It is well-recognised that ambient noise impacts on the accuracy of auscultation. Often, paramedics are required to manually obtain blood pressures on the side of the road where ambient traffic noise might impact on its accuracy. This study aimed to determine the level of agreement between manual blood pressure results obtained in a quiet and simulated roadside environment.
An experimental prospective study in the repeated measures design was utilised to determine whether emergency care students could accurately determine the manual blood pressure in a quiet and simulated roadside environment. A roadside environment was simulated by looping road traffic noise at constant volume. A cross-over control was employed. The accuracy of the blood pressure recorded in the quiet environment was contrasted to that obtained in the simulated roadside environment using the Bland-Altman plot.
The data of 60 students (120 measurements) were analysed. The mean bias (95% CI; standard error) for the Systolic Blood Pressures (SBPs) was -1.28 (-2.83;-2.64; 5.99) while the mean bias for the Diastolic Blood Pressures (DBPs) was -1.2 (-3.12; 0.71; 7.39). The 95% limits of agreement are -13.02 to 10.46 and -15.68 to 13.28 for the SBPs and DBPs respectively.
This experimental study found that emergency care students are able to accurately obtain a manual blood pressure in a simulated roadside environment. However, a clinically significant discrepancy of 20-28mmHg in SBP or DBP might still be appreciable in some cases. Further, more robust studies in a variety of different prehospital settings are recommended to corroborate these findings.
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