Comprehensive information about diving and undersea medicine for the non-medical diver, the non-diving physician and the specialist.
Most divers tend towards an increase in vital
with age but the general conclusion, that divers tend to have larger
capacities than nondivers, was not confirmed by a study of 126
divers by Thorsem et al (1989). They suggest that the increase is
and that there is a greater, but belated, diminution. Any change of
capacity probably has little effect upon the divers general health
recent studies have shown that divers do develop some degree of air
obstruction due to airway narrowing(Elliott et al, 1990).
Pulmonary diffusion capacity is another
function which deteriorates with age. At the present time the work to
a possible acceleration in divers is incomplete. Early studies have
confined to deep diving, where a diminution of pulmonary diffusion
from a particular dive may not be clinically significant and tends to
during the next few weeks. This change is also associated with
of exercise tolerance (Thrones et al, 1990) but only to a degree that
functional rather than clinically significant.
In contrast, a study of 8 divers in a German deep dive (Lehnigk et al) showed no significant diminution of total lung carbon monoxide diffusion (TLCO) though there were a number of other variables, a conclusion also reached from a 450m dive at the National Hyperbaric Center in Aberdeen. However, there may be a possible cumulative effect and the most favored explanation is in association with a cumulative dose of oxygen at tensions greater than 0.3 bar.
Ernest Campbell, MD, FACS All Rights Reserved.