Hyung Bin Kim

The effect of hydraulic bed movement on the quality of chest compressions: A pilot study

Objectives The hydraulic height control systems of hospital beds provide convenience and shock absorption. However, movements in a hydraulic bed may reduce the effectiveness of chest compressions. This study investigated the effects of hydraulic bed movement on chest compressions. Materials and methods Twenty‐eight participants were recruited for this study. All participants performed chest compressions for 2 min on a manikin and three surfaces: the floor (Day 1), a firm plywood bed (Day 2), and a hydraulic bed (Day 3). We considered 28 participants of Day 1 as control and each 28 participants of Day 2 and Day 3 as study subjects. The compression rates, depths, and good compression ratios (> 5‐cm compressions/all compressions) were compared between the three surfaces. Results When we compared the three surfaces, we did not detect a significant difference in the speed of chest compressions (p = 0.582). However, significantly lower values were observed on the hydraulic bed in terms of compression depth (p = 0.001) and the good compression ratio (p = 0.003) compared to floor compressions. When we compared the plywood and hydraulic beds, we did not detect significant differences in compression depth (p = 0.351) and the good compression ratio (p = 0.391). Conclusions These results indicate that the movements in our hydraulic bed were associated with a non‐statistically significant trend towards lower‐quality chest compressions.

Electrocardiogram Sampling Frequency Range Acceptable for Heart Rate Variability Analysis

Objectives Heart rate variability (HRV) has gained recognition as a noninvasive marker of autonomic activity. HRV is considered a promising tool in various clinical scenarios. The optimal electrocardiogram (ECG) sampling frequency required to ensure sufficient precision of R–R intervals for HRV analysis has not yet been determined. Here, we aimed to determine the acceptable ECG sampling frequency range by analyzing ECG signals from patients who visited an emergency department with the chief complaint of acute intoxication or overdose. Methods The study included 83 adult patients who visited an emergency department with the chief complaint of acute poisoning. The original 1,000-Hz ECG signals were down-sampled to 500-, 250-, 100-, and 50-Hz sampling frequencies with linear interpolation. R–R interval data were analyzed for time-domain, frequency-domain, and nonlinear HRV parameters. Parameters derived from the data on down-sampled frequencies were compared with those derived from the data on 1,000-Hz signals, and Lins concordance correlation coefficients were calculated. Results Down-sampling to 500 or 250 Hz resulted in excellent concordance. Signals down-sampled to 100 Hz produced acceptable results for time-domain analysis and Poincaré plots, but not for frequency-domain analysis. Down-sampling to 50 Hz proved to be unacceptable for both time- and frequency-domain analyses. At 50 Hz, the root-mean-squared successive differences and the power of high frequency tended to have high values and random errors. Conclusions A 250-Hz sampling frequency would be acceptable for HRV analysis. When frequency-domain analysis is not required, a 100-Hz sampling frequency would also be acceptable.

Recombinant Activated Factor VII as a Second Line Treatment for Postpartum Hemorrhage

Background Severe or massive postpartum hemorrhage (PPH) has remained a leading cause of maternal mortality for decades across the world and it results in critical obstetric complications. Recombinant activated factor VII (rFVIIa) has emerged as a gold standard adjunctive hemostatic agent for the treatment of life-threatening PPH refractory to conventional therapies although it remains off-licensed for use in PPH. We studied the effects of rFVIIa on coagulopathy, transfusion volume, prognosis, severity change in Korean PPH patients. Methods A retrospective review of medical records between December 2008 and March 2011 indicating use of rFVIIa in severe PPH was performed. We compared age, rFVIIa treatment, transfusion volume, and Sequential Organ Failure Assessment (SOFA) score at the time of arrival in the emergency department and after 24 hours for patients whose SOFA score was 8 points or higher. Results Fifteen women with SOFA score of 8 and above participated in this study and eight received rFVIIa administration whereas seven did not. Patients’ mean age was 31.7 ± 7.5 years. There was no statistically significant difference in initial and post-24 hours SOFA scores between patients administered rFVIIa or not. The change in SOFA score between initial presentation and after 24 hours was significantly reduced after rFVIIa administration (P = 0.016). Conclusions This analysis aimed to support that the administration of rFVIIa can reduce the severity of life-threatening PPH in patients. A rapid decision regarding the administration of rFVIIa is needed for a more favorable outcome in severe PPH patients for whom there is no effective standard treatment.