BAROTRAUMA
BARRIER NURSING
B
BARIUM X-RAY EXAMINATIONS
M onitor_____
showing
barium in the
oesophagus
Patient drinks
a solution of
barium
X-ray machine takes
a series of pictures
BARIUM SWALLOW
cause constipation. Therefore, it is im-
portant to have a high-fibre diet and
drink plenty of water after a barium
examination, until all the barium has
passed through.
barotraum a Damage or pain, mainly af-
fecting the middle ear and facial
sinuses,
that is caused by changes in surround-
ing air pressure. Air travellers are at the
greatest risk, but scuba divers face simi-
lar problems (see
scuba-diving medicine).
Aircraft cabin pressure decreases as
the plane ascends and increases as it
descends. As the aircraft ascends, the
ears may “pop” as the air in the middle
ear expands and is expelled via the eus-
tachian
tubes,
which
connect
the
middle ear to the back of the throat. On
descent, the higher pressure may push
the eardrum inwards and cause pain.
Minor pressure damage in the middle
ear may cause pain, hearing loss, and
tinnitus
for a few days; damage within
the facial sinuses may also cause pain,
and possibly a discharge of mucus or
blood. Symptoms usually wear off with-
in hours or days, but treatment may be
needed if they worsen or persist. Large
pressure changes can rupture the ear-
drum (see
eardrum, perforated).
Barotrauma can be avoided by vigor-
ous swallowing or by forcibly breathing
out with the mouth closed and the nose
pinched (the Valsalva manoeuvre). This
action equalizes the internal and exter-
nal pressures in the middle ear and
sinuses. If the eustachian tubes are
blocked, as commonly occurs with a cold,
use of a nasal spray containing a
decon-
gestant drug
is recommended shortly
before the descent of the aircraft.
Infants should be breast- or bottle-fed
during descent to encourage swallow-
ing. (See also
aviation medicine.)
barrier cream
A cream used to protect
the skin against the effects of irritant
substances and of excessive exposure
to water. (See also
sunscreens
.)
barrier method
A method of prevent-
ing pregnancy by blocking the passage
of sperm to the uterus, for example by
using a condom or a diaphragm. (See
also
contraception, barrier methods of.)
barrier nursing
The nursing technique
by which a patient with an infectious
disease is prevented from infecting
66
previous page 64 BMA Illustrated Medical Dictionary read online next page 66 BMA Illustrated Medical Dictionary read online Home Toggle text on/off