Latest from London 4/3/20

Thanks Richard Davies for the info below:

From the Head of ICU at the Royal Free. Please feel free to disseminate further.

“Dear All,

I have just finished a very useful ICU / NHS Nightingale teleconference, the aim of which was to consolidate experiences about CV19 and how best to manage the disease. I have provided a summary below. Please understand that the information is experience, not evidence. I think it highlights a number of areas that we need to discuss URGENTLY as a group. The take home message is that advice given at the beginning of this journey needs to be adapted as we learn more about CV19. The other important thing to begin to understand is that this disease has distinct phases and treatment will differ as patients move through these phases.

The call had about 80 people on it, most listening. There were about ten “experts” invited to speak, from high volume centres. I represented our site. Others included Georges, GSST & Brompton.

Ventilation

  • Early high PEEP is probably not the right strategy and may be harmful. This is not ARDS in the early phase of the illness.

  • Avoid spontaneous ventilation early in ICU admission as also may be harmful.

  • There is clear microvascular thrombosis happening in the pulmonary circulation, which leads to an increased dead space.

  • Also some evidence of early pulmonary fibrosis reported from Italy, possibly oxygen related, possibly inflammation related.

  • Not many patients have reached extubation yet in London, re-intubation seems to be common. I highlighted our experiences of airway swelling / stridor / reintubation.

  • Brompton are seeing wedge infarcts in the lungs on imaging, along with pulmonary thrombosis without DVT.

  • Proning is essential and should be done early. Don’t just do it once. Threshold for many centres is a PF ratio of 13, but all agreed, do it even earlier.

  • Early on in the disease, the benefit of proning lasts < 4 hours when turned back to supine, as the disease progresses into a more ARDS type picture, the effect is more long lasting.

  • Many centres using inhaled nitric oxide and prostacyclin with good effect. Tachyphylaxis with NO after 4-5 days.

  • Generally people are using humidified circuits with HMEs.

  • A very interesting thing they are doing at Georges is cohorting by phase of disease i.e. early, late, extubation / trachy. It involves more moving of patients but helps each team to focus on things more easily.

  • Leak test before extubation is crucial, others are also seeing airway swelling.

  • Wait longer than usual before extubating, high reintubation rates reported. Do not extubatne if inflam markers still high.

My conclusions from this are:

  • Less aggressive PEEP strategy at the beginning of the disease and go straight for proning.

  • Thromboembolic disease is prevalent, look for it. No one is sure about whether we should anti-coagulate everyone, this is probably too risky.

  • An extubation protocol is needed immediately.

  • We should consider using inhaled prostacyclin again (like we previously did) as it seems to be working early in the disease.

Fluid balance

  • All centres agreed that we are getting this wrong.

  • Most patients come to ICU after a few days of illness where their temp was 38-40 and they were hyperventilating i.e. severely dehydrated.

  • High rates of AKI being caused by over zealous driving with frusemide, leading to unnecessary CVVHF.

  • Hypovolaemia leads to poor pulmonary perfusion and increased dead space.

  • Centres echo’ing their patients are seeing a lot of RV dysfunction without raised PA pressure.

  • Many have improved oliguria by dropping the PEEP i.e. these patients are really hypovolaemic. [On nights I have observed many of our patients with a zero fluid balance and temperature of 39 i.e. they will be 2-3 litres negative in reality.]

  • Most centres are therefore now backing off of strict zero balance, particularly in hyperpyrexia. They are moving more towards avoidance of large positive fluid balance.