Richard Lehman’s journal review—2 October 2017

Richard Lehman reviews the latest research in the top medical journals

richard_lehmanNEJM  28 Sep 2017  Vol 377

Medicine: too big for the human brain?

A while back, there was a New Yorker cartoon consisting of a huge billboard in the middle of nowhere saying “Stop And Think.” Two small wayfarers stood beneath it, and one was saying, “It makes you stop and think, doesn’t it?” Here is a Perspective piece with the titleLost in Thought—The Limits of the Human Mind and the Future of Medicine.” Its central proposition is that the complexity of medicine now exceeds the capacity of the human mind. The article is open access and takes about ten minutes to read slowly. Do you agree with the authors’ formulation of the problem? Do you think the solutions they propose are valid? Don’t send me your answers. Just stop and think.

Oxygen: the burning question in MI

When Joseph Priestley did his first experiments with dephlogisticated air (later called oxygen) he noted two things: it made flammable substances burn more rapidly, and it revived asphyxiated mice. Whether you give oxygen to people with myocardial infarction depends on which action you hope will prevail. Will the oxygen-deprived myocytes simply burn up and necrose faster in the presence of new oxygen, or will they gasp with relief and live to beat another day? If these things happen at all, they cancel out perfectly. A registry-based trial in Sweden recruited 6629 patients with suspected myocardial infarction and randomised them to receive either supplemental oxygen (6 litres per minute for 6 to 12 hours, delivered through an open face mask) or ambient air. Rates of death or rehospitalization for MI over one year were identical between groups, and in all prespecified subgroups.

Storage time and red cells for critically ill

Blood banks usually issue the oldest stored red cells in sequence, and in this five-nation study, that meant an average of about 22 days old. But perhaps the sickest patients needing acute transfusion would benefit from the most recently donated red cells, and in this trial that meant about 11 days. Here is a trial that recruited nearly 5000 critically ill adults, and its primary end-point was death within 90 days. This was a common event, happening in 24.8% of those given freshest-blood red cells and 24.1% in those given oldest-blood red cells. So this is another great trial addressing an important clinical question, and giving a clear answer: no difference.

JAMA 26 Sep 2017  Vol 318

Genotype-guided warfarin treatment

The GIFT randomised trial compared genotype-guided dosing with usual dosing when initiating warfarin in 1650 patients aged 65 or over undergoing elective hip or knee arthroplasty. This was for short-term prophylaxis against venous thrombo-embolism for 11 days: it seems an odd choice to me, but maybe it’s standard practice in the USA. Patients were genotyped for various polymorphisms known to affect the metabolism of warfarin, and the primary end-point was a composite of major bleeding, INR>4, venous thromboembolism or death. In fact there were no deaths, and no significant differences in VTE, but there were fewer bleeds and periods of high INR in the genotype-guided group. Make of it what you will: the scoreline for previous trials of genotype-guided warfarin initiation is about level for both sides.

Good intentions can kill septic patients

Your adult with presumed sepsis is going off: as her blood pressure falls, you pump in the saline and when you are really desperate you add an inotrope. Not for nothing are these sometimes known as embalming fluids. They may have a place, but a trial from Zambia shows that it is not in the routine management of sepsis in resource-poor settings. A randomised trial in 209 patients there showed that a six-hour protocol emphasizing the administration of IV fluids, vasopressors and blood transfusion significantly increased in-hospital mortality compared with usual care (48% v 33%).  

JAMA Intern Med Sep 2017

Does primary care have a future?

It’s pretty difficult to address any meeting in the UK at present without being asked if you think general practice has a future. Seven years after retiring from my partnership, I’m not the best person to ask. But it’s pretty clear that the old British model—which I think was wonderful in many ways—is collapsing and there is no sign of the political will or vision to put it back together again. But at least we are not America. If you want a bit of Schadenfreude there are a few articles on the JAMA Internal Medicine website which bewail the demise of primary care over there. Just when humane, joined-up thinkers are needed more than ever, they are being pushed out of the system, in the US even more comprehensively than here. Stop and think. In an age of information overload and unfathomable new uncertainty, will IBM Watson suffice? Or will each ill and anxious person need an informed friend and advocate within the system?

Ann Intern Med 26 Sep 2017  Vol 167

Within-hospital age differences in MI outcomes

Avedis Donabedian studied quality measures within health systems for about 30 years, and concluded that there were no metrics which were both simple and reliable. Survival and rehospitalisation following myocardial infarction may seem to be simple, but actually they are not. In the great tradition of the Center for Outcomes and Evaluation at Yale, Kumar Dharmarajan explores how these metrics can vary according to the age of patients. Hospitals which have the best outcomes for younger MI patients are not necessarily the same as those with best outcomes for older people, and vice versa.

The Lancet 30 Sep 2017  Vol 390

Promising new typhoid vaccine

The last typhoid outbreak in the UK happened in Aberdeen in 1964. I joined the queue to get vaccinated in far-off Sheffield, and then fainted at the bus stop. This was my only experience of syncope: it was very embarrassing to the adolescent RL, and I vowed never to go near doctors or needles again. Worldwide, there are still 2 million cases of typhoid a year (and 200K deaths), and newer, better typhoid vaccines are needed. It looks as if some that are already around and used in infants may be effective in adults as well: this trial compared Vi-conjugate (Vi-TT), Vi-polysaccharide (Vi-PS), or control meningococcal vaccine in 112 healthy volunteers. It will need proper field trials, but the study showed that Vi-TT is a highly immunogenic vaccine that significantly reduces typhoid fever cases when assessed using a stringent controlled model of typhoid infection.

The BMJ 30 Sep 2017  Vol 358

There’s interference on this phone line

The idea of telephone triage in general practice has been around at least since the early 1990s, when my own practice gave a brief try. Here’s a study a quarter of a century later which confirms that we were probably right to give it up:

“Our study shows that adoption of the telephone first approach in general practice had a major effect on patterns of consultation, with large increases in phone consultations and decreases in face to face consultations. Our patient survey suggests that up to half of patients’ problems could be dealt with on the phone, which could offer potential for practices struggling with demand for face to face consultations. The telephone first approach, however, is not a panacea for management of demand and is on average associated with increased overall GP workload.” There was no sign here of anything to support NHS England’s claim that “the model has shown cost savings of about £100 000 per practice through prevention of avoidable attendance and admissions to hospital.”

Predicting death in over-65s

People reaching my age are required to guess when they are likely to die. It’s bad enough when the question comes from inside one’s head, but it’s also implied by every lawyer, accountant, or insurer one comes across. In fact, actuaries preceded public health physicians by decades in their calculation of prognosis. Julia Hippisley-Cox has probably now turned the tables by coming up with new equations to predict the short term risk of death in men and women aged 65 or more, taking account of demographic, social, and clinical variables. The equations had good performance on a separate validation cohort. At the age of 67 I intend to give them a wide berth.

Plant of the Week: Magnolia delavayi

I have been wanting to smell the flowers of this huge-leaved evergreen magnolia for the last 30 years, and last Friday in Exeter I got lucky. Not many magnolias flower in mid-autumn, but M delavayi is an exception. However, few of its flowers ever meet the human nose, because they are typically borne too high, and only last for a day or two. Moreover, this tree is rare and hard to propagate, and is usually only grown on inaccessibly lofty walls.

But on a south-facing slope overlooking the Exe estuary, on the site of a former botanical garden, I spotted a free-standing healthy tree bearing a big fresh flower at nose height. My hopes were high. Its sister-species, M grandiflora, bears flowers with the most intoxicating scent. As I cupped the delavayi flower towards me, I could smell nothing. Half a centimetre away, I enjoyed a faint sensation of cucumber and honey. The next day, the flower would be a few curls of brownish parchment. This is a majestic plant to be grown for its exotic olive-green leaves and its rarity, not for its flowers or their scent.

  • kidmugsy

    “Its central proposition is that the complexity of medicine now exceeds the capacity of the human mind”

    I remember looking at one of those horrendous biochemical cycle diagrams and realising that there was almost certainly no human who had mastered all the evidence that supported it.

  • That was fascinating post. Thanks. I learned some new things.

  • Angela Davis

    I can not agree with you more mate