The Development Of Field First-aid Device Of Tension Pneumothorax

BackgroundTension pneumothorax(TPT) is often severe and its mortality rate(MR) is higher than other types of pneumothorax.In modern wartimes,the death on battlefield caused directly by tension pneumothorax is more than 5%of the deaths of thoracic wound,70%of which is due to the lack of prompt first aid.In peacetime disaster,the incidence rate(IR) of tension pneumothorax has a rising trend.Thus both in wartime or peacetime,tension pneumothorax play a very important position.During the war,the wounded from tension pneumothorax even rescued by the front lines,only to the division medical station can be certainly treated with close drainage of thoracic cavity/intercostal tube drainage(CDTC/ITD).But it takes more than 6 hours to reach the division medical station.This shows that improved technology and Fire Wire devices for the rescue to save the lives of wounded is very important.In China,tension pneumothorax emergency product has not yet been established which can be used under field conditions.So how to develop a tension pneumothorax first-aid device on the basis of self-rescue,buddy-rescue,easy to carry,simple operation,minor trauma and transit security is an important issue to be solved by the field first-aid unit.To this end,the issue's object is to design a tension pneumothorax emergency device which is applicable to the field conditions.We also hope the emergency device can apply to the pre-Hospital Care(pre-HC) of tension pneumothorax in peace times.It will improve the ability of our military health insurance,and has a very important military and civilian value.ObjectiveThis experimental study aimed at:1,To design and manufacture a sort of portable first aid device for tension pneumothorax on battlefield.2,To establish tension pneumothorax animal models,and operate with puncture decompression device,CDTC/ITD and new designed tension pneumothorax first aid device,then verify their workability,effectness of treatment on tension pneumothorax and so on. Materials and methods1,To design and manufacture the first-aid device for tension pneumothorax on battlefield.It consists of a Thoracic duct with guide pin,a negative pressure ball and fixtures.2,To establish the animal model of tension pneumothorax with Rutherford RB method.3,The experimental animals were randomly divided into 4 groups which were control group(group1 n=8) and three experimental groups(group2,group3,group4 n=8).The group1 disposed by nothing after tension pneumothorax animal model was established.While group2 was disposed with puncture decompression device and group3 was disposed with CDTC/ITD which is often applied in clinic,group4 was dealed with new designed tension pneumothorax first aid device on battlefield.The effect of group 4 was contrast to the effects of the three experimental groups by+dp/dtmax,-dp/dtmax,LVSP,LVEDP,MAP,HR,RR,pH,PaO₂,PaCO₂,SaO₂ and so on.Results1,Group1:The animal model of tension pneumothorax with Rutherford RB method was established and disposed by nothing.And it was difficult for animals to breath.The function of respiration and circulation was decreasing.HR(173.88beat/min),RR(43.88time/min), PaCO₂(45.10mmHg),LVEDP(29.20mmHg) were higher than normal values.MAP (106.43mmHg),+dp/dtmax(3111.17mmHg/s),-dp/dtmax(2602.57mmHg/s),LVSP (159.83mmHg),pH(7.26),PaO₂(83.43mmHg),SaO₂(84.16%) were lower than normal values.There were 2 experimental animals dead within the observation time.Its MR was 25%. It may be concluded that tension pneumothorax was serious and the patients would die if not given the purposeful treatment.2,Group2:The animal model of tension pneumothorax with Rutherford RB method was established and disposed with puncture decompression device.HR,RR,pH,PaO₂,SaO₂,LVSP have changed 0.5h after decompression.HR(162.25beat/min),RR(33.25time/min) were decreasing,while pH(7.32),PaO₂(87.36mmHg),SaO₂(89.59%),LVSP (174.11mmHg) were increasing.The symptoms of tension pneumothorax have improved. Six hours after decompression,LVEDP(19.72mmHg) was more than normal.+dp/dtmax (3501.50mmHg/s),PaO₂(88.36mmHg),PaCO₂(39.80mmHg),SaO₂(92.09%) were less than normal.The function of respiration and circulation was still weaker than normal.Its MR was 0%and operation time was(58.38±15.14)s.So it may be concluded that although puncture decompression method for treating tension pneumothorax is extremely fast,the effect is uncertainty.3,Group3:The animal model of tension pneumothorax with Rutherford RB method was established and disposed with CDTC/ITD which is applied in clinic.HR,RR,pH,PaCO₂,SaO₂,-dp/dtmax,LVSP have changed 0.5h after treatment.HR(161.88beat/min),RR (31.88time/min) were decreasing,while pH(7.33),PaCO₂(40.94mmHg),SaO₂(88.30%), -dp/dtmax(2752.42mmHg/s),LVSP(171.92mmHg) were increasing.The symptoms of tension pneumothorax has improved.After 6 hours of treatment,all of the indicators were as high as normal except RR(165.25time/min) and +dp/dtmax(3929.80 mmHg/s).The function of respiration and circulation was improved.Its MR was 0%and operation time was (503.38±72.82)s.Its length of incision was(2.96±0.44)cm.So it may be concluded that although the effect of CDTC/ITD applied in clinic now is certainty but it is not easy to carry and operate.4,Group4:The animal model of tension pneumothorax was established and disposed with new device.HR,RR,LVEDP,pH,PaO₂,PaCO₂,SaO₂,+dp/dtmax,LVSP have changed 0.5h after treatment.HR(165.63beat/min),RR(26.25time/min),LVEDP(24.30mmHg) were decreasing,while pH(7.30),PaO₂(83.35mmHg),PaCO₂(45.93mmHg),SaO₂ (89.55%),+dp/dtmax(3078.87mmHg/s),LVSP(179.44mmHg) were increasing.The symptoms of tension pneumothorax have improved.Six hours after treatment,all of the indicators were as high as normal except PaCO₂(38.13mmHg).The function of respiration and circulation has improved to as high as normal.Its MR was 0%and operation time was (294.75±36.14)s.Its length of incision was(1.14±0.28)cm.So it may be determined that new first-aid device for tension pneumothorax can improve the respiratory and circulatory function like CDTC/ITD.Its effectiveness was better than puncture decompression method.New device used in group4 was a single-hand operated device,and was conducive to self-rescue and buddy-rescue on the battlefield.New device used in group4 had a shorter Surgical incision(1-1.5cm) than CDTC/ITD's(3-4cm).So New device was a Minor trauma device.The new first-aid device for tension pneumothorax use the 16th duct as its thoracic duct.It can emit the intrathoracic gas as well as the intrathoracic blood.From this way its scope of use on the battlefield can be expanded. ConclusionsThe effect of treatment on tension pneumothorax using newly designed field first-aid device is better than that of puncture decompression device,and has not any difference from the effect of CDTC/ITD applied in clinic now.But it has the characterisitics of minor volume and easy to carry,can be used for self-rescue and buddy-rescue,easy to operate and being secure to transit.It also has certain effectiveness to treat tension pneumothorax.It is well-suited for salvage at the scene of tension pneumothorax wound on battlefield,and also fit for pre-hospital care of tension pneumothorax trauma in peacetime.