Chapter 15 Infection

Pathopharmacology for nurses and integrated approach

What patients are considered immunosuppressed

Patients on high-dose corticosteroids

Relation of vaccine and immunocompromised patient

Live attenuated vaccines replicate in the body and can cause infection in immunocompromised patients

What are examples of Live Vaccines

MMR, Varicella, Rotavirus

What are examples of Non-live Vaccines

Hepatitis B, IPV, Hepatitis A, Inacitvated influenza, Reconbinant vaccine (shingrix)

When to avoid live vaccines

immunocompromised patients and pregnancy

What specific vaccines to avoid in immunocompromised patients on corticosteriods

MMR, varicella

What specific vaccine are acceptable for Immunocompromised patients on corticosteroids

HPV, inactivated influenza, hepatitis A

What specific vaccine should be avoided in pregnancy

Shingrix; not enough safety data to support its use during pregnancy.

Why does vaccination matter

1. reduces severity of the illness

2. lowers complications

3. decreases hospitalization risk

4. help protect vulnerable groups

5. reduces transmission

Why is partial protection is still clinically meaningful

prevents severe infections in immunodeficiency

short term protection is vital for pt at risk of significant harm or death bridging the gap

What is uncomplicated cellulitis caused by

gram positive skin flora

What are the most common pathogens of cellulitis

1. Streptococcus species

2. staphylococcus aureus

What is the first line of treatment for cellulitis

Cephalexin : mild to moderate uncomplicated cellulitis cases

What medications are not first line for typical uncomplicated cellulitis

1. ciprofloxacin

2. meropenem

3. vancomycin (unless severe/resistant/hospitalization)

Connecting likely pathogens to empiric treatment choices

Cephalexin = first line= step+MSSA

Ciproflaxacin= gram negative

Meropenem= Broad-spectrum - too strong/unnecessary

Vancomycin= MARS- reserved for severe cases

How does Community-acquired pneumonia (CAP) occur

Develops outside of the hospital or first 48 hr of admission

Common symptoms of CAP

fever, cough, sputum production, crackles, dyspnes

What is the typical organism for CAP

streptococcus pneumonia

What is initial empiric treatment for CAP

amoxicillin + azithromycin

What is amoxicillin

beta-lactam

What is azithromycin

macrolide

When do Hospital-acquired pneumonia (HAP)

typically 48 or more hours after admission and often requires broader coverage

Is bacterial meningitis a medical emergency

YES

What is the priority sequence of bacterial meningitis

1. Obtain Blood Cultures

2. Start empiric IV antibiotic promptly

3. Lumbar puncture when appropriate based on stability and clinical context

What is bacterial meningitis first line treatment

empiric IV treatment

What are adjunct treatment for bacterial meningitis

Dexamethasone

Dexamethasone usage

Given Before or with first antibiotic dose to reduce inflammatory injury after bacterial lysis

Why is dexamethasone important

Lower risk of:

1. cerebral edema

2. increased ICP

3. hearing loss

4. Neurologic Complications

What does left shift indicate in bacterial infection

an increased WBC count with increased bands indicates a left shift

What does left shift mean

bone marrow is releasing immature neutrophil in response to acute bacterial infection (active inflammatory response; not immune suppression)

What is Absolute Neutrophil Count (ANC) aid in

estimate infection risk

ANC calculation

ANC=WBC x Percentage of Neutrophil

What are the interpretations of ANC

<1500= neutropenia

<1000= moderate risk

<500= severe risk

What does low ANC indicate

Increased susceptibility to bacterial and fungal infection

What are the antibiotic classes by Mechanism

1. Cell wall synthesis inhibitors

2. Protein synthesis inhibitors

3. DNA synthesis inhibitors

What antibiotics are apart of Cell wall synthesis inhibitor

1. penicillins

2. vancomycin

What is the spectrum activity of cell wall inhibitors

working best with gram-positive bacterial (thick cell wall)

What are adverse effects of vancomycin

nephrotoxicity, red man syndrome

What are resistance patterns of cell wall trugs

alter targets (MRSA changing penicillin binding protein)

What antibiotics are apart of Protein synthesis inhibitors

1. amino-glycosides

2. tetracyclines

What is the spectrum activity of Protein synthesis inhibitors

often broad-spectrum

What are adverse effects of amino-glycosides

ototoxicity, nephrotoxicity

What are adverse effects of tetracyclines

teeth discoloration, photosensitivity

What are resistance patterns of protein synthesis drugs

ribosomes changes or drug efflux pumps

What antibiotics are apart of DNA synthesis inhibitors

fluoroquinolone

What is the spectrum activity of DNA synthesis inhibitors

Strong gram-negative coverages

What are adverse effects of fluroquinolones

tendon rupture, QT proglongation

What are resistance patterns of DNA synthesis Drugs

Mutations in DNA enzymes

What is Gentamicin

amino-glycoside used for gram negative infection

What are major toxicities of gentamicin

nephrotoxicity & ototoxicity

Irreversible possibility

What needs to be monitored for Gentamicin

1. renal function

2. drug levels

3. hearing changes

4. tinnitus

5. dizziness/vertigo

What is levofloxacin

fluoroquinolone has safety issues to consider

Risks of Levofloxacin to monitor

1. QT Prolongation

2. arrhythmias

3. tendonitis/tendon rupture

4. glucose disturbance

5. caution and avoid routine use in children

Which population are ate higher risks of tendon rupture on levofloxacin

older adults and patients on corticosteroids

When is Metronidazole used for

anaerobic infection and C. difficile

What are important teachings for Metronidazole

1. Avoid alcohol during tx and for 24-48 hrs afterward

2. may cause metallic taste

3. can potentiate warfarin and increase bleeding risk

Why should alcohol be avoided for Metronidazol

causing disulfiram-like reaction of

1. flushing

2. nausea

3. vomiting

4. tachycardia

5. hypotension