Point-of-care controls for nosocomial legionellosis combined with chlorine dioxide potable water decontamination: a two-year survey at a Welsh teaching hospital.

This study reports a two-year programme of attempted eradication of Legionella colonization in the potable water supply of a 1000-bed tertiary care teaching hospital in Wales. There was a simultaneous, point-of-care, sterile-water-only policy for all intensive care units (ICU) and bone marrow and renal transplant units in order to prevent acquisition of nosocomial Legionnaires' disease. The programme was initiated following a case of nosocomial pneumonia caused by Legionella pneumophila serogroup 1-Bellingham-like genotype A on the cardiac ICU. The case occurred 14 days after mitral and aortic valve replacement surgery. Clinical and epidemiological investigations implicated aspiration of hospital potable water as the mechanism of infection. Despite interventions with chlorine dioxide costing over 25000 UK pounds per annum, Legionella has remained persistently present in significant numbers (up to 20000 colony forming units/L) and with little reduction in the number of positive sites. Two further cases of nosocomial disease occurred over the following two-year period; in one case, aspiration of tap water was implicated again, and in the other case, instillation of contaminated water into the right main bronchus via a misplaced nasogastric tube was implicated. These cases arose because of inadvertent non-compliance with the sterile-water-only policy in high-risk locations. Enhanced clinical surveillance over the same two-year period detected no other cases of nosocomial disease. This study suggests that attempts at eradication of Legionella spp. from complex water systems may not be a cost-effective measure for prevention of nosocomial infections, and to the best of our knowledge is the first study from the UK to suggest that the introduction of a sterile-water-only policy for ICUs and other high-risk units may be a more cost-effective approach.

Infective endocarditis in Europe: lessons from the Euro heart survey.

OBJECTIVES: To describe the characteristics, treatment, and outcomes of active infective endocarditis (IE) in Europe. DESIGN: Prospective survey of medical practices in Europe. SETTING: 92 centres from 25 countries. PATIENTS: The EHS (Euro heart survey) on valvar heart disease (VHD) enrolled 5001 adult patients between April and July 2001. Of those, 159 had active IE. RESULTS: 118 patients (74%) had native IE and 41 (26%) had prosthetic IE. Mean (SD) age was 57 (16) years. Blood cultures were obtained for 113 patients (71%) before antibiotic treatment was started. Surgery was performed in 52% of patients. Reasons for surgery were heart failure in 60%, persistent sepsis in 40%, vegetation size in 48%, or embolism in 18%. Surgery was for implantation of mechanical prosthesis in 63%, bioprosthesis in 21%, aortic homograft in 5%, and valve repair in 11%. In-hospital mortality was 12.6%, being 10.4% in the medical group and 15.6% in the surgical group. Among the total population of 5001 patients, only 50% of those with native VHD had been educated on endocarditis prophylaxis and only 33% regularly attended dental follow up. Of patients with IE who had had a procedure at risk during the preceding year only 50% had received adequate prophylaxis. CONCLUSIONS: The EHS on VHD shows that patients with active IE have a high risk profile and often undergo surgery. However, there are deficiencies in obtaining blood cultures and applying prophylaxis. Mortality remains high, which is a justification for the improvement of patient management through education and the implementation of guidelines.

Changes in cerebral oxygenation during cold (28 degrees C) and warm (34 degrees C) cardiopulmonary bypass using different blood gas strategies (alpha-stat and pH-stat) in patients undergoing coronary artery bypass graft surgery.

BACKGROUND: Impaired cerebral oxygenation, which is reflected by measuring jugular bulb oxygenation, is thought to play an important role in the development of neurological injury after cardiac operations with cardiopulmonary bypass (CPB). The effects of cardiopulmonary temperature and blood gas strategy on cerebral oxygenation are not fully appreciated. METHODS: Sixty patients were randomly allocated into four equal groups (cold alpha-stat, cold pH-stat, warm alpha-stat and warm pH-stat) to compare the effect of these perfusion strategies on cerebral oxygenation monitored by jugular bulb oximetry [jugular bulb oxygen saturation (SjO(2)) and arterial-jugular bulb oxygen content difference (AjDO(2))]. Jugular bulb oxygen saturation and AjDO(2) were measured before CPB, after 5, 20, 40 min on CPB, at start and end of rewarming, 5 min before the end of CPB and 10 min after CPB. Two-way analysis of variance was used to model the lowest SjO(2) and highest AjDO(2) during CPB, with CPB temperature and blood gas management as contributing factors. RESULTS: Significant changes in SjO(2) were only related to the type of blood gas management, with no significant difference between warm and cold CPB patients. In addition, during rewarming, desaturation (SjO(2)

Prevalence and clinical significance of incidental paraprosthetic valvar regurgitation: a prospective study using transoesophageal echocardiography.

OBJECTIVE: To assess the prevalence, mechanisms, and significance of paraprosthetic regurgitation detected incidentally by transoesophageal echocardiography (TOE) in patients after heart valve replacement. DESIGN: Prospective observational study. SETTING: Tertiary referral centre. PATIENTS: 360 consecutive patients (mean (SD) age 65.8(9.5) years, 193 women) undergoing elective first ever valve replacement. METHODS: Postoperative and follow up TOE, and tests for haemolysis and anaemia. RESULTS: There were 243 aortic, 90 mitral, and 27 double valve replacements, using 316 mechanical and 44 tissue valves, giving 270 aortic and 117 mitral valves. One patient with severe paraprosthetic mitral regurgitation underwent immediate reoperation and was excluded from subsequent analyses. Paraprosthetic jets were detected around 16 (6%) of the aortic and 38 (32%) of the mitral valves (p < 0.05) at the postoperative study. Follow up TOE was available for 151 aortic and 67 mitral valves, 0.9 (0.5) years after operation. Paraprosthetic jets were present in 15 (10%) of the aortic and 10 (15%) of the mitral valves (NS). Two thirds of the aortic and a fifth of the mitral jets were new. Paraprosthetic jets were more common in aortic valves in a supra-annular (12 of 88, 14%) than in an intra-annular position (4 or 182, 2%; p < 0.005) and in mitral valves inserted with continuous (36 of 88, 41%) rather than interrupted sutures (2 of 28, 7%; p < 0.001). Lactate dehydrogenase concentration was higher in patients with paraprosthetic jets than in those without (752 (236) v 654 (208) IU/l, p < 0.001). Haemoglobin and haptoglobin concentrations were not different. CONCLUSIONS: Small paraprosthetic leaks are common, are related to surgical factors, are not associated with increased subclinical haemolysis, and are benign during the first year after heart valve replacement.

Incidence of embolism and paravalvar leak after St Jude Silzone valve implantation: experience from the Cardiff Embolic Risk Factor Study.

BACKGROUND: Silver coating of the sewing ring (Silzone) was introduced as a modification of the St Jude Medical standard valve to provide antibacterial protection, but the valve has recently been withdrawn. OBJECTIVE: To study patients with these prostheses to assess possible adverse effects, and to guide their follow up. DESIGN: Prospective observational study of risk factors for stroke after valve replacement. SETTING: Cardiology and cardiac surgery departments in a tertiary centre. PATIENTS: There were 51 patients with Silzone and 116 with St Jude Medical standard valves. Patients undergoing aortic valve replacement were well matched for stroke risk factors. Silzone patients with mitral valve replacement were younger (mean (SD) age 61 (10) v 66 (7) years), more likely to be female (95% v 65%), and had more pulmonary arterial hypertension (100% v 78%), but fewer coronary artery bypass grafts (5% v 33%) than patients with standard mitral valve replacements (all p < 0.05). RESULTS: Follow up was 100% in the Silzone group (mean duration 3.0 (0.9) years) and 97.4% in the standard group (4.7 (1.4) years). Survival, morbidity, and anticoagulant control were documented over 682 follow up years (153 for Silzone and 529 for standard). There were six embolic strokes and one peripheral embolism in the Silzone group, all within three months after operation, and five embolic strokes and one peripheral embolism in the standard group. Freedom from major thromboembolism at three months was 65% in the Silzone mitral valve replacement group and 100% in the standard mitral valve replacement group (difference 35%, 95% confidence interval 8% to 62%). There was one reoperation for paravalvar leak in the standard group, but none in the Silzone group (NS). Anticoagulant control in the two groups was similar. CONCLUSIONS: Patients with Silzone mitral valves had a high rate of early postoperative embolism but no excess paravalvar leak.

Case report: Squamous carcinoma in an oesophageal foregut cyst.

Cysts within the oesophageal wall may represent inclusion cysts, retention cysts or developmental cysts. Foregut duplications are developmental anomalies, which occur as a result of abnormal canalization of the foregut during intrauterine life. Malignant transformation is an extremely rare event occurring within oesophageal cysts, adenocarcinoma being the most common histology. We report a case of squamous cell carcinoma arising within an oesophageal cyst affecting the upper third of the oesophagus. The malignant cyst was not amenable to primary surgical resection and hence was treated using chemo-radiotherapy. The treatment gave good disease control, at the expense of a high oesophageal stricture. Chemo-radiotherapy is an alternative treatment modality to achieve long-term disease control in squamous cell carcinoma complicating oesophageal foregut cyst when primary surgical resection is not possible.

Changes in serum S100beta protein and Mini-Mental State Examination after cold (28 degrees C) and warm (34 degrees C) cardiopulmonary bypass using different blood gas strategies (alpha-stat and pH-stat).

BACKGROUND: The effect of cardiopulmonary bypass temperature and blood gas management on the brain is still controversial. This study was designed to compare the changes in S100beta protein concentration and Mini-Mental State Examination in patients undergoing cold (28 degrees C) vs. warm (34 degrees C) cardiopulmonary bypass using different blood gas strategies (alpha-stat and pH-stat). METHODS: Sixty patients were randomly allocated to one of four equal groups (cold alpha-stat, cold pH-stat, warm alpha-stat, warm pH-stat). Serum S100beta concentrations were measured before CPB, directly after CPB, at 4.5 h and at 24 h after CPB. Mini-Mental State Examination was performed one day before surgery and on day five after the operation. Antegrade warm blood cardioplegia (37 degrees C) was used in all patients. RESULTS: There was no significant difference in postoperative S100beta protein levels between the four groups. Also, there was no interaction between bypass temperature and type of blood gas strategy on S100beta levels after bypass (directly after bypass, 4.5 h and 24 h after bypass). Mini-Mental State Examination score was not affected by blood gas strategy but it was significantly lower in patients undergoing cold cardiopulmonary bypass surgery: median (range), 26 (12-29) vs. 27 (23-30) in warm patients, P = 0.014. There was no significant correlation between Mini-Mental State Examination score 5 days after CPB and S100beta levels at any of the studied time-points after CPB. CONCLUSION: These results support the use of warm CPB (34 degrees C) in patients undergoing coronary artery bypass surgery regardless of the type of blood gas strategy.

Prospective study of routine perioperative transesophageal echocardiography for elective valve replacement: clinical impact and cost-saving implications.

Transesophageal echocardiography (TEE) is widely used during heart valve replacement operations, but its clinical impact and cost-saving profile have not been studied prospectively for this indication. We investigated the clinical benefits and cost-savings of routine TEE for elective valve replacement at a regional tertiary center. We prospectively studied 300 patients (140 men; mean age [+/-SD], 66 +/- 9 years) undergoing aortic valve, mitral valve, or double-valve replacements. Transesophageal echocardiography with a biplane (in 161 patients) or a multiplane probe was performed before and after surgery. We assessed whether the TEE findings changed the operation or the postoperative treatment and the cost of TEE either as an extension of a preexisting service or as a new development. In 2 patients undergoing aortic valve replacement, significant mitral regurgitation on TEE led to additional mitral valve replacement, and in 1 patient undergoing mitral valve replacement, aortic regurgitation also required aortic valve replacement. Immediate reoperation (dehisced mitral valve prosthesis) and delayed extubation (suspected obstruction of an aortic valve prosthesis) were prompted by postoperative TEE. Extending an existing TEE service to routine intraoperative use saved up to $109 (US) per patient per year. Routine intraoperative TEE can provide major clinical benefit to a small proportion of patients undergoing elective valve replacement, and this can lead to cost savings, but only if the service can be provided without major capital investment.

Twenty years' experience with the Medtronic Hall valve.

OBJECTIVE: To assess the performance of the Medtronic Hall valve (Medtronic, Inc, Minneapolis, Minn) in one institution over a 20-year period. METHODS: Since 1979, Medtronic Hall valves have been used in 1766 procedures (736 aortic, 796 mitral, and 234 double). Patients were followed up prospectively at 6- to 12-month intervals for a total of 12,688 follow-up years. Anticoagulation data (international normalized ratio) were recorded for all patients (approximately 95,000 observations). RESULTS: Linearized rates of valve-related late death for aortic, mitral, and double valve replacement were 0.8%/y, 0.9%/y, and 1.1%/y, respectively. Risk factors for late mortality were (relative risk) diabetes (1.9), decade of age (1.6), concomitant coronary artery bypass grafting (1.4), hypertension (1.3), non-sinus rhythm (1.3), large valve size (1.1), valve regurgitation (1.3), and male sex (1.2). For aortic, mitral, and double valve replacement, linearized rates (percent per year) of adverse events were valve thrombosis 0.04, 0.03, and 0.0; all thromboembolism 2.3, 4.0, and 3.4; stroke 0.6, 0.8, and 0.6; major hemorrhage 1.2, 1.4, and 1.6; and prosthetic endocarditis 0.4, 0.4, and 0.7. Risk factors for thromboembolism were (relative risk) mitral valve replacement (1.9), diabetes (1.8), hypertension (1.5), and history of embolism (1.4). CONCLUSION: At 20 years the Medtronic Hall valve demonstrates excellent durability, good hemodynamic performance, and very low thrombogenicity, with a valve thrombosis rate lower than those reported for bileaflet designs. With this prosthesis, both survival and thromboembolic events are predominantly determined by patient risk factors.

The vegetation that was not a vegetation: excusable misinterpretation of transesophageal echocardiography findings in late infective endocarditis of a prosthetic mitral valve.

The echocardiographic detection of a valvar mobile mass with independent mobility is one of the major Duke criteria for diagnosing infective endocarditis.(1) We report a case in which a mobile mass seen by transesophageal echocardiography on a prosthetic mitral valve with proven endocarditis was not a vegetation but pannus. This is an important clinical message for the interpretation of mobile masses on artificial valves.

Surgical treatment of carcinoid tumours.

Carcinoid tumours are the most common endocrine tumour of the gut comprising 75% of appendicular tumours and a third of ileal tumours. They are also an incidental finding in 1% of post mortems. Carcinoid syndrome however is rare and it is estimated that two cases would appear in a quarter of a million population over a decade. We have reviewed a consecutive series of carcinoid tumours accrued from 1976-1999 in order to further study the natural history of the disease and also to examine the relationship between pathological tumour size, extent of disease and prognosis for each tumour site. In this 19 year period 145 patients were treated for the disorder. The bronchus was the commonest site (35.9%) with appendix (24.8%) and ileal (13.8%) carcinoids comprising the majority of known primaries. Overall midgut carcinoids comprised 40.7% of the series with the carcinoid syndrome present in 20.3%. A significant group was constituted by those patients presenting with metastatic disease and an uncertain site of primary tumour (9.7%). Metastatic disease was not found on presentation or follow up in any patient with a foregut primary tumour less than 2 cm diameter or a midgut primary tumour less than 1 cm diameter; a direct correlation of size and metastases being found above these levels. Overall survival for all groups was 60% at 5 years with the best prognosis being seen in patients with bronchial or appendicular carcinoids. Other clinical features, pathology, extent of disease and prognosis of carcinoid tumour will be discussed along with the role of current management strategies.

Morphologic analysis of a strand recovered from a prosthetic mitral valve: No evidence of fibrin.

We report the first morphologic analysis of a linear mobile structure (strand) detected by transesophageal echocardiography on a bioprosthetic mitral valve and then recovered at surgery. Electron microscopy showed it to consist of a sparsely cellular component, with extracellular amorphous or fibrillary areas. Collagen was largely responsible for the fibrillary appearance.

A new strategy of total arterial revascularization.

We report a new strategy of total arterial revascularization based on bilateral internal thoracic arteries (ITAs) and a radial artery (RA). The technique employs a graft extension of the proximal third of the right internal thoracic artery (RITA) with the RA, in combination with the T-graft technique, by which the lower two-thirds of the free RITA is anastomosed to the side of the left internal thoracic artery (LITA).

Mobile echoes on prosthetic valves are not reproducible. Results and clinical implications of a multicentre study.

AIMS: To test the hypothesis that inter-observer variability accounts for the wide variation in reported prevalences of fibrin strands on prosthetic heart valves and to develop criteria for their identification and reporting. METHODS AND RESULTS: A videotape with 30 sequences of prosthetic heart valves imaged by transoesophageal echocardiography and showing abnormalities such as strands, microbubbles, and spontaneous echocardiographic contrast, was assessed in 13 European and three American centres. There were three duplicated examples, unbeknown to the observers. Definitions and reported prevalence rates of the abnormalities were analysed, and inter- and intra-observer agreement estimated with the kappa statistic. Mobile echoes were identified in 40 to 80% of the sequences on the tape. The reported prevalence of mobile echoes correlated with the time spent reporting the tape. There was moderate inter-observer agreement for the identification of any mobile echoes (kappa = 0.38), but no agreement for their labelling (kappa = 0.22), in spite of similar definitions. Intra-observer reproducibility was good (agreement in 76% of the reduplicated sequences). CONCLUSIONS: The true prevalence and potential significance of mobile echoes on prosthetic heart valves cannot be assessed unless inter-observer consensus on echocardiographic criteria for identifying such echoes is reached.

Contemporary management of malignant pleural mesothelioma.

The rapidly increasing incidence of malignant pleural mesothelioma underlines the urgency to achieve a consensus in the management of this tumor, which is biologically distinct from most other tumors. For patients with stage I tumors of epithelial type and good performance status, pleuropneumonectomy combined with chemotherapy and radiotherapy provides the best chance of prolonged survival, but further investigation is required to determine the optimum combination of adjuvant therapy. Debulking pleurectomy/decortication combined with adjuvant therapy is a worthwhile alternative for patients with more advanced disease, impaired performance status or tumors of less favorable histology (sarcomatous or biphasic). More clinical trials are urgently required to identify better adjuvant therapy for tumors containing sarcomatous elements. On currently available evidence, neither radiotherapy nor chemotherapy offer worthwhile prolonged disease control when used in isolation, although both have an important role as part of multimodality therapy. Hyperthermia may enhance the effect of both radiotherapy and chemotherapy, and newer radiosensitizing agents also need evaluating. Research into immunotherapy and gene therapy suggests that these newer approaches may have a place if tumor volume is small. In practice they will probably need to be combined with other therapeutic modalities, and further clinical trials are required. Consensus in mesothelioma management currently remains elusive but it seems clear that the way forward will involve striving for much earlier diagnosis, the use of multimodality therapy and collaboration between centers with special expertise in mesothelioma treatment to organize multicenter trials.

[Recommendations for prevention of thromboembolism in heart valve diseases. Working Group on Valvular Heart Disease, European Society of Cardiology]. / Empfehlungen zur Thromboembolieprophylaxe bei Herzklappenerkrankungen der Working Group on Valvular Heart Disease, European Society of Cardiology.

Thromboembolic events are still a major cause of morbidity and mortality in patients with native valvular heart disease and in patients with prosthetic heart valves. Although the introduction of oral anticoagulation reduced this risk, thromboembolism and anticoagulation-related hemorrhages still represent significant problems in the management of these patients. In this article the guidelines developed by the Working Group on Valvular Heart Disease of the European Society of Cardiology for the management of antithrombotic therapy in heart valve disease are thoroughly discussed. The indication for and intensity of anticoagulation in various clinical situations, the concept of risk factor-adjusted intensity of anticoagulation, and the concept of control of oral anticoagulation with the International Normalized Ratio are presented.