Incidence and outcomes of sepsis after cardiac surgery as defined by the Sepsis-3 guidelines.

BACKGROUND: The Sepsis-3 guidelines diagnose sepsis based on organ dysfunction in patients with either proven or suspected infection. The objective of this study was to assess the incidence and outcomes of sepsis diagnosed using these guidelines in patients in a cardiac intensive care unit (CICU) after cardiac surgery. METHODS: Daily sequential organ failure assessment (SOFA) scores were calculated for 2230 consecutive adult cardiac surgery patients between January 2013 and May 2015. Patients with an increase in SOFA score of ≥2 and suspected or proven infection were identified. The length of CICU stay, 30-day mortality and 2-yr survival were compared between groups. Multivariable linear regression, multivariable logistic regression, and Cox proportional hazards regression were used to adjust for possible confounders. RESULTS: Sepsis with suspected or proven infection was diagnosed in 104 (4.7%) and 107 (4.8%) patients, respectively. After adjustment for confounding variables, sepsis with suspected infection was associated with an increased length of CICU stay of 134.1h (95% confidence interval (CI) 99.0-168.2, P<0.01) and increased 30-day mortality risk (odds ratio 3.7, 95% CI 1.1-10.2, P=0.02). Sepsis with proven infection was associated with an increased length of CICU stay of 266.1h (95% CI 231.6-300.7, P<0.01) and increased 30-day mortality risk (odds ratio 6.6, 95% CI 2.6-15.7, P<0.01). CONCLUSIONS: Approximately half of sepsis diagnoses were based on proven infection and half on suspected infection. Patients diagnosed with sepsis using the Sepsis-3 guidelines have significantly worse outcomes after cardiac surgery. The Sepsis-3 guidelines are a potentially useful tool in the management of sepsis following cardiac surgery.

Cardiopulmonary exercise testing and survival after elective abdominal aortic aneurysm repair†.

BACKGROUND: Cardiopulmonary exercise testing (CPET) is increasingly used in the preoperative assessment of patients undergoing major surgery. The objective of this study was to investigate whether CPET can identify patients at risk of reduced survival after abdominal aortic aneurysm (AAA) repair. METHODS: Prospectively collected data from consecutive patients who underwent CPET before elective open or endovascular AAA repair  (EVAR) at two tertiary vascular centres between January 2007 and October 2012 were analysed. A symptom-limited maximal CPET was performed on each patient. Multivariable Cox proportional hazards regression modelling was used to identify risk factors associated with reduced survival. RESULTS: The study included 506 patients with a mean age of 73.4 (range 44-90). The majority (82.6%) were men and most (64.6%) underwent EVAR. The in-hospital mortality was 2.6%. The median follow-up was 26 months. The 3-year survival for patients with zero or one sub-threshold CPET value ([Formula: see text] at AT<10.2 ml kg(-1) min(-1), peak [Formula: see text]<15 ml kg(-1) min(-1) or [Formula: see text] at AT>42) was 86.4% compared with 59.9% for patients with three sub-threshold CPET values. Risk factors independently associated with survival were female sex [hazard ratio (HR)=0.44, 95% confidence interval (CI) 0.22-0.85, P=0.015], diabetes (HR=1.95, 95% CI 1.04-3.69, P=0.039), preoperative statins (HR=0.58, 95% CI 0.38-0.90, P=0.016), haemoglobin g dl(-1) (HR=0.84, 95% CI 0.74-0.95, P=0.006), peak [Formula: see text]<15 ml kg(-1) min(-1) (HR=1.63, 95% CI 1.01-2.63, P=0.046), and [Formula: see text] at AT>42 (HR=1.68, 95% CI 1.00-2.80, P=0.049). CONCLUSIONS: CPET variables are independent predictors of reduced survival after elective AAA repair and can identify a cohort of patients with reduced survival at 3 years post-procedure. CPET is a potentially useful adjunct for clinical decision-making in patients with AAA.

Comparison of three contemporary risk scores for mortality following elective abdominal aortic aneurysm repair.

OBJECTIVE/BACKGROUND: A number of contemporary risk prediction models for mortality following elective abdominal aortic aneurysm (AAA) repair have been developed. Before a model is used either in clinical practice or to risk-adjust surgical outcome data it is important that its performance is assessed in external validation studies. METHODS: The British Aneurysm Repair (BAR) score, Medicare, and Vascular Governance North West (VGNW) models were validated using an independent prospectively collected sample of multicentre clinical audit data. Consecutive, data on 1,124 patients undergoing elective AAA repair at 17 hospitals in the north-west of England and Wales between April 2011 and March 2013 were analysed. The outcome measure was in-hospital mortality. Model calibration (observed to expected ratio with chi-square test, calibration plots, calibration intercept and slope) and discrimination (area under receiver operating characteristic curve [AUC]) were assessed in the overall cohort and procedural subgroups. RESULTS: The mean age of the population was 74.4 years (SD 7.7); 193 (17.2%) patients were women and the majority of patients (759, 67.5%) underwent endovascular aneurysm repair. All three models demonstrated good calibration in the overall cohort and procedural subgroups. Overall discrimination was excellent for the BAR score (AUC 0.83, 95% confidence interval [CI] 0.76-0.89), and acceptable for the Medicare and VGNW models, with AUCs of 0.78 (95% CI 0.70-0.86) and 0.75 (95% CI 0.65-0.84) respectively. Only the BAR score demonstrated good discrimination in procedural subgroups. CONCLUSION: All three models demonstrated good calibration and discrimination for the prediction of in-hospital mortality following elective AAA repair and are potentially useful. The BAR score has a number of advantages, which include being developed on the most contemporaneous data, excellent overall discrimination, and good performance in procedural subgroups. Regular model validations and recalibration will be essential.

National risk prediction model for elective abdominal aortic aneurysm repair.

BACKGROUND: Mortality results for elective abdominal aortic aneurysm (AAA) repair are published by the Vascular Society of Great Britain and Ireland. These mortality results are not currently risk-adjusted. The objective of this study was to develop a national risk prediction model for elective AAA repair. METHODS: Data for consecutive patients undergoing elective AAA repair from the National Vascular Database between April 2008 and March 2011 were analysed. Multiple logistic regression and backwards model selection were used for model development. The study outcome measure was in-hospital mortality. Model calibration and discrimination were assessed for all AAA repairs, and separately for open repair and endovascular aneurysm repair (EVAR) subgroups. RESULTS: There were 312 in-hospital deaths among 11,423 AAA repairs (2.7 (95 per cent confidence interval (c.i.) 2.4 to 3.0) per cent): 230 after 4940 open AAA repairs (4.7 (4.1 to 5.3) per cent) and 82 after 6483 EVARs (1.3 (1.0 to 1.6) per cent). Variables associated with in-hospital death included in the final model were: open repair, increasing age, female sex, serum creatinine level over 120 µmol/l, cardiac disease, abnormal electrocardiogram, previous aortic surgery or stent, abnormal white cell count, abnormal serum sodium level, AAA diameter and American Society of Anesthesiologists fitness grade. The area under the receiver operating characteristic (ROC) curve was 0.781 (95 per cent c.i. 0.756 to 0.806) with a bias-corrected value of 0.774. Model calibration was good (P = 0.963) based on the Hosmer-Lemeshow goodness-of-fit test, (bias-corrected) calibration curves, risk group assessment and recalibration regression. CONCLUSION: This multivariable model for elective AAA repair can be used to risk-adjust outcome analyses and provide patient-specific estimates of in-hospital mortality risk for open AAA repair or EVAR.

A multicentre observational study of the outcomes of screening detected sub-aneurysmal aortic dilatation.

OBJECTIVES: Currently most abdominal aortic aneurysm screening programmes discharge patients with aortic diameter of less than 30 mm. However, sub-aneurysmal aortic dilatation (25 mm-29 mm) does not represent a normal aortic diameter. This observational study aimed to determine the outcomes of patients with screening detected sub aneurysmal aortic dilatation. DESIGN AND METHODS: Individual patient data was obtained from 8 screening programmes that had performed long term follow up of patients with sub aneurysmal aortic dilatation. Outcome measures recorded were the progression to true aneurysmal dilatation (aortic diameter 30 mm or greater), progression to size threshold for surgical intervention (55 mm) and aneurysm rupture. RESULTS: Aortic measurements for 1696 men and women (median age 66 years at initial scan) with sub-aneurysmal aortae were obtained, median period of follow up was 4.0 years (range 0.1-19.0 years). Following Kaplan Meier and life table analysis 67.7% of patients with 5 complete years of surveillance reached an aortic diameter of 30 mm or greater however 0.9% had an aortic diameter of 54 mm. A total of 26.2% of patients with 10 complete years of follow up had an AAA of greater that 54 mm. CONCLUSION: Patients with sub-aneurysmal aortic dilatation are likely to progress and develop an AAA, although few will rupture or require surgical intervention.

Evaluation of five risk prediction models for elective abdominal aortic aneurysm repair using the UK National Vascular Database.

BACKGROUND: There is no consensus on the best risk prediction model for mortality following elective abdominal aortic aneurysm (AAA) repair. The objective was to evaluate the performance of five risk prediction models using the UK National Vascular Database (NVD). METHODS: Data on elective AAA repairs from the NVD between January 2008 and December 2010 were analysed. The models assessed were: Glasgow Aneurysm Score (GAS), Vascular Biochemical and Haematological Outcome Model (VBHOM), physiological component of the Vascular Physiological and Operative Severity Score for enUmeration of Mortality (V-POSSUM), Medicare and Vascular Governance North West (VGNW). Overall model discrimination and calibration in equally sized risk-group quintiles were assessed. RESULTS: The study cohort included 10,891 patients undergoing elective AAA repair (median age 74 years, 87.3 per cent men). The in-hospital mortality rates following endovascular and open repair were 1.3 and 4.7 per cent respectively (2.9 per cent overall). The Medicare and VGNW models both showed good discrimination (area under receiver operating characteristic (ROC) curve 0.71), whereas the GAS, VBHOM and V-POSSUM models showed poor discrimination (area under ROC curve 0.60, 0.61 and 0.62 respectively). The VGNW model was the only one to predict the overall mortality rate in the cohort (3.3 per cent predicted versus 2.9 per cent observed; P = 0.066). The VGNW model demonstrated good calibration, predicting risk accurately in four risk-group quintiles. The Medicare, V-POSSUM and VBHOM models accurately predicted risk in three, two and no risk-group quintiles respectively. CONCLUSION: The Medicare and VGNW models contain similar risk factors and showed good discrimination when applied to the NVD. Both models would be suitable for risk prediction after elective AAA repair in the UK.

Preoperative cardiopulmonary exercise testing and risk of early mortality following abdominal aortic aneurysm repair.

BACKGROUND: Cardiopulmonary exercise testing (CPET) provides an objective assessment of functional capacity. The aim of this study was to assess whether preoperative CPET identifies patients at risk of early death following elective open and endovascular abdominal aortic aneurysm (AAA) repair. METHODS: Prospective data were collected from a pilot study between September 2005 and February 2007, and from all patients who underwent CPET before elective AAA repair at two vascular centres between February 2007 and November 2011. Symptom-limited, maximal CPET was performed on each patient. Univariable and multivariable analyses were used to identify risk factors for 30- and 90-day mortality. RESULTS: Some 415 patients underwent CPET before elective AAA repair. Anaerobic threshold (AT), peak oxygen consumption (peak V.O(2) ) and ventilatory equivalents for carbon dioxide were associated with 30- and 90-day mortality on univariable analysis. On multivariable analysis, open repair (odds ratio (OR) 4·92, 95 per cent confidence interval 1·55 to 17·00; P = 0·008), AT below 10·2 ml per kg per min (OR 6·35, 1·84 to 29·80; P = 0·007), anaemia (OR 3·27, 1·04 to 10·50; P = 0·041) and inducible cardiac ischaemia (OR 6·16, 1·48 to 23·07; P = 0·008) were associated with 30-day mortality. Anaemia, inducible cardiac ischaemia and peak V.O(2) less than 15 ml per kg per min (OR 8·59, 2·33 to 55·75; P = 0·005) were associated with 90-day mortality on multivariable analysis. Patients with two or more subthreshold CPET values were at increased risk of both 30- and 90-day mortality. CONCLUSION: An AT below 10·2 ml per kg per min, peak V.O(2) less than 15 ml per kg per min and at least two subthreshold CPET values identify patients at increased risk of early death following AAA repair.

Delayed carotid surgery: what are the causes in the north west of England?

INTRODUCTION: Carotid endarterectomy (CEA) should be performed within two weeks of symptoms for patients with carotid stenosis >50%. Whether these standards are being achieved and causes of delay between symptoms and CEA were investigated. DESIGN: An analysis of prospectively collected multi-centre data. MATERIALS: Consecutive data for patients undergoing CEA between January-2006 and September-2010 were collected. Asymptomatic patients and those with no details on the timing of cerebral symptoms were excluded. METHODS: 'Delay' from symptom to CEA was defined as more than two weeks and 'prolonged-delay' more than eight weeks. Univariable and multivariable analyses were used to identify factors associated with these delays. RESULTS: Of 2147 patients with symptoms of cerebral ischaemia, 1522(70.9%) experienced 'delay' and 920(42.9%) experienced 'prolonged delay'. Patients with ischaemic heart disease were more likely to experience 'delay' (OR = 1.56; 95% CI 1.11-2.19, p = 0.011), whereas patients with stroke (OR = 0.77; 95%CI 0.63-0.94, p = 0.011) and those treated at hospitals with a stroke-prevention clinic (OR = 0.57; 95%CI 0.46-0.71, p < 0.001) were less likely to experience 'delay'. Patients treated after the publication of National Institute for Health and Clinical Excellence (NICE) guidelines were less likely to experience 'prolonged delay' (OR = 0.77; 95%CI 0.65-0.91, p = 0.003) but not 'delay'. CONCLUSION: Few patients achieved CEA within two weeks of symptoms. Introducing stroke-prevention clinics with one-stop carotid imaging appears important.

What are the risk factors for renal failure following open elective abdominal aortic aneurysm repair?

OBJECTIVES: Renal failure following abdominal aortic aneurysm (AAA) repair is a common and significant complication. The objective of this study was to identify risk factors for renal failure following open elective AAA repair. DESIGN: A retrospective analysis of prospectively collected multi-centre data. MATERIALS: Consecutive data on patients undergoing open elective AAA repair were collected between January 2000 and December 2010. Patients with pre-operative serum creatinine >200 µmol/L were excluded. METHODS: Renal failure was reported by clinicians and included all patients requiring post-operative renal-replacement therapy. Univariate and multivariate analyses were used to identify renal failure risk factors. A simplified clinical risk score was developed. RESULTS: Post-operative renal failure occurred in 140 (6.0%) of 2347 patients and was associated with age >75 (OR = 1.58, 95%CI 1.11-2.26), symptomatic AAA (OR = 1.77, 95%CI 1.24-2.52), supra/juxta renal AAA (OR = 2.17, 95%CI 1.32-3.57) pre-operative serum creatinine >150 (OR = 2.75, 95%CI 1.69-4.50), treated hypertension (OR = 1.87, 95%CI 1.28-2.74), and respiratory disease (OR = 2.08, 95%CI 1.45-2.97). Patients with post-operative renal failure had significantly higher 30-day mortality (35.0% vs. 4.3%, p < 0.001). CONCLUSIONS: Renal failure following open elective AAA repair was associated with an increased risk of mortality. Risk factors for post-operative renal failure were identified and a simple clinical risk score developed to facilitate focussed care strategies for high-risk patients.

Logistic risk model for mortality following elective abdominal aortic aneurysm repair.

BACKGROUND: The aim was to develop a multivariable risk prediction model for 30-day mortality following elective abdominal aortic aneurysm (AAA) repair. METHODS: Data collected prospectively on 2765 consecutive patients undergoing elective open and endovascular AAA repair from September 1999 to October 2009 in the North West of England were split randomly into development (1936 patients) and validation (829) data sets. Logistic regression analysis was undertaken to identify risk factors for 30-day mortality. RESULTS: Ninety-eight deaths (5·1 per cent) were recorded in the development data set. Variables associated with 30-day mortality included: increasing age (P = 0·005), female sex (P = 0·002), diabetes (P = 0·029), raised serum creatinine level (P = 0·006), respiratory disease (P = 0·031), antiplatelet medication (P < 0·001) and open surgery (P = 0·002). The area under the receiver operating characteristic (ROC) curve for predicted probability of 30-day mortality in the development and validation data sets was 0·73 and 0·70 respectively. Observed versus expected 30-day mortality was 3·2 versus 2·0 per cent (P = 0·272) in low-risk, 6·1 versus 5·1 per cent (P = 0·671) in medium-risk and 11·1 versus 10·7 per cent (P = 0·879) in high-risk patients. CONCLUSION: This multivariable model for predicting 30-day mortality following elective AAA repair can be used clinically to calculate patient-specific risk and is useful for case-mix adjustment. The model predicted well across all risk groups in the validation data set.

Laparoscopic repair of chronic intrathoracic gastric volvulus.

BACKGROUND: Totally intrathoracic gastric volvulus is an uncommon presentation of hiatal hernia, in which the stomach undergoes organoaxial torsion predisposing the herniated stomach to strangulation and necrosis. This may occur as a surgical emergency, but some patients present with only chronic, non-specific symptoms and can be treated electively. The aim of this study is to describe a comprehensive approach to laparoscopic repair of chronic intrathoracic gastric volvulus and to critically assess the pre-operative work-up. METHODS: Eight patients (median age, 71 years) underwent complete laparoscopic repair of chronic intrathoracic gastric volvulus. Symptoms of epigastric pain and early satiety were universally present. Five patients had reflux symptoms. The diagnostic evaluation included a video esophagogram, upper endoscopy, 24-hour pH measurement, and esophageal manometry in all patients. Operative results and postoperative outcome were recorded and follow-up at 1 year included a barium swallow in all patients. RESULTS: All patients had documented intrathoracic stomach. Five of 8 patients had a structurally normal lower esophageal sphincter. All 4 patients with reflux esophagitis on upper endoscopy had a positive 24-hour pH study, and 2 of these patients had a structurally defective lower esophageal sphincter on manometry. None of the patients had preoperative evidence of esophageal shortening. All procedures were completed laparoscopically. The procedure included reduction of the stomach into the abdomen, primary closure of the diaphragmatic defect, and the construction of a short, floppy Nissen fundoplication. There were no major complications. One patient required repair of a trocar site hernia 6 months postoperatively. At 1-year follow-up, there were no radiologic recurrences of the volvulus. One patient complained of temporary swallowing discomfort and another had recurrent gastroesophageal reflux disease (GERD) symptoms caused by a breakdown of the wrap. All other patients remained asymptomatic during follow-up. CONCLUSIONS: The repair of chronic gastric volvulus can be accomplished successfully with a laparoscopic approach. A preoperative endoscopy and esophagogram are crucial to detect esophageal stricture or shortening, and manometry is needed to access esophageal motility; pH measurements do not affect operative strategy. The procedure should include a Nissen fundoplication to treat preoperative GERD, to prevent possible postoperative GERD, and to secure the stomach in the abdomen. The procedure is safe but technically challenging, requiring previous laparoscopic foregut surgical expertise.

Shell structure and distribution of Cloudina, a potential index fossil for the terminal Proterozoic.

Cloudina-bearing biosparites and biomicrites in the lower part of the Nama Group, Namibia, contain a wide morphological diversity of shell fragments that can all be attributed to the two named species C. hartmannae and C. riemkeae. The curved to sinuous tubular shells of Cloudina were multi-layered. Each shell layer was 8 to 50 micrometers thick and in the form of a slightly flaring tube with one end open and the other closed. Growth appears to have been periodic with successive shell layers forming within older layers. Each added layer was slightly elevated from the previous layer at the proximal end and was asymmetrically placed within the older layer so that only a portion of the new shell layer was fused to the previous layer. This type of growth left a relatively large unminerialized area between the shell layers which was often partially or fully occluded by early marine cements. The thin shell layers exhibit both plastic and brittle deformation and were likely formed of a rigid CaCO3-impregnated organic-rich material. Often the shell layers are preferentially dolomitized suggesting an original mineralogy of high-magnesian calcite. Both species in the Nama Group formed thickets, or perhaps bioherms, and this sedentary and gregarious habit suggests that Cloudina was probably a filter-feeding metazoan of at least a cnidarian grade of organization. The unusual shell structure of Cloudina gives rise to a characteristic suite of taphonomic and diagenetic features that can be used to identify Cloudina-bearing deposits within the Nama Group and in other terminal Proterozoic deposits around the world. Species of Cloudina occur in limestones from Brazil, Spain, China, and Oman in sequences consistent with a latest Proterozoic age assignment. In addition, supposed lower Cambrian, pre-trilobitic, shelly fossils from northwest Mexico and the White-Inyo Mountains in California and Nevada, including Sinotubulites, Nevadatubulus, and Wyattia, are all either closely related to or con-generic with Cloudina. Hence, it is probable that these outcrops are latest Proterozoic in age, and that Cloudina or Cloudina-like organisms were widely distributed at that time. It is possible, moreover, to suggest that metazoan biomineralization occurred on a global scale by the latest Proterozoic, at the same time that evidence for complex multicellularity and locomotion in animals appears in siliciclastic "Ediacaran" rocks in the form of body and trace fossils.

Intraabdominal abscess rate after laparoscopic appendectomy.

BACKGROUND: Studies suggest increased intraabdominal abscess (IA) rates following laparoscopic appendectomy (LA), especially for perforated appendicitis. Consequently, an open approach has been advocated. The aim of our study is to compare IA rates following LA performed by a laparoscopic surgery and a general surgical service within the same institution. METHODS: Data of LA patients treated at Los Angeles County-University of Southern California (LAC-USC) Medical Center between March 1992 and June 1997 were reviewed. The main outcome measure was postoperative IA. RESULTS: In all, 645 LA were reviewed. A total of 413 LA (285 acute, 61 gangrenous, 67 perforated appendicitis) were performed by three general surgical services (10 attendings). Ten abscesses occurred postoperatively (2.4%), 6 with perforated appendicitis. After the laparoscopic service was introduced, 232 standardized LA (126 acute, 46 gangrenous, 60 perforated) were performed by two attendings. One IA occurred (gangrenous appendicitis). The IA rate for perforated appendicitis was significantly lower on the laparoscopic service (P = 0.025). There was no difference in IA rates for acute and gangrenous appendicitis. There was no mortality in either group. CONCLUSION: IA rate following LA for perforated appendicitis was significantly reduced on the laparoscopic service. Mastery of the learning curve and addition of specific surgical techniques explained this improved result. Therefore, laparoscopic appendectomy for complicated appendicitis may not be contraindicated, even for perforated appendicitis.

Predictors of response after laparoscopic splenectomy for immune thrombocytopenic purpura.

BACKGROUND: Splenectomy has been shown to produce long term remission in patients with immune thrombocytopenic purpura (ITP). With the development of laparoscopic splenectomy, there is renewed interest in the surgical treatment of ITP. The aim of this study was to identify factors that are predictive of outcome after laparoscopic splenectomy for ITP. METHODS: A case series of 67 consecutive patients with ITP undergoing laparoscopic splenectomy was reviewed. A positive response was defined as a postoperative platelet count greater than 150,000/ml requiring no maintenance medical therapy on follow-up evaluation. A chi-square test and a stepwise logistic regression analysis were performed for the following variables: age, gender, preoperative response to steroids, duration of disease, severity of preoperative bleeding, accessory spleens, and thrombocytosis on discharge. RESULTS: At a median follow-up period of 38 months (range, 2-56 months), 52 patients (78%) had a positive response to laparoscopic splenectomy. Of the 15 patients (22%) who did not have a positive response, 11 were refractory and 4 relapsed. All relapses occurred in patients with a platelet count less than 150,000/microl at discharge. Patient age was the most significant predictive factor for success or failure of the operation. The median age of the responders (31 years; range, 19-71 years) was significantly lower than the median age of the nonresponders (49 years; range, 24-62; p < 0.001). Only 5.6% of those younger than 40 years did not have a positive response, compared with 42% of patients older than 40 years (p < 0.05). Patient age was significantly associated with outcome on univariable chi-square analysis (p = 0.001), and was the only significant factor on multivariable analysis (odds ratio, 2.65; 95% confidence interval, 1.71-4.1). Other significant predictors of outcome on univariable analysis were preoperative response to corticosteroids and platelet count on discharge. CONCLUSIONS: A long-lasting response after splenectomy for ITP is more likely to occur in patients younger than 40 years of age. To avoid the long-term side effects of corticosteroid use, early surgical referral of younger patients with ITP should be considered.

Operative site bacteriology as an indicator of postoperative infectious complications in elective colorectal surgery.

Toward the completion of elective colorectal operations, 75 patients had qualitative aerobic and anaerobic cultures of specimens obtained from peritoneal irrigation fluid, anastomoses sites, and abdominal wound irrigation fluid to determine if a correlation exists between intraoperative flora and postoperative infectious complications. Patients enrolled in this prospective study received a mechanical bowel prep and a 12-18 hour course of perioperative intravenous antibiotics. Comparisons were made between the 60 (80%) patients who had no postoperative infections and the 15 (20%) who developed postoperative infectious complications (9 wound infections, 6 intraabdominal infections). There were significantly more low anterior resections in patients who developed postoperative infection compared to those who had no postoperative infection (26% vs 2%), while there were more colocolostomies in the group with no infections (38% vs 7%). Streptococcus spp., Bacteroides fragilis group, and Escherichia coli were the most commonly isolated organisms from each of the three sites sampled. Isolation of > or = 3 organisms from incisional wound cultures (P = 0.017) and < or = 4 organisms from peritoneal irrigation (P = 0.009) or anastomotic culture (P = 0.004) correlated with development of postoperative infectious complications. Thus, patients with infectious complications had significantly more isolates than those without infectious complications, and were more likely to have had a low anterior resection. These data suggest that future clinical studies should reexamine the duration of perioperative antimicrobials based on early laboratory reports of qualitative and quantitative operative site bacteriology.

Clinical profile of pediatric patients hospitalized with respiratory syncytial virus infection.

To update the clinical profile of pediatric patients hospitalized with RSV infection, we retrospectively reviewed the records of 246 children (male:female ratio 1.44:1) admitted during one season to a tertiary-care hospital. The most common admitting diagnoses were bronchiolitis (37.4%), pneumonia (32.5%), and possible septicemia (13%). Median age was 3 months; median length of stay, three days. Twice as many minorities were admitted with RSV infection as all other admissions during the same year. Family history of asthma, while common (35%), did not affect length of stay or complications. Of the 38 (15%) patients requiring intensive care, 29 (76%) underwent ventilation. Patients with underlying cardiopulmonary disease had more complications, were more likely to require intensive care (about 50%), and had significantly longer hospital stays than others. All three patients (1.2%) who died had congenital heart disease. Common risk factors included young age, chronic cardiopulmonary disease, male sex, and possibly family history of asthma. Although the most typical clinical diagnoses remain bronchiolitis and pneumonia, a systemic illness resembling the sepsis syndrome has emerged at our institution as a significant clinical presentation.

Probable calcified metaphytes in the latest Proterozoic Nama Group, Namibia: origin, diagenesis, and implications.

Samples from the Huns Limestone Member, Urusis Formation, Nama Group, at two adjacent localities in southern Namibia contain thin foliose to arched, sheet-like carbonate crusts that are 100-500 micrometers thick and up to 5 cm in lateral dimension. Morphologic, petrographic, and geochemical evidence supports the interpretation of these delicate crusts as biogenic, most likely the remains of calcified encrusting metaphytes. The original sediments of the fossiliferous samples contained aragonitic encrusting algae, botryoidal aragonite cements, and an aragonite mud groundmass. Spherulites within the precursor mud could represent bacterially induced mineral growths or the concretions of marine rivularian cyanobacteria. Original textures were severely disrupted during the diagenetic transition of aragonite to low-magnesian calcite, but some primary structures remain discernible as ghosts in the neomorphic mosaic. Gross morphology, original aragonite mineralogy, and hypobasal calcification indicate that the crusts are similar to late Paleozoic phylloid algae and extant peyssonnelid red algae. Structures interpreted as possible conceptacles also suggest possible affinities with the Corallinaceae. Two species of Cloudina, interpreted as the remains of a shelly metazoan, are also known from limestones in the Nama Group. It is possible, therefore, that skeletalization in metaphytes and animals arose nearly simultaneously near the end of the Proterozoic Eon.

What is the impact of endoscopic vein harvesting on clinical outcomes following coronary artery bypass graft surgery?

Objective Endoscopic vein harvesting (EVH) is increasingly used as an alternative to open vein harvesting (OVH) for coronary artery bypass graft (CABG) surgery. Concerns about the safety of EVH with regard to midterm clinical outcomes following CABG have been raised. The objective of this study was to assess the impact of EVH on short-term and midterm clinical outcomes following CABG. Design This was a retrospective analysis of prospectively collected multi-centre data. A propensity score was developed for EVH and used to match patients who underwent EVH to those who underwent OVH. Setting Blackpool Victoria Hospital, Plymouth Derriford Hospital and the University Hospital of South Manchester were the main study settings. Patients There were 4709 consecutive patients who underwent isolated CABG using EVH or OVH between January 2008 and July 2010. Main outcome measures The main outcome measure was a combined end point of death, repeat revascularisation or myocardial infarction. Secondary outcome measures included in-hospital morbidity, in-hospital mortality and midterm mortality. Results Compared to OVH, EVH was not associated with an increased risk of the main outcome measure at a median follow-up of 22 months (HR 1.15; 95% CI 0.76 to 1.74). EVH was also not associated with an increased risk of in-hospital morbidity, in-hospital mortality (0.9% vs 1.1%, p=0.71) or midterm mortality (HR 1.04; 95% CI 0.65 to 1.66). Conclusions This multi-centre study demonstrates that at a median follow-up of 22 months, EVH was not associated with adverse short-term or midterm clinical outcomes. However, before the safety of EVH can be clearly determined, further analyses of long-term clinical outcomes are required.

What is the impact of providing a transcatheter aortic valve implantation service on conventional aortic valve surgical activity: patient risk factors and outcomes in the first 2 years.

OBJECTIVES: To assess the impact of introducing a transcatheter aortic valve implantation (TAVI) service on aortic valve surgical activity and outcomes. DESIGN: A retrospective analysis of prospectively collected data. SETTING: University hospital of south Manchester. PATIENTS: 815 consecutive patients undergoing isolated aortic valve replacement (AVR) or coronary artery bypass grafting plus AVR from January 2006 to December 2009. Fifty consecutive patients who underwent TAVI from January 2008 to December 2009. MAIN OUTCOME MEASURES: Aortic valve surgical activity in the 2years before the introduction of a TAVI service and in the 2years following. Outcomes following conventional aortic valve surgery and TAVI. RESULTS: In the 2years following the introduction of TAVI at this centre, conventional AVR activity has increased by 37% compared with an 8% increase nationally (p<0.001). Compared with the 2years before TAVI there was no change in the mean logistic EuroSCORE (7.4 vs 7.9 p=0.16) or crude mortality rate (2.9% vs 2.1% p=0.48). Fifty high-risk patients underwent TAVI with a 30-day mortality rate of 0%. The mean logistic EuroSCORE of the TAVI patients was 25.3. CONCLUSIONS: TAVI is an emerging alternative to AVR in high-risk patients. Since the introduction of a TAVI service at this centre, conventional AVR activity has increased. Despite a trend of increasing mean logistic EuroSCORE indicating that more complex cases are being undertaken, there has been a non-significant reduction in the crude mortality rate. Offering a TAVI service has a positive impact on the volume of conventional AVR surgical activity.

Does the choice of risk-adjustment model influence the outcome of surgeon-specific mortality analysis? A retrospective analysis of 14,637 patients under 31 surgeons.

OBJECTIVES: To compare implications of using the logistic EuroSCORE and a locally derived model when analysing individual surgeon mortality outcomes. DESIGN: Retrospective analysis of prospectively collected data. SETTING: All NHS hospitals undertaking adult cardiac surgery in northwest England. PATIENTS: 14,637 consecutive patients, April 2002 to March 2005. MAIN OUTCOME MEASURES: We have compared the predictive ability of the logistic EuroSCORE (uncalibrated), the logistic EuroSCORE calibrated for contemporary performance and a locally derived logistic regression model. We have used each to create risk-adjusted individual surgeon mortality funnel plots to demonstrate high mortality outcomes. RESULTS: There were 458 (3.1%) deaths. The expected mortality and receiver operating characteristic (ROC) curve values were: uncalibrated EuroSCORE -5.8% and 0.80, calibrated EuroSCORE -3.1% and 0.80, locally derived model -3.1% and 0.82. The uncalibrated EuroSCORE plot showed one surgeon to have mortality above the northwest average, and no surgeon above the 95% control limit (CL). The calibrated EuroSCORE plot and the local model showed little change in surgeon ranking, but significant differences in identifying high mortality outcomes. Two of three surgeons above the 95% CL using the calibrated EuroSCORE revert to acceptable outcomes when the local model is applied but the finding is critically dependent on the calibration coefficient. CONCLUSIONS: The uncalibrated EuroSCORE significantly overpredicted mortality and is not recommended. Instead, the EuroSCORE should be calibrated for contemporary performance. The differences demonstrated in defining high mortality outcomes when using a model built for purpose suggests that the choice of risk model is important when analysing surgeon mortality outcomes.