Post-operative pain is undertreated, in large part because it is often "invisible." In the outpatient setting, pain can go unnoticed or disregarded by physicians, nurses and patients who consider it a natural and physiologic consequence of surgery. The problem is, post-op pain can profoundly hinder outcomes, and the failure to appropriately assess and treat pain is fast becoming a liability issue. In this article, I outline an evidence-based approach that will help you bring some accountability and objectivity to the process of pain assessment.

The importance of pain control
There is a direct link between pain control and good clinical outcomes. Surgery and the pain associated with it trigger stress responses that affect the endocrine, metabolic, cardiovascular, respiratory, genitourinary, gastrointestinal, musculoskeletal, cognitive and immune systems. Unrelieved post-operative pain can also affect patients' temperaments, increase vulnerability to stress disorders, increase the risk of potentially debilitating chronic pain syndromes and reduce quality of life.[1] In the outpatient setting, patients who are relatively comfortable breathe and walk easier, go home sooner, recover faster and are less likely to be readmitted.[1]

Failure to appropriately assess and treat pain is also becoming a liability issue. There have already been a few publicized lawsuits related to undertreated pain, and most experts agree that the JCAHO pain treatment standards and recent pain management guidelines will prompt more patients to hold their practitioners legally accountable for undertreated pain.[2]

There are three crucial steps to accurately assessing post-op pain in the typical adult patient:

• standardize a self-report pain assessment tool [the Numeric Rating Scale (NRS), for example];
• establish a pre-op comfort-function goal;
• and evaluate your progress toward achieving this goal during the post-op period, adjusting the pain treatment plan when needed.

For patients who are unable to report pain, including very young and cognitively impaired patients, other approaches such as behavioral observation are appropriate for assessing pain.

Step 1: Standardize
Research clearly shows that patients' behaviors, the opinions of nurses and physicians, and family estimates are not as reliable as patient self-reports. In fact, studies show that we tend to do a poor job of guessing others' pain, and our estimates become less accurate as pain worsens.[1] There are several reasons for this.

Practitioners may believe that sedated patients are relatively comfortable when, in fact, sedation is not an indicator of patient comfort; patients can be sedated and in pain. Patients also have very different ways of demonstrating their pain. This depends on a host of individual factors like how the patient has learned to deal with and express pain and whether the patient equates pain with personal strength. The manifestation of pain is so individual that each patient has a unique "pain signature."

Since the patient's self report is the most reliable indicator of pain, the outpatient facility should adopt a single, universal assessment tool that helps all able patients report their pain. This lets patients quantify and communicate their level of pain to the healthcare team. The most commonly used, valid and reliable tool is the 0-to-10 pain scale, or the NRS. It is simple to describe and easy for most able patients to use. Standardization with the NRS, both within and across facilities, is also integral to effective communication. Say, for example, a patient undergoes surgery at an ASC and rates his pain there on a 0-to-5 scale. He subsequently goes home and calls the emergency department to report a pain intensity of "5," but the practitioners at the hospital misinterpret this report because they are used to using the 0-to-10 scale.

Step 2: Establish a Comfort-Function Goal
I highly recommend establishing a "comfort-function goal" pre-operatively for every patient. A comfort-function goal is the level of pain relief that a patient feels he will need to easily perform the essential post-op activities. Typically, this goal is no higher than 3 on the 0-to-10 scale: Research shows that a pain rating above 3 will affect function.[1] For example, a patient may decide before surgery that a pain rating of 3 on a scale of 0 to 10 would let him cough, breathe deeply and ambulate after surgery.

The comfort-function goal is an essential part of a good pain management program for two reasons. First, directly linking pain with function helps remove some of the guesswork inherent in trying to determine whether and when to treat post-op pain. Second, by establishing a measurable treatment threshold that goes beyond a subjective assessment of comfort, the comfort-function goal focuses practitioners on the need to perform regular assessments and makes them accountable for treating pain. I view this process much like that of other treatment approaches. Diabetes therapy, for example, has very specific treatment goals such as blood-sugar levels and dietary intakes.

The Hierarchy of Pain Assessment     Patient Self Report using the 0-to-10 Numeric Rating Scale     Presumptive Pain Due to Pathologic Conditions or Procedures that Typically Cause Pain     Behavioral Observation     "Proxy" Pain Ratings from Family Members     Physiologic Measures (Vital Signs)   Source: McCaffery M. Pasero C. Pain: Clinical Manual, 2nd ed. St. Louis: Mosby. 1999.   For More Information About Pain Management    • Herr K. Pain Control: Pain assessment in cognitively impaired older adults. AJN. 2002;102(12):65-66.    • McCaffery M, Pasero C. Pain: Clinical Manual. 2nd ed. St. Louis: Mosby. 1999.    • McCaffery M, Pasero C. Pain Control: Teaching patients to use a numerical pain-rating scale. AJN. 1999;99(12):22.    • Merkel S, Voepel-Lewis T, Malvrya S. Pain Control: Pain assessment in infants and young children: The FLACC scale. AJN. 2002;102(10):55-57.    • Pasero C, McCaffery M. Pain Care: Accountability for pain relief: Use of comfort-function goals. J Perianesth Nurs. 2003;18(1):50-52.    • Pasero C, McCaffery M. Pain Control: The patient's report of pain. AJN. 2001;101(12):73-74.    • Pasero C, McCaffery M. Pain Control: When patients can't report pain. AJN. 2000;100(9):22-23.    • Pasero C, McCaffery M. Pain Control: The undertreatment of pain. Are providers accountable for it? AJN. 2001;101(11):62-63.

Step 3: Evaluate and Adjust
During patient recovery, diligently evaluate patient pain against the pre-set comfort-function goal using the NRS. Be sure to document the goal and all pain findings in the same place, because the overall picture will offer a direction for treatment. In addition, document in the medical record how the clinician treats pain whenever the rating exceeds the comfort-function goal - such as increasing an analgesic dose or adding another type of analgesic.

During evaluation, all practitioners must learn to accept patients' self-reports, even if they do not believe them. In today's healthcare environment, we are obligated to use a valid assessment tool like the NRS, accept the patient's report of pain and provide appropriate management. This is fast becoming the standard of care.[2]

When patients can't report pain
When a patient cannot report pain - as in the case of the very young or very old - use other, albeit less reliable, methods. Before doing so, however, be sure the patient is truly unable to report his or her own pain. Many practitioners make this conclusion prematurely. In fact, one study showed that 83 percent of elderly patients with significant cognitive impairment were able to complete a pain-rating scale once it was explained to them.[3] Clinicians should also treat presumptively for pain whenever a patient undergoes a painful procedure.

These alternate methods (in order of priority) include:

• Behavioral observation. In cognitively-impaired elderly patients, common pain-associated behaviors include grimacing; verbal clues (crying, moaning, words such as "ouch" or "stop") nonverbal vocalizations such as sighs or gasps; rubbing; guarding (remaining very still) and bracing. In pediatric patients ages two months to seven years who cannot report pain, the "FLACC" behavioral pain scale is valid for assessing post-op pain. Whenever possible, assess patients' behaviors during activity. In cognitively-impaired elderly adults and pediatric patients, behavioral indicators may not be noticeable at rest but will be evident during ambulation or repositioning.

In addition, differentiate between what you expect to find and what you actually observe. Many of us have preconceived notions about how people in pain behave or about how much pain any given procedure will cause. Remember that pain is a very individual experience, and any time we predetermine a picture of pain we risk an inaccurate result.

It is also very important to consider the circumstances and environment at the time of the assessment, especially regarding children. For example, crying and body movements can indicate hunger and anxiety rather than pain.

• "Proxy" pain estimates. Since family members are typically unable to guess the severity of a patient's pain, clinicians need to address any discrepancies between behavioral observations and the family's reports of pain. However, do not disregard familial input altogether. Instead, ask family members objective questions, since this can give you insight into the patient's pain signature. For example, ask parents who believe their child is in pain why they have come to that conclusion. Ask parents to describe specific pain-related behaviors in their children, like ear-tugging, thumb-sucking, and specific facial expressions.
• Vital signs. When patients cannot provide a self-report, vital signs are worth considering, but only along with these other indicators. Never use vital signs as the sole gauge of pain, because they are the least sensitive of all indicators. Absence of physiological signs does not mean absence of pain. Physiologic indicators normally vary from person to person, and heart rate and blood pressure may even be below normal in spite of severe pain.[1]

Putting it all together
To create and implement a pain management program, the American Pain Society recommends establishing an interdisciplinary pain care committee.[1] Nurses, recognized as the patient's primary pain manager, often lead this effort but representatives from medicine, pharmacy and other disciplines are also necessary. The committee should evaluate guidelines and standards, and work to integrate regular, accountable pain assessment into clinical practice through changes in policies and procedures, staff education and performance evaluation, revised admissions forms and thorough documentation of pain.

The next step
The more we learn about pain assessment, the more we discover that our old paradigms of pain are often incorrect. Many of us, for example, believe that patients with severe pain will always act in a certain way, or that people who repeatedly ask for analgesics are addicted. Now, we know that some patients cope with severe pain by being stoic or by laughing and joking, and that requests for analgesia usually mean we have not adequately treated pain. It is our responsibility to realize that self-report is the single most reliable indicator of pain and to therefore take the patient at his word. Once we achieve this level of understanding, we have taken the first step toward effective pain management.

References
1. McCaffery M, Pasero C. Pain: Clinical Manual. 2nd ed. St. Louis: Mosby. 1999.
2. Pasero C, McCaffery M. Pain Control: The undertreatment of pain. Are providers accountable for it? AJN. 2001;101(11):62-63.
3. Ferrell BA, et al. Pain in cognitively impaired nursing home patients. J Pain Symptom Management. 1995;19(8):591-598.