noninvasive ventilation oap

NON - INVASIVE VENTILATION IN ACUTE CARDIOGENIC PULMONARY

OEDEMA

ANDREW ADAIRMIDDLESBOROUGH GENERAL HOSPITAL

AIMS AND OBJECTIVESAIMS AND OBJECTIVES

Epidemiology of Heart FailureEpidemiology of Heart Failure

Pathophysiology of Cardiogenic Pulmonary Pathophysiology of Cardiogenic Pulmonary OedemaOedema

Effect of Positive Airway Pressure Ventilation on Effect of Positive Airway Pressure Ventilation on Respiratory and Cardiovascular SystemRespiratory and Cardiovascular System

Review of Literature - CPAP or BiPAP?Review of Literature - CPAP or BiPAP?

Results / ConclusionsResults / Conclusions

? Role in Accident and Emergency ? Role in Accident and Emergency

STATISTICS FOR HEART FAILURE ( 1 )STATISTICS FOR HEART FAILURE ( 1 )

Limited UK dataLimited UK data

IncidenceIncidence 1.4 / 1000 population in males1.4 / 1000 population in males1.2 / 1000 population in females 1.2 / 1000 population in females ( HILLINGDON )( HILLINGDON )

Total of 63,000 new cases / year Total of 63,000 new cases / year ( HILLINGDON )( HILLINGDON )

PrevalencePrevalence 3% >45yrs 3% >45yrs (HEART OF ENGLAND SCREENING STUDY )(HEART OF ENGLAND SCREENING STUDY )

878,000 in UK today 878,000 in UK today Increases with ageIncreases with age

65-74yr65-74yr 1:351:35

75-84yr75-84yr 1:151:15

>85yr>85yr 1:71:7 Increasing rate BUT no evidence of increasing prevalence Increasing rate BUT no evidence of increasing prevalence

in UK!in UK!

STATISTICS FOR HEART FAILURE ( 2 )STATISTICS FOR HEART FAILURE ( 2 ) MortalityMortality 10,000 officially recorded deaths in 10,000 officially recorded deaths in

20002000

PrognosisPrognosis 40% death within 1 year40% death within 1 year>70% at 5 years >70% at 5 years ( HILLINGDON )( HILLINGDON )

‘‘Estimate at Mortality Rates’Estimate at Mortality Rates’

24,000 deaths in 200024,000 deaths in 2000

5% of all deaths5% of all deaths 50% of deaths are ‘sudden’50% of deaths are ‘sudden’

EconomicsEconomics 86,000 admissions ( 13 days )86,000 admissions ( 13 days )

£379 million£379 million

Total cost / year is £625 millionTotal cost / year is £625 million

PATHOPHYSIOLOGY OF C.P.O ( 1 )PATHOPHYSIOLOGY OF C.P.O ( 1 )

““Acute CPO is a sudden rise in Acute CPO is a sudden rise in pulmonary capillary pressure causing pulmonary capillary pressure causing engorgement of pulmonary vessels engorgement of pulmonary vessels ( blood and lymphatic), and exudation ( blood and lymphatic), and exudation into the interstitial and alveolar into the interstitial and alveolar spaces, manifested by varying spaces, manifested by varying degrees of respiratory distress.”degrees of respiratory distress.”

Left Ventricular FailureLeft Ventricular Failure Mitral StenosisMitral Stenosis

PATHOPHYSIOLOGY OF C.P.O ( 2 )PATHOPHYSIOLOGY OF C.P.O ( 2 )weak left ventricleweak left ventricle

increase back pressure, decrease COincrease back pressure, decrease CO

increase BP and fluid volume, increasing LV increase BP and fluid volume, increasing LV pressurepressure

pooling in pulmonary blood vesselspooling in pulmonary blood vessels

fluid leakage and accumulation in interstitial tissuefluid leakage and accumulation in interstitial tissue

poor lung expansionpoor lung expansion

poor gas exchange and pulmonary blood flowpoor gas exchange and pulmonary blood flow

Important sympathetic reflex componentImportant sympathetic reflex component

EFFECT OF POSITIVE AIRWAY EFFECT OF POSITIVE AIRWAY PRESSURE VENTLATION ( 1 )PRESSURE VENTLATION ( 1 )

CPAPCPAP

Improved lung mechanics :Improved lung mechanics :

– recruits collapsed lung unitsrecruits collapsed lung units– redistribution of lung waterredistribution of lung water– greater area for gas exchangegreater area for gas exchange– reduces intrapulmonary shuntreduces intrapulmonary shunt– enhances pulmonary complianceenhances pulmonary compliance– reduces work of breathingreduces work of breathing– negates intrinsic PEEPnegates intrinsic PEEP

EFFECT OF POSITIVE AIRWAY PRESSURE EFFECT OF POSITIVE AIRWAY PRESSURE VENTLATION ( 2 )VENTLATION ( 2 )

CPAPCPAP

Cardiovascular statusCardiovascular status– decreases venous return ( therefore preload decreases venous return ( therefore preload

))– reduction in afterloadreduction in afterload– reduces transmural pressurereduces transmural pressure– no change in myocardial contractiityno change in myocardial contractiity

– improved ejection fraction without increase improved ejection fraction without increase in myocardial oxygen consumptionin myocardial oxygen consumption

EFFECT OF POSITIVE AIRWAY EFFECT OF POSITIVE AIRWAY PRESSURE VENTLATION ( 3 )PRESSURE VENTLATION ( 3 )

BiPAPBiPAP Physiological advantages of CPAP through EPAPPhysiological advantages of CPAP through EPAP

assistance of spontaneous ventilationassistance of spontaneous ventilation promotes inhibition of the diaphragm - reduced work promotes inhibition of the diaphragm - reduced work

of breathing with increase in tidal volume / gas of breathing with increase in tidal volume / gas exchangeexchange

BUTBUT : ? larger decrease in BP : ? larger decrease in BP

? greater variation in intrathoracic pressure? greater variation in intrathoracic pressure

? greater decrease in venous return? greater decrease in venous return

? Reduced myocardial perfusion? Reduced myocardial perfusion

EVIDENCE FOR USE OF CPAP IN ACPO EVIDENCE FOR USE OF CPAP IN ACPO (1)(1)

First reported 1936 ( Poulton ) - use in ‘cardiac asthma’First reported 1936 ( Poulton ) - use in ‘cardiac asthma’

1960’s : benefit of PEEP in mechanical ventilation1960’s : benefit of PEEP in mechanical ventilation

‘‘CPAP’ first described in 1971 ( Gregory ) - neonatesCPAP’ first described in 1971 ( Gregory ) - neonates

Many reports of successful treatment of ACPO with Many reports of successful treatment of ACPO with CPAP but still very variable use :CPAP but still very variable use :

1. Problems with original studies1. Problems with original studies

2. No reporting on adverse effects2. No reporting on adverse effects

3. “research transfer”3. “research transfer”

4. Availability and varying experience4. Availability and varying experience


5 Prospective Randomised Controlled trials 5 Prospective Randomised Controlled trials comparing CPAP with standard medical therapycomparing CPAP with standard medical therapy

4 ‘review’ articles :4 ‘review’ articles :

- 1998 : Pang et al ( Chest )- 1998 : Pang et al ( Chest )

- 1999 : Cross ( EMJ )- 1999 : Cross ( EMJ )

- 2000 : Kosowsky ( Therapeutics )- 2000 : Kosowsky ( Therapeutics )

- 2000 : Ratchford ( CTR )- 2000 : Ratchford ( CTR )

- 2002 : British Thoracic Society - 2002 : British Thoracic Society GuidelinesGuidelines

Many case series reports Many case series reports

Rasanen1985

Finland

40 patientsCPAP (20)

VControl (20)

Intubation

Mortality

6/20 v 12/20

17/20 v 14/20

NS

NS

Bersten1991

Australia


VControl (20)

Intubation

Mortality

0/19 v 7/20

2/19 v 4/20

<0.005

NS

Lin1991

Taiwan


VControl (30)

Intubation

Mortality

7/25 v 17/30

2/25 v 4/30

<0.05

NS

Lin1995

Taiwan


VControl (50)

Intubation

Mortality

8/50 v 18/50

4/50 v 6/50

<0.01

NS

Takeda1998Japan


VControl (11)

Intubation

Mortality

2/11 v 8/11

1/11 v 7/11

<0.03

0.02


In CPAP group all studies showed a significant In CPAP group all studies showed a significant improvement in :improvement in :

Respiratory statusRespiratory status

Cardiovascular parametersCardiovascular parameters

Blood gas analysisBlood gas analysis

No reported complications in any studyNo reported complications in any study

Case studies reported : FAILURE TO TOLERATE, Case studies reported : FAILURE TO TOLERATE, skin ulceration, corneal abrasions, skin ulceration, corneal abrasions, pneumomediastinum, pneumocephalus, sinus / pneumomediastinum, pneumocephalus, sinus / ear pain, gastric insufflationear pain, gastric insufflation


POOLING OF DATAPOOLING OF DATA

PangPang (1998) showed an ARR for intubation of 26% (1998) showed an ARR for intubation of 26% (95% CI -13 to -38%)(95% CI -13 to -38%)

NNT = 4NNT = 4 also showed “a trend to decrease in mortality” with also showed “a trend to decrease in mortality” with

an ARR of 6.6% ( 95% CI +3 to -16%)an ARR of 6.6% ( 95% CI +3 to -16%)

John WrightJohn Wright pooled above results with Takeda trial pooled above results with Takeda trial looking at mortality rates (short term) showing a looking at mortality rates (short term) showing a ARR of 13% (95% CI -3.4 to -24.2%)ARR of 13% (95% CI -3.4 to -24.2%)


BRITISH THORACIC SOCIETYBRITISH THORACIC SOCIETY

““Non-invasive Ventilation in Acute Respiratory Non-invasive Ventilation in Acute Respiratory Failure”Failure”

Standards of Care Report 2002Standards of Care Report 2002

“…“…CPAP has been shown to be effective in patients CPAP has been shown to be effective in patients with Cardiogenic Pulmonary Oedema who remain with Cardiogenic Pulmonary Oedema who remain hypoxic despite maximal Medical management.” hypoxic despite maximal Medical management.” (B)(B)

WHAT ABOUT BiPAPWHAT ABOUT BiPAP ??

EVIDENCE FOR USE OF BiPAP IN ACPO EVIDENCE FOR USE OF BiPAP IN ACPO (1)(1)

Efficacy considered ambiguous when compared to Efficacy considered ambiguous when compared to CPAP despite theoretical advantageCPAP despite theoretical advantage

Introduced late 1980’sIntroduced late 1980’s

Shown to reduce need for intubation in ARFShown to reduce need for intubation in ARF

Meta-analysis (Keenan 1997, Critical Care Medicine) Meta-analysis (Keenan 1997, Critical Care Medicine) showed that efficacy was limited to patients were showed that efficacy was limited to patients were the specific cause of ARF was an exacerbation of the specific cause of ARF was an exacerbation of COPD (Hypercapnic type II Respiratory Failure)COPD (Hypercapnic type II Respiratory Failure)

BUT has been shown to successfully treat ACPOBUT has been shown to successfully treat ACPO


1 Randomised Controlled Trial comparing 1 Randomised Controlled Trial comparing BiPAP to standard medical therapyBiPAP to standard medical therapy

3 Randomised Controlled Trials comparing 3 Randomised Controlled Trials comparing with other treatments : with other treatments :

- CPAP or Oxygen- CPAP or Oxygen

- iv Nitrates- iv Nitrates

- CPAP- CPAP

Several case seriesSeveral case series

Masip2000Spain

37 patientsBiPAP (19)

VControl (18)

Intubation

Mortality

1/19 v 6/18

0/19 v 2/18

0.037

NS

Park2001Brazil


VCPAP (9)

VControl (10)

Intubation

Mortality

0/7 v 3/9 v 4/10

0/7 v 1/9 v 0/10

<0.05

NS

Both studies showed a faster recovery of vital signs and Both studies showed a faster recovery of vital signs and improvement in blood gas analysis in the BiPAP group. improvement in blood gas analysis in the BiPAP group.

Masip resolution time of 30 min v 105 min (p 0.002)Masip resolution time of 30 min v 105 min (p 0.002)

(Clinical improvement with O2 sat of >96% and RR (Clinical improvement with O2 sat of >96% and RR <30/min)<30/min)

Masip (level 1b : EBM) ARR 28.1% (95% CI 4.09% - 52.1%)Masip (level 1b : EBM) ARR 28.1% (95% CI 4.09% - 52.1%)

NNT of 4 at 10 hrs NNT of 4 at 10 hrs

EVIDENCE FOR USE OF BiPAP IN ACPO EVIDENCE FOR USE OF BiPAP IN ACPO (4) (4)

Wood et al (1998)Wood et al (1998)

RCT of BiPAP in variety of causes of ARF ( ACPO RCT of BiPAP in variety of causes of ARF ( ACPO 10/27)10/27)

Faster improvement in all parametersFaster improvement in all parameters

No difference in intubation rates but INC. in mortalityNo difference in intubation rates but INC. in mortality

? Bias in treatment : ? Bias in treatment :

reluctance to abandon BiPAPreluctance to abandon BiPAP

delayed intubationdelayed intubation

inc. multi -organ system derangementsinc. multi -organ system derangements


Combined end point : 17/20 v 5/20 ( p 0.0003)Combined end point : 17/20 v 5/20 ( p 0.0003)

Slower rate of improvement in BiPAP group ( p Slower rate of improvement in BiPAP group ( p 0.017)0.017)

Premature Termination by Safety CommitteePremature Termination by Safety Committee

( Pre- hospital setting)( Pre- hospital setting)

Sharon2000Israel


VRepeated

Iv Nitrates (20)

Intubation

Mortality

MI

16/20 v 2/20

2/20 v 0/20

11/20 v 2/20

NS

0.0004

0.006


Despite negative reports there still exists Despite negative reports there still exists much evidence supporting BiPAP in ACPOmuch evidence supporting BiPAP in ACPO

Intubation rates from 0 - 44%Intubation rates from 0 - 44%

Mortality rates from 0 - 22%Mortality rates from 0 - 22%

Many find it difficult to support BiPAP in a Many find it difficult to support BiPAP in a condition already treated successfully by CPAPcondition already treated successfully by CPAP

BiPAP or CPAP ?BiPAP or CPAP ?

CPAP OR BiPAP INTREATMENT OF ACPO CPAP OR BiPAP INTREATMENT OF ACPO (1)(1)

In addition to PARK (BiPAP) there is 1 Randomised In addition to PARK (BiPAP) there is 1 Randomised Controlled Trial and 1 Retrospective AnalysisControlled Trial and 1 Retrospective Analysis

BiPAP group : improvement in PaC02, pH, HR, RR BiPAP group : improvement in PaC02, pH, HR, RR

(p <0.05)(p <0.05)

CPAP group : improvement in RR only (p <0.05)CPAP group : improvement in RR only (p <0.05)

Mehta1997USA


VCPAP (13)

Intubation

Mortality

MI

1/14 v 1/13

1/14 v 2/13

10/14 v 4/13

NS

NS

0.05

CPAP OR BiPAP INTREATMENT OF ACPO CPAP OR BiPAP INTREATMENT OF ACPO (2) (2)

Reason for increased MI’s ?Reason for increased MI’s ?

Greater variation in intrathoracic pressure and VRGreater variation in intrathoracic pressure and VR

Greater leak with nasal masksGreater leak with nasal masks

No adverse haemodynamic effects of BiPAP in other No adverse haemodynamic effects of BiPAP in other studiesstudies

On entry to study a greater number of BiPAP patients On entry to study a greater number of BiPAP patients had chest pain and elevated cardiac enzymes ( 10 v 4 had chest pain and elevated cardiac enzymes ( 10 v 4 p 0.05)p 0.05)

MI’s already underway at enrollment ?MI’s already underway at enrollment ?

CPAP OR BiPAP INTREATMENT OF ACPO CPAP OR BiPAP INTREATMENT OF ACPO (3) (3)

(4 from each group had elevated enzymes and ECG (4 from each group had elevated enzymes and ECG changes)changes)

Both groups showed statistically significant Both groups showed statistically significant improvements in PaO2, PaCO2, RR, pH, HRimprovements in PaO2, PaCO2, RR, pH, HR

No association found between BiPAP and MI’sNo association found between BiPAP and MI’s

“ “ Increased trend toward prevention of intubation”Increased trend toward prevention of intubation”

Ferrari2000Italy


VCPAP (25)

Intubation

Mortality

MI

O/27 v 3/25

0/27 v 2/25

5/27 v 6/25

CONCLUSIONS FROM STUDIES (1)CONCLUSIONS FROM STUDIES (1)

Modest evidence to support CPAP in ACPO Modest evidence to support CPAP in ACPO associated with decreased intubation rates and associated with decreased intubation rates and “trend towards decrease in mortality”“trend towards decrease in mortality”

Also favourable support for BiPAP but largely from Also favourable support for BiPAP but largely from case series and anecdotal reportscase series and anecdotal reports

Little evidence to support initial hypothesis that Little evidence to support initial hypothesis that BiPAP provides additional benefit over CPAPBiPAP provides additional benefit over CPAP

( ??? Unless associated with greatly elevated ( ??? Unless associated with greatly elevated PACO2 ???)PACO2 ???)

CONCLUSIONS FROM STUDIES (2)CONCLUSIONS FROM STUDIES (2)

BRITISH THORACIC SOCIETYBRITISH THORACIC SOCIETY

““Non-invasive Ventilation in Acute Respiratory Non-invasive Ventilation in Acute Respiratory Failure”Failure”

Standards of Care Report 2002Standards of Care Report 2002

“…“…CPAP has been shown to be effective in CPAP has been shown to be effective in patients with Cardiogenic Pulmonary Oedema patients with Cardiogenic Pulmonary Oedema who remain hypoxic despite maximal Medical who remain hypoxic despite maximal Medical management.management.

NIV should be reserved for patients in whom NIV should be reserved for patients in whom CPAP is unsuccessful.” CPAP is unsuccessful.” (B)(B)

USE OF NIV IN A&E : EVIDENCE & CONCERNS USE OF NIV IN A&E : EVIDENCE & CONCERNS (1) (1)

Most trials conducted in ITU / HDU setting Most trials conducted in ITU / HDU setting

Many A&E patients improve after initial therapyMany A&E patients improve after initial therapy

Intubation rates in controls considered high (~60%) - Intubation rates in controls considered high (~60%) - inevitable that NIV will reduce intubation rate ? inevitable that NIV will reduce intubation rate ?

Leeds 104 ACPO patients : all acidotic on arrivalLeeds 104 ACPO patients : all acidotic on arrival

89% improved clinically and 89% improved clinically and pHpH

11% intubated11% intubated

would NIV alter this rate ?would NIV alter this rate ?

May delay or prevent intubation (concerns regarding May delay or prevent intubation (concerns regarding complications of intubation)complications of intubation)

USE OF NIV IN A&E : EVIDENCE & CONCERNS USE OF NIV IN A&E : EVIDENCE & CONCERNS (2)(2) Increasing incidence of heart failureIncreasing incidence of heart failure

Evidence does exist for CPAP as “first line treatment” Evidence does exist for CPAP as “first line treatment” (Australia, France)(Australia, France)

L`Her (1998) : improvement in mortality from 20% - 11%L`Her (1998) : improvement in mortality from 20% - 11%

Kelly : chart review of 75 patients in urban A&EKelly : chart review of 75 patients in urban A&E safe and effectivesafe and effective

intubation rate of 4%intubation rate of 4%

no increase in mortalityno increase in mortality

average duration of 1.9 hoursaverage duration of 1.9 hours

no delay in clearance of patients from no delay in clearance of patients from departmentdepartment

claimed did not create extra workloadclaimed did not create extra workload

USE OF NIV IN A&E : EVIDENCE & CONCERNS USE OF NIV IN A&E : EVIDENCE & CONCERNS (3) (3)

Written guidelines tailored to local Written guidelines tailored to local expertiseexpertise

Appropriate trainingAppropriate training

With appropriate patient selection and With appropriate patient selection and careful monitoring I feel that NIV (CPAP) careful monitoring I feel that NIV (CPAP) should be considered an acceptable should be considered an acceptable addition to the treatment of ACPO in A&Eaddition to the treatment of ACPO in A&E

ANY QUESTIONS ?

noninvasive ventilation oap

Documents

use of cpap

pulmonary capillary

transmural pressure

intrathoracic pressure

mechanical ventilation

pulmonary compliance

cpap improved lung mechanics

lv pressure pooling