External validation of the Surgical Outcome Risk Tool (SORT) in 3305 abdominal surgery patients in the independent sector in the UK.

BACKGROUND: Assessing the risk of post-surgical mortality is a key component of pre-surgical planning. The Surgical Outcome Risk Tool (SORT) uses pre-operative variables to predict 30-day mortality. The aim of this study was to externally validate SORT in patients undergoing major abdominal surgery. METHODS: Data were collected from patients treated in five independent hospitals in the UK. Individualised SORT scores were calculated, and area under the receiver operating characteristic (AUROC) and precision-recall curves (PRC) plus 95% confidence intervals (CI) were drawn to test the ability of SORT to identify in-hospital death. Outcomes of patients with a SORT predicted risk of mortality of ≥ 5% (high risk) were compared to those with a predicted risk of < 5% (standard risk). RESULTS: The study population comprised 3305 patients, mean age 51 years, 2783 (84.2%) underwent elective surgery most frequently involving the colon (24.6%), or liver, pancreas or gallbladder (18.2%). Overall, 1551 (46.9%) patients were admitted to ICU and 29 (0.88%) died. The AUROC of SORT for discriminating patients at risk of death in hospital was 0.899 (95% CI 0.849 to 0.949) and the PRC 0.247. In total, 72 (2.18%) patients were stratified as high risk. There were more unplanned ICU admissions and deaths in this group compared to the standard risk group (25.0% and 3.3%, versus 3.1% and 0.5%, respectively). CONCLUSION: We externally validated SORT in a large population of abdominal surgery patients. SORT performed well in patients with lower risk profiles, but underpredicted adverse outcomes in the higher risk group.

British Thoracic Society national bronchiectasis audit 2010 and 2011.

There have been two national British Thoracic Society (BTS) bronchiectasis audits from 1 October to 30 November in 2010 and 2011 in patients with non-cystic fibrosis attending secondary care. The first audit was soon after the publication of the BTS guidelines in July 2010 and both audits were based on the BTS guideline recommendations. We had 1460 and 2404 records in the 2 years respectively. The national audits highlight that the majority of guideline recommendations were not currently being adhered to and demonstrate the need for national quality standards, which are currently in preparation.

Glasgow supported self-management trial (GSuST) for patients with moderate to severe COPD: randomised controlled trial.

OBJECTIVE: To determine whether supported self management in chronic obstructive pulmonary disease (COPD) can reduce hospital readmissions in the United Kingdom. DESIGN: Randomised controlled trial. SETTING: Community based intervention in the west of Scotland. PARTICIPANTS: Patients admitted to hospital with acute exacerbation of COPD. INTERVENTION: Participants in the intervention group were trained to detect and treat exacerbations promptly, with ongoing support for 12 months. MAIN OUTCOME MEASURES: The primary outcome was hospital readmissions and deaths due to COPD assessed by record linkage of Scottish Morbidity Records; health related quality of life measures were secondary outcomes. RESULTS: 464 patients were randomised, stratified by age, sex, per cent predicted forced expiratory volume in 1 second, recent pulmonary rehabilitation attendance, smoking status, deprivation category of area of residence, and previous COPD admissions. No difference was found in COPD admissions or death (111/232 (48%) v 108/232 (47%); hazard ratio 1.05, 95% confidence interval 0.80 to 1.38). Return of health related quality of life questionnaires was poor (n=265; 57%), so that no useful conclusions could be made from these data. Pre-planned subgroup analysis showed no differential benefit in the primary outcome relating to disease severity or demographic variables. In an exploratory analysis, 42% (75/150) of patients in the intervention group were classified as successful self managers at study exit, from review of appropriateness of use of self management therapy. Predictors of successful self management on stepwise regression were younger age (P=0.012) and living with others (P=0.010). COPD readmissions/deaths were reduced in successful self managers compared with unsuccessful self managers (20/75 (27%) v 51/105 (49%); hazard ratio 0.44, 0.25 to 0.76; P=0.003). CONCLUSION: Supported self management had no effect on time to first readmission or death with COPD. Exploratory subgroup analysis identified a minority of participants who learnt to self manage; this group had a significantly reduced risk of COPD readmission, were younger, and were more likely to be living with others. TRIAL REGISTRATION: Clinical trials NCT 00706303.

Trends, indications and outcomes of cardiac implantable device system extraction: a single UK centre experience over the last decade.

BACKGROUND: The rising number of device implantation has seen a parallel in the rising numbers of lead extraction. Herein we have analysed our experience in cardiac device and lead extraction in a single tertiary centre over the last decade. METHOD: Retrospective analysis of all consecutive patients undergoing lead extractions performed between 2001 and 2010. Procedural success and complications as defined by the Heart Rhythm Society policy. RESULTS: A total of 745 leads were extracted with a procedural success of 98.9% [382 cases; partial success in 6.9% (26) cases] and failure in 1.1% (4). Major complication rate was 1% (four cases) and minor complication rate was 3.6%. By both univariate and multivariate analysis only duration of lead implantation was an indicator for success (p < 0.0001). The mean implantation time for failed lead extraction was 203 ± 64 months compared with 71.8 ± 16.5 months in the successful cohort (p < 0.0001). Laser-assisted extraction was required in 176 cases. With regard to extraction indication, lead malfunction/recall showed a significant increase during the study period (p = 0.03). On time trend analysis the rise in coronary sinus (CS) lead extraction over time was significant. (p = 0.02) Despite a trend for increased laser use over time this did not achieve statistical significance, p = 0.06. CONCLUSIONS: A decade's experience of percutaneous lead extraction suggests that a high procedural success rate with a low complication rate is achieved in a high-volume centre. During this time, an increase in both defibrillator and CS lead explantation and a rising trend in laser assistance with almost 50% of cases needing laser usage were observed.

British Thoracic Society emergency oxygen audits.

The British Thoracic Society (BTS) guideline for emergency oxygen use in adult patients was commissioned by the BTS and developed in conjunction with 21 other colleges and societies prior to publication in 2008. One of the specific aims of the Guideline Development Group was to audit the use of oxygen in UK hospitals before the guideline was published and at intervals afterwards.

Reliability of perceptions of voice quality: evidence from a problem asthma clinic population.

INTRODUCTION: Methods of perceptual voice evaluation have yet to achieve satisfactory consistency; complete acceptance of a recognised clinical protocol is still some way off. MATERIALS AND METHODS: Three speech and language therapists rated the voices of 43 patients attending the problem asthma clinic of a teaching hospital, according to the grade-roughness-breathiness-asthenicity-strain (GRBAS) scale and other perceptual categories. RESULTS AND ANALYSIS: Use of the GRBAS scale achieved only a 64.7 per cent inter-rater reliability and a 69.6 per cent intra-rater reliability for the grade component. One rater achieved a higher degree of consistency. Improved concordance on the GRBAS scale was observed for subjects with laryngeal abnormalities. Raters failed to reach any useful level of agreement in the other categories employed, except for perceived gender. DISCUSSION: These results should sound a note of caution regarding routine adoption of the GRBAS scale for characterising voice quality for clinical purposes. The importance of training and the use of perceptual anchors for reliable perceptual rating need to be further investigated.

Spectrum of nasal disease in an asthma clinic: when is an ENT opinion indicated?

AIMS: To characterise the spectrum of nasal symptomatology and nasendoscopic abnormalities seen in patients attending an asthma clinic, and to relate these symptoms to the likelihood of finding nasendoscopic abnormalities which merit treatment. METHODS: Forty-three patients attending a problem asthma clinic were enrolled in an observational study. Cardinal nasal symptoms--obstruction, congestion, hyposmia, rhinorrhoea, sneezing, epistaxis or other symptoms--were graded as none (zero), mild (one), moderate (two) or severe (three), giving a maximum nasal symptom score of 21. Asthma symptoms and lung function were measured. Nasendoscopy was then performed. RESULTS: Obstruction was the most common cardinal nasal symptom (seen in 15 patients), the median nasal symptom score was 5.3 (range zero to 14) and only three patients had no nasal symptoms. There was no correlation between nasal symptom score and severity of asthma symptoms or forced expiratory volume in one second. Twenty-two patients had a normal appearance on ENT examination (median nasal symptom score four). The nasendoscopic abnormalities seen comprised polyps (n = 8; median nasal symptom score five), deviated nasal septum (n = 7; median nasal symptom score four), oedematous mucosa (n = 4; median nasal symptom score seven) and other abnormalities (n = 2). Individual nasal symptoms were poor predictors of individual nasal pathologies, with hyposmia the best individual predictor of any abnormality (positive predictive value 80 per cent). The presence of a combination of symptoms increased the likelihood of any nasendoscopic abnormality, with obstruction, rhinorrhoea and hyposmia together having a positive predictive value of 100 per cent. CONCLUSIONS: Nasal symptoms are much more frequent than structural abnormalities in patients attending a problem asthma clinic. The threshold for ENT referral should be lower when the patient complains of a symptom complex including hyposmia. Furthermore, concurrent hyposmia, obstruction and rhinorrhoea should be seen as an indication for ENT referral.

Perceived vocal morbidity in a problem asthma clinic.

AIMS: Asthma treatment has the potential to affect patients' voices. We undertook detailed characterisation of voice morbidity in patients attending a problem asthma clinic, and we determined how patients' perceptions related to objective assessment by an experienced observer. METHODS: Forty-three patients took part in the study. Subjects completed the self-administered voice symptom score (VoiSS) questionnaire and underwent digital voice recording. These voice recordings were scored using the grade-roughness-breathiness-asthenicity-strain system (GRBAS). Laryngoscopy was also performed. RESULTS: The median VoiSS was 26 (range three to 83). VoiSS were significantly lower in the 17 patients with normal laryngeal structure and function (range four to 46; median 22), compared with the 26 patients with functional or structural laryngeal abnormality (range three to 83; median 33) (95 per cent confidence intervals for difference 0.0-21.0; p = 0.044). The overall grade score for the GRBAS scale did not differ between these two groups, and only 13 patients had a GRBAS score of one or more, recognised as indicating a voice problem. There were positive correlations between related GRBAS score and voice symptom score subscales. Although voice symptom scores were significantly more abnormal in patients with structural and functional abnormalities, this score performed only moderately well as a predictive tool (sensitivity 54 per cent; specificity 71 per cent). Nevertheless, the voice symptom score performed as well as the more labour-intensive GRBAS score (sensitivity 57 per cent; specificity 60 per cent). Patients' inhaled corticosteroid dose (median dose 1000 microg beclomethasone dipropionate or equivalent) had a statistically significant relationship with their overall grade score for the GRBAS scale (r = 0.56; p < 0.001), but not with their VoiSS. Only one patient had evidence of laryngeal candidiasis, and only two had any evidence of abnormality suggesting steroid-induced myopathy. CONCLUSIONS: Vocal morbidity is common in patients with asthma, and should not be immediately attributed to steroid-related candidiasis. The VoiSS merits further, prospective validation as a screening tool for ENT and/or speech and language therapy referral in patients with asthma.

Laser-assisted lead extraction: the European experience.

AIMS: The aim of this study is to investigate the safety and effectiveness of Excimer laser-assisted lead extraction in Europe. The final European multi-centre study experience is presented. METHOD AND RESULTS: The Excimer is a cool cutting laser (50 degrees C) with a wavelength of 308 nm. The energy is emitted from the tip of a flexible sheath and is absorbed by proteins and lipids, 64% of the energy is absorbed at a tissue depth of 0.06 mm. The sheath is positioned over the lead, and the fibrosis surrounding the lead is vaporized while advancing the sheath without damaging other leads. From August 1996 to March 2001, 383 leads (170 atrial, 213 ventricular) in 292 patients (mean age 61.6 years, range 13-96) were extracted at 14 European centres. Mean implantation time was 74 months (3-358). Most frequent indications were pocket infection (26%), non-functional leads (21%), patient morbidity (21%), septicaemia or endocarditis (14%), erosion (5%), and lead interference (8%). Median extraction time was 15 min (1-300). Complete extraction was achieved in 90.9% of the leads and partial extraction in 3.4%. Extraction failed in 5.7% of the leads. Major complications = perforations caused 10/22 (3.4/5.7%) of the failures. Most partially extracted patients were considered clinically successful, as only minor lead parts without clinical significance were left. Femoral non-laser technique was used to remove 8/12 of the non-complication failures. The total complication rate, including five minor complications (1.7%), was 5.1%. No in-hospital mortality occurred. CONCLUSION: Pacing and implantable cardioverter-defibrillator leads can safely, effectively, and predictably be extracted. Open-heart extractions can be limited to special cases. The results indicate that the traditional policy of abandoning redundant leads, instead of removing them, may be obsolete in many patients.

Simulation of cardiac pathologies using an electromechanical biventricular model and XMR interventional imaging.

Simulating cardiac electromechanical activity is of great interest for a better understanding of pathologies and for therapy planning. Design and validation of such models is difficult due to the lack of clinical data. XMR systems are a new type of interventional facility in which patients can be rapidly transferred between X-ray and MR systems. Our goal is to design and validate an electromechanical model of the myocardium using XMR imaging. The proposed model is computationally fast and uses clinically observable parameters. We present the integration of anatomy, electrophysiology, and motion from patient data. Pathologies are introduced in the model and simulations are compared to measured data. Initial qualitative comparison on the two clinical cases presented is encouraging. Once fully validated, these models will make it possible to simulate different interventional strategies.

Non-contact left ventricular endocardial mapping in cardiac resynchronisation therapy.

BACKGROUND: Up to 30% of patients with heart failure do not respond to cardiac resynchronisation therapy (CRT). This may reflect placement of the coronary sinus lead in regions of slow conduction despite optimal positioning on current criteria. OBJECTIVES: To characterise the effect of CRT on left ventricular activation using non-contact mapping and to examine the electrophysiological factors influencing optimal left ventricular lead placement. METHODS: and results: 10 patients implanted with biventricular pacemakers were studied. In six, the coronary sinus lead was found to be positioned in a region of slow conduction with an average conduction velocity of 0.4 m/s, v 1.8 m/s in normal regions (p < 0.02). Biventricular pacing with the left ventricle paced 32 ms before the right induced the optimal mean velocity time integral and timing for fusion of depolarisation wavefronts from the right and left ventricular pacing sites. Pacing outside regions of slow conduction decreased left ventricular activation time and increased cardiac output and dP/dt(max) significantly. CONCLUSIONS: In patients undergoing CRT for heart failure, non-contact mapping can identify regions of slow conduction. Significant haemodynamic improvements can occur when the site of left ventricular pacing is outside these slow conduction areas. Failure of CRT to produce clinical benefits may reflect left ventricular lead placement in regions of slow conduction which can be overcome by pacing in more normally activating regions.

Beneficial effects of biventricular pacing in a patient with hypertrophic cardiomyopathy and intraventricular conduction delay.

The beneficial use of biventricular pacing is reported in a patient with hypertrophic cardiomyopathy and intraventricular conduction delay. This resulted in improvements in symptomatic status and exercise tolerance that may be related to cardiac resynchronisation. The improvement in symptoms by biventricular pacing in a patient with hypertrophic cardiomyopathy and intraventricular conduction delay is previously undocumented and requires further investigation.

Clinical audit indicators of outcome following admission to hospital with acute exacerbation of chronic obstructive pulmonary disease.

BACKGROUND: The 1997 BTS/RCP national audit of acute chronic obstructive pulmonary disease (COPD) in terms of process of care has previously been reported. This paper describes from the same cases the outcomes of death, readmission rates within 3 months of initial admission, and length of stay. Identification of the main pre-admission predictors of outcome may be used to control for confounding factors in population characteristics when comparing performance between units. METHODS: Data on 74 variables were collected retrospectively using an audit proforma from patients admitted to UK hospitals with acute COPD. Important prognostic variables for the three outcome measures were identified by relative risk and logistic regression was used to place these in order of predictive value. RESULTS: 1400 admissions from 38 acute hospitals were collated. 14% of cases died within 3 months of admission with variation between hospitals of 0-50%. Poor performance status, acidosis, and the presence of leg oedema were the best significant independent predictors of death. Age above 65, poor performance status, and lowest forced expiratory volume in 1 second (FEV(1)) tertile were the best predictors of length of stay (median 8 days). 34% of patients were readmitted (range 5-65%); lowest FEV(1) tertile, previous admission, and readmission with five or more medications were the best predictors for readmission. CONCLUSIONS: Important predictors of outcome have been identified and formal recording of these may assist in accounting for confounding patient characteristics when making comparisons between hospitals. There is still wide variation in outcome between hospitals that remains unexplained by these factors. While some of this variance may be explained by incomplete recording of data or patient factors as yet unidentified, it seems likely that deficiencies in the process of care previously identified are responsible for poor outcomes in some units.

Atrial flutter ablation: efficacy and cost-effectiveness of a single decapolar electrode to demonstrate bidirectional isthmus block.

AIMS: To evaluate whether a single decapolar electrode is a reliable and cost-effective substitute for the 'Halo' catheter to map the circuit and detect bidirectional isthmus block during atrial flutter (AFL) ablation. METHODS AND RESULTS: Twenty-four patients underwent AFL ablation by using the decapolar electrode in the infero-lateral wall of right atrium (group A) while a 'Halo' catheter was used in 11 patients (group B). Both groups had similar clinical characteristics. Anti-clockwise rotation (20 patients), clockwise (3 patients) or both forms of AFL (1 patient) were detected in group A. All patients in group B had anti-clockwise AFL. Bidirectional isthmus block was completed in 22 patients of group A and in 9 of group B (P=NS) while incomplete isthmus block was detected in 2 patients in each group (P=NS). Mean fluoroscopy and procedure time was 27 +/- 47 min, 107 +/- 36 min in group A and 14 +/- 19 min, 114 +/- 65 min in group B (P=NS). AFL relapsed in 3 patients of group A (follow-up 7 +/- 4 months) and in 2 of group B (4 +/- 2 months). CONCLUSION: A single decapolar electrode is a reliable method to map the circuit and demonstrate bidirectional isthmus block during AFL ablation. The cost of the decapolar electrode is a quarter of that of the 'Halo' catheter. This represents a significant saving particularly for centres with a substantial number of AFL ablations.

Audit of acute admissions of COPD: standards of care and management in the hospital setting.

Despite publication of several management guidelines for COPD, relatively little is known about standards of care in clinical practice. Data were collected on the management of 1400 cases of acute admission with Chronic Obstructive Pulmonary Disease in 38 UK hospitals to compare clinical practice against the recommended British Thoracic Society standards. Variation in the process of care between the different centres was analysed and a comparison of the management by respiratory specialists and nonrespiratory specialists made. There were large variations between centres for many of the variables studied. A forced expiratory volume in one second measurement was found in only 53% of cases. Of the investigations recommended in the acute management arterial blood gases were performed in 79% (interhospital range 40-100%) of admissions and oxygen was formally prescribed in only 64% (range 9-94%). Of those cases with acidosis and hypercapnia 35% had no further blood gas analysis and only 13% received ventilatory support. Long-term management was also deficient with 246 cases known to be severely hypoxic on admission yet two-thirds had no confirmation that oxygen levels had returned to levels above the requirements for long-term oxygen therapy. Only 30% of current smokers had cessation advice documented. To conclude, the median standards of care observed fell below those recommended by the guidelines. The lowest levels of performance were for patients not under the respiratory specialists, but specialists also have room for improvement. The substantial variation in the process of care between hospitals is strong evidence that it is possible for other centres with poorer performance to improve their levels of care.

Atrial arrhythmia suppression by atrial overdrive pacing: pacemaker Holter assessment.

The purpose of this study was to assess the efficacy of overdrive, single-site right atrial appendage pacing to reduce the burden of atrial fibrillation (AF) when compared with a standard lower rate limit of 60 bpm. This was verified by using the pacemaker's Holter. Eighteen subjects with a pre-implant history of paroxysmal AF and implanted DDDR mode-switching pacemakers were recruited. The pacemaker lower rate limit was programmed in random order to 60, 75 or 90 bpm for three 2-month periods and the amount of AF quantified. In addition, the exercise tolerance (ET), general well being (GWB), functional capacity (FC) and specific symptom prevalence (SSP) were assessed. The main finding of the study was that when ranked according to the amount of AF, there was no significant difference in the amount of AF according to the pacing rate. Six patients failed to tolerate pacing at 90 bpm. There were no differences in the ET, GWB, FC and SSP scores. It is concluded that those clinicians that manage patients with paroxysmal

Applications of microscopy to the deformation and fracture of rubber-toughened polymers.

The principal mechanisms of inelastic deformation in rubber-toughened plastics, and in other similar multiphase polymers, are shear yielding and multiple crazing in the rigid matrix phase, and cavitation in the soft disperse phase. Microscopy has played a very important part in the identification and study of these mechanisms. However, no one technique has been predominant. Polarized-light microscopy is useful for observing crazing, and has proved to be the most effective method for studying shear yielding, whereas transmission electron microscopy has provided valuable insights into the cavitation behaviour of complex rubber particles. Scanning electron microscopy has made significant contributions in the study of all three micromechanisms. In some microscopy investigations, thin sections have been strained in situ on the microscope stage. In others, specimens have been deformed in the bulk state before being polished and etched, or stained and microtomed, or coated with a thin layer of metal, in preparation for examination in the microscope. The importance of combining microscopy with other, complementary methods for studying deformation micromechanics is emphasized, and two novel methods for detecting cavitation in multiphase polymers are discussed briefly.