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.

697 An Evaluation of Patient Outcomes Following Percutaneous Cholecystostomy (PC) For Acute Cholecystitis (AC) At Our Health Board Between 2011-2020

Introduction

PC is a radiological intervention used in the management of high-risk patients with AC.

Method

A retrospective study of outcomes following PC, including success rates, complications, AC resolution, readmissions, and subsequent cholecystectomy.

Results

Our database identified 28 patients (14M:14F), median age 73 (range 40-93). 82% were ASA III/IV. Median follow-up was 2 (range 0-8) years. Imaging suggested AC in 61% and empyema in 39%. 86% were calculous. All procedures were USS-guided with 100% success. AC resolution occurred in 89.3%. Of three unresolved, there was 1 death day-1 post-PC (non-procedure related), 1 index cholecystectomy, 1 chronic complicated cholecystitis. 28.6% developed complications, 2 major (1 late biliary peritonitis and 1 cholecystocutaneous fistula with abdominal wall abscess), 17.9% dislodged drain, 10.7% other. 20 patients had bile cultures (70% positive, mainly gram-negative). 17.9% patients were readmitted with AC, 1 had repeat PC. 21.4% had subsequent ERCP. 32.1% underwent subsequent cholecystectomy, 1 laparoscopic cholecystectomy(LC) index, 4 elective (3 LC, 1 open), 4 emergency (2 LC, 1 LC subtotal, 1 failed open with drain insertion).

Conclusions

PC is both safe and effective with significant procedural success rates and resolution rates. There are few major complications but significant morbidities, mainly dislodged drains. One-third of patients have subsequent cholecystectomy.

Comparison of the reverse bevel versus Franseen type endoscopic ultrasound needle

BACKGROUND

Reverse bevel (RB) needle is widely used for endoscopic ultrasound fine needle biopsy (EUS-FNB). A 3-plane symmetrical needle with Franseen geometry (FG) has recently become available.

AIM

To compare the clinical efficacy of FG to that of RB needle.

METHODS

A retrospective cohort study of all adult patients who underwent EUS-FNB for solid and mixed lesions either with 22G RB needle or 22G FG needle between January 2016 and February 2019 was undertaken. All cytology slides were reviewed by an independent gastrointestinal cytopathologist blinded to the needle used and the initial cytology report. The primary and secondary outcomes were to assess the sample adequacy using Euro-cytology criteria and the number of cell clusters, respectively.

RESULTS

Two hundred and twenty six procedures were included in the study. RB needle was used in 128 procedures and FG needle in 98 procedures. The baseline characteristics of both groups were comparable. On multivariable analysis, FG needle (P = 0.02) and location of the lesion (P < 0.01) were independently associated with adequate tissue. Further, the use of FG needle (P = 0.04) and the size of the lesion (P = 0.02) were independently associated with acquisition of increased number of cell clusters.

CONCLUSION

FG needle is superior to RB needle in acquiring adequate tissue and attaining higher number of cell clusters for solid and mixed lesions.

Fluorescence microscopy image noise reduction using a stochastically-connected random field model

Fluorescence microscopy is an essential part of a biologist’s toolkit, allowing assaying of many parameters like subcellular localization of proteins, changes in cytoskeletal dynamics, protein-protein interactions, and the concentration of specific cellular ions. A fundamental challenge with using fluorescence microscopy is the presence of noise. This study introduces a novel approach to reducing noise in fluorescence microscopy images. The noise reduction problem is posed as a Maximum A Posteriori estimation problem, and solved using a novel random field model called stochastically-connected random field (SRF), which combines random graph and field theory. Experimental results using synthetic and real fluorescence microscopy data show the proposed approach achieving strong noise reduction performance when compared to several other noise reduction algorithms, using quantitative metrics. The proposed SRF approach was able to achieve strong performance in terms of signal-to-noise ratio in the synthetic results, high signal to noise ratio and contrast to noise ratio in the real fluorescence microscopy data results, and was able to maintain cell structure and subtle details while reducing background and intra-cellular noise.

Gallbladder sarcoma: a clinicopathological study of seven cases from the UK and Austria with emphasis on morphological subtypes

BACKGROUND

Primary sarcoma of the gallbladder (PGBS) is rare, with only 40 cases reported in the literature. Most of these have been diagnosed as leiomyosarcoma. We aimed to evaluate the histological features of a case series of this rare tumor and correlate these with clinical features.

DESIGN

Cases recorded as "gallbladder sarcoma" from different institutes were reviewed and the clinicopathological features of these cases were recorded. Only primary gallbladder wall mesenchymal tumors were included. Epithelial tumors, mixed tumors (carcinosarcoma or sarcomatoid carcinoma), and tumors extending into the gallbladder from the abdomen or sarcoma with other known primaries were specifically excluded.

RESULT

PGBS occurred in one male and six females with a median age of 70 (range 64-82) years. Patients presented with acute or chronic cholecystitis, abdominal pain, weight loss, and pruritus. They were generally found to have elevated alkaline phosphatase and bilirubin, and leukocytosis. Tumors ranged from 1.1 to 4 cm with a median size of 3 cm. Most PGBS arose in the body but one arose in the fundus. All tumors were associated with ulcerated mucosa. Based on morphological and immunohistochemical features of the PGBS, there were three myxofibrosarcomas (malignant fibrous histiocytoma, MFH, storiform pleomorphic), one leiomyosarcoma (LMS), one angiosarcoma (AS), and two liposarcomas (LS). All patients received cholecystectomy and three received adjuvant chemotherapy. Follow-up revealed that six patients died of the disease 6 weeks to 2 years after diagnosis and one died of unrelated causes.

CONCLUSION

PGBS are rare and mainly occur in the gallbladder body in middle-aged females. They generally present with acute cholecystitis and have a very poor prognosis. A variety of sarcoma types are found with MFH being the predominant variant.

Epithelioid perineurioma: an unusual variant

An unusual epithelioid variant of perineurioma of the groin occurring in a 53-year-old man is described. The lesion appeared to be associated with a femoral nerve branch. The tumour was characterised by the presence of a syncytial proliferation of epithelioid cells, mimicking a meningioma of syncytial type. In addition there was a minor component of a conventional perineurioma. The tumour cells were EMA+, claudin-1+ and collagen type IV+. Bcl 2 was focally expressed. This case highlights the possibility of a common histogenetic pathway for meningiomas and perineuriomas. Although ultrastructural evidence of possible meningiomatous differentiation within an otherwise histologically typical perineurioma has been described, this is the first reported case of an unconventional epithelioid variant of perineurioma, histologically resembling meningioma.

Intraocular vancomycin levels after intravitreal injection in post cataract extraction endophthalmitis

PURPOSE

Intravitreal antibiotics are the mainstay of treatment of endophthalmitis following cataract surgery. The purpose of this study is to determine the range of intraocular vancomycin found after intravitreal therapy and assess the optimum time for repeat injections.

METHODS

Aqueous and vitreous vancomycin was assayed at the time of reinjection in 14 patients with endophthalmitis showing a poor clinical response after their primary injection. Nine patients received vancomycin 2 mg and another five received vancomycin 1 mg. In six patients the injection was repeated at 48 hours and in seven at 72 hours. Two patients received three injections.

RESULTS

Aqueous vancomycin varied from 8.4 to 170 mg/L and the vitreous vancomycin level ranged from 21.2 to 220 mg/L.

CONCLUSIONS

In the current study vitreous vancomycin levels were variable, but well within the therapeutic range for sensitive Gram-positive organisms. At times they exceeded the putative retinotoxic levels (100 mg/L). Higher aqueous levels were found after an injection of 2 mg than after 1 mg. Vancomycin levels were still very high 3 days after injection of 2 mg where results were available. Assay at the time of repeat injection may provide insight into the adequacy of vitreous levels and guide future therapy.

Abdominal aortic aneurysm with aorta-left renal vein fistula with left varicocele

Abdominal aortic aneurysm with spontaneous aorto-left renal vein fistula is a rare but well-described clinical entity usually with abdominal pain, hematuria, and a nonfunctioning left kidney. This report describes a 44-year-old man with left-sided groin pain and varicocele who was treated with conservative measures only. The diagnosis was eventually made when he returned with microscopic hematuria, elevated serum creatinine level, and nonfunction of the left kidney; computed tomography scan demonstrated a 6-cm abdominal aortic aneurysm, a retroaortic left renal vein, and an enlargement of the left kidney. This patient represents the youngest to be reported with aorto-left renal vein fistula and the second case with a left-sided varicocele.

Consequences of cometary aurora on the carbon chemistry at comet P/Halley

Various experimental data acquired during the visit of Halley's comet in 1986 have shown that the amount of carbon produced due to photodissociation of parent carbon bearing species is not ample enough to explain the observations. This requires the presence of an additional source of atomic carbon. One of the possible source could be auroral-type activities resulting from the precipitation of high-energy "auroral electrons" of solar wind origin, the evidence of which have been inferred from many observations at comet Halley. We have developed a coupled chemistry-transport model to study the role of auroral and photoelectron impact as well as of chemistry on the modelling of carbon in the inner coma (< or = 10(4) km) of comet Halley. Our study suggest that electron impact dissociation of CO is the major source of carbon production in the inner coma, not the recombination of CO+ as suggested by earlier workers, while transport is the main loss process.

Temperature distribution in tissues from a regular array of hot source implants: an analytical approximation

An approximate analytical model based upon the bioheat transfer equation is derived and used to calculate temperatures within a perfused region implanted regularly with dielectrically coated hot source implants; for example, hot water tubes, electrically heated rods, or inductively heated ferromagnetic implants. The effect of a regular array of mutually parallel heat sources of cylindrical shape is approximated by idealizing one of the boundary conditions. The solution, as could be expected, is in terms of modified Bessel functions. In calculating the temperature of each thermoregulating source in the array, the steady state power balance is enforced. The important feature of the model is that the finite size of implant diameter and its dielectric coating can be incorporated. The effect of thickness and thermal conductivity of the coating on the source and tissue temperatures along with various other interesting features are deduced from this model. The analytically calculated implant and tissue temperatures are compared with those of a numerical 3-D finite difference model. The analytical model also is used to define a range of parameters such that minimal therapeutic temperatures will be achieved in the implanted volume without exceeding prescribed maximum temperatures. This approach leads to a simple means of selecting implant spacing and regulation temperatures of hot source methods prospectively.

Lid melanoma and parkinsonism

This is a case report of a patient with parkinsonism on levodopa therapy who developed a lid margin melanoma. The possible association is discussed.

Aminoaciduria in handicapped children: a study using ion-exchange chromatography as a screening test

The aminoacid excretion levels of 59 normal and 75 physically and/or mentally handicapped children were measured with ion-exchange chromatography. A computer-assisted statistical analysis of the results from the normal population was used to calculate an approximating frequency distribution. 18 patients were found to be excreting one or more aminoacids above the normal 99.75th or 100th percentiles. They included 1 with dibasic aminoaciduria; 1 six-year-old with phenylketonuria; 1 with hyperphenylalaninuria; 5 with cystathioninuria; 2 with hyperglycinuria; 1 with hyperglycinuria and hypertaurinuria; 5 with hypertaurinuria; 1 excreting high levels of taurine, serine, tyrosine, and histidine, and 1 with asparaginuria.

In vitro isolation, propagation, and characterization of duck hepatitis virus type III

The in vitro isolation, propagation, and characterization of duck hepatitis virus Type III (DHV-III), is described. This virus, which is serologically distinct from the classical (Type I) DHV, replicated in liver and kidney cell cultures of duck origin. Replication was limited in chicken and quail kidney and duck embryo fibroblast cultures. It did not replicate in a variety of other cell cultures of avian or mammalian origin. The virus was grown successfully in embryonating eggs of ducks, but not of chickens. DHV-III passed through a 50-nm membrane filter, was stable at pH 3.0 and resisted treatment with 5% chloroform. Virus growth was not inhibited by treatment with 5-iodo-2-deoxyuridine. Electron-microscope examination revealed crystalline arrays in the cytoplasm; virus particles had cubic symmetry, and were about 30 nm in diameter. By these properties, this virus can be classified as a member of the picornavirus group.

Alkali denaturation of oxyhaemoglobins of some digenetic trematodes and their hosts

Oxyhaemoglobins of six digenetic trematodes,--Srivastavaia indica, Gastrothylax crumenifer, Gigantocotyle explanatum, Fasciolopsis buski, Gastrodiscoides hominis, Isoparorchis hypselobagri, and of their 3 vertebrate hosts, Bubalus bubalis, Sus scrofa, Wallago attu, were subjected to alkali denaturation at a pH of 12.4. All oxyhaemoglobins from trematodes and their hosts differ from each other in the rate and extent of alkali denaturation which may be explained due to variations in the amino acid sequences of a particular haem protein in addition to other factors.

Treatment of atopic eczema in children: clinical trial of 10% sodium cromoglycate ointment

In a double-blind randomised group-comparative trial 21 children with chronic atopic eczema were treated twice daily for up to 12 weeks with an ointment containing 10% sodium cromoglycate (SCG) in white soft paraffin. A similar group of 21 children was treated for up to 12 weeks with a placebo ointment consisting of the white soft-paraffin base only. The number of patients who withdrew from the trial because treatment was ineffective was significantly greater in the placebo group (16) than in the SCG group (four). Comparison between the two groups also showed significant improvement in inflammation, lichenification, and cracking and the symptoms of itching and sleep disturbance among those on SCG treatment. At the end of treatment significantly more patients in the SCG group (16) had benefited from treatment compared with only two patients in the placebo group. No patients experienced side effects. I conclude that SCG ointment may be a safe alternative to topical steroids in the treatment of atopic eczema in children.

Spectrophotometric analysis of haemoglobins of some digenetic trematodes and their hosts

The haemoglobins of six different species of trematodes: Gastrothylax crumenifer, Srivastavaia indica, Gigantocotyle explanatum, Fasciolopsis buski, Gastrodiscoides hominis, Isoparorchis hypselobagri and their three different hosts: Bubalus bubalis, Sus scrofa, and Wallago attu were spectrophotometrically investigated, and were found to contain porphyrin IX as the common prosthetic group. Oxyhaemoglobin, carbonmonoxy-haemoglobin and reduced haemoglobin of all 6 species of trematodes and their 3 hosts under study gave similar absorption maxima. Distinct differences were, however, observed in the nature of the spectral curves of cyanmethaemoglobin which exhibit 2 absorption maxima in the beta and the alpha region in the case of all trematodes whereas in the case of similar host haemoglobin derivatives only one single broad peak in the 536-540 nm region was obtained. With respect to pyridine derivatives all the trematode haemoglobins show a sharp peak in the alpha region and a minor hump in the beta region except Gastrothylax crumenifer. All three host pyridine haemoglobin derivatives show only a single broad peak at 570 nm.

Serum IgM in diagnosis of infection in the newborn

Serum IgM levels were determined at weekly intervals from birth in 100 normal low birthweight and 100 normal birthweight infants during the first 4 weeks of life. The dynamics of serum IgM was also studied in 36 newborn infants with different types of infection and in 19 infants with probable infection. The behaviour of serum IgM in the infants with systemic infection and also in those suffering from superficial infection with systemic symptoms was significantly different from the normal. Serum IgM rose within two days of appearance of symptoms and the rise persisted as long as the infection was `active'. With the eradication of infection the IgM level tended to fall. This characteristic dynamic pattern of serum IgM may be of considerable help in the diagnosis of neonatal infection, especially the clinically inapparent and atypical varieties that may have serious sequelae later in life.

Polymorphomuclear leucocyte count in diagnosis of infection in the newborn

Polymorphonuclear leucocyte counts were done in 200 infants at weekly intervals during the newborn period. In over 80% of the babies the count was below 7000/mm³. The count in 36 neonates with bacterial infection was found to be higher than the normal, in particular in the 18 infants with internal infection.

Raised serum IgM levels in neonatal endemic diarrhoea

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Differential Response of Potato under Sodium Chloride Stress Conditions In Vitrio

In vitro evaluations of salinity (NaCI) effects on three potato cultivars (Atlanta, Shepody and Shilbilaty ) were investigated with five NaCI levels ( 0, 25, 50, 75 and100 mM) by using single node explants. Significant differences were noticed among the cultivars followed by different NaCl levels. Salinity stress gradually depressed plant growth and root development with increased NaCl concentration in MS media. All the cultivars survived at high NaCl (100 mM) containing MS media with exhibiting different growth status. The results indicate that Shilbilaty performed better in shoot length and shoot fresh mass than Shepody and Atlanta. The Atlanta performed better in root growth than Shepody and Shilbilaty at different NaCl media. Highest salinity level drastically inhibits root growth in all the cultivars tested. The control and 25 mM NaCl containing MS media did not affect the growth traits of in vitro potato plantlets. The control was found superior in growth characterized than rest of the tested NaCl levels.  Keywords: Potato, single node, NaCl stress, growth response   DOI:10.3329/jbs.v16i0.3745    J. bio-sci. 16: 79-83, 2008