A new study questions the value of home pulse oximetry in infants with bronchiolitis well enough to be discharged home from the emergency department.

“The main conclusion is that the oximetry is not a very effective way for us to predict the return for care,” Dr. Suzanne Schuh of the Hospital for Sick Children, Toronto, Canada, said in a JAMA Pediatrics podcast.

For children with bronchiolitis “who in the opinion of the treating emergency physicians have satisfactory respiratory assessment to go home, further oximetry measurements should not be done,” she concluded.

Because bronchiolitis involves very young infants with respiratory distress it can at times be a “very scary disease to both the parents and the physicians alike. In addition to the usual clinical methods of judging the severity of bronchiolitis, there is pulse oximetry and the challenge is how to interpret the findings of oxygen saturation in the blood,” Dr. Schuh explained.

Since pulse oximetry started routinely being used in the mid-1980s, the hospitalization rate for bronchiolitis jumped about two and a half fold and experts feel this is largely due to the oxygen saturation measurements, she noted.

“Oxygen saturation is actually very dynamic. It goes up and down and it tends to go down when the infant is asleep or feeding. Sometimes the measurement goes below the comfort level of many physicians, especially when the infants are asleep, but these desaturations are frequently not accompanied by respiratory distress,” Dr. Schuh said.
The problem, she noted, is that these machines have certain preset alarms usually in the vicinity of 90 percent saturation, so when the infant falls asleep and the saturation drops below a predetermined cut-off, the alarm sounds, which often prompts action. “Supplemental oxygen is frequently begun and the child is admitted to hospital.”

As reported online in JAMA Pediatrics, the Toronto team studied the effect of oxygen desaturations on subsequent unscheduled medical visits in 118 infants clinically well enough to be discharged home from the ED. Each infant was sent home with a pulse oximeter.

During an average monitoring period of about 20 hours, desaturations were common: 75 infants (64 percent) had at least one oxygen desaturation to lower than 90 percent for at least one minute; 59 (50 percent) had at least three desaturations; 12 (10 percent) had desaturation for more than 10 percent of the monitored time; and 51 (43 percent) had desaturations lasting three or more minutes continuously.

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.”

The study had no commercial funding and the authors have no disclosures.