Wednesday, August 29, 2007
What is the marginal utility of intelligence? At what point does increasing intelligence provide decreasing returns? I refer to a composite of g, processing speed, size of working memory and pattern recognition applied to a domain that is not in itself limiting.
Monday, August 27, 2007
Sunday, August 26, 2007
People differ; this is a truism. However, they still fall into distinguishable statistical classes. This allows for population level interventions like vaccination and water fluoridation and for double-blind randomised control trials.
The objective measurements that we make as clinicians – point measurements – are generally not useful unless they are obviously deranged / abnormal. Generally, we are interested in trend data: is this normal for the patient? Is it correcting or worsening? How fast is it changing? Is the trend reversible? What is the cause?
The highest priority is always the preservation of brain function. Heart, lungs and kidneys follow.
I look forward to the introduction of real-time sensors with some way to capture and analyse the data stream: emergencies should be fewer and more easily managed.
Friday, August 24, 2007
Thursday, August 23, 2007
There is some reason for these links: tomorrow will be different. How does that matter if today is very different from yesterday and you didn’t notice? It is a truism that change is constant and that most progress is emergent without being accidental. We need to make distinctions – more acutely – and with an action focus.
Wednesday, August 22, 2007
Tuesday, August 21, 2007
Sunday, August 19, 2007
Saturday, August 18, 2007
Patient satisfaction is entirely irrational and reasonably so: it is subject to a host of cognitive biases. Ultimately, satisfaction depends on whether the patient feels cared for, heard and understood. Patients are in no position to judge the technical or cognitive skills of the doctors who attend them and so they rely on their assessments of their clinicians’ social skills as proxy for everything else. I am reminded of Beckwith’s anecdote in which the lawyer stated that she had never had a client who said that she really, really liked her doctor, but that she felt, absolutely, that she had to sue him.
Speaking with patients needs time – time without distraction and time without a pressing deadline. And then there’s the real world. It also needs a history: people are subject to idiosyncratic shames, guilts and other prejudices that lead to omissions, ambiguities, diversions, misrepresentations and lies. No-one is immune: a colleague presented with a history of abdominal pain radiating to his groin when the truth was that he had an acutely painful and swollen testicle. Repeated interaction creates and improves trust which leads to more open and less ambiguous communication.
Communication is inherently and usefully ambiguous. In high pressure situations, the usefulness is inversely proportional to the ambiguity. We all need clarity when the stakes are high and ambiguity is most useful (ego-protective)in those circumstances.
Speaking with patients also needs simple language because stress slows down processing and big words and long sentences don’t make for easy repetition. Simple language is, unfortunately, very difficult and when I am tired almost entirely beyond me. It needs first that one know what is most important medically and to the patient. These may be two different things entirely. It needs also, an assessment of the patient’s receptiveness and the willingness and ability to recall the information given. To hear, to understand, to remember and to recall are all different things.
Information is provided with some end in mind, some action that must be taken or not or some burden that must be accepted. As always, one should begin with the end in mind.
Thursday, August 16, 2007
Tuesday, August 14, 2007
Monday, August 13, 2007
Today I gave a COPD patient Magnesium sulphate IV. My consultant said, ”There’s no evidence of benefit…. Don’t do it.” I didn’t argue: Mondays are too busy for these kinds of arguments.
There is evidence that Magnesium:
- acts as a bronchodilator
- that it improves clinical outcomes in severe asthma not responding to inhaled beta-agonists
- is safe (LD50 in rats is 1200mg/kg)
We know that the following patients have reduced intracellular magnesium:
- those with severe chronic disease
- those who take long-term corticosteroids
- those who take inhaled beta-agonists
- those on diuretics
- those with abnormalities of potassium and/or calcium metabolism
- those with diabetes
- the very elderly
- those on chemotherapy
- those with eating disorders
- those with alcohol dependence disorders
- those with severe COPD
We know from the law of diminishing returns that those most severely affected by disease benefit most from its treatment and that harms and benefits have different curves that cross at different points for all patients.
We also know that “no evidence of benefit” is not evidence of no benefit. We lack data.
In COPD, we know that combination therapy acts synergistically and that steroids and antibiotics for acute exacerbations improve outcomes (even in patients without evidence of bacterial infection).
My patient had severe COPD: she had had multiple admissions this year, had suffered respiratory arrest more than once and was already on maximal therapy before her acute presentation. Did my patient benefit from the IV Magnesium sulphate? Probably. Can I prove it? No, but neither can it be proven that she did not benefit.