Acute Abdomen

The term “acute abdomen” is used to describe the syndrome of peracute, acute or recurrent abdominal pain of sudden onset. Further systemic signs of disease like fever, hypothermia, vomiting, diarrhea, depression, anorexia and shock may be present.

Pain can be generated from serosal tension from distended organs during dilatation or volvulus, as well as capsular stretch of enlarged and/or inflamed organs (pancreas, spleen, kidney, liver, gallbladder). Furthermore can intra-abdominal adhesions lead to serosal traction which induces pain. Forceful contractions can induce pain (obstructive ileus, hypersegmentation) Direct stimulation of nerve endings can occur from the release of cytokines and vasoactive substances during inflammation (pancreatitis, peritonitis) and ischemia (torsion, dilatation, rupture, thromboembolism). 

Differential diagnosis for the acute abdomen

[Table with differential diagnosis for the acute abdomen]

Approach to the patient with acute abdominal pain

GDV and shock should be diagnosed and addressed before all further diagnostic investigations for a patient with acute abdomen are initiated.

! Remember ! : Shock can be hyperdynamic or hypodynamic. Capillary refill time (CRT) can therefore be shortened or prolonged, and the pulse quality can vary between bounding and weak during shock !

Clinical signs of shock

mucous membranes: pale (maybe hyperemic, brick red to muddy during septic shock)
CRT: shortened (<1 second) or pro-longed (>2 seconds)
heart rate: fast
pulse: bounding (hyperdynamic) or weak (hypodynamic)
attitude: depression, weakness
appendages: cold 

Hypoperfusion during shock leads to deficits of tissue oxygenation, which has a major impact on the outcome of the patient. Therefore infusion therapy should be initiated as soon as possible in all patients in shock.

The shock dose of isotonic crystalloid solution for dogs is 90 ml/kg.
The shock dose of isotonic crystalloid solution for cats is 45 ml/kg. [...]