Causes of increased intra-abdominal pressure may include:
(1) pregnancy, especially during the third trimester
(2) chronic constipation, especially with megacolon
(3) diverticulitis
(4) meteorism (presence of gas in the intestine)
(5) abdominal compartment syndrome
These conditions may also cause shunt dysfunction by obstructing the intra-abdominal ports.
Clinical manifestations of increased intra-cranial pressure:
(1) decreased level of consciousness, including coma
(2) worsening of hydrocephalus on imaging studies
(3) headaches
(4) nausea and vomiting
These symptoms should temporarily improve if CSF is aspirated.
Clinical manifestations of increased intra-abdominal pressure:
(1) acute renal dysfunction
(2) abdominal distention
Reversal of the underlying cause (delivery, etc.) will result in restoration of CSF drainage.
Differential diagnosis:
(1) shunt infection
(2) shunt obstruction (mechanical block, adhesions at tip, etc.)
(3) dysfunction of shunt valve
