Mechanical Ventilation in COPD patients Θεόδωρος Βασιλακόπουλος Καθηγητής Πνευμονολογίας-Εντατικής Θεραπείας Εθνικό & Καποδιστριακό Πανεπιστήμιο Αθηνών Νοσοκομείο «ο Ευαγγελισμός» Adjunct Professor, McGill University, Montreal, Canada Γενικός Γραμματέας Ελληνικής Πνευμονολογικής Εταιρείας
Outline Non invasive ventilation during exacerbations to avoid intubation Controlled mechanical ventilation Partial support ventilation Ventilator triggering Wasted efforts Weaning Non Invasive Ventilation after weaning Spontaneous breathing trial failure Post extubation
Non-invasive ventilation during exacerbations to avoid intubation
700 600 500 400 300 200 100 0-100 PTPdi/min (cmh20 x s/min) i-psv n-psv T-piece S.B. * *
% of patients Intubation rate in patients with acute exacerbation of COPD treated with and without NIPPV 80 73 74 70 60 50 40 30 20 10 31 n=16 n=15 26 n=43 n=42 NIPPV Control 0 Kramer et al 1995 Brochard et al 1995
Hospital stay (days) of patients with acute exacerbation of COPD treated with and without NIPPV 80 70 60 50 40 30 20 10 0 * NIPPV Control Brochard et al. NEJM 1995;333:817
% of patients In-hospital mortality (%) in patients with acute exacerbation of COPD treated with and without NIPPV 35 30 25 30 29 20 15 10 5 0 10 9 n=30 n=30 n=43 n=42 Bott et al 1993 Brochard et al 1995 NIPPV Control
% of patients Early use of NIPPV for acute exacerbation of COPD on general wards 30 27 25 20 15 10 15 10 20 NIPPV Control 5 n=118 n=118 n=118 n=118 0 Need for intubation In-hospital mortality Plant et al. Lancet 2000;355:1931
NIV in hypercapnic encephalopathy Scala et al, Intensive Care Med 2007;33:2101-8
Helmet worsens patient-ventilator interaction in COPD Navalesi P et al, Intensive Care Med 2007;33:74-81
Controlled mechanical ventilation
Mechanical Ventilation Volume Control Tidal Volume 520 ml Respiratory Rate = 16 breaths/min TI/TT = 0,25 PEEP = 0-5 cmh2o FiO2 = 50%
Pressure (cmh 2 O) Flow (l/sec) 1.5 1 0.5 Dynamic hyperinflation 0-1 -0.5 0 0.5 1 1.5 2 2.5 3 3.5 4-0.5-1 -1.5 60 50 40 30 20 10 Slope increase Over-distension End expiratory flow 0-1 -0.5 0-10 0.5 1 1.5 2 2.5 3 3.5 4 Time (sec)
Assessment of mechanics Ppeak Pplateau PEEPi End expiratory occlusion Rrs = (Ppeak-Pplateau)/V
When PEEPi is present during CMV Hemodynamic compromise Overdistension with risk of barotrauma Reduce f Reduce VT Increase inspiratory flow to prolong TE
Partial Support Modes
Ventilator triggering
Ptr
Aslanian P, AJRCCM 1998;157:135-43
Partitioning of pressure time product during flow and pressure triggering 9 Pressure Support 9 Assist control 8 8 7 7 6 5 4 3 PTPes PTPtr PTPpost PTPpeepi 6 5 4 3 PTPes PTPtr PTPpost PTPpeepi 2 2 1 1 0 PT FT 0 PT FT Aslanian P, AJRCCM 1998;157:135-43
Paw (cmh 2 O) Flow (l/sec) 0.8 0.6 0.4 0.2 0-2 -0.2 3 8 13 18-0.4-0.6-0.8 35 30 25 20 15 10 5 0-2 -5 3 8 13 18 Fr = 12 b/min Time (sec) 5 sec
Pes (cmh 2 O) Paw (cmh 2 O) Flow (l/sec) 0,8 0,6 0,4 0,2 0-2 -0,2 3 8 13 18-0,4-0,6-0,8 35 30 25 20 15 10 5 0-2 -5 3 8 13 18 20 15 10 5 0-2 3 8 13 18-5 Fr = 33 b/min Time (sec) 5 sec Georgopoulos D
Ptr
Wasted effort PEEPi Ptr Dynamic Hyperinflation Vrel
Ineffective efforts increase as the level of ventilator support increases Leung P, AJRCCM 1997;155:1940-48
Ineffective efforts decrease as expiratory time increases ACV Tidal Volume constant Increased Flow Increased Expiratory time Kondili E, BJA 2003;91:106-19
Ptr
Factors predisposing to ineffective efforts The level of ventilator assistance Large tidal volume of the preceding breath Short expiratory time PEEPi
Pes (cmh 2 O) Paw (cmh 2 O) Flow (l/sec) 0.8 0.6 0.4 0.2 0-2 -0.2 3 8 13 18-0.4-0.6-0.8 35 30 25 20 15 10 5 0-2 -5 3 8 13 18 20 15 10 5 0-2 3 8 13 18-5 Time (sec) 5 sec
Pes (cmh 2 O) Flow (l/sec) 0,8 0,6 0,4 0,2 0-0,2-0,4-0,6-0,8 0 1 2 3 4 5 6 14 12 10 8 6 4 2 0-2 -4 0 1 2 3 4 5 6 Time (sec) 5 sec Georgopoulos D
Wasted efforts reduction during pressure support Cycling off criterion increased in steps of 10% Thille et al Intensive Care Med 2008;34:1477-86 Gradual reduction of PS level-steps of 2 cmh 2 0
Addition of external PEEP Ptr PEEP external
Chao et al, Chest 1997;112:1592-9 Asynchrony between patient ventilator Presence of Dynamic Hyperinflation and PEEPi. Apply external PEEP (~ 5 cmh 2 O)
Weaning
Pressure Support vs T-piece weaning in COPD COPD Screened 77 patients Excluded 2 Eligible T-tube trial 75 Trial Success 23 (31%) Trial Failure 52 (69%) T-tube 26 PS 26 Successful Weaning 20 (77%) Successful Weaning 19 (73%) Failed Weaning 6 (23%) Failed Weaning 7 (27%) Vitacca et al. Am J Respir Crit Care 2001; 164: 225
PSV T-piece AJRCCM 2001;164:225-230.
Non Invasive Ventilation as weaning technique in COPD patients who fail SBT after 2 days of MV Control NIV Nava et al. Ann Intern Med 1998;128:721
% of patients 60 days mortality (%) in patients with acute exacerbation of COPD using NIPPV as a weaning technique 40 35 30 28 * 25 20 15 10 5 0 8 NIPPV Control Nava et al. Ann Intern Med 1998;128:721
Non Invasive Ventilation during persistent (3 days) spontaneous breathing trial failure NIV NIV COPD 25/43 patients Ferrer et al. Am J Respir Crit Care Med 2003;168:70-76
Non-Invasive Ventilation (n.114) Conventional Therapy (n.107) Absolute Risk Difference Relative Risk (95% CI) p-value Mortality 25% 14% 11.4% (0.85-21.63) 1.75 (0.99-3.09) 0.05 Reintubation 49% 49% 0% 0.99 (0.76-1.30) ns
Did this RCT killed NIV?
Mortality % 80 70 60 6/9 50 40 30 7/14 General COPD 20 10 28/114 * 15/107 0 NIV Standard therapy Esteban, A. et al. N Engl J Med 2004;350:2452-2460
TIME to REINTUBATION % 80 70 60 50 40 30 20 10 0 patients deaths 0-12 hr 13-24 hr 25-48 hr 49-72 hr Epstein and Ciubotaru AJRCCM 1998;158:489-93
Another way to see the problem: If timing is a key factor, why should we wait until post-extubation respiratory failure is overt?
NIV to prevent extubation failure in patients with successful SBT Αναπνευστική ανεπάρκεια 33% 16% Ferrer et al. Am J Respir Crit Care Med 2006;173:164-70
Survival of patients receiving NIV to prevent extubation failure in patients with successful SBT subgroup analysis Ferrer et al. Am J Respir Crit Care Med 2006;173:164-70
Ferrer et al, Lancet 2009;374:1082-88
NIV after extubation in patients who develop hypercapnia during a spontaneous breathing trial Ferrer et al, Lancet 2009;374:1082-88
Time elapsed from extubation to development of respiratory failure NIV immediately after extubation in patients who develop hypercapnia during a spontaneous breathing trial Ferrer et al, Lancet 2009;374:1082-88
NIV is beneficial Summary To avoid intubation When spontaneous breathing trial fails in COPD To prevent extubation failure in COPD patients During CMV check mechanics and PEEPi To avoid hemodynamic compromise To avoid overdistention Triggering: not really clinically important Wasted efforts Decrease support Apply external PEEP Weaning: No difference between different techniques PS vs T-piece The best technique is the one you know well