UMEM Educational Pearls

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: 10/28/2020)
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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Category: Cardiology

Title: Myopericarditis

Keywords: myocarditis, pericarditis, myopericarditis (PubMed Search)

Posted: 7/7/2008 by Amal Mattu, MD (Updated: 10/28/2020)
Click here to contact Amal Mattu, MD

Both acute pericarditis and myopericarditis are intensely inflammatory. As a result, CRP testing is extremely sensitive for these conditions and is excellent for evaluating their presence or absence.

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Category: Orthopedics

Title: Joint Fluid Analysis

Keywords: Arthrocentesis, Joint, Fluid, Septic (PubMed Search)

Posted: 7/6/2008 by Michael Bond, MD (Updated: 10/28/2020)
Click here to contact Michael Bond, MD

Joint Fluid Analysis:

This is hte session in Baltimore for crab eating and beer drinking so we begin to see an increase in Gout pain.  For those that are presenting with their first episode and you are concerned that they might have a septic joint, I am including this pearl to help analysis the fluid you will obtain from arthrocentesis.

 

Synovial Fluid Interpretation
Diagnosis Appearance WBC PMNs Glucose % of
Blood Level
Crystals
 Normal  Clear  <200  <25  95 - 100  None
 Degenerative
Joint Disease
 Clear  <4000  <25  95 - 100  None
 Traumatic
Arthritis
 Straw colored  <4000  <25  95 - 100  None
 Acute Gout  Turbid  2000 - 50,000  >75  80 - 100  Negative birefringence
 PseudoGout  Turbid 2000 - 50,000  >75  80 - 100  Positive birefringence  
 Septic Arthritis  Purulent / turbid  5000 - > 50,000  >75  < 50  None
 Rheumatoid
Arthritis
 Turbid  2000 - 50,000  50-75  ~75  None

 To view a gout crystal click this link.

To view a pseudogout crystal. Click this link

Pearls: 

  • A WBC Count >50,000 is septic arthritis until cultures are negative. 
  • Due to the wide range of WBC for septic arthritis have a high index of suspicion and do not discount the diagnosis because the WBC count is only 10,000.

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Category: Critical Care Literature Update

Title: recombinant Factor VIIa for ICH

Keywords: intracerebral hemorrhage, recombinant factor VIIa (PubMed Search)

Posted: 7/6/2008 by Mike Winters, MD (Updated: 10/28/2020)
Click here to contact Mike Winters, MD

 

Recent Articles from the Critical Care Literature

Efficacy and Safety of Recombinant Activated Factor VII for Acute Intracerebral Hemorrhage.

Mayer SA, Brun NC, Begtrup MSc, Broderick J, Davis S, et al. NEJM 2008;358:2127-37.
            Intracerebral hemorrhage (ICH) accounts for approximately 10% to 15% of all strokes, yet has the highest morbidity and mortality, with up to 40% of patients dying within 30 days. Aside from age, size, location, intraventricular extension, and GCS, hematoma expansion is an independent determinant of morbidity and mortality. Hematoma expansion is reported to occur in up to 70% of patients within the first several hours of the ICH. Recent research has focused on therapies to limit hematoma expansion. One such therapy is recombinant human activated Factor VII (rFVIIa). Excitement regarding this expensive drug came from a single phase 2 trial (Mayer SA, et al. NEJM 2005:352:777-85.) that demonstrated rFVIIa significantly reduced hematoma expansion and improved patient mortality.
            The FAST trial (Factor Seven for Acute Hemorrhagic Stroke), was a manufacture sponsored, phase 3 trial performed by the same investigators to confirm the findings of their previous phase 2 study. The FAST trial was a multi-center, randomized, double-blind, placebo-controlled trial conducted at 122 sites in 22 countries. Patients had to be at least 18 years of age with a spontaneous ICH documented by CT within 3 hours of symptom onset. Important exclusion criteria included GCS < 5 at presentation, secondary ICH (trauma, AVM), current anticoagulant therapy, thrombocytopenia, DIC, previous disability from CVA, or a thromboembolic event < 30 days prior to symptom onset. The primary end-point was disability or death defined by a modified Rankin score of 5 or 6 at day 90. The modified Rankin score evaluates global disability and handicap and ranges from 0 to 6. A score of 5 indicates a patient who is bed-bound and incontinent, whereas a score of 6 indicates death.
            Of 8,886 patients screened, 821 underwent randomization and received placebo, 20 mcg/kg of rFVIIa, or 80 mcg/kg of rFVIIa. Treatment had to start within 1 hour of the baseline CT and no more than 4 hours after the onset of symptoms. Patients then underwent a repeat CT at 24 hours and 72 hours to evaluate for hematoma expansion. Of note, the majority of the patients in this study were Caucasian males, older than 65 year of age who had deep gray matter ICHs. 
            As reported by the trial investigators, rFVIIa did reduce hematoma expansion at 24 hours compared to placebo. In the placebo arm, 26% of patients had hematoma growth, whereas only 11% of patients who received 80 mcg/kg of rFVIIa had hematoma expansion. In addition, the investigators report that the reduction in hematoma growth was even greater in those treated in less than 2 hours from onset of symptoms. However, when you look at the data for 72 hours, there was no significant difference in total hematoma volume or edema volume. More importantly, mortality at 90 days did not differ between placebo and the treatment groups. In fact, a higher percentage of patients who received 80 mcg/kg of rFVIIa had a worse outcome than compared with placebo. Furthermore, there was an absolute increase of 5% in the frequency of arterial thromboembolic serious events (MI, ischemia CVA) in the group receiving 80 mcg/kg of rFVIIa.
            Take Home Point: This phase 3 trial failed to demonstrate improved 90 day mortality in patients with spontaneous ICH who received rFVIIa. Although hematoma expansion was reduced at 24 hours in the rFVIIa groups, total lesion volume and edema volume at 72 hours remained unchanged. Although rFVIIa has been used in a variety of clinical settings, the results of this study indicate that it does improve mortality in patients with spontaneous ICH. Given the expense of the drug and lack of benefit, this should not be a drug we are using in the ED to treat patients with spontaneous ICH.

Category: Pediatrics

Title: Cardiac Involvement in Kawasaki Disease

Keywords: Kawasaki Disease; Cardiac; Coronary Aneurysm (PubMed Search)

Posted: 7/4/2008 by Don Van Wie, DO (Updated: 10/28/2020)
Click here to contact Don Van Wie, DO

Cardiac Involvement in Kawasaki Disease

  • 50% can have Myocarditis (tachycardia, decreased ventricular function, arrhythmias, CHF, shock)
  • 30% can have Pericarditis In untreated patients;
  • 20 – 25% will have Coronary Artery Aneurysm during second and third week of illness Coronary Artery Aneurysms have risk of rupture, thrombosis, or stenosis
  • Myocardial Infarction is leading cause of Death due to thrombosis, rupture, or stenosis of a coronary aneurysm
  • Treatment with IVIG in the Acute Phase (within 10 days of onset of fever) reduces the risk of coronary artery dilation and aneurysms from 20-25% to < 5 % for coronary dilation and <1 % for giant coronary aneurysm. BUT NOT TO ZERO.

 

So the Pearl is if you have a pediatric patient with a complaint of Chest Pain, ask if there was any history of Kawasaki Disease and get an EKG ASAP if the answer is yes!

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Category: Toxicology

Title: Trends in Drug Abuse

Keywords: drugs of abuse, heroin (PubMed Search)

Posted: 7/3/2008 by Ellen Lemkin, MD, PharmD (Updated: 10/28/2020)
Click here to contact Ellen Lemkin, MD, PharmD

 ADOLESCENT DRUG ABUSE

  • "Pharming" is prescription drug abuse
  • Teens will take medications from their home medicine cabinets, mix them in bags together indiscriminately and make "trail mix" to pass around parties
  • "Cheese" is a combination of heroin with cough and cold preparations. The heroin concentration in cheese is typically between 2-8% compared to 30% found in black tar heroin, and is considered "starter heroin"

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Category: Neurology

Title: Differentiating Delirium from Dementia

Keywords: delirium, dementia, CAM, MMSE (PubMed Search)

Posted: 7/2/2008 by Aisha Liferidge, MD (Updated: 10/28/2020)
Click here to contact Aisha Liferidge, MD

  • The Confusion Assessment Method (CAM) and Mini-Mental State Exam (MMSE)  can be used in combination to effectively differentiate delirium from dementia, respectively.
  • CAM relies on observations by family members, caregivers, and clinicians to assess the following four symptoms:
    1. acute confusional onset
    2. inattention
    3. disorganized thinking
    4. ltered level of consciousness
  •  

  • Using CAM, the diagnosis of delirium requires the presence of both the first and second features, plus one of the two other features.
  • CAM is 95-100% sensitive and 95% specific for diagnosing delirium in the elderly.
  • MMSE is not a diagnostic tool but identifies cognitive impairment suggestive of delirium by assessing orientation, short-term memory, calculation ability, and language (score 18-26 = mild dementia).
  • A positive CAM and an MMSE score of > 25 is predictive of delirium.
  •  


Category: Infectious Disease

Title: Diabetes and Osteomyelitis

Keywords: diabetes, osteomyelitis, temperature, white blood cell count (PubMed Search)

Posted: 7/1/2008 by Mike Winters, MD (Updated: 10/28/2020)
Click here to contact Mike Winters, MD

Does this Patient with Diabetes have Osteomyelitis?

  • Diagnosis of lower extremity osteomyelitis in the diabetic patient remains challenging
  • Bone biopsy with culture remains the gold standard for diagnosis but is not always obtainable
  • What clinical features, therefore, raise the likelihood of osteomyelitis?
  • In this review, an ulcer size > 2 cm2 (LR 7.2), ability to probe to bone using a sterile stainless steel probe (LR 6.4), and an ESR > 70 mm/h were found to be useful in predicting the presence of osteomyelitis
  • Clinical features NOT found to be useful included fever (sensitivity 19%), presence of erythema, swelling, or purulence (LR 1), elevated white blood cell count (sensitvity 14%-54%), and superficial swab culture
  • A note about radiographic studies:
    • bony changes on plain films may take up to 2 weeks to develop
    • plain films alone are only marginally useful if positive (LR 2.3)
    • MRI is more accurate than bone scan or plain films
    • If you are going to order a radiographic study, your best bet is the MRI

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Category: Vascular

Title: Does a Normal D-Dimer rule out Aortic Dissection?

Keywords: Aortic Dissection, D-Dimer (PubMed Search)

Posted: 6/24/2008 by Rob Rogers, MD (Emailed: 6/30/2008) (Updated: 10/28/2020)
Click here to contact Rob Rogers, MD

Does a normal d-dimer rule out aortic dissection?

A lot of research seems to be focused on using d-dimer as a rule-out strategy for acute aortic dissection. The idea is that a d-dimer <500 (which is what we use for ruling out PE in low-mod risk patients) rules out dissection as well.

A few pearls and pitfalls regarding this:

  • Studies look very promising, but NO accepted cutoff point (d-dimer) has been defined
  • This practice has NOT been widely accepted yet
  • A d-dimer <100 ng/dL rules out aortic dissection with a sensitivity of 100%
  • A d-dimer of <500 ng/dL rules out aortic dissection with a sensitivity of 98%
  • Experts in this area seem to be advocating this as a potential rule out strategy
  • Critics of this approach point out the fact that a subset of patients with dissection (those with intramural hematomas-i.e. no intimal tear) may not release d-dimer into the circulation. But almost all studies include patients with this variant and their d-dimers are almost always elevated.

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Category: Airway Management

Title: Pregnancy and Acute Pulmonary Embolism

Keywords: Pregnancy, Pulmonary Embolism (PubMed Search)

Posted: 6/30/2008 by Rob Rogers, MD (Updated: 10/28/2020)
Click here to contact Rob Rogers, MD

 Pregnancy and Acute Pulmonary Embolism

Women who are pregnant or in the postpartum period and women who take hormonal therapy are at an increased risk of pulmonary embolism.

Some facts:

  • Risk of first episode of venous thromboembolism is 15 times as high in the postpartum period as during pregnancy
  • Diagnostic workup and initial ED therapy is the same as it is for non-pregnant patients
  • Although there are still some concerns about pulmonary CTA, both the American College of Obstetrics & Gynecology and the American College of Radiology agree that it is safe. It is unknown what happens to fetal nephrons after exposure to circulating contrast in the mother. Despite this, CTA can be used without fear if indicated. 
  • Warfarin is a teratogen and should not be used for anticoagulation.

 

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Category: Cardiology

Title: low voltage on ECG

Keywords: low voltage, electrocardiography, effusion (PubMed Search)

Posted: 6/30/2008 by Amal Mattu, MD (Updated: 10/28/2020)
Click here to contact Amal Mattu, MD

Low QRS voltage on the ECG has various definitions; here's my simple definition for low voltage...either one of the following:
     If the added QRS amplitudes (whole R wave + S wave) in leads I + II + III total < 15 mm, OR
     If the added QRS amplitudes (whole R wave + S wave) in leads V1 + V2 + V3 total < 30 mm.

The potential causes of  low QRS voltage includes pericardial effusions, pleural effusions, obesity, COPD, infiltrative cardiac diseases (e.g. sarcoid, amyloid), end-stage cardiomyopathies, severe hypothyroidism.

If the patient has NEW low voltage compared to an old ECG, the only real possibilities are pericardial effusion, pleural effusion, and severe hypothyroidism (e.g. myxedema).


Category: Orthopedics

Title: Calcaneus Fractures

Keywords: calcaneus, fracture, compartment (PubMed Search)

Posted: 6/29/2008 by Michael Bond, MD (Updated: 10/28/2020)
Click here to contact Michael Bond, MD

Calcaneus Fractures

Normally occur due to axial loading mechanism such as:

  •     Fall from height
  •     Motor Vehicle collisions
  •     Repetitive impacts on a hard surface such as seen with running or jumping.

Miscellanous Facts:

  1. 70% of calcaneal fractures are intra-articular
  2. 10-15% are associated with spinal compression fractures
  3. Estimated that 7-10% will have a fracture of the contralateral foot
  4. Monitor for compartment syndrome of the foot.  Deep central compartment is most commonly affected with calcaneus fractures

Pearls:

  1. Strongly consider getting Lumbar Spine Films and x-rays of the opposite foot in anybody that has a calcaneus fracture.
  2. Perform frequent reassessments, and do not hesitate to check compartment pressures if you suspect they might be elevated.

Category: Pediatrics

Title: The Whooping Cough

Keywords: Pertussis (PubMed Search)

Posted: 6/27/2008 by Don Van Wie, DO (Updated: 10/28/2020)
Click here to contact Don Van Wie, DO

Pertussis means "violent cough". 

Think of it with prolonged coughing, inspiratory whoop, absolute lymphocytosis, or chronic cough.

Don't Use cough suppressants.

Pertussis can be a life threatening Infection!!  Especially in infants and young children.

 

 

  • Factors that should prompt a consideration of admitting the patient are the following:
    • Age younger than 1 year
    • Pneumonia
    • Apneic or cyanotic spells or hypoxia
    • Moderate-to-severe dehydration
  •  

     

    Pertussis is a reportable infectious disease in the United States.


    Category: Toxicology

    Title: Dapsone-Induced Methemoglobinemia

    Keywords: dapsone, methemoglobinemia, methylene blue (PubMed Search)

    Posted: 6/27/2008 by Fermin Barrueto, MD (Updated: 10/28/2020)
    Click here to contact Fermin Barrueto, MD

    •  Dapsone has been used to treat leprosy but more commonly to in brown recluse spider bites and to prevent PCP pneumonia and toxoplasmosis in our HIV population
    • It can cause methemoglobinemia: a reduced form of iron (ferrous to ferric) in the Hb molecule that decreases your oxygen carrying capacity. 
    • Due to its color, cyanosis is a predominant symptom out of proportion to symptoms.
    • Treatment: Methylene Blue 1-2 mg/kg IV
    • Pitfall: Dapsone's long half-life may cause reoccurrence of MetHb and require retreatment

     


    Category: Neurology

    Title: Types of Confusion in the Elderly

    Keywords: confusion, dementia, delirium, elderly (PubMed Search)

    Posted: 6/25/2008 by Aisha Liferidge, MD (Updated: 10/28/2020)
    Click here to contact Aisha Liferidge, MD

    • Poor differentiation of the type and cause of confusion in the elderly is associated with poor outcomes (i.e. increased mortality/morbidity, prolonged hospital stays, and functional decline).
    • Confusion in the elderly can be categorized into three types with the following typical features:
    1. Delirium - caused by organic illness, acute onset, agitated or drowsy, variable short-term memory, disorganized thoughts, hallucinations.
    2. Dementia - chronic confusion due to long-term neurologic illness like Alzheimer's disease, progressive, irreversible, short-term memory loss, simple task performance and language impairment, aggression, personality changes.
    3. Acute or Chronic Confusion - treatable illness (i.e. infection) triggers delirium in patient with baseline dementia.

    Category: Cardiology

    Title: pericarditis and cancer

    Keywords: pericarditis, cancer, pericardial effusion, metastastic (PubMed Search)

    Posted: 6/22/2008 by Amal Mattu, MD (Updated: 10/28/2020)
    Click here to contact Amal Mattu, MD

    Patients with cancer that present with pleuritic chest pain often have pulmonary emboli, but don't forget about pericarditis. Lung and breast cancer, especially, are known to metastasize to the pericardium and produce pericarditis or pericardial effusions. Anticoagulation for presumed PE in patients with pericardial mets. can produce hemorrhagic tamponade, a disastrous iatrogenic complication, so think twice before starting empiric anticoagulation on patients...make sure your patient doesn't have pericarditis or an pericardial effusion.

    The ECG in patients with cancer-related pericarditis or pericardial effusion does not always demonstrate the classic ST elevation wtih PR depression (which is most commonly seen in viral pericarditis). Patients with pericardial effusions often demonstrate low voltage and tachycardia. Electrical alternans, though "classic," only appears in 1/3 of patients with pericardial effusions.


    Category: Orthopedics

    Title: Hip Fractures

    Keywords: hip, fracture, mri, plain films (PubMed Search)

    Posted: 6/21/2008 by Michael Bond, MD (Updated: 10/28/2020)
    Click here to contact Michael Bond, MD

    Hip Fractures:

    Typically divided into four types:

    1. Intracapsular,
      1. femoral head and neck fractures
    2. Extracapsular
      1.  trochanteric,
      2. Intertrochanteric
      3. subtrochanteric fractures. 
    • Non-displaced fractures, especially in osteoporotic elderly patients, may be missed on plain films. This is estimated to occur in 2-9% of cases. 
    • It can take up to 72 hours for a fracture to be seen on bone scan. And it is estimated that only 80% of fractures will be seen at 24 hours.
    • MRI is now the preferred imaging modality (100% sensitivity and specificity) to confirm a hip fracture when plain films are negative and equivocal. A MRI will have positive findings in as little as 4 hours after a fracture.
    • Consider CT scan of the hip if MRI is not available at your center.

    Here is a link to a picture with a good representation of the different types of fractures.

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    Category: Toxicology

    Title: Antagonize Anticoagulation

    Keywords: coumadin, vitamin K, anticoagulation (PubMed Search)

    Posted: 6/19/2008 by Fermin Barrueto, MD (Updated: 10/28/2020)
    Click here to contact Fermin Barrueto, MD

    Here is a short list of medications that will actually prevent a patient from being anticoagulated by coumadin. These medications will make it difficult for the patient to reach therapeutic levels and need to be warned about this drug-drug interaction with coumadin:

    • Antacids
    • Antihistamines
    • Barbituates
    • Carbamazepine
    • Cholestyramine
    • Corticosteroids
    • Griseofulvin
    • OCPs
    • Phenytoin
    • Rifampin
    • Vitamin K

    Reference: Goldfrank's Textbook of Toxicologic Emergencies, 6th Edition


    Category: Neurology

    Title: Scales to Assess Acute Risk of Stroke after TIA

    Keywords: Stroke, TIA, ABCD, ABCD2 (PubMed Search)

    Posted: 6/19/2008 by Aisha Liferidge, MD (Updated: 10/28/2020)
    Click here to contact Aisha Liferidge, MD

    • The ABCD and ABCD2 scores are validated scales based on both prospective and retrospective data to assess patients' risk of stroke at 7 and 2 days after a TIA, respectively.  The biggest difference between the two is that the ABCD2 Scale includes diabetes as a factor.
    • ABCD Scale
    • Age:  at least 60 = 1 point
    • BP:  SBP > 140 and/or DBP > 90 = 1 point
    • Clinical features:  unilateral weakness = 2 points; speech disturbance w/o weakness = 1 point;  any other neurologic  finding = 0 points.
    • Duration:  at least 60 min. = 2 points; 10-59 min. = 1 point; < 10 min. = 0 points. 
    • Score:  4 points = 1.1% risk;  5 points = 12.1% risk;  6 points = 31.4% risk.
    • ABCD2 Scale
    • Age:  same as ABCD Scale
    • BP:  same as ABCD Scale
    • Clinical features:  same as ABCD Scale except "any other neurologic finding = 0 points" component is omitted.
    • Duration:  same as ABCD Scale except  "< 10 min. = 0 points" component is omitted.
    • Diabetes:  1 point
    • Score:  4-5 points = 4% risk;  6-7 points = 8% risk;  0-3 points = 1% risk.
    • Question = When considering sending a patient home prior to a thorough and appropriate TIA/stroke work-up, how low of a percent risk is acceptable?

    Show References


    Category: Critical Care

    Title: Passive Leg Raising

    Keywords: passive leg raising, fluid responsiveness (PubMed Search)

    Posted: 6/17/2008 by Mike Winters, MD (Updated: 10/28/2020)
    Click here to contact Mike Winters, MD

    Passive Leg Raising (PLR)

    • We have discussed that static measures of volume (CVP, PA wedge pressures) are not reliable markers of fluid responsiveness
    • PLR has recently gained interest as a simple and transient way to assess fluid responsiveness in the critically ill
    • Patients are placed in the horizontal position (not Trendelenburg) and the legs are raised to 45 degrees
    • A hemodynamic response should be seen in 30 - 90 seconds
    • Patients who have improvement in hemodynamics with PLR are said to be fluid responsive (i.e on the ascending portion of their Starling Curve) and require additional volume resuscitation

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