Clinical Vignette XVI

• The patient is started on intravenous fluid hydration with lactated Ringer’s solution and given additional electrolytes to replete any deficits in serum potassium, magnesium, and phosphorus as needed. After reviewing the patient’s history of present illness, medical history, clinical exam findings, social history, and the available lab testing and imaging study results obtained thus far, a working diagnosis is developed. Which of the following is the most appropriate next step in management of this patient if the working diagnosis is suspected to be infective endocarditis?

A 25-year-old female is initially evaluated in the Urgent Care Clinic and subsequently admitted directly to the Medtigo Medical Center Advanced Diagnostics Unit for a one week history of progressively worsening fever, chills, drenching night sweats, low back pain, and fatigue. The patient reports feeling fairly well until seven days ago when she woke up with a high-grade fever and soaked in sweat. The patient reports the other symptoms seemed to quickly develop within a day or two after waking up with the fever and soaked in sweat and have progressively worsened. She has no other associated complaints and denies any prior history of similar symptoms, recent sick contacts, or recent travel. Upon further questioning, the patient admits to using injection drugs including cocaine, amphetamines, and heroin one to three times a week for the past four years. She confesses to sometimes re-using needles as well as sharing needles with her boyfriend who also uses injection drugs. She reports her most recent use of illicit drugs was an injection of heroin the day before being admitted to the hospital. Her medical history is notable for pneumonia which required two days of hospitalization three years ago and was culture positive for Streptococcus pneumoniae, several different episodes of soft tissue skin abscesses requiring incision and drainage which were culture positive at various times for coagulase-negative Staphylococcus spp., Escherichia coli, methicillin-sensitive Staphylococcus aureus, and methicillin-resistant Staphylococcus aureus, atypical depression, and generalized anxiety disorder. Her current prescribed medications are oral contraceptive pills, citalopram, and buspirone. Her current illicit medications are cocaine, amphetamines, heroin, any opiates she can obtain, and marijuana. She is sexually active with her boyfriend of four years and admits to only sometimes using protection during sexual intercourse. She denies ever being tested for any sexually transmitted infections and does not have a regular primary care provider. She smokes about one pack of cigarettes per day with a 7-pack-year history and occasionally consumes alcohol. She currently lives with her boyfriend and works as a home care aide. The rest of her medical history, social history, and family history is non-contributory.

On physical examination, she appears ill and malnourished. Temperature is 102.9°F (39.4°C), blood pressure is 104/61 mm Hg, pulse rate is 114 beats/min, respiration rate is 18/min, and oxygen saturation is 99% breathing ambient air. Height is 5’4 (162.5 cm), weight is 98 lbs (44.4 kg), and body mass index is 16.8 kg/m². Cardiac exam reveals a normal S1 and S2 and a new previously undocumented soft holosystolic murmur at the lower left sternal border. Pulmonary exam reveals slightly diminished but clear to auscultation breath sounds bilaterally. There is mild tenderness to palpation of the lower spinal region between L1 and L4 vertebrae. Track marks on the arms, legs, and femoral regions without evidence of abscesses or infections are noted. The remainder of the physical examination is unremarkable.

Initial lab tests and imaging studies obtained in the Urgent Care Clinic reveal the following: 

• ECG: sinus tachycardia, rate of 112 bpm, no significant ST-segment or T-wave abnormalities
• PA/Lateral view chest radiographs: unremarkable   
• Urinary β-hCG test: (-) 

• After multiple sets of blood cultures have been properly obtained, which of the following is the most appropriate empiric antimicrobial treatment to initiate in management of this patient with suspected infective endocarditis?

• Approximately eight hours after being directly admitted to the hospital, the patient begins to complain of muscle spasms, diffuse myalgias, abdominal cramping, nausea, diarrhea, vomiting, increased restlessness, and diaphoresis. Given the patient’s medical history and social history, which of the following is the most appropriate next step in management?

• Once multiple blood cultures have been properly obtained, empiric intravenous antimicrobial therapy has been initiated, and the potential opioid withdrawal has been medically addressed, which of the following is the most appropriate next step in management of this patient?

Given the imaging study results, the history of present illness, and the physical examination findings, which of the following is the most appropriate next step in management of this patient?

• The 2-D transthoracic echocardiographic imaging study reveals the following:

Left ventricular size is normal.

Left ventricular systolic function is normal.

The left ventricular ejection fraction (LVEF) is 60% +/- 5%.

Normal right ventricular size and function.

Mild tricuspid valve regurgitation.

Tricuspid valve is minimally thickened.

There is a mobile, 7 mm echogenic vegetation attached to

the anterior leaflet of the tricuspid valve.

No evidence of intracardiac thrombus.

No hemodynamically significant aortic, mitral, pulmonic valve disease.

Noninvasive hemodynamic assessment is consistent with normal pulmonary

artery systolic pressure, a normal CVP.

Given the additional imaging study results, which of the following is the least appropriate next step in management of this patient?

• On day two of the patient’s hospitalization, she is being prepped for a scheduled 2-D transesophageal echocardiogram by the anesthesiologist. After obtaining informed consent, the anesthesiology team takes the patient to one of the operating rooms on the surgical unit to perform the procedure. Two hours later, the patient is returned to her assigned hospital room by the anesthesiology team in clinically stable condition. The patient tolerated the procedure well and there were no reported complications. The procedure note for the 2-D transesophageal echocardiographic imaging study reveals the following:

The left atrium was normal in size.

There were no masses or thrombi seen in the left atrium or the left atrial appendage.

The left ventricle was normal in size with normal systolic function.

There were no obvious regional wall motion abnormalities.

There were no masses or thrombi seen in the left ventricle.

The LVIDd was measured to be 44 mm in thickness.

The LVIDs was measured to be 30 mm in thickness.

The fractional shortening was estimated to be 32%

The left ventricular ejection fraction (LVEF) was estimated to be 64%.

The right atrium and right ventricle were both normal in size.

The tricuspid annular plane systolic excursion was estimated to be 24 mm.

The right ventricular fractional area change was estimated to be 56%.

The mitral valve was structurally normal.

The mitral valve showed no vegetations or prolapse.

The measurements at the mitral valve annulus showed a diameter of 25 mm.

The aortic valve was structurally normal.

The aortic valve showed no vegetations.

The measurements at the aortic annulus showed a diameter of 23 mm.

The sinotubuluar junction was 26 mm in diameter.

The sinus of Valsalva was 30 mm in diameter.

The tricuspid valve showed thickening of the anterior leaflet.

There was a mobile echogenic vegetation attached to the anterior leaflet of the

tricuspid valve which measured 7 mm in length by 4 mm in diameter.

There was mild tricuspid regurgitation.

The measurements at the tricuspid valve annulus showed a diameter of 27 mm.   

The estimated systolic pulmonary artery pressure was 28 +/- 5 mm Hg.

The estimated RA pressure was 5 mm Hg. 

The pulmonic valve was structurally normal.

The pulmonic valve showed no vegetations.

There was an interatrial shunt, confirmed by color flow interrogation and 

agitated saline contrast study.

The IVC was normal in size.

There was no pericardial effusion.

The ascending aorta, aortic arch, and proximal descending aorta were unremarkable.

There was no evidence of dissection.

• On day three of the patient’s hospitalization, six out of the six blood cultures obtained from the patient prior to initiating empiric antimicrobial treatment have demonstrated growth of the most common pathogen associated with native valve infective endocarditis in injection drug users. Which of the following set of characteristics best describes the most likely pathogenic cause of this patient’s clinical signs and symptoms?

According to the culture and sensitivity report and the AHA statement guidelines on IE for Adults, which of the following is the most appropriate next step in management of this patient?

• On day four of the patient’s hospitalization, a total of eight separate blood cultures have been properly obtained from the patient and all eight of the blood cultures have demonstrated growth of Staphylococcus aureus. The cultures and sensitivities testing performed by the Medtigo Microbiology Laboratory reveals the following:

Blood culture

Site:  Blood, Peripheral stick

Gram stain:

**POSITIVE CULTURE REPORT**

Aerobic and anaerobic bottle yields Gram Positive Cocci in Clusters

Culture:  Aerobic and anaerobic bottle yield Staphylococcus aureus

• Upon re-evaluating the patient’s medical history, clinical exam findings, social history, and the available lab testing results, which of the following is the most appropriate next step in management of this patient’s overall health prior to being discharged?

Given the results of the screening tests, which of the following is the least appropriate next step in management of this patient’s overall health? 

• The results of the screening tests are as follows:

• Which of the following is not considered a main indication for early cardiac-valve surgery in patients with native valve infective endocarditis?

• After successfully completing six weeks of dose-adjusted intravenous Vancomycin with blood cultures being negative for any lingering Staphylococcus aureus in the blood stream and without any clinical complications, which of the following is the most appropriate next step in management of this patient?