Generation of ensembles of individually resolvable nitrogen vacancies using nanometer-scale apertures in ultrahigh-aspect ratio planar implantation masks

A central challenge in developing magnetically coupled quantum registers in diamond is the fabrication of nitrogen vacancy (NV) centers with localization below ∼20 nm to enable fast dipolar interaction compared to the NV decoherence rate. Here, we demonstrate the targeted, high throughput formation of NV centers using masks with a thickness of 270 nm and feature sizes down to ∼1 nm. Super-resolution imaging resolves NVs with a full-width maximum distribution of 26 ± 7 nm and a distribution of NV-NV separations of 16 ± 5 nm.

A hypertensive emergency with acute visual impairment due to excessive liquorice consumption

Hypokalaemic hypertension is the classical presentation of primary hyperaldosteronism but may also result from other mineralocorticoid activity, such as liquorice ingestion. Onset of hypertension as well as serum renin and aldosterone levels are central for the diagnosis. Liquorice ingestion has been reported to induce hypertension, hypokalaemia and metabolic alkalosis due to inhibition of the enzyme 11-β-hydroxy steroiddehydrogenase 2. Here, we report the case of a hypertensive emergency with acute visual impairment due to hypertensive retinopathy in clear conjunction with a considerable consumption of liquorice.

Weak diagnostic performance of troponin, creatine kinase and creatine kinase-MB to diagnose or exclude myocardial infarction after successful resuscitation

BACKGROUND

The aim of this study is to evaluate the diagnostic accuracy of the cardiac injury markers troponin (TNT), creatine kinase (CK) and creatine kinase-MB (CK-MB) to diagnose or exclude acute myocardial infarction after cardiac arrest.

METHODS

226 patients who underwent diagnostic coronary angiography after sudden cardiac arrest were analyzed retrospectively. Levels of TNT, CK and CK-MB on admission and 6h, 24h and 36 h later were retrieved from the files and compared with the results of coronary angiography.

RESULTS

Acute myocardial infarction (AMI) as well as non-AMI patients showed increasing levels of TNT and CK after resuscitation, although the AMI group showed significantly higher TNT and CK levels. Receiver operator curves were calculated to determine the diagnostic precision of TNT, CK and CK-MB to differentiate AMI and non-AMI patients. All analyzed markers yielded mediocre diagnostic precision with an area under the ROC curve of 0.7020, 0.6802 and 0.6508 for 6h TNT, CK and CK-MB, respectively. Applying a modified cut-off of 1 μg/l the 6h TNT measurement had a sensitivity of 70.9% and specificity of 61.2% to diagnose AMI after cardiac arrest. Using CK 800 U/l as cut-off level resulted in a sensitivity of 62.5% and specificity of 73.7%, CK-MB levels higher than 100 U/l yielded a sensitivity of 58.8% and specificity of 72.7%.

CONCLUSION

Cardiac injury markers cannot be used to reliably diagnose or rule out AMI after resuscitation. Consequently we propose that indication for coronary angiography should be extended to all patients without a certain alternative diagnosis explaining the occurrence of cardiac arrest.

Scalable fabrication of high purity diamond nanocrystals with long-spin-coherence nitrogen vacancy centers

The combination of long spin coherence time and nanoscale size has made nitrogen vacancy (NV) centers in nanodiamonds the subject of much interest for quantum information and sensing applications. However, currently available high-pressure high-temperature (HPHT) nanodiamonds have a high concentration of paramagnetic impurities that limit their spin coherence time to the order of microseconds, less than 1% of that observed in bulk diamond. In this work, we use a porous metal mask and a reactive ion etching process to fabricate nanocrystals from high-purity chemical vapor deposition (CVD) diamond. We show that NV centers in these CVD nanodiamonds exhibit record-long spin coherence times in excess of 200 μs, enabling magnetic field sensitivities of 290 nT Hz(-1/2) with the spatial resolution characteristic of a 50 nm diameter probe.

Improvement of cerebral oxygen saturation after successful electrical cardioversion of atrial fibrillation

AIMS

Cerebral and microvascular perfusion is reduced in atrial fibrillation (AF). Maintenance of brain perfusion is important in acute disease and long-term course. Assessment of brain perfusion and oxygenation is difficult in clinical practice. Our study aimed to determine changes in cerebral tissue oxygen saturation (SctO2) with bedside near-infrared spectroscopy (NIRS).

METHODS AND RESULTS

Twenty patients (mean age 67.7 ± 10.2 years, 50% men) in whom electrical cardioversion (CV) was successful were prospectively studied. Ten patients (mean age 64.2 ± 7.7 years, 80% men) in whom CV was not successful served as control group. Bilateral SctO2, mean arterial pressure (MAP), arterial oxygen saturation (SaO2), and heart rate were recorded and changes of all parameters before and after CV were compared between the groups. Our results show an increase in SctO2 after successful CV that was significantly higher compared with patients who remained in AF (right SctO2 3.25 ± 2.5 vs. -0.13 ± 0.52%, P = 0.001; left SctO2 4.27 ± 3.56 vs. -0.38 ± 2.4%, P < 0.001). Neither arterial blood pressure nor SaO2 changes differed significantly between the two groups. No correlation could be detected between the significant increase of SctO2 after successful CV and arterial blood pressure, SaO2, or heart rate.

CONCLUSION

Cerebral tissue oxygen saturation increases significantly after restoration of sinus rhythm. Near-infrared spectroscopy monitoring can identify changes of SctO2 after successful CV of AF independent from standard monitoring parameters (MAP, SaO2). Near-infrared spectroscopy can be used to detect cerebral oxygen saturation deficits in AF patients or patients at high risk for AF. Clinical applications may include monitoring during ablation procedures and in critical care.

Measurement of the ultrafast spectral diffusion of the optical transition of nitrogen vacancy centers in nano-size diamond using correlation interferometry

Spectral diffusion is the phenomenon of random jumps in the emission wavelength of narrow lines. This phenomenon is a major hurdle for applications of solid state quantum emitters like quantum dots, molecules, or diamond defect centers in an integrated quantum optical technology. Here, we provide further insight into the underlying processes of spectral diffusion of the zero-phonon line of single nitrogen vacancy centers in nano-size diamond by using a novel method based on photon correlation interferometry. The method works although the spectral diffusion rate is several orders of magnitude higher than the photon detection rate and thereby improves the time resolution of previous experiments with nano-size diamond by 6 orders of magnitude. We study the dependency of the spectral diffusion rate on the excitation power, temperature, and excitation wavelength under off-resonant excitation. Our results bring insight into the mechanism of spectral diffusion and suggest a strategy to increase the number of spectrally indistinguishable photons emitted by diamond nanocrystals.

Integrated and compact fiber-coupled single-photon system based on nitrogen-vacancy centers and gradient-index lenses

A fiber-coupled single-photon system is presented. Gradient-index lenses are utilized for single-photon collection and fiber coupling of a nitrogen-vacancy defect center in a nanodiamond. Integrated filter technology separates excitation and laser light. Therefore, the system is ultracompact with 120 mm(3) in dimension as no bulky free beam optics are used. The commercial availability of all components and their simple assembly allows the implementation of a low-cost single-photon system, possibly approaching single-photon count rates of 500 kcts/s.

A nanodiamond-tapered fiber system with high single-mode coupling efficiency

We present a fiber-coupled diamond-based single photon system. Single nanodiamonds containing nitrogen vacancy defect centers are deposited on a tapered fiber of 273 nanometer in diameter providing a record-high number of 689,000 single photons per second from a defect center in a single-mode fiber. The system can be cooled to cryogenic temperatures and coupled evanescently to other nanophotonic structures, such as microresonators. The system is suitable for integrated quantum transmission experiments, two-photon interference, quantum-random-number generation and nano-magnetometry.

A scanning probe-based pick-and-place procedure for assembly of integrated quantum optical hybrid devices

Integrated quantum optical hybrid devices consist of fundamental constituents such as single emitters and tailored photonic nanostructures. A reliable fabrication method requires the controlled deposition of active nanoparticles on arbitrary nanostructures with highest precision. Here, we describe an easily adaptable technique that employs picking and placing of nanoparticles with an atomic force microscope combined with a confocal setup. In this way, both the topography and the optical response can be monitored simultaneously before and after the assembly. The technique can be applied to arbitrary particles. Here, we focus on nanodiamonds containing single nitrogen vacancy centers, which are particularly interesting for quantum optical experiments on the single photon and single emitter level.

Acute bacterial otitis externa: efficacy and safety of topical treatment with an antibiotic ear drop formulation in comparison to glycerol treatment

OBJECTIVES

To demonstrate the efficacy and safety of an antibiotic ear drop formulation combining polymyxin B sulfate, neomycin sulfate and gramicidin (PS) in patients with acute bacterial otitis externa (AOE). The combination was compared to glycerol ear drops, a non-pharmacologic treatment of AOE.

METHODS

An active controlled, double-blind, randomized, parallel group, multicenter clinical trial study design was performed in ear, nose and throat (ENT) practices with a planned interim analysis for sample size adaptation. In total, 244 patients aged 19-84 with no previous episode of otitis externa within the last year were randomized to receive either PS or glycerol ear drops thrice daily for 10 ± 2 days.

OUTCOME MEASURES

Absolute change in the clinical symptom score (CSS) (with subscores redness, swelling, pain, and secretion) from Day 1 to 4 was measured. As second endpoints, absolute change in CSS, individual subscores, pain perception measured on a visual analog scale (VAS) and intake of paracetamol 500 mg tablets were noted. Moreover, patient's assessment of efficacy at Day 10 and the frequency and type of adverse events were noted.

RESULTS

On Day 4, the CSS showed a clear advantage for the PS group over the glycerol group, being lower by 0.6 (p < 0.03); the clinical outcome was even more pronounced after 10 days (p = 0.006). The swelling subscore showed a statistically significant difference favoring the PS treatment group in Days 1-4 (p = 0.01) and Days 1-10 (p = 0.003). More PS- than glycerol-receiving patients rated the efficacy as good (glycerol: 32%; PS: 36%) or very good (glycerol: 38%; PS: 48%). Males, patients with AOE for >2 days and those with positive microbiologic findings profited most from PS therapy.

CONCLUSION

This study proves that PS is an effective and well-tolerated drug, showing results superior to glycerol, especially in patients with a longer pre-existing condition before therapy. The absence of a group treated with another established antibiotic is a limitation of this trial.

Fiber-integrated diamond-based single photon source

An alignment free, micrometer-scale single photon source consisting of a single quantum emitter on an optical fiber operating at room temperature is demonstrated. It easily integrates into fiber optic networks for quantum cryptography or quantum metrology applications.(1) Near-field coupling of a single nitrogen-vacancy center is achieved in a bottom-up approach by placing a preselected nanodiamond directly on the fiber facet. Its high photon collection efficiency is equivalent to a far-field collection via an objective with a numerical aperture of 0.82. Furthermore, simultaneous excitation and re-collection through the fiber is possible by introducing a fiber-connected single emitter sensor.

Median liver lobe of woodchuck as a model to study hepatic outflow obstruction: a pilot study

BACKGROUND

Hepatic vein outflow obstruction represents an important clinical problem in living-liver transplantation. An animal model is required to study the influence of outflow obstruction on the intrahepatic regulation of liver perfusion and the subsequent effects on liver injury and recovery during liver regeneration. The size of woodchucks enables the use of standard clinical imaging procedures.

AIM

This study aims at describing hepatic vascular and territorial anatomy of the woodchuck liver based on a virtual three-dimensional (3D) visualization of the hepatic vascular tree.

METHODS

Woodchucks (n=6) were subjected to an all-in-one computed tomography (CT) after contrasting the vascular and the biliary tree. CT-images were used for 3D-reconstruction of hepatic and portal veins and calculation of the corresponding portal and hepatic vein territories and their respective volume using hepavision (MeVisLab). A virtual resection was performed following the Cantlie-line and territories at risk were calculated.

RESULTS

The median lobe of the woodchuck liver has a similar vascular supply and drainage as the human liver with two portal (right and left median portal vein) and three hepatic veins (left, middle and right median hepatic vein). The corresponding portal and hepatic vein subterritories are of a similar relative size compared with the human liver. Virtual splitting of the median lobe of the woodchuck liver revealed areas at risk of focal outflow obstruction, as observed clinically.

CONCLUSION

The median liver lobe of the woodchuck represents, to a small extent, the hepatic vascular anatomy of the human liver and is therefore a suitable potential model to correlate repeated imaging of impaired liver perfusion with histomorphological findings of liver damage and regeneration.

One-by-one coupling of single defect centers in nanodiamonds to high-Q modes of an optical microresonator

In this letter, we present the on-demand coupling of single NV(-) defect centers in nanodiamonds to a polystyrene microspherical resonator. From an ensemble on a coverslip, we select single nanodiamonds containing a single defect proven by a pronounced antibunching dip. With the help of a scanning near-field probe, we can attach these nanodiamonds to a microsphere resonator one-by-one. A clearly modulated fluorescence spectrum demonstrates coupling of the single defect centers to high-Q whispering-gallery modes. Our experiments establish a toolbox to assemble complex systems consisting of single quantum emitters and (coupled) microresonators.

[Central induction area. Reduction of non-operative time without additional costs]

BACKGROUND

Induction areas (IA) can lead to more efficient operating sessions through shortening the changeover time between patients. To date IAs have always required additional staff members, whose cost was only partly covered by improvements in productivity. The objective of this project was to demonstrate that a reduction in non-operative time through a newly introduced induction area can be achieved without a need for extra personnel.

METHODS

Non-operative time in 5,963 ENT, orthopedic and cardiac surgical patients from 8 operating theatres were studied for 1 year before and 1 year after the introduction of an induction area. The non-operative time was defined as the time between the end of surgical procedures in one operation and the start of surgical procedures in the next, within regular working hours. Through reallocation of anesthetic nursing and medical staff it was possible to introduce the induction area without increasing staff numbers.

RESULTS

Non-operative time was significantly reduced from 20 min (range 10-30 min) to 14 min (5-25 min). Subgroup analysis showed significant reductions in all specialities: from 10 min (2.5-20 min) to 5 min (0-20 min) in 1,240 cardiac surgical patients, 25 min (20-35 min) to 15 min (5-25 min) in 2,433 ENT patients and 20 min (10-30 min) to 10 min (0-20 min) in 2,290 orthopedic patients. There were no critical incidents attributable to patient handover.

DISCUSSION AND CONCLUSIONS

An induction area can be established and can reduce non-operative time and improve operation theatre throughput without the need for extra personnel. The efficiency of these measures will be increased when the relevant surgical organizational measures are taken to adjust to the faster anesthesiology workflow. The induction area does not lead to a higher rate of critical incidents. To what extent the induction area can be used for structured training of doctors and nurses, remains to be investigated.

[Berliner Simulations training (BeST)--the concept of anesthesia simulation]

Within recent years patient safety has become increasingly important. Within US hospitals more than 98.000 deaths have been reported annually due to medical errors, more than 80 % due to preventable mistakes. To improve patient safety it is therefore important to develop training tools, which center on the complexity of preventable mistakes, analyze underlying factors and eventually train to deal with them. Since the Berlin Simulation training was founded in 1997 it focused on the internationally accepted "global approach" based on three phases of briefing, simulation and debriefing. It concentrates on the reasons of preventable mistakes and their interaction. Problem solving strategies and the application of NTS ( planing, management, teamwork and communication) and TS (sound scientific knowledge and abilities) are practiced under the supervision of experienced trainers. The goal is to provide insight into the cascades of error and terminate them, to ultimately increase patient safety and provider satisfaction.

Prävalenz psychischer Störungen, Psychopathologie und Behandlungsbedarf bei weiblichen und männlichen Gefangenen

BACKGROUND

While the international literature documents a high prevalence of psychiatric disorders in prisoners, German studies in this field are rare. The base of knowledge is even worse with regard to female prisoners. The purpose of this study was to investigate DSM-IV axis I and II psychiatric disorders and current psychopathology and to estimate treatment needs in prisoners.

SAMPLE AND METHODS

On the 1st of May 2002, all female prisoners in Brackwede I Prison in Bielefeld, Germany, were included; and a sample of incarcerated men was matched according to age, nationality, and length of stay. Sixty-three women and 76 men participated. Criminal history and current living conditions were investigated using a questionnaire and prison documents. Psychopathology and psychiatric disorders were investigated using structured clinical interviews.

RESULTS

In 88.2% of the sample, at least one current axis I (83.5%) and/or axis II personality disorder (53.2%) was found. Comorbidity rates were high, with 3.5+/-2.7 diagnoses per case. Mean SCL scores revealed a substantial psychopathologic burden. In female prisoners, opiate-related and polysubstance use disorders and affective and post-traumatic stress disorders were more frequent than in the male subsample, which in turn showed higher rates of alcohol-related disorders. Specific treatment needs were indicated in 83.4% of the sample.

CONCLUSION

These results indicate that the proportion of mentally ill persons in prisons is substantially higher than in specialized hospitals for mentally ill criminals. More treatment options are urgently needed than has been realized up to now.

Topographie des Elektroenzephalogramms: Endotracheale Intubation unter Narkose mit Propofol und Fentanyl

OBJECTIVE

We used quantitative analysis of the electroencephalogram (EEG) during routine clinical practice to assess the effect of tracheal intubation following induction of anesthesia with propofol and fentanyl.

METHODS

The topographic EEG was recorded from eight bipolar electrode derivations in 25 patients. Z-scores relative to age expected normative data were computed for relative power in the delta, theta, alpha and beta frequency bands. Multivariate statistics (Hotellings' t-sqare) were used to evaluate changes in regional brain electrical activity.

RESULTS

Tracheal intubation induced an increase in alpha and beta frequencies, while delta power was reduced (F-values: Delta: 7.68, p = 0.011; Alpha 31.93; p < 0.001; Beta 12.85, p = 0.001). The most pronounced regional effect was seen for the alpha frequency band with the largest increase in both fronto-temporal regions (F-value 33.89, p < 0.001). During clinical practice the patients received propofol 2.7 (+/- 1.2; minimum: 0.5, maximum 6.9) mg kg (- 1) and fentanyl 2 (+/- 1; minimum 1, maximum 4) microg kg (- 1). Vital parameters did not change during intubation.

CONCLUSION

Individual titration of the dose of propofol and fentanyl as done during routine clinical practice is not sufficient to block the strong noxious stimulation of intubation. Tracheal intubation resulted in "classical" cortical arousal. It remains open whether this cortical wake-up phenomenon has a clinical impact.

["The intensive care simulator": a new teaching-concept to train severe sepsis management]

BACKGROUND AND OBJECTIVE

In addition to basic research and development of new therapeutic strategies, the education of health care professionals who manage sepsis patients is an important step to decrease the high mortality of severe sepsis. Patient simulators are increasingly used for teaching in anaesthesia. A training program in sepsis management was developed, using a full-scale anaesthesia simulator including the setting of a modern intensive care unit, and its results were evaluated by means of a questionnaire.

METHODS

The simulator is controlled from a separate room using a controlling computer provided with physiological models and pharmacokinetic as well as pharmacodynamic patterns of substances commonly used in anaesthesia and intensive care. An important element of the training program is the subsequent debriefing with different modules, according to the individual deficits and needs of the participants detected during simulation.

RESULTS

From September 2002 to July 2004 82 physicians participated in the training program. 4 weeks after the training 52 % of the participants stated that they had changed their treatment behaviour due to the training content. They assessed the interactive simulator workshop semiquantitatively on a scale from 1 ("absolutely correct") to 7 ("not correct at all") as follows: Sepsis simulation training (SST) improves identification (mean+/-SD) (2.3 +/- 1.3) and treatment (2.5 +/- 1.2) of patients with severe sepsis, and SST including true-life scenarios is more appropriate than traditional lectures (1.5 +/- 0.7).

CONCLUSION

The presented SST could be an effective way to train intensive care specialists in severe sepsis management.

[Rapidly lethal progression of a therapy-resistant status epilepticus]

We present a case of death after first manifestation of generalised convulsive status epilepticus in a young man. A previously healthy 23-year-old man was admitted to our emergency department by ambulance service with approximately 20 min of generalised convulsive seizures. First line treatment in the emergency ward with benzodiazepines failed. The patient was cardiopulmonary stable until, after more than 30 min of status epilepticus, he developed tachycardia and became bradypnoeic. Intubation and ventilation was performed and anticonvulsive treatment was escalated with thiopental. Fifteen minutes later he developed ventricular fibrillation. CPR was started. The patient became asystolic after 90 min CPR following the ILCOR (International Liaison Committee on Resuscitation) Instructions. CPR was continued for another 30 min without success. The patient died after 120 min of maximal efforts. Autopsy and toxicology were performed, neuropathologic examination showed general brain edema and neuronal cell loss in purkinje cell layers of the cerebellum and olive knots which may be the consequence of generalised convulsive status epilepticus. We conclude: status epilepticus becomes refractory in approximately 30 % of cases. Until now, there are no randomised trials on the optimal treatment of refractory status epilepticus. Better treatment algorithms are urgently needed.

[Is tracheotomy of angioedema associated with ACE-inhibitor therapy?]

Angioedema of the upper airways associated with angiotensin-converting enzyme inhibitors (ACEI) represent a rare but serious problem. We present two cases from our hospital in order to illustrate the therapeutic consequences resulting from angioedema associated with the intake of ACEIs. Surgical airway management should be considered early if medical treatment fails.

Changes in cortical electrical activity during induction of anaesthesia with thiopental/fentanyl and tracheal intubation: a quantitative electroencephalographic analysis

BACKGROUND

There are regional differences in the effects of anaesthetics agents and perioperative stimuli on the EEG. We studied the topography of the EEG during induction of anaesthesia and intubation in patients receiving thiopental and fentanyl to document regional electrical brain activity.

METHODS

EEG was recorded in 25 patients in the awake state, after pre-medication, during induction, at loss of consciousness and after intubation. Eight bipolar recordings were made and the relative power of the frequency bands delta, theta, alpha, and beta were used (after z-score transformation for age) to measure changes in regional EEG activity.

RESULTS

Noxious stimulation during tracheal intubation partially reversed the slowing of the EEG caused by anaesthesia. During induction of anaesthesia alpha activity was most reduced in temporal and occipital regions. The most prominent EEG changes after intubation were an increase in alpha and a decrease in delta power (P<0.001). The largest changes were in the frontal and temporal leads for alpha and in the frontal and central leads for delta. Heart rate and arterial pressure remained constant during intubation.

CONCLUSIONS

Changes in alpha and delta power were identified as the most sensitive EEG measures of regional changes in electrical brain activity during anaesthesia and noxious stimulation.

Non-invasive determination of effective pulmonary blood flow: evaluation of a simplified rebreathing method

PRIMARY OBJECTIVE

To evaluate a new technical approach to measuring effective pulmonary blood flow (PBF) in mechanically ventilated patients.

RESEARCH DESIGN

Prospective clinical study; evaluation of accuracy and reproducibility.

METHODS

Effective pulmonary blood flow was determined non-invasively in 32 mechanically ventilated patients by using a new rebreathing system (PBF(rb)). Cardiac output corrected for intrapulmonary shunt was taken as reference value (PBF(thd)). Bias, precision and reproducibility of the rebreathing method were calculated from duplicate measurements in each patient.

MAIN RESULTS

The mean difference between PBF(rb) and PBF(thd) was - 0.67 +/- 0.83 l min(-1). The mean difference between duplicate measurements with the rebreathing system was 0.16 +/- 0.36 l min(-1). However, the accuracy of the rebreathing system tended to decrease in patients with PBF levels greater than 6 l min(-1).

CONCLUSIONS

The new device appears to be reliable for determination of PBF values below 6 l min(-1). With this limitation, the present method may be used as a trend-indicator of PBF in mechanically ventilated patients.

[Integration of the Aasalid test in an online measurement system for evaluating cerebral autoregulation]

An important question during the intensive care of patients with subarachnoid hemorrhage and craniocerebral trauma is the evaluation of the cerebral autoregulation (CA). The so called Aaslid-Test is a standard method which allows the cerebral autoregulation to be classified. As the results under repetitive conditions show a high variation, it has not been yet possible to draw statistically proved conclusions concerning the performance of the CA. To improve the test results the measuring conditions are discussed and systematized. The algorithms of the Aaslid-Test have been implemented to an online measuring system. The error bandwidth has been estimated. To avoid systematically occurring errors an enhanced measuring protocol is provided.

Effects of epinephrine on the myocardial performance and haemodynamics of the isolated rat heart during moderate hypothermia--importance of calcium homeostasis

Controversies exist concerning myocardial performance in hypothermia. We have studied the effects of epinephrine on myocardial function at various calcium concentrations in moderate hypothermia (28 degrees C) and normothermia (37 degrees C) using an isolated antegrade perfused rat heart. The maximum pressure velocity (dP/dt(max)) developed was significantly higher in normothermia compared with hypothermia and was improved by the addition of calcium in both circumstances. Peak negative pressure velocity (dP/dt(min)) was significantly higher at 37 degrees C compared with 28 degrees C, and was increased by the addition of calcium in normothermia; in contrast to hypothermia, in which no change of dP/dt(min) was observed. A reduction in cardiac output and stroke volume by hypercalcaemia was observed in hypothermia. The addition of epinephrine improved dP/dt(max) and dP/dt(min), but had a depressive effect on stroke volume and cardiac output at normal and elevated calcium concentrations. Myocardial efficiency was significantly higher during hypothermia compared with normothermia, but was impaired by epinephrine during hypothermia. The variable or even paradoxical effects of epinephrine suggest the need for careful haemodynamic monitoring and determination of calcium levels in hypothermia. The impairment of myocardial performance may be explained by impaired diastolic relaxation and calcium overload.

Osseointegrated implants in patients treated for generalized chronic periodontitis and generalized aggressive periodontitis: 3- and 5-year results of a prospective long-term study

BACKGROUND

The successful use of osseointegrated implants in periodontally healthy patients has been documented in numerous longitudinal studies in recent years. However, the extent to which these positive results apply to periodontally diseased patients remains unclear. The aim of the present prospective longitudinal study of partially edentulous patients treated for generalized chronic periodontitis and generalized aggressive periodontitis was a clinical, microbiological, and radiographic comparison of teeth and implants and assessment of the implant success rate.

METHODS

Five partially edentulous patients treated for generalized aggressive periodontitis (GAgP) and 5 treated for generalized chronic periodontitis (GCP) were enrolled in this study. The GAgP patients received 36 implants, and the GCP patients 12 implants. The teeth were examined 2 to 4 weeks before extraction of the non-retainable teeth (baseline), and 3 weeks after insertion of the final abutments (second examination). All further examinations were performed during a 3-month recall schedule over a 5-year period for the GAgP patients and over a 3-year period for the GCP patients. At each session clinical parameters were recorded at teeth and implants and the composition of the subgingival microflora was determined by dark-field microscopy and DNA analysis. Intraoral radiographs of the teeth and implants were taken for control purposes at baseline; after insertion of the superstructure; and 1, 3, and 5 years later.

RESULTS

The clinical findings indicated healthy periodontal and peri-implant conditions in both patient groups throughout the study. However, an increased probing depth and an attachment loss were recorded in the GAgP patients after the third year (P<0.001). The distribution of the microorganisms revealed no significant differences between the patient groups or between implants and teeth. Moderate bone loss at teeth and implants was registered in both groups. The success rates recorded were 100% in the GCP patients and 88.8% (maxilla: 85.7%; mandible: 93.3%) in the GAgP patients.

CONCLUSIONS

The 3-year and 5-year follow-ups show that osseointegrated implants may be successful in oral rehabilitation of partially edentulous patients treated for generalized aggressive periodontitis and generalized chronic periodontitis. However, as no significant differences were recorded between conditions at teeth and at implants, progression of the disease cannot be ruled out.

Enoximone in contrast to dobutamine improves hepatosplanchnic function in fluid-optimized septic shock patients

OBJECTIVE

To investigate the impact of dobutamine and enoximone on hepatosplanchnic perfusion and function in fluid-optimized septic patients.

DESIGN

Prospective, randomized, double-blinded interventional study.

SETTING

Intensive care unit of a university hospital.

PATIENTS

Forty-eight septic shock patients were examined within 12 hrs after onset of septic shock. Patients were conventionally resuscitated, achieving an optimal pulmonary artery occlusion pressure at which the left ventricular stroke work was on the maximal plateau. Liver blood flow was estimated by venous suprahepatic catheterization using the continuous indocyanine green infusion technique. Microsomal liver function was assessed by the plasma appearance of monoethylglycinexylidide, and release of hepatic tumor necrosis factor-alpha (TNF-alpha) was measured to estimate the severity of hepatic ischemia-reperfusion syndrome.

INTERVENTIONS

Patients were randomly treated with dobutamine or enoximone. Within the first 10 hrs after baseline measurements, the dosage was increased until no further increase in the left ventricular stroke work index occurred. Then, positive inotropes were kept constant throughout the study.

MEASUREMENTS AND MAIN RESULTS

Measurements were performed at baseline and after 12 and 48 hrs after baseline measurements. Cardiac index, systemic oxygen delivery, systemic oxygen consumption, and liver blood flow increased significantly in both groups during treatment (p <.01) without a significant difference between groups. Fractional liver blood flow (liver blood flow/cardiac index) did not change in the enoximone group and showed a significant but only minor (median, 10%) decrease in the dobutamine group (p <.05 after 12 hrs and p <.01 after 48 hrs vs. baseline). After 12 hrs of enoximone treatment, monoethylglycinexylidide kinetics and hepatosplanchnic oxygen consumption demonstrated a significant increase (p <.05). The release of hepatic TNF-alpha after 12 hrs of dobutamine treatment was twice as high (p <.05) as during enoximone.

CONCLUSION

The increase in hepatosplanchnic oxygen consumption, together with an increased lignocaine metabolism and decreased release of hepatic TNF-alpha, indicates improved hepatosplanchnic function and antiinflammatory properties after 12 hrs of enoximone treatment. Therefore, if the inflammatory response should be attenuated in high-risk patients, administration of enoximone in fluid-optimized septic shock patients may be favorable compared with dobutamine.

Aortic valve replacement with or without concomitant coronary artery bypass grafting in the ninth decade of life

Due to demographic changes in average life expectancy, the age of patients undergoing cardiac surgery is increasing. We have reviewed the short- and long-term outcome after aortic valve replacement with or without concomitant coronary artery bypass grafting in patients over 80 years of age. From 1 January 1995 until 30 June 1999, 114 patients (83 women and 31 men, 80-89 years of age, 82.8+/-2.4 years) with symptomatic aortic valve disease underwent aortic valve replacement. Of these patients, 54% (group A) received isolated valve replacement and 46% (group B) underwent myocardial revascularization as well. The perioperative mortality rate was 4.8% for group A and 7.7% for group B. The 30-day hospital mortality rate was 4.8% for group A and 15.4% for group B. The follow-up time ranged between 3 months and 63 months (32+/-15 months). None of the patients had to be reoperated for prosthetic valve dysfunction or endocarditis. Bleeding complications due to anticoagulation therapy were not observed. Of the 15 deaths during the follow-up period, seven (47%) were cardiac in nature and two (13%) were related to stroke. Actuarial survival rates for group A were 90%, 84%, and 76% at 1, 2, and 3 years, respectively, and for group B were 75%, 71%, and 68%. One year after the operation, permanent nursing care was not required by 100% of patients in group A (2 years, 98%; 3 years, 95%) and by 100% of patients in group B (2 years, 95%; 3 years, 91%). At a 1-year interval after the operation, 98% of patients in group A had not been hospitalized as a result of cardiac disorders (2 years, 98%; 3 years, 95%). The rates for group B were 90%, 85%, and 85%. Compared with younger age groups, aortic valve replacement in patients 80 years of age and older is associated with a distinctly increased mortality and morbidity. However, our data suggest that, considering the poor prognosis of conservative therapy of symptomatic aortic valve disease, functional status as well as life expectancy in this age group seem to be positively influenced by aortic valve replacement.

[Short and long term results of aortic valve replacement in patients 80 years of age and older]

BACKGROUND

Due to demographic changes in average life expectancy the age of patients undergoing cardiac surgery is increasing as well. We have reviewed the short- and long-term outcome in patients over 80 years of age after aortic valve replacement with or without concomitant coronary grafting.

PATIENTS AND METHOD

From 1.1.1995 until 31.12.1999, 126 patients (93 women, 33 men between 80 and 89 years, 82.8 +/- 2.4) underwent aortic valve replacement. 64 patients (group A) received isolated valve replacement, 62 (group B) underwent myocardial revascularization as well.

RESULTS

The 30-day hospital mortality rate was 6.3% for group A and 14.5% for group B. The follow-up time ranged between 3 and 63 months (32 +/- 16). None of the patients had to be reoperated for prosthetic valve dysfunction or endocarditis. Bleeding complications due to anticoagulation therapy were observed by one patient from group A 3 years after the operation. Of the 15 deaths during the follow-up period seven (47%) were cardiac in nature and two (13%) related to stroke. Acturial survival rates for group A were 89%, 85% and 77% at 1, 2 and 3 years, and for group B 76%, 72% and 70%. Permanent nursing care was not required 1 year after the operation by 100% of patients in group A (2 years: 98%, 3 years 95%) and by 100% of patients in group B (2 years: 93%, 3 years: 90%). At an interval of 1 year after the operation 96% of patients in group A had not been hospitalized as a result of cardiac disorders (2 years: 96%, 3 years: 94%). The rates for group B were 88%, 81% and 75%.

CONCLUSION

Compared with younger age groups, aortic valve replacement in patients 80 years of age and older is associated with a distinctly increased mortality and morbidity. However, our data suggest that considering the poor prognosis of conservative therapy of symptomatic aortic valve disease, functional status as well as life expectancy in this age group seem to be positively influenced by aortic valve replacement.