Pain assessment is critical to optimal pain management interventions. While pain is a highly subjective experience, its management necessitates objective standards of care.
Pain assessment is an ongoing process. An initial assessment is followed by treatment for managing the pain and this treatment is evaluated by subsequent assessment of pain to determine its effectiveness. The patient's pain should therefore be assessed on a regular basis and the resulting treatment options modified as required to ensure effective pain relief.
Pain assessment includes:
- Clinical history
- Physical examination
- Pain measurement using pain assessment tools
A. Presenting complaint
This complaint pertains to the immediate problem for which patient has to seek the clinician's opinion. Best way to elicit this complaint will be asking the patient as to what made him come to you. Once he mentions the problem, one should quickly move to next detail.
B. History of present illness
If the history of the presenting complaint includes pain, ask about it using the mnemonic SOCRATES. SOCRATES is a mnemonic acronym used by emergency medical services, doctors, nurses and other health professionals to evaluate the nature of pain that a patient is experiencing
SOCRATES is a mnemonic acronym used by emergency medical services, doctors, nurses and other health professionals to evaluate the nature of pain that a patient is experiencing
- Site - Where is the pain? Or the maximal site of the pain.
- Onset - When did the pain start, and was it sudden or gradual? Include also whether if it is progressive or regressive.
- Character - What is the pain like? An ache? Stabbing?
- Radiation - Does the pain radiate anywhere?
- Associations - Any other signs or symptoms associated with the pain?
- Time course - Does the pain follow any pattern?
- Exacerbating/Relieving factors - Does anything change the pain?
- Severity - How bad is the pain?
- Site of pain:
refers to the area supplied by a root or nerve. This has to be differentiated from one another because neuralgia paraesthetica over lateral aspect of thigh is because of compression of lateral cutaneous nerve of thigh, while disc prolapse leading to irritation of C- 1,2,3 will refer to whole of thigh. Sometimes there is little bit of difficulty because of referred pain. Diaphragmatic irritation can lead to shoulder pain ipsilaterral; anginal pain can radiate to left upper limb; carcinoma head of pancreas with coeliac axis node will produce dull boring pain over back and upper abdomen. All these are mentioned to highlight the importance of knowing the site of pain.
- Onset / duration:
The mode of onset can give a clue as to what might be wrong with that concerned system. A migraine's pain that has been there for years might be a benign one; an explosive headache started for first time could be a sub-arachnoid hemorrhage secondary to rupture of intracranial aneurysm. Acute onset pain which has a definitive diagnosis and management and hence a better result, on the contrary a chronic body ache (fibromyalgia) is more often refractory. Duration of pain: Also helps in treatment plan. Long duration chronic backache because of bad posture, obesity and lumbar canal stenosis do not respond to treatment that easily. Acute onset back pain like prolapsed inter vertebral disc will require aggressive investigation and treatment. As the chronicity of the disorder is more and more, the satisfaction rate comes down because of associated morbidity. Failed back syndrome (post spine surgery) patients response many a times very poorly to treatment plan.
- Character of pain:
The character of pain many a times gives clue about the underlying disorder. Some of the examples are; burning pain could be because of deafferentation, shooting pain could be due to nerve compression, stabbing pain may be neuralgic, malignancy pain may be of dull nature, tingling sensation might show neuropathy, throbbing of migraine, aching pain of carpal tunnel syndrome so on and so forth. The type of pain gives us an insight into pathology.
It is important to know whether patient feels pain externally, internally or both. In the sense external pain may be because of superficial pain. Internal pain could be because of involvement of deep related structures. Sometimes one may encounter a situation where patient cannot differentiate either external or internal because of standing pain.
Classical example of this clinical entity is back pain to start with can be situated over lower lumbar region, over a course of time might radiate along back of thigh, leg and sole of foot. This signifies that the initial disc protrusion might have reached disc prolapse state most probably. However there are many reasons for change of pain to radiating type. Facet joint arthropathy can also cause same problem, but it rarely reach sole of foot.
- Associated symptoms like:
Bowel and bladder disturbances, numbness, weakness signify serious nerve function impairment. Numbness over intercostal space with burning pain could be post-herpetic neuralgia. Person complaining of severe headache associated with vomiting and seizures might have serious intracranial pathology.
This fact gives an insight as whether it is continuous, intermittent or occasional. A continuous pain of malignancy is different from intermittent pain of complex regional pain syndrome. An occasional pain of muscle cramps secondary to undue strain on calf muscle is of benign nature. For some people the pain just will not allow them to do any of their day to day activities, however some of them continue to work like patients with migraine. All these signify the severity of pain limiting their activities.
- Exacerbating/Relieving factors
Drugs relieve pain as in certain types of backache. Some patient's express they get relief when they take rest for some time, like pain of vascular insufficiency. There are people who feel better when they take off from their work. Work stress might be playing a big role in them. An attempt should be made to relieve work stress, otherwise the planned treatment it will fail. A trial of carbamazepine in a patient with shooting pain might signify neuralgia
By some standards as mentioned under relieving factors, there are quite a few aggregating factors. The classical example being worsening of post-herpetic neuralgia by touch of cloth; aggravation of lumbar radiculopathy in prolapsed interventional disc by walking.
- Severity of pain
One of the biggest problems in assessing pain is that it is subjective there is no way of measuring quantitatively like one measures temperature using thermometer. Experience of pain not only varies from person to person but also from race to race. People belonging to Africa or Asian race might have high threshold when compared to people of European race, of course this need not be true all the time. Tolerance to pain also depends on affluence of the person in the society and his or her sophistication.
So many scales and scores have been devised to asses pain like visual analog scale (VAS), Mc gill's questionnaire… Every scale has its own limitation in assessing pain. By far the most popular scale is VAS.
C. Past history:
- Systemic illness:
Having an idea about the systemic illness helps a lot in correlating findings. Someone who is a known diabetic for 20 years can always develop neuropathy. Associated systemic illness always carry some amount of morbidity in management tolerating the medications prescribed for pain management can be a problem if the person were to have a duodenal ulcer. Patient of ischaemic heart disease might have been put on acetyl salicylic acid as platelet inhibitor; prescribing one more NSAID can trouble him. Person who has asthma can go into exacerbation if he is allergic to NSAIDs. From all these angles it is important to know the underlying systemic illness.
Patients with valvular heart disease most often will be on anticoagulants. Trying to do an intervention on a patient who is on anticoagulants can lead to formation of a haematoma. If a person is on anti diabetic regimen and has to undergo procedure which requires fasting state, better be careful, he might end up in hypoglycemia. Prompt tabulation of medication taken by patient and clear instructions can many a times avoid catastrophe.
- Pain medications:
Most often, patients who come to pain specialist will be on some pain relieving drugs. It should not happen that we end up adding one more pain killer to the list. People on anti-psychotic medication should be carefully handled in adjusting the dosage otherwise whole thing can end up in a mess. People who are on opioids for pain relief should be treated in a different way. They will be dependent on the kind of opioids and achieving good results in pain relief is not that easy. Exceptions for opioid dependent patients are cancer patients whose life span will be limited. In this group of patient's one should not hesitate increasing the dosage of opioids for pain relief, keeping an eye on side effects.
Red flags in patient's history of medications intake are minor/major opioids (morphine, dedextropropoxyphene. Codeine), mood elevators like amphetamine & others. One has to deal carefully in this group of patients.
- Surgical history:
One need not mention the importance of taking this history. Surgical information is important to know whether existing pain has some relation to it. Person, who has undergone laminectomy for PIVD comes back to you with complaints of backache with worse symptoms, can give a tough time. One should suspect adhesions in a patient with a past history of abdominal surgery coming with pain abdomen. An amputee can come to you with phantom limb pain. History of surgery of kidney donation is important in that he cannot be put on NSAIDs for risk of inducing renal failure.
- Physical therapy / physiotherapy:
Previous attempt at physiotherapy has helped the patient or not will guide in subsequent rehabilitation programme. A therapy, which has not helped much, can as well be avoided.
- Other treatment / Nerve blocks:
Whether previous treatment has helped or not, if it has helped then to what extent pain relief was obtained. An associated side effects noticed will have to be noticed.
D. Personal history / family history:
Details regarding occupation, whether full time or part time, job satisfaction, work compensation and others are very important. A particular kind work can initiate a typical pain syndrome. A computer professional who is sedentary otherwise can develop backache; a soldier with ill-fitting shoes can develop bunion over pressure points, which can be painful. Person having job satisfaction can very well complain of all kinds of pain without getting pain relief with any measure. Someone looking for workman's compensation will have to be scrutinized thoroughly.
Habits like tobacco chewing, smoking, alcohol consumption explains the stress the person is going through.
Marital life, children, social circumstances and family disputes will have to be discussed to know the aspects of personal life.
Menstrual history in female patients will be of great importance. Some varieties of migraine get aggravated during menstrual cycle, women in post-menopausal phase will be vulnerable for fractured due to osteoporosis.
E. Other relevant information:
After going through the details of present and past illness, one has to get information regarding certain general details. This information will help in investigation, treatment and follow-up periods.
- Constitutional – Any weight loss in the last 3 to 6 months of significant percentage can guide regarding the possibility of underlying malignancy or malnutrition. Fever of low grade lasting over last few months could be because of malignancy or tuberculosis.
- Skin – Any eruptions or rash could be secondary to allergy, immunosuppressed state or viral induced eruption.
- Allergy – Finding out the allergy history about drugs, contrast, latex, betadine and others will avoid major or anaphylactic reaction during pain management.
- Head / face – Any associated headache, facial pain can guide regarding complete pain. Person deprived of good sleep for very long can complain of chronic headache. This group of patients will require anxiolytics along with pain relieving medication.
- Eyes / ENT – Any history of having undergone cataract extraction procedure can tell you about the implants. Visual and auditory disturbances will have to be recorded.
- CVS – A brief assessment of cardiac symptoms like chest pain, breathlessness, pedal oedema, palpitations and others should be done.
- RS – Cough, breathlessness and previous history of Koch's can rule out respiratory complaints.
- GIT – Symptoms pertaining to gastric / duodenal ulcer like epigastric pain, reflux, vomiting can be warning signals before one prescribe drugs, which can worsen the existing symptoms. Analgesics might have to be combined with H2 blocker or proton pump inhibitors.
Altered bowel habits like diarrhoea or constipation can give clue about irritable bowel syndrom or colonic growth. People who have constipation will benefit with laxatives.
- Urinary disturbances - Urinary disturbances like dysuria, frequency, incontenence might be quite commonly seen in elderly population. Appropriate opinion should be sought from appropriate specialists.
- Haematological disturbances - One should look for haematological disturbances like frequent bruising or excessive bleeding. History of lymphadenopathy features like swelling around neck, armpits and groin should be elicited.
- Psychiatry – History of having met a psychiatrist for any problem in the recent past can throw light on current symptom complex.
- Social history – Regarding development of mental status, type of personality can tell about the respose to suggestion, consultation or treatment plan. Type A personality people may not accept things that easily.
Though extracting this information might appear laborious, over course of time an experienced pain specialist may not take much time in collecting details. These things have to be elicited in this much depth to avoid missing some findings which can hamper the treatment plan. Even for medico legal purpose this will be of great help.