The adequacy of user seal checking for N95 respirators compared to formal fit testing: A multicentred observational study.

OBJECTIVE: The objective of this study was to evaluate the adequacy of the user seal check (USC) in predicting N95 respirator fit. DESIGN: This was a prospective, observational study conducted from May to September 2020. SETTING: The study setting included three private intensive care units (ICUs) in Victoria, Australia. PARTICIPANTS: ICU staff members in three private ICUs in Melbourne and regional Victoria participated in this study. MAIN OUTCOME MEASURES: The main outcome measure is the proportion of participants who passed a USC and subsequently failed fit testing of an N95 respirator. INTERVENTION: Three different respirators were available: two N95 respirator brands and CleanSpace HALO® powered air-purifying respirator. Participants were sequentially tested on N95 respirators followed by powered air-purifying respirators until either successful fit testing or failure of all three respirators. The first N95 tested was based on the availability on the day of testing. The primary outcome was failure rate of fit testing on the first N95 respirator type passing a USC. RESULTS: Of 189 participants, 22 failed USC on both respirators, leaving 167 available for the primary outcome. Fifty-one of 167 (30.5%, 95% confidence interval = 23.7-38.1) failed fit testing on the first respirator type used that had passed a USC. CONCLUSION: USC alone was inadequate in assessing N95 respirator fit and failed to detect inadequate fit in 30% of participants. Mandatory fit testing is essential to ensure adequate respiratory protection against COVID-19 and other airborne pathogens. TRIAL REGISTRATION: Australian New Zealand Clinical Trials Registry: ACTRN12620001193965.

Maternal severity of illness across levels of care: a prospective, cross-sectional study.

BACKGROUND: The severity of illness of women experiencing severe maternal morbidity has not been quantified outside of the intensive care setting yet is likely to have a bearing on clinical needs. AIM: To examine severity of illness in women with severe maternal morbidity. METHODS: A prospective observational study of critically ill pregnant and postpartum women was undertaken in intensive care units (ICU), high dependency units (HDU) and delivery suites (DS) of seven tertiary-level hospitals in Melbourne, during 2002-2004. Severity of illness was scored using the Acute Physiology and Chronic Health Evaluation version II (APACHE II) and Therapeutic Intervention Scoring System 28 items (TISS 28). RESULTS: 137 women participated in the study: ICU (n=33), HDU (n=46) and DS (n=58). The mean APACHE II score was 8.6 (95% CI 7.7-9.5) and mean TISS 28 score was 22.5 (95% CI 21.2-23.9). Women in ICU were sicker according to both APACHE II (mean 12.6, 95% CI 8.3-16.9) and TISS 28 (mean 31.5, 95% CI 28.2-35.5) compared to women not admitted to ICU (p<.005). There was no difference in the mean APACHE II scores of women in HDU (7.7, 95% CI 5.5-9.9) and DS (7.0, 95% CI 5.2-8.8; p=.20). Women born outside of Australia were more likely to be admitted to ICU (OR 3.27, 95% CI 1.19-8.97). Known risk factors like multiple pregnancy, age≥35 years and nulliparity were not associated with ICU admission. CONCLUSIONS: There was no difference in the severity of illness in women cared for in HDU and DS. It was not possible to predict which women would require ICU admission. Measurement of severity of illness adds a valuable dimension to the study of severe maternal morbidity.