Ventillation Rates

[Echoburger]

Okay, I have a question on ventillation rates when using a BVM or any other positive pressure device...

If I remember correctly, the new guidelines call for 8-10 breaths per minute in a cardiac arrest pt (wheter intubated or not)

Well...if you have a pt that is NOT in cardiac arrest...but is presenting inadequate breathing...how would you determine the ventillation rate? BLS speaking?

Also...if I remember...the goal of ventillating a pt is to increase the "volume of air" delievered in each breath over a period of time...

I'm guessing that there is no "set-answer" and every pt's ventillation rate will depend on other things to...

So, how would you determine the ventillation rate of a pt that is breathing...but inadequately?

[AnthonyM83]

You must be thinking of pre-intubation versus post-intubation rates (for adults).

When ventilating with a face-mask due to apnea (rescue breathing), rate is one ventilation every 5-6 seconds (or 10-12 per minute).

After intubation, rate decreases to one ventilation every 6-8 seconds (or 8-10 per minute).

When breathing inadequately at a high rate but low tidal volume, I try to maintain the above rates and ignore their attempts (other than not forcing air in when they're trying exhale).

When breathing inadequately at a low or sporadic rate, I try to maintain the same rates, but assist them when they try to take a breath (even if it's not time for a breath, yet).

What you're saying about increasing volume of air over a period of time seems like another way of describing increasing minute volume. A patient might have a RR of 8 but deep or 20 but shallow...you're looking to see what their overall intake is over time (like a minute).

Of course, even that gets complicated, because if breathing very shallowly, but rapidly, the patient might be getting enough volume passing through throat, but it might not be circulating all the way to the bronchioles.

Anyway, that's how I see and do things based on my limited EMT training. And of course watching for overall patient condition and signs of perfusion or hypoxia (skin/lips color, LOC, medic's O2 sat).

We have some people with much better education and experience to explain further, but from an EMT level that's how I look at it.

[Echoburger]

Thank you Andy.

I understand that if a pt. is presented with a high RR rate but low tidal volume...you will bag them at the 10-12 per minute and don't override if they are exhaling...and if the pt. is presented with a low RR rate but good tidal volume...just assist ventilations and don't override?

[Spock]

Assisting ventilations in a spontaneously breathing patient is a difficult task. If you increase the tidal volume of each spontaneous breath you will improve their ventilation and saturation although both may still be inadequate (low minute volume.) There is nothing wrong with overriding spontaneous respirations other than the patient may quit breathing altogether and you have to breath for them. That actually makes management easier and you can improve ventilation and saturation to optimal levels. I've always considered pulse oximetry to be a BLS skill with proper training although that may vary from state to state.

Mask ventilation is a difficult skill to master under any circumstances. Good question.

Live long and prosper.

Spock

[exodus]

Assisting ventilations in a spontaneously breathing patient is a difficult task. If you increase the tidal volume of each spontaneous breath you will improve their ventilation and saturation although both may still be inadequate (low minute volume.) There is nothing wrong with overriding spontaneous respirations other than the patient may quit breathing altogether and you have to breath for them. That actually makes management easier and you can improve ventilation and saturation to optimal levels. I've always considered pulse oximetry to be a BLS skill with proper training although that may vary from state to state.

Mask ventilation is a difficult skill to master under any circumstances. Good question.

Live long and prosper.

Spock

I wishh, EMT's could monitor SPO2 and ETCO2 as well... It'd be nice. That IS something we can fix most of the time.

EDIT: HOLY CRAP.... This is why I don't like the Similar Topics at the bottom of the page... Old thread =/

Edited March 7, 2010 by exodus

[Kiwiology]

Ozygenation and ventilation are very different things. Just because you bag the snot out of people does not mean it is going to increase the amount of blood that reaches the organs and brain.

ETCo2 and SPO2 are helpful but not all encompasing. My concern is if we give them to people with what amounts to almost zero education in pulmonary physiology how many will pull the ambo trick of "more is better" and try to get everybody up to 99% SPO2/30-40 ETCO2 and possibly do more damage than good?

How many people here would ventilate an asthma patient who has stopped breathing ... 10, 12, 15 times a minute and then wonder why he had a PEA arrest?

Edited March 7, 2010 by kiwimedic

[VentMedic]

SpO2 will show oxygenation but not ventilation. I've seen some patients with an SpO2 of 100% and a pH of 6.9 with triple digit PaCO2. I've also seen some high SpO2 on patients with a very wide A-a gradient that qualified for ARDS with their PaO2 FiO2 ratio.

Now for ETCO2, here is a couple of decent articles about trauma and ETCO2 that emphasizes what I have stated in previous posts.

(The EMS review)

Prove it: Using capnography to guide ventilation rates

Review: The Utility of End-Tidal Capnography in Monitoring Ventilation Status after Severe Injury

http://www.ems1.com/airway-management/articles/764519-Prove-it-Using-capnography-to-guide-ventilation-rates/

There is a growing body of evidence that suggests that hyperventilation of intubated head injured patients increases both morbidity and mortality (Davis, et al, 2004; Davis, et al, 2006; Warner, Cuschieri, Copass, Jurkovich, & Bulger, 2008). As a result, emergency medical service administrators, educators, and medical directors stress the importance of maintaining capnography levels within normal limits when assisting ventilation in these patients.

The International Trauma Life Support (ITLS) guidelines recommend that EMS providers should ventilate head injured patients at a rate necessary to keep the end-tidal carbon dioxide (EtCO2) levels between 35 and 40 mm Hg (Alson, & Campbell, 2008). Hyperventilation (EtCO2 less than 35 mmHg) is appropriate only when the patient has evidence of cerebral herniation (Badjatia, et al, 2008).

The question, however, is whether EMS can rely on end-tidal capnography readings to estimate arterial carbon dioxide levels within the patient's blood stream.

(The Original-abstact)

The Utility of Early End-Tidal Capnography in Monitoring Ventilation Status After Severe Injury

Warner, Keir J.; Cuschieri, Joseph; Garland, Brandon; Carlbom, David; Baker, David; Copass, Michael K.; Jurkovich, Gregory J.; Bulger, Eileen M.

The Journal of Trauma. 66(1):26-31, January 2009.

doi: 10.1097/TA.0b013e3181957a25

http://journals.lww.com/jtrauma/Abstract/2009/01000/The_Utility_of_Early_End_Tidal_Capnography_in.3.aspx

Background: An arterial CO2 (Paco2) of 30 mm Hg to 39 mm Hg has been shown to be the ideal target range for early ventilation in trauma patients; however, this requires serial arterial blood gases. The use of end-tidal capnography (EtCO2) has been recommended as a surrogate measure of ventilation in the prehospital arena. This is based on the observation of close EtCO2 Paco2 correlation in healthy patients, yet trauma patients frequently suffer from impaired pulmonary ventilation/perfusion. Thus, we hypothesize that EtCO2 will demonstrate a poor reflection of actual ventilation status after severe injury.

Methods: Prospective observational study on consecutive intubated trauma patients treated in our emergency department (ED) during 9 months. Arterial blood gas values and concomitant EtCO2 levels were recorded. Regression was used to determine the strength of correlation among all trauma patients and subgroups based on injury severity (Abbreviated Injury Score and Injury Severity Score) and physiologic markers of perfusion status (lactate, shock index, and arterial base deficit).

Results: During 9 months, 180 patients were evaluated. The EtCO2 Paco2 correlation was poor at R2 = 0.277. Patients ventilated in the recommended EtCO2 (range, 35 to 40) were likely to be under ventilated (Paco2 > 40 mm Hg) 80% of the time, and severely under ventilated (Paco2 > 50 mm Hg) 30% of the time. Correlation was best for patients with isolated traumatic brain injury and worst for those with evidence of poor tissue perfusion.

Conclusion: EtCO2 has low correlation with Paco2, and therefore should not be used to guide ventilation in intubated trauma patients in the ED. Better strategies for guiding prehospital and ED ventilation are needed.

Other articles:

http://journals.lww.com/jtrauma/pages/results.aspx?k=ETCO2%202009&Scope=AllIssues&txtKeywords=ETCO2%202009

Edited March 7, 2010 by VentMedic

[kohlerrf]

Okay, I have a question on ventillation rates when using a BVM or any other positive pressure device...

If I remember correctly, the new guidelines call for 8-10 breaths per minute in a cardiac arrest pt (wheter intubated or not)

Well...if you have a pt that is NOT in cardiac arrest...but is presenting inadequate breathing...how would you determine the ventillation rate? BLS speaking?

Also...if I remember...the goal of ventillating a pt is to increase the "volume of air" delievered in each breath over a period of time...

I'm guessing that there is no "set-answer" and every pt's ventillation rate will depend on other things to...

So, how would you determine the ventillation rate of a pt that is breathing...but inadequately?

Interesting question! it just so happens Im hosting a free webinar today that is reviewing actual cases our medics have had using a BVM or our Vortran Automatic Respiratprator explaining why you need to control not only your respiratory rate but also the volume you infuse with each breath. We use the End tidal CO2 and Pulsox in conjunction to determine our rate and you will learn why that is critical. The webinar is free and you and anyone else interested can log in from any computer with speakers to attend. here are the details:

You are invited to attend a free Webcast titled:

“Critical Control of End Tidal CO2”

Summary:

An introduction to the need for critical monitoring of the End tidal CO2 and a case study review comparing results of ventilated patents using a BVM as opposed to those ventilated with the Vortran Automatic Resuscitator model VAR-Plus.

Date/Time:

Thursday March 25th 2010 at 1pm and then again at 7pm

(Log in will be accepted 15min prior to start time to adjust your settings)

The Webcast is scheduled to last 1 about hour but may run longer if there are questions.

Click on this URL or copy an paste it to your browser and it will direct you to the meeting.

http://connectpro44528521.acrobat.com/etco2/

Please follow the onscreen instructions to enter. This is an interactive Webcast and you will have the option to ask questions by raising your hand then typing them into a text buffer of if you have a microphone you may type in the letters VP and then click to raise you hand. You microphone will temporarily be turned on and while depressing the talk key with your mouse you can address the forum.

If You miss this WebCast please email me so I can tell you when the next series is schedule at robert.aguard@gmail.com

Hope to see you there!