The episode that started it all, the pilot and proof of concept. In this episode John, Scott, Caleb, and Ray discuss the two most prevalent CPAP systems in the University Hospital system, their features, benefits, and drawbacks. Not surprisingly the conversation turns in many directions from things that concern out of hospital CPAP use.

 New device introduced into UH equipment inventory

Pulmodyne O2-Max disposable CPAP device

Legacy devices in the system

Emergent Respiratory products PortO2Vent

Pros / Cons

Pulmodyne Device

Pro - More transportable - can now go in first in bag - treat in place

Pro - Single patient use - minimize contamination

Pro - Has all nebulization pieces in kit (UH supplied kit also supposed to have EtCo2 nasal cannula as well)

Pro - Better mask design - easier to get on / easier to tip up corner to admin NTG if CHF patient

Pro - Comes with quick disconnect adapter in kit / plug and play

Pro - Plugs directly into high pressure port on O2 source 

Pro - Unrestricted flow - patient can take any inspiratory volume needed

Pro - Less “up front cost”

Con - Consumes oxygen quickly

Con - Fixed CPAP settings 5 / 7.5 / 10 cmH20 - Nothing in between (As Supplied)

Con - Fixed FiO2 (% of Oxygen) at 30% - May need to titrate additional oxygen in through nasal cannula

Emergent Respiratory Products Device

Pro - High FiO2 (% of Oxygen) - Fixed at 95%

Pro - Variable CPAP 0-20 mmHg

Pro - Conserves more oxygen as it only delivers during inspiration

Con - Inspiratory flow limited to about 100 lpm

Con - Requires routine biomedical service

Con - “Box” is bulky and requires cleaning (Only circuit  / mask disposable)

Con - Mask and strap more difficult to put on, and less amenable to giving NTG to patients

Con - Requires extra parts to administer concurrent aerosols

Con - Upfront cost of the “box”

Both of these are high flow systems, use unrestricted flow directly from the oxygen outlet

Do not hook esther of these devices up to a flowmeter

Low flow systems hooked to flowmeter may “throttle” inspiratory flow

Put on Etco2 nasal cannula under any system mask - trend EtCo2 and augment delivered O2 if necessary  - follow Spo2

EtCo2 may not be “normal” due to oxygen wash out - trend this patient numbers specific to this therapy

Indications - Protocol

• Flail chest

• CHF

• Asthma/COPD

• Failed oxygenation

• CO poisoning >10

• Shock

• Blunt chest trauma

Indications - Non Protocol

• Non cardiogenic pulmonary edema

• ARDS

• HAPE
  Drugs / toxins

• PE

• Drowning

• Smoke / Gasses

• Viral illnesses

• Preoxygenation for RSI / Intubation

DNR - OK

• Allowed all levels of certification - EMT > BiPAP Paramedic only

CPAP is not a ventilator - patient must have spontaneous respirations 

Physiology

• Normal breathing negative pressure

• “Bellows Effect”

• Chest out and diaphragm down - sucks in air

• Any positive pressure alters this and is not natural

CPAP / PEEP same physiological effects and pressures =

One is actively supplying pressure, the other is passively keeping pressure in airway

Positive pressure benefits

• Inflates alveoli (recruitment)

• Increase alveolar surface area = better gas exchange

• Can help breathing treatments reach bases of lungs

• Makes work of breathing easier (lower dyspnea scores)

Positive pressure issues / concerns

• Increased intrathoracic pressure may limit venous return and thus cardiac output

• The bellows effect during normal spontaneous breathing lost - this temporary negative “sucks” blood back into thorax, helps “normal” blood pressure

• Follow BP - turn down if hypotension occurs - consider volume status

• Normal central venous pressures (CVP) 8-12 mmHg

• 1 cmH2O approx 0.75 mmhg - So 10 cmH2O = 7.5ish mmHg of intrathoracic pressure - close to central venous pressure (CVP)

• Already volume depleted patients may be at higher risk of hypotension when CPAP added

Contraindications

• AMS vs unresponsive - hypoxia treatable cause - if unresponsive use BVM is altered due to hypoxia reasonable to trial CPAP

• Not protecting airway - use advanced airway and BVM

Transition to BVM

• If patient not ventilation well on CPAP (Rate, Effort, Co2)

• Leave CPAP mask, remove CPAP circuit, add BVM

• PEEP valve required to keep CPAP pressures in airway and not loose any previous advantages gained - patient will de-recruit