A 48-year-old man on ICU has severe ARDS requiring PEEP 18 cmH2O. He also has abdominal distension from an ileus. Measured intra-abdominal pressure (I...

Question

A 48-year-old man on ICU has severe ARDS requiring PEEP 18 cmH2O. He also has abdominal distension from an ileus. Measured intra-abdominal pressure (IAP) is 18 mmHg. The team is concerned that the high IAP is contributing to the elevated plateau pressure and poor compliance. What is the relationship between IAP and respiratory mechanics?

Accepted Answer

Elevated IAP is transmitted through the diaphragm, increasing pleural pressure and reducing chest wall compliance; this increases plateau pressure and decreases respiratory system compliance WITHOUT necessarily reflecting worsening lung disease - higher PEEP may be needed to counteract the elevated pleural pressure and maintain alveolar patency

Answer

IAP has no effect on respiratory mechanics

Answer

IAP only affects the kidneys

Answer

Elevated IAP improves lung compliance

Answer

IAP should always be treated with decompressive laparotomy

uk-fficm MCQ (SBA): IAP and Respiratory Mechanics