UMEM Educational Pearls - By Haney Mallemat

Question

CXR shown below, what's the diagnosis? ...and name 3 differential diagnoses.

 

 

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Vasopressors are used in shock-states to increase mean arterial pressure (MAP) and improve distal tissue perfusion. Additionally, some agents have effects on the heart to augment cardiac output.

Receptors that vasopressors work on include: 

  • Alpha-1: increase arterial tone (increases MAP) and venous tone to reduce venous pooling and augment cardiac preload 
  • Beta-1: increase inotropy and chronotropy on heart muscle; also increases arterial tone
  • Beta-2 and Dopamine: cause vasodilation but may actually be beneficial because this increases perfusion to cardiac, renal, and GI tissues.
  • V1: arterial vasoconstriction to increase MAP
  • The chart below is a summary; please note that quoted receptor effects vary depending on the source reviewed

Norepinephrine (NE): excellent vasopressor for most types of shock and recommended as a first-line agent in the Surviving Sepsis Guidelines.

  • Works on alpha-1, beta-1, and beta-2 receptors. 
  • Initial dosing 0.05 mcg/kg/min with a maximum dose often cited as 0.5 mcg/kg/min (though there is technically no maximum dose).

Epinephrine (a.k.a. Adrenaline): in several countries the first-line agent for shock (including sepsis).

  • Works similarly to NE on alpha-1, beta-1 and beta-2; it is a more potent inotrope than NE.
  • One downside is the production of lactic acid, which can sometimes lead to confusion when following serial lactates during resuscitation. 

 

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Question

You are scaning the liver with ultrasound and you see this. What's the diagnosis?

 

 

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Question

50 year-old female with diabetes complains of pain and discharge from a poorly healing wound. XRay below. What's the diagnosis?

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Question

A critically-ill patient requires fluid resuscitation. Someone hands you a bag of this. What’s the pH of this fluid? 

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Question

30 year-old female with complains of night sweats and painful lesions on her fingertips. What’s the diagnosis and list some things to have in the differential diagnosis?

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There are many ventilator modes to choose from, but almost every mode can be distilled down to its basic principles by understanding the “Three T's of Mechanical Ventilation”

Trigger: You must determine whether the vent or patient will trigger a mechanical breath. For example, machine-triggered breaths (a.k.a. control mode of ventilation) are used for paralyzed patients and will deliver a breath after a period of time has elapsed (e.g., if RR is 10/min, then a breath is given every 6 seconds). On the other hand, if a patient’s respiratory drive is intact (a.k.a. assist-mode) than the patient triggers the breath when the vent detects a patient induced change in airflow or airway pressure. These two modes can also be mixed together.

Target: Mechanical breaths must have a specific target, either a target airway pressure or a tidal volume. Because pressure and volume are directly related, pick the variable you want to target and the other parameter will vary depending on the patient’s intrinsic physiology. For example, if you choose to target a specific tidal volume, we may get one plateau pressure in a patient with normal lungs, but a higher plateau pressure in another patient with stiffer lungs.

Terminate: You must decide when the mechanical breath (i.e., inspiration) terminates and expiration begins. Termination occurs: 1) after a set inspiratory time has elapsed in certain pressure-targeted modes, 2) when a predefined target volume has been achieved (i.e., volume-cycled modes), or 3) when airflow has been reduced by a certain percentage (as in pressure-support ventilation; to be discussed separately)

Let’s put this all together by looking at an example: pressure control ventilation (rate = 12/min and target pressure 20cm H20). Trigger: Because this is a “control”, not assist mode, the machine will trigger a breath 12 times per minute or every 5 seconds. Target: Here we chose to have pressure be the target, so when the ventilator triggers a breath it will deliver a constant airway pressure of 20 cmH2O until we tell the vent terminate that breath. Terminate: the constant airway pressure will be turned off after a fixed period of time has elapsed; for this example we will set the inspiratory time as 1 second, then expiration begins. Now, after a few vent breaths we will observe the results of our settings and reassess; if the resulting tidal volume is lower than what we wanted, we will increase the target pressure to increase the tidal volume. If the tidal volume is higher than what we wanted, we will reduce the target pressure to reduce the tidal volume. We can also tweak the inspiratory time to manipulate the tidal volume, but this does so to a lesser degree.

Try to break down your favorite modes of ventilation using the Three T’s and see if this helps you understand vent modes better. 

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Question

40 year-old female presents with painful lesions and ulcers on lower extremities. She has had this before, but never to this extent. She also has a history of DVT. What’s the diagnosis?

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Category: Visual Diagnosis

Title: What's the Diagnosis? Case by Dr. Swati Singh

Posted: 7/27/2014 by Haney Mallemat, MD (Emailed: 7/28/2014) (Updated: 7/28/2014)
Click here to contact Haney Mallemat, MD

Question

2-day old baby boy presents with forceful vomiting of entire feeds, bloated belly, and has not passed stools since birth. What's the diagnosis?

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Question

45 year-old right-hand dominant patient presents with right hand pain from a prior injury to hand. Patient has also been injecting subcutaneous heroin into hand for relief. What's the diagnosis?

 

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Question

30 year-old presents with cough & fever. CXR shows mild right lower lobe pneumonia. The lung ultrasound of the right lower lobe is shown below. What's the diagnosis? 

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  • When considering starting a patient on non-invasive ventilation (NIV), ask yourself whether the patient is having a problem of oxygenation (Type I respiratory failure) or a problem of CO2 removal or ventilation (i.e., Type II respiratory failure); don’t forget both types can be present, simultaneously
  • Examples of Type I problems are pneumonia and pulmonary edema; examples of Type II problems are COPD, drug overdose, and neuromuscular disease (e.g., myasthenia gravis). Once the underlying problem is identified, selecting the type of NIV is straight-forward. 
  • There are only two interventions for type I disorders: 1) increase fio2 and/or 2) increase mean airway pressure (positive end-expiratory pressure; a.k.a. PEEP). There are only two interventions for type II disorders: 1) increase tidal volume and/or 2) increase respiratory rate 
  • Continuous positive airway pressure (CPAP) only provides support for type I problems (i.e., can titrate FiO2 and PEEP); CPAP does not provide a tidal volume or a respiratory rate (needed for type II support)
  • Bi-level positive airway pressure (BPAP) provides support for type II problems; tidal volume can be titrated by increasing the pressure support and a respiratory rate can be dialed in.

Editors note: The new Back 2 Basic series will review essential critical care concepts on the first Tuesday of each month. Want a specific topic reviewed? Contact us by email or Twitter.

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Question

10 year-old male complains of fever and rash (shown below); no other complaints. He went camping 10-days ago. What’s the diagnosis...and what medication(s) should he receive?

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Question

49 year-old female on trimethoprim/sulfamethoxazole presents with a rash & lesions on her oral mucus membranes. What's the diagnosis?

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Category: Visual Diagnosis

Title: What's the Diagnosis?

Posted: 6/22/2014 by Haney Mallemat, MD (Emailed: 6/23/2014) (Updated: 6/23/2014)
Click here to contact Haney Mallemat, MD

Question

35 year-old female presents with nausea and vomiting 1 week post-op for an abdominal surgery. Abdominal ultrasound is below; what's the diagnosis? 

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Question

41year-old male without past medical history presents with the image below. What's the diagnosis and what's the most likely causative organism?

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  • A feared complication of patients taking vitamin K antagonists (VKA) is life-threatening bleeding (LTB), including intracranial hemorrhage (ICH).
  • Prothrombin complex concentrate (PCC; containing factors 2,7,9,and 10) rapidly reverses VKA-associated bleeding. Despite a rapid reversal of the INR, there is little literature demonstrating a mortality benefit.
  • The EPAHK study was observational-cohort that examined the 7-day mortality of guideline-concordant administration of PCC and vitamin K (GC-PCC-K) for multiple-types of patients with warfarin-associated bleeding.
  • The study demonstrated patients who received GC-PCC-K within 8 hours of presentation had a two-fold decrease in 7-day morality; there was a three-fold reduction when only ICH was considered.

 

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Question

28 year-old female with history of chronic back pain presents with right-foot numbness and inability to move her foot at the ankle joint. What’s the diagnosis and what neurologic finding would you expect to find?

 

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Question

30 year-old female with elbow pain following a fall. What's the diagnosis? (bonus points if you name the fracture with an associated radio-ulnar joint dislocation)

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Question

Diabetic patient with active intravenous drug use presents with hypotension, fever, and tenderness of right arm. What's the diagnosis and what antibiotic(s) would you start?

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