[Unilateral spinal anesthesia : Literature review and recommendations]. / Einseitige Spinalanästhesie : Literaturübersicht und Handlungsempfehlung.

Unilateral spinal anesthesia is a cost-effective and rapidly performed anesthetic technique. An exclusively unilateral block only affects the sensory, motor and sympathetic functions on one side of the body and offers the advantages of a spinal block without the typical adverse side effects seen with a bilateral block. The lack of hypotension, in particular, makes unilateral spinal anesthesia suitable for patients with cardiovascular risk factors e. g. aortic valve stenosis or coronary artery disease. Increasing numbers of surgical procedures are now being performed on an outpatient basis. Until now, spinal anesthesia has been considered unsuitable for this, not only because of the high incidence of intraoperative hypotension and postoperative urinary retention but also because of the prolonged postoperative stay before home discharge. This is not the case with unilateral spinal anesthesia: motor function returns rapidly, the incidence of urinary retention is extremely low, and patients are usually eligible for home discharge sooner than after bilateral spinal anesthesia or general anesthesia. The success of the technique depends on a number of factors. In addition to the local anesthetic, its concentration and dose, and the baricity of the injected solution, the shape of the spinal needle, the injection speed, the patient's position during injection, and the time the patient remains in this position after injection are equally important parameters. A number of intrathecally applied adjuvant drugs are used to give a more intense and/or longer-lasting block. For this review, we collated the published data on unilateral spinal anesthesia from journals with an impact factor greater than 1.0 and defined an optimized method for performing the technique. In order to achieve an exclusively unilateral block one should use 0.5 % hyperbaric bupivacaine injected at a rate of 0.33 ml/min or slower. During the injection and the following 20 min the patient should lie in the lateral decubitus position on the side intended for surgery with knees drawn to the chest. An injection of 5 mg (1 ml) hyperbaric bupivacaine 0.5 % provides an hour-long block to T 12, and a dose of 7.5 to 10 mg (1.5-2.0 ml) extends the block to T 6. Adding clonidine (0.5 to 1.0 µg/kg BW) to the injection prolongs the duration of the block to approximately two to three hours. During the 20-minute fixation period, the cephalad spread of the block can be influenced to a certain extent by raising or lowering the head of the table.

[Performance development of a university operating room after implementation of a central operating room management]. / Leistungsentwicklung eines universitären OP-Bereichs nach Implementierung eines zentralen OP-Managements.

The difficult financial situation in German hospitals requires measures for improvement in process quality. Associated increases in revenues in the high income field "operating room (OR) area" are increasingly the responsibility of OR management but it has not been shown that the introduction of an efficiency-oriented management leads to an increase in process quality and revenues in the operating theatre. Therefore the performance in the operating theatre of the University Medical Center Göttingen was analyzed for working days in the core operating time from 7.45 a.m. to 3.30 p.m. from 2009 to 2014. The achievement of process target times for the morning surgery start time and the turnover times of anesthesia and OR-nurses were calculated as indicators of process quality. The number of operations and cumulative incision-suture time were also analyzed as aggregated performance indicators. In order to assess the development of revenues in the operating theatre, the revenues from diagnosis-related groups (DRG) in all inpatient and occupational accident cases, adjusted for the regional basic case value from 2009, were calculated for each year. The development of revenues was also analyzed after deduction of revenues resulting from altered economic case weighting. It could be shown that the achievement of process target values for the morning surgery start time could be improved by 40 %, the turnover times for anesthesia reduced by 50 % and for the OR-nurses by 36 %. Together with the introduction of central planning for reallocation, an increase in operation numbers of 21 % and cumulative incision-suture times of 12% could be realized. Due to these additional operations the DRG revenues in 2014 could be increased to 132 % compared to 2009 or 127 % if the revenues caused by economic case weighting were excluded. The personnel complement in anesthesia (-1.7 %) and OR-nurses (+2.6 %) as well as anesthetists (+6.7 %) increased less compared to the revenues or were slightly reduced. This improvement in process quality and cumulative incision-suture times as well as the increase in revenues, reflect the positive impact of an efficiency-oriented central OR management. The OR management releases due to measures of process optimization the necessary personnel and time resources and therefore achieves the basic prerequisites for increased revenues of surgical disciplines. The method presented can be used by other hospitals as a guideline to analyze performance development.

[OR minute myth : Guidelines for calculation of DRG revenues per OR minute]. / Mythos OP-Minute : Leitfaden zur Kalkulation von DRG-Erlösen pro Op-Minute.

The economic situation in German Hospitals is tense and needs the implementation of differentiated controlling instruments. Accordingly, parameters of revenue development of different organizational units within a hospital are needed. This is particularly necessary in the revenue and cost-intensive operating theater field. So far there are only barely established productivity data for the control of operating room (OR) revenues during the year available. This article describes a valid method for the calculation of case-related revenues per OR minute conform to the diagnosis-related groups (DRG).For this purpose the relevant datasets from the OR information system and the § 21 productivity report (DRG grouping) of the University Medical Center Göttingen were combined. The revenues defined in the DRG browser of the Institute for Hospital Reimbursement (InEK) were assigned to the corresponding process times--incision-suture time (SNZ), operative preparation time and anesthesiology time--according to the InEK system. All full time stationary DRG cases treated within the OR were included and differentiated according to the surgical department responsible. The cost centers "OR section" and "anesthesia" were isolated to calculate the revenues of the operating theater. SNZ clusters and cost type groups were formed to demonstrate their impact on the revenues per OR minute. A surgical personal simultaneity factor (GZF) was calculated by division of the revenues for surgeons and anesthesiologists. This factor resembles the maximum DRG financed personnel deployment for surgeons in German hospitals.The revenue per OR minute including all cost types and DRG was 16.63 €/min. The revenues ranged from 10.45 to 24.34 €/min depending on the surgical field. The revenues were stable when SNZ clusters were analyzed. The differentiation of cost type groups revealed a revenue reduction especially after exclusion of revenues for implants and infrastructure. The calculated GZF over all surgical departments was 2.2 (range 1.9-3.6). A calculation of this factor at the DRG level can give economically relevant information about the case-related personnel deployment.This analysis shows for the first time the DRG-conform calculation of revenues per OR minute. There is a strong dependency on the considered cost type and the performing surgical field. Repetitive analyses are necessary due to the lack of reference values and are a suitable tool to monitor the revenue development after measures for process optimization. Comparative analyses within different surgical fields on this data base should be avoided. The demonstrated method can be used as a guideline for other hospitals to calculate the DRG revenues within the OR. This enables pursuing cost-effectiveness analysis by comparing these revenues with cost data from the cost unit accounting at a DRG or case level.

[Acute pain therapy in German hospitals as competitive factor. Do competition, ownership and case severity influence the practice of acute pain therapy?]. / Akutschmerztherapie in deutschen Krankenhäusern als Wettbewerbsfaktor. Wird die Praxis der Akutschmerztherapie von Wettbewerb, Trägerschaft und Fallschwere beeinflusst?

BACKGROUND: Due to the implementation of the diagnosis-related groups (DRG) system, the competitive pressure on German hospitals increased. In this context it has been shown that acute pain management offers economic benefits for hospitals. The aim of this study was to analyze the impact of the competitive situation, the ownership and the economic resources required on structures and processes for acute pain management. MATERIAL AND METHODS: A standardized questionnaire on structures and processes of acute pain management was mailed to the 885 directors of German departments of anesthesiology listed as members of the German Society of Anesthesiology and Intensive Care Medicine (DGAI, Deutsche Gesellschaft für Anästhesiologie und Intensivmedizin). RESULTS: For most hospitals a strong regional competition existed; however, this parameter affected neither the implementation of structures nor the recommended treatment processes for pain therapy. In contrast, a clear preference for hospitals in private ownership to use the benchmarking tool QUIPS (quality improvement in postoperative pain therapy) was found. These hospitals also presented information on coping with the management of pain in the corporate clinic mission statement more often and published information about the quality of acute pain management in the quality reports more frequently. No differences were found between hospitals with different forms of ownership in the implementation of acute pain services, quality circles, expert standard pain management and the implementation of recommended processes. Hospitals with a higher case mix index (CMI) had a certified acute pain management more often. The corporate mission statement of these hospitals also contained information on how to cope with pain, presentation of the quality of pain management in the quality report, implementation of quality circles and the implementation of the expert standard pain management more frequently. There were no differences in the frequency of using the benchmarking tool QUIPS or the implementation of recommended treatment processes with respect to the CMI. CONCLUSION: In this survey no effect of the competitive situation of hospitals on acute pain management could be demonstrated. Private ownership and a higher CMI were more often associated with structures of acute pain management which were publicly accessible in terms of hospital marketing.

[Implementation of a new emergency room protocol at a University Medical Center in Germany: basis for improved flow of information, adequate quality management and scientific assessment]. / Implementierung eines neuen Schockraumprotokolls an einem Universitätsklinikum in Deutschland: Grundlage für einen verbesserten Informationsfluss, adäquates Qualitätsmanagement und wissenschaftliche Auswertungen.

BACKGROUND: After analyzing the existing documentation protocol for the emergency room (ER), the department of anesthesiology of the Medical University of Göttingen (UMG) developed a new department-specific ER protocol. AIM: The objective was to improve the flow of patient information from the preclinical situation through the emergency room to the early inpatient period. With this in mind a new emergency protocol was developed that encompasses the very heterogeneic patient collective in the ER as well as forming a basis for quality management and scientific investigation, taking user friendliness and efficiency into consideration. MATERIAL AND METHODS: A strategical development of a new emergency room protocol is represented, which was realized using a self-developed 8-step approach. Technical support and realization was carried out using the Scribus 1.4.2 open source desktop and GIMP 2.8.4 GNU image manipulation graphic programs. RESULTS: The new emergency room protocol was developed based on scientific knowledge and defined targets. The following 13 sections represent the contents of the new protocol: general characteristics, emergency event, initial findings and interventions, vital parameters, injury pattern, vascular access, hemodynamics, hemogram/blood gas analysis (BGA), coagulopathy, diagnostics, emergency interventions, termination of ER treatment and final evaluation. CONCLUSION: The structured and elaborated documentation was limited to the target of two sides and succeeds in incorporating trauma patients as well as non-trauma patients in the ER.

Surgical pleth index-guided remifentanil administration reduces remifentanil and propofol consumption and shortens recovery times in outpatient anaesthesia.

BACKGROUND: The surgical pleth index (SPI) is an index based on changes in plethysmographic characteristics that correlate with the balance between the sympathetic and parasympathetic nervous system. It has been proposed as a measure of the balance between nociception and anti-nociception. The goal of this study was to test whether it could be used to titrate remifentanil in day-case anaesthesia. METHODS: A total of 170 outpatients were given total i.v. anaesthesia with propofol and remifentanil. The patients were randomized to have the remifentanil dose either adjusted according to the SPI (SPI group) or to clinical parameters (control group). The propofol dose was adjusted according to entropy in both groups. The consumption of anaesthetic drugs, recovery times, and complications were compared. RESULTS: The mean [standard deviation (SD)] remifentanil and propofol infusion rates in the SPI and control groups were 0.06 (0.04) vs 0.08 (0.05) µg kg(-1) min(-1) and 6.0 (2.1) vs 7.5 (2.2) mg kg(-1) h(-1), respectively (both P<0.05). The mean (SD) times to eye opening were -0.08 (4.4) and 3.5 (4.3) min and to extubation were 1.2 (4.4) and 4.4 (4.5) min in the SPI and control groups, respectively (both P<0.05). There was no difference between the groups with regard to satisfaction with the anaesthetic or intensity of postoperative pain. No patient reported intraoperative awareness. CONCLUSIONS: Adjusting the remifentanil dosage according to the SPI in outpatient anaesthesia reduced the consumption of both remifentanil and propofol and resulted in faster recovery.

[Pre-existing pain as comorbidity in postoperative acute pain service]. / Vorbestehender Schmerz als Komorbidität im postoperativen Akutschmerzdienst.

BACKGROUND: Pre-existing or chronic pain is a relevant risk factor for severe postoperative pain. The prevalence of pre-existing and chronic pain in hospital depends on the time definition used and is approximately 44 % and 33%, at 3 or 6 months, respectively. The aim of this study was to determine the prevalence and importance of pre-existing pain in patients treated by a postoperative acute pain service (APS) and to evaluate the requirements for treatment and resources as well as its quality in this context. MATERIAL AND METHODS: This study involved an evaluation of all visits by the APS of the University Hospital in Göttingen over an 8-week period including patient subjective quality assessment on the basis of the quality improvement in postoperative pain therapy (QUIPS) questionnaire. Pre-existing pain (>12 weeks) was assessed by recording patients history of pain by members of the APS. The results from patients with and without pre-existing pain were compared. RESULTS: A total of 128 patients (38% female, 62% male, aged 15-88 years old, mean age 59.8 ± 14.4 years) were seen by the APS on 633 occasions. Of these patients 91% had been admitted to hospital for surgery (66% for tumor surgery, 8% joint replacement, 9% other joint surgery and 16% other interventions), 50% had acute postoperative pain without pre-existing pain, 50% had had pre-existing pain for at least 12 weeks, 31% had chronic non-cancer pain and 19% pain possibly related to cancer. Patients with pre-existing pain showed no significant differences in the treatment requirements (e.g. adjustment of medication), use of resources (e.g. number of visits to the APS and time spent in hospital) and quality of care (e.g. pain intensity, functional aspects, side effects and complications) in the setting of the APS. However, there was an additional subsequent support by chronic pain and palliative care services. CONCLUSION: Pre-existing pain is a common comorbidity in surgery patients treated by the APS. There were no significant differences in treatment requirements and quality of care between the patients. This is in contrast to other studies of postoperative pain management which showed that patients with pre-existing postoperative pain had higher pain intensity. This indicates indirectly that the presence of pre-existing pain should be further evaluated as a potentially useful indication for the support by an APS. However there is an urgent need for further studies to clarify whether this indirect effect can be replicated at other hospitals or in other patient collectives. Also it has to be clarified what benefits pain patients have from this kind of treatment: if they benefit from the APS in general or from the special technique, if there is a long-term effect lasting beyond treatment in the APS or if this group of patients would benefit in general from multiprofessional and non-invasive concepts of acute pain treatment.

Laser-direct-drive fusion target design with a high-Z gradient-density pusher shell.

Laser-direct-drive fusion target designs with solid deuterium-tritium (DT) fuel, a high-Z gradient-density pusher shell (GDPS), and a Au-coated foam layer have been investigated through both 1D and 2D radiation-hydrodynamic simulations. Compared with conventional low-Z ablators and DT-push-on-DT targets, these GDPS targets possess certain advantages of being instability-resistant implosions that can be high adiabat (α≥8) and low hot-spot and pusher-shell convergence (CR_{hs}≈22 and CR_{PS}≈17), and have a low implosion velocity (v_{imp}<3×10^{7}cm/s). Using symmetric drive with laser energies of 1.9 to 2.5MJ, 1D lilac simulations of these GDPS implosions can result in neutron yields corresponding to ≳50-MJ energy, even with reduced laser absorption due to the cross-beam energy transfer (CBET) effect. Two-dimensional draco simulations show that these GDPS targets can still ignite and deliver neutron yields from 4 to ∼10MJ even if CBET is present, while traditional DT-push-on-DT targets normally fail due to the CBET-induced reduction of ablation pressure. If CBET is mitigated, these GDPS targets are expected to produce neutron yields of >20MJ at a driven laser energy of ∼2MJ. The key factors behind the robust ignition and moderate energy gain of such GDPS implosions are as follows: (1) The high initial density of the high-Z pusher shell can be placed at a very high adiabat while the DT fuel is maintained at a relatively low-entropy state; therefore, such implosions can still provide enough compression ρR>1g/cm^{2} for sufficient confinement; (2) the high-Z layer significantly reduces heat-conduction loss from the hot spot since thermal conductivity scales as ∼1/Z; and (3) possible radiation trapping may offer an additional advantage for reducing energy loss from such high-Z targets.

Investigation of the agreement of a continuous non-invasive arterial pressure device in comparison with invasive radial artery measurement.

BACKGROUND: Arterial pressure (AP) monitoring should be accurate, easy to use, free of risks, and ideally continuous. The continuous non-invasive arterial pressure (CNAP) device is non-invasive and provides continuous pressure readings. This study was performed to compare the agreement of CNAP and invasive AP monitoring. METHODS: Ninety patients undergoing surgery under general anaesthesia were enrolled. Invasive pressure monitoring was established at the radial artery. CNAP monitoring using a finger sensor recording was begun before induction of anaesthesia. Statistical analysis was conducted with the Bland-Altman method for comparisons of repeated measures. RESULTS: We obtained 16 843 valid pressure readings from 85 patients. Mean (sd) bias during maintenance of anaesthesia was: systolic AP: 4.2 (16.5) mm Hg; mean AP (MAP): -4.3 (10.4) mm Hg; and diastolic AP: -5.8 (6) mm Hg. The results of a subgroup analysis of patients who had a mean intra-arterial pressure of <70 mm Hg were as follows: systolic pressure: -0.3 (9.7) mm Hg; mean pressure: -6.8 (7.6) mm Hg; and diastolic pressure: -7.9 (7.2) mm Hg. Bias and percentage error during the induction period were greater in both the main and subgroup analyses, probably due to recalibration being omitted after induction. CONCLUSIONS: The CNAP monitor showed an acceptable agreement and was interchangeable with invasive pressure monitoring for MAP during normotensive conditions. During induction of anaesthesia and when the AP was low, the agreement was less good and interchangeability was not achieved. These results suggest that CNAP is not statistically equivalent to invasive monitoring during all periods of anaesthesia but may be a useful additional AP monitor.

An erythropoietin gene polymorphism in the hypoxia-responsive element at position 3434 is possibly associated with hypertension.

BACKGROUND/AIMS: Several polymorphisms of vasoactive hormones have been implicated in hypertension. Erythropoietin (EPO) interacts with vasoactive substances, such as angiotensin II. Previously detected single nucleotide polymorphisms in the hypoxia-responsive element of EPO might be associated with hypertension and hypertensive end organ damages. METHODS: 400 hypertensive patients and 200 age- and gender-matched normotensive controls were genotyped for an EPO polymorphism [cytosine (C)/thymine (T) single nucleotide polymorphism] at position 3434. Patients were grouped according to their genotype into the CC group (CC genotype) and the CT/TT group (CT and TT genotype). BP was measured by ambulatory BP monitoring. RESULTS: The CC genotype was present in 87% of hypertensive patients and in 78.5% of controls (p = 0.007). In addition, patients with the CC genotype had higher BP levels compared with CT/TT genotypes (BPsys 143.7 ± 20.4 vs. 136.1 ± 13.5 mm Hg, p = 0.01, and BPdias 85.8 ± 11.6 vs. 82.4 ± 8.9, p = 0.043) despite a nearly identical number of antihypertensive drugs (2.3 ± 1.5 vs. 2.3 ± 1.6; p = 0.257). 100% of the small number of patients with end-stage renal disease (n = 15) had the CC genotype. CONCLUSION: The CC genotype of the EPO gene at position 3434 is more frequently found in patients with hypertension and is associated with higher BP levels.

[Age rationing : means of resource allocation in healthcare systems]. / Altersrationierung : Mittel zur Ressourcenverteilung im Gesundheitswesen.

The necessity of limiting resource in healthcare systems is becoming increasingly more evident. The population has requirements especially in the field of healthcare which are principally unlimited. However, there are only limited financial resources which can be used to satisfy the wishes of the population. For this reason rationing models are being discussed increasingly more often. One example of these models is called age rationing which means that defined services are only offered to patients up to a particular age. The aim of this article is to discuss the model of age rationing in the context of an optimized use of resources in the healthcare system.

A neuronal mechanism for motivational control of behavior.

Acting to achieve goals depends on the ability to motivate specific behaviors based on their predicted consequences given an individual's internal state. However, the underlying neuronal mechanisms that encode and maintain such specific motivational control of behavior are poorly understood. Here, we used Ca2+ imaging and optogenetic manipulations in the basolateral amygdala of freely moving mice performing noncued, self-paced instrumental goal-directed actions to receive and consume rewards. We found that distinct neuronal activity patterns sequentially represent the entire action-consumption behavioral sequence. Whereas action-associated patterns integrated the identity, value, and expectancy of pursued goals, consumption-associated patterns reflected the identity and value of experienced outcomes. Thus, the interplay between these patterns allows the maintenance of specific motivational states necessary to adaptively direct behavior toward prospective rewards.

Clinical relevance of eNOS T-786C polymorphism for hospital mortality and morbidity in cardiac surgical patients.

AIM: The endothelial nitric oxide (eNOS) gene T-786C polymorphism may influence as a genetic risk factor cardiovascular diseases and shows association with cardiovascular mortality. We hypothesized that this polymorphism may lead to increase mortality and morbidity after cardiac surgery with cardiopulmonary bypass (CPB). METHODS: In 500 patients who underwent cardiac surgery with CPB we investigated the eNOS T-786C polymorphism by DNA-sequencing. The patients were grouped according to their genotype in three groups (TT, TC, and CC). RESULTS: The overall genotype distribution of T-786C polymorphism was TT=41.6%, TC=51.2%, and CC=7.2% respectively. The groups did not differ in age and gender. No significance was shown in preoperative risk factors, excluding peripheral disease (P=0.03). No difference was shown in Euroscore, APACHE II, and SAPS II. The usage of norepinephrine (P=0.03) and nitroglycerine (P=0.01) was significant higher in TC allele carrier. The mortality was quite uniform across elective and urgent subgroup. However, we found a significant difference concerning mortality and emergency cardiac procedures in homozygous C-allele carrier (P=0.014). CONCLUSION: The present study demonstrates that this polymorphism contributes to a higher prevalence of postoperative mortality after emergency cardiac surgery. Thus, the eNOS T-786C polymorphism could serve as a possibility to differentiate high risk subgroups in heterogeneous population of individuals with cardiac diseases who need cardiac surgery with CPB.

[The Göttingen manual for OR managers]. / Göttinger Leitfaden für OP-Manager.

Economic pressures are forcing German hospitals to take measures to secure the cost effectiveness of medical care. Surgical facilities are particularly affected as a high-cost segment. As a consequence hospital operators and administrators have begun to hire surgical facility (OR) managers whose task it is to implement efficiency-oriented steps and reorganization measures aimed at increasing productivity and profitability of the surgical services. The OR manager is confronted with high expectations in a complex environment full of potential conflicts. With this in mind, the following article defines and comments on the most important aspects of OR managerial duties and responsibilities. The authors are experienced in OR management and are able to give the reader not only the theoretical fundamentals but also recommendations and guidelines which are particularly valuable to those contemplating a career as OR manager.

[Preoperative prewarming as a routine measure. First experiences]. / Präoperative Vorwärmung in der klinischen Routine. Erste Erfahrungen.

BACKGROUND: Despite the broad application of intraoperative warming new studies still show a high incidence of perioperative hypothermia. Therefore a prewarming program in the preoperative holding area was started. METHODS: The efficacy of the prewarming program was assessed with an accompanying quality assurance check sheet over a period of 3 months. RESULTS: During the 3 month test period 127 patients were included. The median length from arrival in the holding area to beginning prewarming was 6 min and the average duration of prewarming was 46±38 min. During prewarming the core temperature rose by 0.3±0.4°C to 37.1±0.5°C and decreased to 36.3±0.5°C after induction of anesthesia. At the end of the operation the core temperature was 36.4±0.5°C and 14% of the patients were hypothermic. CONCLUSION: These data allow 2 conclusions: 1. Prewarming in the holding area is possible with a sufficient duration. 2. Prewarming is highly efficient even when performed over a relatively short duration.

Influence of airway management strategy on "no-flow-time" in a standardized single rescuer manikin scenario (a comparison between LTS-D and I-gel).

BACKGROUND: In 2005 the European Resuscitation Council (ERC) published a revised version of the guidelines for Advanced Life Support (ALS). One of the aims was to reduce the time without chest compression in the first period of cardiac arrest (no-flow-time; NFT). We evaluated in a manikin study the influence on NFT using the single use laryngeal tube with suction option (LTS-D) compared to single use I-gel for emergency airway management. METHODS: A randomised prospective study with 200 paramedics who performed standardised simulated cardiac arrest management in a manikin. RESULTS: The use of the LTS-D did not significantly reduce NFT compared with the I-gel (104.7s vs. 105.1s; p>0.05). The LTS-D was inserted as fast as the I-gel (10.4s vs. 9.3s; p>0.05). The LTS-D was correctly positioned by 98% of the participants on the first attempt compared to 96% with the I-gel. During the cardiac arrest simulation, establishing and performing first ventilation took an average of 40.5s with the LTS-D compared to 40.9s with the I-gel. CONCLUSION: In our manikin study, NFT was comparable using the LTS-D and the I-gel. Therefore, for personnel not experienced in tracheal intubation, the LTS-D and the I-gel seem to be equal alternatives in establishing the airway during cardiac arrest. However, relevant clinical studies are appropriate because any change in guidelines in this area must be based on clinical evidence.

Influence of angiotensin-I-converting-enzyme insertion/deletion gene polymorphism on perioperative hemodynamics after coronary bypass graft surgery.

AIM: The angiotensin I-converting enzyme insertion/ deletion polymorphism (ACE-I/D), including three genotypes (II, ID, DD), with a known impact on midterm mortality and morbidity in patients after coronary artery bypass graft surgery (CABG), was studied. Since this polymorphism has been linked with increased vascular response to phenylephrine during cardiopulmonary bypass (CPB), we investigated its possible effect on perioperative hemodynamics in patients undergoing CABG. METHODS: Genotyping for the ACE-I/D was performed by polymerase chain reaction (PRC) amplification in 110 patients who underwent elective CABG with CPB. Patients were assigned to two groups according to their genotype (group II [II genotype] and group ID/DD [ID and DD genotypes]). Systemic hemodynamics were measured directly before and at 4 h, 9 h, and 19 h after CPB. RESULTS: Genotype distribution of ACE-I/D was 18%, 57%, and 25% in genotypes II, ID, and DD, respectively. The two groups were similar in age (group II: 66+/-6 years, group ID/DD: 66+/-8 years), body-mass-index (BMI) (group II: 28+/-2, group ID/DD: 29+/-5 kg/m2), male: female ratio (group II: 16: 4, group ID/DD: 63: 27) and Euroscore (group II: 3.1+/-1.9, group ID/DD: 3.5+/-2.1). There were no differences in mortality rate or perioperative systemic hemodynamics. The pulmonary vascular resistance before cardiopulmonary bypass was higher in the ID/DD genotypes than in the II genotypes (227+/-121 vs 297+/-169 dyn.s(-1).m2.cm(-5)). Four hours after CPB no difference remained; at 9 h after cardiopulmonary bypass there was a slight difference in pulmonary vascular resistance between the two groups (247+/-134 vs 290+/-117 dyn.s(-1).m2.cm(-5)) and a significant difference in pulmonary arterial pressure (19+/-6 vs 23+/-8); at 19 h after CPB the differences were no longer detectable. CONCLUSION: ACE-I/D had no influence on perioperative systemic hemodynamics. However, transitory differences in pulmonary hemodynamic were observed after CPB. These differences may have been due to changes in serum ACE activity during CPB.

CMV monitoring using blood cells and plasma: a comparison of apples with oranges?

Quantitative cytomegalovirus (CMV) monitoring is still far from being standardized between transplant centers. In the present study, we compared assays for quantitative CMV monitoring using blood cells and plasma. Four hundred and thirty-five consecutive samples from 29 patients with active CMV infection after allogeneic T-cell-depleted hemopoietic stem cell transplantation were tested in parallel using pp65 antigenemia and quantitative CMV polymerase chain reaction (PCR) in blood cells and plasma (COBAS AMPLICOR CMV MONITOR). Although only 142 (53.1%) of 253 positive samples were concordantly identified by all three assays, the number of positive samples detected by each assay was not different and the quantitative values were correlated, provided that nucleic acid (NA) in plasma was isolated by COBAS AmpliPrep and not by the manual protocol. Six (18%) of 34 episodes with active CMV infection were not detected using CMV PCR in plasma; whereas in times of white blood cell aplasia or blast crisis of leukemia, samples with active CMV infection in plasma could not be detected using blood cells. We conclude that CMV monitoring in whole blood could be favorable compared with assays using plasma or blood cells alone. Automated NA isolation could become an attractive tool for a more sensitive and better standardized molecular diagnostics.

Imaging pathologic pulmonary air and fluid accumulation by functional and absolute EIT.

The increasing use of EIT in clinical research on severely ill lung patients requires a clarification of the influence of pathologic impedance distributions on the validity of the resulting tomograms. Significant accumulation of low-conducting air (e.g. pneumothorax or emphysema) or well-conducting liquid (e.g. haematothorax or atelectases) may conflict with treating the imaging problem as purely linear. First, we investigated the influence of stepwise inflation and deflation by up to 300 ml of air and 300 ml of Ringer solution into the pleural space of five pigs on the resulting tomograms during ventilation at constant tidal volume. Series of EIT images representing relative impedance changes were generated on the basis of a modified Sheffield back projection algorithm and ventilation distribution was displayed as functional (f-EIT) tomograms. In addition, a modified simultaneous iterative reconstruction technique (SIRT) was applied to quantify the resistivity distribution on an absolute level scaled in Omega m (a-EIT). Second, we applied these two EIT techniques on four intensive care patients with inhomogeneous air and fluid distribution and compared the EIT results to computed tomography (CT) and to a reference set of intrathoracic resistivity data of 20 healthy volunteers calculated by SIRT. The results of the animal model show that f-EIT based on back projection is not disturbed by the artificial pneumo- or haematothorax. Application of SIRT allows reliable discrimination and detection of the location and amplitude of pneumo- or haematothorax. These results were supported by the good agreement between the electrical impedance tomograms and CT scans on patients and by the significant differences of regional resistivity data between patients and healthy volunteers.