It’s got electrolytes – Real Medical Case Presentation Number Two

But why? Why does Brawndo have electrolytes?

Because you need electrolytes to live. Every cell in your body uses electrolytes like sodium (Na), Potassium (K), Calcium (Ca), Magnesium (Mg) and other critical ions for cellular functions, proper osmotic gradients, enzymatic activity and even coordination of complex functions like muscle contraction and nerve conduction. All the cells in your body are full of little ion channels that are importing or exporting (or passively diffusing) these ions for physiological functions, and several organ systems (pituitary, adrenals, kidneys) in your body are in charge of maintaining tight control of their concentration in the blood. Very small changes in their concentration – often as little as a doubling or halving of their normal concentrations – can lead to disaster. If, for instance, you became profoundly low in calcium your heart will very quickly fail to beat as muscle requires calcium gradients for contraction.

The measurement of the electrolytes in your blood is a critical component of the evaluation of the health of almost every patient in the hospital. The basic metabolic panel is collected on most inpatients every single day as a critical tool in understanding what’s going on with your patient’s overall health. It provides vital clues into what their kidneys are doing, how their endocrine system is functioning, what disease processes may be at play, and occasionally whether someone is in acute need of rescue. We usually present the data like so:

Na+ | Cl – | BUN
——————————–< Glucose K+ | bicarb | Creatinine 135-145 | 98-106 | 7-18 ------------------------------------< 70-115 3.5 - 5.1 | 22-29 | 0.6-1.2 (BUN = Blood Urea Nitrogen) Seeing this little diagram gives you a great deal of information about what's going on with your patient in a minimum of space. Also of note is what is called the anion gap. The primary cation - Sodium (Na) - and the primary anions (cloride and bicarbonate) don't balance out in terms of charge. Usually if you add the chloride concentration to the bicarb concentration (e.g. 104 + 22 = 126), and then subtract this from the sodium (138 - 126 = 12) you get a value called the "gap" which represents other cations in the blood that are not measured in the basic panel. I realize this seems complicated but it's really not. Basically if it's in the normal range (12 +/-2) it means there likely isn't some hidden anion not being measured and causing trouble - like the ketoacids that run amok in diabetic ketoacidosis. So with that little introduction it's time to go over electrolyte troubles, and because you guys liked the last case presentation so much, I think it’s time for another. This one will be much more challenging. Let’s start with the case, again, based on a true story but jumbled/scrubbed for privacy.

Chief complaint:
Shortness of breath (SOB)

History of Present Illness: A 53 year old white male farmer with a 5 year history of chronic obstructive pulmonary disease (COPD) and three year history of type II diabetes presented to his doctors office with SOB of 5 days duration. His primary care doctor had managed several previous episodes of COPD exacerbation with 2-4 week courses of prednisone, and nebulizer treatments (bronchodilators). Concerned that the patient was failing to adequately oxygenate after several such treatments in her office his doctor refers him to the ER for admission to the hospital.

The rest of the case, and more fun with electrolytes below the fold.
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