Continuous Positive
Airway Pressure Devices
ALS / BLS CONTINUING EDUCATION
AMY GUTMAN MD ~ EMS MEDICAL DIRECTOR
Overview
 Review CPAP goals & physiology
 Indications & contraindications
 EBM literature review
 OEMS protocol & medical
director review
What is CPAP (Continuous
Positive Airway Pressure)?
 High-flow, pressurized & concentrated O2 delivery system
 Exhalation port flow restriction device provides positive end expiratory
pressure (PEEP) at a set level throughout inspiration & expiration preventing
upper airway structures from collapsing &“splinting” open alveoli
 By placing airway under a constant level of pressure throughout the
respiratory cycle, obstructions are "pushed" out of the alveoli

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Increased intrathoracic pressure reduces preload & afterload, improving left
ventricular function
Maintains patency of small airways & alveoli
Improves gas exchange & reduces work of breathing by moving fluid into vasculature
Improves bronchodilator delivery
 Noninvasive option to support pts through a respiratory crisis, avoid ETI, or
buy time until ETI can be performed in a more controlled environment
CPAP vs BiPAP
 CPAP

“Continuous” constant positive pressure throughout respiratory cycle
 BiPAP
 “Bilevels” (2) of positive pressure during different phases of the respiratory cycle
 When pt breathing in, Inspiratory Positive Airway Pressure (IPAP) exerted
 When pt breathing out, Expiratory Positive Airway Pressure (EPAP) exerted
 “Effects of BiPAP in patients with COPD” (European Respiratory Journal; 2000 )


BiPAP causes higher intrathoracic pressures & reduces myocardial perfusion
BiPAP causes lower tidal volumes & increases work of breathing (vs CPAP)
CPAP O2 Delivery
 Prehospital CPAP devices powered by an O2 source that can deliver
50 psi
 Some generators have a fixed flow rate, while others can be adjusted


Fixed rates are either 35% or 100% but actual O2 concentration will be less
depending on leaks and minute ventilation
Variable rate increases chance of inadequate oxygen supply
 The percentage of oxygen delivered (FiO2) usually starts at 30% &
can be increased depending on pt needs
 At 28-30% FiO2 , a full tank should last approximately:



D cylinder
E cylinder
M cylinder
=
=
=
28 minutes
40-50 minutes
4 hours
Branson R, Davis K, Johannigman J. Comparison of continuous
flow & a demand CPAP system for use in emergency care of CHF.
Prehosp Emerg Care. 2001 Apr-Jun;5(2):190-6.
 The low flow Whisperflow device had a lower gas consumption than the
fixed Whisperflow. E-cylinder operation duration was highest with the
Whisperflow fixed compared to other devices
 Whisperflow Low Flow


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
FIO2
Gas Consumption
Gas Consumption with 5L/min Leak
Duration of Operation
30%
10 L/ min
10 L/ min
60 mins
 Whisperflow Fixed




FIO2
Gas Consumption
Gas Consumption with 5L/min Leak
Duration of Operation
30%
15 L / min
15 L/ min
30 mins
Indications
 Increased work of breathing &
inability to effectively remove
CO2
 Poor respiratory effort &
decreased air movement results
in CO2 levels rising, causing a
narcotic like effect on the brain
(“CO2 Narcosis”)
 Combined effects of fatigue &
rising blood levels of CO2 lead
to further lowering of the
ventilation rate & respiratory
failure
Contraindications

Need for emergent ETI

Hypotension

Cannot follow commands

Aspiration risk

Upper GI bleed / persistent vomiting

Recent facial trauma / surgery

Tracheostomy

Chest trauma / suspected pneumothorax

Claustrophobic (make an attempt)
Side Effects
 Anxiety (most common)
 As CPAP increases intra-
thoracic pressure & gastric
distention, there is a risk of
hypotension & PTX
 Abruptly stopping treatment
can result in acute
decompensation & need for ETI
 Give hospital advance notice, so
they can prepare
COPD
 Lungs lose elastic recoil from scarred
alveoli & bronchioles scar
 Hypercarbic (ventilation issue)
 Traditional therapies involve brochodilators (requires adequate ventilation)
 Difficult to ETI prehospitally without RSI
 Bronchioles collapse during exhalation leading to alveolar air trapping
 “Pursed lip” breathing increases “auto-PEEP”
 COPD patients requiring ETI have worse outcomes than if managed
conservatively

Higher mortality & difficult to wean off ventilator rate if ETI
Aultman Study: COPD
 55 pts in CPAP group

35%
3 intubations
35%
 43 pts in no CPAP group

15 intubations
 30% reduction in ETI
30%
25%
20%
15%
10%
5%
5%
0%
CPAP
CONTROL
Congestive Heart Failure

Incidence




1:100 pt transports > age 65 yo
25% medicare admissions
Average LOS 6.7 days (longer if ETI) = 6.5 million hospital days annually
Increased interstitial fluid interferes with gas exchange / oxygenation


Lymphatics remove 10-20cc pulmonary fluid/ hr
When capability exceeded, fluid accumulates in alveolar air spaces, “drowning” pt

Increased myocardial workload resulting in higher O2 demands in pts who often have
concominant ischemic heart disease

Traditional therapies designed to reduce pre-load & after-load as well as remove
interstitial fluid

CPAP “pushes” fluid out of alveoli back into the vascular & lymphatic tissues


33% have ETI if no attempts at non-invasive pressure support
Intubated pts have 4 X greater mortality of non-intubated pt
Aultman Study: CHF Patients
 51 pts in CPAP group

1 Intubation
 82 pts in no CPAP group

22 Intubations
 25% reduction in ETI
27%
30%
25%
20%
15%
10%
5%
2%
0%
CPAP
CONTROL
Asthma
 Bronchospasm & increased
work of breathing
 Pts cannot physically move air
in & out of the lungs due to
spasm
 CPAP delivers aerosolized
medications & “splints” open
spasming alveoli & bronchioles
Aultman Study: Asthma
 19 pts in CPAP group

3 intubations
 7 pts in no CPAP group

2 intubations
 12% reduction in ETI
28%
30%
25%
20%
16%
15%
10%
5%
0%
CPAP
CONTROL
Equipment
 Easy to use & portable
 Adjustable to patient’s needs
 Easily started & discontinued
 Provide quantifiable & reliable
airway pressures
 Conservative oxygen utilization
 Limited interference with
administration of “traditional”
cardio-respiratory therapies
Necessary Components
 Oxygen source capable of
producing 50 psi
 Tight fitting mask
 Flow regulator


30% fixed O2 concentration
When attached to an O2 cylinder, the
primary regulator delivers 50 psi & device
"sucks" in room air to dilute the 100% O2
PEEP Valve
 PEEP valve connected to
exhalation port to maintain a
constant circuit pressure
 Each PEEP valve rated at a
certain level measured in 2.5
cmH2O increments
 Common increments are 5.0 or
7.5 cmH20
Important Points
 Continually check for air leaks
& pt tolerance
 Do not break seal to administer
medications
 Even if status improves,
continue CPAP until
transferred to ED & personnel
transfer pt to their equipment
 If status deteriorates,
discontinue CPAP & prepare
for ETI
 Notify destination hospital that
CPAP is been used
CPAP vs. Intubation
CPAP
ETI
 Non-invasive
 Invasive
 Easily discontinued
 Requires mechanical
 Easily adjusted
 BLS skill*

 Minimal complications

 Does not require sedation

 Minimal infection risk

 Comfortable and physiologic

*Not according to MA OEMS, unfortunately
ventilation
ALS skill
Significant complications
Requires sedation or RSI
Potential for infection
Uncomfortable and nonphysiologic
Prehospital CPAP Research
 Provides greatest benefit when initiated early
 Decreases intubations & improvement in respiratory symptoms with no
major complications
 In Helsinki CPAP used for >12 yrs on mobile ICUs for respiratory
distress

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Improved oxygenation, lowered respiratory rate, HR & SBP
Patients who were initially misdiagnosed as having CHF (i.e. pneumonia or effusion)
had no adverse side effects from CPAP
Prehospital Use of CPAP for Acute Severe CHF (JEMS. 2011)

OBJECTIVE:
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METHODS:
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Retrospective review of pts treated for acute CHF
Inclusion criteria: were: RR >25 bpm, respiratory distress, history of CHF, intact mental status
Data collected: demographics, vitals, need for ETI, complications
RESULTS (STATISTICALLY SIGNIFICANT):
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To describe the prehospital use of CPAP for patients presenting with acute severe HF in urban NJ
387 pts met inclusion criteria, 149 had CPAP placement (39%)
Prehospital treatment times :CPAP 30 min; non-CPAP 31 min
Increase in O2 sat: CPAP 9%; non-CPAP 5%
SBP reduction: CPAP 27 mmHg; non-CPAP 19.9 mmHg
HR reduction: CPAP 17 bpm; non-CPAP 9 bpm
RR reduction: CPAP 6 bpm; non-CPAP 4 bpm
ETI reduction: CPAP 2%; non-CPAP 6%
CONCLUSION:

CPAP for eligible patients with acute severe CHF feasible & beneficial
Evaluation of the effect of prehospital application of CPAP
therapy in acute respiratory distress. (Prehospital Disaster Med. 2010)
 OBJECTIVE:

Test impact of CPAP on rural prehospital pts with acute respiratory distress
 METHODS:

8 month, crossover, observational, non-blinded study
 RESULTS:
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During the 4 months of baseline data collection, 8% pts with respiratory distress were ETI
within 1st 48 hours of care with an average ICU LOS of 8 days
During the four months when CPAP available in the prehospital setting, ETI not required for
any patients in the field or in the ED, with 2 ICU admissions (average LOS 4 days)
 CONCLUSIONS:

The use of the CPAP in the prehospital setting is beneficial in acute respiratory distress
Current Prehospital CPAP Research

“Noninvasive Ventilation in Acute Cardiogenic Edema” JAMA, 2005

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Warner. “Evaluation of the effect of prehospital application of CPAP therapy
in acute respiratory distress”. Prehosp Disaster Med. 2010


The use of prehospital CPAP is beneficial for pts in acute respiratory distress
Sullivan. “Prehospital use of CPAP: Positive pressure = positive patient
outcomes”. Emerg Med Serv, 2005
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Meta-analysis of 22 studies with “good to excellent data” showed a 45% reduction in mortality and
a 60% reduction in ETI
CPAP alleviates symptoms & decreases need for ETI for pts with CHF, COPD & asthma. CPAP does
not replace ETI, rather is a less-invasive means of providing respiratory support while medications
work to correct underlying causes of distress
Bledsoe. Low-fractional oxygen concentration continuous positive airway
pressure is effective in the prehospital setting. PEC, 2012

CPAP using a low FiO2 (28%-30%) was highly effective in the treatment of commonly encountered
prehospital respiratory emergencies
Hubble. “Estimates of cost-effectiveness of prehospital CPAP in
the management of acute pulmonary edema” PEC. 2008
 METHODS

A cost-effectiveness model of implementing CPAP in an urban EMS system was derived from the societal
and implementing EMS systems’ perspectives
 RESULTS
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Cost of consumables, equipment & training = $89 per CPAP pt
An EMS system would be expected to use CPAP 4:1000 EMS pts & expected to save 0.75
lives:1000 EMS pts at a cost of $490 per life saved
CPAP results in one less intubation per 6 CPAP applications to reduce hospitalization costs
by $4075 per year per CPAP application
 CONCLUSION

Aside from the ultiple studies have demonstrated the effectiveness of CPAP in the
management of acute pulmonary edema, prehospital CPAP also appears to be a costeffective treatment for these patients
Aultman Study: Summary
CPAP Group (n = 148)
Diagnosis
ETI
%
No ETI
Control Group (n = 161)
%
ETI
%
No ETI
CHF
1
50
22
60
Asthma
3
16
2
5
COPD
3
52
15
28
Pneumonia
0
3
2
6
Pulmonary
Edema
4
11
6
1
Other
2
3
9
5
Total
13
9%
135
91%
56
35%
105
%
65%
Key Point: 91% of all comers in the CPAP Group did not require prehospital ETI;
65% in the Control Group did require ETI to equal a 26% reduction in prehospital ETI
Wisconsin EMT–Basic Study
 Can EMT-Bs apply CPAP as safely as EMT-Ps?

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50 EMT-Basic services
2 hour didactic, 2 hour lab, written & practical test
 Because EMT–Basics don’t diagnose a unique “Respiratory Distress”
protocol used to capture patients
 Required data collection
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Criteria used to apply CPAP
Absence of contraindications
Q 5 min. vitals
Subjective dyspnea score
Wisconsin EMT–Basic Study Results
 500 applications of CPAP in 114 services

99% met criteria for appropriate CPAP application
 No field intubations required by ALS intercepts and no significant
complications
 All O2 sats improved, dyspnea scores reduced by 50%
 Results replicated in 20+ studies since, demonstrating that pts
receiving prehospital CPAP have a significantly lower incidence of ETI
compared to conventional “respiratory distress” therapy
 Pts not receiving prehospital CPAP 6 x more likely to require ETI
(Marchetta et al)

CPAP group 355 days less LOS

If CPAP + intubation patients still had 6 days fewer LOS

ICU Admission reduced 62%
Points to Consider
 How good is your current therapy for respiratory distress?

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Aggressive nitrates for CHF?
Aggressive use of bronchodilators?
Prehospital & ED intubation rate?
 Do you have active medical oversight?

Advanced airway management is considered a sentinel event
 ALS or BLS or BOTH?
OEMS 3.4 Bronchospasm / Respiratory Distress Assessment &
Treatment Priorities
 Scene safety, BSI
 Maintain open airway, assist ventilations prn, administer oxygen as needed
 Check hemodynamic stability, symptoms, LOC, ABCs, vitals, monitor / ECG
 Obtain OPQRST & SAMPLE
 Determine level of respiratory distress
 Mild: Slight wheezing. mild cough, able to move air without difficulty
 Severe: Poor air movement, dyspnea, use of accessory muscles, tachypnea, tachycardia. May
present without wheezes
 Rapid transport w/ wo ALS. Do not allow pt to exert themselves in a position of
comfort or appropriate to treatment(s) required
OEMS 3.4 Bronchospasm / Respiratory Distress BLS
Procedures
 Activate ALS intercept but initiate rapid transport w / wo ALS
 Mild Distress:


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Encourage &/or assist pt to self-administer their prescribed inhaler if indicated
Continually reassess vitals
Contact Medical Control to:
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Repeat a 2nd MDI dose if required & if maximum dose not reached
Assist in using MDI
Use MDI if not specifically been prescribed for patient
OEMS 3.4 Bronchospasm / Respiratory
Distress ALS Procedures

Mild Distress:
 Albuterol 2.5-3 mg neb, with additional treatments prn

Severe Distress:
 Advanced airway management prn with capnography
 Albuterol 2.5-3 mg neb or MDI +/- Ipratropium 500 mcg
 Additional neb treatments administered prn w / wo magnesium 2 gms IV
 IV NS KVO; if SBP <100 mmHg administer 250 cc bolus or titrate to HD status
 Administer CPAP if not contraindicated; nebulizer therapy can be continued with CPAP
 Contact Medical Control to/for:




Repeated albuterol or ipratropium neb or MDI
Epinephrine 0.15-0.3 mg IM (may q15 min.) or 1:10,000 (NOT 1:1000), 0.1 mg- 0. 5 mg slow IVP
Magnesium Sulfate 2-4 gms IV over 5 mins
CAUTION

Use of epinephrine in pts >40 yo or with known cardiac disease or in pts who have already taken
high dosage of inhalant bronchodilator medications may result in cardiac complications
OEMS 3.5 CHF / Pulmonary Edema
Treatment / Assessment Priorities
 Scene safety & BSI
 Maintain open airway, assist
ventilations & administer O2 prn
 Place pt in position of comfort
 Determine hemodynamic stability,
symptoms, LOC, ABCs, vitals, +/monitor & ECG
 OPQRST & SAMPLE history
 Rapid transport w / wo ALS, do not
allow pt to exert themselves & place
in position of comfort
OEMS 3.5 CHF / Pulmonary Edema BLS Procedures
 Activate ALS intercept if
necessary & available
 Rapid transport, w / wo ALS
 Notify receiving hospital
OEMS 3.5 CHF / Pulmonary Edema ALS Procedures
 Advanced airway management w/ capnography if indicated
 IV NS KVO en route to the hospital
 If SBP < 100 mmHg administer 250 cc bolus or titrate to HD status
 NTG SL or spray if SBP > 100 mmHg; may repeat q5 mins x 2


If pt has taken a PDE5- inhibitor (i.e. Viagra) do not administered without a medical control order
Contact Medical Control if SBP <100 mmHg
 Contact Medical Control for / if:




Nitropaste 1 inch to anterior chest wall
Furosemide 20-40 mg IVP or 40-80mg IVP if patient already on diuretics
Dopamine 2 - 20 mcg/kg/min
To facilitate ETI Medical Control may order Midazolam 2.5 mg IN or slow IVP. Repeat prn to a
total dose of 5 mg
Summary
 CPAP alleviates respiratory symptoms &
decreases need for intubation for patients
with respiratory distress
 Safe, portable & easy to apply
 Does not replace ETI, but is a less-invasive
means of providing respiratory support
while medications work to correct the
underlying cause of respiratory distress
 Better results with rapid & aggressive
utilization for the majority of patients with
respiratory distress
 The earlier CPAP placed, the better the
outcomes
 Use your medical control!
References
 Keith Wesley MD. Wisconsin State EMS Medical Director
 Mark Marchetta RN, BS, NREMT-P; Mark Resanovich, EMT-P.
Aultman Health Foundation (Canton, Ohio)
 OEMS website and MA State Prehospital Treatment Protocol
 Brady & Mosby Textbooks “Respiratory Distress”
 Also see references cited throughout presentation