They’ve not been overwhelmed yet, but ICUs could face new challenges against the oncoming Delta storm.
A leading Melbourne hospital specialist has warned that intensive care units (ICUs) might be in for the long haul in the COVID-19 fight, facing increasing admissions despite rising vaccination numbers across the country. But new treatments may ease the burden, limiting the number of critical cases and helping ICUs from being overwhelmed.
“We’ve been very, very lucky in Australia to prevent the large-scale public-health disasters [seen] in some places around the world,” says Associate Professor Jai Darvall, an anaesthetist and intensivist – intensive care specialist – at the Royal Melbourne Hospital.
“But it does mean that we’ve got a lot of work ahead of us now in a predominantly unvaccinated community still. The great hope from all of us in ICUs is that that vaccination target will be met soon. But how it plays out in our ICUs next year, as restrictions lift and we start to get back to some semblance of normal life, I think we’re all a little nervous about that. I think this is going to be a long haul.”
The Royal Melbourne’s ICU is one of two trauma centres in Victoria, which placed it at the forefront of the response to the state’s so-called second wave last year, when Melbourne went into lockdown for 112 days and COVID-19 cases surged to more than 700 per day.
The impact of such outbreaks on ICUs has been a major focus and source of concern during the pandemic, with worries that the health system could be overwhelmed. Once little considered, the machinations of an intensive care unit are now front and centre in the nation’s mind and conversation.
“I think one thing that this pandemic has really done is open the door a little bit on what often is a bit of a black box,” says Darvall. “Not a lot of people in the community know what it is that an intensive care unit does.”
The machinations of an intensive care unit are now front and centre in the nation’s mind and conversation.
In normal times, pre-COVID, a hospital ICU was a demanding and hectic place. The Royal Melbourne’s ICU contained 42 beds and managed a range of presentations. Trauma cases from the likes of car accidents were common, as well as emergency presentations such as infections, sepsis and organ failures. Typically, around half of all admissions were post-operative patients needing advanced monitoring or care after surgery.
“On a pretty typical day in the ICU, we might start at about 7am or 7.30am, and we’d do a ward round with the night team,” says Darvall. “We have a look at all of the patients in the unit – which ones are able to be discharged to the ward, and which ones are perhaps more sick and need a bit more of our attention.
“Then there’ll be a whole lot of work that goes into getting their test results together, trying to progress their care for the day – what new organ failures have turned up overnight, or perhaps which machines we can take away that day. So, the ICU is a very busy place under normal circumstances.”
Patients would typically stay in the ICU for a day or two, with only a few remaining for extended periods of time, requiring prolonged management for persistent critical illness.
“It’s actually quite a short duration of average stay in the ICU,” says Darvall. “I think that’s in large part because many of those patients are fairly routine – post-operative patients that need that first day or two to recover from a big operation, or a trauma, or sepsis or an infection. Often those illnesses resolve quite quickly, and we can get them to the ward very quickly.”
Patients would typically stay in the ICU for a day or two, with only a few remaining for extended periods of time.
It was a slick approach to the sick, but it was all upended once ICUs began filling with COVID patients.
“COVID is a little different when it comes to the intensive care management,” says Darvall. “By and large, these patients stay a lot longer – at least twice as long. The average duration of stay throughout 2020 in COVID patients around the country – most of whom, of course, were managed in Melbourne – was six days. And whereas usually about a third of all patients coming through will require what we call invasive mechanical ventilation – that’s the ventilator and the breathing tubing into the windpipe – more than half of all of the COVID-19 admissions to the ICU require that. So, it’s a much more complex, high-intensity patient mode.”
A COVID patient on mechanical ventilation faces, on average, a stay of two weeks in ICU, exacerbating the potential for bed exhaustion in the unit. The treatment is also a high-stress situation for all involved.
“[Ventilation] is one of the most invasive things we do as intensive care specialists,” says Darvall. “We give the patient a general anaesthetic, and then we place the breathing tube into the windpipe and connect them to a ventilator, which is a machine that breathes the gas in and out of the lungs. One of the more challenging things for a patient with COVID-19 disease is they’re very unwell when this is happening. It really is a last-ditch therapy. So, the speed with which that needs to be performed is much faster. And we have to be really quite diligent in getting the patient as stable as possible through the process.
It was all upended once ICUs began filling with COVID patients.
Darvall points out that the results for treatment for COVID-19 disease in ICUs in Australia were on a par with best practice around the world in 2020. About 10%, or a little higher, of all patients who were sick enough to require the ICU did not survive – but he emphasises how age really plays into outcomes from the disease.
“Let’s say for patients younger than 60 years old, the mortality rate was less than 5%,” he says. “But once you get up to older than 70, that’s at about 20%. Older than 80, it’s more than half of patients are dying, unfortunately, if they’re unwell enough to need ICU with COVID-19 disease.”
Most patients that succumb to COVID-19 do so as a result of hypoxia. “That’s a problem getting oxygen into the blood. What we’ve seen in the patients that have severe COVID-19 disease and ultimately die, is that they move into a state of multi-organ failure.
“Then there are those patients where the disease is mainly confined to such severe respiratory failure that there’s no prospect of getting off the ventilator. And that is a really sad outcome – where there’s a point at which it becomes apparent that we can’t get the person back home.”
It’s this simple cause and effect – beds being occupied for far longer periods by patients – that most stretches ICU capabilities
It’s this simple cause and effect – beds being occupied for far longer periods by patients – that most stretches ICU capabilities, though Darvall says that even at the height of the second wave the Royal Melbourne Hospital’s ICU never exhausted its supply of beds.
“As these [COVID] patients were staying a lot longer, it had a lot of effects on the day-to-day business of the ICU,” he recounts. “Patients continue to have heart attacks and crash their cars and have strokes and have all the usual indications for requiring us in the ICU. And that adds a lot of complexity once the ICU starts to fill up with patients that are going to be there for a long time.
“Fortunately, we weren’t really faced with the situation of bed exhaustion last year. Things certainly got very busy. But one of the quite fortunate things we were able to do in Australia, as we saw what was happening overseas, was plan for so-called surge capacity. So, although we have 42 physical beds in our ICU, in our hospital we have a lot of scope to expand that relatively rapidly, scaling up to different wards around the hospital. I know that’s happening in Sydney to some degree already as the patient numbers increase.
“One of the greatest challenges in that kind of circumstance is not so much the physical bed space, it’s actually the human capital, in particular, the ICU nursing pool. They really are the most precious resource in the ICU, and that is the most difficult factor to account for in a surge environment – the vast numbers of staff, particularly nurses, that are needed to care for the patients.”
There’s cause for hope over and above vaccination, with new drugs emerging.
While growing vaccination numbers hold the promise of an eventual return to normality in ICU units, Darvall remains nervous about the immediate future as community restrictions ease in accordance with vaccination rates. But he also sees cause for hope over and above vaccination, with new drugs emerging that may give intensive care professionals more ability to treat the disease before it becomes critical.
“There are some novel therapeutics that are coming onto the market, and we hopefully will have a few more drugs in our armamentarium to handle patients once they have contracted COVID-19 pneumonia,” he says.
“So, although much of the focus has been on preventing the disease with vaccinations, there’s the potential for some of these new drugs to give us a little bit more ammunition in the kit bag to treat those patients to try and prevent them becoming critically unwell and/or dying.
“Antiviral drugs, steroids, have been shown in in large-scale trials to offer some benefit. But there are some even newer monoclonal antibodies that have recently been FDA-approved in the US and TGA approved here that look somewhat promising at preventing that severe spectrum of illness.
“That hopefully gives us some promise going forwards that we’ve got more than just public-health measures and vaccines to prevent ICU overwhelm.”
Andrew Bain is a contributor to Cosmos Magazine based in Hobart, Tasmania.