Assessing Pain When the Patient Cannot Self-report

   Pain is completely subjective, and the gold standard of pain assessment is self-report by the patient. Several assessment tools can facilitate determining the patient's assessment of pain intensity, and hospitals nationwide have implemented policies and procedures outlining the use of these instruments.

   The most commonly used self-report tools in patients who are able to quantify their pain are the 0-10 numerical pain rating scale and the 0-10 Wong-Baker FACES pain rating scale or the Faces Pain Scale-Revised; many patients who can self-report pain but are unable to quantify it may be able to select the face that best characterizes their pain on a faces pain rating scale. However, not all patients are able to report pain using customary assessment tools, and this presents a significant challenge for the healthcare team who must ensure that pain is recognized and treated appropriately.

   For patients unable to report pain through traditional methods, an alternative approach based on the Hierarchy of Pain Measures is recommended (Table). The key components of the hierarchy are as follows:

- Attempt to obtain self-report;
- Consider underlying pathology or conditions and procedures that might be painful;
- Observe behaviors;
- Evaluate physiologic indicators; and
- Conduct an analgesic trial.

Table. Hierarchy of Pain Measures

   1. Attempt to obtain the patient's self-report, the single most reliable indicator of pain. Do not assume that a patient cannot report pain; many cognitively impaired patients are able to use a self-report tool, such as the Wong-Baker FACES Scale, Faces Pain Scale-Revised, or Verbal Descriptor Scale.

   2. Consider the patient's condition or exposure to a procedure that is assumed to be painful. If appropriate, assume pain is present (APP) and document APP when approved by institution policy and procedure.

   3. Observe behavioral signs (eg, facial expressions, crying, restlessness, and changes in activity). Many available behavioral pain assessment tools will yield a pain behavior score and may help to determine whether pain is present. However, a behavioral score is not the same as a pain intensity score. Pain intensity is unknown if the patient is unable to provide it. A surrogate who knows the patient well (eg, parent, spouse, or caregiver) may be able to provide information about underlying painful pathology or behaviors that may indicate pain.

   4. Evaluate physiologic indicators with the understanding that they are the least sensitive indicators of pain and may signal the existence of conditions other than pain or a lack of it (eg, hypovolemia, blood loss). Patients may have normal or abnormal vital signs in the presence of severe pain. The absence of elevated blood pressure or heart rate does not mean the absence of pain.

   5. Conduct an analgesic trial to confirm the presence of pain and to establish a basis for developing a treatment plan if pain is believed to be present. An analgesic trial involves administration of a low dose of nonopioid or opioid and observing patient response. The initial low dose may not be enough to elicit a change in behavior and should be increased if the previous dose was tolerated, or another analgesic may be added. If behaviors continue despite optimal analgesic doses, other possible causes should be investigated. In patients who are completely unresponsive, no change in behavior will be evident and the optimized analgesic dose should be continued.

Pain Assessment Options in the Absence of Self-report

   Evidence-based guidelines recommend against the rating of pain intensity by anyone other than the person who is experiencing the pain. The importance of relying on self-report has been underscored by research over the years, which has shown a lack of correlation between the patient's perception of pain and that of nurses and other members of the healthcare team. Furthermore, the greatest discrepancies often occur at the highest pain levels.

   Various explanations for such discrepancies have been proposed, including care provider experience, patient gender, language barriers, and ability to distinguish pain behaviors from other behaviors. A principle of pain management is that the patient is the authority on pain intensity, and if he or she cannot report the intensity, then it is unknown.

   Estimation of pain by others. Research has shown that individuals who know the patient well (eg, parents, caregivers) often overestimate or underestimate the patient's pain. Discrepancies are influenced by a various factors, including the presence and level of cognitive impairment in the patient, caregiver gender, perceived burden of caregiving, preconceived ideas of acceptable pain relief, and fear of analgesic side effects. A concern has been raised that discrepancies occur when pain is more severe. Although individuals who know the patient should not be asked to rate pain intensity, they can facilitate assessment by providing the healthcare team with information about underlying painful pathology or behaviors that may indicate the presence of pain.

Exposure to painful procedures.

   When self-report cannot be obtained, the Hierarchy of Pain Measures calls for consideration of any potentially painful underlying conditions or procedures that the patient might be experiencing (Table). In this case, the patient has sustained painful traumatic injuries. He is also being subjected to endotracheal intubation, mechanical ventilation, and suctioning, all of which have been identified as painful procedures. However, he cannot report pain and is unable to demonstrate pain behaviors.

   According to the Hierarchy of Pain Measures, pain should be assumed to be present in such patients and treatment should be initiated with recommended starting doses of appropriate analgesics. The subanesthetic doses of propofol that are used for goal-directed sedation produce negligible analgesia. This underscores the importance of co-administering appropriate analgesics, such as nonopioids and opioids. Reassessing analgesic treatment may yield no change in behavior in unresponsive patients; therefore, the optimized analgesic dose should be continued.

   The patient's ability to self-report or the appropriateness of using a behavioral pain assessment tool should be evaluated regularly (eg, every shift). The decision to switch from assessment based on assumption of painful pathology to the use of behavioral tools or the patient's report of pain always depends on the patient's ability to demonstrate pain behaviors or report pain.

Patient behaviors.

   Patient behaviors often provide clues about whether a patient has pain. For example, facial expressions, restlessness, bracing, and changes in activity have been shown to be indicators of pain. Behavioral pain assessment tools facilitate pain assessment. One of the most commonly used tools in the ICU setting is the Critical-Care Pain Observation Tool (CPOT), which has been shown to be reliable and valid in a variety of critically ill patient populations. The tool requires evaluation of the following 4 categories:

   - Facial expression;
   - Body movements;
   - Muscle tension; and
   - Compliance with ventilator (intubated patients) or vocalization (extubated patients).

   A score of 0-2 is assigned to each category, depending on the degree of the patient's response. The maximum total score is 8. A limitation of many of the behavioral tools, such as the CPOT, is that they designate specific behaviors that must be observed, making it essential for nurses to carefully evaluate each patient for the patient's ability to demonstrate the requisite behaviors in the tool. In patients such as the one described above, behaviors are absent, rendering behavioral tools ineffective.

   Although it is tempting to rely on physiologic indicators, such as heart rate and blood pressure, vital signs have been shown to be the least sensitive indicators of pain and are known to be influenced by a variety of factors other than pain (eg, hypovolemia, blood loss, hypothermia, and anesthetic and analgesic agents).

Outcomes of Pain Assessment

   The healthcare team caring for this patient used the Hierarchy of Pain Measures as a framework for pain assessment. The patient was unresponsive, unable to self-report pain, and did not demonstrate any pain behaviors. As directed by the Hierarchy, those caring for him assumed that he had pain on the basis of his underlying painful pathology (eg, head trauma and ulnar fracture) and painful procedures (eg, endotracheal intubation, mechanical ventilation, and suctioning). A continuous IV morphine infusion at 2.5 mg/hour was initiated. Bolus doses of 1 mg IV morphine were administered before painful procedures. In addition, scheduled doses of IV acetaminophen and IV ibuprofen were administered around-the-clock.