Ancillary tests and procedures Flashcards
What gives the color to sputum?
PMNs
Rust colored sputum = ?
Strep pneumoniae
Currant jelly sputum = ?
Klebsiella
Should a patient rinse their mouth prior to giving a sputum sample?
Yes
How many hours prior to giving a sputum sample should a patient be NPO?
1-2 hours
What fraction of patients with bacterial pneumonia will not be able to produce a sputum specimen?
1/3
What is the cutoff of epithelial cells in a sputum sample before it is discarded? Why?
More than 10 per HPF.
Likely an oral sample.
What are the two urine tests that, when positive, warrant a sputum sample?
Urine antigen for pneumococcus
Urine antigen for legionella
What other lung pathologies beside pneumonia should a sputum sample be obtained?
- Pleural effusion
- Severe obstructive or structural lung disease
What type of culture should be obtained with intubated patients?
Tracheal swab
True or false: for outpatient treatment, sputum samples are optional
True
What is the most common causative agent of pneumonia?
Strep pneumoniae
What is the usual treatment for community acquired pneumonia?
Ceftriaxone
When is a sputum cytology indicated?
For patients with non-small cell lung CA who are unable or unwilling to undergo other diagnostic testing
What is the yield for sputum cytology?
Low; only 20-25% sensitivity
Why, besides the low sensitivity, are sputum cytologies not a good test for NSCLC?
Does not provide staging information, nor is it likely to provide ideal specimens for immunohistological or molecular studies
When is a thoracentesis indicated?
Pleural effusions
Empyema
What is yellow nail syndrome?
Rare syndrome characterized by pleural effusions and yellow, thickend nails.
What are the contraindications of a thoracentesis?
- Coagulopathy
- Hemodynamic instability
- Pt on mechanical ventilation
True or false: you do not do thoracocentesis unless under US or CT guidance. Why or why not?
True
Do not want to puncture the lung
Why do you not want to do a thoracentesis on a pt who is on mechanical ventilation?
More likely to puncture lung, and will create a tension pneumothorax
When is it okay to perform a thoracentesis in patients who are anticoagulated?
Likely safe if PTT or PT is less than 1.5 ULN
While doing a thoracocentesis, the needle should not be placed below which rib?
9th rib
What is the max amount of pleural fluid that should be removed? Why?
1.5 L
Post expansion pulmonary edema
What are the three major causes of transudate?
CHF
Cirrhosis
Nephrosis
What are the three major causes of exudate?
Bacterial pneumonia
CA
Trauma
What is the ratio of pleural fluid protein to serum fluid protein in exudate?
Greater than 0.5
What is the ratio of pleural fluid protein to serum fluid protein in transudate?
Less than 0.5
What are the complications of performing a thoracentesis?
- Pneumothorax
- Air embolism
- Post-expansion pulmonary edema
When should a CXR be ordered after a thoracentesis? (3)
- Air is aspirated
- Pt develops SOB, hypoxia, or chest pain
- Pt is critically ill or mechanically ventilated
Why should you stop a thoracentesis if the patient coughs during the procedure?
Will cause a pneumothorax
What are the ssx of a pneumothorax?
Chest pain
Cough
Why should the needle be inserted above the rib while performing a thoracentesis?
Do not want to damage the neurovascular bundle
When can a needle drainage be used for a pneumothorax? What should be done following this procedure?
For a first time occurrence
CXR needed afterward
Why is it that needle decompression of a pneumothorax is only indicated if done with proper equipment? What is the proper equipment?
Need to have large enough needle (gauge and length) to get through the chest wall
When should a chest tube be used over a catheter for a pneumothorax?
If fluid has a high density or protein content
Trauma
When is a catheter indicated for draining a pneumothorax?
- Uncomplicated pleural effusions
- Atraumatic
Why should you use a chest tube for a hemothorax and not a catheter?
Will clot
What is medical thoracoscopy?
Percutaneous insertion of an endoscope into the pleural space to directly visualize and collect specimens from both the pleura and pleural space
What is a pleurodesis?
Inflammation of pleural surfaces to promote adhesion formation and prevent reaccumulation of fluid
What is the usual drug used to perform a pleurodesis?
Talc or abx
What are the indications for a pleurodesis?
Malignant effusions
Refractory, symptomatic effusions
What are malignant pleural effusions?
a condition in which cancer causes an abnormal amount of fluid to collect between the pleura
What are the two major contraindications to a pleurodesis?
- Trapped lung
- Underlying severe lung disease
What is a trapped lung?
Lung that has undergone fibrosis secondary to some inflammatory etiology, and will not re-expand with pleurodesis
What is a bronchoscopy?
Fiberoptic bronchoscope is passed through the bronchi is collect visualize and/or collect specimens
What are the indications for a bronchoscopy?
Anytime where you suspect there is something in the airways that needs to be looked at or removed
What are the contraindications to bronchoscopy?
- recent MI
- Recent oral intake
- High grade obstruction
Why is bronchoscopy contraindicated in patient on a ventilator?
More likely to puncture lungs
What is a bronchoalveolar lavage?
a medical procedure in which a bronchoscope is passed through the mouth or nose into the lungs and fluid is squirted into a small part of the lung and then collected for examination. It is typically performed to diagnose lung disease.
At least what amount of saline is needed for an adequate bronchoalveolar lavage?
100 mL
