Monday Back to Basics

Transvenous Pacing

The last two weeks, Dr. Cash taught us about bradycardia and transcutaneous pacing. This week, we dug back years into the archives and pulled out Dr. Pelletier-Bui’s famous post on transvenous pacing.

A timeless classic! Just be sure to know what supplies are available in your department, where to find them, and alternate options if your supplies differ.

References:

Bessman, E. (2019). Emergency cardiac pacing. In Roberts et al (Eds.), Roberts and Hedges’ clinical procedures in emergency medicine and acute care (pp. 288-308).  Elsevier, Inc.

Bohanske. (2013, November 4). Transvenous pacemaker placement – Part I: The walkthrough.  Taming the Sru.  https://www.tamingthesru.com/blog/procedural-education/transvenous-pacemaker-placement-part-1-the-walkthrough 

Mason, J. [EM:RAP Productions] (2018, October 11).  Placing a transvenous pacemaker [Video]. YouTube. https://www.youtube.com/watch?time_continue=24&v=00-T8PcbStE&feature=emb_title

Monday Back to Basics

Bradycardia, Part 2 with Dr. Allison Cash

  1. Treat possible underlying cause if known 
  1. Atropine
    •  Class 2a treatment
    • Dose 0.5 mg IV every 3-5 minutes, up to total dose 3 mg 
    • Can produce paradoxical worsening bradycardia 
    • Less effective in patients with cardiac transplant 
    • Skip if unstable, move directly to pacing 
  1. Transcutaneous pacing  
    • Class 1a recommendation
    • Place pads in anterior lateral or anterior posterior position 
    • Consider sedation or pain control  
    • Set monitor to “Pacer” 
    • Set rate, usually around 60 bpm 
    • Start current at 0 mA and slowly increase until capture is obtained. Consider different placement of pads if capture not achieved by 130 mA 
    • Confirm capture by feeling pulse or cardiac ultrasound 
    • Transcutaneous pacing is ultimately a bridge to transvenous pacing or permanent pacemaker – discuss with cardiology or transfer to center with these capabilities  
    • Capture (pictured below) shows pacer spike followed by a wide QRS and then ST and/or T wave  

References: 

  1. Judith E. Tintinall, et al. (2020). Tintinalli’s Emergency Medicine : A Comprehensive Study Guide (Ninth Edition). New York: McGraw-Hill. 
  1. Doukky R, Bargout R, Kelly RF, Calvin JE. Using transcutaneous cardiac pacing to best advantage: How to ensure successful capture and avoid complications. J Crit Illn. 2003 May;18(5):219-225. PMID: 30774278; PMCID: PMC6376978. 
  1. Holger J S, Lamon R P, and Minnigan H J et al.: Use of ultrasound to determine ventricular capture in transcutaneous pacing. Am J Emerg Med.  2003; 21: 227 
Monday Back to Basics

Bradycardia, Part 1 with Dr. Allison Cash

A ACS Myocardial infarction, also consider cardiomyopathies, myocarditis 
T Thyroid Hypothyroidism 
Rhythms  Second degree AV block (type I & II), complete AV block 
O Overdose Digoxin, beta blockers, calcium channel blockers, amiodarone, clonidine, organophosphates, naturally occurring cardiac glycosides (e.g. foxglove), opioids 
P Pressure Increased intracranial pressure (Cushing’s response) 
Infection Lyme disease, diphtheria, typhoid fever, aortic root abscess 
N Nippy  Hypothermia  
E Electrolytes Glucose, potassium, calcium, and magnesium 

Other Considerations:

  • Hypoxia
  • Infiltrative Disorders (Amyloidosis, Sarcoidosis, Hemochromatosis)
  • Autoimmune disorders (SLE)

References: 

  1. Judith E. Tintinall, et al. (2020). Tintinalli’s Emergency Medicine : A Comprehensive Study Guide (Ninth Edition). New York: McGraw-Hill. 
  1. Briggs, Blake & Husain, Iltifat. (2024, Jan 16) Bradycardia: “But my Apple Watch…?” (208). Emergency Medicine Board Bombs. 
Monday Back to Basics

Feel the Burn?

Additional Considerations

· Any patients with concerns of airway burns should be considered for intubation.

· Calculate total surface area burned.

Rules of Nine or Lund-Browder

· After initial fluid resuscitation, use Parkland formula to calculate fluid resuscitation over first 24 hours.

· Provide appropriate analgesia.

· Address tetanus vaccination.

· Wound care is highly dependent on local burn center protocols and guidelines.

Monday Back to Basics

Slit Lamp Basics

Revamped from our archives, the fabulous Dr. Alexis Pelletier-Bui teaches us how to use a slit lamp! This comprehensive post reviews all the knobs and buttons of the equipment, then shows how to use it to perform the exam.

COMPONENTS OF THE SLIT LAMP

(These photos are based on a Weiss SL 120 Slit Lamp – other models might be slightly different but the ideas are the same!)

Think of this part as a microscope.

#1 – Oculars – Adjust for your personal interpupillary distance

#2 – Magnification Dial – Can set to 5x, 8x, 12x, 20x, or 32x

#3 – Focusing Ring – Accounts for your personal refractive error.  If you have 20/20 vision or correction lenses, it should be set to 0. 

This part is your light source.  It can be swung 180 degrees side to side to allow for examination from the temporal or nasal side.

This image has an empty alt attribute; its file name is slit-lamp-3.png

#4 – Beam height – Move to the right of examiner > shorter.  

#5 – Beam widgth – Move to the right of the examiner > smaller

#6 – Color of light – 3 options: White (used for most of the exam), Cobalt blue (used with fluorescein exam), Green (aka red free filter; allows blood vessels to appear black; rarely used by ED doc)

#8 – Forehead Strap

#9 – Chin Rest

#10 – Height Adjustor – twist this to raise or lower the chin rest

#11 – Joystick – Allows movement of the viewing & illumination arms in tandem.  Large movements forward & backward are often required to obtain initial focus which will require pressure on the joystick to move the entire base.  Smaller microadjustments can be made with smaller movements of the joystick (without moving the base).  Movement side to side and up & down (the latter performed by twisting the joy stick) allow for you to examine different aspects of the eye (temporal to nasal, upper to lower lid, etc).

#12 – Light Brightness Knob – Most models have this component on the illumination arm but the Weiss SL 120 has this on the base.  Turn right > brighter

#13 – Locking Knob – May need to unlock to move the base.  Put the lock on if you are moving the whole slit lamp (i.e. in and out of the patient’s room)

PREPARING/POSITIONING

#14 – Table Height Adjustor – To increase patient comfort (and therefore compliance), lower or elevate the table as needed.  You may need to adjust your own chair height accordingly so try to use a stool.

#15 – Power Button – Make sure you’re plugged in!

PERFORMING A SLIT LAMP EXAM:

Step 1: Positioning your patient 

  • Adjust the height of the table to your patient
  • Make sure the patient’s chin is against the forehead strap or you will be unable to focus the slit lamp 
  • Align the lateral canthus of the patient with the red line on the supporting rod of the patient-positioning frame

Step 2: Position yourself

  • Adjust your stool so you can comfortably look in the oculars
  • Adjust the oculars to your interpupillary distance & the focusing ring to your refractive error
  • Pick your magnification (8x or 12x is a good start)

Step 3: Performing Diffuse Illumination

  • Move the illumination arm to 30 degrees off center, preferably to the temporal aspect of the eye you are examining (we usually avoid the nasal aspect because the illumination arm tends to hit the patient’s nose with movement of viewing & illumination arms)
  • Start with a tall & wide (3-8 mm) beam for your initial assessment
  • Adjust the light brightness to patient tolerance
  • Utilizing the white light, globally assess the eye with a systematic approach (i.e. the “Ls & Cs” – lids, lashes, lacrima, lens, limbus, conjunctiva, cornea & chamber [anterior])
  • Stain the eye with fluorescein then examine using the cobalt blue light (assess for corneal abrasions, ulcers, Seidel’s sign, herpes simplex, etc)

Step 4: Perform Direct Focal Illumination

  • Narrow the beam as thin as possible (~1 mm) but keep it tall
  • Maximize the light brightness
  • Move the illumination arm to 60 degrees off center – a curved quadrilateral block should become apparent (aka cornea parallelepiped – see below) – This allows for examination of the depth of the cornea

Photo source: Vislisel, J & Critser, B. Normal cornea. https://webeye.ophth.uiowa.edu/eyeforum/atlas/pages/Normal-Cornea/index.htm. Published June 2, 2015. Accessed July 3, 2020.

  • Next, shorten the beam height (~1 mm x 1 mm).
  • Keep the same max brightness and 60 degree angle.
  • Move your joystick until the space between the lightsource & the parelleliped is overlying the pupil. The black pupil will allow for visualization of cell and flare (see below).

Photo source: Root, T. “Cell and flare” in the eye (video). https://timroot.com/cell-and-flare-in-the-eye-video/. Accessed July 3, 2020.

Monday Back to Basics

Measles Part 1: Identification with Drs. Edward Guo and Simon Sarkisian

While most cases of measles are mild and will self-resolve, the high infectivity of the virus is a public health hazard due to rare complications of the disease that can cause long-term morbidity and mortality. Particularly high risk populations include unvaccinated individuals, children < 5 years, adults > 20, pregnant women, and immunocompromised patients.  

Look forward to part 2 for more details on measles management, treatment, and complications! 

References: 

https://www.nj.gov/health/cd/topics/measles.shtml

https://www.cdc.gov/measles/hcp/index.html

Takhar SS, Moran GJ. Serious Viral Infections. In: Tintinalli JE, Ma O, Yealy DM, Meckler GD, Stapczynski J, Cline DM, Thomas SH. eds. Tintinalli’s Emergency Medicine: A Comprehensive Study Guide, 9e. McGraw-Hill Education; 2020. 

Nguyen M, Dunn AL. Rashes in Infants and Children. In: Tintinalli JE, Ma O, Yealy DM, Meckler GD, Stapczynski J, Cline DM, Thomas SH. eds. Tintinalli’s Emergency Medicine: A Comprehensive Study Guide, 9e. McGraw-Hill Education; 2020. 

Monday Back to Basics

Preeclampsia Management with Dr. Erica Westlake

Use these medications for aggressive blood pressure control

Load patients with magnesium early

Ultimate treatment is delivery – involve OB/NICU teams early, transfer patients if these teams are not available

Referneces: