Strange question here. I was doing a manual blood pressure on a patient today and got the Systolic fine, but could still hear the korkotoff (spelling??) sound even when the cuff was deflated giving a diastolic of zero. I tried this twice and got the same result, although I couldn't hear it if I just placed the stephoscope on the arm without doing a BP first.
This only happened in the left arm and not the right. I mentioned it to one of the doctors and clinical matron, both of whom said it was something they had heard of, but couldn't remember the reasons why, but was nothing to worry about.
Anyone heard of anything similar or can shed any light!!!
These days, when dr's ask me for B/P, they normally want the systolic.
Ex: 'What's her b/p?", "110".
In 10 yrs, we'll all be using mean arterial pressure (MAP). The Mean is the 'average' pressure of the system as opposed to sys/dia, which are the high and low of the system.
Hint: I'm using the terms MAP and 'Mean' interchangeably.
MAP = Sys +(Dia x2)/3 or also, Dia + (Sys-Dia/3).
Or, to use both formulas:
Ex 120/80 = Sys 120 + (Dia x2) 160 = 280/3 = 93.3
or
120/80 = 80 + (120-80 = 40/3) = 13.3 +80 = 93.3
A mean is a better indicator than the high and low. But that being the case, an accurate diastolic is even MORE important, because it will affect the mean.
You might be interested to know that when you manually ascultate BP, you find the high and the low (sys/dia) and then calculate the mean (MAP) - see above.
When a non-invasive b/p machine (NIBP) takes a b/p, it uses an oscillometric method of finding the MAP (or rather, the 'pulse envelope' surrounding the MAP), and then uses a formula/algorithm to calculate the high and the low (sys/dia) from the mean.
But the take home point is this: the mean better seats the 'pulse envelope' of a blood pressure than its outlier values (sys and dia). What this means in English is that MAP is a better and more predictable and reliable indicator of a B/P's ability to get blood to the the right organs. And so, it is in the process of becoming the standard measurement. What it also means is that, while the sys/dia is a more reliable value w/ ascultation (because they are measured and the mean is calculated), the MAP is a more reliable machine value (because the MAP is measured and the sys/dia are calculated).
And you might also be interested to know that the gold standard for an acceptable MAP that reliably 'perfuses' vital organs is a minimum of 60.
From a manual:
"When the NIBP method is the source for determining BP, the Oscillometric method is used. This method measures the pressure pulse within the cuff in incremental steps and has a maximum value of approximately 1 mmHg, which occurs at the MAP. A sophisticated algorithm is then applied to plot the Oscillometric Envelope of pulse pressure measurements vs. cuff pressure measurements. This oscillometric envelope is used to determine the MAP, SBP and DBP values.
The shape of an actual patient Oscillometric Envelope varies from measurement-to-measurement and from individual-to-individual. Therefore, it is quite possible to have different systolic and diastolic pressures for the same measured MAP, as well as different MAPs for the same systolic and diastolic pressures."
The guy was about 70 years old, with no cardiac hx. BP in the right arm was 115/40, which was consistent with all other readings. As far as I can remember he was in for poorly controlled diabetes and a Pneumonia.
I agree it does seem strange that they thought it was nothing to worry about, the only other time I seen this kind of thing mentioned (on the internet) was in pregnant women! Didn't say why though!
Don't think it could have been a high Cardiac output, because systolic was fairly low, and it was only in one arm.
Pregnancy causes increased cardiac output and decreased peripheral resistance.
Timothy, where did you read we will ALL be using MAP in 10 years? Plus of a lot clinicians use it anyway. Some nurses also can quickly "guesstimate" the MAP when they take a pressure anyway.
What you heard was most likely a aortic regurgitation or aortic insufficience as it is commonly called. This is what gives the low diastolic pressures.
Sometimes I (myself) get a diastolic reading of zero. Usually happens when my heart starts racing (150-180) for no aparent reason. Doesn't happen very often, but I had never heard of this. Saw my NP and she said it was most likely a panic attack (I'm a SN). First time it happened I was puzzled. My systolic would stay normal (117) and I would get a loud diastolic of zero (verified by another person without a cuff just listening to my arm). I did not think a diastolic could be zero. Weird.
Try doing your blood pressure using a automatic machine, if you don't have one at work, they have them at the grocery store, you probably just didn't hear the beat. If you had a diastolic BP of zero for real you'd be dead, or you wouldn't have any blood flow in that arm.
ZASHAGALKA, RN
3,322 Posts
Warning: Long and technical - but interesting.
These days, when dr's ask me for B/P, they normally want the systolic.
Ex: 'What's her b/p?", "110".
In 10 yrs, we'll all be using mean arterial pressure (MAP). The Mean is the 'average' pressure of the system as opposed to sys/dia, which are the high and low of the system.
Hint: I'm using the terms MAP and 'Mean' interchangeably.
MAP = Sys +(Dia x2)/3 or also, Dia + (Sys-Dia/3).
Or, to use both formulas:
Ex 120/80 = Sys 120 + (Dia x2) 160 = 280/3 = 93.3
or
120/80 = 80 + (120-80 = 40/3) = 13.3 +80 = 93.3
A mean is a better indicator than the high and low. But that being the case, an accurate diastolic is even MORE important, because it will affect the mean.
You might be interested to know that when you manually ascultate BP, you find the high and the low (sys/dia) and then calculate the mean (MAP) - see above.
When a non-invasive b/p machine (NIBP) takes a b/p, it uses an oscillometric method of finding the MAP (or rather, the 'pulse envelope' surrounding the MAP), and then uses a formula/algorithm to calculate the high and the low (sys/dia) from the mean.
But the take home point is this: the mean better seats the 'pulse envelope' of a blood pressure than its outlier values (sys and dia). What this means in English is that MAP is a better and more predictable and reliable indicator of a B/P's ability to get blood to the the right organs. And so, it is in the process of becoming the standard measurement. What it also means is that, while the sys/dia is a more reliable value w/ ascultation (because they are measured and the mean is calculated), the MAP is a more reliable machine value (because the MAP is measured and the sys/dia are calculated).
And you might also be interested to know that the gold standard for an acceptable MAP that reliably 'perfuses' vital organs is a minimum of 60.
From a manual:
"When the NIBP method is the source for determining BP, the Oscillometric method is used. This method measures the pressure pulse within the cuff in incremental steps and has a maximum value of approximately 1 mmHg, which occurs at the MAP. A sophisticated algorithm is then applied to plot the Oscillometric Envelope of pulse pressure measurements vs. cuff pressure measurements. This oscillometric envelope is used to determine the MAP, SBP and DBP values.
The shape of an actual patient Oscillometric Envelope varies from measurement-to-measurement and from individual-to-individual. Therefore, it is quite possible to have different systolic and diastolic pressures for the same measured MAP, as well as different MAPs for the same systolic and diastolic pressures."
~faith,
Timothy.