Respiratory - Blood gas Flashcards
Gm+ diplococci
purulent and rusty hemoptysis = strep
Gm+ cocci in clusters
purulent, staph
Gm- bacilli (rods)
purulent bright streaks hemoptysis - pseudomonas
Pre-Procedure: of sputum collection
Saliva is NOT sputum!
Rinse mouth with water before sputum collection
No antiseptic mouth wash
Procedure: of sputum collection
Morning samples are best (upon awakening)
1 tsp of sputum in sterile container
Cough after several deep breaths
Stimulate coughing by warm aerosol treatment
Adequate specimen= <10 epithelial cells per low-power field - is a contaminated specimen (seen with microscopy)
virus Nasopharyngeal (NP) swab antigen tests
influenza A
RSV
NP swab procedure ?
Dacron swab is gently inserted into the nostril until resistance is met
Rotated several times and then withdrawn
Proper technique is key
what is the direct exam for sputum testing Legionella (atypical)
Fluorescent Ab stain
Allows rapid ID of Legionella
Bacteria concentration is often not high enough to ID from sputum
Sensitivity 25-75% - a lot of false negatives
Specificity >95%
Legionella Culture (best one?)
Legionella media
Difficult to grow
↑ false negatives
Sensitivity 20-80%
Specificity 100%
Legionella Urine antigen
Performed from a clean catch urine specimen
Transport in a sterile container
Positive findings = Legionella
+ after 2-3 days of infection ( so we don’t really have to wait for ABS to develop)
Sensitivity ~70%
Specificity ~100%
Legionella ABS tests
Single titer of >1:256
Paired titers with fourfold rise to titer of 1:128 between week 1 and week 3
May take 4-6 weeks for titers to become positive
Sensitivity 80-90%
Specificity >99%
Pneumocystis jiroveci is a culture useful?
NO
Pneumocystis jiroveci Direct tests?
DFA (main)
Giemsa stain
Methenamine silver
TB tests?
Direct (AFB Microscopy) Culture Nucleic Acid testing Quantiferon PPD
What will TB show on AFB microscopy?
acid-fast bacilli
TB definitive diagnosis?
Mycobacterial Culture
3 morning samples
TB Nucleic Acid Amplification:?
Not as sensitive as culture
Performed on one respiratory
specimen
Expensive
Tuberculosis:
PPD (purified protein derivative)
Most used to screen for latent TB infxn
Not specific to TB (could detect other mycobacterium infxns)
Tuberculosis:
Quantiferon-TB Gold:
Blood is mixed with antigens and then interferon (released by WBC) is measured
Increased in those with active or latent TB
Indications to use Quantiferon-TB Gold?
Used to dx active TB in patients recently exposed to or suspected to have TB infection
Pts with previous BCG vaccination
Indications for thoracentesis?
Determine cause of unexplained pleural effusion
Relieve intrathoracic pressure from large volume of fluid
Transudate effusion (fluid is coming from another part of the body)
CHF
Cirrhosis
Nephrotic syndrome
hypoproteinemia
Exudates effusion (exudate coming from right in the like like a pneumonia )
Inflammatory
Infectious
Neoplastic
> 1000
Cloudy fluid from Thoracentesis
Infectious
Inflammatory
Bloody fluid from Thoracentesis
Traumatic tap
Tumor - vascular and bleeding
Intrathoracic bleeding
> 50% small lymphocytes = ?
TB or tumor
PMNs found in thoracentesis fluid = ?
acute inflammatory condition (pneumonia, TB, infarction)
Exudate protein level?
> 3 g/dL
Transudate protein level?
< 3 g/dL
Exudate Glucose level?
<60 mg/dL
it is low cause the bacteria is eating it all if we have an infection
serum albumin minus effusion albumin levels and indications?
Transudate = > 1.1
Exudate = < 1.1 (0.5 ratio)
Contraindications to Thoracentesis?
Thrombocytopenia
Anticoagulation
Rash in area of tap
