Mersey Burns User's Manual
This is the manual for version 1.2.0 of Mersey Burns.
Mersey Burns is designed to be only an aid to professional medical judgement. Mersey Burns must always be used in conjunction with proper medical training, references and protocols. All output that Mersey Burns produces must be manually checked by the user. Mersey Burns should never been relied on as an independent decision making tool, and should never replace professional clinical observation, diagnosis, prescription or management.
The authors and copyright holders accept no responsibility for any adverse events including protocol errors, data errors, calculation errors, loss of data or any other errors associated with use of Mersey Burns. The authors and copyright holders cannot ensure the accuracy of Mersey Burns or the data it outputs and disclaim all liability for its use. Users of Mersey Burns will not hold the authors or copyright holders of Mersey Burns liable for any adverse events due to its use. Mersey Burns is, to the extent permitted by law, provided on an "as is" basis without warranties of any kind, express or implied.
Use of Mersey Burns is permitted only on acceptance of these terms, restrictions, guidance and conditions and is at the risk of the user.
Mersey Burns was written by Chris Seaton, Rowan Pritchard Jones MD FRCS(Plast), and Professor Paul McArthur PhD FRCS(Plast), and is a product of Medicapps Ltd. It is regulated in the UK by the MHRA.
Mersey Burns is copyright © 2010-2012 St Helens and Knowsley Teaching Hospitals NHS Trust. All rights reserved. Not to be reproduced in whole or part without the express permission of the copyright holder.
Introduction
Mersey Burns is a free clinical tool for calculating burn area percentages, prescribing fluids using Parkland, background fluids and recording patients details. It is designed for physicians and runs on the iPad™, iPhone®, and iPod touch®. This document describes how to use the app. The screenshots show the iPad but it works the same on all devices.
Drawing Burns
When you start the app, you will see the obverse outline of a male patient. The same outline is used for all ages and both sexes, with the model factoring in these details. You can tap the turn button, bottom left, to view the reverse of the patient.
Touch, hold for a moment and move to draw burnt areas onto the patient. To scroll the patient's outline, touch and move straight away.
Buttons at the top left allow you to draw, erase or clear. You can also clear by shaking the device. Buttons at the top right allow you to draw full thickness (FT) and partial thickness (PT) burns.
If you don't know where a patient is burned but do know the percentage burns, perhaps because you are not physically with the patient, you can set the percentage burns by clicking the burn area label and selecting the percentage.
Time of Burn
To set the time of the burn, tap the icon of a clock in the toolbar at the bottom. Times wrap around within 24 hours, so if you set a time 2 hours in the future, you are saying that the burn occurred 22 hours in the past.
To set the time to be now, an hour ago, or four hours ago, tap the buttons beneath the time picker.
Prescribing Fluids
When you have entered all the details of the patient and the burn, tap the icon of a fluids bag in the toolbar at the bottom for a recommended prescription of fluids. You must always check the calculated values manually.
You can select between a 2ml/hr and a 4ml/hr rate based on your assessment of the patient and burn.
Clinical Basis
This section describes the clinical basis for all calculations made by Mersey Burns.
Fraction of surface area for each body part
From Lund and Browder.
| Part | Fraction |
|---|---|
| Front head | A |
| Front neck | 0.0100 |
| Front chest | 0.1300 |
| Front right arm upper | 0.0200 |
| Front right arm lower | 0.0150 |
| Front right hand | 0.0150 |
| Front left arm upper | 0.0200 |
| Front left arm lower | 0.0150 |
| Front left hand | 0.0150 |
| Crotch | 0.0100 |
| Front right upper leg | B |
| Front right lower leg | C |
| Front right foot | 0.0175 |
| Front left upper leg | B |
| Front left lower leg | C |
| Front left foot | 0.0175 |
| Back head | A |
| Back neck | 0.0100 |
| Back chest | 0.1300 |
| Back right arm upper | 0.0200 |
| Back right arm lower | 0.0150 |
| Back right hand | 0.0150 |
| Back left arm upper | 0.0200 |
| Back left arm lower | 0.0150 |
| Back left hand | 0.0150 |
| Left buttock | 0.0250 |
| Right buttock | 0.0250 |
| Back right upper leg | B |
| Back right lower leg | C |
| Back right foot | 0.0175 |
| Back left upper leg | B |
| Back left lower leg | C |
| Back left foot | 0.0175 |
Fractions that vary by age
Also from Lund and Browder.
| Age (years) | A | B | C |
|---|---|---|---|
| 0 | 0.0950 | 0.0275 | 0.0250 |
| 1 | 0.0850 | 0.0325 | 0.0250 |
| 5 | 0.0650 | 0.0400 | 0.0275 |
| 10 | 0.0550 | 0.0450 | 0.0300 |
| 15 | 0.0450 | 0.0450 | 0.0325 |
| 18 | 0.0350 | 0.0475 | 0.0350 |
Linear interpolation of fractions that vary by age
Calculated using the Microsoft Excel forecast function.
| Age (years) | A | B | C |
|---|---|---|---|
| 0 | 0.0950 | 0.0275 | 0.0250 |
| 1 | 0.0850 | 0.0325 | 0.0250 |
| 2 | 0.0800 | 0.0344 | 0.0256 |
| 3 | 0.0750 | 0.0363 | 0.0263 |
| 4 | 0.0700 | 0.0381 | 0.0269 |
| 5 | 0.0650 | 0.0400 | 0.0275 |
| 6 | 0.0630 | 0.0410 | 0.0280 |
| 7 | 0.0610 | 0.0420 | 0.0285 |
| 8 | 0.0590 | 0.0430 | 0.0290 |
| 9 | 0.0570 | 0.0440 | 0.0295 |
| 10 | 0.0550 | 0.0450 | 0.0300 |
| 11 | 0.0530 | 0.0450 | 0.0305 |
| 12 | 0.0510 | 0.0450 | 0.0310 |
| 13 | 0.0490 | 0.0450 | 0.0315 |
| 14 | 0.0470 | 0.0450 | 0.0320 |
| 15 | 0.0450 | 0.0450 | 0.0325 |
| 16 | 0.0417 | 0.0458 | 0.0333 |
| 17 | 0.0383 | 0.0467 | 0.0342 |
| 18 | 0.0350 | 0.0475 | 0.0350 |
Average weight by age
Average weight (kg) = 3 × age (years) + 3
Prescribed fluids
From Parkland:
If age < 18 and area burnt (fraction) < 10%; give no fluids
If age >= 18 and area burnt (fraction) < 15%; give no fluids
Total fluids = area burnt (fraction) × weight (kg) × rate (ml)
Rate = 2ml or 4ml
If the time since the burn is greater than or equal to 16+8 hours: give the total fluid now.
Else, if the time since the burn is greater than or equal to 8 hours; give half the total fluid now, and half in the subsequent (16+8 hours - hours since burn).
Else, give half the total fluid in (8 hours - hours since burn), and half in the subsequent 16 hours.
Background fluids
If age < 16:
Background fluids = 4ml for the first 10kg of weight + 2ml for the next 10kg of weight + 1ml for the rest of the weight, per hour
Change Log
This section describes what changes have been made to Mersey Burns between each version.
Version 1.2.0
- Made the User's Manual available offline within the app.
- Added a German language translation.
Version 1.1.0
- New icon.
- Fixed the location of the turn button on the iPad in landscape orientation.
- Fixed the "1 hr ago" and "4 hrs ago" buttons when they cross midnight.
- Fixed warning text on startup.
- Added shake to clear.
- Changed clear to also reset age, weight, time and fluid rate.
- Lowered minimum iOS version to 4.0, down from 5.0.
Version 1.0.0
- First release.