以流通測試裝置探討甲殼素傷口敷料的止血性能

Abstract

在敷料止血性能評估研究上，除已有許多文獻利用靜態方式進行外，文獻中目前已有兩項以動態方式進行測量的裝置與方法，本文稱之為定壓及定流量裝置。當測試液(本研究採用者為人類全血)流通敷料紗布時，我們在定壓及定流量裝置中分別量測其流量及壓力降，以判定敷料紗布的止血性能。兩者各有優缺點，而本文旨在研發一項兼具上述兩項動態裝置特性的流通裝置。 本研究的裝置含一個進口及兩個出口，在入口處以固定流量輸入測試血液，再分流至主及副流道，其中主流道所流經處均沒紗布阻檔、但副流道卻需流經待測試紗布(含敷料)後再流出裝置，我們就“一段主流道及一段副流道(含待測試紗布的區域)的壓力降”和“流出主及副流道出口的血液量”，紀錄二者隨時間的演變，以作敷料紗布止血性能優劣的判定。副流道壓力降愈大、流出血液量愈少且愈快趨於平緩乃至停止者，其止血性能愈佳。本裝置以PDMS分三部份製作，可簡易地分開更換紗件試件後再予結合而進行下一次測試，且也可對測試過的紗布進行影像擷取與觀察，以了解血球聚結及止血部份細節。另本流通測試裝置之血流狀況有別於文獻中定壓及定流量裝置者，而更接近於血管破損時傷口出血時用紗布掩蓋止血的狀況。 根據本研究的實驗結果，我們得到以下結論: (1)本實驗設計之流通測試裝置操作簡單，可在更接近血管破損出血的動態狀況下測試各式含敷料紗布的止血性能。 (2)就含甲殼素的紗布言，初步研判“酸化處理”此一變因比“提升紗布的甲殼素含量”更能有效提升止血效果。以上結論使本裝置可應用供相關產品開發，也可作為研究止血機制的工具。希望本論文對未來止血性能評估發展與欲投入這領域的研究者有所幫助。

Besides many static tests, there are two types of dynamic devices and methods for testing the hemostatic performance of wound dressings (or gauzes) in a flowing environment, and are called here the constant pressure head (CPH) device and the constant flow rate (CFR) devices, respectively. The “mass through the device” and the “pressure drop across the gauze section” were measured, respectively, for the CPH and CFR devices, for accessing the hemostatic performance when test fluids (human whole blood here) were let to flow through the gauzes. Both devices have their advantages and disadvantages. The goal of the present study is to develop a dynamic flow-through device which possesses the characteristics of both the CPH and CPR devices. There are one inlet and two outlets in the present proposed device. The test blood was injected at a constant flow rate into the device, and then divided into two streams: the main stream without gauzes in its passage, and the secondary stream flowing through the test gauzes. Both the time evolution of the pressure drops across a section of the main stream channel and that of the secondary stream channel (containing the gauze section) and the flow-through blood masses at both outlets were measured for accessing the dynamic hemostatic performance of gauzes. The gauze possesses a better hemostatic performance when the associated pressure drop is higher and the flow-through blood mass is less in the secondary channel. The device has three parts which are made of PDMS, and are bonded together. The parts can be separated and re-bonded easily for exchanging the gauze samples. The aggregation of red blood cells on gauzes after test was examined for understanding some of the details of hemostasis. The blood flow in the present device is more closely related to the bleeding at wound in comparison with those in the CPH and CFR devices. Some findings from the present experimental study are as follows. (1) It has been proved that the present device is an effective and easy-operated device, for accessing the hemostatic performance of vary gauzes. (2) For the chitosan-based gauzes, the acidification of gauzes can enhance substantially the hemostatic performance, and is more effectively by comparing with the enhancement associated with increasing the chitosan content in the gauzes. It is hoped that the present study is helpful for the development of more effective gauzes for hemostasis, for better understanding of the hemostatic mechanisms, and for the new researchers who wish to devote to the related subject.