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.

Acquired bedaquiline resistance in Karakalpakstan, Uzbekistan

BACKGROUND: The WHO recommends the use of bedaquiline (BDQ) in longer, as well as shorter, multidrug-resistant TB (MDR-TB) treatment regimens. However, resistance to this new drug is now emerging. We aimed to describe the characteristics of patients in Karakalpakstan, Uzbekistan, who were treated for MDR-TB and acquired BDQ resistance during treatment.METHODS: We performed a retrospective study of routinely collected data for patients treated for MDR-TB in Karakalpakstan between January 2015 and December 2020. We included patients on BDQ-containing regimens with baseline susceptibility to BDQ who developed BDQ resistance at any point after treatment initiation. Patients resistant to BDQ at baseline or with no confirmed susceptibility to BDQ at baseline were excluded.RESULTS: Of the 523 patients who received BDQ-containing regimens during the study period, BDQ resistance was detected in 31 patients (5.9%); 20 patients were excluded-16 with no prior confirmation of BDQ susceptibility and 4 who were resistant at baseline. Eleven patients with acquired BDQ resistance were identified. We discuss demographic variables, resistance profiles, treatment-related variables and risk factors for unfavourable outcomes for these patients.CONCLUSION: Our programmatic data demonstrated the acquisition of BDQ resistance during or subsequent to receiving a BDQ-containing regimen in a patient cohort from Uzbekistan. We highlight the need for individualised treatment regimens with optimised clinical and laboratory follow up to prevent resistance acquisition.

Beware of spurious tracheo-bronchial stents

OBJECTIVE

To present a case of accidental sheath removal of tracheo-bronchial self-expandable metallic airway stent in a patient with endotracheal tumour.

METHODS

Design: Case Report; Setting: Tertiary care hospital; Patient: One.

RESULTS

A 65 years male, follow up case of endotracheal tumor with tracheo-bronchial self-expandable metallic stenting done presented with dry cough and difficulty in breathing since 8-10 days and suddenly coughed out thin whitish paper-like material 2 days back (which later proved as sheath of metallic stent). Direct laryngoscopy with flexible videobronchoscopy was done which showed tracheal stent well placed and intact, coughed out sheath couldn't be replaced back. Procedure was uneventful and patient was discharged in satisfactory condition and is doing well on regular follow up.

CONCLUSION

Self-expandable metallic airway stents (SEMAS) represents a standard method of airways stenting especially when employed for the management of malignant central airway obstruction. Despite the obvious stenting advantages, it may be complicated with stent migration and accidental removal or coughing out of stent especially in high tracheal stenosis. In our case, as a peculiar complication there was accidental removal of the tracheal stent sheath which couldn't be replaced back whereas stent was well in place and intact. We need to be beware of such spurious tracheo-bronchial stents.

Time-resolved hadronic particle acceleration in the recurrent nova RS Ophiuchi

Recurrent novae are repeating thermonuclear explosions in the outer layers of white dwarfs, due to the accretion of fresh material from a binary companion. The shock generated when ejected material slams into the companion star's wind can accelerate particles. We report very-high-energy (VHE, [Formula: see text]) gamma rays from the recurrent nova RS Ophiuchi, up to a month after its 2021 outburst, observed using the High Energy Stereoscopic System. The VHE emission has a similar temporal profile to lower-energy GeV emission, indicating a common origin, with a two-day delay in peak flux. These observations constrain models of time-dependent particle energization, favoring a hadronic emission scenario over the leptonic alternative. Shocks in dense winds provide favorable environments for efficient acceleration of cosmic-rays to very high energies.

Trajectory of Serum Bilirubin Predicts Spontaneous Recovery in a Real-World Cohort of Patients With Alcoholic Hepatitis

BACKGROUND AND AIMS

Alcoholic hepatitis (AH) is a severe condition with poor short-term prognosis. Specific treatment with corticosteroids slightly improves short-term survival but is associated with infection and is not used in many centers. A reliable method to identify patients who will recover spontaneously will minimise the numbers of patients who experience side effects of available treatments.

METHODS

We analysed the trajectory of serum bilirubin concentration over the course of hospital admissions in patients with AH to predict spontaneous survival and the need for treatment.

RESULTS

data from 426 patients were analysed. Based on bilirubin trajectory, patients were categorized into three groups: 'fast fallers' (bilirubin <0.8 x admission value at day 7), 'static' (bilirubin of >0.9 - <1.2 x admission value) and 'rapid risers' (bilirubin of ≥1.2 x admission bilirubin). Fast fallers had significantly better 90-day survival compared to other groups (log rank p < .001), and showed no benefit of corticosteroid therapy (OR for survival at 28 days of treatment, 0.94, 95% CI 0.06 - 8.41). These findings remained even amongst patients with severe disease based on initial DF, GAHS or MELD scores.

CONCLUSIONS

We present an intuitive method of classifying patients with AH based on the trajectory of bilirubin over the first week of admission. It is complimentary to existing scores that identify candidates for corticosteroid treatment or assess response to treatment. This method identifies a group of patients with AH who recover spontaneously and can avoid corticosteroid therapy.

Introducing Clinical Pathology Course to Fourth Year Medical Students as a Bridge between Pre-clinical and Clinical Medical Sciences

There isn't any vertical integration of pre-clinical and clinical sciences subjects in the existing Kathmandu University MBBS curriculum. Many of the graduates are not able to correlate the clinico-pathological aspects of various diseases as a result the rational use of investigations for diagnosing various diseases is compromised. There are few published examples of implementation of pathology instruction courses during the clinical years of medical training but it is not universally practiced. This lack of exposure to pathology may lead to poor understanding of laboratory testing and the role of pathologists in patient care. To set and implement an exemplary vertical integration of pre-clinical science with clinical science. A 12 credit hours clinical pathology education course comprising clinical hematology, cytopathology and histopathology was developed. Students belonging from the ongoing fourth year MBBS course of Birat Medical College were enrolled in the course. All of the interactive lecture sessions were delivered via an e-learning interface, using the Zoom platform as the main teaching methods. Evaluation of students' achievement of learning objectives was conducted through distributing pre and post-test online multiple-choice questionnaires. Chi-square tests were used to compare the variables between pre-test and post-test questionnaire responses. Results suggested that the designed clinical pathology course is valuable. The pretest and post-test questionnaire responses revealed the positive impact regarding the importance of introducing clinical pathology courses within the clinical year of MBBS undergraduate curriculum. Response rate to the online session was 100%. The point of agreement between the pre-test and post-test questionnaire responses were highly achieved after intervention of the clinical pathology course. A statistically significant result (p < 0.05) between all of the pre-test and post-test questionnaire responses was noted. There was a strong positive recommendation for incorporating clinical laboratory medicine courses within the MBBS clinical science curriculum. The improvement observed among fourth-year MBBS students on learning the importance of clinical pathology courses was encouraging. This experience thus contributed to set and implement an exemplary vertical integration of pre-clinical science with clinical science.

ADRENAL HISTOPLASMOSIS: AN EASTERN INDIAN PERSPECTIVE

CONTEXT

The clinical presentation of histoplasmosis is varied. Due to its propensity for adrenal involvement, histoplasmosis is an important differential diagnosis in any patient presenting with adrenal mass, bilateral in particular.

OBJECTIVE

Data on clinical presentation, pattern of adrenal involvement, radiological appearance and long-term follow-up of adrenal histoplasmosis are relatively sparse; hence we looked at it.

DESIGN

This record based single-centre retrospective study was conducted in one of the tertiary care hospitals, situated in eastern India catering the Gangetic delta.

SUBJECTS AND METHODS

Data on demographic characters, presenting manifestations, biochemical & hormonal parameters and radiological appearance of confirmed adrenal histoplasmosis cases (n=9), admitted between 2015-2019 have been retrieved. The treatment outcome and condition of patients after 1-4 years of follow-up has also been discussed.

RESULTS

Four out of the nine (44.4%) patients had predisposing immunocompromised conditions in the form of diabetes and/or chronic alcoholism while rest were immunocompetent. Seven out of nine patients (77.8 %) had signs and symptoms suggestive of adrenal insufficiency, while two (22.2%) presented with only pyrexia of unknown origin. All of them had bilateral adrenal mass, though the radiologically appearances were different. All patients received anti-fungal agents with/without hydrocortisone and/or fludrocortisone. One patient died (11.1%), while majority responded favourably to treatment. Adrenocortical function did not recover completely.

CONCLUSIONS

The possibility of adrenal histoplasmosis should always be considered in patients presenting with bilateral adrenal mass, irrespective of adrenal morphology. Treatment is effective, but many of them require supplemental hydrocortisone for quite a long period, if not lifelong. Mineralocorticoid deficiency, however, is not permanent.

Collapse of the Liangzhu and other Neolithic cultures in the lower Yangtze region in response to climate change

The Liangzhu culture in the Yangtze River Delta (YRD) was among the world’s most advanced Neolithic cultures. Archeological evidence suggests that the Liangzhu ancient city was abandoned, and the culture collapsed at ~4300 years ago. Here, we present speleothem records from southeastern China in conjunction with other paleoclimatic and archeological data to show that the Liangzhu culture collapsed within a short and anomalously wet period between 4345 ± 32 and 4324 ± 30 years ago, supporting the hypothesis that the city was abandoned after large-scale flooding and inundation. We further show that the demise of Neolithic cultures in the YRD occurred within an extended period of aridity that started at ~4000 ± 45 years ago. We suggest that the major hydroclimatic changes between 4300 and 3000 years ago may have resulted from an increasing frequency of the El Niño–Southern Oscillation in the context of weakened Northern Hemisphere summer insolation.

198 Immediate Post-Operative PDE5i Therapy Improves Early Erectile Function Outcomes after Robot-Assisted Radical Prostatectomy (RARP)

Aim

To assess whether the timing of post-operative Phosphodiesterase Inhibitor (PDE5i) therapy after Robot Assisted Radical Prostatectomy (RARP) is associated with a change in early erectile function, continence, or safety outcomes.

Method

Data was prospectively collected from a single surgeon in one tertiary centre and retrospectively evaluated. 158 patients were treated with PDE5i therapy post RARP over a two-year period.

Results

There were no significant differences in pre-operative characteristics between the therapy groups. Patients that had bilateral nerve sparing had a mean drop in Erectile Function (EF) score by 5.4 compared to 8.8 in the unilateral group. Additionally, 34.9% of bilateral nerve sparing patients returned to baseline compared to 12.1% of unilateral. Drop in EF scores and percentage return to baseline for unilateral nerve sparing was respectively 9 and 11.1% of immediate (day 1-2), 7 and 14.8% of early (day 3-14) and 9.7 and 9.5% of late (day &gt;14) therapy (p = 0.9 and p = 0.6). For bilateral nerve sparing this was respectively 3.5 and 42.9% immediate therapy, 5.5 and 35.5% early therapy and 7.3 and 25% late therapy (p = 0.017 and p = 0.045). Pad free and social continence was achieved in 54% and 37% of those receiving immediate therapy, 60% and 33% for early therapy and 26% and 54% for late therapy. There were no differences in compliance, complication, or readmission outcomes.

Conclusions

Immediate PDE5i therapy should be considered in patients following nerve sparing RARP in order to maximise functional outcomes, especially in those undergoing bilateral nerve spare.

81 VIRTUAL: Virtual Interactive Surgical Skills Classroom – An Ongoing Randomized Controlled Trial

Introduction

High costs and inaccessibility are significant barriers to face-to-face basic surgical skills (BSS) training. Virtual classrooms enable the combination of computer-based learning with interactive expert instruction. They may optimise resources and increase accessibility, facilitating larger-scale training with a similar educational benefit. We aim to evaluate the efficacy of virtual BSS classroom training compared to both non-interactive video and face-to-face teaching.

Method

72 medical students will be randomly assigned to three equal intervention groups based on year group and surgical skill confidence. Interventions will be implemented following an instructional video. Group A will practice independently, Group B will receive face-to-face training, and Group C will attend a virtual classroom. Participants will be recorded placing three interrupted sutures with hand tied knots pre- and post-intervention, and Objective Structured Assessment of Technical Skills (OSATS) will be blind marked by two experts. Change in confidence, time to completion and a granular performance score will also be measured. Each intervention’s feasibility and accessibility will be assessed.

Results

Data collection will be completed in January 2021. Significant improvement in OSATS within groups will be indicative of intervention quality. Difference in improvement between groups will determine the relative performance of the interventions.

Conclusions

To our knowledge, this will be the largest randomised control trial investigating virtual BSS classroom training. It will serve as a comprehensive appraisal of the virtual classroom’s suitability as an alternative to face-to-face training. The findings will assist the development and implementation of further resource-efficient training programs during the COVID-19 pandemic and in the future.

Malaria, COVID-19 and angiotensin-converting enzyme 2: what does the available population data say?

The etiopathogenesis of COVID-19 and its differential geographic spread suggest some populations are apparently 'less affected' through many host-related factors that involve angiotensin-converting enzyme 2 (ACE2) protein, which is also the entry receptor for SARS-CoV-2. The role of ACE2 has been well studied in COVID-19 but not in the context of malaria and COVID-19. We have previously suggested how malaria might intersect with COVID-19 through ACE2 mutation and here we evaluate the currently available data that could provide a link between the two diseases. Based on the existing global and Indian data on malaria, COVID-19 and the suggested ACE2 mutation, the association could not be examined robustly, neither accepting nor refuting the suggested hypothesis. We strongly recommend targeted evaluation of this hypothesis through carefully designed robust molecular epidemiological studies.

O43 Virtual: virtual interactive surgical skills classroom: a randomized controlled trial (protocol)

Introduction

High costs and inaccessibility are significant barriers to face-to-face basic surgical skills (BSS) training. Virtual classrooms enable the combination of computer-based learning with interactive expert instruction. They may optimise resources and increase accessibility, facilitating larger-scale training with a similar educational benefit. We aim to evaluate the efficacy of virtual BSS classroom training compared to both non-interactive video and face-to-face teaching.

Method

72 medical students will be randomly assigned to three equal intervention groups based on surgical skills experience and confidence. Interventions will be implemented following an instructional video. Group A will practice independently, Group B will receive face-to-face training, and Group C will attend a virtual classroom. Participants will be recorded placing three interrupted sutures with hand tied knots pre- and post-intervention. Objective Structured Assessment of Technical Skills (OSATS) will be blind marked by two experts.

Result

Change in confidence, time to completion and a novel granular performance score will also be measured. Each intervention’s feasibility and accessibility will be assessed. Significant improvement in OSATS within groups will be indicative of intervention quality. Difference in improvement between groups will determine the relative performance of the interventions.

Conclusion

This will be the largest randomised control trial investigating virtual BSS classroom training. It will serve as a comprehensive appraisal of the suitability of virtual classrooms as an alternative to face-to-face training. The findings will assist the development and implementation of further resource-efficient training programs during the COVID-19 pandemic and beyond.

Take-home Message

This is the first RCT assessing virtual basic surgical skill classroom training and serves as a comprehensive appraisal of the suitability of virtual classrooms as an alternative to face-to-face training. The findings will assist the development and implementation of further resource-efficient training programs during the COVID-19 pandemic and in the future.

Revealing x-ray and gamma ray temporal and spectral similarities in the GRB 190829A afterglow

Gamma-ray bursts (GRBs), which are bright flashes of gamma rays from extragalactic sources followed by fading afterglow emission, are associated with stellar core collapse events. We report the detection of very-high-energy (VHE) gamma rays from the afterglow of GRB 190829A, between 4 and 56 hours after the trigger, using the High Energy Stereoscopic System (H.E.S.S.). The low luminosity and redshift of GRB 190829A reduce both internal and external absorption, allowing determination of its intrinsic energy spectrum. Between energies of 0.18 and 3.3 tera-electron volts, this spectrum is described by a power law with photon index of 2.07 ± 0.09, similar to the x-ray spectrum. The x-ray and VHE gamma-ray light curves also show similar decay profiles. These similar characteristics in the x-ray and gamma-ray bands challenge GRB afterglow emission scenarios.

The significance of urgent ultrasound scan for shoulder dislocation in patients above the age of 40: A prospective British Elbow and Shoulder Society pathway implementation study

BACKGROUND

The highlight of the British Elbow and Shoulder Society pathway for the management of traumatic anterior shoulder instability is early imaging in patients aged over 40 years to assess rotator cuff integrity and early repair, if indicated to optimise function. The senior author set up a protocol in our institute to streamline the diagnostic process for this cohort of patients. This was a retrospective analysis from a prospectively collected database to highlight the importance of early specialist imaging.

METHODS

Our protocol is to perform urgent ultrasound scans for all suitable patients above 40 years after first-time traumatic shoulder dislocation. Demographics, associated injuries, ultrasound scan results, operations and functional outcomes were collated.

RESULTS

One year following the introduction of our protocol, 40 patients with a mean age of 67 (range, 42-89; SD = 13.1) had ultrasound. The incidence of full-thickness rotator cuff tears was 57.5% (n = 23). Eleven patients with confirmed full-thickness rotator cuff tears underwent surgery. The mean age of surgical patients was significantly younger than the non-surgical group (p = 0.004).

DISCUSSION

The use of early diagnostic imaging demonstrated a high incidence of full-thickness rotator cuff tears in this cohort of patients. This allowed early surgical repair to optimise function.

31 Immediate Post-Operative Phosphodiesterase-5 Inhibitors (PDE5i) Therapy Improves Early Erectile Function Outcomes After Robot Assisted Radical Prostatectomy (RARP)

Introduction

To assess whether the timing of post-RARP PDE5i therapy affects early erectile function, continence, or safety outcomes.

Method

Data from 158 patients treated with PDE5is post-RARP was prospectively collected over two years from a single surgeon at one tertiary centre and retrospectively evaluated. Therapy was started: immediately (day 1-2) in 29%, early (day 3-14) in 37% and late (after day 14) post-op in 34%. EPIC-26 Erectile Function (EF) scores were collected pre-op and post-op after a median 43-day follow-up interval.

Results

Drop in EF scores and percentage return to baseline post unilateral nerve sparing (UNS) compared to bilateral nerve sparing (BNS) RARP was respectively 9 and 11.1% versus 3.5 and 42.9% of immediate therapy, 7 and 14.8% versus 5.5 and 35.5% of early and 9.7 and 9.5% versus 7.3 and 25% of late. Pad free and social continence was achieved in 54% and 37% of those receiving immediate therapy, 60% and 33% for early and 26% and 54% for late.

Conclusions

Immediate post RARP PDE5i therapy may protect EF and should be considered clinically, with more benefits for BNS than UNS patients. Immediate or early, rather than late, PDE5i therapy improved early continence in BNS patients.