By Elodie Lawley, Nicola Vousden, Hannah Nathan, Andrew Shennan
Obstetric haemorrhage, sepsis, and pregnancy-related hypertension kill 830 women every day. About 99 percent of these pregnancy- or childbirth-related deaths occur in low- and middle-income countries, where women in rural communities with limited access to healthcare are at greatest risk. These deaths are preventable, but only if these life-threatening complications are identified early. In many cases, simply monitoring blood pressure (BP) and heart rate (HR) could save lives. However, often women do not have access to working BP devices, leading to delays in identifying those at greatest risk. Even when devices are available, the majority tend to be unsuitable for use in pregnancy.
Professor Andrew Shennan and the CRADLE research team at King’s College London developed the CRADLE Microlife Vital Signs Alert (CRADLE VSA). It is a cheap (£12), robust, and easy-to-use device, which accurately detects abnormalities in BP and HR measurements, fulfilling the World Health Organisation criteria for use in low-resource settings. The device can be easily charged through a universal USB port; phone chargers can be used as a convenient charging method.
Extensive validation showed it is accurate in non-pregnant and pregnant women (even in those with pre-eclampsia and low BP). The CRADLE VSA device also features a ‘traffic light’ early warning system, which acts as a visual alert for healthcare providers who are less familiar with recognising serious conditions like pre-eclampsia or sepsis. For sepsis and obstetric haemorrhage, multi-centre retrospective analysis showed that Shock Index (ratio of HR to systolic BP) is the most reliable predictor of serious maternal adverse outcome. Appropriate thresholds for shock index were therefore incorporated into the traffic light algorithm, together with universally understood hypertensive thresholds, to trigger the coloured lights. These features make it ideal for those healthcare providers in rural, community settings that have limited training. The VSA is being used by Traditional Birth Attendants in Haiti and community healthcare workers in India.
The CRADLE 3 trial is a stepped-wedge randomized control trial over 20-months, where the device is introduced into a new site every two months until all 10 sites have the device available. The aim is to prospectively evaluate the device’s ability to reduce maternal mortality and morbidity by increasing timely referral and management of obstetric haemorrhage, sepsis, and pregnancy-related hypertension. In June 2016, researchers began implementation in 10 low-income countries, including Uganda, Sierra Leone, Ethiopia, and Haiti. Evaluation of training materials commenced in November 2015, with the definitive trial starting in April 1, 2016.
The CRADLE VSA has been recognised as one of the top thirty high impact innovations in global health in a PATH-led award (2015) identifying and showcasing technologies and interventions with great potential toward solving the world’s most urgent health issues. Consequently, other areas and industries are showing great interest in the device, such as its potential use in cardiovascular disease and emergency triage in conflict zones. The Science Museum, London is also including the device in their national archives.
Support for the CRADLE Project came from the Bill and Melinda Gates Foundation (BMGF) and the Medical Research Council. For more information on the device and the CRADLE Project, please visit www.cradletrial.com. You can also email Andrew.firstname.lastname@example.org for information regarding the device development or use in other settings. The CRADLE VSA is currently available to purchase ($26 USD) for use in LMICs only from global distributors, Maternova (www.maternova.org).