Centrifugal and Roller Pumps in Neonatal and Pediatric Extracorporeal Membrane Oxygenation: A Systematic Review and Meta-Analysis of Clinical Outcomes.

Extracorporeal membrane oxygenation (ECMO) is an invaluable means of supporting critically ill children with refractory respiratory or cardiac failure. Controversy remains; however, whether roller or centrifugal pumps are superior, particularly in infants. We performed a comprehensive search on PubMed, Embase, and Scopus for studies comparing the use of centrifugal and roller pumps in the pediatric and neonatal population from 1973 until March 1, 2020. All prospective and retrospective comparative studies were screened. Single-arm studies and those that included adult patients were excluded. The primary endpoint was survival to discharge. Secondary endpoints were complications (mechanical, cardiac, pulmonary, neurologic, renal, and hemolytic) and requirements for inotropic support. Random effects meta-analyses across all clinical endpoints were conducted. A total of four studies with 9111 patients were included. There was a statistically significant difference in in-hospital mortality, favoring the groups where roller pumps were used. Roller pumps were associated with fewer episodes of hemolysis, mechanical complications, cardiac complications, renal complications, and less inotropic support. ECMO with roller pumps may be associated with lower mortality in children. Roller pumps were associated with fewer complications, as well as reduced hemolysis and use of inotropes.

Partial Versus Complete Thymectomy in Non-Myasthenic Patients With Thymoma: A Systematic Review and Meta-Analysis of Clinical Outcomes.

OBJECTIVE: The optimal extent of surgical resection for non-myasthenic patients with thymoma is controversial. The objective of this meta-analysis was to compare complete to partial thymectomy in non-myasthenic patients for oncological and postoperative clinical outcomes. METHODS: We performed a PubMed and EMBASE search (from inception to January 2020) for English-language studies directly comparing partial thymectomy (thymomectomy) to complete thymectomy for thymoma resection. Clinical endpoints studied included overall and disease-free survival, Masaoka and World Health Organization staging, adjuvant therapy, postoperative complications, postoperative drainage, length of hospital stay, thymoma-related deaths, postresection development of myasthenia gravis, incomplete resection, and recurrence. Random effects meta-analyses across all clinical endpoints was done. RESULTS: There was no statistically significant difference between the two approaches with regard to recurrence (odds ratio [OR], 1.22; 95% confidence interval [CI], 0.78-1.92), completeness of resection (OR, 1.17; 95% CI, 0.66-2.10), adjuvant therapy (OR, 0.71; 95% CI, 0.40-1.26), or thymoma-related deaths (OR, 0.76; 95% CI, 0.12-4.66). There was a statistically significant decrease in postoperative complications (OR, 0.61; 95% CI, 0.39-0.97), drainage (mean difference [MD], -0.99; 95% CI, -1.98 to -0.01), and length of hospital length (MD, -1.88; 95% CI, -3.39 to -0.36) with partial thymectomy. CONCLUSIONS: The evidence appeared to suggest that partial thymectomy is oncologically equivalent to complete thymectomy for non-myasthenic patients with early-stage thymoma. There is an additional advantage of reduced postoperative complications and decreased length of hospital stay with partial thymectomy.

Anticoagulation After Isolated Mitral Valve Repair: A Systematic Review and Meta-Analysis of Clinical Outcomes.

Recommendations from international guidelines on optimal thromboprophylaxis after mitral repair are controversial and based on underpowered observational studies. This study aimed to evaluate the prophylactic use of warfarin after isolated mitral valve repair (MVr). A PubMed, EMBASE and Scopus search for studies in English on postoperative thromboprophylaxis for isolated MVr published to February 2020 was performed. The analysis excluded all studies with combined operations, mitral valve replacement and preoperative or postoperative atrial fibrillation. Clinical endpoints that were studied were thromboembolic events, bleeding complications and mortality. Random effects meta-analyses of the effect of postoperative warfarin use as compared with no warfarin use across all clinical endpoints was conducted. Warfarin use did not confer benefit in terms of thromboembolic prophylaxis after isolated MVr in patients without atrial fibrillation (OR, 0.97; 95% CI, 0.72-1.31). At the same time, it did not increase the risk of bleeding complications (OR, 1.10; 95% CI, 0.53-2.30) or affect overall survival during the follow-up period of the included studies (OR, 1.06; 95% CI, 0.28-4.05). To conclude, warfarin use is not necessary for patients after isolated MVr who remain in sinus rhythm. Recommendations from international guidelines may need to be revisited for this group of patients.

Organization of extracorporeal membrane oxygenation services for COVID-19.

BACKGROUND: Extracorporeal membrane oxygenation has been used for COVID-19 patients with refractory hypoxemia. METHODS: We share our institution's experience in organizing extracorporeal membrane oxygenation services in Singapore during the COVID-19 pandemic. We also share our first COVID-19 extracorporeal membrane oxygenation case report. RESULTS: We encountered initial difficulties in providing extracorporeal membrane oxygenation services in Singapore in view of the considerations of managing COVID-19 patients. By adopting rigorous planning, patient selection, staff training, adhering to infection control measures and preparing transport essentials, we were able to reorganize the extracorporeal membrane oxygenation services to serve the nation's needs. This culminated in our first successful COVID-19 extracorporeal membrane oxygenation retrieval case. CONCLUSIONS: Extracorporeal membrane oxygenation is an option for COVID-19 patients but preparation must be taken to prepare the extracorporeal membrane oxygenation teams to deal with this pandemic and future challenges.

Left heart bypass versus circulatory arrest for open repair of thoracoabdominal aortic pathologies.

BACKGROUND: Most large-volume centres use left heart bypass (LHB) as their preferred organ protection strategy during repair of descending thoracic aortic (DTA) and thoracoabdominal aortic (TAA) pathologies. We investigate the use of hypothermic circulatory arrest (HCA) for similar pathologies and compare the outcomes of both. METHODS: A PubMed, Embase and Scopus search for studies in English on LHB versus HCA for repair of DTA and TAA pathologies published from inception till February 2020 was performed. Our analysis excluded studies without direct comparison of the two organ protection strategies. Clinical endpoints that were studied were 30-day mortality, post-operative stroke, spinal cord deficit, renal failure and respiratory failure. Random effects meta-analyses of the effect of the two strategies across all clinical endpoints were conducted. RESULTS: HCA is non-inferior to LHB across all clinical endpoints. In terms of 30-day mortality (odds ratio (OR) 1.19, 95% confidence interval (CI) 0.31-4.59, P = 0.14, I2 = 49%), stroke (OR 0.41, 95% CI 0.12-1.39, P = 0.97, I2 = 0%), spinal cord deficit (OR 0.56, 95% CI 0.22-1.45, P = 0.78, I2 = 0%), renal failure (OR 1.33, 95% CI 0.37-4.76, P = 0.98, I2 = 0%) and respiratory failure (OR 0.86, 95% CI 0.37-1.97, P = 0.16, I2 = 46%), there was no statistically significant difference between the two cohorts. CONCLUSION: Evidence is limited, but suggests that HCA alone provides adequate organ protection during repair of DTA and TAA pathologies, and has equivalent outcomes when compared to LHB.

Assessment of Flow after Lower Extremity Endovascular Revascularisation: A Feasibility Study Using Time Attenuation Curve Analysis of Digital Subtraction Angiography.

OBJECTIVES: Endovascular revascularisation is the mainstay of the treatment of lower extremity peripheral arterial disease. Improvement in perfusion after treatment is often quantified by a corresponding increment in ankle or toe brachial indices. These measurements are difficult to obtain in patients with foot wounds, and have to be performed at a separate time and setting after revascularisation. This preliminary study aimed to evaluate the use of parametric colour coding and analysis of time attenuation curves as a real time quantitative measure of perfusion after endovascular revascularisation. METHODS: Forty-seven consecutive patients with critical limb ischaemia were retrospectively enrolled and analysed. Parametric colour coding and generation of time attenuation curves in the main pedal vessel was performed for pre- and post-intervention digital subtraction angiograms of each patient. The change in time attenuation curve parameters was compared with the change in ankle or toe brachial indices before and after intervention. RESULTS: Comparing before and after lower extremity endovascular intervention, there were significant changes in the washout parameters derived from the time attenuation curve. The percentage of contrast decay 4 seconds after peak (I 4s) demonstrated the strongest correlation (R = .482) with the change in ankle or toe brachial indices. CONCLUSIONS: Parametric colour coding and time attenuation curve analysis might be a helpful tool that can provide real time intra-procedural quantitative data on pedal perfusion which can improve clinical outcomes.

A Score for Predicting Acute Kidney Injury After Coronary Artery Bypass Graft Surgery in an Asian Population.

OBJECTIVE: To develop a scoring system to predict acute kidney injury in Asian patients after coronary artery bypass grafting. DESIGN: A retrospective analysis of data collected in an institutional cardiac database. SETTING: A tertiary academic hospital in a large metropolitan city. PARTICIPANTS: The study comprised 954 patients with coronary artery disease. INTERVENTIONS: All patients underwent coronary artery bypass surgery with cardiopulmonary bypass but did not undergo any other concomitant procedures. MEASUREMENTS AND MAIN RESULTS: The main outcome measured was acute kidney injury as defined by the Acute Kidney Injury Network criteria. The following 6 clinical variables were independent predictors of kidney injury: age>60 years, diabetes requiring insulin, estimated glomerular filtration rate<60 mL/min/1.73 m(2), ejection fraction<40%, cardiopulmonary bypass time>140 minutes, and aortic cross-clamp time>100 minutes. These variables were used to develop the Singapore Acute Kidney Injury score. CONCLUSION: The Singapore Acute Kidney Injury score is a simple way to predict, at the time of admission to the intensive care unit, an Asian patient's risk of developing acute kidney injury after coronary artery bypass surgery.

Contribution of stress to asthma worsening through mast cell activation.

OBJECTIVE: To review the available evidence linking stress to asthma and to investigate whether mast cells contribute to the effect of stress through activation by corticotropin-releasing hormone (CRH). DATA SOURCE: The PubMed database was searched for articles (1998-2011) using the keywords anxiety, asthma, exacerbation, inflammation, mast cells, socioeconomic status, stress, violence, and worsening. STUDY SELECTION: Articles were selected based on their relevance to the topic, with emphasis on clinical or epidemiologic data linking stress to asthma and studies that offered possible explanations for how stress may affect asthma. RESULTS: Many articles point to an association between stress (socioeconomic status, interpersonal conflicts, emotional distress, terrorism) and asthma exacerbations but without any distinct pathogenetic mechanism. A few articles have reported reduced circulating cortisol and/or sensitivity to corticosteroids. We propose that mast cells, known to be involved in the pathophysiology of asthma, can be activated by CRH, which is secreted under stress in the lungs, leading to selective release of proinflammatory mediators. This effect may be augmented by neuropeptides or cytokines. CRH also reduces T-regulatory cell production of interleukin 10, which in known to inhibit allergic mast cell activation. CONCLUSION: More studies are required to investigate lung levels of CRH and selective mast cell mediators. Reducing stress and using CRH receptor antagonists and/or mast cell blockers may serve as possible new therapeutic approaches for asthma.