1. Continuous Positive Airway Pressure Devices
ALS / BLs Continuing Education
Amy Gutman MD ~ EMS medical Director

2. Overview CPAP physiology Indications & contraindications
EBM literature review
OEMS protocol & medical director review

3. 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
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

4. CPAP vs BiPAP CPAP BiPAP
“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)

5. CPAP O2 Delivery
Prehospital CPAP devices powered by O2 source delivering >50 psi
Some have a fixed flow rate, while others can be adjusted
Fixed either 35% or 100% but actual O2 concentration 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 = 28 minutes
E cylinder = minutes
M cylinder = 4 hours

6. Indications Increased work of breathing limits ability to remove CO2
Rising CO2 levels cause narcotic like brain effect (“CO2 Narcosis”)
Fatigue & high CO2 lead to further lowering of ventilation rate & respiratory failure

7. Contraindications Need for emergent ETI Hypotension
Cannot follow commands
Aspiration risk
Upper GI bleed / vomiting
Recent facial trauma
Tracheostomy
Chest trauma / suspected pneumothorax
Claustrophobic (make an attempt)

8. 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 decompensation & need for ETI
Give hospital advance notice

9. 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 pts requiring ETI have worse outcomes than if managed conservatively

10. Aultman Study: COPD 55 pts in CPAP group 43 pts in no CPAP group
3 intubations
43 pts in no CPAP group
15 intubations
30% reduction in ETI

11. Congestive Heart Failure
Incidence
1:100 pt transports >65 yo
25% medicare admissions
Increased interstitial fluid interferes with gas exchange / oxygenation
Lymphatics remove 10-20cc pulmonary fluid/ hr
Increased myocardial workload results in higher O2 demands in pts who often have ischemic heart disease
Traditional therapies 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

12. Aultman Study: CHF Patients
51 pts in CPAP group
1 Intubation
82 pts in no CPAP group
22 Intubations
25% reduction in ETI

13. 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

14. Aultman Study: Asthma 19 pts in CPAP group 7 pts in no CPAP group
3 intubations
7 pts in no CPAP group
2 intubations
12% reduction in ETI

15. 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

16. 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

17. 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

18. Important Points Continually check for air leaks & pt tolerance
Do not break seal to give meds
If pt improves, continue CPAP until ED personnel transfer pt to their equipment
If pt deteriorates, discontinue CPAP & prepare for ETI
Notify destination hospital that CPAP is been used

19. *Not according to MA OEMS, unfortunately
CPAP vs. Intubation
CPAP
ETI
Non-invasive
Easily discontinued
Easily adjusted
BLS skill*
Minimal complications
Does not require sedation
Minimal infection risk
Comfortable and physiologic
Invasive
Requires mechanical ventilation
ALS skill
Significant complications
Requires sedation or RSI
Potential for infection
Uncomfortable and non- physiologic
*Not according to MA OEMS, unfortunately

20. Prehospital CPAP Research
Provides greatest benefit when initiated early, decreasing intubations & improving respiratory symptoms with few major complications
“Noninvasive Ventilation in Acute Cardiogenic Edema” JAMA, 2005
Meta-analysis of 22 studies showed a 45% reduction in mortality and a 60% reduction in ETI
“Evaluation of the effect of prehospital application of CPAP therapy in acute respiratory distress”. Prehosp Disaster Med. 2010
Prehospital CPAP beneficial for pts in acute respiratory distress
“Prehospital use of CPAP: Positive pressure = positive patient outcomes”. Emerg Med Serv, 2005
CPAP alleviates symptoms & decreases need for ETI for pts with CHF, COPD & asthma. CPAP is a less-invasive means of providing respiratory support while meds correct underlying causes of distress
“Low-fractional oxygen concentration continuous positive airway pressure is effective in the prehospital setting” PEC, 2012
Low FiO2 (28%-30%) CPAP effective in treatment of common prehospital respiratory emergencies

21. OBJECTIVE: RESULTS: CONCLUSIONS:
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
RESULTS:
During 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 4 months of CPAP use, ETI not required for any patients in the field or in the ED, with 2 ICU admissions (average LOS 4 days)
CONCLUSIONS:
Use of prehospital CPAP beneficial in acute respiratory distress

22. 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
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 1 less intubation per 6 CPAP applications reducing hospitalization costs by $4075 / year / CPAP application

23. Aultman Study: Summary
CPAP Group (n = 148)
Control Group (n = 161)
Diagnosis
ETI %
No ETI
CHF 1 50 22 60
Asthma 3 16 2 5
COPD 52 15 28
Pneumonia 6
Pulmonary Edema 4 11
Other 9
Total 13 9%
135
91% 56
35%
105
65%
Key Point: 91% of all comers in the CPAP Group did not require prehospital ETI; % in the Control Group did require ETI to equal a 26% reduction in prehospital ETI

24. Wisconsin EMT–Basic Study
Can EMT-Bs apply CPAP as safely as EMT-Ps?
50 EMT-Basic services with 2 hr didactic, 2 hr lab, written & practical test
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 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 decreasing ICU admissions by 62% (Marchetta et al)

25. Points to Consider
How good is your current therapy for respiratory distress?
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?

26. 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

27. OEMS 3.4 Bronchospasm / Respiratory Distress BLS Procedures
Activate ALS intercept but initiate rapid transport w / wo ALS
Mild Distress:
Encourage &/or assist pt to self-administer their prescribed inhaler if indicated
Continually reassess vitals
Contact Medical Control to:
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

28. OEMS 3.4 Bronchospasm / Respiratory Distress ALS Procedures
Mild Distress:
Albuterol mg neb, with additional treatments prn
Severe Distress:
Advanced airway management prn with capnography
Albuterol 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 mg IM (may q15 min.) or 1:10,000 (NOT 1:1000), 0.1 mg 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

29. 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

30. OEMS 3.5 CHF / Pulmonary Edema BLS Procedures
Activate ALS intercept if necessary & available
Rapid transport, w / wo ALS
Notify receiving hospital

31. 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 mg IVP or 40-80mg IVP if patient already on diuretics
Dopamine 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

32. Summary
CPAP alleviates respiratory symptoms & decreases need for ETI for pts with respiratory distress
Safe, portable & easy to apply
Does not replace ETI, but a less-invasive means of providing respiratory support while meds work to correct the underlying cause of respiratory distress
Best results with rapid & aggressive use
Use your medical control!

33. 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