ACUTE ABDOMINAL PAIN Patrick Nee and Robert Kiff GENERAL PRINCIPLES 1 Early, specific diagnosis determines appropriate treatment. It depends upon careful history, thorough physical examination (including extra-abdominal systems) and special tests such as xray, USS, CT, Lab tests and urine WTU and MC&S. 2 Early surgical intervention reduces mortality in eligible patients, resist the temptation to see how s/he is in the morning 3 Symptoms and signs may radiate to remote sites in the abdomen, genital area, to the chest, back or shoulder. There may be no pain or tenderness over the affected organ or viscus initially. 4 Extra-abdominal conditions (pneumonia, DKA, cardiac failure, diseases of the spine or nerves, porphyria) may mimic abdominal emergencies. Uraemia may cause abdominal distension and vomiting. 5 Abdominal emergencies may mimic cardiovascular conditions, sepsis and shock (especially with very high plasma lactate). 6 Atypical presentations of appendicitis are common. The appendix may lie in an abnormal position (pelvic, retrocaecal) and fever and local tenderness may be unimpressive. 7 Steroids therapy, immunocompromise and antibiotics may mitigate signs and symptoms of abdominal emergencies. In patients with impaired sensorium, spinal cord injury or epidural analgesia the physical signs of abdominal catastrophe may be blunted. Have a low threshold for use of imaging in these circumstances. Do not omit opiate analgesia on the grounds that it may impair the assessment. 8 Relieve pain. Do not omit opiate analgesia on grounds that it may impair the surgical assessmenrt 9 Strangulated hernias account for a large percentage of small bowel obstruction in adults. Always examine the hernial (including femoral and umbilical) orifices. 10 Elderly patients with a diagnosis of Renal/Ureteric Colic may well have a leaking abdominal aortic aneurysm. Radiation of abdominal or flank pain to groin or testicle is common in ruptured AAA. HISTORY Note the age and gender, past medical and surgical history and drugs. Any recent foreign travel? Record the chronology of the chief complaint from the last period when the patient was completely well. Note the onset, periodicity and duration of pain and any precipitating or relieving factors. What were you doing when the pain began? What is the character of the pain (constant vs. colicky), where is it located and where does it radiate? Discuss associated features; fever, anorexia, dysphagia, appetite, weight loss, nausea and vomiting. Is the vomitus clear, bilious or faeculent (distal small bowel)? What is the relationship of vomiting to the pain? Enquire about bowel habit and any recent change. Urinary symptoms and detailed menstrual history are important. Could the patient be pregnant?
EXAMINATION Begin with general observations (distress, pallor, sweating, jaundice etc). Repeat the nursing observations (T,P,R and BP) unless very recently recorded. Is the patient shocked (evidence of organ hypoperfusion, regardless of the blood pressure). Examine the chest. Note the patient’s position in the bed (restless, still, one or both knees drawn-up). Psoas irritation from a pelvic inflammation causes flexion of the ipselateral thigh, a sign that can be elicited by passive extension of the hip with the patient lying on his opposite side. Observe the abdomen for evidence of distension, free fluid, masses and movement on respiration (local or generalised peritonitis). Begin gentle palpation away from the area of maximum pain. Evaluate the hernial orifices, including the femorals. Examine the loins with a bimanual technique. Percuss gently for evidence of local peritonitis. Do not try to elicit rebound tenderness. Auscultate and note frequency and character of bowel sounds. Measurement of the abdominal girth adds nothing to the evaluation. Causes of generalised peritonitis are listed in the box: SOME CAUSES OF PERITONITIS Perforation of: Appendix Peptic Ulcer Small bowel ulcer (Chrohns, TB) Colon (ulcer, colitis, Cancer, diverticulum) Gangrene of: Strangulated coil of gut Intussusception Volvulus (Stomach, Caecum, Sigmoid) Infection from: Pyosalpinx Pyometrium Pyonephritis Rupture of: Liver abscess Splenic abscess Other: Leakage of sterile bile or urine into peritoneal cavity Primary pneumococcal peritonitis Primary peritonitis in hepatic cirrhosis
Vaginal and rectal (or colostomy) examinations should be routinely performed. Feel for specific pelvic structures anteriorly, posteriorly and laterally, left and right. Examine the glove for faeces, blood or mucus. Remember chart review, including clinical notes, drug chart, lab results and fluid balance chart. Now draw up a differential diagnosis SPECIAL TESTS Investigations supplement but do not replace the gold standard; repeat clinical evaluation. Plain films of the chest/abdomen may demonstrate free air, evidence of small or large bowel obstruction and radio-opaque faecolith, ureteric stones (80%) or gallstones (20%). Contrast studies are useful for stenosing or obstructing lesions. Barium should not be given by mouth if colonic obstruction is suspected. Order IVP in suspected ureteric stone, determines bilateral renal function. Angiograms of the splanchnic vasculature are of value in occlusive ischaemia of the intestine but are rarely done in the acutely ill patient. Plain AXR is of limited value in patients with abdominal pain. Radiologists guidelines 2003 for plain AXR. Indicated
Acute GI bleed
Palpable mass (renal or colon)
Acute Inflammatory bowel disease
Gallstones Pancreatitis UTI/haematuria/renal colic (For renal colic/haematuria do KUB with IVU series) Non-specific abdominal pain Trauma
Ultrasound of the abdomen may demonstrate renal size in the oligo/anuric patient. It may also show gallstones but may not demonstrate cholecystitis. It is useful to exclude abscesses, AAA and pelvic lesions such as tubal pregnancy and pyosalpinx. In traumatic and inflammatory conditions Ultrasound may show fluid collections in the peritoneal spaces between the liver and right kidney (Morrison’s pouch), between the spleen and left kidney, in the paracolic gutters or in the pelvis. CT scanning is useful for solid organ masses and abscesses, free gas and the complications of pancreatitis (necrosis, abscess or pseudocyst). Fat streaking is a non-specific sign of inflammatory process. Blood tests should include: FBC, U&E, glucose, clotting, LFTs and amylase. The urine should be examined for cells, casts, protein, leukocytes and nitrites, and sent for culture. Perform a pregnancy test on all females 12-60 years old. Send stool for culture and, for diarrhoea in the antibiotic-experienced patient, Cl. difficile toxin. GENERIC MANAGEMENT In the initial management of surgical emergencies select appropriate tests from the above and ensure that the results are reviewed. Start IV fluids, nil by mouth, parenteral analgesia and antibiotics (Cefuroxime and metronidazole) NGT and urinary catheter. Other tests (Eg. USS) may be deferred to next day. ABDOMINAL APOPLEXY Sudden exsanguinating haemorrhage into the peritoneal cavity retroperitoneal space. Presents with abdominal pain, collapse and shock. Note history of anticoagulant therapy .
Causes include: o Rupture of AAA (until proven otherwise). o Ruptured ectopic pregnancy o Ruptured ovarian cyst o Solid organ trauma or trivial injury in abnormal spleen (malaria, glandular fever) Very rare causes: o o o o
Rupture of a splenic artery aneurysm Rupture of coeliac axis aneurysm Rupture of renal artery aneurysm Ruptured hepatic angioma (contraceptive pill)
Treatment is resuscitation and surgery.
INTESTINAL ISCHAEMIA Presents with colicky abdominal pain, often insidious onset, in a patient who may have a history of atherosclerosis, endocarditis, heart failure or atrial fibrillation. The severity of the physical signs depends upon the extent of involved bowel and the completeness of the occlusion. There may be frequent, bloody stools. Fever, tachycardia, leukocytosis and raised plasma lactate are late manifestations. The development of perforation and generalised peritonitis are premortem complications. The diagnosis is confirmed at laparotomy or (rarely) by arteriography. The treatment is surgical, or ‘TLC’. ACUTE INTESTINAL OBSTRUCTION Symptoms vary in severity and acuity. Combinations of colicky pain, vomiting, constipation and abdominal distension. Alternatively, diarrhoea, including bloody, may be seen. It may be difficult to determine the site of the obstruction (high small bowel, low small bowel, colon). Patency of the ileocaecal valve (15%) influences the clinical presentation of large bowel obstruction. Unrelieved obstruction leads to strangulation, perforation and fatal peritonitis. Plain radiographs may be diagnostic. SOME CAUSE S OF INTESTINAL OBSTRUCTION Causes in adults
Causes in children
Pyloric stenosis 15%
Ileocaecal intussusception 15%
Cancer 10% Volvulus 4% *
Atresias 14% Adhesions 7%
Miscellaneous 4% * Stomach, Sigmoid (commonest), ileo-caecal
THE POST-OPERATIVE ABDOMEN The evaluation is difficult because of the confounding factors; painful incision, surgical drains, analgesics and impaired sensorium, variable bowel sounds and bowel habit. There are also numerous potential causes of fever, including anastamotic failure, wound infection, peritonitis, abscess, DVT/PE and extra-abdominal infections. Mild fever is common after an abdominal operation The patient should be evaluated twice a day for emergence of new or different signs and symptoms, or failure to improve with the passage of time (a few days). A persistent tachycardia is often an early warning sign of something amiss. Potential post-operative complications include: o Anastamotic failure (consider contrast studies) o Intestinal obstruction o Wound infection o Other abdominal condition (appendicitis, cholecystitis, pancreatitis, gastro-duodenal perforation) o Fluid collection, drain obstruction or abscess (ultrasound, CT) o Intestinal obstruction (plain films) o Extra-abdominal; cardiac, respiratory, DVT/PE Post operative ileus is common. However, consider intestinal obstruction, ischaemia or perforation in post-op patients with abdominal distension, high NG aspirates and absent/scanty bowel sounds (prolonged ileus). If a patient with an intestinal anastamosis becomes unwell/deteriorates post-operatively call senior surgical colleague urgently. Do not allow a label (chest infection, IHD, ileus) to deflect from the possible diagnosis of anastamotic leak. FUTHER READING: Cope’s early diagnosis of the acute abdomen. William Silen (Ed) 20th edition. OUP