Richard Lehman’s journal review – 5 September 2011

Richard LehmanNEJM  1 Sep 2011  Vol 365
787    Studies of out-of-hospital cardiac arrest require heroic feats of organization and generally provide survival-to-discharge rates around 7%. In this randomized trial, the research question was whether in a person found pulseless out of hospital, it’s best to start CPR immediately or to analyze the heart rhythm immediately. In fact it made no difference at all whether emergency medical staff put a monitor on right away or waited till after a couple of minutes of CPR. Survival to discharge without major disability was 5.9% in either group.

798   The same US/Canadian research group (ROC, for Resuscitation Outcomes Consortium) earns itself a second NEJM paper with a randomised study of the thing known as an impedance threshold device which is supposed to increase the degree of negative intrathoracic pressure during out-of hospital CPR. They went to the trouble of comparing it with a sham device and blinding the allocation, but the results were once again 6.0% in one group and 5.8% in the other. All that these heroic efforts have achieved is to cut the mean survival of out-of-hospital arrest by a percentage point or so. Most people who drop dead stay dead.

Lancet  3 Sep 2011  Vol 378
For no medical reason I can think of, Richard Horton has decided to run an entire issue of The Lancet to commemorate the 10th anniversary of the massacre by 19 Saudi Arabians of 2,977 people in the USA. I am surprised he didn’t choose the date closest to September 11th. “The events of that day changed the historical trajectory of America and the world. They have had—and continue to have—profound consequences for health” intones The Lancet. No they haven’t – the list of consequences he enumerates were entirely the result of the foreign wars decided upon, probably a bit earlier, by George W Bush and Donald Rumsfeld.

First Online:

The PURE Study is the successor to INTERHEART and is a noble attempt to do global cardiovascular cardiology by following up a cohort of 154,000 individuals in 18 high-, middle- and low-income countries for a minimum of 10 years. (As Tennyson wrote for Sir Galahad, “My strength is as the strength of ten/ Because my heart is PURE”). At present, three-quarters of cardiovascular disease occurs in the last two categories of country, and this report confirms what we already had guessed: the poorer the economy, the fewer people take drugs for secondary cardiovascular protection. It seems a particular shame that fewer than 9% of those with known cardiovascular disease in the poorest countries even take aspirin: but then in the richest countries, the figure is only 65% following myocardial infarction, and 53% following stroke. What is going on?

Acne vulgaris gets a good review here, which examines the evidence base for treatment of this ubiquitous condition and finds that a lot of it is not much better than the recommendations on YouTube (toothpaste is apparently a teenage favourite). Or indeed the lotio alba tinct. prescribed in William Carlos Williams’ 1934 tale of American general practice, The Girl with a Pimply Face. Benzoyl peroxide is apparently a better topical treatment than local isotretinoin. Mercifully, although acne is a strongly hereditary condition, it does not seem to have attracted the attention of gene gnomes, so we are spared several pages of discussion about polymorphisms at the ZIT locus and how they affect putative molecular reactions between sebum degradation products and Propionibacterium acnis. Talking of the latter, there is little evidence of the superiority of one antibiotic over another; and none whatever to choose any particular combined oral contraceptive.

BMJ   3 Sep 2011  Vol 343
It’s now over a year since I had to pay much attention to the Quality and Outcomes Framework for UK primary care, and what a relief it is. Amongst the many idiocies of the system is the requirement to use “validated depression scores” in a variety of circumstances including chronic disease. This systematic review drifts about trying to discover just how and in what populations these depression scores were validated and against what “gold standard”. In a great number of cases, the validation cohort included people already receiving antidepressants. At best, these scoring systems are just a reminder of the kind of questions to ask; I’m yet to be persuaded that there is any evidence to support their use as screening tools in general practice, still less for their use in monitoring response to treatment.

In fact the BMJ is rather heavy on “what to believe” papers this week: I’ll spare you further discussion on verification problems in diagnostic accuracy studies but it’s worth mentioning a “meta-epidemiological” study of the inconsistency between direct and indirect comparisons of competing interventions. The dream of Evidence Based Medicine is that jobbing doctors should habitually seek evidence to inform their daily practice. I still sign up to that, but boy is it difficult when the right evidence is so hard to find, to compare and to trust. The most fundamental question we have to face is “is this treatment better than that?” and all too often there are no head on comparisons. This paper warns of the perils of indirect comparisons and then gets too technical for most clinician readers. Which is exactly the problem.

Without a huge increase in the medical workforce, British general practice looks set to remain the art of trying to practise good medicine in ten-minute bites. And as more and more consultations are not about acute treatable illness but involve chronic disease management and care of the elderly, ten minutes is simply too short to do good medicine. We may love our old ladies, and they us, but do we actually do a proper functional assessment of the elderly? I hope the answer is yes, sometimes, in the course of a prolonged home visit. Or we send them to others with more time. Here is a superb practical guide on how to do it.

Arch Intern Med  Vol 171
Last week the journals reached a new low in volume of worthwhile content, but this week they have broken the record again. To keep you going, here are a few morsels from the Archives website:

For thousands of years, doctors have loved taking blood. Even William Osler retained a vestigial folk-belief in the benefit of phlebotomy for pneumonia, well into the twentieth century. When the moon is full, doctors are particularly dangerous and sometimes grow hair in unusual places. In teaching hospitals especially, young doctors partake in vampiric initiation rites which involve the filling of innumerable tubes of blood in pursuit of ever more improbable diagnoses. Following such youngsters round a prestigious American hospital recently, after many years in British general practice, I found this mildly amusing: but I learn from this paper that it can actually do harm to patients with acute myocardial infarction in Kansas. Believe it or not, quantities of blood as small as 180ml can make a difference to the incidence of post-MI unexplained anaemia, which in turn can worsen outcomes. The severity of this anaemia seems to correlate well with the amount of blood removed: some particularly hungry doctors take more than 300ml. As the authors of this study note, we could all let our patients retain their rightful lifeblood if we simply used paediatric tubes. But stay! what is that distant howling in the moonlight?

Now the Archives are supposed to be the B-journal for JAMA, which is a pretty impossible feat at the moment. This Italian study of radiography at home is definitely B-level stuff but hey, it is from Italy, and also interesting. Show respect. They took modern lightweight X-ray machines out to frail old Italians and proved (well, actually, claim from a single descriptive case series) that X-rays done at home are just as interpretable as those taken in hospital; and also this spares the patient the horrors of admission, especially delirium. Moreover, “almost all patients” were satisfied. I would love to hear what was said by the patients who weren’t.

Plant of the Week: Diospyros virginiana

This lovely East American tree is the origin of our word “persimmon,” as Eric Larson explains below. I came across one in its native Virginia on the slopes of a fort guarding the Potomac River, where its fruits lay on the ground and attracted the sporadic attention of local marmots. I guess this is yet another American plant that you could, in theory, grow in England, but never to much effect. If you wanted to taste its sweet golden fruit, you would have to plant it where the sun beat down upon it for three months with hardly any interruption.

The persimmon we buy in the shops comes from a much-hybridized Far Eastern species, Diospyros kaki. But the original lotus-fruit comes from Diospyros lotos, widely grown around the Mediterranean, and my favourite guess for the forbidden fruit of the Tree of Knowledge in the Garden of Eden,
                   ….whose mortal taste
Brought Death into the world, and all our woe

I will let Eric Larson, keeper of the Yale Botanical Gardens, take over:

Persimmon (Diospyros species)
by Eric Larson

Persimmon is one of those very misunderstood edible items, like brussel sprouts. If you have ever partaken of a Persimmon fruit when it wasn’t “dead ripe,” then your impression will be one of astringency, sourness, even discomfort. One of the tricks that I learned from my beloved sister and her husband is to place the persimmon in the freezer overnight. After taking it out and thawing it, all astringency is removed and the true sweetness of the fruit will remind us of why the Greeks considered it the “fruit of the gods.”

In fact, the genus name is Greek: dios of Zeus (later Jove) and pyros for grain, alluding to the edible fruits. The common name actually comes from the Powhatan (an Algonquian language) word for the fruit: depending on the written translation putchamin, pasiminan, or pessamin. The family is Ebenaceae, the Ebony family which includes five hundred species in two genera, Diospyros and Euclea, the genus for Ebony trees.

Diospyros virginiana is an American native persimmon, which one would guess if the Algonquin had a word for it. But persimmons are distributed world wide. The Far Eastern species provide the greatest reliability of ripeness and taste, and have been selected and perhaps hybridized for countless generations. The most widely cultivated species, D. kaki, is called kaki in Japan, shiziz in Chinese. China, Korea, and Japan make up the largest part of the worldwide production of persimmon.

Two basic types of Persimmon fruit: astringent and non-astringent.

There are varieties of almost every species that fall into each category.  I’m not sure why this should be in an evolutionary sense. Perhaps something to do with offspring dispersal. Perhaps, like humans, there are astringent sourpusses and then happy-go-lucky folks. As I said earlier, freezing releases astringency, breaking down the cell walls and allowing the tannin to be solubalized into the sugar solutions. Non-astringent fruit can be eaten when firm, without freezing, and therefore are considered a delicacy. There are other ways to achieve the same result as freezing, including using alcohol and carbon dioxide in what is called a “bletting” process. My advice is: go ahead and freeze the fruit.

Another historical/literary note: the species native to southeastern Europe and western Asia, D. lotus, is referred to in several languages as “date-plum,” because its taste and texture are reminiscent of both of those fruits. This species is thought by some to be the fruit referred to as “the lotus” in the Odyssey: it was so exquisite in flavor and nutrition that it made those who ate it forget about returning home, wanting to stay and eat lotus with the lotus-eaters.

Nutritionally, Persimmons are high in vitamin C (the American native is the highest in this regard), and other nutrients, but also have tannins in the form of catechin and gallocatechin, and anti-tumor compounds betulinic acid and shibuol, the latter which may cause some intestinal discomfort. As a matter of fact, my tummy is feeling a bit “off” right now after having eaten two small ones. No real problem, just a slight “eh.”  It is said that they should not be eaten with crab-meat nor eaten on an empty stomach. Well there goes my favorite breakfast, crab and persimmon omelette.

The trees themselves are small, depending on the species.  They grow from twenty to forty feet depending on where they are located.  They will grow in light shade to full sun, with full sun best for flowering and fruit production.  The American species or those crosses that have some of that parentage are the most cold-hardy for us. The kaki and other types are more tender.  They leaf out very late in spring, making one think that the winter might have got them. Be patient though. They flower well after leafing out, which makes them a good candidate for those areas with late spring frosts.  The fruit doesn’t form until very late, and on the American species they aren’t ripe until after the leaves drop in the fall.

The fall color is a nice yellow, sometimes orange. They are very adaptable as to soils, tolerating flooding conditions or droughty sandy soils. I would advise you to look into persimmons as an alternative to the fruits that need so much spraying that are subject to disease and insect problems.  They are available through mail order and sometimes in the better nurseries.