Early detection of subclinical organ dysfunction by microdialysis of the rectus abdominis muscle in a porcine model of critical intra-abdominal hypertension

The aim of this study was to evaluate microdialysis of the rectus abdominis muscle (RAM) for early detection of subclinical organ dysfunction in a porcine model of critical intra-abdominal hypertension (IAH). Microdialysis catheters for analyses of lactate, pyruvate, and glycerol levels were placed in cervical muscles (control), gastric and jejunal wall, liver, kidney, and RAM of 30 anesthetized mechanically ventilated pigs. Catheters for venous lactate and interleukin 6 samples were placed in the jugular, portal, and femoral vein. Intra-abdominal pressure (IAP) was increased to 20 mmHg (IAH20 group, n = 10) and 30 mmHg (IAH30, n = 10) for 6 h by controlled CO2 insufflation, whereas sham animals (n = 10) exhibited a physiological IAP. In contrast to 20 mmHg, an IAH of 30 mmHg induced pathophysiological alterations consistent with an abdominal compartment syndrome. Microdialysis showed significant increase in the lactate/pyruvate ratio in the RAM of the IAH20 group after 6 h. In the IAH30 group, the strongest increase in lactate/pyruvate ratio was detected in the RAM and less pronounced in the liver and gastric wall. Glycerol increased in the RAM only. After 6 h, there was a significant increase in venous interleukin 6 of the IAH30 group compared with baseline. Venous lactate was increased compared with baseline and shams in the femoral vein of the IAH30 group only. Intra-abdominal pressure-induced ischemic metabolic changes are detected more rapidly and pronounced by microdialysis of the RAM when compared with intra-abdominal organs. Thus, the RAM represents an important and easily accessible site for the early detection of subclinical organ dysfunction during critical IAH.

Intra-Arterial MSC Transplantation Restores Functional Capacity After Skeletal Muscle Trauma

Skeletal muscle trauma leads to severe functional deficits, which cannot be addressed by current treatment options. Our group could show the efficacy of local transplantation of mesenchymal stroma cells (MSCs) for the treatment of injured muscles. While local application of MSCs has proven to be effective, we hypothesized that a selective intra-arterial transplantation would lead to a better distribution of the cells and so improved physiological recovery of muscle function.

Intra-articular calcium phosphate cement: Its fate and impact on joint tissues in a rabbit model

Clinical application of injectable ceramic cement in comminuted fractures revealed penetration of the viscous paste into the joint space. Not much is known on the fate of this cement and its influence on articular tissues. The purpose of this experimental study was to assess these unknown alterations of joint tissues after intra-articular injection of cement in a rabbit knee. Observation periods were from 1 week up to 24 months, with three rabbits per group. Norian SRS cement was injected into one knee joint, the contralateral side receiving the same volume of Ringers' solution. Light microscopic evaluation of histologic sections was performed, investigating the appearance of the cement, inflammatory reactions, and degenerative changes of the articular surface. No signs of pronounced acute or chronic inflammation were visible. The injected cement was mainly found as a single particle, anterior to the cruciate ligaments. It became surrounded by synovial tissues within 4 weeks and showed signs of superficial resorption. In some specimens, bone formation was seen around the cement. Degeneration of the articular surface showed no differences between experimental and control side, and no changes over time became apparent. No major degenerative changes were induced by the injected cement. The prolonged presence of cement still seems to make it advisable to remove radiologically visible amounts from the joint space.

Long-term effect of intra-arterial thrombolysis in stroke

BACKGROUND AND PURPOSE: Thrombolysis has been shown to improve the 3-month outcome of patients with ischemic stroke, but knowledge of the long-term effect of thrombolysis is limited. METHODS: The present study compares the long-term outcome of stroke patients who were treated with intra-arterial thrombolysis (IAT) using urokinase with the outcome of patients treated with aspirin. The modified Rankin Scale (mRS) was used to assess the outcome; 173 patients treated with IAT and 261 patients treated with aspirin from the Bernese Stroke Data Bank were eligible for the study. A matching algorithm taking into account patient age and stroke severity on admission (as measured by the National Institute of Health Stroke Scale [NIHSS]) was used to assemble an IAT and an aspirin group. RESULTS: One hundred and forty-four patients treated with IAT and 147 patients treated with aspirin could be matched and included in the comparative analysis. The median NIHSS score was 14 in each group. At 2 years, 56% of the patients treated with IAT and 42% of the patients treated with aspirin achieved functional independence (mRS, 0 to 2; P=0.037). Clinical outcome was excellent (mRS, 0 to 1) in 40% of the IAT and in 24% of the aspirin patients (P=0.008). Mortality was 23% and 24%, respectively. CONCLUSIONS: The present study provides evidence for a sustained effect of IAT when assessed 2 years after the stroke.

Intra-subject variability in attention-deficit hyperactivity disorder

BACKGROUND: This study is based on a comprehensive survey of the neuropsychological attention-deficit hyperactivity disorder (ADHD) literature and presents the first psychometric analyses of different parameters of intra-subject variability (ISV) in patients with ADHD compared to healthy controls, using the Continuous Performance Test, a Go-NoGo task, a Stop Signal Task, as well as N-back tasks. METHODS: Data of 57 patients with ADHD and 53 age- and gender-matched controls were available for statistical analysis. Different parameters were used to describe central tendency (arithmetic mean, median), dispersion (standard deviation, coefficient of variation, consecutive variance), and shape (skewness, excess) of reaction time distributions, as well as errors (commissions and omissions). RESULTS: Group comparisons revealed by far the strongest effect sizes for measures of dispersion, followed by measures of central tendency, and by commission errors. Statistical control of ISV reduced group differences in the other measures substantially. One (patients) or two (controls) principal components explained up to 67% of the inter-individual differences in intra-individual variability. CONCLUSIONS: Results suggest that, across a variety of neuropsychological tests, measures of ISV contribute best to group discrimination, with limited incremental validity of measures of central tendency and errors. Furthermore, increased ISV might be a unitary construct in ADHD.

Assessing the intra- and inter-reader reliability of dynamic ultrasound images in power Doppler ultrasonography

OBJECTIVE: To assess the intra-reader and inter-reader reliabilities of interpreting ultrasonography by several experts using video clips. METHOD: 99 video clips of healthy and rheumatic joints were recorded and delivered to 17 physician sonographers in two rounds. The intra-reader and inter-reader reliabilities of interpreting the ultrasound results were calculated using a dichotomous system (normal/abnormal) and a graded semiquantitative scoring system. RESULTS: The video reading method worked well. 70% of the readers could classify at least 70% of the cases correctly as normal or abnormal. The distribution of readers answering correctly was wide. The most difficult joints to assess were the elbow, wrist, metacarpophalangeal (MCP) and knee joints. The intra-reader and inter-reader agreements on interpreting dynamic ultrasound images as normal or abnormal, as well as detecting and scoring a Doppler signal were moderate to good (kappa = 0.52-0.82). CONCLUSIONS: Dynamic image assessment (video clips) can be used as an alternative method in ultrasonography reliability studies. The intra-reader and inter-reader reliabilities of ultrasonography in dynamic image reading are acceptable, but more definitions and training are needed to improve sonographic reproducibility.

Symptomatic intracranial haemorrhage after intra-arterial thrombolysis in acute ischaemic stroke: assessment of 294 patients treated with urokinase

BACKGROUND: The PROACT II trial showed that intra-arterial thrombolysis (IAT) is effective for treatment of acute ischaemic stroke attributable to M1 and M2 segment occlusions. Incidence of symptomatic intracranial haemorrhage (sICH) was 10%. OBJECTIVE: To evaluate the risk and predictors of sICH after IAT by using urokinase in a large number of patients presenting with the whole spectrum of cerebral vessel occlusions. METHODS: 294 patients with stroke treated with intra-arterial urokinase were retrospectively analysed. The risk of sICH as well as bleeding characteristics were assessed. Demographic and radiological data, time to treatment, urokinase dose, recanalisation rates, stroke aetiology and severity were analysed for predictors. RESULTS: sICH occurred in 14 of 294 (4.8%) patients. The median National Institute of Health Stroke Scale score of all patients was 15. All but one sICH were located in the infarcted brain tissue, and no sICH occurred in patients with peripheral vessel occlusions (M3 or M4 segments of the middle cerebral artery). Poor collaterals (p = 0.001), early signs of ischaemia on computed tomography (p = 0.003), higher urokinase dose (p = 0.019), lower recanalisation rate (p = 0.02) and higher diastolic blood pressure on admission (p = 0.04) were found to be correlated with sICH on univariate analysis. On multivariate analysis, poor collaterals (p = 0.004), urokinase dose (p = 0.021) and early signs on computed tomography (p = 0.026) remained predictors of sICH. CONCLUSIONS: With regard to the whole spectrum of cerebral vessel occlusions, an incidence of <5% sICH after IAT is distinctly low. This result underlines the important role of IAT in the treatment of acute stroke.

Recanalization and outcome after intra-arterial thrombolysis in middle cerebral artery and internal carotid artery occlusion: does sex matter?

BACKGROUND AND PURPOSE: Recent studies have reported sex differences in recanalization and outcome after intravenous thrombolysis (IVT) in acute ischemic stroke. METHODS: We analyzed sex differences in outcome in consecutive patients with middle cerebral artery (MCA) M1 or M2 and internal carotid artery (ICA) occlusion treated with intra-arterial thrombolysis (IAT). Recanalization immediately after thrombolysis and outcome after 3 months were assessed. RESULTS: Two hundred five patients (111 men) with MCA and 43 (22 men) with ICA occlusion were identified. Baseline variables did not differ between the sexes except for a higher prevalence of smokers among men in the MCA group (31% vs 12%; P=0.001). Partial or complete recanalization (TIMI flow 2 or 3) of the MCA was observed in 71 (75%) women and 80 (72%) men (P=0.488). In the ICA group, 14 (67%) women and 11 men (50%) showed TIMI 2 or 3 recanalization (P=0.425). Favorable outcome (modified Rankin Scale score 0 to 2) was seen in 57 women (61%) and 63 men (57%) with MCA occlusion (P=0.512) and in 6 women (28%) and 4 men (18%) with ICA occlusion (P=0.656). After multiple-regression analyses, there was still no association between sex and outcome (P=0.763 for MCA and P=0.813 for ICA occlusion) or recanalization (P=0.488 for MCA and P=0.104 for ICA occlusion). CONCLUSIONS: There was no association between sex and recanalization or outcome after IAT. These findings are in contrast to previous studies reporting better recanalization and outcome after IVT in women and might have implications in the selection of patients for IAT or IVT.

Effects of continuous remifentanil administration on intra-operative subcutaneous tissue oxygen tension

Surgical stress response markedly increases sympathetic nerve activity and catecholamine concentrations. This may contribute to peripheral vasoconstriction, reduced wound perfusion and subsequent tissue hypoxia. Opioids are known to depress the hypothalamic-adrenal response to surgery in a dose-dependent manner. We tested the hypothesis that continuous remifentanil administration produces improved subcutaneous tissue oxygen tension compared to fentanyl bolus administration. Forty-six patients undergoing major abdominal surgery were randomly assigned to receive either fentanyl bolus administration or continuous remifentanil infusion. Mean subcutaneous tissue oxygen values over the entire intra-operative period were significantly higher in the remifentanil group, when compared to the fentanyl group: 8 (2) kPa vs 6.7 (1.5) kPa, % CI difference: - 2.3 kPa to - 0.3 kPa, p = 0.013. Continuous intra-operative opioid administration may blunt vasoconstriction caused by surgical stress and adrenergic responses more than an equi-effective anaesthetic regimen based on smaller-dose bolus opioid administration.

Limited open reduction and internal fixation of displaced intra-articular fractures of the calcaneum

The extended lateral L-shaped approach for the treatment of displaced intra-articular fractures of the calcaneum may be complicated by wound infection, haematoma, dehiscence and injury to the sural nerve. In an effort to reduce the risk of problems with wound healing a technique was developed that combined open reduction and fixation of the joint fragments and of the anterior process with percutaneous reduction and screw fixation of the tuberosity. A group of 24 patients with unilateral isolated closed Sanders type II and III fractures was treated using this technique and compared to a similar group of 26 patients managed by the extended approach and lateral plating. The operation was significantly shorter (p < 0.001) in the first group, but more minor secondary procedures and removal of heel screws were necessary. There were no wound complications in this group, whereas four minor complications occurred in the second group. The accuracy and maintenance of reduction, and ultimate function were equivalent.

[Neuromonitoring and neuroprotection in cardiac anaesthesia. Nationwide survey conducted by the Cardiac Anaesthesia Working Group of the German Society of Anaesthesiology and Intensive Care Medicine]

OBJECTIVE: The primary objective of this nationwide survey carried out in department of cardiac anesthesia in Germany was to identify current practice with regard to neuromonitoring und neuroprotection. METHODOLOGY: The data are based on a questionnaire sent out to all departments of cardiac anesthesia in Germany between October 2007 und January 2008. The anonymized questionnaire contained 26 questions about the practice of preoperative evaluation of cerebral vessels, intra-operative use of neuromonitoring, the nature und application of cerebral protective measures, perfusion management during cardiopulmonary bypass, postoperative evaluation of neurological status, and training in the field of cerebral monitoring. RESULTS: Of the 80 mailed questionnaires 55% were returned and 90% of department evaluated cerebral vessels preoperatively with duplex ultrasound. The methods used for intra-operative neuromonitoring are electroencephalography (EEG, 60%) for type A dissections (38.1%), for elective surgery on the thoracic and thoraco-abdominal aorta (34.1% and 31.6%, respectively) and in carotid surgery (43.2%) near infrared spectroscopy (40%), evoked potentials (30%) and transcranial Doppler sonography (17.5%), with some centers using combined methods. In most departments the central nervous system is not subjected to monitoring during bypass surgery, heart valve surgery, or minimally invasive surgery. Cerebral protective measures used comprise patient cooling on cardio-pulmonary bypass (CPB 100%), extracorporeal cooling of the head (65%) and the administration of corticosteroids (58%), barbiturates (50%) and antiepileptic drugs (10%). Neuroprotective anesthesia consists of administering inhalation anesthetics (32.5%; sevoflurane 76.5%) and intravenous anesthesia (20%; propofol and barbiturates each accounting for 46.2%). Of the departments 72.5% cool patients as a standard procedure for surgery involving cardiovascular arrest and 37.5% during all surgery using CPB. In 84.6% of department CPB flow equals calculated cardiac output (CO) under normothermia, while the desired mean arterial pressure (MAP) varies between 60 and 70 mmHg (43.9%) and between 50 and 60 mmHg (41.5%), respectively. At body temperatures less than 18 degrees C CPB flow is reduced below the calculated CO (70%) while 27% of departments use normothermic flow rates. The preferred MAP under hypothermia is between 50 and 60 mmHg (59%). The results of intra-operative neuromonitoring are documented on the anesthesia record (77%). In 42.5% of the departments postoperative neurological function is estimated by the anesthesiologist. Continuing education sessions pertaining to neuromonitoring are organized on a regular basis in 32.5% of the departments and in 37.5% individual physicians are responsible for their own neuromonitoring education. CONCLUSION: The present survey data indicate that neuromonitoring and neuroprotective therapy during CPB is not standardized in cardiac anesthesiology departments in Germany. The systemic use of available methods to implement multimodal neuromonitoring would be desirable.

Attributions of Responsibility for Terrorist Attacks: The Role of Group Membership and Identification

Three studies examine how people’s attributions of responsibility for terrorist attacks depend on their group membership and their identification with the victim (study 1) or their identification with the victim’s or perpetrator’s ingroup (studies 2 and 3). We observe that people’s group membership (perpetrator group versus victim group) determines the judgments of responsibility for recent terrorist attacks. Members of the perpetrator group hold the direct perpetrators responsible, while members of the victim group perceive the perpetrator world as a whole as relatively responsible as well. Identification with the victim (study 1) or victim group (studies 2 and 3) strengthens attributions of responsibility to the whole perpetrator group, and this relationship is partially mediated by the perceived typicality of the perpetrator for the whole group. We discuss possible explanations for this pattern, and indicate the implications of these results in terms of improving intergroup relations.

Target difficulty, intra-year target revisions and firm performance: evidence from business units' targets

Target difficulty is often argued to increase performance. While this association is well established in experimental research, empirical evidence in field research is rather mixed. We attempt to explain this inconsistency by analyzing the importance of intra-year target revisions, which are especially prevalent in real-world field settings. Using survey and archival data from 97 firms, we find that firms with more challenging business unit targets revise targets more often, in line with asymmetric, downward target revisions. Results further show that the degree to which targets are revised during a period results in negative effects on firm performance, as the anticipation of revision negatively affects the business unit management’s performance incentives. Additionally, we find that using targets predominantly for either decision-making or control influences the overall performance effects of target revisions. Our findings may partially explain the mixed field study evidence regarding the effects of target difficulty.

Relaxation in hypertrophic cardiomyopathy and hypertensive heart disease: relations between hypertrophy and diastolic function

AIM To determine the relation between the extent and distribution of left ventricular hypertrophy and the degree of disturbance of regional relaxation and global left ventricular filling. METHODS Regional wall thickness (rWT) was measured in eight myocardial regions in 17 patients with hypertrophic cardiomyopathy, 12 patients with hypertensive heart disease, and 10 age matched normal subjects, and an asymmetry index calculated. Regional relaxation was assessed in these eight regions using regional isovolumetric relaxation time (rIVRT) and early to late peak filling velocity ratio (rE/A) derived from Doppler tissue imaging. Asynchrony of rIVRT was calculated. Doppler left ventricular filling indices were assessed using the isovolumetric relaxation time, the deceleration time of early diastolic filling (E-DT), and the E/A ratio. RESULTS There was a correlation between rWT and both rIVRT and rE/A in the two types of heart disease (hypertrophic cardiomyopathy: r = 0.47, p < 0.0001 for rIVRT; r = -0.20, p < 0.05 for rE/A; hypertensive heart disease: r = 0.21, p < 0.05 for rIVRT; r = -0.30, p = 0.003 for rE/A). The degree of left ventricular asymmetry was related to prolonged E-DT (r = 0. 50, p = 0.001) and increased asynchrony (r = 0.42, p = 0.002) in all patients combined, but not within individual groups. Asynchrony itself was associated with decreased E/A (r = -0.39, p = 0.01) and protracted E-DT (r = 0.69, p < 0.0001) and isovolumetric relaxation time (r = 0.51, p = 0.001) in all patients. These correlations were still significant for E-DT in hypertrophic cardiomyopathy (r = 0.56, p = 0.02) and hypertensive heart disease (r = 0.59, p < 0.05) and for isovolumetric relaxation time in non-obstructive hypertrophic cardiomyopathy (n = 8, r = 0.87, p = 0.005). CONCLUSIONS Non-invasive ultrasonographic examination of the left ventricle shows that in both hypertrophic cardiomyopathy and hypertensive heart disease, the local extent of left ventricular hypertrophy is associated with regional left ventricular relaxation abnormalities. Asymmetrical distribution of left ventricular hypertrophy is indirectly related to global left ventricular early filling abnormalities through regional asynchrony of left ventricular relaxation.

Illegitimate tasks associated with higher cortisol levels among male employees when subjective health is relatively low: an intra-individual analysis

Objectives Illegitimate tasks refer to tasks that do not conform to what can appropriately be expected from an employee. Violating role expectations, they constitute “identity-stressors”, as one’s professional role tends to become part of one’s identity. The current study investigated the impact of illegitimate tasks on salivary cortisol. We analyzed data on an intra-individual level, that is, by examining fluctuations in illegitimate tasks and cortisol within individuals. Furthermore, we investigated the moderating role of perceived health, expecting that illegitimate tasks evoke stronger reactions when perceived health is relatively poor. Methods Illegitimate tasks, salivary cortisol, and perceived health were assessed in each of three waves (time lag: 6 months) in a sample of 104 male employees. Data were analyzed by multilevel analysis using group mean centering. Results Controlling for social stressors, work interruptions, and emotional stability, the experience of more illegitimate tasks was associated with increased cortisol release if personal health resources were low compared to one’s mean value of perceived health. Results cannot be explained by inter-individual differences. Conclusions This is the first study showing that illegitimate tasks predict a biological indicator of stress, thus confirming and extending previous research on illegitimate tasks. The moderating role of perceived health confirms its importance as a personal resource, implying augmented vulnerability when perceived health is below its usual value. It is plausible to assume that increased stress reactions due to relatively poor health may further weaken available personal resources. Both avoiding illegitimate tasks and restoring personal health seem to be crucial.