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MEDICAL CAUSES OF THE ACUTE ABDOMEN. Dr. T.H De Klerk Critical Care 12 May 2014. DEFINITION. The term, acute abdomen, is the medical slang word that denotes an acute, serious abdominal condition, usually treated best by surgical operation.
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MEDICAL CAUSES OF THE ACUTE ABDOMEN Dr. T.H De Klerk Critical Care 12 May 2014
DEFINITION • The term, acute abdomen, is the medical slang word that denotes an acute, serious abdominal condition, usually treated best by surgical operation. • More appropriately referred to as a “surgical abdomen”.
EPIDEMIOLOGY • Acute abdominal pain comprises 5% of all emergency medicine consultations (USA) • 18-25% of these patients are admitted to hospital • 10% of those admitted require surgery • 8% of admissions are purely medical cases
ANATOMY AND PHYSIOLOGY • Visceral pain – poorly localised to mainly the midline • Parietal pain - better localised to a dermatomal distribution • Referred pain – certain structures share central pathways due to their specific embryonic development • Central pain – from thalamic and cortical structures
HISTORY • Time course – hyperacute (seconds), acute (minutes) and gradual (hours) • Location – often misleading, e.g. cholecystitis • Radiation, exacerbating and relieving factors and associated symptoms • Surgical conditions- pain generally preceeds vomiting • Non-surgical conditions – vomiting generally preceeds pain • Fever, vomiting, diarrhoea, leucocytosis are unhelpful
BACKGROUND • Risk factors, e.g. DM, HPT, vascular or cardiac disease • Previous surgical procedures - risk for obstruction • Previous similar episode (consider medical cause) • Familial disease • Age group specific diseases, e.g. appendicitis in the young, or diverticulitis in the elderly
CLINICAL EXAMINATION • Must be seen in the context of patient’s history and risk factors • 2004 Israel study: more than 600 patients evaluated for acute abdomen clinically vs CT diagnosis 37% correlation between the groups, 8% of patients underwent surgery unnecessarily due to incorrect diagnosis • The art of the abdominal examination: time very important, recurrent re-evaluation • Abdominal x-rays: dilated bowel loops, intra-peritoneal air • Abdominal ultrasound & CT scan: confirm diagnosis and plan further management
CATEGORIES OF MEDICAL CAUSES • Referred pain – adjacent structures • Lung: pneumonia, pleuritis, pulmonary embolus/infarct, empyema, pneumothorax • Heart: myocardial infarction, myocarditis, pericarditis, congestive cardiac failure • Oesophagus: oesophagitis, spasm, rupture • Pelvis: PID, ovarian/testicular torsion, follicular rupture, ovarian hyperstimulation syndrome
MEDICAL CAUSES CONTINUED • Metabolic • Adrenal insufficiency – gastric dysmotility, serositis • DKA - gastritis, gastric distension, ileus • Thyrotoxicosis – unknown, probably ileus • Porphyria – visceral autonomic neuropathy • Hypercalcaemia – ileus, increased gastrin which leads to gastritis, pancreatitis, ureterolithiasis • Hyperlipidaemia – pancreatitis • Uraemia – ileus, gastritis • Haemochromatosis - SBP
MEDICAL CAUSES CONTINUED • Infection • Toxins – tetanus, botulism • Dysentry – shigella, salmonella, campylobacter, amoebiasis • Severe gastroenteritis – giardiasis, isospora belli • Mesenteric lymphadenitis – yersinia, extrapulmonary TB, CMV • Infestations – helminths, schistosomiasis, obstruction • Infiltration – malaria, EBV • Translocation - SBP
MEDICAL CAUSES CONTINUED • Vascular • Arterial – mesenteric ischaemiaand infarction, dissection (abdominal pain out of proportion to clinical findings) • Vasculitis – large vessel: Takayasu, medium vessel: PAN, small vessel: Wegeners • Coagulopathy – arterial and/or venous thrombosis, primary e.g. APLS, secondary e.g. malignancy • Specific vascular syndromes, e.g. Budd-Chiari, portal vein thrombosis
MEDICAL CAUSES CONTINUED • Haematological • Acute leukaemia, lymphoma – infiltration, tumour necrosis • Haemolyticanaemia, Sickle cell anaemia, polycythaemiavera – vascular spasm and/or thrombosis • Haemophilia – abdominal wall haematomas
MEDICAL CAUSES CONTINUED • Drugs and toxins • Mucosal irritants and corrosives – iron, mercury, NSAIDs • Ileus – anticholinergics, narcotics (opioid bowel syndrome) • Bowel ischaemia – cocaine, amphetamines, ergotamines • Heavy metals – lead, arsenic • Biological – black widow spider: hyperstimulation of NMJ
MEDICAL CAUSES CONTINUED • Neurological • Central – abdominal migraine, abdominal epilepsy, • Neuropathies – tabesdorsalis, secondary to syphilis. Radiculopathy: degenerative spine disease, disc herniation, post-herpetic neuralgia
MEDICAL CAUSES CONTINUED • Miscellaneous • Lactose intolerance • Eosinophillic gastroenteritis • SLE– pancreatitis, serositis, vasculitis • Periodic fever syndromes • Radiation enteritis • Glaucoma • Angioedema – C1-esterase inhibitor deficiency, ACE inhibitors
SPECIAL POPULATION GROUPS • Pregnancy – abdominal examination difficult, uterus obscures rest of abdomen • Neurological disease – no pain sensation, quadroparesis, inability to communicate – delirium, dementia • ICU patients – altered pain perception, 38% of patients with peritonits have peritoneal signs. Consider acalculuscholecystitis • Post-procedural patients • vena cava filters which migrate, fracture, thromboseetc • PEG tubes – peri-stomal leakage • Biopsies – subcapsularhaematoma
Immunocompromised • Blunted inflammatory response • Organ transplants lack nerve innervation • Opportunistic infections, e.g. PCP, CMV • Weakening of connective tissue, e.g. corticosteroids and bowel wall perforation • Drugs: ARV’s (pancreatitis, lactic acidosis), Chemotherapeutic agents, e.g. vincristine • Neutropenicenterocolitis (typhlitis)
Elderly patients • Immunosenescence – decreased immunosurveillance, decreased antibodies and T cells, decreased pyrogen response • GI tract – decreased motility and secretion • CNS – dementia, delirium, decreased peripheral sensation • Increased amount of chronic diseases • Increased drug usage – decreased pain and sympathetic response, increased drug interactions, e.g. digoxin toxicity
REMEMBER… • An atypical presentation of a common condition is much more likely than the typical presentation of an uncommon condition
REFERENCES • Farthing MJG. Pearls and Pitfalls in the Diagnosis of the Acute Abdomen. Indian J Gastroenterol. 2006;25(1):33-35. • Cheng EH, Mills AM. Abdominal Pain in Special Populations. Emerg Med Clin N Am. 2011;29:449-458. • Ragsdale L, Southerland L. Acute Abdominal Pain in the Older Adult. Emerg Med Clin N Am. 2011;29:429-448. • Fields JM, Dean AJ. Systemic Causes of Abdominal Pain. Emerg Med Clin N Am. 2011;29:195-210. • Chang CC, Wang SS. Acute Abdominal Pain in the Elderly. Int J Gerontol. 2007 Jun;1(2):77-82. • Gajic O, Urrutia LE, Sewani H, Schroeder DR, Cullinane DC, et al. Acute Abdomen in the Medical Intensive Care Unit. Crit Care Med. 2002;30(6):1187-1190. • Mueller PD, Beneowitz NL. Toxicologic Causes of Acute Abdominal Disorders. Emerg Med Clin N Am. 1989;7:667-682.