Oximetry Fails to Predict Future Bronchiolitis Care

Diedtra Henderson

March 11, 2016

Pulse oximetry does not effectively predict which infants diagnosed with bronchiolitis will return for unscheduled medical care after an emergency department (ED) discharge, according to a prospective cohort study published online February 29 in JAMA Pediatrics.

"Our study shows that the majority of infants with mild bronchiolitis experienced recurrent or sustained desaturations after discharge home. Children with and without desaturations had comparable rates of return for care, with no difference in unscheduled return medical visits and delayed hospitalizations within 72 hours. These findings challenge the concept that infants with desaturations were sicker and suggest that pulse oximetry is not an effective tool to predict morbidity leading to escalated return for care," write Tania Principi, MD, FRCPC, from the Research Institute and Department of Pediatrics, The Hospital for Sick Children, Toronto, Ontario, Canada, and colleagues.

Bronchiolitis is the leading cause of infants' hospitalization and accounts for $1.73 billion in annual spending, Dr Principi and coauthors write. When routine use of oximetry began in the 1980s, hospitalizations soared from 12.9 to 31.2 per 1000 infants.

To better understand the clinical significance of desaturation, the research team enrolled 118 infants between February 6, 2008, and April 30, 2013. The infants, aged 6 weeks to 12 months, had been discharged from a Toronto pediatric ED with acute bronchiolitis and did not need supplemental oxygen. A saturation probe was securely applied to the foot, and the infants were sent home with portable oxygen saturation monitors with the saturation value display screen disabled.

Nurses interviewed parents 72 hours after discharge to determine whether infants had unscheduled medical visits for bronchiolitis. The team also used software to analyze data downloaded from the oxygen saturation monitors to learn how many infants had experienced desaturations, which the researchers defined as a drop in oxygen level to less than 90% that lasted at least 1 minute. Desaturations were classified as "major" if infants experienced at least three such episodes, if they were desaturated at least 10% of the time they were monitored, or if they experienced prolonged desaturations that lasted at least 3 minutes. Some 75 of the 118 infants, or 64%, experienced at least one desaturation at home.

"Of the 118 infants, 29 (25%) had unscheduled medical visits for bronchiolitis within 72 hours of the index ED visit: 15 returned to their primary care physician, 11 visited an ED, and 3 both saw their primary care physician and visited an ED," Dr Principi and colleagues write.

The rate of unscheduled medical visits was not different between those with desaturations (18 of 75 infants; 24%) vs those without desaturations (11 of 43 infants; 26%; P = .66).

In an accompanying editorial, Lalit Bajaj, MD, MPH, from the Department of Pediatrics, Section of Emergency Medicine, University of Colorado School of Medicine/Children's Hospital Colorado, Aurora, and Joseph J. Zorc, MD, MSCE, from the Department of Pediatrics, The Children's Hospital of Philadelphia and University of Pennsylvania, Philadelphia, note that the study was relatively small and only included a single center. They also question whether unscheduled return at 72 hours after discharge was "the most important clinical outcome measure to assess the effect of desaturations."

Still, Dr Bajaj and Dr Zorc said the study results "call into question" current overreliance on pulse oximetry for decision-making in bronchiolitis. "Pulse oximetry has undoubtedly contributed to improved quality and safety of pediatric care, as these boxes have become a fixture at virtually every hospital bedside during recent decades. For bronchiolitis, however, some may view the oximeter as a Pandora's box that was opened before the research had been done to appropriately interpret this stream of data. This has led to arbitrary thresholds for oxygen implementation and widespread use of continuous pulse oximetry," the commentators write.

Both the study authors and the commentators point to recent guidelines from the American Academy of Pediatrics that argue against providing supplemental oxygen to patients with oxygen saturation levels of at least 90% and that counsel against continuous pulse oximetry for most patients. Dr Bajaj and Dr Zorc write that the "American Academy of Pediatrics guidelines serve as a good start, but more work is needed to rationalize the use of this important but overemphasized technology."

In a tape-recorded interview that accompanies the article, study coauthor Suzanne Schuh, MD, FRCPC, from the Research Institute and Department of Pediatrics, The Hospital for Sick Children, says that oxygen saturation is a dynamic measurement that routinely rises and falls and tends to drop during certain activities, such as sleeping. Even drops that are not accompanied by respiratory distress trip preset oxygen monitor alarms that prompt decisive action, such as providing supplemental oxygen and admitting the infant to the hospital.

"Because the numbers during the night, when they fall asleep, are not to people's likings, they stay in hospital for extra time, which in many, many instances — we cannot say for sure all, but certainly many instances — is probably unwarranted," Dr Schuh says. "So, I think we need to concentrate on the sicker patients, in terms of monitoring, as opposed to" infants with relatively mild disease.

Financial support for the study was provided by the Physician's Services Incorporated Foundation and the Canadian Association of Emergency Physicians. The authors and the editorialists have disclosed no relevant financial relationships.

JAMA Pediatr. Published online February 29, 2016. Article full text, Editorial full text


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