|What are some overall uses of chest x-ray?||
Baseline for perioperative care.
Diagnosis of disease.
Detection of acute changes.
|What is the importance of chest x-ray?||
Essential for anesthetists to understand basic concepts in chest x-ray methods & interpretation.
|What should you look for in a preoperative chest x-ray?||
Significant cardiopulmonary changes.
Positioning of invasive monitoring lines (swan, CVL).
Trauma (Chest injuries, pneumothorax. cardiac tamponade.)
Pre-existing chest disorders (tumor).
Reveal new pathology (Emphysema.)
|What is the diagnosis of pulmonary disease based upon?||
Known medical history.
Presence of dyspnea.
note: Up to 10% of normal chest x-rays have chronic infiltrative pulmonary disease
|Considerations with the "Routine Chest X-ray"||
Under 40 years old, chest x-ray detects new pathology in <1.5% of population.
Routine preoperative chest x-rays not indicated for patients <60 y/o if no disease is suspected from history or exam.
|What lesions may affect anesthetic management?||
|What is associated w/ Tracheal obstruction?||
|What are some complications associated w/ tracheal obstruction?||
Pathology may lead to difficult visualization, intubation, & ventilation.
|Complications resulting from Pleural effusions.||
Resulting in decreased vital capacity & functional reserve capacity.
|Complications resulting from Cardiac Enlargement?||
Possible cardiopulmonary disease, hypertension, & greater sensitivity to cardio-depressive effects of anesthetic agents.
|Complications associated w/ Bullous disease.||
Possibility of rupture & compression of lung tissue with + pressure ventilation.
|Complications associated w/ Infectious abscess.||
Air-fluid cavity w/ risk of enlargement.
|Complications associated w/ Infiltrates.||
Can be alveolar or interstitial, resulting in shunting & V/Q mismatching & hypoxia.
|What is the importance of chest x-ray identification?||
Identification of such lesions through chest x-ray provides the ability to provide appropriate anesthetic management.
|Why is recognition of infiltrates significant on a chest x-ray?||
Further evaluation may be necessary from a pulmonologist or cardiologist. Specific detection may indicate medical therapy: antibiotics (Infection) or diuretics (CHF).
|What is the physics of radiography? How do they work?||
X-rays have a specific range of radiation darkening photographic film’s emulsion (White to gray.)
Varying densities are produced d/t different absorption of x-rays by body tissues to foreign materials.
|What are the five densities associated with x-rays from radiopaque to radiolucent?||
|What is radiopaque & example?||
Significant absorption of x-ray beam thus fewer x-rays strike film.
Bone (White area on film)
|What is radiolucent & example?||
Small amount of absorption thus most of x-rays strike film.
Air (Dark area on film)
|What are some other tissues seen in an x-ray & how do they appear?||
Tissue, fluid, & foreign material produce varying gray densities.
Muscle, blood, & solid organs appear the same gray density.
Fat is slightly darker.
|What are some geometric considerations when taking x-rays?||
Altered image size (D/T distance changes b/n x-ray tube, film plate & pt)
X-ray tube closer to pt (Image size inc.)
X-ray tube moves further from pt (Image size decr.)
If pt rotates against the film plate, image size may enlarge.
|What distance, from a patient, should a standard chest x-ray be?||
Six feet from x-ray tube to patient.
|What are the three (3) interpretations from a systematic approach, regarding x-rays?||
1.) Initial evaluation
2.) Radiographic technique evaluation
3.) Systematic analysis
|Name considerations w/ Initial evaluation. (1st)||
Examine for common errors.
Name, time and date correct?
Film markers (right or left).
Artifact (ECG leads, metal snap on gown).
|Explain radiographic technique evaluation (2nd) w/ position & distance when comparing x-rays.||
Ensure that position & distance are consistent (May not be realistic in ED, ICU, OR; Was patient able to cooperate?)
|Explain radiographic technique evaluation (2nd) in ERECT position.||
1) Examination of normal mediastinum
2) Correct interpretation of fluid & air levels
|Explain radiographic technique evaluation (2nd) in SUPINE position.||
1) Flattened mediastinum looks unusually wide
2) Pleural fluid will settle posteriorly to lung (Appear as haziness in hemithorax)
3) Air will rise to anterior surface of lung (Appears more lucent in hemithorax)
|Explain radiographic technique evaluation (2nd) in POSTEROANTERIOR (PA) position.||
1) Routine chest x-ray for baseline
2) X-ray beam passes from posterior to the anterior surface of chest & strikes film plate
|Explain radiographic technique evaluation (2nd) in ANTEROPOSTERIOR (AP) position.||
1) Portable chest x-rays in OR or at bedside are usually AP
2) X-ray beam passes from anterior to the posterior surface of chest & strikes film plate
|What are two advantages of the PA position?||
Yields least distortion.
Gives best view of pulmonary fields.
|What are some considerations concerning distortion w/ the AP position.||
AP films make heart & mediastinum appear larger because of their anterior location in the chest (farther from the film)
|Explain radiographic technique evaluation (2nd) concerning INSPIRATION.||
1) Was patient able to inhale & hold breath?
2) Should observe 10-11 posterior ribs over lung fields
3) Begin counting with 1st rib (difficult to find, look for anterior end just below mid-clavicle & follow to posterior)
|Explain radiographic technique evaluation (2nd) concerning EXPIRATION.||
1) Lung tissue will be compressed making heart & mediastinum appear larger d/t high position of diaphragm.
2) However….identifying pneumothorax (maximal expiration used to compress lung tissue increasing its density in contrast to pleural air aiding in its diagnosis)
|What is seen w/ proper exposure in x-rays?||
Soft tissues of lung visible.
Vertebra slightly visible through heart.
|What is seen when penetration too intense in x-rays?||
Normal lung markings blacked out.
Vertebrae well visualized.
|What is seen when penetration too light in x-rays?||
Radiopaque or washed out.
|What are some key points when addressing systematic analysis (3rd) & chest x-rays.||
Assessment of A&P
Begin with chest periphery & progress toward center
If reading film is a non-emergency, save the problem area for last (this avoids a “tunnel-vision” focus on the suspected pathology thus overlooking another situation)
|WHat are some considerations of Systematic analysis (3rd) pertaining to bony & soft tissue?||
Find ribs, clavicles, vertebrae, & scapula
Count vertebrae (remembering each corresponding rib is connected posteriorly)
Are they symmetrical? (Kyphosis, degenerative joint disease, FXs)
Presence of SQ air in soft tissues? (Remember air will appear dark & may be localized as lines or beads)
|What can SQ air be indicative of ?||
Ventilator trauma, lung or bronchial injury after chest trauma (may be d/t pneumomediastinum from migration of CO2 during laparoscopic nissen fundoplication.)
|What are some considerations of Systematic analysis pertaining to the Diaphragm?||
Normally rounded (Rt side slightly higher d/t location of liver)
Bilateral elevation (Pregnancy, obesity, peritoneal fluid)
Flattened (Emphysema, asthma, pleural effusion, tension pneumothorax)
Unilateral L elevation (Perforated ulcer, gastric gas)
|What are some other pathologies that may cause uni- or bilateral elevation?||
pneumonia, pulmonary infection, mass or distension of abdomen.
|What are some considerations of Systematic analysis pertaining to the Breasts?||
Breasts may alter density in lower lung fields producing contour line above diaphragm.
If one breast removed, may mimic pulmonary disease d/t increased radiopacity (scar tissue.)
|What are some considerations of Systematic analysis pertaining to Lung Fields?||
With inspiration, air will appear Radiolucent.
Pulmonary vessels give distinct pattern decreasing in size from medial to lateral.
Find the visceral pleural border next to radiopaque thoracic cage (Point of contact b/w pulmonary & parietal pleura)
|What are some landmarks associated w/ Lung Fields?||
Find visceral pleural border.
Diaphragm higher on right than left.
Find costophrenic angles (lateral border of rib cage & diaphragm)
|What could be present if the costophrenic angles are not sharp & well-defined?||
Air or fluid.
|What could be indicated if the border of lung is seen separate from chest wall w/ an abnormal density?||
Pneumothorax (air), hemothorax (blood).
Air will be darker than fluid.
What are some key points pertaining to Systematic analysis
w/ the Trachea?
Translucent air column.
Should be midline w/ slight Rt deviation at level of aortic arch.
May be straight in children (deviated in tension pneumo, atelectasis, effusion, tumor, or pneumonia consolidation)
Mass pushes trachea away & collapse pulls trachea toward abnormality.
|What will you see when systematic analysis deals w/ the tracheal bifurcation?||
R & L main bronchi (barely visible)
Enhance their view by holding film at 45 degree angle to light.
|What are some points w/ Systematic analysis associated w/ Vascular or hilar shadows?||
Hila w/ major bronchi & pulmonary vessels.
Above heart w/ Lt higher than Rt extending 1/3 into lung fields.
|What are key points when Systematic analysis pertains to the Mediastinum?||
B/n lungs containing heart, great vessels, trachea, esophagus, & lymph nodes.
Trachea will be seen as slightly lucent stripe down center.
Is it widened? (Cancer, hemorrhage, aneurysm, cor pulmonale, mediastinitis, recent CABG)
Is it shifted? (Tension pneumo, atelectasis, effusion)
|What should you do if an NGT is placed in the patient?||
Follow radiopaque stripe down esophagus & compare to trachea
|What key points of Systematic analysis are associated w/ the Cardiac silhouette?||
Heart visible lower Lt w/ 1/3 located to Rt of midline.
Normal size if < 50% of width of chest.
Cardiac tamponade or pericardial effusion will give “water bottle” round appearance.
|When evaluating invasive devices such as ETT, what are some considerations?||
Positioned w/ tip straight 4-6cm above carina in adult (located b/w 5th & 7th thoracic vertebrae).
Flexion of neck produces upward carina shift causing ETT to descend 2-3cm.
Extension of neck produces downward carina shift causing ETT to ascend up to 5cm.
Rotation can elevate ETT tip 1-2cm.
|What does this tell you about manipulation of patient’s head w/ ETT or Tracheostomy?||
Poss Rt mainstem w/ subsequent improper ventilation w/ ETT.
Neck movement in trach pt has little effect on tube position (usually @ T3)
|When evaluating invasive devices such as CVL what are some considerations?||
Proper placement shows catheter extending into Rt or Lt brachiocephalic vein in the SVC.
Tip should be in SVC at Rt lateral border T5-T6.
Should be medial to anterior aspect of 1st rib. (If tip has perforated into pericardial sac, fluid can be infused leading to pericardial effusion & tamponade).
|When evaluating invasive devices such as SWAN, what are some considerations?||
Should be seen through Rt heart & into large interlobar pulmonary artery 3-4cm beyond vertebral midline at T7 level. (If it is wedged into a smaller pulmonary artery, a pulmonary infarction may be seen as patchy infiltrate or consolidation around tip.)
|When evaluating invasive devices such as NGT, what are some considerations?||
Follow down esophagus through mediastinal shadow.
Should extend into stomach below Lt hemidiaphragm.
Watch for coiling in pharyngeal cavity or placement in pulmonary tree.
|When evaluating invasive devices such as CHEST TUBE, what are some considerations?||
Should be straight (unkinked).
Ensure all ports of tube (breaks in radiopaque stripe) are located w/n pleural cavity.
|When evaluating invasive devices such as IABP, what are some considerations?||
Usually contains 30-40 ml & is 8.5-10"
Should be in descending aorta b/w Lt subclavian artery & renal arteries.
Counterpulsation balloon used to enhance CO & coronary artery perfusion in weak hearts.
|What are some common Chest pathologies seen?||
ARDS (Acute respiratory distress syndrome).
Cardiogenic pulmonary edema.
COPD or emphysema.
|What is the significance of common chest pathologies associated w/ x-rays?||
Pulmonary disease x-ray findings are similar in appearance & non-specific
thus a history & exam are mandatory.
|What can air filled bronchi visible d/t surrounding infiltrated or consolidated lung tissue indicate? Examples?||
Pulmonary edema, pneumonia, pulmonary infarct, lung lesions.
|What can a loss of normally sharp edge of air-filled lung against dense tissue indicate?||
|What can accumulation of fluid in pleural space indicate?||
|What are some causes of Pleural Effusion? Give examples of each type.||
Exudate (inflammation). [Pneumonia, TB, pulmonary infarction, malignancy]
Transudate (elevation in vascular pressure).
[CHF, liver cirrhosis, Meig’s syndrome (ovarian tumors complicated by pleural effusions)]
What is common following surgery
resulting in air or fluid collapsing lung parenchyma (pneumothorax)?
Atelectasis (lungs will look increasingly opaque as it progresses)
|What are the classifications of & important factors when dealing w/ Pneumonia?||
Bacterial, viral, mycoplasmal, or parasitic (Early pneumonia chest x-ray may look normal).
Pulmonary infiltrate slowly progressing.
May include tracheal or mediastinal shifting.
|What are indications/significance of ARDS?||
Rapidly progresses from perhilar edema to patchy consolidation.
Atelectasis 2nd to destruction of surfactant.
Can be d/t shock, post-trauma resuscitation, pneumonia, sepsis.
|What is seen in Cardiogenic pulmonary edema?||
1st (Pulmonary venous congestion
Upper lobe vessels dilate)
2nd (Increase in Lt atrial pressure
Interstitial pulmonary linear densities between alveoli looking hazy).
3rd (Symmetrical opacities like a butterfly distribution from interstitial fluid in air spaces).
|What causes & may be seen in Aspiration pneumonitis?||
Irritating acidic substance (gastric).
X-ray changes can be immediate, delayed or non-existant.
Hypoxemia &/or bronchospasm.
Atelectasis from destruction of surfactant.
|What can be seen in COPD or Emphysema?||
Can be present w/o x-ray evidence.
Usually both lungs are extremely radiolucent d/t excess air & vessel compression.
Ribs wide & horizontal (barrel-chest).
Diaphragm low & flat.
Heart narrow & vertical d/t lung overinflation.
|What is essential to anesthesia practice & why?||
Knowledge of basic chest x-ray recognition.
Often you will view film first w/ latter confirmation by radiologist, esp. during on-call hours (emergency intubation)
|What is Dextracardia?||
refers to the heart being situated on the right side of the body.