Pulmonary Infections_Dr. Shiv Flashcards
List some common pulmonary infections we went over in this section.
Pneumonia Lung Abscess TB Fungal infections : Aspergillosis Parasitic infection : hydatid cyst URTIs
What is the general definition of pneumonia?
Pneumonia is an infection of the pulmonary parenchyma
What is CAP (community-acquired pneumonia)?
Pneumonia that is acquired in the communityoutside of health care facilities. Compared with health care–associated pneumonia, it is less likely to involve multidrug-resistantbacteria. Although the latter are no longer rare in CAP they are still less likely.
What is (HCAP/MCAP) Health/Medical Care-Associated Pneumonia?
an infection associated with recent exposure (within 3 months) to thehealth caresystemincluding hospital, outpatient clinic,nursing home,dialysiscenter, chemotherapytreatment, orhome care. HCAP is sometimes called MCAP (Medical Care–associated pneumonia).
What is Hospital-acquired pneumonia (HAP)?
is acquired in ahospitalthat occurs 48 hours or more after admission, and likely to involvehospital-acquired infections, with higher risk ofmultidrug-resistantpathogens.
Ventilator-associated pneumonia (VAP)
occurs in patients onmechanical ventilationthat arises more than 48 to 72 hours after endotracheal intubation.
A 32 years old male was brought to Emergency Room for Traumatic Brain Injury (TBI) due to high-velocity road traffic accident 30 mins back. He was unconscious at that time with GCS (Glasgow Coma Scale) of 5, HR of 92/min, BP of 98/54 mmHg, RR of 20/min and SpO2 of 84% which was still falling so e was intubated with cuffed endotracheal tube and put on Ventilator for invasive ventilation. There was past medical history of Hypertension with dyslipidemia and patient is on statins with ACE inhibitor. There was no other previous significant surgical history. After 30 hours of intubation and invasive ventilation, patient showed consolidation in middle lobe of right lung and diagnosed for Pneumonia. On the basis of this clinical vignette, which of the following type best describes patient’s condition?
A. CAP B. HAP C. VAP D. MCAP E. Sorry, Not sure.
A. CAP (community-acquired pneumonia)
Be able to compare and contrast these different types of pneumonia.
Reproduce chart if possible.
What is your diagnosis and why?
Lobar pneumonia
Involves single lobe
Unilateral
Air bronchogram
What is your diagnosis and why?
Interstitial pneumonia
Involves interstitial space
Ground glass appearance
Bilateral, symmetrical
What is your diagnosis and why?
Bronchopneumonia
Central bronchi involved
Patchy bilateral disease
asymmetrical
What are ways that microorganisms gain access to the lower respiratory tract?
Aspiration (Impaired consciousness, impaired gag reflex, increased GI reflux)
Inhaled contaminated droplets
Hematogenous spread (rare)
Contiguous extension (rare)
How does the defense mechanism of the body become impaired when one has pneumonia?
Chemical mediators from immune cells lead to fever, capillary leak, increased WBCs, infiltrates, hemoptysis, cough, rales, hypoxia, increased RR/Drive, Respiratory alkalosis.
What are the 2 classifications of etiological agent that can be found in community-acquired pneumonia?
Typical or Atypical
What is the most common cause of CAP? (pathogen)
Strep pneumonia
What are some newly identified pathogens that are causes of CAP?
hantaviruses, metapneumo-viruses and the coronavirus.
List the common microbial causes of CAP by site of care. List in descending order of frequency. Just be familiar with about 4 of these that are common pathogens for pneumonia.
Reproduce chart.
Do all forms of pneumonia present with fever and cough?
yes
Chills or rigors when one has bacterial pathogens that cause pneumonia in their body is a sign of what?
toxemia
Describe the characteristic of cough in pneumonia?
Cough may be either non-productive or productive of mucoid, purulent, or blood-tinged sputum.
Cough, from any etiology, may be associated with hemoptysis.
T/F. Severe infection in pneumonia patients is not associated with dyspnea.
False.
Is associated with dyspnea
Chest pain result from what when a patient has pneumonia?
inflammation of the pleura
What are some GI symptoms that may occur when one has pneumonia?
nausea, vomiting, and/or diarrhea
What are the main diagnostic hallmarks of pneumonia?
dyspnea, high fever, and an abnormal chest x-ray is main hallmark
Know how different organism present.
Reproduce chart.
Upon Physical Exam, what may one with pneumonia present with?
Finding vary by degree of pulmonary consolidation and presence or absence of significant pleural effusion
abnormalities of vital signs
altered mental status
Tactile fremits increases upon palpation
Percussion dull
Auscultation Rhonchi, crackles, bronchial breath sounds, pleural friction rubs
Septic shock and evidence organ failure.
Are specific sputum color diagnostic of etiology behind the pneumonia?
no
Infections often with “dry” or nonproductive cough preferentially involve what areas of the lung?
interstitial space and more often leave the air spaces of the alveoli empty. That is why there is less sputum production.
Pathogens that produce dry cough.
-Mycoplasma • Viruses • Coxiella • Pneumocystis • Chlamydia
What is characteristic of X-rays in individuals who have atypical pneumonia?
X-rays lag behind clinical findings
What type of imaging is this? (Tool) What are these X-rays indicating?
Chest Skiagram
Consolidation from left to right:
Rt lower lobe consolidation, Rt middle lobe consolidation, Rt upper lobe consolidation
Is it possible to make a specific diagnosis of the cause of pneumonia from history and examination?
no; impossible
Describe what are some characteristic features of pneumonia upon lab investigations.
Leukocytosis (elevated white blood cell count) is often present, but is a nonspecific marker of infection.
Blood Cultures are positive in 5% to 15% of cases of CAP, particularly with S. pneumoniae.
What are the best ways to first try to determine a specific microbial etiology in cases of pneumonia. Unfortunately, many organisms will not be detected by this method.
Sputum gram stain and sputum culture
The term atypical pneumonia has what characteristic Gram Stain pattern? (explain)
not visible on Gram stain and not culturable on standard blood agar. The use of sputum stain and culture is somewhat controversial because of their low sensitivity.
Even after thorough sputum examination, no etiology is found in at least 50% of cases.
What is the treatment for CAP (outpatients)? (If previously healthy and no antibiotics in past 3 months, Comorbidities or antibiotics in past 3 months)
If previously healthy and no antibiotics:
A macrolide (Clarithromycin or Azithromycin)
Doxycycline
Comorbidities or Antibiotics in past 3 months
A respiratory fluoroquinolone (moxifloxacin, gemifloxacin, levofloxacin)
A B-lactam (amoxicillin) plus a macrolide
What is risk stratification?
Tool used for determination of site of care.
These rules have been used to identify patients who can be safely treated as outpatients and those who require hospitalization because of high risk of complications.
How does the CURB-65 point system work for determining treatment of pneumonia?
In CURB-65, 1 point is allotted for each of the following risk factors:
Confusion
Uremia (BUN ≥19 mg/dL or >7mmol/L)
Respiratory rate > 30 breaths/min
SystolicBP< 90 mm Hg or diastolic BP ≤ 60 mm Hg
Age ≥65yr
Scores can be used as follows:
0 or 1 points: Risk of death is < 3%. Outpatient therapy is usually appropriate.
2 points: Risk of death is 9%. Hospitalization should be considered.
≥ 3 points: Hospitalization is indicated, and, particularly with 4 or 5 points, ICU admission considered.
In the treatment of pneumonia are hypoxia and hypotension as single factors a reason to hospitalize a patient?
yes
For patients with pneumonia, can an X-ray tell the severity of hypoxia?
no
What are some Inpatient treatment plans for CAP? (non-icu)
non-ICU
A respiratory fluoroquinolone [Moxifloxacin
A β-lactam [Cefotaxime (1–2 g IV q8h), Ceftriaxone plus a macrolide
Treatment for CAP Inpatients, ICU
B-lactam plus azithromycin or fluoroquinolone
How to you treat CAP if pseudomonas is consideration?
B lactam plus fluoroquinolone
or
B lactam plus aminoglycoside
or
B-lactam plus amino glycoside plus and anti-pneumococcal fluorquinolone
In CAP if CA-MRSA is a consideration what is the treatment plan?
Linezolid or Vancomycin
What are some supportive measure for treating CAP?
Adequate Hydration,
Antipyretics,
Analgesics,
O2 therapy (for patients with hypoxemia),
Assisted Ventilation,
Prophylaxis against thromboembolic disease
Early mobilization improve outcomes for patients hospitalized with pneumonia.
Cessation counseling should also be done for smokers.
What are some complications of CAP?
Failure to Improve Respiratory failure, Shock Multi-organ failure, empyema Exacerbation of comorbid illnesses Metastatic infection (e.g., brain abscess or endocarditis), Lung abscess, Complicated pleural effusion
Thoracentesis
Analysis of a pleural effusion can sometimes be useful to determine the presence of an empyema if the diagnosis is unclear. Any new large effusion should be analyzed. Empyema is an infected pleural effusion. Empyema acts like an abscess and will improve more rapidly if it is drained with a chest tube.
This tool can be used to remove the fluid from the lungs.
What are these images indicative of from left to right?
Pleural Effusion
Mild
moderate
severe
What forms of CAP are preventable with vaccination?
influenza and pneumococcal
What is the follow up plan for an individual with CAP?
Fever and leukocytosis usually resolve within 2–4 days but physical findings may persist longer.
Chest radiographic abnormalities are slowest to resolve (4–12 weeks).
Patients may be discharged once their clinical conditions are stable.
A follow-up radiograph can be done ~4–6 weeks later.
Persistence of an infiltrate raises suspicions of TB or an underlying, possibly malignant endobronchial lesion.
Patients with HAP have a higher incidence of what pathogens infiltrating their body?
Gram-negative bacilli such as E. coli or Pseudomonas
What is the main difference in management of HAP from CAPs?
macrolides (azithromycin or clarithromycin) are NOT acceptable as empiric therapy
What is treatment of HAP centered around?
therapy for Gram-negative bacilli
What treatment is used for HAP? (drugs used)
Antipseudomonal cephalosporin’s
or
antipseudomonal penicillin or Carbapenems (imipenem, doripenem)
Piperacillin and ticarcillin are always used in combination with what drugs in the treatment of HAP?
In combo with a B-lactam inhibitor such as tazobactam or clavulanic acid
What are the Treatment plans of HAP for patients without risk factors for MDR pathogens?
Ceftriaxone or Ertapenem or Ampicillin/sulbactam or moxifloxacin or all the floxacins
What is the antibiotic treatment plan for patients of HAP with risk factors of MDR pathogens?
B-lactam plus a second agent active against gram negative bacteria plus gram-positive bacteria
What is a Lung Abscess
is a necrotizing lung infection characterized by a pus-filled cavitary lesion.
Primary lung abscesses
usually arise from aspiration, are often caused principally by anaerobic bacteria, and occur in the absence of an underlying pulmonary or systemic condition.
Secondary lung abscesses
arise in the setting of an underlying condition, such as a post-obstructive process (e.g. a bronchial foreign body or tumor) or a systemic process (e.g. HIV infection or another immunocompromising condition).
What are some causes of aspiration?
During deep sleep (especially in elderly)
Decreased consciousness
Loss of gag reflex
Increased gastro-intestinal reflux
prolonged or un-cuffed endotracheal intubation
T/F. Signs of lung abscess: are nonspecific and resemble those of pneumonia: decreased breath sounds indicating consolidation or effusion, temperature≥38°C, crackles over the affected area and dullness to percussion in the presence of effusion.
True
How do you decipher if one has a lung abscess from an individual with pneumonia? Clinical Presentation
Look for a person with one of these risk factors:
-(decreased breath sounds, high temp, crackles, dullness to percussion)
presents a chronic infection developing over several weeks
-large-volume sputum that is foul smelling because of anaerobes.
Weight loss is common.
What are some hallmark features of lung abscess?
round cavity with air fluid levels
What is your diagnosis and why?
Lung abscess- Hallmark feature- round cavity with air-fluid levels
Pneumocystis
Pneumocystis is an opportunistic fungal pulmonary pathogen that is an important cause of pneumonia in the immunocompromised host.
What are the organisms that cause pneumocystis pneumonia?
P. jirovecii
P. carinii (infects rats)
PCP occurs almost exclusively in what types of patients?
exclusively in patients with AIDS whose CD4 cell count has dropped below 200/μl and who are not on prophylactic therapy
What is the hint to look for to determine if an individual has been infected with pneumocystis pneumonia?
patient with AIDS presenting with dyspnea on exertion, dry cough, and fever. The question will often suggest or directly state that the CD4 count is low (below 200/μl) and that the patient is not on prophylaxis.
What is the best initial test for determining Pneumocystis Pneumonia?
a chest x-ray showing bilateral interstitial infiltrates
or
check arterial blood gas looking for hypoxia or an increased A-a gradient
What levels are always elevated in patients with pneumocystis pneumonia?
LDH levels are always elevated.
What is the most accurate test for testing pneumocystis pneumonia? What is a test for a confirmatory diagnosis?
The most accurate test is a Broncho alveolar lavage.
Sputum stain for pneumocystis is quite specific if it is positive.
If the stain is stated to be positive, there is no need to do further testing.
What does this image depict?
P. jirovecii cysts in tissue
What is the treatment plan for pneumocystis pneumonia?
Trimethoprim/sulfamethoxazole (TMP/SMX) is the best therapy both for treatment and for prophylaxis.
Which type of pneumonia presents as such:
patchy inflammtory changes, often confined to pulmonary interstitium, most commonly bacteriological etiologies that are different than normal?
atypical pneumonia
Organisms causing atypical pneumonia?
mycoplasma pneumoniae (mc), chlamydia pneumoniae, klebsiella pneumophila (immunocompromised hosts)
C/F of atypical pneumonia?
similar to typical pneumonia, radiological findings lagging, other systemic involvement
Upon X-ray what is the hallmark of atypical pneumonia?
perihilar reticular opacities (hallmark)
What is a more sensitive radio imaging test than X-ray for diagnosis of atypical pneumonia?
CT
How would you treat patients with atypical pneumonia?
Rx should be specifically directed against the causative organism.
Describe what is being seen in the picture and the diagnosis.
Reticular opacities near hilum indicative of atypical pneumonia
What is this chest radiograph showing? What is the diagnosis?
Chest radiograph shows a vague ill-defined opacity in left lower lobe - mycoplasma pneumonia
What is the leading killer of HIV-positive people?
TB
What are the ways that TB can be conventionally categorized?
Primary Pulmonary TB
Postprimary (adult-type, secondary) Pulmonary TB.
Who are the individuals that may be at higher risk for developing TB?
Recent immigrants from TB prevalent countries
Prisoners
HIV positive
Healthcare workers (practitioners, staff and other employee)
Close contacts of someone with TB
Steroid use
Hematologic malignancy
Alcoholics
Diabetes mellitus
Studies of household contacts indicated the transmissibility of TB ends within how many weeks of patients starting effective treatment?
2 weeks
TB almost always spreads through what? Disperse how?
inhalation of airborne particles (droplet nuclei) containing M. tuberculosis
Through coughing, sneezing, and other forced respiratory maneuvers by people with active pulmonary TB
Primary pulmonary tuberculosis is often seen in what age group?
children
What part of the lungs are most often involved in primary TB?
middle and lower
Small tubercle at lung periphery; small calcified nodule in cases of primary TB.
Ghon lesion
The ghon focus, with or without overlying pleural reaction, thickening, and regional lymphadenopathy, is referred to as what?
Ghon complex
Calcification of Ghon’s complex.
Ranke’s complex
Ranke’s complex is a feature of what condition?
primary TB
What is this a picture suggestive of? What is going on?
Ghon’s complex seen in Primary TB
What is this an image of?
military TB
What is this an image of?
Ranke’s complex seen in primary TB
This disease is also known as reactivation or secondary TB?
post primary (adult type disease) (pulmonary tb)
Where is pulmonary TB (adult-type) commonly found?
Usually localized to the apical and posterior segments of the upper lobes, due to the higher mean oxygen tension (compared with that in the lower zones).
What type of pulmonary tuberculosis is being described:
Small infiltrates to extensive cavitary disease
Non-specific symptom
Cough , hemoptysis, pleuritic chest pain, dyspnea.
Weight loss, evening rise of temperature
Highly infectitious
Postprimary (adult-type) disease
Complications of postprimary (adult-type) TB disease.
Pleural effusion Cavitation Lung collapse Large-airway wheezing Segmental/lobar hyperinflation Pneumonia Hemoptysis Disseminated or miliary disease Extra-pulmonary Tuberculosis
What is the key to diagnosis of TB?
a high index of suspicion
What is an important Drug susceptibility test for TB?
should be tested for susceptibility to isoniazid and rifampin to detect MDR-TB
PPD testing is not a general screening test for the whole population in testing those with TB. When is it used?
only in high risk groups
When is PPD testing not useful? What type of test should be done on these individuals?
PPD testing is not useful in those who are symptomatic or those with abnormal chest x-rays. These patients should have sputum acid fast testing done.
What is considered a positive PPD test?
only induration is counted. Erythema irrelevant
What cases may induration in PPD testing be larger than 5 millimeters?
- HIV-positive patients
- Glucocorticoid users
- Close contacts of those with active TB
- Abnormal calcifications on chest x-ray
- Organ transplant recipients or other immunosuppressed pts
In what cases will a PPD test yield an induration larger than 10 mmm?
Recent immigrants from high prevalence countries.
iv drug users,
Healthcare workers
Residents and employees of high-risk congregate settings (e.g., prisons, nursing homes, hospitals, homeless shelters, etc.)
Close contacts of someone with TB
Hematologic malignancy, alcoholics, diabetes mellitus, ESRD,
Children ≤4 yrs age.
Children and adolescents exposed to adults in high-risk categories
In which situation would the PPD test yield and induration larger than 15 mm?
those with no risk factors
Everyone with a reactive PPD test should have what done to exclude active disease?
X-Ray
Once a PPD is positive, will it always be positive in the future?
yes
In what cases would a false positive PPD reaction take place?
Infections with nontuberculous mycobacteria
BCG vaccination
Fasle-negative reactions in PPD testing are common in what groups?
In immunosuppressed patients
Overwhelming TB
A negative PPD reaction indicates what?
Implies anergy from immunosuppression, old age, malnutriton, and does not rule out TB.
What are the 4 major drugs that are considered the first-line agents for the treatment of TB?
isoniazid, rifampin, pyrazinamide, and ethambutol
What are some second line drugs to treat TB?
Second line drugs
The injectable aminoglycosides, streptomycin (formerly a first-line agent), kanamycin, and amikacin;
The injectable polypeptide capreomycin;
The oral agents ethionamide, cycloserine, and PAS;
The fluoroquinolone antibiotics. : Levofloxacin, and moxifloxacin.
amithiozone (thiacetazone) is used very rarely (mainly for mdr-tb).
Jeopardy!!!
Some drugs of unproven efficacy that have been used in the treatment of patients with resistance to most of the first- and second-line agents include clofazimine, amoxicillin/clavulanic acid, clarithromycin, imipenem, and linezolid.
Two novel drugs currently under clinical development—OPC-67683, a nitroimidazole; and TMC207(bedaquiline), a diarylquinoline
What are some other drugs that may be used to treat TB?
What are 2 aims of TB treatment?
(1) to interrupt transmission by rendering patients noninfectious and
(2) to prevent morbidity and death by curing patients and preventing the emergence of drug resistance
T/F When the smear is positive for TB you must being therapy with RIPE drugs.
True; RIPE Rifampin, Isoniazid, Pyrazinamide, and Ethambutol (RIPE).
What is the standard time for care of TB?
6 months of total therapy
Describe the use of steroids in the treatment of TB?
Glucocorticoids decrease the risk of constrictive pericarditis in those with pericardial involvement. They also decrease neurologic complication in TB meningitis.
What safety concerns exist in the treatment of latent tuberculosis?
mainly related to the development of hepatotoxicity
What is the recommended regimen for treatment of LTBI?
6-month or 9-month isoniazid daily,
3-month rifapentine plus isoniazid weekly,
3- or 4-month isoniazid plus rifampicin daily,
3– or 4-month rifampicin alone daily
What are 2 broad categories of fungal infections?
endemic human mycoses
opportunistic mycoses
What are some endemic human mycoses examples?
1-Histoplasmosis
2-Coccidioidomycosis
3-Blastomycosis
What are example of opportunistic mycoses?
1-Aspergillosis
2-Candidiasis
3-Cryptococcosis
4-Mucormycosis
Aspergilosis
collective term used to refer to a number of conditions caused by infection with a fungus of the Aspergillus species , usually Aspergillus Fumigatus
What are the types of aspergillosis? Note how they are ranked.
According to immune status : 1-Hypersensitivity : ABPA 2-Normal : Aspergilloma 3-Mild Suppression : Semi-invasive 4-Severe Suppression : Invasive form
What is ABPA?
Allergic Bronchopulmonary Aspergillosis represents a complex hypersensitivity reaction (type 1) to Aspergillus occurring almost exclusively in patients with asthma and occasionally cystic fibrosis
Pathology of ABPA.
The hypersensitivity initially causes bronchospasm and bronchial wall edema (IgE mediated) , ultimately there is bronchial wall damage , bronchiectasis and pulmonary fibrosis b)
Clinical picture of those with ABPA?
Patients have atopic symptoms (especially asthma) and present with recurrent chest infection
-They may expectorate orange-coloured mucous plug
What are some radiographic features of ABPA? (plain radiography)
Early in the disease chest x-rays will appear normal or only demonstrate changes of asthma
- Transient patchy areas of consolidation may be evident representing eosinophilic pneumonia
- Eventually bronchiectasis may be evident
What are some radiographic feature of ABPA? (CT)
Fleeting pulmonary alveolar opacities (common manifestation)
- Central upper lobe saccular bronchiectasis (hallmark)
- Mucus plugging and bronchial wall thickening (common)
Aspergilloma
Mass like fungus balls that are typically composed of Aspergillus fumigatus
Aspergillomas occur in what type of patients?
Aspergillomas occur in patients with normal immunity but structurally abnormal lungs with pre-existing cavities such as : 1-T.B. 2-Sarcoidosis 3-Bronchiectasis 4-Other pulmonary cavities (bronchogenic cyst , pulmonary sequestration)
What is the clinical picture of those with Aspergilloma?
most are asymptomatic
Occasionally due to surrounding reactive vascular granulation tissue , hemoptysis may be present
What location in the body do aspergillomas occur?
Location : -Aspergillomas typically occur in the cavities of post-primary pulmonary tuberculosis Therefore they most frequently are found in the posterior segments of the upper lobes and the superior segments of the lower lobes
What are some radiographic features of aspergillomas?
Radiographic Features : -Rounded soft tissue attenuating masses outlined by a crescent of air
What is a confirmatory diagnoses of Aspergilloma?
altering the position of the patient usually demonstrates that the mass is mobile which confirms the diagnosis
Hydatid Cyst is what type of infection?
parasitic
Location of Hydatid cyst?
predominantly in lower lobes, unilateral or bilateral
Hydatid Cyst is usually found where? (what organ)
The lung is the second most common site of involvement with echinococcosis granulosus in adults after the liver
What are the radiological features that hydatid cyst can present? (uncomplicated cyst)
uncomplicated cysts
- Multiple or solitary cystic lesion (most common)
- Round or oval mass with well-defined borders
- Enhancement after contrast injection
- Hypodense content relative to capsule
What are the radiological features hydatid cyst can present? (complicated cysts)
- Meniscus sign or air crescent sign (rupture between the layers of the cyst)
- Cumbo sign or onion peel sign (air lining between the endocyst and pericyst has the appearance of an onion peel)
- Water-lily sign (Rupture in a bronchus = wavy fluid level)
- Serpent sign (internal rupture of the cyst with collapse of membranes of parasite into the cyst )
- Rupture in a pleura = hydropneumothorax
- Consolidation adjacent to the cyst (ruptured cyst)
What is this condition?
Hydatid cyst
What is the arrow pointing to in this picture and what is this indicative of? (condition)
Water lily sign
complicated hydatid cyst
