The performance of 11 fingertip pulse oximeters during hypoxemia in healthy human participants with varied, quantified skin pigment.

BACKGROUND: Fingertip pulse oximeters are widely available, inexpensive, and commonly used to make clinical decisions in many settings. Device performance is largely unregulated and poorly characterised, especially in people with dark skin pigmentation. METHODS: Eleven popular fingertip pulse oximeters were evaluated using the US Food and Drug Administration (FDA) Guidance (2013) and International Organization for Standardization Standards (ISO, 2017) in 34 healthy humans with diverse skin pigmentation utilising a controlled desaturation study with arterial oxygen saturation (SaO 2) plateaus between 70% and 100%. Skin pigmentation was assessed subjectively using a perceived Fitzpatrick Scale (pFP) and objectively using the individual typology angle (ITA) via spectrophotometry at nine anatomical sites. FINDINGS: Five of 11 devices had a root mean square error (ARMS) > 3%, falling outside the acceptable FDA performance range. Nine devices demonstrated worse performance in participants in the darkest skin pigmentation category compared with those in the lightest category. A commonly used subjective skin colour scale frequently miscategorised participants as being darkly pigmented when compared to objective quantification of skin pigment by ITA. INTERPRETATION: Fingertip pulse oximeters have variable performance, frequently not meeting regulatory requirements for clinical use, and occasionally contradicting claims made by manufacturers. Most devices showed a trend toward worse performance in participants with darker skin pigment. Regulatory standards do not adequately account for the impact of skin pigmentation on device performance. We recommend that the pFP and other non-standardised subjective skin colour scales should no longer be used for defining diversity of skin pigmentation. Reliable methods for characterising skin pigmentation to improve diversity and equitable performance of pulse oximeters are needed. FUNDING: This study was conducted as part of the Open Oximetry Project funded by the Gordon and Betty Moore Foundation, Patrick J McGovern Foundation, and Robert Wood Johnson Foundation. The UCSF Hypoxia Research Laboratory receives funding from multiple industry sponsors to test the sponsors' devices for the purposes of product development and regulatory performance testing. Data in this paper do not include sponsor's study devices. All data were collected from devices procured by the Hypoxia Research Laboratory for the purposes of independent research. No company provided any direct funding for this study, participated in study design or analysis, or was involved in analysing data or writing the manuscript. None of the authors own stock or equity interests in any pulse oximeter companies. Dr Ellis Monk's time utilised for data analysis, reviewing and editing was funded by grant number: DP2MH132941.

Factores asociados al no control de la hipertensión arterial.Matanzas. Año 2005 / Factors associated to non-controlled arterial hypertension. Province of Matanzas. Year 2005

Se realizó un estudio observacional analítico de caso-control no apareado, para estudiar los factores asociados al hipertenso no controlado en la provincia de Matanzas, 2005. El universo estuvo constituido por los hipertensos dispensarizados en Consultorios Médicos de la Familia. La muestra quedó formada por 700 casos y 700 controles. Se utilizó la encuesta recogiéndose información por entrevista y de Historia Clínica Individual. La información se procesó en EpiInfo para el estudio bivariado, calculándose el Odds Ratio y el Riesgo Atribuible, con intervalos Confianza 95 por ciento, considerándose estadísticamente significativa con p inferior a 0,05 (p<0,05). Las variables significativas se pasaron por análisis multivariado en regresión logística del Programa SPSS10 resultando estar asociados al no control: el hipertenso grado 2, no cumplir con 6 de 8 variables del tratamiento no farmacológico, no tener un tratamiento farmacológico adecuado y no adherencia al mismo, no cumplir la dieta baja de grasa y baja de sal, no consumir vegetales, fumar, ingerir excesivamente bebidas alcohólicas y no realizar ejercicios físicos...(AU)

We carried out an analytic, observational, non matched case-control study, to study the factors associated to non-controlled hypertension patients in the province of Matanzas, 2005. The universe was formed by hypertension patients attended in Family Doctor's Offices. The sample was formed by 700 cases and 700 controls. We used the inquiry, collecting information from interviews and Individual Clinic Records. Information was processed in EpiInfo for a bi-variable study, calculating Odds Ratio and Attributable Risk, with confidence intervals of 95 percent, considered as statistically significant with p less than 0,05 (p<0,05). Significant variables were subject of multivariable analysis in logistic regression of SPSS10 Program, being associated with non-control: 2 grade hypertensive patients did not fulfil 6 of the 8 variables of non-pharmacologic treatment: absence of an adequate pharmacologic treatment and not adherence to it, high salt and fat diet, lack of vegetables consumption, smoking, excessively drinking alcoholic beverages and not doing physic exercises...(AU)