Mersey Burns for calculating fluid resuscitation volume when managing burns

CE marking

Medicapps was awarded a class I CE mark for Mersey Burns for use with iPad, iPhone, iPod touch, Android devices, BlackBerry PlayBook and HTML5‑compatible browsers in September 2011.

The Medicines and Healthcare Products Regulatory Agency has issued guidance that explains what medical device software applications are and how this type of technology is regulated.

Description

Mersey Burns is a mobile application (app) for use by clinicians in managing burn injuries caused by any means. It has been developed to calculate the percentage of the body surface area affected and the amount of replacement fluid required intravenously (referred to in the app as the fluid prescription) in the first 24 hours to ensure the patient remains haemodynamically stable. It also calculates the additional intravenous background (or maintenance) fluids needed by children younger than 16 years.

The app calculates the TBSA using the Lund and Browder method, the resuscitation fluids using the Parkland formula and background fluids for children. The mobile device versions of the app allow details about the burn and the fluid prescription to be emailed, for example to the receiving hospital.

Mersey Burns is free to download and requires iOS 6.0 or later, Android OS v2.3.3 or later, BlackBerry PlayBook or a HTML5‑compatible browsers.

There have been 8 versions of Mersey Burns:

On opening the app, the device screen shows a diagram of the front of a person's body. Regions of the body are shown by dividing lines. A diagram of the back of the body is displayed by tapping on the 'turn' button. Scrolling up and down allows the full body to be seen. These diagrams are used for people of both sexes and all ages. Areas affected by the burn can be 'drawn' on the diagram by selecting the 'draw' button, and highlighting the relevant area. Both full and partial thickness burns can be drawn. Buttons allow the user to partially erase or clear the burn area. The TBSA is calculated as the burn is being drawn on the diagram and displays in a label on the screen. Alternatively, if the percentage area is already known, it can be added by tapping the burn area label and selecting the appropriate percentage in 1% increments. A pop‑up message advises the user not to include simple erythema.

The user also enters the patient's age and weight and the time of the burn injury. The default setting is for an adult weighing 60 kg with a burn occurring 5 minutes earlier. The age can be set using the 'birthday cake' button. This allows the selection of a specific age for those under 18 years, or 'adult' for those 18 years and over. An average weight for age can be selected, or the patient's weight can be entered using the 'scales' button. Weight measurements are in 1 kg increments up to 30 kg and in 5 kg increments thereafter. The time of the burn injury is set using the 'clock' button.

When details have been entered, the 'fluid bag' button should be tapped. The recommended intravenous fluid prescription is displayed, separated into the first 8 hours after the burn injury and the next 16 hours. For children younger than 16 years, the rate of intravenous background fluids needed is also displayed. The user can select from 2 ml/hour, 3 ml/hour and 4 ml/hour infusion rates depending on the clinical assessment. The manufacturer's instructions for use recommend that calculated values should always be checked manually and that clinical judgement should be applied.

The mobile device version of the app can email details about the burn and the fluid prescription if the user presses the 'envelope' button. The app itself does not allow patient identifiers to be entered or stored, but these can be added manually to the text of the email. Emails are marked as 'medical in confidence'. The app includes (from version 1.6.2) an information governance warning that person‑identifiable information must only be sent and received by NHS.net email accounts.

The app is validated each time it starts. A battery of 5000 test cases are run, as if the data has been entered manually. The results of these calculations are compared with the test case solutions stored in the app. If there is a difference between the results, the app will not run to avoid a risk to patient safety.

Setting and intended use

The Mersey Burns app would be used in any healthcare setting, both in and out of hospital, but it may be particularly useful in acute care settings such as emergency departments. The app is intended for use by qualified medical professionals, with or without specialist experience in burns injury management. It can be used if the patient is not present as long as the TBSA and other details are available.

Current NHS options

Superficial (minor) burns and scalds are generally managed in primary care. More severe, complex burns may need to be treated in specialist departments.

There are no guidelines about when to refer someone presenting with a burn injury in primary care to an emergency department. This is also noted in the NICE clinical knowledge summary on burns and scalds. The Joint Royal Colleges Ambulance Liaison Committee Guideline Development Group (JRCALC) has produced the UK Ambulance Services Clinical Practice Guidelines (2013) for paramedics, which includes guidance on assessing and managing burns and scalds in adults and children. The National Network for Burn Care provides guidance for primary and secondary care providers on when to refer to specialised burn care services (National Burn Care Referral Guidance, 2012).

NICE is not aware of any other CE‑marked devices that have a similar function to the Mersey Burns app, although a review of smartphone applications related to burns (Wurzer et al. 2015) identified 13 calculator apps in the Google Play Store, of which 6 were free to download, and 21 calculator apps in Apple's App Store, of which 8 were free to download. None of these apps are CE marked.