Abdel-Rahman et al reported the Mercy tape for estimating pediatric weight in an emergency. The authors are from Children's Mercy Hospitals in Kansas City.
Patient selection: 2 months to 16 years
Parameters:
(1) length of humerus in cm, from 9 to 39 cm
(2) mid-upper arm circumference (MAC) in cm, from 10 to 40 cm
partial weight in kg from humerus length =
= (0.03084 * ((length)^2)) - (0.1839 * (length)) - 0.6679
Humerus length in cm |
Partial Weight |
9 |
0.5 |
10 |
0.7 |
11 |
0.9 |
12 |
1.5 |
13 |
2.0 |
14 |
2.8 |
15 |
3.4 |
16 |
4.2 |
17 |
5.0 |
18 |
6.1 |
19 |
7.2 |
20 |
8.1 |
21 |
9.1 |
22 |
10.4 |
23 |
11.4 |
24 |
12.6 |
25 |
13.7 |
26 |
14.7 |
27 |
16.6 |
28 |
18.3 |
29 |
19.6 |
30 |
21.4 |
31 |
23.7 |
32 |
25.5 |
33 |
27.3 |
34 |
29.2 |
35 |
31.0 |
36 |
33.5 |
37 |
34.5 |
38 |
36.5 |
39 |
38.2 |
partial weight in kg from MAC =
= (0.06502 * ((length)^2)) - (1.090 * (length)) + 7.427
= (-0.000943 * ((length)^3)) + (0.1358 * ((length)^2)) - (2.723 * (length)) + 18.78
MAC in cm |
Partial Weight |
10 |
2.8 |
11 |
3.8 |
12 |
4.6 |
13 |
4.9 |
14 |
5.3 |
15 |
5.9 |
16 |
6.5 |
17 |
7.4 |
18 |
8.0 |
19 |
9.4 |
20 |
10.9 |
21 |
12.4 |
22 |
14.3 |
23 |
16.5 |
24 |
18.0 |
25 |
20.5 |
26 |
23.4 |
27 |
25.5 |
28 |
27.8 |
29 |
30.5 |
30 |
33.3 |
31 |
36.3 |
32 |
39.6 |
33 |
44.8 |
34 |
46.5 |
35 |
50.2 |
36 |
53.2 |
37 |
55.7 |
38 |
60.3 |
39 |
61.1 |
40 |
67.0 |
weight in kilograms =
= (partial weight from humerus length) + (partial weight from MAC)
Performance:
• The quality of the tape and the site of measurement affects the accuracy.