Pulmonary Function Tests

Pulmonary Function TestsPresenter: Dr. Sofia PatialModerator: Dr. Gian ChauhanGOALS To predict presence of pulmonary dysfunctionTo know the functional nature of disease.To assess the severity of diseaseTo assess the progression of diseaseTo assess the response to treatmentMedicolegal- to assess lung impairment as a result of occupational hazard.To identify patients at perioperative risk of pulmonary complications

INDICATIONS OF PFT IN PAC

TISI GUIDELINES FOR PREOPERATIVE SPIROMETRYAge > 70 yrs.Morbid obesity Thoracic surgeryUpper abdominal surgerySmoking history and coughAny pulmonary disease

ACP GUIDELINES FOR PREOPERATIVE SPIROMETRYLung resectionH/o smoking, dyspnoeaCardiac surgeryUpper abdominal surgeryLower abdominal surgeryUncharacterized pulmonary disease (defined as history of pulmonary Disease or symptoms and no PFT in last 60 days)Contraindications:Hemoptysis of unknown originPneumothoraxUnstable cardiovascular status, recent MI, pulmonary embolismThoracic, abdominal or cerebral aneurysmsRecent eye surgery (cataract)Nausea, vomitingRecent surgery on thorax or abdomenComponents of PFTs: Spirometry for measuring airway mechanics (dynamic flow rates of gases)Measuring lung volumes and capacitiesMeasuring diffusion capacity of lungSpirometry

PREREQUISITIESPrior explanation to the patientNot to smoke /inhale short acting bronchodilators 4 hrs prior or oral aminophylline and long acting bronchodilator 12hrs prior. Remove any tight clothings/ waist belt/ denturesPt. Seated comfortablyIf obese, child < 12 yrs- standingNose clip to close nostrils.3 acceptable tracings taken & largest value is used.

FVCForced vital capacity (FVC):Total volume of air that can be exhaled forcefully from TLCExhalation time at least 6sec for adults & children> 10 yrs3 sec for children< 10 yearsInterpretation of % predicted:80-120% Normal70-79% Mild reduction50%-69% Moderate reduction25 sec.-normal 15-25 sec- limited CPR 15 : normal 60 L/minFEV1 > 1.6LMODIFIED MATCH TEST: DISTANCE MBC 9 >150 L/MIN. 6 >60 L/MIN. 3 > 40 L/MIN.

5) GREENE & BEROWITZ COUGH TEST:deep breath f/by cough ABILITY TO COUGH STRENGTH EFFECTIVENESSINADEQUATE COUGH IF: FVC