Symptom To Diagnosis - Cough/Congestion Flashcards
1
Q
Although there are a myriad of viral and bacterial infections that infect the respiratory tree, a practical approach addresses 3 issues:
A
- Where is the infection (sinuses, tracheobronchial tree, alveoli)?
- Will the patient benefit from antibiotics?
- Among patients with pneumonia, clinicians must separate the common CAPs from the less common but important pneumonias due to aspiration, TB, opportunistic.
2
Q
DDX of acute cough and congestion:
A
- Common cold.
- Sinusitis.
- Bronchitis.
- Influenza.
- Pneumonia. (CAP, Aspiration, TB, opportunistic).
3
Q
Influenza occurs when?
A
From December to May - Highly unlikely at other times.
4
Q
Acute bronchitis has low or high fever?
A
ABSENCE of high fever.
5
Q
MCC of infectious death in US?
A
Pneumonia.
6
Q
3.4% of pneumonias are associated with?
A
An underlying malignancy.
7
Q
Pneumonia complications:
A
- Respiratory failure.
- Death.
- Empyema.
8
Q
Prognosis of pneumonia:
A
It is good overall.
8% hospitalization rate.
95% radiographic cure in 1 month.
1.2% mortality.
9
Q
Prevalence of symptoms in patients with pneumonia:
A
96% --> Cough. 81% --> Fever (53% in the elderly). 46-66% --> Dyspnea. 37-50% --> Pleuritic chest pain. 59% --> Chills. 58% --> Headache.
10
Q
Physical exam of pneumonia:
A
No single finding is very sensitive.
A normal lung does NOT rule out pneumonia.
11
Q
Neither a normal lung exam nor the absence of fever rule out pneumonia:
A
LR- 0.6 and 0.8 respectively.
12
Q
Normal vital signs make pneumonia?
A
LESS LIKELY (LR- 0.18).
13
Q
Combination of normal vital signs and normal chest exam make pneumonia?
A
HIGHLY UNLIKELY (95% sens, LR- 0.09).
14
Q
LR+ for findings in pneumonia:
A
- 4 –> Fever >37.8.
- 3-3.0 –> Any chest finding.
- 2 –> Normal vital sings.
- –> Normal vital signs + lung exam.
- 6 –> Egophony.
- 7 –> Crackles.
15
Q
LR- for physical findings in pneumonia:
A
- 8 –> Fever >37.8.
- 6 –> Any chest finding.
- 18 –> Normal vital signs.
- 09 –> Normal vital signs + lung exam.
- 0 –> Egophony.
- 9 –> Crackles.
16
Q
Egophony LR+?
A
8.6 –> Fairly specific finding –> significantly increases the likelihood of pneumonia when present.
17
Q
WBC> 10.400 cells/mcL in pneumonia?
A
LR+ 3.7.
LR- 0.6.
18
Q
Chest film in pneumonia:
A
- Sensitivity is lower in dehydrated patients.
2. Compared with high res chest CT, chest film sens is 69%.
19
Q
Bottom line about chest film in pneumonia:
A
Normal does NOT rule out pneumonia when the pretest probability is very high (ie cough, crackles, fever) –> Antibiotics should still be administered.
20
Q
…% of infiltrates in pneumonia are in the lower and middle regions.
A
94%.
21
Q
CAP rarely affects the?
A
UPPER lobes. Consider TB or aspiration.
22
Q
Sputum Gram stain in pneumonia:
A
Often unreliable due to poor quality, preparation, and interpretation.
- Only 14% of hospitalized patients have adequate specimen with a dominant organism.
- 63-80% of patients with pneumococcal bacteremia.
23
Q
Blood cultures are positive in?
A
5-14% of patients.
24
Q
Pneumococcal urinary antigen:
A
- Sens for pneumococcal pneumonia - 50-80%.
2. Spec 90%.
25
Legionella urinary antigen:
Sens 70-90%.
| Spec 99%.
26
Indications for polyvalent pneumococcal vaccine:
1. >65 yo or any age with:
2. DM.
3. Chronic heart, lung, renal, liver disease.
4. Alcoholism.
5. Immunosuppression (incl. asplenia).
6. Native Americans, Alaskans, residents of long-term care facilities.
27
Indications for admission for pneumonia:
1. Hypoxia.
2. Shock.
3. Pleural effusion.
4. Multilobar infiltrates on CXR.
5. Failure of prior outpatient therapy.
6. Confusion.
7. Unable to tolerate oral intake.
8. Unreliable social situation.
9. Certain underlying diseases (SCD, immunocompromise, severe COPD, HF).
28
The CURB65 is a validated model that predicts mortality:
Confusion (to person, place, or time).
Uremia (BUN>20).
RR>30
BP65yo.
A score >1 is associated with increased mortality and the need for hospital admission.
29
Important point about SaO2:
Normal does NOT exclude HYPERCARBIA and respiratory failure. A blood gas to check PaCO2 is required for patients with respiratory distress.
30
Acute bronchitis - Textbook presentation:
Cough of 1-3 weeks duration. Myalgias and low-grade fevers may be seen. This is distinct from an acute exacerbation of COPD.
31
Acute bronchitis - Viral etiology:
1. Influenza.
2. Parainfluenza.
3. RSV.
4. Adenovirus.
5. Rhinovirus.
6. Coronavirus.
32
Acute bronchitis - Etiology - Bacterial:
1. <10% of cases are caused by bacteria.
| 2. Organisms include B.pertussis, Mycoplasma, and Chlamydia.
33
Acute bronchitis - Noninfectious etiology:
1. Asthma.
2. Pollution.
3. Tobacco.
4. Cannabis.
34
Acute bronchitis - symptoms in initial phase:
Cough and systemic symptoms 2o to infection are seen.
35
Acute bronchitis - Fever:
May be low grade. Consider pneumonia in patients whose fever is high-grade or persistent.
36
Acute bronchitis - Symptoms in protracted phase:
1. In 26% of patients, cough persists 2o to bronchial hyperresponsiveness and lasts 2-4 weeks or more.
2. 40-65% of patients without prior pulmonary disease show evidence of reactive airway disease during acute bronchitis.
37
Purulent sputum in acute bronchitis:
Purulent sputum is NOT an indication for antibiotic therapy in patients with acute bronchitis.
38
Indications for chest film in acute bronchitis:
1. Abnormal vital signs including high fever (temperature >38C), tachypnea RR>24, HR>100.
2. Dyspnea.
3. Focal findings on lung exam.
4. Elderly patients.
5. Presence of COPD, HF, cancer, or immunocompromised state.
39
Antibiotics in acute bronchitis:
NOT recommended.
40
...-...% of patients with pneumonia do NOT have crackles on auscultation.
25-50%.
| CXR is required when pneumonia is suspected.
41
Risk factors for aspiration:
1. Neurologic disease (dementia, CVA, seizures).
2. Sedation (illicit drug or alcohol OD, general anesthesia).
3. Impaired oral pharyngeal clearance (status post head and neck surgery).
4. GERD, vomiting.
5. Endoscopy, tracheostomy, bronchoscopy, nasogastric feeding.
42
Aspiration PNEUMONITIS - Clinical features:
1. Usually follows large volume aspiration (during anesthesia).
2. Cyanosis and shortness of breath develop within 2hr.
3. Fever is usually low grade.
43
Aspiration PNEUMONITIS - Outcome?
1. Rapid recovery within 24-36hr (62%).
2. Bacterial superinfection (26%).
3. ARDS (12%).
44
Aspiration pneumonia refers to?
Infection due to aspirated organisms.
| 5-15% of pneumonias.
45
Chest film in aspiration pneumonia:
1. Classic location of infection is in the basal segment of lower lobes, but it can involve UPPER lobes if aspiration occurred while the patient was recumbent.
2. Cavitation is more common in aspiration pneumonia than in CAP.
46
Several studies suggest that ... increase the cough reflex and decrease the rate of pneumonia in persons at-risk.
ACEIs.
47
... promotes dopamine release (which facilitates cough and decreases dysphagia).
Amantadine.
| --> Has also been shown to decrease the rate of pneumonia in elderly patients with prior stroke.
48
Aspiration pneumonitis - Management:
1. Antibiotics if infiltrates have do NOT resolve within 48hr or if the patient likely has gastric colonization (resulting from a H2 blocker, PPI, or from bowel obstruction).
2. Corticosteroids are controversial.
49
PCP - Textbook presentation:
Commonly complain of progressive shortness of breath and dry cough of 1-3 weeks duration.
50
PCP is the MC...?
MCC of acute diffuse lung disease in immunocompromised patients and is the leading cause of AIDS-related death in HIV(+).
51
PCP - Exact classification of the organism?
UNCLEAR.
52
PCP - Historical findings:
79-100% --> Fever.
95% --> Cough (usually but not always) non productive.
95% --> Progressive dyspnea.
53
PCP - Physical exam findings:
84% --> Fever.
62% --> Tachypnea.
50% --> NORMAL chest.
54
PCP - Chest film:
1. Usually shows diffuse symmetric bilateral alveolar or interstitial infiltrates (81-93%).
2. HIV-infected patients, interstitial infiltrates are present in 69% --> LR+ 4.25.
3. Dyspnea and oral thrush combined with a diffuse interstitial pattern on chest radiograph strongly suggest PCP in HIV-infected persons.
4. Isolated upper lobe --> May be seen in patients taking inhaled pentamidine as PCP prophylaxis.
5. Occasionally shows pneumothorax.
6. NORMAL in 10-25%.
55
Bottom line about PCP and chest film:
PCP should be considered in dyspneic patients with HIV and CD4 counts <200cells/mcL even when the exam and chest radiograph are normal.
56
PCP - Clinical diagnosis without sputum stain or BAL is incorrect in ...% of patients:
43%.
57
PCP - Induced sputum:
First test used to diagnose PCP:
55-92% sensitive.
100% specific.
58
BAL is used to diagnose PCP when?
Sputum stains are negative.
59
Marker that falls with PCP:
S-adenosylmethionine - Falls in patients infected with PCP.
60
Concomitant glucocorticoid therapy is lifesaving in patients with PCP whose PaO2 is
70mmHg.
61
TB - Common and serious:
1. Infects 33% of population.
| 2. 9 million new cases per year and 2 million deaths (worldwide).
62
...% of US population is PPD(+).
7%.
63
... of TB cases occur in the nonwhite population.
67%.
64
Median age of TB in whites and non whites:
Whites --> 62.
| Non whites --> 39.
65
Reactivation TB accounts for ...% of TB in older patients and ...% of TB in younger patients.
90%.
| 67%.
66
High risk groups for TB - HIV(+):
200 times increased incidence.
TB may be the first manifestation of HIV.
--> Patients with active or latent TB should be tested for HIV.
67
TB - Inhaled organism lands?
In the middle and lower lobes (due to increased ventilation).
68
TB - Organism lodges preferentially in areas of?
High PaO2:
1. Lung apices.
2. Kidneys.
3. Vertebrae.
69
PPD is positive 6-8 weeks after the initial infection. These patients are:
Resistant to subsequent EXOGENOUS infection.
70
Percentage of primary TB:
Approx. 10%.
71
Primary TB accounts for ...-...% of adult cases:
23-34%.
72
Most cases of primary TB...?
Resolve spontaneously without treatment.
73
Pleural TB takes 2 forms:
1. TB empyema.
| 2. Tuberculous pleural effusions.
74
Only ...-...% of patients with TB have fever.
31-62%.
75
...% of TB patients have fever, night sweats or night sweats alone.
50%.
76
TB - Cough was present for >1 month in ...% of patients and may be mild, non productive, purulent, or bloody.
70%.
77
Hemoptysis in TB:
In 24% of patients with tuberculous pneumonia compared with 15% of those with CAP (LR+ 1.6).
78
...% of TB cases are diagnosed after admission for an unrelated complaint.
33%.
79
Compared with older patients, younger TB patients usually have a?
```
Wilder clinical presentation:
66% vs 37% --> Alcoholism.
62% vs 31% --> Fever.
48% vs 6% --> Night sweats.
40% vs 17% --> Hemoptysis.
```
80
Indications for annual PPD:
1. HIV.
2. Health care workers.
3. Correctional facility workers.
4. Residents in long term care facilities.
5. Medical conditions that carry an increased risk of active TB.
6. Homeless persons.
81
Indications for a single PPD test:
1. Clinical suspicion for active TB.
2. Immigrants.
3. Status post exposure to TB.
4. Fibrotic lung lesion.
82
IFN-γ test for TB is highly specific for?
Active or latent infection.
83
CXR in TB:
```
Usually presents in 1 of 3 patterns:
1. Apical disease.
2. Cavitary disease.
3. Reticular Nodular pattern.
Such patterns are consistent with TB.
```
84
CXR in TB - Features:
Sens - 86%.
Spec - 83%.
LR+ 5.0.
LR- 0.16.
85
Cavitation is seen in ... of TB cases.
19-50%.
86
...% of patients with reactivation pulmonary TB have normal chest radiographs.
5%.
87
BAL in TB:
1. Smears: 38% Sens, 100% spec.
2. Culture or smear: 74% Sens, 75% spec.
3. Comparable to data for a single induced sputum.
4. Not routine or superior to induced sputums.
5. Use when induced sputums are unavailable.
88
Diagnostic approach of TB - 1st step:
1. Typical chest radiograph (apical or cavitary).
| 2. Risk factors (IVDA or endemic area).
89
Diagnostic approach of TB - 2nd step:
1. Blood culture.
2. Sputum AFB smear and culture.
3. Urine culture.
4. PPD.
5. Chest radiograph.
90
Hepatitis of isoniazid:
Reported incidence is 0.1-2.3%.
91
Peripheral neuropathy with isoniazid:
Develops in 2% of patients and can be prevented with pyridoxine (10-25mg/d) .
92
Influenza - Adults and children are infectious from when until when?
From the day prior to the onset of symptoms until about 5 days later (10 for children).
93
Incubation period for influenza:
1-4 days.
94
Influenza - Onset is sudden in?
75% of cases.
95
Influenza - Fever:
Present in 51% of cases.
1. Peaks within 12-24hr of onset of illness.
2. Typically 38-40, occasionally 41.
3. Typical duration is 3 days, but may last 1-5 days.
96
High fever within 12-24h of symptom onset is typical of?
Influenza, but NOT other viral respiratory pathogens.
97
Fever that suggests pneumonia over influenza?
Fever that increases over several days and is accompanied by cough.
98
Prevalence of symptoms in influenza:
58-81% --> Headache.
48-94% --> Cough.
46-70% --> Sore throat.
GI symptoms are NOT characteristic of influenza.
99
Comparison of influenza, CAP, and acute bronchitis - High fever:
Cap --> Common.
Influenza --> Common.
Acute bronchitis --> Uncommon.
100
Comparison of cap, influenza, bronchitis - Localized lung findings:
Cap --> Common.
Influenza --> Uncommon.
Bronchitis --> Uncommon.
101
Comparison of influenza, cap, bronchitis - Shortness of breath:
CAP --> Variable.
Influenza --> Uncommon.
Bronchitis --> Uncommon.
102
Influenza - Crackles are seen in ...% of patients.
<25%.
103
Influenza mortality rates are how much greater in patients over 65 than in patients aged 0-49.
200 times.
104
HIV infected patients also suffer a ... Times increase in mortality:
100
105
Patients with influenza pneumonia complain of shortness of breath more often than patients with uncomplicated influenza:
82% vs 17%.
106
Influenza pneumonia has a ...% mortality.
29%.
107
Among patients hospitalized for influenza pneumonia, ...% have concomitant bacterial pneumonia caused by S.aureus or S.pneumoniae.
30%.
108
Less common complications of influenza pneumonia:
1. HF.
2. Myositis.
3. Myocarditis.
4. Pericarditis.
5. Meningoencephalitis.
6. Guillain-Barré syndrome.
109
Contraindications for influenza vaccine?
1. Egg allergy.
2. Significant febrile illness at the time of vaccination.
3. History of Guillain-Barre.
110
Framework for the DDX of acute respiratory complaints:
Anatomic and microbiologic.
