Category Archives: General Medicine

No I won’t do it and here is the proof!

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As a junior doctor how many times were you called to replace an iv catheter on a veinless patient because with was 3 days old (and “hospital policy” and all that). There was no point asking to see the evidence on which this “policy” was based. Whatever! – here is the counter evidence, and it is in the Lancet (here).

The study in question was a multicentre, randomised, non-blinded equivalence trial recruited adults (≥18 years) with an intravenous catheter of expected use longer than 4 days from three hospitals in Queensland, Australia in 2008-09 (why so long to publish?). There were 3283 patients randomised (5907 catheters- 1593 clinically indicated; 1690 routine replacement).

The mean time the iv cannulae lasted when they were in situ on day 3 was 99 h (SD 54) when replaced as clinically indicated and 70 h (13) when routinely replaced. In other words – not routinely changing the catheter resulted in it being in place for 1.25 extra days. Phlebitis occurred in 114 of 1593 (7%) patients in the clinically indicated group and in 114 of 1690 (7%) patients in the routine replacement group: ABSOLUTELY NO DIFFERENCE, NONE, STOP ASKING ME LEAVE ME ALONE!

So, if the iv site looks ok – it is ok. Don’t go prodding the patient.

The sweet smell of obesity

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You may recall a movie from a few years ago called “Super Size Me” that featured Morgan Spurlock eating nothing but McDonalds food for a month. If offered a super sized meal, he said – yes. He became lethargic, gained weight and developed a fatty liver. The message was that if you ate highly calorific fatty food, you would become seriously unhealthy. I have argued, for some time, that Morgan should go back to McDonalds for a month and eat the same food, but drink diet sodas. There is an abundance of data that the high fructose corn syrup (HFCS) in US drinks defeats the normal satiety pathways, increases appetite and leads to visceral obesity and metabolic disease (don’t believe me? Click here). Sugar sweetened drinks are likely nearly as bad. I have never understood why anyone overweight would voluntarily drink sugar sweetened drinks when they can get essentially the same product calorie free (“diet” drinks). I remember American colleagues justifying this with comments like “I don’t trust aspartame” (it has been used for 40 years no evidence it causes harm to humans – click here) – the reply <but you trust HFCS! A Frankenfood>.
Last week Philip Boucher Hayes presented an RTE documentary on Ireland’s dietary habits. The programme painted a nice picture of how today’s obesity epidemic is turning into tomorrow’s cancer horror story. It turns out that Irish people are among the biggest sugar consumers in Europe; we are particularly fond of chocolate: we are a nation of carb addicts. Carb addiction shares many of the traits of opioid addiction.
So those of us who have long argued that the obesity epidemic is a problem of excess carbohydrates rather than excess fat will take note of no fewer than 3 papers in this weeks New England Journal. The most interesting of the papers, which came from Holland, randomized children aged 5 to 12 to 8oz (236ml) of sugar sweetened drinks per day (link here) (we don’t know exactly what product but it was not a common brand in Ireland (company) let’s call it “sugar drink”) versus blinded administration of 8oz of calorie free drink per day (“diet drink”). Thats it. They started with 641 normal weight children. 18 months later the children given the sugar drink had gained, on average, 1kg more in weight (2.2 pounds) compared with the other group. Children in the sugar drink group were pudgier (skinfold-thickness measurements, waist-to-height ratio, and fat mass).
So, sugar-drinks make you fat, and diet-drinks probably don’t. But what if we have been drinking sodas for years, are overweight and decide to quit? A second study, of adolescents, conducted in the USA (click here), randomized 224 adolescents (overweight/obese) to a programme (1 year) that involved giving up sweetened-sodas (HFCS). At 1 year there was a 2kg difference in weight and a significant difference in BMI between the 2 groups. This had disappeared at 2 years. In other words, presumably, they started drinking sodas again.
What about that skinny guy that you know who drinks 5 cans of Coke a day. It turns out that if you are genetically predisposed to becoming obese (your parents are overweight) then you are more likely to suffer the adipogenic effects of sweetened sodas (click here). In other words, if you have a belly, don’t give your kids sugar cola  – ever. Don’t start them drinking sodas. Don’t buy sodas.
So here is the issue – they have banned smoking just about everywhere (including potentially in your own car if your children are present), based on very questionable evidence that secondary inhalation of (“passive”) smoke injures you. These data represent clear evidence of the dangers associated with a series of food products with no nutritional value that have a ready made replacement (diet soda) made by the same manufacturers. Shouldn’t we be banning the sale and administration of sugar-sodas to children (I was horrified to hear in the RTE documentary that babies at 6 months were being give carbonated drinks)? Read here to enjoy a wonderful discussion of this topic.
Now if they could only come up with diet pizza, diet chips and diet scones……

Don’t Understand Balloon Pumps – don’t bother

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Alas – another intervention bites the dust. For decades the intra-aortic balloon pump has been heralded as the great savior of the patient with cardiogenic shock. If you have always found these devices confusing (when to use, when to wean, what difference 1:1 versus 1:2 augmentation etc), then worry not: they are heading to the Swan Ganz junkyard. In this week’s NEJM the IABP-SHOCK II trial is published (read here). Six hundred patients were recruited in 37 locations in Germany in 3 years – randomized to IAB-counterpulsation at 1:1 or control, essentially catecholamine, therapy. Patients were eligible for the trial if they had had any form of myocardial infarction complicated by cardiogenic shock, or needed an emergency percutaneous coronary intervention. The majority of patients had PCIs and the IABP could be placed before or after.

There is a widespread belief that using IABP improves pump function, restoring cardiovascular health and preventing the development of multi-organ failure. The primary endpoint of the study was 30 day all cause mortality. This is a flawed measure in critical care, as many patients will still be alive at 30 days, awaiting withdrawal of life sustaining therapy. The authors are in the process of collecting 90 day and 6 month data. The authors also looked for evidence of multi-organ failure (using SAPS II), infectious and ischaemic (using lactate) complications.

Previous studies have reported mortality rates of 42-48% in cardiogenic shock. The authors reported 30 day mortality of 39.7% in the IABP group and 41.3% in the control group (not significant). There was no significant difference in any of the other endpoints either..

Criticisms and generalizability? The mortality rate was lower than expected, but this was a heterogenous German population, a single health system, with an average BMI of 27. So maybe the patients were less unhealthy than comparable North American Studies. More likely, the IABP can be added to a long list of devices that receive religious like devotion, but have little clinical benefit. Further data of interest would be whether or not IABP really benefits postoperative cardiac patients. In the meantime, it is likely that we will encounter these devices less frequently in the future.