Il Reclutamento Alveolare

1. Il Reclutamento Alveolare Giuseppe Foti Istituto di Anestesia e Rianimazione Università di Milano-Bicocca dir. Prof. A. Pesenti Ospedale S. Gerardo Monza

2. Reclutamento Alveolare:riapertura zone collassate PEEP10 PEEP 15 PEEP5 • E’ la PaO2 il miglior indicatore di Rec ? • E’ la PEEP il maggior determinante del Rec ?

3. PaO2 dipende non solo da quello che accade agli alveoli… • Cardiac Output • Emoglobina • VO2 • pH, CO2 • Vasocostrizione Ipossica (per es: NO) etc… Perché non misurare  Rec dal versante alveolare ?

4. Chord Cpl  Alveolar recruitment 

5. Estimating Δrec by P/V curve analysis Assumes that FRC immediately equalizes coming from different PEEP

6. FRC is different coming from different Ventilatory SET UP !!

7. Vrec20 (ml) Vrec20,He (ml) 1200 * 1000 800 600 * 400 200 0 5 - 10 5 - 15 -200 Vrec20 underestimates, not homogeneously , Alveolar recruitment

8. Pneumonia Volume (ml) 3000 2500 2000 1500 1000 All Δrec in ΔFRC !! 500 0 0 10 20 30 40 50 60 70 Paw (cmH2O)

9. HOW TO MEASURE FRC ? IT WORKS ! IT’S NOT CLINICAL PRACTICE !

10. OXYGEN WASHIN WASHOUT Portable PC sidestream O2 analyser (OXIMON, Drager) (suction flow 200 ml/min). O2 analyser Gas sampling FRC

11. FRC = QO2 / ΔFeO2(Δ FeO2 min: 20%)QO2 = Q totale erogata – Q restituita al sistema – Q consumata FiO2 FeO2

12. SLOPE 0.953 INTERCEPT 53 r2 0.960 Controlled 4000 200 150 3000 100 50 0 Differences 2000 0 1000 2000 3000 4000 -50 -100 1000 -150 -200 averages -250 0 0 1000 2000 3000 4000 WASHOUT vs HELIUM IT WORKS ! MAY BE CLINICAL PRACTICE in near FUTURE

13. PEEP keep it open Pplat Open the Lung Opening pressure Closing pressure Determinanti del Reclutamento alveolre 50 40 30 % 20 10 0 0 5 10 15 20 25 30 35 40 45 50 Paw [cmH2O] Crotti et al. Am J Respir Crit Care Med 2001

14. Recruitment maneuvers&SIGH

15. Slutsky style • Pressure = 35-50 cmH2O • Time = 20-40sec, 1-3 manoeuvre • Mode: CPAP,APRV (lo vediamo nelle prove più tardi) • Check: BP,SpO2, on-line blood gas • If vanishing effect   PEEP

16. 15 12 10 10 7 Recruitment maneuver

17. Lachmann’s style

18. Effects of periodic lung recruitment maneuvers on gas exchange and respiratory mechanics in mechanically ventilated acute respiratory distress syndrome (ARDS) patients. Foti G.,Cereda M.,et al. Intensive Care Med 2000, 26 (5) 501-07

19. Effects of periodic lung recruitment maneuvers on gas exchange and respiratory mechanics in mechanically ventilated acute respiratory distress syndrome (ARDS) patients. Foti G.,Cereda M.,et al. Intensive Care Med 2000, 26 (5) 501-07

20. Alveolar Recruitment and positioning PRONATION

21. Perché funziona la pronazione ? Cominciamo dalle cose semplici Am. J. Respir. Crit. Care Med., Volume 161, Number 5, May 2000, 1660-1665The Prone Position Eliminates Compression of the Lungs by the Heart RICHARD K. ALBERTand ROLF D. HUBMAYR

22. PRONE SUPINE Diaphragm position andDistribution of ventilation

23. Oxygenation Response to a Recruitment Maneuver during Supine and Prone Positions in an Oleic Acid–Induced Lung Injury Model NAHIT CAKAR, THOMAS VAN der KLOOT, MELYNNE YOUNGBLOOD, ALEX ADAMS, and AVI NAHUM Am J Respir Crit Care Med Vol 161. pp 1949–1956, 2000 Prone + RMs effect Proning effect RMs effect RMs should be repeated following prone position

24. Recruitment by recover of spontaneous breathing

25. Diaphragm activity and recruitment controlled ventilation, NMBA spontaneous breathing

26. BIPAPeRespiro Spontaneo

27. BIPAP PCV BIPAP vs PCV: Gas exchange Putensen et al. AJRCCM 2001; 164, 43-49

28. Set: BIPAP+PSV, Pmax = 35-40cmH2O Ti = 3-5 s. RRBIPAP = 0.5-1 b.p.m.

29. 1sec. Start 1.5sec. 3.5sec. Dynamics of re-expansion of atelectasis during general anesthesiaRothen HU,Neuman p, Berglund J, Valtaysson J,Magnusson a and Hedenstierna G.British J of Anesthesia (1999):82, 4, 551-6 L’insufflazione deve durare almeno 3 sec.

30. Sigh improves tollerance to spontaneous breathing

31. Conclusioni: -Pao2 ma…. non per molto -Pplat per aprire -PEEP per mantenere aperto

33. SIGH Why SIGH during PSV ? Low PSV  Muscle activity  TV Derecruitment

34. Is it Partial Ventilatory Support ?

35. End Inspiratory occlusion: PMI = Pel,rsi - (PEEP+PS) PMI = PMuscIndex Foti G., Cereda M et al. AJRCCM 1997

36. Prone positioning attenuates and redistributes ventilator-induced lung injury in dogs PRONE Alain Broccard, MD, FCCP; Robert S. Shapiro, MD; Laura L. Schmitz, MD; Alex B. Adams, MPH, RRT; Avi Nahum, MD, PhD; John J. Marini, MD CRITICAL CARE MEDICINE 1999;27:2574-2575 SUPINE Prone position as “Lung Protective Strategy”?

37. What has been proven ? Prone - supine study

38. “The common theme of all the letter is that the use of prone position should not be descarded on the basis of the negative study by Gattinoni and collegues” • Slutsky • NEJM Vol 346, n° 4,Jannuary 24, 2002 pag 297

42. End Inspiratory occlusion: • Low PMI & low effort (A) • High PMI & high effort (B) Foti G., Patroniti N. Pesenti A. in “Tecniche di ventilazione artificiale”ed .Torri G.-Calderini E.

43. MV day7.1±1.5 1.0 ± 0.3 Est,cw10 ±2 6 ±1 Pao-Pes 19 ±3 29 ±2

44. Conclusion: 1) what stays open at end expiration depends on what has been opened at end inspiration 2) Adjusty PEEP to mantain recruitment

45. BIPAP PCV Respiratory mechanics Putensen et al. AJRCCM 2001; 164, 43-49

46. Recruitment maneuver and anesthesia FiO2 0.4 FiO2 1 Post induction Post recruitment 5’ 45’

47. Br J Anaesth 1993 Dec;71(6):788-95Re-expansion of atelectasis during general anaesthesia: a computed tomography study.Rothen HU, Sporre B, Engberg G, Wegenius G, Hedenstierna G. Area of atelectasis (cm2) Ci vogliono almeno 30 cmH2O per riaprire le zone collassate

48. During OA injury PEEP trial

49. Legionella Pneumoniae Volume (ml) 2000 1800 1600 1400 1200 1000 800 600 All Δrec in ΔEELV !! 400 200 0 0 10 20 30 40 50 60 70 Paw (cmH2O)

50. Ci = - FRC Vi Vi Cf Closed Dilution Technique Ci Vi Cf Vf Mass conservation FRC ?