Health care providers have different perspectives on pain, different knowledge bases or skills to diagnose chronic pain conditions and differing capabilities or differing "tools" in their own personal tool box, so people with chronic pain must understand that—depending on who they see to manage their pain—they may get different diagnoses and different treatment plans. Patients should also know that not all physicians know all of the possible "tools of the trade" to treat patients in pain. Some physicians only practice non-invasive pain management and others only offer invasive therapies. Some physicians offer both non-invasive and invasive therapies in their practice. This article discusses both invasive and non-invasive therapies and offers the concept of a Pain Treatment Continuum, which is my attempt to place these therapies in logical sequence. Figure 1 is a listing of therapies by invasiveness.

Figure 1: Tools of the Trade—This figure lists possible therapies for pain management, "the tools of the trade," to be used in pain management listed in order of increasing levels of invasiveness. This list might not be all-inclusive and might raise some controversy as to which therapies are more invasive than others.
 

Non-invasive Therapies	Invasive Therapies
Exercise	Medication management
Psychologic pain management	Anesthetic blocking techniques
Physical and occupational therapies	Spinal cord stimulators
Biofeedback	Implanted pumps
Chiropractic manipulation	Peripheral nerve stimulators
Nutritional therapy	Surgery
Massage therapy	Chemical, surgical or thermal nerve destruction
Psychotherapy
Complementary medicine

Non-invasive Therapies
Non-invasive therapies include psychologic pain management, rehabilitation pain medicine through physical and occupational therapies and alternative pain relieving therapies such as acupuncture, acupressure, meditation/relaxation, nutrition, Qui-gong, and others. The purpose of psychologic pain management is to increase awareness and understanding of the pain experience, promote activity that does not harm the patient or activate pain, increase relaxation time, and promote behaviors that are healing and reduce behaviors that perpetuate the chronic painful experience.

Invasive Therapies
Interventional pain management includes medication management of pain, nerve blocking with local anesthetics, destruction of painful nerves, implantable devices for pain control such as morphine pumps or spinal cord stimulators, and surgery for pain.

Medicines used for pain control include short- and long-acting opioid medications, non-opioid pain medications, muscle relaxants, antidepressants, and anticonvulsant medications. Although not approved by the US Food and Drug Administration (FDA) for pain control, antidepressants and anticonvulsant medications do have pain-relieving properties, especially in patients with pain emanating from the nervous system (i.e., neuropathic pain). These antidepressant and anticonvulsant medications are called adjuvant medications. Non-opioid pain relieving medications include acetaminophen and the non-steroidal anti-inflammatory agents (NSAIDs), such as aspirin or ibuprofen. Opioid pain medications are either short or long acting. For constant pain, long-acting opioids are a better choice. Sometimes other medications, such as steroids, anti-hypertensive medications, oral local anesthetics, and others, are used for pain control.

Thinking Algorithmically: Using a Pain Treatment Continuum
An algorithm is a step-by-step plan to achieve a goal. The Pain Treatment Continuum is an algorithm for the logical use of pain treatments that suggests using less invasive, less costly therapies before resorting to more invasive and more costly therapies.

Because of growing awareness in the 1970s that it was not acceptable for patients dying from disease, such as cancer, to have unrelieved pain and suffering, the World Health Organization (WHO) provided guidelines for pain management for the dying patient. These guidelines are still used today by most caregivers who treat dying patients in pain (Figure 2).

Figure 2: World Health Organization Narcotic Ladder—The WHO guidelines suggest steps for pain control. For mild pain, the guidelines suggest using non-opioid pain relievers with or without an adjuvant medication (that is, medications that do have pain relieving properties not approved by the FDA for pain control). If pain persists, the guidelines suggest adding a mild opioid to the above therapy. If pain still persists after the addition of mild opioids, the guidelines suggest going to a strong opioid.

The WHO guidelines group cancer-related pain by severity into mild, moderate, and severe pain and suggest matching the strength of pain medications to the severity of the pain complaint of the patient. The WHO suggests non-opioid medications such as the NSAIDs and adjuvant medications (antidepressants and/or anticonvulsant medications) for mild to moderate cancer pain and weak to moderate strength opioids such as acetaminophen with codeine and hydrocodone (such as Vicodin, Lortab, or Norco) in combination with non-opioid and adjuvant medications for moderately severe cancer pain. Potent opioids such as morphine, together with non-opioids and adjuvant medications, are used for strong and severe cancer-related pain. Approximately 50% to 80% of patients dying of cancer, depending on the type of pain, should have their pain well controlled using these WHO guidelines.

For the treatment of chronic nonmalignant pain (that is, pain from disease that is not life-threatening), I suggest using a Pain Treatment Continuum such as the one suggested by the WHO for patients with cancer. The following Pain Treatment Continuum for nonmalignant pain obeys a time-honored medical principle of using simpler, less invasive, and least costly interventions before using more invasive and more costly therapy. This plan suggests either using one therapy or more therapy at a time, abandoning those that do not work, and advancing to more invasive therapies, as in climbing a ladder (Figure 3).

Figure 3: The Pain Treatment Continuum is a step-by-step plan (algorithm) for the appropriate use of possible pain management therapies. These therapies are listed in order of increasing invasiveness. These therapies can be used one at a time or in combination.

An example of using more than one suggested therapy at one time is the patient who continues to have back and leg pain after spinal surgery who takes aspirin, hydrocodone, an antidepressant, and who participates in physical therapy and a psychologic-oriented pain management program. This patient also may have had an epidural steroid injection in his or her back that allows for participation in physical therapy.

When All Else Fails
Because the WHO "ladder" to pain control provides good pain relief in only 50% to 80% of patients depending on what type of pain that they have, and because interventional approaches do work, we also propose the addition of interventional strategies to the WHO ladder as a fourth "rung" (Figure 4).

Figure 4: The Fourth Rung of the Ladder—Because the WHO ladder approach provides adequate pain management to only 50% to 80% of patients suffering from pain of terminal illness, and because interventional approaches do work, we propose the addition of invasive therapies.

Interventional strategies, as last resort interventions "when all else fails" include anesthetic nerve blocks, epidural steroid injections, continuous spinal pain-relieving techniques with implanted catheters and external pumps, neurodestructive techniques and implantable devices for pain such as spinal cord stimulators and morphine pumps.