Recent pet peeve, of which many healthcare writers and physicians are guilty: using the incorrect article before an acronym.
Everyone knows that you use “a” before a consonant and “an” before a vowel. What people may not realize is that it’s not the spelling that matters of the following word but its pronunciation. The actual rule is to use “a” before a consonant sound and “an” before a vowel sound.
A MICU admission
A HIPPA violation
An HIV patient
I know it may look funny, and your word processor may punish you with a colored underline, and Clippy may scoff at you from his digital paper clip grave, but thems the rules.