William Rejault, a former nurse, is the author of "Quel beau métier vous faites" ('What a beautiful job you do').

Yes, we know these things happen, they just don't happen to you. I've read outraged reactions from hospital users (what we used to call patients), in various papers, and they're right - a child is dead because of a mistake, and that's unacceptable.

When someone does make a mistake, the right questions need to be asked to avoid the same thing happening again. I still remember when a doctor stopped me just before I was about to inject a patient with the wrong medicine. I couldn't believe I'd been wrong. I swore that I'd never ever make that mistake again. He gave me a sad smile and said: "If you swear you'll never make a mistake again, you will. We're not perfect, there's no such thing as a zero percent risk - we still have to work and will always have to work under circumstances that will push us to make mistakes."

How can you make a mistake when you've got someone's life in your hands? How can the impossible suddenly become imminently probable; the same thing that's unspeakable of in some jobs, inescapable in others? Here are the risk factors:

The 'famous' lack of staff. I put quotation marks around 'famous' because the ministry of health was quick to remind us that the number of employees in the A&E department was more than enough. So it would be unfortunate to end up in the only hospital in the country that isn't always fully stocked, that's operating at half strength because there aren't enough trained arms and volunteers! We can skirt around the lack of staff issue as much as we like, but the problem is real - nurses do not want to and physically cannot work under these worsening conditions.

Social problems are a big distracter in hospitals. Misery and his mother pour into A&E on a daily occasion, violent and abusive. The pitch rises and confidences wanes while we're trying to talk about procedures. Basically, it's hard to work when you're scared to death.

Accountability and proper procedure is forgotten, and yet there are various systems - for example putting data into a software program - that just take up time you could be using to ensure safety without being weighed down with bureaucracy. Human contact is minimised, spoken instructions no longer exist. Orders are given before the person disappears to do something else, leaving professional relationships strained, if not non-existent. If you're worried about something, you don't talk about it. You just check who signed what paper and at what time.

And even if nurses are ready to address the cause of the problem, what about the politics behind it? With management's "calculated risk mode" already at work in the psychiatric department, bed numbers have halved in the past decade. How many of those who are schizophrenic are a danger to the people because they're out on the street? Many of them. How many nurses have to make a mistake for it to be a danger to the people?"