Perferable place to get vitals

[Obstructions]

I was wandering around on the Facebook machine this morning and come up on an interest topic on where to take vitals, optimally. I learned that it is better to take a BP on the left arm, due to it being closer to the heart will get a more accurate reading. I also learned the left ring finger is the optimal place to put a Sp02 reader.

Anybody heard of these or have any studies on them? Are there other best places for other vital monitors to be placed?

 

[NYMedic828]

I was wandering around on the Facebook machine this morning and come up on an interest topic on where to take vitals, optimally. I learned that it is better to take a BP on the left arm, due to it being closer to the heart will get a more accurate reading. I also learned the left ring finger is the optimal place to put a Sp02 reader.

Anybody heard of these or have any studies on them? Are there other best places for other vital monitors to be placed?

Anatomically the difference in distance from the heart to the upper extremities is not clinically significant. It is minimally further and both ultimately come off of the same vessels.

Aorta -> left subclavian artery -> left brachial artery
Aorta -> brachiocephalic trunk -> right subclavian artery -> right brachial artery.

The only real difference is the brachiocephalic trunk feeds the right common carotid as well...

It doesn't really come down to what region is better to take a BP, it is more important for the measured BP to be relevant to the area it was taken. A BP in the arm may be higher than a BP in the leg but that doesn't make the leg hypotensive or a bad place to assess BP. The pressure exerted by the heart naturally decreases the further the blood travels.


As far as SPo2, it doesn't matter... You can use the index, middle or ring finger all the same. You can use the thumb and pinky if you had to be its less than optimal.

 

[JPINFV]

Three big things.

1. The right brachiocephalic artery, which supplies the right subclavian, comes off the aorta before the left subclavian artery does.

2. If there's a difference between a blood pressure on the arm and the left arm, it can be a sign of aortic dissection.

3. There's a margin of error of 3 on most blood pressure cuffs. In reality, this means that you need a difference of 6 (100 and 106 are both +/-3 from 103) for any statistically meaningful difference in blood pressure.

 

[Merck]

Many things can affect the accuracy of a non-invasive BP including machine if using one or practioner skill and patience. Even how hast you deflate the cuff will adjust the pressure you report.

The most important point to me would be to do all your pressures on the same arm you start with. The one set of VS is moderately helpful but it's generally the trend that's important. Switching arms after the first may provide some bad data.

The SpO2 should work fine as long as the machine indicates good capture, seems to correlate to the pulse and, most importantly, the numbers make sense in the context of the patient's presentation.

 

[Tigger]

The most important point to me would be to do all your pressures on the same arm you start with. The one set of VS is moderately helpful but it's generally the trend that's important. Switching arms after the first may provide some bad data.

This is the biggest takeaway here. A single value doesn't tell you much, it's the trend that counts. Get rid of as many confounding variables as possible to make a more accurate trend.

 

[Veneficus]

In the ideal world you should take a pressure on both arms, as there are a handful of pathologies that might register a difference.

Because of normal anatomical variation, with "textbook" anatomy is found only roughly 30% of the population (the largest group in the variation) I would be rather cautious about inferring pathology based on the possible route without some other findings that support it.

 

[leoemt]

Many things can affect the accuracy of a non-invasive BP including machine if using one or practioner skill and patience. Even how hast you deflate the cuff will adjust the pressure you report.

The most important point to me would be to do all your pressures on the same arm you start with. The one set of VS is moderately helpful but it's generally the trend that's important. Switching arms after the first may provide some bad data.

The SpO2 should work fine as long as the machine indicates good capture, seems to correlate to the pulse and, most importantly, the numbers make sense in the context of the patient's presentation.

I disagree with taking all your BP's on the same arm. As mentioned by Veneficus there are many pathologies where trending on both arms is necessary. Me personally, I use the left arm for convience sake since its next to the bench seat. Fire normally takes the on scene vitals.

However, if I get an abnormal reading I will typically check the other arm too - depending on the reading.

Other things to remember are there may be things such as shunts that prevent you from taking a BP on a particular arm.

As for Spo2 we don't do it in the field, yet we do it in the hospital. I have never had an issue with a particular finger, just remember to not take it on the same arm as your BP. I've done that a couple of times in the ER and you will get a pretty low Sat when that cuff inflates.

 

[Bullets]

I take vitals on whatever arm is easier. In the truck its usually the left, but otherwise its random. While some illnesses may be revealed through taking a BP on both, i tend to let my assessment guide that. Things like an AAA for example

 

[Veneficus]

I take vitals on whatever arm is easier. In the truck its usually the left, but otherwise its random. While some illnesses may be revealed through taking a BP on both, i tend to let my assessment guide that. Things like an AAA for example

You mean a thoracic pseudoaneurysm, sometimes improperly described as a "dissecting aneurysm?"

 

[Medic Tim]

I usually get at least 1 bp on each and, then stick with whichever is more convenient.

 

[Tigger]

I usually get at least 1 bp on each and, then stick with whichever is more convenient.

This. When on scene I make an effort to get the right arm. Since I'm in a type II rig, the left arm is far easier to access but in the event of a serious discrepancy I can get the other one if I must.

 

[Merck]

I disagree with taking all your BP's on the same arm. As mentioned by Veneficus there are many pathologies where trending on both arms is necessary. Me personally, I use the left arm for convience sake since its next to the bench seat. Fire normally takes the on scene vitals.

However, if I get an abnormal reading I will typically check the other arm too - depending on the reading.

Other things to remember are there may be things such as shunts that prevent you from taking a BP on a particular arm.

As for Spo2 we don't do it in the field, yet we do it in the hospital. I have never had an issue with a particular finger, just remember to not take it on the same arm as your BP. I've done that a couple of times in the ER and you will get a pretty low Sat when that cuff inflates.

You can take them on both arms if you want but it's kind of silly. That's like saying you do a glucose on everyone. If there is a chief complaint of chest pain with which one of your differential diagnoses is an aneurysm then by all means check them. But the sensitivity of that test (i.e. a variance >20mmHg in systolic pressure) is not very high and therefore not that useful, especially in the context of other signs and symptoms.

As for 'many' pathologies - I'd suggest that looking for zebras in prehospital care is a foolish passtime. Common things are common. In the long run you will do better by patients trending accurate blood pressures than you will looking for the wonderful diagnosis.