Effect of SAM junctional tourniquet on respiration when applied in the axilla: A swine model / 中华创伤杂志(英文版)

PURPOSE@#SAM junctional tourniquet (SJT) has been applied to control junctional hemorrhage. However, there is limited information about its safety and efficacy when applied in the axilla. This study aims to investigate the effect of SJT on respiration when used in the axilla in a swine model.@*METHODS@#Eighteen male Yorkshire swines, aged 6-month-old and weighing 55 - 72 kg, were randomized into 3 groups, with 6 in each. An axillary hemorrhage model was established by cutting a 2 mm transverse incision in the axillary artery. Hemorrhagic shock was induced by exsanguinating through the left carotid artery to achieve a controlled volume reduction of 30% of total blood volume. Vascular blocking bands were used to temporarily control axillary hemorrhage before SJT was applied. In Group I, the swine spontaneously breathed, while SJT was applied for 2 h with a pressure of 210 mmHg. In Group II, the swine were mechanically ventilated, and SJT was applied for the same duration and pressure as Group I. In Group III, the swine spontaneously breathed, but the axillary hemorrhage was controlled using vascular blocking bands without SJT compression. The amount of free blood loss was calculated in the axillary wound during the 2 h of hemostasis by SJT application or vascular blocking bands. After then, a temporary vascular shunt was performed in the 3 groups to achieve resuscitation. Pathophysiologic state of each swine was monitored for 1 h with an infusion of 400 mL of autologous whole blood and 500 mL of lactated ringer solution. Tb and T0 represent the time points before and immediate after the 30% volume-controlled hemorrhagic shock, respectively. T30, T60, T90 and T120, denote 30, 60, 90, and 120 min after T0 (hemostasis period), while T150, and T180 denote 150 and 180 min after T0 (resuscitation period). The mean arterial pressure and heart rate were monitored through the right carotid artery catheter. Blood samples were collected at each time point for the analysis of blood gas, complete cell count, serum chemistry, standard coagulation tests, etc., and thromboelastography was conducted subsequently. Movement of the left hemidiaphragm was measured by ultrasonography at Tb and T0 to assess respiration. Data were presented as mean ± standard deviation and analyzed using repeated measures of two-way analysis of variance with pairwise comparisons adjusted using the Bonferroni method. All statistical analyses were processed using GraphPad Prism software.@*RESULTS@#Compared to Tb, a statistically significant increase in the left hemidiaphragm movement at T0 was observed in Groups I and II (both p < 0.001). In Group III, the left hemidiaphragm movement remained unchanged (p = 0.660). Compared to Group I, mechanical ventilation in Group II significantly alleviated the effect of SJT application on the left hemidiaphragm movement (p < 0.001). Blood pressure and heart rate rapidly increased at T0 in all three groups. Respiratory arrest suddenly occurred in Group I after T120, which required immediate manual respiratory assistance. PaO2 in Group I decreased significantly at T120, accompanied by an increase in PaCO2 (both p < 0.001 vs. Groups II and III). Other biochemical metabolic changes were similar among groups. However, in all 3 groups, lactate and potassium increased immediately after 1 min of resuscitation concurrent with a drop in pH. The swine in Group I exhibited the most severe hyperkalemia and metabolic acidosis. The coagulation function test did not show statistically significant differences among three groups at any time point. However, D-dimer levels showed a more than 16-fold increase from T120 to T180 in all groups.@*CONCLUSION@#In the swine model, SJT is effective in controlling axillary hemorrhage during both spontaneous breathing and mechanical ventilation. Mechanical ventilation is found to alleviate the restrictive effect of SJT on thoracic movement without affecting hemostatic efficiency. Therefore, mechanical ventilation could be necessary before SJT removal.

Evaluation of gastric lavage effi ciency and utility using a rapid quantitative method in a swine paraquat poisoning model / 世界急诊医学杂志（英文）

@#BACKGROUND: Gastric lavage (GL) is one of the most critical early therapies for acute paraquat (PQ) poisoning; however, details of the treatment protocol remain to be established. METHODS: A rapid quantitative method involving sodium dithionite testing was developed. It was validated for the determination of the PQ concentrations in gastric juice and eluate samples from a swine acute PQ poisoning model with early or delay GL, or without. The vital signs, laboratory testing, and PQ plasma concentrations were collected for therapeutic effect evaluation. RESULTS: The reaction conditions of the test were optimized for two types of samples. Early GL at one hour (H1) could improve the signs and symptoms after acute PQ poisoning at 24 hours (H24). In contrast, GL at 6 hours (H6) could only partially relieve the vital signs. The H1 GL group effectively reduced the peak of the plasma PQ concentration. In addition, the PQ concentrations in the plasma and the gastric juice were signifi cantly decreased in both the GL groups as compared to the untreated group at H24. Moreover, there was no signifi cant difference in the washing effi ciencies calculated from the total eluates between the two GL groups. However, the washing effi ciency of the fi rst 10 L eluate is superior to that of the additional 10 L eluate. CONCLUSION: GL only at early stage may it benefit PQ poisoning in an animal model. The currently used 20 L GL volume may need to be reduced in view of the low washing efficiency in the later 10 L eluate. The rapid quantitative method can be used for gastric juice sample and has a certain value for clinical GL practices.

Laparoscopic ureterocalicostomy in pigs - experimental study / Ureterocalicostomia laparoscópica em suínos - estudo experimental

This study aimed to evaluated laparoscopic ureterocalicostomy as treatment of experimental ureteropelvic junction (UPJ) obstruction in pigs. Ten male Large White pigs weighting approximately 28.4 (±1.43) kg were used in the current study. The UPJ obstruction was created laparoscopically by double-clipping of the left ureter. After 14 days the animals underwent laparoscopic ureterocalicostomy f The animals were sacrificed for subsequent retrograde pyelography in order to assess the anastomotic patency on the 28th day. The laparoscopic procedure for experimental obstruction of UPJ was successfully performed in all animals, as well as the laparoscopic ureterocalicostomy. There was intestinal iatrogenic injury in one animal. Satisfactory UPJ patency was noted in 75% of the animals. There was no stenosis of the proximal anastomosis between the ureter and the lower pole of the kidney in 37.5%, mild stenosis in 37.5% and severe stenosis in 25% of the animals. The laparoscopic approach for reestablishment he urinary flow by ureterocalicostomy was feasible in the porcine model. The ascending pyelography revealed satisfactory results of the laparoscopic ureterocalicostomy.

O estudo teve como objetivo avaliar a ureterocalicostomia laparoscópica no tratamento de obstrução da junção ureteropiélica (JUP) em modelo experimental suíno. Foram selecionados 10 suínos machos da raça Large White com peso médio de 28,4(±1,43) kg. A obstrução da JUP foi criada por técnica laparoscópica transperitoneal, com aplicação de dois clipes de titânio no ureter esquerdo. Passados 14 dias, os animais foram submetidos à ureterocalicostomia laparoscópica. No 28º dia após a ureterocalicostomia, foram sacrificados para a remoção dos rins e posterior pielografia retrógrada para avaliação da permeabilidade anastomótica. A obstrução da JUP foi obtida com sucesso em todos os animais, assim como a ureterocalicostomia laparoscópica, apesar de ter havido lesão intestinal em um dos animais. Boa permeabilidade foi observada em 75% dos casos, posteriormente à anastomose entre o ureter proximal e o cálice maior caudal do rim, onde 37,5% dos animais não apresentaram estenose, 37,5% apresentaram estenose leve, enquanto 25% apresentaram estenose severa. Foi possível restabelecer o fluxo urinário por ureterocalicostomia laparoscópica e os resultados anatômicos obtidos por meio das pielografias ascendentes foram considerados satisfatórios.