A systematic review of CT chest in COVID-19 diagnosis and its potential application in a surgical setting

Diagnostic accuracy of a set of clinical and radiological criteria for screening of COVID-19 using RT-PCR as the reference standard

BACKGROUND

The gold-standard method for establishing a microbiological diagnosis of COVID-19 is reverse-transcriptase polymerase chain reaction (RT-PCR). This study aimed to evaluate the accuracy, sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of a set of clinical-radiological criteria for COVID-19 screening in patients with severe acute respiratory failure (SARF) admitted to intensive care units (ICUs), using reverse-transcriptase polymerase chain reaction (RT-PCR) as the reference standard.

METHODS

Diagnostic accuracy study including a historical cohort of 1009 patients consecutively admitted to ICUs across six hospitals in Curitiba (Brazil) from March to September, 2020. The sample was stratified into groups by the strength of suspicion for COVID-19 (strong versus weak) using parameters based on three clinical and radiological (chest computed tomography) criteria. The diagnosis of COVID-19 was confirmed by RT-PCR (referent).

RESULTS

With respect to RT-PCR, the proposed criteria had 98.5% (95% confidence interval [95% CI] 97.5-99.5%) sensitivity, 70% (95% CI 65.8-74.2%) specificity, 85.5% (95% CI 83.4-87.7%) accuracy, PPV of 79.7% (95% CI 76.6-82.7%) and NPV of 97.6% (95% CI 95.9-99.2%). Similar performance was observed when evaluated in the subgroups of patients admitted with mild/moderate respiratory disfunction, and severe respiratory disfunction.

CONCLUSION

The proposed set of clinical-radiological criteria were accurate in identifying patients with strong versus weak suspicion for COVID-19 and had high sensitivity and considerable specificity with respect to RT-PCR. These criteria may be useful for screening COVID-19 in patients presenting with SARF.

Safe Surgery During the COVID-19 Pandemic

PURPOSE OF REVIEW

Coronavirus Disease-2019 (COVID-19) has had an enormous impact on all aspects of healthcare, but its effect on patients needing surgery and surgeons has been disproportionate. In this review, we aim to understand the impact of the pandemic on surgical patients and teams. We compiled the emerging data on pre-operative screening methods, vaccinations, safe-surgery pathways and surgical techniques and make recommendations for evidence-based safe-surgical pathways. We also present surgical outcomes for emergency, oncological and benign surgery in the context of the pandemic. Finally, we attempt to address the impact of the pandemic on patients, staff and surgical training and provide perspectives for the future.

RECENT FINDINGS

Surgical teams have developed consensus guidelines and established research priorities and safety precautions for surgery during the COVID-19 pandemic. Evidence supports that surgery in patients with a peri-operative SARS-CoV-2 infection carries substantial risks, but risk mitigation strategies are effective at reducing harm to staff and patients. Surgery has increased risk for patients and staff, but this can be mitigated effectively, especially for elective surgery. Elective surgery can be safely performed during the COVID-19 pandemic employing the strategies discussed in this review.

An Umbrella Review With Meta-Analysis of Chest Computed Tomography for Diagnosis of COVID-19: Considerations for Trauma Patient Management

Background

RT-PCR testing is the standard for diagnosis of COVID-19, although it has its suboptimal sensitivity. Chest computed tomography (CT) has been proposed as an additional tool with diagnostic value, and several reports from primary and secondary studies that assessed its diagnostic accuracy are already available. To inform recommendations and practice regarding the use of chest CT in the in the trauma setting, we sought to identify, appraise, and summarize the available evidence on the diagnostic accuracy of chest CT for diagnosis of COVID-19, and its application in emergency trauma surgery patients; overcoming limitations of previous reports regarding chest CT accuracy and discussing important considerations regarding its role in this setting.

Methods

We conducted an umbrella review using Living Overview of Evidence platform for COVID-19, which performs regular automated searches in MEDLINE, Embase, Cochrane Central Register of Controlled Trials, and more than 30 other sources. The review was conducted following the JBI methodology for systematic reviews. The Grading of Recommendations, Assessment, Development, and Evaluation approach for grading the certainty of the evidence is reported (registered in International Prospective Register of Systematic Reviews, CRD42020198267).

Results

Thirty studies that fulfilled selection criteria were included; 19 primary studies provided estimates of sensitivity (0.91, 95%CI = [0.88–0.93]) and specificity (0.73, 95%CI = [0.61; 0.82]) of chest CT for COVID-19. No correlation was found between sensitivities and specificities (ρ = 0.22, IC95% [–0.33; 0.66]). Diagnostic odds ratio was estimated at: DOR = 27.5, 95%CI (14.7; 48.5). Evidence for sensitivity estimates was graded as MODERATE, and for specificity estimates it was graded as LOW.

Conclusion

The value of chest CT appears to be that of an additional screening tool that can easily detect PCR false negatives, which are reportedly highly frequent. Upon the absence of PCR testing and impossibility to perform RT-PCR in trauma patients, chest CT can serve as a substitute with increased value and easy implementation.

Systematic Review Registration

[www.crd.york.ac.uk/prospero], identifier [CRD42020198267].

Supervised and weakly supervised deep learning models for COVID-19 CT diagnosis: A systematic review

Artificial intelligence (AI) and computer vision (CV) methods become reliable to extract features from radiological images, aiding COVID-19 diagnosis ahead of the pathogenic tests and saving critical time for disease management and control. Thus, this review article focuses on cascading numerous deep learning-based COVID-19 computerized tomography (CT) imaging diagnosis research, providing a baseline for future research. Compared to previous review articles on the topic, this study pigeon-holes the collected literature very differently (i.e., its multi-level arrangement). For this purpose, 71 relevant studies were found using a variety of trustworthy databases and search engines, including Google Scholar, IEEE Xplore, Web of Science, PubMed, Science Direct, and Scopus. We classify the selected literature in multi-level machine learning groups, such as supervised and weakly supervised learning. Our review article reveals that weak supervision has been adopted extensively for COVID-19 CT diagnosis compared to supervised learning. Weakly supervised (conventional transfer learning) techniques can be utilized effectively for real-time clinical practices by reusing the sophisticated features rather than over-parameterizing the standard models. Few-shot and self-supervised learning are the recent trends to address data scarcity and model efficacy. The deep learning (artificial intelligence) based models are mainly utilized for disease management and control. Therefore, it is more appropriate for readers to comprehend the related perceptive of deep learning approaches for the in-progress COVID-19 CT diagnosis research.

Review and classification of AI-enabled COVID-19 CT imaging models based on computer vision tasks

This article presents a systematic overview of artificial intelligence (AI) and computer vision strategies for diagnosing the coronavirus disease of 2019 (COVID-19) using computerized tomography (CT) medical images. We analyzed the previous review works and found that all of them ignored classifying and categorizing COVID-19 literature based on computer vision tasks, such as classification, segmentation, and detection. Most of the COVID-19 CT diagnosis methods comprehensively use segmentation and classification tasks. Moreover, most of the review articles are diverse and cover CT as well as X-ray images. Therefore, we focused on the COVID-19 diagnostic methods based on CT images. Well-known search engines and databases such as Google, Google Scholar, Kaggle, Baidu, IEEE Xplore, Web of Science, PubMed, ScienceDirect, and Scopus were utilized to collect relevant studies. After deep analysis, we collected 114 studies and reported highly enriched information for each selected research. According to our analysis, AI and computer vision have substantial potential for rapid COVID-19 diagnosis as they could significantly assist in automating the diagnosis process. Accurate and efficient models will have real-time clinical implications, though further research is still required. Categorization of literature based on computer vision tasks could be helpful for future research; therefore, this review article will provide a good foundation for conducting such research.

Experiences of diagnostic radiographers through the Covid-19 pandemic

Introduction

Diagnostic Radiography plays a major role in the diagnosis and management of patients with Covid-19. This has seen an increase in the demand for imaging services, putting pressure on the workforce. Diagnostic radiographers, as with many other healthcare professions, have been on the frontline, dealing with an unprecedented situation. This research aimed to explore the experience of diagnostic radiographers working clinically during the Covid-19 pandemic.

Methods

Influenced by interpretative phenomenology, this study explored the experiences of diagnostic radiographers using virtual focus group interviews as a method of data collection.

Results

Data were analysed independently by four researchers and five themes emerged from the data. Adapting to new ways of working, feelings and emotions, support mechanisms, self-protection and resilience, and professional recognition.

Conclusion

The adaptability of radiographers came across strongly in this study. Anxieties attributed to the provision of personal protective equipment (PPE), fear of contracting the virus and spreading it to family members were evident. The resilience of radiographers working throughout this pandemic came across strongly throughout this study. A significant factor for coping has been peer support from colleagues within the workplace. The study highlighted the lack of understanding of the role of the radiographer and how the profession is perceived by other health care professionals.

Implications for practice

This study highlights the importance of interprofessional working and that further work is required in the promotion of the profession.

The Omic Insights on Unfolding Saga of COVID-19

The year 2019 has seen an emergence of the novel coronavirus named severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) causing coronavirus disease of 2019 (COVID-19). Since the onset of the pandemic, biological and interdisciplinary research is being carried out across the world at a rapid pace to beat the pandemic. There is an increased need to comprehensively understand various aspects of the virus from detection to treatment options including drugs and vaccines for effective global management of the disease. In this review, we summarize the salient findings pertaining to SARS-CoV-2 biology, including symptoms, hosts, epidemiology, SARS-CoV-2 genome, and its emerging variants, viral diagnostics, host-pathogen interactions, alternative antiviral strategies and application of machine learning heuristics and artificial intelligence for effective management of COVID-19 and future pandemics.

Impact of the COVID-19 pandemic On Emergency Adult Surgical Patients and Surgical Services: An International Multi-Center Cohort Study and Department Survey

OBJECTIVES

The PREDICT study aimed to determine how the COVID-19 pandemic affected surgical services and surgical patients and to identify predictors of outcomes in this cohort.

BACKGROUND

High mortality rates were reported for surgical patients with COVID-19 in the early stages of the pandemic. However, the indirect impact of the pandemic on this cohort is not understood, and risk predictors are yet to be identified.

METHODS

PREDICT is an international longitudinal cohort study comprising surgical patients presenting to hospital between March and August 2020, conducted alongside a survey of staff redeployment and departmental restructuring. A subgroup analysis of 3176 adult emergency patients, recruited by 55 teams across 18 countries is presented.

RESULTS

Among adult emergency surgical patients, all-cause in-hospital mortality (IHM) was 3 6%, compared to 15 5% for those with COVID-19. However, only 14 1% received a COVID-19 test on admission in March, increasing to 76 5% by July.Higher Clinical Frailty Scale scores (CFS >7 aOR 18 87), ASA grade above 2 (aOR 4 29), and COVID-19 infection (aOR 5 12) were independently associated with significantly increased IHM.The peak months of the first wave were independently associated with significantly higher IHM (March aOR 4 34; April aOR 4 25; May aOR 3 97), compared to non-peak months.During the study, UK operating theatre capacity decreased by a mean of 63 6% with a concomitant 27 3% reduction in surgical staffing.

CONCLUSION

The first wave of the COVID-19 pandemic significantly impacted surgical patients, both directly through co-morbid infection and indirectly as shown by increasing mortality in peak months, irrespective of COVID-19 status.Higher CFS scores and ASA grades strongly predict outcomes in surgical patients and are an important risk assessment tool during the pandemic.

Thoracic Anesthesia during the COVID-19 Pandemic: 2021 Updated Recommendations by the European Association of Cardiothoracic Anaesthesiology and Intensive Care (EACTAIC) Thoracic Subspecialty Committee

The novel coronavirus pandemic has radically changed the landscape of normal surgical practice. Lifesaving cancer surgery, however, remains a clinical priority, and there is an increasing need to fully define the optimal oncologic management of patients with varying stages of lung cancer, allowing prioritization of which thoracic procedures should be performed in the current era. Healthcare providers and managers should not ignore the risk of a bimodal peak of mortality in patients with lung cancer; an imminent spike due to mortality from acute coronavirus disease 2019 (COVID-19) infection, and a secondary peak reflecting an excess of cancer-related mortality among patients whose treatments were deemed less urgent, delayed, or cancelled.

The European Association of Cardiothoracic Anaesthesiology and Intensive Care Thoracic Anesthesia Subspecialty group has considered these challenges and developed an updated set of expert recommendations concerning the infectious period, timing of surgery, vaccination, preoperative screening and evaluation, airway management, and ventilation of thoracic surgical patients during the COVID-19 pandemic.

Pre-operative testing for SARS-CoV-2 and outcomes in otolaryngology surgery during the pandemic: A multi-center experience

Introduction

Preoperative testing for COVID‐19 has become widely established to avoid inadvertent surgery on patients with COVID‐19 and prevent hospital outbreaks.

Methods

A prospective cross sectional study was carried out in two university hospitals examining the pre‐operative protocols for patients undergoing otolaryngology surgery and the incidence of COVID‐19 within 30 days of surgery in patients and the otolaryngologists performing surgery.

Results

One hundred and seventy‐three patients were recruited. One hundred and twenty‐three (71%) patients “cocooned” for 14 days prior to surgery. All completed a questionnaire prior to admission. One hundred and fifty‐six patients (90%) had reverse transcriptase‐polymerase chain reaction (RT‐PCR) nasopharyngeal swabs, 14 patients (8%) had CT thorax. No cases of COVID‐19 were detected among patients followed up at 30 days. Two surgeons developed COVID‐19 early during the study period.

Conclusion

Current pre‐operative testing protocols consisting primarily of questionnaires and RT‐PCR resulted in zero cases of COVID in this cohort. It is possible that COVID‐19 restrictions and high proportion of patients cocooning preoperatively were factors in ensuring a low rate of COVID‐19 post‐operatively.

Highlighting COVID-19: What the imaging exams show about the disease

Coronavirus disease 2019 (COVID-19), a global emergency, is caused by severe acute respiratory syndrome coronavirus 2. The gold standard for its diagnosis is the reverse transcription polymerase chain reaction, but considering the high number of infected people, the low availability of this diagnostic tool in some contexts, and the limitations of the test, other tools that aid in the identification of the disease are necessary. In this scenario, imaging exams such as chest X-ray (CXR) and computed tomography (CT) have played important roles. CXR is useful for assessing disease progression because it allows the detection of extensive consolidations, besides being a fast and cheap method. On the other hand, CT is more sensitive for detecting lung changes in the early stages of the disease and is also useful for assessing disease progression. Of note, ground-glass opacities are the main COVID-19-related CT findings. Positron emission tomography combined with CT can be used to evaluate chronic and substantial damage to the lungs and other organs; however, it is an expensive test. Lung ultrasound (LUS) has been shown to be a promising technique in that context as well, being useful in the screening and monitoring of patients, disease classification, and management related to mechanical ventilation. Moreover, LUS is an inexpensive alternative available at the bedside. Finally, magnetic resonance imaging, although not usually requested, allows the detection of pulmonary, cardiovascular, and neurological abnormalities associated with COVID-19. Furthermore, it is important to consider the challenges faced in the radiology field in the adoption of control measures to prevent infection and in the follow-up of post-COVID-19 patients.

Is minor surgery safe during the COVID-19 pandemic? A multi-disciplinary study

BACKGROUND

To assess the risk of postoperative SARS-CoV-2 infection during the COVID-19 pandemic.

METHODS

The CONCEPTION study was a cohort, multidisciplinary study conducted at Conception University Hospital, in France, from March 17th to May 11th, 2020. Our study included all adult patients who underwent minor surgery in one of the seven surgical departments of our hospital: urology, digestive, plastic, gynecological, otolaryngology, gynecology or maxillofacial surgery. Preoperative self-isolation, clinical assessment using a standardized questionnaire, physical examination, nasopharyngeal RT-PCR and chest CT scan performed the day before surgery were part of our active prevention strategy. The main outcome was the occurrence of a SARS-CoV-2 infection within 21 days following surgery. The COVID-19 status of patients after discharge was updated during the postoperative consultation and to ensure the accuracy of data, all patients were contacted again by telephone.

RESULTS

A total of 551 patients from six different specialized surgical Departments in our tertiary care center were enrolled in our study. More than 99% (546/551) of included patients underwent a complete preoperative Covid-19 screening including RT-PCR testing and chest CT scan upon admission to the Hospital. All RT-PCR tests were negative and in 12 cases (2.2%), preoperative chest CT scans detected pulmonary lesions consistent with the diagnosis criteria for COVID-19. No scheduled surgery was postponed. One patient (0.2%) developed a SARS-CoV-2 infection 20 days after a renal transplantation. No readmission or COVID-19 -related death within 30 days from surgery was recorded.

CONCLUSIONS

Minor surgery remained safe in the COVID-19 Era, as long as all appropriate protective measures were implemented. These data could be useful to public Health Authorities in order to improve surgical patient flow during a pandemic.

The role of computed tomography scan in the diagnosis of COVID-19 pneumonia

PURPOSE OF REVIEW

To summarize current literature evidence on the role of computed tomography (CT) scan in the diagnosis and assessment of coronavirus disease 2019 (COVID-19) pneumonia.

RECENT FINDINGS

Recent guidelines on the use of CT scans in COVID-19 vary between countries. However, the consensus is that it should not be used as the first line; a notion supported by the WHO. Currently, several investigations are being used including reverse transcription PCR testing, chest radiographs, and ultrasound scans, and CT scans. They are ideally performed later during the disease process as the sensitivity and specificity are highest by that time. Typical COVID-19 features on CT scans vary but include vascular enlargement, ground-glass opacities, and ground glass opacification together with consolidation.

SUMMARY

Since COVID-19 was declared as a global pandemic, there was a push towards identifying appropriate diagnostic tests that are both reliable and effective. There is a general agreement that CT scans have a high sensitivity but low specificity in diagnosing COVID-19. However, the quality of available studies is not optimal, so this must always be interpreted with the clinical context in mind. Clinicians must aim to weigh up the practicalities and drawbacks of CT scans when considering their use for a patient. The ease and speed of use of CT scans must be balanced with their high radiation doses, and infection control considerations.

Covid-19 and Ear Surgery: Treatment Strategies and Triage during the Post-lockdown Period

The accumulated disease burden during lockdown period, due to postponement of regular surgeries, is expected to put additional pressure on surgeons during the post-lockdown period. Due to the contagious nature of SARS-CoV-2 and its suspected presence in middle ear mucosa and mastoid, Ear surgeons are bound to face a challenging situation in present times as well as in times to come. Through this article we aim to streamline fresh management strategies particularly for the post-lockdown period keeping in mind that immunity after vaccination may take a few months to develop due to various factors discussed in the article. The ENT Cochrane, Pubmed and Web of Science databases were searched extensively using the terms ‘Covid-19 and SARS-CoV-2 in conjunction with Ear surgery and Otology. Data collected from these, put together with our experience helped us in putting forward fresh management strategies to deal with the current situation being experienced worldwide. To reduce the risk of infection to the healthcare staff, we have suggested a new triage strategy for ear surgeries to reduce the accumulated disease burden in the post-lockdown period until immunity by vaccination develops amongst a good number of Ear surgeons. Also we have put forward certain operating guidelines that might prove helpful for the Ear surgeon during these times. Fresh Triage guidelines mentioned in this article are particularly meant to help ear surgeons reduce the accumulated disease burden in the post lockdown-period with ease and efficacy. Since ear surgery poses a risk of infection to the healthcare workers, specific guidelines pertaining to ear surgery during the pandemic are mentioned in detail which in our opinion can be of immense help to all the healthcare professionals involved in ear procedures till the time the vaccine is administered on a large scale.

EACTA/SCA Recommendations for the Cardiac Anesthesia Management of Patients With Suspected or Confirmed COVID-19 Infection: An Expert Consensus From the European Association of Cardiothoracic Anesthesiology and Society of Cardiovascular Anesthesiologists With Endorsement From the Chinese Society of Cardiothoracic and Vascular Anesthesiology

The European Association of Cardiothoracic Anaesthesiology (EACTA) and the Society of Cardiovascular Anesthesiologists (SCA) aimed to create joint recommendations for the perioperative management of patients with suspected or proven severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection undergoing cardiac surgery or invasive cardiac procedures.

To produce appropriate recommendations, the authors combined the evidence from the literature review, reevaluating the clinical experience of routine cardiac surgery in similar cases during the Middle East Respiratory Syndrome (MERS-CoV) outbreak and the current pandemic with suspected coronavirus disease 2019 (COVID-19) patients, and the expert opinions through broad discussions within the EACTA and SCA. The authors took into consideration the balance between established procedures and the feasibility during the present outbreak. The authors present an agreement between the European and US practices in managing patients during the COVID-19 pandemic.

The recommendations take into consideration a broad spectrum of issues, with a focus on preoperative testing, safety concerns, overall approaches to general and specific aspects of preparation for anesthesia, airway management, transesophageal echocardiography, perioperative ventilation, coagulation, hemodynamic control, and postoperative care.

As the COVID-19 pandemic is spreading, it will continue to present a challenge for the worldwide anesthesiology community. To allow these recommendations to be updated as long as possible, the authors provided weblinks to international public and academic sources providing timely updated data.

This document should be the basis of future task forces to develop a more comprehensive consensus considering new evidence uncovered during the COVID-19 pandemic.

Preoperative nasopharyngeal swab testing and postoperative pulmonary complications in patients undergoing elective surgery during the SARS-CoV-2 pandemic

BACKGROUND

Surgical services are preparing to scale up in areas affected by COVID-19. This study aimed to evaluate the association between preoperative SARS-CoV-2 testing and postoperative pulmonary complications in patients undergoing elective cancer surgery.

METHODS

This international cohort study included adult patients undergoing elective surgery for cancer in areas affected by SARS-CoV-2 up to 19 April 2020. Patients suspected of SARS-CoV-2 infection before operation were excluded. The primary outcome measure was postoperative pulmonary complications at 30 days after surgery. Preoperative testing strategies were adjusted for confounding using mixed-effects models.

RESULTS

Of 8784 patients (432 hospitals, 53 countries), 2303 patients (26.2 per cent) underwent preoperative testing: 1458 (16.6 per cent) had a swab test, 521 (5.9 per cent) CT only, and 324 (3.7 per cent) swab and CT. Pulmonary complications occurred in 3.9 per cent, whereas SARS-CoV-2 infection was confirmed in 2.6 per cent. After risk adjustment, having at least one negative preoperative nasopharyngeal swab test (adjusted odds ratio 0.68, 95 per cent confidence interval 0.68 to 0.98; P = 0.040) was associated with a lower rate of pulmonary complications. Swab testing was beneficial before major surgery and in areas with a high 14-day SARS-CoV-2 case notification rate, but not before minor surgery or in low-risk areas. To prevent one pulmonary complication, the number needed to swab test before major or minor surgery was 18 and 48 respectively in high-risk areas, and 73 and 387 in low-risk areas.

CONCLUSION

Preoperative nasopharyngeal swab testing was beneficial before major surgery and in high SARS-CoV-2 risk areas. There was no proven benefit of swab testing before minor surgery in low-risk areas.