Evaluation of comprehensiveness and reliability of electronic health records concerning resuscitation efforts within academic intensive care units: a retrospective chart analysis.

BACKGROUND: According to the literature, the validity and reliability of medical documentation concerning episodes of cardiopulmonary resuscitation (CPR) is suboptimal. However, little is known about documentation quality of CPR efforts during intensive care unit (ICU) stays in electronic patient data management systems (PDMS). This study analyses the reliability of CPR-related medical documentation within the ICU PDMS. METHODS: In a retrospective chart analysis, PDMS records of three ICUs of a single university hospital were searched over 5 y for CPR check marks. Respective datasets were analyzed concerning data completeness and data consistency by comparing the content of three documentation forms (physicians' log, nurses' log, and CPR incident form), as well as physiological and therapeutic information of individual cases, for missing data and plausibility of CPR starting time and duration. To compare data reliability and completeness, a quantitative measure, the Consentaneity Index (CI), is proposed. RESULTS: One hundred sixty-five datasets were included into the study. In 9% (n = 15) of cases, there was neither information on the time points of CPR initiation nor on CPR duration available in any data source. Data on CPR starting time and duration were available from at least two data sources in individual cases in 54% (n = 90) and 45% (n = 74), respectively. In these cases, the specifications of CPR starting time did differ by a median ± interquartile range of 10.0 ± 18.5 min, CPR duration by 5.0 ± 17.3 min. The CI as a marker of data reliability revealed a low consistency of CPR documentation in most cases, with more favorable results, if the time interval between the CPR episode and the time of documentation was short. CONCLUSIONS: This study reveals relevant proportions of missing and inconsistent data in electronic CPR documentation in the ICU setting. The CI is suggested as a tool for documentation quality analysis and monitoring of improvements.

[The disaster task force medical officer as a pivotal decision maker in the superordinate pandemic hospital capacity management : A field report covering the initial COVID-19 surge in a Bavarian district]. / Der Ärztliche Leiter Führungsgruppe Katastrophenschutz als zentrale Entscheidungsinstanz bei der Steuerung regionaler Krankenhauskapazitäten in der Pandemie : Ein Erfahrungsbericht zur ersten Welle der COVID-19-Pandemie in einem bayerischen Regierungsbezirk.

BACKGROUND AND OBJECTIVE: During the initial phase of the COVID-19 pandemic the government of the state of Bavaria, Germany, declared a state of emergency for its entire territory for the first time in history. Some areas in eastern Bavaria were among the most severely affected communities in Germany, prompting authorities and hospitals to build up capacities for a surge of COVID-19 patients. In some areas, intensive care unit (ICU) capacities were heavily engaged, which occasionally made a redistribution of patients necessary. MATERIAL AND METHODS: For managing COVID-19-related hospital capacities and patient allocation, crisis management squads in Bavaria were expanded by disaster task force medical officers ("Ärztlicher Leiter Führungsgruppe Katastrophenschutz" [MO]) with substantial executive authority. The authors report their experiences as MO concerning the superordinate patient allocation management in the district of Upper Palatinate (Oberpfalz) in eastern Bavaria. RESULTS: By abandoning routine patient care and building up additional ICU resources, surge capacity for the treatment of COVID-19 patients was generated in hospitals. In parts of the Oberpfalz, ICU capacities were almost entirely occupied by patients with corona virus infections, making reallocation to other hospitals within the district and beyond necessary. The MO managed patient pathways in an escalating manner by defining local (within the region of responsibility of a single MO), regional (within the district), and cross-regional (over district borders) reallocation lanes, as needed. When regional or cross-regional reallocation lanes had to be established, an additional management level located at the district government was involved. Within the determined reallocation lanes, emitting and receiving hospitals mutually agreed on any patient transfer without explicitly involving the MO, thereby maintaining the established interhospital routine transfer procedures. The number of patients and available treatment resources at each hospital were monitored with the help of a web-based treatment capacity registry. If indicated, reallocation lanes were dynamically revised according to the present situation. To oppose further virus spreading in nursing homes, the state government prohibited patient allocation to these facilities, which led to considerably longer hospital length of stay of convalescent elderly and/or dependent patients. In parallel to the flattening of the COVID-19 incidence curve, routine hospital patient care could be re-established in a stepwise manner. CONCLUSION: Patient allocation during the state of emergency by the MO sought to keep up routine interhospital reallocation procedures as much as possible, thereby reducing management time and effort. Occasionally, difficulties were observed during patient allocations crossing district borders, if other MO followed different management principles. The nursing home blockade and conflicting financial interests of hospitals posed challenges to the work of the disaster task force medical officers.

[Management of COVID-19 mass casualty incidents in nursing and retirement homes]. / Managementstrategie für den Massenanfall von Erkrankten/Infizierten in Alten- und Pflegeheimen im Kontext der COVID-19-Pandemie.

BACKGROUND: During the coronavirus disease 2019 (COVID-19) pandemic, outbreaks in inpatient care facilities, which grow into a large-scale emergency scenario, are frequently observed. A standardized procedure analogous to algorithms for mass casualty incidents (MCI) is lacking. METHODS: Based on a case report and the literature, the authors present a management strategy for infectious MCI during the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic and distinguish it from traumatic MCI deployment tactics. RESULTS: This management strategy can be divided into three phases, beginning with the acute emergency response including triage, stabilization of critical patients, and transport of patients requiring hospitalization. Phase 2 involves securing the facility's operational readiness, or housing residents elsewhere in case staff are infected or quarantined to a relevant degree. Phase 3 marks the return to regular operations. DISCUSSION: Phase 1 is based on usual MCI principles, phase 2 on hospital crisis management. Avoiding evacuation of residents to relieve hospitals is an important operational objective. The lack of mission and training experience with such situations, the limited applicability of established triage algorithms, and the need to coordinate a large number of participants pose challenges. CONCLUSION: This strategic model offers a practical, holistic approach to the management of infectious mass casualty scenarios in nursing facilities.

Detection of free radicals by isolated perfusion of the rat brain following hemorrhagic stroke: a novel approach to cerebrovascular biomarker research.

Blood-borne biomarkers are a mainstay of diagnosis and follow-up in many diseases. For stroke, however, no reliable biomarkers have thus far been identified. To remedy this situation, we investigated the usefulness of a modified in situ isolated brain perfusion (IBP) technique for screening potential biomarker candidates. As a proof of concept, the production of reactive oxygen species (ROS) was estimated in a rat model of experimental intracerebral hemorrhage (ICH). After stereotactic infusion of whole blood into the rat striatum, we initiated IBP without intracranial manipulation or discontinuation of cerebral blood flow. To detect ROS, we employed the salicylate trapping method, which involves the hydroxylation of salicylic acid during oxidative stress into dihydroxybenzoic acid (DHBA), and quantification of the latter in venous eluate by using high-performance liquid chromatography. Venous eluate was collected separately from both injured and healthy hemispheres (n=10). Control groups consisted of sham-injured (n=4) and healthy animals (n=3). In animals subjected to ICH (n=10), 50% more 2,5-DHBA was detected in venous eluate on the injured side than in eluate on the contralateral side. Hemorrhagic hemispheres produced more 2,5-DHBA than hemispheres in sham-injured and healthy animals (72 and 110% more 2,5-DHBA, respectively). Isolated brain perfusion combined with salicylate trapping produced data indicating an elevation in the formation of ROS subsequent to ICH. Our findings suggest that isolated in situ brain perfusion is a promising approach to detecting biomarkers of cerebrovascular pathologic conditions.

Flow-cytometric measurement of respiratory burst in rat polymorphonuclear granulocytes: Comparison of four cell preparation procedures, and concentration-response evaluation of soluble stimulants.

Polymorphonuclear neutrophils (PMNs) contribute to organ injury in sepsis, stroke, and other diseases. Evaluation of the oxidative burst by flow cytometry (FCM) is frequently applied to examine PMN status in humans, but rarely in rats. We established a method to assess granulocyte activation in rats by means of FCM analysis of oxidative burst. Two methods for PMN isolation involving Histopaque separation were investigated, and additionally two whole blood techniques. In addition, the concentration-response relation of the stimulants fMLP, PMA, TNF-alpha, and LPS has been determined, both as sole stimulants and for priming. A novel technique with diluted rat whole blood proved to be most appropriate for PMN preparation. One micromolar PMA and fMLP, respectively, are effective concentrations for PMN stimulation in rat whole blood. Priming with 0.1 mug/ml TNF-alpha and 1 mug/ml LPS, respectively, resulted in optimal additional stimulation. This study defined the appropriate conditions for evaluating the reactive oxygen derivate production in rat PMNs by flow cytometry. The rapid, simple, and reliable cell preparation procedure of whole blood dilution that preserves cell integrity and requires only small sample quantities. This is the first systematic dose-response evaluation of soluble stimulants of neutrophil respiratory burst in rats.

Primary mass casualty incident triage: evidence for the benefit of yearly brief re-training from a simulation study.

BACKGROUND: Triage is a mainstay of early mass casualty incident (MCI) management. Standardized triage protocols aim at providing valid and reproducible results and, thus, improve triage quality. To date, there is little data supporting the extent and content of training and re-training on using such triage protocols within the Emergency Medical Services (EMS). The study objective was to assess the decline in triage skills indicating a minimum time interval for re-training. In addition, the effect of a one-hour repeating lesson on triage quality was analyzed. METHODS: A dummy based trial on primary MCI triage with yearly follow-up after initial training using the ASAV algorithm (Amberg-Schwandorf Algorithm for Primary Triage) was undertaken. Triage was assessed concerning accuracy, sensitivity, specificity, over-triage, under-triage, time requirement, and a comprehensive performance measure. A subgroup analysis of professional paramedics was made. RESULTS: Nine hundred ninety triage procedures performed by 51 providers were analyzed. At 1 year after initial training, triage accuracy and overall performance dropped significantly. Professional paramedic's rate of correctly assigned triage categories deteriorated from 84 to 71%, and the overall performance score decreased from 95 to 90 points (maximum = 100). The observed decline in triage performance at 1 year after education made it necessary to conduct re-training. A brief didactic lecture of 45 min duration increased accuracy to 88% and the overall performance measure to 97. CONCLUSIONS: To improve disaster preparedness, triage skills should be refreshed yearly by a brief re-education of all EMS providers.

Fischer-344 rats are unsuitable for the MCAO filament model due to their cerebrovascular anatomy.

Middle cerebral artery occlusion (MCAO) in Fischer-344 rats results in a small variance of infarct size. However, complications are frequent especially in aged Fisher-344 rats undergoing endovascular suture occlusion of the middle cerebral artery. Analyzing our experiences with 165 Wistar, 13 Sprague-Dawley and 10 F-344 rats, we compared the incidence of impossible thread advancement and subarachnoid hemorrhage, respectively. Magnetic resonance angiography (MRA) was applied to study the course of the internal carotid artery (ICA) in Fischer and Wistar rats. Finally, we performed a structured review of the literature from 1991 to 2005 evaluating reports on Fischer rats subjected to intraluminal filament MCAO. Complications like fruitless filament advancement or subarachnoid hemorrhage were found to be significantly more frequent in Fischer rats than in other strains. MRA revealed significantly more pronounced kinking of the ICA in F-344 than in Wistar rats. In seven publications available on filament MCAO in F-344 rats, complication rates of 50-100% were reported, corroborating our data. Surgical difficulties accompanied by high complication rates due to their cerebrovascular anatomy make Fischer rats unsuitable for filament MCAO. If the use of Fischer rats for studies on focal cerebral ischemia is indicated, other ischemia models than intraluminal suture occlusion should be chosen.

Application of clinical scanners in rats: experimental carotid imaging using magnetic resonance imaging, spiral computed tomography, and color duplex ultrasound.

BACKGROUND AND PURPOSE: Noninvasive small animal imaging allows for reduction of the required numbers of animals in research by providing the possibility of long-term follow-up at various time points. Additionally, correlation to the investigated respective human disease is possible as equivalent equipment is employed. The authors therefore evaluate feasibility and potential of color duplex sonography, computed tomography angiography (CTA), and magnetic resonance angiography (MRA) by the use of clinical scanners for carotid artery imaging in rats. METHODS: Male Wistar rats (n = 17) were subjected to color duplex sonography, CTA, and MRA of the common carotid artery (CCA) and the carotid bifurcation. Clinical scanners were used for the experiments and optimal parameter settings evaluated accounting for the different size of the animals. The applied imaging methods were analyzed in regard to image quality and practicability in laboratory settings. RESULTS: The CCA could be clearly displayed by all imaging modalities in all rats. Duplex sonography provided distinct images and reproducible basic functional information. CTA and MRA provided distinct images of the CCA and the carotid bifurcation in both axial and reconstructed 3-dimensional images. The authors further describe different indications for these imaging methods regarding spatial resolution, acquisition times, possible scanning range, and application of contrast agent. CONCLUSIONS: Color duplex sonography, CTA, and MRA are all feasible methods for imaging of the carotid arteries in rats. Images of sufficient clarity and resolution could be obtained by the use of clinical scanners, yielding information about vessel size, direction of blood flow, and adjacent structures. Further studies need to be performed that address investigations of pathological conditions such as flow disturbances or vessel stenosis.

In Vitro Induction of Endothelial Apoptosis of the Post-Hypoxic Blood-Brain Barrier by Isoflurane but Not by Sevoflurane and Midazolam.

BACKGROUND: The effects of anesthetics on the injured brain continue to be the subject of controversial discussion. Since isoflurane has recently been shown to induce apoptosis of cerebral endothelial cells, this study compared different anesthetic compounds regarding their potential to induce cerebro-vascular apoptosis. METHODS: The in vitro model of the blood-brain barrier used in this study consisted of astrocyte-conditioned human umbilical vein endothelial cells (AC-HUVEC) has been used. After 24 h of deep hypoxia and reoxygenation or control treatment, AC-HUVEC were exposed to 0, 0.5, 1.0, or 2.0 times the minimum alveolar concentration of isoflurane or sevoflurane, or 0, 75, 150, or 300 nM of midazolam for 2 h. After 24 h, AC-HUVEC were harvested, and the degree of apoptosis was assessed by means of Western blots for the Bax and Bcl-2 ratio and, for controls and the highest concentration groups, terminal deoxynucleotidyl-mediated dUTP-biotin nick end labeling (TUNEL). RESULTS: Without hypoxic pretreatment, 2.0 MAC of isoflurane slightly increased TUNEL intensity compared to control and sevoflurane, but without any significant changes in the Bax and Bcl-2 ratio. After hypoxic pretreatment, exposure to isoflurane led to a multifold increase in the Bax and Bcl-2 ratio in a dose dependent manner, which was also significantly higher than the ratio observed in the 2 MAC sevoflurane group. TUNEL intensity in the post-hypoxic 2 MAC isoflurane group was increased by a factor of 11 vs. control and by 40 vs. sevoflurane. Sevoflurane and midazolam did not significantly alter these markers of apoptosis, when compared to the control group. CONCLUSIONS: Isoflurane administered after hypoxia elevates markers of apoptosis in endothelial cells transdifferentiated to the cerebro-vascular endothelium. Endothelial apoptosis may be a previously underestimated mechanism of anesthetic neurotoxicity. Administration of high concentrations of isoflurane in experimental settings may have negative effects on the blood-brain barrier.

Ketamine/xylazine anesthesia for radiologic imaging of neurologically impaired rats: dose response, respiratory depression, and management of complications.

In vivo imaging of rats represents an important tool for outcome evaluation in research on stroke, brain trauma, and other neurologic diseases. Since sedation of animals is necessary to avoid artifacts, a mixture of ketamine and xylazine is frequently used for anesthesia. We assessed the suitable dosage of narcotics and its correlation to severe respiratory adverse events in 269 cases of ketamine/xylazine anesthesia in male Wistar rats for performance of magnetic resonance imaging after middle cerebral artery occlusion (MCAO) or sham surgery. Anesthesia depth was not measured. Anesthesia was efficacious in avoiding movement artifacts during imaging. Necessary dosage was lower if rodents were subjected to MCAO instead of sham surgery, if body weight was below baseline, and if time since surgery was short. If anesthesia was induced during the first 2 days after surgery in animals with body weight loss, necessary dose rates were 27% below doses required for rats more than 10 days post-surgery with body weight above baseline (91.4/8.3 versus 125.1/11.3 mg of ketamine/xylazine/kg). A dose adaptation scale for the prediction of necessary dose rates was developed. Apnea developed in 3.3% of all animals. Use of ketamine/xylazine anesthesia for imaging procedures is feasible and safe, though it is associated with a small risk of respiratory arrest. In case of apnea, inspiration can be provoked by a puff of air into the rat's pelt. If unsuccessful, endotracheal intubation and mechanical ventilation are needed until spontaneous breathing is restored or xylazine effects are antagonized.

Evaluation of a novel algorithm for primary mass casualty triage by paramedics in a physician manned EMS system: a dummy based trial.

BACKGROUND: The Amberg-Schwandorf Algorithm for Primary Triage (ASAV) is a novel primary triage concept specifically for physician manned emergency medical services (EMS) systems. In this study, we determined the diagnostic reliability and the time requirements of ASAV triage. METHODS: Seven hundred eighty triage runs performed by 76 trained EMS providers of varying professional qualification were included into the study. Patients were simulated using human dummies with written vital signs sheets. Triage results were compared to a standard solution, which was developed in a modified Delphi procedure. Test performance parameters (e.g. sensitivity, specificity, likelihood ratios (LR), under-triage, and over-triage) were calculated. Time measurements comprised the complete triage and tagging process and included the time span for walking to the subsequent patient. Results were compared to those published for mSTaRT. Additionally, a subgroup analysis was performed for employment status (career/volunteer), team qualification, and previous triage training. RESULTS: For red patients, ASAV sensitivity was 87%, specificity 91%, positive LR 9.7, negative LR 0.139, over-triage 6%, and under-triage 10%. There were no significant differences related to mSTaRT. Per patient, ASAV triage required a mean of 35.4 sec (75th percentile 46 sec, 90th percentile 58 sec). Volunteers needed slightly more time to perform triage than EMS professionals. Previous mSTaRT training of the provider reduced under-triage significantly. There were significant differences in time requirements for triage depending on the expected triage category. CONCLUSIONS: The ASAV is a specific concept for primary triage in physician governed EMS systems. It may detect red patients reliably. The test performance criteria are comparable to that of mSTaRT, whereas ASAV triage might be accomplished slightly faster. From the data, there was no evidence for a clinically significant reliability difference between typical staffing of mobile intensive care units, patient transport ambulances, or disaster response volunteers. Up to now, there is no clinical validation of either triage concept. Therefore, reality based evaluation studies are needed.

Neurovascular protection by targeting early blood-brain barrier disruption with neurotrophic factors after ischemia-reperfusion in rats*.

The 'new penumbra' concept imbues the transition between injury and repair at the neurovascular unit with profound implications for selecting the appropriate type and timing of neuroprotective interventions. In this conceptual study, we investigated the protective effects of pigment epithelium-derived factor (PEDF) and compared them with the properties of epidermal growth factor (EGF) in a rat model of ischemia-reperfusion injury. We initiated a delayed intervention 3 hours after reperfusion using equimolar amounts of PEDF and EGF. These agents were then administered intravenously for 4 hours following reperfusion after 1 hour of focal ischemia. Magnetic resonance imaging indices were characterized, and imaging was performed at multiple time points post reperfusion. PEDF and EGF reduced lesion volumes at all time points as observed on T2-weighted images (T2-LVs). In addition PEDF selectively attenuated lesion volume expansion at 48 hours after reperfusion and persistently modulated blood-brain barrier (BBB) permeability at all time points. Intervention with peptides is suspected to cause edema formation at distant regions. The observed T2-LV reduction and BBB modulation by these trophic factors is probably mediated through a number of diverse mechanisms. A thorough evaluation of neurotrophins is still necessary to determine their time-dependent contributions against injury and their modulatory effects on repair after stroke.

Isoflurane induces endothelial apoptosis of the post-hypoxic blood-brain barrier in a transdifferentiated human umbilical vein endothelial cell model.

Isoflurane is a popular volatile anesthetic agent used in humans as well as in experimental animal research. In previous animal studies of the blood-brain barrier (BBB), observations towards an increased permeability after exposure to isoflurane are reported. In this study we investigated the effect of a 2-hour isoflurane exposure on apoptosis of the cerebral endothelium following 24 hours of hypoxia in an in vitro BBB model using astrocyte-conditioned human umbilical vein endothelial cells (AC-HUVECs). Apoptosis of AC-HUVECs was investigated using light microscopy of the native culture for morphological changes, Western blot (WB) analysis of Bax and Bcl-2, and a TUNEL assay. Treatment of AC-HUVECs with isoflurane resulted in severe cellular morphological changes and a significant dose-dependent increase in DNA fragmentation, which was observed during the TUNEL assay analysis. WB analysis confirmed increases in pro-apoptotic Bax levels at 4 hours and 24 hours and decreases in anti-apoptotic Bcl-2 in a dose-dependent manner compared with the control group. These negative effects of isoflurane on the BBB after a hypoxic challenge need to be taken into account not only in experimental stroke research, but possibly also in clinical practice.

Comprehensive small animal imaging strategies on a clinical 3 T dedicated head MR-scanner; adapted methods and sequence protocols in CNS pathologies.

BACKGROUND: Small animal models of human diseases are an indispensable aspect of pre-clinical research. Being dynamic, most pathologies demand extensive longitudinal monitoring to understand disease mechanisms, drug efficacy and side effects. These considerations often demand the concomitant development of monitoring systems with sufficient temporal and spatial resolution. METHODOLOGY AND RESULTS: This study attempts to configure and optimize a clinical 3 Tesla magnetic resonance scanner to facilitate imaging of small animal central nervous system pathologies. The hardware of the scanner was complemented by a custom-built, 4-channel phased array coil system. Extensive modification of standard sequence protocols was carried out based on tissue relaxometric calculations. Proton density differences between the gray and white matter of the rodent spinal cord along with transverse relaxation due to magnetic susceptibility differences at the cortex and striatum of both rats and mice demonstrated statistically significant differences. The employed parallel imaging reconstruction algorithms had distinct properties dependent on the sequence type and in the presence of the contrast agent. The attempt to morphologically phenotype a normal healthy rat brain in multiple planes delineated a number of anatomical regions, and all the clinically relevant sequels following acute cerebral ischemia could be adequately characterized. Changes in blood-brain-barrier permeability following ischemia-reperfusion were also apparent at a later time. Typical characteristics of intra-cerebral haemorrhage at acute and chronic stages were also visualized up to one month. Two models of rodent spinal cord injury were adequately characterized and closely mimicked the results of histological studies. In the employed rodent animal handling system a mouse model of glioblastoma was also studied with unequivocal results. CONCLUSIONS: The implemented customizations including extensive sequence protocol modifications resulted in images of high diagnostic quality. These results prove that lack of dedicated animal scanners shouldn't discourage conventional small animal imaging studies.

Cerebral ischemia-reperfusion injury in rats--a 3 T MRI study on biphasic blood-brain barrier opening and the dynamics of edema formation.

Serial magnetic resonance imaging (MRI) was performed to investigate the temporal and spatial relationship between the biphasic nature of blood-brain barrier (BBB) opening and, in parallel, edema formation after ischemia-reperfusion (I/R) injury in rats. T(2)-weighted imaging combined with T(2)-relaxometry, mainly for edema assessment, was performed at 1 h after ischemia, after reperfusion, and at 4, 24 and 48 h after reperfusion. T(1)-weighted imaging was performed before and after gadolinium contrast at the last three time points to assess BBB integrity. The biphasic course of BBB opening with a significant reduction in BBB permeability at 24 h after reperfusion, associated with a progressive expansion of leaky BBB volume, was accompanied by a peak ipsilateral edema formation. In addition, at 4 h after reperfusion, edema formation could also be detected at the contralateral striatum as determined by the elevated T(2)-values that persisted to varying degrees, indicative of widespread effects of I/R injury. The observations of this study may indicate a dynamic temporal shift in the mechanisms responsible for biphasic BBB permeability changes, with complex relations to edema formation. Stroke therapy aimed at vasogenic edema and drug delivery for neuroprotection may also be guided according to the functional status of the BBB, and these findings have to be confirmed in human stroke.

Closing microvascular lesions with fibrin sealant-attached muscle pads.

Fibrin sealants are used in a variety of surgical procedures, mainly for purposes of hemostasis and assisted wound healing. The combined use of fibrin sealant and autologous muscle pads for hemostasis was not reported previously. Arterial incisions in the common carotid artery in rats were closed by the combined application of fibrin sealant and an autologous muscle pad. Postsurgical vessel patency and degree of stenosis were evaluated by color duplex sonography, computed tomography angiography, and postmortem histology. The combined application of muscle pad and fibrin sealant and achievement of hemostasis was feasible in all animals. Seventy-eight percent of animals showed no or only slight postsurgical vessel stenosis. Our method is simple and quick to perform, showing a high potential for hemostasis in microvascular lesions. Therefore, it might be used in future experimental studies for conservation of vessel patency after arterial catheterization and in experimental or clinical vascular surgery.

Thrombolysis for stroke in the elderly.

INTRODUCTION: Systemic thrombolysis with intravenous recombinant tissue plasminogen activator (rt PA) for acute ischemic stroke had been licensed for patients up to 75 years in age in many European countries and was recently extended to 80 years. This age restriction results from the potential higher risk of cerebral bleeding in the elderly. The major rt PA trials included only 42 patients above 80 years showing a potential benefit from treatment. Further data is still rare. METHODS: Using our stroke database we identified all patients beyond 75 years with middle cerebral artery ischemia treated with intravenous rt PA in our stroke unit from 02/1999 until 07/2004. Clinical course and outcome until day 5 in addition to mortality after 3 and 6 months were analysed. RESULTS: Twenty-nine patients (80.8+/-4 years, 16 of them over 80 years old) met the inclusion criteria representing 21.2% of those receiving thrombolytic therapy. The median NIH-SS score on admission was 14 points. On day 5 after thrombolysis, 13/29 showed a good recovery (NIH-SS improvement >or=4 pts). The remaining exhibited only small or no benefit (n=11), deterioration (n=3) or died (n=2). A total of 3/29 patients developed non-symptomatic parenchymal hemorrhage or hemorrhagic transformation. One patient died due to space-occupying cerebral hemorrhage. Extracerebral bleeding was found in 3/29 requiring substitution in one. One other died for primary cardiac reasons. Median NIH-SS on day 5 was 10 points. Mortality after 3 and 6 months was 20.7%. We did not find factors predicting clinical outcome. Most importantly, there was no significant difference regarding outcome in patients 76--80 vs. 81--87 years old. DISCUSSION: Intravenous rt PA resulted in good neurological in-hospital outcome in almost 45% and six-months survival of almost 80% of the patients beyond 75 years. In 10.3% non-symptomatic and in 3.4% symptomatic cerebral bleeding was found. Thus, seniors beyond 75 and even beyond 80 years in good medical condition may benefit from systemic treatment with rt PA. Prospective studies are needed to clarify which part of the senior population might be most eligible for systemic thrombolysis.

The role of ECA transection in the development of masticatory lesions in the MCAO filament model.

In the intraluminal suture model of middle cerebral artery occlusion (MCAO) in the rat, lesions of the masticator muscles associated with impaired functional outcome occur. We evaluated the role of external carotid artery (ECA) transection. We assessed whether isolated interruption of an arterial or a venous connection to the ECA territory was sufficient to induce masticatory hypoperfusion and lesions. We also evaluated a direct access to the common carotid artery (CCA) with subsequent vascular closure with regard to its feasibility, frequency of masticatory lesions, complications, and cerebral ischemia. Cerebral and masticatory lesions and perfusion deficits were assessed by in vivo magnetic resonance imaging (MRI). Vessel patency was evaluated using computerized tomography angiography and histology. An interruption of arterial blood flow led to masticatory hypoperfusion. Masticatory lesions occurred in 6% of the rats. Access to and closure of the CCA were feasible in all animals, leading to moderate or severe vessel stenosis in 20%, and intraarterial thrombosis in 25% of the rats. Reproducible cerebral infarctions were obtained in all animals. In 24% of the rats, hyperintense MRI signal changes were observed in the ipsilateral temporal muscle. Thus, the induction of masticatory hypoperfusion and lesions by arterial transection supports the role of the ECA in this context. Direct access to the CCA with subsequent vessel closure led to stenosis in most animals. Preservation of ECA continuity was not suitable to fully prevent masticatory lesions.