di
Anna Giulia Cattaneo, M.D.
Pressure ulcers are a known and previously debated cause
of major invalidity in aging people. Those localized at the
foot pose additional problems if the old person suffers from
type II diabetes mellitus: in the western world this condition
remains the main cause of amputation of the leg. The diabetic
condition supports a complex pathogenesis for ulcer development
with low probability of healing. From minor lesions up to
the Charcot deformities, the diabetic foot represents a complex
of lesions involving all the structures of lower extremities,
from skin to bones.
Summarizing the main component supporting lesions at the
lower extremities in diabetics, one must consider the defect
of autonomic nervous system regulation, which acts in synergy
with the poor vascularisation due to both the micro- and macro-angiopathy,
aggravating it by impaired venous drainage. The peripheral
nervous system alteration is principally responsible for altered
sensitivity to temperature and possibly to other painful stimuli,
with higher exposure to traumas and delay in recognizing and
reporting minimal lesions.
Another condition complicating the outcome of diabetic ulcers
in the foot is the presence of infections. Wound infections
are often associated with poor diabetic control, and are supported
by a polymicrobial flora of fastidious or resistant organisms:
Pseudomonas aeruginosa, Staphylococcus aureus and fungi, frequently
Candida albicans.
Ulcers of foot in older diabetic subjects are associated
with high mortality rates. Principal conditions enhancing
the risk of death are the spread of infections through blood,
the general physical decline following the forced immobilization,
the sequelae of major amputations. The high mortality rate
associated to serious lesions in the foot in diabetic and
older patients seems to be associated in several cases to
concomitant cardiac failure, even at sub clinical level: aggressive
treatment of this underlying condition can significantly improve
survival even in subjects requiring major amputation.
Preventive measures to avoid lower extremities ulcerations
are typically multidisciplinary, involving optimization of
metabolic control, good hygiene of the foot, here including
the use of appropriate socks to maintain the feet warm and
wet, and of well designed shoes to avoid undue pressures or
unbalanced gait and rehabilitative counselling. Attention
should be paid to potential traumas deriving from banal events,
like prolonged contact with warm surfaces or water, not recognized
by the patient suffering from neuropathy. However, educational
measures added to traditional care did not seem to be able
to improve prevention in this class of individuals (Diabetologia.
2008, 51:1954-61).
Once the ulcer has developed, all efforts should be done
to avoid amputations. The conservative treatment of ulcers
is time requiring and expensive, and the outcome uncertain.
Different epidemiological studies evaluated that primary healing
occurred in no more than 60 to 70 % of patients, the inequality
of samples explaining the diversity of results. A cohort study
recently conducted in Sweden (Diabetologia. 2009, 52:398)
evaluated factors impairing the tendency of serious wounds
heal without amputation: the most important factors seemed
to be the extent of neuro-vascular ischemia, the anamnesis
positive for previous amputations, and the presence of multiple
or very large lesions. Complicated diabetes and other co-morbidity,
greater toe pressure and local infection represented additional
pejorative prognostic signs. Aging was responsible for additional
risk.
The importance of prevention of major amputation in aged,
diabetic subjects is intuitively important, and it should
represent a primary target in geriatric care. In recent years
a decrease of major amputations has been observed, as a consequence
of amelioration of therapeutic means for diabetic control
as well as for local lesions. New treatments and technologies
have been experienced, in addition to better compliance and
control of the diabetes itself. A number of innovative treatments
have been experienced: hyperbaric oxygen therapy, treatment
with new formulations and growth factors, newest type of dressing
or support for the foot, newer materials with bacteriostatic
and bactericidal properties or enhanced ability for stimulate
the skin repair (Diabetes Care 2007, 30: 586-90; J Control
Rel 2007, 121:190-9; J Nanosci Nanotechnol. 2007, 7: 3888-91).
Attention has been paid to the availability of simplest predictive
methods to score the risk of developing diabetic foot lesions
and give a precocious and attainable prediction of risk for
ulcer development and healing. A similar score has been proposed
by a Scottish group (Diabetes Care, 2007, 30: 2064-9). More
recently, a simplest score has been proposed at the Department
of General and Transplant Surgery, University of Tübingen,
(Germany). The evaluation of the prognostic output was attained
on the basis of clinical parameters easily recorded by nurses
or generic care givers, and namely the palpable pedal pulses,
the wound area, the ulcer duration, and the presence of multiple
ulcerations. The score was given by the sum of simplified
sub-scores, 1 or 0, given respectively to the presence or
the absence of palpable pedal pulses, wound areas at least
4 cm wide, lesions lasting at least 130 days and multiple
lesions. The theoretical maximum score is 4. Not only the
score in itself seemed to be correlated with the propensity
to healing, but even its progression can be a diagnostic predictive
value: an increase of 1 was indicative of 37% reduction in
healing chance.
In conclusion, type II diabetes mellitus and its complications
should never be considered as an unavoidable burden or fatality
of the older age, but as a hazardous association charged by
additional risks, that of ischemic wounds at lower extremities
between others. The presence of diabetic neuropathy, peripheral
or autonomic, should be remembered and diagnosed as a pejorative
condition, seriously influencing the evolution of lesions.
Because the sequelae of this complication should be seriously
invalidating and even life threatening, all the concomitant
pathologies and associated events should be carefully considered
and adequately treated.
Independently from the age of the subject, every effort should
be done to warrant the best care, preventive measures and
treatment to the aged persons suffering from diabetes, having
as the main target the higher degree of wellbeing and personal
autonomy for the longer period possible.
Anna Giulia Cattaneo, Università
dell'Insubria, DBSM, Via J-H Dunant 3, 21100 Varese
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