NEW YORK (Reuters) -- Mechanical ventilators can be
essential life-support for critically ill patients with
compromised respiratory systems. However, experts warn
that lung tissue can suffer permanent damage during
long-term ventilator use. Now, scientists believe they have
developed a means of reducing that level of damage.
The new design "could have a significant effect on
morbidity by breaking the chain of injury propagation in
acute lung injury," concludes an international team of
researchers led by investigators at Boston University in
Massachusetts. Their report appears in the May 14th issue
of the journal Nature.
Conventional mechanical ventilators mimic human
respiration, but in an unvarying, repetitious manner. "The
respiratory rate and volume of air inspired (drawn into the
lungs) per breath are fixed," the researchers explain,
"although during natural breathing these parameters vary
appreciably."
They say the regimented rhythms of conventional
ventilator-driven breathing often leave certain peripheral
areas of the lung closed for long periods of time, triggering
the eventual collapse of these tissues.
However, the study authors report they have now devised
computer-controlled ventilation that contains random
variations within its programmed respiration pattern. This
enhanced breathing pattern closely resembles normal
variations in shallow/deep breathing found in healthy
respiration. The researchers believe their new ventilator
design means "fewer (peripheral) regions will remain
collapsed," reducing the level of lung tissue damage linked
to assisted breathing.
SOURCE: Nature (1998;393:127-128)
-- Maksim (Max) Bilymail to: imax(AT)odyssee.net