| BackgroundThe incidence rate(IR) of thoracic trauma(TT) is about8%in previous wars,resulting in the direct death accounting for25%of trauma deaths, thus it is thesecond leading reason of deaths only secondary to traumatic brain injury in traumatypes. Open chest trauma(OCT) is a major cause of deaths in thoracic trauma injury.The open chest trauma(OCT) is more common in wartime caused by blast injuries.The open chest trauma(OCT) accounts for7%to12%of the total number ofwounded in land battles and up to20%in naval battle. The frontline spot treatmentwill create opportunities for the follow-up treatment and greatly reduce the mortalityrate(MR)of open chest trauma(OCT). The most important first aid for open chesttrauma (OCT)is to timely rescue and ascertain injuries at the same time, restore theintegrity of the chest wall and intrathoracic negative pressure as soon as possible,and prevent severe respiratory and circulatory dysfunctions. Therefore, it is the keyhow to promptly and effectively close the thoracic cavity. Open chest trauma(OCT)is often combined with rib fractures and even flail chest (FC), so that in theevacuation way after chest closure, patients often appeared severe chest pains andbreathing difficulties, which severely suppress patient’s respiratory movements.Therefore, selection of suitable materials for fixation of patient’s chest wall has aneffectively analgesic effect and can prevent chest wall retraction, which has alsobecome an indispensable part in the treatment of patients with chest trauma. In thepast treatment programs and devices, our military was failed to find the standardtemporary chest closure device and chest fixation device for emergency treatment ofopen chest trauma. A variety of shortcomings appeared in the typically simple gauzeand dressings used in first aid, which were unable to meet the need of emergencytreatment on battlefield (ETOB) and pre-hospital care(pre-HC). Development andassembling with simple first-aid devices can simplify the surgical procedures,provide timely and correct frontline spot and pre-hospital emergency, thus it has animportant practical significance in reducing the mortality rate(MR).PART ONE：Design, preparation and clinical trial of temporary chest closuredevice with one-way valveObjective:To design and prepare a temporary chest closure device with one-way valve, and evaluate its closing effect on the emergency treatment of open chesttrauma(OCT) via the animal experiments on emergency treatment of open chesttrauma(OCT).Methods:The experimental dogs were randomly divided into the control group and theexperimental group, n=4. The animal model of open chest injury was established.The control group was closed by applying and pressuring common used in clinicalpractice, while the experimental group was closed with a temporary chest closuredevice with one-way valve. The operating time of chest closure, the operating timeof closed thoracic drainage, canine heart rat（eHR）, changes in respiratory rate（RR）,the oxygen saturation（SpO2）, the maximum tension exposed on the chest closuredevice, and drainage effect were observed.Results:The operating time of chest closure was (0.58±0.14) min in the experimentalgroup and (1.17±0.21) min in the control group; the difference was statisticallysignificant (P<0.01); the former was better than the latter. The operating time ofsubsequent closed thoracic drainage was (0.48±0.07) min in the experimental groupand (2.20±0.11) min in the control group; the difference was statistically significant(P<0.01); the former was better than the latter. The changes in the heart rate,respiratory rate and oxygen saturation before and after the chest closure in theexperimental group were significantly different from the control group(P<0.01). Thedrainage amount of pleural effusion and blood at each point in time after drainagewere not significantly different between two groups (P>0.05).Conclusion:The temporary chest closure device with one-way valve can quickly andeffectively close the thoracic cavity, with an exact fixing effect. It can createconditions for implementation of effective closed thoracic drainage and subsequenttreatment, thus being suitable for emergency treatment on battlefield(ETOB)andpre-hospital rescue（pre-HC） of patients with open chest trauma（OCT）.PARTTWO：Design, preparation and clinical trial of gas pressure-regulatingexternal fixation beltObjective:To design and prepare the gas pressure-regulating external fixation belt, andevaluate its effects on the fixation, analgesia and breathing improvement during emergency treatment of chest trauma through clinical controlled trials.Methods:By using the digital table method,50patients underwent thoracotomy in ourdepartment were randomly divided into the experimental group and the controlgroup, n=25. The experimental group received chest fixation by using a gaspressure-regulating external fixation belt, while the control group used an ordinaryelastic chest belt. The calm and cough pain scores (VAS), and respiratory rates (RR)in two groups were observed at all points in time after surgery. The preoperative andpostoperative pulmonary functions at24h,48h and72h were tested with a portablespirometer. Patients underwent preoperative and postoperative24h,48h,72h bloodgas analysis, and the postoperative first active cough time, the total amount of chestdrainage, the removal time of drainage tube, postoperative hospital stay, theincidence rate(IR) of pulmonary complications and the dosage of analgesic drugswere recorded, respectively.Results:The differences in calm pain scores and respiratory rates were statisticallysignificant at3h,6h,24h,48h, and72h postoperatively between the experimentalgroup and the control group (P<0.05); the differences in cough pain scores andrespiratory rates were statistically significant at3h,6h,24h,48h, and72hpostoperatively between the experimental group and the control group (P<0.05);FVC, FEV1, MVV, FVC%predicted value, FEV1%predicted value, and MVV%predicted value in the experimental group were significantly different from thecontrol group (P<0.05), while FEV1/FVC in the experimental group was notsignificantly different from the control group (P>0.05); PaO2, PaCO2and SpO2inthe experimental group were not significantly different from the control group(P>0.05). The first active cough time and postoperative dosage of analgesic drugs inthe experimental group were significantly different from the control group (P<0.05);the total amount of chest drainage, the removal time of drainage tube, postoperativehospital stay and the incidence rate of pulmonary complications in the experimentalgroup were not significantly different from the control group (P>0.05).Conclusion:The gas pressure-regulating external fixation belt has a beautiful appearanceand is made with safe and soft materials, with a strong proper sense and exact effect.It can increase patient’s pain threshold, reduce patient’s pains, promote active coughand sputum, and contribute to the recovery of lung function, thus it is suitable foremergency treatment of patients with chest trauma and chest fixation after clinical chest surgery.In conclusion, this study showed that a temporary chest closure device withone-way valve could promptly and effectively close the thoracic cavity, and transferopen chest trauma (OCT)to blunt chest trauma, thus it was suitable for theemergency treatment on battlefield (ETOB) and pre-hospital care of open chesttrauma(OCT). The gas pressure-regulating external fixation belt could promptly andeffectively fix the chest wall, reduce patient’s pains, improve breathing, and promotethe recovery of lung function, thus it was suitable for the frontline treatment,pre-hospital care (pre-HC)of chest trauma, and chest fixation after clinical chestsurgery. |
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