Construct validity of a novel assessment tool for ultrasound-guided axillary brachial plexus block.

The purpose of this study was to examine the construct validity and reliability of a novel metrics-based assessment tool, previously developed for ultrasound-guided axillary brachial plexus block. Five expert and eight novice anaesthetists performed a total of 18 ultrasound-guided axillary brachial plexus blocks on the same number of patients. A trained investigator video-taped procedures according to a pre-defined protocol. Two trained consultant anaesthetists independently scored the videos using the assessment tool. Compared with novices, experts completed more steps (mean 41.0 vs. 33.1, p = 0.001), had fewer procedural errors (2.8 vs. 7.9, p < 0.0001), had fewer critical errors (0.8 vs. 1.3, p = 0.030), and fewer total errors (3.5 vs. 9.1, p < 0.0001). The mean inter-rater reliability for scoring of experts' performance was 0.91, for novices' performance was 0.84, and for all performance combined (n = 18) was 0.88. This assessment tool is valid, and discriminates reliably between expert and novice performance for placement of ultrasound-guided axillary brachial plexus blocks.

[Influence of prenatal hospitalization on parental stressful experience in the case of a premature birth]. / Influence d'une hospitalisation prénatale sur les facteurs de stress parentaux lors d'une naissance prématurée.

OBJECTIVES: To investigate the influence of prenatal hospitalization before a premature birth, on the parental stressful experience, parental symptoms of post-traumatic stress and quality of parent-infant interaction during the hospitalization in neonatology. POPULATION: 51 preterm infants born and 25 full term infants control. Four groups: controls, premature without prenatal hospitalization, premature with a short (<8 days) prenatal hospitalization and premature with a long (≥ 8 days) prenatal hospitalization. INSTRUMENTS: the Parental Stressor Scale: Neonatal Intensive Care Unit (PSS: NICU, Miles et al., 1993 [14]) and the Perinatal PTSD Questionnaire (PPQ, Quinnell and Hynan, 1999 [16]). RESULTS: When prenatal hospitalization of the mother occurred, parents acknowledged increased stress induced by the environmental factors during the infant's hospitalization. Furthermore, mothers from the group with a short prenatal hospitalization presented significantly more symptoms of post-traumatic stress. Parents presenting more symptoms of post-traumatic stress describe a significantly more difficult interaction with their infant in neonatology. CONCLUSION: This study highlights the necessity to deliver special care to women hospitalized shortly (<8 days) prior to the delivery of their premature baby. This group is at high risk of presenting post-traumatic stress symptoms, which could have a negative impact on the quality of parent-infant interactions.

Oxegen 2004: the impact of a major music festival on the workload of a local hospital.

This prospective observational study was undertaken to assess the impact of a major music festival on the workload of a local hospital. Data were collected on all attendances at Naas General Hospital from the nearby Oxegen 2004 music festival. Patient demographics, disposition and diagnoses were recorded. Emergency department activity levels were compared before, during and after the festival. Seventy-two attendees were referred to Naas emergency department over a 3-day period, representing a 45% increase in the hospital's emergency department attendance rate. Thirty-seven of these attendees (51%) required inpatient or tertiary centre services. Thirty-four attendees (47%) were noted as having consumed alcohol and/or used illicit substances. We conclude that despite the provision of on-site medical facilities, major music events are associated with a significant increase in local health care activity and expenditure.

Parental post-traumatic reactions after premature birth: implications for sleeping and eating problems in the infant.

BACKGROUND: Progress in perinatal medicine has made it possible to increase the survival of very or extremely low birthweight infants. Developmental outcomes of surviving preterm infants have been analysed at the paediatric, neurological, cognitive, and behavioural levels, and a series of perinatal and environmental risk factors have been identified. The threat to the child's survival and invasive medical procedures can be very traumatic for the parents. Few empirical reports have considered post-traumatic stress reactions of the parents as a possible variable affecting a child's outcome. Some studies have described sleeping and eating problems as related to prematurity; these problems are especially critical for the parents. OBJECTIVE: To examine the effects of post-traumatic reactions of the parents on sleeping and eating problems of the children. DESIGN: Fifty families with a premature infant (25-33 gestation weeks) and a control group of 25 families with a full term infant participated in the study. Perinatal risks were evaluated during the hospital stay. Mothers and fathers were interviewed when their children were 18 months old about the child's problems and filled in a perinatal post-traumatic stress disorder questionnaire (PPQ). RESULTS: The severity of the perinatal risks only partly predicts a child's problems. Independently of the perinatal risks, the intensity of the post-traumatic reactions of the parents is an important predictor of these problems. CONCLUSIONS: These findings suggest that the parental response to premature birth mediates the risks of later adverse outcomes. Preventive intervention should be promoted.

[Heart assist systems with integrated microsensors (HIM 2)]. / Herzunterstützungssystem mit Integrierter Mikrosensorik (HIM 2).

The use of intracardiac pump systems is leading to more physiological support for coronary surgery patients. But the currently available micro blood pump with an integrated micro pressure sensor and an outer diameter of 6.5 mm is not suitable for a transfemoral placement of the device. Therefore a significantly smaller pump with an outer diameter of 4 mm (12F) is been developed and tested. To transfer the sensor technology in this, for the first time the MID (moulded interconnected device) technology is applied in a medical device. In a first step MID is used to integrate a smaller pressure sensor on the existing blood pump. The result should help to find a new packaging and connecting solution for integration of the miniaturized sensor on the 4 mm pump.

From a lab type to a product: a retrospective view on Impella's assist technology.

A lab type is best described by its value as a result of its handcrafted uniqueness in small numbers. Logically, there is not one lab type like another, and the fact that it has been realized does not mean that this special effort can be easily reproduced. Furthermore, most lab types have undergone stand alone test runs revealing fingerprints rather than universal results at a 20% effort to 80% effect ratio. A product development, on the other hand, is best described by an 80% effort to 20% effect ratio in terms of measurable results. Products are producible and cost effective goods which are well documented and have undergone numerous test runs and test procedures assuring safety and quality, a basic requirement for market approval and cost effective marking. Based on the intravascular pump technology, comprising a sensorized axial flow pump with an integrated micromotor, the iterative dependence of the product development on lab types is demonstrated showing in particular the importance of having highly developed lab types before initiating the product development. By example, we demonstrated that high product quality has a greater impact on the reduction of blood damage than numerous redesigns. Reengineering issues are addressed, which are part of the product development process. Furthermore, the previously mentioned technology serves as a platform leading directly from the perioperative biventricular system to a 7 day pump as well as a miniaturized 12 Fr version.

A novel implantable electromechanical ventricular assist device. First acute animal testing.

A novel ventricular assist device (HIA-EMLVAD-AT1, Helmholtz Institute Aachen-Electromechanical Left Ventricular Assist Device-Animal Test Version 1), driven by a uniformly and unidirectionally rotating actuator and a patented hypocycloidic pusherplate displacement gear unit, was developed and tested in an acute animal experiment. The excellent free filling behavior of the pump chamber with a stroke volume of 65 ml is obtained by a 2:3 ejection-filling time relationship. The uniform motor rotation facilitates simple sensorless pre and afterload detection by motor current analysis. In contrast to common apical cannulation, the inlet cannula was placed via the left atrium through the mitral valve into the left ventricle. This connection mode is preferable for left ventricular recovery and preservation. Left atrial, left ventricular, and aortic pressure curves, as well as pulmonary artery flow data, were obtained. The data show very effective unloading of the natural ventricle and demonstrate the feasibility of this novel assist device. Directions for further improvement of technical features were also identified.

The implantable fuzzy controlled Helmholtz-left ventricular assist device: first in vitro testing.

To perform first experimental tests for validation of a new left ventricular assist device (LVAD) with a high efficiency energy converter, a new pump design and a novel type of perfusion control, a functional labtype, were manufactured. With a stroke volume of 65 ml, a total pump housing volume of 450 ml (including valves and connectors), and a weight of 430 g, it is one of the smallest and lightest implantable pulsatile electromechanical LVADs. Pulsatile operation is generated by a special reduction and displacement gear which transforms a uniform rotational movement of a sensorless, electronically commutated DC motor into a translatory pusher plate movement. A prolonged duration for filling (60% of the cycle time) supports full-empty pumping and consequently a high overall pump efficiency. Active adaptation of output flow to organ perfusion demand is achieved by changing the rotational speed of the motor by means of a sensorless fuzzy controller, which detects preload and afterload induced effects at the motor current input. First in vitro test results obtained within a circulatory mock loop that simulates physiological preloads and afterloads are presented. They comprise preload sensitivity and the function of the novel perfusion controller as well as preload and afterload related flow data. The results prove the feasability of the energy conversion with the novel gear and control concept for an implantable electromechanical pulsatile LVAD.

Development of content: influences on girls' junior high school volleyball success in practice and achievement.

The purpose of this study was to examine the success of practice by lower- and higher-skilled girls in Grades 7 and 8 in response to different tasks (extension, refinement, and application) throughout an 11-day instructional and practice period for volleyball. More highly skilled girls were more successful than those lower in skill for all skills (forearm pass, set, serve) and tasks. Girls had nearly equal success in practice for different tasks.

Fuzzy control concept for a total artificial heart.

The development of an electromechanically driven total artificial heart (Helmholtz-TAH) was initiated in 1990. Anatomical fitting, biocompatibility, and automatic physiologic adaptation of pump output are the basic requirements that characterize the overall TAH concept. For evaluation of these features, a TAH labtype was developed. It provides most features of the conceptual artificial heart and supports in vitro testing of energy conversion, pump behavior, structural parts, sensors, and control concepts. A fuzzy controller has been implemented for adaptation of the pump rate to body perfusion demand by left pump chamber filling detection. This controller will be an important element of a future extensive TAH control system. The implementation is supported by a professional fuzzy control development tool that allows on-line and real time optimization of control strategies for dynamic processes. The first experiments proved the feasibility and the advantages of this fuzzy control concept. The first in vitro test results are presented.

Isolation of insecticide resistance-related forms of cytochrome P-450 from Drosophila melanogaster.

Significant purification of the ubiquitous cytochrome P-450-A and the strain-specific P-450-B from Drosophila melanogaster has been achieved by sequential chromatography on octylamino-agarose, DEAE-cellulose and hydroxyapatite. Preparations of P-450-A (specific contents of 7-9 nmol/mg) were homogeneous as determined by SDS/polyacrylamide-gel electrophoresis (PAGE) analysis. Preparations enriched for P-450-B (specific contents of 4-7 nmol/mg) contained significant amounts of P-450-A but were essentially free of other proteins as judged by SDS/PAGE. Partial reconstitution of 7-ethoxycoumarin de-ethylase activity was achieved using rabbit NADPH: cytochrome P450 reductase and purified preparations containing P450-B.

Relations between preventive health behavior and hardiness.

To estimate the relationship between hardiness and preventive health behaviors a hardiness scale and a health hazard appraisal were administered to 211 college students. Multiple regression analysis indicated that modest amounts of variance on the hardiness measures were explained by the components of the health-hazard appraisals. Indications are that the concepts of hardiness and preventive health behavior are related and need further clarification.

Natural variation in the expression of cytochrome P-450 and dimethylnitrosamine demethylase in Drosophila.

Electrophoresis of Drosophila microsomes resolves two major heme-containing protein bands with apparent molecular weights of 59,290 (band a) and 55,750 (band b). The hemoproteins in these two bands can account for most of the cytochrome P-450 in the organism. Band a is present in all strains examined: band b is not. Dimethylnitrosamine demethylase, a P-450 enzyme, is a component of band b.