Pulmonary Assessment Flashcards
Pulmonary History
Baseline pulmonary function:exercise tolerance, dyspnea, orthopnea, smoking history, sleep apnea
Chronic lung disease: severity, medications hx, recent hospitalizations, frequency of exacerbations, and effective treatment
Acute lung disease: recent URI’s, abx, current symptoms
Previous anesthesia experiences: procedures, pulmonary complications, anesthesia technique utilized
Medical clearance:evaluations of current status and therapies
availability of laboratory and diagnostic studies
*Smokers
Physical Assessment Observation and Inspection:
Observation / Inspection: Rate, pattern and effort of respiration Tracheal position Expansion of thorax and use of accessory muscles of respiration Characteristics of skin and soft tissue
Physical Assessment Auscultation:
Breathing normally, mouth open
Diaphragm of stethoscope
Auscultate apices, middle and lower lung fields posterior, laterally and interiorly
Alternate and compare sides
Quiet respirations first, then deep breaths
Bronchial
What are Vesicular sounds?
Vesicular lung tissue Quality: lower pitched Softer expiration shorter
What is normal auscultation of the bronchial tree sound like?
Tracheobronchial tree Heard best: trachea, right sternoclavicular joint, posterior right interscapular space Quality: higher pitch
What are abnormal auscultation sounds?
Bronchial Breath Sounds Anywhere other than expected No ventilation into alveoli Consolidation low pitched bronchial breathing Cavitary Disease high pitched bronchial breathing Adventitious sounds: Wheeze, Stridor, Crackles
Pulmonary Function Test Purpose and Indication
Purpose Standardized Objective Indication Assist in diagnosis of disease Evaluate treatment Disease progression Assessing the risk
Who are appropriate candidates for PFTs?
Appropriate candidates for testing: Patients with evidence of COPD Smokers with a persistent cough Wheezing or dyspnea on exertion Morbid obesity Thoracic surgery patients Open upper abdominal procedures Patients >70 years of age
How do we classify Pulmonary function Tests? 2 ways.
- Tests that assess abnormalities of gas exchange:
ARTERIAL BLOOD GAS
PULSE OXIMETRY
CAPNOGRAPHY - Tests that assess mechanical dysfunction of the lungs and chest wall:
SPIROMETRY
What are the normal values of Spirometry and what are the predicted values based on?
Spirometry Volume –Normal 80-120% of predicted value Flow –Normal 80% of predicted value Predicted values based on Age Height/Weight Gender Ethnicity
Obstructive v. Restrictive Pulmonary Disease
Obstructive disease Airflow obstruction chronic bronchitis or emphysema Asthma chronic inflammatory disorder Restrictive disease Proportional decrease in all lung volumes
What is Vital Capacity measured by and what is it, whats the normal?
Most commonly measured
Measured by simple spirometry
Maximal inspiration followed by maximal exhalation to RV
Independent of rate of effort
Values decrease as subject goes from sitting to supine position
NORMAL is >/=80% of the predicted value
What is FVC, and what are the interpretations of the percentages predicted?
Forced Vital Capacity (FVC) Max insp. with forced exp. Function of volume/time Measures resistance to flow Effort and cooperation dependent
Interpretation of % predicted: 80-120% Normal 70-79% Mild 50%-69% Moderate <50% Severe
What is FEV1 and what are the interpretations of % of the FEV1/FVC ratios:
Forced expiratory volume in 1 second: (FEV1)
Volume of air forcefully expired from full inspiration in the first second
Normal is 75-80% of FVC
Effort and cooperation dependent
Interpretation of % FEV1/FVC: >75% Normal 60%-75% Mild 50-59% Moderate <49% Severe obstruction
What is FEF25-75 and what do the vales mean?
Forced expiratory flow 25-75% (FEF25-75)
Mean forced expiratory flow during middle of FVC
May reflect effort independent expiration and the status of the small airways
Sensitive in early stages of obstructive disease
More reliable than FEV1/FVC
Interpretation of % predicted:
>60% Normal
40-60% Mild
20-40% Moderate
<10% Severe obstruction
What is Maximum Voluntary Ventilation?
Maximum voluntary ventilation (MVV)
MVV is the largest volume that can be breathed in one minute by voluntary effort
Test is actually performed over 10, 12, or 15 seconds
Normal results may vary up to 30%
MVV reduced in OBSTRUCTIVE disease
MVV normal in RESTRICTIVE disease
What is FRC?
Volume of gas in the lungs after passive exhalation (residual volume is the volume of gas in the lungs after forced maximal expiration)
Function:
Point on the pressure-volume curve for resting ventilation
Quantify the degree of pulmonary restriction
How is FRC measured?
Measured:
Indirectly
Nitrogen wash-out
Nitrogen analyzer attached to a spirometer
End point = alveolar nitrogen concentration falls below 7%, usually takes about 7-10 minutes
What does the flow volume curve look like for restrictive?
Spirometry results
Rapid upstroke
Low volume
What is the distribution of blood flow in the zones of the lung?
Zone 1: PA>Pa>Pv Zone 2: Pa>PA>Pv Zone 3: Pa>Pv>PA
What does Zone 1 in the lung represent?
Zone 1
Pulmonary artery (Pa) pressure falls below alveolar pressure (PA)
DOES NOT occur under normal circumstances
Decrease BP < alveolar pressure
Increase in alveolar pressure
What does zone 2 and 3 in the lung represent?
Zone 2
Pulmonary artery pressure increases due to hydrostatic effect (gravity) and now exceeds alveolar pressure
Zone 3
Venous pressure now exceeds alveolar pressure
What is the normal pulmonary blood flow?
UPRIGHT POSITION: Gravity SUPINE POSITION: Uniform blood flow from apices to base Anterior v posterior
When sitting up, awake and breathing spontaneously what the ventilation and perfusion like?
When sitting up, awake and breathing spontaneously
Ventilation smallest at highest portion of lung
Ventilation increases in more dependent part of lung
Alveoli most compressed d/t gravity
Good compliance
Perfusion increases in more dependent part of lung.
What are the pulmonary physiological effects of PPV?
Increased:
Risk for atelectasis
Increase in blood flow to the dependent lung
Ventilation to the independent areas causing an increase in V/Q mismatch.
Dead space
Potential for barotrauma
What are treatment options for the pulmonary physiologic effects of PPV?
Peak airway pressure Deliver an adequate TV Maintain perfusion pressures to the lung PEEP FiO2 Assess & reassess
What are the cardiovascular effects of PPV and it’s treatment?
Cardiovascular effects Decreased Preload Blood pressure Increase Right to left shunt with atrial-septal defect Treatment: Position Fluid administration Pharmacology Alpha & Beta stimulants Inotropic support
What are the goals and methods to maximize pulmonary function?
Goal:
Reduce intraoperative and postoperative morbidity and mortality
Methods: Smoking cessation Mobilization of secretions/Treat infection Bronchospasm treatment Improve motivation and stamina
What are the timelines for smoking cessation?
12 - 24 hours = will reduce carboxyhemoglobin levels to normal
2-3 weeks mucociliary function returns; increased secretions
4 weeks = reduction in secretions
8 weeks = rate of postoperative pulmonary complications decreases
How do you treat infections and mobilize secretions?
Antibiotic therapy in the presence of Chronic bronchitis Mobilization of secretions Mucolytic agents ???? Hydration Aerosol therapy Mechanical therapy
How do you treat bronchospasm?
β2 –Sympathomimetic (stimulate)
Anticholinergic compounds
Methylxanthines
Corticosteroids
Anesthetic Management for Restrictive Pulmonary Disease
Preoperative sedation
titrate carefully due to reduced FRC
Nitrous Oxide +/-
Regional anesthesia
>T10 level = loss of accessory respiratory muscles may be crucial to spontaneous ventilation in these patients
Inhalation agents have accelerated uptake due to decreased FRC
Efficiency
decreased FRC=lower O2 stores = SaO2 drops quickly with apnea despite preoxygenation
What do you expect when you are mechanically ventilating someone with restrictive pulmonary disease?
Expect increased peak airway pressures
Decrease volume (4-8 ml/kg)
Increase respiratory rate (14-18 bpm)
PEEP
What are the anesthesia effects on FRC and VC in the patient with restrictive pulmonary disease?
Anesthesia effects on FRC
Normal healthy patients
10-15% reduction in supine position
Additional 5-10% reduction with GA
Plateau develops after 10 minutes regardless of ventilation
May take 3-7days to recover after upper abdominal procedures
VC may have up to a 40% reduction and take up to 14 days to return to normal after an upper abdominal procedure
What are things to keep in mind when managing the patient with obstructive pulmonary disease?
1. Reducing airway reactivity Aggressive bronchodilator therapy High alveolar concentrations of IA IV opioids/lidocaine prior to airway manipulation Single dose corticosteroids 2. Avoid spontaneous ventilation with GA 3. Regional anesthesia >T10 level = loss of accessory respiratory muscles may be crucial to spontaneous ventilation in these patients 4. Use of Nitrous Oxide +/-
What do you do with tidal volume and expiratory time with the patient with obstructive pulmonary disease?
- Positive pressure ventilation:
Large tidal volume
slow respiratory rate
Keep PIP below 40cmH20 - Goal = Balance
Avoid high peak airway pressures; allow longest possible expiratory time
Intrinsic PEEP may occur due to air trapping
