| Objectives:To compare the effects of dexmedetomidine(DEX)on oxygenation index(OI)and inflammatory factors,such as interleukin-6(IL-6),tumor necrosis factor-a(TNF-?)in burn Organism with inhalation injury.To provide a theoretical basis for the selection of anesthetics for lung protection in burn patients during operation.Methods:From March 2018 to January 2020,40 cases of severe burn patients with inhalation injury were treated in the Department of Burns,Second Affiliated Hospital of Kunming Medical University and scheduled for elective surgery 4 to 7 days after burn.They were randomly divided into experimental group and control group with 20 cases in each group.All patients received routine anesthesia induction.Anesthesia was induced with sufentanil(0.3?g/kg)?propofol(2.5mg/kg)and rocuronium(0.6mg/kg).When The patients were unconscious and their muscles were relaxed,tracheal intubation was performed with the help of visual laryngoscope.After successful intubation,the anesthesia machine was connected to perform mechanical ventilation at the setting of tidal volume 8?10mL/kg,airway pressure<20mmHg,respiratory frequency 12?14/min.SpO2 95%?100%,PetCO2 35?45mmHg.In the experimental group,dexmedetomidine 1 u g/kg was infused intravenously within 15 minutes before anesthesia induction,and dexmedetomidine 0.4 ?g/(kg.h)was infused continuously during the operation,and the infusion was stopped 30 minutes before the end of the operation.The same dose of saline was continuously infused intravenously before and during the operation.Remifentanil 0.1?0.3 ?g/(kg.min)was infused continuously in both the experimental and control groups.The Clinical data including age,sex,body mass index(BMI),ASA grades,burn area,bispectral index(BIS)and 5mL of arterial blood were collected from all patients before induction(T1),at 50 min(T2),80 min(T3)and at the end of operation(T4).After centrifugation,the serum was taken from the upper layer to detect inflammatory factors(TNF-??IL-6)by ELISA.Oxygenation index(OI)?percutaneous oxygen saturation(SPO2)?mean arterial pressure(MAP)and heart rate(HR)at the four time points were recorded.The vital signs were maintained within ± 20%of the basic vital signs at rest in the operating room.If necessary,a warming blanket was used to maintain body temperature,and vasoactive drugs(ephedrine,metaraminol,norepinephrine,etc.)were used to maintain hemodynamic stability.All patients were followed up one week after the operation,and whether tracheotomy was performed or not was recorded.In order to better carry out clinical research,animal experiments were carried out in the early stage,animal experiments were also divided into experimental group and control group(n=32 in each group)and blank group(n=8,no injury,no drug),the three groups were fed SPF level.The Rats in the experimental group and the control group were subjected to inhalation injury,and the drugs were administered at 4 time points after injury:half an hour(T1),12 hours(T2),24 hours(T3)and 48 hours(T4).Eight SD Rats were injected dexmedetomidine 4.5 a g/kg into the tail vein at each time point from T1 to T4 in the experimental group and the control group was injected with the same dose of normal saline at the same time.Anesthetic dissection was performed after all the drugs were given,the supernatant of abdominal aorta blood was centrifuged to detect the concentration of TNF-? and IL-6 by ELISA;The right main bronchus was ligated,and the supernatant of bronchoalveolar lavage fluid of the left lung was collected to measure the concentration of TNF-? and IL-6 by ELISA;Take the right lower lobe of lung tissue to make pathological sections,and observe the pathological changes of lung tissue(bronchi,alveoli)at each time point in the three groups under the light microscope.Results:In the 40 patients included,the sex,age,ASA grade,burn area,operation time of the experimental group and the control group were compared,there was no significant difference between the two groups(P>0.05).There was also no significant difference between the two groups in the depth of anesthesia(BIS)before anesthesia induction(T1),during operation(T2,T3)and at the end of operation(T4)(P>0.05).There was significant difference in vital sign HR between the two groups at T1,but no significant difference at T2-T4;And there was no significant difference in MAP and SPO2(T1?T4).ELISA was used to detect the serum inflammatory factors(IL-6,TNF-?)of all patients.The results showed that the levels of inflammatory factors(IL-6,TNF-?)and OI were significantly different between the experimental group and the control group(P<0.05).The levels of IL-6 and TNF-?in experimental group were significantly lower than those in control group,but the OI was higher.At different time points,the levels of IL-6,TNF-? and 01 in experimental group and control group were significantly different(P<0.05).There was no significant difference in IL-6?TNF-? concentration and oxygenation index at before induction(T1)and at 50 min(T2)(P>0.05),but there was significant difference at 80 min(T3)and at the end of operation(T4)between the two groups(P<0.05).Inflammatory factors in the experimental group were significantly lower than those in the control group,while oxygenation index in the experimental group was higher than that in the control group.As time went on,the levels of IL-6,TNF-? and OI in the experimental group and the control group were also significantly different(P<0.05).The concentration of IL-6 in the experimental group increased first and then decreased gradually with time,while that in the control group increased gradually;The level of TNF-? in the control group increased gradually with the increase of time.In the experimental group,the level of TNF-? increased slightly from T1 to T2,but decreased signi:ficantly from T2 to T3.and the level of T3?T4 decreased less than that in the experimental group;The Of level of the experimental group increased gradually with time,while the control group showed a downward trend,and the decline was obvious in T1?T2 time period.All the patients were followed up one week after the operation.In the experimental group,1 patient(5%)underwent tracheostomy and 19 patients(95%)did not undergo tracheostomy;There were 19 cases in the control group,1 case lost to follow-up,5 cases underwent tracheotomy(26.3%),14 cases did not undergo tracheotomy(73.7%).And there was no difference between the two groups(P>0.05).In the animal experiment,The levels of inflammatory factors(TNF-?,IL-6)in serum and bronchoalveolar lavage fluid in the experimental group,control group and blank group were significantly different(P<0.05),and there were significant differences in T1?T4 between the experimental group and the control group(P<0.05),and there were also significant differences between the two groups with the increase of time(P<0.05).After dissection,the lung tissue of the experimental group and the control group was pale and swollen,with large hemorrhagic spots;Under the light microscope,there were coal dust precipitates,a large number of inflammatory cells infiltration and even obstruction in the bronchial lumen in the two groups;Inflammatory cell infiltration was also seen around the alveoli,with alveolar interstitial edema,fibrous hyperplasia,some obvious hemorrhagic lesions,alveolar epithelial cells disappeared.Statistical analysis showed that the experimental group,the control group,the blank group of bronchus/pulmonary alveolus inflammation was statistically different(P<0.05),The degree of bronchus/pulmonary alveolus inflammation was also significantly different between the experimental group and the control group(P<0.05).Conclusions:1.Dexmedetomidine can decrease the concentration of inflammatory factors(IL-6,TNF-?)and improve the pathological changes of lung in rats with inhalation injury;2.Dexmedetomidine can improve the oxygenation index and decrease the concentration of inflammatory factors(IL-6,TNF-?)in patients with burns combined with inhalation injury,and has lung protective effect,the specific mechanism needs to be further confirmed by relevant studies. |
PDF Full Text Request