Questions of the Week for 7/11/2023

Author: Christian Gerhart

1)      A patient is admitted to the hospital with fever and what appears to be pyelonephritis. Her urine culture grows MSSA on day 2 of her hospital stay. What diagnosis should be considered?  

• Answer

  Endocarditis. Staph aureus in the urine should always raise concern for endocarditis, especially in patients who are systemically ill. Blood cultures, further history and possible and echocardiogram would be helpful. 

2)      A 37 yo patient presents to the TCC CT scanner as a stroke alert. The patient’s vital signs are T: 38.7 HR: 120 BP: 180/95 RR: 24 O2 sat: 96% on RA. Their LKN was about 45 minutes prior. Their NIHSS is 8 for R sided weakness, and speech. Their non contrast CT does not show any intracranial hemorrhage. POC glucose is 125. Nursing is having difficulty getting an IV and thinks they see “track marks” on his arms. You listen to his heart and think you hear a 3/6 systolic murmur at the left sternal border. How would you treat this patient? Should they receive thrombolysis?  

• Answer

  This patient has a clinical picture highly concerning for endocarditis with a fever, IVDU history and cardiac murmur and therefore should NOT receive tPA. Antibiotics would be the treatment. Embolic stroke is a common phenomenon seen in endocarditis and can occur with both left and right sided (typically PFO present) endocarditis. These patients have a high risk of mycotic aneurysms, which are infective blood vessels that are at a very high risk of rupture with thrombolytics are administered.  

3)      You have a 75 yo patient present to the ED as a referral from his primary care doctor. He has been experiencing fevers, chills, and dyspnea for about two weeks but didn't want to go to the hospital. The patient has a history of a mitral valve repair for mitral stenosis. He is compliant on his anticoagulation. After your evaluation, are concerned for endocarditis. The patient is febrile and tachycardic in the ED. How should this patient be managed? What is the approximate sensitivity of transthoracic echo to assess for vegetations?    

• Answer

  This patient needs blood cultures (3 sets if possible!) and admission for a TEE. The sensitivity of TEE for endocarditis is far greater (usually 90ish%) compared to TTE (around 60%). It is especially important that TEE be used for patients with suspected prosthetic endocarditis (like this patient), since TTE is even less sensitive for these cases. After cultures are obtained, he should be started on empiric antibiotics. For this patient with a prosthetic valve, empiric therapy would probably consist of vancomycin, gentamicin and possibly rifampin (usually rifampin administration is delayed).

4)      A 27 yo non pregnant female with a history of two prior uncomplicated UTIs presents with right flank pain and vomiting. Her vitals are normal. She is overall well appearing with an exam notable only for mild L CVA tenderness. Her UA demonstrates 3+ LE, +nitrites, and >50WBCs. You review her chart and note that she has never grown any resistant organisms on her previous cultures. You think she has pyelonephritis and give her a dose of Ceftriaxone in the ED. She feels better after symptomatic treatment and would like to go home. What would your outpatient antibiotic regimen be?  

• Answer

  There are a few different acceptable regimens. Cephalexin (10-14 days) is a good step-down therapy from Ceftriaxone. Amoxicillin-Clavulanate, Cefuroxime or Cefdinir are other options. Ciprofloxacin and Bactrim can be used but have high resistance rates in our region. One option that is NOT acceptable is Nitrofurantoin (Macrobid) since this should only be used for uncomplicated cystitis (infections confined to the bladder).  
  

5)      The above female patient presents with identical symptoms a year later but this time is 11 weeks pregnant. You again think she has pyelonephritis. She has a live IUP. Her vital signs are normal. She feels better after symptomatic therapy and is well appearing. How should this patient be managed?  

• Answer

  Generally, pregnant patients with pyelonephritis should be admitted for IV antibiotics. Ceftriaxone is usually a good choice of antibiotic for patients with mild-moderate symptoms, assuming the patient’s previous cultures have not grown resistant organisms. If the patient does well after IV antibiotics during their admission, they can generally be treated with a beta lactam antibiotics (Cephalexin is generally a good choice). Fluoroquinolones are typically not used in pregnancy and Bactrim should be avoided in the first trimester and near term (probably safest for us to just avoid in general).  

6)      A 26 yo male with a history of IVDU presents with hypotension. He is toxic appearing. His vitals are 75/40, HR 135, T: 38.5C, RR 35, O2 sat 90% RA. You suspect he is septic shock from right sided, native valve, endocarditis. What antibiotics would you administer?   

• Answer

  Cefepime or Piperacillin-Tazobactam (Zosyn <3) and vancomycin would be appropriate empiric therapy for this patient. However, remember that the loading dose of vancomycin in these patients is much higher (25-30 mg/kg, max 3000mg) than our usual (15-20mg/kg) loading dose! As Dr. Croft says “kill the bacteria with a flamethrower” … or something like that. Surgery usually plays a larger role for left sided endocarditis compared to right sided and many times right sided endocarditis is managed medically with antibiotics. However, in patients with severe tricuspid regurgitation causing heart failure, persistent or very large vegetations despite antibiotics, surgery may be indicated.