1111

Italian perspectives: HelmetItalian perspectives: HelmetItalian perspectives: HelmetItalian perspectives: Helmet

Courtesy of Dr Massimo Antonelli (Rome)Courtesy of Dr Massimo Antonelli (Rome)

Latex-free transparent PVCLatex-free transparent PVC

Secured by 2 arm = pit Secured by 2 arm = pit

braces (A) at two hooks (B) braces (A) at two hooks (B)

of the metallic ring (C) joining of the metallic ring (C) joining

helmet with a soft collar (D) helmet with a soft collar (D)

A seal connection (E) allowsA seal connection (E) allows

the passage of NGTthe passage of NGT

Latex-free transparent PVCLatex-free transparent PVC

Secured by 2 arm = pit Secured by 2 arm = pit

braces (A) at two hooks (B) braces (A) at two hooks (B)

of the metallic ring (C) joining of the metallic ring (C) joining

helmet with a soft collar (D) helmet with a soft collar (D)

A seal connection (E) allowsA seal connection (E) allows

the passage of NGTthe passage of NGT

A

BC

D

E

2222

HelmetHelmetHelmetHelmet

InP = Inspiratory port; ExP = expiratory port; SC = sealed connector; BR= armpit braces

3333

Hypoxemic Hypercapnic

IPPVIPPV Augment ventilationAugment ventilation

CPAPCPAPRecruit lung unitsRecruit lung unitsDecrease afterloadDecrease afterload Offset PEEPiOffset PEEPi

Modes of Ventilation

4444

Recruits lung unitsRecruits lung units• improved V/Q matching > rapid correction of PaOimproved V/Q matching > rapid correction of PaO22 & PaCO & PaCO22

11

• increased functional residual capacityincreased functional residual capacity• decreased respiratory rate and WOB2 decreased respiratory rate and WOB2

Reduces airway resistanceReduces airway resistance22

Improves hemodynamics in pulmonary edemaImproves hemodynamics in pulmonary edema• decreases venous return decreases venous return • decreases afterload and increases cardiac index (in 50%)decreases afterload and increases cardiac index (in 50%)1-41-4

• decreases heart ratedecreases heart rate1-31-3

Average requirement: 10cmHAverage requirement: 10cmH22OO

Recruits lung unitsRecruits lung units• improved V/Q matching > rapid correction of PaOimproved V/Q matching > rapid correction of PaO22 & PaCO & PaCO22

11

• increased functional residual capacityincreased functional residual capacity• decreased respiratory rate and WOB2 decreased respiratory rate and WOB2

Reduces airway resistanceReduces airway resistance22

Improves hemodynamics in pulmonary edemaImproves hemodynamics in pulmonary edema• decreases venous return decreases venous return • decreases afterload and increases cardiac index (in 50%)decreases afterload and increases cardiac index (in 50%)1-41-4

• decreases heart ratedecreases heart rate1-31-3

Average requirement: 10cmHAverage requirement: 10cmH22OO

Mask CPAP in Hypoxemic FailureMask CPAP in Hypoxemic Failure

1. Bersten NEJOM 19911. Bersten NEJOM 1991 3. Rasanen AJC 19853. Rasanen AJC 1985

2. Lenique AJRCCM 19942. Lenique AJRCCM 1994 4. Bradley ARRD 19924. Bradley ARRD 1992

1. Bersten NEJOM 19911. Bersten NEJOM 1991 3. Rasanen AJC 19853. Rasanen AJC 1985

2. Lenique AJRCCM 19942. Lenique AJRCCM 1994 4. Bradley ARRD 19924. Bradley ARRD 1992

5555

CPAP in Congestive Heart FailureCPAP in Congestive Heart FailureCPAP in Congestive Heart FailureCPAP in Congestive Heart Failure

CPAP in CHFCPAP in CHF

• Reduces systolic LVPReduces systolic LVPtmtm by changing by changing

PPeses from negative to positive from negative to positive

CPAP in CHFCPAP in CHF

• Reduces systolic LVPReduces systolic LVPtmtm by changing by changing

PPeses from negative to positive from negative to positive

Naughton et al Circulation 1995; 91:1725Naughton et al Circulation 1995; 91:1725

LVPLVPtmtm during systole during systole

• LVPLVPtmtm = ventricular systolic pressure - = ventricular systolic pressure -

extracardiac pressure (i.e., pericardial pr.) extracardiac pressure (i.e., pericardial pr.)

• Changes in PChanges in Pes es = changes in pericardial pr. = changes in pericardial pr.

• During inspiration > large negative During inspiration > large negative intrathoracic pressure swings increase intrathoracic pressure swings increase LVPLVPtmtm and afterload and afterload

LVPLVPtmtm during systole during systole

• LVPLVPtmtm = ventricular systolic pressure - = ventricular systolic pressure -

extracardiac pressure (i.e., pericardial pr.) extracardiac pressure (i.e., pericardial pr.)

• Changes in PChanges in Pes es = changes in pericardial pr. = changes in pericardial pr.

• During inspiration > large negative During inspiration > large negative intrathoracic pressure swings increase intrathoracic pressure swings increase LVPLVPtmtm and afterload and afterload

Pes

Negative

Negative

Pes

Positive

Positive

• Lung inflation Lung inflation parasympathetic tone parasympathetic tone sympathetic outflow sympathetic outflow HRHR

• Reduction in OReduction in O22 consumption consumption – MyocardialMyocardial: systolic LVP: systolic LVPtmtm x HR x HR– PulmonaryPulmonary: P: Peses x RR x RR

• Lung inflation Lung inflation parasympathetic tone parasympathetic tone sympathetic outflow sympathetic outflow HRHR

• Reduction in OReduction in O22 consumption consumption – MyocardialMyocardial: systolic LVP: systolic LVPtmtm x HR x HR– PulmonaryPulmonary: P: Peses x RR x RR

6666

Expiratory flow limitation Expiratory flow limitation

Dynamic hyperinflationDynamic hyperinflation

Respiratory muscle fatigueRespiratory muscle fatigue

Respiratory acidosis Respiratory acidosis

Expiratory flow limitation Expiratory flow limitation

Dynamic hyperinflationDynamic hyperinflation

Respiratory muscle fatigueRespiratory muscle fatigue

Respiratory acidosis Respiratory acidosis

COPD: Pathophysiology of ARFCOPD: Pathophysiology of ARF

7777

COPD: Dynamic HyperinflationCOPD: Dynamic Hyperinflation

Auto PEEP = inspiratory threshold loadAuto PEEP = inspiratory threshold load Flattened diaphragm = reduced efficiency and enduranceFlattened diaphragm = reduced efficiency and endurance

• shortening of the sarcomere length and decreased maximal forceshortening of the sarcomere length and decreased maximal force• reduced zone of apposition with the chest wall (expansion on insp.)reduced zone of apposition with the chest wall (expansion on insp.)• reduced blood supplyreduced blood supply

8888

COPD patient stableCOPD patient stable

• average PEEPi 2.4 ± 1.6 cm Haverage PEEPi 2.4 ± 1.6 cm H22OO11

COPD patient with acute exacerbationCOPD patient with acute exacerbation• average PEEPi 6.5 ± 2.5 cm H2O2,3average PEEPi 6.5 ± 2.5 cm H2O2,3• PEEPi = 43±5% total work by respiratory PEEPi = 43±5% total work by respiratory

systemsystem44

Increased OIncreased O22 cost correlates with diaphr. flattening cost correlates with diaphr. flattening

on CXRon CXR55

COPD patient stableCOPD patient stable

• average PEEPi 2.4 ± 1.6 cm Haverage PEEPi 2.4 ± 1.6 cm H22OO11

COPD patient with acute exacerbationCOPD patient with acute exacerbation• average PEEPi 6.5 ± 2.5 cm H2O2,3average PEEPi 6.5 ± 2.5 cm H2O2,3• PEEPi = 43±5% total work by respiratory PEEPi = 43±5% total work by respiratory

systemsystem44

Increased OIncreased O22 cost correlates with diaphr. flattening cost correlates with diaphr. flattening

on CXRon CXR55

COPD: Intrinsic PEEPCOPD: Intrinsic PEEP

1. Dal Vecchio et al Eur Respir J 1990; 3:741. Dal Vecchio et al Eur Respir J 1990; 3:74 3. Brocard et al NEJOM 1990; 323: 15233. Brocard et al NEJOM 1990; 323: 1523

2. Appendini et al AJRCCM 1994; 149: 10692. Appendini et al AJRCCM 1994; 149: 1069 4. Jubran et al AJRCCM 1995; 152: 129 4. Jubran et al AJRCCM 1995; 152: 129

5. Pitcher et al J Appl Physiol 1993; 74: 27505. Pitcher et al J Appl Physiol 1993; 74: 2750

1. Dal Vecchio et al Eur Respir J 1990; 3:741. Dal Vecchio et al Eur Respir J 1990; 3:74 3. Brocard et al NEJOM 1990; 323: 15233. Brocard et al NEJOM 1990; 323: 1523

2. Appendini et al AJRCCM 1994; 149: 10692. Appendini et al AJRCCM 1994; 149: 1069 4. Jubran et al AJRCCM 1995; 152: 129 4. Jubran et al AJRCCM 1995; 152: 129

5. Pitcher et al J Appl Physiol 1993; 74: 27505. Pitcher et al J Appl Physiol 1993; 74: 2750

9999

Etiology of ARFEtiology of ARF Pharmacological TreatmentPharmacological Treatment• precipitating condition • bronchodilator, anti-inflammatory

antibiotics, etc.

Physiology of ARFPhysiology of ARF Positive pressurePositive pressure

• expiratory flow limitation expiratory flow limitation • causes bronchodilation • causes bronchodilation

• • dynamic hyperinflationdynamic hyperinflation • offsets intrinsic PEEP ( • offsets intrinsic PEEP ( load) load)

• • respiratory muscle fatigue respiratory muscle fatigue • reduces diaphragmatic activity • reduces diaphragmatic activity

• • respiratory acidosis respiratory acidosis • increases VE ( • increases VE ( Vt, Vt, RR) RR)

Etiology of ARFEtiology of ARF Pharmacological TreatmentPharmacological Treatment• precipitating condition • bronchodilator, anti-inflammatory

antibiotics, etc.

Physiology of ARFPhysiology of ARF Positive pressurePositive pressure

• expiratory flow limitation expiratory flow limitation • causes bronchodilation • causes bronchodilation

• • dynamic hyperinflationdynamic hyperinflation • offsets intrinsic PEEP ( • offsets intrinsic PEEP ( load) load)

• • respiratory muscle fatigue respiratory muscle fatigue • reduces diaphragmatic activity • reduces diaphragmatic activity

• • respiratory acidosis respiratory acidosis • increases VE ( • increases VE ( Vt, Vt, RR) RR)

COPD: Management of ARFCOPD: Management of ARF

10101010

11111111

Hypoxemic Hypercapnic

IPPVIPPV Augment ventilationAugment ventilation

CPAPCPAPRecruit lung unitsRecruit lung unitsDecrease afterloadDecrease afterload Offset PEEPiOffset PEEPi

Modes of Ventilation

12121212

COPD: Inspiratory Effort and PEEPiCOPD: Inspiratory Effort and PEEPi

isometric contraction to counterbalance PEEPi (inspiratory threshold load)

isometric contraction to counterbalance PEEPi (inspiratory threshold load)

atmospheric

pressure

atmospheric

pressure

Auto PEEP

8cm H2O

external

PEEP

6 cm H2O

external

PEEP

6 cm H2O

Auto PEEP

8cm H2O

Inspiratory Pressure4 cm H2O

Inspiratory Pressure4 cm H2O

Appendini et al. AJRCCM 1994; 149: 1069Appendini et al. AJRCCM 1994; 149: 1069Appendini et al. AJRCCM 1994; 149: 1069Appendini et al. AJRCCM 1994; 149: 1069

in COPD with ARF the inspiratory effort to lower alveolar pressure below ambient pressure is divided into two components:

in COPD with ARF the inspiratory effort to lower alveolar pressure below ambient pressure is divided into two components:

Inspiratory Pressure

10 cm H2O

Inspiratory Pressure

10 cm H2O isotonic contraction to generate inspiratory flow and tidal volume

isotonic contraction to generate inspiratory flow and tidal volume

IT

13131313

Offsets PEEPiOffsets PEEPi11

acute COPD exacerbation: average PEEPi 6.5 acute COPD exacerbation: average PEEPi 6.5 ++ 2.5 cmH 2.5 cmH22OO11

apply PEEP at 80-90% of PEEPi to avoid overdistentionapply PEEP at 80-90% of PEEPi to avoid overdistention11

Reduces transdiaphragmatic pressureReduces transdiaphragmatic pressure22

May improve Vt, VE, or PaCOMay improve Vt, VE, or PaCO2244

no response within 30 min in 4 studies no response within 30 min in 4 studies 1,2,5,6 1,2,5,6

delayed response (> 4 h) in clinical studiesdelayed response (> 4 h) in clinical studies44

Average CPAP requirement: Average CPAP requirement: 5 cmH5 cmH2200

Offsets PEEPiOffsets PEEPi11

acute COPD exacerbation: average PEEPi 6.5 acute COPD exacerbation: average PEEPi 6.5 ++ 2.5 cmH 2.5 cmH22OO11

apply PEEP at 80-90% of PEEPi to avoid overdistentionapply PEEP at 80-90% of PEEPi to avoid overdistention11

Reduces transdiaphragmatic pressureReduces transdiaphragmatic pressure22

May improve Vt, VE, or PaCOMay improve Vt, VE, or PaCO2244

no response within 30 min in 4 studies no response within 30 min in 4 studies 1,2,5,6 1,2,5,6

delayed response (> 4 h) in clinical studiesdelayed response (> 4 h) in clinical studies44

Average CPAP requirement: Average CPAP requirement: 5 cmH5 cmH2200

COPD: Mask CPAP in ARFCOPD: Mask CPAP in ARF

1. Appendeni AJRCCM 19941. Appendeni AJRCCM 1994 3. Martin ARRD 19823. Martin ARRD 1982 5. Shivaram Resp 19875. Shivaram Resp 1987

2. Gottfried Chest 19872. Gottfried Chest 1987 4. De Lucas Chest 19934. De Lucas Chest 1993 6. Elliot BMJ 19946. Elliot BMJ 1994

1. Appendeni AJRCCM 19941. Appendeni AJRCCM 1994 3. Martin ARRD 19823. Martin ARRD 1982 5. Shivaram Resp 19875. Shivaram Resp 1987

2. Gottfried Chest 19872. Gottfried Chest 1987 4. De Lucas Chest 19934. De Lucas Chest 1993 6. Elliot BMJ 19946. Elliot BMJ 1994

14141414 BMJ 2003; 326:185.

15151515

Resetting responses to PaCOResetting responses to PaCO22Resetting responses to PaCOResetting responses to PaCO22

In COPD, the ventilatory response to raised PaCOIn COPD, the ventilatory response to raised PaCO22 is is

decreased especially during sleep. decreased especially during sleep.

NPPV lowers nocturnal PaCONPPV lowers nocturnal PaCO22 and resets the respiratory and resets the respiratory

control centre to become more responsive to increased control centre to become more responsive to increased

PaCOPaCO22 by increasing the neural output to the diaphragm and by increasing the neural output to the diaphragm and

other respiratory muscles. other respiratory muscles. These patients are then able to maintain a more normal These patients are then able to maintain a more normal

PaCOPaCO22 throughout the daylight hours without the need for throughout the daylight hours without the need for

mechanical ventilation.mechanical ventilation.

In COPD, the ventilatory response to raised PaCOIn COPD, the ventilatory response to raised PaCO22 is is

decreased especially during sleep. decreased especially during sleep.

NPPV lowers nocturnal PaCONPPV lowers nocturnal PaCO22 and resets the respiratory and resets the respiratory

control centre to become more responsive to increased control centre to become more responsive to increased

PaCOPaCO22 by increasing the neural output to the diaphragm and by increasing the neural output to the diaphragm and

other respiratory muscles. other respiratory muscles. These patients are then able to maintain a more normal These patients are then able to maintain a more normal

PaCOPaCO22 throughout the daylight hours without the need for throughout the daylight hours without the need for

mechanical ventilation.mechanical ventilation.

16161616

Hypoxemic Hypercapnic

IPPVIPPV Augment ventilationAugment ventilation

CPAPCPAPRecruit lung unitsRecruit lung unitsDecrease afterloadDecrease afterload Offset PEEPiOffset PEEPi

Modes of Ventilation

17171717

Synchrony between patient effort and delivered assistanceSynchrony between patient effort and delivered assistance NPPV with PSV is superior to (ABG and RMR)NPPV with PSV is superior to (ABG and RMR)

• spontaneous breathingspontaneous breathing1-51-5

• CPAPCPAP Comparison to volume-cycled ventilation (COPD)Comparison to volume-cycled ventilation (COPD)66

• equally effective in improving gas exchangeequally effective in improving gas exchange

• better tolerated and lower incidence of complicationsbetter tolerated and lower incidence of complications

• lower mask air leakage (lower peak mask pressure)lower mask air leakage (lower peak mask pressure)

Synchrony between patient effort and delivered assistanceSynchrony between patient effort and delivered assistance NPPV with PSV is superior to (ABG and RMR)NPPV with PSV is superior to (ABG and RMR)

• spontaneous breathingspontaneous breathing1-51-5

• CPAPCPAP Comparison to volume-cycled ventilation (COPD)Comparison to volume-cycled ventilation (COPD)66

• equally effective in improving gas exchangeequally effective in improving gas exchange

• better tolerated and lower incidence of complicationsbetter tolerated and lower incidence of complications

• lower mask air leakage (lower peak mask pressure)lower mask air leakage (lower peak mask pressure)

Mask Inspiratory Pressure SupportMask Inspiratory Pressure Support

1. Appendeni AJRCCM 19941. Appendeni AJRCCM 1994 3. Broachard NEJOM 19903. Broachard NEJOM 1990 5. Ambrosino Chest 19925. Ambrosino Chest 1992

2. Belman Chest 19902. Belman Chest 1990 4. Carrey Chest 19904. Carrey Chest 1990 6. Vitacca ICM 19936. Vitacca ICM 1993

1. Appendeni AJRCCM 19941. Appendeni AJRCCM 1994 3. Broachard NEJOM 19903. Broachard NEJOM 1990 5. Ambrosino Chest 19925. Ambrosino Chest 1992

2. Belman Chest 19902. Belman Chest 1990 4. Carrey Chest 19904. Carrey Chest 1990 6. Vitacca ICM 19936. Vitacca ICM 1993

18181818

Effect of Mask Pressure Effect of Mask Pressure

COPD patient with acute exacerbationCOPD patient with acute exacerbationCOPD patient with acute exacerbationCOPD patient with acute exacerbation

PSV 15 cmHPSV 15 cmH22OO

Positive Pes swings

Additional reduction

PSV 12 cmHPSV 12 cmH22OO

synchrony

Reduction Pes swings

spontaneousspontaneousbreathingbreathing

AsynchronyPAM

Carrey et al. Chest 1990; 97:150Carrey et al. Chest 1990; 97:150

19191919

Timing to Suppression of EMG Activity Timing to Suppression of EMG Activity

Carrey et al. Chest 1990; 97: 150.Carrey et al. Chest 1990; 97: 150.Carrey et al. Chest 1990; 97: 150.Carrey et al. Chest 1990; 97: 150.

Initiation of NPPV

Within5 breathes

20202020

Mask CPAP and PSV in COPDCritical Pdi max

Mask CPAP and PSV in COPDCritical Pdi max

Seven COPD patients with acute exacerbation Seven COPD patients with acute exacerbation Nasal mask - 15 min. recordingsNasal mask - 15 min. recordingsSeven COPD patients with acute exacerbation Seven COPD patients with acute exacerbation Nasal mask - 15 min. recordingsNasal mask - 15 min. recordings

5 cmH5 cmH22OO 10 cmH10 cmH22OO

Appendini AJRCCM 1994; 149: 1069Appendini AJRCCM 1994; 149: 1069Appendini AJRCCM 1994; 149: 1069Appendini AJRCCM 1994; 149: 1069

21212121

Hypercapnic Hypoxemic

Gas

Exchange Transdiaphragmatic

Pressure Gas

Exchange Transdiaphragmatic

Pressure

CPAP —

PSV

CPAP + PSV

Hypercapnic Hypoxemic

Gas

Exchange Transdiaphragmatic

Pressure Gas

Exchange Transdiaphragmatic

Pressure

CPAP —

PSV

CPAP + PSV

Data obtained from:Data obtained from: Ambrosino Ambrosino ChestChest 1992; 1992; Apprendini Apprendini AJRCCMAJRCCM 1994; 1994; Brochard Brochard NEJOMNEJOM 1990; 1990; Carrey Carrey ChestChest 1990; 1990; De Lucas De Lucas ChestChest 1993; 1993; Elliot Elliot Anaesthesia Anaesthesia 19941994

Data obtained from:Data obtained from: Ambrosino Ambrosino ChestChest 1992; 1992; Apprendini Apprendini AJRCCMAJRCCM 1994; 1994; Brochard Brochard NEJOMNEJOM 1990; 1990; Carrey Carrey ChestChest 1990; 1990; De Lucas De Lucas ChestChest 1993; 1993; Elliot Elliot Anaesthesia Anaesthesia 19941994

Effects of CPAP and IPPVEffects of CPAP and IPPVHypercapnic vs Hypoxemic ARFHypercapnic vs Hypoxemic ARF

Effects of CPAP and IPPVEffects of CPAP and IPPVHypercapnic vs Hypoxemic ARFHypercapnic vs Hypoxemic ARF