Abberancy or VTach?

[Job13_5]

Now you guys have got me worried that I'm miss understanding the AVR criteria...I thought it was pretty straight forward (except for the last test, but even that one's pretty simple once you get it...unless I've missed something). Are there more intricacies than I know about? For instance, it was posted above that you have to pick the correct QRS when evaluating excursion. I hadn't heard that before.

[crotchitymedic1986]

The first rule should be to do no harm. If the patient is stable we should not be "shock happy". Sure, start your IV, do your 12-lead, put on some pads if it makes you feel better, but anyone who shocks this patient should have their certification pulled. It's a funny thing, you give a medical clinician a tool, and they abuse it. Go to any EMS/Fire Dept that has recently purchased the "drill" and then look at how many patients have been "drilled" since that purchase, versus how many IOs were attempted in the year before. Technology is a good thing, but you have to treat the patient first. What would you do if you were a wilderness EMT out in the boonies with this patient, and had no cardiac monitor or 12Lead ? All us old-timers found a way to treat our patients without glucometers, pulse oximeters, capnography, IOs/Drills, or 12 lead EKG.

[chbare]

The questions to ask in response would include; how many inadvertent oesophageal intubations occurred before capnography proliferated, or how many RVI's were given nitro and subsequently crashed prior to XII lead proliferation, or how many people having a stroke were delivered to the ER rather hypoglycaemic before the proliferation of POC blood glucose testing?

Take care,

chbare.

[crotchitymedic1986]

The questions to ask in response would include; how many inadvertent oesophageal intubations occurred before capnography proliferated, or how many RVI's were given nitro and subsequently crashed prior to XII lead proliferation, or how many people having a stroke were delivered to the ER rather hypoglycaemic before the proliferation of POC blood glucose testing?

Take care,

chbare.

Intubations: I think we had a better percentage of that, if you read recent literature about how bad today's medics perform in this area. RVIs, I would say 12 lead has made no difference in this, as most medics can still not accurately read a 12lead. I have never had any problem differentiating between stroke and hypoglycemia with or without a glucometer. But to retort:

How often does RSI result in a non-successful intubation these days (and how often do you see medics digging in an airway for 20 minutes onscene, without ventilating properly in between attempts? How many non MI chest pain patients are treated as such by EMS, because we were taught in school that chest pain =s MONA no matter what ? How many CVAs and Hypoglycemic patients are not even transported by EMS these days versus the old days ? We didnt leave folks at home at a 40-50% rate.

I grant you that the internet and 24 hour media make it easier to hear of EMS mistakes than it was in the old days, but I just don't remember us killing as many patients as what I read on a weekly basis today.

[mobey]

How often does RSI result in a non-successful intubation these days (and how often do you see medics digging in an airway for 20 minutes onscene, without ventilating properly in between attempts? How many non MI chest pain patients are treated as such by EMS, because we were taught in school that chest pain =s MONA no matter what ? How many CVAs and Hypoglycemic patients are not even transported by EMS these days versus the old days ? We didnt leave folks at home at a 40-50% rate.

I grant you that the internet and 24 hour media make it easier to hear of EMS mistakes than it was in the old days, but I just don't remember us killing as many patients as what I read on a weekly basis today.

I hardly think Medics are digging for an airway for 20 mins without ventilating.

I agree, there were probably less pt's "killed" in the old dayss however, how many STEMIs were re-perfused?

How many people aquired aspiration pneumonia/hypoxic injury prior to RSI?

How many people were left without appropriate Tx because an IV could not be established?

It is really easy to do nothing....

The greatest development in prehospital medicine is pro-active treatment based on evidence.

How was the morbidity/mortality rate prior to progressive prehospital medicine?

[Tom B.]

Now you guys have got me worried that I'm miss understanding the AVR criteria...I thought it was pretty straight forward (except for the last test, but even that one's pretty simple once you get it...unless I've missed something). Are there more intricacies than I know about? For instance, it was posted above that you have to pick the correct QRS when evaluating excursion. I hadn't heard that before.

In the first place I made a typo.

I wrote:

"44 had an initial voltage (in the first 40 ms of a bi- or multi-phasic QRS complex) greater than the terminal voltage (in the last 40 ms of the QRS complex)"

It should have read:

"44 had an initial voltage (in the first 40 ms of a bi- or multi-phasic QRS complex) less than the terminal voltage (in the last 40 ms of the QRS complex)"

Or as the paper itself describes it:

"[E]stimation of initial (v_i) and terminal (v_t) ventricular activation velocity ratio (v_i/v_t) by measuring the voltage change on the ECG tracing during the initial 40 ms (v_i) and the terminal 40 ms (v_t) of the same bi- or multiphasic QRS complex. A v_i/v_t >1 was suggestive of SVT and a v_i/v_t ≤1 of VT."

As for "selecting the correct QRS" call up the full text of the article. Here is one small excerpt:

"The v_i and v_t were measured in an individual QRS complex in any lead having a bi- or multiphasic QRS complex, in which the onset and end of the QRS were clearly visible and the initial ventricular activation was the most rapid (fastest). When either the initial or terminal 40 ms of the QRS complex displayed both positive and negative deflections, the sum of their absolute values (disregarding polarity) were used as the values of v_i and v_t. Because three channels were recorded simultaneously on the ECG tracings, the onset and end of the QRS were defined by the earliest and latest ventricular depolarization, respectively, among the three simultaneously recorded leads that included the lead with the fastest initial ventricular activation. Most frequently (in 87% of WCTs), the v_i was the fastest in the precordial leads and the leads most commonly used for analysis of v_i/v_t were v₃, v₅, and v₂ in decreasing order of frequency."

Also see the caption in Figure 1.

Does this really seem simple to you? I mean, I think I get it, but I'm a serious ECG dork.

Tom

[Job13_5]

In the first place I made a typo.

I wrote:

"44 had an initial voltage (in the first 40 ms of a bi- or multi-phasic QRS complex) greater than the terminal voltage (in the last 40 ms of the QRS complex)"

It should have read:

"44 had an initial voltage (in the first 40 ms of a bi- or multi-phasic QRS complex) less than the terminal voltage (in the last 40 ms of the QRS complex)"

Or as the paper itself describes it:

"[E]stimation of initial (v_i) and terminal (v_t) ventricular activation velocity ratio (v_i/v_t) by measuring the voltage change on the ECG tracing during the initial 40 ms (v_i) and the terminal 40 ms (v_t) of the same bi- or multiphasic QRS complex. A v_i/v_t >1 was suggestive of SVT and a v_i/v_t ≤1 of VT."

As for "selecting the correct QRS" call up the full text of the article. Here is one small excerpt:

"The v_i and v_t were measured in an individual QRS complex in any lead having a bi- or multiphasic QRS complex, in which the onset and end of the QRS were clearly visible and the initial ventricular activation was the most rapid (fastest). When either the initial or terminal 40 ms of the QRS complex displayed both positive and negative deflections, the sum of their absolute values (disregarding polarity) were used as the values of v_i and v_t. Because three channels were recorded simultaneously on the ECG tracings, the onset and end of the QRS were defined by the earliest and latest ventricular depolarization, respectively, among the three simultaneously recorded leads that included the lead with the fastest initial ventricular activation. Most frequently (in 87% of WCTs), the v_i was the fastest in the precordial leads and the leads most commonly used for analysis of v_i/v_t were v₃, v₅, and v₂ in decreasing order of frequency."

Also see the caption in Figure 1.

Does this really seem simple to you? I mean, I think I get it, but I'm a serious ECG dork.

Tom

Point taken. I think some of these instructions are unnecessary because the morphologies described are necessary to even measure a Vi and Vt per the simple criteria. But, I'm going to read the article a few times to make sure I get it...which proves your point.