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Michael
Peel BMJ 1997;315:829-830 (4 October)
Editorials
Hunger strikes Understanding the underlying physiology will help
doctors provide proper advice Hunger strikes
in different parts of the world are regularly in the news. Doctors
with an interest in human rights may be asked to give independent medical advice to an asylum seeker intending to
start a hunger strike. Several recent
articles have addressed the ethics of treating hunger strikers,1 2 but there is less information available on the
physiological issues. It is essential to
understand both these issues to be able to advise the individual appropriately. There
have been several studies of fasting for a few days, but in the past 15 years only three studies have described voluntary
total fasting for prolonged periods. The
first was of a monk who tried to fast for 40 days for religious reasons but was forced to stop on day 36 because of
unacceptable symptoms.3 The second was of
four adults who were planning to fast indefinitely. One became very unwell on day 38, and the others ceased
fasting on day 40.4 The third was a retrospective
study of 33 South African political prisoners on hunger strike for up to 28 days.5 Hunger
strikes have been around since Roman times, and the suffragettes brought the tactic to public awareness in Britain earlier
this century. Gandhi fasted at least 14 times
but never for more than 21 days. After the second world war Ancel Keys published an extensive review of people
subjected to prolonged starvation and a study
replicating these conditions in the laboratory.6 The hunger strikers of the Maze Prison in Belfast in the early 1980s
died after 45-61 days, but no results have
been published. For the first few days of
starvation the body uses its stores of glycogen in liver
and muscle.7 This is accompanied by glucagon induced naturesis, with substantial weight loss. The next phase lasts up to
day 10-14, during which time glycogen stores
are exhausted and certain amino acids take over as the substrate for gluconeogenesis. This is associated with a loss
of muscle, including heart muscle. In the
final phase protein is protected, so that it forms only about 10% of energy source. Most energy comes from ketones
produced by the breakdown of fatty acids.
When fat stores are used up there is catastrophic protein catabolism,
but generally other complications arise first. Conclusions
from studies recommend independent medical monitoring after a weight loss of 10% in lean healthy individuals.7 If the
pre-hunger strike weight is unknown, a
maximum of 10 days' hunger strike, or a body mass index of less than 16.5 kg/m2, should be the trigger. Major problems
arise at a weight loss of about 18%. The main disabling symptom is feeling faint and
dizzy. Hunger strikers learn to stand up
very slowly and may become almost bed bound. This may affect their ability to state their case. Bradycardia and drop
in blood pressure are well recognised as
effects of even relatively short fasting and were seen in all the individuals studied closely.4 5 Orthostatic
hypotension was present by about day 20 in
all cases in which it was recorded and in at least one case was almost disabling. Weakness and lightheadedness was common.
The cause of this is not clear, but could be
partly due to electrolyte imbalance. Although thyroxine concentrations
are maintained in fasting, tri-iodothyronine is converted rapidly to an inactive metabolite, thus reducing effective
thyroid function. This is an important
physiological protective function but will lead to weakness and a sensation of feeling cold. Abdominal pain was
described by around three quarters of those
studied, even in the early stages.5 Dehydration
is a risk in voluntary total fasting, as individuals may lose their feelings of thirst and hunger.1 This is in complete
contrast to prolonged severe undernutrition,
where people may drink to relieve feelings of hunger.6 Average fluid intake needs to be maintained at around 1.5
l/day. Ideally water should be supplemented
with up to 1.5 g sodium chloride (half a teaspoon of salt) per day. More than this may precipitate hypokalaemia, and
monitoring of potassium concentrations may be
helpful where possible. Of the five
individuals monitored closely, one developed symptomatic hypokalaemia,
which eventually needed intravenous rectification. This individual went on to develop acute Werneke's encephalopathy.
The risk is increased by ingested glucose;
some hunger strikers eat small amounts of chocolate that are brought in by friends trying to help. The study of detainees showed 77% of hunger
strikers to be clinically depressed at the
time of admission to hospital, measured by an independent psychiatrist, although they also demonstrated features similar
to those of the post-traumatic stress
syndrome.5 Emotional liability is a later feature of voluntary total fasting. Once
a hunger strike of more than three weeks is over, re-alimentation is potentially dangerous. Werneke's encephalopathy has
been recorded in patients taking
inappropriate food after fasting. Ingesting carbohydrate after fasting will also cause a reverse of the initial naturesis,
causing measurable weight gain and
potentially acute oedema. In South Africa, diluted proprietary lactose free balanced feed was used until a light diet was
tolerated.5 Elsewhere, boiled vegetables have
been the nutrients taken in the initial period. The patient needs to consume small amounts of food which are
high in neither processed sugars nor protein.
Hospital monitoring needs to be continued for several days after
eating has restarted. Cardiac problems are
potential hazards of refeeding. Hypokalaemia is a risk, and a sudden increase in fluid volume can precipitate
cardiac failure as the physiological load is
increased. The bradycardia and hypotension of starvation resolve
and often overshoot.6 The exact cause is unclear. These fatalities may be related to loss of cardiac muscle in parallel to
skeletal muscle loss. The deaths were also
associated with prolonged QT intervals on electrocardiographic monitoring. Laboratory studies showed that the QT
interval was one of the variables that took
the longest to recover on refeeding.6 Hunger
strikers are not aware of the complex physiological processes that they are disrupting or the risks on restarting eating.
Doctors working with hunger strikers must be
aware of the processes and potential problems so that they can advise them fully. *Michael
Peel, Senior medical examiner a a Medical Foundation for the Care of Victims of Torture,
London NW5 3EJ
Johannes Weir Foundation for Health and Human
Rights. Assistance in hunger strikes:
a manual for physicians and other health personnel dealing with hunger strikes. Amersfoort: JWFHHR,
1995. Annas
GJ. Hunger strikes. BMJ 1995;311:1114-5. [Full Text] Kerndt PR, Naughton JL, Driscoll CE,
Loxterkamp DA. Fasting: the history, pathophysiology and complications. West J
Med 1982;137:379-99. Frommel D, Gautier M, Questiaux E,
Schwarzenberg L. Voluntary total fasting: a challenge
for the medical community. Lancet 1984;i:1451-2. Kalk
WJ, Felix M, Snoey ER, Veriawa Y. Voluntary total fasting in political prisoners: clinical and biochemical
observations. S Afr Med J 1993;83:391-4. Keys A, Brozek J, Henshel A, Mickelsen O,
Longstreet Taylor H. The biology of human starvation. Minneapolis: University of
Minnesota Press, 1950. Keeton GR. Hunger strikers: ethical and
management problems. S Afr Med J 1993;83:380-1. [Medline] |
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