Concurrent left ventricular myocardial diffuse fibrosis and left atrial dysfunction strongly predicts incident heart failure and all-cause mortality

Funding Acknowledgements

Type of funding sources: Foundation. Main funding source(s): British Heart Foundation

Academy of Medical Sciences

Background

LV myocardial interstitial fibrosis has been reported to influence LA morphology and function via LV remodelling and diastolic dysfunction. However, this association, as well as their combined influence on clinical outcomes remains poorly characterised.

Aim

To evaluate the relationship between left ventricular (LV) fibrosis quantified by native T1 times and left atrial (LA) global and phasic function and their impact on clinical outcomes.

Methods

A total of 40,818 UK Biobank participants with cardiovascular magnetic resonance data were included. Native T1 mapping was performed using Shortened Modified Look-Locker Inversion recovery sequence with global myocardial T1 estimated by an automatic segmentation framework. Ten parameters of LA phasic function were calculated from normalised LA volume-time curves derived by a three-dimensional sparse active shape model. LV parameters (mass, end-diastolic volume, and ejection fraction) were extracted by a fully convolutional neural network. Multivariable regression models were used to assess the associations between T1 and LA parameters. Lastly, survival analysis was performed to assess the interplay between T1, LA function and incident heart failure, atrial fibrillation, major adverse cardiovascular event (MACE) and all-cause mortality.

Results

The mean age of study population was 64.0 ± 7.7 years; 47.8% were men. Higher T1 values were associated with larger LA minimum size (Beta= 0.89ml per 100ms; 95% confidence interval (CI) = 0.62, 1.17), and lower LA global emptying fraction (Beta= -0.012 per 100ms; CI= -0.015, -0.010), LA reservoir function (Beta= -0.060 per 100ms; CI= -0.083, -0.037) and LA booster function (Beta= -0.014 per 100ms; CI= -0.017, -0.011). Among LA phasic functional parameters, LA booster function is most strongly associated with T1. Survival analysis revealed concurrent high T1 and low LA function had a significant influence on incident heart failure (Hazard Ratio [HR] = 2.99; CI=1.91,2.01), atrial fibrillation (HR = 4.86; CI=3.51-6.54), MACE (HR = 1.86; CI = 1.36-2.54) and all-cause mortality (HR = 1.86; CI=1.22-2.82) compared to either parameter alone, even after accounting for LV parameters (Figure 1).

Conclusion

This is the first study to robustly demonstrate the associations between myocardial diffuse fibrosis and reduced LA global and phasic functional measurements. We reveal the independent prognostic role of high T1 values accompanied by low LA function in predicting adverse clinical outcomes in a general population. These findings advance our understanding of the relationships between myocardial fibrosis and LA biomechanics at an early, subclinical stage, and highlight the additive value of incorporating these biomarkers into clinical decision making.

The association between native myocardial T1 relaxation times and left atrial phasic structure and function: the UK Biobank Imaging Enhancement study

Introduction

Left ventricular (LV) myocardial fibrosis is posited to result in left atrial (LA) changes via LV remodelling and diastolic dysfunction, though the association remains poorly characterised. Native myocardial T1 mapping is a non-invasive modality that quantifies diffuse myocardial fibrosis. This study examines the relationship between LV fibrosis (quantified by native T1 times) and LA function, drawing upon data from the UK Biobank.

Methods

40,818 participants underwent cardiovascular magnetic resonance (CMR) using steady-state free precession imaging at 1.5 Tesla. Native T1-mapping was performed using the Shortened Modified Look-Locker Inversion recovery technique (ShMOLLI), with global myocardial T1 estimated by an automatic segmentation framework. Nine parameters of LA phasic function were calculated (representing global, reservoir, conduit and booster components) from normalised LA volume-time curves. LV parameters (LV Mass, end-diastolic volume and ejection fraction) were extracted by a convolutional neural network. Multivariable logistic regression models were used to assess the association between T1 (exposure) and LA function (outcome). Mediation analysis was performed to assess the role of LV parameters as a mediator for the association between T1 and LA function. Lastly, potential non-linear relationships between T1 and LA function were investigated using Restrictive Cubic Spline (RCS) modelling, with model fit assessed via the Akaike Information Criterion (AIC).

Results

Higher T1 values were positively associated with larger LA volumes, and negatively associated with markers of LA global, reservoir and booster function. In the fully adjusted model, T1 was positively associated with larger LA minimum size (Beta: +0.034 SD per T1 SD; Confidence Interval (CI): 0.024, 0.045), and negatively associated with LA emptying volume (Beta: −0.017; CI: −0.027, −0.006), LA booster volume (Beta: −0.019; CI: −0.030, −0.008), LA emptying fraction (Beta: −0.052; CI: −0.062, −0.041), and LA reservoir function (Beta: −0.028; CI: −0.039, −0.017). Though adjustment for LV parameters did not fully attenuate the above relationships, LV parameters were consistent mediators between T1 and LA function, with proportional mediative effects ranging from 15% to 75%. Lastly, there is evidence of an inverted J-shaped relationship between T1 and LA function, with the associations becoming more apparent in the upper half of T1 ranges (turning points within 925–950 ms, median T1 = 930 ms) (p<0.05).

Conclusion

This study demonstrates a consistent association between higher native T1 values (as a marker of myocardial fibrosis) and lower LA global and phasic functions. We also highlighted an interplay between T1 values, LV remodelling and LA dysfunction. These findings will facilitate our understanding of the disease processes underlying cardiac dysfunction and myocardial remodelling at an early, subclinical stage.

Funding Acknowledgement

Type of funding sources: Public hospital(s). Main funding source(s): This work was part of the portfolio of translational research of the National Institute for Health Research Biomedical Research Centre at Barts and The London School of Medicine and DentistryDr Nay Aung is supported by a Wellcome Trust Research Training Fellowship (203553/Z/16/Z)

423 Endoscopic Balloon Dilatation for Paediatric Subglottic Stenosis: Systematic Review and Meta-Analysis

Aim

Subglottic stenosis (SGS) is a rare life-threatening condition that involves a narrowing of the airway. It may be congenital or acquired affecting children predominantly. Traditionally, it has been treated by surgical interventions, but in recent times a shift towards minimally invasive Endoscopic Balloon Dilatation (EBD) has been observed. This review aims to identify whether EBD is a safe approach in the treatment of SGS in the paediatric population.

Method

A systematic review was performed on EBD for paediatric SGS in compliance with the PRISMA guidelines. Studies published from 2000 onwards, with sample size greater than 5 and described EBD without adjuvant procedures were included. A meta-analysis of proportions was performed using the R software.

Results

25 studies were included, with a total of 1109 patients, of which 920 underwent EBD. The mean sample size of the studies is 43.48 (range 5–166), and the grand mean age is 3.77 years (range 0.7–17 years). Primary outcome assessed was technical success. A high overall technical success rate (successful decannulation and avoidance of tracheostomy/laryngotracheal reconstruction) was observed (83.95%, 95% CI [75.08% - 89.58%]). Similarly, low levels of mortality (3.29%, 95% CI [1.14% - 9.14%]), and high rates of symptom improvement (73.65%, 95% CI [57.81% - 85.09%]) were also observed.

Conclusion

EBD is a successful procedure in majority patients, with low levels of adverse events and marked symptom improvement. It is therefore a safe alternative to current procedures in the management of paediatric SGS.

Comparison of Multisystem Inflammatory Syndrome (MIS-C) and Dengue in Hospitalized Children

OBJECTIVE

Multisystem inflammatory syndrome (MIS-C) in children is a febrile illness that has overlapping presentation with other locally prevalent illnesses. Clinicolaboratory profile of children admitted with MIS-C and dengue were compared to understand their presentation at the outset.

METHODS

This was a retrospective study of children ≤ 12 y admitted with MIS-C (WHO definition) or laboratory-confirmed dengue between August 2020 and January 2021 at a tertiary center in North India.

RESULTS

A total of 84 children (MIS-C - 40; dengue - 44) were included. The mean (SD) age [83.5 (39) vs. 91.6 (35) mo] was comparable. Rash (72.5% vs. 22.7%), conjunctival injection (60% vs. 2.3%), oral mucocutaneous changes (27.5% vs. 0) and gallop rhythm (15% vs. 0) were seen more frequently with MIS-C, while petechiae [29.5% vs. 7.5%], myalgia (38.6% vs. 10%), headache (22.7% vs. 2.5%), and hepatomegaly (68.2% vs. 27.5%) were more common with dengue. Children with MIS-C had significantly higher C-reactive protein (124 vs. 3.2 mg/L) and interleukin 6 (95.3 vs. 20.7 ng/mL), while those with dengue had higher hemoglobin (12 vs. 10.2 g/dL) lower mean platelet count (26 vs. 140 × 10⁹/L), and greater elevation in aspartate (607 vs. 44 IU/L) and alanine (235.5 vs. 56 IU/L) aminotransferases. The hospital stay was longer with MIS-C; however, PICU stay and mortality were comparable.

CONCLUSION

In hospitalized children with acute febrile illness, the presence of mucocutaneous features and highly elevated CRP could distinguish MIS-C from dengue. The presence of petechiae, hepatomegaly, and hemoconcentration may favor a diagnosis of dengue.

Functional Outcomes in Survivors of Pediatric Sepsis: A Scoping Review and Discussion of Implications for Low- and Middle-Income Countries

BACKGROUND

Pediatric sepsis is an important cause of mortality and morbidity in low- and middle-income countries (LMIC), where there is a huge burden of infectious diseases. Despite shortage of resources, adapting protocol-based care has reduced sepsis-related deaths but survivors of pediatric sepsis are at risk of poor functional outcomes.

OBJECTIVES

To perform a scoping review of the literature on functional outcomes of pediatric sepsis survivors after discharge from the intensive care unit (ICU) and discuss the implications for patients in LMICs. The outcomes include prevalence of survival with reduced functional outcomes or quality of life (QoL) and changes over time during follow-up or recovery, and these outcomes were compared with other groups of children.

METHODS

We searched major medical electronic databases for relevant literature from January 2005 until November 2021, including Medline (via PubMed), Embase, CINAHL, and Google Scholar databases. We included observational studies and follow-up data from clinical trials involving children/adolescents (≤18 years) who were admitted to pediatric intensive care unit (PICU) and got discharged finally. Major focus was on survivors of sepsis in LMIC. We followed PRISMA guidelines for scoping reviews (PRISM-ScR).

RESULTS

We included eight papers reporting data of functional outcomes in 2,915 children (males = 53%, and comorbidity present in 56.6%). All included studies were either a prospective or retrospective cohort study. Studies were classified as Level II evidence. Disabilities affecting physical, cognitive, psychological, and social function were reported in children following discharge. Overall disability reported ranged between 23 and 50% at hospital discharge or 28 days. Residual disability was reported at 1, 3, 6, and 12 months of follow-up with an overall improving trend. Failure to recover from a baseline HRQL on follow-up was seen in one-third of survivors. Organ dysfunction scores such as pSOFA, PeLOD, vasoactive inotrope score, neurological events, immunocompromised status, need for CPR, and ECMO were associated with poor functional outcome.

CONCLUSIONS

The research on functional outcomes in pediatric sepsis survivors is scarce in LMIC. Measuring baseline and follow-up functional status, low-cost interventions to improve management of sepsis, and multidisciplinary teams to identify and treat disabilities may improve functional outcomes.

Postmortem Findings in Patients with COVID19 Using Multiple Organ Core Needle Biopsies

Introduction/Objective

The coronavirus disease 2019 (COVID19) pandemic had caused more than 500,000 deaths in the United States. Although it mainly manifests with respiratory symptoms, postmortem examination reveals that it is more of a systemic disease affecting mutliple body organs.

Methods/Case Report

Postmortem needle core biopsies from multiple organs were obtained from 9 patients who died at our institution in the months of April and May of 2020 due to a confirmed SARS-CoV-2 infection by RT-PCR testing of nasopharyngeal swabs. The core biopsies from body organs included lungs (8), liver (7), kidneys (5), heart (2), spleen (2), and brain (2). Histopathological examination was performed in conjunction with a set of special and immunohistochemical stains. Electron microscopy examination was also done in 4 cases.

Results (if a Case Study enter NA)

The cohort consisted of 6 males and 3 females with a mean age of 70.4 years (range: 68–79). The majority had comorbidities (8/9) and presented with respiratory symptoms (9/9). The most significant postmortem findings were mainly in the lungs, including alveolar hemorrhage, hyaline membranes, fibrin thrombi, intraalveolar macrophages, type-2 pneumocyte hyperplasia, and interstitial myofibroblast reaction and collagen deposition. Immunohistochemical stains showed predominance of T-lymphocytes with a mixture of CD4 and CD8 positive cells. Examination of liver showed minimal to marked microvesicular and macrovesicular steatosis and centrilobular congestion and necrosis. Tissue from kidneys revealed mild to severe acute tubular injury. Microglial activation and Alzheimer type-II astrocytosis were noted in brain, and mild white pulp depletion was seen in the spleen. Electron microscopy showed the presence of foreign bodies suspicious for viral particles ranging in size from 52.6 to 97.9 nm in 2/4 cases.

Conclusion

Our findings based on postmortem core needle biopsies confirm the observation that most severely affected patients have significant pulmonary pathology. However, other organs show findings that may lead to a better understanding of this disease. Postmortem examination will continue to be an invaluable tool for studying the pathologic manifestations of COVID-19.

Application of bench studies at the bedside to improve outcomes in the management of severe diabetic ketoacidosis in children-a narrative review

OBJECTIVE

In this review, we address a few key issues and the challenges faced in the management of severe diabetic ketoacidosis (DKA) in children, highlighting the existing standard of care, supported by evidence and bench studies.

BACKGROUND

The classic triad of DKA namely hyperglycemia, metabolic acidosis and ketonemia warrants immediate attention with fluids and insulin. Correction of dehydration in DKA is of utmost priority and the calculation of fluid volume and choice of fluid have remained a matter of debate. Insulin therapy, to halt the ketone production, in DKA has undergone wide variations in dose and preparation since its discovery. Although the mortality due to severe DKA has remarkably decreased, complications like cerebral edema and acute kidney injury (AKI) continue to haunt the intensivists and endocrinologists on a few occasions.

METHODS

We have selected a few important questions in the management of severe DKA in children, addressing the challenges, reviewing the studies, guidelines and bedside practices with evidence in this narrative review.

CONCLUSIONS

The focus of management should be to understand and normalise the deranged physiology rather than trying to get normal laboratory reports. This needs careful understanding of the pathogenesis and deriving conclusion from bench studies. With newer studies and evidence, guidelines are revised every few years. There is a trend towards more conservative therapy, with continuous and advanced monitoring. Switching to subcutaneous insulin and oral hydration is done as early as possible with clinical monitoring and resolution of DKA. Management of severe DKA in children can vary from simple fluid titration and insulin infusion in mild cases to a scenario with multiorgan dysfunction requiring intensive monitoring and advanced organ support. Individualisation of therapy to suit the needs with the available evidence and expertise is extremely essential.

Impact of Recent SARS-CoV-2 Infection on the Course and Severity of Dengue in Children: A Prospective Observational Study from North India

In 2020, a considerable overlap occurred between the COVID-19 pandemic and seasonal dengue transmission in India. This study aimed to evaluate the effects of acute or recent infection with SARS-CoV-2 on the course and outcomes of dengue fever in children. We prospectively enrolled 44 children with a clinical and laboratory diagnosis of dengue fever. Assessment of acute and recent SARS-CoV-2 infection was done using reverse transcription–polymerase chain reaction and IgG antibody through ELISA. Children were grouped based on evidence of SARS-CoV-2 exposure and clinical severity, and outcomes were compared. The median age of the study cohort was 96 months (interquartile range [IQR]: 69–129 months). Fever (98%), vomiting (78%), abdominal pain (68%), hepatomegaly (68%), and edema (32%) were the common features. About two-thirds (N = 30) had severe dengue; 20 (45%) had dengue shock. Liver dysfunction (58%) and acute kidney injury (25%) were other major organ dysfunctions. Nineteen (43%) children stayed in the pediatric intensive care unit for a median duration of 5 days (IQR: 2–11 days). None had acute SARS-CoV2 infection; however, IgG against SARS-CoV-2 was detected in 15 (34%) cases. Children with recent exposure to SARS-CoV-2 showed a trend toward a lower incidence of acute kidney injury, fewer organ dysfunctions, and a lower frequency of invasive ventilation. Four children (9%) died; none of the deaths were in the SARS-CoV-2–exposed group. The present study exposes preliminary evidence that dengue fever might follow a less severe course in children with recent exposure to SARS-CoV-2 infection. However, it is pertinent to understand the antigenic similarity and cross-protective antibody response between the two viruses and their clinical relevance.

Nasal End-tidal Carbon Dioxide Monitoring during Procedural Sedation: Is it time for Wider Adoption?

How to cite this article: Ravikumar N, Nallasamy K. Nasal End-tidal Carbon Dioxide Monitoring during Procedural Sedation: Is it time for Wider Adoption? Indian J Crit Care Med 2020;24(8):611-612.

0604 Comorbidities and Admission Rates in Inpatients Undergoing Sleep Studies

Introduction

Uncontrolled sleep-disordered breathing (SDB) and hypoventilation, which are common in COPD, CHF and obesity hypoventilation patients can lead to death and readmissions. It is unknown whether inpatient sleep studies to diagnose and optimize treatment improve care and prevent readmissions.

Methods

All patients > 18 years old with sleep studies while inpatient at Baystate Medical Center between October 2015 and September 2017 were included. Patient characteristics, comorbidities, sleep study diagnoses, and treatment recommendations were evaluated. Admission (inpatient or observation) and death rates were determined for 1-year before admit date and 1-year after discharge date of index admission.

Results

326 adult inpatients had 120 portable and 304 in-laboratory tests performed. Average age was 62.9±14.4, mean BMI was 37.2±12.3 and 56% were male. Principal diagnoses were CHF (50%), COPD (39%), both COPD and CHF (20%) and obesity hypoventilation (27%). 31 used PAP and 71 used oxygen prior to admission. Sleep diagnoses included OSA (73%), central sleep apnea (CSA) (29%), treatment emergent CSA (8%), hypoxia (48%), hypoventilation (41%), and normal or non-diagnostic (6%). Treatment recommendations included CPAP (25%), BiPAP (18%), BiPAP ST (3%), ASV (4%), iVAPS (22%), oxygen only (5%) and further titration (20%). The average length of stay was 11.6 ± 9.6 days. There was no difference in the percentage of patients who had an admission before or after their sleep study (53% vs 56%, respectively). In addition, no difference was seen in the median number of admissions before and after the sleep study (median=1.0, IQI=0-2, p=0.77). 90-day readmission rate was 19%. 14% died.

Conclusion

SDB, hypoxia and hypoventilation were common in inpatients evaluated with sleep studies with PAP therapy recommended in most patients. Further research is needed to determine whether inpatient testing and subsequent treatment can result in decreased readmissions and death.

Support

None

Continuous Venovenous Hemofiltration as a Rescue Therapy for Severe Acetaminophen Toxicity in a Toddler

Acetaminophen poisoning is one of the common accidental poisoning in children. Accidental administration of mismatched doses of drops for syrups can lead to life-threatening overdose. N-acetylcysteine (NAC) is the specific antidote; however, extracorporeal therapy such as continuous venovenous hemofiltration (CVVH) can be used as a rescue measure when there is no improvement despite adequate NAC therapy and can be lifesaving. We reported an 18-month-old male infant patient who presented with acetaminophen poisoning following accidental ingestion of acetaminophen drops in place of syrup and developed fulminant hepatic failure. Treatment with NAC did not lead to improvement and CVVH was used as a rescue therapy for 24 hours which led to dramatic clinical and biochemical improvement with intact neurological outcome.

Novel Coronavirus 2019 (2019-nCoV) Infection: Part II - Respiratory Support in the Pediatric Intensive Care Unit in Resource-limited Settings

The 2019-novel coronavirus predominantly affects the respiratory system with manifestations ranging from upper respiratory symptoms to full blown acute respiratory distress syndrome (ARDS). It is important to recognize the risk factors, categorize severity and provide early treatment. Use of high flow devices and non-invasive ventilation has been discouraged due to high chances of aerosol generation. Early intubation and mechanical ventilation areessential to prevent complications and worsening, especially in resource-limited settings with very few centers having expertise to manage critical cases. Hydrophobic viral filter in the ventilator circuit minimizes chances of transmission of virus. Strategies to manage ARDS in COVID-19 include low tidal volume ventilation with liberal sedation-analgesia. At the same time, prevention of transmission of the virus to healthcare workers is extremely important in the intensive care setting dealing with severe cases and requiring procedures generating aerosol. We, herein, provide guidance on non-invasive respiratory support, intubation and management of ARDS in a child with COVID-19.

Novel Coronavirus 2019 (2019-nCoV) Infection: Part I - Preparedness and Management in the Pediatric Intensive Care Unit in Resource-limited Settings

First reported in China, the 2019 novel coronavirus has been spreading across the globe. Till 26 March, 2020, 416,686 cases have been diagnosed and 18,589 have died the world over. The coronavirus disease mainly starts with a respiratory illness and about 5-16% require intensive care management for acute respiratory distress syndrome (ARDS) and multi-organ dysfunction. Children account for about 1-2% of the total cases, and 6% of these fall under severe or critical category requiring pediatric intensive care unit (PICU) care. Diagnosis involves a combination of clinical and epidemiological features with laboratory confirmation. Preparedness strategies for managing this pandemic are the need of the hour, and involve setting up cohort ICUs with isolation rooms. Re-allocation of resources in managing this crisis involves careful planning, halting elective surgeries and training of healthcare workers. Strict adherence to infection control like personal protective equipment and disinfection is the key to contain the disease transmission. Although many therapies have been tried in various regions, there is a lack of strong evidence to recommend anti-virals or immunomodulatory drugs.

Novel Coronavirus 2019 (2019-nCoV) Infection: Part II - Respiratory Support in the Pediatric Intensive Care Unit in Resource-limited Settings

The 2019-novel coronavirus predominantly affects the respiratory system with manifestations ranging from upper respiratory symptoms to full blown acute respiratory distress syndrome (ARDS). It is important to recognize the risk factors, categorize severity and provide early treatment. Use of high flow devices and non-invasive ventilation has been discouraged due to high chances of aerosol generation. Early intubation and mechanical ventilation areessential to prevent complications and worsening, especially in resource-limited settings with very few centers having expertise to manage critical cases. Hydrophobic viral filter in the ventilator circuit minimizes chances of transmission of virus. Strategies to manage ARDS in COVID-19 include low tidal volume ventilation with liberal sedation-analgesia. At the same time, prevention of transmission of the virus to healthcare workers is extremely important in the intensive care setting dealing with severe cases and requiring procedures generating aerosol. We, herein, provide guidance on non-invasive respiratory support, intubation and management of ARDS in a child with COVID-19.

Novel Coronavirus 2019 (2019-nCoV) Infection: Part I - Preparedness and Management in the Pediatric Intensive Care Unit in Resource-limited Settings

First reported in China, the 2019 novel coronavirus has been spreading across the globe. Till 26 March, 2020, 416,686 cases have been diagnosed and 18,589 have died the world over. The coronavirus disease mainly starts with a respiratory illness and about 5-16% require intensive care management for acute respiratory distress syndrome (ARDS) and multi-organ dysfunction. Children account for about 1-2% of the total cases, and 6% of these fall under severe or critical category requiring pediatric intensive care unit (PICU) care. Diagnosis involves a combination of clinical and epidemiological features with laboratory confirmation. Preparedness strategies for managing this pandemic are the need of the hour, and involve setting up cohort ICUs with isolation rooms. Re-allocation of resources in managing this crisis involves careful planning, halting elective surgeries and training of healthcare workers. Strict adherence to infection control like personal protective equipment and disinfection is the key to contain the disease transmission. Although many therapies have been tried in various regions, there is a lack of strong evidence to recommend anti-virals or immunomodulatory drugs.

Impacted Pen Cap in Pharynx Leading to Pharyngojugular and Pharyngocutaneous Fistula in an Infant

Foreign body-related injuries to aerodigestive tract and large neck vessels are rare but can be catastrophic if not identified and treated in time. We report an infant with impacted foreign body (pen cap) in the pharynx which went unnoticed until it led to the formation of a fistula with the internal jugular vein (IJV) and massive hemorrhage. His course was complicated by ventilator-associated pneumonia, air leaks, shock, acute kidney injury, prolonged mechanical ventilation, and pharyngocutaneous fistula. The surgical removal of foreign body, ligation of IJV, closure of pharyngeal defect, and supportive treatment in pediatric intensive care unit led to a favorable outcome. This is the first case of pharyngojugular and pharyngocutaneous fistula following an impacted foreign body in the pharynx.

Comparative Evaluation of Fracture Resistance of Root Dentin Treated with Calendula Officinalis L. and Calcium Hydroxide as Intracanal Medicaments- An In vitro Study

Introduction: Intracanal Medicaments (ICMs) play a major role in disinfection of root canal system. The use of interappointment ICM during endodontic treatment may affect the mechanical properties of dentin which results in decreased fracture resistance of teeth. The use of synthetic medicament is associated with many limitations such as antibiotic overdose, side effects and cytotoxic reactions. In order to overcome this, recent research has been directed towards herbal ICMs with better efficacy and lesser side effects. Aim: To evaluate the effect of a novel herbal ICM Calendula officinalis L. (CO) on fracture resistance of root dentin in comparison to Calcium Hydroxide (CH). Materials and Methods: This in vitro study was conducted in the Department of Conservative Dentistry and Endodontics, SRM Dental College and Hospital, Ramapuram, Chennai, Tamil Nadu. Thirty freshly extracted single rooted human premolar teeth were selected for the in vitro study and randomly assigned into three groups: Group 1: No medication (Control group) (n=10), Group 2: CH (n=10), Group 3: CO (n=10). The samples were decoronated and biomechanical preparation was done followed by placement of respective ICMs in the root canal space, sealed with glass ionomer cement and immersed in saline for a storage period of 7 and 14 days. Each group was subdivided into 5 teeth, depending on the storage period. After each storage period, ICMs were removed and samples were subjected to fracture resistance test using universal testing machine. Data were analysed using One-way Anova followed by Tukey HSD post-hoc test with level of statistical significance set at p<0.05. Results: On evaluation of compressive strength, CO group showed more fracture resistance compared to CH group on 7th day and no statistical significant differences were seen between CO and CH groups on 14th day. Conclusion: CO can be efficiently used as an alternative to CH because of its low toxicity and increased resistance to fracture.

Nanochitosan modified glass ionomer cement with enhanced mechanical properties and fluoride release

Conventional glass-ionomer cements (GIC) are one of the most prevalent dental restorative materials, but their use is limited by their relatively low mechanical strength. Efforts have been made to improve the mechanical properties by addition of various fillers of which nano-sized particles appears to be a promising strategy. In the current study, effect of addition of nanochitosan particles in GIC (NCH-GIC) on compressive strength, flexural strength, wear resistance and fluoride release has been evaluated and compared with conventional GIC (C-GIC). Nanochitosan was synthesized by ionic cross linking method and its particle size was found to be 110-235nm. Nanochitosan was mixed with glass ionomer powder at a concentration of 10wt.% and cement samples were prepared. NCH-GIC had significantly higher compressive strength values which could be attributed to early formation of aluminium polysalts. Similarly, flexural strength of NCH-GIC (21.26MPa) was significantly higher than C-GIC (12.67MPa). Wear resistance was also found to increase due to better integrated interface between the glass particle and polymer matrix bonding in NCH-GIC. Fluoride release was significantly higher in NCH-GIC compared to C-GIC for 7 days. It can be anticipated that addition of nanochitosan to GIC will improve the anti-cariogenic and mechanical properties for high strength applications.

The effects of severe iron-deficiency anaemia on maternal and neonatal outcomes: A case-control study in an inner-city London hospital

This case-control study investigates the effects of severe iron-deficiency anaemia in pregnancy on maternal and neonatal outcomes in a relatively deprived inner-city population in a North London hospital. The study group comprised of 106 women with haemoglobin (Hb) < 8 g/dl at any point during pregnancy, while controls were 106 women with Hb > 11 g/dl throughout pregnancy. The study group lost an average of 80 ml more blood at delivery (p = 0.032) and had higher rates of postpartum haemorrhage than the control group (27 vs 12 patients, p = 0.012). However, anaemia did not appear to influence other maternal or neonatal outcomes; these may have been confounded by antenatal intervention with oral haematinics or blood transfusion.

3,3'-[(4-Nitro-phen-yl)methyl-ene]bis-(4-hy-droxy-2H-chromen-2-one)

The molecular conformation of the title compound, C(25)H(15)NO(8), is stabilized by strong intramolecular O-H⋯O hydrogen bonds, resulting in the formation of S(1) (1)(7) ring motifs. In the crystal, π-π stacking inter-actions are observed between adjacent nitrobenzene and pyranone rings with a centroid-centroid distance of 3.513 (12) Å. The dihedral angles between the nitrobenzene ring and the coumarin ring systems are 65.61 (8) and 66.11 (8)° while the coumarin ring systems are inclined at 65.69 (8)°.

Shear bond strengths of two dentin bonding agents with two desensitizers: An in vitro study

AIM

The aim of this in vitro study was to compare the shear bond strengths of two different dentin bonding agents with two different desensitizers.

MATERIALS AND METHODS

Eighty molars were taken which were ground to expose the dentin. The teeth were divided into two major groups. Each major group was subdivided into four subgroups of 10 samples each. Groups Ia and IIa were treated as dry bonding groups, groups Ib and IIb were treated as a moist bonding groups, groups Ic and IIc were rewetted with Gluma desensitizer, and groups Id and IId were rewetted with vivasens desensitizer. Major group I was treated with Gluma comfort bond and Charisma. Major group II was treated Prime and Bond NT and TPH. The samples were thermo cycled and shear bond test was performed using an Instron machine. The data were analyzed using one-way analysis of variance and Tukey's Honestly significant different test.

RESULTS

The results revealed that the specimens rewetted with Gluma desensitizer showed the highest shear bond strength compared to all other groups, irrespective of the bonding agent or composite resin used.

CONCLUSIONS

It can be concluded that rewetting with desensitizer provided better bond strength than the other groups.

(Z)-2-(4-Nitro-benzyl-idene)-1-benzofuran-3(2H)-one

In the crystal structure of the title compound, C(15)H(9)NO(4), weak C-H⋯O inter-actions generate rings with R(2) (2)(8) motifs. The supra-molecular aggregation is completed by the presence of C-H⋯O and van der Waals inter-actions.

Trends in the obstetric features and management of twin pregnancies

There are no reports outlining the trends in obstetric features and clinical management of twin pregnancies in an Irish obstetric population. The aim of this study was to investigate these factors for all twin pregnancies delivered during the 19 year period between 1989 and 2007, at Galway University Hospital (GUH). There were 52,199 infants delivered at GUH, of which 1594 infants (3.05% of births) were twins, related to 797 twin pregnancies. The overall incidence of twin pregnancies was 1.52%, increasing from 0.8%-1.0% in the early years of the study to 1.7-1.8% in the latter years of the study (P<0.001). There was a significant increase in incidence of twins born to mothers aged 30-39 years, alongside a significant reduction to mothers aged 20-29 years (P<0.01). The caesarean section rate overall was 41.5% (331/797), of which 54% (n=179) were elective, and 46% (n=152) were emergency, representing an emergency caesarean section rate of 19.1% of all twin pregnancies, and of 24.6% after exclusion of elective caesarean sections. The caesarean section rate for twins increased from 30% in 1989 to greater than 50% in the latter years of the study (P<0.01), related largely to a significant increase in elective caesarean sections (P<0.01). The combined vaginal-caesarean delivery rate was remarkably low at 0.75% of all twin pregnancies, and 1% after exclusion of elective caesarean sections. The preterm delivery rates were 4.1% (<32 weeks), and 16.3% (<36 weeks), with an overall perinatal mortality rate of 37 per 1000. These findings highlight the altered demographic and clinical aspects of twin pregnancies in an Irish obstetric population.