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
When is sputum testing generally used
- Hospitalized CAP
- Travel or exposure history
- Known public health concerns
*TB
*influenza
What is the urine antigen assay (pneumonia diagnostic study)
Inpatients
1. Available for S. Pneumonia and Legionella species
2. Results available immediately
3. Not affected by early ATB treatment
What is the rapid antigen detection for influenza and SARS-Cov and procalcitionin level?
Rapid antigen
1. Quick detection need for isolation and consideration of any need interventions
Procalcitonin level
1. Potential additional lab to aid in length of treatment
What is the treatment and management of CAP
- Prompt initiation of empiric therapy
*administer a drug to which the pathogen is susceptible - Early administration of ATB to acutely ill patients with improved outcomes
- Obtaining specimens or test results should not delay initiation of treatment
What is the CAP treatment (outpatient)
For previously healthy patients with no risk factors for MRSA or pseudomonas
1. Mono therapy is ok (macrolide = clarihtromycin or Azithromycin) BID 500mg X 5 days
2. Amoxicillin 1g PO TID
3. Doxycycline 100mg PO BID
What is the CAP treatment if the patient has co-morbidities or ATB use in the last 90 days
- Macrolide or doxycycline + oral beta lactam
- Fluoroquinolone only (levofloxacin)
*BBW of tendon rupture
How long should you treat CAP
Consider
1. Severity of disease
2. Pathogen
3. Response to therapy
5. Comorbdites
Minimum of 5 days
1. Need to be afebrile for at least 48 to 72 hours y the conclusion of ATB tx
2. No benefit proven in continuing beyond 3 days after the last day of fever
When should corticosteroid therapy be used for CAP
- Septic shocks
- Acute exacerbation of asthma
- COPD
- Adrenal insufficiency
What is the prognosis for CAP
- Follow up should be scheduled with the patient to assess for signs of improvement
*S. Pneumoniae is the most common cause of death
*atypical pathogens (mycoplasma) have a good prognosis
When is mortality higher in patients with CAP
- In patients who do not respond to initial empiric
ATB and in those whose treatment regimen dose not conform with guidelines
What is the prevention for CAP
- Polyvalent pneumococcal vaccines
- Annual seasonal influenza vaccine
When should you admit someone with CAP
- CURB 65 score
*five independent predictors to assess 30 day risk of mortality
*confusion, uremia, respiratory rate, BP, 65 years old - Pneumonia severity index (PSI)
*20 items used to determine need to admit
What is nosocomial pneumonia
- Hospitalized patients have different flora with different reassurance patterns
- Increased risk for more serious infections
What is hospital acquired pneumonia, ventilator acquired pneumonia
HAP
1. >48 hours after admission to the hospital or other health care facility and excludes any infection present at the time of admission
VAP
1. Develops in mechanically ventilated patient >48 hours after endotracheal intubation
