NIV in emergency department

Dr.Venugopalan.P.PDA,DNB,MNAMS,MEM[GWU]

Director ,Emergency Medicine, Aster –DM health care Site Director ,MEM program –GWUDeputy Director –MIMS Academy

Founder and Executive Director -ANGELS

Emcon2014 Mumbai November 6 to 9

What is it?

• Respiratory support given without an ETT

• Spontaneously breathing patients

Emcon2014 Mumbai November 6 to 9

Normal breathing

• Negative pressure• Air drawn when the

Diaphragm descends

Lung capacities

Types • IPPB –intermittent Positive pressure breathing

• CPAP- Continues positive airway pressure

• BiPAP- Bi-level positive airway pressure

CPAP

• High flow oxygen plus PEEP• Raises FRC away from Residual volume • Splints alveoli open -Reduce work of breathing -Increase PaO2 Re-expands atlectasis • Resolution of pulmonary edema

BiPAP

• IPAP +EPAP• EPAP =PEEP• Inspirtory pressure increases Tidal volume Decreases PaCO2 Increases PaO2 Decreases WOB

Terminology

0

4

8

12

16

EPAP

IPAP

Pressure Support

- IPAP: assists in improving tidal volume, thus decreasing CO2- EPAP : improve FRC, helps recruit more alveoli, thus increasing O2. may reduce work of

breathing associated with autopeep

20

10

0

IPAP = 12

EPAP = 4PS = 8

BiPAP

NIV - Changes in EPAP Pressure

5 cm

Delta P 10 cm

10 cm

15 cm

Delta pressure 5 cm

EPAP increased to 10 cm

IPAP increased to 20 cm

Delta P returned to 10 cm

PRESSURE

Decreasing delta pressure will usually result in lower Vt

• Differential in pressure between inspiration and expiration allows for better patient-ventilator synchrony and thus more comfort

• EPAP CPAP PEEP• IPAP PS–Augments TV –Reduces Atelectasis–Reduces WOB

PAV

• New Assist Mode of Ventilation– Fundamentally different concept

• Ventilator Generates Pressure in Proportion to Patient Effort– Follows and adjusts to patient changes

PatientEffort

Pressure

PSV PAV

From Pressure Support to PAV

Non-invasive PAV for Acute Respiratory Insufficiency

• Peter Gay and coll, Am J Respir Crit Care• General ICU• COPD patients with acute exacerbation• 44 patients were randomized to receive NPPV with PAV or Pressure Support (PS)

Mortality and intubation rate were similar but refusal rate was lower with PAV

Reduction in respiratory rate was more rapid with PAV and there were fewer complications in the PAV group

Respiratory Failure • Type 1 –Low PaO2, All else Normal • Type 2 –Low PaO2,High

PaCO2

CPAP or BiPAP

ABG Normal Value

• PH- 7.35 -7.45• PaO2 -10.7 to 13.3 kPa• PaCO2- 5.6 to 6.7 kPa• HCO3 – 22 to 26 mmol• BE- -2 - +2

• Type 1 respiratory failure

• Type 2 Respiratory failure

Hypoxia

CPAP

Hypoxia Hypercapnea

BiPAP

Clinical Benefits

• Type 1 respiratory failure• Type 2 respiratory failure• Pulmonary Edema

Acute

Clinical Benefits

• Weaning • Post intubation

Sub acute

Clinical Benefits• Sleep apnea • Type 2 respiratory failure COPD CF Neuromuscular Disease

Chro

nic

Precautions • Impaired conscious level• Agitation ,Confusion• Consolidation• Copious secretions • Inability to protect airway• Hemodynamic instability • Bowel obstruction• Recent GI surgery

Contra Indications • Need for immediate

intubation• Facial Trauma and Burns • Frequent vomiting • Recent facial /Upper airway

surgery • Undrained pneumothorax

Avoid intubation • No paralysis or sedation• Ability to move –pressure

relief • Able to communicate • Able to eat and drink• Self care • Less need of invasive

monitoring • Less risk of infection

Advantages

No intubation

• Less infection risk • No tracheal Damage • Able to communicate

Decreased need of ICU admin

• Cost • Patient and Care givers

experience• Less debilitating

Implications of Physiotherapy

• Mask fitting • Deoxygenation • Expectoration• Familiarity with Machine

and Alarms

Skills needed • Patient handling

&communication• Knowledge of respiratory

physiology• Familiarity with interfaces • Knowledge of pressure

area care• Time to spend with patient• Patience

NIPPV in COPD

Meta-analysis of fourteen RCT • Decreased mortality (Relative Risk 0.52; 95%CI 0.35 to 0.76) • Decreased need for intubation (RR 0.41; 95%CI 0.33 to 0.53) • Reduction in treatment failure (RR 0.48; 95%CI 0.37 to 0.63)• Less complications associated with treatment (RR 0.38; 95%CI 0.24

to 0.60) • Shorter hospital stay ( -3.24 days; 95%CI -4.42 to -2.06) • “Data from good quality randomised controlled trials

show benefit of NPPV as first line intervention as an adjunct therapy to usual medical care in all suitable patients for the management of respiratory failure secondary to an acute exacerbation of COPD.”

Cochrane Database Syst Rev. 2004

NIPPV &COPD

• Noninvasive ventilation is most effective in patients with moderate-to-severe disease

• Hypercapnic respiratory acidosis may define the best responders (pH 7.20-7.30). – Noninvasive ventilation is also effective in patients with a

pH of 7.35-7.30, but no added benefit is appreciated if the pH is greater than 7.35.

– The lowest threshold of effectiveness is unknown, but success has been achieved with pH values as low as 7.10.

Respir Care. 2005 May• NIV in pts with milder COPD exacerbations: RCT.• Patients with mild COPD + pH of >7.30 were eligible .• MEASUREMENTS: Borg dyspnea index at baseline, 1 hour, and

daily, Length of hospital stay, endotracheal intubation, hospital survival

• RESULTS : NPPV was poorly tolerated, sig. decrease in dyspnea at 1 hour and 2 days, No differences were seen for any measured variable.

• CONCLUSIONS: The effectiveness and cost-effectiveness of the addition of NPPV to standard therapy in milder COPD exacerbations remains unclear.

NIPPV & Cardiogenic pulmonary edema• There are clear benefits in meta-analysis of

randomized trials for CPAP– risk of mortality 0.59 • 95%CI 0.38-0.90

– risk of intubation 0.44 • 95%CI 0.29-0.66

Peter JV, Moran JL, Phillips-Hughes J, Graham P, Bersten AD. Effect of non-invasive positive pressure ventilation (NIPPV) on mortality in patients with acute cardiogenic pulmonary oedema: a meta-analysis. Lancet 2006; 367: 1155–1163.

Rasanen 1985

Finland

40 patients CPAP (20)

V Control (20)

Intubation

Mortality

6/20 v 12/20 17/20 v 14/20

NS

NS

Bersten 1991

Australia

39 patients CPAP (19)

V Control (20)

Intubation

Mortality

0/19 v 7/20

2/19 v 4/20

<0.005

NS

Lin 1991

Taiwan

55 patients CPAP (25)

V Control (30)

Intubation

Mortality

7/25 v 17/30

2/25 v 4/30

<0.05

NS

Lin 1995

Taiwan

100 patients CPAP (50)

V Control (50)

Intubation

Mortality

8/50 v 18/50

4/50 v 6/50

<0.01

NS

Takeda 1998 Japan

22 patients CPAP (11)

V Control (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 improvement in :

Respiratory statusCardiovascular parametersBlood gas analysis

• No reported complications in any study

Asthma &NIPPV

• Number of studies investigating the use of NPPV in acute asthma exacerbations is limited

• Available data suggests that it is safe .• There are some studies to support the use of BiPAP

for acute asthma exacerbations in the pediatric population .

• Lot of papers that address the question there are • Only 3 completed RCTs and all these have relatively

small numbers. Addition of NIV in treating status asthmaticus is safe

and well tolerated. NIV shows promise as a beneficial adjunct to

conventional medical treatment. further prospective investigation is warranted

NIPPV & Pneumonia

– Noninvasive ventilation not established to be beneficial

– Secretions may be limiting factor– Improvement with noninvasive ventilation best

achieved in patients also with COPD– Hypercapnic respiratory acidosis may define group

likely to respond– Decrease in intubation rate and mortality may be

limited to those also with COPD

Conclusion

• Judicious use of NIV is a useful tool to manage respiratory emergencies

• Close observation and timely interference is absolutely essentials.

• EP and EMS should familiar with equipment , usages and guidelines

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