Paramedics thought the pandemic would mean emergency crews racing to help patients in respiratory distress.

EMS traffic was slow in the spring. But in the fall, the second COVID surge boosted emergency runs and has now pumped up trips between hospitals to create space for those critically ill with COVID-19.

"You would sit around for a long time without calls coming in, because everyone was staying in — everyone was kind of scared of doing stuff," paramedic Devin Orchard said Wednesday after bringing a patient to Mercy Hospital in Coon Rapids.

"When this next wave hit, I feel like it's almost been kind of disbelief. This time our call volumes are way up. … The volume of inter-facility transfers has just gone through the roof."

State data show that ambulances during the week before Thanksgiving handled 780 calls — the highest since the start of the pandemic — where patients either tested positive for COVID-19, reported symptoms or said they might have been exposed to the coronavirus, said David Rogers, data manager and analyst with the Emergency Medical Services Regulatory Board.

The COVID-related volume amounted to just over 7% of the more than 10,000 transfers and 911 calls that week alone, Rogers said, before falling the week of Thanksgiving to 599 calls — still the third highest weekly total of the pandemic. State data also show that transfers involving non-COVID patients have been up compared with this time last year.

The Federal Emergency Management Agency responded last month by sending 25 ambulances and crews to help with the transfers, which have burdened emergency services in Minnesota as they struggle with more staff out because of coronavirus exposures. Deployed two weeks ago, 20 of the ambulances will continue working here for an additional week starting Friday, state officials said.

The FEMA ambulances have been a big help, said Dr. Andrew Stevens, the vice president for clinical operations and chief with Allina Health Emergency Medical Service. Call volumes have moderated some since Thanksgiving, Stevens added, but ambulance services remain very busy — and the relative lull has health care workers on edge.

"We know there's going to be another wave, you just don't know — you don't know when it's coming, and you don't know what's coming with it," he said. "I think that's the uncertainty with this kind of disaster."

On Wednesday morning, Stevens' vehicle sat idling in a parking lot as his dashboard computer listed several "code 36" calls, where emergency dispatchers knew or suspected COVID-19 could be at play. He activated lights and sirens while racing to one call in the north metro for a 12-year-old boy who'd lost his sense of taste and smell after two days of body aches and headaches.

Upon arrival, a device showed the boy's blood-oxygen level at 91, a reading that's a little low, Stevens said, for a pediatric patient without a history of breathing problems. As the boy got up to tie his shoes and climbed on a tall chair before heading to the ambulance, the reading dipped to 86.

"We'll need a nasal cannula," Stevens said to paramedics who brought oxygen. "I don't want him to get real short of breath."

As the ambulance took the boy to the hospital, Stevens predicted the child probably wouldn't need much hospital care unless a chest X-ray showed viral pneumonia. In that case, the boy wouldn't need much more than a night in the hospital — children can be infected with the virus, Stevens said, but it seldom results in serious illness.

"I'm not worried about that kid," he said. "If that was my 12-year-old, I know that they're going to be just fine. But that doesn't mean they don't need help."

COVID calls have increased significantly this fall, said Crystal Gaughan, one of the paramedics who helped the boy. On Tuesday alone, she said, half of her patients were infected with the coronavirus.

Ambulance call volume overall is probably steady, added paramedic Gregory Harvey, but staff absences mean the remaining crews have to hustle to handle more runs.

"We've had a couple of days now when it hasn't been as bad," Gaughan said, but otherwise "it's been nonstop."

More COVID means medics must don more protective gear, which can make it harder to communicate with patients, said Kieran Gallagher, an emergency medical technician for 23 years. The unknowns in responding to patients somehow seem worse in this pandemic, Gallagher said, than with other infectious diseases.

"It hits so many different people so differently," she said. "I live with my sister who has MS, and the fear of taking it home to her — to your loved ones — is scary."

Inter-facility transfers are an important part of "load leveling" at hospitals, which means patients who are well enough can move from a large metro medical center to an outlying facility, Stevens said. Transfers also can help spread demand, Stevens said, when there's an influx of patients at one hospital as another nearby medical center is relatively quiet.

The work of transferring patients usually falls to basic life support ambulances, but higher-level crews are helping shoulder the increased burden, said emergency medical technician Kayla Peterson. Even so, "it does get hard sometimes," Peterson said while waiting to transfer a patient from United Hospital in St. Paul.

Transfers help prevent hospitals from being overwhelmed — a term that's often invoked when describing the pandemic's stress on health care, and one that Stevens said he dislikes for being vague.

"Overwhelmed means the Alamo has fallen," he said. "I don't think that's where we are, or that's where we're going."

The emergency medical system is built with excess capacity for responding to occasional incidents that generate mass casualties, Stevens said. But most of those emergencies last hours or days, he said, raising concerns that health care workers will just get worn out.

"EMS and public safety are built for disasters," Stevens said. "It's just maybe they're not built for disasters that are supposed to last for a year."