The United States is poised to surpass its record for covid-19 hospitalizations as soon as Tuesday, with no end in sight to skyrocketing case loads, falling staff levels and the struggles of a medical system trying to provide care amid an unprecedented surge of the coronavirus.

Monday’s total of 141,385 people in U.S. hospitals with covid-19 fell just short of the record of 142,273 set on Jan. 14, 2021, during the previous peak of the pandemic in this country.

But the highly transmissible omicron variant threatens to obliterate that benchmark. If models of omicron’s spread prove accurate — even the researchers who produce them admit forecasts are difficult during a pandemic — current numbers may seem small in just a few weeks. Disease modelers are predicting total hospitalizations in the 275,000 to 300,000 range when the peak is reached, probably later this month.

As of Monday, Colorado, Oregon, Louisiana, Maryland and Virginia had declared public health emergencies or authorized crisis standards of care, which allow hospitals and ambulances to restrict treatment when they cannot meet demand.

Nurses and other hospital staff continued to fall sick themselves, raising nurse to patient ratios in some places to high levels.

“Our systems and personnel are under extreme strain and I’m not sure how long we can sustain it,” Russell Buhr, a pulmonary and critical care physician at Ronald Reagan UCLA Medical Center in Los Angeles, said in an email.

The omicron variant of the virus still appears to cause less severe illness and fewer deaths, and vaccines and boosters are holding up as bulwarks against both. But the sheer number of cases among unvaccinated people, as well as breakthrough cases, was putting pressure on intensive care units and hospital covid wards anyway, even as fewer people are in the ICU than during last January’s peak. Throughout the pandemic, deaths have also lagged behind jumps in the number of infections by a few weeks. Those numbers may rise as well in days to come.