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.

Overview of diagnostics on a small-scale RF source for fusion (ROBIN) and the one planned for the diagnostic beam for ITER

India is responsible for the supply of diagnostic neutral beam systems for ITER to diagnose its helium ash during the deuterium-tritium plasma phase using the charge exchange recombination spectroscopy technique. Considering the many first of its kind in terms of technologies and beam development aspects, ITER Indian domestic agency has adopted a strategy of developing the technology and beam experimentation in parallel. On the beam development front three test beds, namely, the ROBIN (Rf Operated Beam source in India for Negative ion research), the TWIN (TWo rf driver-based Indigenously built Negative ion source), and the INTF (INdian Test Facility) are presently in their various phases of operation, optimization, and setting up at IPR, respectively. Experiments related to plasma production, beam production, and acceleration up to 30 keV in volume and surface mode have been performed on ROBIN. The maximum negative hydrogen ion current density to a tune of 27 mA/cm² is obtained in the surface mode with Cs injection. Optimal source performance requires optimal surface conditions, minimum impurities, careful characterization of the plasma, cesium feed and its redistribution, and optimal wall temperatures of the surfaces of the plasma box and the plasma grid. A combination of probe, optical, vacuum, laser based, electrical, and calorimetric diagnostic measurements enables such a control. At ROBIN, the above diagnostics are being used regularly. The operational and diagnostic experiences on ROBIN shall provide the desired experience and database for operations of TWIN and INTF in the coming years. A large number of conventional and advanced diagnostic techniques are used for plasma and beam characterization. These diagnostics are suitable not only to detect and understand the plasma but also for studies related to impurity evolution. The temporal evolution of impurities significantly impacts the plasma and beam properties. The studies help in establishing correlations between physical parameters and operational parameters to optimize the source performance ensuring adequate safety and investment protection. This paper will present a brief overview of various diagnostics implemented, lessons learned, and the results obtained from ROBIN. In addition, an outline of the diagnostics planned for INTF based on the experience and understandings developed during the present experiments on ROBIN and TWIN and considering the requirements of large systems shall be discussed.

Multiple delivery cesium oven system for negative ion sources

Distribution of cesium in large negative ion beam sources to be operational in ITER, is presently based on the use of three or more cesium ovens, which operate simultaneously and are controlled remotely. However, use of multiple Cs ovens simultaneously is likely to pose difficulties in operation and maintenance of the ovens. An alternate method of Cs delivery, based on a single oven distribution system is proposed as one which could reduce the need of simultaneous operation of many ovens. A proof of principle experiment verifying the concept of a multinozzle distributor based Cs oven has been carried out at Institute for Plasma Research. It is also observed that the Cs flux is not controlled by Cs reservoir temperature after few hours of operation but by the temperature of the distributor which starts behaving as a Cs reservoir.

Targeting both Notch and ErbB-2 signalling pathways is required for prevention of ErbB-2-positive breast tumour recurrence

BACKGROUND

We reported that Notch-1, a potent breast oncogene, is activated in response to trastuzumab and contributes to trastuzumab resistance in vitro. We sought to determine the preclinical benefit of combining a Notch inhibitor (γ-secretase inhibitor (GSI)) and trastuzumab in both trastuzumab-sensitive and trastuzumab-resistant, ErbB-2-positive, BT474 breast tumours in vivo. We also studied if the combination therapy of lapatinib plus GSI can induce tumour regression of ErbB-2-positive breast cancer.

METHODS

We generated orthotopic breast tumour xenografts from trastuzumab- or lapatinib-sensitive and trastuzumab-resistant BT474 cells. We investigated the antitumour activities of two distinct GSIs, LY 411 575 and MRK-003, in vivo.

RESULTS

Our findings showed that combining trastuzumab plus a GSI completely prevented (MRK-003 GSI) or significantly reduced (LY 411 575 GSI) breast tumour recurrence post-trastuzumab treatment in sensitive tumours. Moreover, combining lapatinib plus MRK-003 GSI showed significant reduction of tumour growth. Furthermore, a GSI partially reversed trastuzumab resistance in resistant tumours.

CONCLUSION

Our data suggest that a combined inhibition of Notch and ErbB-2 signalling pathways could decrease recurrence rates for ErbB-2-positive breast tumours and may be beneficial in the treatment of recurrent trastuzumab-resistant disease.

A phase II trial of motexafin gadolinium (MGd) in advanced non-small cell lung cancer (NSCLC) patients who had failed platinum-based chemotherapy: Preliminary results of stage 1

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Background: Motexafin gadolinium (MGd) is a tumor-selective antineoplastic agent that disrupts redox dependent pathways by targeting oxidative stress-related proteins such as thioredoxin reductase (TRX). TRX often is overexpressed in NSCLC and is associated with a poor prognosis. Inhibition of TRX reverses tumor phenotype in lung carcinoma cells in vitro and in vivo. This randomized 2-stage phase II trial investigated tumor response and survival with 2 regimens of single agent MGd for the 2nd line treatment of advanced NSCLC. Methods: Patients with locally advanced or metastatic NSCLC ± brain metastases, ECOG PS 0–1, who had received one prior platinum-based chemotherapy regimen ± kinase inhibitor were randomized to intravenous MGd (10 mg/kg/week - Group A) or MGd (15 mg/kg/q 3 weeks - Group B) given in 21 day cycles. The sample size was 30 per arm in stage 1, and 24 per arm in stage 2. Response was evaluated by RECIST every 6 weeks. Results: 51 evaluable patients, median age of 62 years (range 41–85), with locally advanced (14%) or metastatic (86%) adenocarcinoma (47%), squamous cell carcinoma (14%), large cell carcinoma (10%), bronchoalveolar carcinoma (2%) or other NSCLC (27%) were randomized to group A (N=22) or group B (N=29). 37% had not responded to first line chemotherapy. MGd treatment was well tolerated, with 1–12 cycles (median 2, mean 3) administered. The most common grade 3+ adverse events were hypophosphatemia (15.7%), fatigue (13.7%), dyspnea (9.8%), hypoxia (7.8%), and finger blisters (5.9%). 48 patients were evaluable for response, with a confirmed response rate of 4.2% (2 PR). Median time to progression was 7 weeks in each group, with 26% and 15% free from progression at 4 and 6 months, respectively. Median survival of 51 evaluable patients was 10.2 months (95% CI: 6.7 months - not reached), 9.2 months for group A and not reached at > 1 year for group B. Conclusions: MGd appears active as a single agent for second line treatment of NSCLC patients with advanced or metastatic NSCLC who have failed prior platinum-based chemotherapy, with a modest response rate and promising survival. The trial has met the criteria for continuation into stage 2 for each treatment group.

No significant financial relationships to disclose.

Effect of oral administration of bismuth compounds on Campylobacter colonization in broilers

Bismuth compounds have been used since the 18th century to treat gastrointestinal ailments in man. Colloidal bismuth subcitrate (De-Nol) is currently used in combination with antibiotics to reduce enteric Helicobacter pylori colonization as a treatment of stomach ulcers. We investigated whether bismuth citrate or its parent compound, colloidal bismuth subcitrate, would reduce colonization of the closely related foodborne pathogen, Campylobacter jejuni in chickens. In 2 studies, birds were either fed 0, 50, or 200 ppm bismuth citrate or bismuth subcitrate (De-Nol) for 10 or 21 d and were orally challenged with 7 combined strains of C. jejuni (n = 6 birds/treatment). For both treatment groups, cecal Campylobacter colonization was reduced when birds were fed 200 ppm for 10 d but not 21 d. For the 50 ppm treatment group, only birds dosed with bismuth citrate for 21 d demonstrated any reduction in cecal Campylobacter concentrations when compared with controls. These data suggest that bismuth citrate and colloidal bismuth subcitrate may reduce cecal colonization by Campylobacter in broilers, but these effects are inconsistent.

Marek's disease virus reactivation from latency: changes in gene expression at the origin of replication

Marek's disease is a contagious lymphoma of chickens caused by Marek's disease virus (MDV). MDV replicates in chicken lymphocytes and establishes latency within and transforms chicken CD4+ T-cells. Transformed T-cells are seen as skin leukosis or as lymphomas in visceral organs. A major focus of our laboratory is the functional study of genes flanking the origin of replication. This origin (OriLyt) is contained within the repeats flanking the unique long (UL) region of the genome (IRL and TRL). To the left of this Ori are genes associated with MDV latent/transforming infection [1.8-kb RNA family, pp14, Meq), and to the right (UL) are genes associated with early stages of MDV lytic infection [BamHI-H-encoded protein (Hep), pp38/pp24, Mys]. During latency, MDV suppresses lytic gene expression and has evolved mechanisms for blocking the apoptosis of latently-infected CD4+ T-cells. Of the genes expressed during MDV latency and in the transformed cell, the Meq (Marek's EcoRI-Q-encoded protein) has been shown to block apoptosis and transactivate gene expression. Upon reactivation to lytic infection, we have found that splice variants of Meq predominate and that these forms lack several of the domains important to Meq trans-activation and trans-repression. We have found that rightward from the origin of replication, a family genes, including phosphoprotein 38 (pp38) are expressed during early stages of reactivation. Three separate open reading frames (Hep, Mys, and pp38) are encoded by distinct transcripts from this region. We are now determining the kinetics of expression of these transcripts and their relative abundance during reactivation.

Schedule-dependent pulsed paclitaxel radiosensitization for thoracic malignancy

The objective of this study was to apply preclinical research of paclitaxel radiosensitization to the treatment of thoracic malignancy. Human lung cancer cell line NCI520 and epidermoid cell line A431 were investigated in vitro for radiosensitizing effects of paclitaxel. Optimal schedule of paclitaxel treatment was applied to a clinical protocol as well as off-protocol treatment of thoracic malignancy. Pulsed paclitaxel with concurrent once-daily radiation was delivered every 48 hours during the week using doses of 15 mg/m2, 20 mg/m2, or 25 mg/m2 in a phase I clinical trial of dose escalation. Preclinical data support the finding that low-dose paclitaxel is sufficient for radiosensitization. Data also support that delaying radiation is better than immediate radiation after drug treatment. Twenty-three patients have enrolled in the phase I clinical trial. Seventeen patients completed treatment (6 at 15 mg/m2; 5 at 20 mg/m2; and 6 at 25 mg/m2). Mean tumor shrinkage at 4 to 6 weeks after therapy was 82%, 84%, and 84% for dose levels I, II, and III, respectively [average primary tumor shrinkage was 83% +/- 8% (95% C.I.)]. Locoregional tumor response rate was 100% [12% (2/17) complete response and 88% (15/17) partial response] with low rates of toxicity. It is concluded that pulsed low-dose paclitaxel and radiation is a very effective and well-tolerated regimen for thoracic malignancy.