Editing The acute abdomen (section)

== '''Evaluating the acute abdomen''' ==

=== History ===

* Age/demographics
** Think about which conditions are likely
* Exact time and mode of onset
** Sudden onset - think perforated ulcer, acute pancreatitis, ruptured AAA/ectopic, ovarian torsion
* Pain
** Character
** Radiation
** Shifting
*** Irritation of somatic nerves
*** Either direct inflammation of an organ, or fluid (e.g. gastric contents moving to RIF in perforated ulcer)
** Postural 
*** Retroperitoneal pain is worse when lying back
** Worse with eating - SBO, biliary colic, pancreatitis, diverticulitis, bowel perforation
** Better with eating - non-perforated PUD or gastritis
* Vomiting
*# Severe irritation of peritoneal/mesenteric nerves
*#* Vomiting will be early
*# Obstruction of an involuntary muscular tube
*#* Vomiting can be later
*#* Early vomiting in SBO indicates high obstruction
*#* Pain almost always prior to vomiting in appendicitis
** Acute gastritis - non-bilious
** Obstructions - bilious
*** First gastric contents, then bilious, then yellow-green, then yellow, then orange/brown faeculent 
** In surgical conditions, vomiting will come after pain. The vomiting is secondary to stimulation of medullary afferent fibres triggered by visceral afferent pain fibres. In medical causes of vomiting, the vomiting often precedes abdominal pain.
* Bowels
* Menstruation

=== Examination ===
General inspection

* Observe facial expression
* Check for shock
* Anaemia - conjunctivae, hands
* Posture
** Colic - restlessness. This is seen in diseases that cause pain without peritoneal irritation, as patients try to get comfortable.
** Peritonitic - still
** Hip flexion on one side - psoas irritation
** Both hips flexed - peritonitis
** Pancreatic/retroperitoneal - sitting up

Vitals

* Pulse
* RR
** Tachypnoea is a late sign in abdo disease - metabolic acidosis
* Temperature
** Fluctuates during day. >37.2 at 0600 and >37.7 at 1600 signify fever
** Oral temperature is generally 0.6 deg lower than rectal would be
** TM temp is close to central
** However, for best real temperature, get bladder/rectal/oesophageal/pulmonary artery catheter
** We lose the ability to develop a fever with old age, so temperature increases may be modest even with severe sepsis
** Temperature is known to rise by about 0.6 deg with ovulation and remain at that level until menstruation
** Hyperpyrexia > 41.5 - probably CNS haemorrhage

Abdomen

* Watch movement with respiration - should move freely
** Contrast with chest - thorax will move less in pneumonia but abdomen will move more
* Gentle palpation
** Remember to palpate for bladder
* Percussion/rebound
** Check for tympanism - if heard all over, suspect free gas. If all but RUQ, could be distended bowel. If any focal dullness other than RUQ, suspect a mass.
* Rigidity
** If you suspect the patient to be avoiding abdominal breathing by choice rather than because of severe pain, try resting left hand on the sternum with a fair amount of pressure while you examine with the right. This prevents costal breathing
* Hyperaesthesia - can give clues as to which nerve is affected by inflammation - probably more useful in chronic cases
** Suggests nerve root compression if present
* Psoas sign
* Obturator sign (obturator internus)
* Liver dullness
** Normal: midclavicular line fifth rib to costal margin; midaxillary line ribs 7-11
** Resonant note over liver in midaxillary line - consider atrophic liver, abdominal distension, free air. Not a useful test when the abdomen is very distended.
* Shifting dullness - so non-specific as to be not that useful