What made you think it needs an icu?
Tip: Chromatopelma cyaneopubescens love bone dry enclosures.

Just an update... No improvement. In fact it looks like it is doing worst.

Moved it to a clean ICU last night and at the bottom of the T there were this funny white stuff.
It can be a fluid as there is a stain on the paper where it laid.

Any advice?
Is it time to cut my loss?

No fight to the end. My chaco left its inclosure and only came back nine months later and I never gave up hope. These spiders are capable of doing anything just have faith and keep on doing the icu treatment

Best of luck

Call me an idiot but I can't see anything wrong from that picture. Isn't it just resting after a moult. Most of my T's will remain motionless for a few days after moulting and they turn out fine. Never had any problems with them.

I'll just add my 2 cents

I had 14 GBB's and when it was winter time I placed all my containers on a heated surface "the surface was a heat-mat and on top of the heat mat was 3 ply wood and then that green carpet you get at a petshop. I noticed with those not on the surface will be less active than the rest, but as soon as I placed them on the heated area they will be active like the rest, I would also just add a small water bowl to their enclosure.

In my experience with the 14 GBB's I had I would move it over to a heat surface, and keep observing the GBB for a few days, they also don't like to much moisture. I am sure a few GBB breeders would also suggest that.

But if you really like some advice please contact PinkT, as she had bred them a few times and it's one of her beloved species.