Factors associated with family decision-making after pediatric out-of-hospital cardiac arrest.

AIM: This study aims to identify demographic factors, area-based social determinants of health (SDOH), and clinical features associated with medical decision-making after pediatric out-of-hospital cardiac arrest (OHCA). METHODS: This is a retrospective, exploratory, descriptive analysis of patients < 18 years old admitted to the pediatric intensive care unit (ICU) after OHCA from 2011 to 2022 (n = 217) at an urban tertiary care, free-standing children's hospital. Outcomes of interest included: (1) whether a new advance care plan (ACP) (defined as a written advance directive including do not resuscitate and/or do not intubate) was ordered during hospitalization, and (2) whether the patient was discharged with new medical technology (defined as tracheostomy and/or feeding tube). Logistic regression models identified features associated with these outcomes. RESULTS: Of the 217 patients, 78 patients (36%) had a new ACP placed during their admission. Of the survivors, 26% (27/102) were discharged home with new medical technology. Factors associated with ACP were greater change in Pediatric Cerebral Performance Category (PCPC) score (aOR = 1.49, 95% CI [1.28-1.73], p-value < 0.001) and palliative care consultation (aOR = 2.39, 95% CI [1.16-4.89], p-value 0.018). Factors associated with new medical technology were lower change in PCPC score (aOR = 0.76, 95% C.I. [0.61-0.95], p-value = 0.015) and palliative care consultation (aOR = 7.07, 95% CI [3.01-16.60], p-value < 0.001). There were no associations between area-based SDOH and outcomes. CONCLUSIONS: Understanding factors associated with decision-making related to ACP after OHCA is critical to optimize counseling for families. Multi-institutional studies are warranted to identify whether these findings are generalizable.

Exposure to medium and high ambient levels of ozone causes adverse systemic inflammatory and cardiac autonomic effects.

Epidemiological evidence suggests that exposure to ozone increases cardiovascular morbidity. However, the specific biological mechanisms mediating ozone-associated cardiovascular effects are unknown. To determine whether short-term exposure to ambient levels of ozone causes changes in biomarkers of cardiovascular disease including heart rate variability (HRV), systemic inflammation, and coagulability, 26 subjects were exposed to 0, 100, and 200 ppb ozone in random order for 4 h with intermittent exercise. HRV was measured and blood samples were obtained immediately before (0 h), immediately after (4 h), and 20 h after (24 h) each exposure. Bronchoscopy with bronchoalveolar lavage (BAL) was performed 20 h after exposure. Regression modeling was used to examine dose-response trends between the endpoints and ozone exposure. Inhalation of ozone induced dose-dependent adverse changes in the frequency domains of HRV across exposures consistent with increased sympathetic tone [increase of (parameter estimate ± SE) 0.4 ± 0.2 and 0.3 ± 0.1 in low- to high-frequency domain HRV ratio per 100 ppb increase in ozone at 4 h and 24 h, respectively (P = 0.02 and P = 0.01)] and a dose-dependent increase in serum C-reactive protein (CRP) across exposures at 24 h [increase of 0.61 ± 0.24 mg/l in CRP per 100 ppb increase in ozone (P = 0.01)]. Changes in HRV and CRP did not correlate with ozone-induced local lung inflammatory responses (BAL granulocytes, IL-6, or IL-8), but changes in HRV and CRP were associated with each other after adjustment for age and ozone level. Inhalation of ozone causes adverse systemic inflammatory and cardiac autonomic effects that may contribute to the cardiovascular mortality associated with short-term exposure.

Allergen and ozone exacerbate serotonin-induced increases in airway smooth muscle contraction in a model of childhood asthma.

BACKGROUND: Serotonin (5-HT) modulates cholinergic neurotransmission and exacerbates airway smooth muscle (ASM) contraction in normal animal and nonasthmatic human tissue. Exposure to house dust mite allergen (HDMA) and ozone (O(3)) leads to airway hyperreactivity and 5-HT-positive cells in the airway epithelium of infant rhesus monkeys. Research shows that concomitant exposure in allergic animals has an additive effect on airway hyperreactivity. OBJECTIVES: In this study, the hypothesis is that the exposure of allergic infant rhesus monkeys to HDMA, O(3) and in combination, acting through 5-HT receptors, enhances 5-HT modulation of postganglionic cholinergic ASM contraction. METHODS: Twenty-four HDMA-sensitized infant monkeys were split into 4 groups at the age of 1 month, and were exposed to filtered air (FA), HDMA, O(3) or in combination (HDMA+O(3)). At the age of 6 months, airway rings were harvested and postganglionic, and parasympathetic-mediated ASM contraction was evaluated using electrical-field stimulation (EFS). RESULTS: 5-HT exacerbated the EFS response within all exposure groups, but had no effect in the FA group. 5-HT(2), 5-HT(3) and 5-HT(4) receptor agonists exacerbated the response. 5-HT concentration-response curves performed after incubation with specific receptor antagonists confirmed the involvement of 5-HT(2), 5-HT(3) and 5-HT(4) receptors. Conversely, a 5-HT(1) receptor agonist attenuated the tension across all groups during EFS, and in ASM contracted via exogenous acetylcholine. CONCLUSIONS: HDMA, O(3) and HDMA+O(3) exposure in a model of childhood allergic asthma enhances 5-HT exacerbation of EFS-induced ASM contraction through 5-HT(2), 5-HT(3) and 5-HT(4) receptors. A nonneurogenic inhibitory pathway exists, unaffected by exposure, mediated by 5-HT(1) receptors located on ASM.

Effects of exercise on systemic inflammatory, coagulatory, and cardiac autonomic parameters in an inhalational exposure study.

BACKGROUND: Intermittent moderate-intensity exercise is used in human inhalational exposure studies to increase the effective dose of air pollutants. OBJECTIVE: To investigate the inflammatory, coagulatory, and autonomic effects of intermittent moderate-intensity exercise. METHODS: We measured hemodynamic, electrocardiographic, inflammatory, and coagulatory parameters in peripheral blood of 25 healthy subjects across an exercise protocol that included running on a treadmill or pedaling a cycle ergometer for 30 minutes every hour over 4 hours in a climate-controlled chamber with a target ventilation of 20 L/min/m2 body surface area. RESULTS: Intermittent moderate-intensity exercise induced a systemic proinflammatory response characterized by increases in leukocyte counts, C-reactive protein, monocyte chemoattractant protein-1, and interleukin-6, but did not change coagulation tendency or heart rate variability. CONCLUSION: Interpretation of pollutant-induced inflammatory responses in inhalational exposure studies should account for signals and noises caused by exercise, especially when the effect size is small.

Secreted osteopontin is highly polymerized in human airways and fragmented in asthmatic airway secretions.

BACKGROUND: Osteopontin (OPN) is a member of the small integrin-binding ligand N-linked glycoprotein (SIBLING) family and a cytokine with diverse biologic roles. OPN undergoes extensive post-translational modifications, including polymerization and proteolytic fragmentation, which alters its biologic activity. Recent studies suggest that OPN may contribute to the pathogenesis of asthma. METHODOLOGY: To determine whether secreted OPN (sOPN) is polymerized in human airways and whether it is qualitatively different in asthma, we used immunoblotting to examine sOPN in bronchoalveolar lavage (BAL) fluid samples from 12 healthy and 21 asthmatic subjects (and in sputum samples from 27 healthy and 21 asthmatic subjects). All asthmatic subjects had mild to moderate asthma and abstained from corticosteroids during the study. Furthermore, we examined the relationship between airway sOPN and cellular inflammation. PRINCIPAL FINDINGS: We found that sOPN in BAL fluid and sputum exists in polymeric, monomeric, and cleaved forms, with most of it in polymeric form. Compared to healthy subjects, asthmatic subjects had proportionately less polymeric sOPN and more monomeric and cleaved sOPN. Polymeric sOPN in BAL fluid was associated with increased alveolar macrophage counts in airways in all subjects. CONCLUSIONS: These results suggest that sOPN in human airways (1) undergoes extensive post-translational modification by polymerization and proteolytic fragmentation, (2) is more fragmented and less polymerized in subjects with mild to moderate asthma, and (3) may contribute to recruitment or survival of alveolar macrophages.