UMEM Educational Pearls

CVP and Fluid Responsiveness

• Central venous pressure (CVP) has been used over the last 50 years to assess volume status and fluid responsiveness in critically ill patients.
• Despite widespread practice habit, CVP has not been shown to reliably predict fluid responsiveness in the critically ill.
• In a recent updated meta-analysis, Marik et al reviewed 43 studies, totaling over 1800 patients.
  • 57% of patients were fluid responders
  • The mean CVP was 8.2 mm Hg for fluid responders and 9.5 mm Hg for non-responders
  • For studies performed in ICU patients, the correlation coefficient for CVP and change in cardiac index was just 0.28.
• Bottom line: Current literature does not support the use of CVP as a reliable marker of fluid responsiveness.

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Question

Name three differential diagnoses based on the CXR below.

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Bifascicular block

1. Right bundle branch block (RBBB) + left anterior fascicular block (LAFB) 
2. RBBB + left posterior fascicular block (LPFB)
3. Complete left bundle branch block (LBBB)

Incomplete Trifascicular block

1. Bifascicular block w/1^st degree AV block    *classically referred to as “trifascicular block”*
2. Bifascicular block w/2^nd degree AV block
3. Alternating LBBB + RBBB

Complete Trifascicular block

1. Bifascicular block w/3^rd degree AV block 

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Tennis Elbow

The tendon usually involved in tennis elbow is called the Extensor Carpi Radialis Brevis (ECRB).

 The ECRB  muscle helps stabilize the wrist when the elbow is straight.

Ask the patient to straighten the arm at the elbow and then perform resisted long finger extension. This will stress the ECRB and reproduce the pain. One can also ask the patient to lift the top of a chair in the air with the elbow extended.

General Information:

Hepatitis A is a food-borne illness that is prevalent in developing countries.  Currently in the US we are experiencing an outbreak in 8 states related to a frozen blend of organic berries. (Linked to Townson Farms brand sold at Costco and Harris Teeter)

Clinical Presentation:

- Case definition: sudden onset of S/S + jaundice or elevated liver enzyme levels

- S/S: nausea, anorexia, fever, malaise, abdominal pain

Diagnosis:

- Hepatitis A IgM

Treatment:

- Exposed patients should be given the Hep A vaccine within 2 weeks of exposure

- Exposed patients >40 yrs old, <1 yr old, immunocompromised, or with chronic liver disease: give immunoglobulin instead (risk of more severe disease)

- Supportive care

Bottom Line:

Patients potentially exposed to Hepatitis A in the past 2 weeks should be given either the vaccination or immunoglobulin, depending on comorbid conditions.  Treatment of active infection is supportive.

University of Maryland Section of Global Emergency Health

Author: Andi Tenner, MD, MPH

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Keep Immune Thrombocytopenic Purpura (ITP) in your differential for patients with thrombocytopenia and evidence of bleeding. Although ITP has classically been described in children, it can occur in adults; especially between 3^rd- 4^th decade.

Thrombocytopenia leads to the extravasation of blood from capillaries, leading to skin bruising, mucus membrane petechial bleeding, and intracranial hemorrhage.

ITP occurs from production of auto-antibodies which bind to circulating platelets. This leads to irreversible uptake by macrophages in the spleen. Causes of antibody production include:

• Medication exposure
• Infection (usually viral), including HIV and hepatitis
• Immune disorders (e.g., lupus)
• Pregnancy
• Idiopathic

Suspect ITP in patients with isolated thrombocytopenia on a CBC without other blood-line abnormalities. Abnormality in other blood-line warrants consideration of another diagnosis (e.g., leukemia).

ITP cannot be cured; treatments include:

• Steroid to suppress antibody production (first-line therapy)
• Intravenous immunoglobulin (IVIG)
• IV Rho immunoglobulin (for Rh+ patients only)
• Rituximab +/- dexamethasone
• Splenectomy (rare cases of massive hemorrhage refractory to pharmacologic treatment)

Stanford type A (proximal) aortic dissection accounts for ~60% of all aortic dissections

Classic treatment includes direct surgical replacement of the ascending aorta w/prosthetic graft (+/- AV  aortic repair/replacement)

~20-30% of these patients (*institutional dependent) are considered poor candidates for surgery and receive only medical management, which innately results in substandard outcomes

In this study those who were considered poor candidates for surgical repair underwent novel endovascular treatment

Endovascular repair in this study was considered both appropriate and improved traditional medical outcomes in patients who were considered poor candidates 

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Trapezium Fractures

• The trapezial body is often fractured due to an axial load through the thumb
• The trapezial ridge is often fractured during a fall on an outstretched hand
• Accounts for 1% to 5% of all carpal fractures.

Suspect the Diagnosis when you note

• Tenderness  over trapezium 
• Often have increased pain with axial loading of thumb.
• Point tenderness at the volar base of the thumb just distal to the scaphoid, at the base of the first metacarpal.
• Since the trapezium is obscured by superimposed bones in PA and lateral views, fractures are most easily identified on the oblique radiographs

If you are suspected the diagnosis oblique radiographs or a CT scan of the wrist will note the fracture the best.

Treatment consists of placing the patient in a thumb spica splint.

• enterovirus which lives in digestive tract, and is highly contagious
• outbreaks worse in summer and fall, but is a self-limited illness
• causes mild flu-like symptoms such as fever, headache, muscle aches, sore throat. with fever usually lasting less than 3 days
• hand, foot, and mouth disease: syndrome of painful blisters in oropharynx and plams of hands and soles of feet
• herpangina: painful blisters in oropharynx, usually posterior in location
• hemorrhagic conjunctivitis: eye pain with injected conjunctivia
• serious complications include: viral meningitis and encephalitis, myocarditis, and secondary bacterial infections

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In the treatment of acetaminophen poisoning with N-acetylcysteine (NAC), the PT/INR can be slightly elevated even in the absence of hepatotoxicity. Considering Prothombin Time (PT) is one of the criteria used to assess severity of liver damage in this setting, it is important to know how much the PT/INR can be affected by NAC and if it has an actual effect on coagulation factor levels.

1. N-acetylcysteine has been shown to slightly increase the PT) by up to 3.5 seconds in healthy volunteers.
2. A more recent study by the same authors demonstrated a reduction in vitamin K-dependent clotting factor activity (II, VI, IX, and X) after NAC administration in healthy volunteers.

Clinical Practice Pearls

• The elevation in PT/INR after NAC administration is real, not simply laboratory interference.
• However, the PT/INR elevation and decrease in coagulation factors is modest and not likely clinical signficant.
• Many poison center guidelines allow for an INR up to 2 to be considered 'normal' to account for this phenomenon in this setting.

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General Information:

-Listeria can cause serious infections in vulnerable groups: adults >65 years old, pregnant women, newborns, immunocompromised

-In a recent CDC report, infection with Listeria was associated with a 20% mortality rate.

Clinical Presentation:

- History of cantaloupe, soft cheese, or raw produce ingestion

- Non-specific symptoms: fever, myalgias, occasionally preceded by GI symptoms

-Can have headache, stiff neck, confusion, AMS, miscarriage or stillbirth in pregnant women

Diagnosis:

- Blood, CSF, or amniotic fluid culture showing Listeria monocytogenes

- Listeria is a reportable disease

Treatment:

- Ampicillin and Penicillin G are the drugs of choice

- Add gentamycin in CSF infection, endocarditis, the immunocompromised, and neonates.

Bottom Line:

Listeria infections have a high mortality rate and can be found worldwide.  Suspect in patients who have febrile syndromes and travel to areas where they may consume unpasteurized cheese.

University of Maryland Section of Global Emergency Health

Author: Andi Tenner, MD, MPH

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Rhabdomyolysis in the Critically Ill

• Rhabdomyolysis can be disastrous in the critically ill patient, resulting in metabolic acidosis, life-threatening hyperkalemia, acute kidney injury, and acute renal failure (ARF).  In fact, mortality can be as high as 60% for those that develop ARF secondary to rhabdomyolysis.
• Although creatine kinase (CK) is a sensitive marker of muscle injury and used for diagnosis, it is actually the presence of myoglobinuria that results in ARF.
• Current guidelines recommend treatment when the CK level is > 5000 U/L.
• The mainstay of treatment remains aggressive fluid resuscitation with crystalloids.
• The administration of bicarbonate to alkalinize the urine, diuretics to increase urine output, and osmotic agents (mannitol) to augment urine output remain controversial and are not supported by current literature.

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Question

13 year-old female with ankle pain following fall down escalator. What's the diagnosis?

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• Syncope is a sudden lack of blood supply to the brain typically caused by a problem in the regulation of blood pressure or a problem with the heart
• Syncope can be broadly classified in 3 categories neural reflex (~60%), orthostatic (~15%), and cardiac (~15%) 
• >Even in the absence of a firm diagnosis of cardiac syncope, the presence of known structural heart disease (CAD) or evidence a primary electrical disorder is associated with a poor prognosis
• Cardiac causes of syncope can also be divided into 3 categories: structural heart disease, obstructive lesions, and arrhythmogenic potential
  • Structural: Ischemic heart disease, dilated cardiomyopathy, ARVD, 
  • Obstructive: HCM, aortic/mitral stenosis, atrial myxoma, pulmonary HTN, PE, tamponade
  • • Brady: AV block, sick sinus, sinus arrest/pause
    • Tachy: SVT (AVNRT/AVRT), accessory pathways (WPW), or primary arrhythmias (LQTS, SQTS, CPVT, Brugada) 

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The adolescent brain has not yet reached full maturation and is in a period of rapid development from ages 14 - 16. 

Adolescents have been found to be more sensitive to the effects of concussion than adults

Concussed adolescents have deficits in attention and executive function lasting up to 2 months post injury.

Be aware that the adolescent brain will require  extended recuperation time following injury

In the future, discharge instructions might need to say more than "don't get hit in the head till your headache goes away." Because of deficits in attention and executive function, physicians should consider recommendations about adolescents and jobs, school work and driving an automobile. 

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Infant lumbar puncture is often difficut and may require repeated attempts.  The traditional body positioning is lateral decubitus.  Previous studies have examined the saftey of having the patient in a sitting position, and neonatal studies have suggested that the subarachnoid space increases in size as the patient is moved to the seated position.  A study by Lo et al published last month looked to see if the same held true in infants.
 
50 healthy infants less then 4 months old had the subarachnoid space measured by ultrasound between L3-L4 in 3 positions: lateral decubitus, 45 degree tilt and sitting upright.
 
This study found that the size of the subarachnoid space did not differ significantly between the 3 positions.  Authors postulated that a reason for increase sitting LP success rate that had been reported in anestesia literature with tilt position could be due to other factors such as increased CSF pressure, intraspinous space widening or improved landmark identification.

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• Opioid analgesia can actually INCREASE sensitivity to pain in some cases

• The exact cause is unclear, but may be due to up-regulation of NDMA receptors in spinal cord dorsal horn neurons

• Pain tends to be DIFFERENT and DIFFUSE from the underlying condition for which the narcotics were prescribed

• Switching from shorter acting opiates to methadone may be effective, as it is a weak NDMA antagonist and has only partial cross tolerance with other opioids

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General Information:

-The global health world is faced with an unprecedented challenge of a trio of threats:

     1. Infections, undernutrition, reproductive health issues

     2. Rising global burden of non-communicable diseases and risk factors

     3. Challenges arising from globalization (climate change and trade politics)

-Definitions of global health are variable and can emphasize anything from types of health problems, populations of interest, geographic area or a specific mission.  This makes governance and analysis difficult.

-During the past decade there has been an explosion of more than 175 initiatives, funds, agencies, and donors.  Health is increasingly influenced by decisions made in other global policymaking areas.

-The major governance challenges for global health are:

     1. Defining national sovereignty in the context of deepening health interdependence

     2. Maximizing cross-sector interdependence

     3. Developing clear mechanisms of accountability for non-state actors

Relevance to the US physician:

The Global Health System and its governance affects our ability to work effectively within the US and how we structure efforts to expand the reach of timely, effective emergency care worldwide.

Bottom Line:

The Global Health System has become more complex. Any development of Emergency Care Systems must take into account the complexity of actors in the field of global health.

The University of Maryland Section of Global Emergency Health

Author: Emilie J. B. Calvello, MD, MPH

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Therapeutic hypothermia (TH) following out-of-hospital cardiac arrest (OHCA) has increasingly been utilized since it was first described. TH following in-hospital cardiac arrest (IHCA), on the other hand, is not as commonplace or consistent despite a recommendation by the American Heart Association (AHA).

A recent prospective multi-center cohort-study demonstrated that of 67,498 patients with return of spontaneous circulation (ROSC) following IHCA only 2.0% of patients had TH initiated; of those 44.3% did not even achieve the target temperature (32-34 Celsius). 

The factors found to be most associated with instituting TH were:

• Younger patients
• Admission to non-ICU units
• Arrests occurring Monday through Friday (as compared to weekends)
• Arrests within teaching hospitals (as compared to non-teaching institutions)

Bottom-line: Hospitals should consider instituting and adhering to local TH protocols for in-house cardiac arrests.

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Ever wonder how to place a pigtail catheter?

Check out this video to learn how, click here

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