General principles of clinical examination of the patient with pain

The key to a proper diagnosis is a complete history and physical examination. The findings from the examination, together with a review of the patient's previous discharge and diagnostic work-up, provide the key to differential diagnosis and treatment. In pain medicine, most patients have seen a variety of specialists, undergone a variety of diagnostic tests, and ultimately come to a pain clinic as a last resort. With advances in research and better training for first responders, this trend is beginning to change, with more patients being referred to pain specialists earlier in the course of their illness, with a more favorable outcome as a result.

• Patient survey

Pain history: pain localization, time of attack onset, intensity, character, associated symptoms, factors that aggravate and reduce pain.

It is important to know when and how the pain started. The onset of pain should be accurately described (e.g. sudden, gradual or rapid). If the trigger, time and circumstances of the onset of pain are known, then the cause is easier to determine. In cases of industrial injuries and car accidents, the condition of patients before and after the injury must be correctly interpreted and documented.

The duration of pain is very important. If the pain episode is short-lived, like acute pain, treatment should be aimed at eliminating the cause. In the case of chronic pain, the underlying cause has usually already been eliminated and treatment should focus on optimal long-term therapy.

Various methods are used to determine the intensity of pain. Since pain complaints are entirely subjective, it can only be compared with the person's own pain that he or she has ever experienced; it cannot be compared with another person's description of pain. Several scales are used to describe the so-called level of pain. The most commonly used scale is the visual analogue scale (VAS) of pain intensity. Using this scale, patients are asked to place a marker on a 100 mm continuous line between the value of "no pain" and "maximum imaginable pain". The mark is assessed using a standard ruler and recorded as a numerical value between 0 and 100. An alternative "method of assessing pain intensity is to use a verbal numerical rating scale. The patient immediately identifies a number from 0 (no pain) to 100 (maximum imaginable pain). The verbal numerical rating scale is often used in clinical practice. Another commonly used method is the verbal rating scale, where the intensity is ranked from no pain to mild, moderate, severe to maximum tolerable.

The patient's description of the pain pattern is quite useful when considering different types of pain. For example, burning or shooting pain often describes neuropathic pain, while cramping pain usually describes nociceptive visceral pain (e.g., spasm, stenosis, or occlusion). Pain described as throbbing or pounding suggests a vascular component.

Also of note is the evolution of pain from the onset of the attack. Some types of pain change location or extend beyond the primary site of injury or trauma. The direction of pain spread provides important clues to the etiology and, ultimately, to the diagnosis and treatment of the condition. An example is complex regional pain syndrome (CRPS), which may begin in a localized area, such as the distal extremities, and then extend proximally and, in some cases, even to the contralateral side.

The patient should be asked about the presence of associated symptoms, including numbness, weakness, gastrointestinal and/or genitourinary disturbances, swelling, sensitivity to cold, and/or decreased mobility of the limb due to pain.

It is important to identify factors that aggravate the pain, as they sometimes reveal the pathophysiological mechanism of the pain. Irritating mechanical factors such as different postures or activities (e.g. sitting, standing, walking, bending, lifting) may help differentiate one cause of pain from another. Biochemical changes (e.g. glucose and electrolyte levels or hormonal imbalances), psychological factors (e.g. depression, stress, and other emotional problems), and environmental factors (effects of diet and weather changes, including changes in barometric pressure) may be important diagnostic clues. It is also important to identify factors that relieve pain. Certain body positions may relieve pain more than others (e.g., in most cases of neurogenic claudication, sitting is a relieving factor, whereas standing or walking aggravates the pain). Pharmacological interventions and "nerve blocks" help the clinician establish the diagnosis and choose the appropriate treatment.

The patient should be asked about previous treatments. Information about analgesic efficacy, duration of treatment, dosages, and side effects of medications helps to avoid repeating methods or using drugs that were ineffective last time. The list should include all treatments, including physical therapy, occupational therapy, manual therapy, acupuncture, psychological interventions, and visits to other pain clinics.

Anamnesis of life

• Evaluation of systems.

Assessment of systems is an integral part of the complete evaluation of patients with chronic and acute pain. Some systems may be directly or indirectly related to the patient's symptoms, while others may be important to the management or treatment of the disease state. An example is a patient with poor blood clotting who cannot receive injection therapy; or someone with renal or hepatic impairment who requires adjustments to medication dosages.

• Previously suffered illnesses.

Previous health problems should be described, including those that have resolved. Previous injuries and past or present psychological or behavioral disorders should be recorded.

• History of surgical interventions.

A list of surgeries and complications should be compiled, preferably in chronological order, since some cases of chronic pain are a consequence of surgical procedures. This information is important for diagnosis and treatment decisions.

Drug history

The physician should limit and adjust the patient's medication intake because complications, interactions, and side effects of these drugs must be taken into account. The survey should include pain relievers, over-the-counter medications, and mutually exclusive drugs (e.g., acetaminophen, aspirin, ibuprofen, and vitamins). Allergies to drugs and any other allergies (e.g., latex, food, environmental factors) should be noted. The nature of the specific allergic reaction to each drug or agent should be described in detail.

Social history

• General social history.

In analyzing psychological factors, it is necessary to understand the patient's social status, financial security, and behavioral motivations. It is important whether the patient is married, has children, and has a job. The level of education, job satisfaction, and attitude toward life in general are important. Smoking and a history of alcohol or drug addiction are important in assessing and developing a treatment strategy. Lifestyle questions, such as how long it takes to get to work or how much time is spent in front of the TV, favorite types of recreation and hobbies, sports, and sleep give the practitioner a more complete picture of the patient.

• Family history

A detailed family history, including the health of the patient's parents, siblings, and descendants, provides important clues to the patient's biological and genetic profile. The presence of rare diseases should be noted. A history of chronic pain, alcohol or drug abuse, and disabilities in family members (including the spouse) should be established. Clues that do not have a direct genetic or biological basis may help to uncover hereditary mechanisms and codependent behaviors.

• Professional history

It is important to establish whether the patient has completed higher education and any academic degrees. Pay attention to the specifics of the current job and previous profession. The amount of time spent on each job, reasons for leaving, any history of litigation, job satisfaction, and whether the patient works full-time or part-time are important for the professional assessment. It is important to establish whether the patient had a disability group, decreased ability to work, or whether he or she has undergone vocational training for the disabled.

Examination of the patient

The clinical examination is a fundamental and valuable diagnostic tool. Over the past several decades, advances in medicine and technology and a better understanding of pain pathophysiology have greatly improved the way we assess the status of various systems, but the deficiencies in accurate diagnosis in the majority of patients referred to a pain clinic highlight the need for examinations that focus on detail and detail.

The types of examinations include both general multisystem examinations (ten organ systems: musculoskeletal, nervous, cardiovascular, respiratory, ear/nose/throat, vision, genitourinary, circulatory/lymphatic/immune, mental, and skin) and examination of a single system. In pain medicine, the most commonly examined systems are musculoskeletal and nervous.

If part of the diagnostic or therapeutic procedure is invasive, the examination should show whether the patient has risk factors for these procedures that need to be taken into account. Coagulopathy, untreated infection, and constitutional neurologic dysfunction should be noted before insertion of a needle or catheter or implantation of any device. Particular caution should be exercised when administering local anesthetics to patients with unspecified paroxysms, conduction anesthesia to patients with poor tolerance to vasodilation, or glucocorticoids to patients with diabetes.

The examination begins with an assessment of individual systems and typically moves from the head to the feet.

General inspection

• Constitutional factors.

Body weight, vital signs (blood pressure, heart rate, respiratory rate, body temperature, and pain intensity) should be measured and recorded. Note appearance, development, deformities, nutrition, and body care. Any equipment brought by the patient should be carefully examined. Patients who abuse alcohol or smoke may emit a specific odor. Observing a patient who is unaware that he or she is being watched may reveal inconsistencies that were not noticed during the examination.

• Pain behavior.

Pay attention to facial expression, color, and grimaces. Speech patterns indicate the presence of emotional factors, as well as alcohol or drug intoxication. Some patients try to convince the doctor that they are suffering from severe pain by confirming their verbal complaints with groans, crying, convulsive movements, grasping the painful area, overemphasizing antalgic gait or posture, or straining muscle groups. This, unfortunately, complicates an objective examination.

• Skin.

Assess the color, temperature, rash, and swelling of soft tissues. Changes in the trophism of the skin, nails, and hair are often observed in complex regional pain syndrome. In patients with diabetes, vascular pathology, and peripheral neuropathy, it is necessary to look for lesions that may be the cause of chronic bacteremia, which requires treatment before implantation of metal structures (e.g., a spinal cord stimulator or an infusion pump).

Systemic examination

• Cardiovascular system.

A systolic murmur with distribution suggests aortic stenosis, and the patient may have decreased tolerance to the hypovolemia and tachycardia that accompany rapid vasodilation (eg, after spinal local anesthetics and sympathetic or solar plexus block). The patient with an arrhythmia may have atrial fibrillation and may be taking anticoagulants. Arterial pulsatility (diabetes, complex regional pain syndrome, and thoracic outlet syndrome), venous filling, varices, and spider veins should be checked. Vascular claudication should be differentiated from neurogenic claudication in patients presenting with a diagnosis of lumbar spinal stenosis. The rise of invasive cardiac procedures such as coronary artery bypass grafting has increased the number of young patients receiving antiplatelet agents.

• Pulmonary system.

A lung examination may reveal breath sounds such as crackles, which may indicate congestive heart failure and decreased cardiac reserve. High-pitched wheezing may indicate chronic obstructive pulmonary disease. Caution should be exercised with chest blocks because of the risk of pneumothorax.

• Musculoskeletal system.

Examination of the musculoskeletal system includes assessment of gait and posture. Deformities and asymmetries are assessed. After collecting the anamnesis, the physician usually already has an idea of the part of the body where the symptoms of the lesion have developed. Otherwise, a short examination of the clinically significant area is required. Positive tests serve as a basis for further and more thorough examination of the affected segment. Palpation of soft tissues, bone structures, slightly mobile and mobile joints can reveal temperature differences, the presence of swelling, fluid accumulation, cracks, cracks, clicks and pain. Functional comparison of the right and left sides, measurement of normal spinal curves and provocation of typical symptoms by manipulation can help in determining the mechanism and localization of the pathological process. Measuring the amplitude of movements helps to identify hyper- and hypomobility of joints. Checking active movements determines flexibility, muscle strength and the patient's willingness to cooperate. Passive movements, on the other hand, if performed correctly, allow us to identify the presence of pain, determine the amplitude and volume. Most of the difficulty arises when examining patients with persistent pain because they tend to respond positively to most manipulations, thus making the specificity of tests low.

• Special tests.

Straightened lower limb raise (Lasegue's sign): determines the mobility of the dura mater and dural sac at the L4-S2 level. The sensitivity of this test in diagnosing lumbar disc herniations is 0.6-0.97, specificity 0.1-0.6.

Tension of the sciatic nerve, starting from 15 to 30 degrees, is assessed in the supine position. This puts tension on the nerve roots from L4 to S2 and the dura mater. Normally, the amplitude is limited by tension of the hamstrings at a level of 60 to 120 degrees. Elevation of more than 60 degrees causes movement in the sacroiliac joint and therefore can be painful if there is dysfunction of this joint.

Basic sacroiliac joint tests that cause buttock pain: (These tests are done to find out when the buttock pain occurs):

• With the patient lying on his back, press the iliac bones outward and downward with his arms crossed. If pain occurs in the buttocks, repeat the test with the patient's forearm placed under the lumbar spine to stabilize the lumbar vertebrae.
• The patient lies on the sore side, the examiner presses hard on the ilium in the direction of the midline, stretching the sacral ligaments.
• The patient lies on his stomach, press on the center of the sacrum in the central direction.
• Patrick's test (pain due to ligament tension) - flexion, abduction, and outward rotation of the femur at the hip joint with simultaneous compression of the anterior superior iliac spine of the contralateral side, which leads to tension of the anterior sacroiliac ligament.
• forced lateral rotation of the thigh with the lower leg bent at the knee joint at 90° with the patient lying on his back.

Spinal flexibility assessment: flexion, extension, lateral bending and rotation may be limited and/or painful due to pathology of the facet joints, discs, muscles and ligaments.

Adson maneuver: The Adson maneuver is used to confirm thoracic outlet syndrome. The examiner detects a change in the radial pulse filling with the patient standing with arms outstretched. Turning the head ipsilaterally during inspiration may cause compression of the vessels by the anterior scalene muscle. In a modified Adson maneuver, the patient's head is turned to the contralateral side. The change in pulse filling suggests compression by the middle scalene muscle. Some experts consider both maneuvers unreliable, as they can be positive in 50% of healthy individuals.

Tinel's test involves percussion of the carpal tunnel. If positive, paresthesias appear distal to the percussion site. It can be performed on any other area (e.g., the ulnar or tarsal nerve canal) where nerve entrapment is suspected. Phalen's test is positive for carpal tunnel syndrome if numbness occurs less than 1 minute after passive wrist flexion.

Neurological examination

• Evaluation of the motor system begins with an assessment of muscle mass, muscle tone, and the presence of spasm.

Muscle strength is measured in the upper and lower extremities. Weakness may be due to the patient's unwillingness to cooperate, fear of pain, insufficient effort, reflex inhibition of motor impulses in the affected limb due to pain, or organic damage. Additional information may be obtained by testing deep tendon reflexes, clonus, and abnormal reflexes such as the Babinski reflex. Evaluation of coordination and higher motor skills may help identify associated dysfunctions.

The integrity of the cranial nerve functions is checked by examining the visual fields, eye movements, pupils, sensitivity of the eye, symmetry and strength of the facial muscles, hearing (for example, using a tuning fork, whispered speech, or friction of the fingers), spontaneous and reflex (movements of the soft palate, and protrusion of the tongue.

Sensitivity is determined by light touch (Ab fibers), needle prick (A8 fibers), and hot and cold stimuli (A8 and C fibers). Tactile sensitivity can be measured quantitatively using Frey's hairs. The following symptoms are often observed in neuropathic pain: hyperesthesia, dysesthesia, allodynia, hyperpathy, temporary summation (gradual increase in pain sensation with repeated impact of the sharp end of a B needle at intervals longer than 3 seconds).

Assessing the state of intelligence is part of the neuropsychological examination. It is necessary to assess the level of mental abilities, orientation in space and time, speech, mood, affect, attention, thinking. A useful assessment method is the Mini-Mental Status Exam. Orientation in place and time, praxis, attention, counting, memory and speech are tested. For each correct answer 1 point is given. The maximum number of points is 30. Cognitive disorders can be assumed if the number of points scored is less than 24.

History and physical examination are the basis for pain assessment and treatment and are essential prerequisites for effective pain therapy. They are individual for each patient, due to the complexity of the pain problem and the patient's condition.

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