Defining, understanding, and treating chronic and acute pain: adapted from a presentation at the SLE Workshop at Hospital for Special Surgery
Pain is conceptualized to be a response to an injury or a marker of illness. It is a very complex problem because it embraces physical, emotional, and social components. It is a mechanism in which the body tells us that something is wrong.
While for many people pain is a persistent daily challenge to treat and cope with, the science of understanding pain is rapidly developing. This is an exciting time to be working in the field of Pain Management. In the last ten years, a wealth of information has emerged through research and patient experience. As we learn through scientific investigation about how pain originates and how it progresses, we will better understand how to relieve it.
In this presentation, we will:
- Review some terminology related to pain. It’s important that when one clinician talks to another we share a similar language – this helps us to communicate about pain.
- Discuss the clinical differences between acute and chronic pain.
- Outline some treatment options.
- Mention some of the scientific advances in the field of pain management.
What is Pain?
Dr. Harold Merskey, a professor of psychiatry, defines pain as “…an unpleasant sensory and emotional experience associated with actual or potential tissue damage, or described in terms of such damage.”
This is a very scientific way to talk about pain, because it focuses on tissue injury. That is easy to understand. Yet, we know that there is also a powerful emotional aspect to pain.
In 1968, Margo McCaffery, a nurse and pain educator, defined pain as “…whatever the experiencing person says it is, existing whenever he/she says it does.”
In other words, pain is personal. You, the person experiencing it, define it. Pain is what it is to you; it is your experience. A report from the patient is the single most reliable indicator of pain. So, tell your healthcare provider how you are feeling.
Basic Pain Terms
Nociceptive – pain that results from acute tissue injury. It is divided into two classifications: somatic and visceral. Somatic pain is best understood as pain of the musculoskeletal system and is described as pounding, throbbing, and well localized - affecting an isolated area. An example is a cut or a sprain. Visceral pain originates in an organ. It is not localized and can be experienced somewhere other than the source, being diffuse in presentation. An example is pain from a kidney stone.
Neuropathic – nerve injury or dysfunction affecting the central or peripheral parts of the nervous system involved in bodily feeling (the somatosensory system). It is often described as a burning, stabbing, tingling, electrical, or pins-and-needles type of feeling. It is most frequently used when describing a chronic pain condition.
Breakthrough – episodic pain. It’s an acute, sudden break in relief from pain medication, which spikes and then returns to “normal”. The term came from cancer pain literature, going from a “steady state” (when medicated) and then having a spike.
Referred – pain felt at a site other than where injury occurs; e.g., pain from the pancreas that can be felt in the back.
Psychogenic – associated with psychological factors. There isn’t a definable source, but there are multiple causes. An example is a headache, which could come from not having coffee, as well as stress, low magnesium level, etc. It’s not rooted in one physical problem.
Classifications of Pain
is limited in duration. This type of pain has a defined time period in which it occurs, and it presentation matches the pathology (i.e., it has an identifiable cause).
Chronic Pain is now becoming known as “persistent pain.” It lasts well beyond the cycle of what pain should be, with a duration of over six months. The pain may not match the pathology (e.g., when the back is causing the problem when a patient presents with a knee problem). It might be intermittent – persistent but not constant, coming and going (e.g., migraine headaches). It is associated with other symptoms.
There are a variety of ways to treat pain, depending upon the symptoms. The following are some general treatment strategies.
Acute pain is treated with opioids/NSAIDS (non-steroidal anti-inflammatory medications). Note that the term “opioids” is now used instead of “narcotics” because it’s more scientifically accurate. Patients with persistent or chronic pain may also be prescribed NSAIDS and opioids, but antidepressants & anticonvulsants are commonly added.
Remember – no drug is completely harmless! Check with your prescriber before taking any new medication.
- Acetaminophen (Tylenol®): for some people, this is a wonder drug. However, it can be a problem to use regularly if taken in large amounts. The current recommended dose should not exceed 4g/day or 4000mg/day. However, this recommendation is under review by the FDA and will likely be changed to a maximum of 3000mg/day. Recent guidelines by the American Geriatric Society warn people about the use of acetaminophen, particularly in patients who have problems with their liver. For elderly patients and those with liver disease, the maximum will likely be lower than 3000mg/day.
Many medications combine acetaminophen with an opioid, like percocet. The most frequent dose of this medication contains 325mg of acetaminophen. So, if you are taking an opioid like percocet (5/325), pay attention to the total amount that you take in a day (six tablets will equal 3900mg of acetaminophen – which is now considered a high dose). If you are taking extra strength Tylenol® that contains 500mg of acetaminophen, it is recommended that you do not take more than six tablets per day. If you are taking a lot of acetaminophen, by itself or in a combination pill, you should ask your physician what the maximum should be in your case.
- Non-steroidal anti-inflammatory drugs (NSAIDS) include COX-2 selective drugs, such as Celebrex. When you have an injury, the way your body responds is to inflame the surrounding tissue to stimulate the healing process. These drugs attack that inflammation and diminish its effects while still allowing the process to continue. NSAIDS can be over-the-counter (e.g., alleve/advil/motrin) or be given in prescription strengths. Side effects, especially in older populations, include ulcerations and bleeding. It is recommended that you can take a medication like Pepcid or Prilosec to coat your stomach lining while taking NSAIDS. If you have a bleeding disorder or GI (gastrointestinal) problems, consult your prescriber before using any NSAIDS.
NSAIDS work well for acute pain. Besides pill form, they also come in patches, creams, or gels. Note that if you use the cream, don’t combine it with the pills – it’s the same effect but cream works more slowly. The only difference is the routing administration.
- Analgesics – oral opioids. These include drugs like Percocet, Vicodin, Norco, and Tramadol. Once you take them, they begin to work in about 30 to 45 minutes. Opioids can be associated with constipation, even with limited use. If you are taking opioids for pain, ask your prescriber about how to best treat constipation. They might recommend drinking a lot of fluid, eating fruits and vegetables, or starting a bowel regime. Avoid bulk formers such as Metamucil, as this can make your constipation worse. Just a side note on two old opioids - the FDA recalled Darvon and Darvocet; they are off the market. Demerol leaves metabolites that are dangerous and can make you ill, and is rarely used anymore.
- Anticonvulsants & Antidepressants. Medications in this classification can be helpful additions to a pain regime. They can help reduce anxiety and depression that can occur because of a pain condition. Many of these medications also seem to help reduce the intensity of pain, particularly nerve pain. Examples of these medications are Cymbalta (antidepressant) and Lyrica (anticonvulsant).
- Corticosteroids are given via intra-articular injections (e.g., Cortisone) or orally (e.g., Prednisone).
- DMARDS (Disease-modifying anti-rheumatic drugs) were developed for rheumatoid arthritis (e.g., Cytoxan).
- Nutraceuticals - A food or part of a food that allegedly provides medicinal or health benefits, including the prevention and treatment of disease. A nutraceutical may be a naturally nutrient-rich or medicinally active food, such as garlic or soybeans, or it may be a specific component of a food, such as the omega-3 fish oil that can be derived from salmon and other cold-water fish. These agents are commonly used today although their risk/benefits as a classification of pharmacologic treatment remains unclear.
Benefits and Risks of these Medications
Corticosteroids risk: Long term use can reduce your body’s ability to use calcium to build bones, which could promote osteoporosis.
DMARDS risk: These work slowly and can suppress the immune system.
Nutraceuticals risks: Always tell your doctor if you are intending to use these (including rose hips, fish oil, etc.), as they are not regulated and can interact negatively with other medications.
- Benefits: Opioids are very good for acute pain. These medications come in many formulations, including injections, sprays, pills, patches, and suppositories. In other words, if you can’t get a pill down, there are options. Opioids are used for moderate to severe pain. Also, they are shown to help reduce the degree of pain intensity and improve physical function. So they don’t eradicate the underlying problem, but they do allow you to gain some control over your symptoms.
- Risks: The #1 side effect of opioids is constipation. You will need to take something (e.g., a stool softener), particularly as you get older. Other effects include sedation, nausea (your doctor will often give something prophylactically to settle your stomach); slowed thinking (making you less sharp); and increased tolerance to the medication. Note that tolerance does not mean that you will become addicted; addiction hinges on craving, while tolerance does not. Be sure to tell your doctor what you’re taking and how often you are taking it so your dosage can be adjusted accordingly.
Benefits: Non-steroidal anti-inflammatory drugs relieve pain and inflammation, but they will not help you heal.
- Risks: They do not affect the course of the disease. They can cause ulcers and bleeding.
General medication tips:
- If your medication has no apparent effect, talk to your health care provider.
- If you are having side effects from the medication, talk to your health care provider.
- Consider the schedule – you may need to take it at night instead of noon, etc.
- Consider changing the dose/frequency – this can change as your body responds.
- Consider trying another medication in the same class.
- Combining two types of agents can help (i.e., opioid + non-steroidal).
- Consult with your health care provider before stopping your medications.
- Keep your medications is a safe place, clearly marked
- Remember the medication ordered is for you. Don’t share it with another person.
Your body is like a walking pharmacy. You have chemical agents in your body that, when stimulated with activity, produce a healing effect. Options include, but are not limited to, meditation, supportive therapy, acupuncture, exercise (which releases endorphins in the body), and TENS (transcutaneous electrical nerve stimulation). TENS uses a portable device which sends electrical signals to the nerve fibers leading to the brain, which then releases natural pain-relieving substances.
Also, assistive devices increase safety, decrease stress on joints, compensate for unstable or weak joints, and increase independence. These help you by taking stress off the body.
Options for Acute Pain Relief
The main objective when relieving severe pain is the use of multimodal analgesia, which refers to a combination of solutions for pain relief; these include pharmacological and non-pharmacological sources.
- Use thermal therapy – applying hot and cold compresses. If you’re running and your joints are hurting, use ice. If you have arthritic pain and bones are hurting, consider using heat.
- Nerve blocks, performed by anesthesiologists, can numb your elbow by applying anesthetics.
- Physical therapy
- Assisted devices
Recent Developments in Understanding Chronic Pain
- Biological studies have given us insights into the neurotransmitter system (chemical messengers that pass nerve signals). Old theories about how pain signals travel through the body are being modified. Recent findings have shown that the pain pathways are more complicated and are effected by many different types of stimulation.
- Neurobiologic studies through MRI imaging are looking into pain and emotion. They have been able to visually identify pain in the brain and emotional responses to pain. So, when someone says the pain is in your head – well, it literally is.
- Psychosocial research shows that your feelings about your pain are more important in many ways than what caused the pain. How you respond is important. A lot of literature shows that support groups and individual responses matter.
- Chronic pain research has shown numerous things:
- Smokers tend to be more sensitive to painful stimuli.
- Smokers are more prone to depression.
- Individuals exposed to nicotine are at increased risk to develop back pain and other pain related problems.
- Behavior impacts on pain.
What does this all mean?
Today we have a much better appreciation of the mind-body connection and how it effects pain. They work together to help us respond and cope with pain.
As we learn more, we work with patients to offer insight into painful conditions and how to deal with them. With greater utilization of both pharmacology and non-pharmacologic treatment, there are more pain management therapy options for patients than ever before.
So, the best things you can do to improve your own ability to understand and manage pain is to stay connected, stay educated, and ask questions. We will do our best to help find the answers.
Barbara Wukovits has 23 years of working in the Anesthesia Department at HSS, and 20 years working in pain management.
The SLE Workshop at HSS
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1. Merskey, H. (1979). Pain terms: a list with definitions and notes on usage. Pain 6:249-252.
2. McCaffery M. (1968). Nursing practice theories related to cognition, bodily pain, and man-environment interactions. Los Angeles: UCLA Students Store.
3. Acute Pain Management Guideline Panel: Acute pain management:operative or medical procedures and trauma. Clinical practice guidelines. AHCPR Pub No 92-0032, Rockville MD, Agency for Health Care Policy and Research, Public Health Service, U.S. Department of Health and Human Services, Feb 1992.
4. Definition of Nutraceutical – Medicine net.com April 27, 2011
5. Warner, David O. (2010). Smoking and Pain: Pathophysiology and Clinical Implications. Anesthesiology. 113(4):977-992.
Summary by Steve Rudolf, SLE Workshop Intern