Seong Hwa Lee

A 10-s rest improves chest compression quality during hands-only cardiopulmonary resuscitation: A prospective, randomized crossover study using a manikin model

OBJECTIVES This study was designed to assess changes in cardiopulmonary resuscitation (CPR) quality and rescuer fatigue when rescuers are provided with a break during continuous chest compression CPR (CCC-CPR). METHODS The present prospective, randomized crossover study involved 63 emergency medical technician trainees. The subjects performed three different CCC-CPR methods on a manikin model. The first method was general CCC-CPR without a break (CCC), the second included a 10-s break after 200 chest compressions (10/200), and the third included a 10-s break after 100 chest compressions (10/100). All methods were performed for 10 min. We counted the total number of compressions and those with appropriate depth every 1 min during the 10 min and measured mean compression depth from the start of chest compressions to 10 min. RESULTS The 10/100 method showed the deepest compression depth, followed by the 10/200 and CCC methods. The mean compression depth showed a significant difference after 5 min had elapsed. The percentage of adequate compressions per min was calculated as the proportion of compressions with appropriate depth among total chest compressions. The percentage of adequate compressions declined over time for all methods. The 10/100 method showed the highest percentage of adequate compressions, followed by the 10/200 and CCC methods. CONCLUSION When rescuers were provided a rest at a particular time during CCC-CPR, chest compression quality increased compared with CCC without rest. Therefore, we propose that a rescuer should be provided a rest during CCC-CPR, and specifically, we recommend a 10-s rest after 100 chest compressions.

Usefulness of ultrasonography for the evaluation of catheter misplacement and complications after central venous catheterization

Objective To assess whether ultrasonographic examination compared to chest radiography (CXR) is effective for evaluating complications after central venous catheterization. Methods We performed a prospective observational study. Immediately after central venous catheter insertion, we asked the radiologic department to perform a portable CXR scan. A junior and senior medical resident each performed ultrasonographic evaluation of the position of the catheter tip and complications such as pneumothorax and pleural effusion (hemothorax). We estimated the time required for ultrasound (US) and CXR. Results Compared to CXR, US could equivalently identify the catheter tip in the internal jugular or subclavian veins (P=1.000). Compared with CXR, US examinations conducted by junior residents could equivalently evaluate pneumothorax (P=1.000), while US examinations conducted by senior residents could also equivalently evaluate pneumothorax (P=0.557) and pleural effusion (P=0.337). The required time for US was shorter than that for CXR (P<0.001). Conclusion Compared to CXR, US could equivalently and more quickly identify complications such as pneumothorax or pleural effusion.

Usefulness of Rotational Thromboelastometry as a Mortality Predictor of Hyperfibrinolysis in Patients with Severe Trauma

Background Hemorrhage is the major cause of traumatic death and the leading cause of preventable death. Hyperfibrinolysis is associated with trauma severity. Viscoelastic hemostatic assays show complete clot formation dynamics. The present study was designed to identify the relationship between hyperfibrinolysis and mortality, metabolic acidosis, and coagulopathy in patients with trauma. Methods Patients with severe trauma (injury severity score [ISS] of 15 or higher) who were assessed using rotational thromboelastometry (ROTEM) were included in the present study from January 2017 to December 2017. Variables were obtained from the Korea Trauma Database or the medical charts of the patients. To identify whether hyperfibrinolysis is an independent predictor of mortality, univariate and multivariate Cox regression analyses were performed. Results During the 1-year study period, 190 patients were enrolled. In total, 21 (11.1%) had hyperfibrinolysis according to the ROTEM analysis and 46 (24.2%) died. Patients with hyperfibrinolysis had a higher ISS (P=0.014) and mortality rate (P<0.001) than did those without hyperfibrinolysis. In multivariate Cox analysis, hyperfibrinolysis (hazard ratio [HR], 4.960; 95% confidence interval [CI], 2.447 to 10.053), age (HR, 1.033; 95% CI, 1.013 to 1.055), lactic acid level (HR, 1.085; 95% CI, 1.003 to 1.173), and ISS (HR, 1.037; 95% CI, 1.004 to 1.071) were independent predictors of mortality. Conclusions Hyperfibrinolysis is associated with increased mortality, worse metabolic acidosis, and severe coagulopathy and is an independent predictor of mortality in patients with trauma.

Comparison between an instructor-led course and training using a voice advisory manikin in initial cardiopulmonary resuscitation skill acquisition

Objective We compared training using a voice advisory manikin (VAM) with an instructor-led (IL) course in terms of acquisition of initial cardiopulmonary resuscitation (CPR) skills, as defined by the 2010 resuscitation guidelines. Methods This study was a randomized, controlled, blinded, parallel-group trial. We recruited 82 first-year emergency medical technician students and distributed them randomly into two groups: the IL group (n=41) and the VAM group (n=37). In the IL-group, participants were trained in “single-rescuer, adult CPR” according to the American Heart Association’s Basic Life Support course for healthcare providers. In the VAM group, all subjects received a 20-minute lesson about CPR. After the lesson, each student trained individually with the VAM for 1 hour, receiving real-time feedback. After the training, all subjects were evaluated as they performed basic CPR (30 compressions, 2 ventilations) for 4 minutes. Results The proportion of participants with a mean compression depth ≥50 mm was 34.1% in the IL group and 27.0% in the VAM group, and the proportion with a mean compression depth ≥40 mm had increased significantly in both groups compared with ≥50 mm (IL group, 82.9%; VAM group, 86.5%). However, no significant differences were detected between the groups in this regard. The proportion of ventilations of the appropriate volume was relatively low in both groups (IL group, 26.4%; VAM group, 12.5%; P=0.396). Conclusion Both methods, the IL training using a practice-while-watching video and the VAM training, facilitated initial CPR skill acquisition, especially in terms of correct chest compression.