Boris Johnson will likely need a ventilator | The Standard

The British Prime Minister Boris Johnson is "extremely sick" and it is very likely he will need a ventilator, according to a medical expert, Sky News reports.

Boris Johnson has spent the night in intensive care after his health deteriorated - 11 days after he initially tested positive for the new coronavirus.

Downing Street says Johnson has been suffering from "persistent" coronavirus symptoms - and Sky's Beth Rigby reports he had been struggling to breathe and needed oxygen on Monday.

Derek Hill, professor of medical imaging at University College London, said Jonson could be given a breathing aid known as continuous positive airway pressure.

This bridges the gap between an oxygen mask and full ventilation, sending a blend of air and oxygen into the mouth at a steady rate.

However, Prof Hill warned many patients eventually "progress to invasive ventilation", which is for people whose illness is so severe that they are struggling or unable to breathe for themselves.

A mechanical ventilator either does all the breathing for the patient or assists the patient's own breathing, and they are normally placed under heavy sedation.-Photo: Sky News