Effects of high altitude on respiratory rate and oxygen saturation reference values in healthy infants and children younger than 2 years in four countries: a cross-sectional study

Abstract

Background In resource-limited settings, pneumonia diagnosis and management are based on thresholds for respiratory rate (RR) and oxyhaemoglobin saturation (SpO 2 ) recommended by WHO. However, as RR increases and SpO 2 decreases with elevation, these thresholds might not be applicable at all altitudes. We sought to determine upper thresholds for RR and lower thresholds for SpO 2 by age and altitude at four sites, with altitudes ranging from sea level to 4348 m. MethodsIn this cross-sectional study, we enrolled healthy children aged 0-23 months who lived within the study areas in India, Guatemala, Rwanda, and Peru. Participants were excluded if they had been born prematurely (<37 weeks gestation); had a congenital heart defect; had history in the past 2 weeks of overnight admission to a health facility, diagnosis of pneumonia, antibiotic use, or respiratory or gastrointestinal signs; history in the past 24 h of difficulty breathing, fast breathing, runny nose, or nasal congestion; and current runny nose, nasal congestion, fever, chest indrawing, or cyanosis. We measured RR either automatically with the Masimo Rad-97, manually, or both, and measured SpO 2 with the Rad-97. Trained staff measured RR in duplicate and SpO 2 in triplicate in children who had no respiratory symptoms or signs in the past 2 weeks. We estimated smooth percentiles for RR and SpO 2 that varied by age and site using generalised additive models for location, shape, and scale. We compared these data with WHO RR and SpO 2 thresholds for tachypnoea and hypoxaemia to determine agreement.

A Risk Assessment Tool for Resumption of Research Activities During the COVID-19 Pandemic

“…In developing our risk assessment tool, we drew on a combination of expert consultations, national and local expertise, institutional guidance and review of emerging literature. [9][10][11][12][13][14][15][16][17] We convened a multinational panel of scientists and eld team leaders from across the trial with expertise in the disciplines of clinical medicine and imaging, nursing, environmental science, epidemiology, behavioral science, community engagement and statistics, along with the trial funders who provide scienti c guidance to the HAPIN trial. We sought input from local community leaders, the Ministries of Health, universities and nongovernmental organizations regarding appropriate operations and safety concerns.…”

“…[21,[26][27][28][29] Furthermore, the risk of transmission is greatest in the two days preceding onset of symptoms and continues afterward for at least ten days, and up to twenty days in immunosuppressed patients. [12,13] Because documented asymptomatic carriage has been widely reported, we assumed that any staff member, collaborator or community participant might be shedding the virus. [30] Small children (especially infants) appear to be infected at the same rate as adults, but have more mild disease and thus may be unknowingly spreading disease.…”

Pulse oximetry curves in healthy children living at moderate altitude: a cross-sectional study from the Ecuadorian Andes

“…Pulse oximetry identi es between 20 and 30% more cases than clinical signs alone [21,22,24,25]. However, the determination of a threshold to identify hypoxemia is di cult, especially in high altitude populations [26]. Some studies have previously used average SpO2 values -2 SD to de ne hypoxemia, however others have used the 2.5 th percentile measurement as a cut-off point to decide to use oxygen [8].…”

Pulse oximetry curves in healthy children living at moderate altitude: a cross-sectional study from the Ecuadorian Andes

“…Pulse oximetry identi es between 20 and 30% more cases than clinical signs alone [22,23,25,26]. However, the determination of a threshold to identify hypoxemia is di cult, especially in high altitude populations [27]. Some studies have previously used average SpO2 values -2 SD to de ne hypoxemia, however others have used the 2.5 th percentile measurement as a cut-off point to decide to use oxygen [8].…”