By Mark Bachand, RRT-NPS, RPFT I have no actual or potential conflict of interest in relation to this presentation.
Objectives Review state protocols regarding CPAP use. Touch on the different modes that could be seen in the pre-hospital setting. CPAP, Bilevel, APAP, and AVAPS AE. Give an overview of the physiology of ETCO2 Teach basic ETCO2 waveform interpretation.
There are Two Parts to Breathing
Oxygenation Effectiveness is frequently measured by looking at the PaO2 in the blood. However, the true measure is how well is the tissue oxygenated Your secondary drive to breathe is located your carotid sinus and aortic arch. PO2 of less than 55 mmhg will trigger breathing.
Oxygen Chemoreceptors
CO2 Retainers It s not the FiO2 that matters, it s the PaO2!!! The oxygen has to get into the blood in order to effect their respirations! Target a SpO2 of 88-92% and the patient will be okay.
O2: Assess and Treat How to (non-invasively) assess? Heart rate, then SpO2, Color (cyanosis) and Confusion How to increase O2? Increase FiO2 or increase the MAP (Mean Airway Pressure) Give blood if anemic http://respiratorytherapycave.blogspot.com/2012/08/are-all-copd-patients-co2- retainers.html
Oxygen Transport
Transport: Low SpO2
Transport: 100% SpO2
How was that that we increase PaO2? Increase FiO2 or Increase MAP = CPAP, PEEP, I T, etc
CPAP: Oxygen and Pressure
CPAP
De-recruitment Of FRC
Indications for CPAP Oxygen SpO2 < 94% Retractions or accessory muscle use Adult RR of > 25 (see chart for peds) Moderate to severe respiratory distress due to CHF / pulm edema, asthma / COPD, pneumonia, submersion or undifferentiated resp distress. Tissue level hypoxia in the face of severe anemia
Additional Indications Obstructive Sleep Apnea Hypopnea Chronic hypoventilation syndrome Neuromuscular injuries / trauma
Contraindications Patient is dead / Ventilatory failure (cardio-pulmonary arrest) Vomiting or blood in NP/OP Pneumothorax (untreated) Unable to follow commands combative No gag can t protect airway Facial trauma BP is noted because you can tamponade the return blood flow to the right heart
Plus one more
Too Much CPAP
Home Devices (after the sleep study) During REM sleep the body becomes much more relaxed and your throat muscles get more flaccid requiring increased pressures. CPAP targets REM Devices (and there are many, many more ): CPAP Continuous Positive Airway Pressure Bilevel (BiPAP ) BiLevel Positive Airway Pressure APAP Automatic Positive Airway Pressure AVAPS AE Average Volume Assured Pressure Support with Auto EPAP
CPAP and Bilevel CPAP Bilevel
APAP APAP has two settings, a low range setting and a high range setting, that the machine will fluctuate between throughout the night as it automatically adjusts itself to suit your particular needs at any given moment throughout your sleep. APAP machines use algorithms that sense subtle changes in your breathing and adjusts itself to the best pressure setting at any time of the night.
AVAPS AE This is used with nocturnal hypoventilation syndrome, neuromuscular diseases, spinal chord injuries and central sleep apnea. It has a tidal volume, set respiratory rate, and peep. Does this remind you of anything?
It is the exact same mode as Assist Control on a Dräger ICU ventilator.
What s the difference? How will you know if your patient is on AVAPS?
Read the Fine Print AVAPS is a VENTILATOR! It has a tidal volume and a respiratory rate! Only difference is that it uses a mask instead of a ETT or trach!
When to Use on Peds Same indications & contraindications as adults Plus Laryngeal trachealmalacia (LTM) floppy airway Hypoxic respiratory failure asthma, congenital cardiac deformations, CP kids with collapsed lung due to anatomy http://www.ems1.com/ems-products/medical- equipment/airway-management/articles/1594995- Expanding-the-pre-hospital-use-of-CPAP-in-pediatrics/
Ventilation Effectiveness is determined by the amount of PaCO2 in the blood. 35 to 45 mmhg is normal. Your primary drive to breathe stimulated in your central and peripheral chemoreceptors.
CO2 Chemoreceptors
CO2: Assess and Treat ETCO2 is the partial pressure of carbon dioxide as it is plotted against time. How to (non-invasively) assess? ETCO2 then lethargy. (Not agitation) Invasive assessment is done via an blood gas How to decrease CO2? Breathe faster and/or deeper
Main Stream vrs Side Stream Analyzers
Side Stream ETCO2 Analyzers
Main Stream ETCO2 Analyzer
ETCO2 Monitoring
Parts of ETCO2 Waveform
Breathing
Look a Little Closer
Indications Have you ever wanted to know if your patient is breathing? You can tell if your patient has ROSC or loss thereof You can infer a lot of information. Like if your neb is working Cardiac Output If nutrition is adequate (vent weaning)
Contraindications Side stream analyzer with a really small patient. It may syphon off too much of the tidal volume on the ventilator. Deadspace is too much on a main stream monitor
ETCO2 Waveform Interpretation Normal Obstructive (COPD) Curare Cleft Dilution with another gas source Cardiac artifact
Hyper and Hypo Ventilation Hypoventilation Hyperventilation
ETCO2 Waveform Analysis
Additional Waveforms
Other Factors in ETCO2 Waveforms
Relevant Info Not always accurate sometimes only good for trending (sometimes, not even that). ETCO2 will ALWAYS be lower than your PaCO2 Reading wave forms is a skill to be developed
ETCO2 Summary Know what a normal wave form looks like Know if it has been calibrated against an ABG Know what the correct normal value Use as a trending tool Use other clinical indicators to confirm what the monitor is implying!
ETCO2 and CPAP Combined Umm. No.
CPAP Effect on ETCO2
Thank you all I look forward to seeing you in the ER