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.

The testosterone prescribing practice of BMS menopause specialists

The NICE Guidelines published in 2015 state that testosterone supplementation can be considered for menopausal women with low sexual desire if hormone replacement therapy alone is not effective. There is however, no detail on what to prescribe, how much to prescribe or whether monitoring is required. At the time of conception of this project, there was no national guideline or official advice from the British Menopause Society. We decided to ask menopause experts from around the UK to see if a consensus could be reached about good prescribing practice. The method and results as discussed below may be helpful in future recommendations and guidance.

The management of menopausal symptoms in women following treatment for cancer at a specialist menopause service

OBJECTIVE

The aim of this study was to identify prescribing patterns at a specialist menopause service in a central London teaching hospital for women following treatment for a malignancy.

STUDY DESIGN

This was a prospective cohort study with data collected over a seven-month period from December 2019 to June 2020. All women reviewed at the specialist menopause services following treatment of a malignancy, BRCA carriers and Lynch syndrome were included in the study, with management options divided into three categories: hormonal, non-hormonal and no treatment.

MAIN OUTCOME MEASURES

The primary outcome of this study was to identify prescribing patterns for all women reviewed following a diagnosis of a malignancy, as well as those with genetic mutations necessitating risk-reducing prophylactic bilateral salpingo-oopherectomy (BSO).

RESULTS

Altogether 71 women were included in this study, with the majority of women post management of a non-gynaecological malignancy (51/71, 72%), of which breast cancer was the most common (37/71, 52%). While non-hormonal treatment was the most popular among those treated for breast cancer, for all other malignancies, hormonal treatment was more widespread. Fourteen women also had genetic mutations, with all of these women commencing hormonal treatment post risk reducing surgery.

CONCLUSION

With the exception of those with a history of hormone-sensitive breast cancer, the use of hormonal treatment for menopausal symptoms remained widespread. While this was a relatively small study, the need for long-term follow-up across specialist menopause services, to assess the risk of recurrence is vital.

Evaluation of a tertiary and district general hospital menopause service

OBJECTIVE

Requests for management of menopausal symptoms and hormone replacement are increasing in the UK. Referrals to specialist clinics have to be balanced with increasing recommendations within the NHS to improve efficiency and patient care.

STUDY DESIGN

Retrospective evaluation of clinic records over two months at a district general (Poole Hospital) and tertiary (Guy's Hospital) menopause service. Data on referral origin, reason for referral, interval from referral to review and outcome were collected and compared between trusts.

MAIN OUTCOME MEASURES

To evaluate and compare referrals and outcomes in a tertiary and district general menopause service and provide recommendations for improving efficiency.

RESULTS

Most referrals are from primary care but up to 25% are from other specialties. Half of the appointments are new referrals and 95% of women attend. Of the new referrals, 50% have multiple medical comorbidities, 25% a personal or family history of cancer and 25% treatment resistance; 30% have premature ovarian insufficiency. At Guy's Hospital, 30% are reviewed more than 18 weeks after referral, at Poole Hospital this is 6%. Treatment resistance is reported in half of the women reviewed at follow-up.

CONCLUSIONS

Menopause services review a complex patient population and the majority of referred women have more than one co-morbidity; they require time, specialist knowledge of current treatment options and a multidisciplinary approach. The main barrier to service efficiency is capacity, particularly in population dense areas; cognitive behavioural therapy and non-hormonal methods appear under-utilised in primary care, as do alternative methods of follow-up within the clinics such as telephone and patient-initiated appointments.

Analysis of a paediatric orthopaedic network: a six-year experience in the South West of the United Kingdom

PURPOSE

We report our experience of a paediatric orthopaedic network, based on a 'hub and spoke' model, covering the South West of the United Kingdom. We identify the areas of most clinical concern, the effect of the network on stream-lining patient management and the benefits of the network to the clinician.

METHODS

Prospective data were collected from the minutes of the bi-annual meetings of the South West Paediatric Network (UK) between November 2006 and May 2012. Data collected included details of the condition, previous treatment, problems, complications and advice given. Cases continue to be followed up in subsequent meetings.

RESULTS

In total 131 cases were included and hip conditions were discussed most frequently (35.1%). The most common indication for discussion was to support and confirm the local management plan. In total, a mean average of 8.75 cases in total were presented per consultant during the study period, with those within ten to 12 years of starting independent practice presenting the majority. The clinical outcome for patients discussed in this forum was local provision of care in 74%, with transfer to the regional centre in 15.7%. Following advice, 14% of direct referrals were given appropriate advice and avoided a journey to the tertiary centre.

CONCLUSION

The network has enabled local provision of care, reduced the burden of travel on patients and prevented unnecessary referrals to the tertiary centre. Additionally, it provides a mechanism to reassure and educate clinicians.

Complete Genome Sequence of Alkaliphilus metalliredigens Strain QYMF, an Alkaliphilic and Metal-Reducing Bacterium Isolated from Borax-Contaminated Leachate Ponds

Alkaliphilus metalliredigens strain QYMF is an anaerobic, alkaliphilic, and metal-reducing bacterium associated with phylum Firmicutes QYMF was isolated from alkaline borax leachate ponds. The genome sequence will help elucidate the role of metal-reducing microorganisms under alkaline environments, a capability that is not commonly observed in metal respiring-microorganisms.

Flow Field Analysis of Both the Trilobal Element and Mixing Disc Zones within a Closely Intermeshing, Co-Rotating Twin-Screw Extruder

Of the different mixing modules contained within the closely intermeshing, co-rotating twin-screw extruder (CICo-TSE), the trilobal elements and mixing discs are of major importance to the mixing efficiency. These two types of mixing element impose contrasting mixing behaviour on the viscous melt and are thus used selectively to perform differing mixing tasks. Problems encountered when solving the flow problem within these two mixing element zones arise from both the complex 3D geometry and the time dependent flow boundaries as each respective element type rotates about its fixed axes. Following on from the 2D results reported, the computational fluid dynamics package, Polyflow, was employed to investigate the mixing mechanisms exhibited by both a set of three trilobe element pairs and by a pair of staggered mixing discs, as utilised within the Betol BTS40 CICo-TSE. The flow fields were simulated using the ideal rheological properties of polypropylene and characterised in terms of velocity vectors, shear stresses generated and a mixing parameter λ, which quantifies the elongational and rotational flow components. Each flow field exhibited different characteristics for the configurations investigated and it has been found that the average flow field parameter values for the trilobe elements change periodically, whereas minimal changes are observed as the mixing discs rotate.

Complete Genome Sequence of a thermotolerant sporogenic lactic acid bacterium, Bacillus coagulans strain 36D1

Bacillus coagulans is a ubiquitous soil bacterium that grows at 50-55 °C and pH 5.0 and ferments various sugars that constitute plant biomass to L (+)-lactic acid. The ability of this sporogenic lactic acid bacterium to grow at 50-55 °C and pH 5.0 makes this organism an attractive microbial biocatalyst for production of optically pure lactic acid at industrial scale not only from glucose derived from cellulose but also from xylose, a major constituent of hemicellulose. This bacterium is also considered as a potential probiotic. Complete genome sequence of a representative strain, B. coagulans strain 36D1, is presented and discussed.

Controlling the cost of breast cancer

Breast cancer management is an important part of the health-care system. In the current harsh economic climate, these costs have to be controlled, and achieving this without compromising quality of care is a daunting challenge. This article discusses the need to find effective and well-targeted chemotherapeutic regimens, which, when combined with appropriate implementation of novel strategies, will provide the optimum treatment for patients while maintaining economic viability.

The long-term effects of tibolone on aortic stiffness and endothelial function

OBJECTIVE

To investigate the effect of 10 years of treatment with tibolone on aortic stiffness and endothelial function.

DESIGN

Cross-sectional study of women currently participating in an open-label, non-randomized study of the long-term efficacy of tibolone. A total of 113 recently postmenopausal women were recruited in 1988. Fifty-eight agreed to take tibolone 2.5 mg daily and 55 were followed during the study as matched controls (who chose not to take any form of hormone replacement therapy (HRT) for the duration of the study). The groups were matched for age, weight and time since last menstrual period.

SETTING

A Central London Teaching Hospital.

SUBJECTS

After 10 years, 60 women remained in the study, 32 in the tibolone group and 28 in the control group. All of these women were invited to participate in this pilot study and attend the Menopause Research Unit. Fourteen women from each group agreed to attend. The main outcome measures were aortic stiffness, measured by pulse wave velocity, and endothelial function, as assessed by flow-mediated dilatation of the brachial artery.

RESULTS

Pulse wave velocity was significantly lower in the tibolone group (10.4 +/- 1.2) than in the control group (11.6 +/- 1.2), p = 0.042. The flow-mediated dilatations were similar in both groups.

CONCLUSION

In this study, long-term use of tibolone over 10 years has a beneficial effect on aortic stiffness. The differences seen in brachial artery vasoreactivity failed to reach statistical significance. Whether this is a true indication of the effects of long-term tibolone on brachial artery vasoreactivity will only be determined by performing a larger, placebo-controlled, randomized study.

Elevated circulating levels of matrix metalloproteinase-9 and -2 in patients with symptomatic coronary artery disease

BACKGROUND

Matrix metalloproteinases (MMP-9 and MMP-2) have been implicated in development of atherosclerosis and plaque rupture in acute coronary syndromes (ACS).

AIM

To determine the relationship between circulating MMPs and symptomatic coronary artery disease.

METHODS

Plasma levels of MMP-9 and MMP-2 were measured in patients with ACS, stable angina (SA) and in controls, using a quantitative gelatin zymography. These measurements were correlated with markers of systemic inflammation (hs-CRP) in all subjects and myocardial injury (troponin T) in patients with ACS.

RESULTS

Plasma MMP-9 in ACS was greater than in SA, and was greater in SA than in controls (P < 0.01 ACS vs SA and controls, P < 0.01 SA vs control). Plasma MMP-2 was significantly greater in ACS than SA or controls (P < 0.01 vs SA and controls). There was strong overall relationship between hs-CRP and MMP-9 (r = 0.65, P < 0.0001) driven by a significant relationship in ACS patients (r = 0.58, P = 0.02), as there was no significant association in SA or controls. A weaker overall correlation was found between hs-CRP and MMP-2 (r = 0.39, P = 0.02), but no significant relationship was present for either of the two patient subgroups or controls. There was no correlation between levels of troponin T and MMP-9, MMP-2 or hs-CRP in ACS patients.

CONCLUSION

Quantitative gelatin zymography identifies increased circulating levels of MMP-9 and MMP-2 in patients with symptomatic coronary disease. MMP-9 and MMP-2 are higher in ACS than SA patients and might have use as markers of plaque rupture or instability. The strong relationship between MMP-9 and hs-CRP in ACS patients suggests MMP-9 might be an additional marker and/or consequence of the inflammatory component in ACS.

Long-term effects of tibolone on the endometrium as assessed by bleeding episodes, transvaginal scan and endometrial biopsy

INTRODUCTION

Period-free hormone replacement therapy (HRT) obliterates the need for withdrawal bleeds. There is a need to ensure that, if these preparations are to be used in the long term, they still achieve amenorrhea.

AIMS

To assess the bleeding rates and the endometrial status over 10 years in women who were taking tibolone compared to an age-matched control group.

METHODS

A total of 110 recently postmenopausal women were recruited into a prospective, non-randomized, open-label study. Bleeding episodes were assessed by 6-monthly symptomatology questionnaires. Annual transvaginal scans were performed to assess endometrial thickness in all women who gave consent from 1997 onwards. In the tibolone group, endometrial biopsies were performed every year; in the control group, they were performed only if the reported vaginal bleeding and/or endometrial thickness on ultrasound were >5 mm.

RESULTS

Over the entire 10-year period, 39.7% of women in the tibolone group and 12.7% of control subjects experienced vaginal blood loss. However, the rate of amenorrhea in the tibolone group after 1 year of treatment was 86.4%; in the control group, it was 94.1%. At the 10-year visit, the rates of amenorrhea were 60.3% in the tibolone groups and 87.3% in the control group. This is statistically significant, p = 0.001. The mean (+/- standard deviation) endometrial thickness after 10 years was 2.2 mm (+/- 1.2 mm) in the tibolone group vs. 1.8 mm (+/- 0.4 mm) in the control group. These differences were not statistically significant (p = 0.33). Sufficient material from endometrial biopsies could only be obtained in three subjects in the tibolone group. One case of simple hyperplasia was detected.

CONCLUSION

Tibolone therapy leads to high rates of amenorrhea after 10 years, with minimal evidence of adverse effects on endometrial pathology.

Nutritional supplements after hip fracture: poor compliance limits effectiveness

BACKGROUND

Undernutrition and weight loss are important determinants of clinical outcome in older patients after hip fracture but the effectiveness of nutritional support programs in routine clinical practice remains controversial. AIMS OF THE PROJECT: To determine if oral nutritional supplements given daily for 28 days after hip fracture surgery could prevent weight loss and/or lead to improved clinical outcomes (mortality rates, discharge destination, activities of daily living or length of hospital stay) in non-malnourished community-dwelling older women with hip fracture.

METHODS

One hundred and nine women with BMI range 20-30 kg/m(2) were allocated to either nutritional supplements (352 kcal/day) or usual hospital nutrition using a quasi-randomisation technique. Body weight changes were monitored at 4 and 8 weeks and clinical outcomes were recorded at discharge and at 6 months.

RESULTS

No significant differences in weight change or clinical outcomes were seen between the two groups. Compliance with consuming the nutritional supplements was quite variable and there was a significant negative correlation between the amount of supplement consumed and subsequent weight change (r=-0.36, P=0.019).

CONCLUSIONS

Poor compliance with oral nutritional supplements is an important determinant of the effectiveness of oral nutritional interventions in preventing weight loss after hip fracture. Whilst this may explain the lack of clinical improvements seen, our data do not support the routine use of oral nutritional supplements in non-malnourished hip fracture patients.

Craniofacial trauma in children

Craniofacial trauma is relatively uncommon in children, but the potential involvement of the structures at the base of the skull and the intracranial space makes it important for physicians to understand the potential dangers presented by such injuries. This report delineates the different types of injury that can damage the upper facial skeleton and the brain of a child. The author reviews initial management and diagnosis of such injuries and examines the approach to definitive reconstructive surgery using three case studies as examples for discussion.

Prognostic value of laparoscopic ultrasound in patients with gastro-esophageal cancer

Forty-four patients with gastro-esophageal tumors regarded as resectable by conventional staging underwent laparoscopic ultrasonography (LUS). Following LUS, seven were found to be irresectable and were managed by palliative therapies. Thirty-seven patients proceeded to surgical exploration and 36 were resected (R0 80%, R1 11%, and R2 9%). All patients were reviewed until death or for a minimum of 24 months. Patients undergoing resection had a 62% 1-year survival (median 17 months; confidence intervals, CI 6-28). LUS defined nodal status indicated a trend toward prolonged survival in the node-negative group, median 22 months (CI 5-39), compared with 13 months (CI 6-20) in the node-positive group. Disease-free survival was greater in LUS node-negative patients at 29 months (CI 23-35) compared with node-positive patients at 13 months (CI 5-21) P=0.0083. LUS staging allows prediction of the likelihood of recurrence of gastro-esophageal malignancies. This may prove useful for the appropriate allocation of patients to primary and adjuvant therapies.

Don't overlook disease management programs for low-incidence, high-cost diseases to improve your bottom line

Comprehensive coordinated care management for low-incident, high-cost diseases, like chronic renal failure, can provide a great opportunity for health plans to add immediate and significant profit to their bottom line. The resultant benefits of improved operations, improved clinical outcomes and increased patient satisfaction add further incentive for health plans to take action to implement outsourced disease management for this condition.

Fifty years since Lashley's In search of the Engram: refutations and conjectures

In his well-known article 'In Search of the Engram' published in 1950, Karl Spencer Lashley summarized his 33 years of research and theory on memory and the brain. He concluded that (1) memories are not localized but are instead distributed within functional areas of the cortex and (2) memory traces are not isolated cortical connections between inputs and outputs. Though not the first time he had expressed such convictions, their reiteration in this article was backed by Lashley's estimable reputation and expressive power and they have taken firm root in the collective knowledge of today's memory and neuropsychological research community.

Electrochemiluminescence of copper(I) bis(2,9-dimethyl-1,10- phenanthroline)

The electrochemical and electrochemiluminescence (ECL) properties of Cu[dmp]2+ (dmp = 2,9-dimethyl-1,10-phenanthroline) have been investigated. ECL has been observed for Cu(dmp)2+ in aqueous, nonaqueous, and mixed solvent solutions using tri-n-propylamine as an oxidative-reductive coreactant. The ECL intensity peaks at potential corresponding to oxidation of both the coreactant and Cu(dmp)2+. The peak potential corresponding to maximum ECL emission is approximately 500 mV more anodic than corresponding oxidative peak potentials, indicating that the ECL emission may be due to the formation of either the *Cu(dmp)2+ metal-to-ligand charge-transfer excited state or an excited-state product of Cu(dmp)2+ oxidation. ECL efficiencies (phiecl = photons generated per redox event) are solvent-dependent (phiecl (CH3CN) > phiecl (50:50 (v/v) CH3CN:H20) > phiecl (H2O)) and correspond fairly well with photoluminescence efficiencies. Increased ECL efficiencies (> or = 50-fold) are observed in the presence of the nonionic surfactant Triton X-100.

Characterization of the electrochemical oxidation of peroxynitrite: relevance to oxidative stress bursts measured at the single cell level

The electrochemical signature of peroxynitrite oxidation is reported for the first time, and its mechanism discussed in the light of data obtained by steady-state and transient voltammetry at microelectrodes. Peroxynitrite is an important biological species generated by aerobic cells presumably via the near diffusion-limited coupling of nitric oxide and superoxide ion. Its production by living cells has been previously suspected during cellular oxidative bursts as well as in several human pathologies (arthritis, inflammation, apoptosis, ageing, carcinogenesis, Alzheimer disease, AIDS, etc.). However, this could only be inferred on the basis of characteristic patient metabolites or through indirect detection, or by observation of follow-up species resulting supposedly from its chemical reactions in vivo. In this work, thanks to the independent knowledge of the electrochemical characteristics of ONO2- oxidation, the kinetics and intensity of this species released by single human fibroblasts could be established directly and quantitatively based on the application of the artificial synapse method. It was then observed and established that fibroblasts submitted to mechanical stresses produce oxidative bursts, which involve the release within less than a tenth of a second of a complex cocktail composed of several femtomoles of peroxynitrite, hydrogen peroxide, nitric oxide, and nitrite ions.

Excited-state dynamics in photosystem II: insights from the x-ray crystal structure

The heart of oxygenic photosynthesis is photosystem II (PSII), a multisubunit protein complex that uses solar energy to drive the splitting of water and production of molecular oxygen. The effectiveness of the photochemical reaction center of PSII depends on the efficient transfer of excitation energy from the surrounding antenna chlorophylls. A kinetic model for PSII, based on the x-ray crystal structure coordinates of 37 antenna and reaction center pigment molecules, allows us to map the major energy transfer routes from the antenna chlorophylls to the reaction center chromophores. The model shows that energy transfer to the reaction center is slow compared with the rate of primary electron transport and depends on a few bridging chlorophyll molecules. This unexpected energetic isolation of the reaction center in PSII is similar to that found in the bacterial photosystem, conflicts with the established view of the photophysics of PSII, and may be a functional requirement for primary photochemistry in photosynthesis. In addition, the model predicts a value for the intrinsic photochemical rate constant that is 4 times that found in bacterial reaction centers.