Virus risk factors show who is likely to land in the hospital

Hospitals might not know how many COVID-19 patients they'll be treating as the wave of the pandemic peaks in the next month or so in Minnesota, but they're starting to get a better idea of who will end up in their beds.

While there remains a random or yet-to-be understood aspect to COVID-19 — and why it causes no symptoms in some, but sends others gasping into hospitals — the latest state and federal data show some clear risk factors.

Hypertension and obesity — the same scourges fueling diabetes and heart disease in Minnesota over the past two decades — have each been identified in at least half of all COVID-19 hospital patients, according to COVID-NET, a federal tracking site that receives hospitalization data from Minnesota and a dozen other states.

Labored breathing and low blood-oxygen levels are what typically prompt doctors to admit COVID-19 patients, but those patients rarely have no other health concerns, said Dr. Aaron Rutzick, a Hennepin Healthcare specialist who treats COVID-19 patients and assesses their needs for hospital care.

The connection might be as simple as an infection making a sick person sicker, he added. "Your body just has other medical conditions it's working on. Then you throw this other element at it."

The state reported 16,372 lab-confirmed COVID-19 cases and 731 deaths as of Monday, which marked the end of a statewide stay-at-home order that lasted 51 days. The number of patients needing hospital care on Monday was 488, including 229 needing intensive care.

While the state's number of hospitalized patients has remained largely unchanged over the past week, health officials do expect more disease transmission following the end of the stay-at-home order and a resulting surge in cases.

Modeling by the University of Minnesota and state health researchers suggested that nearly two months of reduced contact under the stay-at-home order made a difference. Face-to-face contact and opportunities for disease transmission were reduced by 55%, although initial predictions suggested a larger 80% reduction.

Even so, modeling of a scenario similar to Minnesota's current strategy predicted a peak in just over a month of 3,397 patients needing ICU beds with ventilators, which are needed for COVID-19 cases that cause severe respiratory symptoms and difficulty breathing. The state's preparation website lists a total capacity of 3,696 ventilators in Minnesota — though with 858 on back order.

State health officials said they will be closely watching hospitalization numbers and that the best way to conserve bed capacity is to continue to take steps to reduce transmission of the virus.

The latest state guidance is to avoid gatherings outside of immediate households of 10 or more people, to wear cloth face masks or bandannas when possible, and to maintain a social distance of 6 feet or more from others.

While there are no separate recommendations for people with underlying health problems, they should be especially aware of these safety measures recommended by the state health commissioner and their elevated risks of hospitalization, said Kris Ehresmann, state infectious disease director.

"Those are all things that need to be considered as people are hearing the commissioner's admonition to social distance, to wear masks, to do all of the things that we've advised," Ehresmann said. "There's a large portion of our population that falls into the at-risk category."

Statewide, 2,128 COVID-19 patients have been admitted to hospitals. The state so far has reviewed 1,104 COVID-19 patients, mostly those in the seven-county Twin Cities metro area whose aggregate hospital results are part of the federal COVID-NET program.

The median body mass index of those patients was 30, the bottom threshold for obesity. About 48% had diabetes or other metabolic diseases; 39% had asthma or other lung diseases; and 33% had hypertension — the technical term for high blood pressure.

Cardiovascular problems were found in 43% of hospitalized patients and are of particular concern for COVID-19, which tends to cause blood clots that can lead to strokes or other problems.

Doctors have become fairly aggressive at admitting and prescribing blood thinners for many COVID-19 patients to address those clot risks, said Dr. Andrew Olson of M Health Fairview.

There are still many unknowns about COVID-19 and why it strikes similar patients in different ways, he added: "Why do some with ... hypertension not end up in the hospital and others do? I don't think we quite know that yet."

Admissions vary by race; black people make up 23% of hospital admissions, but only 6% of Minnesota's population. While chronic disease rates are higher in this minority group in Minnesota, Olson said there are likely social and economic disparities that predispose blacks in Minnesota to worse COVID-19 cases.

COVID-19 deaths have been more common in the elderly. The median age of death is 83, compared with the median age of hospitalization, which is only 61.

Among reviewed COVID-19 cases whose hospitalizations ended, 85% were discharged alive while 15% died. The death rate is much higher, at 53%, when examining outcomes of 152 patients who were intubated due to respiratory failure and placed on ventilators or heart-lung bypass machines.

Sometimes patients with COVID-19 who have other conditions get admitted because they already have worse respiratory symptoms when they seek medical care, said Dr. Chris Kapsner, medical director of emergency care at Abbott Northwestern Hospital in Minneapolis.

Other times, doctors are just trying to predict which patients are more likely to hit the "brick wall" that seems to come with COVID-19 when their health plummets, he added. "We're tying to predict the future, and so if you have high blood pressure, heart disease, you're 55 and a man, your prognosis is worse than a 50-year-old women with no health problems."

Hospital resources have improved over the last three weeks, particularly in regard to personal protective equipment that reduces the threat of doctors, nurses and other caregivers being infected by the virus.

As of Monday morning, the state's pandemic response page listed a stockpile of 1.2 million N95 masks that are fitted and offer more protection than standard surgical masks — as well as 2.6 million scheduled for delivery. Three weeks ago, the site listed only 478,000 such masks obtained with 1.6 million awaiting delivery.

Kapsner said the decisionmaking on who to place in hospital care today could well change in a month when bed space gets tight and masks and ventilator supplies shrink.

Studies of outcomes of COVID-19 patients will help to guide decisions at that time. Allina Health is devising a COVID-19 home care strategy for patients who can avoid hospitalization with appropriate monitoring and treatment at home.

"Let's say the hospitals are full, there's no room," he said. "What we might admit today we will send home tomorrow."

Jeremy Olson • 612-673-7744