Discrete Wavelet-Aided Delineation of PCG Signal Events via Analysis of an Area Curve Length-Based Decision Statistic

The aim of this study is to describe a robust unified framework for segmentation of the phonocardiogram (PCG) signal sounds based on the false-alarm probability (FAP) bounded segmentation of a properly calculated detection measure. To this end, first the original PCG signal is appropriately pre-processed and then, a fixed sample size sliding window is moved on the pre-processed signal. In each slid, the area under the excerpted segment is multiplied by its curve-length to generate the Area Curve Length (ACL) metric to be used as the segmentation decision statistic (DS). Afterwards, histogram parameters of the nonlinearly enhanced DS metric are used for regulation of the α-level Neyman-Pearson classifier for FAP-bounded delineation of the PCG events. The proposed method was applied to all 85 records of Nursing Student Heart Sounds database (NSHSDB) including stenosis, insufficiency, regurgitation, gallop, septal defect, split sound, rumble, murmur, clicks, friction rub and snap disorders with different sampling frequencies. Also, the method was applied to the records obtained from an electronic stethoscope board designed for fulfillment of this study in the presence of high-level power-line noise and external disturbing sounds and as the results, no false positive (FP) or false negative (FN) errors were detected. High noise robustness, acceptable detection-segmentation accuracy of PCG events in various cardiac system conditions, and having no parameters dependency to the acquisition sampling frequency can be mentioned as the principal virtues and abilities of the proposed ACL-based PCG events detection-segmentation algorithm.     

A standardized approach to assessing physician expectations and perceptions of continuing medical education

INTRODUCTION: Rapidly expanding science and mandates for maintaining credentials place increasing demands on continuing medical education (CME) activities to provide information that is current and relevant to patient care. Quality may be seen as the perceived level of service measured against consumer expectations. Standard tools have not been developed to determine how well CME activities meet consumer expectations. METHODS: A widely used approach for evaluating perceptions of service quality in other fields, SERVQUAL, was adapted for CME by eliciting perspectives from physician consumers of CME and CME providers through nominal group techniques. These perspectives were used to develop a CMEQUAL evaluation survey instrument. Feasibility testing was conducted. Data were analyzed and items were tested for internal consistency. RESULTS: CME participants were individuals willing to complete items related to expectations before participation and perceptions after participation in a CME activity. Of the CME activity participants who provided CMEQUAL rating data for the study, 43% rated their overall perceptions of the CME activity below their overall expectations. CME activities most clearly met participant expectations in providing fair and balanced evidence-based content. Areas of lower priority for participants included opportunities for self-assessment, solving cases, and interactive learning. Two areas highly valued by participants but not adequately addressed by CME activities were (1) translating trial data to patient seen in practice and (2) addressing barriers to optimal patient management. DISCUSSION: Developing standards for evaluating physician perceptions of the quality of CME activities may assist CME providers in improving the effectiveness of CME activities in meeting physician learning needs.     

Low risk of intra-abdominal infections in rectal cancer patients treated with Hartmann’s procedure: a report from a national registry

Purpose

To describe the postoperative surgical complications in patients with rectal cancer undergoing Hartmann’s procedure (HP).

Methods

Data were retrieved from the Swedish Colorectal Cancer Registry for all patients with rectal cancer undergoing HP in 2007–2014. A retrospective analysis was performed using prospectively recorded data. Characteristics of patients and risk factors for intra-abdominal infection and re-laparotomy were analysed.

Results

Of 10,940 patients resected for rectal cancer, 1452 (13%) underwent HP (median age, 77 years). The American Society of Anesthesiologists (ASA) score was 3–4 in 43% of patients; 15% had distant metastases and 62% underwent a low HP. The intra-abdominal infection rate was 8% and re-laparotomy rate was 10%. Multivariable logistic regression analysis identified preoperative radiotherapy (OR, 1.78; 95% CI, 1.14–2.77), intra-operative bowel perforation (OR, 1.99; 95% CI, 1.08–3.67), T4 tumours (OR, 1.68; 95% CI 1.04–2.69) and female gender (OR, 1.73; 95% CI, 1.15–2.61) as risk factors for intra-abdominal infection. ASA score 3–4 (OR, 1.62; 95% CI, 1.12–2.34), elevated BMI (OR, 1.05; 95% CI, 1.02–1.09) and female gender (OR, 2.06; CI, 1.41–3.00) were risk factors for re-laparotomy after HP. The rate of intra-abdominal infection was not increased after a low HP.

Conclusions

Despite older age and co-morbidities including more advanced cancer, patients undergoing Hartmann’s procedure had low rates of serious postoperative complications and re-laparotomy. A low HP was not associated with a higher rate of intra-abdominal infection. HP seems to be appropriate for old and frail patients with rectal cancer.

     

A program encouraging early defibrillation results in improved in-hospital resuscitation efficacy

OBJECTIVES: The purpose of this study was to determine whether survival to discharge after in-hospital cardiopulmonary arrest could be improved by a program encouraging early defibrillation that included switching from monophasic to biphasic devices. BACKGROUND: In-hospital resuscitation continues to have a low success rate. Biphasic waveform devices have demonstrated characteristics that might improve survival, and outside the hospital, automated external defibrillators (AEDs) have shown promise in improving survival of patients suffering cardiopulmonary arrest. METHODS: A program including education and replacement of all manual monophasic defibrillators with a combination of manual biphasic defibrillators used in AED mode and AEDs in all outpatient clinics and chronic care units was implemented. RESULTS: With program implementation, the percentage survival of all patients with resuscitation events improved 2.6-fold, from 4.9% to 12.8%. Factors independently predicting survival included event location outside an intensive care unit, younger age, an initial rhythm of pulseless ventricular tachycardia (VT) or ventricular fibrillation (VF), pre-arrest beta-blocker, and program initiation. The outcome was independent of gender, race, work shift, number of previous resuscitation attempts, body mass index, comorbidity index, presence of diabetes, presence of hypertension, or use of angiotensin-converting enzyme inhibitors. The improvement in mortality was attributable solely to an effect on patients presenting with VT/VF. Patients with these initial rhythms were 14-fold (odds ratio = 0.07 of death, confidence interval = 0.02 to 0.3) more likely to survive to discharge after program initiation. Automated external defibrillators performed similarly to biphasic manual defibrillators in AED mode. CONCLUSIONS: A program including education and use of biphasic manual defibrillators in AED mode and selective use of AEDs improved survival to discharge in hospitalized patients suffering from cardiopulmonary arrest.     

The preventive and therapeutic potential of natural polyphenols on influenza

Influenza virus belongs to orthomyxoviridae family. This virus is a major public health problems, with high rates of morbidity and mortality. Despite a wide range of pharmacotherapeutic choices inhibiting specific sequences of pathological process of influenza, developing more effective therapeutic options is an immediate challenge. In this paper, a comprehensively review of natural polyphenolic products used worldwide for the management of influenza infection is presented. Cellular and molecular mechanisms of the natural polyphenols on influenza infection including suppressing virus replication cycle, viral hemagglutination, viral adhesion and penetration into the host cells, also intracellular transductional signaling pathways have been discussed in detail. Based on cellular, animal, and human evidence obtained from several studies, the current paper demonstrates that natural polyphenolic compounds possess potential effects on both prevention and treatment of influenza, which can be used as adjuvant therapy with conventional chemical drugs for the management of influenza and its complications.     

Association of lipids, lipoproteins, apolipoproteins and paraoxonase enzyme activity with premature coronary artery disease

BACKGROUND AND DESIGN: The association of serum apolipoprotein (apo) A-I and apo B concentrations and paraoxonase (PON) enzyme activity with angiographically determined coronary artery disease (CAD) was investigated in Iranian non-diabetic patients with premature CAD and control participants in a sex- and age-matched case-control study. METHODS: The study population consisted of 59 non-diabetic patients with premature CAD and 55 CAD control participants. Premature CAD was defined as the presence of angiographically proven coronary stenosis (> or =50% involvement) in men and women younger than 55 and 65 years, respectively. Apolipoprotein concentrations were measured by immunoturbidometric assay and paraoxonase/arylesterase activities by spectrophotometric assay of p-nitrophenol/phenol production following addition of paraoxon/phenylacetate to serum. RESULTS: In CAD patients, increased concentrations of total cholesterol (215 +/- 43 compared with 193 +/- 43, P < 0.001), low-density lipoprotein cholesterol (137 +/- 46 compared with 116 +/- 39, P < 0.05) and apo B (102 +/- 24 compared with 84 +/- 17, P < 0.001) and a decreased ratio of apo A-I/apo B (1.7 +/- 0.4 compared with 2.0 +/- 0.6, P < 0.001) were observed compared to the control group. Other study variables were not significantly different between the two groups. On multiple logistic regression analysis, the only marker for discrimination between the CAD+ group and the CAD- control group was apo B level. CONCLUSIONS: In Iranian non-diabetic patients with premature CAD, the concentration of apo B is a better marker than traditional lipids in discriminating between CAD+ and CAD- patients. The lack of significant difference in PON activity between CAD patients and control participants supports the concept of interethnic variability in PON activity and gene polymorphism observed in other studies.     

Acute Complex Type A Dissection associated with peripheral malperfusion syndrome treated with a staged approach guided by lactate levels

Acute type A aortic dissection can be complicated by visceral malperfusion and is associated with a significant surgical morbidity and mortality. We describe a case of successful management of a complex acute type A dissection with mesenteric and lower limb ischemia treated with endovascular thoracic stenting and femoro-femoral crossover bypass grafting followed by aortic arch repair. To accomplish this, we applied a staged therapeutic approach using serial lactate measurements to assess the adequacy of peripheral perfusion and metabolic status prior to surgical repair of the proximal dissection.