CME INDIA Presentation by Dr. Rajeev Jayadevan, MD, DNB, MRCP, ABIM (Med) ABIM (Gastro), NY. Vice Chairman, Kerala state IMA Research Cell. Member, National IMA Task Force on Corona Epidemic, Cochin.

• Before reading this story, please note that this study examined the use of pulse oximeters amid an established program of remote monitoring, noting that patients don’t have access to a system like COVID Watch or on-call clinicians.
• Self-monitoring with pulse oximeters may still be a reasonable approach until there is evidence to the contrary.

Changing Outcomes In COVID-19 Monitoring by Pulse Oximeters Could Be a Myth?

Pulse Oximeter – Covid-19 – Quick Take Away

  • Pulse oximetry at home did not improve patient outcomes in a randomised trial.
  • Telemedicine monitoring was good enough, finds this US study, NEJM April 6.
  • The groups were age matched, <50% were >50 years.
  • Death was the primary outcome.

What Dr. M. Kit Delgado, MD, MS narrates?

Changing Outcomes In COVID-19 Monitoring by Pulse Oximeters Could Be a Myth?

It was thought that use of a pulse oximeter could detect declining oxygen levels before symptoms develop, and provide an opportunity for the patients to get to the ER faster where they could be stabilized faster.
In the meantime, within two weeks of the first local #Covid19 diagnosis in March 2020, our health system, @PennMedicine launched an automated text-messaging program called COVID Watch to check-in on newly diagnosed #Covid19 patients at home.
Patients who texted-back that they were experiencing symptoms of shortness of breath would receive phone calls within 1 hour from an on-call nurse to either guide them to the ER, arrange an urgent tele med appointment, or continue to self-monitor.
We found that enrolment in the symptom-based monitoring program (COVID Watch) was associated with a significant reduction in mortality with faster presentation to the ER compared with no monitoring.
We then set up a pragmatic randomized trial from Dec 2020 – Feb 2021 in which patients enrolled in COVID Watch as part of usual care were randomized to receive an overnight mailed pulse oximeter or just the standard COVID Watch program.
We hypothesized that the addition of pulse oximeters could help in two ways: 1) Enable patients who feel “dyspnoea” (aka shortness of breath) but have normal oxygen level to continue to self-monitor at home 2) And help patients who develop silent hypoxia to the hospital faster
Under the outstanding, tactical leadership of co-lead authors @katleemd and @AnnaUma
We enrolled 2,097 during the winter 2021 #Covid19 wave. The primary analysis was specified to be among the 1,217 with confirmed positive Covid19 tests within our health system.
The main result: There was no difference in days alive and out of the hospital between the standard program and program + pulse oximetry. In sensitivity analyses this held up for all randomized patients and when just looking at those who actually used their pulse oximeter

Changing Outcomes In COVID-19 Monitoring by Pulse Oximeters Could Be a Myth?

Courtesy: M. Kit Delgado, MD, MS@kit_delgadoMDER doc, epi prof @PennNudgeUnit

This is why randomised trials are important

  • We often believe that some interventions are effective, when they are really not.
  • The study was done during the first wave, which means people did not have the protection of vaccine and were relatively unlikely to have natural immunity from prior infection.
  • They included over 600 people in each group, there were a total of 8 deaths. One can argue the sample size is not very large, but it is still a very good (and difficult) study to execute, and was adequately powered.
  • The downside of having a Pulse Oximeter was that it prompted more phone calls – it must have caused needless anxiety for those being monitored at home.

This also ADDED to the workload of the telemedicine unit.

  • This could be significant, especially in resource constrained settings, when more time is wasted to evaluate and counsel each of these instances.
  • Think of it like repeated false fire alarms disrupting regular office work and that of the fire force (when there is no ‘real fire’ 🔥) .

One important message

  • It was not a comparison between Pulse Oximeter and no monitoring.
  • Both groups were diligently monitored by trained and qualified personnel by telemedicine.
  • Therein lies the difference.
  • The real message is that well-administered telemedicine is good enough, and such monitoring was sufficient to pick out those who needed to be at hospital, while keeping the rest at home.

Having a pulse Oximeter at home (in addition to telemedicine) did not change outcomes.

  • In the post vaccination era, (and protection from natural immunity by prior infection), fewer people will likely be getting severe disease (unless new variants with unusual biological properties emerge).
  • Thus, the role of pulse Oximeter will perhaps be even less.

Changing Outcomes In COVID-19 Monitoring by Pulse Oximeters Could Be a Myth?

Bottom line

  • It might seem like a good thing, but it did not make a difference.

CME INDIA Learning Points

  • Among patients with Covid-19, the addition of home pulse oximetry to remote monitoring may not result in a greater number of days alive and out of the hospital than subjective assessments of dyspnoea alone.
  • Using a pulse oximeter to measure oxygen levels appears no better than just regularly asking patients with COVID-19 if they are short of breath, according to new research at the Perelman School of Medicine of the University of Pennsylvania.
  • We are aware of the stories when patients were referred in panic due to false readings of pulse oximeters.
  • Early in the pandemic, there was a prevalent theory that oxygen levels in the blood dropped before a COVID-19 patient became symptomatic and short of breath (Happy Hypoxia).
  • So, detecting this earlier with a home pulse oximeter might provide an opportunity to get patients who are on the cusp of deteriorating to the hospital faster and initiate time-sensitive therapies to improve outcomes.
  • More than 2,000 patients enrolled in COVID Watch between Nov. 29, 2020, and Feb. 5, 2021, were randomized to receive standard COVID Watch care or the same program with the addition of a pulse oximeter in this very important study.
  • Clearly, we have got an answer that the pulse oximeter does not make the patients any better off.

CME INDIA Tail Piece

  • A low-tech approach for remote monitoring systems based on symptoms is just as good as a more expensive one using additional devices.
  • “Automated text messaging is a great way for health systems to enable a small team of on-call nurses to manage large populations of patients with COVID-19 and there are a lot of other medical conditions where the same kind of approach might really help.”  – Krisda Chaiyachati, MD, an assistant professor of Internal Medicine and now the physician lead for Value-based Care and Innovation at Verily.



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