chapter012

Copyright © 2010 Wolters Kluwer Health | Lippincott Williams & Wilkins

Timby/Smith: Introductory Medical-Surgical Nursing, 10/e

Timby/Smith: Introductory Medical-Surgical Nursing, 10/e

Chapter 12: Infection


Infectious Agents and Disorders Infectious Agents and Disorders • Introduction

– Infectious disorders

• Cause: Infectious agents

• Microorganisms: Invasion; eliminate, reside, and cause infection

• Factors affecting infection development

• Characteristics of microorganisms

• Components of infectious process cycle

• Diseases: Emerging, reemerging

• Unchecked: Epidemics, pandemics


Infectious Agents and DisordersInfectious Agents and Disorders• Types of Infectious Agents

– Bacteria: Single-celled

• Shapes: Round, rod shaped, spiral

• Types: Aerobic, anaerobic

• Multidrug resistant bacteria: Unaffected by antibiotics and pharmacologic agents

• Greater risk of death


Infectious Agents and DisordersInfectious Agents and Disorders• Types of Infectious Agents

– Viruses

• Electron microscopes; filterable

• Two types: Nucleic acid of DNA or RNA

• Multiplication: Metabolic and reproductive materials; self-limiting; fatal infections; dormant

– Fungi

• Two groups: Yeasts, molds

• Fungal infections: Superficial, intermediate, deep


Infectious Agents and DisordersInfectious Agents and Disorders

• Types of Infectious Agents

– Rickettsias: Resemble bacteria; invade living cells; cannot survive outside host; disease transmitted by arthropods

– Protozoans: Single-celled animals; classified according to motility

– Mycoplasmas: Single-celled; lack cell wall (pleomorphic); infect specific surface linings

– Helminths: Infectious worms such as roundworms, tapeworms, flukes


Infectious Agents and DisordersInfectious Agents and Disorders

• Types of Infectious Agents

– Prions: Proteins; atypical infectious agents; do not contain nucleic acid

• Normal prions protect against dementia

• Can mutate into infectious agents

• Acquisition: Genetic predisposition and transmission; transmissible spongiform encephalopathies (TSEs)

• Research: Prion contribution to Alzheimer’s, Parkinson’s, and Huntington’s diseases?


Infectious Agents and DisordersInfectious Agents and Disorders• Characteristics of Infectious Agents

– Nonpathogens: Usually harmless or beneficial

– Pathogens: High potential to cause infectious diseases

– Factors affect microbes’ ability to become pathogenic

– Infection protection: Immunization, natural body defenses

– Increased risk: Compromised defenses

– Superinfections: Nonpathogenic or remotely pathogenic microorganisms overwhelm host


QuestionQuestionIs the following statement true or false?

Only pathogenic microbes cause disease or infection.


AnswerAnswerFalse

Although nonpathogens usually are harmless or beneficial, when they are introduced into an atypical body area (e.g., into a wound bed from skin), they can also cause disease or infection.


Infection TransmissionInfection Transmission• Infectious process cycle components

• Chain of infection

– Infectious agent

– Appropriate reservoir

– Portal of exit

– Means of transmission

– Portal of entry

– Susceptible host


Infection TransmissionInfection Transmission

Remove one link, infection is prevented


QuestionQuestion

Is the following statement true or false?

All links in the infectious process cycle must be present for infection to occur.


AnswerAnswer

True.

Preventing or interrupting one link in the cycle can prevent infection.


Defenses Against InfectionDefenses Against Infection• Types of Defense Mechanisms

– Mechanical: Physical barriers

– Chemical: Natural biologic substances

• Mechanical Defenses

– Skin and mucous membranes: Normal flora on skin retard pathogenic growth

• Skin: Acidic; does not promote pathogenic multiplication

• Mucus: Traps microorganisms and debris


Microorganisms and Infectious DisordersMicroorganisms and Infectious Disorders• Mechanical defenses (cont’d)

– Physiologic reflexes: Forceful expulsion through sneezing, coughing, and vomiting

– Macrophages: Specialized cells; mononuclear phagocyte system

• Location: Body tissues, liver, spleen, lymphoid tissue

• Function: Ingestion of dead cells; foreign material


Microorganisms and Infectious DisordersMicroorganisms and Infectious Disorders• Chemical Defenses

– Enzymes: Lysozyme: bactericidal

– Antibodies: Complex proteins

• Functions: Work with other WBCs to render microbes more easily phagocytized

– Secretions: Interferon produced by WBCs and other cells; chemical protein

• Triggers infected cells; inhibits cell reproduction


Pathophysiology of InfectionPathophysiology of Infection

Figure 12-3The inflammatory process

• Localized infection

– Activation of inflammatory process; three responses; cellular; colloids; ions

– Vascular: Redness, heat

– Chemical response: Pain


Pathophysiology of InfectionPathophysiology of Infection

• Localized infection (cont’d)

– WBCs: Destroy toxins and remove debris

– Fibrin barrier: Abscess formation

– Lymphadenitis

– Bacteremia or septicemia: May lead to sepsis (systemic)


Pathophysiology of InfectionPathophysiology of Infection• Generalized infection

– Systemic

– Fever usual defense; immunocompromised

– Sepsis

• Characteristics: Temperature, heart rate, respiratory rate, WBC count

• Fever and chills; leukocytosis

• Inflammatory response: Homeostasis


Pathophysiology of InfectionPathophysiology of Infection• Generalized infection (cont’d)

– Severe sepsis

• Organ dysfunction, hypotension, hypoperfusion

• Manifestation: Lactic acidosis, oliguria, alteration in mental status

• Unchecked proinflammatory mechanisms

• Systemic microvascular clotting

• Possible cause: Deficiency of protein C

• Treatment: Antimicrobial drugs; Xigris

• Probable outcome: Septic shock, death


Types of InfectionsTypes of Infections

• Community-acquired infections: TB and meningitis

– Clusters of signs and symptoms reflect dysfunction of invaded organs or tissues

• Nosocomial infections: Acquired in healthcare agency

– Hospitalized clients: Greater susceptibility to infection; some lead to sepsis; complications


Types of InfectionsTypes of Infections

• Opportunistic infections

– Also known as superinfections

– Nonpathogens or pathogens

• Take advantage of favorable situation

• Overwhelm host

– Common among immunocompromised clients


Infection Control and PreventionInfection Control and Prevention• Precautions and Asepsis

– Standard precautions

– Application of principles of medical asepsis

• Conscientious handwashing

– Transmission-based precautions

– Prevent and control nosocomial and community-acquired infections

• Intentional, consistent nursing measures


QuestionQuestionIs the following statement true or false?

A nurse can lose her nursing license for not washing her hands before and after client care.


AnswerAnswerTrue.

A nurse can lose her license for not washing her hands before and after client care. It’s considered practicing nursing in an unsafe manner.


Infection Control and PreventionInfection Control and Prevention• Needlestick Inuries

– Threats: Infectious diseases, e.g., Hepatitis B, AIDS

– Standard precautions; Gloves, new needleless access devices

– Postexposure recommendations

• Report injury; document in writing; identify person or source

• Obtain HIV and HBV status of source

• Counseling about infection potential

• Postexposure prophylaxis; disease antibody testing; medical follow-up


Diagnostic TestsDiagnostic Tests• Thorough History, Physical Examination, and Lab

Examination

• White Blood Cell Count and Differential

– WBC: Elevation in number and type

– Differential: Percentage of WBC subtypes

– Elevated neutrophils and monocytes

• Culture and Sensitivity Test

– Culture: Bacteria identification

– Sources of specimen; incubation

– Microscopic examination


Diagnostic TestsDiagnostic Tests• Culture and Sensitivity Test (cont’d)

– Gram stain: Positive, negative

– Coagulase test: Positive, negative

– Sensitivity studies: Antibiotics inhibiting growth


Diagnostic TestsDiagnostic Tests• Examination for Ova and Parasites

– Stool examination; dispose of urine and toilet paper separately

– Client teaching: Scrupulous handwashing

• Skin Tests

– Determine active or inactive infection

– Diseases: Histoplasmosis, mumps, TB, diphtheria, coccidioidomycosis

– Intradermal injection; reaction period; induration size


Diagnostic TestsDiagnostic Tests• Immunologic Tests

– Determine presence of antigen, antibody reactions

– Agglutination tests: Cold agglutinins test

– Precipitation tests: C-reactive protein test, erythrocyte sedimentation rate

– Complement fixation tests

– Immunofluorescence tests

– Other tests: Radiography, CT, MRI


Medical Management of InfectionMedical Management of Infection

• Supportive therapy

• Drug therapy: Antimicrobials

• Wound debridement; irrigation

• Hydrotherapy; wet-to-dry dressings

• Immunosuppressed clients: Bone marrow transplantation; administration of drugs to boost WBC production


Nutrition ConsiderationsNutrition Considerations• Infection: Changes body metabolism

• Fever: Caloric needs; increased BMR

• Increased protein and fluid needs

• Avoid tea, coffee, and carbonated beverages

• Acutely ill clients: Full liquid diet

• Between-meal supplements

• Transmission-based precautions: Disposable dinnerware, disposal of uneaten food


Pharmacologic ConsiderationsPharmacologic Considerations

• Drugs: Administration, effects, regimen

• Antibiotics: Superinfection

– Life-threatening diarrhea

• Report fever, abdominal cramps, and severe diarrhea; antipyretics

• Suppository insertion, expulsion; penicillin injections; antibiotic regimen; observe adverse drug effects

• Distinguish symptoms: Infectious disease and antibiotics; history


Gerontologic ConsiderationsGerontologic Considerations• Greater risk of infection; symptoms of infectious

disease

• Nursing home residents: Infections

• Influenza: Death; immunization needed

• Family teaching: Respiratory infections; use a mask; transmission-based precautions; increased confusion

• Possible reactivation of TB if infected as child


End of Presentation

chapter012

Documents

infectious agents acquisition

infectious worms

infectious diseases

infection transmissionremove

cause infection factors

debris copyright

deep copyright

pandemics copyright