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‘Bad’ differentials will always trump ‘likely’

I have to admit, working in A&E focuses the mind. With four-hour targets looming over us all, there isn’t much time for pussy-footing around. Decisions must be made, and promptly. Once you have established that the patient in front of you isn’t about to expire, it’s time to swiftly move on to the question of whether this patient needs to be admitted to hospital, and under which specialty.

This can be beautifully obvious (cardiac-sounding chest pain? With risk factors? Refer medics. Next!), or frustratingly vague. I’d find myself mentally flipping form one set of differentials to another based on the often long and winding history provided, desperately trying to find some sort of order in the chaos that was being presented to me.

Symptoms became drop-down menus of possible conditions. ‘Likely’ differential diagnoses vied for position with ‘bad’ differential diagnoses (and lost). Then, with at least an inkling of what might be wrong, I’d arrange a few investigations and refer on to the relevant team. Then I’d move on to the next patient.

Like I said, it did focus the mind, but I missed any sense of continuing care. Occasionally I’d be able to follow up an interesting case, but mostly it was a matter of never seen again. Was I making any difference for these patients? It was this thought that lead me to jump on any opportunity I could for health education. Give up smoking! Drink less! Eat more fruit and veg! In essence, anything that made me think that I might, just might, make some sort of a difference beyond the perpetual here-and-now of A&E.

John, a man in his seventies who was continually in and out of hospital with ‘acopia’, and I was determined to make whatever difference I could – not just by managing his current presenting complaint. It turns out John had only been out of hospital for a few weeks, had refused all care on discharge and had been found ‘in a state’ by his neighbours, who alerted the paramedics.

Ostensibly he was in this time with ‘breathing problems’, but his dishevelled appearance told the story of a man who hadn’t been taking care of himself. Taking a history, John reported that his breathing was fine. Certainly he didn’t look to be struggling, his respiratory rate and oxygen saturations were in the normal range and his chest sounded clear. It was all a bit odd. Then I noticed his fingers.

‘How much do you smoke?’ I asked, happy to have found something I could advise him about.

‘I don’t smoke,’ he replied.

Ah, yes of course not. A surprising number of people give up smoking a few days before coming into hospital, if not in the ambulance on their way in.

‘When did you stop smoking?’ I tried.

‘I’ve never smoked in my life.’

For a second I was confused. Was this man blatantly lying to me? Or was he incredibly confused? He clearly had tobacco-stained fingers.

Or at least, I realised somewhat too late, he had brown fingers. What I had failed to consider was the differential diagnoses for brown fingers other than tobacco staining. I rather hurriedly finished speaking to John and went and spent the next few minutes practicing the five moments of hand hygiene in considerable detail.

Whilst washing my hands like Lady Macbeth, I reflected that from now on not only would diagnoses have differentials, but so too would physical signs. And ‘bad’ differentials will always trump ‘likely’. 

Dr Tim Cassford is a GPST1 in Chichester.