A Dynamic Animal Modeling And The Relative Clinical Research Of Sinus Barotrauma

Sinus barotrauma (SB), which is also called to barotaumatic sinusitis or barosinusitis,is an acute sinuses mucosal inflammation caused by unbalanced pressure betweeninside sinuses and out sinuses during the rapid changes of atmospheric pressure. It isalso called to aero-sinusitis in aviation medical，which would endanger to flight safetyin aircrew because of incapacitating problems. It is not only found in professionalaircrew, parachutist and diver, but also found in airline passengers and divingenthusiasts. In this paper, through establishing animal model of SB to observe thechanges of rabbit behavior, sinus cavities structure and cell morphology. And throughresearching the clinical SB case in aircrew with different types of military aircraft toapproach the qualitative and quantitative testing methods, pathology characteristics andpathogenesis.Part one: Establishment a dynamic model of SBThe70Japanese big-ear rabbits were randomized to three groups. there were themodel group, the condition control group and the blank control group respectively. Andthe model group,which was obstructed to the right sinus by expension foam, wasdivided into①-groups.There were three methods of the hypobaric chamber tests inmodel group:(1)The hypobaric chamber rose rapidly to4km or2km of differentspeeds with100m/s,75m/s or50m/s, stopping5min and then fell to the ground of thesame speed with15m/s. Repeated the process three times at all.(2)The hypobaricchamber rose to4km or2km of the same speeds with15m/s, stopping5min and thenfell rapidly to the ground of different speeds with100m/s,75m/s or50m/s. Repeatedthe process three times at all. The hypobaric chamber rose to4km of the samespeeds with15m/s, stopping5min and then fell rapidly to the ground of differentspeeds with15m/s. Repeated the process three times at all. The condition control groupwas the left sinus of the model group. The blank control group was the right sinus of rabbit that did not treatted in the hypobaric chamber.There were performed the tests ofnasal endoscopic, sinus MRI, sinus mucosal pathological before and after hypobaricchamber tests. And then the Kruskal-Wallis rank sum test was used to statisticalanalysis the result of SB. The results were as follow:(1)when the hypobaric chamberrose or fell rapidly as different speeds in the①-groups of model group, the rabbitsall occurred characteristic behavioral changes of SB.(2)when the hypobaric chamberrose or fell rapidly with different speeds, the①-groups of model group all occurredSB by endoscopic nasal test and sinus MRI.(3)when the hypobaric chamber rose or fellrapidly as different speeds in the①-groups of model group, the sinus cavity mucosaloccurred cilia missing, inflammatory cell infiltration, inflammatory cells exudation outof the glandular cavity. And the damage in the hypobaric chamber with100m/s weremore severely than the speed of75m/s and50m/s.(4)According to the pathologicalreseach，the SB could be divided into mild and severe degree. The group ofmodel group, the condition control group and the blank control group did not anydamaged in behavioral, imaging and cellular pathology.The results showed that therabbit model occurred changes of sinus function and cell morphology in the hypobaricchamber tests. The damage degree of SB was direct proportional to the rise and fallspeed in the hypobaric chamber test, and the damage was most obvious less than2km.Part two: the clinical research of SB and the relative rhinology diseases inaircrewCollection and statistically analyzed the55patients of SB and the elative rhinologydiseases in aircrew. The research results were as follow:(1) For disease location，42cases were located in frontal sinus (76.36%)，6cases were located in maxillarysinus(10.91%)，1case was located in ethmoid sinus(1.20%)，4cases were located infrontal sinus and maxillary sinus(7.27%)，2cases were located in frontal sinus andethmoid sinus(1.2%)， and2cases were located in frontal sinus and sphenoidsinus(1.2%). classified as primary SB which resulted from abnormal of sinus ostiumwere9cases(16.36%) while the secondary SB which resulted from the pathologicalchange around sinus ostium were46cases(83.64%). In type statistics，the type I(anatomical abnormalities of nasal cavity) and the type II(inflammation in nasal cavity)were13cases(27.66%) respectively, the type Ⅲ(allergy in nasal cavity) and the typeIV(cyst or tumor in nasal cavity) were2cases(4.26%) respectively, the typeⅤ(compound) were17cases(36.16%). There were17cases of in-sinus type,18casesof out-sinus type and8cases of compound. For graduate analysis，19cases(34.55%)were mild and36cases(65.45%)were severe. For treatment，mild SBwas conservative treatment,and severse SB was surgical treatment. For medicalevaluation，48cases were qualified while the other7cases were permanentgrounding． And the SB with aural barotrauma would mostly result in aircrewgrounded．It showed that the frontal sinus and the maxillary sinus occurs were themainly reason for SB. According to the lesion, parts and etiology, the types,classification, indexing for SB were important clinical significance in aviation medicineThe secondary SB were the mainly cause by the relative rhinologydiseases.anatomical abnormalities and inflammation of nasal cavity were the mainlyreason for secondary SB. Surgery is suggested for severe SB．SB with AB was themainly reason for permanent grounding.According to establishment dynamic animal model of SB and research the clinicalcases in aircrew, further deepened the understanding of pathophysiology characteristicsand the pathogenesis of SB with different pressure levels and different rise or fall speed.Summarizes the clinical cases of SB in aircrew, which would provide referred basis withmedical evolution, prevention and control measures of SB.