The effect of speed and road conditions on the physiological stability of sick and preterm babies undergoing inter-hospital transfer by ambulance
To investigate whether speed and road conditions have an effect on the physiological stability of sick and preterm babies undergoing inter-hospital transfer by ambulance.
This was an observational cohort study that compared the stability of physiological parameters (heart rate, arterial blood pressure, respiratory rate and blood oxygen saturation) against speed and g forces experienced in three dimensions: longitudinal (x-axis), lateral (y-axis) and vertical direction (z-axis). Data was collected using a DL1 Race Technology device with a 5Hz GPS receiver and digital accelerometer to measure the forces acting on the baby. The sample was twelve babies undergoing ambulance transfer between neonatal or paediatric units in the North West of England in a neonatal intensive care incubator mounted on an ambulance trolley. The results from seven complete data sets are presented. Physiological variability was compared between two types of road conditions: motorways and other roads.
The babies demonstrated more stability during motorway journeys, though predictable situations in the journey promoted instability. Speed was not a factor in physiological instability, but acceleration and deceleration exerted pronounced effects on physiological status, more so when combined with marked lateral forces. Other changes in physiological status during apparently stable transit require further investigation, as does the optimum positioning of the baby along or across the fore-and-aft axis of the ambulance. This was the first study to investigate real-time physiological effects on live neonates during required transfer journeys including measurements in three axes throughout the episode while exerting no research effect on the babies.
Team: Dr Viv Hall, Professor Tony Long, Dr Ian Dady Full Report: Neonatal Transport