MED SURG PN 105 Infection ATI Notes Infection ATI Notes

MED SURG PN 105 Infection ATI Notes Infection ATI Notes Types of Organisms • Bacteria shapes o Round: cocci o Rod: bacilli • Cell wall surrounding bacteria o Gram-positive: thin ▪ Staphylococcus, streptococcus, diphtheria, listeria o Gram-negative: thick ▪ Neisseria meningitides, neisseria gonorrhea, Escherichia coli, salmonella Types of Organisms: Mycobacterium • Waxy cell wall (hard to kill) • Most common mycobacterium • Tuberculosis Types of Organisms: Viruses • Invade cells of host (intracellular parasites) • Reproduce inside cell • Efforts to kill viruses tend to kill host cells • New drugs target virus-specific process • Antibiotics ineffective • Types of Organisms: Fungi • Plant-like organisms • Live in damp, dark places • "Eat" dead tissue • May infect through opportunistic opening in skin • Common skin infections are: o Tinea pedis (athletes foot) o Tinea corporis (ringworm) • Antibiotics ineffective • Types of Organisms: Parasites • Live in blood cells, organs, structures (intestines, vagina) • Malaria: travels to liver o Proliferates, infects red blood cells • Helminths: worms in intestines • Trichomonas: reproductive tracts Types of Organisms: Aerobic and Anaerobic Aerobic • Require oxygen to survive • Mouth, gastrointestinal tract, and lungs • Staphylococcus aureus (skin infections) and Pseudomonas aeruginosa (lung disease) Anaerobic • Do not require oxygen to survive • Produces abscesses and tissue necrosis Clostridium perfringens (gangrene) and Actinomyces (abdominal/pelvic infections) Types of Antibiotics • Bactericidal o Kills bacteria directly o Weaken cell wall (lysis) o Bind to ribosomes, decrease protein synthesis o Interfere with enzymes o Eventually destroys all bacteri • Bacteriostatic o Kills bacteria indirectly o Bind to ribosomes, decrease protein synthesis o Decrease number of bacteria o Body’s immune system kills remaining bacteria • Antibiotics fall under two categories: Broad and narrow spectrum o Broad spectrum ▪ Effective against a broad range of bacteria ▪ Exerts action on a structure that has similar characteristics between several different types of bacteria o Narrow spectrum o Effective against a narrow range of bacteria o Exerts action on a characteristic that is specific to only one or a few types of bacteria. Sensitivity and Resistance Sensitivity • Determine type of bacteria. • Obtain sample; view under microscope. • Sample can be blood, urine, exudate from wound • If it can’t be identified, they will Grow a sample over 24 to 48 hr. • Expose to various antibiotics. Resistance • Grow in culture. • Expose to various antibiotics. • Broad-spectrum antibiotics create more resistant strains of bacteria. Goal of drug Therapy for Infections • Kill bacteria through: • Interrupt cell-wall synthesis • Inhibit protein synthesis • Inhibit DNA replication/cell division • Inhibit folic-acid synthesis • Kill virus, parasites, fungi Four types of antibacterials: Antibacterials: Drugs that Interfere with Cell Wall Synthesis • Penicillins • Cephalosporins • Beta lactams • Other Penicillin • Treats broad-spectrum infections (ear and throat, urinary tract) • Amoxicillin: treats gonorrhea • Addition of clavulanic acid increases spectrum of disorders (allows amoxicillin to kill bacteria)’ • Treats gram positive cocci and bacilli Antibacterials: Drugs that Interfere with Cell Wall Synthesis • Penicillins • Cephalosporins • Beta lactams • Other Penicillin • Treats broad-spectrum infections (ear and throat, urinary tract) • Amoxicillin: treats gonorrhea • Addition of clavulanic acid increases spectrum of disorders (allows amoxicillin to kill bacteria) Penicillin • Prototype drug: o Amoxicillin (Amoxil) o Amoxicillin and clavulanic acid (Augmentin) • Other drugs: o Nafcillin (Unipen) o Methicillin o Ticarcillin-clavulanate (Timentin) o Piperacillin (Zosyn) Penicillin • Weakens and destroys cell wall o Inhibits enzyme necessary for cell-wall formation (transpeptidase) o Activates enzyme that opens cell wall during replication (autolysin) o No effect on human cells, no cell wall • Bactericidal o Many aerobic gram positive o Some aerobic gram negative • Penicillin G is active constituent Penicillin- side effects • Gastrointestinal symptoms: diarrhea, nausea, vomiting • Rare, but may cause pseudomembranous colitis due to suprainfection (more frequent with other penicillins than amoxicillin) • Suprainfection with Candida albicans • Allergy to penicillin (rash, hives) • Anaphylactic reaction (swelling of the airway, wheezing, difficulty breathing) Interventions: • Monitor for gastrointestinal symptoms. • Report bloody stools or long period of watery diarrhea. • Monitor for and report Candida infections of mouth or vagina. • Expect to treat Candida infections with an antifungal agent. • Monitor for allergy manifestations and notify provider. SAFETY ALERT Safety Alert – • Patients allergic to penicillin are at risk for anaphylactic shock if they take a penicillin-type drug. • Before an initial dose, ask patients if they have ever had an allergic reaction to penicillin. • Even if they had a reaction as a child, providers should not prescribe penicillin unless they receive a sensitivity test first. • If patients don't remember having a reaction as a child, do a subdermal allergy test. • This test places a very small amount of penicillin under the skin. • If no reaction occurs, you can give a dose of it. But, observe patients closely for signs of a reaction. If one occurs, give epinephrine and diphenhydramine.