noninvasive ventilation

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The earliest known ventilators, developed during the late 19th century,were the ‘body or tank’ type

Noninvasive ventilation !!

CPAP, initially used for the treatment ofacute pulmonary

oedema, became popular in the 1980s for management of

obstructive sleep apnoea

CPAP, initially used for the treatment ofacute pulmonary

oedema, became popular in the 1980s for management of

obstructive sleep apnoea

Noninvasive ventilation (NIV): a form of ventilatory support that avoids airway invasion improved outcomes in certain types

of acute respiratory failure (ARF)

The successful application of NIV requires the training & collaboration of an experienced ICU team, including intensivists, nurses, and respiratory therapists

The successful application of NIV requires the training & collaboration of an experienced ICU team, including intensivists, nurses, and respiratory therapists

“NIV should be considered first-line therapy in the

management of ARF caused by COPD exacerbations”

BMJ 2003;326:185–7

BMJ 2003;326:185–7

A trial of NIV can be considered in asthmatics who fail torespond adequately to initial bronchodilator therapy to improve air flow obstruction &decrease the work of breathing

CHEST 2003; 123:1018–1025

large randomized controlled trials (RCTs) are needed before recommending NIV use in status asthmaticus

Cochrane Database Syst Rev 2005; 1:CD004360

Am J Respir Crit Care Med Vol 168. pp 70–76, 2003

a prospective, randomized, controlled trial in 43 mechanically ventilated patients who had failed a weaning trial for 3 consecutive days

Am J Respir Crit Care Med Vol 168. pp 70–76, 2003

Am J Respir Crit Care Med Vol 168. pp 70–76, 2003

The probabilityof weaning success

The cumulative survival probability

Am J Respir Crit Care Med Vol 168. pp 70–76, 2003

NIVNIV

Earlier extubation with NIV results in shorter mechanicalventilation & length of stay, less need for tracheotomy, lower incidence of complications, and improved survival

Am J Respir Crit Care Med Vol 168. pp 70–76, 2003

Facilitating Extubation in Facilitating Extubation in COPDCOPD

Facilitating Extubation in Facilitating Extubation in COPDCOPD

The main physiologic benefit from NIV or CPAP in these patients is likely due to an increase in FRC that reopens collapsed alveoli & improves oxygenation

Crit Care Med 2007 352402; :2407–

increases lung compliance &reduces work of breathing

increases lung compliance &reduces work of breathing

Anesthesiology 2005; 103:419–28

decrease afterload

decrease preload &

decreasing ventricular

preload & afterload

decreasing ventricular

preload & afterload

JAMA. 2005;294:3124-3130

NIV reduces the need for intubation & mortality in patients with acute cardiogenic pulmonary edema.

There are no significant differences in clinical outcomes when comparingCPAP vs NIPSV

NIV reduces the need for intubation & mortality in patients with acute cardiogenic pulmonary edema.

There are no significant differences in clinical outcomes when comparingCPAP vs NIPSV

JAMA. 2005;294:3124-3130

JAMA. 2005;294:3124-3130

JAMA. 2005;294:3124-3130

a cautious trial of NIV may be considered in patients with pneumonia deemed to be excellent candidates, but they need careful monitoring, because the risk of failure is high

AM J RESPIR CRIT CARE MED 1999;160:1585–1591

Relapse of pneumonia was the leading cause of death after hospital discharge, and relapse

occurredin previously intubated patients with COPD

AM J RESPIR CRIT CARE MED 1999;160:1585–1591

Studies on NIV to treat acute lung injury & ARDS have reported failure rates ranging from 50% to 80%Independent risk factors for NIV failure: severe hypoxemia, shock, & metabolic acidosis

Independent risk factors for NIV failure: severe hypoxemia, shock, & metabolic acidosis

Crit Care Med 2007; 35:18–25

In expert centers, NPPV applied as first-line interventionin ARDS avoided intubation in 54% of treated patients

SAPS II >34 & the inability to improve PaO2/FIO2 after 1 hr of NPPV were predictors of failure

In expert centers, NPPV applied as first-line interventionin ARDS avoided intubation in 54% of treated patients

SAPS II >34 & the inability to improve PaO2/FIO2 after 1 hr of NPPV were predictors of failure

PaO2/FIO2 >175

The data support NIV as the preferred initial ventilatory modality for these patients, to avoid intubation and itsassociated risks (reduced infectious complications)

JAMA. 2000;283:235-241

JAMA. 2000;283:235-241

JAMA. 2000;283:235-241

JAMA. 2005;293:589-595

Oxygen at an FiO2 of Oxygen at an FiO2 of 0.5 plus a CPAP of 0.5 plus a CPAP of 7.5 cmH7.5 cmH22OO

Elective abdominal surgery & GA extubated & underwent 1-hour screening test(PaO2/FiO2 300)

6 hours with oxygen 6 hours with oxygen through a Venturi through a Venturi mask at an FiOmask at an FiO22 of of 0.50.5

JAMA. 2005;293:589-595

Patients who received oxygen plus CPAP had a lower intubation rate (1% vs 10%; P=.005; relative risk [RR], 0.099; 95% CI, 0.01-0.76)

JAMA. 2005;293:589-595

CPAP may decrease the incidence of endotrachealintubation and other severe complications in patients who develop hypoxemia after elective major abdominal surgery

CPAP

Crit Care Med 2007 352402; :2407–

A, multiple RCTs & meta-analyses B, more than one RCT, case control series, or cohort studies C, case series or conflicting data

Crit Care Med 2007 352402; :2407–

When in doubt, a brief,cautious trial of NIV

can be attempted,with plans to intubate if the

patient fails to improve sufficiently

When in doubt, a brief,cautious trial of NIV

can be attempted,with plans to intubate if the

patient fails to improve sufficiently

Selection of a properly fit & comfortable interface iscritical to NIV success

face mask group

nasal mask group

Leaks &Asynchrony

A process of balancing the ability to reduce work of breathing byproviding an adequate level of pressure support (usually 8–10 cm H2O) against the discomfort & greater air leaking imposed by higher pressures

Am J Respir Crit Care Med 2005; 172:1112–1118

Dyspnea score assessment

CPAP alone wasunable to reduce inspiratory effort

PEEP level of 10 cmH2O improved oxygenation

highest level of PSV :greatest improvementin dyspnea

both PSV settings reduced

neuromuscular drive, unloaded the inspiratory

muscles, & improveddyspnea

Crit Care Med 2007 352402; :2407–

Monitoring of

NIV for ARF

1.Consideration the etiology of the ARF & evidence for efficacy 2.Good candidates for NIV ? & no contraindications3.Consideration of predictors of success & failure 4.Selection of an Interface & ventilator settings5. Experience of caregivers

Keys to success

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