Based on the limited information we have about President Trump’s health, it’s too risky to send him back to the White House on Monday.

Admittedly, there is a lot that we don’t know. On Sunday morning, the president’s physician, Sean Conley, gave a second briefing to the public about Trump’s condition. Like the first one Saturday, this briefing omitted critical pieces of information. The American people are forced to play detective work. What little information we have raises alarms.

Let’s begin with what we know about the president’s vital signs, which are called “vital” for a reason. They are the single most important descriptor of how patients are doing. It’s also not enough to have one set of vitals, but to see trends. When doctors and nurses do rounds in the hospital, we pore over charts of all of the patient’s vitals during the past 24 hours.

We don’t have these numbers for Trump. During Saturday’s news conference, Conley described his patient’s vitals as “great.” Less than an hour later, an anonymous source (later identified as White House Chief of Staff Mark Meadows) said that the president’s vital signs had been “very concerning.” If both are true, then that in itself is worrisome: It points to a changing clinical picture that must be closely followed.

In particular, we need to be watchful of the president’s respiratory status. In many patients, covid-19 causes a bilateral pneumonia affecting both lungs. Air sacs in the lungs become inflamed and filled with fluid, leading to breathing difficulties and low oxygen saturation. If the pneumonia becomes extremely severe, patients need to be intubated and put on a ventilator.

On Saturday, Conley repeatedly evaded questions about whether the president required supplemental oxygen. On Sunday, he stated that Trump was not on oxygen at that time but did have two episodes, one on Friday and one on Saturday, where his oxygen level dropped. When asked whether it fell below 90 percent, Conley answered that it wasn’t “into the low 80s or anything.” So we are left to surmise that perhaps the oxygen levels were, at some point, in the mid or high 80s — a concerning finding that points to substantial lung involvement.

Even more concerning is Conley’s admission that the drop in numbers on Friday was what prompted the president’s transfer to Walter Reed National Military Medical Center. This was in line with Meadows saying in an interview that he was worried about the president’s “plummeting oxygen levels.”

I’m worried, too. A covid-19 patient who experiences a substantial drop in oxygen saturation is unstable. It was correct to transfer him to the hospital to watch for signs of deterioration in case he needs further respiratory support. Here’s my question: What’s changed for Americans to be assured that the president is now stable to return to his residence, as doctors suggested could happen as early as Monday?

On Sunday, we learned that Trump has been started on dexamethasone, a steroid medication that has been shown to reduce mortality in critically ill patients. Importantly, this medication is not recommended for patients with non-severe disease. Given the use of steroids and oxygen saturation drops, it seems likely that the president has at least moderate pneumonia.

This is something else that Conley won’t confirm; when asked about Trump’s chest X-ray or CT findings, he would only say they are as “expected.” Notably, he did not say that they were “normal.”

Also consider that Days 7-10 are when patients are most at risk for further deterioration. According to the time course provided by the White House, Day 1 of illness was Thursday, in which case discharging the following Monday would be on Day 5. If the president was brought into the hospital for closer monitoring, what sense does it make to discharge him just before the time period that’s potentially the most fraught?

It’s true that the White House has medical monitoring capabilities. But this is a highly complex situation. In addition to steroids, Trump is on remdesivir for a five-day course that wouldn’t be completed by Monday. This is a medication that itself requires in-hospital monitoring, including frequent lab draws.

He has also received an experimental antibody cocktail from the company Regeneron. As far as I’m aware, no patient in the world has received this combination of treatments. Surely, someone with the president’s risk factors — and who is the president — deserves careful supervision in the event he develops side effects or becomes suddenly ill, as often happens with moderately to severely ill covid-19 patients.

There is another possibility. Perhaps the president is further along in his illness than we’ve been told. Maybe he is already past Day 10 and, while the nation is on edge, his medical team is confident the worst is behind him.

We don’t know, and this is the point: In the absence of trusted information, we are left to speculate on a matter as consequential as the president’s health. Based on what we know, discharging Trump from the hospital on Monday seems premature and potentially dangerous.

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