With the incidence of diabetes increasing year by year, more and more people are facing the problem of diabetic foot. In developed countries, the incidence of diabetic foot is about 4-10% of diabetic patients. The Chinese Society of Ulcerative Medicine confirms that 15% of diabetic patients in China have foot ulcers of varying degrees, and about 1% of patients require amputation treatment, with an amputation rate 15 times that of non-diabetic patients. Most worryingly, it has been reported that more than 15-19% of the diabetic patients whose limbs were amputated were found to have diabetes only when they were hospitalized.
Typical diabetic foot
I. Definition of diabetic foot
Diabetic foot refers to a diabetic patient’s lower limb infection, ulcer formation and/or deep tissue destruction due to combined neuropathy and various degrees of peripheral vasculopathy; that is, foot ulceration or gangrene caused by a series of diseases such as dystrophic lesions of peripheral nerves, arterial occlusive lesions, and easily combined bone and cartilage tissue infections.
Second, the etiology and pathophysiological changes
High-risk factors that can easily lead to diabetic foot include: 1) peripheral neuropathy; 2) peripheral vascular disease; 3) previous history of foot ulcers; 4) foot deformities; 5) calluses; 6) patients with blindness or severely reduced vision; 7) combined renal disease; 8) elderly people; 9) people who cannot observe their own feet or have dulled senses; 10) people who lack knowledge of diabetes.
Neurotrophic disorders and ischemia are the main causes of foot ulcers complicating diabetic patients, and their pathophysiological changes include.
1, neurotrophic disorders: due to defective Schwann cell metabolism causes sensory nerve and motor nerve denervation, thus delaying the speed of nerve conduction, and the protective function of the nervous system is gradually lost. It may manifest as nocturnal limb spasms and sensory abnormalities, loss of tactile and pain sensation, and finally loss of deep tendon reflexes; the patient’s foot develops a typical arched foot (Figure 2) with claw-shaped toes; tissue thickening, stiffness, Charcot osteoarthropathy; upright hypotension, diarrhea; loss of sweat gland function in the foot, causing dry and cracked skin, etc.
2, Ischemic disease: About 10 years after the onset of the disease, atherosclerotic occlusive lesions of the lower extremities appear in the average patient, the incidence of which is four times that of non-diabetic patients. In diabetic patients, the sclerotic lesions are mostly limited to the beginning segments of the tibial and peroneal arteries and sometimes involve the distal superficial femoral arteries, manifesting as extensive luminal narrowing and occlusion of these arteries. The arteries of the lower extremities and feet often have intimal calcification, and in older patients or those with a long history of disease, there may be calcification of the middle layer of the artery, but the lumen remains open. As a result, the ankle/brachial index of the affected limb may appear normal or above normal. Clinically, the affected foot often presents with cool skin temperature, no arterial pulsation, intermittent claudication, and resting pain.
III. Diagnosis
The diagnosis of diabetic foot includes three elements: 1, diabetic patients; 2, with vascular neuropathy; 3, with foot ulcers or gangrene. Those without ulcers and gangrene should not be called diabetic foot; diabetic foot can be co-infected, but not necessarily. Ulcers can be of varying depths, and gangrene can be localized or cumulative throughout the foot.
Tests commonly used for diagnosis include: (1) Neurological examination: to find out whether the patient still has protective sensation. For example, the 10g nylon wire method of measurement. (2) Skin temperature examination. (3) Pressure measurement: to understand whether the patient has abnormal foot pressure and to perform gait analysis, which can provide a basis for correction of abnormal foot pressure. (4) Peripheral vascular examination: palpation of dorsalis pedis artery pulsation, ankle artery-brachial artery blood pressure ratio (ABI), and transdermal partial pressure of oxygen reflect the blood supply of peripheral arteries. (5) Vascular ultrasound and angiography: they can be used to understand the degree and location of lower extremity vascular occlusion, which can provide a basis for deciding the amputation plane and also prepare for vascular bypass surgery. (6) Examination of diabetic foot ulcers combined with infection: signs of local infection include redness, swelling, pain and tenderness. More reliable signs of infection are purulent exudate, twisted pronation (due to gas-producing bacteria), or deep sinus tracts. The ulcer suspected of being infected should be explored with a probe. If sinus tracts are found and bone tissue is probed, osteomyelitis is considered. A specimen from the base of the ulcer may be taken for bacterial culture using the probe. x-rays may reveal gas in the local tissue, which is indicative of a deep infection in the patient. Erosion of bone tissue seen on plain radiographs indicates osteomyelitis.
The commonly used clinical wagner grading method for diabetic foot is as follows.
(1) Grade 0 – foot with high risk factors for ulceration and no current ulceration.
(2) Grade 1 – foot with skin surface ulceration and no clinical infection. These ulcers tend to occur on prominent areas of the foot i.e. pressure bearing points, such as the heel, foot or base of the toe, where the ulcer is surrounded by callus.
(3) Grade 2 – deeper, penetrating ulcers, often combined with soft tissue infection, but without osteomyelitis or deep abscesses, and some specific bacteria may be present at the ulcer site, such as anaerobic and gas-producing bacteria. Deeper ulcers, often combined with soft tissue infection, without abscess or infection of the bone.
(4) Grade 3 – there are deep ulcers, often affecting bone tissue, with deep abscesses or osteomyelitis.
(5) Grade 4 – An ischemic ulcer, localized or gangrene of the foot. Gangrene without severe pain is suggestive of neuropathy. The surface of the necrotic tissue may be infected.
(6) Grade 5 – Gangrene affects the entire foot. Aortic obstruction plays a major etiologic role.
IV. Comprehensive treatment
Diabetic foot is a common, complex and chronic disease that consumes high medical costs and is difficult to treat, which requires active and effective preventive evaluation measures by general practitioners or specialists. For diabetic patients with risk factors, regular follow-up, effective control of blood glucose levels, enhanced education on foot protection, and specific guidance from a podiatrist when necessary can prevent the development of foot ulcers. As for the formed diabetic foot, the treatment needs to be “a combination of internal medicine, intervention and surgery; emphasize the combination of local and overall; the combination of drug therapy, biological therapy and surgical treatment; the combination of Chinese medicine and Western medicine; the combination of treatment and care, prevention”.
1, control blood sugar: subcutaneous injection of insulin to control blood sugar at the basic normal level. This is the basis of all diabetic foot treatment and the key to prevent the recurrence of ulcers.
2, active prevention and control of infection: any ulcer and gangrene have the potential for infection, so it is important to actively prevent and control infection while controlling blood sugar. This includes: ensuring the cleanliness of the ward environment, bed sheets and patient’s skin; reasonable application of antibiotics; and ensuring adequate drainage of the ulcer wound and cleanliness of the wound surface.
3.Improve circulation: impaired blood supply in the affected foot is the main cause of diabetic foot. Therefore, actively improving blood circulation and increasing blood supply to the affected foot is an important part of diabetic foot treatment. This includes the use of drugs (prostaglandin E1, anti-platelet aggregation drugs, low-molecular heparin, thrombolytic agents, antioxidants and Chinese medicinal preparations that warm the Yang and benefit the Qi and activate the blood) to expand and unblock the blood vessels; the use of autologous bone marrow stem cell transplantation or peripheral blood stem cell transplantation to establish collateral circulation and neovascularization in the affected limb; the use of distal arterial diversion, interventional balloon dilation, placement of endovascular stents and ultrasonic ablation to increase the patency of blood vessels. The patency of blood vessels can be increased by distal artery diversion, interventional balloon dilation, endovascular stenting and ultrasonic ablation.
4.Nutritional nerve and nutritional support treatment: nourish the nerve and restore the neurological perception function; promote reasonable diet, meat and vegetables, less spicy and stimulating food, and adhere to the principle of light diet. Promote the purpose of muscle healing.
5.Wound treatment: In addition to incision and drainage of the formed abscess, local treatment of the necrotic wound is very important to improve the efficacy, shorten the course of treatment and preserve the limb. The “nibbling therapy” is often used: the necrotic tissue is removed in batches. The specific methods are: distal necrotic tissue is removed first, proximal tissue is removed later; loose necrotic tissue is removed first, firm tissue is removed later; soft tissue is removed first, dead bone is removed later; complete removal is done after the inflammation is completely subsided or controlled and the boundary between necrotic tissue and healthy tissue is obviously formed, but attention should be paid to the local blood supply condition, so as to preserve the limb and avoid amputation as much as possible. And use biological factors such as fibroblast growth factor and other local spraying trauma, or the reasonable application of new dressing to fully mobilize the body’s trauma healing response and greatly shorten the time of trauma healing. If the active limb preservation treatment is not effective and brings the threat of infection to the whole body, the limb should be amputated in time; the amputation site should be precisely estimated to ensure a good circulation height.
V. Application of negative pressure closed drainage in the treatment of severe diabetic foot
The negative pressure sealing drainage technique (vacuum sealing drainage, VSD) is wrapped with medical foam outside the drainage tube, so that the foam becomes the intermediary between the drainage tube and the drained cavity or wound, and the blocky drainage material and the tissues and organs adjacent to the drained area cannot enter or touch the drainage tube. To ensure that the drainage area has sufficient negative pressure and to ensure the drainage effect, the drainage area must be closed to isolate the traffic between the drainage area and the outside world. This is the basic idea of the negative pressure closed drainage technique. In the case of using negative pressure closed drainage, it can significantly improve the trauma blood flow and promote the removal of necrotic material and bacteria; accelerate the growth of trauma granulation tissue and the proliferation of repair cells; increase capillary flow and promote capillary neovascularization; also reduce the matrix immunoprotease activity in the trauma and increase the fibronectin content. Therefore, it can effectively promote the healing of the infected ulcerated wound of diabetic foot.
Compared with other forms of drainage, negative pressure closed drainage has some obvious advantages.
1, negative pressure closed drainage is a kind of high efficiency drainage. The high efficiency is reflected in the all-round drainage and the thoroughness of drainage under high negative pressure. That is, the drainage area of the exudate, pus and shedding necrotic tissue can be timely, thorough drainage out of the body, creating a “zero accumulation” including the drainage channel is drained area.
2, medical foam material wrapping to ensure the drainage tube in a relatively long period of time, and thus ensure the drainage effect.
3, can significantly accelerate the closure of the infected lumen and the healing of infected wounds, and effectively prevent the accumulation of fluid in the surgical field.
4, significantly reduce the application of antibiotics, effectively preventing the occurrence of nosocomial cross-infection.
5. it is a purely physical method, avoiding the possible side effects caused by various chemical treatments and, in general, resulting in lower medical costs.
6.Easy care, transparent adhesive film facilitates the observation of wounds or wounds.
7. Patients are spared the pain of frequent medication changes and medical personnel are spared the labor of frequent medication changes.