The posts in my blog are my study notes posted just to reinforce my learning of subjects I review. Other readers should just go directly to Episode 42: Mesenteric Ischemia and Pancreatitis.
In this post I’m only reviewing the first 50 minutes of the podcast and show notes that cover Mesenteric Ischemia.
In a future post I’ll review the show notes from 50 minutes on concerning Pancreatitis.
*Written Summary and blog post by Claire Heslop, edited by Anton Helman, March, 2014. Steinhart, B, Dushenski, D, Helman, A. Mesenteric Ischemia and Pancreatitis. Emergency Medicine Cases. March, 2014. https://emergencymedicinecases.com/episode-42-mesenteric-ischemia-pancreatitis-3/. Accessed 12-27-2020.
Here are my big take home points from this podcast:
If you are thinking about the possibility of mesenteric ischemia, alert your consulting radiologist. And order a triple phase CT of abdomen and pelvis which is a non-contrast CT, an arterial phase CT, and a venous phase CT. Again discuss with your radiologist.
A routine contrast CT is not near as sensitive as the above tests.
Here are excerpts:
Dr. Helman writes: In this episode Dr. Brian Steinhart, (one of my biggest mentors – the doc that everyone turns to when no one can figure out what’s going on with a patient in the ED), & Dr. Dave Dushenski, (a master of quality assurance and data analysis, who would give David Newman a run for his money), discuss the 4 diagnoses that make up the deadly & difficult diagnosis of Mesenteric Ischemia, it’s key historical and physical exam features, the value of serum lactate, D-dimer & blood gas, when CT can be misleading, ED management of Mesenteric Ischemia, the difficult post-ERCP abdominal pain patient, the pitfalls in management of Pancreatitis, the BISAP score for Pancreatitis compared to the APACHE ll & Ranson Score, the comparative value of amylase and lipase, ultrasound vs CT for pancreatitis and much more…
High mortality (59-93%) associated with mesenteric ischemia.
Early diagnosis and intervention associated with improved mortality and morbidity.
Often missed early in presentation
Mesenteric Ischemia consists of four entities
Mesenteric Arterial Emboli
- Commonly secondary to cardiac embolic source.
- Sudden onset abdominal pain, often presents with blood in stool.
Mesenteric Arterial Thrombosis
- Caused by atherosclerosis of splanchnic vasculature.
- “Abdominal angina”, commonly presents with post-prandial abdominal pain.
Non-occlusive Mesenteric Ischemia
- Hypoperfusion to mesenteric vasculature due to low cardiac output or splanchnic vasoconstriction.
- May have blood in stool. Common in elderly, septic patients, patients on vasopressors.
Mesenteric Venous Thrombosis
- Often secondary to coagulopathy.
- Non-specific abdominal pain, +/-diarrhea and anorexia.
Risk Factors for Mesenteric Ischemia
- Age > 50
- Vascular risk factors
- Atrial Fibrillation
- Low flow state (e.g. septic shock)
Laboratory Testing for Mesenteric Ischemia
- Lactate – can be normal early, sensitivity can be as low as 52% depending on stage of disease – do not rely on lactate to rule out mesenteric ischemia
- D-dimer – 96% sensitivity for mesenteric ischemia In one study – Neg LR = 0.12 -higher sensitivity than lactate! poor specificity
- Amylase – can be elevated so don’t be fooled into assuming pancreatitis!
- Troponin often elevated & can mislead you to assume AMI and delay diagnosiss of mesenteric ischemia resulting in higher morbidiy/mortality
- Venous Blood Gas – may have metabolic acidosis
Imaging Mesenteric Ischemia
Plain film: Consider plain films if patient too unstable for transport to CT. May see: bowel dilation, thumb printing, ileus, (often misinterpreted as mechanical bowel obstruction), pneumatosis in severe cases.
CT Abdomen for Mesenteric Ischemia
pooled sensitivity of 94% (95% CI = 90% to 97%) and specificity of 95% (95% CI = 93% to 97%). The positive likelihood ratio (+LR) for a positive CT = 17.5 (95% CI = 5.99 to 51.29), and the negative likelihood ratio (-LR) = 0.09 (95% CI = 0.05 to 0.17).
Neg LR = 0.09 – almost at 0.1 threshold of a rule out test!
CT – Speak with radiology regarding protocol:
- Venogram – if suspicion of venous thrombosis
- Angiogram – if suspicion of arterial emboli
- Triple phase (plain, venous and arterial phase CTs) – increased sensitivity for mesenteric ischemia; but, increased radiation exposure
Early CT Findings: non-specific findings, such as: bowel wall thickening, bowel dilation, mesenteric edema, ascites
*pitfall: to assume alternate Dx like infectious colitis when you get the non-specific early findings of mesenteric ischemia
Late CT Findings: pneumatosis, pneumoperitoneum, portal gas
ED Management of Mesenteric Ischemia
- Fluid resuscitation: can have massive 3rd space losses, +/- bleeding. Aggressive IV fluid resuscitation often required.
- Antibiotics: consider broad spectrum antibiotics if patient presents with a septic picture
- Anticoagulation (controversial): if embolic source, no urgent OR, and no bleeding, consider heparin
- Early surgical consult
- Vasopressors: try to avoid vasopressors in mesentric ischemia as they may worsen ischemia, but if required, choose pressors with least effect on splanchnic circulation (i.e. dobutamine/ milrinone). Avoid epinephrine, phenylephrine because of vasoconstrictive effects.