Chapter 18 PNA-2

Antibiotic: A drug specifically targeting and treating bacterial infections.
Antimicrobial: A broader category of substances aimed at killing or treating various microorganisms, including bacteria, fungi, and viruses.
Pathogen: A microorganism that can cause disease.
Normal Flora: Beneficial microorganisms, including bacteria, protozoa, and fungi, that reside in or on certain areas of the body.
Empiric Therapy: An informed decision regarding which antibiotic to use based on typical infections.
Aerobic vs. Anaerobic: Aerobic bacteria require oxygen for survival, while anaerobic bacteria do not.
Gram Staining: A laboratory technique to classify bacteria as gram-positive or gram-negative based on their cell wall composition.

Overuse of broad spectrum antibiotics can eliminate normal microorganisms, leading to resistance.
Narrow Spectrum Antibiotics: Recommended when possible to reduce this overkill.
Forms of Resistance:
- Bacterial enzymes that can degrade specific drugs.
- Genetic mutation and gene transfer resulting in altered receptors that antibiotics cannot bind to.
- Non-compliance with prescribed antibiotic regimens increases the chances of resistant bacteria surviving.

Required tests can be conducted on various body fluids, including urine, sputum, and blood, to identify specific pathogens and their sensitivities to different antibiotics.
A well-collected sputum sample is critical for accurate testing, which is performed in sterile containers.
Initial tests include sputum gram stain to determine the presence and type of bacteria, followed by culturing to find the most effective antibiotics for treatment.
Results often take up to three days, necessitating the initiation of empirical therapy beforehand.

Antibiotics can be categorized as bacteriostatic (inhibit growth) or bactericidal (kill bacteria), with most being bacteriostatic at lower doses and bactericidal at higher doses.
They are also classified by spectrum:
- Narrow Spectrum: Targets specific microorganisms.
- Broad Spectrum: Targets a wide range of microorganisms, including potentially harmful effects on beneficial microbiota.
Common examples include:
- Bacteriostatic: Tetracycline.
- Bactericidal: Penicillins.

Gram-Positive Specific: Vancomycin, Levofloxacin, and various penicillin derivatives.
Gram-Negative Specific: Tobramycin, Gentamicin, Cefepime.

Aerosolized medications like tobramycin are critical for treating lung infections, particularly in cystic fibrosis for combating Pseudomonas aeruginosa. The dosing is specific and is associated with fewer systemic side effects compared to intravenous administration.
Note that aerosolized colistin use is increasingly observed in certain regions, but specific administration guidelines must be followed to ensure safety.

Key Viruses: Influenza, HIV, rabies, and herpes.
Primary Treatment: Involved immunizations to prevent infections, supported by antivirals like Valtrex for herpes and Tamiflu for influenza.

Fungi reproduce via spores and can lead to infections in immunocompromised individuals. Common Fungal Infections: include thrush (Candida), athlete's foot, and Aspergillus.
Antifungal Agents: Nystatin, Monistat, Diflucan, Pentamidine.

Definition: Pneumonia is defined as the inflammation of the lungs, mainly affecting the alveoli.
It can be caused by various pathogens, primarily bacteria.
Types of pneumonia include community-acquired and healthcare-associated pneumonia, with risk factors including age, previous respiratory illnesses, and surgical history.

Infections lead to fluid accumulation in the lungs (effusion) and impaired gas exchange, resulting in a restrictive disease process and V/Q mismatching.

The typical V/Q ratio is 0.8. Mismatches in this ratio can have significant clinical implications, such as hypoxemia.

Shunt Definitions:
- Anatomical Shunt: Blood bypasses non-ventilated areas.
- Physiological Shunt: Alveoli are not ventilated due to disease processes, leading to refractory hypoxemia.

Evaluating the A-a gradient, the a/A ratio, and P/F ratio are essential for assessing oxygenation status and identifying potential respiratory disorders.

Treatment protocols depend significantly on whether pneumonia is bacterial or viral, guiding use of antibiotics, antivirals, and supportive care measures.

Sepsis is a severe response to infection with pneumonia being a leading cause. Clinical signs of sepsis include elevated heart rate, fever, and altered mental status.

Guidelines encompass oxygen therapy, lung expansion therapies, and clearance techniques to optimize patient outcomes in respiratory distress.