Factors predicting length of stay in bronchiolitis

Acute viral bronchiolitis phenotype in response to glucocorticoid and bronchodilator treatment

OBJECTIVE

To analyze whether infants admitted to hospital with Acute Viral Bronchiolitis (AVB), who received glucocorticoids and bronchodilators, and who had an atopic phenotype, spent less time in hospital and/or less time on oxygen therapy when compared to those who did not have the phenotype.

METHOD

A cross-sectional, retrospective epidemiological study was developed with data from medical records of infants admitted to hospital due to AVB from 2012 to 2019 in a sentinel public hospital. It was verified that the frequency of prescription of glucocorticoids, bronchodilators and antibiotics. Length of stay and oxygen therapy duration were then compared in the group that used glucocorticoids and bronchodilators between those who had a personal or family history of atopy and those who did not. Subsequently, the length of hospital stay was compared among infants who received antibiotic therapy and those who did not.

RESULTS

Fifty-eight infants were included. Of these, 62.1 % received an antibiotic, 100 % a bronchodilator and 98.3 % a glucocorticoid. When comparing infants without a family history of atopy, those who received antibiotics had a longer hospital stay (p = 0.01).

CONCLUSION

The presence of an atopic phenotype did not interfere with the length of stay and/or oxygen therapy duration of those who received bronchodilators and glucocorticoids. Increased length of stay of infants without a family history of atopy, who used antibiotics without evidence of bacterial co-infection, and the high frequency of prescription of non-recommended drugs call attention to stricter protocol implementation and professional training in AVB diagnosis and care.

Does weight influence the course of RSV bronchiolitis in hospitalized infants?

Acute bronchiolitis is among the most common causes of hospitalizations in infants worldwide. Associations between weight and severity of respiratory syncytial virus (RSV) bronchiolitis remain unclear. The aim of this study was to evaluate this association. A single-center, retrospective cohort study of infants aged under 24 months, who were hospitalized between 2018 and 2022 for RSV bronchiolitis. Data from computerized medical records were extracted using the MDclone platform. Participants were divided into three groups according to weight percentiles: underweight (below 5th percentile), normal-weight, and overweight (above 85th percentile). A total of 1936 infants (mean age 6.3 months, 55% males) were included, comprising 274 infants who were underweight, 1470 with normal weight, and 192 with overweight. Underweight infants had a higher rate of admission to the pediatric intensive care unit (PICU) (9.1% vs. 3.5%, P < 0.005) and prolonged length of stay (LOS) in the hospital (3.13 vs. 2.79 days P < 0.001) compared to those with normal weight. Hyponatremia was also more common in the underweight group (23% vs. 15%, P < 0.001). A multivariable model accounting for prematurity and birthweight predicted a relative risk of 2.01 (95% CI 1.13-3.48, P = 0.015) for PICU admission and 1.42 (95% CI 1.17-1.7, P < 0.001) for a prolonged LOS. Being overweight was not associated with a more severe disease.  Conclusion: Underweight infants, hospitalized for RSV bronchiolitis, had a more severe disease course with a higher complication rate, including PICU admission and prolonged LOS. Thus, careful attention and supervision should be given to this subgroup of infants. What is Known: • Established risk factors for severe bronchiolitis include prematurity, BPD, CHD, and compromised immunity. • Abnormal weight status has been associated with an increased risk for morbidity and mortality from infectious diseases, proposedly due to the effects on endocrine and immunologic systems. What is New: • Underweight infants hospitalized with RSV bronchiolitis face an independent risk of PICU admission and prolonged hospital stay. • Conversely, overweight infants did not display associations with severity measures in our study.

Synthetic data in cancer and cerebrovascular disease research: A novel approach to big data

OBJECTIVES

Synthetic datasets are artificially manufactured based on real health systems data but do not contain real patient information. We sought to validate the use of synthetic data in stroke and cancer research by conducting a comparison study of cancer patients with ischemic stroke to non-cancer patients with ischemic stroke.

DESIGN

retrospective cohort study.

SETTING

We used synthetic data generated by MDClone and compared it to its original source data (i.e. real patient data from the Ottawa Hospital Data Warehouse).

OUTCOME MEASURES

We compared key differences in demographics, treatment characteristics, length of stay, and costs between cancer patients with ischemic stroke and non-cancer patients with ischemic stroke. We used a binary, multivariable logistic regression model to identify risk factors for recurrent stroke in the cancer population.

RESULTS

Using synthetic data, we found cancer patients with ischemic stroke had a lower prevalence of hypertension (52.0% in the cancer cohort vs 57.7% in the non-cancer cohort, p<0.0001), and a higher prevalence of chronic obstructive pulmonary disease (COPD: 8.5% vs 4.7%, p<0.0001), prior ischemic stroke (1.7% vs 0.1%, p<0.001), and prior venous thromboembolism (VTE: 8.2% vs 1.5%, p<0.0001). They also had a longer length of stay (8 days [IQR 3-16] vs 6 days [IQR 3-13], p = 0.011), and higher costs associated with their stroke encounters: $11,498 (IQR $4,440 -$20,668) in the cancer cohort vs $8,084 (IQR $3,947 -$16,706) in the non-cancer cohort (p = 0.0061). A multivariable logistic regression model identified 5 predictors for recurrent ischemic stroke in the cancer cohort using synthetic data; 3 of the same predictors identified using real patient data with similar effect measures. Summary statistics between synthetic and original datasets did not significantly differ, other than slight differences in the distributions of frequencies for numeric data.

CONCLUSION

We demonstrated the utility of synthetic data in stroke and cancer research and provided key differences between cancer and non-cancer patients with ischemic stroke. Synthetic data is a powerful tool that can allow researchers to easily explore hypothesis generation, enable data sharing without privacy breaches, and ensure broad access to big data in a rapid, safe, and reliable fashion.

Association of Socioeconomic Factors and Severity of Bronchiolitis Hospitalizations

It is unclear if socioeconomic status (SES) factors influence severity of illness of patients hospitalized with bronchiolitis. This study was conducted to identify SES factors including the Center for Disease Control and Prevention's Social Vulnerability Composite Index (SVI), estimated income, proportion of minority, proportion of living below poverty, insurance status, and number of household members associated with length of stay (LOS) and intensive care unit admission. Infants hospitalized at a tertiary care urban center for bronchiolitis were identified using International Classification of Diseases codes. Federal information processing system codes were identified from home address and paired with SVI and 2018 census tract. Other measures of SES were obtained from the Federal Financial Institutions Examination Council. Number of household members, insurance, age, sex, and history of prematurity were recorded from patient chart. Length of stay was modeled with mixed effects negative binomial regression and pediatric intensive care unit (PICU) admission with mixed effects logistic regression with random intercept at the census tract and adjustment for clinical factors. A total of 417 infants had median age of 144 days (interquartile range (IQR): 61, 357) and 136 (33%) were born premature. Median LOS was 62 hours (24, 136) with 97 (23%) patients admitted to the PICU. Median household members were 4 (4, 5). For each increase in household member, there was 7% increase in LOS (incidence rate ratio 1.07, 95% confidence interval: 1-1.14, P = .038). Social Vulnerability Composite Index, subcategories, insurance status, estimated income, percent of minority, and percent of poverty did not show any associations with length of hospitalization or PICU admission. Increasing number of household members may be associated with increased bronchiolitis hospital LOS. We find no associations with other SES measures.

Monocyte and neutrophil to lymphocyte ratios in hospitalized children with RSV bronchiolitis

OBJECTIVE

Acute bronchiolitis is the most common cause of hospitalization in young children. Data on monocyte-to-lymphocyte-ratio (MLR) and neutrophil-to-lymphocyte-ratio (NLR) as biomarkers are limited. We aim to evaluate these ratios in children hospitalized with respiratory syncytial virus (RSV) bronchiolitis and their value as biomarkers for severe clinical outcomes.

STUDY DESIGN

A single-center retrospective cohort study of children aged <2 years hospitalized due to RSV bronchiolitis, between January 2018 and March 2022, with a complete blood count upon admission. We divided the cohort into quartiles based on MLR and NLR values. We examined associations between quartiles and four clinical severity outcomes.

RESULTS

A total of 2038 children (median age: 4.4 months, IQR: 1.9-9.8) were included in the study. The median MLR and NLR values for quartiles 1-4 were 0.14, 0.22, 0.30, 0.47, and 0.37, 0.70, 1.16, 2.29, respectively. Children with higher MLR had higher hospitalization rates to the pediatric intensive care unit (PICU) (Q1 2.4%, Q4 9.4%, p < .001), extended hospital stays (Q1 19.4%, Q4 32%, p < .001), and lower minimal oxygen saturation (Q1 90%, Q4 87%, p < .001). Cut-off values of 0.34 for MLR and 0.67 for NLR optimally identified PICU admissions. In a model accounting for age and sex, the fourth MLR quartile had an RR of 3.4 (95% CI: 1.76-7.22) and successfully predicted PICU admissions (area under the curve = 0.73; 95% CI: 0.681-0.789).

CONCLUSIONS

MLR and NLR are potential biomarkers for identifying children with RSV bronchiolitis at a higher risk for severe outcomes, specifically PICU admission.

Development and validation of a nomogram for predicting severe respiratory syncytial virus-associated bronchiolitis

BACKGROUND

Respiratory syncytial virus (RSV) is the most common cause of bronchiolitis and is related to the severity of the disease. This study aimed to develop and validate a nomogram for predicting severe bronchiolitis in infants and young children with RSV infection.

METHODS

A total of 325 children with RSV-associated bronchiolitis were enrolled, including 125 severe cases and 200 mild cases. A prediction model was built on 227 cases and validated on 98 cases, which were divided by random sampling in R software. Relevant clinical, laboratory and imaging data were collected. Multivariate logistic regression models were used to determine optimal predictors and to construct nomograms. The performance of the nomogram was evaluated by the area under the characteristic curve (AUC), calibration ability and decision curve analysis (DCA).

RESULTS

There were 137 (60.4%) mild and 90 (39.6%) severe RSV-associated bronchiolitis cases in the training group (n = 227) and 63 (64.3%) mild and 35 (35.7%) severe cases in the validation group (n = 98). Multivariate logistic regression analysis identified 5 variables as significant predictive factors to construct the nomogram for predicting severe RSV-associated bronchiolitis, including preterm birth (OR = 3.80; 95% CI, 1.39-10.39; P = 0.009), weight at admission (OR = 0.76; 95% CI, 0.63-0.91; P = 0.003), breathing rate (OR = 1.11; 95% CI, 1.05-1.18; P = 0.001), lymphocyte percentage (OR = 0.97; 95% CI, 0.95-0.99; P = 0.001) and outpatient use of glucocorticoids (OR = 2.27; 95% CI, 1.05-4.9; P = 0.038). The AUC value of the nomogram was 0.784 (95% CI, 0.722-0.846) in the training set and 0.832 (95% CI, 0.741-0.923) in the validation set, which showed a good fit. The calibration plot and Hosmer‒Lemeshow test indicated that the predicted probability had good consistency with the actual probability both in the training group (P = 0.817) and validation group (P = 0.290). The DCA curve shows that the nomogram has good clinical value.

CONCLUSION

A nomogram for predicting severe RSV-associated bronchiolitis in the early clinical stage was established and validated, which can help physicians identify severe RSV-associated bronchiolitis and then choose reasonable treatment.

Bronchiolitis before and after the SARS-CoV-2 pandemic: Twelve years of experience in a Spanish paediatric hospital

INTRODUCTION

Acute bronchiolitis is the main cause of hospitalization in children under 2 years of age, with a regular seasonality, mostly due to the respiratory syncytial virus.

OBJECTIVES

To describe the epidemiology of bronchiolitis hospitalizations in our center in the last 12 years, and analyze the changes in clinical characteristics, microbiology, and adverse outcomes during the SARS-CoV-2 pandemic.

METHODS

Observational study including patients admitted for bronchiolitis between April 2010 and December 2021 in a Spanish tertiary paediatric hospital. Relevant demographic, clinical, microbiological, and adverse outcome variables were collected in an anonymized database. The pandemic period (April 2020 to December 2021) was compared to 2010-2015 seasons using appropriate statistical tests.

RESULTS

There were 2138 bronchiolitis admissions, with a mean of 195.6 per year between 2010 and 2019 and a 2-4-month peak between November and March. In the expected season of 2020, there was a 94.4% reduction of bronchiolitis hospitalizations, with only 11 cases admitted in the first year of the pandemic. Bronchiolitis cases increased from the summer of 2021 during a 6-month long peak, reaching a total of 171 cases. Length of stay was significantly shorter during the pandemic, but no differences were found in clinical and microbiological characteristics or other adverse outcomes.

CONCLUSIONS

The SARS-CoV-2 pandemic has modified the seasonality of bronchiolitis hospitalizations, with a dramatic decrease in cases during the expected season of 2020-2021, and an extemporaneous summer-autumn peak in 2021 with longer duration but similar patient characteristics and risk factors.

Child characteristics and health conditions associated with paediatric hospitalisations and length of stay: a population-based study

Background

Paediatric hospital length of stay (LoS) is often used as a benchmark for resource use of hospitalisations. Previous studies have mostly focused on LoS of admissions for specific conditions or medical specialties. We aimed to conduct an evaluation of LoS of all paediatric hospitalisations exploring the frequency and characteristics; and associated childhood conditions.

Methods

This population-based cross-sectional study included all hospital admissions in children aged <16 years between January 2017 and December 2019 in New South Wales, Australia. LoS was categorised into: day or overnight stay, 2-7, 8-21 and ≥ 22 days. Socio-demographic and health service characteristics of each individual admission by LoS and age groups were evaluated.

Findings

A total of 324,083 children had 518,768 admissions comprising 1,064,032 bed days. Most admissions wereday/overnight stays (71.9%) or 2-7 days (25.3%). While LoS >7 days represented 2.8% of total admissions, they accounted for 27% of total bed days. Children aged 1-4 years had the highest proportion of admissions (35%), with a majority lasting ≤7 days, whereas 45.6% of admissions ≥22 days were for children aged ≥12 years. Respiratory conditions, diseases of the digestive system and traumatic injuries were the most common reasons for hospitalization. LoS >7 days were more common in children from most disadvantaged backgrounds, residing further from hospital and those aged ≥12 years with mental health conditions.

Interpretation

The majority of paediatric hospitalizations are for short stay and require programs that target acute conditions that can be managed in primary care. Interventions such as care coordination, tailored models of care and enhanced outpatient/community treatment programs for high-risk groups will help reduce extended LoS and improving child health and well-being.

Funding

Australian National Health and Medical Research Council.

Overweight Infants Hospitalized for Bronchiolitis Associated With Severe Disease

OBJECTIVES

Overweight negatively affects pediatric respiratory function. In this study, we evaluate if overweight is associated with more severe bronchiolitis in hospitalized infants.

METHODS

This retrospective cohort study analyzed infants aged 30 to 365 days hospitalized for bronchiolitis from September 2019 to April 2020. Exclusion criteria included known risk factors for severe bronchiolitis, asthma treatment, or bacterial pneumonia. Weight-for-length z-score was categorized per the World Health Organization's growth assessments as overweight (z-score >2), underweight (z-score <-2), and standard weight (between -2 and ≤2). Primary outcomes included respiratory support, ICU stay, and local bronchiolitis score. Secondary outcomes included supplemental interventions.

RESULTS

After exclusion criteria, 385 of 644 infants were categorized as overweight (n = 24), standard (n = 335), or underweight (n = 26). There were differences in need for respiratory support (overweight, 100%; standard weight, 81.8%; underweight, 76.9%; P = .03), highest support of high-flow nasal cannula (overweight, 75%; standard weight, 48%; underweight, 42%; P = .03), admission to ICU (overweight, 54.2%; standard weight, 21.5%; underweight, 34.7%; P < .001), and median bronchiolitis score (overweight, 8 [interquartile range 5-10]; standard weight, 4 [3-7]; underweight, 4 [3-7]; P = .01). Findings remained significant after age adjustments. Additionally, overweight experienced higher frequency of certain treatments.

CONCLUSIONS

This study suggests overweight is associated with more severe bronchiolitis in hospitalized infants supported by increased respiratory support level, bronchiolitis scores, and interventions. Higher need for ICU admission may be related to high-flow nasal cannula limitations on the acute care floor.

Vitamin D and Healthcare Service Utilization in Children: Insights from a Machine Learning Approach

Vitamin D deficiency and insufficiency is a global health issue: an association has been demonstrated between vitamin D deficiency and a myriad of acute and chronic illnesses. Data regarding vitamin D status among children hospitalized with non-critical illnesses are scanty. We aimed to: (1) identify profiles of children hospitalized due to non-critical illnesses, using vitamin D levels as the driving outcome; (2) assess the association between patient profiles and length of stay. The study included 854 patients (1−17 years old) who underwent blood tests for detecting vitamin D levels. A regression tree was used to stratify patients. The relationship between vitamin D levels and length of stay was explored using Poisson regression. The regression tree identified three subgroups. Group A (16%): African, North African, Hispanic, and Indian patients. Group B (62%): Caucasian and Asian patients hospitalized for respiratory, metabolic, ill-defined, infective, and genitourinary diseases. Group C (22%): Caucasian and Asian patients hospitalized for digestive, nervous, and musculoskeletal diseases, blood and skin diseases, and injuries. Mean serum vitamin D level (ng/mL) was 13.7 (SD = 9.4) in Group A, 20.5 (10.0) in Group B, and 26.2 (12.6) in Group C. Group B was associated with the highest BMI z-score (p < 0.001) and the highest frequency of preterm births (p = 0.041). Mean length of stay was longer in Group A than in the other groups (p < 0.001) and decreased significantly by 9.8% (p = 0.024) in Group A and by 5% (p = 0.029) in Group B per 10 ng/mL increase in vitamin D level. We identified three subgroups of hospitalized children, defined according to ethnicity and discharge diagnosis, and characterized by increasing vitamin D levels. Vitamin D levels were associated with length of hospitalization.

Predicting prolonged length of stay in hospitalized children with respiratory syncytial virus

BACKGROUND

Respiratory syncytial virus (RSV) is the most common cause of lower respiratory tract infections in children. This study aimed to predict the prolonged length of stay in children admitted to hospital with RSV.

METHODS

Children aged <2 years with RSV in the National Inpatient Sample (NIS) were included in the analyses. The primary outcome was prolonged length of stay (≥90th percentile). Logistic regression models were developed using data from 2016; internal validation was completed using a bootstrapped sample. Data from 2017 were used to validate out-of-sample discrimination and calibration of the models.

RESULTS

The sample included 9589 children; 1054 had prolonged length of stay (≥7 days). Children who were younger, transferred from another hospital, and required intubation during admission had a higher risk of prolonged length of stay. The prediction model included age, transport, intubation, comorbidities, hospital location, and teaching status. The area under the receiver operating characteristic curve was 0.73, demonstrating good predictive ability. The model performed similarly in external validation.

CONCLUSIONS

Variables that predict the prolonged length of stay for RSV include younger age, transport, intubation, comorbidities, hospital location, and teaching status. This can be used to predict children who will have a prolonged length of stay when hospitalized for RSV.

IMPACT

There are no recommended treatments for RSV; medical care involves supportive treatment such as oxygen delivery, hydration, and antipyretics. The clinical course is difficult to predict, partially attributable to the supportive nature of care and the sparsity of evidence-based therapies for this population. A prediction model was developed, demonstrating variables that predict prolonged length of stay in RSV hospitalizations, including age, interhospital transport, intubation, comorbidities, hospital location, and teaching status. The model was developed with a sample size of 9589 that is representative of all hospitalizations in the United States.

Importance of respiratory syncytial virus as a predictor of hospital length of stay in bronchiolitis

Introduction : Bronchiolitis is the leading cause of hospitalization in children. Estimate potentially preventable variables that impact the length of hospital stay are a priority to reduce the costs associated with this disease. This study aims to identify clinical variables associated with length of hospital stay of bronchiolitis in children in a tropical middle-income country Methods: We conducted a retrospective cohort study in 417 infants with bronchiolitis in tertiary centers in Colombia. All medical records of all patients admitted through the emergency department were reviewed. To identify factors independently associated we use negative binomial regression model, to estimate incidence rate ratios (IRR) and adjust for potential confounding variables Results : The median of the length of hospital stay was 3.68 days, with a range of 0.74 days to 29 days, 138 (33.17%) of patients have a hospital stay of 5 or more days. After modeling and controlling for potential confounders age <6 months, comorbidities (CHD or neurological), BPD,  chest indrawing, detection of RSV, and C-reactive protein were independent predictors of LOS Conclusions : Our results show that in infants with bronchiolitis, detection of RSV, age <6 months, comorbidities (CHD or neurological), BPD,  chest indrawing, and C-reactive protein were independent predictors of LOS. As a potentially modifiable risk factor, efforts to reduce the probability of RSV infection can reduce the high medical cost associates with prolonged LOS in bronchiolitis.

Predicting the severity of viral bronchiolitis in children

Acute viral bronchiolitis is one of the common causes of hospitalization and mortality, especially among children in the first year of life who have risk factors (prematurity, congenital heart defects, bronchopulmonary dysplasia, immunosuppression). As factors associated with the severe course of bronchiolitis, along with the traditional ones, single nucleotide polymorphisms of the genes of the immune response molecules can be considered.The aim. Based on the analysis of clinical, laboratory and molecular genetic parameters, to identify prognostic criteria for the severe course of acute viral bronchiolitis in children.Materials and methods. The study included 106 children with acute viral bronchiolitis (severe course – 34, mild course – 72), the etiology of which in 67.9 % was respiratory syncytial virus. Forty-seven anamnestic, clinical, traditional laboratory and molecular genetic parameters were assessed as prognostic criteria. Determination of SNP genes of cytokines IL-4 (C-589T), IL-10 (G-1082A), IL-10 (C-592A), IL-10 (C-819T), TNF-α (G-308A), IL-17A (G197A), IL-17F (His161Arg), TLR2-753ArgGln, TLR6-Ser249Pro in venous blood was carried out by the polymerase chain reaction method.Results. An additional criterion for the risk of developing a severe course of bronchiolitis can be the mutant genotype (AA) SNP of the IL-10 gene (C-592A), which was detected exclusively in the group of patients with severe bronchiolitis, increasing the risk of developing a severe disease by 16.11 times (OR = 16.11; 95 % CI: 0.81–121.22, p = 0.02) in conjunction with already established modifying factors: the presence of congenital heart disease, bronchopulmonary dysplasia, prematurity, birth weight < 1500 g. Based on a comprehensive assessment of the established risk factors, a method has been developed that allows calculate the likelihood of developing a severe course of acute viral bronchiolitis. Conclusion. The use of the developed prediction method will not only increase the likelihood of developing severe acute viral bronchiolitis in children, but also determine the priority group among children with predictors of severe viral bronchiolitis for priority immunoprophylaxis against RS-virus infection.

Factors associated with complicated pneumonia in children

INTRODUCTION

Community acquired pneumonia (CAP) is a leading cause of morbidity in children, despite advances in health care and anti-pneumococcal vaccine. Complicated pneumonia accounts for a significant burden with prolonged hospitalization. Finding risk factors for complicated pneumonia may help in tailoring management. We aimed to identify risk factors for developing complicated pneumonia and need for intervention.

METHODS

A retrospective single tertiary center study. Children admitted with a diagnosis of CAP and/or complicated pneumonia (parapneumonic effusion, empyema, necrotizing pneumonia, and lung abscess) on January 2001-March 2020 were included. Demographic, clinical, and laboratory parameters were collected using MDclone, a data acquisition tool. Risk factors for complicated pneumonia (on admission or during hospitalization) and risk for intervention were analyzed.

RESULTS

A total of 6778 children with pneumonia were included; 323 arrived at the Emergency Department with complicated pneumonia while 232 developed a complication during hospitalization. Risk factors for complicated pneumonia (on admission or during hospitalization) were Arab ethnicity, cardiac disease, increased age, and CRP and low O₂ Sat (OR = 2.236 p < .001, OR = 4.376 p < .001, OR = 1.131 p < .001, OR = 1.065 p < .001 and OR = 0.959 p = .029, respectively). O₂ Sat was lower, while fever and CRP were higher in patients with complicated pneumonia requiring intervention.

CONCLUSIONS

Identifying children at risk for complicated pneumonia may help in decision-making in the Emergency Department and during hospitalization. The increased risk of the Arab population for complicated pneumonia requires further understanding. Addressing the underlying socioeconomic and ethnic health inequities may help to decrease the disease burden in this population.

Severity of bronchiolitis in infants is associated with their parents' tobacco habit

The aim of this study was to investigate the effect of tobacco smoke exposure among severely pediatric ICU patients. A prospective epidemiological observational study was conducted among children with bronchiolitis younger than 2 years of age admitted to the Pediatric Intensive Care Unit of Children's University Hospital La Paz during the October 2017 to March 2018 outbreak. On admission, parents were asked whether they smoked. In children who required invasive mechanical ventilation, endotracheal aspirate was collected at the time of intubation. A total of 102 patients with bronchiolitis were studied. Among these, 14 (47%) of 30 infants whose parents smoked required invasive mechanical ventilation vs. 14 (19%) of 72 whose parents were nonsmokers (p = 0.007). Among patients on invasive mechanical ventilation, 10 (71%) of 14 infants with secondhand smoke exposure presented pulmonary bacterial superinfection vs. 3 (21%) of 14 in the unexposed (p = 0.012).Conclusion: Secondhand smoke exposure is an additional high risk for pulmonary bacterial superinfection and invasive mechanical ventilation in infants with severe acute bronchiolitis What is known: •Environmental tobacco smoke exposure is known to be an important risk factor for childhood lower respiratory tract infections. •Tobacco smoke makes structural changes in the respiratory tract and reduces the immune response. What in new: •Secondhand smoke exposure showed to be associated with the increased need and duration of invasive mechanical ventilation, and pediatric intensive care length of stay. •Tobacco smoke exposure is an additional risk factor for the presence of bacteria in the endotracheal aspirate.

Age-dependent Interactions Among Clinical Characteristics, Viral Loads and Disease Severity in Young Children With Respiratory Syncytial Virus Infection

BACKGROUND

Age-dependent differences in clinical presentation and viral loads in infants and young children with respiratory syncytial virus (RSV) infection, and their correlation with disease severity are poorly defined.

METHODS

Previously healthy children <2 years old with mild (outpatients) and severe (inpatients) RSV infection were enrolled and viral loads measured by polymerase chain reaction in nasopharyngeal swabs. Patients were stratified by age in 0-<3, 3-6 and >6-24 months, and multivariable analyses were performed to identify clinical and viral factors associated with severe disease.

RESULTS

From 2014 to 2018, we enrolled 534 children with RSV infection, 130 outpatients with mild RSV infection and 404 inpatients with severe RSV disease. Median duration of illness was 4 days for both groups, yet viral loads were higher in outpatients than in inpatients (P < 0.001). In bivariate analyses, wheezing was more frequent in outpatients of older age (>3 months) than in inpatients (P < 0.01), while fever was more common in inpatients than outpatients (P < 0.01) and its frequency increased with age. Adjusted analyses confirmed that increased work of breathing and fever were consistently associated with hospitalization irrespective of age, while wheezing in infants >3 months, and higher RSV loads in children >6-24 months were independently associated with reduced disease severity.

CONCLUSIONS

Age had a significant impact defining the interactions among viral loads, specific clinical manifestations and disease severity in children with RSV infection. These observations highlight the importance of patient stratification when evaluating interventions against RSV.

Association between ionised calcium and severity of postpartum haemorrhage: a retrospective cohort study

BACKGROUND

Postpartum haemorrhage (PPH) is often complicated by impaired coagulation. We aimed to determine whether the level of ionised calcium (Ca²⁺), an essential coagulation co-factor, at diagnosis of PPH is associated with bleeding severity.

METHODS

This was a retrospective cohort study of women diagnosed with PPH during vaginal delivery between January 2009 and April 2020. Ca²⁺ levels at PPH diagnosis were compared between women who progressed to severe PPH (primary outcome) and those with less severe bleeding. Severe PPH was defined by transfusion of ≥2 blood units, arterial embolisation or emergency surgery, admission to ICU, or death. Associations between other variables (e.g. fibrinogen concentration) and bleeding severity were also assessed.

RESULTS

For 436 patients included in the analysis, hypocalcaemia was more common among patients with severe PPH (51.5% vs 10.6%, P<0.001). In a multivariable logistic regression model, Ca²⁺ and fibrinogen were the only parameters independently associated with PPH severity with odds ratios of 1.14 for each 10 mg dl^-1 decrease in fibrinogen (95% confidence interval [CI], 1.05-1.24; P=0.002) and 1.97 for each 0.1 mmol L^-1 decrease in Ca²⁺ (95% CI, 1.25-3.1; P=0.003). The performance of Ca²⁺ or fibrinogen was not significantly different (area under the curve [AUC]=0.79 [95% CI, 0.75-0.83] vs AUC=0.86 [95% CI, 0.82-0.9]; P=0.09). The addition of Ca²⁺ to fibrinogen improved the model, leading to AUC of 0.9 (95% CI, 0.86-0.93), P=0.03.

CONCLUSIONS

Ca²⁺ level at the time of diagnosis of PPH was associated with risk of severe bleeding. Ca²⁺ monitoring may facilitate identification and treatment of high-risk patients.