The accuracy of manual blood pressures obtained by paramedic students in both quiet and simulated roadside environments

Introduction 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. Methods An experimental prospective study in the repeated measures design was utilised to determine whether paramedic 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. Results The data of 60 paramedic 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. Conclusions This experimental study found that paramedic students are able to accurately obtain a manual blood pressure in a simulated roadside environment. However, a clinically significant discrepancy of 20-28 mmHg in SBP or DBP might still be appreciable in some cases. Further, more robust studies in a range of different pre-hospital settings are recommended to corroborate these findings.