Assessing the Accuracy of ECG Chest Electrode Placement by EMS and Clinical Personnel Using Two Evaluation Methods

Background and purpose:  A valid 12-lead electrocardiogram (ECG) depends on correct acquisition technique, particularly on the accurate location of precordial (chest) electrodes.  The emergency medical services (EMS) segment of the care continuum is under-represented in previous clinically oriented studies of electrode placement.  This study sought to assess the accuracy of chest electrode placement by EMS and clinical personnel in one geographic area, to identify patterns of misplacement to inform future training and continuing education, and to compare two methods of assessing electrode placement.  Methods:  This prospective observational study recruited a convenience sample of EMS and clinical personnel.  Participants placed simulated electrodes on a CPR-style manikin and completed a questionnaire about their training and experience.  A subset also marked electrode locations on a printed diagram of the ribcage.  Digitized placement data and questionnaire responses were analysed statistically. Results:  Findings from 149 participants showed misplacement patterns consistent with prior studies, with 41.6% rated as “acceptable” and 34.2% placing £ 3 electrodes acceptably.  Correctness of electrode placement was comparable between EMS and clinical participants. More correct electrode placement correlated with classroom vs. on-the-job training, frequent vs. infrequent practice, and greater self-confidence. The diagram data collection method proved not equivalent to, and probably less reliable than, the hands-on manikin method for assessing placement skills. Conclusions:  Significant variation in ECG chest electrode placement by EMS personnel was comparable to that previously reported for clinical personnel, suggesting that existing concerns about placement errors by clinical personnel may apply equally to EMS personnel.  More frequent practice and classroom-based initial ECG training were associated with significantly greater placement accuracy.  Participants used diverse strategies to identify electrode locations.  Further research is warranted to clarify optimal strategies for placing chest electrodes, especially on diverse body types.  Sound initial ECG training and continuing education are necessary to reinforce high-quality ECG skills.