Prehospital assessment of perinatal patients by ambulance clinicians: development, implementation, review and national application

Prehospital maternity care is complex due to limited diagnostic equipment and access to pertinent information, constraints on resources, environmental challenges, minimal education and exposure to maternity cases. NEWS2 is used to assess adults in the prehospital setting but is not validated to assess perinatal patients. This paper describes the development, implementation, review, refinement and national implementation of a bespoke prehospital assessment tool which accounts for the altered physiology of perinatal patients. An initial modified Delphi approach, using expert focus groups, reached a consensus on the early warning parameters and other red flags required for a prehospital maternity decision tool. The tool was implemented and retrospectively applied to anonymised patient data in a large urban ambulance service in the UK. A further modified Delphi approach was then used to revise the tool to ensure national applicability. The initial modified Delphi resulted in a tool which included maternity early warning score parameters and other red flags. Following implementation within one ambulance service, data from 251 ambulance clinical records of pregnant or recently pregnant women identified a high proportion of women with abnormal signs and symptoms which would not have been identified using NEWS2. Through a second modified Delphi, a national tool underpinned by national MEWS parameters alongside additional time-critical red flags was produced. A national prehospital maternity decision tool was created using modified Delphi methodology. Further research is required to formally validate the tool and to understand the effectiveness when screening for perinatal deterioration in the prehospital setting.