Particle and bioaerosol characteristics in a paediatric intensive care unit

Abstract

The paediatric intensive care unit (PICU) provides care to critically ill neonates, infants and children. These patients are vulnerable and susceptible to the environment surrounding them, yet there is little information available on indoor air quality and factors affecting it within a PICU. To address this gap in knowledge we conducted continuous indoor and outdoor airborne particle concentration measurements over a two-week period at the Royal Children's Hospital PICU in Brisbane, Australia, and we also collected 82 bioaerosol samples to test for the presence of bacterial and viral pathogens. Our results showed that both 24-hour average indoor particle mass (PM) (0.6-2.2μgm, median: 0.9μgm) and submicrometer particle number (PN) (0.1-2.8×10pcm, median: 0.67×10pcm) concentrations were significantly lower (p<0.01) than the outdoor concentrations (6.7-10.2μgm, median: 8.0μgm for PM and 12.1-22.2×10pcm, median: 16.4×10pcm for PN). In general, we found that indoor particle concentrations in the PICU were mainly affected by indoor particle sources, with outdoor particles providing a negligible background. We identified strong indoor particle sources in the PICU, which occasionally increased indoor PN and PM concentrations from 0.1×10 to 100×10pcm, and from 2μgm to 70μgm, respectively. The most substantial indoor particle sources were nebulization therapy, tracheal suction and cleaning activities. The average PM and PN emission rates of nebulization therapy ranged from 1.29 to 7.41mgmin and from 1.20 to 3.96pmin×10, respectively. Based on multipoint measurement data, it was found that particles generated at each location could be quickly transported to other locations, even when originating from isolated single-bed rooms. The most commonly isolated bacterial genera from both primary and broth cultures were skin commensals while viruses were rarely identified. Based on the findings from the study, we developed a set of practical recommendations for PICU design, as well as for medical and cleaning staff to mitigate aerosol generation and transmission to minimize infection risk to PICU patients.

Clinical evidence based review and recommendations of aerosol generating medical procedures in otolaryngology – head and neck surgery during the COVID-19 pandemic

“…For the protection of HCWs during this COVID-19 pandemic, it is not only essential to recognize which procedures are aerosolizing, but physicians should also [36] Environmental study N/A N/A Air samples in PICU Air samples from rooms in PICU were measured for particle concentration and mass.…”

“…Four studies revealed that air samples obtained during open endotracheal suctioning in mechanically ventilated patients result in higher concentrations of particulate matter and pathogens like bacteria, viruses and fungi (Table 7) [ [36][37][38][39]. Three retrospective studies, evaluating risk factors for SARS-CoV-1 transmission while providing patient care to SARS patients did not demonstrate that endotracheal suctioning was a significant risk factor for SARS infection [34,40,41].…”

Evaluation of bioaerosol samplers for the detection and quantification of influenza virus from artificial aerosols and influenza virus–infected ferrets

“…Assessing the burden of influenza virus in the air is technically and operationally challenging in real‐world settings such as healthcare institutions . Clinical and environmental studies have utilized a range of instruments to determine the risk of exposure to virus‐laden bioaerosols in health care and agriculture . Limited study sizes underscore the need for consistent approaches across studies in similar settings in order to generate robust comparative data to form clearer conclusions.…”

Clothing as a transport vector for airborne particles: Chamber study

“…Hospital patients are particularly vulnerable owing to their health status as evidenced by the rate of nosocomial infections representing a major source of morbidity and mortality worldwide . It is well established that human occupancy and associated activities materially influence the total and biological aerosol burden indoors . One potentially overlooked exposure pathway mediated by humans is exposure to aerosols formerly deposited on clothing and subsequently released to air.…”