Performance of five pulse oximeters to detect hypoxaemia as an indicator of severe illness in children under five by frontline health workers in low resource settings – A prospective, multicentre, single-blinded, trial in Cambodia, Ethiopia, South Sudan, and Uganda

Abstract

Background: Low blood oxygen saturation (SpO 2 ), or hypoxaemia, is an indicator of severe illness in children. Pulse oximetry is a globally accepted, non-invasive method to identify hypoxaemia, but rarely available outside higher-level facilities in resource-constrained countries. This study aims to evaluate the performance of different types of pulse oximeters amongst frontline health workers in Cambodia, Ethiopia, South Sudan, and Uganda. Methods: Five pulse oximeters (POx) which passed laboratory testing, out of an initial 32 potential pulse oximeters, were evaluated by frontline health workers for performance, defined as agreement between the SpO 2 measurements of the test device and the reference standard. The study protocol is registered with the Australia New Zealand Clinical Trials Registry (Ref: ACTRrn12615000348550). Findings: Two finger-tip pulse oximeters (Contec and Devon), two handheld pulse oximeters (Lifebox and Utech), and one phone pulse oximeter (Masimo) passed the laboratory testing. They were evaluated for performance on 1,313 children under five years old by 207 frontline health workers between February and May 2015. Phone and handheld pulse oximeters had greater overall agreement with the reference standard (56%; 95% CI 0.52 -0.60 to 68%; 95% CI 0.65 -0.71) than the finger-tip POx (31%; 95% CI 0.26 to 0.36 and 47%; 95% CI 0.42 to 0.52). Fingertip POx performance was substantially lower in the 0À2 month olds; having just 17% and 25% agreement. The finger-tip devices more often underreported SpO 2 readings (mean difference -7.9%; 95%CI -8.6,-7.2 and -3.9%; 95%CI -4.4,-3.4), and therefore over diagnosed hypoxaemia in the children assessed. Interpretation: While the Masimo phone pulse oximeter performed best, all handheld POx with age-specific probes performed well in the hands of frontline health workers, further highlighting their suitability as a screening tool of severe illness. The poor performance of the fingertip POx suggests they should not be used in children under five by frontline health workers. It is essential that POx are performance tested on children in routine settings (in vivo), not only in laboratories or controlled settings (in vitro), before being introduced at scale.

Cost-effectiveness and sustainability of improved hospital oxygen systems in Nigeria

“…Pulse oximeters have particular challenges when used for young children (who move and cry), severely unwell patients (with poor perfusion) and people with deeply pigmented skin tone 47–49. The quality of oximeters comes both from hardware (eg, robust probes that fit comfortably) and software (eg, computers that can account for low perfusion and darker skin tone).…”

“…The quality of oximeters comes both from hardware (eg, robust probes that fit comfortably) and software (eg, computers that can account for low perfusion and darker skin tone). Most hospitals in our study invested in replacing broken oximeters but selected low-cost, finger-tip oximeters that may not be appropriate for severely unwell children in hospital 47–49…”

Hypoxaemia prevalence and management among children and adults presenting to primary care facilities in Uganda: a prospective cohort study

“…Pulse oximeter accuracy depends on the quality of the oximeter probe, internal computer/algorithm, and how it is used. 48 In lab conditions, pulse oximeters provide oxygen saturations with accuracy of +/- 2-3% and can be less accurate in patients with dark skin, low perfusion states, very low saturations, and those who are moving (e.g. crying child).…”

“…39 49 Previous studies have raised concerns about the quality of some low-cost oximeters, particularly finger-tip oximeters. [48][49][50][51] We used handheld oximeters that met global quality standards and did not conduct any independent validation of results.…”

Paediatric pneumonia research priorities in the context of COVID-19: An eDelphi study

“…Socioeconomic improvements have also led to better health for children and families. Innovations in commercially available medical technologies, such as portable lung ultrasound, pulse oximetry and multi-modal devices [ 11 - 15 ], provide new diagnostic approaches but raise implementation questions. And seminal epidemiological studies [ 16 , 17 ], clinical trials for oxygen therapies [ 18 - 20 ], and antibiotic treatment regimens [ 21 - 23 ] have reinforced challenges in optimal case management.…”