Respiratory Procedures - Stasio Flashcards
Tests & Procedures
Pulse Oximetry
CXR – chest x-ray
Arterial Blood Gas - ABG
Spirometry – PFT (pulmonary function tests)
Intubation – endotracheal or nasotracheal
Chest Tube
V/Q Scan
Pulse Ox
The 5th Vital Sign
Measures:
% of O2 saturation
Pulse rate
Clinical Pearls
Reads the Color Red – refraction of light
Hypothermia – decreased peripheral circulation can cause a falsely lowered O2 saturation
Fingernail polish – light cannot penetrate through nail polish. Ear lobe is an alternate site for measurement.
Carboxyhemoglobin – the pulse oximeter cannot discriminate between oxyhemoglobin and carboxyhemoglobin (need an ABG)
Chest X-rays
Most common X-ray procedure in the US.
Used to evaluate heart, lungs, aorta, esophagus, pleura, tracheobronchial tree, thoracic lymph nodes, thoracic skeleton, chest wall and upper abdomen.
Typically done with PA and lateral studies (patients hold breath after maximal inhalation).
If done correctly will allow for visualization of 9-10 ribs posteriorly and 5-6 anteriorly.
AP views for bed bound patients.
Lateral decubitus - Patient on left and right side.
Lordotic view – bending backwards. View apices.
When to order a CXR
Suspecting disease of the lungs, mediastinum, heart, or chest wall.
Suspecting systemic disease & suspicion of chest involvement.
Neoplasm or Connective Tissue Disease (CTD)
* Monitor life-support devices.
Central venous catheters, nasogastric tubes, endotracheal tubes, chest tubes, etc.
* Pneumoperitoneum – gas in abdominal cavity
Reading a CXR
Technical quality of the film
RIP (rotation, inspiration, penetration)
- White on film = opacity
Mass, fluid, space occupying lesion
- Black = air
-* Heart size = transverse size of heart divided by transverse diameter of thorax should be < 0.5
- Hemi-diaphragm – right usually 1.0-1.5 cm higher than the left (d/t the liver)
- Penetration – under or over penetrated
- Inspiration – diaphragm to the 9-10 rib
Taking A CXR
On an AP CXR view the heart shadow will be falsely enlarged because of the divergence of the x-ray beams and the heart being further away from the x-ray plate
Limitations of CXR
Patient Cooperation
- Inspiratory effort & posture – age, pain, disability
Skill of the technician and interpreting physician
- 400 shades of gray
Normal x-rays can correlate poorly with actual disease
- Early pneumonia - may not show an infiltrate
- Pulmonary embolus – normal CXR
- Early COPD/Chronic bronchitis/Asthma
Hyperinflation, loss of vascular markings, flattened hemidiaphragms, PA diameters, retrosternal air space seen in more advanced disease.
- Interstitial Dx – pneumoconiosis & asbestosis, unless in the presence of PMF (progressive massive fibrosis)
ARTERIAL BLOOD GASES
ABG is used to determine:
(acid-base balance and oxygen status)
* pH of blood
Partial pressure of oxygen in the blood (PaO2)
Partial pressure of carbon dioxide (PaCO2)
Bicarbonate level (HCO3)
Oxygen saturation of hemoglobin (O2 sat.)
Arterial blood is used, most common sites:
Radial artery
Brachial artery
Femoral artery
Indications for ABG
Assess for hypoxia and severity
Evaluation of acid-base disorders
Assess need for home O2 use (chronic patients)
Measure carboxyhemoglobin levels in patients suffering from smoke inhalation or other exposures (with a CO – oximeter )
Calculate arterial O2 saturation content
Blood sample in difficult draw patients (obese)
Calculating Arterial O2 Saturation
The ABG machine cannot differentiate between O2 and CO hemoglobin.
Given as a separate CO measurement
Example:
O2 Saturation = 98%
CO hemoglobin = 25%
Actual O2 Saturation = 73% (very hypoxic)
Contra-indications to ABG
No absolute contraindications
Relative
Invasive procedure – bleeding, arterial laceration
Coagulopathy, including thrombolytic therapy
Severe PAD with poor collaterals (Allen’s test)
Trauma or infection at draw site
Difficult to standardize d/t factors such as:
Hyperventilation
Breath holding
Altitude
Obesity
Equipment for ABG Collection
Sterile gloves
Rolled towel or other support for wrist or elbow
Ice for transport to lab
ABG kit (2ml heparinized syringe with 25 gauge needle, Iodophor and alcohol pads, 2X2 sterile gauze and band-aid)
*Can consider lidocaine for local anesthetic if desired
*(Should you stick the patient once or twice?)
ABG Collection Technique:
Palpate artery while resting patient’s arm on bedside table. Can support wrist with towel
Confirm with “Allen’s Test”
Cleanse area first with Iodophor than wipe once with alcohol pad
Anesthetize area if desired
Locate artery with index and middle finger of one hand, then insert needle at a
45° angle to skin bevel up. Slowly advance until artery is punctured and
Blood begins to fill syringe
Collect 2-3 ml of blood, then slowly remove needle
Apply firm pressure over site with 2X2 gauze and hold for up to 5 minutes.
Once no bleeding occurs apply band-aid and dispose of sharp properly
7. Transport to lab on ice ASAP
ET/NT Tube INTUBATION
Indications:
Respiratory failure
Airway protection for patients at risk of compromise
Maintenance of airway
Help facilitate pulmonary treatments and medication
Use positive pressure ventilation
Maintain adequate oxygenation
Contraindications:
Operator unskilled to administer tube
Excessive trauma to face, neck, c-spine (relative)
Inability to extend the head and neck (Endotracheal)
Preparing for ET Tube Placement
Determine the most appropriate method
Make sure all equipment is functioning
Ensure adequate IV access *
Remove any foreign bodies if present (food, teeth, dentures, secretions)
Hyperventilate with high concentration of oxygen if possible
Can place temporary oropharyngeal airway if needed
Monitor BP, pulse ox, cardiac status
Have appropriate staff and equipment ready for CPR
Contemplate Sedation of the Conscious Patient
Not required for the unconscious patient
Use rapid sequence intubation for patients at risk for regurgitating or aspirating
To sedate patients use rapid IV administration of sedative first(ex. Propofol, Thiopental, midazolam) *risk is sudden drop of BP
Then may also need fast acting muscle relaxant
(ex. Succinylcholine, Rocuronium)
*Risk of arrhythmias and post-op myalgias
Intubation Sequence
Recheck all equipment is functioning
Hyperventilate the patient.
Cricoid pressure by assistant if needed (Sellick’s maneuver)
Position patient in sniffing position, extending head at OA joint. Jaw thrust or chin lift if needed
Curved blade intubation
Place laryngoscope in right side of mouth and sweep blade to left displacing tongue.
Curved blade: tip is inserted into the vallecula
Lift scope upward & forward, keep your wrist stiff, (don’t use a lever action or you may break teeth)
With cords in view, insert tip of ET tube between cords, such that tip is 2-3 cm below cords. Remove scope and inflate cuff. If stylet was used, remove this now. Correct placement should be at 21 cm mark on tube form women and 23 cm mark for men. Ensures tip is 3-4 cm above carina
straight blade intubation
Place laryngoscope in right side of mouth and sweep blade to left displacing tongue.
Straight blade
tip is just below epiglottis.
Lift scope upward & forward, keep your wrist stiff, (don’t use a lever action or you may break teeth)
With cords in view, insert tip of ET tube between cords, such that tip is 2-3 cm below cords. Remove scope and inflate cuff. If stylet was used, remove this now. Correct placement should be at 21 cm mark on tube form women and 23 cm mark for men. Ensures tip is 3-4 cm above carina.
Verify ET Tube Placement
Look for: a symmetrical rise of the chest wall.
Listen for: equal breath sounds bilaterally and over the epigastrium. epigepigastrium.
Secure tube to skin with tape or strap
Do CXR to confirm placement is correct.
Monitor respiratory values to confirm proper function
CHEST TUBES indications, contraindictions
Indications:
Pneumothorax causing respiratory distress
Hemothorax
Large pleural effusions causing respiratory distress
Empyema
Post thoracotomy
Contraindications: Small pneumothorax not causing resp. distress Pleura adherent to chest wall Coagulopathy (relative) Previous chest tube in the same site
Preparation for Chest Tube Placement
Explain procedure & obtain informed “written” consent if possible.
Place patient in lateral decubitus position with affected side up
Prep and drape (sterile) 5th and 6th intercostal space in mid-axillary line (least amount of muscle in this area)
*Do not go below this area because of risk of injury to diaphragm or liver
Chest Tube Procedure
Anesthetize subcutaneous tissues first along top edge of rib to avoid neurovascular bundle.
Slowly advance needle while infiltrating along costal periosteum until air or fluid is aspirated -- in pleural space
Make small incision through skin, fat and muscle, just superior to lower rib of interspace
Enlarge incision using curved clamp. Perforate through to pleural space. Avoid lung injury, grip clamp with other hand so that distance from hand to tipIs just greater than chest wall thickness.
Use the clamp to guide the chest tube into pleural space.
Pneumothorax: direct the tube posteriorly & toward apex
Fluid: direct tube posteriorly, keeping in a dependent position
Verify all holes are in the pleural space
Once the Chest Tube is in-place
Attach opposite end of tube to multi-chamber water seal with suction at 20 cm of water suction.
Have patient cough, if possible, bubbles should appear in water
Suture through skin and with long ends of suture, tie tube down.
Place petroleum gauze around tube exit site for airtight seal.
Apply sterile gauze and secure around tube to skin with tape.
* CXR should be done to confirm tube placement
Continue to monitor for resolution of problem.
Spirometry & Pulmonary function Tests
A quantitative measure of lung function based on air flow rates and lung volumes
In General Terms:
Simple Spirometry Graph Plots:
Volume as a function of Time
Pulmonary Function Tests Plot: Flow - volume loops Expiratory flow rates against volumes Expiratory & Inspiratory flow rates against volumes Diffusion rates of gases*
Indications for Spirometry/PFT
Screening (smoker, toxic exposures, asthma, COPD)
Diagnostic testing
obstructive lung disease and restrictive lung disease
Evaluate efficacy of treatments
Tracking the course of disease
Disability determinations
Spirometry Limitations and Contraindications
Results very patient dependent
Severe debilitation and excessive tiring
Severe or moderately severe respiratory distress
Patient not motivated or desiring to take the test
Medications affecting the respiratory cycle or function of the chest muscles
PFT Volumes
FEV 1 – Forced expiratory volume in 1 second (volume of gas exhaled during first second of exhalation)
FVC – forced vital capacity (total exhaled volume)
FEV 1/FVC – ratio of the two expressed as a percentage
FEF 25-75 – forced expiratory flow between 25% & 75% of VC. Average flow rate during middle 50% of FVC
How do we use the results of PFT’s
Good correlation
FEV 1 & ADL/work status
FEV 1 < 1 L = not working
FEV 1 >1 & <2 L = severe
effects on ADL’s
FEV 1 >2 L mod effect on ADL’s
FEV 1 correlates better with exercise capacity than does the partial pressure of arterial oxygen (ie: ABG)
Good correlation between FEV 1/FVC ratio < 40% and shortened life spans
Diminished FVC is a reliable and valid index of significant impairment in patients with interstitial lung disease
Ventilation/Perfusion Scan
Aka: V/Q Scan
Indications
Evaluate for the presence of blood clots or other abnormalities in ventilation(V) and circulation(Q).
Can be use to evaluate COPD or Pneumonia.
Contraindications: Kidney failure Allergy to radioactive materials Risks Radiation exposure Renal toxicity
Two step test Two Scans Ventilation – inhale radioactive gas such as xenon or technetium Perfusion – IV technetium A gamma camera acquires the images for both phases Results Normal Low probability Intermediate probability High probability
V/Q results
low- less than 20% probabiliy of PE
intermediate: 20-80% chance
High probability: more than 80% chancee
