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%.
Legionella urinary antigen:
Sens 70-90%.
Spec 99%.
Indications for polyvalent pneumococcal vaccine:
- > 65 yo or any age with:
- DM.
- Chronic heart, lung, renal, liver disease.
- Alcoholism.
- Immunosuppression (incl. asplenia).
- Native Americans, Alaskans, residents of long-term care facilities.
Indications for admission for pneumonia:
- Hypoxia.
- Shock.
- Pleural effusion.
- Multilobar infiltrates on CXR.
- Failure of prior outpatient therapy.
- Confusion.
- Unable to tolerate oral intake.
- Unreliable social situation.
- Certain underlying diseases (SCD, immunocompromise, severe COPD, HF).
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.
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.
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.
Acute bronchitis - Viral etiology:
- Influenza.
- Parainfluenza.
- RSV.
- Adenovirus.
- Rhinovirus.
- Coronavirus.
Acute bronchitis - Etiology - Bacterial:
- <10% of cases are caused by bacteria.
2. Organisms include B.pertussis, Mycoplasma, and Chlamydia.
Acute bronchitis - Noninfectious etiology:
- Asthma.
- Pollution.
- Tobacco.
- Cannabis.
Acute bronchitis - symptoms in initial phase:
Cough and systemic symptoms 2o to infection are seen.
Acute bronchitis - Fever:
May be low grade. Consider pneumonia in patients whose fever is high-grade or persistent.
Acute bronchitis - Symptoms in protracted phase:
- In 26% of patients, cough persists 2o to bronchial hyperresponsiveness and lasts 2-4 weeks or more.
- 40-65% of patients without prior pulmonary disease show evidence of reactive airway disease during acute bronchitis.
Purulent sputum in acute bronchitis:
Purulent sputum is NOT an indication for antibiotic therapy in patients with acute bronchitis.
Indications for chest film in acute bronchitis:
- Abnormal vital signs including high fever (temperature >38C), tachypnea RR>24, HR>100.
- Dyspnea.
- Focal findings on lung exam.
- Elderly patients.
- Presence of COPD, HF, cancer, or immunocompromised state.
Antibiotics in acute bronchitis:
NOT recommended.
…-…% of patients with pneumonia do NOT have crackles on auscultation.
25-50%.
CXR is required when pneumonia is suspected.
Risk factors for aspiration:
- Neurologic disease (dementia, CVA, seizures).
- Sedation (illicit drug or alcohol OD, general anesthesia).
- Impaired oral pharyngeal clearance (status post head and neck surgery).
- GERD, vomiting.
- Endoscopy, tracheostomy, bronchoscopy, nasogastric feeding.
Aspiration PNEUMONITIS - Clinical features:
- Usually follows large volume aspiration (during anesthesia).
- Cyanosis and shortness of breath develop within 2hr.
- Fever is usually low grade.
Aspiration PNEUMONITIS - Outcome?
- Rapid recovery within 24-36hr (62%).
- Bacterial superinfection (26%).
- ARDS (12%).
Aspiration pneumonia refers to?
Infection due to aspirated organisms.
5-15% of pneumonias.