EMS Medical Director, State of Tennessee Member, ACEP EMS Committee

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24 Οκτ 2013 (πριν από 3 χρόνια και 5 μήνες)

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Joe Holley, MD FACEP

EMS Medical Director, State of Tennessee

Member, ACEP EMS Committee

Objectives


Review the goal & physiology of CPAP


Discuss the indications and contraindications for
CPAP use


Review the literature supporting CPAP use


Explore the role of CPAP use by pre
-
hospital providers


Discuss the methods for implementing pre
-
hospital
CPAP


PREHOSPITAL EMERGENCY CARE 2011;15:418

NIPPV
is an important
prehospital

treatment
modality
for acute dyspnea.


EMS agencies should select NIPPV systems and develop

dyspnea care protocols suited to their patient

populations, clinical capabilities, and receiving

emergency department


resources.


EMS agencies must conduct quality assurance and

inspection efforts to verify the safety and effectiveness

of NIPPV.

Reduce the need for pre
-
hospital intubation!

CPAP vs. Intubation

CPAP


Non
-
invasive


Easily discontinued


Easily adjusted


Use by EMT
-
B


Minimal complications


Does not require sedation


Comfortable


Intubation


Invasive


Intubated stays intubated


Requires highly trained
personnel


Significant complications


Can require sedation or RSI


Potential for
infection


Intensive Resource
Utilization


Impact on the System


The Problem


Congestive Heart Failure


Incidence 10 per 1000 patient (over age 65) transports


25% of Medicare Admissions


Average LOS is 6.7 days


6.5 million hospital days


Those who get intubated have significantly longer LOS


33% get intubated without non
-
invasive pressure support


Intubated patients have 4 times the mortality of non
-
intubated patients

The Problem


CHF/Pulmonary Edema


Interstitial fluid interferes with gas exchange
(ventilation and oxygenation)


Increased myocardial workload resulting in higher
oxygen demands (many of these patients are suffering
ischemic heart disease)


Traditional therapies designed to reduce pre
-
load and
after
-
load as well as remove interstitial fluid

The Problem


COPD/Asthma


Increased work of breathing


Hypercarbic (ventilation issue)


Traditional therapies involve brochodilators which
require adequate ventilation


Higher mortality rate if intubated


Difficult to wean once intubated


Extremely difficult patient to intubate in the pre
-
hospital arena


usually requires RSI

Physiology of CPAP


Airway pressure maintained at set level throughout
inspiration and expiration


Maintains patency of small airways and alveoli


Improves gas exchange


Improves delivery of bronchodilators


Moves extracellular fluid into vasculature


Reduces work of breathing

Supporting Literature


JAMA December 28, 2005 “Noninvasive Ventilation in
Acute Cardiogenic Edema”, Massip et. al.


Meta
-
analysis of studies with good to excellent data


45% reduction in mortality


60% reduction in need to intubate

EFFECTIVENESS OF

PREHOSPITAL CONTINUOUS POSITIVE AIRWAY PRESSURE

IN THE

MANAGEMENT OF ACUTE PULMONARY EDEMA

Michael W. Hubble, PhD, NREMT
-
P, Michael E. Richards, MD, MPA, Roger Jarvis,

EMT
-
P,
Tori

Millikan, EMT
-
P, Dwayne Young, BS, EMT
-
P

PREHOSPITAL EMERGENCY CARE 2006;10:430

439


95 patients received standard

therapy, and 120 patients
received CPAP and standard therapy for Pulmonary Edema


Intubation was required in 8.9% of CPAP
-
treated patients
compared with 25.3% in the control group (p = 0.003), and
mortality was lower in the CPAP group than in the control
group


When compared with the control group, the CPAP group
had more improvement


Patients receiving standard treatment were more likely to
be intubated and more likely to die than those receiving
standard therapy and CPAP.

Supporting Literature


Reviews in Cardiovascular Medicine, vol. 3 supl. 4 2002,
“Role of Noninvasive Ventilation in the Management of
Acutely Decompensated Heart Failure”


“Though BLPAP has theoretical advantages over CPAP, there
are questions regarding its safety in a setting of CHF. The
Key to success in using NIV to treat severe CHF is proper
patient selection, close patient monitoring, proper
application of the technology, and objective therapeutic
goals. When used appropriately, NIV can be a useful
adjunct in the treatment of a subset of patients with acute
CHF at risk for endotracheal intubation.”

Supporting Literature


Brochard (French abstract) “ Noninvasive ventilation
for acute exacerbations of COPD”

“…can reduce the need for intubation, LOS in hospital,
and mortality rate”

Pre
-
hospital CPAP


PEC 2000 NAEMSP Abstract, “Pre
-
hospital use of CPAP for
presumed pulmonary edema: a preliminary case series”,
Kosowsky, et. al.


19 patients


Mean duration of therapy 15.5 minutes


Oxygen sat. rose from 83.3% to 95.4%


None were intubated in the field


2 intubated in the ED


5 subsequently intubated in hospital


“Pre
-
hospital CPAP is feasible and may avert the need for
intubation”




Types of Positive Pressure
Ventilation


1) continuous positive airway pressure (CPAP)


applies uniform supportive pressure during both
inspiratory and expiratory phases.

2)
bilevel

positive airway pressure (
BiPAP
) is similar to
CPAP but alternates different levels of inspiratory and
expiratory pressure.



Both CPAP and
BiPAP

systems typically provide
pressure support of 4
-
10 cmH2O.

Is it Cost Effective?


Hubble et al. evaluated the cost
-
effectiveness of
prehospital

CPAP in acute pulmonary edema.


Using data from their 2006 publication, they predicted
that four of every 1,000 EMS patients would require
CPAP for acute pulmonary edema, resulting in 0.75
lives saved.

Is it Cost Effective?


Accounting for the cost of CPAP equipment, including the
cost of the CPAP
-
generating system, disposable mask, and
tubing for each patient, training of personnel, and oxygen
usage, the authors estimated that the cost
-
benefit

of
prehospital

CPAP was $490 per life saved.



They also predicted that CPAP would reduce
hospitalization costs by $4,075 per year per application.


Didn’t include the value of avoiding the ICU, Mechanical
Ventilation, Complications, or availability of ICU bed for
“the Next Patient”….potentially worth thousands of dollars

Delivery System Types



External Pressure Regulated



Turbulent Flow Virtual Valve

External Pressure Regulated


Regulator
-
based portable NIPPV systems generate
continuous pressure from oxygen
flow
, directly
controlling inspiratory and expiratory pressure.


Regulator
-
based NIPPV systems allow different
inhaled oxygen fractions, reducing oxygen
consumption.


At 10 cmH2O pressure and 100% inspired oxygen
(
flowrate

of 15 L/min), a size D oxygen cylinder will last
between 20 and 30 minutes.


At 65% inspired oxygen, a size D oxygen cylinder may
last approximately 35 minutes.


Regulator
-
based systems are often compatible with
end
-
tidal
capnometry

and in
-
line medication
nebulizers.

Disadvantages


A disadvantage of regulator
-
based systems is their size;
portable NIPPV regulators weigh approximately 3
pounds.


Regulator
-
based systems are also expensive; the
regulator costs $1,000
-
1,500, and each disposable hose
circuit costs $25
-
50.


Portable NIPPV systems may not be compatible with
hospital wall oxygen outlets.


During transition of care to the ED, EMS personnel
may need to rely on portable oxygen tanks to maintain
NIPPV operation until the availability of hospital
NIPPV equipment.

Turbulent Flow Virtual valve.


The
Boussignac

CPAP system uses a different NIPPV
approach, accelerating oxygen
flow

through a series of
channels to create turbulence.


The turbulence acts as a virtual valve, generating
positive airway pressure.


The system is lightweight and disposable (single use)
and uses a conventional oxygen source and
flow

regulator.


Each disposable circuit costs approximately $70.


On arrival at the ED, EMS personnel may transfer the
system to hospital wall oxygen, thus minimizing care
transfer delays.

Disadvantages


A disadvantage of the
Boussignac

system is its limited
maximum positive pressure of ~10 cmH2O with an
oxygen
flow

of 25 L/min.



Consequently, the system requires large quantities of
oxygen.


For a CPAP pressure of 5.0 cmH2
O, a size D oxygen
cylinder will last approximately 23 minutes.


To generate a CPAP pressure of 10 cmH2
O, a size D
cylinder
will last 14 minutes.

Transport Ventilators


Select transport ventilators may be designed to provide
BiPAP

or CPAP.



While dependent on the individual brand and model,
the process involves placing the ventilator in pressure
support mode, setting a desired inspiratory pressure
support value, and setting a desired positive end
-
expiratory pressure (PEEP) value.


Indications for CPAP


The general indication for NIPPV is dyspnea accompanied
by early respiratory failure in patients with intact protective
airway
reflexes

and mental status.


CHF


Pulmonary Edema


Near Drowning


Inhalation Exposure


COPD


Asthma


Pneumonia


Possible Indications


While utilized in in
-
hospital practice, the role of
NIPPV for pneumonia
-
associated respiratory failure is
less clear.



ContraIndications


Patients with severe respiratory distress may not
tolerate NIPPV.


not suitable for patients with an absence of a gag
reflex

or altered mental status.


not be able to cooperate with NIPPV


increased risks of vomiting and aspiration


consider ETI for these patients.



Use In Trauma?


The utility in major trauma is unclear



Invasive airway management of major trauma is
difficult
, and NIPPV may provide transient
ventilatory

support in these patients.


However, potential NIPPV pitfalls in the setting of
trauma include the risk of
pneumocephalus
,
subcutaneous emphysema or bacterial meningitis in
patients with
midface

fractures, pneumothorax in
thoracic trauma, and increased
intrathoracic

pressure
causing hypotension

Generally Accepted
ContraIndications


Patient less than eight years of age (Fitment Issues)


Unable to maintain a patent airway


Decreased level of consciousness (LOC)


Pneumothorax


Facial trauma/burns


Systolic BP < 90 mmHg


Recent surgery to face or mouth


Epistaxis


Patient unable to tolerate mask or pressure


Pneumonia (relative contraindication)

What about the Hypoxic Drive
Issue?


Certainly this physiologic phenomenon exists, it is relatively
uncommon and many hypoxic COPD patients have been denied much
needed oxygen out of fear of causing worse
hypercapnia
. As a result,
left ventricular function suffers as does renal, mental and other related
issues.



Moreover, when this phenomenon does occur, it is in the setting of
non
-
pressurized oxygen delivery (read nasal cannula or face masks)
and not with CPAP,
BiPAP

or intubation and placement of the patient
on mechanical artificial ventilation. All three of these modalities
resolve
hypercapnia

by increasing alveolar ventilation. Recall that as
alveolar ventilation goes up, PaCO2 goes down and respiratory acidosis
lessens.



The COPD patient with known
hypercapnia

should never be
transported to the ED on non
-
pressurized oxygen. However, hypoxic
COPD patients can be safely transported with supplemental oxygen
driven by CPAP.



Intubation


Patients who cannot cooperate, maintain their own airway,
or have adequate respiratory effort are not candidates for
CPAP. They require immediate intubation.



Monitor your patient for a failure to respond to CPAP, as
noted by a declining mental status or ability to comply with
CPAP. Not all patients will respond, and may require
intubation.



Patients who have intractable vomiting may not be able to
protect their airway, and need intubation.

Training

Key elements of training should cover:



Pathophysiology of acute dyspnea



Physiology of NIPPV systems



Description of CPAP and
BiPAP

mechanics, with focus on the systems available to the
individual EMS agency



Indications and contraindications for NIPPV



Initiation and titration of NIPPV therapy



Titration of concurrent pharmacologic therapy



Management of adverse events



Transition of care at the receiving hospital



Alternate care strategies

Training


The technique of NIPPV application will vary with the
employed system.



Application of the face mask must ensure a tight seal.


Facial hair may require trimming to achieve a tight
seal.


An adequate mask seal may not be possible with
edentulous patients or individuals with facial
abnormalities.


Patient Coaching is very important to successful
application

Application in the Field


Continuous positive airway pressure systems have single
pressure setting for both inspiration and expiration. A
typical initial setting is 5 cmH2O, with pressure
adjustments every few minutes in response to the patient’s
subjective and objective work of breathing, respiratory rate,
and oxygen saturation.


The typical range of pressure settings is 5
-
10 cmH2O.



Bilevel

positive airway pressure is similar to CPAP, but
alternates a higher inspiratory pressure with a lower
expiratory pressure.


Typical initial settings include an inspiratory pressure of 10
cmH2O and an expiratory pressure of 5 cmH2O, with
subsequent adjustments according to patient response.

Medication Administration


Many CPAP devices allow for the concurrent
administration of
nebulized

medications.



Medications are generally more effective due to
improved recruitment, airway patency, and pressure
support.



Indications for Bronchodilators are the
same
regardless
of the use of CPAP

Patient Monitoring



Respiratory rate:
A reduction in respiratory rate (and effort) may indicate clinical response to
NIPPV.



Heart rate
: Improvement in ventilation and perfusion with NIPPV may reduce the heart rate.
However, the heart rate may also increase in response to increased
intrathoracic

pressure and
decreased venous return.



Systolic blood pressure
: The increase in
intrathoracic

pressure from NIPPV may decrease venous
return to the heart, leading to a decrease in blood pressure. The development of hypotension (systolic
blood pressure <100 mmHg) or hypoperfusion (cyanosis, decreased capillary
refill
) may indicate the
need for reduced NIPPV support.



Oxygen saturation
: Oxygen saturation may improve with application of NIPPV.



End
-
tidal
capnography
:
End
-
tidal carbon dioxide (ETCO2) monitoring to gauge NIPPV response.


Upon initial application of NIPPV, ETCO2 may increase from improvement in
ventilatio
/perfusion
mismatch. Decreasing ETCO2 may
reflect

respiratory improvement from NIPPV.



Subjective dyspnea

ratings of patient subjective dyspnea, auscultation intensity, cyanosis, and
accessory respiratory muscle use.

Wisconsin EMT

Basic Experience


Question: Can EMT
-
Basics apply CPAP as safely as
Paramedics?


50 EMT
-
Basic services


2 hour didactic, 2 hour lab, written and practical test


Required data collection


Compared to same data collected by ALS services
during same period

Wisconsin EMT

Basic Experience


Required data collection


Criteria used to apply CPAP


Absence of contraindications


Q 5 min. vital signs including oxygen sats.


Subjective dyspnea score


Because EMT

Basics don’t diagnose a unique
“Respiratory Distress” protocol used to capture
patients

Adult Respiratory Distress Protocol

(Age greater than 12)

Routine Medical Assessment

Oxygen

2 LPM via Nasal Cannula

Titrate to maintain Pulse ox of >92
%

Is Patient a candidate for Mask CPAP?

-
Respiratory Rate > 25 / min

-
Retractions or accessory muscle use

-
Pulse ox < 94% at any time

See Mask CPAP Protocol

No

Yes

No

No

Is the Patient wheezing and/or does

the Patient have a history of Asthma/COPD?

Does the Patient have rales and/or does the

Patient have a history of congestive heart

failure (CHF)?

Yes

Administer Albuterol /

Atrovent

by Nebulizer

If Basic IV Tech:

Administer 1 spray

sublingual NTG every

5 minutes as long as

systolic BP is greater than

100mmHg

Yes

Contact Medical Control

Consider ALS Intercept and Transport

Asses Patient, record vital signs

and pulse ox before applying oxygen

Does the Patient meet two or more

Inclusion Criteria?

No

Yes

Does the Patient meet any

Exclusion Criteria?

Continue standard BLS

Respiratory Distress Protocol

Administer CPAP

5 cm H2O of pressure
AND

Reassess patient, vital signs, and

respiratory distress scale every 5 min.

Notify Medical Control

Consider ALS Intercept

and continue BLS

Respiratory Distress Protocol

Patient condition is stable

or improving

Continue CPAP

Reassess patient every

5 minutes

Patient condition is deteriorating

Decreasing LOC

Decreasing Pulse Ox

Notify Medical Control

Remove CPAP

Apply BVM Ventilation

Mask CPAP for EMT
-
Basic

CPAP Inclusion Criteria

(2 or more of the following)

-
Retractions or Accessory muscle use

-
Respiratory Rate > 25 / minutes

-
Pulse Ox < 94% at any time


CPAP Exclusion Criteria

-
Unable to follow commands

-
Apnea

-
Vomiting or active GI bleed

-
Major trauma / pneumothorax


Conditions Indicated for CPAP

Congestive Heart Failure

COPD / Asthma

Pneumonia

Yes

No

Wisconsin EMT
-
Basic Experience


Results (preliminary


study completed 11/05)


500 applications of CPAP (114 services)


99% met criteria for CPAP on review of medical director


No field intubations by those services with ALS intercepts


No significant complications


All oxygen sats. improved, dyspnea reduced by average of
50%

Wisconsin EMT


Basic Experience


State approved CPAP for EMT
-
Basic scope of practice
2/06


Questions yet to be answered


What conditions did the patients have?


Was it applied too liberally?


Key Point


Services without ALS intercept did just as well as those
with it

Implementation in Your System


How good is current care for respiratory distress?


Aggressive nitrates for CHF?


Aggressive use of bronchodilators?


Pre
-
hospital and hospital intubation rate?


Requires active medical oversight


Airway management is a sentinel event



ALS or BLS or BOTH?

Items to Consider


Equipment


Must be easy to use and portable


Adjustable to patient’s need


Easily started and discontinued


Provide quantifiable and reliable airway pressures


Conservative oxygen utilization


Not interfere with administration traditional therapies
for underlying condition


Items to Consider


Oxygen concentration


Fixed versus Variable rates


Fixed rates are either 35% or 100% in current models but
actual concentration will be less depending on leaks and
minute ventilation


Variable rate increases chance of inadequate oxygen supply


Pressure level


Most studies show 5cm H20 sufficient


Complication rate goes up with pressure

Summary


CPAP is a non
-
invasive procedure that is easily applied
and can be easily discontinued without untoward
patient discomfort


CPAP is an established therapeutic modality


Data supports its use in CHF, pulmonary edema,
COPD/Asthma, and pneumonia


The Future


NAEMSP is a strong supporter of CPAP in the field


The Data is very solid supporting its use


Safety


Cost effectiveness


Its SIMPLY the RIGHT THING for OUR Patients!!

What’s the holdup?


Yet to be recognized by
payors

as a separate billable
service.


Medicare currently will only pay if its used in
conjunction with Endotracheal Intubation!!


What’s the Point!!!!



Hospitals have been slow to adopt



Efficiencies Improve if adopted on a system wide basis





Joe Holley, MD FACEP