Few people know that a quarter of patients needing ventilators to treat Covid-19 also need artificial kidneys to support their renal function. But are there enough to go around?
We were short of ICU beds. We were short of ventilators. We were short of PPE and testing equipment. And now we could face another shortage – kidney dialysis machines.
Nephrology consultant Graham Lipkin, president of the Renal Association, told the British Medical Journal the problem was an “under-recognised challenge”.
He said: “It has become apparent that there is a high incidence of acute kidney injury requiring some form of renal replacement therapy through dialysis. With the volume of people coming into intensive care, there are increasing challenges to capacity.”
Mr Lipkin explained that Covid-19 patients may develop acute kidney injury for several reasons.
“When patients with Covid-19 arrive at hospital, they are often dehydrated because of prolonged fever and because they have not been eating or drinking as normal,” he said.
“There does appear to be a direct viral invasion of the kidney. Severe Covid-19 is associated with a ‘cytokine storm’ and, during all this inflammation, the kidneys fall victim.”
At the onset of the pandemic, he said there was a “well-founded direction to keep patients on the dry side to try to sustain lung function because patients were dying of viral pneumonia”.
However, we know now this strategy increases the risk of kidney injury and is also unlikely to improve survival. Instead, “keeping patients optimally hydrated reduces the risk of acute kidney injury without worsening chest function”, Mr Lipkin said.
Patients in intensive care usually receive dialysis which requires a machine, plastic disposables, the dialyser and filtrate replacement fluid.
“Given the increased demand in the UK, across Europe and particularly in the US, the disposables and the fluid are in short supply,” Lipkin warned. “We started getting concerned weeks ago, when the true incidence of acute kidney injury started to be apparent”.
He said kidney units are helping intensive care units with dialysis and innovative solutions wherever possible, but they still have to keep up normal service to the UK’s 26,000 patients on dialysis.
For patients with acute kidney injury, doctors have to consider not using drugs that may worsen renal function such as nonsteroidal anti-inflammatory drugs like ibuprofen, while adjusting the dose of drugs such as opiates, metformin, antibiotics (such as penicillin and vancomycin), anticoagulants and heart drug digoxin.