Al Heuer, PhD, MBA, RRT, RPFTProfessor

Rutgers- School of Health Related Professions

• Describe the etiology and pathophysiology of pulmonary infectious diseases– Children– Adults

• Review the manifestations of such diseases. • Discuss the treatment of such diseases• Provide resources & how to find additional

information

Brief History & Evolution of Infectious Disease

• Over 100 years ago, there were little to no knowledge of infectious disease.

• The prevailing belief was that disease was caused by “bad air” or “night air”; known as the miasma theory .

• In 1676, Antonie van Leeuwenhoek discovered bacteria, but he did not know it caused disease

• However, in 1928, Alexander Fleming discovered penicillin.

• Virus-RNA/DNA, Protein Coat and a Lipid Envelope

• Bacteria-Cells which can independently multiply• Other microbes: Protozoa• Pathogenic-Ability to cause disease• Virulence-Ability to cause severe disease• Transmission-Route of spreading• Sterilization Vs. Disinfection

Diseases We’ll Focus on Today• Pediatric Respiratory Disease

– Croup– Epiglottitis– Bronchiolititis- respiratory syncytial virus

• Adult Diseases:– TB– Pneumonia Viral & Bacterial– PCP– SARS – Others: Pulmonic Plague

Croup--Etiology

• Viral Infection: – Parainfluenza– Influenza– RSV– Adenovirus

• Gradual onset

• Affects children 6 months to 3 years-old

Croup--Pathophysiology

• Swelling and inflammation of subglottic structures.– Larynx– Trachea– Larger Bronchi

• Can affect mid-sized and smaller airways

Croup--Clinical Manifestations

• Slow onset, like a “cold”• Brassy/barking cough• Horseness & Audible stridor• Neck X-Ray: Steeple Sign• If Severe:

– Tachycardia/tachypnea– Retractions– Decrease in SPO2– ABG: Hypoxemia & Respiratory Acidosis

Steeple Sign-Often Found in Croup

Croup--Treatment• Cool Mist w/oxygen via tent or face mask

• Reassurance--Parental presence

• Racemic Epinephrine via SVN or IPPB

– 6 Y.O. or less: 0.25 mls of 2.25% w/NSS

– More than 6 Y.O. 0.5mls w/NSS

• Systemic Steroids: Dextramethasone

– 0.3 to 0.6 mg/KG

• Intubation: Mainly if respiratory failure present: e.g., muscle fatigue, change in sensorium, cyanosis, ABG results.

Epiglottitis--Etiology

• Bacterial infection

• Most common microorganisms:– Staphylococcus Aureus– Group A & B Streptococci– Strep Pneumoniae

• Other causes:– thermal injury– caustic ingestion– radiation exposure

Epiglottitis--Pathophysiology

• Supra-glottic swelling

• Epigottis turns bright, cherry red & swollen

• Inflamation leads to a/w narrowing and dysphagia

• If severe, a/w can become completely obstructed

Epiglottitis--Clinical Manifestations

• Patient appears acutely ill• Rapid Onset• Affects mainly children 1 - 5 years old• Drooling, sore throat, dysphagia• Stridor & hoarseness w/diminished breath

sounds in lung regions• High fever• Lateral neck x-ray: Balloon-shaped

epiglottis/”thumb sign”

Lateral Neck X-Ray—Thumb Sign

Epiglottitis-Treatment

• Minimal patient stimulation-keep patient calm!• Cool mist aerosol w/supp’l O2• Antibiotics and fluids (steroids generally not effective)

• If severe obstruction, intubation shouldn’t be attempted in ER

• Intubate patient in OR as trach may be necessary and patient may need to be paralyzed

Epiglottitis Vs. Croup

• Epiglottitis– Bacterial– Rapid On-set– Profound illness– Hospitalization common

required.– Pt. may be drooling and

leaning forward with compromised speech

– May need emergent care and airway management.

• Croup– Viral– More gradual onset– Mild to moderate illness– Occasionally requires

hospitalization– Mainly supportive care

17

Bronchiolititis

Etiology—Caused by respiratory syncytial virus (RSV)Pathophysiology: Inflamed upper and lower airways, excessive

mucus.Clinical manifestations

– Usually follows a URI– Slight fever and cough worsen to dyspnea, tachypnea – Inspiratory and expiratory wheezing may develop– Radiograph shows hyperinflation and consolidation

Prophylaxis: Immunization recommended BPD infantsTreatment:

– Supportive: Hydration, nutrition, rest, monitoring– Humidified supplemental oxygen, HF nasal cannula– Bronchodilators and mucous clearance (CPT, mucolytics)– If severe: Intubation and mechanical ventilation with prolonged

expiration time.

Adult Infectious Pulmonary Diseases

TB

Pneumonia

Viral

Bacterial

PCP

SARS

Others:

Pulmonic Plague

Tuberculosis--Etiology

• Microorganism- Mycobacterium “family”

• Airborne transmission of droplet nuclei

• Droplet nuclei settle into the lungs and can start the infection

• Risk of infection is determined by many factors:– Length of exposure– Immune status

Tuberculosis-Pathophysiology

• Acid-fast bacilli are inhaled and begin to multiply• Bacilli may migrate to kidneys, brain and bones• 6-8 weeks after infection-immune system often

localizes and contains infection.

• TB Infection Vs TB Disease – TB Infection: Bacilli become inactive but

remain– TB Disease: Active bacilli are not stopped by

immune system and continue to multiply.

TB-Clinical Manifestations• Positive Mantoux Test (PPD)-5mm,10mm,15mm

• CXR-Lesion in apical or posterior upper lobe. Affinity for higher oxygen environment

• Positive sputum culture. • Laboratory data: Increased bands, elevated

alkaline phosphate• Signs/Symptoms--Productive Cough, chest

pain, hemoptisis, weakness, weight loss, fever/chills, night sweats.

TB Lesion in Right Apex

TB-Treatment

• Antibiotics: Cure most cases– 6-month: Isoniazid, Rifampin and initially,

pyrazinamide– 9-month: Isoniazid and Rifampin – Other ABX combinations for multiple drug

resistant (MDR) strains.

• Supportive– Proper rest and nutrition– Avoid high risk activities

HIV/TB--Treatment

• First Two-Months– Isoniazid-INH– Rifampin– Pyrazinomide– Ethambutal

• Next Five-Six Months– INH– Rifampin

Pneumonia--Etiology

• Community Acquired vs nosocomial

• Pathogens– Bacterial– Viral– Other--fungal, rickettesia

Pneumonia--Pathophysiology

• Route - Often Inhalation of microbes or aspiration of stomach contents or other substances

• Microbes– Bacteria– Viral– Other-Fungus-coccidiodes = “valley fever”

Pneumonia-Clinical Findings

• Acutely ill patient

• Hypoxemia & possible cyanosis

• CXR-Consolidation

• Unilateral Chest expansion

• Dull percussion note

• Decreased breath sounds &/or rhonchi

• Cough-Productive or non-productive

• Sputum- Green, yellow, brown, red

Types of Bacterial Pneumonia

• Gram positive - aerobic

• Gram negative - aerobic

• Anaerobic

• Mycobateria

Gram stain will showBacilli (rods) or Cocci (round)

Positive (blue) or Negative (red)

Gram Stain - E. coli

Lower LobeLower Lobepneumoniapneumonia

Pneumonia--Treatment

• Supportive– Oxygen therapy– Rest– Proper hydration & nutrition

• Isolate the microbe - Sputum C&S

• Antibiotics/antimicrobials

• CPT

• Bronchodilators

HIV/PCP--Etiology • HIV- Viral infection via bodily fluid exchange

• Helper T-Cells are invaded and destroyed– Helper T-Cells have the CD-4 antigen on the

surface.

• Immune system is compromised: Helper T-cell count of 800-1200/ml drops < 600/ml.

• Opportunistic Infections take hold– Pneumocystis Carinii PCP: Now renamed as

pneumocystis jirrevecii pneumonia and it is a protozoal-like microbe.

PCP--Pathophysiology

• PCP-An opportunistic Protozoal Infection

• Generally only affects immunosuppressed– HIV– Chemotherapy– Organ Transplantation/Immunosuppressant

Drugs

PCP--DX & Clinical Manifestations• High Index of Suspicion

– HX of:• IVDA or other “high risk” behavior• Immunosuppression due to other causes (Chemo, organ

transplantation)

• DX via Sputum staining– Silver staining– Obtained via BAL

• Review of Labs– Positive HIV antibodies (HIV positive)– Reduced CD 4 Count (w/AIDS)

PCP--DX & Clinical Manifestations (cont.)

• Fever/Chills• Malaise• Weight loss• Lymphadenopathy• Dyspnea/SOB• CXR

– Early-Ground Glass Appearance– Later-Diffuse infiltrates, lymph node enlargement

Initial Treatment• Oxygen for Hypoxemia• Bronchodilators for bronchoconstriction• Mucolytics, for mucous plugging• Supportive Therapy

– Nutrition, hydration, rest

• Monitoring– Vital signs– Pulse oximetry– I’s & O‘s

• Chart review for Relevant Orders and Advanced Directive and/or DNR

PCP--Treatment

• Prophylaxis– 1st choice--Daily administration of SMX-TMP

(Triamethoprim-Sulfomethoxazole)– 2nd choice--Pantamidine (if can’t tolerate

sulfa)

• Active Disease– 1st Choice--TMP-SMX– 2nd choice--Pantamidine– 90% recovery rate

Severe Acute Respiratory Syndrome (SARS)

• Occurrence: 2003 Outbreak, 8,000 cases Worldwide, Several Hundred in N. America.– 23 % of victims were healthcare workers.

• Etiology/Pathophysiology: Airborne transmission via respiratory droplets of Coronavirus (SARS-CoV).

• Clinical Manifestations: High Fever, body aches, dry cough progressing to pneumonia.

• Diagnosis: Sputum, nasal secretions analysis.• Treatment: Antiviral Meds and supportive therapy. •

Hantavirus• Natural Occurrence: 3-4,000 cases/Yr. in US.

• Etiology/Pathophysiology: Virus found in the urine and feces of rodents, mainly mice. Does not make the mouse sick. Humans get sick if they inhale dust containing mouse excrement. 2 – 5 day incubation period.

• Clinical Manifestations: Flu-like symptoms, rapid progression to Respiratory Failure. Approx. 50% mortality.

• Diagnosis: Blood tests for antigen or virus.

• Treatment: Ribavirin, Supportive care.

Pulmonic Plague (Yersinia Pestis)

• Natural Occurrence: 5 - 15 cases/Yr. in US.

• Etiology/Pathophysiology: Bacteria commonly spread by aerosol droplets. 1 – 6 day incubation period.

• Clinical Manifestations: High fever, chills, hemoptysis, shock, stridor, B/S crackles, ARF. High mortality (> 75%) with late diagnosis.

• Diagnosis: Gram stain, C&S, Immunoassay for capsulated antigen

• Treatment: Streptomycin 30 mg/kg/day IM. Oral Doxycycline or Ciprofloxin. No vaccine.

Smallpox (Variola Major)• Natural Occurrence: Last case in Somalia, 1977.

• Etiology: Viral infection with an incubation period of 7 – 17 days– Most contagious in “early rash” phase.

• Clinical Manifestations: Fever, back pain, vomiting, malaise, headache, rigors; papules to pustular vessicles face/ extremities.

• Diagnosis: Modified silver stain, PCR and viral isolation IHC

• Treatment: Immediate vaccination (if exposure < 5 days) and supportive care.

Inhaled Anthrax (Bacillus Anthraxis)• Etiology:

– Natural Occurrence: Few via Inhalation.– Mostly transmitted via livestock. No Known Human-to-

Human Transmission

• Clinical Manifestations: Fever, malaise, cough, mild chest discomfort; later dyspnea, diaphoresis, stridor, cyanosis, hypotension, hemorrhagic meningitis. 50% Mortality, with treatment.

• Diagnosis: Mediastinal widening w/o infiltrates on CXR, Serology, Gram stain, PCR

• Treatment: Supportive care, Doxycycline 200 mg IV

then 100 mg IV Q12 hr. Vaccine - high risk groups.

What RTs and other Healthcare Professionals Can and Should Do

• Protect Thy Self and Patient.– Proper use of Protective Equipment: Seal mask from bridge of

nose down…don’t pinch nose.– Get Vaccinated– Handwashing!!!

• Get Educated: Understand Prevention and Disease Identification.

• Educate homecare patients: Disease Recognition, Vaccination, Prevention, Infection Control and Contingency Planning.

• Be Aware: If It Seems Unusual, Maybe it Is!!!• Report suspicious cases per plan or protocol.• Consider joining the US Dept of Health & Human

Services Disaster Response Team (Visit: HHS website)

• Use proper Infection Control Techniques• Maintain and index of suspicion• If it does not look right, take special

precautions and communicate with other members of the health care team.

• Identify and utilize practical resources• Participate in all appropriate training • Exercise common sense and good judgment.• Don’t let your ego get in the way. • If you have questions…or need add’l info…

Ask!

• Guideline for Hand Hygiene in Health-care Settings. MMWR 2002; vol. 51.

• The Centers of Disease Control and Prevention -- http:www.cdc.gov

• Egan’s Fundamentals of Respiratory Care, ed 10 2012.• Clinical Assessment in Respiratory Care, ed. 5, 2010.• AARC: www.aarc.org/education/aarc • Pubmed• Medline