Tuesday Advanced Cases

Critical Cases – Fistula Hemorrhage Emergency!

Kane McKenzie M.D.

Dialysis Fistula Bleeding Aneurysm


69 year-old female with a past medical history of ESRD on HD, HIV, Pulmonary HTN, HFrEF (EF 25%), anemia, thrombocytopenia presents after dialysis with left upper extremity pain and swelling. The dialysis RN reports there was shiny skin present over the LUE AVF and they cannulated to avoid that area, the patient received one hour of treatment that was stopped due to pain. Patient reports the her arm above the AVF has been slowly enlarging


BP: 98/54, HR: 78, RR 20, T: 97.6


Alert and oriented, no acute distress, chronically-ill appearing

LUE with no external bleeding, fistula has a palpable thrill. Swelling and tenderness are present above the AVF, over the medial upper arm.

Cap refill >2 seconds

Rest of exam unremarkable

Clinical Course

-CTA upper extremity was obtained to assess for active bleeding – showed AV fistula with aneurysmal dilatation, large hematoma with upper arm approximating a volume of 1000cc. No evidence of active hemorrhage

-Direct pressure was held above and below the AVF.

-Repeat BP 58/24

-Central line placed, resuscitated with 2U PRBC, 1 platelets, 1 FFP. Required norepinephrine and vasopressin drip

-Taken level 0 to OR for Brachiocephalic fistula ligation and hematoma evacuation with 500cc hematoma removed

-The patient was stabilized and recovered after being treated for hemorrhagic shock


-AVF aneurysms can develop from repeated ruptures, increased venous pressure, and immunosuppression. They are usually asymptomatic, rarely rupture. Aneurysm formation is present in 5-7% of AVF

-Skin changes, pain, high output heart failure, and thrombosis can result from aneurysms and are an indication for operative management.

-AVF pseudoaneurysms can develop from extravasation of blood from cannulation sites, are more prone to rupture, develop more quickly

-Aneurysms/pseudoaneurysms can be identified by their shiny, thin, atrophic skin. In more severe cases can present with necrosis.

-Apply pressure and/or tourniquet above and below the AVF if life threatening hemorrhage is suspected

-Emergent consultation with vascular surgery warranted for operative repair


Pasklinsky G, Meisner RJ, Labropoulos N, Leon L, Gasparis AP, Landau D, Tassiopoulos AK, Pappas PJ. Management of true aneurysms of hemodialysis access fistulas. J Vasc Surg. 2011 May;53(5):1291-7. doi: 10.1016/j.jvs.2010.11.100. Epub 2011 Jan 26. PMID: 21276676.

Lok CE, Huber TS, Lee T, Shenoy S, Yevzlin AS, Abreo K, Allon M, Asif A, Astor BC, Glickman MH, Graham J, Moist LM, Rajan DK, Roberts C, Vachharajani TJ, Valentini RP; National Kidney Foundation. KDOQI Clinical Practice Guideline for Vascular Access: 2019 Update. Am J Kidney Dis. 2020 Apr;75(4 Suppl 2):S1-S164. doi: 10.1053/j.ajkd.2019.12.001. Epub 2020 Mar 12. Erratum in: Am J Kidney Dis. 2021 Apr;77(4):551. PMID: 32778223.

Saeed F, Kousar N, Sinnakirouchenan R, Ramalingam VS, Johnson PB, Holley JL. Blood Loss through AV Fistula: A Case Report and Literature Review. Int J Nephrol. 2011;2011:350870. doi: 10.4061/2011/350870. Epub 2011 May 30. PMID: 21716705; PMCID: PMC3118665.

Friday Board Review

Board Review by Dr. Guo (Edited by Dr. Parikh)

A 30 year old obese female presents to the emergency department for a persistent headache. You have a high suspicion for idiopathic intracranial hypertension and perform a lumbar puncture. The opening pressure is 28 cm H2O. Approximately how much volume of CSF should be removed to reach a target CSF pressure of 20 cm H2O prior to removal of the spinal needle?

A: 4 mL

B: 8 mL

C: 16 mL

D: 20 mL

Answer: 8 mL

Part of the diagnostic criteria for idiopathic intracranial hypertension in adults includes an elevated opening pressure > 25 cm H2O on lumbar puncture. The feared complication is permanent vision loss from papilledema. Treatment includes removal of CSF which can also provide relief of headache symptoms. As a general rule, removal of 1 mL of CSF will lower the CSF pressure by about 1 mL H2O. It is recommended to remove the desired amount of CSF and then re-measure the CSF pressure prior to removal of the spinal needle. Excess removal of CSF can result in intracranial hypotension and a low pressure headache.


Fiorito-Torres  F, Rayhill  M, Perloff  M: Idiopathic intracerebral hypertension (IIH)/pseudotumor: removing less CSF is best (I9-1.006). Neurology 82 (10 Suppl): I9–1.006, 2014.

Koyfman A, Long B. Headache. 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.

Thurtell, Matthew & Bruce, Beau & Newman, Nancy & Biousse, Valérie. (2010). An Update on Idiopathic Intracranial Hypertension. Reviews in neurological diseases. 7. e56-68. 10.3909/rind0256.

Wednesday Image Review

From the Archives: What’s the Diagnosis? By Dr. Katie Selman

A 76 yo female presents after a fall down several stairs. She is diagnosed with bilateral pubic rami fractures on x-ray. The patient has difficulty with urination. A foley is placed and there is blood return. A CT cystogram is shown below. What’s the diagnosis?

Answer: Bladder injury (extraperitoneal)

  • Occurs with direct blunt trauma to distended bladder
    • 70-97% associated with pelvic fractures
  • Clinically, patient will have gross hematuria, lower abdominal tenderness, perineal or scrotal edema, difficulty voiding
  • Gold standard diagnosis: retrograde cystogram (either x-ray or CT)
    • Can be missed on routine CT or US
  • Intraperitoneal rupture: contrast material leaks into peritoneal cavity
    • Require surgical repair
  • Extraperitoneal rupture: contrast material leaks into retroperitoneum
    • Most common
    • Usually managed conservatively and heal within 2 weeks


Gratton MC, French L. Genitourinary Trauma. In: Tintinalli JE, Stapczynski J, Ma O, Yealy DM, Meckler GD, Cline DM. eds.Tintinalli’s Emergency Medicine: A Comprehensive Study Guide, 8eNew York, NY: McGraw-Hill; 2016.

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.


(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)


#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!


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.

Friday Board Review

Board Review by Dr. Guo (Edited by Dr. Parikh)

A 40 year old male with a past medical history of polysubstance use, epilepsy, and housing insecurity presents to the emergency department for drug intoxication. His ED course is uncomplicated, and he is deemed ready for discharge 3 hours after his initial presentation. Upon handing him his discharge paperwork, he appears to trip and fall to the ground. He then demonstrates diffuse shaking of his entire body with his eyes tightly shut, not responding to external stimuli. The episode lasts approximately 2 minutes, and he afterward remains unresponsive to stimuli. Vital signs and point-of-care glucose are within normal limits. Physical exam shows no obvious injuries. Which of the following laboratory tests is most helpful in determining if the patient had an epileptic seizure?

A: Creatine kinase

B: Lactic acid

C: Potassium

D: White blood cell count

Answer: Lactic acid

Distinguishing between true epileptic seizures, psychogenic non-epileptic seizures (PNES), and convulsions following a syncopal episode can be difficult. PNES is psychogenic in nature and has highly variable features which may include forceful closing of the eyelids, side-to-side movements, or shrieking. An elevated serum lactic acid concentration obtained shortly after the event has been shown to help differentiate true epileptic seizures from PNES or convulsions following syncope. Creatine kinase levels typically do not rise early after a seizure and are furthermore not specific in the setting of falls or trauma. Potassium levels are not expected to be elevated following an uncomplicated seizure. An elevated white blood cell count may be due to several non-specific reasons including infection, trauma, steroid use, or stress response. Definitive diagnosis is determined using electroencephalography (EEG).


Kornegay J. Seizures and Status Epilepticus in Adults. 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.

Patel J, Tran QK, Martinez S, Wright H, Pourmand A. Utility of serum lactate on differential diagnosis of seizure-like activity: A systematic review and meta-analysis. Seizure. 2022;102:134-142. doi:10.1016/j.seizure.2022.10.007

Wednesday Image Review

What’s the Diagnosis? By Dr. Erica Westlake

A 33 year old male presents to the ED reporting he was assaulted last night. He is unsure what weapons were used, and is complaining of pain to his head and face. He reports a loss of consciousness during the assault. He denies pain or injuries to his extremities, visual changes, hearing loss, neck pain. His exam is significant for a lacrosse ball sized injury to his left forehead above his eyebrow. Pupils are equal, reactive and circular, EOMs intact, no midline tenderness in the cervical/thoracic/lumbar spine, no hemotympanum, no otorrhea/rhinorrhea, no facial instability, no nasal deformity or dental injury. No signs of injury on chest, back, abdomen or extremities, neurologic exam is unremarkable and intact in all 4 extremities, gait steady. You obtain CT imaging of the facial bones, head and neck, which reveal:  

Diagnosis: isolated anterior table frontal bone fracture 

  • Mechanism: high-energy mechanism required to generate force, ie: unrestrained motor vehicle crashes, assault with blunt objects (bricks, baseball bat)
  • High occurrence for concomitant injuries in facial bones, intracranial injury, cervical spine injury and ocular injuries 
  • Incident of intracranial injury up to 87% and ocular injuries up to 25%
  • If extension into the temporal bones, patients require hearing and facial nerve function evaluation 
  • Important to evaluate the anterior and posterior tables of the frontal sinus as involvement of the posterior table requires surgical repair
    • Dura is attached to the posterior table, surgical repair required to prevent complications such as pneumocephalus, CSF leak or infection 
  • Consider nonaccidental trauma especially in children, elders, pregnant women 
  • Management of isolated anterior table frontal bone fracture: sinus precautions, augmentin course, ENT/plastics follow up 


Hedayati T, Amin DP. Trauma to the Face. 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; 2020.

Gaillard F, Bell D, Frontal sinus fracture. Reference article, Radiopaedia.org