Artificial respiration, respiratory changes during exercise, respiratory disorders

1. Artificial respiration, respiratory changes during exercise, respiratory disorders Dr B.kalpana

2. At the end of class students should be able to: 1. Mention the conditions in which artificial respiration is done. 2. Explain the different types of artificial respiration and mention its merits and demerits. 3. List the indications for CPR 4. What are main stages of CPR 5. Explain the respiratory changes during exercise 6. Mention the ventilatory abnormalities and their clinical features.

3. The purpose of giving artificial respiration is -- To maintain the gaseous interchange. It also helps to maintain circulation. It is expected that after sometime, the respiratory centers will start functioning spontaneously. During artificial respiration, the alternate inflation and deflation of lungs reflexly stimulate the respiratory center that leads to spontaneous respiration

4. Two types: Instrumental method Manual method

5. Manual methods • The different types of manual methods are-- • Schafer’s method- Subject in prone position; Head tilted side; Operator-side by • Holger-Nielsen method (Arm-lift back pressure method) –Subject in prone position, hands folded rested under head; Operator –head end • Sylvester’s method —subject in supine position, Operator at head end • Mouth-to-mouth method –better than others • Eve’s rocking method

7. Both Inspiration and Expiration are actively assisted • TV is 1000 ml • Easy to perform if the procedure is known thoroughly by the operator. • 10-12 times/min

8. Mouth to mouth respiration(10-15 times /min)

9. Instrumental methods Negative pressure breathing method By alternately compressing and relaxing the chest wall • Drinker’s method –iron lung chamber-alternatively increase and decrease the pressure-Expiration and Inspiration • Bragg-Paul’s method-hollow elastic rubber bag around chest. Inflate and deflate the bag-Expiration and Inspiration Positive-pressure breathing By introducing air or oxygen directly into the lungs • Continuous inflation method • Intermittent inflation method

10. Bragg paul`s method • A rubber bag is wrapped around chest-air is pumped in and out of rubber bag. • Positive pressure • Used in Ots • In animals

11. Cardiopulmonary resuscitation Cardiorespiratory arrest. Shock Drowning Head injury Accident Cardiac surgery Airway obstruction

12. Initiate and facilitate pumping of heart -effective circulation • Adequate PV –Partial pressure of oxygen in arterial blood is maintained.

13. Open the airway using a head tilt lifting of chin. Do not tilt the head too far back Check the pulse on carotid artery using fingers of the other hand

14. Main stages of resuscitation C (Circulation) – restore the circulation by external cardiac massage A (Airway) – ensure open airway by preventing the falling back of tongue, tracheal intubation if possible B (Breathing) – start artificial ventilation of lungs D (Differentiation, Drugs, Defibrilation) – quickly perform differential diagnosis of cardiac arrest, use different medication and electric defibrillation in case of ventricular fibrillation

15. C. Circulation Restore the circulation, that is start external cardiac massage 2 times every sec About 2 inch Rescue breath 2:30 Chest compression-100/min

16. A (Airway)  ensure open airway

17. B (Breathing) Tilt the head back and listen for. If not breathing normally, pinch nose and cover the mouth with yours and blow until you see the chest rise.

18. Advanced life support: • Defibrillation • Airway management and oxygen therapy.

19. BREATH SOUNDS • Two types • Vesicular • Bronchial

20. Vesicularbreath sound • Low pitch, rustling in nature • Normally heard over lungs • Inspiration more than expiration • Intensity of inspiration greater than expiration • No gap between inspiration and expiration no gap Inspiration Expiration

21. Bronchial breath sounds • High pitch, harsh in nature • Normally heard over trachea and lung disease like consolidation • Expiration equal or more than inspiration • Intensity of expiration greater than inspiration • Gap between inspiration and expiration Inspiration expiration, gap in between

22. In muscular exercise

23. In Heavy exercise body’s metabolism increases about 2000% above normal . • For sustaining exercise extra fuel & O2 should supply by Respiration & CVS adjustments • O2 consumption increases proportional to severity of exercise up to a maximum

24. VO2 max. • The maximum rate of O2 consumption by the large part of working muscle mass during exercise with maximum effort is known as VO2 max. • Varies depends on age, sex, & state of physical training. • It is higher in young adult & less in old age.

25. Increased O2 consumption during exercise is achieved by – Increased pulmonary ventilation Increased O2 diffusion capacity of lungs about 3 times increased perfusion opening of more capillaries.

26. Factors increase pulmonary ventilation • In moderate exercise –by increase depth of respiration • In severe exercise –by increase depth & rate of respiration

27. Mechanism of increased ventilation • Neural • Chemical • Thermal • Hormonal

28. Neural: • At the beginning for initial abrupt rise • Impulses from proprioceptors

29. Chemical: • pCO2, • pO2 • pH • K+

30. Arterial pO2- • Alveolar and arterial pO2 remain normal almost throughout the exercise • In spite of rapid utilization by exercising muscle arterial pO2 is maintained due to proportionate increase in ventilation

31. Arterial pCO2 • Remains normal in mild to moderate exercise due to hyperventilation • as CO2 stimulates chemoreceptors to increase ventilation • pCO2 falls in severe exercise as lactate threshold is reached.

32. Arterial pH • Initially lactic acid CO2increased ventilation • Buffering of acid-isocapnicbuffereing • Beyond lactate threshold lactate level increases and pH falls-accumulation of lactic acid

33. Plasma K+ • Moderate to severe exercise K+ released from exercising muscles stimulates stimulates peripheral chemoreceptor and stimulates respiration.

34. Thermogenic mechanism Increased temperature stimulates ventilation Hormonal mechanism Epinephrine released during exercise increases sensitivity of respiratory center to chemical changes

35. Respiratory quotient • CO2 released/ O2 consumed • In severe exercise it is high

36. Effect of exercise on pulmonary ventilation & O2 consumption • Pulmonary Ventilation at rest – 6L/min • Pulmonary Ventilation at max. exercise – 100L/min • MBC –150L/min (50% more than pulmonary ventilation at maximum exercise) • Provide safety factor –for athletes in exercise at high altitude, hot conditions & abnormality in respiratory system. • Normal O2 consumption at rest –250ml/min • Max O2 consumption during exercise –4000ml/min • VO2 max. is 80% even in maximum exercise • Thus, the respiratory system is not the limiting factor for O2 delivery; but the blood supply.

37. Accumulation of lactic acid (in vigorous exercise) –increase in O2 uptake is proportional to work load up to a maximum. What is oxygen deficit? The time required for circulation to deliver extra oxygen required by working muscle. This oxygen deficit is repaid in form of oxygen debt.

38. O2 debt • To regenerate depleted stores of ATP and creatinine phosphate • To resupply O2 to myoglobin • To remove the blood lactate • to resupply O2 in tissue fluid and blood

39. Causes for Fatigue • Acidosis (due to accumulation lactic acid) • Lactic acid stimulate pain fibers that aid in on set of fatigue • Due to sustain muscle contraction –muscle become ischemic leads to release of substance P which stimulate to pain receptors lead to fatigue • Muscle stiffness due to accumulation of interstitial fluid leads to fatigue

40. 5.Hypoglycemia 6. Decrease tissue & blood pH –at CNS level to feel fatigue

41. Obstructive and restrictive lung disorder: Obstructive diseases: • Asthma • COPD • Cystic fibrosis Features: TLC is normal or increased RV elevated, RV/TLC increases FEV1 less,FEV1/FVC-decreases

42. Restrictive diseases Pulmonary fibrosis Radiation-induced interstitial lung diseases. Paralysis of diaphragm Features Decreased TLC,VC,RV FEV1/FVC –more than normal.

43. Asthma • Obstructive type of respiratory disease • Due to air way obstruction • Air way hypersensitivity due to allergy • Attack usually occur in morning & also during exercise • Treatment – • β2 adrenergic agonists • Administration of steroids

44. Emphysema • Obstructive type of respiratory disease • Degenerative potentially fatal disease • Lungs are voluminous & inelastic with widespread destruction of alveolar walls & pulmonary capillaries • Most common cause heavy cigarette smoking

45. Features of Emphysema • Barrel-shaped chest • Work of breathing (both inspiration & expiration is labored) • Compliance • FRC (normal 3L to 8L) • FVC duration • FEV1 (normal 3.2L to 0.75L) • Physiological dead space (doubled) • Physiological shunt

46. Summary

47. References • Comprehensive Textbook of Medical physiology (Vol 2 first edition) G K Pal • Text book of medical physiology (Vol 2 6 th edition) A K Jain • Text book of medical physiology (Twelfth edition) GUYTON and HALL AEJ

48. This was reviewed by the review committee on 12.1.19