Thank you to Kendra and Intelly for presenting a super fascinating case from SFCards. We discussed a middle aged man with poorly controlled HIV, who presented in respiratory distress, in shock, and ultimately found to have purulent pericarditis associated with staph MV endocarditis.
We reviewed EKG findings of diffuse pericarditis, which ultimately helped prompt the TTE, recognition of pleural effusion and pericardiocentesis in this patient.
Pts with acute pericarditis can often have 4 stages of typical EKG changes, with the first stage being the most classic.
Stage 1: diffuse ST segment elevation (typically concave up). We also often see PR changes with PR elevation in aVR, and PR depression in other limb leads. **Major point here is ST segment elevation beyond territory of just one coronary artery**
Stage 2: normalization of ST and PR segments, seen in the first week
Stage 3: diffuse TWI, usually at this point the ST segments have normalized to isoelectric
Stage 4: normal EKG
Pericarditis itself does not always cause effusion, but remember to also look for electrical alternans as a suggestion there may be associated effusion!
What is Purulent Pericarditis? And why the heck is there pus in the pericardial space?
What is it: gross pus in the pericardium, or microscopic purulence (>20 wbc/field)
What organisms: Staph aureus is the most common. Gram positive pathogens cause 40-45% of all associated infections. Less frequently implicated pathogens to consider are salmonella, fungal (candida) and TB (most common cause in developing countries, and esp when high HIV prevalence rates)
How does this happen:
- direct spread from intrathoracic focus: frequently occurs with strep pneumo and preceding pneumonia and/or empyema. Also consider esophageal pathology, surgical intervention.
- hematogenous spread to the pericardial sac
- extension from a myocardial focus (eg perivalvular abscess), or from subdiaphragmatic purulent focus
- traumatic injury or thoracic surgery
How to Diagnosis? Must get pericardial fluid for culture and microscopy!
Management? Source control with pericardiocentesis and pericardial drain, identify underlying infectious source and treat with antibiotics.
Also check out this blog post from earlier this year in the VA with a great framework and differential for pericarditis with schema by Rabih!