"Thirty minutes, skin-to-skin," he says confidently. This is the surgeon's guesstimate, to me, the anaesthetist, on how long it will take to get the appendix out of the patient laid out on the operating table before us.
It's midnight and I'm hoping to be able to grab a nap on a row of chairs somewhere in the hospital before the next comatose student turns up in resus, having indulged in that age-old freshers'-week game of Amateur Anaesthesia with Alcohol.
You should know, however, that the surgical fraternity lives apart in a relativistic time frame of its own. It is 4am before we get off the table. It's not the surgeon's fault - this is not an episode of House we're talking about here, and we are mere mortals. None of us is Dr Gregory Bloody House MD - how could we be? We must live in the now: on a good day I am Prefab; tonight the surgeon is Tent.
This is the last in a run of four night shifts. In a weak moment earlier in the year, seeing a free day in my diary, I agreed to give the introductory lecture to the new class of students on my course. That day is here; it started when Tent told me we'd be done in half an hour. I struggle from the hospital in the morning, fix myself with coffee and cross the road to the university.
My rather esoteric course in space medicine and extreme-environment physiology, arranged by enthusiasts for would-be enthusiasts, has been running now for a decade. It's popular, which doesn't necessarily make it good, but we are oversubscribed and get pretty good end-of-course feedback, which is not a bad place to start. It's a carefully crafted labour of love, and we drag our extramural faculty in from all over the world - a few of them even come from outer space.
We usually try to inject some energy into the introductory lecture. In my sleep-deprived state, it is tempting to run the opening hour of the thing as a deadpan exercise in university admin: deadlines, timetables, aims and objectives, then sayonara and off to bed. But in the years when we have been too busy to pay attention to this seemingly irrelevant hour, the impact on the rest of the course has been noticeable.
I think it's probably because if you stuff up the opening, you and your students aren't on the same page. And if there's no shared vision of the coming weeks, then you'll wind up transmitting all that information but with your class tuned into the wrong frequency.
So, year on year, we do a few things. First, we try to remember all of their names. This is a set piece straight out of the tree-huggers' playbook, takes more than a bit of time and effort and is getting harder year on year. But your recall doesn't have to be 100 per cent perfect - this year there are at least three students who will always be George-or-Joseph to me - but it has the effect of letting them know they're on your radar. It seems to improve attendance in a way that the work of master forgery otherwise known as the signing-in sheet cannot.
Next, we tell them exactly how to get good grades on the course. This, we believe, should be a Ronseal affair: there should be no mystery in it for anybody. Then we tell them how to get maximum personal value from the course; something that we try to convince them is different from simply achieving a first-class exam result. This is the toughest bit and is often met with quizzical expressions, but convincing them that the metric by which a thing is judged is not necessarily equivalent to its intrinsic value is, we feel, an important lesson in itself.
Then, as a coup de grace, we tell them that we include some lectures for their own edification whose content we do not examine directly. This is often met with gasps of astonishment: occasionally someone faints, and it's not just the students we're talking about here. Nevertheless, we do it all the same.
Not everybody gets it and every year one or two students let rip via their feedback. "Can you please get rid of those lectures which amount to nothing more than someone showing off their holiday snaps?" wrote one. "It pains me to think of all the money and time I have wasted, struggling in during the rush hour, just to hear some dude bragging about his adventures, only to find out that it's not even in the exam."
This was a comment about a lecture given by the youngest person to climb the highest mountain peak on every continent, relating his experience of reaching the summit of Mount Everest for the first time. To us, it was a way of contextualising the otherwise impersonal description of extreme high-altitude hypoxia and human performance, to which much of the course is dedicated; to the student, it was a waste of a Tube fare. Go figure.
And so the course begins again; how it will pan out this time, only the next ten weeks will tell. How long the sleep-dodging can continue I don't know either. Lecturing while fatigued is a bit like drink-driving; you shouldn't do it and you shouldn't let a friend do it. I'll have to have a word with Tent and get him to sharpen up his scalpel skills. But then the start of a lecture course is very much like taking out somebody's appendix: easy to do quickly and badly, difficult to do with flair, and injurious in the long run if you stuff it up.