It is PAN PAN PAN "xxx Emergency Descent". If, as we are led to believe, the Spanish and French do not understand this emergency prefix, then make it "Mayday". Turn off track (helps the descent) and down you go. ATC can sort it out. The odds are stacked in favour of not hitting anything against losing control.
Do not linger in SEVERE turbulence waiting for Pedro or Louis to respond, or you will find yourself descending anyway, but out of control.
