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.

Low Perfusion and Missed Diagnosis of Hypoxemia by Pulse Oximetry in Darkly Pigmented Skin: A Prospective Study.

BACKGROUND: Retrospective clinical trials of pulse oximeter accuracy report more frequent missed diagnoses of hypoxemia in hospitalized Black patients than White patients, differences that may contribute to racial disparities in health and health care. Retrospective studies have limitations including mistiming of blood samples and oximeter readings, inconsistent use of functional versus fractional saturation, and self-reported race used as a surrogate for skin color. Our objective was to prospectively measure the contributions of skin pigmentation, perfusion index (PI), sex, and age on pulse oximeter errors in a laboratory setting. METHODS: We enrolled 146 healthy subjects, including 25 with light skin (Fitzpatrick class I and II), 78 with medium (class III and IV), and 43 with dark (class V and VI) skin. We studied 2 pulse oximeters (Nellcor N-595 and Masimo Radical 7) in prevalent clinical use. We analyzed 9763 matched pulse oximeter readings (pulse oximeter measured functional saturation [Sp o2 ]) and arterial oxygen saturation (hemoximetry arterial functional oxygen saturation [Sa o2 ]) during stable hypoxemia (Sa o2 68%-100%). PI was measured as percent infrared light modulation by the pulse detected by the pulse oximeter probe, with low perfusion categorized as PI < 1%. The primary analysis was to assess the relationship between pulse oximeter bias (difference between Sa o2 and Sp o2 ) by skin pigment category in a multivariable mixed-effects model incorporating repeated-measures and different levels of Sa o2 and perfusion. RESULTS: Skin pigment, PI, and degree of hypoxemia significantly contributed to errors (bias) in both pulse oximeters. For PI values of 1.0% to 1.5%, 0.5% to 1.0%, and <0.5%, the P value of the relationship to mean bias or median absolute bias was <.00001. In lightly pigmented subjects, only PI was associated with positive bias, whereas in medium and dark subjects bias increased with both low perfusion and degree of hypoxemia. Sex and age was not related to pulse oximeter bias. The combined frequency of missed diagnosis of hypoxemia (pulse oximeter readings 92%-96% when arterial oxygen saturation was <88%) in low perfusion conditions was 1.1% for light, 8.2% for medium, and 21.1% for dark skin. CONCLUSIONS: Low peripheral perfusion combined with darker skin pigmentation leads to clinically significant high-reading pulse oximeter errors and missed diagnoses of hypoxemia. Darkly pigmented skin and low perfusion states are likely the cause of racial differences in pulse oximeter performance in retrospective studies.

Chlamydial and gonorrheal neglected sexually transmitted diseases among Pacific Islanders of the Western Pacific Region-A narrative review and call to action.

The Pacific Island countries of the Western Pacific Region have some of the highest rates of sexually transmitted Chlamydia trachomatis and Neisseria gonorrhoeae infections in the world. Despite this, there are few research studies that include Pacific Islanders. We conducted a narrative review of original research and surveys, including World Health Organization and Pacific Community reports, to determine the prevalence, management, and treatment of C. trachomatis and N. gonorrhoeae compared to HIV and syphilis from 1980 to 2022. Available epidemiologic data on C. trachomatis and N. gonorrhoeae indicated an extremely high prevalence-approximately 30% and 13%, respectively-among Pacific Islanders during this timeframe. These neglected sexually transmitted infections represent a significant burden and health disparity. Robust epidemiologic research is needed to identify modifiable risk factors for designing interventions and control strategies. Appropriate policies along with regional and international advocacy and aid are required to improve reproductive health among these vulnerable, understudied populations to avert preventable infections and sequelae.

Transitioning to Telehealth During the COVID-19 Pandemic: Patient Perspectives and Attendance at an HIV Clinic in San Francisco.

Approximately 1.2 million people are living with HIV in the United States, with 16,000 in San Francisco. Many HIV-positive individuals have difficulty maintaining follow-up clinic visits under normal circumstances, and this is complicated by the coronavirus disease 2019 (COVID-19) pandemic as many institutions transition to a telehealth-focused model of care to maintain patient and provider safety. However, it was unknown how telehealth would impact patient attendance and perceptions about their care, particularly in populations at high risk of appointment nonattendance. To quantify the impact of telehealth on retention in care for a vulnerable HIV-infected population and to identify patient perspectives of telehealth and its effect on appointment attendance, we studied patients at the University of California, San Francisco (UCSF) 360 Wellness Center, an HIV primary care clinic in urban San Francisco, California. Anonymous surveys were conducted to assess patient perceptions of telehealth, and 21% of patients sent surveys responded. Appointment attendance rates for all visits were analyzed before and after the shelter-in-place order in San Francisco on March 16, 2020. With the transition to telehealth, the overall nonattendance rate decreased by ∼3%. Most common perceived strengths of telehealth included convenience and safety, whereas disadvantages included technical barriers and unfamiliarity. Despite barriers and disadvantages listed by patients, a majority are willing to attend telehealth visits, as 80.5% of respondents reported being equally or more likely to attend telehealth visits. This is a critical finding during the COVID-19 pandemic and beyond; we believe that telehealth can improve appointment attendance for vulnerable populations who often face barriers to receiving health care.

Tinea capitis in adults.

BACKGROUND: Tinea capitis is caused by dermatophyte fungi that utilize keratin as a nutrient source.  Scalp erythema, scaling, andcrusting are typical signs of this disease.  Although most commonly seen in prepubescent children, tinea capitis can occur in adults. RESULTS: Endothrix tinea capitis owing to Trichophyton tonsurans commonly produces generalized scaling and localized perifollicular inflammation reminiscent of lichen planopilaris. Ectothrix tinea capitis owing to Microsporum sp. produces well- demarcated erythematous plaques suggestive of psoriasis. H&E stained biopsy specimens, KOH preparations or fungal cultures will confirm the diagnosis. CONCLUSION: Because of a low index of suspicion for tinea capitis in adults with scaling and alopecia, diagnosis and appropriate treatment are often delayed. Resistance to treatment for seborrheic dermatitis or psoriasis should prompt a KOH, fungal culture orbiopsy to confirm the diagnosis of tinea capitis and initiate systemic antifungal agents.