
RES 131 Pulmonary Function Testing
Spirometric Technique • Patient preparation • Begins when the patient is scheduled • Medication discontinuation • Smoking abstinence • Purpose of test • Determine contraindications • Height and weight
Spirometric Technique • Explaining and Demonstrating the maneuver • Demonstrate the noseclip and mouthpiece • help the patient get accustomed to the mouthpiece and noseclip • Lip seal
Spirometric Technique • Tongue position • Dentures • Proper chin and neck position • Body position • Do not let the patient bend at the waist
Spirometric Technique • Oxygen use • Stop the oxygen during testing • Attaching to the mouthpiece • Open mouth method • Preferable for infection control concerns • Requires patient to position and obtain seal while lungs are full
Spirometric Techniques • Closed mouth method • Patient rebreathes on circuit • Allows for assessment of inspiratory flows • Often easier for the patient • Instructions • Give clear concise instructions • Demonstrate the maneuver
Spirometric Techniques • Summary of Important points for Procedure Explanation • Keep the explanation simple and brief • Demonstrate the maneuver • Remind the patient of key points
Patient Testing • Measurable results • Volumes • Capacities • Flowrates
Patient Testing • Vital Capacity
Vital Capacity • Figure 2-1 (pg 40)
Criteria for acceptability – VC • End-expiratory volume varies by less than 100 ml for three attempts • Volume plateau observed at maximal inspiration and expiration • Two acceptable VC maneuvers should be obtained; volumes within 200 ml • VS should be within 200 ml of FVC value
Patient Testing • Forced Vital Capacity (FVC)
Forced Vital Capacity Measurable values
Forced Vital Capacity • Patient inhales as deeply as possible and then blows out as hard and fast as possible.
Patient Testing • Criteria for Acceptability • Must have a minimum of three (3) acceptable maneuvers • Allow the patient sufficient time to rest between trials • Coach the patient • Administer oxygen between trials if needed • No more than eight trials
Patient Testing • Criteria for Acceptability • Four main criteria for acceptability • Good start of test • No coughing • No Variable Flow • No Early Terminations
Patient Testing • Criteria for Acceptability • Good Start of Test • Start of test must be quick and forceful • No excessive hesitation • Best evaluated using the Flow-Volume tracing • No excessive back extrapolated volume
Patient Testing • Start of Test
Patient Testing • Criteria for Acceptability • No Coughing • Especially during the first 1 second of the maneuver • Best if no coughing present during maneuver, however: • Some patients cough near the end of each test, if present then document
Patient Testing • Criteria for Acceptability • No Variable Flow • Flow rate should be maximal and consistent throughout testing • Volume-Time and Flow-Volume tracings should be smooth
Patient Testing • Criteria for Acceptability • No Early Termination of Effort • Best if maneuver lasts at least six (6) seconds • Less than six seconds acceptable if a plateau of al least one (1) second is present • If patient is unable to meet the above criteria, document in comment section
Patient Testing • Reproducibility • In addition to the criteria for acceptability discussed previously, the maneuvers must demonstrate reproducibility (consistency) of efforts.
Reproducibility • After three acceptable maneuvers are obtained • End Expiratory Volume varies by less than 100 ml for three attempts • Volume plateau observed at maximal inspiration and expiration • Two largest FVC Maneuvers should agree within 200 ml • VC should be within 100 ml of FVC