The Abdomen

Abstract

The position which a patient with an acute abdomen takes can be suggestive of the underlying pathology. A patient lying clenched on the side and with severe discomfort is likely to have colicky pain (e.g. from urolithiasis). Patients lying flat with their knees flexed and holding the abdomen with their hands often have spasmodic pain from gallstones or an obstructive ileus. Patients with peritonitis usually lie still and flat and breathe shallowly avoiding unnecessary movements. Their face often expresses a mixture of severe pain, anxiety and distress for which this appearance has been referred to as facies abdominalis. Occasionally, patients with pancreatitis or those vomiting lean forward and remain in a sitting position.

Clinical Practices

Box 1 Pearls of Severe Food Poisoning and Associated Critical Illness

• In non-allergic food poisoning, most or all the persons sharing the same meal are affected.

• In patients with mushroom poisoning, delayed onset of gastrointestinal symptoms indicates potentially severe disease, whereas early onset of gastrointestinal symptoms usually indicates mild poisoning. Be sure to recognize the correct mushroom toxidrome!

• Intense vomiting with (watery) diarrhoea occurring 1–6 h after a meal indicates ingestion of Staphylococcus aureus or Bacillus cereus toxins.

• Delayed onset (>8–12 h) of abdominal cramps with bloody diarrhoea after a meal indicates ingestion of enterotoxin-producing Clostridium perfringens, enterotoxic Escherichia coli, Shigella or Salmonella species. Associated necrotizing enteritis has a substantial mortality.

• Consumption of raw oysters (from the Gulf of Mexico) can be associated with life-threatening Vibrio vulnificus infection in immunocompromised patients (particularly patients with chronic liver disease). Typical symptoms include vomiting and diarrhoea but may progress to septic shock with cutaneous blistering if bacteraemia occurs.

• Descending weakness (resembling the Miller-Fisher variant of Guillain-Barré syndrome) 1–4 days after ingestion of canned food suggests Clostridium botulinum intoxication. Similarly, ingestion of carnivorous fish (ciguatera toxin), shellfish (brevetoxin) or pufferfish (tetrodotoxin) may cause perioral or oral paraesthesia and general/respiratory muscular weakness following an episode of gastrointestinal symptoms.

• Sepsis and septic shock (with or without meningitis) following consumption of raw or fresh milk products can be caused by Listeria monocytogenes poisoning. Mortality is highest among all food poisonings. Immunosuppressed, elderly and pregnant persons are at particular risk.

• Food allergies are common after ingestion of specific ingredients (nuts, eggs, shellfish, fruits) and may cause severe respiratory syndromes including airway swelling. China restaurant syndrome relates to an oversensitivity to glutamate in which there is no specific food allergy.

• Scombroid food poisoning presents with anaphylaxis but is due to the ingestion of histamine-containing fish flesh (e.g. tuna, mackerel, kingfish).

Box 2 Appendicitis: Summary of Clinical Signs

McBurney’s point tenderness	Pain on palpation and local tenderness over McBurney’s point (Fig. 8.14)
Rovsing’s sign	Palpation of the left lower quadrant causes reflex pain in the right lower quadrant (Fig. 8.15)
Rectal tenderness	Tenderness found on rectal examination
Psoas sign	If the appendix is directed posteriorly towards the right psoas muscle, local inflammation of the psoas muscle occurs. To relieve muscular tension, the patient lies with the right knee flexed. The psoas sign is elicited by asking the patient to lift the extended leg, while the examiner applies resistance over the knee. Alternatively, the patient lies on the left side, while the examiner extends the stretched leg. With both manoeuvers, pain occurs in the right lower quadrant
Obturator sign	Flexion of the right hip and knee followed by passive internal rotation causes pain in the right lower quadrant. Similar to a positive psoas sign, a positive obturator sign indicates retrograde position of the appendix with associated inflammation of the psoas muscle. However, other local processes (e.g. abscess, haematoma) can also induce a positive psoas or obturator sign