pain, as follows:
* Low risk-provide conservative medical management with advice, reassurance, and a review of medication;
* Medium risk-refer to a physical therapist for a standard course of conservative treatment with a defined end point in time; and
* High risk-refer for psychologically informed physical therapy care.
Extensive research into the validation, translation, and clinical use of the STarT Back Screening Tool has been conducted within several national health systems. Findings have shown a mean increase in health outcomes and health system cost savings relative to a one-size-fits-all primary care strategy.46
Psychologically Informed Physical Therapy
Psychologically informed care in physical therapy is performed with a physical therapist who is trained to address psychosocial barriers to recovery during the usual course of physical therapy care. Although accreditation requirements of entry-level physical therapy professional programs include a significant amount of psychologic content, physical therapy is fundamentally centered on exercise and functional activity. Administering psychologically informed physical therapy requires that a physical therapist has received formal training in addressing more complex psychosocial issues that arise in response to physical activity. As such, these discussions take place during a physical therapy session with immediate guidance from a physical therapist who can provide specific counsel in the context of physical activity and exercise.
Interventions may include graded exposure to painful activity, thought monitoring, and cognitive restructuring. Graded exposure entails listing feared physical activities, ranking them, and then cautiously performing them in safe increments while systematically escalating physical activity over several weeks (Table 4). In this manner, the patient is able to confront the feared physical activity while demonstrating to himself or herself that the consequences should not elicit panic or anxiety.
Thought monitoring and cognitive restructuring are paired techniques that involve the patient keeping a pain diary of their thoughts and behavioral responses to episodes of pain and then reviewing this with the physical therapist to identify unhelpful patterns of behavior (Table 5).
Initially, the therapist would guide the patient through an exploration of alternate responses that would be more helpful through a discussion of strategies to break a problematic cycle and develop a plan that the patient can implement. For example, the patient may be encouraged to use positive self-talk, using phrases such as: "This increase in pain is only temporary. I won't let it defeat me."
This may help curb negative pain-related thoughts and feelings while helping plan adjustments in physical activities to avoid sedentary behavior. Another example of self-talk: "Instead of watching television all day, I will plan to do yard work in manageable amounts, so I don't exceed my tolerance."
Eventually, the therapist may guide a patient through this process during the functional exercise portion of a physical therapy session if a patient experiences an exacerbation of pain. In this way, the behavioral management of chronic pain is performed by incorporating basic CBT principles and applying them to a patient's problematic responses to pain experienced during or after physical activity. Ultimately, by coaching the patient to actively self-manage the next painful episode, the therapist empowers the patient to be able to confront his or her pain.
Conclusion
Chronic pain and CPSP are both intimately related to the opioid crisis. Opioids have poor effectiveness in the long term and are not able to cure painful chronic musculoskeletal conditions. Although there are aspects of pain management that can be categorized as iatrogenic, appropriate psychosocial screening and patient selection can optimize selection of surgical candidates and minimize the likelihood of CPSP.
Risk factors for CPSP are highly recognizable, preoperatively, intraoperatively, and postoperatively, when adequate screening is performed using multidimensional risk factors screening tools. Stratifying risk for chronic pain in general can be performed using a validated prognostic tool. The risks and benefits of opioids and all other reasonable treatment options for pain management should be discussed with patients.
Personalized multidimensional treatment for chronic pain, including CPSP, should prioritize nonpharmacologic interventions,47-49 incorporate nonopioid pharmacologic interventions when appropriate, and add opioid analgesia to a management strategy of nonpharmacologic care only if the anticipated benefits for function and pain are expected to outweigh the risks.
Among nonpharmacologic pain management approaches, those that include physical activity should be prioritized in accordance with existing clinical practice guidelines. Passive pain management treatment risks fostering dependency and an external locus of control and may undermine a patient's sense of self-efficacy.
Although nonpharmacologic pain management approaches are often less effective in the immediate term relative to opioids, they do not carry the risk associated with appropriately administered, long-term, physician-prescribed opioid medication. The wide variety of nonpharmacologic pain management options available allows prescribers to offer patients an informed choice regarding safer pain management to mitigate the risk of chronic postsurgical pain.
References