Copd introduction and pft

anaesthesia for copd ptients (introduction)

1. ANAESTHESIA AND COPD Dr PRASHANTH Dr GANESH Dr KARAN Dr KIRAN

2. DEFINITION PATHOPHYSIOLOGY DIAGNOSIS PRE OPERATIVE OPTIMISATION

3. www.goldcopd.com, Updated 2006 INTRODUCTION “A common preventable and treatable disease characterised by persistent airflow limitation that is usually progressive and associated with an enhanced chronic inflammatory response in the airways and the lung to noxious particles or gases’’ 3 rd Leading cause of morbidity & mortality

4. COPD INCLUDES.. CHRONIC BRONCHITIS : (clinical definition) Chronic productive cough for 3 months in each of 2 successive years EMPHYSEMA : (anatomical definition) Permanent enlargement of the airspaces distal to the terminal bronchioles SMALL AIRWAY DISEASE : Narrowing of small bronchioles due to hyperplasia, mucus and fibrosis

5. Comparative features of COPD Feature Chronic Bronchitis Emphysema Mech of Airway Obstruction Decreased Lumen d/t mucus & inflammation Loss of elastic recoil Dyspnoea Moderate Severe FEV 1 Decreased Decreased PaO 2 Marked Decrease (Blue Bloater) Moderate Decrease (Pink Puffer) PaCO 2 Increased Normal or Decreased Diffusing capacity Normal Decreased Hematocrit Increased Normal Cor Pulmonale Marked Mild Prognosis Poor Good

6. Differences Between COPD and Asthma Parameters COPD Asthma Onset Middle age Early in life (often childhood) Symptoms Slowly progressive Diurnal and seasonal variation History Long smoking history or exposure to smoking and bio-mass fuel History of allergy, rhinitis and/or eczema. Inflammatory cells Neutrophils Eosinophils Airway hyperresponsiveness ++ ++++ Airflow limitation Largely irreversible usually < 15% or 200 ml change Largely reversible usually > 15% or 200 ml change. (irreversible in later stages)

7. Risk factors SMOKE: CIGARETTE smoking passive smoking environmental occupational Genetic factors: α 1 anti trypsin deficiency

8. PATHOGENESIS

9. PATOGENESIS contd.. Elastase & antielastase hypothesis Imbalance between elastin and elastase Deficiency of α 1 antitrypsin which is elastase inhibitor Autoimmune contribution Cigarette smoke induced loss of cilia & impaired macrophage phagocytosis

10. PATOGENESIS contd ..

11. PATHOLOGY contd.. Types of emphysema

12. PATHOPHYSILOGY :PULMONARY PULMONARY AIRWAY OBSTUCTION HYPERRESPONSIVENESS ALVEOLAR DESTRUCTION SECRETIONS HYPERINFATION

13. PATHOPHYSIOLOGY contd..: EXTRA PULMONARY IL6,TNF a, CRP, OXIDANTS, HYPOXEMIA RT HEART DISEASE,IHD SKELETAL MUSCLE WEAKNESS OSTEOPOROSIS DM, DEPRESSION

14. PATHOPHYSIOLOGY contd..: EXTRA PULMONARY

15. PRE OPERATIVE OPTMISATION

16. Pre-operative assessment: History: Smoking Cough: Type, Progression, Recent RTI Sputum: Quantity, color, blood Dyspnea Exercise intolerance Occupation, Allergies Symptoms of cardiac or respiratory failure

17. Physical findings Early stage: signs of smoking Advanced stage: prolonged expiratory phase with wheeze Signs of hyperinflation: barrel chest Use of accessory muscles Tripod position Cyanosis Cachexia , bitemporal wasting & diffuse loss of subcutaneous adipose tissue Clubbing : ?? carcinoma

18. PHYSICAL FINDINGS contd.. Pink puffers emphysema Thin patients Non cyanotic at rest Use of accessory muscles Good prognosis Blue bloaters Chronic bronchitis Heavy patients Cyanotic at rest Bad prognosis

19. Investigations: Routine blood investigations Chest Radiograph: To exclude other diseases Emphysematous changes Spirometry Diagnosis Assessment of severity Following progress Bronchodilator Reversibility Exclude Bronchial Asthma <20% Diagnosis

20. Investigations: Chest X-Ray Overinflation Depression or flattening of diaphragm Increase in length of lung ↑ size of retrosternal airspace ↑ lung markings- dirty lung Bullae +/- Vertical Cardiac silhouette ↑ transverse diameter of chest, ribs horizontal, square chest Enlarged pulmonary artery with rapid tapering in MZ Diagnosis contd

21. Indications for PFT (American College of Physicians consensus statement) Cardiac, thoracic or upper abdominal surgery with a history of dyspnea, smoking Lower abdominal surgery with a history of dyspnea, smoking and anticipated prolonged surgery All patients undergoing lung resection Morbid obesity Any pulmonary disease Age > 70 years

22. Bed side PFT Sabrasez breath holding test: >25 sec- normal cardio pulmonary reserve (CPR) 15-25 sec- limited CPR <15 sec-very poor CPR (contra indication for elective surgery) 25-30 sec -3500ml VC 20-25 sec -3000ml VC 15-20 sec -2500 ml VC 10-15 sec-2000 ml VC 5-10 sec- 1500 ml VC

23. Bed side PFT contd.. Schneider’s match blowing test : measures maximum breathing capacity Ask to blow a match stick from a distance of 15 cm Mouth wide open Chin rested/supported No pursing of lips No head movement No air movement in the room Mouth and match at same level

24. Bed side PFT contd.. Can not blow the match -MBC<60L/min -FEV1<1.6L Able to blow out a match -MBC>60 L/min -FEV>1.6L Modified match test Distance MBC 9’’ >150L/min 6’’ >60 L/min 3’’ >40L/min Match blowing test

25. Bed side PFT contd.. Cough test: deep breath followed by cough Ability to cough Strength Effectiveness Inadequate cough : FVC <20 ml/kg FEV1<15ml/kg PEFR<200L/min A wet productive cough /self propagated paraxysms of coughing –patient susceptible for pulmonary complication

26. Bed side PFT contd.. Forced expiratory time: A deep breath, exhale maximally and forcefully & keep stethoscope over trachea &listen normal:3-5 sec obstr . Lung disease: >6sec restr . Lung disease : <3 sec

27. Bed side PFT contd.. Wright peak flow meter : measures peak expiratory flow rate Normal: Males 450-700L/min Females 350-500L/min DE-BONO whistle blowing test : measure PEFR Patient blows down a wide bore tube at the end of which is a whistle ,on the side is hole with adjustable knob. As patient blows whistle blows, leak hole is gradually increased till intensity of whistle disappears Last position at which the whistle can be blown, the PEFR can be read off the scale

28. Bed side PFT contd.. MIROSPIROMETERS: measures vital capacity BED SIDE PULSE OXYMETRY ABG

29. Pulmonary Function Tests: spirometry Measure Normal Obstructive Restrictive FVC (L) 80% of TLC (4800)    FEV 1 (L) 80% of FVC   FEV 1 /FVC(%) 75- 85% N to  N to  FEV 25%-75% (L/sec) 4-5 L/ sec  N to  PEF(L/sec) 450- 700 L/min  N to  Slope of FV curve   MVV(L/min) 160-180 L/min  N to  TLC 6000 ml N to   RV 1500 mL   RV/TLC(%) 0.25  N

30. FEV1 FEV1 FVC seconds 2 1 3 4 5 1 2 3 4 Litres 5 COPD NORMAL 60% 3900 2350 COPD 80% 5200 4150 Normal FEV1/FVC FVC FEV1 FVC Spirometric tracing in COPD patients Spirometry contd

31. FLOW VOLUME LOOP Spirometry contd

32. GOLD Classification (severity of disease) Stage Characteristics I: Mild FEV 1 /FVC < 70% FEV 1 ≤ 80% predicted, with/without chronic symptoms II: Moderate FEV 1 /FVC < 70% 50% ≤ FEV 1 ≤ 80% predicted, with/without chronic symptoms III: Severe FEV 1 /FVC < 70% 30% ≤ FEV 1 ≤ 50% predicted, with/without chronic symptoms IV: Very severe FEV 1 /FVC < 70% FEV 1 < 30% predicted or < 50% predicted plus chronic respiratory failure (PaO 2 < 60mm Hg &/or PaCO 2 > 50mm Hg)

33. Preoperative Assessment: Investigations contd. ECG May be normal Signs of RVH: RAD p Pulmonale in Lead II,III,avF Predominant R wave in V 1-3 Supraventricular arrhythmias common in exacerbations

34. Preoperative Assessment: Investigations contd. ABG Not done routinely Indicated Severe pulmonary disease : FEV1/FVC <50% Good predictor of post op pulmonary complication PaCO2>50mm Hg  need for post op mechanical ventilation

35. Exercise testing: -expensive, cumbersome -Not validated in nonthoracic surgery -Parameter with greatest utility is decreased maximum O2 consumption

36. Pre-operative optimization Cessation of smoking Dilation of airways Loosening & Removal of secretions Eradication of infection Recognition of Cor Pulmonale and treatment Improve strength of skeletal muscles – nutrition, exercise Correct electrolyte imbalance Familiarization with respiratory therapy, education, motivation & facilitation of patient care

37. Pre operative optimization : Smoking Cessation Motivation, Counseling & behavioral support Nicotine replacement Patches chewing gum Inhaler nasal spray lozenges Bupriopion

38. Smoking cessation and time course of beneficial Effects Time after smoking Physiological Effects 12-24 Hrs Fall in CO & Nicotine levels 48-72 Hrs COHb levels normalise Airway function improves 1-2 Weeks Decreased sputum production 4-6 Weeks PFTs improve 6-8 Weeks Normalisation of Immune function 8-12 Weeks Decreased overall post operative morbidity

39. Effect of smoking and smoking cessation on Lung Function: Loss of lung function over 11 yrs in the Lung Health Study for continuous smokers (–––) , intermittent quitters (–––) and sustained quitters (–––) . FEV1: forced expiratory volume in one second. Smoking and lung function of Lung Health Study participants after 11 years. Am J Respir Crit Care Med 2002; 166: 675–679.

40. Pre operative optimization: Dilatation of Airways: Bronchodilators: Only small increase in FEV 1 Alleviate symptoms by decreasing hyperinflation & dyspnoea Improve exercise tolerance Anticholinergics Beta Agonists Methylxanthines

41. Pre operative optimization:Anticholinergics : Block muscarinic receptors Onset of action within 30 Min Ipratropium – 40-80 μ g by inhalation 20 μ g/ puff – 2 puffs X 3-4 times 250 μ g / ml respirator soln. 0.4- 2 ml X 4 times daily Tiotropium - long lasting Side Effects: Dry Mouth, metallic taste Caution in Prostatism & Glaucoma

42. Pre operative optimisation: Beta agonists: Act by increasing cAMP Specific β 2 agonist – Salbutamol : oral 2-4 mg/ 0.25 – 0.5 mg i.m / s.c ,100-200 μ g inhalation muscle tremors, palpitations, throat irritation Terbutaline : oral 5 mg/ 0.25 mg s.c ./ 250 μ g inhalation Salmeterol : Long acting (12 hrs) 50 μ g BD- 200 μ g BD Formeterol , Bambuterol

43. Pre operative optimisation: Methylxathines : Mode of Action – inhibition of phospodiesterase , ↑ cAMP , cGMP – Bronchodilatation Adenosine receptor antagonism ↑ Ca release from SR Oral( Theophyllin ) & Intravenous ( Aminophylline , Theophyllin ) loading – 5-6 mg/kg Previous use – 3 mg/kg Maintenace – 1.0mg/kg h for smokers 0.5mg/kg/h for nonsmokers 0.3 mg/kg/h for severely ill patients.

44. Pre operative optimisation : Inhaled Corticosteroids: Anti-inflammatory Restore responsiveness to β 2 agonist Reduce severity and frequency of exacerbations Do not alter rate of decline of FEV 1 Beclomethasone , Budesonide , Fluticasone Dose: 200 μ g BD ↑ upto 400 μ g QID

45. Loosen secretions -Hydration: systemic, jet/USG nebulizer - Mucolytics ( acetylcysteine ) not of much use Remove secretions -Postural drainage - Purcussion (chest physiotherapy) -Coughing -Breathing exercises Pre operative optimisation contd..

46. History of smoking (current or >40 pack-years ) ASA-PS > 2 Age >70 years Neck, thoracic, upper abdominal, aortic, or neurologic surgery Anticipated prolonged procedures (>2 hours ) G eneral anesthesia (especially with endotracheal intubation Albumin less than 3  g/ dL Exercise capacity of less than two blocks or one flight of stairs BMI greater than 30 Arozullah AM, Ann Surg 232:242-253,2000 . Risk factors for post op pulmonary complications

47. To be contd..... Thank you