Why does the negative pressure drainage ball have half negative pressure and full negative pressure?

Negative pressure closed drainage (VSD)

First, the definition of drainage

Drainage is a surgical method to establish an open channel between a certain part of the body and other parts of the body, or between it and the outside world, so as to achieve the purpose of treatment. It is an important part of surgical treatment and one of the basic operations of surgical operation.

Second, the purpose of drainage

1, timely eliminate harmful substances such as purulent effusion, necrotic tissue, foreign body, abnormal hematocele, digestive juice, etc. in body cavity, thus reducing pressure, eliminating dead cavity, eliminating the stimulation of inflammation to the body, changing the biological environment of infected site, alleviating the inflammatory reaction of the body, inhibiting local bacterial reproduction, preventing the spread of infection, and promoting the regression of inflammation, that is to say, preventing or treating diseases caused by purulent exudate, necrotic tissue and digestive juice.

2. Ensure the normal healing of the suture site and reduce the occurrence of complications;

3. Observe the quantity and characteristics of the extract to judge the drainage area;

Third, the classification of drainage

1, therapeutic drainage: drainage of infected focus, such as abscess drainage, or drainage of fluid in body cavity after operation and trauma.

2. Preventive drainage: drainage aimed at preventing effusion, infection or anastomotic leakage. Strictly speaking, drainage can not prevent anastomotic leakage, but can only avoid diffuse peritonitis when anastomotic leakage occurs.

3. Diagnostic drainage: such as diagnostic peritoneal lavage, percutaneous transhepatic bile duct puncture, fiberoptic endoscopic pancreaticobiliary duct intubation and duodenal drainage.

Fourth, the drainage principle

1, carefully decide whether to place drainage, unnecessary drainage is harmful;

2, serious pollution or possible infection of the wound, should be drainage;

3. The purpose of drainage is to establish an effective channel from the drainage area to the outside world;

4. Drainage can be driven by gravity, capillary action, siphon action or negative pressure suction;

5. Drainage is a foreign body to the human body, which can increase the chance of infection (abdominal drainage may be the cause of intestinal obstruction, digestive tract leakage or abdominal hernia avoidance), and materials that are not irritating to human tissues should be used for drainage as much as possible;

6. Open drainage provides a way for bacterial retrograde pollution, and closed drainage should be used as far as possible to avoid retrograde infection.

7. Soft and flexible drainage can reduce the possibility of erosion and necrosis of adjacent tissues due to mechanical compression, and the drainage tube with side holes can be blocked by inhalation or growth of adjacent tissues;

8. Packing can not only play the role of drainage, but also play the role of compression and hemostasis, but it will induce infection if it is left for too long;

9, drainage tube should take the shortest route as far as possible, when placed, should ensure its unobstructed, avoid distortion, compression, poking empty, when placing drainage tube or other drainage tube should pay attention to the size of the poking empty, elasticity and tissue layer in a channel (plane);

10, and important structures (blood vessels, nerves, organs) should be avoided when placing drainage;

1 1, passive gravity drainage should be as low as possible;

12. After placing the drainage, fix its outer end accurately to avoid slipping into deep tissue or body cavity, closely observe or record the quantity and characteristics of the drainage, and accurately record the quantity and date of placing and pulling out the drainage;

13, drainage should be removed as soon as possible, usually on the 3rd to 5th day after operation, and drainage placed to prevent diffuse peritonitis after anastomotic leakage should be removed on the 5th to 7th day after operation; When a large amount of XOR occurs, corresponding measures should be taken as appropriate, such as immediately exploring the operating field in this operation, pulling out or replacing the drainage;

14, the existence of drainage does not necessarily guarantee the drainage effect. Always check the patency of drainage, and immediately deal with it if the drainage is not smooth.

Five, negative pressure closed drainage technology (VSD)

Definition of VSD

It refers to a brand-new treatment method of covering or filling the wound surface of skin and soft tissue defect with polyvinyl alcohol hydrated alginate foam dressing (VSD auxiliary material) containing drainage tube, then sealing it with biological semi-permeable membrane to make it a closed space, and finally connecting the drainage tube to a negative pressure source to promote wound healing through controllable negative pressure.

Materials of VSD

The materials required for VSD include 1, medical foam: it is a foamed PVA foam dressing (PVA foam) placed directly in the drainage area, which is white, spongy, soft and elastic, with strong tension resistance, a large number of interconnected voids, with a diameter of 0.2 ~ 1.0 mm, excellent plasticity, good water permeability and good biocompatibility. There are three specifications: 10cm× 15cm×0.9cm, 5cm× 15cm×0.9cm, 5cm× 15cm×0.9cm, which should be trimmed when used. 2. Drainage tube: porous drainage tube: CH 14- 18 porous hard silica gel drainage tube produced by B.Braun Company in Germany, with a length of 50cm and a dense side hole at one end within the range of 14cm. During drainage, the porous drainage tube was inserted with medical foam, and CH- 18 was inserted. 3. Breathable membrane: A transparent dressing made of polyurethane produced by American 3M Company is a kind of breathable membrane with molecular valve function. The finished product is packaged in sterile plastic bags for one-time use. Used to seal the drainage area and isolate it from the outside; 4. Negative pressure source: provide drainage power to ensure that the extracted objects in the drainage area should be led out.

Characteristics of VSD

1) controllable negative pressure can promote the increase of blood flow and protein synthesis, granulation growth and wound healing; At the same time, it provides power for all-round active drainage.

2) The biological semipermeable membrane is closed, which isolates the infection opportunity of the wound from the external environment.

3) Omni-directional drainage, which changes the traditional point or local drainage into surface drainage to ensure that the necrotic tissue and exudate of each part of the wound can be excluded from the body at any time.

Indications for VSD use

1, severe soft tissue contusion and soft tissue defect; 2. A large number of hematoma or effusion; 3. Osteofascial compartment syndrome; 4. Open fracture may be accompanied by infection; 5、

Patients with joint cavity infection need incision and drainage; 6. Acute and chronic osteomyelitis needs window drainage; 7, body surface abscess and suppurative infection; 8, postoperative incision infection. 9. Skin grafting area after skin grafting; 10, ulcer, bedsore.

Advantages of VSD

The treatment time of 1 was obviously shortened, which alleviated the pain of patients and reduced the workload. Patients are exempt from dressing change, and doctors are exempt from dressing change.

2

Effectively avoid cross-infection VSD in a closed system, negative pressure drainage can remove exudate and necrotic tissue in the drainage area in time, so that the drainage area can achieve zero accumulation. In addition, VSD can prevent wound pollution, fully drain and stimulate the rapid and good growth of wound granulation tissue. Accelerate the healing of infected wounds and reduce the use of antibiotics;

three

High efficiency, omnibearing and zero accumulation, ensuring drainage effect and promoting blood supply to the wound. The method of continuous negative pressure suction is adopted to change passive drainage into continuous active suction, leaving no cavity. The pressure basically meets the requirements of physiological conditions, so it does not affect the blood supply. More importantly, continuous negative pressure suction promotes the body fluid of wound tissue to flow to the drainage tube continuously, providing effective, continuous and auxiliary power for blood supply to the wound.

four

Avoid the formation of dead space, reduce the VSD of the wound, and lead to the invagination of the drainage cavity wall. With the gradual withdrawal of medical foam materials, the cavity wall is closely attached, effectively preventing the formation of residual abscess and dead cavity. For superficial wounds, it can close the tissue, reduce the wound and reduce the skin graft area.

Disadvantages of VSD

1

Orthopedic trauma mostly occurs in limbs, and the depth around the wound is different, so it is not easy to fully contact with the wound surface when placing materials. In some cases, it is difficult to seal the wound with external fixator. In order to solve this problem, continuous negative pressure can be generated by aspirator to make up for the lack of tight sealing.

VSD is only a transitional measure for bone exposed infected wounds, and other methods should be used to cover the wounds after infection control and granulation growth.

3, the cost is more expensive.

VSD mechanism

1 seal can maintain high negative pressure as the driving force of drainage, and at the same time isolate the drainage area from the outside world, effectively preventing pollution and cross-infection;

High negative pressure sealing can continuously drain wound exudate, necrotic tissue and bacteria, so that the drainage area can achieve "zero accumulation" and the wound surface can quickly obtain a clean environment;

3. Increase the blood supply of the wound, improve the microcirculation of the wound and promote the growth of granulation tissue. VSD can obviously enhance the proliferation and microvessel density of vascular endothelial cells and fibroblasts in superficial dermis of traumatic tissue. In recent years, some experimental studies have found that the blood flow of wound surface increases significantly after negative pressure is applied.

4. Regulate the activity of gelatinase in chronic wound, improve the microcirculation of wound base, inhibit the degradation of collagen and gelatin, and promote the healing of chronic wound.

5. Reduce edema and vascular permeability around trauma.

6 increase the neuropeptide sP and substance p secreted by nerve endings around the wound. VSD can enhance the expression of substance P and calcitonin-related gene peptide secreted by peripheral nerve endings, and affect the expression of endogenous epidermal growth factor, thus obviously promoting wound healing.

Recent studies show that proto-oncogenes play an important role in early embryonic development, cell growth control, cell differentiation and tissue repair. In the process of promoting chronic wound healing, VSD can quickly start the healing process of skin wounds, reduce the apoptosis of repair cells and accelerate wound healing.

Enhance the inflammatory response of infected wounds. It can make the infiltration of wound lymphocytes quickly subside, the collagen synthesis in proliferative phase is advanced, and the contraction fiber synthesis in repair phase is increased.

Promote wound healing and inhibit secondary necrosis of infected wound.