Failure to rescue the elderly: a superior quality metric for trauma centers.

BACKGROUND: Trauma centers require reliable metrics to better compare the quality of care delivered. We compared mortality after a reported complication, termed failure to rescue (FTR), and FTR in the elderly (age >65 years) (FTRE) to determine which is a superior metric to assess quality of care delivered by trauma centers. METHODS: This was a retrospective review of the National Trauma Databank (NTDB) research data sets 2010 and 2011. Patients ≥16 years admitted to centers reporting ≥80% of AIS and/or ≥ 20% of comorbidities with > 200 subjects in the NTDB were selected. Centers were classified based on the rate of FTR and FTRE (<5 vs. 5-14 vs. ≥15%). The primary outcome was adjusted mortality for each group of trauma centers based on FTR and FTRE classifications. RESULTS: The overall mean ± SD FTR rate was 7.2 ± 5.2% and FTRE was 10.4 ± 7.9%. The adjusted odds ratio (AOR) for mortality was not different when centers with FTR <5% were compared to those with FTR of 5-14 or ≥15%. In contrast, a stepwise increase in FTRE predicted a significantly higher mortality when centers with FTRE 5% were compared to those with 5-14% (AOR: 1.05, p = 0.031) and ≥15% (AOR: 1.13, p < 0.001). Similarly, stepwise increase in FTRE predicted higher adjusted mortality for severely and critically injured patients, whereas FTR did not. CONCLUSIONS AND RELEVANCE: Higher FTRE predicts increased adjusted mortality better than FTR after trauma and should, therefore, be considered an important metric when comparing quality care delivered by trauma centers.

Design guidelines for perovskite/silicon 2-terminal tandem solar cells: an optical study.

Perovskite/silicon 2-terminal tandem cells have made significant advances towards >25% efficiency. Despite this, there is limited understanding of how the optical properties of the materials affect the optical losses within the tandem cell. Using an accurate optical model, we investigate, identify and propose solutions to the optical loss mechanisms inherent in a typical perovskite/silicon 2-terminal tandem cell. The results highlight, firstly, the requirement for low absorption in all layers above the perovskite film, and secondly, the importance of the proper choice of refractive index and thickness of charge transport layers of the perovskite cell, in order to minimize reflection at the interfaces formed by these layers. We demonstrate that the proper choice of these parameters is based on, and can be guided by, basic optics principles which serve as design guidelines. With careful selection of charge transport materials, optimization of the perovskite absorber thickness and the introduction of light trapping within the silicon cell, a matched current of over 20 mA/cm2 can be realized, enabling efficiencies greater than 30% using currently available cell processing methods and materials.

Compliance and use of the World Health Organization checklist in U.K. operating theatres.

BACKGROUND: The World Health Organization (WHO) Surgical Safety Checklist is reported to reduce surgical morbidity and mortality, and is mandatory in the U.K. National Health Service. Hospital audit data show high compliance rates, but direct observation suggests that actual performance may be suboptimal. METHODS: For each observed operation, WHO time-out and sign-out attempts were recorded, and the quality of the time-out was evaluated using three measures: all information points communicated, all personnel present and active participation. RESULTS: Observation of WHO checklist performance was conducted for 294 operations, in five hospitals and four surgical specialties. Time-out was attempted in 257 operations (87.4 per cent) and sign-out in 26 (8.8 per cent). Within time-out, all information was communicated in 141 (54.9 per cent), the whole team was present in 199 (77.4 per cent) and active participation was observed in 187 (72.8 per cent) operations. Surgical specialty did not affect time-out or sign-out attempt frequency (P = 0.453). Time-out attempt frequency (range 42-100 per cent) as well as all information communicated (15-83 per cent), all team present (35-90 per cent) and active participation (15-93 per cent) varied between hospitals (P < 0.001 for all). CONCLUSION: Meaningful compliance with the WHO Surgical Safety Checklist is much lower than indicated by administrative data. Sign-out compliance is generally poor, suggesting incompatibility with normal theatre work practices. There is variation between hospitals, but consistency across studied specialties, suggesting a need to address organizational culture issues.

Resonant enhancement of dielectric and metal nanoparticle arrays for light trapping in solar cells.

We numerically investigate the light trapping properties of two-dimensional diffraction gratings formed from silver disks or titanium dioxide pillars, placed on the rear of Si thin-film solar cells. In contrast to previous studies of front-surface gratings, we find that metal particles out-perform dielelectric ones when placed on the rear of the cell. By optimizing the grating geometry and the position of a planar reflector, we predict short circuit current enhancements of 45% and 67% respectively for the TiO2 and silver nanoparticles. Furthermore, we show that interference effects between the grating and reflector can significantly enhance, or suppress, the light trapping performance. This demonstrates the critical importance of optimizing the reflector as an integral part of the light trapping structure.

Resonant SPP modes supported by discrete metal nanoparticles on high-index substrates.

We provide a new physical interpretation of scattering from plasmonic nanoparticles on high-index substrates. We demonstrate the excitation of different types of resonant modes on disk-shaped, Ag nanoparticles. At short wavelengths, the resonances are localised at the top of the particle, while at longer wavelengths they are localised at the Ag/substrate interface. We attribute the long wavelength resonances to geometric resonances of surface plasmon polaritons (SPPs) at the Ag/substrate interface. We show that particles that support resonant SPP modes have enhanced scattering cross-sections when placed directly on a high-index substrate; up to 7.5 times larger than that of a dipole scatterer with an equivalent free-space resonance. This has implications for designing scattering nanostructures for light trapping solar cells.

Interventions to improve teamwork and communications among healthcare staff.

BACKGROUND: Concern over the frequency of unintended harm to patients has focused attention on the importance of teamwork and communication in avoiding errors. This has led to experiments with teamwork training programmes for clinical staff, mostly based on aviation models. These are widely assumed to be effective in improving patient safety, but the extent to which this assumption is justified by evidence remains unclear. METHODS: A systematic literature review on the effects of teamwork training for clinical staff was performed. Information was sought on outcomes including staff attitudes, teamwork skills, technical performance, efficiency and clinical outcomes. RESULTS: Of 1036 relevant abstracts identified, 14 articles were analysed in detail: four randomized trials and ten non-randomized studies. Overall study quality was poor, with particular problems over blinding, subjective measures and Hawthorne effects. Few studies reported on every outcome category. Most reported improved staff attitudes, and six of eight reported significantly better teamwork after training. Five of eight studies reported improved technical performance, improved efficiency or reduced errors. Three studies reported evidence of clinical benefit, but this was modest or of borderline significance in each case. Studies with a stronger intervention were more likely to report benefits than those providing less training. None of the randomized trials found evidence of technical or clinical benefit. CONCLUSION: The evidence for technical or clinical benefit from teamwork training in medicine is weak. There is some evidence of benefit from studies with more intensive training programmes, but better quality research and cost-benefit analysis are needed.

The Oxford NOTECHS System: reliability and validity of a tool for measuring teamwork behaviour in the operating theatre.

INTRODUCTION: The frequency of adverse events in the operating theatre has been linked to the quality of teamwork and communication. Developing suitable measures of teamwork may play a role in reducing errors in surgery. This study reports on the development and evaluation of a method for measuring operating-theatre teamwork quality. METHODS: The Oxford Non-Technical Skills (NOTECHS) scale was developed from an aviation instrument for assessment of non-technical skills. Consultation with experts and task analysis led to modifications reflecting the complexities of the theatre teamwork, particularly the coexistence of three subteams (surgeons, anaesthetists and nurses). The scale was then evaluated using teams performing laparoscopic cholecystectomy (n = 65) before and after teamwork training. Attitudes to teamwork and surgical error rates were assessed by questionnaire and direct observation methods, and used to assess the reliability and validity of the Oxford NOTECHS scale. RESULTS: The interobserver reliability was excellent in 24 operations independently assessed by two observers (R(wg) = 0.99), confirmed by a third observer in 11 cases (R(wg) = 0.99). Validity was demonstrated through improved scores after teamwork training (t = -3.019, p = 0.005), concurrent with improved attitudes to teamwork after training; inverse correlation between NOTECHS scores and surgical errors (rho = -0.267, p = 0.046); strong inverse correlation between surgical subteam score and surgical errors (rho = -0.412, n = 65, p = 0.001); and strong correlation with teamwork scores from an alternative system (n = 5, r = 0.886, p = 0.046). CONCLUSION: The Oxford NOTECHS scale appears to be a reliable and valid instrument for assessing teamwork in the operating theatre, and is ready for further application.

The effects of aviation-style non-technical skills training on technical performance and outcome in the operating theatre.

Unintended harm to patients in operating theatres is common. Correlations have been demonstrated between teamwork skills and error rates in theatres. This was a single-institution uncontrolled before-after study of the effects of "non-technical" skills training on attitudes, teamwork, technical performance and clinical outcome in laparoscopic cholecystectomy (LC) and carotid endarterectomy (CEA) operations. The setting was the theatre suite of a UK teaching hospital. Attitudes were measured using the Safety Attitudes Questionnaire (SAQ). Teamwork was scored using the Oxford Non-Technical Skills (NOTECHS) method. Operative technical errors (OTEs), non-operative procedural errors (NOPEs), complications, operating time and length of hospital stay (LOS) were recorded. A 9 h classroom non-technical skills course based on aviation "Crew Resource Management" (CRM) was offered to all staff, followed by 3 months of twice-weekly coaching from CRM experts. Forty-eight procedures (26 LC and 22 CEA) were studied before intervention, and 55 (32 and 23) afterwards. Non-technical skills and attitudes improved after training (NOTECHS increase 37.0 to 38.7, t = -2.35, p = 0.021, SAQ teamwork climate increase 64.1 to 69.2, t = -2.95, p = 0.007). OTEs declined from 1.73 to 0.98 (u = 1071, p = 0.009), and NOPEs from 8.48 to 5.16 per operation (t = 4.383, p<0.001). These effects were stronger in the LC group than in CEA procedures. The operating time was unchanged, and a non-significant reduction in LOS was observed. Non-technical skills training improved technical performance in theatre, but the effects varied between teams. Considerable cultural resistance to adoption was encountered, particularly among medical staff. Debriefing and challenging authority seemed more difficult to introduce than other parts of the training. Further studies are needed to define the optimal training package, explain variable responses and confirm clinical benefit.

Factors influencing incident reporting in surgical care.

OBJECTIVES: To evaluate the process of incident reporting in a surgical setting. In particular: the influence of event outcome on reporting behaviour; staff perception of surgical complications as reportable events. DESIGN: Anonymous web-based questionnaire survey. SETTING: General Surgical Department in a UK teaching hospital. POPULATION: Of 203 eligible staff, 55 (76.4%) doctors and 82 (62.6%) nurses participated. MAIN OUTCOME MEASURES: Knowledge and use of local reporting system; propensity to report incidents which vary by outcome (harm, no harm, harm prevented); propensity to report surgical complications; practical and psychological barriers to reporting. RESULTS: Nurses were significantly more likely to know of the local reporting system and to have recently completed a report than doctors. The level of harm (F(1.8,246) = 254.2, p<0.001), incident type (F(1.9,258) = 64.4, p<0.001) and profession (F(1,135) = 20.7, p<0.001) all significantly affected the likelihood of reporting. Staff were most likely to report an incident when harm occurred. Doctors were significantly less likely to report surgical complications than other types of incident (15% vs 53%, z = 4.633, p<0.001). Fear was a significantly less important barrier to reporting than other reasons (z = -3.49, p<0.0002). CONCLUSION: An incident is more likely to be reported if harm results. Surgical complications are not generally perceived to be "reportable incidents," but they are addressed in Mortality and Morbidity meetings (M&M). Integrating M&M and incident reporting data will result in more comprehensive healthcare safety systems.

Plasmonic solar cells.

The scattering from metal nanoparticles near their localized plasmon resonance is a promising way of increasing the light absorption in thin-film solar cells. Enhancements in photocurrent have been observed for a wide range of semiconductors and solar cell configurations. We review experimental and theoretical progress that has been made in recent years, describe the basic mechanisms at work, and provide an outlook on future prospects in this area.

Teamwork and error in the operating room: analysis of skills and roles.

OBJECTIVE: To analyze the effects of surgical, anesthetic, and nursing teamwork skills on technical outcomes. SUMMARY BACKGROUND DATA: The value of team skills in reducing adverse events in the operating room is presently receiving considerable attention. Current work has not yet identified in detail how the teamwork and communication skills of surgeons, anesthetists, and nurses affect the course of an operation. METHODS: Twenty-six laparoscopic cholecystectomies and 22 carotid endarterectomies were studied using direct observation methods. For each operation, teams' skills were scored for the whole team, and for nursing, surgical, and anesthetic subteams on 4 dimensions (leadership and management [LM]; teamwork and cooperation; problem solving and decision making; and situation awareness). Operating time, errors in surgical technique, and other procedural problems and errors were measured as outcome parameters for each operation. The relationships between teamwork scores and these outcome parameters within each operation were examined using analysis of variance and linear regression. RESULTS: Surgical (F(2,42) = 3.32, P = 0.046) and anesthetic (F(2,42) = 3.26, P = 0.048) LM had significant but opposite relationships with operating time in each operation: operating time increased significantly with higher anesthetic but decreased with higher surgical LM scores. Errors in surgical technique had a strong association with surgical situation awareness (F(2,42) = 7.93, P < 0.001) in each operation. Other procedural problems and errors were related to the intraoperative LM skills of the nurses (F(5,1) = 3.96, P = 0.027). CONCLUSIONS: Detailed analysis of team interactions and dimensions is feasible and valuable, yielding important insights into relationships between nontechnical skills, technical performance, and operative duration. These results support the concept that interventions designed to improve teamwork and communication may have beneficial effects on technical performance and patient outcome.

Safety in anaesthesia: a study of 12,606 reported incidents from the UK National Reporting and Learning System.

The incident reporting database at the National Patient Safety Agency was interrogated on the nature, frequency and severity of incidents related to anaesthesia. Of 12,606 reports over a 2-year period, 2842 (22.5%) resulted in little harm or a moderate degree of harm, and 269 (2.1%) resulted in severe harm or death, with procedure or treatment problems generating the highest risk. One thousand and thirty-five incidents (8%) related to pre-operative assessment, with harm occurring in 275 (26.6%), and 552 (4.4%) related to epidural anaesthesia, with harm reported in 198 (35.9%). Fifty-eight occurrences of anaesthetic awareness were also examined. This preliminary analysis is not authoritative enough to warrant widespread changes of practice, but justifies future collaborative approaches to reduce the potential for harm and improve the submission, collection and analysis of incident reports. Practitioners, departments and professional bodies should consider how the information can be used to promote patient safety and their own defensibility.

The influence of non-technical performance on technical outcome in laparoscopic cholecystectomy.

INTRODUCTION: Evidence from other professions suggests that training in teamwork and general cognitive abilities, collectively described as non-technical skills, may reduce accidents and errors. The relationship between non-technical teamwork skills and technical errors was studied using a behavioural marker system validated in aviation and adapted for use in surgery. METHOD: 26 elective laparoscopic cholecystectomies were observed. Simultaneous assessments were made of surgical technical errors, by observation clinical human reliability assessment (OCHRA) task analysis, and non-technical performance, using the surgical NOTECHS behavioural marker system. NOTECHS assesses four categories: (1) leadership and management, (2) teamwork cooperation, (3) problem-solving and decision-making, (4) situation awareness. Each subteam (nurses, surgeons and anaesthetists) was scored separately on each of the four dimensions. Two observers - one surgical trainee and one human factors expert - were used to assess intra-rater reliability. RESULTS: The mean NOTECHS team score was 35.5 (95% C.I. +/- 1.88). The mean subteam scores for surgeons, anaesthetists and nurses were 13.3 (95% C.I. +/- 0.64), 11.4 (95% C.I. +/- 1.05), and 10.8 (95% C.I. +/- 0.87), respectively, with a significant difference between surgeons and anaesthetists (U = 197, p = 0.009), and surgeons and nurses (U = 0.134, p

A framework for the design of ambulance sirens.

Ambulance sirens are essential for assisting the safe and rapid arrival of an ambulance at the scene of an emergency. In this study, the parameters upon which sirens may be designed were examined and a framework for emergency vehicle siren design was proposed. Validity for the framework was supported through acoustic measurements and the evaluation of ambulance transit times over 240 emergency runs using two different siren systems. Modifying existing siren sounds to add high frequency content would improve vehicle penetration, detectability and sound localization cues, and mounting the siren behind the radiator grill, rather than on the light bar or under the wheel arch, would provide less unwanted noise while maintaining or improving the effective distance in front of the vehicle. Ultimately, these considerations will benefit any new attempt to design auditory warnings for the emergency services.

Identification of systems failures in successful paediatric cardiac surgery.

Patient safety will benefit from an approach to human error that examines systemic causes, rather than blames individuals. This study describes a direct observation methodology, based on a threat and error model, prospectively to identify types and sources of systems failures in paediatric cardiac surgery. Of substantive interest were the range, frequency and types of failures that could be identified and whether minor failures could accumulate to form more serious events, as has been the case in other industries. Check lists, notes and video recordings were employed to observe 24 successful operations. A total of 366 failures were recorded. Coordination and communication problems, equipment problems, a relaxed safety culture, patient-related problems and perfusion-related problems were most frequent, with a smaller number of skill, knowledge and decision-making failures. Longer and more risky operations were likely to generate a greater number of minor failures than shorter and lower risk operations, and in seven higher-risk cases frequently occurring minor failures accumulated to threaten the safety of the patient. Non-technical errors were more prevalent than technical errors and task threats were the most prevalent systemic source of error. Adverse events in surgery are likely to be associated with a number of recurring and prospectively identifiable errors. These may be co-incident and cumulative human errors predisposed by threats embedded in the system, rather than due to individual incompetence or negligence. Prospectively identifying and reducing these recurrent failures would lead to improved surgical standards and enhanced patient safety.