Detection of coronary microembolisation by Doppler ultrasound during percutaneous coronary interventions

OBJECTIVE

To validate an intracoronary Doppler ultrasound device for high intensity transient signals (HITS) detection and to assess the incidence of HITS during percutaneous coronary intervention (PCI).

METHODS AND RESULTS

In an in vitro model, particle count and number of HITS detected by an intracoronary 0.014 inch Doppler wire were closely correlated (r = 0.97, p < 0.001). In the clinical study, 32 patients (mean (SD) age 61 (11) years; 23 men, nine women) with coronary artery disease were treated with balloon dilatation and stent implantation for a single vessel stenosis. In these patients HITS were detected during PCI in 84% (27 of 32). Reproducibility (r = 0.99, p < 0.001) and interobserver agreement (r = 0.84, p < 0.001) of HITS counts were significant. The number of HITS after stent implantation was significantly higher than after balloon dilatation (11 (7) v 2 (4), p < 0.001). Postprocedural coronary flow velocity reserve (CFVR) was < 2.0 in 55% (16 of 29) of all patients after balloon dilatation and < 2.0 in 23% (six of 26) after stent implantation. The number of HITS after stent implantation did not differ significantly between patients with CFVR < 2.0 and patients with CFVR > or = 2.0 (12 (8) v 10 (7), not significant).

CONCLUSIONS

Embolic particles can be detected as HITS by an intracoronary Doppler ultrasound device. Coronary microembolism is often observed during PCI, especially after stent implantation. However, the incidence of HITS alone does not explain a reduced CFVR after PCI.

Diagnosing aortic valve stenosis by correlation analysis of wavelet filtered heart sounds

Traditional auscultation performed by the general practitioner remains problematic and often gives significant results only in a late stage of heart valve disease. Valve stenoses and insufficiencies are nowadays diagnosed with accurate but expensive ultrasonic devices. This study aimed to develop a new heart sound analysis method for diagnosing aortic valve stenoses (AVS) based on a wavelet and correlation technique approach. Heart sounds recorded from 373 patients (107 AVS patients, 61 healthy controls (REF) and 205 patients with other valve diseases (OVD)) with an electronic stethoscope were wavelet filtered, and envelopes were calculated. Three correlations on the basis of these envelopes were performed: within the AVS group, between the groups AVS and REF and between the groups AVS and OVD, resulting in the mean correlation coefficients rAVS, rAVSv.REF and rAVSv.OVD. These results showed that rAVS (0.783 +/- 0.097) is significantly higher (p < 0.0001) than rAVSv.REF (0.590 +/- 0.056) and rAVSv.OVD (0.516 +/- 0.056), leading to a highly significant discrimination between the groups. The wavelet and correlation-based heart sound analysis system should be useful to general practitioners for low-cost, easy-to-use automatic diagnosis of aortic valve stenoses.

Surgical smoke and infection control

Gaseous byproducts produced during electrocautery, laser surgery or the use of ultrasonic scalpels are usually referred to as 'surgical smoke'. This smoke, produced with or without a heating process, contains bio-aerosols with viable and non-viable cellular material that subsequently poses a risk of infection (human immunodeficiency virus, hepatitis B virus, human papillomavirus) and causes irritation to the lungs leading to acute and chronic inflammatory changes. Furthermore, cytotoxic, genotoxic and mutagenic effects have been demonstrated. The American Occupational Safety and Health Administration have estimated that 500000 workers are exposed to laser and electrosurgical smoke each year. The use of standard surgical masks alone does not provide adequate protection from surgical smoke. While higher quality filter masks and/or double masking may increase the filtration capability, a smoke evacuation device or filter placed near (2-5 cm) the electrocautery blade or on endoscope valves offers additional (and necessary) safety for operating personnel and patients.

Staphylococcus aureus carriage among participants at the 13th European Congress of Clinical Microbiology and Infectious Diseases

The aim of this study was to measure the rate of Staphylococcus aureus nasal colonization among attendees of the 13th European Congress of Clinical Microbiology and Infectious Diseases (ECCMID), particularly with regard to methicillin-resistant (MRSA) strains. The 31.4% rate of Staphylococcus aureus colonization detected among the participants was in line with colonization rates reported previously for healthcare workers. A statistical difference was found between the rates of Staphylococcus aureus carriage in physicians (37.4%) and non-physicians (21.7%) but not between males (35.0%) and females (28.9%). Only one participant (a Belgian physician) was found to carry MRSA. Surprisingly, the rate of methicillin-susceptible Staphylococcus aureus carriage was significantly higher among participants from countries with a low prevalence of MRSA.

[Sex/Gender research -- introduction and anesthesiological aspects]

On the one hand gender studies are based on the differentiation of biological (sex) and social (gender) identities. Above all, gender studies in public health research are seen as an biological, psychological and social entity. To understand the complexity linked to the term "gender" in medicine, different perspectives are required. Apart from the uncertainty, which may occur by the changing perspective on gender, it also holds the option for innovation in anesthesiology, too. The goal of gender based medicine is an optimized, individual adjusted medical care. Precondition to realize this aim is the understanding of the genesis, the consolidation, and the elimination of gender biases in all fields of research, publications and education. The transfer of methods and guidelines for gender sensitive research, adapted from the public health research, allows an access to detect the meaning of gender specifics and gender differences, to verify its clinical relevance and to exercise the results in clinical daily work. With gender sensitive methods desiderata should be reduced, and methodological standards for gender sensitive medical/clinical research can be developed and implemented into medical education. In the light of knowledge about sex specific differences in pharmacokinetic and pharmacodynamic as well as undesired drug interactions, basic research may help to overcome the gender gap and to individualize and optimize the anesthesiological approach as well. A main problem in implementing gender studies into medicine is the limitation of sex sensitive biomedical significance. Nevertheless, the already existing measures in public health should be evaluated and modified for clinical practice. The current review is to be read as an introduction into different aspects of gender studies in medicine, in order to extend the understanding of its importance for anesthesiology, too. It shows that the relevance transcends still existing studies based on biomedical gender diversities.

A putative regulatory polymorphism in PD-1 is associated with nephropathy in a population-based cohort of systemic lupus erythematosus patients

The association between polymorphisms in the programmed death (PD-1) gene and susceptibility to systemic lupus erythematosus (SLE) was determined using genomic DNA, isolated from a population-based cohort of 95 SLE patients and 155 healthy controls. Polymorphisms in the complete PD-1 gene except the large intron 1 were detected by sequencing. Furthermore, the patients were stratified according to the presence or absence of lupus nephropathy. The influence of the detected single nuclear polymorphisms (SNPs) on this specific clinical disease parameter was determined. In total, we identified 12 single nucleotide polymorphisms, of which six were novel and eight were considered to be rare (the frequency of the minor allele of these was less than 1% in our study populations). We found a significant association of an intronic 6867C/G SNP in the PD-1 gene with the presence of lupus nephropathy. As the 6867C/G SNP is located in a putative binding site for the transcriptional repressor ZEB, the associated allele of this SNP potentially alters the transcriptional regulation of PD-1. This report, for the first time, indicates that a 6867C/G SNP of the PD-1 gene is associated with lupus nephropathy in Caucasian SLE patients.

Autoantibodies and self-reported health complaints in relatives of systemic lupus erythematosus patients: a community based approach

First-degree relatives (FDRs) and spouses to a population-derived cohort of lupus patients were investigated for the occurrence of selected autoantibodies and self-reported health complaints. A healthy reference population was included. The lupus population consisted of 103 index cases. A total of 275/375 available relatives accepted to enter the study. Two hundred and twenty-six/315 (72%) were FDRs and 49/60 (82%) were spouses. Serum was analysed for ANA using indirect immunofluorescence on Hep-2 cells at the following dilutions: 1:40, 1:80 and 1:160 and in addition sera were tested for anti-dsDNA, IgM RF, ACA (IgM, IgG), anti-beta2GPI (IgM, IgG) and antibodies to prothrombin. ANA positivity occurred more frequently in FDRs compared with spouses and controls at serum dilution 1:160 (10 versus 0% and 2.5%, respectively, P = 0.04 and P < 0.01), 1:80 (24 versus 4% and 5%, respectively, P = 0.003 and P < 0.001) and 1:40 (31 versus 10% and 10%, respectively, P = 0.006 and P < 0.0001). ANA positivity in FDRs occurred randomly, irrespective of family relationship. Fifty-three/184 versus 2/32 FDRs to patients with definite SLE (D-SLE) and incomplete SLE (I-SLE), respectively, tested ANA positive at 1:80 (P < 0.05). FDRs with ANA titer at 80 were affiliated to lupus probands with high SLICC scores (P < 0.05). Self-reported health complaints, cardiovascular/thromboembolic events in particular, were more frequent among FDRs than in spouses. The population-based approach adopted in the present study supports previous clinic-based evidence of an increased propensity for autoantibody occurrence in relatives to SLE patients. In FDRs, present ANA positivity was associated with increased prevalence of health complaints and ANA positivity in FDRs was related to the criterial burden and cumulated damage in corresponding lupus probands. The low ANA frequency among spouses of SLE patients argues against a significant autoantibody triggering effect of shared environment in adult life.

Baroreflex sensitivity, heart rate, and blood pressure variability in hypertensive pregnancy disorders

Hypertensive pregnancy disorders are a leading cause of perinatal and maternal morbidity and mortality. Heart rate variability (HRV), blood pressure variability (BPV), and baroreflex sensitivity (BRS) are relevant predictors of cardiovascular risk in humans. The aim of the study was to evaluate whether HRV, BPV, and BRS differ between distinct hypertensive pregnancy disorders. Continuous heart rate and blood pressure recordings were performed in 80 healthy pregnant women as controls (CON), 19 with chronic hypertension (CH), 18 with pregnancy-induced hypertension (PIH), and 44 with pre-eclampsia (PE). The data were assessed by time and frequency domain analysis, nonlinear dynamics, and BRS. BPV is markedly altered in all three groups with hypertensive disorders compared to healthy pregnancies, whereby changes were most pronounced in PE patients. Interestingly, this increase in PE patients did not lead to elevated spontaneous baroreflex events, while BPV changes in both the other hypertensive groups were paralleled by alterations in baroreflex parameters. The HRV is unaltered in CH and PE but significantly impaired in PIH. We conclude that parameters of the HRV, BPV, and BRS differ between various hypertensive pregnancy disorders. Thus, distinct clinical manifestations of hypertension in pregnancy have different pathophysiological, regulatory, and compensatory mechanisms.

The training curriculum in hospital infection control

Standardised training curricula for infection control nurses (ICNs) and recognition of the specialty exist in many European countries, but infection control physician (ICP) is not a specialty recognised by the UEMS. To gather information on curricula for ICPs, members of the ESCMID Study Group on Nosocomial Infections received a questionnaire. There is discussion about which 'professions' should be included in an infection control team. Within the 12 countries included, the average full-time equivalents (FTEs) for ICPs and ICNs per 1000 beds were 1.2 and 3.4, respectively. In addition to ICNs and ICPs, an infection control team should also include a data manager, an epidemiologist, secretarial/administrative support, and possibly, surveillance technicians. Overall, the composition of an ideal infection control team was estimated to be 9.3 FTE per 1000 beds. The background of ICPs can be clinical microbiology or infectious diseases. Among the participants, it was predominantly clinical microbiology. The ideal training curriculum for the ICP should include 6 years of postgraduate training. Of these, at least 2 years should be 'clinical training' (e.g., internal medicine) to acquire experience in the management of high-risk patients. Furthermore, training with regard to infection control and hospital epidemiology should be offered as a 'common trunk' for those being trained in clinical microbiology or infectious diseases. Important issues that remain are: implementation/standardisation of training curricula for doctors, recognition of ICP as a separate specialty or sub-specialty of clinical microbiology and/or infectious diseases, validation of on-the-job training facilities in terms of the number of doctors and nurses who can give training and the category of patients/problems present, and mandatory postgraduate education/continuing medical education specific for infection control for doctors and nurses in the field.

A European perspective on intravascular catheter-related infections: report on the microbiology workload, aetiology and antimicrobial susceptibility (ESGNI-005 Study)

The laboratory workload, microbiological techniques and aetiology of catheter-related infections in European hospitals are mostly unknown. The present study (ESGNI-005) comprised a 1-day (22 October 2001), laboratory-based, point-prevalence survey based on a questionnaire completed by microbiology laboratories in European (European Union (EU) and non-EU) hospitals. Also included were questions requesting retrospective information for the year 2000. In total, 151 hospitals from 26 European countries participated, of which 78.1% were teaching institutions. Overall, the estimated population served by these institutions was 121,363,800, and the estimated number of admissions during 2000 was 6,712,050. The total number of catheter tips processed during 2000 was 142,727, or 21/1,000 admissions, of which 23.7% were considered to be positive in the institutions using semiquantitative or quantitative techniques. Overall, EU centres received significantly more catheter tip samples/1,000 admissions and had a significantly higher rate of 'positivity' (p < 0.0001) than non-EU centres. Of the institutions surveyed, 11.4% (7.2% in EU countries and 23.7% in non-EU countries; p 0.04) used only qualitative techniques for catheter tip sample processing. On the day of the study, 167 microorganisms were recovered from significant catheter tip cultures (122 patients), of which Gram-positive bacteria represented 70.7%, Gram-negative bacteria 22.2%, and yeasts 7.2%. The five most common microorganisms were coagulase-negative staphylococci, Staphylococcus aureus, Candida spp., Enterococcus spp. and Pseudomonas spp. Overall, 19% of catheter tip cultures were polymicrobial. In the case of S. aureus, 40% of isolates were resistant to oxacillin, as were 63.4% of coagulase-negative staphylococcus isolates. Of 37 Gram-negative isolates, 35% were resistant to cefotaxime, 31% to ceftazidime, and 27% to ciprofloxacin. Imipenem and cefepime had the lowest reported rates of resistance (11%).

Clinical-epidemiological characteristics and outcome of patients with catheter-related bloodstream infections in Europe (ESGNI-006 Study)

This study analysed 89 episodes of catheter-related bloodstream infection (CR-BSI) occurring during one week in 107 hospitals from 21 European countries (1.02 episodes/1,000 admissions). Patients from European Union (EU) countries had a higher incidence of CR-BSI than patients from non-EU countries (1.55 vs. 0.33/1,000 admissions). Most (67%) catheters were non-tunneled central venous catheters, were in the jugular vein (44%), had been implanted for > 7 days (70%), were made of polyurethane (61%) and were multi-lumen (67%). In 36% of cases, catheters were implanted by physicians other than anaesthetists or surgeons, and 50% were inserted by junior staff.

Hospital infection control in Europe: evaluation of present practice and future goals

The objective of this study was to assess current infection control practice in Europe and its structure, future research priorities, and how infection control should be organised. A questionnaire was sent to 223 hospital infection control physicians throughout Europe, of whom 54 in 18 countries responded. With respect to future research priorities in infection control in Europe, the largest proportion (69%) of the infection control specialists sampled expressed the need for standardisation of surveillance systems for international comparison of nosocomial infection rates. The results of this survey might help to create a basis for standardised guidelines which take into account European-wide interests.

Low prevalence of methicillin-resistant Staphylococcus aureus (MRSA) at hospital admission in the Netherlands: the value of search and destroy and restrictive antibiotic use

In the Netherlands, less than 1% of clinical isolates of Staphylococcus aureus are methicillin-resistant (MRSA). A national search and destroy policy prevents MRSA from becoming endemic. Some MRSA outbreaks cannot be related to patients at risk for MRSA carriage. This study was designed to measure the prevalence of MRSA among patients without risk factors for MRSA carriage at the time of admission to the hospital. In four Dutch hospitals, patients admitted to non-surgical departments in the period 1999-2000 were screened for MRSA nasal carriage. Nasal swabs were streaked on 5% sheep blood agar (BA), submerged in a selective broth, and incubated for two to three days at 35 degrees C. Colonies suspected of being S. aureus were identified with an agglutination test. Susceptibility testing was performed by an automated system and additional oxacillin disk diffusion. Methicillin resistance was confirmed by a DNA hybridization test and mecA PCR. MRSA strains were genotyped by pulsed-field gel electrophoresis (PFGE). Twenty-four percent (2332/9859) of the patients were S. aureus nasal carriers. Only three (0.03%) patients were MRSA carriers. These patients were not repatriated, nor known to be MRSA carriers before screening. Genotyping revealed that the strains were not clonally related and were not related to MRSA outbreaks in the hospital where the patients were admitted. We conclude that at routine admission to a Dutch hospital (excluding high-risk foreign admissions) the MRSA prevalence is low (0.03%), due to the Dutch search and destroy policy and restrictive antibiotic prescribing.

Estimating respiratory pattern variability by symbolic dynamics

OBJECTIVES

The traditional techniques of data analysis are often not sufficient to characterize the complex dynamics of respiration. In this study the respiratory pattern variability was analyzed using symbolic dynamics.

METHODS

A group of 20 patients on weaning trials from mechanical ventilation were studied at two different pressure support ventilation levels. Breath duration (T(TOT)) time series and the relation T(I)/T(TOT), that contains the influence of inspiratory time (T(I)), were considered. Length-3 words and 3 different symbols were proposed. The incidence of the overlapping tau and the parameter alpha were analyzed.

RESULTS

From the breath duration time series, the distribution of words with probability of occurrence higher than 6% was concentrated on one word for low respiratory variability, whereas high variability was characterized by 4 words, presenting a statistically significant difference (p </= 0.0005). The probability occurrence of words "110" and "111" was also significantly different (p</= 0.0005) when comparing both variabilities.

CONCLUSION

The analysis carried out obtained discriminant functions able to correctly classify all the testing set series. These results permit the consideration of symbolic dynamics as a promising methodology to study the respiratory pattern variability.

Forecasting of life threatening arrhythmias using the compression entropy of heart rate

OBJECTIVES

Ventricular tachycardia (VT) provoking sudden cardiac death (SCD) are a major cause of mortality in the developed countries. The most efficient therapy for SCD prevention are implantable cardioverter defibrillators (ICD). In this study heart rate variability (HRV) measures were analyzed for short-term forecasting of VT in order to improve VT sensing and to enable a patient warning of forth-coming shocks.

METHODS

The last 1000 normal beat-to-beat intervals before 50 VT episodes stored by the ICD were analyzed and compared to individually acquired control time series (CON). HRV analysis was performed with standard parameters of time and frequency domain as suggested by the HRV Task Force and furthermore with a newly developed and optimized nonlinear parameter that assesses the compression entropy of heart rate (Hc).

RESULTS

Except of meanNN (p = 0.02) we found no significant differences in standard HRV parameters. In contrast, Hc revealed highly significant (p = 0.007) alterations in VT compared with CON suggesting a decreased complexity before the onset of VT.

CONCLUSION

Compression entropy might be a suitable parameter for short-term forecasting of life-threatening tachycardia in ICD.

Severe acute respiratory syndrome: lessons and uncertainties

The outbreak of severe acute respiratory syndrome (SARS) has produced scientific and epidemiological discoveries with unprecedented speed, and this information has been spread instantaneously to the global health community through the internet. Within a few weeks, the coronavirus associated with SARS (SARS-CoV) was identified and sequenced. The source of the outbreak and the exact modes of transmission are still subjects of research. Important lessons can be learned from the SARS outbreak about both the scientific and the public health approach to emerging pathogens.

Two cases of subcutaneous Scedosporium apiospermum infection treated with voriconazole

Scedosporium apiospermum is a mold that is increasingly being recognized as an opportunistic pathogen in immunocompromised patients, and treatment is complicated by intrinsic resistance to several antifungal agents. In our hospital, two cases of S. apiospermum infection occurring within 2 weeks were successfully treated with voriconazole. Since both patients were infected with an uncommon pathogen, a search for a common nosocomial source was performed. As environmental cultures yielded no S. apiospermum, and random amplified polymorphic DNA (RAPD) fingerprinting showed that the patients' strains were genotypically unrelated, we considered a common nosocomial source of S. apiospermum to be unlikely.

[Quantitative analysis of cardiovascular interactions in patients with cardiomyopathy and after myocardial infarct]

The aim of this study was to detect pathological changes of the complex autonomous regulation of ecg, blood pressure and respiration (synchronously recordings of 30 minutes) in patients with cardiac diseases. We investigated the cardiovascular and cardiorespiratory linear and nonlinear interactions in 10 patients with dilative cardiomyopathy (dcm) and in 10 patients after myocardial infarction (mi). We compared results from the classical linear correlation function analysis with results from the mutual information method (transinformation) for analysis of nonlinear and linear interactions. Both methods yield high significant parameters (p < 0.01). Thus, we found both linear and nonlinear interactions with partly different specificity in patients with dcm and mi compared to healthy subjects (ref).

[Heart rate and blood pressure interaction in normotensive and chronic hypertensive pregnancy]

Pregnancy has impact on autonomic control. Since hypertensive pregnancy disorders are a major cause of maternal mortality we investigated the baroreflex sensitivity (BRS) in chronic hypertensive pregnant women (CH), normotensive pregnant (PRE) and non-pregnant (NPRE) women. In addition to the traditional 'sequence method' we used joint symbolic dynamics (JSD). BRS was significantly reduced in all pregnancies compared with NPRE (p < 0.00001) but there was no significant difference between CH and PRE. Contrary, the JSD measures revealed significant differences (p < 0.00001) in the heart rate and blood pressure interactions between PRE and CH. In conclusion, JSD measures uncovered a different gestation related adaptation of autonomic regulation in women with chronic.

[Effect of post-extrasystole potentiation on blood pressure and heart rate regulation]

Noninvasive finger arterial blood pressure and ECG were recorded for 30 min in patients with idiopathic dilated cardiomyopathy (IDC) and healthy control subjects (CON) for the investigation of blood pressure and heart rate regulation following a premature ventricular complex (PVC). The potentiation of blood pressure amplitude of the postextrasystolic beat was fivefold increased in IDC compared with CON (48.7 +/- 32.6% vs. 9.8 +/- 5.4%, p < 0.01). PVC starts a baroreflex response, which last about 10 s in physiological regulation. In contrast, the baroreflex response in IDC is immediately suppressed by the augmented potentiation of the blood pressure amplitude from the first postextrasystolic beat. Thus, the regulation after PVC is determined by the PVC itself and postextrasystic potentiation.

[Validation of simultaneously acquired blood pressure data by statistical coincidence determination of heart rate variability and blood pressure variability]

We report on the comparison of simultaneous non-invasive measurements of finger blood pressure obtained at both hands with two Portapres systems. We investigated the impact of altering the measurement location on heart rate and blood pressure variability (HRV,BPV) parameters. Two 30 minutes recordings were done twice in 21 volunteers swapPing the systems. HRV and BPV parameters meanNN, sdNN, HF/P and Fw-Shannon were determined. Left and right side corresponding parameters were compared by U-test and correlations. Coincidence matrices were analysed by Mahalanobis distance. The minimal total divergence in HRV was 4.8%, in systolic BPV 6.7% and diastolic BPV 12.1%. These estimates recommend those parameters for multi-center studies that are insensitive to the measurement location.