Restarting Hearts.pdf

Restarting hearts

Crash course

How long should doctors spend trying to restart a stopped

heart?

Sep 8th 2012 | from the print edition

ANY given episode of a television medical drama is likely to feature a

patient going into cardiac arrest. As the victim thrashes around, a

telegenic doctor summons a posse of helpers, who start zapping the

patient, compressing his chest or administering adrenalin jabs until the

heart starts ticking again.

On TV these efforts almost always succeed, spectacularly and

immediately. The real world, sadly, is crueller: doctors manage to

restart only about half of the hearts that stop in a hospital, and only

about a sixth of patients will go on to survive long enough to be

discharged. One of the toughest decisions faced by hospital staff is

how long to keep trying, and when to give up on a particular patient as

a lost cause.

A new paper, published in the Lancet , aims to provide some scientific

backing for such decisions. A team of researchers led by Brahmajee

Nallamothu at the University of Michigan looked at data from more than

64,000 patients who had suffered cardiac arrests in 435 American

hospitals between 2000 and 2008. There are no official guidelines

specifying how long doctors should keep trying to resuscitate flatlining

hospital patients. As a result, the authors wondered whether the

amount of time spent attempting resuscitation might vary from hospital

to hospital. Sure enough, it did. The median resuscitation attempts in

patients who eventually died lasted 16 minutes for the bottom quarter

of hospitals; for the top quarter it was 25 minutes.

That matters, for the researchers also found that a greater willingness

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to persist correlated with better survival chances for patients.

Circulation was restored in 45.3% of patients in the bottom quarter of

hospitals; 14.5% survived long enough to be discharged. For the top

quarter, the figures were 50.7% and 16.2% respectively, a boost of

12% in both cases.

One reason why doctors are reluctant to spend too long attempting to

revive patients is that they worry about brain damage caused by

prolonged lack of oxygen. But the study found that, after adjusting for

factors such as age and general health, patients from hospitals more

willing to try long resuscitations showed no greater risk of brain

damage.

Such a big discrepancy in a fairly common procedure may look odd—if

all hospitals performed as well as the best, thousands of lives a year

might be saved. But plenty of medicine has only a thin base in

scientifically reviewed evidence, meaning that the opinions, judgments

and prejudices of individual doctors often determine how treatment is

given.

A difficulty is that medical decisions are complicated. A doctor

considering whether to continue with chest compressions, for instance,

must weigh any number of factors, from the patient’s age to other

conditions he may be suffering from or the effects of drugs used to

treat them. The presence of so many confounding factors makes it hard

to assess the general effectiveness of any given treatment—unless, like

Dr Nallamothu and his colleagues, you have access to a great deal of

data.

As with any piece of scientific research, there are caveats. Dr

Nallamothu points out that the study could simply be picking up an

effect of better hospitals, with a willingness to persist with

resuscitation a consequence of better technology or better-trained

doctors, neither of which can be detected by the study. And the tricky

clinical particulars of any given resuscitation mean that the paper

cannot give rise to hard-and-fast rules about exactly how long doctors

should persist. But it does suggest that plenty of lives might be saved

if medics are willing to keep trying for a little bit longer.

from the print edition | Science and technology

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