ARE 826 VENTILATORS ENOUGH FOR SAN DIEGO?

Officials say yes, but only if people stay home, stick to social-distancing practices

The massive social-distancing campaign now unfolding throughout the state and nation is meant to buy the health care system enough time to manage the inevitable onslaught of COVID-19 cases.

It’s the same life-saving edge that mechanical ventilators give the small percentage of patients who get the sickest from novel coronavirus infection.

Hospital impact models suggest that it’s quite possible to make it through the coming spread of disease across the region without outstripping ventilator and hospital bed capacity, but only if a signifi

cant percentage of the populace actually follows through with the social-distancing measures that have been ordered.

It’s hard to overstate exactly what access to mechanical ventilation buys for the small percentage of patients who end up needing them, said Dr. Jess Mandel, director of pulmonary critical care and sleep medicine at UC San Diego Health. Because severe respiratory symptoms appear very quickly, there is an opportunity, if patients have immediate access to ventilation, to use pressure to “pop” open collapsed air sacs in the lungs before an unrecoverable amount of damage occurs.

This kind of action is what’s needed to give the immune system a fighting chance.

“Ventilation is a tool that really just allows us to keep the patient’s body as oxygenated and well-nourished as possible for the, in most cases, few days that they need until the body’s own immune system is able to fight off the virus,” Mandel said.

Writ large, then, a community’s ventilator supply is its collective ability to buy recovery time for patients in respiratory distress who need it most. Studies out of China, where the disease originated, indicate that about 5 percent of patients get sick enough to be admitted to an intensive care unit for treatment and an even smaller group, perhaps 1 percent, of all diagnosed patients need a ventilator.

County officials said Friday that the collective ventilator capacity in local hospitals, excluding those run by the military, currently stands at 826. A snapshot that afternoon showed that about 500 of those vents were in use, leaving roughly 300 available. The county also has an unspecified number of emergency ventilators it can draw on and can also tap strategic and national supplies.

Ventilator capacity has become a growing concern worldwide, especially as the health care industry watches from afar as COVID-19 overwhelms supply in Italy, forcing physicians, nurses and technicians to choose who to save.

An analysis published by the Society of Critical Care Medicine, which was revised Thursday, cites a recent estimate from the American Hospital Association that about 30 percent of the American population will test positive for COVID-19, with about 4.8 million hospitalized, 1.9 million needing intensive care and about 960,000 nationwide requiring ventilation.

These numbers have caused much concern that the nation simply does not have enough ventilators to go around, even with a strategic national stockpile of 12,700 breathing machines maintained by the U.S. Centers for Disease Control and Prevention.

Concern about overwhelming this vital resource, or simply having more COVID patients than there are respiratory technicians to effectively take care of them, is what has driven the sudden rush to social distancing. The idea is to simply slow the spread of the virus enough that cases arrive in hospitals steadily over as long a time period as possible, rather than crashing in all at once as they have in Italy.

Public health departments do sophisticated epidemiological modeling to predict how rapidly an epidemic will generate new cases and, in San Diego at least, that modeling has not been shared with the public.

But many hospitals in the U.S. have been using a modeling tool put together by Penn Medicine at the University of Pennsylvania, to get a rough order-of-magnitude understanding of what might be headed their way under different scenarios.

Plugging in San Diego’s population of 3.3 million and the 18 hospitalizations listed in the county’s daily COVID tracking report, the model indicates that, with only a 10 percent reduction in social contact from social distancing, the local situation would be catastrophic. Hospitalizations would peak at more than 1,327 per day, eventually producing a daily hospital census of more than 9,138 patients, swamping the local bed capacity of 8,500.

But that’s with a 10 percent reduction, what we would get if people were only paying lip service to social distancing but still gathering for recreational reasons.

The model shows a dramatic difference if social contact were reduced by 45 percent instead of just 10 percent.

With that level of social unmixing, daily admissions never surpass 140, and the maximum daily number of COVID patients in local hospital beds never crosses the 1,000 mark. The maximum number of ventilators in use by these patients never exceeds 300, the number that were available Friday.

Dr. Eric Mcdonald, medical director of epidemiology and immunization services for San Diego County, said in an email that, while nobody should be striving for anything less than 100 percent compliance, the Penn model does effectively but roughly show the gains that are possible if we all just stay put.

At the moment, at least until widespread testing becomes available and we can quickly know who is infected and needs to be isolated, Mcdonald, and many of his colleagues, are stressing that the amount of bang we get for our social-distancing buck comes down to a whole lot of individual behavior, to our collective ability and will to keep those symptoms that are occurring from circulating.

“Any person with even the mildest symptoms MUST self-isolate until seven days after the onset of symptoms, or three days after symptoms resolve, whichever is longer,” Mcdonald said. “People sequestering themselves is the intervention that will make the biggest impact.”

There is no true gauge of the exact amount that the current stay-home situation has reduced social contact. Many who are in vital jobs must still go to work and people have to eat and heal, so they’ll keep coming together, while simultaneously trying to keep at least 6 feet away from each other, in locations such as grocery stores and doctors’ offices.

Mandel, the UC San Diego pulmonary director, said he has his own gauge of how well the distancing directive is delivering.

His morning commute, he said, involves riding his bike across a bridge over Interstate 5. These days, the amount of traffic pumping through this particular community artery is dramatically less than it was just a week ago.

The physician said he has treated several COVID patients in UCSD intensive care units. He is one of the few in the region who has experienced the satisfaction of removing a COVID patient from a ventilator and may soon be in the position of sending patients who were in critical condition home.

It’s a situation that he desperately hopes can continue. He and his colleagues, he said, see the boredom-driven Netflix recommendations fly by on social media and feel a wistful pang at missing out on the current rash of couch surfing. But they also know that wave can save.

“From our perspective, we are totally dependent on that couch sitting,” Mandel said. “Among my heroes would be anyone who develops mild symptoms and just stays home, doesn’t go to work, stays away from friends and family, for however long it takes until they’re not infectious.”

CLAUDIO FURLAN AP Ventilator shortages have been a problem not just locally and in the U.S. but worldwide, especially in hard-hit areas such as Italy, where this patient was being treated Thursday at a hospital in Brescia.