Pneumonia
Antibiotic Anti-Infective Therapy: Pneumonia
Introduction to Bacteria
Bacilli (rod-shaped)
Single bacillus
Chain of bacilli
Bacilli with flagella
Cocci (spherical)
Diplococci (in pairs)
Staphylococci (in clusters)
Streptococci (in chains)
Other shapes
Spirella
Vibrio (comma-shaped)
Treponema
Borrelia
A Little Microbiology Review
Pathogens:
Gram Positive:
Staphylococcus aureus
Streptococcus pneumoniae
Group A Beta Hemolytic Strep
Enterococcus
Mycobacterium
Gram Negative:
Pseudomonas aeruginosa
E. coli
Haemophilus pneumoniae
Neisseria meningitidis
Proteus mirabilis
Acinetobacter
Types of Pneumonia
Treatment Approach:
Treat empirically until culture results are confirmed.
Types of Pneumonia:
Community Acquired: May be a complication of influenza.
Healthcare Acquired:
Occurs >48 hours after admission.
Associated with high mortality.
Organisms may show resistance.
Aspiration Pneumonia:
Caused by stomach contents, drowning; often involves anaerobic bacteria from the mouth or fresh water.
Ventilator-Associated Pneumonia:
Develops >48 hours after intubation in critically ill patients.
Case Study: Mr. Jones
Patient Profile:
72-year-old with shortness of breath (SOB), fever, productive cough for 3 days.
Fatigue with a pulse oximetry range of 90-92% on 2 L O2.
Clinical Findings:
Initiated IV Ampicillin.
Patient’s ABG results:
pH: 7.32, pCO2: 50, HCO3-: 25, pO2: 70
Reference Ranges: 7.35-7.45 (pH), 35-45 (pCO2), 22-26 (HCO3-), >75/80 (pO2).
Additional Nursing Assessments Needed:
Assess lung sounds, re-evaluate clinical status, vital signs, and obtain further lab results.
Exemplar - Pneumonia
Pathophysiology:
Inflammation/Infection of lung results in fluid/exudate filling alveoli.
Signs and Symptoms:
Fever, chills, fatigue, anorexia, weakness, chest pain, productive cough, anxiety, hypoxemia, tachycardia.
Confusion is common in older adults.
Nursing Care:
Obtain sputum culture and appropriate antibiotics.
Administer bronchodilators and glucocorticoids.
Encourage fluid intake (oral or IV).
Risks include immobility and pre-existing respiratory conditions.
Common aspects of diagnosis:
Chest X-ray, CBC (WBC count), and ABG/Pulse Ox.
Lung changes indicative of infection include:
Alveolar capillaries exhibiting frothy serous or rust/blood-tinged fluid.
Radiography
Chest X-ray (CXR):
Can show right middle lobe pneumonia (infiltrate).
Documentation Check:
Assess sputum findings to document in patient records.
Anti-infectives - Antibiotics
Action of Antibiotics:
Act on invading organism’s cells through various mechanisms:
Interfere with normal cellular function, prevent reproduction, and induce cell death without harming host cells.
Classifications:
Narrow Spectrum:
Effective against a specific bacteria type (e.g., Vancomycin for MRSA).
Broad Spectrum:
Effective against a large range of bacteria (e.g., tetracycline, cephalosporins).
Pharmacokinetics:
The longer an antibiotic binds to a target, the greater its effects.
Longer half-life leads to increased concentration at binding sites, resulting in less frequent dosing.
Monitor for drug toxicity if peak levels are too high or efficacy if trough levels are too low.
Resistance Mechanisms in Antibiotics
How Resistance Occurs:
Beta-Lactamase Production:
Enzymes produced by certain bacteria that deactivate antibiotics (e.g., Penicillin).
Altered Cellular Permeability:
Changes that prevent drugs from entering bacterial cells.
Prevention Methods:
Ensure proper dosing and duration to eradicate infections.
Avoid premature cessation of antibiotics even if symptoms improve.
Use around-the-clock dosing to maintain therapeutic levels.
Utilize culture and sensitivity tests to tailor antibiotic therapy.
Penicillins: A Class of Antibiotics
Mechanism of Action:
Inhibits bacterial cell wall synthesis, obstructing the enzyme required for bacterial cell division.
Classification:
Typically Broad Spectrum.
Contraindications:
Known allergies to penicillins or cephalosporins; cross-sensitivity may occur.
Beta-Lactam Definition:
Refers to the chemical structure of antibiotics that includes the beta-lactam ring; these antibiotics inhibit cell wall synthesis.
Types include:
Penicillins
Cephalosporins
Carbapenems
Monobactams
Broad/Extended Spectrum Penicillins
Use Case:
Treats both gram-positive and gram-negative infections.
Amoxicillin:
Most common drug; effective against Streptococcus pneumoniae and some gram-negative bacteria such as E. coli.
Ampicillin:
Administered parenterally (IV), combined with Clavulanic Acid to create Augmentin for resistance purposes (beta-lactamase resistant organisms).
Penicillinase Resistant Penicillins
Examples:
Imipenem-cilastatin (Primaxin) & Doripenem (Doribax)
Oxacillin (IV/IM)
Nafcillin (IV/IM)
Dicloxacillin (oral)
Indications:
Effective against Penicillinase-producing Staphylococcus aureus, often for bone infections.
Cephalosporins
Class Features:
Chemically similar to penicillins with a 1-8% risk of cross-reactivity in those allergic to PCN.
Usage in Surgical Care:
Administer antibiotics like Cefazolin or Vancomycin within 1 hour of incision and continued for 24 hours post-surgery.
Generations:
First Generation: Good for gram-positive but poor for gram-negative (Cefazolin, Cephalexin).
Second Generation: Improved gram-negative coverage but decreased gram-positive efficacy.
Includes coverage for Haemophilus influenzae and Klebsiella species.
Third Generation: Expanded gram-negative coverage with effectiveness against resistant strains. (Ceftriaxone is an example).
Fourth & Fifth Generation:
Greater activity against gram-negative and resistant strains, such as MRSA.
Aminoglycosides
Indications:
Effective for gram-negative and aerobic bacterial infections.
Works through bactericidal effects by inhibiting protein synthesis.
Administration:
Typically administered once daily to reduce nephrotoxicity risk.
Forms:
Injectable with poor GI absorption; Neomycin for bowel sterilization pre-surgery.
Side Effects:
Include nausea, vomiting, diarrhea, palpitations, hypotension, hypertension, ototoxicity.
Causes potential renal failure and glomerular toxicity.
Contraindications:
Renal disease, hearing loss, mycobacterial infections, or when pregnancy risks outweigh benefits.
Fluoroquinolones
Pharmacokinetics:
Absorbed from the gastrointestinal tract, metabolized in the liver, and excreted through urine and feces.
Indications:
Treats gram-negative respiratory, urinary tract, and skin infections.
Dosage Notes:
Important to separate antacids, iron, and calcium by 4 hours to ensure absorption.
Macrolides
Mechanisms of Action:
Bind to ribosomes and inhibit bacterial protein synthesis.
Common Drugs:
Erythromycin, Azithromycin, Clarithromycin.
Uses:
Treats a variety of infections including community-acquired pneumonia and sexually transmitted infections.
Drug Interactions:
Erythromycin can be used in patients with PCN allergy.
Side Effects:
Diarrhea, skin rash, liver function alterations.
Miscellaneous Antibiotics
Vancomycin:
Effective against MRSA and resistant gram-positive bacteria. Intravenous administration for systemic infections; oral for C. difficile.
Careful monitoring for infusion reactions and nephrotoxicity is required.
Tetracyclines:
Broad-spectrum antibiotics affecting protein synthesis.
Contraindicated in children under age 8 due to teeth and bone impacts.
Clindamycin:
Used for severe infections where other antibiotics cannot be used; caution due to potential for C. difficile colitis.
Understanding Normal Microbial Flora
Normal Flora:
Microorganisms present in non-pathogenic states that protect hosts (e.g., on skin, upper respiratory tract, colon).
Disruption of Flora:
Can lead to opportunistic infections in the elderly, immunocompromised, or debilitated patients, enabling suppressed pathogens to thrive.
Adverse Reactions of Antibiotics
Allergic Reactions:
Urticaria, angioedema, anaphylaxis, hypersensitivity.
Superinfections:
Occurrence of secondary infections due to disrupted normal flora, often affecting oral, skin, and gastrointestinal sites.
Toxicities:
Organ toxicity affecting the liver, kidneys, and ears especially with aminoglycosides and vancomycin.
Antibiotic Resistance
Introduction to Resistance:
Refers to bacteria that have developed resistance to numerous antimicrobial agents, posing treatment challenges.
Prevention Strategies:
Appropriate dosing and duration, avoiding overindulgent use, and adhering to proper laboratory protocols when administering antibiotics.
Current Recommendations:
Consult infectious disease specialists and comply with CDC guidelines to effectively manage infections and reduce resistance prevalence.
Summary of Antimicrobial Mechanisms
Sulfamides: Block synthesis necessary for cell metabolism and growth.
Beta-lactams: (Penicillins, Cephalosporins) hinder cell wall construction.
Fluoroquinolones: Impede DNA gyrase affecting reproduction.
Ribosome-acting Agents: (Aminoglycosides, Macrolides, Tetracyclines) disrupt protein synthesis vital for bacterial survival.
Enrichment - Miscellaneous Anti-Infective Agents
Rifaximin: Used for traveler's diarrhea caused by E. coli.
Linezolid: Effective against aerobic gram-positive bacteria including VRE.
Quinupristin/Dalfopristin: A streptogramin with activity against resistant gram-positive bacteria including vancomycin-resistant strains.
EKG Changes in Fluoroquinolones
Normal QT interval:
Prolonged QT interval:
Can lead to Torsade de Pointes.