The Pain Physician

The consulting anesthesiologist in an inpatient setting may be called on to provide care for one of three reasons. First, the patient may need a regional nerve block, such as an epidural steroid injection for magnetic resonance imaging–confirmed discogenic pain or epidural catheter placement to assist physical therapy. This consultation is fairly straightforward and is an extension of basic regional anesthesia principles. Second, a child who has been prescribed opioids chronically or other medications that have implications for anesthesia or postoperative pain management may present for consultation. The anesthesiologist must investigate possible drug interactions and determine which chronic medications have been prescribed; this approach is an extension of basic perioperative anesthesia skills. Third, a consultation may be requested to assess and diagnose the source of pain. This scenario is the most complex and requires taking a detailed history and performing a thorough physical examination. These children often require multidisciplinary care beginning with the initial evaluation and extending through treatment.

The Psychologist

Pain is more than just a physical phenomenon. It can cause and be worsened by stress, suffering, family dysfunction, social tension, anxiety, and depression.^5,13 Pain can disrupt almost any aspect of the life of the child or family. Family and school problems can worsen a painful condition and dramatically reduce a child’s level of function. The family is always involved in the child’s suffering and should therefore be included in the pain evaluation process.

Families often are wary about seeing a psychologist and are afraid of being stigmatized. It is important to emphasize that pain is what the child says it is, regardless of whether an obvious organic cause is identified. The child is being treated as a person, not just as the painful body part, and this approach should be emphasized for the child’s family.

Psychology-based therapy includes relaxation training, biofeedback, hypnotherapy, coping skills training, and psychotherapy. Biofeedback is a modality that trains the child to become more aware of his or her body, enhancing the sense of control over it. Therapies aimed at parental and familial aspects of the child’s pain include teaching strategies for behavioral interventions (e.g., distraction), activity pacing, consistent discipline, coaching skills training, stress management, and occasionally, family therapy.

The Physical Therapist

Physical therapy is a crucial component of evaluating and treating chronic pain. The painful condition can cause loss of muscle strength and range of motion. Alterations in the use of a limb affect the biomechanics and daily function of the body. Children can become deconditioned and require a conditioning program to regain lost strength and stamina. These changes affect the original pain site and generate secondary pain problems that need to be addressed.

Physical therapy can benefit many painful conditions (e.g., myofascial pain improves with stretching and range-of-motion exercises) and is the cornerstone of treatment for others (e.g., chronic regional pain syndromes [CRPS]).¹⁴ Emphasizing self-reliance and responsibility for their own care is an important aspect of caring for adolescents. However, young children and older ones in pain cannot be expected to work aggressively at home without beginning with a structured program. Parental involvement is especially important for younger children, but the caretakers must be taught to be encouraging and supportive while not making them the child’s taskmasters.

Therapies provided by physical therapy include stretching, strengthening, and reconditioning programs. Range-of-motion exercises and endurance training are also important. Aquatic therapy is very useful for children who cannot bear weight on lower limbs or have limited range of motion or strength. Massage, heat, and cold therapies are helpful adjuncts to increase functioning and enhance other physical therapy modalities.

Transcutaneous electrical nerve stimulation (TENS) is an effective,¹⁵ low-risk, analgesic therapy that is usually provided under the guidance of a physical therapist. TENS is excellent for localized pain. The fact that it is portable, can be used discreetly, and has few side effects makes it attractive for use at school. Because tolerance to TENS can develop with prolonged use, children need to limit use to no longer than 2 hours at a time. They can take a break for an amount of time equal to the TENS use and then restart it.

The Nurse

Pain nurses play a major role in hospital-wide education of floor nurses regarding assessment and treatment of pain, including the use of epidural and patient-controlled analgesia (PCA) pumps. When starting to see chronic pain patients, the first personnel recruitment should be an advanced practice nurse who can be trained to triage, perform the initial evaluation and intake assessment, and assist with all subsequent pain-related issues that do not require the direct input of a physician.

The Consultant

Anesthesiologists should be cognizant of their limitations and judiciously use of consultants to help make or confirm diagnoses and fashion the best treatment plan. Neurologists typically are well versed in headache management and in the use of many of the medications used for neuropathic pain. Physical medicine and rehabilitation specialists can assist in structuring a treatment plan for a variety of musculoskeletal pains and are accomplished in the treatment of spasticity.

History

The basic history focuses on the pain: location, duration, quality, intensity, aggravating and alleviating factors, associated symptoms, therapies that have been tried, and which tests have been performed and by whom. Pain intensity is often assessed by a 0 to 10 numeric rating scale for children older than approximately 8 years of age. The child must be asked about the current pain level and about the best and worst pain levels to obtain an idea of the pattern of pain and when it peaks. Quality descriptors include burning, sharp, aching, throbbing, tingling, numb, weird, and others; each may give a clue about the type of pain the child is experiencing. Odd descriptors, burning, and tingling suggest neuropathic pain; sharp, tight, and aching may indicate bony or muscular causes; throbbing suggests a vascular component; cramping or pain that comes in waves often suggests spasms of a muscle or hollow viscus.

A vital part of the chronic pain evaluation process is to look for red flags, which are signs or symptoms that may indicate a serious illness. Some of the red flag signs and symptoms for major pain types can be found in Tables 44-1, 44-2, and 44-3. For example, a child with back pain who also has weak legs and incontinence may have a tethered spinal cord. Headache that is worse in the morning and associated with vomiting suggests increased intracranial pressure. Back pain with loss of ankle jerk suggests compression of the S1 nerve root.

TABLE 44-1 Red Flag Signs and Symptoms for Abdominal Pain

TABLE 44-2 Red Flag Signs and Symptoms for Secondary Headache

TABLE 44-3 Red Flag Signs and Symptoms for Back Pain

A complete pain evaluation comprises further history regarding medications, allergies, family history, and a thorough review of systems. Certain painful conditions, such as migraine headaches,¹⁶ fibromyalgia,¹⁷ irritable bowel syndrome,¹⁸ and sickle cell disease, have a genetic basis. Knowing the family history can assist in making the diagnosis. The child sometimes may model his or her behavior after a family member. For example, if a parent has a “bad back” and is functionally compromised, the child also may complain of back pain. This does not mean the child is faking the complaints but simply patterning the behavioral response to pain after a model that he or she understands. Treatment can include reassurance, cognitive behavioral therapy, and gentle physical therapy to restore the child’s functional ability and help him or her with any underlying issues. Family and social histories can be useful in fashioning a treatment plan in conjunction with the general history, physical examination, and relevant testing.

Physical Examination

The physical examination should focus on the area of interest, but a brief general examination is also important. A full screening examination, including a neurologic examination, takes only a few minutes and can be combined with the social history. A systemic illness may manifest as a localized complaint; for example, diabetes can manifest as abdominal pain or leukemia as focal bone pain

When examining a child of the opposite sex, the physician should have a nonfamily observer of the same gender as the child present. Some children are very conscious of their bodies and may consider routine examination maneuvers as invasions of their privacy. The occasional child has a history of being abused and can be further traumatized by even a standard examination. Physicians can demonstrate examination techniques that may make the child uneasy. For example, a pinprick examination requires a needle or sharp object; the examiner should touch his or her own skin with a pin first to demonstrate that blood is not being drawn. Children are often fascinated by the deep tendon reflexes and usually have fun with that examination. Children with chronic pain often have had many examinations, and doing something a little different or fun can help them accept the current evaluation and enhance rapport.

Ancillary Data

By the time chronic pain patients have reached a pain clinic, they usually have undergone several investigative tests, and those data should be reviewed. After it becomes clear that there is no life-threatening illness, the focus should shift away from further testing. This is often a hard transition for families and children to accept, especially if no concrete diagnosis has been made to explain the pain. It is a challenge for them to embrace the thought that the pain itself is the disease rather than something that is still undiagnosed. Any study that may help to explain the pain or make a diagnosis that had not been entertained should be recommended. However, pursuing tests and imaging in an unfocused manner wastes resources and causes families to postpone treatment while waiting for a diagnosis. Until the patient wholeheartedly endorses the treatment plan and becomes active in it, the child or adolescent’s pain will continue unabated.

Abdominal Pain

Abdominal pain is a major source of distress in children that causes anxiety and invites a large amount of testing. This painful condition, formerly referred to as recurrent abdominal pain, is now described as functional gastrointestinal disorders (FGIDs).²⁰ Specific criteria exist for the major categories so that FGIDs are no longer considered diagnoses of exclusion. The pain is thought to be caused by abnormal interactions between the enteric nervous system and central nervous system.²¹ Research suggests that peripheral sensitization and abnormal central processing of afferent signals at the level of the central nervous system play roles in the pathophysiology of visceral hyperalgesia—a decreased threshold for pain in response to changes in intraluminal pressure.²² The history and physical examination focus on excluding warning signs and symptoms of underlying disease (see Table 44-1).^20,23 The role for testing, endoscopy, and radiographic evaluation is limited.

Multidisciplinary treatment of FGIDs includes medication, psychological interventions, and education, which often need to be ongoing. The most important aspect of the treatment plan is to establish realistic goals, which frequently means return of function rather than complete elimination of pain. Although the literature for treatment is sparse, tricyclic antidepressants such as amitriptyline, nortriptyline, or doxepin have been used effectively for FGID-related pain. Anticonvulsants also are useful because they modify nerve conductivity and transmission. Antacids, antispasmodic agents, smooth muscle relaxants, laxatives, and antidiarrheal agents can be added to address symptoms. Data support the use of peppermint oil capsules in managing irritable bowel syndrome, although gastroesophageal reflux can be a limiting adverse effect.²⁴ Children with functional bowel disorders can have abnormal bowel reactions to physiologic stimuli, noxious stressful stimuli, or psychological stimuli (e.g., parental separation, anxiety). Children benefit from cognitive- behavioral therapy, coping skill development, biofeedback, hypnosis, and relaxation techniques (Table 44-4).^25,26

TABLE 44-4 Care Pathway for Abdominal Pain

Headache

Headaches can be categorized as primary or secondary. Primary headaches include migraine, tension, cluster, and trigeminal neuralgia headaches. Secondary headaches are those attributable to head and neck traumas; muscle spasms; vascular disorders; nonvascular intracranial disorders; infection; eye, ear, cranium, nose, sinus, and teeth or mouth diseases; homeostatic disturbances; and psychiatric disorders. Headaches represent one of the more poorly tolerated types of chronic pain, with greater medication use than for other types. Of 77 children with long-term headaches who were followed up to 20 years after the initial diagnosis, 27% were headache free, and 66% had improved.²⁷

Migraines (especially migraine without aura) and tension-type headaches are the most common types of pediatric headaches. The prevalence of migraine ranges from 2.7% to 10%. It occurs more frequently in boys than girls between 4 and 7 years of age, and then the prevalence equalizes between 7 and 11 years of age. After 11 years of age, three times more girls than boys have migraines.^28,29 Studies are not routinely recommended in the absence of focal neurologic findings. However, the practitioner must be alert to red flag signs and symptoms that warrant imaging and laboratory studies to rule out an underlying condition as a cause of the headaches (see Table 44-2).

There is a genetic component to migraine and chronic tension headaches; 50% to 77% of children with migraines have a positive family history for migraine headaches, especially on the maternal side. The clearest genetic link has been established for familial hemiplegic migraine.¹⁶

Children with frequent headaches often suffer from medication overuse headaches due to chronic or repeated use of over-the-counter analgesics. If possible, children should be weaned off analgesics gradually.

Treatments for migraine and tension-type headaches overlap greatly. Pharmacologic interventions can be divided in two types. In the first, abortive treatment focuses on stopping the acute headache. In the second, prophylactic therapy is indicated for patients with more than two headaches per month, for children with severe attacks, and for those with frequent headaches unresponsive to medication (Table 44-5).³⁰

TABLE 44-5 Care Pathway for Headaches

Older medications that have been used successfully to prevent headaches in adolescents include amitriptyline and trazodone. These medications tend to make children drowsy and are prescribed 30 to 60 minutes before bedtime each night. Younger children appear to respond well to the antihistamine cyproheptadine. Overall, few evidence-based recommendations can be made; the lack of randomized, controlled pediatric trials precludes an evidence-based recommendation.³¹ However, the anticonvulsant topiramate is a promising medication for the prevention of migraine headaches.^32–34

Complex Regional Pain Syndrome

Type I and type II CRPS are different only in the presence of a documented nerve injury in type II (formerly called causalgia