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.

Role of selenium and myo-inositol supplementation on autoimmune thyroiditis progression

Previous reports indicate that selenium supplementation may be useful to reduce cell oxidative stress. In particular, selenium may decrease the level of thyroid autoantibodies in patients with Hashimoto's thyroiditis (HT). Recent studies also indicate that myo-inositol may have beneficial effects on thyroid function in patients with HT. Hence, the aim of the present study is to evaluate whether myo-inositol may enhance the protective effect of selenium on HT progression to hypothyroidism. The study was designed as observational and retrospective. Thyroid hormones were evaluated in patients with HT who were either euthyroid or subclinically hypothyroid. These patients were subdivided into three groups: untreated, treated with selenomethionine alone (Se-meth: 83 μg/day) and treated with Se-meth plus myo-inositol (Se-meth + Myo-I: 83 μg/day + 600 mg/day). Outcome evaluation was performed at baseline and after 6 and 12 months of treatment. High-resolution ultrasound of the thyroid gland was performed to evaluate changes in thyroid echoic pattern during the study. Compared to baseline, levels of thyroid-stimulating hormone (TSH) increased significantly in untreated patients but decreased by 31% and 38%, respectively, in those treated with Se-meth and Se-meth + Myo-I. Moreover, in the latter group the TSH reduction was observed earlier than in the Se-meth-treated group. Densitometric analysis of thyroid ultrasonography showed an echoic pattern improvement in both treated groups compared to untreated patients, although this difference was not statistically significant. Thus, Se-meth treatment is effective in patients with HT and its effect may be improved in combination with Myo-I through earlier achievement of TSH levels closer to physiological concentrations.

New generation non-stationary portable neutron generators for biophysical applications of Neutron Activation Analysis

BACKGROUND

Neutron sources are increasingly employed in a wide range of research fields. For some specific purposes an alternative to existing large-scale neutron scattering facilities, can be offered by the new generation of portable neutron devices.

SCOPE OF REVIEW

This review reports an overview for such recently available neutron generators mainly addressed to biophysics applications with specific reference to portable non-stationary neutron generators applied in Neutron Activation Analysis (NAA).

MAJOR CONCLUSIONS

The review reports a description of a typical portable neutron generator set-up addressed to biophysics applications.

GENERAL SIGNIFICANCE

New generation portable neutron devices, for some specific applications, can constitute an alternative to existing large-scale neutron scattering facilities. Deuterium-Deuterium pulsed neutron sources able to generate 2.5MeV neutrons, with a neutron yield of 1.0×10⁶n/s, a pulse rate of 250Hz to 20kHz and a duty factor varying from 5% to 100%, when combined with solid-state photon detectors, show that this kind of compact devices allow rapid and user-friendly elemental analysis. "This article is part of a Special Issue entitled "Science for Life" Guest Editor: Dr. Austen Angell, Dr. Salvatore Magazù and Dr. Federica Migliardo".

Circulating natriuretic peptide concentrations in hyperthyroid cats

OBJECTIVES

To assess the influence of thyroid function on natriuretic peptide concentration in hyperthyroid cats before and after treatment.

METHODS

Serum natriuretic peptide concentration was measured in 61 hyperthyroid cats recruited from first-opinion clinics before and after treatment.

RESULTS

Following successful treatment, total thyroxine, heart rate, systolic blood pressure and packed cell volume all decreased and bodyweight and creatinine concentrations increased. Furthermore, a significant (P < 0·001) decline in NT-proBNP concentration but not NT-proANP was identified.

CLINICAL SIGNIFICANCE

Thyroid function has a modest but significant effect on NT-proBNP concentration. Thyroid status should be taken into account when interpreting NT-proBNP concentrations in cats.

An unusual presentation of an ectopic third molar in the condylar region

We describe the case of a 53-year-old patient who presented with an intermittent discharging sinus on his face which, following a number of investigations, was found to be secondary to an ectopic third molar in the condylar region. The ectopic tooth was surgically removed with complete resolution of the facial swelling. This case highlights the possibility of dental pathology presenting with completely unrelated signs and symptoms, and the importance of the clinician maintaining an open mind when it comes to the differential diagnosis of such a presentation.

[Affective temperaments and psychopathological dimensions of personality in Bipolar Disorder]

OBJECTIVES

The first objective of our study is the evaluation of correlation between affective temperaments and psychopathological dimensions in a clinical sample of patients with Bipolar Disorder and the individualization of possible differences within the three diagnostic subtypes (bipolar I, II and cyclothymia). The second one is to observe whether any specific temperament may influence the number of hospitalizations or the age of the bipolar depression onset.

MATERIALS AND METHODS

At the Bipolar Disorder Unit of Policlinico Gemelli (Rome, Italy) a group of 60 patients with Bipolar Disorder (BD) has been enrolled. All patients have been submitted to the TEMPS-A for the evaluation of affective temperament and TCI-R for the evaluation of psychopathological dimensions of personality.

RESULTS

BD I group showed 5 significant correlations from moderate (r=0.40) to high degree (r=0.60). SD dimension of TCI shows 3 significant correlations with TEMPS-A dimensions: it is inversely correlated with Cyclothymia (r= -0.57; p<0.01), Irritability (r=0.60; p<0.01) and Anxiety (r=-.45; p<0.05). BDII group showed 5 significant correlations. Irritability dimension of TEMPS-A presented the highest number of correlations with TCI dimensions: it was inversely correlated to SD (r= -.65; p<0.01) and directly correlated with HA (r=0.48; p<0.05) and ST (r=-0.49; p<0.05). In the comparison of diagnostic groups with regards to temperamental dimensions, only Hyperthymia and Irritability dimensions were significative.

CONCLUSIONS

Many works have evaluated temperament through the use of these two tools (TEMPS-A and TCI-R) but few have analysed correlation between them and none has focused attention on patients with bipolar disorder diagnosis only.

Upregulation of TNF receptor type 2 in human and experimental renal allograft rejection

An important role of TNF interacting with TNFR2 has been shown in different models of ischemic, nephrotoxic and immune-mediated renal injury. To systematically evaluate the expression of TNFR2 in renal allograft rejection, we investigated human renal allograft biopsies and, in addition, established an experimental transplantation model in rats to verify the human data under standardized conditions. The expression of TNFR2 was analyzed in 96 human renal allograft biopsies with different disease entities. In a 6-day and a 28-day experimental protocol, TNFR2 was examined in kidney specimens and in the urine of control, uni-nephrectomized and transplanted rats +/- cyclosporine treatment (n = 114). In human biopsies and in rat allografts on day 6 with acute allograft rejection, significantly elevated expression of TNFR2 was observed in tubular epithelial cells, podocytes, B cells and monocytes/macrophages. The expression level was associated with renal function. The TNFR2 expression level at day 28 was significantly lower compared to day 6. TNFR2 is markedly upregulated both in human and experimental acute renal allograft rejection. Our data are robust and consistent between different species, suggesting a role for TNFR2 in the early course of rejection.

Ultrasensitive low noise voltage amplifier for spectral analysis

Recently we have proposed several voltage noise measurement methods that allow, at least in principle, the complete elimination of the noise introduced by the measurement amplifier. The most severe drawback of these methods is that they require a multistep measurement procedure. Since environmental conditions may change in the different measurement steps, the final result could be affected by these changes. This problem is solved by the one-step voltage noise measurement methodology based on a novel amplifier topology proposed in this paper. Circuit implementations for the amplifier building blocks based on operational amplifiers are critically discussed. The proposed approach is validated through measurements performed on a prototype circuit.

An algorithm for separating multilevel random telegraph signal from 1/f noise

In this work, we propose a robust algorithm for the separation of two- and multilevel dominant random telegraph signals (RTSs) from 1/f noise in the time domain. The method does not associate each RTS level to a fixed range of the signal values, as assumed by other methods, but it is based on a efficient recognition of the jumps between the different RTS levels. The proposed algorithm can extract the 1/f component even in the presence of several dominant RTSs with different corner frequencies. The procedure has been validated by using a two-level and a four-level synthesized signals.

Experimental study of single-electron phenomena in silicon nanocrystal memories

In this paper we present experimental evidence for single-electron phenomena in solid-state memories based on silicon nanocrystals as storage elements. The stepwise evolution of the channel current of a written memory cell biased in the subthreshold regime is monitored by means of a purposely designed low noise acquisition system with a bandwidth of 1 kHz. Each channel current step-up is ascribed to a single-electron emission from the silicon nanocrystal to the silicon substrate and each current step-down is ascribed to a single-electron capture from the silicon substrate into the silicon nanocrystal. The effect of the measurement system bandwidth on the detection of single-electron events is discussed and a procedure for extracting the threshold voltage shift associated to these events is proposed. It is shown that single-electron charging and discharging events in a memory cell with an area of 4.5 x 10(-10) cm2 can cause threshold voltage shift at room-temperature of the order of several millivolts. Qualitative explanation for the observed threshold voltage shift distribution is given.

Lung metastases from differentiated thyroid carcinoma. A 40 years' experience

AIM

Retrospective studies have been carried out to estimate the survival of 96 patients with lung metastases from differentiated thyroid carcinoma, observed from 1958 to 2000.

METHODS

All patients had undergone total thyroidectomy. Case histories were analysed with respect to age at diagnosis, sex, histology, local lymph node involvement, size of lung metastases and 131I uptake by metastases. Survival functions were calculated. Cox regression was performed.

RESULTS

There was no statistically significant difference in histological type and lymph node involvement, whereas a significantly longer survival time was observed in patients under 45 years of age at diagnosis (p= or <0.0001), in those with metastases concentrating 131I (p= or <0.0001) and in those with fine miliaric metastases (p=0.0037). Multi-variate analysis revealed that the risk of death increases about 5.4-fold in patients over 45 years old, whereas 131I treatment is likely to reduce this risk to nearly 1/6. Conclusion. In conclusion, in patients with lung metastases from differentiated thyroid carcinoma, young age at diagnosis and 131I uptake by metastases are the most important factors positively affecting survival time. Radioiodine therapy, also with high cumulative 131I activity, can lead to longer survival time or complete recovery.

[Anesthesia for non-cardiac surgery in children with congenital heart diseases]

The incidence of congenital heart diseases accounts for 8-10 over 1000 liveborn. In Italy about 4000-4500 babies each year are born with congenital heart diseases; 50% of those babies (2000-2200) need cardiac surgery shortly after birth or within the first few months of life. Of the remaining 50%, half undergoes cardiac surgery later on in life and half does not necessitate any surgery; 30% of all cardiac operations consist of palliative procedures and the remaining 70% consist of one-stage corrective procedures. Improvements achieved both in surgical and anesthesiologic techniques, and in cardiopulmonary bypass and myocardial protection, have led to better results in pediatric cardiac surgery, with excellent long term survival rate, even for the more complex variants of congenital heart malformations. Therefore anesthesiologists are now more often required to deal with patients affected by congenital heart defects, for other than cardiac problems. Accurate investigation of patient's clinical history is strongly suggested. Moreover knowledge and familiarity with the modifications of the physiology, occurring in congenital heart disease patients, are mandatory for the choice of the more appropriate anesthesiologic strategy for each patient, in order to optimise the risk-benefits ratio and achieve a less traumatic impact on the cardio-circulatory and respiratory equilibrium. With the aim of achieving better results, interaction between anesthesiologist, cardiologist, pediatrician, surgeon and sometime neonatologist and cardiac surgeon, is strongly recommended in the evaluation of risks, and in decision making of strategies and timing of treatment.

Love matters. A profile of Connecticut Hospice

After 25 years, America's first hospice looks back at its past challenges and successes, and looks forward to continuing its mission into the 21st century.

Comparison of regimens containing oral micronized progesterone or medroxyprogesterone acetate on quality of life in postmenopausal women: a cross-sectional survey

A cross-sectional survey was conducted to examine quality of life (QOL) related to physiological, somatic, and vasomotor effects of changing progestogen treatment from medroxyprogesterone acetate (MPA) to micronized progesterone in postmenopausal women. Eligible women (n = 176) were currently using hormone replacement therapy (HRT) containing micronized progesterone for 1-6 months and had previously received HRT containing MPA. QOL was assessed via telephone interview using the Greene Climacteric Scale and the Women's Health Questionnaire. When compared with the MPA-containing regimen, women using micronized progesterone-containing HRT experienced significant improvement in vasomotor symptoms, somatic complaints, and anxiety and depressive symptoms. Women reported improved perceptions of their patterns of vaginal bleeding and control of menopausal symptoms while on the micronized progesterone-containing regimen. Approximately 80% of women reported overall satisfaction with the micronized progesterone-containing regimen. A micronized progesterone-containing HRT regimen offers the potential for improved QOL as measured by improvement of menopause-associated symptoms.

Advanced learning technology for a bilingual education of deaf children

Italian deaf children in elementary and middle school have limited competence in written Italian, which is in part caused by difficulties with lexical and morphosyntactic aspects of the Italian language. This study describes a recently developed interactive multimedia application designed to facilitate deaf children's access to new information and reports the results of an initial experiment conducted with deaf elementary and middle school children. Subjects were twelve deaf children with varying backgrounds and linguistic competencies, ranging in age from 6;6 to 16;1 years. Experimentation was structured in three phases. In the initial phase, children explored the computer environment freely, and in the two subsequent phases, children were presented with activities requiring use of the application to obtain information. Results of a final evaluation indicated that all children were able to use and profit from the application. Findings are discussed in terms of bilingual methods of education for deaf children and their implications for increasing deaf children's competence in written language.

Use of zinc acetate to treat copper toxicosis in dogs

Zinc acetate was used for the treatment and prophylaxis of hepatic copper toxicosis in 3 Bedlington Terriers and 3 West Highland White Terriers. Two dogs of each breed were treated for 2 years, and 1 of each breed for 1 year. A dosage of 200 mg of elemental zinc per day was required to achieve therapeutic objectives related to copper, which included a doubling of plasma zinc concentration to 200 micrograms/dl and a suppression of oral 64 copper absorption. The dosage was later reduced to 50 to 100 mg/day to avoid an excessive increase in plasma zinc concentration. The preliminary clinical results were good. Three dogs had mild to moderate active liver disease and high liver copper concentrations at the time of initiation of zinc administration. Biopsy of the liver 2 years later revealed a reduction in hepatitis and copper concentrations. One other dog without active hepatitis also had a reduction in hepatic copper concentrations over a 2-year period. All 6 dogs have done well clinically. On the basis of these findings, we believe zinc acetate to be an effective and nontoxic treatment for copper toxicosis in dogs.

Altered electrical responses of B-cells after goldthioglucose-induced lesions in the ventromedial hypothalamus

Goldthioglucose was used to induce necrosis of the ventromedial hypothalamus in mice. This produced an obese mouse that exhibited syndromes associated with non-insulin dependent diabetes mellitus (NIDDM). We found enhanced glucose-induced electrical activity from B-cells with impaired neurotransmitter input. This information indicates that the electrical events of the B-cell plasma membrane are influenced by altered neurotransmitter input and may play a causal role in the enhanced secretory response.

Functional and morphological studies of long-term islet allografts in the renal subcapsular space of the BB/W rat

Our primary objective in this study was to determine whether transplanted pancreatic islet B cells display normal glucose-stimulated insulin secretory responses. Since transplanted islets are deinnervated and are located in a potentially unfavorable hormonal environment, it is possible that transplanted islets can maintain blood glucose levels but still not be completely normal. Since immune mechanisms may alter secretory responses but fail to cause overt islet necrosis (rejection), we used the BB/W spontaneously diabetic rat as the recipient in these studies. Islets harvested from inbred Lewis rats were transplanted beneath the renal capsule with minimal ALS immunosuppression posttransplantation. The transplanted animals showed a normal response to a glucose tolerance test. After 122-155 days of normoglycemia, the islets were retrieved and subjected to 2.8 and 16.7 mM glucose. The results indicate that the islet allografts maintain their secretory response to glucose when compared to donor Lewis islets acutely isolated from the pancreas. Furthermore, the transplanted islets maintained their morphologic integrity.

Oxidation-reduction properties of glycolate oxidase

This is the first report of the redox potentials of glycolate oxidase. The pH dependence of the redox behavior as well as the effects of activators and inhibitors was studied. At pH 7.1 in 10 mM imidazole-chloride, Eo1' (EF1ox/EF1-.) is -0.033 +/- 0.010 V and Eo2' (EF1-./EF1redH-) is -0.017 +/- 0.017 V vs. the standard hydrogen electrode at 10 degrees C. A maximum of 29% flavin mononucleotide (FMN) anion radical is stabilized at half-reduction at pH 7.1 and 10 degrees C. Both redox couples of glycolate oxidase are pH-dependent from pH 7 to pH 9, and the FMN anion radical is stabilized in this range. The redox potentials of glycolate oxidase are shifted markedly positive of those of unbound FMN, consistent with the enzyme's function. The midpoint potential of glycolate oxidase is more positive than that of the glyoxalate/glycolate couple, and two-electron reduction of glycolate oxidase is thermodynamically favorable. The redox behavior of glycolate oxidase markedly contrasts that of other flavoprotein oxidases. For most flavoprotein oxidases, Eo1' is independent of pH from pH 7 to pH 9 and is much more positive than Eo2', which is pH-dependent. We present a mechanism that suggests a structural basis for the positive shifts and pH dependence of both Eo1' and Eo2' of glycolate oxidase.

Health library for patients in general practice

We describe the establishment of a health lending library for patients in a suburban general practice. The library is housed in the surgery waiting room and comprises 413 books and 35 audio tapes on topics related to health. Analysis of the first year's use showed 703 borrowings (677 books and 26 audio cassettes). Borrowers ranged the spectrum of social class and educational status but women predominated, and borrowers included many who admitted that they seldom read books. Most borrowings were opportunistic, though some were planned by the patient and a few recommended by a health care professional. Most readers claimed to have learned from their reading and to have found their reading useful. We think that a health library is a useful tool of primary care, particularly for prevention.