Challenger Medical Education Blog

Question Report - Dyspnea secondary to metabolic acidosis / DKA Path: Emergency Medicine

Written by Med-Challenger | Jul 17, 2023 6:18:57 PM

Challenger's 'Report Question' button allows people using a course to comment on questions, ask for clarification, or tell us about inaccuracies or issues with a question.  These are sent to an AI model, and to human clinical editors to determine if the question needs to be changed.

Comments can be as simple as a question being overly complicated for the level of test preparation or CME intended, or point out conflicting guidelines and publications.  We are publishing most of these reports on our blog, to see what other clinicians think.

Question Dyspnea secondary to metabolic acidosis / DKA
Path: Emergency Medicine
Question Stem A 56-year-old surgical nurse presents to you with a history of shortness of breath while at work in the operating room.

He reports a 2- to 3-day history of gradually worsening shortness of breath, which he describes as difficulty catching his breath. He says he was tachypneic while at work in the operating room.

He denies fever, cough, chest pain, or palpitations. His past medical history is unremarkable. His family history is remarkable for diabetes mellitus, including an adult brother with insulin-dependent diabetes mellitus.

Vital signs are: temperature 99°F, heart rate 120 beats/minute, respiratory rate 26 breaths/minute, blood pressure 120/80 mm Hg, and oxygen saturation 99% on room air. Cardiac examination is remarkable only for tachycardia. Lungs are clear to auscultation. You observe that the patient is taking deep frequent breaths that interrupt his speech. Abdomen is soft and nontender. The physical examination is remarkable for a severe gangrenous wound with partial loss of the right great toe.

Which of the following tests or imaging modalities is most likely to reveal the etiology of this patient’s dyspnea?
Answer 1 complete blood count
Answer 2 electrocardiography
Answer 3 chest x-ray
Answer 4 complete metabolic panel (correct answer)
Answer 5

cardiac markers

Incorrect Answer Remediation

This patient is demonstrating the deep rapid pattern of Kussmaul breathing. Kussmaul breathing represents respiratory compensation for severe metabolic acidosis, and it is most commonly associated with diabetic ketoacidosis.

A complete blood count, electrocardiography, chest x-ray, and cardiac markers are all helpful in the evaluation of dyspnea but are not likely to reveal this patient’s primary pathology. The metabolic panel is most likely to reveal the etiology of the patient’s dyspnea and support the diagnosis of diabetic ketoacidosis, including a blood glucose level above 250 mg/dL, anion gap greater than 10, and a bicarbonate level below 15 mEq/L. An arterial blood gas level revealing pH less than 7.3 and positive serum ketones would further confirm the diagnosis.

References

Chansky ME, Lubkin CL. Diabetic ketoacidosis. In: Tintinalli JE, et al. Tintinalli’s Emergency Medicine: A Comprehensive Study Guide. 7th ed., 2011:1432-1438.

Sarko J, Stapczynski JS. Respiratory distress. In: Tintinalli JE, et al. Tintinalli’s Emergency Medicine: A Comprehensive Study Guide. 7th ed., 2011:465-473.

Question has been reported with the following comment:

This would be much more believable if the patient was in his twenties.

Challenger's AI Responded

It appears the user is questioning the plausibility of the clinical scenario given the patient's age. While it's true that diabetic ketoacidosis (DKA) is more common in younger people, especially those with type 1 diabetes, it's important to note that DKA can occur at any age and in any type of diabetes when glucose regulation is significantly disrupted.

In the scenario presented, the patient has a family history of diabetes mellitus, and also presents with a severe gangrenous wound on his toe, which could be a sign of undiagnosed or poorly controlled diabetes mellitus, potentially leading to a situation of uncontrolled hyperglycemia and DKA. The signs of DKA, such as the Kussmaul breathing described, can occur in any individual with severe metabolic acidosis, irrespective of their age.

Therefore, while the scenario might be less typical (given the patient's age and absence of known diabetes), it is still medically plausible. This question might have been designed to challenge the learner's ability to recognize DKA even in less typical presentations. Nonetheless, feedback like this is valuable for improving the real-world applicability of the learning materials.

Clinical Editor Response

While the case is plausible, this is an exam preparation course, and the learning objective of the question was to recognize Kussmaul breathing as a DKA sign in absence of other indicators, not specifically to show that DKA can occur at any age.  Given the learning objective, the scenario should be rewritten.

If we're going to do atypical presentations, it should go into the confounding signs and symptoms section.

What do you think?