Evaluation of prognostic risk models for postoperative pulmonary complications in adult patients undergoing major abdominal surgery: a systematic review and international external validation cohort study

BACKGROUND

Stratifying risk of postoperative pulmonary complications after major abdominal surgery allows clinicians to modify risk through targeted interventions and enhanced monitoring. In this study, we aimed to identify and validate prognostic models against a new consensus definition of postoperative pulmonary complications.

METHODS

We did a systematic review and international external validation cohort study. The systematic review was done in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. We searched MEDLINE and Embase on March 1, 2020, for articles published in English that reported on risk prediction models for postoperative pulmonary complications following abdominal surgery. External validation of existing models was done within a prospective international cohort study of adult patients (≥18 years) undergoing major abdominal surgery. Data were collected between Jan 1, 2019, and April 30, 2019, in the UK, Ireland, and Australia. Discriminative ability and prognostic accuracy summary statistics were compared between models for the 30-day postoperative pulmonary complication rate as defined by the Standardised Endpoints in Perioperative Medicine Core Outcome Measures in Perioperative and Anaesthetic Care (StEP-COMPAC). Model performance was compared using the area under the receiver operating characteristic curve (AUROCC).

FINDINGS

In total, we identified 2903 records from our literature search; of which, 2514 (86·6%) unique records were screened, 121 (4·8%) of 2514 full texts were assessed for eligibility, and 29 unique prognostic models were identified. Nine (31·0%) of 29 models had score development reported only, 19 (65·5%) had undergone internal validation, and only four (13·8%) had been externally validated. Data to validate six eligible models were collected in the international external validation cohort study. Data from 11 591 patients were available, with an overall postoperative pulmonary complication rate of 7·8% (n=903). None of the six models showed good discrimination (defined as AUROCC ≥0·70) for identifying postoperative pulmonary complications, with the Assess Respiratory Risk in Surgical Patients in Catalonia score showing the best discrimination (AUROCC 0·700 [95% CI 0·683-0·717]).

INTERPRETATION

In the pre-COVID-19 pandemic data, variability in the risk of pulmonary complications (StEP-COMPAC definition) following major abdominal surgery was poorly described by existing prognostication tools. To improve surgical safety during the COVID-19 pandemic recovery and beyond, novel risk stratification tools are required.

FUNDING

British Journal of Surgery Society.

Breast Cancer Survivors’ Preferences and Barriers Related to ICT-Based Diet and Physical Activity Interventions

Objectives

To establish the preferences and perceived barriers related to physical activity and diet programming of breast cancer survivors (BCS) to inform the development of Information and Communication Technology (ICT)-based lifestyle interventions.

Methods

This was a cross-sectional study of 197 BSC aged 18 years or older and diagnosed with ductal carcinoma in situ (DCIS) or Stage I-IV breast cancer. The BCS were recruited during routine oncology appointments at a Midwestern cancer center. A survey was conducted to query survivors’ level of interest in, preferences for, and perceived barriers to participating in an exercise and dietary intervention program, with a specific emphasis on ICT-based programming.

Results

Overall, 85% of BCS reported they would consider participating in exercise and diet intervention research. Approximately 45% of participants reported that they had received diet and/or exercise information as part of their cancer care. However, only 15% of the participants received such information from healthcare professionals with the appropriate expertise (e.g., Dietitian, Exercise Specialist). Over two-thirds of the participants reported frequent use of mobile devices and the internet, and 80% indicated comfort using these devices (e.g., tablet, smart phone). The top three preferred formats for an ICT-based diet and exercise intervention program were “website”, “mobile apps” and “e-mails”. Older participants (>60 years) were more likely to report a preference for e-mails while younger participants (<60 years) were more likely to report a preference for websites or mobile apps. The most common perceived barriers to participation in a lifestyle intervention included fatigue, family responsibility and work.

Conclusions

Most BCS in this study were interested in exercise and diet interventions and would be comfortable with an ICT-based format with a preference for delivery via websites, mobile apps or e-mails. Future ICT-based lifestyle interventions should be designed with consideration of BCS’ age, barriers, facilitators and other characteristics.

Funding Sources

USDA-NIFA Hatch Project 1,011,487

Risk prediction models for delirium in the intensive care unit after cardiac surgery: a systematic review and independent external validation

Numerous risk prediction models are available for predicting delirium after cardiac surgery, but few have been directly compared with one another or been validated in an independent data set. We conducted a systematic review to identify validated risk prediction models of delirium (using the Confusion Assessment Method-Intensive Care Unit tool) after cardiac surgery and assessed the transportability of the risk prediction models on a prospective cohort of 600 consecutive patients undergoing cardiac surgery at a university hospital in Hong Kong from July 2013 to July 2015. The discrimination (c-statistic), calibration (GiViTI calibration belt), and clinical usefulness (decision curve analysis) of the risk prediction models were examined in a stepwise manner. Three published high-quality intensive care unit delirium risk prediction models (n=5939) were identified: Katznelson, the original PRE-DELIRIC, and the international recalibrated PRE-DELIRIC model. Delirium occurred in 83 patients (13.8%, 95% CI: 11.2-16.9%). After updating the intercept and regression coefficients in the Katznelson model, there was fair discrimination (0.62, 95% CI: 0.58-0.66) and good calibration. As the original PRE-DELIRIC model was already validated externally and recalibrated in six countries, we performed a logistic calibration on the recalibrated model and found acceptable discrimination (0.75, 95% CI: 0.72-0.79) and good calibration. Decision curve analysis demonstrated that the recalibrated PRE-DELIRIC risk model was marginally more clinically useful than the Katznelson model. Current models predict delirium risk in the intensive care unit after cardiac surgery with only fair to moderate accuracy and are insufficient for routine clinical use.

A NOVEL OLEAGINOUS YEAST STRAIN WITH HIGH LIPID PRODUCTIVITY AND ITS APPLICATION TO ALTERNATIVE BIODIESEL PRODUCTION

Five lipid-producing yeast strains, CHC08, CHC11, CHC28, CHC34, and CHC35, were revealed by Sudan Black B staining to contain lipid droplets within cells. Molecular analysis demonstrated that they were 2 strains of Candida parapsilosis, Pseudozyma parantarctica, Pichia manshurica, and Pichia occidentalis. Following batch fermentation, P. parantarctica CHC28 was found to have the highest biomass concentration, total lipids and lipid content levels. The major fatty acids in the lipids of this yeast strain were C16 and C18. Predictions of the properties of yeast biodiesel using linear equations resulted in values similar to biodiesel made from plant oils. Preliminary production of yeast biodiesel from P. parantarctica CHC28 was accomplished through esterification and transesterification reactions. It was found that yeast lipids with high acid value are easily converted to biodiesel at an approximately 90% yield. Therefore, it is possible to use crude lipids as alternative raw materials for biodiesel production.

Cortical involvement in the StartReact effect

The rapid release of prepared movements by a loud acoustic stimulus capable of eliciting a startle response has been termed the StartReact effect (Valls-Solé et al., 1999), and premotor reaction times (PMTs) of <70 ms are often observed. Two explanations have been given for these short latency responses. The subcortical storage and triggering hypothesis suggests movements that can be prepared in advance of a "go" signal are stored and triggered from subcortical areas by a startling acoustic stimulus (SAS) without cortical involvement. Alternatively, it has been hypothesized that the SAS can trigger movements from cortical areas through a faster pathway ascending from subcortical structures. Two experiments were designed to examine the possible role of the primary motor cortex in the StartReact effect. In Experiment 1, we used suprathreshold transcranial magnetic stimulation (TMS) during the reaction time (RT) interval to induce a cortical silent period in the contralateral primary motor cortex (M1). Thirteen participants performed 20° wrist extension movements as fast as possible in response to either a control stimulus (82 dB) or SAS (124 dB). PMTs for startle trials were faster than for control trials, while TMS significantly delayed movement onset compared to No TMS or Sham TMS conditions. In Experiment 2, we examined the StartReact effect in a highly cortically represented action involving speech of a consonant-vowel (CV) syllable. Similar to previous work examining limb movements, a robust StartReact effect was found. Collectively, these experiments provide evidence for cortical (M1) involvement in the StartReact effect.

Distance dependence of energy transfer from InGaN quantum wells to graphene oxide

We report the distance-dependent energy transfer from an InGaN quantum well to graphene oxide (GO) by time-resolved photoluminescence (PL). A pronounced shortening of the PL decay time in the InGaN quantum well was observed when interacting with GO. The nature of the energy-transfer process has been analyzed, and we find the energy-transfer efficiency depends on the 1/d² separation distance, which is dominated by the layer-to-layer dipole coupling.

Optical coupling from InGaAs subcell to InGaP subcell in InGaP/InGaAs/Ge multi-junction solar cells

Spatially-resolved electroluminescence (EL) images in the triple-junction InGaP/InGaAs/Ge solar cell have been investigated to demonstrate the subcell coupling effect. Upon irradiating the infrared light with an energy below bandgap of the active layer in the top subcell, but above that in the middle subcell, the EL of the top subcell quenches. By analysis of EL intensity as a function of irradiation level, it is found that the coupled p-n junction structure and the photovoltaic effect are responsible for the observed EL quenching. With optical coupling and photoswitching effects in the multi-junction diode, a concept of infrared image sensors is proposed.

Cancellation of elective operations on the day of intended surgery in a Hong Kong hospital: point prevalence and reasons

OBJECTIVE

To determine the point prevalence of elective surgical case cancellations and the reasons.

DESIGN

Cross-sectional study.

SETTING

Teaching hospital, Hong Kong. PATIENTS; Operating theatre records of elective surgery cancellations from 1 January 2009 to 31 December 2009 were retrospectively reviewed. MAIN OUTCOME MEASURES. Cancellation of scheduled elective surgery on the day of surgery and the corresponding reasons.

RESULTS

Of 6234 cases scheduled, 476 were cancelled, which yielded a point prevalence of 7.6%, with a 95% confidence interval of 7.0-8.3%. The highest number of cancellations occurred in patients scheduled for major general surgical procedures (n=94, 20%), major urological procedures (n=64, 13%), major orthopaedic surgery (n=38, 8%), and ultra-major cardiothoracic surgery (n=29, 6%). The most common category for cancellation was facility (73%), followed by work-up (17%), patient (10%), and surgeon (1%). No available operating room time due to overrun of the previous surgery was the most common reason for case cancellation (n=310). Compared to general surgery, the odds of no available operating time was significantly less in orthopaedics (odds ratio=0.26; 95% confidence interval, 0.17-0.39), otolaryngology (0.25; 0.13-0.46), neurosurgery (0.36; 0.16-0.70), paediatrics (0.53; 0.31-0.87), gynaecology (0.18; 0.11-0.29), ophthalmology (0.19; 0.07-0.41), and dentistry (0.10; 0.00-0.60). CONCLUSIONS. Case cancellations were mainly due to facility factors, such as no operating room time being available. The odds of having no operating room time available varied between surgical specialties.

Energy transfer from InGaN quantum wells to Au nanoclusters via optical waveguiding

We present the first observation of resonance energy transfer from InGaN quantum wells to Au nanoclusters via optical waveguiding. Steady-state and time-resolved photoluminescence measurements provide conclusive evidence of resonance energy transfer and obtain an optimum transfer efficiency of ~72%. A set of rate equations is successfully used to model the kinetics of resonance energy transfer.

Certification of international allied professionals in cardiac pacing and electrophysiology: Opportunities?

Allied professionals with diverse backgrounds and training are essential to the delivery of quality care to patients with heart rhythm disorders. There is a growing worldwide demand for defined educational requirements and certification pathways to ensure uniformity of knowledge and competence of those practicing in electrophysiology. The present viewpoint article reviews the current deficiencies of education and training, and advocates for the establishment of certification pathways by professional societies.

Oblique electron-beam evaporation of distinctive indium-tin-oxide nanorods for enhanced light extraction from InGaN/GaN light emitting diodes

This paper presents a novel and mass-producible technique to fabricate indium-tin-oxide (ITO) nanorods which serve as an omnidirectional transparent conductive layer (TCL) for InGaN/GaN light emitting diodes (LEDs). The characteristic nanorods, prepared by oblique electron-beam evaporation in a nitrogen ambient, demonstrate high optical transmittance (T>90%) for the wavelength range of 450nm to 900nm. The light output power of a packaged InGaN/GaN LED with the incorporated nanorod layer is increased by 35.1% at an injection current of 350mA, compared to that of a conventional LED. Calculations based on a finite difference time domain (FDTD) method suggest that the extraction enhancement factor can be further improved by increasing the thickness of the nanorod layer, indicating great potential to enhance the luminous intensity of solid-state lighting devices using ITO nanorod structures.

Broadband and omnidirectional antireflection employing disordered GaN nanopillars

Disordered GaN nanopillars of three different heights: 300, 550, and 720 nm are fabricated, and demonstrate broad angular and spectral antireflective characteristics, up to an incident angle of 60? and for the wavelength range of lambda=300-1800 nm. An algorithm based on a rigorous coupled-wave analysis (RCWA) method is developed to investigate the correlations between the reflective characteristics and the structural properties of the nanopillars. The broadband and omnidirectional antireflection arises mainly from the refractive-index gradient provided by nanopillars. Calculations show excellent agreement with the measured reflectivities for both s- and p- polarizations.

Enhanced light output from a nitride-based power chip of green light-emitting diodes with nano-rough surface using nanoimprint lithography

Enhanced light extraction from a GaN-based power chip (PC) of green light-emitting diodes (LEDs) with a rough p-GaN surface using nanoimprint lithography is presented. At a driving current of 350 mA and with a chip size of 1 mm × 1 mm packaged on transistor outline (TO)-cans, the light output power of the green PC LEDs with nano-rough p-GaN surface is enhanced by 48% when compared with the same device without a rough p-GaN surface. In addition, by examining the radiation patterns, the green PC LED with nano-rough p-GaN surface shows stronger light extraction with a wider view angle. These results offer promising potential to enhance the light output powers of commercial light-emitting devices by using the technique of nanoimprint lithography under suitable nanopattern design.

Characterisation of plasmids encoding CTX-M-3 extended-spectrum β-lactamase from Enterobacteriaceae isolated at a university hospital in Taiwan

CTX-M-3 is the most common extended-spectrum beta-lactamase produced by Enterobacteriaceae in Taiwan. The present study was conducted to characterise the genetic environment surrounding bla(CTX-M-3). A total of 11 ceftriaxone-resistant isolates were studied: Escherichia coli (n=4), Klebsiella pneumoniae (n=5) and Salmonella enterica serotypes Anatum (SA831R) and Potsdam (SC72). Molecular methods used included polymerase chain reaction, sequencing, DNA-DNA hybridisation, conjugation, physical mapping and restriction fragment length polymorphism (RFLP) analysis. All isolates examined carried bla(CTX-M-3) on large plasmids (>70kb). The resistance plasmids of the two Salmonella and two K. pneumoniae strains (KP104 and KP116) were confirmed to be conjugative in vitro. RFLP analysis indicated that the plasmids were different. Physical mapping also revealed the difference between the two Salmonella plasmids, pSA831R (82kb) and pSC72 (74kb). An insertion sequence, ISEcp1, was found upstream of each bla(CTX-M-3) gene. However, sequencing of downstream regions of the bla genes showed two different patterns: the presence of orf477 in pSA831R and of orf1-mucA in pSC72, pKP104 and pKP116. IncI1-type oriT and nikA sequences were present in the plasmids of all the clinical isolates tested, except S. Anatum. Different bla(CTX-M-3)-carrying plasmids were identified among the enterobacteria studied. The presence of ISEcp1 in all isolates may be associated with the widespread resistance among Enterobacteriaceae. Although the plasmids were not identical, they appeared to belong to the same incompatibility group (IncI1-like plasmids), suggesting that they are genetically related but may have evolved divergently over time.

Compound and double mutations in patients with hypertrophic cardiomyopathy: implications for genetic testing and counselling

OBJECTIVE

To report the frequency of single and multiple gene mutations in an Australian cohort of patients with hypertrophic cardiomyopathy (HCM).

METHODS

Genetic screening of seven HCM genes (beta-MHC, MyBP-C, cTnT, cTnI, ACTC, MYL2, and MYL3) was undertaken in 80 unrelated probands. Screening was by denaturing high performance liquid chromatography and direct DNA sequencing. Clinical data were collected on all patients and on genotyped family members.

RESULTS

26 mutations were identified in 23 families (29%). Nineteen probands (24%) had single mutations (11 beta-MHC, 4 MyBP-C, 3 cTnI, 1 cTnT). Multiple gene mutations were identified in four probands (5%): one had a double mutation and the others had compound mutations. Six of 14 affected individuals from multiple mutation families (43%) experienced a sudden cardiac death event, compared with 10 of 55 affected members (18%) from single mutation families (p = 0.05). There was an increase in septal wall thickness in patients with compound mutations (mean (SD): 30.7 (3.1) v 24.4 (7.4) mm; p<0.05).

CONCLUSIONS

Multiple gene mutations occurring in HCM families may result in a more severe clinical phenotype because of a "double dose" effect. This highlights the importance of screening the entire panel of HCM genes even after a single mutation has been identified.