Estimating patients' weight

DrParasite

The fire extinguisher is not just for show
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The following is taken from the lawyer for the McClain family:
<the paramedic>was not in a position to make a reasonable estimate of Mr. McClain’s weight due to the poor lighting conditions, concealing clothing, Mr. McClain’s movements, and other factors that made visual weight estimation difficult
While not going into the McClain tragedy, one skill I have always lacked throughout my career is estimating a person's weight properly. And yes, I have asked people their weight, to get an appropriate dose of weight-based medications, but I realize that isn't always a possibility.

Does anyone have any tips, tricks, or guidelines that allow them to accurately estimate a person's weight, especially in situations involving "poor lighting conditions, concealing clothing, <patients> movements" or several cops on top of a combative person?
 
When in doubt...adults are 85 kg...if you're wrong the over/under isn't that big.
 
There is no way to accurately and reliably estimate a weight just by looking at a person. At any given attempt, you can easily be off 10kg or more.

Fortunately, that is rarely a big deal when it comes to the drugs used in EMS. You just need to be intelligent about it. In some cases (dosing sux for an RSI, for instance) you are better off erring on the heavy side, and in other cases (fentanyl for analgesia) you are probably better off erring on the light side because there are potential consequences to dosing heavy and you can always just give more if you need to.

For RSI's in the field, I always dosed "small, medium, or large", meaning 20/100, 30/150, or 40/200 (mg of etomidate and sux, respectively), and when in doubt give the larger amount.

Most drugs given by bolus are ideally based on IBW or LBM, which would result in underdosing most American adults if you are just dosing by a unit per kg of estimated body weight. But IME, most of the time you are fine going by actual body weight, at least when it comes to the drugs we are using in the field, and at least when we aren't talking about very obese patients.
 
Does make you wonder why they haven't added a scale to the stretcher.
 
When I was in the ICU 4 days a week I was remarkably accurate, like circus sideshow freak accurate, but I always used the (calibrated bed) scale weight for dosing.
 
My company doses off IBW so anymore I'm guessing height.
 
Scale on the stretcher would be a problem still because of clothing, blankets, equipment etc.
 
Scale on the stretcher would be a problem still because of clothing, blankets, equipment etc.
Ehh, not too big of a deal for EMS. Our medication doses do not need to be 100% exact based on the patient’s weight. An extra KG or two isn’t going to hurt instead of the 30kg that someone could easily be off by just guessing.
 
My company doses off IBW so anymore I'm guessing height.
We’re supposed to do our RSIs and subsequent vent settings off IBW, even carry a tape measure in the vent. Is this viable for the rest of our weight based meds (that we seek to have precious few of)?
 
Scale on the stretcher would be a problem still because of clothing, blankets, equipment etc.
No. You zero the scale before the pt goes on it.
 
Mack: that is a good point: but in the winter time when it is 15 below outside, and the patient has heavy boots on, heavy pants, 3 shirts, 2 or 3 layers of clothing; 2 blankets they weigh more; I was curious last winter when I came in from walking my dog (he things it is more fun to walk in the cold); I weighed 22 pounds more with all my gear on than I did in sweats 10 minutes later.
So do we take everything off then weigh them? so the patient that is crazy and combative we need to strip to their underwear?
 
Mack: that is a good point: but in the winter time when it is 15 below outside, and the patient has heavy boots on, heavy pants, 3 shirts, 2 or 3 layers of clothing; 2 blankets they weigh more; I was curious last winter when I came in from walking my dog (he things it is more fun to walk in the cold); I weighed 22 pounds more with all my gear on than I did in sweats 10 minutes later.
So do we take everything off then weigh them? so the patient that is crazy and combative we need to strip to their underwear?
Gotcha. My answer was average, simplistic, not situational. The average for everyday clothing is 3-5 lbs additional. As for winter clothing, best "guestimate". Unless you're doing TPA in the back of the bus (obviously not), a few pounds either way is not a problem.
 
Wait! We are supposed to actually know or guess weights for meds???? Ooopsie, all these years....oh well.
 
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