Device to improve accuracy of weighing ventilated neonates

Device to improve accuracy of weighing ventilated neonates

The Problem

It is important to gain accurate daily weights particularly in premature babies in neonatal intensive care to ensure accurate fluid and electrolyte balance and to ensure any electrolyte imbalance (e.g. sodium) can be rapidly identified and treated.  Problems are particularly encountered in the most sick premature, low birth weight babies whose clinical instability often precludes weighing, resulting in potentially reversible problems with fluid and electrolytes becoming irreversible.

Currently, sick, ventilated, premature babies (typically 500 – 1500g) can only be weighed accurately by disconnecting them from the ventilator and taking them out of the incubator to weigh them on stand alone scales.  If the baby is weighed on the incubator scales whilst connected to the ventilator, the weights obtained on the incubator scales are very inaccurate and therefore, unhelpful and in fact detrimental if relied upon, since they do not reflect the accurate weight of the baby.

Disconnecting an extremely low birth weight, premature baby from a ventilator and taking it out of the incubator to obtain an accurate weight can be problematic in that the baby’s temperature can drop and the baby can be destabilised particularly if on a form of ventilation called high frequency oscillatory ventilation where disconnection from the ventilator results in loss of alveolar recruitment (collapsing down of the small air spaces, alveoli in the lungs) which then can lead to deterioration in the baby’s critical condition.

The Solution

Dr Ula El-Kafrawy (Consultant Neonatal Paediatrician) and Rod Hammer and David Harrison (Medical Physics Department) based at Salford Royal NHS Foundation Trust (a level 3 neonatal intensive care unit in a teaching hospital) have developed a device that allows these small babies to be accurately weighed while still connected to the ventilator on incubator scales.

The Advantages

The device allows accurate baby weight to be obtained whilst the baby remains ventilated within the incubator, based on the findings from two studies carried out at Salford Royal:

A study using 90 ventilated manikins of different weights showed that the device provided significantly more accurate incubator baby weights than the incubator baby weight without the device: the mean error in weight was 42.2g (2 standard deviations = 8g) without the device and 1.2g (2 standard deviations = 3.9g) with the device; p<0.0001.

A trial of 23 ventilated babies (500g – 2.5kg) on the neonatal intensive care unit showed that the mean difference in weight from the gold standard was 43.5g (2 standard deviations: -28 to 115g) without the device and -5.6g (2 standard deviations: -36 to +25g) with the device; p<0.0002.

These results will be submitted for publication in the next few months.

The neonatal nurses at Salford Royal like the device, as it removes the need to move the babies from the incubator and ventilator.  The babies are less distressed and they have less work.  A Consultant Neonatologist at Leeds Teaching Hospitals NHS Trust has reviewed the device and said: “I am a believer in daily weight for certain babies and this sounds like a good device if costed correctly”.

The Potential Market

Figures from BLISS (premature baby charity) indicate that in 2005/06 inEngland, 3,600 babies were born weighing under 1000g, and 4,100 babies were born weighing 1,000-1,499g (total 7,700).  If we assume that 25% of these babies require ventilation, then nearly 2,000 babies inEnglandalone could benefit from the device per year.  In terms of the numbers of low weight babies (<2500g) born worldwide (30 million per year), the World Health Organisation estimates the prevalence to be 5% in many industrialised countries, rising to 5-30% in underdeveloped or developing countries.  It has been estimated in theUSthat there are 79,400 hospitalisations per year for neonates undergoing mechanical ventilation.

The Opportunities 

We are seeking a commercial partner experienced in the development, manufacture and sale of neonatal incubators or weighing devices.  A licence arrangement or a collaborative development project are both possibilities.

Contact

For more information about this or other technologies available for commercialisation through TrusTECH, contact:

Dr Joanne Thomas, Senior Technology Manager, TRUSTECH. 0161 276 6965 or joanne.thomas@cmft.nhs.uk.