Pulse ox less accurate in non-White patients, affects COVID-19 treatment
One study compared measures of oxygen saturation by pulse oximetry and arterial blood in COVID-19 patients by race, finding that overestimates may delay treatment for Black patients. Another study found potential overuse of opioids and benzodiazepines at discharge from COVID-19 hospitalization.
Pulse oximetry (SpO2) can overestimate oxygen saturation levels in non-White patients with COVID-19, a recent study found.
The study compared 32,282 concurrent (within 10 minutes) measures of oxygen saturation by SpO2 and arterial blood (SaO2) in 1,216 inpatients with COVID-19 (63 Asian, 478 Black, 215 Hispanic, and 460 White). It also looked at 6,673 patients with available pulse oximetry measurements and covariate data to assess rates of overestimation of arterial oxygen saturation levels by pulse oximetry and effects on treatment. Results were published by JAMA Internal Medicine on May 31.
The study found that occult hypoxemia occurred in 19 Asian (30.2%), 136 Black (28.5%), and 64 Hispanic (29.8%) patients compared with 79 White patients (17.2%). Compared with measurements in White patients, SpO2 overestimated SaO2 by an average of 1.7%, 1.2%, and 1.1% among Asian, Black, and Hispanic patients, respectively. An analysis of 1,903 patients who had predicted SaO2 levels of 94% or less before oxygen treatment found that Black and Hispanic patients were significantly less likely to be judged eligible for related COVID-19 treatments (hazard ratios, 0.71 [95% CI, 0.63 to 0.80] and 0.77 [95% CI, 0.66 to 0.89], respectively). A total of 451 patients never had their treatment eligibility recognized, 54.8% of them Black. Among the remaining 1,452 patients who received the treatments, Black patients had a median delay of 1.0 hour (95% CI, 0.23 to 1.9 hours; P=0.01) compared to White patients.
“While pulse oximetry has become a fundamental tool in diagnosis, triage, and management decisions in the acute care setting, the device's lack of accuracy in certain populations has not been adequately investigated or addressed, although it has been recognized for several decades and was highlighted in a 2020 safety communication by the US Food and Drug Administration,” the study authors wrote. “Differential inaccuracies in pulse oximetry should be examined as a potential explanation for disparities in COVID-19 outcomes and may have implications for the monitoring and treatment of other respiratory illnesses.”
An accompanying editorial connected the study's findings to broader disparities, noting that the failure of hospitals to act on this known issue “could suggest that racial equity in patient care is not something these institutions are willing to pay for—or at least not enough of a priority to insist on devices that work equitably,” the editorialists wrote.
In other COVID-19 research, a retrospective study of hospitalized patients in Michigan, published by the Journal of Hospital Medicine on May 27, found potentially problematic use of opioids and benzodiazepines. Among 857 opioid- and benzodiazepine-naive patients not requiring mechanical ventilation during hospitalization for COVID-19, 22% received opioids, 13% received benzodiazepines, and 6% received both. At discharge, 8% received an opioid prescription and 3% received a benzodiazepine prescription. “The rate of new opioid or benzodiazepine starts among naïve individuals in this cohort is notable,” the authors wrote, noting that “opioids and benzodiazepines are not recommended for COVID-19 patients due to the risk of respiratory impairment, and respiratory failure is an independent risk factor for opioid-related adverse events,” in addition to the general risk for future use and dependence. It was also notable that 24% of the discharge opioid prescriptions went to patients who hadn't taken the drugs during admission, the study authors said. “Previous work suggests that individuals who do not consume opioids in the 24-48 hours before discharge need few, if any, at discharge,” they wrote.
