respiratory labs Flashcards
Causes of Respiratory Disease
Tumors:
Infections:
Airway diseases:
- emphysema
- bronchitis
-asthma
- RDS
Pulmonary vascular disease:
-PE
- P HTN
Interstitial lung disease:
- affect the tissue and space around the alveoli
- impaired diffusion of gases
- sarcoidosis, pneumoconiosis
Common Locations for an ABG: where do you palpate the arteries
Radial artery: *
- Palpated between the distal radius and the tendon of the flexor carpi radialis
- need to do modified allen test to make sure collateral circulation working
Femoral artery:
- Palpated below the midpoint of the inguinal ligament
Modified Allen Test
- Tests for sufficient arterial blood flow to the hand prior to an ABG draw
1) hold hand high and make a fist while compressing ulnar and radial arteries (blanched hand)
2) lower hand and release fist
3) release pressure off ulnar artery
4) watch hand turn pink within 6s to indicate patent collateral blood flow
- patent ulnar artery
- intact superficial palmar arch
- -if flow is not restored to hand -> you cant do an ABG on this hand -> no collateral flow
components of typical arterial blood gas kit
-arterial blood gas syringe
-protective needle
-syringe cap
-iodine and alcohol preparation swabs
-gauze
-pt label
-biohazard ice bag
-adhesive bandage
-sample goes on ice
femoral artery anatomy/puncture
NAVEL:
-outside to inner- femoral nerve, artery, vein
-femoral artery can be palpated just below midpoint of inguinal ligament
-blood draw- 90 degree angle
-catheter: 45 degree angle -> “snaking a line:” threading a thin tube through the artery to reach various parts of the body
Code type situation: we all need to be able to check femoral pulse
Key Components of the Blood Gas Test Panel:
pO2 (Partial Pressure of Oxygen)
- low = hypoxemia
pCO2 (Partial Pressure of Carbon Dioxide)
- high = hypercapnia
pH
- Normal: 7.35 to 7.45
Body’s Response to Acid-Base Disturbances
Lungs respond within MINUTES:
-ex. if you put a pt on a ventilator, the lungs respond in mins, redraw ABG can be done within mins
-Respiratory Acidosis: can increase rate on ventilator to tx
-Respiratory Alkalosis: reduce ventilator
Renal response takes hours/DAYS:
-can’t check immediately
- response: can excrete H+ and retain HCO3-: INCREASE pH
- retain H+ and excrete HCO3-: lower pH
Respiratory Acidosis
ABG Findings:
- Low pH
- high pCO2
Cause: HYPOventilation*
- COPD exacerbations
- severe asthma
- airway obstruction
Metabolic Acidosis
Low pH (acidic) and low bicarbonate (HCO3−)
Examples:
- DKA: uncontrolled DM* tx with IV insulin
- lactic acidosis from shock
- severe dehydration
need to calculate ANION GAP
- normal anion gap: acidosis is due to a loss of bicarbonate, which could be from GI or renal causes
- elevated: due to additional acids in blood - MUDPILES (DKA, renal failure)
Respiratory alkalosis
High pH, low CO2
Causes: hyperventilation *
- severe anxiety/pain
- pneumonia
- PE
- high altitudes
- pregnancy
ALKalosis: “tALKative ppl need to hyperventilate to talk more”
Metabolic alkalosis
High pH, high HCO3
Causes: loss of H+ or HCO3- excess
- Severe chronic vomiting *: huge loss of H+ in stomach
- diarrhea
- laxatives
- loop diuretics
- hyperaldosteronism: mineralocorticoid excess
importance of Proper ABG Sample Handling
ABG blood draws must always be placed on ICE IMMEDIATELY after collection:
- at room temperature: metabolic processes continue within the blood sample -> consumption of O2 and production of CO2
- not on ice = alterations in pH*
- pO2 will decrease and pCO2 increases: pH will be skewed to be more acidic
Anion Gap: what electrolytes
Cations: Na+ and K+
Anions: Cl− and HCO3−
Normal anion gap: <12
Elevated: greater than 12-16
- indicates presence of additional acids in the blood (DKA!!)
Causes of Increased Anion Gap
“MUDPILES”
M methanol
U uremia
D DKA
P Propylene glycol
I iron tablets or INH
L lactic acidosis
E ethylene glycol
S salicylates (aspirin)
Causes of normal Anion Gap
HARDASS
H hyperalimentation
A addison’s ds
R renal tubular acidosis
D diarrhea
A acetazolamide
S spironolactone
S saline infusion
thoracentesis: asesses what
asses:
-color
-characteristics
-odor
-exudate vs transudate
transudative vs exudative
Transudative:
-low protein and LDH
-increased hydrostatic pressure or low osmotic pressure (lack of proteins)
-water/fluid (CLEAR) in lungs
- integrity of capillary walls is maintained
-ex. CHF, cirrhosis, nephrotic syndrome, PE, hypoalbuminemia
Exudative:
-high protein and LDH
-inflammation and INCREASED capillary permeability
-ex. pneumonia, cancer, TB, viral infection, PE, autoimmune
-pus, yellow color, odor, thick
Light’s criteria for pleural effusions
Transudate causes:
- hypoalbuminuria: cirrhosis, nephrotic syndrome
- CHF
- pericarditis
Exudate causes:
- autoimmune ds
- esophageal rupture
- infection
- malignancy
-pancreatitis
- post-CABG
- PE
Bronchoalveolar Lavage Fluid Analysis: diagnostic for what
Pulmonary infection
Acquired Pneumonia
Interstitial Lung Diseases-SARCOIDOSIS
Lung Cancer
Lung Transplant monitoring
Bronchoalveolar Lavage Fluid Analysis: testing
Can: culture, WBC count, Gram stain
- Bloody BAL → diffuse alveolar hemorrhage
- Cloudy → pulmonary alveolar proteinosis
- process BAL: microscopy and find biomarkers,
Bronchoalveolar Lavage Fluid Analysis: procedure
- Several aliquots of warmed saline are instilled in different areas of the lungs
- At least 30% of the instilled fluid is carefully aspirated
- BAL fluid is collected with the aid of a bronchoscope
Asthma
Spirometry:
- helping in the diagnosis and monitoring of asthma
Pulmonary function test
Chest X-Ray
Allergy testing
COPD
Pulmonary Function Tests:
- Obstructive pattern: decrease in FEV1 and FVC, FEV1/FVC lower than 1, decrease DLCO
-CBC: secondary polycythemia from chronic hypoxemia
-Rule out infections: can exacerbate COPD sx
-Symptoms: chronic cough, sputum production, and SOB
-r/o Alpha-1 antitrypsin Deficiency, elastin degradation
Community acquired Pneumonia organisms
Streptococcus pneumoniae
Mycoplasma pneumoniae
Haemophilus influenzae
Legionella species
Bordetella pertussis
