08. Antibiotics

8/3/2019 08. Antibiotics

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Common Hospital Infections


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If you want three opinions then

ask two infectious diseasedoctors- KBA


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Fever

Its 1am and the nurse on Lakeside 65 justcalled you because Mrs. Price has a T of101.5 . . . What do you do?


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More cowbell!


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What is the definition of a fever?

Textbook Elevation in the bodys thermoregulatory set point

In the different IDSA guidelines dealing withfever

T >101 at any timepoint

T >100.4 for greater than one hour

Use your judgement


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Fever

1) Assess the patient

- As always this is #1 when you are calledabout a patient

- What are they in for?

- Have they been febrile?

- What do they look like?

- Are there any symptoms consistent withinfection or non-infectious causes of fever(which are?)


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Non-infectious causes of fever

Venous thromboembolism

Medications

Transfusion reaction Neuroleptic malignant syndrome

Connective tissue disease

Malignancy Just drank hot coffee


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Fever

2) Orders

Blood cultures

Urinalysis, urine culture

Chest x-ray


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Sepsis

Documented or suspected infectionplus

Systemic Inflammatory Response Syndrome (2

of the following 4) Pyrexia or hypothermia- T >38C or 90

Respiratory- RR >20 or PaCO2 12,000, 10%

Keep in mind that many clinical scenarios can produce2 of 4 SIRS criteria


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Hypotension

Systolic BP 40mmHg frombaseline


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Types of sepsis

Severe sepsis- sepsis associated withorgan dysfunction, hypoperfusion, orhypotension

Septic shock- Sepsis with hypotension,despite adequate fluid resuscitation, along

with the presence of perfusionabnormalities- lactic acidosis, oliguria,mental status change


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Treatment

Antibiotics

Targeted at known organism or empirictreatment

Early goal directed therapy


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Sepsis- Early goal directed therapy


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Sepsis considerations

Corticosteroids

given only to adult septic shock patients after

it has been confirmed that their blood

pressure is poorly responsive to fluidresuscitation and vasopressor therapy

Activated Protein C (Xigris)

APACHE II >25 Talk with your fellow


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Your clinic patient is . . .

44 yo female h/o HTN who complains of 2days of dysuria and subjective fever

On exam T is 99.7, HR 68, BP 120/64

Abdominal exam with suprapubictenderness


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UTI risk

Females

Atrophic vaginal mucosa with altered flora

Use of diaphragms and spermaticides

Foley catheter

Males

Stricture or obstruction of the urethra (e.g.BPH)

Foley catheter


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Etiology of UTI

Uncomplicated

E. coli- 85% of females with uncomplicatedinfection

Staph. Saprophyticus

Recurrent

Enterococci (faecium and faecalis)

Klebsiella

Proteus


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UTI pathogenesis

Introduction of bacteria into the urinarybladder

Incomplete emptying of the bladder (aslittle as 10mL of residual)

Fast reproduction time of many of thebacteria that cause UTI (e.g. E. coli whichreproduces in 20 minutes)


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Urinalysis

Leukocyte esterase- test for esterase which isreleased from leukocytes

Nitrite- produced when bacteria convert nitratesto nitrites

WBC- pyuria is defined as . . . >5WBC per HPF in women >2WBC per HPF in men

Bacteruria- different for clinical scenario

The presence of bacteria in male urine should alwaysbe considered abnormal

Females- >10^5 per HPF (100,000)


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Complicated UTI

Abnormal anatomy- residual urine,neurogenic bladder, BPH

Foreign bodies- Catheters, Calculi,Tumors

Vesicoureteral reflux

Diabetes


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Uncomplicated UTI treatment

Oral Bactrim

Nitrofurantoin

Augmentin Cephalosporin

Fluoroquinolone

IV Cephalosporin- ceftriaxone

Fluoroquinolone


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54 yo male h/o HTN, DM who presentswith raised erythematous lesion on rightleg and subjective fevers.

T 99.7 HR 86 RR 16 BP 140/90


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Soft tissue infections

Cellulitis Erythematous lesions with less clear line of

demarcation compared to erysipelas

Involves deeper dermis and subcutaneous fat Erysipelas

raised above the level of surrounding skin,and there is a clear line of demarcationbetween involved and uninvolved tissue

Involves upper dermis and superficiallymphatics


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Treatment of routine cellulitis

MRSA coverage?

Beta-lactam

Often in hospital would use Unasyn

Consider Pseudomonas coverage fordiabetics (Piperacillin-tazobactam)

PCN allergic

Consider fluoroquinolone


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When is cellulitis not cellulitis?

Myositis

Osteomyelitis


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When is cellulitis not cellulitis?

Toxic appearance to patient

Pain out of proportion to exam

Quickly spreading infection Presence of crepitation

Bullae formation


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Risk of necrotizing fasciitis- score

>6 is suggestive and score >8 is

highly predictive Serum C-reactive protein 150 mg/L (4 points) White blood cell count 15,000 to 25,000/microL (1 point) or

>25,000/microL (2 points)

Hemoglobin 11.0 to 13.5 g/dL (1 point) or 11 g/dL (2 points) Serum sodium less than 135 meq/L (2 points) Serum creatinine greater than 1.6 mg/dL (141 mmol/L) (2 points) Serum glucose greater than 180 mg/dL (10 mmol/L) (1 point) A total score 6 should raise the suspicion for necrotizing fasciitis

while a score 8 was highly predictive (>75 percent). Among the

patients with necrotizing fasciitis, 75 to 80 percent had a score 8,while only 7 to 10 percent had a score less than 6. Thus, the scoreis only useful when severe soft tissue infection is stronglysuspected.


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Treatment of necrotizing fasciitis

Stat surgical consult for debridement

Clindamycin or metronidazole

plus

Beta-lactam/beta-lactamase inhibitor or3rd gen cephalosporin or carbapenem orfluoroquinolone or aminoglycoside


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The DACR paged you and thereport is . . .

73 yo male h/o CHF, CKD, CAD who presentswith fever, productive cough x 2 days.

On exam, the patient is febrile to 101. You notethat the patient has mildly labored breathing withRR of 28, HR 106. Has crackles at the rightlower lung field.

Labs- WBC 13.5 Hct 34 Plt 175 Na 134 BUN

35 What do you think?

What studies would you like?


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Initial investigation

CXR

Sputum culture

Blood culture

Consider ABG if respiratory distress or hypoxia

None of the above should delay antibiotic

treatment and guidelines dictate that antibioticsshould be given within four hours of initialencounter


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Clinical manifestations-Signs and Symptoms

Cough- 90%

Dyspnea- 66%

Sputum production-

60% Pleuritic chest pain-

50%

Subjective fever Nonspecific

symptoms

Temp>37C- 78%

Crackles- 78%

Confusion- 30%

Consolidation- 29%


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Epidemiology

Risk factors for CAP

Older age

COPD

Renal Insufficiency Congestive Heart Disease

CAD

Diabetes

Malignancy

Chronic Neurologic Disease

Chronic Liver Disease


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Pneumonia- Etiology

The clinical features of community-acquiredpneumonia cannot be reliably used to

establish the etiologic diagnosis of

pneumonia with adequate sensitivity andspecificity- IDSA guidelines on

Community Acquired Pneumonia


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CAP- Etiology

The bugs . . .

Strep. Pneumoniae

Mycoplasma pneumoniae

Haemophilus influenza

Chlamydia pneumoniae

Respiratory viruses


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Risk stratificationThe PORT score

Usually prior to you seeing the patient

May or may not be documented


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Pneumonia Severity Index-PORT Score


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Fine, M. J. et al. N Engl J Med 1997;336:243-250

Applying the PORT score


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PORT in our patient

Age 73

CHF 10

CKD 10

BUN 20

Total= 113 PORT score


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PORT Categories and mortality

Class I- age


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CAP- Initial empiric treatment

Respiratory fluoroquinolone (e.g.moxifloxacin)

Or . . .

Macrolide (e.g. azithromycin) + beta-lactam (usually ceftriaxone)


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CAP- special considerationsLegionella

Legionella risk (relative risk in parentheses) Glucocorticoids or Cushings disease (2-5) Cytotoxic chemo (5) Cigarette smoking (2-5) Diabetes (2)

Male gender (>2) Age >50 (>2) AIDS (40) Renal failure requiring dialysis (20) Lung or hematologic cancer (7-20)

Diagnostics- urine legionella antigen Treatment- Erythromycin or tetracycline (usually

doxycycline)


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CAP- special considerationsAspiration pneumonia

Risk Think of patients with loss of consciousness

(seizures, alcoholics), patients with neurologicalimpairment

The bugs Gram-negative enteric pathogens Mouth anaerobes

Treatment for the hospitalized patient Piperacillin/tazobactam 3.375g q6H Imipenem 500mg q6H Clindamycin 900mg IV q8H plus ciprofloxacin 400mg

q12H or Aztrenoam 1-2g q8H


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83 yo male with h/o CKD, COPD,Alzheimers who presents from nursing

home with mental status change.

T 102 HR 135 BP 86/40 RR 40

On exam you find that patient has lowerlobe rhonchi.

How is this different from your otherpatient with pneumonia?


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Defining Healthcare AssociatedPneumonia

Pneumonia in someone who. . . Has developed pneumonia after being in

hospital 2 days

Was hospitalized for 2 days in the last 90days

Resident of nursing home or long term carefacility (e.g. SNF)

Recently received IV antibiotics,chemotherapy or wound care in past 30 days

Attended a hospital or hemodialysis clinic


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Etiology of HCAP Think of MDR pathogens


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Risks for MDR


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Common bugs

Strep pneumo and H. flu- usually cause early ratherthan late infections

Staph- worry about MRSA Gram negative bacilli

Pseudonas aeruginosa

E. coli

Klebsiella

Acinetobacter- if you suspect this then consider ID consultand utilize full barrier and respiratory precautions


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Treating HCAP

Empiric antibiotics should be differentclasses than recently prescribedantibiotics

R d ti f i i


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Recommendation for empirictherapy

Em i i t tm t f HAP l


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Empiric treatment of HAP- early

onset and no known risk factors for

MDR


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Empiric treatment of HAP

R d ti f i i


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Recommendation for empirictherapy

Therapy can decreased to 7 days unlessthe infection is proven to be Acinetobacteror Pseudomonas

Th DACR d d th


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60 yo male with pancreatic cancer whoreceived gemcitabine 8 days ago presentswith fever.

On exam, T is 101.8, HR is 94, RR is 18,BP is 128/64. Exam is largelyunremarkable.

On labs his WBC is 0.8 with % neutrophilsof 50%

What do you think?


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Neutropenic fever

Fever (single oral temperature >101 or>100.4 for greater than one hour) inpatient with ANC < 500 or in patient who

has ANC


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Epidemiology of Neutropenic fever

of patients who have ANC


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Problem with neutropenia

They may not act infected

Patient with cellulitis may not have erythemaand induration

Patient with pneumonia may be without aradiographic infiltrate

Patient with meningitis may not have

pleocytosis in CSF Patient with UTI may not have pyuria on

urinalysis


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Initial workup

Blood cultures

Urine cultures

Sputum cultures

CXR


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Etiology

Gram positive cocci account for 60-70% ofproven bacterial infection in these patients


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Low risk vs. high risk

Empiric therapy for high risk


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Empiric therapy for high riskpatients


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Antivirals

Should be used if signs and symptoms ofHSV or VZV are present to heal portal ofentry for bacteria


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Duration of therapy


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Fever resolved in first 3-5 days


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Persistent fever in first 3-5 days


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Colony-stimulating factors

Not routinely recommended for therapy

Consider in patients who are severely ill orwho have documented bacterial infection,

persistent neutropenia and are notresponding to antimicrobial therapy


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Uh-oh

Your patient that you are treating for HAPbegins to have profuse, watery diarrhea!


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C. Diff Infection

Clostridium difficileis the most commoninfectious cause of healthcare associateddiarrhea in the United States

3.4 to 8.4 cases per 1000 admissions


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Suspect C. diff

What do you order?

C. diff toxin assay from 3 separate stools

Fecal leukocytes


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Spectrum of disease

Asymptomatic carrier state 3% of healthy adults 16-35% of hospitalized patients

Antibiotic associated diarrhea

Accounts for 10-25% of cases Colitis without pseudomembrane formation

60-75% of antibiotic associated colitis

Pseudomembranous colitis

90-100% of antibiotic associatedpseudomembanous colitis

Fulminant colitis- 1-3% of patients May lead to ileus, toxic megacolon, perforation and

death

Pathogenesis- 3 hit theory


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g yFrom Cohen and Powderly

Figure 44.1The pathogenesis model for hospital-acquired Clostridiumdifficile-associated diarrhea (CDAD).]

Risk factors associated with


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Risk factors associated withClostridium difficile

Risk factor Comments

Specific antibiotics-Clindamycin-3rd generation cephalosporins-Fluoroquinolones

Cefazolin OR=3.5Levofloxacin OR=2.1

Increasing age OR=2.8 for age >71

Use of proton pump inhibitor OR=2.1

Gastrointestinal surgery OR=7.9

Length of stay >7 days OR=2.3

Feeding via NG tube OR=2.8

Admission to intensive care unit


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Treatment of clostridium difficile

Stop offending antibiotic Leads to resolution in 15-23% of patients

Antibiotics - similar efficacy with resolution inapproximately 93% of patients

Oral metronidazole 500mg TID Oral vancomycin 125mg QID as second line

treatment

Avoid anti-motility agents

Leads to ileus and toxic megacolon formation Supportive measures


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THE END

08. Antibiotics

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