Tunnel Vision

Tunnel vision is something that happens to all doctors, even though they'll adamantly deny it's something they could ever be accused of. It refers to how a practitioner's diagnostic ability becomes impaired by habit - how seeing a particular disease process particularly frequently prejudices us to making that diagnosis whilst perhaps missing something less common with a similar presentation.

A good example is a case that happened here in my first month as an intern: a diagnosis of abdominal tuberculosis (very common around these parts) was made in a youngish and chronically ill female. It was only six days later, when it was discovered that her haematocrit (a measure of the number of cells in the blood) was dropping alarmingly that someone thought of doing a pregnancy test. A few hours later we were unzipping her belly to remove a ruptured ectopic pregnancy, six days' worth of blood gushing out onto the theatre floor and running out under the doors. Tunnel vision: a physician, used to diagnosing several cases of abdominal TB a day, didn't even think of a slowly leaking ectopic as a cause for a distended and painful tummy.

A few weeks ago, I was also the victim af tunnel vision in a most dramatic and embarrassing fashion. I was in casualties interviewing some patient or the other, when a screaming banshee of a lady pushed a wheelchair up to me and started yelling loudly at me. The wheelchair contained a chubby middle-aged woman who was, well, gasping. I asked her whether her chest hurt or whether she was short of breath (yes, I know, rule number one of patient interviewing: never ask leading questions). She told me she was short of breath and I wheeled her over to Asthma Corner and strapped an oxygen mask onto her face. I know this was silly, but I really just wanted to get her out of the way so I could carry on with what I'd been doing before. I then told the casualty officer that there was some lady in the corner who might be having some unstable angina (something that, as a medical intern, I see very often), and then asked a nurse to get her into resus when a bed opened up and to do an ECG ASAP.

I went back to my patient and fiddled around there for a while. The next thing I knew, chubby wheelchair lady was standing in the middle of casualties, oxygen mask dangling uselessly around her neck, screaming 'Oooooooh! I need to pou-pou!' I noticed with interest that the crotch of her tracksuit pants was looking rather full, and that her belly was indeed rather round, but more uterus-shaped than excess-abdominal-fat shaped. I was still processing all of this new information when the casualty officer whipped her onto a stretcher, wheeled her into resus in the place of a drunken stab victim, ripped off her pants, and pulled a crying baby boy out from between her legs. I stood slack-jawed and amazed - I really hadn't seen that coming.

I was, naturally, the laughing stock of casualties for several days thereafter. In a small hospital, it's amazing how rapidly a story like this can spread: within an hour everyone had heard the tale of the intern whose unstable angina turned into an unstable vagina.


Well done, me.