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.
In this post I link to and excerpt from Emergency Medicine Cases‘ podcast and show notes of Episode 42: Mesenteric Ischemia and 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.
Search results for “mesenteric ischemia” from Radiopedia.
See CT angiography of the splanchnic vessels from Radiopedia.
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!
Cudnik MT, The diagnosis of acute mesenteric ischemia: A systemiatic review and meta-analysis. Acad Emerg Med. 2013 Nov;20(11):1087-100. doi: 10.1111/acem.12254.
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.