Negative pressure wound therapy (NPWT) includes closed vacuum drainage (VSD) technology and vacuum assisted closure (VAC) technology, which have been used as the new treatments to promote acute and chronic wound healing for nearly 20 years. Currently, the Medline database has collectively referred to these techniques as the negative pressure wound therapy (NPWT) . Among them, VAC is a medical foam material with pore spaces (commonly using hydrophobic polyurethane foam dressing) to cover the wound after debridement, and is sealed with a transparent film to form a confined space. Then it is connected with a dedicated negative pressure pump for continuous or discontinuous negative pressure suction, so as to fully drain wound exudate and infectious substances, reduce edema, increase local blood flow, reduce the number of bacteria on the wound, and accelerate the growth rate of granulation tissue, thereby effectively promoting of secondary or tertiary (delayed) wound healing. In recent years, VAC has been widely used in trauma orthopedics, mainly for acute and chronic wounds, soft tissue infections, ulcers (such as diabetic ulcers or pressure sores) , and wounds before and after flap transplantation. Due to the complexity of the VAC tubing connection, the lack of preventive measures against unplanned extubation during clinical care can result in wound exposure, increase the incidence of complications, and lead to adverse care events. Different methods of tubing fixation have various effects in preventing unplanned extubation. Therefore, the innovative fixation of the VAC tubing fixation method ensures safe and effective treatment while also reducing unplanned accidental extubation.

1. General information: From July 2016 to June 2018, our department treated 77 patients with upper extremity trauma and infection, including 43 males and 34 females. Their ages ranged from 12 to 79 years. The reasons for VAC included 1 case of compartment syndrome, 28 cases of dog bite, 25 cases of open injury, 9 cases of soft tissue infection, 3 cases of postoperative wound nonunion, and 11 cases of postoperative wound infection. Forty-one patients received VAC tubing fixation with conventional methods, including 23 males and 18 females, and their ages ranged from 12 to 71 years (48.32±17.36) years; 36 patients received VAC tubing fixation with sandwich method, including 20 males and 16 females, and their ages ranged from 22 to79 years (55.19±14.27) years. 2. Intervention methods: (1) Conventional tube fixation group. The hydrophobic polyurethane foam dressing was cut during surgery to fit the wound size, including the fistula and ulcer; the sealing membrane was trimmed to completely cover the dressing and the area beyond the edge of the wound 3-5 cm. The operator used the index finger and thumb to pinch the sealing film, cut a small hole in the film to allow the wound to seep through (without opening the dressing) , opened the suction cup, and fixed the suction cup on the sealing film. Finally, the treatment host was connected, and the pressure was set by touching the screen of VAC negative pressure wound therapy device. (2) Sandwich method fixation group. On the basis of the last step of the conventional tubing fixation method, the film was covered on the fixed suction cup and the proximal end of the VAC tube, and the VAC tube was fixed on the corresponding limb with the high lift method. If the suction cup was fixed near the joint, it should be protected by a brace to prevent from falling off due to repeated movement of the joint. 3. Statistical methods: SPSS23.0 statistical software was used to analyze and process the data. The measurement data was expressed as±s; the count data was described by the number of cases and percentage, and the chi-square test was used. A value of P<0.05 was considered significant difference.

There were no significant differences in gender and age between the two groups (P>0.05) . In the conventional tube fixation group, there were 8 cases of dissociations, 3 cases of sudden position change, 4 cases of postoperative delirium with postoperative sputum self-extraction, and 1 case of patient consciously uncomfortable to pull the tube accidentally. In the sandwich method group, 1 case of unplanned extubation occurred due to the reason of postoperative delirium and inability to corporate with care. There was a statistically significant difference in the unplanned extubation of the two tube fixation methods (P=0.032) .

The use of the sandwich method to fix the upper limb VAC vacuum suction tube can reduce the incidence of unplanned extubation to a certain extent, and help to reduce the incidence of negative clinical care events, which is worth promoting.