Acute Abdomen Ischaemic Bowel

Acute Abdomen

Ischaemic Bowel Philomena Corrigan Nurse Consultant Cardiac Care Senior Lecturer Adult Nursing

Acute Abdomen

Ischaemic Bowel • Ischaemia more likely to affect small bowel than large bowel • The Superior Mesenteric Artery (SMA) supplies: - Small bowel - Ascending Transverse colon - Proximal 2/3 of Transverse colon • The Inferior Mesenteric Artery (IMA) supplies: - Distal 1/3 of Transverse colon - Descending colon - Sigmoid colon

Acute Abdomen

Ischaemic Bowel

The Splenic Flexure: • Is the junction between the transverse and descending colon • Is supplied by the most distal portions of both the IMA & SMA • Is especially vulnerable to ischemia during periods of systemic hypoperfusion, such as in shock

Acute Abdomen

Ischaemic Bowel

Due to: • A thromboemoblism from the left side of the heart occluding the SMA e.g. during A.F. = transmural infarction • Nonocclusive ischemia, such as that seen in hypotension secondary to heart failure = mucosal or mural infarct • Primary mesenteric vein thromboses precipitated by hypercoagulable states such as polycythemia vera

Acute Abdomen

Ischaemic Bowel

Clinical Presentation • • • • •

Diffuse abdominal pain Bowel distention Bloody diarrhoea Absent bowel sounds Neutrophilic leucocytosis (sometimes with a left shift) • Increased serum amylase • Abdo X-ray shows: - many air-fluid levels - widespread oedema

Leucocytosis • An abnormally large increase in the number of white blood cells in the blood, often occurring during an acute infection or inflammation

Neutrophilic leucocytosis • A "left shift" refers to the presence of increased proportions of younger, less well differentiated neutrophils and neutrophil-precursor cells in the blood • This generally reflects early or premature release of myeloid cells from the bone marrow, the site where neutrophils are generated.

References • Patient UK website: Acute Abdomen