Accidental falls involving medical implant re-operation

Implantation of medical devices is becoming more prevalent, and as a result, a greater number of patients who fall accidentally are expected to have a medical implant. The Nationwide Inpatient Sample (NIS) was used to evaluate hospital admissions following accidental falls involving re-operation of existing medical implants (hip, knee, spine, and fracture fixation) from 1990 to 2005. From 1990 to 2005, hospitalisations due to accidental falls on level surfaces increased by 306%, and hospitalisations due to falls from stairs increased by 310%. Falls involving orthopaedic revision surgery (re-operation) are relatively rare, but the incidence has increased by approximately 35%. Hospital stays after falls on level surfaces involving re-operation were 1.0 day (median) longer and cost 50% (median) more than those that did not involve re-operation in 2005. After staircase falls, hospital stays for patients undergoing re-operations were 2.0 days (median) longer and cost 108% (median) more. The greater hospital costs and hospital stay for patients needing re-operations indicate that additional medical treatment was required.     

The neural correlates of deficient error awareness in attention-deficit hyperactivity disorder (ADHD)

The ability to detect and correct errors is critical to adaptive control of behaviour and represents a discrete neuropsychological function. A number of studies have highlighted that attention-deficit hyperactivity disorder (ADHD) is associated with abnormalities in behavioural and neural responsiveness to performance errors. One limitation of previous work has been a failure to determine the extent to which these differences are attributable to failures of conscious error awareness, a process that is dependent on the integrity of the frontal lobes. Recent advances in electrophysiological research make it possible to distinguish unconscious and conscious aspects of error processing. This study constitutes an extensive electrophysiological investigation of error awareness and error processing in ADHD. A Go/No-Go response inhibition task specifically designed to assess error awareness was administered to a group of adults diagnosed with ADHD and a group of matched control participants. The ADHD group made significantly more errors than the control group but was less likely to consciously detect these errors. An analysis of event-related potentials elicited by errors indicated that an early performance monitoring component (early positivity) was significantly attenuated in the ADHD group as was a later component that specifically reflects conscious error processing (Pe). Dipole source modelling suggested that abnormal Pe amplitudes were attributable to decreased activation of the anterior cingulate cortex. Decreased electrodermal activity in the ADHD group also suggested a motivational insensitivity to performance errors. Our data provide evidence that neuropsychological deficits associated with ADHD can be exacerbated by error processing abnormalities. Error awareness may represent an important cognitive and physiological phenotype for ADHD.     

Late measures of microstructural alterations in severe neonatal hypoxic–ischemic encephalopathy by MR diffusion tensor imaging

Neonatal hypoxic–ischemic encephalopathy is a major cause of brain damage in infants, and is associated with periventricular white matter injury and chronic neurological dysfunctions. However, the mechanisms of the chronic white matter injury and reorganization are still unclear. In this study, in vivo diffusion tensor imaging (DTI) was employed to evaluate the late changes of white matter microstructural integrity in the rat brains at 10 weeks after severe neonatal hypoxic–ischemic insults at postnatal day 7. In the fractional anisotropy directionality map, qualitative evaluation showed that a dorsoventrally oriented fiber bundle extended from the corpus callosum into the cyst in the anterior brain, whilst the posterior peri-infarct areas had similar fiber orientations as the contralateral internal capsule, optic tract and fimbria of hippocampus. Compared to the contralateral hemisphere, significantly higher fractional anisotropy, axial diffusivity and diffusion trace value were observed quantitatively in the distal end of the extended fiber bundle connecting the anterior and posterior white matters rostrocaudally. A significantly lower fractional anisotropy but higher axial and radial diffusivities and trace were also found in the ipsilateral corpus callosum, proximal external capsule and anterior commissure, while slightly lower fractional anisotropy and axial diffusivity were noticed in the ipsilateral internal capsule and optic nerve. It was suggested that increased fractional anisotropy, axial diffusivity and trace characterize white matter reorganization in chronic neonatal hypoxic–ischemic insults, whereas reduction in fractional anisotropy appears to characterize two types of white matter lesions, with significantly higher axial and radial diffusivities and trace being primary and slightly lower axial diffusivity being secondary. Combined with fractional anisotropy directionality map, in vivo DTI provides important indices to differentiate the chronic effects of severe neonatal hypoxic–ischemic injury and recovery globally, quantitatively and non-invasively.     

Blood transfusion practices in military medicine

Background: This observational study was conducted in a small, 45 bed border static hospital, located in a field area, where no blood bank facilities were available. The present study was conducted to elucidate the blood transfusion practices of this hospital.     

Reference values of diffusing capacity of non-smoking Chinese in Hong Kong

BACKGROUND AND OBJECTIVE: This study was conducted to define normal reference values and lower limits of normal (LLN) for single-breath carbon monoxide diffusing capacity (DLco) and DLco per unit of alveolar volume (Kco) for Chinese adults in Hong Kong. METHODS: Healthy non-smoking men and women aged 18-80 years were recruited by random digit dialing. DLco and Kco were measured according to American Thoracic Society standards. Reference equations were obtained by multiple linear regression; LLN were derived by distribution-free method for estimation of age-related centiles. RESULTS: Tests from 568 subjects (259 men, 309 women) were analysed. DLco declined with age in both genders, and increased with height and the interaction term of height and age in men and women, respectively. Considering Hb values did not improve the reference equations. Kco declined with age and increased with weight in both genders, while height and its interaction term with age were additional determinants in women. The reference DLco was lower than some Caucasian values, and was only explained partially by a smaller body size and alveolar volume in Chinese. The distribution-free method yielded better overall approximation to the fifth percentile compared with the traditional method of determining LLN. CONCLUSIONS: The equations for reference values and LLN of diffusing capacity derived in this study are of clinical relevance to Chinese subjects.