Pulse Ox?

[Carlos Danger]

By being super aggressive in improving her ventilation. Bronchodilators, steroids, etc.

That didn't answer my question at all.

What I would like to know is, how does having an Etc02 change your treatment?

We have a pt we run frequently that calls for sob. She has a hx of chf and copd among other things. Many times the crew will just roll out there, put her on the pulse ox, and get a reading of 100, leave her on nrb, and say she's fine. If you don't put her on etco2, you can't gauge how sick she actually is. She'll be in ventilatory failure with a pa02 100+. You're just pissing in the wind with your nrb mask. This pt works very hard to maintain that 100%, but it'll get dismissed as anxiety. She'll eventually tire and require intubation in the hospital. By using both tools, and understanding them, intubation and respiratory acidosis can be avoided in the pt.

Let me get this straight....

Are you saying that if you have a patient with a history of CHF and COPD, who presents with increased work of breathing and complaints of shortness of breath, that you need an Etc02 to decide whether or not to treat her?

If you don't put her on etco2, you can't gauge how sick she actually is.

This is 100% false. The clinical presentation is far more important than the Etc02 or Sp02 readings.

An Etc02 reading, like most objective measurements, is simply a snapshot in time. It's useful for trending, but that's about it.

Would you really not treat a patient in obvious respiratory distress, just because their Etc02 was normal?

Would you aggressively treat a patient whose Etc02 was abnormal, even if they were breathing just fine?


There are many things that can affect an Etc02. If you have a low CO or a shunt (neither of which are unlikely in a CHF patient), you can have a normal or near-normal Etc02 and be nearing respiratory failure. Or you can have an abnormal Etc02 and be fine, respiratory-wise, if the origin is metabolic. In some severe cases of metabolic acidosis, intubation can prove fatal since it's difficult with a mechanical ventilator to match the minute volume that a spontaneously-breathing patient achieves.

Without a blood gas, you are just guessing, especially in a patient with a complex history.

It's far better to base your treatments on clinical presentation.

I believe that as a snapshot in time, Sp02 is a better reflection of the criticality of a patient's condition.

 

[JPINFV]

The sense to viewing pulse oximetry as a nigh-vital sign is that it's a physiologic endpoint. Many things contribute to maintaining that sat, and if you only consider the endpoint you can totally fail to account for those compensatory or pathological processes, but nevertheless it's valuable and irreplaceable insofar as endpoints like that (or blood pressure, for instance) are always important.

So what you're saying is that if we don't like the blood pressure number, we should disregard it and bolus them anyways? Therefore, blood pressures are useless. Treat the patient... not the number... and all that jazz...

 

[Aidey]

I believe that as a snapshot in time, Sp02 is a better reflection of the criticality of a patient's condition.

Actually, since EtCO2 also displays whether or not the patient is breathing I think it might have a slight edge on showing how sick the pt is. Not breathing tends to be one of those critical condition things.

 

[Brandon O]

So what you're saying is that if we don't like the blood pressure number, we should disregard it and bolus them anyways? Therefore, blood pressures are useless. Treat the patient... not the number... and all that jazz...

:glare:

I sayin' that while a lot of factors go into a number like BP or O2 saturation... and if you're using it as your sole marker to dictate care, you're going to be tragically behind the 8-ball in many cases, because in compensating patients they are often the LAST thing to change... and they are, at best, sensitive yet totally unspecific for severe illness... nevertheless they are important.

The air gauge on a diver's tank is important for the same reason. If you're using that as your only means of guiding your dive, you're a total ninny, but still -- ya want to know, don't ya?

 

[JPINFV]

:glare:

Problem?
h34r:

 

[systemet]

It's far better to base your treatments on clinical presentation.

I believe that as a snapshot in time, Sp02 is a better reflection of the criticality of a patient's condition.

I like these statements.

I think the numbers become an objective measurement that support the clinical diagnosis.

In the COPD patient, you're not usually intubating because the pO2 is low, or the PaCO2 is high. You're generally intubating because there's signs of impending decompensation, i.e. that the patients work of breathing is decreasing or that their level of consciousness is deteriorating (an indirect measure that PaCO2 is going up).

A PETCO2 doesn't always correlate well with PaCO2, especially when there's lung pathology involved. True, the PaCO2 is usually at least as high as PETCO2, but it can be substantially higher. The PETCO2 can make the patient look better than the PaCO2 does.

This particular subset of patients may have chronically elevated PaCO2. So at what point do we decide this PETCO2 is abnormal for them? An ABG gives you a PaCO2, and a pH and bicarbonate that help you determine whether this is an acute change.

In a healthier person, like a 19 year old you've just sedated, or the heroin overdose you're monitoring, but are holding back on giving narcan to, number like a PETCO2 of 50 mmHg take on a little more meaning. If a COPDer has a high PETCO2, but is oxygenating ok, maintaining their respiratory effort, and is alert, then we're not thinking advanced airway yet, right?

I guess my long and rambling point is that the ETCO2 is an adjunct to a physical examination, a relatively minor part of the clinical picture and is not always reliable.