Symptom To Diagnosis - Cough/Congestion Flashcards
Although there are a myriad of viral and bacterial infections that infect the respiratory tree, a practical approach addresses 3 issues:
- 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.
DDX of acute cough and congestion:
- Common cold.
- Sinusitis.
- Bronchitis.
- Influenza.
- Pneumonia. (CAP, Aspiration, TB, opportunistic).
Influenza occurs when?
From December to May - Highly unlikely at other times.
Acute bronchitis has low or high fever?
ABSENCE of high fever.
MCC of infectious death in US?
Pneumonia.
3.4% of pneumonias are associated with?
An underlying malignancy.
Pneumonia complications:
- Respiratory failure.
- Death.
- Empyema.
Prognosis of pneumonia:
It is good overall.
8% hospitalization rate.
95% radiographic cure in 1 month.
1.2% mortality.
Prevalence of symptoms in patients with pneumonia:
96% --> Cough. 81% --> Fever (53% in the elderly). 46-66% --> Dyspnea. 37-50% --> Pleuritic chest pain. 59% --> Chills. 58% --> Headache.
Physical exam of pneumonia:
No single finding is very sensitive.
A normal lung does NOT rule out pneumonia.
Neither a normal lung exam nor the absence of fever rule out pneumonia:
LR- 0.6 and 0.8 respectively.
Normal vital signs make pneumonia?
LESS LIKELY (LR- 0.18).
Combination of normal vital signs and normal chest exam make pneumonia?
HIGHLY UNLIKELY (95% sens, LR- 0.09).
LR+ for findings in pneumonia:
- 4 –> Fever >37.8.
- 3-3.0 –> Any chest finding.
- 2 –> Normal vital sings.
- –> Normal vital signs + lung exam.
- 6 –> Egophony.
- 7 –> Crackles.
LR- for physical findings in pneumonia:
- 8 –> Fever >37.8.
- 6 –> Any chest finding.
- 18 –> Normal vital signs.
- 09 –> Normal vital signs + lung exam.
- 0 –> Egophony.
- 9 –> Crackles.
Egophony LR+?
8.6 –> Fairly specific finding –> significantly increases the likelihood of pneumonia when present.
WBC> 10.400 cells/mcL in pneumonia?
LR+ 3.7.
LR- 0.6.
Chest film in pneumonia:
- Sensitivity is lower in dehydrated patients.
2. Compared with high res chest CT, chest film sens is 69%.
Bottom line about chest film in pneumonia:
Normal does NOT rule out pneumonia when the pretest probability is very high (ie cough, crackles, fever) –> Antibiotics should still be administered.
…% of infiltrates in pneumonia are in the lower and middle regions.
94%.
CAP rarely affects the?
UPPER lobes. Consider TB or aspiration.
Sputum Gram stain in pneumonia:
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.
Blood cultures are positive in?
5-14% of patients.
Pneumococcal urinary antigen:
- Sens for pneumococcal pneumonia - 50-80%.
2. Spec 90%.