In the era of the “ageing population”, Diabetes Mellitus is an increasing problem, and so are its complications and total burden to patients, society and health care systems. Lower extremities lesions in the diabetic patients, especially the foot (diabetic foot), are of special concern, as the undesirable outcome of diabetic foot disease is amputation that affects morbidity, mortality and results in various psychological, social and financial consequences. However, the majority of amputations are preceded by signs of arterial disease (microcirculation) and local hypoxia, resulting initially in foot ulcers that can be treated. It is very important that such lesions are early identified and managed in order to avoid infection and further progression that becomes limb and life threatening.
Life-time risk for a diabetic person to develop foot ulceration is as high as 25%. Worldwide, more than 1 million diabetic patients require limb amputation every year. That means that every 30 sec, one major amputation takes place because of diabetes. Studies and meta-analyses have shown that Hyperbaric Oxygen Therapy (HBOT) decreases frequency of amputations by 1/3 (11% from 32% without HBOT) as well as duration of hospitalisation of the diabetic patient.

The term “Diabetic Foot” is actually a group of pathologies and includes Diabetic Neuropathy, Charcot’s Arthropathy, Peripheral Vascular (Arterial) Disease, Lower Extremities Ulcers, Osteomyelitis, dislocation of the small bones and eventually gangrene and amputation. Severe complications including amputation are potentially preventable, and as in most cases it all starts with an ulcer, it is of great importance for medical practice to prevent ulceration and/or manage effectively ulcers to achieve complete healing – when they appear

The fact that tissues in the diabetic foot are hypoxic by default, offers an easy explanation and the rationale for the use of hyperbaric oxygen and its beneficial effects. Currently, hyperbaric oxygen therapy is indicated for the management of diabetic foot ulcers and this is supported by substantial evidence. Moreover, it has synergistic effect to various antibiotics and offers the potential to treat resistant infections that involve the hypoxic tissues.

 

Pathogenesis

Many factors contribute to the diabetic foot pathology, such as neuropathy, micro vascular disease, trauma and infection. Neuropathy is considered to play a central role, while micro vascular disease and the resulting hypoxia are important obstacles to the normal healing process.

Risk factors for Diabetic Foot Ulcers

Diabetic neuropathy affects sensory, motor and autonomic function, usually being unnoticed by the patient. Motor deficit leads to muscle weakness and atrophy, leading to foot deformity and altered biomechanics, affecting pressure distribution to the foot and predisposing to ulceration. Sensory deficit leads to decrease or absence of the normal warning sensation regarding improper pressure on the foot or trauma, especially the minor ones. Repetitive trauma continues unnoticed by the diabetic, until an ulcer is established. Autonomous nervous dysfunction affects cutaneous blood flow and sweating, leading to dry skin predisposed to cracks and fissures.

Diabetes increases the risk for atherosclerosis, and peripheral arterial disease leads to poor wound healing. Poor diabetes control impairs collagen cross linking and polymorphonuclear leukocyte function, leading to impaired wound healing and predisposing to fungal infections that may lead to skin disruption.

Epidemiology
Diabetic neuropathy is present in > 50% of patients ≥ 60 years and increases the risk of foot ulceration by 7-fold. Annual incidence for diabetic foot ulcers is 1-4%, with prevalence of 4-10% (1 in 10 diabetics may develop foot ulcer). Lifetime risk is estimated to be 25% - 1 in 4 diabetics will develop foot ulcer at some point of his life. Amputation occurs 10-30 times more often in diabetics than in the general population. Diabetes accounts for up to 80% of non-traumatic amputations, with 85% of these being preceded by a foot ulcer. Amputation increases mortality at follow-up, ranging from 13-40% at 1 year to 39-80% at 5 years.

 

Diabetic foot ulcer is usually the result of a minor trauma that goes unnoticed by the patient because of the neuropathic changes described earlier. The delay in seeking medical attention is the usual scenario, because of the absence of pain, and this result in initiation of treatment for relatively severe forms of ulcers. Inappropriate footwear, foreign objects and walking barefoot or on hot surface (walking barefoot on the hot sand in summertime) may be the cause of trauma