Hypotension begins at 110 mmHg?

• Many of us use the historical SBP cut-off point of 90 mmHg or less to identify hypotension and shock
• Importantly, there is no data to support this arbitrary value
• Particularly in older patients, hypotension, hypoperfusion, and increased mortality may begin sooner than previously realized
• In this study of over 80,000 patients from the National Trauma Data Bank, a SBP < 110 mmHg was found to be more clinically relevant for identifying hypotension and hypoperfusion
• Take Home Point: strongly consider raising your threshold for identifying hypotension and initiating resuscitation, especially in the older trauma patient.

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Recent Articles from the Critical Care Literature

Duration of adrenal insufficiency following a single dose of etomidate in critically ill patients

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.

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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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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.

 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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Recent Articles from the Critical Care Literature

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

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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 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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• 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.

 

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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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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 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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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).

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.

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.

Pertussis is a reportable infectious disease in the United States.

•  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

• 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.

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.

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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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