Effect of chest compressions only during experimental basic life support on alveolar collapse and recruitment

AIM: The importance of ventilatory support during cardiac arrest and basic life support is controversial. This experimental study used dynamic computed tomography (CT) to assess the effects of chest compressions only during cardiopulmonary resuscitation (CCO-CPR) on alveolar recruitment and haemodynamic parameters in porcine model of ventricular fibrillation. MATERIALS AND METHODS: Twelve anaesthetized pigs (26+/-1kg) were randomly assigned to one of the following groups: (1) intermittent positive pressure ventilation (IPPV) both during basic life support and advanced cardiac life support, or (2) CCO during basic life support and IPPV during advanced cardiac life support. Measurements were acquired at baseline prior to cardiac arrest, during basic life support, during advanced life support, and after return of spontaneous circulation (ROSC), as follows: dynamic CT series, arterial and central venous pressures, blood gases, and regional organ blood flow. The ventilated and atelectatic lung area was quantified from dynamic CT images. Differences between groups were analyzed using the Kruskal-Wallis test, and a p<0.05 was considered statistically significant. RESULTS: IPPV was associated with cyclic alveolar recruitment and de-recruitment. Compared with controls, the CCO-CPR group had a significantly larger mean fractional area of atelectasis (p=0.009), and significantly lower PaO(2) (p=0.002) and mean arterial pressure (p=0.023). The increase in mean atelectatic lung area observed during basic life support in the CCO-CPR group remained clinically relevant throughout the subsequent advanced cardiac life support period and following ROSC, and was associated with prolonged impaired haemodynamics. No inter-group differences in myocardial and cerebral blood flow were observed. CONCLUSION: A lack of ventilation during basic life support is associated with excessive atelectasis, arterial hypoxaemia and compromised CPR haemodynamics. Moreover, these detrimental effects remain evident even after restoration of IPPV.

Long-term effects of supervised exercise training on walking capacity and quality of life in patients with intermittent claudication

Supervised exercise training has been shown to improve walking capacity in several studies of patients with intermittent claudication. However, data on long-term outcome are quite limited. The aim of this prospective study was to evaluate long-term effects of supervised exercise training on walking capacity and quality of life in patients with intermittent claudication. Patients and methods: Sixty-seven consecutive patients with intermittent claudication who completed a supervised 12-week exercise training program were asked for follow up evaluation 39 +/- 20 months after program completion. Pain-free walking distance (PWD) and maximum walking distances (MWD) were assessed by treadmill test and several questionnaires. Results: Forty (60%) patients agreed to participate, 22 (33%) refused participation, and 5 (7%) died during follow-up. PWD and MWD significantly improved at completion of 12-weeks supervised exercise training as compared to baseline (PWD 114 +/- 100 vs. 235 +/- 248, p = 0.002; MWD 297 +/- 273 vs. 474 +/- 359, p = 0.001). Improvement of PWD and MWD could be maintained at follow up (197 +/- 254, p = 0.014; 390 +/- 324, p = 0.035, respectively) with non-smokers showing significantly better sustained PWD and MWD improvement as compared to baseline. Overall, walking capacity correlated with functional status of quality of life. Conclusions: Major findings of this investigation were that improvement in walking capacity is sustained after completion of supervised exercise training program with best results in patients who quitted or never smoked. Improved walking capacity is associated with increased functional status of quality of life.

Mental health and quality of life after genetic testing for Huntington disease: a long-term effect study in Germany

Predictive genetic testing for Huntington disease (HD) might cause severe short-term psychological reactions in patients with poor mental health. Very few studies exist on the long-term effects of genetic HD testing. The aim of this study was to assess mental health and quality of life in persons who were tested for HD mutation, to compare mental health depending on the result of the genetic test (non-carriers, gene carriers, and patients with HD) and to identify predictors of mental health and quality of life via linear regression. The data were collected by self-report questionnaires. In total, 121 individuals participated in this study: 52 were non-carriers, 54 were gene carriers, and 15 were gene carriers suffering from HD. Non-carriers and gene carriers showed better mental health and quality of life than HD-patients but did not differ from each other. In non-carriers four variables predicted increased depression and low mental quality of life: low perceived social support, no intimate relationship, female sex and younger age. For gene carriers three predictors were found: low perceived social support, the expectation of an unfavorable genetic test result before the testing procedure and being childless. To prevent detrimental effects of HD testing on mental health and mental quality of life, specific attention should be paid to persons with limited social networks during genetic counseling. Assessment of expectations related to the test result and mental health prior to a genetic testing procedure may help to identify gene carriers at risk of poor coping after an unfavorable test result.

Long-term health-related quality of life and walking capacity of lung recipients with and without bronchiolitis obliterans syndrome

BACKGROUND: Outcome after lung transplantation (LTx) is affected by the onset of bronchiolitis obliterans syndrome (BOS) and lung function decline. Reduced health-related quality of life (HRQL) and physical mobility have been shown in patients developing BOS, but the impact on the capacity to walk is unknown. We aimed to compare the long-term HRQL and 6-minute walk test (6MWT) between lung recipients affected or not by BOS Grade > or =2. METHODS: Fifty-eight patients were prospectively followed for 5.6 +/- 2.9 years after LTx. Assessments included the St George's Respiratory Questionnaire (SGRQ) and the 6MWT, which were performed yearly. Moreover, clinical complications were recorded to estimate the proportion of the follow-up time lived without clinical intercurrences after transplant. Analyses were performed using adjusted linear regression and repeated-measures analysis of variance. RESULTS: BOS was a significant predictor of lower SGRQ scores (p < 0.01) and reduced time free of clinical complications (p = 0.001), but not of 6MWT distance (p = 0.12). At 7 years post-transplant, results were: 69.0 +/- 21.8% vs 86.9 +/- 5.6%, p < 0.05 (SGRQ); 58.5 +/- 21.6% vs 88.7 +/- 11.4%, p < 0.01 (proportion of time lived without clinical complications); and 82.2 +/- 10.9% vs 91.9 +/- 14.2%, p = 0.27 (percent of predicted 6MWT), respectively, for patients with BOS and without BOS. CONCLUSIONS: Despite significantly less time lived without clinical complications and progressive decline of self-reported health status, the capacity to walk of patients affected by BOS remained relatively stable over time. These findings may indicate that the development of moderate to severe BOS does not prevent lung recipients from walking independently and pursuing an autonomous life.

Evaluating the relationship between moisture induced expansion and horizontal stress orientation in samples from the nonesuch formation

High horizontal stresses can cause numerous ground control problems in mines and other underground structures ultimately impacting worker safety, productivity and the economics of an underground operation. Mine layout and design can be optimized when the presence and orientation of these stresses are recognized and their impact minimized. A simple technique for correlating the principal horizontal stress direction in a sedimentary rock mass with the preferential orientation of moisture induced expansion in a sample of the same rock was introduced in the 1970s and has since gone un-reported and unused. This procedure was reexamined at a locality near the original test site at White Pine, Michigan in order to validate the original research and to consider its usefulness in mining and civil engineering applications in high horizontal stress conditions. This procedure may also be useful as an economical means for characterizing regional stress fields.

STRUCTURAL CONTROL OF A SMALL-SCALE TEST-BED SHAKER STRUCTURE USING A SPONGE-TYPE MAGNETO-RHEOLOGICAL FLUID DAMPER

Semi-active damping devices have been shown to be effective in mitigating unwanted vibrations in civil structures. These devices impart force indirectly through real-time alterations to structural properties. Simulating the complex behavior of these devices for laboratory-scale experiments is a major challenge. Commercial devices for seismic applications typically operate in the 2-10 kN range; this force is too high for small-scale testing applications where requirements typically range from 0-10 N. Several challenges must be overcome to produce damping forces at this level. In this study, a small-scale magneto-rheological (MR) damper utilizing a fluid absorbent metal foam matrix is developed and tested to accomplish this goal. This matrix allows magneto-rheological (MR) fluid to be extracted upon magnetic excitation in order to produce MR-fluid shear stresses and viscosity effects between an electromagnetic piston, the foam, and the damper housing. Dampers for uniaxial seismic excitation are traditionally positioned in the horizontal orientation allowing MR-fluid to gather in the lower part of the damper housing when partially filled. Thus, the absorbent matrix is placed in the bottom of the housing relieving the need to fill the entire device with MR-fluid, a practice that requires seals that add significant unwanted friction to the desired low-force device. The damper, once constructed, can be used in feedback control applications to reduce seismic vibrations and to test structural control algorithms and wireless command devices. To validate this device, a parametric study was performed utilizing force and acceleration measurements to characterize damper performance and controllability for this actuator. A discussion of the results is presented to demonstrate the attainment of the damper design objectives.

Age and gender differences in health-related quality of life of children and adolescents in Europe: a multilevel analysis

OBJECTIVES: To determine age and gender differences in health-related quality of life (HRQOL) in children and adolescents across 12 European countries using a newly developed HRQOL measure (KIDSCREEN). METHODS: The KIDSCREEN-52 questionnaire was filled in by 21,590 children and adolescents aged 8-18 from 12 countries. We used multilevel regression analyses to model the hierarchical structure of the data. In addition, effect sizes were computed to test for gender differences within each age group. RESULTS: Children generally showed better HRQOL than adolescents (P < 0.001). While boys and girls had similar HRQOL at young age, girls' HRQOL declined more than boys' (P < 0.001) with increasing age, depending on the HRQOL scale. There was significant variation between countries both at the youngest age and for age trajectories. CONCLUSIONS: For the first time, gender and age differences in children's and adolescents' HRQOL across Europe were assessed using a comprehensive and standardised instrument. Gender and age differences exist for most HRQOL scales. Differences in HRQOL across Europe point to the importance of national contexts for youth's well-being.

Quality of life of grown-up congenital heart disease patients after congenital cardiac surgery

BACKGROUND: Due to better early and long-term outcome, the increasing population of grown-ups with congenital heart disease (GUCH) brings up unexpected quality of life (QoL) issues. The cardiac lesion by itself is not always the major problem for these patients, since issues pertaining to QoL and psychosocial aspects often predominate. This study analyses the QoL of GUCH patients after cardiac surgery and the possible impact of medical and psychosocial complications. PATIENTS AND METHODS: A questionnaire package containing the SF-36 health survey (health related QoL), the HADS test (anxiety/depression aspects) and an additional disease specific questionnaire was sent to 345 patients (mean 26+/-11 years) operated for isolated transposition of the great arteries (TGA), tetralogy of Fallot (TOF), and ventricular septal defect (VSD). The scores were compared with age- and gender-matched standard population data and in relation to the underlying congenital heart disease (CHD). RESULTS: In all SF-36 and HADS health dimensions the GUCH patients showed excellent scores (116+/-20), which are comparable to the standard population (100+/-15), regardless of the initial CHD (p=0.12). Eighty-two percent of the patients were found to be in NYHA class I and 83% patients declared that they do not consider their QoL to be limited by their malformation. Complications like reoperations (p=0.21) and arrhythmias (p=0.10) do not show significant impact on the QoL. The additional questionnaire revealed that 76% of adult patients have a fulltime job, 18% receive a full or partial disability pension, 21% reported problems with insurances, most of them regarding health insurances (67%), and 4.4% of adult patients declared to have renounced the idea of having children due to their cardiac malformation. CONCLUSION: QoL in GUCH patients following surgical repair of isolated TOF, TGA and VSD is excellent and comparable to standard population, this without significant difference between the diagnosis groups. However, these patients are exposed to a high rate of complications and special psychosocial problems, which are not assessed by standardized questionnaires, such as the SF-36 and HADS. These findings highlight the great importance for a multidisciplinary and specialized follow-up for an adequate management of these complex patients.

Can a novel web-based computer test predict poor simulated driving performance? A pilot study with healthy and cognitive-impaired participants

BACKGROUND Driving a car is a complex instrumental activity of daily living and driving performance is very sensitive to cognitive impairment. The assessment of driving-relevant cognition in older drivers is challenging and requires reliable and valid tests with good sensitivity and specificity to predict safe driving. Driving simulators can be used to test fitness to drive. Several studies have found strong correlation between driving simulator performance and on-the-road driving. However, access to driving simulators is restricted to specialists and simulators are too expensive, large, and complex to allow easy access to older drivers or physicians advising them. An easily accessible, Web-based, cognitive screening test could offer a solution to this problem. The World Wide Web allows easy dissemination of the test software and implementation of the scoring algorithm on a central server, allowing generation of a dynamically growing database with normative values and ensures that all users have access to the same up-to-date normative values. OBJECTIVE In this pilot study, we present the novel Web-based Bern Cognitive Screening Test (wBCST) and investigate whether it can predict poor simulated driving performance in healthy and cognitive-impaired participants. METHODS The wBCST performance and simulated driving performance have been analyzed in 26 healthy younger and 44 healthy older participants as well as in 10 older participants with cognitive impairment. Correlations between the two tests were calculated. Also, simulated driving performance was used to group the participants into good performers (n=70) and poor performers (n=10). A receiver-operating characteristic analysis was calculated to determine sensitivity and specificity of the wBCST in predicting simulated driving performance. RESULTS The mean wBCST score of the participants with poor simulated driving performance was reduced by 52%, compared to participants with good simulated driving performance (P<.001). The area under the receiver-operating characteristic curve was 0.80 with a 95% confidence interval 0.68-0.92. CONCLUSIONS When selecting a 75% test score as the cutoff, the novel test has 83% sensitivity, 70% specificity, and 81% efficiency, which are good values for a screening test. Overall, in this pilot study, the novel Web-based computer test appears to be a promising tool for supporting clinicians in fitness-to-drive assessments of older drivers. The Web-based distribution and scoring on a central computer will facilitate further evaluation of the novel test setup. We expect that in the near future, Web-based computer tests will become a valid and reliable tool for clinicians, for example, when assessing fitness to drive in older drivers.

A test of genetic association among male nuptial coloration, female mating preference, and male aggression bias within a polymorphic population of cichlid fish

Both inter- and intrasexual selection have been implicated in the origin and maintenance of species-rich taxa with diverse sexual traits. Simultaneous disruptive selection by female mate choice and male-male competition can, in theory, lead to speciation without geographical isolation if both act on the same male trait. Female mate choice can generate discontinuities in gene flow, while male-male competition can generate negative frequency-dependent selection stabilizing the male trait polymorphism. Speciation may be facilitated when mating preference and/or aggression bias are physically linked to the trait they operate on. We tested for genetic associations among female mating preference, male aggression bias and male coloration in the Lake Victoria cichlid Pundamilia. We crossed females from a phenotypically variable population with males from both extreme ends of the phenotype distribution in the same population (blue or red). Male offspring of a red sire were significantly redder than males of a blue sire, indicating that intra-population variation in male coloration is heritable. We tested mating preferences of female offspring and aggression biases of male offspring using binary choice tests. There was no evidence for associations at the family level between female mating preferences and coloration of sires, but dam identity had a significant effect on female mate preference. Sons of the red sire directed significantly more aggression to red than blue males, whereas sons of the blue sire did not show any bias. There was a positive correlation among individuals between male aggression bias and body coloration, possibly due to pleiotropy or physical linkage, which could facilitate the maintenance of color polymorphism.

Computational and experimental methodology for site-matched investigations of the influence of mineral mass fraction and collagen orientation on the axial indentation modulus of lamellar bone

Relationships between mineralization, collagen orientation and indentation modulus were investigated in bone structural units from the mid-shaft of human femora using a site-matched design. Mineral mass fraction, collagen fibril angle and indentation moduli were measured in registered anatomical sites using backscattered electron imaging, polarized light microscopy and nano-indentation, respectively. Theoretical indentation moduli were calculated with a homogenization model from the quantified mineral densities and mean collagen fibril orientations. The average indentation moduli predicted based on local mineralization and collagen fibers arrangement were not significantly different from the average measured experimentally with nanoindentation (p=0.9). Surprisingly, no substantial correlation of the measured indentation moduli with tissue mineralization and/or collagen fiber arrangement was found. Nano-porosity, micro-damage, collagen cross-links, non-collagenous proteins or other parameters affect the indentation measurements. Additional testing/simulation methods need to be considered to properly understand the variability of indentation moduli, beyond the mineralization and collagen arrangement in bone structural units.

Notification of abnormal lab test results in an electronic medical record: do any safety concerns remain?

BACKGROUND: Follow-up of abnormal outpatient laboratory test results is a major patient safety concern. Electronic medical records can potentially address this concern through automated notification. We examined whether automated notifications of abnormal laboratory results (alerts) in an integrated electronic medical record resulted in timely follow-up actions. METHODS: We studied 4 alerts: hemoglobin A1c > or =15%, positive hepatitis C antibody, prostate-specific antigen > or =15 ng/mL, and thyroid-stimulating hormone > or =15 mIU/L. An alert tracking system determined whether the alert was acknowledged (ie, provider clicked on and opened the message) within 2 weeks of transmission; acknowledged alerts were considered read. Within 30 days of result transmission, record review and provider contact determined follow-up actions (eg, patient contact, treatment). Multivariable logistic regression models analyzed predictors for lack of timely follow-up. RESULTS: Between May and December 2008, 78,158 tests (hemoglobin A1c, hepatitis C antibody, thyroid-stimulating hormone, and prostate-specific antigen) were performed, of which 1163 (1.48%) were transmitted as alerts; 10.2% of these (119/1163) were unacknowledged. Timely follow-up was lacking in 79 (6.8%), and was statistically not different for acknowledged and unacknowledged alerts (6.4% vs 10.1%; P =.13). Of 1163 alerts, 202 (17.4%) arose from unnecessarily ordered (redundant) tests. Alerts for a new versus known diagnosis were more likely to lack timely follow-up (odds ratio 7.35; 95% confidence interval, 4.16-12.97), whereas alerts related to redundant tests were less likely to lack timely follow-up (odds ratio 0.24; 95% confidence interval, 0.07-0.84). CONCLUSIONS: Safety concerns related to timely patient follow-up remain despite automated notification of non-life-threatening abnormal laboratory results in the outpatient setting.

Real-life results of balloon kyphoplasty for vertebral compression fractures from the SWISSspine registry

BACKGROUND CONTEXT The Swiss Federal Office of Public Health mandated a nationwide health technology assessment-registry for balloon kyphoplasty (BKP) for decision making on reimbursement of these interventions. The early results of the registry led to a permanent coverage of BKP by basic health insurance. The documentation was continued for further evidence generation. PURPOSE This analysis reports on the 1 year results of patients after BKP treatment. STUDY DESIGN Prospective multicenter observational case series. PATIENT SAMPLE The data on 625 cases with 819 treated vertebrae were documented from March 2005 to May 2012. OUTCOME MEASURES Surgeon-administered outcome instruments were primary intervention form for BKP and the follow-up form; patient self-reported measures were EuroQol-5D questionnaire, North American Spine Society outcome instrument /Core Outcome Measures Index (including visual analog scale), and a comorbidity questionnaire. Outcome measures were back pain, medication, quality of life (QoL), cement extrusions, and new fractures within the first postoperative year. METHODS Data were recorded preoperatively and at 3 to 6-month and 1-year follow-ups. Wilcoxon signed-rank test was used for comparison of pre- with postoperative measurements. Multivariate logistic regression was used to identify factors with a significant influence on the outcome. RESULTS Seventy percent of patients were women with mean age of 71 years (range, 18-91 years); mean age of men was 65 years (range, 15-93 years). Significant and clinically relevant reduction of back pain, improvement of QoL, and reduction of pain killer consumption was seen within the first postoperative year. Preoperative back pain decreased from 69.3 to 29.0 at 3 to 6-month and remained unchanged at 1-year follow-ups. Consequently, QoL improved from 0.23 to 0.71 and 0.75 at the same follow-up intervals. The overall vertebra-based cement extrusion rates with and without extrusions into intervertebral discs were 22.1% and 15.3%, respectively. Symptomatic cement extrusions with radiculopathy were five (0.8%). A new vertebral fracture within a year from the BKP surgery was observed in 18.4% of the patients. CONCLUSIONS The results of the largest observational study for BKP so far are consistent with published randomized trials and systematic reviews. In this routine health care setting, BKP is safe and effective in reducing pain, improving QoL, and lowering pain_killer consumption and has an acceptable rate of cement extrusions. Postoperative outcome results show clear and significant clinical improvement at early follow-up that remain stable during the first postoperative year.

Life-threatening adverse events following therapeutic opioid administration in adults: Is pharmacogenetic analysis useful?

BACKGROUND Systemic approaches are needed to understand how variations in the genes associated with opioid pharmacokinetics and response can be used to predict patient outcome. The application of pharmacogenetic analysis to two cases of life-threatening opioid-induced respiratory depression is presented. The usefulness of genotyping in the context of these cases is discussed. METHODS A panel of 20 functional candidate polymorphisms in genes involved in the opioid biotransformation pathway (CYP2D6, UGT2B7, ABCB1, OPRM1, COMT) were genotyped in these two patients using commercially available genotyping assays. RESULTS In case 1, the patient experienced adverse outcomes when administered codeine and morphine, but not hydromorphone. Genetic test results suggested that this differential response may be due to an inherent propensity to generate active metabolites from both codeine and morphine. These active metabolites are not generated with hydromorphone. In case 2, the patient experienced severe respiratory depression during postoperative recovery following standard doses of morphine. The patient was found to carry genetic variations that result in decreased morphine efflux transporter activity at the blood-brain barrier and increased sensitivity to opioids. CONCLUSIONS Knowledge of the relative contribution of pharmacogenetic biomarkers and their influence on opioid response are continually evolving. Pharmacogenetic analysis, together with clinical history, has the potential to provide mechanistic insight into severe respiratory depressive events in patients who receive opioids at therapeutic doses.