BiPAP và CPAP Theory and Uses (Chế độ BiPAP và CPAP và cách sử dụng trong gây mê hồi sức)

CPAP and BiPAP Theory and Uses By Rudy Koch BSRT,RRT Adult Clinical Coordinator Respiratory Care Department Strong Memorial Hospital What is CPAP? • CPAP delivers a continuous positive air pressure • This is delivered throughout the respiratory cycle • designed to deliver a positive pressure of between 4 and 25 cm H2O • been described as being similar to breathing with your head stuck out of a moving car multiple reasons why CPAP might improve breathing. • Counteract intrinsic PEEP (autonomic PEEP) • decrease preload and afterload in CHF ( not totally proven why yet) • improve lung compliance in CHF • decrease the work of breathing (increasing FRC) • helps treat obstructive sleep apnea BiPAP • BiPAP delivers CPAP but also senses when an inspiratory effort is being made and delivers a higher pressure during inspiration. When flow stops, the pressure returns to the CPAP level. This positive pressure wave during inspirations unloads the diaphragm decreasing the work of breathing. BiPAP Terms • EPAP expiratory positive airway pressure. • This is the CPAP level and the end of expiration. • IPAPinspiratory positive airway pressure. • This is the pressure given during the inspiratory cycle. If you think about it….. • CPAP is for oxygenationto increase the PaO2SpO2 • BiPAP is for ventilation to decrease the PaCo2 Indications for BiPAP • Obstructive sleep apnea • Nocturnal hypoventilation • Chronic ventilator muscle dysfunction accompanied by CO2 retention • Post extubation difficulty in whom reintubation may be avoided • Impending respiratory failure • CHF afterdiagnosis is confirmed Contraindications for BiPAP • Patients with altered level of consciousness ( not hypercapnia) • Head gear cannot be secured secondary to the extent of their injury • Patients with respiratory rates greater than 30 breaths per minute • Patients who has a history of vomiting. • Patients who have high FiO2 needs. WHAT TO ORDER • Mode of BiPAP( CPAP or BiPAP) • EPAP level • IPAP level • O2 saturation goalor specified O2 flow rate • Durationcircumstances of use Initial settings on BiPAP a common technique is begin with the expiratory level(EPAP) at 5 and the inspiratory level(IPAP) at 15. The levels are adjusted based on patient comfort tidal volume achieved and blood gases. • The use of BiPAP machines has increased over the last several years. • There are also more types of masks available and this has improved patient comfort and compliance. • The patient must always be shown how to remove it in case of panic or vomiting. If the patient has a decreased level of consciousness, copious secretions, can not protect his airway or is unstable hemodynamically, then intubation is warranted. I MEAN NEVER……… TRANSPORT A PATIENT ON BiPAP The BiPAP has no battery backup So the patient cannot clear Their CO2 SOMETHING TO NOTE • Patient understanding and cooperation is important for the success of this modality • Proper mask sizing is a crucial component of success. Mask comfort is often the limiting factor to success. • select the smallest mask possible for the patients nasal contour NOTE………. • Patients placed on NIPPV or BiPAP for acute respiratory distress or for conditions in which inadvertent cession of support would produce an immediate life threatening risk are to be considered as if on full mechanical ventilatory support. These patients may be considered to be placed into the ICU. Adjustments • Increasing IPAP in increments of 2 cmh2o provides a pressure boost on inspiration that may provide an increase in alveolar ventilation andor decrease the work of breathing. • Increasing EPAP in increments of 2 cm H2O may result in some increase in FRC and along with manipulations in FiO2 improve oxygenation. REMEMBER • BiPAP settings are manipulated based on the patients physiologic response. Failure to see an improvement in the patients respiratory status within hours of implementing BiPAP is an indication to discontinue and evaluate other supportive options. Monitoring: Things that should be assessed • Neuro assessment • Respiratory assessment (R.R., breath sounds, resp. pattern etc.) • BiPAP settings • O2 liter flow, SaO2 and vitals • Any adverse effectsresponse New study • Latest studies have show that placing people with COPD or Asthma early in their exacerbation can prevent them from being intubated and increase their mortality. • But almost 100 %of patients with advanced pneumonia ended up intubated • There is still controversy on how and why CPAP works in CHF. There is no dispute that it reduces the work of breathing by improving atelectasis and VQ ratios. Some studies have suggested it also improves preload and afterload and that there is actually an improvement in cardiac index. Of even more interest, studies out of

CPAP and BiPAP

Theory and Uses

By Rudy Koch BSRT,RRT Adult Clinical Coordinator Respiratory Care Department Strong Memorial Hospital

• been described as being similar to

breathing with your head stuck out of a

moving car

multiple reasons why CPAP

might improve breathing

• Counteract intrinsic PEEP (autonomic PEEP)

• decrease preload and afterload in

CHF ( not totally proven why yet)

• improve lung compliance in CHF

• decrease the work of breathing

(increasing FRC)

• helps treat obstructive sleep apnea

• BiPAP delivers CPAP but also senses when an inspiratory effort is being

made and delivers a higher pressure

during inspiration When flow stops, the pressure returns to the CPAP level

This positive pressure wave during

inspirations unloads the diaphragm

decreasing the work of breathing

• IPAP- inspiratory positive airway pressure.

• This is the pressure given during the

inspiratory cycle.

If you think about it…

• CPAP is for oxygenation-to increase the PaO2/SpO2

• BiPAP is for ventilation- to

decrease the PaCo2

Indications for BiPAP

• Obstructive sleep apnea

• Nocturnal hypoventilation

• Chronic ventilator muscle dysfunction accompanied by CO2 retention

• Post extubation difficulty in whom

reintubation may be avoided

• Impending respiratory failure

• CHF after diagnosis is confirmed

Contraindications for BiPAP

• Patients with altered level of

consciousness ( not hypercapnia)

• Head gear cannot be secured secondary

to the extent of their injury

• Patients with respiratory rates greater

than 30 breaths per minute

• Patients who has a history of vomiting

• Patients who have high FiO2 needs

Initial settings on BiPAP

a common technique is begin with the expiratory level(EPAP) at 5 and the

inspiratory level(IPAP) at 15 The

levels are adjusted based on patient comfort tidal volume achieved and

blood gases

• The use of BiPAP machines has

increased over the last several years

• There are also more types of masks

available and this has improved patient comfort and compliance

• The patient must always be shown

how to remove it in case of panic or

vomiting If the patient has a

decreased level of consciousness,

copious secretions, can not protect his airway or is unstable

hemodynamically, then intubation is

warranted

I MEAN NEVER………

TRANSPORT A PATIENT ON

BiPAP!!!!!!

The BiPAP has no battery backup

So the patient cannot clear

Their CO2

SOMETHING TO NOTE

• Patient understanding and

cooperation is important for the

success of this modality

• Proper mask sizing is a crucial

component of success Mask comfort

is often the limiting factor to success

• select the smallest mask possible for the patient's nasal contour

• Patients placed on NIPPV or BiPAP for acute respiratory distress or for

conditions in which inadvertent cession

of support would produce an immediate life threatening risk are to be considered

as if on full mechanical ventilatory

support These patients may be

considered to be placed into the ICU

• Increasing IPAP in increments of 2 cmh2o

provides a "pressure boost" on inspiration

that may provide an increase in alveolar

ventilation and/or decrease the work of

• BiPAP settings are manipulated based on the patient's physiologic response Failure

to see an improvement in the patient's

respiratory status within hours of

implementing BiPAP is an indication to

discontinue and evaluate other supportive options.

• O2 liter flow, SaO2 and vitals

• Any adverse effects/response

New study

• Latest studies have show that placing

people with COPD or Asthma early in their exacerbation can prevent them from being intubated and increase their mortality.

• But almost 100 % of patients with

advanced pneumonia ended up intubated!!

• There is still controversy on how and why CPAP works in CHF There is no dispute

that it reduces the work of breathing by

improving atelectasis and V/Q ratios Some studies have suggested it also improves

preload and afterload and that there is

actually an improvement in cardiac index

Of even more interest, studies out of

Toronto by Bradley suggest that up to 50%

of patients with CHF have sleep apnea It is possible that obstructive sleep apneas can put a severe strain on the heart by

markedly increasing afterload and leading

to hypertension

• In conclusion, for those patients who

present to the on the floors with acute

respiratory failure but with normal levels

of consciousness, no major secretion

problems and who are hemodynamically

stable, a trial of BiPAP or CPAP should

be attempted prior to considering

intubation and a mechanical ventilator

• Any questions please contact the

respiratory supervisor or clinical

coordinator