Coronavirus: Inside hospital negative pressure isolation rooms where Covid-19 patients could be treated

There can be extensive protocols to isolate patients within a hospital. Photo / 123rf

New Zealand's first coronavirus Covid-19 patient is being treated in a special isolation facility within Auckland City Hospital.

Such negative pressure rooms use lower air pressure to prevent internal air from reaching other patient areas and common spaces in a hospital, allowing patients with infectious conditions to be isolated.

An electronic keypad controls access, displaying the pressure reading and is coloured green when it is within acceptable range. When in use, rooms are monitored by engineers to make sure they are working correctly.

Protocols vary by a patient's condition and hospital. However, an insight into how extensive measures can be is provided by the approach to a suspected Ebola virus disease patient in Christchurch Hospital in 2015, later described in a paper by Dr Ruth Barratt.

The patient, a nurse, had recently returned from Sierra Leone, and contacted authorities after developing possible symptoms while self-monitoring at home.

She was in an isolation room for more than 60 hours until testing negative. A 20-bed hospital wing was closed off, security personnel posted at the doors and everyone signed in and out.

Three negative pressure rooms were used, all with anterooms to give an additional buffer to the outside world. One had the patient, one was used for staff to put on protective clothing, double gloves and full-length visors (using a buddy system to check and help, with a third nurse reading instructions), and another pressure room for departing staff to shower and change.

Problems discovered included protective hoods being too small for some of the bigger-headed doctors, and face visors fogging up - medical staff wearing them would take blood samples after entering the room when visibility was best.

Coloured tape of the floor around the patient's room was marked in red, orange and green zoning. Waste was double-bagged and put in hard shell drums with another packaging liner. Disposable bed linen was used, and touch points and surfaces wiped daily with a sodium hypochlorite solution. When possible, disposable medical equipment was used.

There are 268 negative pressure rooms across the country. Director-General of Health, Dr Ashley Bloomfield, said DHBs already worked cooperatively to manage illness and workload, and would do so if Covid-19 necessitated patient transfers. However, only a small number of cases would likely need hospital-level care, with the majority of people able to recover from mild symptoms at home.