Wei-Lung Chen

Heart rate variability measures as predictors of in-hospital mortality in ED patients with sepsis

OBJECTIVE To determine the predictive capability of heart rate variability (HRV) measures of patients with sepsis in the ED for in-hospital death. METHODS This was a prospective, observational study. A consecutive cohort of patients visiting the ED of a university teaching hospital who met the criteria of sepsis over a 6-month period were enrolled in this study. General demographics, vital signs, laboratory data, and Mortality in Emergency Department Sepsis score were obtained in the ED; the in-patient medical record was reviewed; and a series of continuous 10-minute electrocardiographic signals were recorded for off-line HRV analysis to assess the in-hospital mortality of the patients. RESULTS One hundred thirty-two patients aged 27 to 86 years who met the inclusion criteria were enrolled. According to the in-hospital outcome, the patients were categorized into 2 groups: nonsurvivors (n = 10) and survivors (n = 122). The baseline HRV measures, including SDNN, TP, VLFP, LFP, and LFP/HFP ratio, of nonsurvivors were significantly lower, whereas the nHFP was significantly higher, than those of survivors. Multiple logistic regression model identified SDNN and nHFP as the significant independent variables in the prediction of in-hospital mortality for ED patients with sepsis. The receiver operating characteristic area for SDNN and nHFP in predicting the risk of death was 0.700 and 0.739, respectively. CONCLUSIONS Heart rate variability measures, especially the SDNN and nHFP, may be used as valuable predictors of in-hospital mortality in patients with sepsis attending the ED.

Heart rate variability predicts short-term outcome for successfully resuscitated patients with out-of-hospital cardiac arrest

OBJECTIVE To assess the possibility of heart rate variability (HRV) measures as predictors of 24-h mortality in successfully resuscitated patients with out-of-hospital cardiac arrest (OHCA). METHODS This prospective cohort study was conducted at a 40-bed emergency department (ED) of a university-affiliated medical centre. Adult patients with OHCA who were successfully resuscitated were consecutively enrolled over an 18-month period. A 10-min electrocardiogram was recorded for retrospective off-line HRV analysis 30-60 min after the return of spontaneous circulation and further correlated with 24-h mortality of the patients. RESULTS Sixty-nine patients aged 31-82 years who met the inclusion criteria were enrolled. According to the 24-h mortality, the patients were categorised into non-survivors (n=28) and survivors (n=41) groups. The HRV measures were compared between these two groups. The low-frequency power (LFP), normalized LFP (nLFP) and low-/high-frequency power ratio in the non-survivors were significantly lower than those of the survivors, whereas root mean square successive difference, high-frequency power (HFP), HFP/tidal volume, normalized HFP (nHFP), and nHFP/tidal volume in the non-survivors were significantly higher than those of the survivors. Multiple logistic regression model identified nLFP as the independent variable to predict 24-h mortality (odds ratio, 1.354; 95% confidence interval [CI], 1.124-1.632; p=0.001). Receiver operating characteristic area for nLFP in the prediction of 24-h mortality was 0.946 (95% CI, 0.897-0.995; p<0.001). CONCLUSIONS HRV measures, especially the nLFP, may be used as predictors of 24-h mortality for successfully resuscitated patients with OHCA in the ED.

The 12-lead electrocardiogram in patients with subarachnoid hemorrhage: early risk prognostication

OBJECTIVE The aim of this study was to investigate if the electrocardiographic (ECG) abnormalities assessed early in the emergency department (ED) are associated with the in-hospital mortality of the patients with spontaneous subarachnoid hemorrhage (SAH). METHODS We studied prospectively a cohort of 222 adult patients with spontaneous SAH in an ED. A 12-lead ECG was performed for these patients in the ED. The patients were stratified into nonsurvivors and survivors based on the in-hospital mortality. The clinical characteristics, heart rate, corrected QT interval (QTc) and 7 predefined morphologic abnormalities were compared between these 2 groups of patients. RESULTS Compared with the survivors (n=178), the nonsurvivors (n=44) had significantly slower heart rate (75±23 vs 83±16, P=.018) and more prolonged QTc (492±58 vs 458±40, P=.001). There were significantly higher frequency of occurrence of ECG morphologic abnormalities (66% vs 37%, P=.001) and nonspecific ST- or T-wave changes (NSSTTCs; 32% vs 12%, P=.015) in the nonsurvivors compared with those in the survivors. Multiple logistic regression model identified QTc (odds ratio, 1.0; 95% confidence interval, 1.0-1.0; P=.005) and NSSTTC (odds ratio, 3.3; 95% confidence interval, 1.0-10.7; P=.047) as the significant ECG variables associated with in-hospital mortality. CONCLUSIONS The occurrence of NSSTTC and prolonged QTc assessed early in the ED are independently associated with the in-hospital mortality in adult patients with spontaneous SAH.

Spontaneous dissection of the celiac artery: a case report and literature review.

Epigastralgia is a common chief compliant in the emergency department. Most of them are not fetal events, but some are life threatening such as aortic dissection or abdominal aneurysm rupture. Spontaneous visceral artery dissection is an uncommon occurrence with an unpredictable natural history and is rarely considered in the diagnosis of acute abdominal pain; however, it is as critical as aortic dissection and even easier to be ignored because of its rarity. We present a case of a 48-year-old man who presented to our emergency department with the chief concern of epigastric pain and diagnosed as having isolated spontaneous celiac artery dissection involving the hepatic artery, gastroduodenal artery, and splenic artery. Most cases required surgical intervention in previous reports; there are some, as in this case, managed well nonoperatively.

Effects of ephedra on autonomic nervous modulation in healthy young adults

AIM OF THE STUDY Given the popularity of the use of ephedra in traditional Chinese medicine around the world, a greater understanding of its actions is required. This study aims to assess the effects of ephedra on autonomic nervous modulation using power spectral analysis of heart rate variability (HRV). METHODS This was a randomized, double-blind, placebo-controlled, crossover study. Twenty healthy subjects were given 1g of ephedra dry extract or placebo once per day for 14 days in a crossover fashion with a 7-day washout period between treatments. Sequential HRV measures at baseline and at 30, 60, 120, and 180 min after taking ephedra or the placebo on days 1 and 14 were obtained and compared. In addition, the baseline HRV measurements on days 1, 3, 7, 10, and 14 were also obtained and compared. RESULTS The normalized low-frequency component (LF%) and the low/high-frequency component ratio (LF/HF) of the HRV were significantly increased, whereas the high-frequency component (HF) and normalized HF (HF%) were significantly decreased at 120 and 180 min after taking ephedra on days 1 and 14. In addition, the baseline LF% and LF/HF were significantly increased, whereas the baseline HF% was significantly decreased on days 10 and 14, as compared to day 1. CONCLUSIONS By power spectral analysis of the HRV of healthy young adults, it is suggested that ingestion of ephedra dry extract acutely and chronically affects autonomic nervous activity by tilting the sympathovagal balance toward increased sympathetic activity, whereas parasympathetic activity was impaired.

Predicting the hyperglycemic crisis death (PHD) score: a new decision rule for emergency and critical care.

BACKGROUND We investigated independent mortality predictors of hyperglycemic crises and developed a prediction rule for emergency and critical care physicians to classify patients into mortality risk and disposition groups. METHODS This study was done in a university-affiliated medical center. Consecutive adult patients (> 18 years old) visiting the emergency department (ED) between January 2004 and December 2010 were enrolled when they met the criteria of a hyperglycemic crisis. Data were separated into derivation and validation sets-the former were used to predict the latter. December 31, 2008, was the cutoff date. Thirty-day mortality was the primary endpoint. RESULTS We enrolled 295 patients who made 330 visits to the ED: derivation set = 235 visits (25 deaths: 10.6%), validation set = 95 visits (10 deaths: 10.5%). We found 6 independent mortality predictors: Absent tachycardia, Hypotension, Anemia, Severe coma, Cancer history, and Infection (AHA.SCI). After assigning weights to each predictor, we developed a Predicting Hyperglycemic crisis Death (PHD) score that stratifies patients into mortality-risk and disposition groups: low (0%) (95% CI, 0-0.02%): treatment in a general ward or the ED; intermediate (24.5%) (95% CI, 14.8-39.9%): the intensive care unit or a general ward; and high (59.5%) (95% CI, 42.2-74.8%): the intensive care unit. The area under the curve for the rule was 0.946 in the derivation set and 0.925 in the validation set. CONCLUSIONS The PHD score is a simple and rapid rule for predicting 30-day mortality and classifying mortality risk and disposition in adult patients with hyperglycemic crises.

Postresuscitation autonomic nervous modulation after cardiac arrest resembles that of severe sepsis

INTRODUCTION This study explored whether post-resuscitation status resembles severe sepsis in terms of autonomic nervous modulation by using heart rate variability (HRV) analysis. METHODS Successfully resuscitated nontraumatic out-of-hospital cardiac arrest (OHCA) adult patients in an emergency department were prospectively enrolled as the study group. Age- and sex-matched patients with severe sepsis with and without mechanical ventilation were included as positive controls, while sepsis patients and healthy volunteers were included as negative controls. The HRV measures obtained from 10-minute electrocardiogram were compared among 5 groups of subjects. RESULTS Sixty-four successfully resuscitated OHCA patients were studied. There were no significant differences in all HRV measures (standard deviation of R-R intervals [SD(RR)], coefficient of variation of R-R intervals [CV(RR)], total power [TP], very-low-frequency component [VLF], low-frequency component [LF], high-frequency component [HF], normalized LF [LF%], normalized HF [HF%], and LF/HF) among the successfully resuscitated OHCA patients and severe sepsis patients with and without mechanical ventilation. Also, no significant differences in all HRV measures were found between nonsurvivors of OHCA group and nonsurvivors of severe sepsis group. In the nonsurvivors of OHCA group and severe sepsis group, the LF% and LF/HF were significantly lower, whereas the HF and HF% were significantly higher, as compared with the survivors of these 2 groups. CONCLUSIONS The autonomic nervous modulation in the initial phase of OHCA patients resembles that of severe sepsis in that both groups of patients have decreased global HRV (TP, SD(RR), and CV(RR)), sympathovagal balance (LF% and LF/HF), and renin-angiotensin-aldosterone modulation (VLF), as compared to healthy subjects.

Depressed sympathovagal balance predicts mortality in patients with subarachnoid hemorrhage

OBJECTIVES The objective of this study is to investigate the role of sympathovagal balance in predicting inhospital mortality by assessing power spectral analysis of heart rate variability (HRV) among patients with nontraumatic subarachnoid hemorrhage (SAH) in an emergency department (ED). METHODS A cohort of 132 adult patients with spontaneous SAH in an ED was prospectively enrolled. A continuous 10-minute electrocardiography for off-line power spectral analysis of the HRV was recorded. Using the inhospital mortality, the patients were classified into 2 groups: nonsurvivors (n=38) and survivors (n=94). The HRV measures were compared between these 2 groups of patients. RESULTS Having compared the various measurements, the very low-frequency component, low-frequency component, normalized low-frequency component (LF%), and low-/high-frequency component ratio (LF/HF) were significantly lower, whereas the normalized high-frequency component was significantly higher among the nonsurvivors than among the survivors. A multiple logistic regression model identified LF/HF (odds ratio, 2.16; 95% confidence interval [CI], 1.18-3.97; P=.013) and LF% (odds ratio, 0.78; 95% CI, 0.69-0.88; P<.001) as independent variables that were able to predict inhospital mortality for patients with SAH in an ED. The receiver operating characteristic area for LF/HF in predicting inhospital mortality was 0.957 (95% CI, 0.914-1.000; P<.001), and the best cutoff points was 0.8 (sensitivity, 92.1%; specificity, 90.4%). CONCLUSIONS Power spectral analysis of the HRV is able to predict inhospital mortality for patients after SAH in an ED. A tilt in the sympathovagal balance toward depressed sympathovagal balance, as indicated by HRV analysis, might contribute to the poor outcome among these patients.

Circadian variation of acute myocardial infarction in young people

AIMS The aim was to investigate the circadian and weekly variation in Chinese young patients with acute myocardial infarction (AMI). METHODS This was a 10-year retrospective cohort study. We studied patients (>18 to <45 years of age) with a first attack of AMI from the emergency departments of 3 university teaching hospitals in Taiwan from January 1, 2001, to December 31, 2010. We analyzed patients in the standard circadian fashion using 6-hour intervals (00:01-06:00, 06:01-12:00, 12:01-18:00, and 18:01-24:00). We also did an analysis by day of week. RESULTS The database had 505 patients with AMI with complete data. The percentage of total AMIs that occurred in the 6-hour intervals were as follows: 00:01 to 06:00, 30.9%; 06:01 to 12:00, 23.4%; 12:01 to 18:00, 25.9%; and 18:01 to 24:00, 19.8%. The percentage of AMIs between 00:01 and 06:00 was significant higher compared with that in the other three 6-hour intervals (df = 3, χ(2) = 91.7, P < .001). However, there was no significant weekly variation for these patients in the present study. CONCLUSIONS There was a significant circadian variation with a peak from 00:01 to 06:00 in Chinese young patients with AMI. However, there was no significant weekly variation in these patients. The circadian periodicity may create new possibilities for disease prevention and medication prescription.

Clinical characteristics of hyperglycemic crises in patients without a history of diabetes.

Hyperglycemic crises without a history of diabetes have not been well studied. We compared the clinical characteristics of patients with and without a history of diabetes, and evaluated the glycated hemoglobin levels.