The characteristics of SARS-CoV-2-positive children in Australian hospitals: a PREDICT network study.

OBJECTIVES: To examine the clinical characteristics and short term outcomes for children with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections who presented to Australian hospitals during 2020 and 2021. DESIGN, SETTING: Retrospective case review study in nineteen hospitals of the Paediatric Research in Emergency Departments International Collaborative (PREDICT) network from all Australian states and territories, including seven major paediatric tertiary centres and eight Victorian hospitals. PARTICIPANTS: SARS-CoV-2-positive people under 18 years of age who attended emergency departments or were admitted to hospital during 1 February 2020 - 31 December 2021. MAIN OUTCOME MEASURES: Epidemiological and clinical characteristics, by hospital care type (emergency department [ED] or inpatient care). RESULTS: A total of 1193 SARS-CoV-2-positive children and adolescents (527 girls, 44%) attended the participating hospitals (107 in 2020, 1086 in 2021). Their median age was 3.8 years (interquartile range [IQR], 0.8-11.4 years); 63 were Aboriginal or Torres Strait Islander people (5%). Other medical conditions were recorded for 293 children (25%), including asthma (86, 7%) and premature birth (68, 6%). Medical interventions were not required during 795 of 1181 ED presentations (67%); children were discharged directly home in 764 cases (65%) and admitted to hospital in 282 (24%; sixteen to intensive care units). The 384 admissions to hospital (including 102 direct admissions) of 341 children (25 infants under one month of age) included 23 to intensive care (6%); the median length of stay was three days (IQR, 1-9 days). Medical interventions were not required during 261 admissions (68%); 44 children received respiratory support (11%) and 21 COVID-19-specific treatments, including antiviral and biologic agents (5%). Being under three months of age (v one year to less than six years: odds ratio [OR], 2.6; 95% confidence interval [CI], 1.7-4.0) and pre-existing medical conditions (OR, 2.5; 95% CI, 1.9-3.2) were the major predictors of hospital admission. Two children died, including one without a known pre-existing medical condition. CONCLUSION: During 2020 and 2021, most SARS-CoV-2-positive children and adolescents who presented to participating hospitals could be managed as outpatients. Outcomes were generally good, including for those admitted to hospital.

Pharmacological Emergency management of Agitation in Children and Young people: protocol for a randomised controlled trial of intraMuscular medication (PEAChY-M).

INTRODUCTION: Acute severe behavioural disturbance (ASBD) is a condition seen with increasing frequency in emergency departments (EDs) in adults and young people. Despite the increasing number of presentations and significant associated risks to patients, families and caregivers, there is limited evidence to guide the most effective pharmacological management in children and adolescents. The aim of this study is to determine whether a single dose of intramuscular olanzapine is more effective than intramuscular droperidol at successfully sedating young people with ASBD requiring intramuscular sedation. METHODS AND ANALYSIS: This study is a multicentre, open-label, superiority randomised controlled trial. Young people aged between 9 and 17 years and 364 days presenting to an ED with ASBD who are deemed to require medication for behavioural containment will be recruited to the study. Participants will be randomised in a 1:1 allocation between a single weight-based dose of intramuscular olanzapine and intramuscular droperidol. The primary outcome is the proportion of participants who achieve successful sedation at 1-hour post randomisation without the need for additional sedation. Secondary outcomes will include assessing for adverse events, additional medications provided in the ED, further episodes of ASBD, length of stay in the ED and hospital and satisfaction with management.Effectiveness will be determined using an intention-to-treat analysis, with medication efficacy determined as part of the secondary outcomes using a per-protocol analysis. The primary outcome of successful sedation at 1 hour will be presented as a percentage within each treatment group, with comparisons presented as a risk difference with its 95% CIs. ETHICS AND DISSEMINATION: Ethics approval was received from the Royal Children's Hospital Human Research Ethics Committee (HREC/69948/RCHM-2021). This incorporated a waiver of informed consent for the study. The findings will be disseminated in a peer-reviewed journal and at academic conferences. TRIAL REGISTRATION NUMBER: ACTRN12621001238864.

Pharmacological emergency management of agitation in children and young people: protocol for a randomised controlled trial of oral medication (PEAChY-O).

INTRODUCTION: Acute severe behavioural disturbance (ASBD) is a condition seen with increasing frequency in emergency departments (EDs) in adults and young people. Despite the increasing number of presentations and significant associated risks to patients, families and caregivers, there is limited evidence to guide the most effective pharmacological management in children and adolescents. The aim of this study is to determine whether a single dose of oral olanzapine is more effective than a dose of oral diazepam at successfully sedating young people with ASBD. METHODS AND ANALYSIS: This study is a multicentre, open-label, superiority randomised controlled trial. Young people aged between 9 years and 17 years and 364 days presenting to an ED with ASBD who are deemed to require medication for behavioural containment will be recruited to the study. Participants will be randomised in a 1:1 allocation between a single weight-based dose of oral olanzapine and oral diazepam. The primary outcome is the proportion of participants who achieve successful sedation at 1-hour post randomisation without the need for additional sedation. Secondary outcomes will include assessing for adverse events, additional medications provided in the ED, further episodes of ASBD, length of stay in the ED and hospital and satisfaction with management.Effectiveness will be determined using an intention-to-treat analysis, with medication efficacy determined as part of the secondary outcomes using a per-protocol analysis. The primary outcome of successful sedation at 1 hour will be presented as a percentage within each treatment group, with comparisons presented as a risk difference with its 95% CIs. ETHICS AND DISSEMINATION: Ethics approval was received from the Royal Children's Hospital Human Research Ethics Committee (HREC/66478/RCHM-2020). This incorporated a waiver of informed consent for the study. The findings will be disseminated in a peer-reviewed journal and at academic conferences. TRIAL REGISTRATION NUMBER: ACTRN12621001236886.

Infrared thermometers and infants: The device is hot the baby maybe not.

AIM: The risk of serious illness in febrile infants (<60 days old) is high, and so fever often warrants aggressive management. Infrared thermometers are unreliable in young infants despite their ubiquity. We aim to describe the: (i) frequency of infrared thermometer usage; (ii) progression to documented fever in the emergency department (ED) and (iii) rate of serious illness (meningitis, urinary tract infection and bacteremia). METHODS: In this single-centre retrospective chart review at The Royal Children's Hospital, Melbourne, we audited medical records of infants (<60 days old) presenting to the ED with pre-hospital fever on history over a 12-month period. We described the type of thermometer used at home (tympanic or forehead, 'infrared' vs. axillary or rectal, 'direct') correlated to peak temperature in ED, investigations, treatment and diagnosis. The primary outcome was subsequent fever in ED. RESULTS: Of 159 infants, two of three had infrared temperature measurement at home. Fifty-one (32.1%) developed fever in ED (direct 28/54, 52% vs. infrared 23/105, 22% RR 2.36 (95% CI 1.52-3.69)). Investigations (75%) and admission (60%) were common. Pre-hospital fever alone was less likely to be associated with serious illness, with fever in ED a much stronger predictor. CONCLUSIONS: In young infants, infrared thermometer use is common and less likely to predict subsequent fever. Twenty-two percent of infants with fever via infrared measurement had fever in ED. History of fever without confirmation is less likely to signal serious illness. Education to public and health-care providers is required to avoid usage of infrared devices in this population.

The characteristics of SARS-CoV-2-positive children who presented to Australian hospitals during 2020: a PREDICT network study.

OBJECTIVES: To examine the epidemiological and clinical characteristics of SARS-CoV-2-positive children in Australia during 2020. DESIGN, SETTING: Multicentre retrospective study in 16 hospitals of the Paediatric Research in Emergency Departments International Collaborative (PREDICT) network; eleven in Victoria, five in four other Australian states. PARTICIPANTS: Children aged 0-17 years who presented to hospital-based COVID-19 testing clinics, hospital wards, or emergency departments during 1 February - 30 September 2020 and who were positive for SARS-CoV-2. MAIN OUTCOME MEASURES: Epidemiological and clinical characteristics of children positive for SARS-CoV-2. RESULTS: A total of 393 SARS-CoV-2-positive children (181 girls, 46%) presented to the participating hospitals (426 presentations, including 131 to emergency departments [31%]), the first on 3 February 2020. Thirty-three children presented more than once (8%), including two who were transferred to participating tertiary centres (0.5%). The median age of the children was 5.3 years (IQR, 1.9-12.0 years; range, 10 days to 17.9 years). Hospital admissions followed 51 of 426 presentations (12%; 44 children), including 17 patients who were managed remotely by hospital in the home. Only 16 of the 426 presentations led to hospital medical interventions (4%). Two children (0.5%) were diagnosed with the paediatric inflammatory multisystem syndrome temporally associated with SARS-CoV-2 (PIMS-TS). CONCLUSION: The clinical course for most SARS-CoV-2-positive children who presented to Australian hospitals was mild, and did not require medical intervention.

Community use of paracetamol and ibuprofen in children with fever.

OBJECTIVE: To establish, in children aged from 3 months to less than 13 years with a febrile illness, caregiver medication usage patterns and drivers. Secondary objectives assessed caregiver knowledge and concern about fever. METHODOLOGY: This was a prospective, observational study of a convenience sample of 147 children presenting to a tertiary Paediatric Emergency Department, where the caregivers reported a concern of fever within the preceding 48 h. A paper-based survey was completed by the caregivers, and the results analysed both qualitatively and quantitatively. RESULTS: Caregivers of 92.4% had administered medication for fever in the 48 h prior to presentation. Dual therapy of paracetamol and ibuprofen was used by 45.8%, with paracetamol used more frequently as monotherapy (35.4%). Almost one-third of caregivers woke their child to administer medication. Just over one-third of respondents stated that a temperature of less than 38.0°C is a fever. The majority of caregivers (67.6%) said that fever is bad for their child, with 97.9% being concerned by fever. Almost half the children (46.8%) were given medication purely to treat the degree of the temperature. General practitioners were reported as the strongest influence on medication decision (60%). CONCLUSIONS: This study provides insight into current knowledge and practices of parents regarding fever and its treatment. The results of this study may be used to direct future interventions to educate caregivers on this topic.

Intranasal immunization strategy to impede pilin-mediated binding of Pseudomonas aeruginosa to airway epithelial cells.

Prevention of pulmonary Pseudomonas aeruginosa infections represents a critical unmet medical need for cystic fibrosis (CF) patients. We have examined the tenet that a mucosal immunization approach can reduce interactions of a piliated form of this opportunistic pathogen with respiratory epithelial cells. Vaccinations were performed using ntPEpilinPAK, a protein chimera composed of a nontoxic form of P. aeruginosa exotoxin A (ntPE), where the C-terminal loop amino acid sequence of the PAK strain pilin protein was inserted in place of the ntPE Ib domain. Intranasal (i.n.) immunization of BALB/c mice with ntPEpilinPAK generated both serum and saliva immune responses. A series of in vitro studies showed that diluted samples of saliva obtained from immunized mice reduced pilin-dependent P. aeruginosa binding to polarized human tracheal epithelial cells, protected human pulmonary epithelial cells from cytotoxic actions associated with bacterial challenge, and reduced exotoxin A toxicity. Overall, i.n. administration of ntPEpilinPAK induced mucosal and systemic immune responses that may be beneficial for blocking early stage adhesion and/or infection events of epithelial cell-P. aeruginosa interactions at oropharyngeal surfaces.

Enalapril attenuates angiotensin II-induced atherosclerosis and vascular inflammation.

Angiotensin converting enzyme (ACE) inhibitors prevent a wide variety of key events underlying atherogenesis. Whether these actions depend solely on reduction of angiotensin II (Ang II) generation is still to be determined. This study was undertaken to determine whether enalapril, an ACE inhibitor, prevents atherosclerosis and vascular inflammation induced by Ang II in apolipoprotein E-deficient (apoE-KO) mice. Subcutaneous infusion of Ang II (1.44 mg/(kg day)) for 4 weeks increased blood pressure and accelerated atherosclerosis development in the carotid arteries. The expression of the endothelial adhesion molecules E-selectin, intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1), as well as the chemokines monocyte chemotactic protein-1 (MCP-1) and macrophage-colony stimulating factor (M-CSF) was up-regulated in the aortas of Ang II-treated mice. Enalapril co-treatment (25 mg/(kg day), in drinking water) prevented the development of atherosclerosis without affecting blood pressure or circulating cholesterol. In addition to preventing the Ang II-induced over-expression of adhesion molecules and chemokines in the aorta, enalapril up-regulated the expression of peroxisome proliferator-activated receptors (PPARs)-alpha and -gamma, potential anti-inflammatory transcription factors. In the aortic arch, a lesion-prone site, the co-treatment with enalapril reduced the percentage of arterial wall occupied by macrophages and foam cells, medial sclerosis and elastin reduplication. Together, these data suggest an important role for Ang II-independent mechanisms in the antiatherogenic and anti-inflammatory effects of ACE inhibitors.

17 Beta-estradiol attenuates development of angiotensin II-induced aortic abdominal aneurysm in apolipoprotein E-deficient mice.

OBJECTIVE: Angiotensin II (Ang II) promotes vascular inflammation, accelerates atherosclerosis, and induces abdominal aortic aneurysm (AAA). These changes were associated with activation of nuclear factor (NF)-kappaB-mediated induction of proinflammatory genes. The incidence of AAA in this model was higher in male than in female mice, and the vascular effects of estrogen may be associated with anti-inflammatory actions. The present study was undertaken to test the hypothesis that estrogen can attenuate Ang II-induced AAA in apolipoprotein E-deficient mice via its anti-inflammatory mechanism. METHODS AND RESULTS: Infusion of Ang II (1.44 mg/kg per d for 1 month) induced AAA in 90% of the animals (n=20) with an expansion of the suprarenal aorta (diameter 1.9+/-0.14 mm versus <1 mm in normal mice). In mice treated with 17beta-estradiol (E2, 0.25-mg subcutaneous pellets), Ang II induced AAA only in 42% of the animals (n=19) with a significant reduction of average diameters of the suprarenal aorta (1.5+/-0.14 mm). E2 also decreased the expressions of intracellular adhesion molecule-1, vascular cellular adhesion molecule-1, E-selectin, monocyte chemotactic protein-1, and macrophage-colony stimulating factor in the aorta. CONCLUSIONS: These data suggest that attenuation of AAA by E2 is associated with inhibition of proinflammatory gene expression.

Modulation of vascular inflammation by PPARs.

The activation of cells in atherosclerotic lesions leads to the release of proinflammatory molecules and the onset of a chronic inflammatory response. Recent evidence suggests that peroxisome proliferator-activated receptors (PPARs) exert their antiinflammatory activities in vascular and immunological cell types such as endothelial cells, vascular smooth muscle cells and monocytes/macrophages. In these cells, PPARs regulate the gene expression of key proteins involved in the vascular inflammation contributing to atherogenesis. By modulating transcription of proinflammatory genes such as cytokines, chemokines, endothelial cell adhesion molecules and metalloproteinases, one can affect the events involved in atherogenesis, such as monocyte/macrophage and lymphocyte recruitment to the arterial wall and foam cell formation. Thus, PPAR agonists have emerged as a potential tool to modulate the inception and progression of atherosclerosis by exerting direct antiinflammatory and antiatherogenic actions at the level of the arterial wall. In this review, we will describe the current understanding of PPARs, the antiinflammatory activities of PPAR agonists and their proposed mechanisms of action.

Differential regulation of gene expression by ovariectomy in mouse aorta.

The purpose of this study was to investigate the effects of ovarian hormones on gene expression in the vascular wall. Our approach employed an RT-PCR-based cloning strategy of DNA differential display analysis and verification/confirmation of differential expression by semi-quantitative PCR and real-time PCR. mRNA analysis of normal aortas from intact and ovariectomized female C57BL/6J mice, showed altered expression of 20 genes with significant (>70%) sequence homology to known genes. Eight were selected for further study based on the genes' known function and potential relevance to vascular physiology. Differential expression of mRNA for three genes was confirmed by both semi-quantitative and real-time RT-PCR using gene-specific primers. Ovariectomy downregulated expression of elongation factor-1alpha (3.5-fold), ganglioside-induced differentiation associated protein (8.2-fold), and NADH:ubiquinone oxidoreductase (3.8-fold). Thus, in normal mouse aortas, ovariectomy resulted in significant differential downregulation of a number of vascular genes important to vascular cell growth and angiogenesis, cellular differentiation, and mitochondrial energy metabolism, respectively. These studies have implications for our understanding of hormonal regulation of vascular gene expression and the therapeutic targeting of specific vascular genetic sequences by female sex steroid hormones.

Angiotensin II is associated with activation of NF-kappaB-mediated genes and downregulation of PPARs.

Angiotensin II (ANG II) promotes vascular inflammation through nuclear factor-kappaB (NF-kappaB)-mediated induction of pro-inflammatory genes. The role of peroxisome proliferator-activated receptors (PPARs) in modulating vascular inflammation and atherosclerosis in vivo is unclear. The aim of the present study was to examine the effects of ANG II on PPARs and NF-kappaB-dependent pro-inflammatory genes in the vascular wall in an in vivo model of atherosclerosis and aneurysm formation. Six-month-old male apolipoprotein E-deficient (apoE-KO) mice were treated with ANG II (1.44 mg/kg per day for 30 days). ANG II enhanced vascular inflammation, accelerated atherosclerosis, and induced formation of abdominal aortic aneurysms. These effects of ANG II in the aorta were associated with downregulation of both PPAR-alpha and PPAR-gamma mRNA and protein and an increase in transcription of monocyte chemotactic protein-1 (MCP-1), macrophage-colony stimulating factor (M-CSF), endothelial-selectin (E-selectin), intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1), inducible nitric oxide synthase (iNOS), and cyclooxygenase-2 (COX-2) throughout the entire aorta. ANG II also activated NF-kappaB with increases in both p52 and p65 NF-kappaB subunits. In summary, these in vivo results indicate that ANG II, through activation of NF-kappaB-mediated pro-inflammatory genes, promotes vascular inflammation, leading to acceleration of atherosclerosis and induction of aneurysm in apoE-KO mice. Downregulation of PPAR-alpha and -gamma by ANG II may diminish the anti-inflammatory potential of PPARs, thus contributing to enhanced vascular inflammation.

Angiotensin II injures the arterial wall causing increased aortic stiffening in apolipoprotein E-deficient mice.

Cardiovascular diseases, such as atherosclerosis and hypertension, are associated with arterial stiffening. Previous studies showed that ANG II exacerbated atherosclerosis and induced hypertension and aneurysm formation in apolipoprotein E-deficient (apoE-KO) mice. The aim of the present study was to examine the effects of chronic treatment of ANG II on the arterial elastic properties in apoE-KO mice. We hypothesized that ANG II will injure the arterial wall resulting in increased arterial stiffening. Male apoE-KO mice were infused with either ANG II (1.44 mg. kg(-1). day(-1)) or vehicle (PBS) for 30 days. ANG II treatment accelerated atherosclerosis in the carotid artery by sixfold (P < 0.001) and increased blood pressure by 30% (P < 0.05). Additionally, our data demonstrated that ANG II increased arterial stiffening using both in vivo and in vitro methods. ANG II significantly increased pulse wave velocity by 36% (P < 0.01) and decreased arterial elasticity as demonstrated by a more than 900% increase in maximal stiffening (high strain Young's modulus) compared with vehicle (P < 0.05). These functional changes were correlated with morphological and biochemical changes as demonstrated by an increase in collagen content (60%), a decrease in elastin content (74%), and breaks in the internal elastic lamina in the aortic wall. In addition, endothelium-independent vasorelaxation to sodium nitroprusside was impaired in the aortic rings of ANG II-treated mice compared with vehicle. Thus, the present data indicate that ANG II injures the artery wall in multiple ways and arterial stiffening may be a common outcome of ANG II-induced arterial damage.

Extracellular glutathione peroxidase is secreted basolaterally by human renal proximal tubule cells.

Extracellular glutathione peroxidase (eGPx) is a secreted selenoenzyme with GPx activity. eGPx protein and activity are found in blood plasma and other extracellular fluids. eGPx in plasma is predominantly derived from the proximal tubules of kidneys in humans. Two types of human proximal tubule cells were cultured on semipermeable polycarbonate membranes to determine whether these cells secrete eGPx in a polarized direction. Immortalized human proximal tubule HK-2 cells and primary human proximal tubule cells formed confluent monolayers when cultured on these membrane inserts in culture dishes, as evidenced by transepithelial resistance. Both cell lines also constituted a barrier to diffusion of a fluoresceinated dextran of 75 kDa, a size similar to eGPx homotetramers. In both cell lines, 6- to 12-fold more 35S-methionine-labeled eGPx was immunoprecipitated from the basolateral media than from the apical media, indicating basolateral secretion of eGPx. eGPx was immunolocalized to the extracellular fluid at the basolateral surface of proximal tubules in human kidney. These data support the conclusion that eGPx is secreted through the basolateral membrane of human kidney proximal tubule cells into the extracellular fluid of the kidney, and from there enters blood plasma.

Increased expression of extracellular glutathione peroxidase in mice with dextran sodium sulfate-induced experimental colitis.

Extracellular glutathione peroxidase (E-GPx) is a selenoenzyme that reduces hydrogen peroxide and organic peroxides. All plasma glutathione peroxidase (GPx) activity in humans is attributable to E-GPx. The gastrointestinal (GI) tract also synthesizes and secretes E-GPx into the extracellular milieu. Endogenously generated oxidants have been implicated in inflammatory bowel disease (IBD). We evaluated E-GPx levels in a mouse model of IBD using dextran sodium sulfate (DSS). Histologic lesions of the lower GI tract consisted of multifocal areas of mucosal erosion denuded of epithelial cells, reduction in goblet cells, dilated crypts, crypt collapse, submucosal edema, and transmural distribution of mixed inflammatory infiltrates. On d 7, plasma GPx activity in the DSS group increased by 61% compared with the control group (p < 0.05). Western blot analysis demonstrated a 64% increase in E-GPx protein in the plasma of the DSS group after 7 d of treatment (p < 0.01). As the major source of plasma GPx is the kidney, we determined whether the increase in plasma GPx activity and protein was caused by a change in E-GPx synthesis by the kidney. After 3 and 7 d of DSS treatment, E-GPx mRNA levels, relative to glyceraldehyde-3-phosphate dehydrogenase, increased in the kidney (p < 0.05) without a concomitant increase in cellular GPx mRNA on d 7. These results suggest that the inflammatory injury in the intestine elicits an increase in E-GPx in the plasma that is associated with an increase in E-GPx mRNA in the kidney. This implies that renal production of E-GPx may be sensitive to insults distal to the kidney.