Among the 75 infants with desaturations, 59 (79 percent) had desaturation to 80 percent or less for at least one minute and 29 (39 percent) had desaturation to 70 percent or less for at least one minute.

“So about two-thirds of the kids desaturated and the majority . . . met criteria for major desaturation,” Dr. Schuh said. Despite this, the rate of unscheduled medical visits to the primary care physician or ED was “virtually identical; 24 percent came back in the group that desaturated versus 26 percent that did not, so the difference was about 1.5 percent and that was neither clinically nor statistically significant. We also looked at the patients that had to be hospitalized after the initial discharge from the emergency department and that difference was also negligible.”

Among the 62 infants with desaturations who had diary information, 48 (77 percent) experienced them during sleep or while feeding, the investigators note.

“We need to figure out who we need to concentrate on in terms of [home pulse oximetry] monitoring. Are there special groups, because right now everyone is being monitored. I think we need to concentrate on the sicker patients in terms of monitoring as opposed to the ones who have relatively mild disease,” Dr. Schuh said.

The authors of a linked editorial say this study “places the issue of transient desaturations and their clinical importance at the forefront of the discussion around management of these patients. In addition, it adds to the dilemma of which patients should receive pulse oximetry in their evaluation and how to interpret the values.”

“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,” write Dr. Lalit Bajaj of Children’s Hospital Colorado, Aurora, and Dr. Joseph Zorc of Children’s Hospital of Philadelphia, Pennsylvania.

“With this study,” they add, “we now have a clearer view” that transient hypoxemia events likely occur in many infants with bronchiolitis “and are not associated with apparent negative outcomes. Incorporating this information into clinical practice will require health care professionals to take a more judicious approach to the use of pulse oximetry in the evaluation of the patient. The evidence points to a clinical evaluation that incorporates oxygen saturation into the decision making but does not absolutely determine disposition. The time has come to stop focusing on the numbers on Pandora’s box and to develop strategies to thoughtfully use the data it provides us in the overall clinical care of the patient.”