Assessment in Pulmonary Medicine - Pulmonary Medicine - Lecture Slides, Slides of Pneumology

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FUNCTIONAL ASSESSMENT IN PULMONARY MEDICINE Types of Clinical Exercise Testing        6‐minute walk test Sh ttl lk t tu e wa   es Exercise induced bronchoconstriction Cardiac stress test C di l i t tar opu monary exerc se  es s Docsity.com Performing 6MWT  Should be performed indoors along long, flat, straight  corridors (30 m) Instruct and demonstrate properly Walk AS FAR AS POSSIBLE for 6 minutes, but don’t run or jog Permitted to slow down, to stop, and to rest as necessary May lean against the wall while resting St d d h f tan ar  p rases  or encouragemen “You are doing well” “Keep up the good work”        If practice test is done wait for ~1 hr, and report the  highest 6MWD Am J Respir Crit Care Med 2002;166:111–117 Docsity.com VariablesMeasured  6MWD Secondary measures include      Fatigue and dyspnea, measured by modified Borg or  VAS Arterial O2 saturation Optimal reference equations from healthy population            not yet available 6MWD range from 400 to 700 m            Statistically significant mean increase in 6MWD in a  group of COPD patients 70 m      ‐   Am J Respir Crit Care Med 1997;155:1278–1282 Respir Care 2003;48(8):783–785 Docsity.com Interpretation  A low 6MWD is nonspecific and non‐diagnostic The following tests may then be helpful:            Pulmonary function Cardiac function  Ankle–arm index M l t thusc e s reng Nutritional status O h di f irt ope c  unct on Cognitive function Docsity.com Shuttle walk test    A walk test based on the 20m              shuttle run test Measures maximal distance  walked by the patient at a  pace set by audio signals  Requires patients to walk at  increasing speeds up and  down a 10m course      S d f lki i i dpee  o  wa ng  s  ncrease   every minute (by 0.17 m/s) Heart 1996;75:414‐418 Docsity.com Shuttle walk test    Terminated when pt becomes too breathless to  maintain the required speed or if he fails to                  complete a shuttle in the time allowed Incremental maximal symptom limited test    ‐   Correlates better with VO2max than 6MWT Disadvantages: Does not reflect daily activities Greater risk of complications than CPET (as no ECG) Eur Respir J 1994;7:2016–2020 Docsity.com Endurance SWT  Walk test for the assessment of endurance capacity  of individuals Work rate of ESWT is set at 85%of maximal capacity  which is obtained from a prior ISWT Constantwork load field walking test which  complements ISWT  Field equivalents of the symptom limited laboratory  exercise test    While ISWT measures maximal capacity, ESWT  examines the ability to use that capacity            Thorax 1999; 54:213–222 Docsity.com Exercise Induced Bronchoconstriction Test‐   Used to determine the presence of airway  hyperreactivity FVC and FEV1 measured at baseline and at 5, 15 and  30 min post exercise Positive test is reflected as a reduction of FEV1 or FVC  of 15% after exercise      EIB observed in 70% to 80% of patients with clinically  recognized asthma  Less sensitive than methacholine challenge test Docsity.com Cardiac Stress Test or Graded Exercise Test            Most widely used clinical exercise testing  modality in the United States        Used primarily for the diagnosis of CAD and  arrhythmias Performed on a treadmill‐ Bruce protocol is the  t lmos  popu ar Single most reliable indicator of exercise‐induced  ischemia is ST‐segment depression Docsity.com CARDIOPULMONARY EXERCISE  TESTING Docsity.com Field tests CPET Lack of reference values  Absence of physiological Provides global assessment Can pinpoint system      measures  Cannot differentiate system       involvement Relatively noninvasive      involvement    Dynamic physiologic  overview Permits evaluation of both  submaximal and peak  exercise responses Docsity.com When to perform    Clinical decision   Hi t h i l ns ory, p ys ca  exam CXR ECG PFT’s Docsity.com Clinical Indications  Evaluation of exercise intolerance and  unexplained dyspnea  Cardiovascular diseases R i t di / tesp ra ory  seases   symp oms Preoperative evaluation‐ lung resection, LVRS Pulmonary rehabilitation Impairment / disability assessment      Docsity.com Preoperative evaluation  Lung cancer resection surgery VO peak <50‐60% predicted is associated with2             higher rates of morbidity and mortality after lung  resection A J R i C i C M d 1999 159 1450 1456 LVRS m    esp r r t are  e   ; : – Currently investigational National Emphysema Treatment Trial‐ the maximal  work rate derived from CPET as its primary  h i l i t tp ys o og c ou come parame er Am J Respir Crit Care Med 2003;167:211‐77 Docsity.com Contraindications Absolute CI Relative CI AMI (3 5 d ) USA L ft i t i  ‐   ays  or  Uncontrolled arrhythmia with  HD compromise e  ma n coronary s enos s Moderate stenotic valvular heart disease Syncope Respiratory or Heart failure Severe untreated HTN  (>200/120) Tachy or bradyarrhythmia/ AV Active endocarditis or  myocarditis S AS         block Hypertrophic cardiomyopathy Si ifi t PAHevere  PE or lower limb DVT  Uncontrolled asthma gn can   Advanced pregnancy Orthopedic disease    Rate of death during testing 2‐5/ lakh tests Docsity.com Protocol  History, PFT, ECG ↓ Ma imal incremental e ercise on c cle ergometerx     x     y   ↓ Cardiopulmonary measurements 3 min resting 3 min unloaded cycling 10 min incremental/ Ramp      Exercise (5‐30 W/min) ↓ 10 min recovery (3 min unloaded cycling) ECG monitoring  Docsity.com Variablesmeasured by CPET      Variables Noninvasive Invasive Work Work rate  Metabolic VO2 , VCO2, RER, AT (A.K.A. LT) Lactate Cardiovascular HR HRR ECG BP O pulse,  ,  ,  ,  2 Respiratory VE, VT, VR, PETO2 , PETCO2 P l S O P O P(A )Ou monary gas  exchange SpO2 , VE/VCO2 , VE/VO2 a 2 ,  a 2 ,  ‐a 2 VD/VT Acid base pH PaCO HCO −‐ ,  2 ,  3 Symptoms Dyspnea, leg fatigue, chest pain Docsity.com Oxygen Uptake (VO )    2 Best available index for the assessment of  exercise capacity VO2 max: when plateau is achieved VO2 peak: VO2 at max exercise, but no plateau            Global assessment of respiratory, cardiac, blood  & muscle function    >84% predicted normally Resting VO2: 3 5 ml/kg/min (250 ml/min)    .       VO2 max: 30‐50 ml/kg/min (15 times basal) Trained athletes: 80 ml/kg/min Docsity.com Oxygen Uptake (VO )    2 Decreased slope: Inadequate O2  transport/ utilization Disease of heart, lung or  circulation Musculoskeletal disease Poor effort Am J Respir Crit Care Med 2003;167:211‐77 Docsity.com Anaerobic threshold  Noninvasive  V‐slope method  Ventilatory equivalents method I invas ve  Arterial lactate Arterial bicarbonate Docsity.com Anaerobic threshold  Helpful as an indicator of level of fitness and  to monitor the effect of physical training            Reduced in a wide spectrum of clinical  entities— so limited discriminatory value Docsity.com Cardiac parameters  CO increases linearly with VO2 and does not vary  with training‐ best indicator of cardiac function          Initial ↑ in CO by ↑ HR and SV, later exclusively by  ↑ HR Predicted maximum HR = 210 − (age × 0.65) or  220 ‐ age Normally, max HR >90% age predicted HRR = Age predicted max HR − max HR achieved Normally, HRR <15 bpm      Docsity.com Ventilatory reserve Denotes potential ventilation in L that could be  increased during exercise Difference or ratio between max minute ventilation  (VEmax) and MVV VEmax/MVV × 100 <75% MVV − VEmax >11 L      MVV can be measured directly or calculated (FEV1 × 40) Pulmonary diseases have reduced reserve  Cardiac diseases have normal reserve        Docsity.com VE and VO    2 Relation complex  Usually nonlinear Am J Respir Crit Care Med 2003;167:211‐77 Docsity.com VE and VCO    2 Usually linear    relationship Slope indicates    ventilatory equivalent  for VCO  2 Am J Respir Crit Care Med 2003;167:211‐77 Docsity.com CPET responses at peak exercise        Resp COPD/ILD Cardiac PVD Deconditioned VO2max Decreased Decreased Decreased Decreased AT N/ Decreased Decreased N/ Decreased N/ Decreased HRR Increased Decreased N/ Decreased N VE/MVV Decreased Normal  N N P(A )O I d N l I d N‐a 2 ncrease   orma   ncrease Docsity.com Interpretation: Integrative approach    Review clinical and laboratory information Identify key variables: VEmax MVV HR SaO2      , ,  ,  Compare exercise responses with appropriate normal  reference values  Evaluate cause of exercise limitation P tt f ia erns o  exerc se responses Results are rarely clear‐cut Interpretation may be challenging Docsity.com Cardiac disease  Reduced work rate and VO2peak Low AT (early onset metabolic acidosis)          Low oxygen pulse High HR response (decrease HRR) Ventilatory reserve normal No desaturation Docsity.com Pulmonary vascular disease    Reduced peak work rate and peak VO2 AT reduced (early metabolic acidosis)        Reduced oxygen pulse Ventilatory reserve normal HRR usually near normal (low‐ cor pulmonale) Significant hypoxemia Wide P(A a)O gradient  ‐ 2 Docsity.com Deconditioning Reduced peak VO2 (lower limit of N) Normal or low AT      Reduced O2 pulse  Normal peak HR (no HRR) Normal ventilatory reserve Diff to distinguish from early cardiac disease ‐ history and response to training        May be coexistent with chronic diseases Docsity.com Conclusions  Exercise tests provide reliable estimate of  functional capacity and activities of daily living Amongst walk tests 6MWT is test of choice                CPET provide global assessment of various            systems involved in exercise Interpretation to be done using integrative  approach Docsity.com