Common Hospital InfectionsandRational Antibiotic Choices

Intern Boot Camp 2009Nora Colburn, MD

“If you want three opinions, then ask two infectious disease doctors.” ---KBA

“Zosyn is mother’s milk.”

Syndrome + Host

Microorganisms

Antibiotic

It’s 1am and the nurse on Lakeside 65 just called you because Mrs. Price has a T of 101.5 . . . What do you do?

What is the definition of fever?

Textbook Elevation in the body’s

thermoregulatory set point. IDSA guidelines

T >101 (38.3) at any time T >100.4 (38.0) for greater than one

hour Use your judgment

Fever

1) Assess the patient As always, this is the #1 priority when you

are called about a patient. Go see the patient. Why are they admitted? Have they been febrile? What do they look like?

Are there any signs or symptoms consistent with infectious or non-infectious causes of fever?

When in doubt---GO SEE THE PATIENT!

Non-infectious causes of fever

Medications Anticonvulsants, Antibiotics, histamine

blockers, NSAIDs Transfusion reaction Neuroleptic malignant syndrome Serotonin Syndrome Connective tissue disease Malignancy Hyperthyroidism Hematoma

Fever

2) Write Orders Blood cultures Urinalysis, urine cultures CXR Other tests based on your history and

exam

3) Follow up on the results and start treatment if needed.

Sepsis

Source of infection plus Systemic Inflammatory Response

Syndrome (2 of 4) Fever or hypothermia T >38 or <36 Tachycardia HR >90 Tachypnea RR >20, or PaCO2 <32 WBC >12,000, <4000 or Bands >10%

Types of sepsis

Severe sepsis Sepsis associated with organ

dysfunction Septic shock

Sepsis with hypotension despite adequate fluid resuscitation

Treatment

Antibiotics Targeted at known organisms or

empiric treatment Within 4-6 hours

Early Goal Directed Therapy

Early Goal Directed Therapy

Some common scenarios…

The DACR paged you and the report is…

73 yo male h/o HF, CKD, CAD who presents with fevers, productive cough x2 days.

On exam, patient is febrile to 101. Breathing is mildly labored with RR 28, HR 106, pulse ox 92% RA. Has crackles at the right lower lung field.

Labs: wbc 13.5, Hct 34, plt 175. Na 134, BUN 35.

What do you think? What studies would you like?

Initial Investigation

CXR Sputum culture Blood culture Consider ABG if respiratory distress or

hypoxia Consider legionella or pneumococcal

antigen if history indicates. None of the above should delay antibiotic

treatment! Antibiotics should be given within 4 hours of initial evaluation!

Working Diagnosis: Pneumonia

Risk Factors? Age COPD/chronic lung disease Renal insufficiency Heart failure CAD DM Malignancy Chronic neurological disease Chronic liver disease

Signs and Symptoms: Pneumonia

Fever (may be absent in the elderly or immunocompromised)

Cough Sputum production Dyspnea Pleuritic chest pain GI Sx: nausea, vomiting, diarrhea Mental status changes Tachycardia Tachypnea Leukocytosis or leukopenia Infiltrate on CXR - remember that an infiltrate may not

appear in a hypovolemic patient!

Pneumonia - Who is our patient (host)?

Community Acquired Pneumonia (CAP) Healthcare-Associated Pneumonia (HCAP)

IV therapy, chemotherapy, or wound care in the last 30 days.

Resident of a nursing home/long term care facility Hospitalized >2 days in the last 90 days Attended HD in the last 30 days.

Hospital-Acquired Pneumonia (HAP) Occurs >48 hours after admissions Not present on admission

Ventilator-Associated Pneumonia (VAP) Occurs >48 hours after intubation

CAP: the bugs

Typical S. pneumoniae Haemophilus influenza S. aureus

Atypical Legionella Mycoplasma pneumoniae Chlamydia pneumoniae Moraxella catarrhalis

CAP: treatment

Respiratory fluoroquinolone Moxifloxacin

OR….

Beta-lactam + macrolide Ceftriaxone + azithromycin

Another f&@$% page from the DACR….

83 yo man with h/o CKD, COPD, Alzheimer’s who presents from his nursing home with mental status changes.

T 102, HR 135, BP 86/40, RR 40 On exam, patient has right lower lobe

rhonchi. What is the diagnosis? What are the potential bugs?

HCAP: The Bugs

S. pneumoniae H. influenza S. aureus – (MRSA) Gram negative bacilli

Pseudomonas aeruginosa

E. coli Klebsiella Acinetobacter

MDR Risk Factors

-Abx in last 90 days

-Current hospitalization >5 days

-High frequency of resistance in community or hospital

-HCAP risk factors

-Immunosuppressive disease or therapy

HCAP/HAP/VAP: Treatment

Hint: go through past micro…can help you identify any MDRO immediately!

Broad spectrum Abx: Anti-pseudomonal cephalosporin or beta

lactam/beta lactamase inhibitor – cefepime or zosyn +

Vancomycin +/- Aminoglycoside

Your clinic patient is…

44 yo female with h/o HTN complaining of 2 days of dysuria and subjective fever.

On exam, temperature is 99.7, HR 68, BP 120/64. Abdominal exam notable for suprapubic tenderness.

UA - +LE, +nitrates, 4+ bacteria, >100 wbc

Any thoughts?

What is a “dirty urine”?

Leukocyte esterase - release from leukocytes

Nitrite - produced when bacteria convert nitrates to nitrites

WBC - pyuria is defined as… >5 wbc/HPF in women >2 wbc/HPF in men

Bacteruria - depends on the scenario The presence of bacteria in male urine should

always be considered abnormal. Females - >10^5 per HPF

Not all UTIs are the same…

Uncomplicated Usually a female without recurrent

infections Bugs: E coli (85%), S. saprophyticus Rx: Bactrim, cipro, nitrofurantoin Can treat for 3 days

Not all UTIs are the same…

Complicated Forgein bodies: Catheter, calculi, tumors Anatomic problem: residual urine, neurogenic

bladder, BPH Male Pregnant Recurrent infection Diabetes Bugs: Enterococci, Klebsiella, Proteus Did this bug come from the community or is it

hospital associated? Rx: zosyn, cipro Treat for 7 days, followup culture

So what about…

82 yo man with COPD, CAD, h/o CVA, chronic foley that your co-intern admitted for falls. UA is positive and urine culture is growing Gram negative bacilli.

What do you do?

Don’t forget to change the foley!!!!

Another page from the DACR…

60 yo man with pancreatic cancer who received chemotherapy through his MediPort 8 days ago is being admitted with fever.

T 101.8, HR 94, RR 18, BP 101/64. Exam unremarkable.

WBC 0.8 with 50% neutrophils What do you think?

Neutropenic Fever

Neutropenia Absolute neutrophil count <500 Nadir typically reached at day 7-10

Neutropenic Fever single temperature of >38.3ºC (101ºF),

or a sustained temperature >38ºC (100.4ºF) for more than one hour

This is a medical emergency!

Initial Workup

Careful examination head to toe DO NOT DO A RECTAL EXAM! Be sure to look at the MediPort.

2 sets of blood cultures – one off the line, one peripheral

Urine cultures Sputum cultures CXR

Bugs and Drugs

Need to cover Pseudomonas, MRSA (esp if they have a line). Push the dose: zosyn 4.5 grams 6h, vanco

1gram q12, goal trough 15-20 Consider adding an aminoglycoside. Remember: these people do not have an

immune system!!! Do you suspect viral infection (HSV?,

VZV?)? Do you suspect fungal infection (thrush)?

Just as you are about to head to the call room….

The micro lab calls you and tells you that a patient on Carpenter has a blood culture growing gram positive cocci in clusters…

What do you do?

Infection vs. Contamination

Go see the patient! Read the chart! Consider giving dose of vancomycin

and redrawing blood cultures. Drop a short note describing your

medical decision making in the chart and discuss with the primary team in the morning.

While pre-rounding….

Your patient that you are treating for HCAP tells you that they had 5 watery bowel movements last night.

What do you think?

Clostridium difficile

Most common infectious cause of healthcare associated diarrhea in the United States.

3.4 – 8.4 cases per 1000 admissions

Diagnosis

C. diff toxin/Antigen Fecal leukocytes If clinical suspicion is high--start

antibiotics!

Pathogenesis – 3 Hit Theory

Risk Factors – C. Difficile

Antibiotics Clindamycin, 3rd generation cephalosporins,

fluoroquinolones Age Proton Pump Inhibitor GI surgery LOS >7 days Feeding via NG tube Admission to ICU

Treatment – C. Difficile

Stop the offending antibiotic!

Oral metronidazole 500mg q8

Oral vancomycin 125mg q6

Contact precautions! Avoid anti-motility

agents. Leads to ileus and

toxic megacolon

Helpful Hints/Suggestions

AKA – things that make your life easier…

Sanford…your best friend

Page 5 – suggested empiric antibiotics based on organ system

Page 179 – renal dosing Don’t forget GFR!

Vancomycin

When you write the order for vancomycin, order a trough before the 4th dose.

Just do it…