UMEM Educational Pearls - Vascular

Category: Vascular

Title: Neurologic Manifestations of Acute Aortic Dissection

Keywords: Acute, Aortic Dissection, Neurologic (PubMed Search)

Posted: 1/6/2009 by Rob Rogers, MD (Updated: 11/19/2019)
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Neurologic Manifestations of Acute Aortic Dissection

A myriad of neurologic presentations of acute aortic dissection have been reported in the literature. Although classic CVA symptoms may occur, nonspecific neurologic symptoms are much more common

These include:

  • Classic stroke-like/TIA symptoms
  • Encephalopathy (may look like a drug overdose)
  • Seizures (ask Mike Abraham about his abdominal pain/seizure case)

Take Home Point:

  • Consider the diagnosis of acute aortic dissection in patients with these findings who ALSO HAVE chest, back, or abdominal pain +/- risk factors for the disease (i.e. HTN, family history, Marfans, cocaine, etc.)

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Category: Vascular

Title: Hypertension and Epistaxis

Keywords: Hypertension, Epistaxis (PubMed Search)

Posted: 12/8/2008 by Rob Rogers, MD (Updated: 11/19/2019)
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Hypertension and Epistaxis

We commonly encounter patients with epistaxis who are found to be hypertensive. Some have taught over the years that hypertension causes nosebleeds and that some nose bleeds won't stop until the BP is lowered...

Some pearls about HTN/Epistaxis:

  • Most patients we see with hypertension are not experiencing epistaxis, casting serious doubt on a causal relationship
  • Studies show that the degree of blood pressure elevation does not correlate with risk of nose bleed
  • No studies have ever shown that acute BP reduction in the ED for a nose bleed is beneficial or reduces bleeding
  • Much of the debate is sparked by our ENT colleagues who swear that hypertension leads to nose bleeds and that bleeding will not stop until the BP is "treated." Much of this is based on experience with patients in the OR or IR suite. These blood pressures tend to be treated with IV antihypertensives by the ENT folks, and they feel pretty strongly about this relationship.

Category: Vascular

Title: Warfarin Induced Skin Necrosis

Keywords: Warfarin, Skin Necrosis (PubMed Search)

Posted: 12/1/2008 by Rob Rogers, MD (Updated: 11/19/2019)
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Warfarin-Induced Skin Necrosis (WISN)

Some pearls about a rare, but serious side effect of Warfarin...

  • WISN Occurs in 0.01-0.1% of patients taking Warfarin
  • More common in middle-age, perimenopausal women being treated for DVT/PE
  • Symptoms usually begin on days 3-6 of Warfarin treatment
  • Underlying pathophysiology is complex but involves thrombosis of superficial dermal capillaries
  • Postulated to be associated with deficiencies of protein C, protein S, and antithrombin III
  • Rash is most common on the breats, with thighs/buttocks being second most common site (see picture)
  • Diagnosis usually made clinically based on appearance of rash
  • Treatment is aimed at restoring Vitamin K dependent clotting factors by administering Vit K and FFP
  • For patients with the need for anticoagulation (DVT/PE, etc.) Heparin therapy is usually started

 

55 yo female presented to the ED on the day of hospital discharge for evaluation of this rash.

The rash began 4 days after starting Warfarin. Was being treated for a DVT.


Attachments

photo.jpg (137 Kb)


Category: Vascular

Title: What Hypertensive Patient Needs a Workup for End-Organ Damage?

Keywords: Hypertension (PubMed Search)

Posted: 11/24/2008 by Rob Rogers, MD (Updated: 11/19/2019)
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What Hypertensive Patient Needs a Workup for End-Organ Damage?

Ah, the age old question...which hypertensive patients need an ED workup for end-organ damage? The "workup" for patients includes renal function, urinalysis, CXR, ECG, etc.

Some pearls regarding working patients up: 

  1. Asymptomatic patients in general do not need a workup. There is pretty good literature that shows you just won't find much (expecially anything that will change your treatment plan) if you go hunting in this group of patients.
  2. If you set asymptomatic patients aside, you won't find much good data on how much of a workup other patients need. Does a 45 yo patient with a BP of 160/110 and a mild HA need a serum creatinine? What if they have had some mild, atypical CP? The answer is...no one knows. Much of what we we do depends on what we were taught and our current mood. 
  3. Asymptomatic patients (truly asymptomatic) don't need chest xrays and ECGs as a rule of thumb...what you find won't help you make a decision. If you find LVH on the ECG, so what? 
  4. Obtaining a serum creatinine makes sense, especially of you are going to start a BP agent. 
  5. There is a pretty good study by Karas, et al. that showed that a urinalysis without protein or blood predicts a normal creatinine. Use caution, however, if you use this as a screen for renal disease, because many patients with HTN spill protein (despite a normal creatinine)

Category: Vascular

Title: Key Pitfall to Avoid in Severely Hypertensive Patients

Keywords: hypertension (PubMed Search)

Posted: 11/10/2008 by Rob Rogers, MD (Updated: 11/19/2019)
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Key Pitfall to Avoid in Severely Hypertensive Patients One of the biggest pitfalls committed when treating severely hypertensive patients (asymptomatic or minimally symptomatic) is in "stacking" antihypertensive (oral) medications. Mike Winters has mentioned this previously. This occurs when several medications are given one after another...resulting in a precipitous drop in blood pressure. This could result in severe hypotension and stroke. Pearls: 1. Don't stack too many BP meds in the ED (resist the urge to do this. 2. If the patient's BP is sky high (i.e. 250/170), forget oral meds and get control of the BP with a drip. This is a safer approach than adding many different medications and taking the risk of hypotension. 3. Don't just treat the number 4. Hypertensive patients can go home (with prompt followup)

Category: Vascular

Title: PERC Rules have been validated

Keywords: PERC Rules (PubMed Search)

Posted: 11/4/2008 by Rob Rogers, MD (Updated: 11/19/2019)
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Pulmonary Embolism Rule Out Critieria (PERC) A brief reminder about the PERC rules... Use of the PERC (Pulmonary Embolism Rule-out Criteria) rule can significantly decrease work-up for pulmonary embolism. To apply this rule, the clinician must first use clinical gestalt to classify the patient as low risk. The PERC rule, which consists of eight clinical criteria including history, physical and vital signs, can then be used. If both of these criteria are met, then there is less than a 2 percent risk that this patient has a PE and no further work-up is needed. PERC Rule: Age < 50 years Pulse < 100 bpm SaO2 > 94% No unilateral leg swelling No hemoptysis No recent trauma or surgery No prior PE or DVT No hormone use This rule has now been validated in a large, multicenter trial. Bottom line: If you walk out of the room and your clinical gestalt is "no PE" and the PERC rule is negative, there is a <2% chance of pulmonary embolism (<2% probability, by the way, is what many PE experts consider the test threshold)

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Category: Vascular

Title: Reversal of Warfarin

Keywords: Warfarin (PubMed Search)

Posted: 10/27/2008 by Rob Rogers, MD (Updated: 11/19/2019)
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Reversal of Warfarin

Reversal of Warfarin can be accomplished by administering any of the following:

  • Fresh Frozen Plasma (traditional reversal agent)
  • Vitamin K (po, sub q, or IV)
  • Prothrombin Complex Concentrates (PCC)-not yet available for use in the US (yet)

A few pearls:

  • It doesn't take many units of FFP to lower someone's INR
  • Don't forget volume considerations if you use FFP
  • Vit K is pretty well tolerated but some patients will have an allergic reaction (more common with IV administration)
  • These medications in general will be used for life-threatening bleeding (GI, CNS bleeds, retroperitoneal bleeds, etc)
  • Prothrombin Complex Concentrates-rich in factors 2,7,9, and 10...perfect drug since Warfarin depletes these factors
  • PCC associated with some increased thrombosis

 


Category: Vascular

Title: Reversal of Heparin

Keywords: HeparinPro (PubMed Search)

Posted: 10/20/2008 by Rob Rogers, MD (Updated: 11/19/2019)
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Anticoagulation with Heparin-How to Reverse?

So you just started Heparin on that ACS patient? Just bolused the patient in room 12 with the large PE with a slug of Heparin? The nurse tells you that one of them just vomited blood and the other just had a large bloody bowel movement. What to do, oh, what to do?

How to reverse Heparin...use Protamine:

  • Protamine is obtained from the sperm of salmon and other species of fish....glad you know that now?
  • Given IV, it binds to Heparin (Unfractionated Heparin) and inactivates it
  • Administer Protamine (IV) at a dose of 1 mg for every 100 Units of Heparin given within the last four hours. Max dose 50 mg of Protamine. May give more than 50 mg, but use caution as may lead to bleeding
  • If the dose of Protamine is exceeded, patients may bleed. Protamine is actually an anticoagulant. 
  • Give slowly over 10 minutes as may cause anaphylactoid reaction
  • Can use to reverse LMWH as well: 1mg Protamine per 1 mg of LMWH (Lovenox)

Category: Vascular

Title: Cerebral Venous Sinus Thrombosis (CVST)

Keywords: Thrombosis, Cerebral (PubMed Search)

Posted: 10/13/2008 by Rob Rogers, MD (Updated: 11/19/2019)
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Cerebral Venous Sinus Thrombosis (CVST)

An uncommon but very serious entity that leads to three distinct types of presentations:

  • Headache
  • Seizures
  • Stroke

Caused by thrombosis of one of the intracerebral venous sinuses (most commonly the transverse sinus) The major risk factor is hypercoagulable disease. May be the underlying cause of a majority of cases of idiopathic intracranial hypertension.

When to suspect:

  • Headache with negative CT, negative LP, but high opening pressure
  • In any patient with new onset idiopathic intracranial hypertension (i.e. pseudotumor cerebri). Can't be formally diagnosed without a negative MRI.
  • Stroke syndrome that doesn't quite fit. May see bilateral infarcts in the posterior regions. These are actually venous infarcts secondary to the sinus thrombosis.

Diagnosis:

  • Just like a lot of other things in medicine, "If you don't think about it, you can't diagnose it."
  • 1 in 3 head CT scans will be normal
  • MRI with MRV (venous phase) is the diagnostic standard

Treat:

  • Anticoagulation with heparin then warfarin

Category: Vascular

Title: Does Hypertension Cause Headache?

Keywords: Hypertension, Headache (PubMed Search)

Posted: 10/6/2008 by Rob Rogers, MD (Updated: 11/19/2019)
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 Does Hypertension (elevated BP) Cause Headache?

This is an age old question that many of us have struggled with in the ED for many years...

Other questions include: Does elevated BP cause headaches? Do we need to scan hypertensive patients with headache just because they have a headache? At what level of BP does the BP actually cause headache? 

A few quick pearls:

  • Although incredibly high BPs (diastolics above 130 mm Hg) have been correlated with headache, the general concensus is that hypertension doesn't really cause headaches. 
  • At really high blood pressures (again, diastolic BP > 130-140), cerebral autoregulation breaks down and may lead to cerebral edema and headache...hypertensive encephalopathy.
  • Elevated systolic BP may actually be protective for developing headaches
  • CT scanning the hypertensive patient with a headache is not warranted a lot of the time, unless the patient has a neuro deficit, or if the headache was acute onset or associated with other findings of hypertensive encephalopathy.
  • Patients with HTN are as likely to have a headache in the ED as non-hypertensive patients

 


Category: Vascular

Title: Avoidable Pitfalls in Managing the Hypertensive Patient

Keywords: Hypertension (PubMed Search)

Posted: 9/29/2008 by Rob Rogers, MD (Updated: 11/19/2019)
Click here to contact Rob Rogers, MD

Avoidable Pitfalls in Managing the Hypertensive Patient

We all see very hypertensive patients on almost every shift. Dr. Winters has an earlier pearl related to pitfalls in treating patients with hypertensive encephalopathy, but I thought it was time to reiterate just a few points.

  • No evidence to date has ever shown a benefit to acutely lowering someone's BP in the ED prior to discharge
  • Probably the best thing you can do for the patient with out of control BP is to arrange (and make sure they have) followup for the next day or two after discharge
  • In patients with severe HTN (eg. admitted patients with pressure to high to go to their inpatient bed), avoid agents like IV Hydralazine. This agent is pretty reliable in being completely unpredictable when it comes to BP response. Some will really bottom out their BPs.
  • Avoid Clonidine unless the patient is on it and stopped taking it recently (rebound HTN). May worsen someone's already crappy mental status.
  • If a patient is being admitted, say to a unit or step down unit, don't bother titrating oral agents for people with pressures > 240/130 mm Hg or so. Consider a drip-oral agents may "stack" and take effect, thus lowering someones BP way lower than you wanted.
  • Don't treat the number, treat the patient.

Category: Vascular

Title: What is the sensitivity of a CXR for aortic dissection?

Keywords: aortic dissection, chest xray (PubMed Search)

Posted: 9/23/2008 by Rob Rogers, MD (Updated: 11/19/2019)
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So, how good is a screening CXR for aortic dissection?

  • Classic CXR finding is a wide mediastinum
  • Pooled literature shows that the overall sensitivity of a CXR is about 67-70% for aortic dissection (even if upright, or PA and Lateral)
  • Most authorities agree that a screening CXR alone is not sufficient to r/o aortic dissection

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Category: Vascular

Title: Cardiovascular Complications of Cocaine

Keywords: Cardiovascular, CocaineC (PubMed Search)

Posted: 9/15/2008 by Rob Rogers, MD (Updated: 11/19/2019)
Click here to contact Rob Rogers, MD

Key Cardiovascular complications of cocaine:

  • Myocardial ischemia and infarction
  • Myocarditis and cardiomyopathy
  • Aortic dissection
  • Vessel thrombosis
  • Stroke (usually hemorrhagic) 
  • Visceral ischemia

Pearls:

  • Cocaine and abdominal pain=mesenteric ischemia, hemoperitoneum (described)
  • Cocaine and chest pain=MI, aortic dissection
  • Cocaine and extremity pain=arterial thrombosis, aortic dissection
  • ~ 6% of cocaine chest pain patients rule in for MI

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Category: Vascular

Title: Acute Limb Ischemia

Keywords: Ischemia (PubMed Search)

Posted: 9/9/2008 by Rob Rogers, MD (Updated: 11/19/2019)
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 Management of acute limb ischemia

Just a few pearls regarding acute limb ischemia

  • Presents with an acutely painful extremity (may be pale and cool as well)
  • Common etiologies include atrial fibrillation, embolism from aortic plaques, and thrombosis of extremity vessels
  • Most patients need to be anticoagulated (heparin) 
  • Vascular surgery should be consulted immediately or the patient needs transfer to a facility that can handle acute vascular emergencies
  • Use caution when performing the physical examination, because there may be a pulse present
  • Perform bedside ABI to the best of your ability and document
  • Diabetics with stiff vasculature may have ABIs of 1 or greater so may be less reliable

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Category: Vascular

Title: Subarachnoid Hemorrhage-Complications

Keywords: subrachnoid hemorrhageRebeleeding (PubMed Search)

Posted: 8/19/2008 by Rob Rogers, MD (Updated: 11/19/2019)
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Complications of Subarachnoid Hemorrhage

The three dreaded complications of SAH include the following:

  • Rebleeding
  • Hydrocephalus-occurs in as many as 33-50% of patients with SAH. Intraventricular blood (in 20% of cases) acutely occludes the foramen of Monroe and Luschka and obstructs CSF outflow. This is treated by inserting a ventriculostomy catheter. 
  • Vasospasm-Usually develops several days after the initial SAH. May be an asymptomatic angiographic phenomenon or cause cerebral ischemia-an important cause of morbidity after SAH. Prophylactic administration of Nimodipine improved outcomes. 

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Category: Vascular

Title: Currently Approved LMWH for Treatment of PE

Keywords: LMWH, PE, Pulmonary Embolism (PubMed Search)

Posted: 8/11/2008 by Rob Rogers, MD (Updated: 11/19/2019)
Click here to contact Rob Rogers, MD

Currently Approved LMWHs for the Treatment of Acute PE:

  • Enoxaparin-1 mg/kg every 12 hours subcut
  • Tinzaparin 175 Units/kg once daily subcut
  • The pentasaccharide: Fondaparinux- at a dose of 5 mg for body weight <50 kg, 7.5 mg for 50-100 kg, and 10 mg for >100 kg, once daily

Make sure to monitor platelet counts regardless of agent chosen.

 

 

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Category: Vascular

Title: Causes of Elevated D-Dimer

Keywords: D-Dimer (PubMed Search)

Posted: 7/29/2008 by Rob Rogers, MD (Updated: 11/19/2019)
Click here to contact Rob Rogers, MD

Causes of an Elevated D-Dimer 

Don't forget the multiple causes of an elevated d-dimer:

  • PE/DVT
  • Sepsis/infection
  • Malignancy 
  • Renal disease
  • Pregnancy
  • MI
  • Stroke

**See attached PDF-Differential Diagnosis of Elevated D-Dimer

 

 

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Attachments

Causes_of_Elevated_D-Dimer.pdf (43 Kb)


Category: Vascular

Title: How Good Was That CT Pulmonary Angiogram You Ordered?

Keywords: CT, Pulmonary (PubMed Search)

Posted: 7/21/2008 by Rob Rogers, MD (Updated: 11/19/2019)
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How good was that CT Pulmonary Angiogram You Ordered?

CT is currently the gold standard imaging modality for pulmonary embolism. Since we order these quite a bit in the ED, we should know some of the important nuances regarding interpretation of the scan. All of us at some point have looked at a pulmonary CTA and thought that it looked a bit "fuzzy" or perhaps it didn't "look right"  This happens more often in obese patients. There is good literature to show that a suboptimal CTA misses clinically significant PE. So, it is important for emergency physicians to know a little about the CT scan ordered for our patients. 

How can you know if the CT scan YOU ordered to rule out PE is really "good enough" to rule out PE?

  • Well, you can rely on the radiologist. But remember they may not comment of the quality of the scan. Or, they may simply recommend another test.
  • Look at the Hounsfield Units (HU). For those who have PACS or some other computer radiology display,all you need to do is move the cursor to the main pulmonary artery and see what value (usually on the bottom of the screen) is displayed. 
  • A HU >280 indicates that the CT is "good" (i.e. good enough contrast bolus to detect clot). By the way, >350 looks white.

So, a 34 yo obese patient who gets a CT scan to rule out PE, who has 170 HU in the main pulmonary artery, has not had an optimal CT. Thus, you really haven't ruled out PE even if the read is "negative." Often this is due to poor bolus timing. 

 

 

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Category: Vascular

Title: Ruling Out Pulmonary Embolism During Pregnancy

Keywords: Pulmonary Embolism, Pregnancy (PubMed Search)

Posted: 7/14/2008 by Rob Rogers, MD (Updated: 11/19/2019)
Click here to contact Rob Rogers, MD

Evaluating for Pulmonary Embolism During Pregnancy

Highest risk of PE is within the first week postpartum

Acceptable, safe, and medico-legally sound strategies to rule out PE in pregnancy:

  • Pulmonary CTA-this strategy is safe and accepted. Plenty of data to support you if you choose this strategy. Some evidence recently that shielding the baby may actually increase scatter radiation to the fetus. Check with your Radiologist. 
  • V/Q scan-also an acceptable strategy. Probably more radiation to the fetus. If you choose this test, remember that many experts recommend you insert a foley to drain the bladder (reduces radiation exposure to the fetus). 
  • Negative PERC (Pulmonary Embolism Rule Out Criteria) + Negative, trimester adjusted d-dimer level. Adjusted trimester cutoffs for d-dimer in pregnancy are: 1st 750 ng/dL, 2nd 1000 ng/dL, and 3rd 1250 ng/dL. So, figure out what trimester your patient is and if they are PERC - and the d-dimer falls below the cutoff,  you are done. Remember to adjust the pulse to 105 bpm if using the PERC rule for rule out as heart rate goes up in pregnancy.
  • Start with lower extremity US, if DVT +, you are done

**For explanation of PERC rule, see earlier pearl.

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Category: Vascular

Title: Ruling Out Pulmonary Embolism in Cancer Patients

Keywords: Pulmonary Embolism, Cancer (PubMed Search)

Posted: 7/7/2008 by Rob Rogers, MD (Updated: 11/19/2019)
Click here to contact Rob Rogers, MD

Ruling Out PE in Cancer Patients: Use D-Dimer??

Most of us are aware of the data that suports using a highly-sensitive d-dimer combined with low-moderate risk score to r/o PE. Sounds simple enough. What about using d-dimer in a cancer patient to rule it out? Well, this is being studied more and more.

Most of us would be a little uneasy about using a d-dimer as a stand-alone test to r/o PE in a cancer patient. After all, they have cancer, aren't they high risk?

The following study showed that the there was a VERY high negative predictive value and a VERY high sensitivity of a negative d-dimer in this group of cancer patients.


Abstract
PURPOSE: To prospectively evaluate (a) the diagnostic performance of D-dimer assay for pulmonary embolism (PE) in an oncologic population by using computed tomographic (CT) pulmonary angiography as the reference standard, (b) the association between PE location and assay sensitivity, and (c) the association between assay results and clinical factors that raise suspicion of PE. MATERIALS AND METHODS: This HIPAA-compliant study had institutional review board approval; informed consent was obtained. Five hundred thirty-one consecutive patients were clinically suspected of having PE; 201 were enrolled (72 men, 129 women; median age, 61 years) and underwent CT pulmonary angiography and D-dimer assay. Relevant clinical history, symptoms, and signs were recorded. CT images were interpreted, and the location of emboli was recorded. The negative predictive value (NPV), positive predictive value (PPV), sensitivity, specificity, and diagnostic likelihood ratios of the D-dimer assay results were calculated. RESULTS: Forty-three patients (21%) had pulmonary emboli at CT. D-Dimer results were positive in 171 patents (85%). The NPV and sensitivity were 97% and 98%, respectively. The specificity and PPV were 18% and 25%, respectively. No association was shown between clinical history, symptoms, or signs and NPV, PPV, sensitivity, or specificity or between location of PE and sensitivity.
CONCLUSION: D-Dimer results have high NPV and sensitivity for PE in oncologic patients and, if negative, can be used to exclude PE in this population. Combining the assay with clinical symptoms and signs did not substantially change NPV, PPV, sensitivity, or specificity.

Whether this is ready from prime time or not remains to be determined, but it is interesting that we might be able to do this in the future to r/o PE in cancer patients.
 

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