Effects
Respiratory
- Diaphragmatic splinting and extrinsic compression of lung tissue
- Leads to:
- Reduced compliance and increased airway pressures 1
- Increased ventilation/perfusion (V/Q) mismatch 1
- Basal atelectasis and collapse 1, hypoxemia and hypercapnia
Cardiovascular
- Cardiac output reduced due to:
- Decreased venous return due to venous compression 1
- Increased afterload due to aortic compression 1
- Increased intra-thoracic pressure due to diaphragmatic splinting may compromise CO further:
- Decreased ventricular compliance and contractility 1
Neurological
- Raised ICP due to:
- Impaired CSF absorption in the lumbar plexus
- Impaired jugular venous return
- Increased further due to cerebral vasodilatation caused by concomitant hypoxaemia and hypercapnia
Renal
- Renal failure due to:
- Reduced renal blood flow 1
- Increased pressure within the tubules and reducing the filtration gradient 1
- Compensatory activation of the renin-angiotensin-aldosterone (RAA) worsening the renal insult
Gastrointestinal
- Bowel wall venous obstruction and hypertension due to compression effect resulting in oedema and further reduced compliance
- Bowel ischaemia and bacterial translocation increases the risk of sepsis
- Reduced hepatic artery, vein and portal system flow leading to liver dysfunction
- Biliary stasis due to increased pressure within the biliary tree