Electrolyte Imbalances and Emergency Challenges

Contributors: Travis Barlock MD, Jeffrey Olson MS4

Feel free to use the cases below for your own practice. All of the scenarios are completely made up and designed to hit several teaching points.

Case 1

25 M, presents to the ED with chest pain.

Stabbing, started a few hours ago, substernal. Thinks it is GERD.

After 2-3 minutes, pain worsens and radiates to the back.

VS: BP 125/50 (Right arm 190/110). HR 120. RR of 18. Sat 98% on RA.

Additional VS: Temp of 37.2, height of 6'5", BMI of 18.

PMH: None, doesn't see a doctor. Meds: None

FH: Weird heart thing (Mitral Valve Prolapse), weird lung thing (spontaneous pneumothorax), tall family members with long fingers and toes

Physical Exam:

Cards: Diastolic decrescendo at the RUSB, diminished S2. UE pulses are asymmetric, LE pulses are asymmetric, carotid pulses are asymmetric, BP is asymmetric

MSK: Knees, elbows, and wrists are hypermobile.

Imaging: CXR #1 normal, #2 widened mediastinum (no read yet but shows widened mediastinum), POCUS shows small effusion

CTA/MRA doesn't come back until after the case.

ECG: Sinus Tach

Labs:

NT-proBNP 500 pg/mL

D-Dimer: 7000 ng/L

CBC: Hemoglobin: 13.5 g/dL, WBC: 20,000/µL, Platelets: 250,000/µL

Chem 7: Na 138, K, 5.7, Cl 102, Bicarb 17, BUN 45, Creatinine: 3.5 mg/dL, Glucose: 180

LFTs: Albumin 2.4, Total protein 5.5, ALP: 140, AST: 3500, ALT: 2800, TBili: 3.2, DirectBili: 2.4,

Ca: 7.8

LDH: 2200

PT: 20.5, INR: 2.2, Fibrinogen: 170

5th gen High-Sensitivity Troponin: <3

Lactate: 7 mmol/L

VBG: pH 7.22, paCO2 28, bicarb 15

Notes: Can have patient crash somewhere in middle and show 2nd xray

Case 2:

A 67-year-old female is brought to the ED by her daughter due to progressive weakness, confusion, and fatigue that have worsened over the past week.

Unable to get out of bed and has become increasingly lethargic. Also having some nausea, constipation. The daughter denies any preceding illness, recent trauma, or travel. Does not know her meds but will head home to get them after talking with you.

VS: BP 88/55 mmHg, HR 110, RR 20, O2 Sat 98% on room air.

Additional VS: Temp 36.8°C.

PMH: Hypertension, osteoarthritis, and depression.

Physical exam:

General: Thin, somnolent but arousable.

HENT: Dry mucous membranes

Neuro: Confused, A&Ox1 (self), hyporeflexia

Labs (Includes many that would not return in the ED in case you want to take this case forward to the floor)

CBC: WBC 9,500, Hb 16.5, Hct: 50%, Platelets 220,000

Chem7: Na 129, K 2.1, Cl 95, HCO3 34, Creatinine 1.6, BUN 40, Glucose 115

LFTs: normal

Magnesium: 1.1

Calcium: 10.8 mg/dL (corrects to 12.8)

iCal: 3.2

Phosphate: 2.3 mg/dL

Albumin: 2

BUN:Cr ratio: 25

VBG: pH: 7.49, PaCO2 45, HCO3: 34

Lactate: 2.8

Serum Osmolality: 276 mOsm/kg (Osmolal gap of 2)

Urine Osmolality: 550 mOsm/kg

Urine Sodium (UNa): 10 mEq/L (low). Urine Potassium (UK): 25 mEq/L (elevated). Urine Chloride (UCl): 12 mEq/L (low). Urine Magnesium (UMg): 20 (Elevated). Urine Calcium (UCa): 50 in 24 hrs (Low)

100 cc of urine with foley

FeNa

Plasma renin activity: 15 mg/mL/hr (elevated), Aldosterone: 25 ng/dL (Elevated), ADH: Elevated, Diuretic screen: Positive for thiazides

PTH: 8 (low), HsTrop: 32, Cortisol and ACTH: Normal.

EKG: Hypokalemia features

CXR: Normal

Renal US: shows stones

Improves with fluids

Note: Can have daughter return with med list at some point including HCTZ, ibuprofen, and sertraline

Case 3:

Patient Presentation

EMS Report: A 27-year-old male involved in a high-speed motorcycle collision is brought to the emergency department by EMS. The patient was found unconscious at the scene with evidence of severe thoracic and extremity trauma. He was intubated en route for airway protection due to altered mental status (GCS 7).

VS: HR 130, BP 90/60, RR: bagging at 12 bpm, satting 88% on 100% FiO2

Primary Survey

Airway: Endotracheal tube in place.

Breathing: Decreased breath sounds on the left side with visible chest asymmetry and paradoxical chest wall movement.

Circulation: Mottled extremities noted, with significant deformity of the right thigh. Pulses are diminished in the right leg

Disability: GCS remains 7 (E1 V2 M4). Pupils equal and reactive.

Exposure: Full-body examination reveals an open fracture of the right femur, multiple abrasions, and bruising over the chest wall.

Vent alarms

Peak Inspiratory Pressure (PIP) 40 cm H₂O (elevated)

Plateau Pressure (Pplat) 35 cm H₂O (elevated)

EtCO₂ (End-Tidal CO₂) 55 mmHg

High-Pressure Alarm Triggering frequently

Glucose 120

CBC: Hgb 8.9, Hct 27, WBC 14.2, platelets 220,000

VBG: pH 7.28, pCO2 33, bicarb 18, lactate 4.5

CXR with tension pneumothorax

Patient improves after chest tube, pigtail catheter, or needle decompression.

Ready to be transferred upstairs and O2 starts tanking again

Vent alarms- second episode

Peak Inspiratory Pressure (PIP) 35 cm H₂O (elevated)

Plateau Pressure (Pplat) 30 cm H₂O (elevated)

EtCO₂ (End-Tidal CO₂) 20 mmHg

HR: 140, satting 84%, temp 38.5,

ABG: pH 7.32, pCO₂ 30 mmHg, pO₂ 60 mmHg on 100% FiO₂, HCO₃⁻ 18 mmol/L (hypoxemia and metabolic acidosis).

D-dimer: Elevated

Thrombocytopenia: Platelets 90,000/µL.

US shows blown right ventricle

ECG shows new RBBB

CT PE: Ground glass opacities, consolidation, centrilobular nodules, septal thickening, and fat-attenuating lesions.

Note: Management is largely supportive care so once the diagnosis is made, end the case.

References

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• Reed MJ. Diagnosis and management of acute aortic dissection in the emergency department. Br J Hosp Med (Lond). 2024 Apr 30;85(4):1-9. doi: 10.12968/hmed.2023.0366. PMID: 38708978.

• Roberts DJ, Leigh-Smith S, Faris PD, Blackmore C, Ball CG, Robertson HL, Dixon E, James MT, Kirkpatrick AW, Kortbeek JB, Stelfox HT. Clinical Presentation of Patients With Tension Pneumothorax: A Systematic Review. Ann Surg. 2015 Jun;261(6):1068-78. doi: 10.1097/SLA.0000000000001073. PMID: 25563887.

• Rothberg DL, Makarewich CA. Fat Embolism and Fat Embolism Syndrome. J Am Acad Orthop Surg. 2019 Apr 15;27(8):e346-e355. doi: 10.5435/JAAOS-D-17-00571. PMID: 30958807.

Produced by Jeffrey Olson, MS4

Special thanks to Evan Fisch MD

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