Community Acquired pneumonia (CAP) Flashcards
What is Community acquired pneumonia (CAP)
- Patient who is outside of hospital or within 48 hours of hospital admission
*immunocompetent patients
What is nosocomial pneumonia
- Hospital acquired (HAP)
- Ventilator associated (VAP)
How many people required hospitalization for CAP and what is the mortality rate?
- 25% require hospitalization
*one of the deadliest infectious disease in the US - Outpatient cases <1% (mortality)
*in patient 12%
*over 65 >40%
What population has the higher incidence of of CAP
Under 5 and over 65
*mortality is disproportionately higher in those over 65 years old
What are some risk factors for those who are immunocompetent but can have the increase need for hospital admit
- Age
- Alcohol or tobacco use
- Comorbidities
- Temporary degree of immunosuppresion (steroids)
What helps to reduce the chance of developing pneumonia
- Cough reflex
- Mucociliary clearance system
- Immune response
*CAP can develop when one or more defense fails OR there is a large invasion of extremely powerful pathogens
What is the most common causes of pneumonia
Micro-aspiration of oropharyngeal contents
*colonization of the oropharynx with the pathogenic organisms will weaken the defense mechanisms
What is the 2nd most common cause of pneumonia
- Inhalation of aerosolized droplets
*mycobacterium tuberculosis, legionella, yersinia pestis, bacillus anthrcis
What is a less common cause of pneumonia
- Systemic blood infections
*staphyloccoal septicemia / bacteremia or right sided endocarditis)
What leads to ventilation / perfusion ratio mismatch
Pathogen binds to respiratory epithelium
1. Immune response happens
2. Then cellular inflammation
3. Leaky capillaries
4. Causes fluid accumulates in alveoli
What is perfusion
The blood is going from the circulatory system to the tissues
What are some of the symptoms of CAP
- Fever
- Cough (productive or non productive)
- Chest discomfort
- Sweats, chills rigors
- Hemoptysis
- Fatigue, myalgias
- Head ache
PE findings
- Appear acutely ill
- Fever or hypothermia
- Tachypnea
- Tachycardia
- Arterial oxygen desaturation (less than 95%)
- Confusion or mental status
- Purulent sputum
- Inspiratory crackles
What PE findings strongly increases the chance that the diagnosis is pneumonia
- Asymmetric chest expansion
- Bronchial breath sounds
*rales - Dullness to percussion (consolidation, pleural effusion)
*egophony, bronchophony
What are the DDx of CAP
- Pneumonia
- AB
- Cardiopulmonary morbidly exacerbation
- Pneumonitis
- Atelectasis
- Pulmonary embolism
What is needed for the diagnosis of CAP
- History
- Physical examination
- Imaging
*can’t confirm CAP until there is imaging done (definitive tool)
What imaging studies will help with the diagnosis of CAP
- Chest radiograph (outpatient)
- Chest CT scan (inpatient)
*infiltrate
*may be consolidation or opacity
*can also see air bronchograms, effusion, cavitation
What is condiolidation, opacity or bronchograms
Consolidation
*compress-able area of the lung that now has fluid
Opacity
*decreases in the ratio of gas to soft tissues in the lungs (turns white)
Air bronchograms
*areas of the lung parachymea that consolidates so mulch that the bronchi are noticeable
Can imaging identify the infectious agent
No
*Chest CT is not indicated for ambulatory outpatient and initiation of treatment with suspected CAP
What is required to establish a confirmed diagnosis of CAP
Visualized pulmonary opacity
*resolution of opacities can take 6 weeks or longer
What is point of care lung ultrasound
Ranks superior in studies to chest radiography in diagnosing
1. At bedside results are available in real time serial examination can be completed
What are some of the issues with point of care lung ultrasound
- Do not have a way to save POC imaged
- Limited experience of the clinicians using POC
- Availability and cost
What other diagnostic studies can be used for CAP
Sputum testing (not usually indicated for CAP)
1. Gross appearance of sputum can give clues
2. Rusty / bloody tinged = s. Pneumonia
3. Green = h. Influenza, or pseudomonas
4. Currant jelly = klebsiella
5. Foul smelling = anaerobic in nature
Why is septum testing not generally used for CAP
- Patient cannot produce appropriate amount for sample
- Lack sensitive or specificity for the most common cause of pneumonia