Frequency Analysis of Ventricular Fibrillation and Resuscitation Success

SUMMARY In 56 patients, frequency analysis of the electrocardiogramof ventricular fibrillation exhibited power spectra with a distinctdominant frequency. The greatest success for resuscitation fromventricular fibrillation is recorded when ventricular fibrillationdevelops after the patient comes under coronary care. Of the41 patients in whom the onset and first 8 s of ventricular fibrillationwere artefact-free the mean dominant frequency of primary ventricularfibrillation (no cardiogenic shock or cardiac failure) in 21patients was 6.2±0.2 Hz, significantly higher than themean dominant frequency of the first 8 s of secondary ventricularfibrillation (cardiogenic shock or heart failure) (4.0±0.2Hz, 20 patients, p =0.0001). In these patients the peak-to-troughamplitude (ECG) of the first 8 s of ventricular fibrillationwas similar in both primary and secondary ventricular fibrillationas was the mean duration of ventricular fibrillation prior tothe first DC shock. There was a significantly lower successrate for resuscitation from secondary ventricular fibrillation(6 of 20 patients) compared with resuscitation from primaryventricular fibrillation (18 of 21 patients, x² 17.8, p=0.001).Of the remaining 15 patients who were collapsed between 3 and20 min before the arrival of the mobile coronary care unit,the dominant frequency of the first 8 s of ventricular fibrillationfell with increased duration of collapse (from 5.5 Hz at 3 minto a mean of 2.1 Hz at 20 min). Four of these 15 patients whosurvived the initial arrest had a mean dominant frequency of5.2±0.3 Hz, which was significantly higher than the meandominant frequency (3.1±0.3 Hz, p<0.01) of the 11patients who were not resuscitated. This study shows that low frequency ventricular fibrillationis indicative of a poor chance of successful resuscitation.Alteration of the frequency may increase resuscitation success.     

A Survey of Oregon Emergency Physicians to Assess Mandatory Reporting Knowledge and Reporting Patterns Regarding Intoxicated Drivers in the State of Oregon

Objectives: To assess emergency physician reporting patterns in Oregon before and after the passage of a mandatory intoxicated driving reporting law. Methods: A one‐page survey was mailed to 504 emergency physicians in Oregon in April 2004. Data on reporting frequency were collected using a four‐point ordinal scale regarding motor vehicle crash–involved drivers (MIDs) and intoxicated persons attempting to drive away from the emergency department (DAEDs). Paired observations were assessed for a stated increase in reporting activity following passage of the law using the Wilcoxon signed‐rank test. Associations of postlaw reporting and demographic and knowledge factors were sought using Spearman rank correlation analysis. Results: Of the 504 surveys mailed, 298 (59%) were adequate for analysis. Many respondents (57%) were already aware of the law. Most (92%) agreed that physicians should be mandated to report some crimes. MIDs were always reported by 18% of physicians before the law and by 47% afterward, whereas DAEDs were always reported by 56% of physicians before the law and by 69% afterward. Emergency medicine–trained physicians, higher emergency department census, and increased years of experience were associated with a significantly higher increase in reporting pattern after passage of the law for both MIDs and DAEDs. Conclusions: Although 44% of responding emergency physicians in Oregon were unaware of a mandated reporting law for intoxicated drivers presenting to the ED, most physicians stated an increase in their reporting practice.     

Detection of antibodies to Trypanosoma cruzi among blood donors in the southwestern and western United States. II. Evaluation of a supplemental enzyme immunoassay and radioimmunoprecipitation assay for confirmation of seroreactivity

BACKGROUND: Chagas' disease, caused by the protozoan parasite Trypanosoma cruzi, is endemic to Latin America and may be transmitted in the United States via blood donated by infected immigrants. Blood- borne pathogens such as T. cruzi require supplemental testing for confirmation of seroreactivity. STUDY DESIGN AND METHODS: A study was undertaken to determine an optimal scheme for confirmation of seroreactivity in repeatedly reactive samples identified by the Chagas antibody enzyme immunoassay (EIA). The procedure for initial confirmation involves three purified antigens coated onto three separate polystyrene beads and uses an EIA format. If the sample is reactive with two of three or three of three antigens, it is confirmed as seroreactive. If none or one of three beads is reactive, the sample is indeterminate and subjected to a radioimmunoprecipitation assay (RIPA). The RIPA must demonstrate characteristic bands at 32, 34, and 90 kDa. RESULTS: When tested with sera from persons with potentially cross-reactive diseases (n = 39) or against a presumed negative population from southeast Wisconsin (n = 289), the confirmatory EIA had a specificity of 100 percent. Sensitivity was 100 percent (28/28) with xenodiagnosis-positive sera and 97.6 percent (80/82) with chagasic sera from Latin America. The RIPA showed a specificity of 100 percent in EIA- nonreactive samples (n = 100) and a sensitivity of 100 percent with both xenodiagnosis-positive (28/28) and chagasic (82/82) sera. CONCLUSION: The confirmatory EIA and the RIPA together provide a highly specific and sensitive means of confirming seroreactivity for antibodies to T. cruzi.     

Interventional cardiology live case presentations: Regulatory considerations

Live case presentations are increasingly common at interventional cardiology conferences. Taking advantage of significant advances in communication technology, broadcasts of procedures can be viewed as an extension of traditional medical education targeted to large groups of practitioners. However, there are important ethical, commercial, and patient safety issues associated with live cases that deserve attention. Use of investigational devices in live case demonstrations is subject to review and approval by FDA's Center for Devices and Radiological Health (CDRH), and the outcomes of patients participating in live cases are considered in the overall clinical study results. This article discusses CDRH's regulatory view of live case presentations with a focus on patient safety, clinical trial integrity, and concerns regarding improper medical device promotion. © 2010 Wiley‐Liss, Inc.     

The Outcome of Cardiac Dysfunction in Critically Ill Trauma Patients: Myocardial Contusion Complicated by Refractory Hypotension

Abstract Background:  This work attempted to define the care and course of those most severely affected patients in the setting of blunt chest trauma, who had hypotension refractory to routine fluid resuscitation. Methods:  Twenty-three critically ill blunt trauma ICU patients were resuscitated and enrolled with ongoing hypotension required placement of a pulmonary artery catheter. The REF^?Explorer (Baxter, Edwards, Anaheim, CA) catheter was placed in the right heart measuring pressure, volume and oxygen utilization information, as well as recording Injury Severity Score, EKG, CXR, CPK/MB and echocardiography over the initial 72-h time period. Results:  There were an approximately 2,300 Level I trauma patients admitted annually over a 4-year period with an overall mortality rate of 4.3% (100) patients with 3.4% (79) patients “ruling in” with elevated cardiac enzymes, associated with an increased mortality rate of 6.7% (p < 0.05). The 23 patients were male (17, 74%), mean age 41.2 years, with no past medical history (19, 83%), in a motor vehicle accident (21, 91%), with pulmonary injury (9, 39%), undergoing celiotomy in (10, 44%). They presented with moderate to severe trauma acuity defined as mean GCS of 8.6, TS of 11.3, and ISS of 34 with an increased mean hospital stay of 15 days versus 6 days in the ICU; and a 26 days versus 10 days overall stay for those with myocardial contusion (p < 0.05). Analysis of diagnostic variables found an abnormal EKG in (21, 91%), CXR in (20, 87%) and echocardiogram in (8, 37%). The total CPK was found to be elevated, mean 2,219 (204–8,278 U/l), while the MB fraction was normal 2.3 ± 1.3%. Invasive cardiac monitoring found an increase in CO of 1.6 l/min from 5.9 to 7.8 l/min during the first 24 h of recovery. Survival was worsened with increased ISS (29 vs. 43) p < 0.02, but improved with longer ICU (17 vs. 8) p < 0.03 and hospital (39 vs. 7) p < 0.05 stay in days. The analysis of commonly used diagnostic modalities – EKG, CXR, ECHO, or CO, did not correlate with survival, but the total CPK was increased in survivors (2,715 vs. 1,432 U/l) p < 0.009. Conclusion:  There is worsened morbidity with a 2-fold increase in ICU LOS and hospital stay, and a 1.5-fold increase in mortality in the severe myocardial contusion group. The diagnostic dilemma posed by lack of definitive testing continues unresolved after analysis of routinemodalities – EKG, CXR, ECHO, CPK or CO – failing to yield a “best test”.     

Clinical and histologic findings after use of a novel combined retinol,tripeptide, and glaucine containing cream in the treatment of photo-aged skin

Background

Neck skin is thinner and has a more delicate dermal layer than facial skin. The studied product was specifically formulated for the neck combining a hydrating delivery system with a trifunctional corrective technology composed of 0.2% pure retinol, 2.5% tripeptide concentrate, and 5.0% glaucine complex to help improvement in signs of aging.

Objectives

To evaluate cosmetic and histologic changes 3 months after treatment using immunostains for Type I collagen, Type III collagen, and glycosaminoglycan (GAGS). In addition, overall clinical improvement in photoaged skin was measured by both Griffith's photonumeric photoaging scale, photographic improvement, and questionnaires.

Methods

This study was an open-label, blinded clinical trial evaluating a combined retinol, tripeptide, and glaucine containing cream in the treatment of photo-aged skin. The study enrolled a total of 20 healthy male or female subjects, who applied the product for 3 months to their face and neck.

Results

Clinical as well histologic changes were consistent with improvement in all 20 subjects.

Conclusion

Use of a combined retinol, tripeptide, and glaucine containing cream led to both clinical and histologic improvement of phototoaging.