A Decision Tree Model for Postoperative Pain Management

Cynthia W. Ward, DNP, RN-BC, CMSRN, ACNS-BC


Urol Nurs. 2015;35(5):251-256. 

In This Article

Recommendations for Special Populations

Older Adults

Older adults commonly experience pain. Barriers to effective recognition and treatment of pain in older adults may be related to caregivers' misconceptions. These include beliefs that older adults have a higher pain tolerance, do not tolerate opioids, or are addicted easily to analgesics. In addition, older adults may fear the loss of independence, or believe acknowledging pain is a sign of weakness or pain is a punishment for past actions. Older adults also may not refer to a sensation as pain, instead describing it as soreness, aching, or hurting (Knight, 2012).

Normal effects of aging may cause the presentation of pain to be different than in younger individuals. Physiologic conditions that typically cause pain in younger individuals may be present, but the usual expected pain may not be present. For example, classic appendicitis symptoms of pain and tenderness are rare in older adults (Ignatavicius, 2013; Knight, 2012).

Declining renal function with aging causes slower elimination of medications, creating prolonged effects (Knight, 2012). Aging also may contribute to decreased blood flow and liver function. Such physiologic changes may interfere with the absorption, distribution, metabolism, and elimination of medications, resulting in higher rates of adverse effects (Pasero et al., 2011; Varner, 2012).

A general rule when treating pain with analgesics in older adults is to start low and go slow, meaning to start with the lowest effective recommended dose and increase the dose slowly if needed (Knight, 2012). Older adults may obtain the same amount of pain management as younger patients with a lower opioid dose; however, there is variability among individuals and doses should be titrated to effect (Macintyre, Scott, Shug, Visser, & Walker, 2010). Short-acting analgesics should be used for episodic pain. Because the least invasive route of medication administration is recommended, oral administration should be used whenever possible (Knight, 2012). Intravenous opioids may be given safely in older adults (Hallingbye et al., 2011; Sieber & Barnett, 2011), making the IV route an acceptable option for postoperative patients who may be unable to take oral medications or liquids. A multi-modal pain management plan including nonopioid analgesics may reduce the amount of opioid analgesics required, also reducing the potential side effects of opioids (Sieber & Barnett, 2011).

Caregivers may be hesitant to administer opioids to older adults due to the fear of causing confusion. Because the presence of pain itself also can cause delirium, opioids should not be withheld because of the presence of delirium. Very low doses may be given safely. Opioid-naïve individuals should be started with half the recommended low dose (Knight, 2012).

In a descriptive study of 100 medical-surgical patients who developed delirium during hospitalization, data were collected from a retrospective chart review regarding risk factors for delirium present on admission (Robinson et al., 2008). In addition, researchers noted the type, administration schedule, number of doses, and total milligrams of analgesics received by the patients in the 24 hours before onset of delirium. Identified risk factors for delirium included vision impairment, hearing impairment, cognitive impairment, sleep deprivation, immobility, and dehydration. Mean age of study participants was 76.71. The most common documented symptom of delirium was disorientation. Re searchers calculated the amount of analgesic the patients could have received based on the health care provider's order. Patients in fact received an average of 27.67% of the amount they could have been given. Authors concluded un managed pain, when added to other risk factors for delirium, could be a precipitating factor for delirium.

A similar study using a matched group design was done to determine if a difference existed in the amount of analgesia received by patients who developed delirium compared to patients who did not (mean age 80) (Robinson & Vollmer, 2010). Data were collected through retrospective chart review and a two-sample t-test was used to compare the groups on the dependent variable of percentage of allowed analgesic received. A significant difference was found in the amount of allowed analgesic used (p <0.001). The group that did not develop delirium used 48.21% of the allowed analgesic, while the group with delirium used 26.14% of the allowed analgesic. Authors suggested a relationship exists between low doses of analgesic and the development of delirium; however, a causal relationship could not be established.

The Beers Criteria for Potentially Inappropriate Medication Use in Older Adults should be consulted by providers choosing medications for adults age 65 and older (The American Geriatrics Society 2012 Beers Criteria Update Expert Panel, 2012). It identifies medications for which the potential risks outweigh the potential benefits. The list was developed through systematic review and use of a modified Delphi method by a panel of 11 experts in geriatrics and pharmacology. Medications were divided into three categories: "potentially inappropriate medications and classes to avoid in older adults, potentially inappropriate medications and classes to avoid in older adults with certain diseases and syndromes that the drugs listed can exacerbate, and finally medications to be used with caution in older adults" (The American Geriatrics Society 2012 Beers Criteria Update Expert Panel, 2012, p. 1).

Based on the Beers Criteria (The American Geriatrics Society 2012 Beers Criteria Update Expert Panel, 2012), several medications that may be used for pain management or as adjuncts are not recommended for use in older adults. For example, the opioid meperidine (Demerol®) should be avoided in older adults because it may cause neurotoxicity. Chronic use of nonsteroidal anti-inflammatory drugs (NSAIDs) should be avoided because of the increased risk of gastrointestinal (GI) bleeding and peptic ulcer disease unless alternatives are ineffective and the patient can take medications to provide GI protection (e.g., proton pump inhibitor). Use of indo methacin (Indocin®) and ketorolac (Toradol®) should be avoided because of the risk of peptic ulcers and GI bleeding in individuals over age 75, or persons taking corticosteroids, anticoagulants, or antiplatelet agents. Use of NSAIDs also should be avoided in individuals with stages IV and V chronic kidney disease because of increased risk of kidney injury. Tricyclic antidepressants, which of ten are used as adjuncts to treat neuropathic pain, should be avoided because of anticholinergic effects that may cause sedation and orthostatic hypotension.

Individuals With Renal Disease

The long-term use of acetaminophen (Tylenol®) has been associated with renal disease; however, it is preferred over NSAIDs for individuals with renal insufficiency. NSAIDs' ability to block the enzyme cyclo-oxygenase 1 (COX 1) can cause decreased renal blood flow in individuals with volume depletion or hypotension, and cause renal ischemia and acute renal failure. Individuals with cardiac failure, liver cirrhosis, diabetes, or hypertension, or who take angiotensin-converting enzyme inhibitors, may be more susceptible to perioperative renal failure caused by NSAID use (Pasero et al., 2011). NSAID and COX inhibitor use is not recommended in individuals with chronic renal failure (Macintyre et al., 2010; Pasero et al., 2011).

Opioid excretion may be prolonged in the presence of renal disease, causing active metabolites of medications to accumulate. Accum ulation is most problematic when medications are administered orally and when meperidine is given, but morphine also may cause problems. Morphine should be avoided in individuals with end-stage renal disease. Codeine also should be avoided. Hydromorphone (Dilaudid®) or fentanyl (Sublimaze®) may be tolerated better than morphine for shortterm use. Fentanyl can accumulate when used long-term and is not removed by dialysis. Epidural or intrathecal routes allow administration of lower opioid doses and may be an alternative (Pasero et al., 2011).

Individuals With Substance Use Disorders

Treating pain in individuals who also have a substance use disorder can be both challenging and ethically distressing. Health care providers may be reluctant to prescribe opioids and nurses may be reluctant to administer them be cause they fear contributing to patients' addiction. Requests for analgesics by individuals with illnesses associated with chronic pain, such as sickle cell disease, may be misinterpreted by health care providers as drug-seeking behavior (Finney, 2010; Pasero & Portenoy, 2011).

Addiction is a chronic neurologic and biologic disease influenced by genetic, psychosocial, and environmental factors. It includes one or more of the following behaviors: "inability to consistently abstain, impairment in behavioral control, craving, diminished recognition of significant problems, or a dysfunctional emotional response" (Ameri can Society of Addiction Medi cine, 2011, p. 2). Physical dependence is a normal physiologic response to the administration of opioids or other medication for more than 2 weeks (American Academy of Pain Medicine, American Pain Society, & American Society of Addiction Medicine, 2001; Pasero & Portenoy, 2011). The body adapts to the presence of the medication; if the medication is stopped or reduced suddenly, the body reacts with symptoms of withdrawal. Physical dependence does not indicate addiction (Pasero & Portenoy, 2011). Similarly, tolerance does not indicate addiction. Tolerance is adaptation by the body that causes decreased effects of the drug over time (American Academy of Pain Medicine et al., 2001; Pasero & Portenoy, 2011). Increased doses of the medication are needed (Pasero & Portenoy, 2011). Pseudoaddiction occurs when individuals demonstrate some behaviors asso ciated with addiction. Un like true addiction, however, the similar symptoms are related to unmanaged pain and will resolve when the pain is treated effectively (American Academy of Pain Medicine et al., 2001; Pasero & Portenoy, 2011).

An individual having surgery is expected to have pain that must be treated, even if he or she has a history of a substance use disorder. Nonpharmacologic interventions, such as heat, cold, or massage, can be tried for mild-tomoderate acute pain. Nono pioid medications (e.g., acetaminophen, NSAIDs) are op tions as well. Nerve blocks also may be used (American Society of Anesthesiologists Task Force on Acute Pain Management, 2012). Opioids should not be withheld if indicated for acute pain, al though the best choice of opioid is a pure opioid agonist or mu re ceptor agonist, such as morphine, methadone (Dolophine®), co deine, fentanyl, oxycodone, levorphanol, oxymorphone (Opana®), or hydromorphone (Pasero et al., 2011).

Scheduled administration of medications on an around-the-clock basis is preferred (Pasero et al., 2011). Early consultation with addiction medicine and pain management specialists is recommended (Krupnick, 2009). Individuals with a substance use disorder generally require more opioid than opioid-naïve individuals because they have developed tolerance. Individuals who take opioids daily will need more than their usual daily dose to achieve pain management. They should continue their usual opioid dose (Eksterowicz, Quinlan-Colwell, Venderveer, & Menez, 2010; Pasero et al., 2011). Care must be taken to prevent withdrawal (Pasero et al., 2011).

Individuals receiving methadone for the treatment of addiction should continue to receive their usual dose and receive a different opioid for the treatment of acute pain. This aids in medication tapering as acute pain resolves. Treatment of acute pain in individuals receiving buprenorphine (Bu prenex®) for the treatment of addiction is difficult because this drug binds to opioid receptors and blocks the action of opioids. When possible, buprenorphine should be stopped a few days before a surgical procedure. In the case of unplanned surgery or an accident, pain should be treated with mu opioids (e.g., morphine, methadone, codeine, fentanyl, oxycodone, hydro morphone) (Pasero et al., 2011) and may require high doses (Huxtable et al., 2011). Opioids should be administered on a schedule or using a patient-controlled analgesia (PCA) pump instead of on an as-needed basis to provide longer duration of analgesia and decrease adverse central nervous system effects (Drew & St. Marie, 2011).

Individuals With Persistent Pain

Individuals with persistent pain who are treated with daily doses of opioids also will have tolerance to opioids and will require larger doses than opioidnaïve persons (Macin tyre et al., 2010). Individuals who take daily doses of opioids should not be treated with a nonopioid regimen or with mixed opioid agonistantagonists (e.g., nalbuphine [Nubain®], butorphanol [Stadol®], buphrenorphine [Buprenex®], pentazocine [Talwin®]) because of the risk of opioid withdrawal (Macintyre et al., 2010; Oliver et al., 2012). The usual opioid dose should be maintained. Post-operatively, the additional opioid dose required may be 30%-100% greater than the dose required by an opioid-naïve individual. However, opioid doses must be individualized based on the person's response to the medication (Eksterowicz et al., 2010).

Individuals With Obstructive Sleep Apnea

Persons with obstructive sleep apnea (OSA) are at greater risk of developing respiratory depression and sedation when receiving opioids. In addition to causing sedation that could lead to respiratory depression, opioids cause relaxation of the tongue and muscles of the upper airway (American Pain Society, 2008; Macintyre et al., 2011). These effects of opioids may intensify the mechanisms causing OSA. This challenges the health care provider to provide pain management while preventing respiratory complications.

Several strategies may decrease the risk of respiratory complications in individuals with OSA receiving opioids for pain management. Patient-controlled analgesia should be used with caution, if at all; a basal or continuous rate should not be used because of the increased risk of respiratory depression (Adesanya, Lee, Greilich, & Joshi, 2010; Bolden, Smith, & Auckley, 2009; Jarzyna et al., 2011; Macintyre et al., 2010). The type of opioid used and its peak effect time, the patient's other medications, and his or her sedation level should be considered to help prevent respiratory depression (Jungquist, Karan, & Perlis, 2011). The use of capnography to measure expired carbon dioxide levels is recommended for use in individuals with OSA receiving opioids by PCA to detect early signs of respiratory depression (Jarzyna et al., 2011).