Metabolic Cooperation among Commensal Bacteria Supports Drosophila Juvenile Growth under Nutritional Stress

The gut microbiota shapes animal growth trajectory in stressful nutritional environments, but the molecular mechanisms behind such physiological benefits remain poorly understood. The gut microbiota is mostly composed of bacteria, which construct metabolic networks among themselves and with the host. Until now, how the metabolic activities of the microbiota contribute to host juvenile growth remains unknown. Here, using Drosophila as a host model, we report that two of its major bacterial partners, Lactobacillus plantarum and Acetobacter pomorum, engage in a beneficial metabolic dialogue that boosts host juvenile growth despite nutritional stress. We pinpoint that lactate, produced by L. plantarum, is utilized by A. pomorum as an additional carbon source, and A. pomorum provides essential amino acids and vitamins to L. plantarum. Such bacterial cross-feeding provisions a set of anabolic metabolites to the host, which may foster host systemic growth despite poor nutrition.

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L. plantarum feeds lactate to A. pomorum

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A. pomorum supplies essential amino acids and vitamins to L. plantarum

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Microbiota metabolic dialogue boosts Drosophila's larval growth

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Lactate utilization by Acetobacter releases anabolic metabolites to larvae

Drosophila-associated bacteria differentially shape the nutritional requirements of their host during juvenile growth

The interplay between nutrition and the microbial communities colonizing the gastrointestinal tract (i.e., gut microbiota) determines juvenile growth trajectory. Nutritional deficiencies trigger developmental delays, and an immature gut microbiota is a hallmark of pathologies related to childhood undernutrition. However, how host-associated bacteria modulate the impact of nutrition on juvenile growth remains elusive. Here, using gnotobiotic Drosophila melanogaster larvae independently associated with Acetobacter pomorum^WJL (Ap^WJL) and Lactobacillus plantarum^NC8 (Lp^NC8), 2 model Drosophila-associated bacteria, we performed a large-scale, systematic nutritional screen based on larval growth in 40 different and precisely controlled nutritional environments. We combined these results with genome-based metabolic network reconstruction to define the biosynthetic capacities of Drosophila germ-free (GF) larvae and its 2 bacterial partners. We first established that Ap^WJL and Lp^NC8 differentially fulfill the nutritional requirements of the ex-GF larvae and parsed such difference down to individual amino acids, vitamins, other micronutrients, and trace metals. We found that Drosophila-associated bacteria not only fortify the host’s diet with essential nutrients but, in specific instances, functionally compensate for host auxotrophies by either providing a metabolic intermediate or nutrient derivative to the host or by uptaking, concentrating, and delivering contaminant traces of micronutrients. Our systematic work reveals that beyond the molecular dialogue engaged between the host and its bacterial partners, Drosophila and its associated bacteria establish an integrated nutritional network relying on nutrient provision and utilization.

A study of gnotobiotic fruit flies shows that the animal is involved in an integrated nutritional network with its facultative commensal bacteria, centered around the utilization and sharing of nutrients.

D-Alanylation of teichoic acids contributes to Lactobacillus plantarum-mediated Drosophila growth during chronic undernutrition

The microbial environment influences animal physiology. However, the underlying molecular mechanisms of such functional interactions are largely undefined. Previously, we showed that during chronic undernutrition, strains of Lactobacillus plantarum, a major commensal partner of Drosophila, promote host juvenile growth and maturation partly through enhanced expression of intestinal peptidases. By screening a transposon insertion library of Lactobacillus plantarum in gnotobiotic Drosophila larvae, we identify a bacterial cell-wall-modifying machinery encoded by the pbpX2-dlt operon that is critical to enhance host digestive capabilities and promote animal growth and maturation. Deletion of this operon leads to bacterial cell wall alteration with a complete loss of D-alanylation of teichoic acids. We show that L. plantarum cell walls bearing D-alanylated teichoic acids are directly sensed by Drosophila enterocytes to ensure optimal intestinal peptidase expression and activity, juvenile growth and maturation during chronic undernutrition. We thus conclude that besides peptidoglycan, teichoic acid modifications participate in the host-commensal bacteria molecular dialogue occurring in the intestine.

[Indirect laryngoscopy/video laryngoscopy. A review of devices used in emergency and intensive care medicine in Germany]

Airway management in intensive care or emergency medicine is particularly challenging and is often associated with life-threatening complications. An innovation in the field of airway management is the use of indirect laryngoscopy by means of video laryngoscopes. A digital camera or an optical system at the tip of a laryngoscope blade enables an indirect "look around the corner" to the glottis. Studies have shown that the advantages of video laryngoscopes for endotracheal intubation are particularly beneficial in difficult airway situations. However, the successful use in challenging intubations requires experience and regular use in daily practice. This review gives an overview of indirect laryngoscopes commonly used in Germany and also presents new study results for these novel devices.

[Nasal septum perforation and bevacizumab]

A 52-year-old woman, with a metastatic breast cancer, presented with a nasal septum perforation while receiving a treatment combining paclitaxel and bevacizumab. This is the fifth reported case of nasal septum perforation probably related to an anti-angiogenic therapy. A literature review and a discussion concerning the different causes of nasal septum perforation were performed.

[Importance of material logistics in the interface management of operation departments: is the supply of sterile equipment a new business area of operation room organization?]

The implementation of diagnosis-related groups (DRGs) sharply increased economic pressure on hospitals. Hence, process optimization was focussed on cost-intensive areas, namely the operation room (OR) departments. Work-flow in the OR is characterized by a mandatory interlocking of the job functions of many different occupational groups and the availability of a variety of different materials. Alternatives for staff assignment optimization have been published in numerous publications dealing with the importance of OR management. In this connection the issue of material logistics in the context of OR management has not been frequently addressed. In order to perform a surgical procedure according to plan, one depends on personnel and on timely availability of the materials needed. Supply of sterilized materials is of utmost importance, because in most hospitals sterilized surgical devices constitute a critical resource. In order to coordinate the OR process with the production flow of sterilized materials, an organizational connection to the OR management makes sense. Hence, in a German university hospital the Department of Hospital Sterile Supplies was integrated into the OR management of the Department of Anesthesiology. This led to a close coordination of work-flow processes, and concomitantly a significant reduction of production costs of sterile supplies could be achieved by direct interaction with the OR. Thus, hospital sterile supplies can reasonably be integrated into an OR management representing a new interesting business area for OR organization.

Superior temporal sulcus anatomical abnormalities in childhood autism: a voxel-based morphometry MRI study

The underlying neurobiology of autism, a severe pervasive developmental disorder, remains unknown. Few neocortical brain MRI abnormalities have been reported. Using rest functional brain imaging, two independent studies have described localized bilateral temporal hypoperfusion in children with primary autism. In order to search for convergent evidence of anatomical abnormalities in autistic children, we performed an anatomical MRI study using optimized whole-brain voxel-based morphometry (VBM). High-resolution 3-D T1-weighted MRI data sets were acquired in 21 children with primary autism (mean age 9.3 +/- 2.2 years) and 12 healthy control children (mean age 10.8 +/- 2.7 years). By comparing autistic children to normal children, we found bilaterally significant decreases of grey matter concentration located in superior temporal sulcus (STS) (P < 0.05 corrected, after small volume correction; SVC). Children with autism were also found to have a decrease of white matter concentration located in the right temporal pole and in cerebellum (P < 0.05, corrected) compared to normal children. These results suggest that autism is associated with bilateral anatomical abnormalities localized in the STS and are remarkably consistent with functional hypoperfusion previously reported in children with autism. The multimodal STS areas are involved in highest level of cortical integration of both sensory and limbic information. Moreover, the STS is now recognized as a key cortical area of the "social brain" and is implicated in social perceptual skills that are characteristically impaired in autism. Therefore, the convergent anatomical and functional temporal abnormalities observed in autism may be important in the understanding of brain behavior relationships in this severe developmental disorder.

Initial chemotherapy in gliomatosis cerebri

BACKGROUND

Because of the diffuse nature of gliomatosis cerebri (GC), surgery is not suitable, and large field radiotherapy carries the risk of severe toxicity. In this setting, initial chemotherapy warrants further investigation.

METHODS

The authors treated 63 consecutive patients with GC with initial chemotherapy consisting of either PCV (procarbazine, 60 mg/m2 on days 8 to 21; CCNU, 110 mg/m2 on day 1; and vincristine, 1.4 mg/m2 on days 8 and 29) or temozolomide (TMZ; 150 to 200 mg/m2 for 5 days every 4 weeks). There were 40 men and 23 women, with a median age of 48 years (range, 17 to 74 years) and a median Karnofsky performance status of 90 (range, 50 to 100). GC was initially present at diagnosis in 49 patients (primary GC), whereas 14 patients with a circumscribed glioma at onset developed secondary GC after a median follow-up period of 5.11 years. GC was classified based on the predominant tumor cells as astrocytic, oligodendroglial, or mixed GC.

RESULTS

Seventeen patients received 1 to 6 cycles (median, 5) of PCV, and 46 received 2 to 24 courses (median, 13) of TMZ. Grade 3 to 4 hematologic toxicity was seen in 4 of 17 (23.5%) patients treated with PCV and in 4 of 46 (8.6%) of those treated with TMZ. Clinical objective responses were observed in 21 of 63 (33%) patients, and radiologic responses were seen in 16 of 62 (26%), with no significant difference between the two regimens. For all patients combined, the median progression-free survival (PFS) and overall survival (OS) were 16 months and 29 months, respectively. Regardless of the chemotherapeutic regimen, oligodendroglial GC had a better prognosis than astrocytic and oligoastrocytic GC in terms of PFS (p < 0.02) and OS (p < 0.0001).

CONCLUSION

Initial chemotherapy is useful for some patients with gliomatosis cerebri. Temozolomide is well tolerated and appears to be a valuable alternative to procarbazine-CCNU-vincristine, especially for those with slow-growing, low-grade GC.

[Hemichorea, hemiballism disclosing non-ketotic hyperglycemia]

Non ketotic hyperglycemia is a metabolic disorder which can induce various hyperkinetic disorders. We report the case of a 74-year old woman admitted to hospital because of choreo-ballic movements of her left hemibody. Laboratory tests revealed non-ketotic hyperglycemia. CT scan showed an increased density in the right putamen and head of caudate. Magnetic resonance imaging disclosed a hyperintense signal involving the right putamen on T1-weighted images. On T2-weighted images, there was a slight hyperintensity in the right putamen and head of caudate. Correction of the underlying hyperglycemia led to complete resolution of abnormal movements. Pathophysiology of this clinicoradiologic syndrome is briefly discussed.

Improved outcome prediction in unconscious cardiac arrest survivors with sensory evoked potentials compared with clinical assessment

OBJECTIVE

To compare the prognostic ability of sensory evoked potentials in cardiac arrest survivors with the outcome predicted by a panel of experienced emergency physicians based on detailed prehospital, clinical, and laboratory data.

DESIGN

Inception cohort study.

SETTING

Medical intensive care unit and department of emergency medicine at a university hospital.

PATIENTS

A total of 162 unconscious, mechanically ventilated patients who survived > or =24 hrs after resuscitation from cardiac arrest.

INTERVENTIONS

Recording of sensory evoked potentials and outcome prediction after review of detailed clinical and laboratory data by emergency physicians within 24 hrs after cardiac arrest.

MEASUREMENTS AND MAIN RESULTS

At 6 months, the outcome of 36 patients was classified as favorable and 126 patients were rated as poor. After review of prehospital data, emergency physicians predicted favorable vs. poor outcome with a sensitivity of 70% and a specificity of 65%. After additional assessment of data 1 hr after cardiac arrest, the sensitivity of emergency physician predictions increased to 80%, whereas the specificity decreased to 48%. Outcome prediction by emergency physicians was most accurate after obtaining detailed patient data 24 hrs after cardiac arrest (sensitivity, 81%; specificity, 58%). In 35 of 36 patients with favorable outcomes, the cortical evoked potential N70 peak was detected between 72 and 128 msec. Of 113 patients with an N70 peak latency >130 msec or an absent N70 peak, all except one had a poor outcome. By using a cutoff of 130 msec, the N70 peak latency alone had a sensitivity of 94% and a specificity of 97%. The predictive accuracy of the N70 peak latency was significantly higher than the clinical assessment 24 hrs after cardiac arrest (91% vs. 76%, p = .0003).

CONCLUSION

In unconscious cardiac arrest survivors, a recording of long-latency sensory evoked potentials is more accurate in predicting individual outcome than an emergency physician review of clinical data.

Pharmacokinetics and pharmacodynamics of hydroxyethyl starch in hypovolemic pigs; a comparison of peripheral and intraosseous infusion

Intraosseous (i.o.) infusion is considered a useful technique for the administration of medications and fluids in emergency situations when peripheral intravascular access is not possible. This study investigated the effectiveness of i.o. versus intravenous (i.v.) infusion of hydroxyethyl starch (HES 200/0.5) in hypovolemic pigs. Twenty-three pigs (8- to 9-week-old) were anaesthesized, instrumented and blood was withdrawn (25-30 ml/kg) to < 50 mmHg mean arterial pressure (MAP). The animals were left untreated in haemorrhage for 30 min. Relevant haemodynamic parameters were monitored and blood samples were collected for blood gas and HES concentration analysis. Infusion of HES via i.v. or i.o. line (20 ml/kg per h) carried out over a period of 30 min for volume resuscitation and measurements were taken every 5 min. Infusion was discontinued after 30 min and the animals were monitored for 1 h. Analysis of HES-pharmacokinetics and pharmacodynamics revealed no significant differences between i.o. and the i.v. administration. The results demonstrate i.o. infusion of HES to be a rapid and effective method for fluid resuscitation in hypovolemic shock.

Cerebral resuscitation from cardiac arrest: treatment potentials

In 1961, in Pittsburgh, PA, "cerebral" was added to the cardiopulmonary resuscitation system (CPR --> CPCR). Cerebral recovery is dependent on arrest and cardiopulmonary resuscitation times, and numerous factors related to basic, advanced, and prolonged life support. Postischemic-anoxic encephalopathy (the cerebral postresuscitation disease or syndrome) is complex and multifactorial. The prevention or mitigation of this syndrome requires that there be development and trials of special, multifaceted, combination treatments. The selection of therapies to mitigate the postresuscitation syndrome should continue to be based on mechanistic rationale. Therapy based on a single mechanism, however, is unlikely to be maximally effective. For logistic reasons, the limit for neurologic recovery after 5 mins of arrest must be extended to achieve functionally and histologically normal human brains after 10 to 20 mins of circulatory arrest. This goal has been approached, but not quite reached. Treatment effects on process variables give clues, but long-term outcome evaluation is needed for documentation of efficacy and to improve clinical results. Goals have crystallized for clinically relevant cardiac arrest-intensive care outcome models in large animals. These studies are expensive, but essential, because positive treatment effects cannot always be confirmed in the rat forebrain ischemia model. Except for a still-elusive breakthrough effect, randomized clinical trials of CPCR are limited in their ability to statistically document the effectiveness of treatments found to be beneficial in controlled outcome models in large animals. Clinical studies of feasibility, side effects, and acceptability are essential. Hypertensive reperfusion overcomes multifocal no-reflow and improves outcome. Physical combination treatments, such as mild resuscitative (early postarrest) hypothermia (34 degrees C) plus cerebral blood flow promotion (e.g., with hypertension, hemodilution, and normocapnia), each having multiple beneficial effects, achieved complete functional and near-complete histologic recovery of the dog brain after 11 mins of normothermic, ventricular fibrillation cardiac arrest. Calcium entry blockers appear promising as a treatment for postischemic-anoxic encephalopathy. However, the majority of single or multiple drug treatments explored so far have failed to improve neurologic outcome. Assembling and evaluating combination treatments in further animal studies and determining clinical feasibility inside and outside hospitals are challenges for the near future. Treatments without permanent beneficial effects may at least extend the therapeutic window. All of these investigations will require coordinated efforts by multiple research groups, pursuing systematic, multilevel research--from cell cultures to rats, to large animals, and to clinical trials. There are still many gaps in our knowledge about optimizing extracerebral life support for cerebral outcome.

Thiopentone, thiopentone/ketamine, and ketamine for induction of anaesthesia in caesarean section

Seventy-five healthy patients were randomly allocated to receive thiopentone, thiopentone/ketamine or ketamine for induction of anaesthesia for elective Caesarean section. Thiopentone resulted in the most pronounced and ketamine in the smallest drop in blood pressure, while the combination induced only moderate haemodynamic changes. Intra-operative awareness occurred in one patient in the thiopentone group, six of the ketamine patients had nightmares, and one patient of the combination group reported pleasant dreams but no awareness. The muscle tone of neonates in the thiopentone group was more reduced than in neonates in the other two groups. Infants delivered after uterine incision-to-delivery intervals exceeding 3 min more often had Apgar scores < 7 than those delivered in less than 3 min.

Epinephrine dosage effects on cerebral and myocardial blood flow in an infant swine model of cardiopulmonary resuscitation

Although epinephrine increases cerebral blood flow (CBF) and left ventricular blood flow (LVBF) during cardiopulmonary resuscitation (CPR), the effects of high dosages on LVBF and CBF and cerebral O2 uptake have not been examined during prolonged CPR. We determined whether log increment dosages of epinephrine would enhance LVBF and CBF and cerebral O2 uptake in an infant swine CPR model. We compared these responses with epinephrine to those with the alpha-adrenergic agonist, phenylephrine. CPR was performed in five groups (n = 6) of pentobarbital-anesthetized piglets (3.5-5.6 kg) receiving a continuous epinephrine infusion (0, 1, 10, and 100 micrograms.kg-1.min-1) or phenylephrine infusion (40 micrograms.kg-1.min-1). Plasma epinephrine concentrations increased 10-100-fold in the control group during CPR and in a stepwise manner such that concentrations were increased by more than 10(4) in the 100 micrograms.kg-1.min-1 epinephrine group. In the control group with no epinephrine infusion, LVBF decreased to less than 10 ml.min-1.100 g-1 by 5 min of CPR. With epinephrine in dosages of 10 and 100 micrograms.kg-1.min-1, LVBF at 5 min was 75 +/- 19 and 44 +/- 15 ml.min-1.100 g-1, respectively, which was significantly greater than values in the control group. With more prolonged CPR, LVBF remained significantly greater than that in the control group but only at 10 micrograms.kg-1.min-1 of epinephrine. Phenylephrine also increased LVBF for 10 min of CPR when compared with the control group. All dosages of epinephrine and phenylephrine maintained CBF close to prearrest values for 20 min of CPR. With prolonged CPR, 10 and 100 micrograms.kg-1.min-1 epinephrine resulted in significantly greater CBF than that in the control group. Incremental dosages of epinephrine did not statistically increase cerebral O2 uptake or lower the cerebral fractional O2 extraction when compared with the control group, despite the higher CBF that was generated. In this immature animal CPR model, 10 micrograms.kg-1.min-1 epinephrine is an optimal dosage for maximizing both CBF and LVBF, a dosage that substantially exceeds the current recommended epinephrine dosage for human infant CPR. In addition, for short periods of CPR, 40 micrograms.kg-1.min-1 phenylephrine increases CBF and LVBF to levels similar to those generated by high dosages of epinephrine.

Improved blood flow during prolonged cardiopulmonary resuscitation with 30% duty cycle in infant pigs

BACKGROUND

Sustained compression is recommended to maximize myocardial and cerebral blood flow during cardiopulmonary resuscitation (CPR) in adults and children. We compared myocardial and cerebral perfusion during CPR in three groups of 2-week-old anesthetized swine using compression rates and duty cycles (duration of compression/total cycle time) of 100 per minute, 60%; 100 per minute, 30%; and 150 per minute, 30%.

METHODS AND RESULTS

Ventricular fibrillation was induced and CPR was begun immediately with a sternal pneumatic compressor. Epinephrine was continuously infused during CPR. Microsphere-determined blood flow and arterial and sagittal sinus blood gas measurements were made before cardiac arrest was induced and after 5, 10, 20, 35, and 50 minutes of CPR. At 5 minutes of CPR, ventricular and cerebral blood flows were greater than 25 ml.min-1 x 100 g-1 and were not significantly different between groups. When CPR was prolonged, however, myocardial and cerebral blood flows were significantly higher with the 30% duty cycle than with the 60% duty cycle. By 35 minutes, all myocardial regions had less than 5 ml.min-1 x 100 g-1 flow with the 60% duty cycle. In contrast, CPR with the 30% duty cycle at either compression rate provided more than 25 ml.min-1 x 100 g-1 to all ventricular regions for 50 minutes. By 20 minutes, most brain regions received 50% less flow with the 60% duty cycle compared with animals undergoing CPR with the 30% duty cycle (p less than 0.05). Cerebral oxygen uptake was better preserved with the 30% duty cycle. Chest deformation from loss of recoil was greater with the 60% duty cycle compared with the 30% duty cycle.

CONCLUSIONS

We conclude that the shorter duty cycle provides markedly superior myocardial and cerebral perfusion during 50 minutes of CPR in this infant swine model. These data do not support recommendations for prolonged compression at rates of 100 per minute during CPR in infants and children.

[Characteristics of cardiopulmonary resuscitation in pregnant women]

Cardiopulmonary resuscitation (CPR) during pregnancy is a rare event, but due to the increasing number of pregnant women with significant medical disorders it will gain more importance in the near future. Effective CPR with respect to survival of mother and infant can only be accomplished under optimal conditions. We discuss important pathophysiological alterations during pregnancy and, including recommendations in the available literature, we present a standardized protocol for life support for mother and infant. The protocol depends on the progress of the pregnancy. Compared to non-pregnant patients, pregnant women must be placed in a left lateral position immediately. If possible, the decision to perform open-chest CPR has to be made within 15 min of unsuccessful closed-chest CPR. In addition, during late pregnancy there should be no delay in performing an emergency cesarean section, even during CPR.

Organ blood flow and somatosensory-evoked potentials during and after cardiopulmonary resuscitation with epinephrine or phenylephrine

Pure alpha-adrenergic agonists, such as phenylephrine, and mixed alpha- and beta-adrenergic agonists, such as epinephrine, raise perfusion pressure for heart and brain during cardiopulmonary resuscitation (CPR). However, with the high doses used during CPR, these drugs may directly affect vascular smooth muscle and metabolism in brain and heart. We determined whether at equivalent perfusion pressure, continuous infusion of phenylephrine (20 micrograms/kg/min) or epinephrine (4 micrograms/kg/min) leads to equal organ blood flow, cerebral O2 uptake, and cerebral electrophysiologic function. During 20 minutes of CPR initiated immediately upon ventricular fibrillation in anesthetized dogs, left ventricular blood flow was similar with epinephrine (45 +/- 9 ml/min/100 g) or phenylephrine (47 +/- 8 ml/min/100 g) infusion. The ratio of subendocardial to subepicardial blood flow fell equivalently during CPR with either epinephrine (1.23 +/- 0.06 to 0.70 +/- 0.05) or phenylephrine (1.32 +/- 0.07 to 0.77 +/- 0.05) administration. At similar levels of cerebral perfusion pressure (44 +/- 3 mm Hg), similar levels of cerebral blood flow were measured in both groups (27 +/- 3 ml/min/100 g). Cerebral O2 uptake was maintained at prearrest levels in both groups. Somatosensory-evoked potential amplitude was modestly reduced during CPR, but it promptly recovered after defibrillation. During CPR and at 2 hours after resuscitation, there were no differences between drug groups in the level of regional cerebral or coronary blood flow, cerebral O2 uptake, or evoked potentials. Therefore, with minimal delay in the onset of CPR and with equipotent pressor doses of phenylephrine and epinephrine, we found no evidence that one agent provides superior coronary or cerebral blood flow or that epinephrine by virtue of its beta-adrenergic properties adversely stimulates cerebral metabolism at a critical time that would impair brain electrophysiologic function. Moreover, epinephrine did not preferentially impair subendocardial blood flow as might be expected if it enhanced the strength of fibrillatory contractions.

[Value of preoperative screening studies]

In order to develop a sensitive and economically reasonable preoperative screening program capable of identifying perioperative risk factors, we performed a prospective study on patients scheduled for elective urological surgery. According to age, 379 patients were assigned to six groups. After the history and physical examination had been completed the attending anesthesiologist classified the patient's anesthetic risk according to ASA criteria. Furthermore, based on his clinical impression he ordered an individual set of screening parameters (laboratory tests, X-ray films, electrocardiography (ECG), and other appropriate diagnostic procedures) to be done. This "individual" screening and its results were compared with the results of the larger "routine" preoperative screening program performed independently of the study for all patients. All cases were then followed up in order to document perioperative complications. We were thus, able to recognize risk-identifying screening parameters resp. pathological findings missed by the "individual" screening. Laboratory tests from the nonselective "routine" screening yielded pathological results in a relatively high percentage of 31.4% of cases. ECG alterations or chest X-ray findings relevant to the patient's anesthetic management were present in 26.1% resp. 13.6%. Observations missed by the "individual" screening, though important for the prevention of perioperative complications, were pathological ECGs in only 1.9% of all cases. An influence of patient age on the frequency of pathological screening results and perioperative complications could be shown. Laboratory tests, chest X-rays and additional diagnostic procedures should be restricted to patients with pathological results or physiological examination. Our results underline once more the importance of a carefully taken history, a meticulous physical examination and the preoperative performance of an ECG for patients of every age scheduled for anesthesia and surgery.

[Models and methods in animal experiments in resuscitation]

Various animals models and several different methods are used in cardiopulmonary resuscitation (CPR) research. The animals used most frequently are dogs and pigs, but in each species thorax configurations, which might be an important factor in the mechanism of blood flow during CPR, are at great variance. The influence of anesthetics on cardiopulmonary and cerebral functions during and following resuscitation are largely unknown, and accordingly there is great variance in the techniques employed by individual researchers. The experimental design chosen with regard to the effect of heparin and epinephrine, induction, form, and duration of cardiac arrest as well as duration of CPR is often very different; comparisons are therefore difficult to make. During CPR ventilation is monitored using ventilatory pressure, frequency, tidal volume, and arterial blood gases. Thorax compressions are characterized by frequency, direction (sagittal, transversal), technique (mechanical, manual), relationship of time between compression and relaxation (50:50, 40:60), and depth of compression (power used, esophageal pressure, arterial blood pressure). Effects of CPR techniques are demonstrated during CPR by cardiovascular parameters. In addition to recording of blood pressure and blood flow, examination of regional perfusion rates using radioactive microsphere techniques is common. 24-h surveillance and extensive neurological tests are carried out during recovery following CPR.