The Challenge of Acute Back Pain

The Challenge of Acute Back Pain Emergency Department, WanFang Hospital Ping Hsun, Lee Introduction    Back pain is one of the most common symptoms that brings patients to the ED Elderly patient with back pain and osteophyte Young athlete with pain caused by back trauma Cannot miss diagnoses 0.7% - spinal malignancy 0.01% - spinal infections  The Diagnostic Imperative Correctly diagnose - Minimizing expensive diagnostic testing 1. Is there likely to be a serious systemic disease causing the pain? 2. Does the patient have a neurologic disease requiring neuro-surgical evaluation? 3. Is there psychological stress that might be excerbating the patient's condition? The Diagnostic Imperative 1. Those patients with serious spinal conditions. 2. Those patients with sciatica, suggesting nerve root compression. 3. Those patients with non-specific symptoms who fit into neither of the above categories. Patient Satisfaction     Providing a likely diagnosis A discussion of maneuvers that will restore functional status A brief explanation A plan directed at pain management Anatomic and Physiological Considerations      Clinical anatomy is essential for diagnostic purposes Anteriorly - vertebral bodies Laterally - pedicles and transverse process Posterior - laminae and spinous processes The spinal cord itself ends at the L1-L2 interspace Anatomic and Physiological Considerations     Intervertebral disks are a common site for back pain-related pathology The pressure within the disks increases with cough, straining, bending, and sitting These disks often begin to degenerate at about 30 y/o Most often posterolaterally Anatomic and Physiological Considerations   The epidural space lies between the vertebral periosteum and the dura that envelops the - Fat - Connective tissue - Extensive venous plexus Requires about a 50% reduction in the A-P diameter of the spinal canal to produce neurological symptoms Differential Diagnosis  Spinal causes Central disk herniation Tumor Infection: vertebral osteomyelitis, epidural abscess, brucellosis, Tuberculosis Epidural hematoma Transverse myelitis Ankylosing spondylitis Spinal stenosis Differential Diagnosis  Abdominal causes Billiary disease: cholecystitis, pancreatitis GI: posterior penetrating ulcer, esophageal disease GYN disease: ovarian torsion, mass, abscess Retroperitoneal causes Vascular: AAA, dissection, RPH Renal: stone, tumor, abscess, obstruction Pancreatic: abscess, pancreatitis, mass  Differential Diagnosis  Pulmonary causes Any process inflaming the posterior parietal pleura: tumor, infarction, infection, pleurisy Systemic causes Endocarditis and bacteremia Transfusion reactions  Clinical Approach        Sudden onset of acute back pain in an older patient History of cancer Elder patient with hypertension History of a known aortic aneurysm History of peptic ulcer disease Medication history Recent back surgery Clinical Approach  History taking - Onset of pain - Duration - Character - Factors that exacerbate or ameliorate the pain - Trauma history - Fever or chills - Back that worse at night or with rest - Radiation of pain Clinical Approach   Abdomen - Unilateral distribution - Bilateral Social history Physical Examination     Careful and meticulous neurological examination of the lower extremities The back should be inspected for ecchymosis and deformity Range of motion Straight leg raise test Physical Examination   About 95-98% of all lumbar disk herniations involve the L5 and S1 roots The majority of other herniations affect the L3 and L4 roots (the femoral nerve) Physical Examination    L3-L4 lesion - decreased strength of knee extension - decreased sensation of the medial knee - a compromised knee reflex L5 lesion - impaired extension of the great toe - decreased sensation of the first dorsal web space - no reflex changes S1 lesion - weakened plantar flexion of the foot - decreased sensation in the lateral aspect of the fifth toe - decreased or absent ankle jerk Physical Examination     Rectal examination is usually useful and essential in - those with extreme pain - whose history suggests sphincter abnormalities - those with any abnormality found by neurological examination - those at risk for serious, “cannot-miss” diagnoses Urinary retention (90%) Diminished anal sphincter tone (70%) Assessing the ability of the patient with back Laboratory and Radiographic Studies     Presence of neurological abnormalities Known malignant disease HIV infection or other immunocompromise Elderly patient with progressive systemic symptoms Laboratory and Radiographic Studies      Urinalysis Complete blood count Erythrocyte sedimentation rate Calcium Alkaline phosphatase levels Laboratory and Radiographic Studies       Plain films Radionuclide scans CT scans MR scans Myelography Bone scans Risk Stratification for Imaging       Duration > 4 weeks Failure of conservative therapy or increasing symptoms during conservative therapy Bilateral radicular symptoms Focal lower extremity weakness (recent use of walking aid, frequent falls) History of malignancy (or suspicion of recent nonintensional weight loss) HIV infection with CD4 counts of < 200 Risk Stratification for Imaging      Urinary urgency or loss of sphincter control Fever (without alternative source), recent infections Claudication (neurogenic or vascular) Drug history immunosuppressive drugs or chronic steroids IVDA anticoagulation with INR > 3.0 Recent back surgery or spinal anesthesia and on anticoagulants Risk Stratification for Imaging    Fever (without alternative source) Abdominal mass or tenderness Abnormal neurological findings - cord lesion - cauda equina lesion - nerve plexus lesion - nerve root (radicular) lesion Simple and Mechanical Cause    The most non-traumatic low back pain are musculoskeletal origin Only a few percent of which are sciatica Benign natural history Simple and Mechanical Cause     Highly selective imaging in patients with back pain The clinician should explain that based on a careful history and physical examination, that there is nothing to suggest a serious cause of the back pain The physician should explain that plain X-rays frequently do not show the relevant structures that may be causing back pain That MR scanning, while it will show those details, is so snesitive that it often shows Simple and Mechanical Cause      Traditionally, bed rest has been the cornerstone of therapy for simple, mechanical low back pain or a herniated disk without neuromotor signs Continuation of normal activities as tolerated had a more rapid recovery Strenuous activities or heavy lifting, even if “normal” for an individual patient, should be limited Prolong sitting may cause increased discomfort If bed reat is prescribed, it should be only for a short period Simple and Mechanical Cause     Acetaminophen Aspirin Other NSAIDs COX-2 inhibitor Muscle relaxants Injections of facet joints and trigger points Physical manipulation Epidural injections     Simple and Mechanical Cause  Despite documented success with conservative therapy, the occasional patient with a herniated disk will require surgery - Sciatica is both severe and disabling - Symptoms of sciatica persist without improvement or show progression - Clinical evidence of nerve compromise “Cannot Miss” Conditions   Non-spinal causes - aortic dissection - expansion or rupture of an abdominal aortic aneurysm - abdominal disease Disk herniation - the vast majority of herniated disk rupture posterolaterally - fewer than 1% displace directly posteriorly (or centrally) Disk Herniation      Cauda equina syndrome - back and bilateral leg pain, numbness - sphincter dysfunction Urinary retention (90%) Anal sphincter dysfunction (70%) Anesthesia of the perineum (saddle anesthesia) and of the posteromedial thigh (75%) Patient who rapidly develop neurologic dysfunction must be decompressed surgically Ankylosing Spondylitis        Young male Slowly progressive back ache and stiffness Worse in the morning and improves over the course of the day Gradually, these patients develop diminished ROM of the back PE reveals diminished excursion of the lumbar spine and chest Plain film ESR Abdominal Aortic Aneurysm    Older, hypertensive patients Back pain, high blood pressure, and a pulsatile abdominal mass Shock Differential diagnosis - Osteoarthritic back pain - Renal colic - Acute diverticulitis - GI bleeding  Abdominal Aortic Aneurysm       The abdominal examination is highly unreliable for diagnosing an AAA Abdominal bruit An AAA generally can be palpated above the umbilicus and to the right of the midline When palpation of the aorta reveals lateral displacement of the pulse wave, AAA should be suspected Diminished lower extremity pulses Peripheral emboli or arterial occlusive disease Abdominal Aortic Aneurysm     > 80% of patients who present with ruptured aneurysms have never been diagnosed as having an AAA Abdominal, flank, or back pain are the most common symptoms in patients with a rapidly expanding or ruptured AAA Syncope A pulsatile abdominal mass Abdominal Aortic Aneurysm  Ultrasonography - 100% sensitive - noninvasive - relatively inexpensive - distinguish free intraperitoneal blood - aneurysmal rupture - complications evluation - thoracic or suprarenal aorta Abdominal Aortic Aneurysm  CT scan - able to measure the size - show the full anatomic involvement - aortic lumen size - presence of mural thrombus - hematoma (from rupture) - dissection - retroperitoneal structures Abdominal Aortic Aneurysm     Patient in whom AAA is strongly suspected must be managed in a rapid, directed manner To stabilize and monitor the patient’s hemodynamic status Surgical and radiological consultation Unstable patients should be taken directly to the operation room Infections of the Spine and Spinal Canal    Vertebral Osteomyelitis Epidural abscess Intra-medullary abscess  Early diagnosis and definitive therapy Vertebral Osteomyelitis      The vertebral bodies have a rich, but sluggish blood supply One artery supplies two vertebrae along with the interventing disk Vertebral osteomyelitis of the spine typically involve two adjacent vertebral bodies Tumor infiltration may involve only a single vertebral body Vertebral osteomyelitis can develop from hematogenous or contiguous spread of infection Vertebral Osteomyelitis        Back pain Fever (50%) Radicular pain, including hip pain Dysphagia, pleural effusions Spinal tenderness Diminished ROM Positive straight leg raising test Vertebral Osteomyelitis    Because this process usually involves the anterior vertebral body, the back pain can percede onset of neurologic findings by some time Pyogenic vertebral osteomyelitis of the posterior elements has been reported but is far less common Staphylococcus aureus is the most common offending organism Gram-negative enteric species Salmonella Vertebral Osteomyelitis     Bacterial cases - lumbar (50%) - thoracic (35%) - cervical (15%) Tuberculous cases are much more common in the thoracic spine Plain films are abnormal in as many as 95% of cases MR scanning Epidural Abscess          Vertebral osteomyelitis Genitourinary infections Soft-tissue infections Epidural anesthesia Back surgery Trauma Diabetes IVDA Alcoholism Epidural Abscess        Back pain Radicular pain Motor, sensory, sphincter symptoms Back (or neck) stiffness Fever (75%) Spinal tenderness Normal neurological examination (approximately 50%) Epidural Abscess        WBC > 11000 (less than 70%) ESR Positive blood culture (60%) Staphylococcus aureus is by far the most common organism Streptococcal and gram-negative enteric organism Cervical location is not uncommon Usually extends over multiple vertebral segments (> 4) Plain X-ray are positive in 44 - 65% of cases Epidural Abscess      Intravenous antibiotics Surgical decompression Early neurosurgical consultation is important Patient outcome are largely a function of the neurologic condition at the time of presentation and duration of neurological deficits prior to examination Mortality rate: 5 - 23% Spinal Cancer   Metastatic disease in the spine Lung cancer Breast cancer Prostate cancer Lymphoma Renal cell carcinoma Melanoma Sarcoma Multiple myeloma Thyroid cancer Spinal Cancer     Among cases of metastatic bone involvement, the spine is the most commonly involved site The vertebral body is usually involved first Direct epidural extension (85%) Radiographic evidence of vertebral metastatic disease can be a late event Spinal Cancer      Thoracic location is most common (60 - 70%) Prostate and colon cancer tend to spread to the lumbar area Lung cancer preferentially affect the thoracic spine Breast and prostate cancer tend to spread multiple areas The rate of development of compression Spinal Cancer       Pain (back pain to radicular pain to neurological signs) The pain produced by spinal metastatic disease is similar to herniated disk SLR test Cancer pain can occur at any area in the spine Pain from cancer tends to be unaffected or worse with rest or at night Delayed diagnosis Spinal Cancer      For patient with neurological findings, MR scanning is clearly indicated, the only issue being how urgent Knowledge of the primary tumor Proceeding to MR scanning directly as the best policy 25% of cancer patients whose symptoms or signs suggest radiculopathy, and who have normal plain films, have metastatic epidural cord compression Conventional CT scan or myelography Spinal Cancer      Patients with signs of cord or cauda equina lesion should be imaged within hours Those with root or plexus lesions and with isolated back pain can be imaged urgently, preferably within 24 hours Consultation with the patient’s oncologist, as well as with a radiation oncologist and neurosurgeon Steroids and radiation therapy Decompressive surgery Spinal Hematomas     Rare but serious disease Peak incidence between 50 and 80 years of age Posterolateral in location Rupture of veins in the spinal epidural plexus Anticoagulation Recent spinal surgery Spinal anesthesia Lumbar puncture     Back Pain in the Elderly     Patients older than the age of 50 years have a higher incidence of “cannon miss” diagnoses Herniated disk is less common Age older than 70 as a risk factor for spinal fracture Spinal stenosis - central canal diameter less than 11mm - lateral recesses depth less than 3mm - hypertrophic soft tissue - bony degenerative change Spinal Stenosis  Neurogenic claudication (60 - 100%) - pain in the legs - with or without neurologic symptoms (especially paresthesias)  - occur with walking, exercise in the erect posture, even standing Indication for surgery - increasing symptoms - incapacitation Osteoarthritis    The clinician must always consider osteoarthritis in the differential diagnosis of elderly patients presenting to the ED Osteoarthritis is the most commonly diagnosed joint disorder in the elderly population Radiographic criteria - joint space narrowing - bony sclerosis - cyst formation - osteophyte formation Osteoarthritis     Primary and secondary Final common pathway More prevalent symptomatically in female Secondary osteoarthritis - mechanical - congenital - development disorder - systemic disease Osteoarthritis        Historical support and radiographic confirmation of osteophytes Joint pain Pain with use and relief with rest The pain is usually aching and will progress to chronic pain Insidious and usually takes months to years to develop Monoarticular in its early presentation Involvement of the wrist, shoulder, or elbow is uncommon Osteoarthritis    Pain management Functional improvement Acetaminophen NSAIDs (Ibuprofen, Napoxen) COX-2 inhibitor (Celecoxib, Rofecoxib) Neuro-Imaging of Back Pain Patients Low Risk    Patients with none of the high-risk criteria No imaging studies needs Patient education - Thorough explanation of medical decision making prognosis with realistic time course (3-6 weeks) explanation of why imaging studies are not indicated  Treatment - non-narcotic analgesia - consider physical therapy, heat, cold, other - early return to routine activities - delayed exercise of back, abdomen  Follow-Up - With PCP if not improving as expected Neuro-Imaging of Back Pain Patients Medium Risk    Risk factors plus normal exam Risk factors plus exam showing root or plexus lesion MRI done urgently (< 24 hours) MRI negative - careful follow-up by PCP - consultation as appropriate  MRI positive - treatment and consultation appropriate for diagnosis Neuro-Imaging of Back Pain Patients High Risk    Exam shows cord or cauda equina lesion Fever and suspicion of epidural abscess or hematoma Abdominal exam suggest AAA Urinary urgency or sphincter symptoms MRI done emergently (within several hours) MRI (or other imaging study) negative - consultation to determine etiology of symptoms and signs  MRI (or other imaging study) positive - treatment and consultation appropriate for diagnosis Summary and Diagnostic Algorithm    To identify the vast majority of back pain patients with serious disease Simultaneously avoiding unnecessary imaging studies Whatever algorithm is chosen, the emergency physician must remain alert for patients whose back pain falls into the “cannot miss” group Thank You!