Pathophysiology,diagnosis and treatment of neonatal sepsis

Sepsis is a major cause of death in neonatal foals and, in recent years, significant progress in the understanding of the underlying pathophysiology has been made. To achieve a successful outcome, early diagnosis and treatment focusing on supporting vital functions and neutralising the effects of the causative organisms are essential. The pharmacokinetics of many drugs differ in neonatal foals and more information for appropriate dosing of antimicrobial and anti‐inflammatory drugs for neonatal foals is now available to guide clinicians in choosing the best dosages. Prevention remains difficult and focuses on early recognition while prophylactic use of antimicrobials is discouraged.     

大鼠血管生成素-2在脓毒症型急性肺损伤的变化及影响

目的 探讨血管生成素-2(angiopoietin-2,Ang-2)在脓毒症型急性肺损伤(Acute Lung Injury,ALI)中的变化及影响。方法 45只SD大鼠随机分为对照组10只,采用假手术处理;模型组35只,采用盲肠结扎穿孔术(cecal ligation and puncture,CLP)制作ALI模型(即盲肠结扎／脓毒症型);于假手术及CLP术后24h处死全部大鼠,取肺石蜡包埋,行苏木素-伊红(HE)染色观察肺组织变化及酶联免疫吸附试验(ELISA)检测血清Ang-2的水平。结果 对照组大鼠光镜下肺组织结构清楚,肺泡腔清晰,肺泡隔基本无水肿、炎症等特殊改变;模型组光镜下见部分肺泡萎陷,肺泡壁通透性增加,可见较多中性粒细胞及少许巨噬细胞浸润,肺泡间隔增宽等。S模型组血清Ang-2水平(10.72±1.49)ng/ml明显高于对照组(3.87±0.26)ng/ml(P<0.01);死亡鼠血清Ang-2水平(11.48±1.52)ng/ml亦显著高于存活鼠(7.69±1.83)ng/ml(P<0.05)。结论 Ang-2在脓毒症型ALI中具有重要病理作用,血清高Ang-2水平提示预后较差。     

大鼠盲肠结扎与穿刺脓毒症模型的建立与分析

脓毒症是重症监护病房(ICU)的一种常见疾病,目前临床上对脓毒症的治疗效率不高。更为严重的是脓毒症患者的死亡率仍然很高,其内部的病理生理过程尚不清楚。许多种类的脓毒症的动物模型已经建立,其中盲肠结扎穿孔(CLP)模型,代表临床脓毒症最理想的模型。然而就CLP模型造模的死亡率、炎症反应以及病理变化而言不同的实验室之间结果有较大差异。目的:为了建立在有限实验条件下稳定性重复性好的大鼠模型,为后续的研究打下了基础。方法:1、确定了实验条件下盲肠结扎程度与大鼠死亡率之间关系。2、收集组织切片,确定其病理改变。3、在相同造模程度下,2种不同麻醉(水合氯醛和异氟烷)分别麻醉的大鼠,观察CLP大鼠死亡率的影响。结果:1、成功确定模型中大鼠盲肠结扎的程度。2、组织病理切片显示脓毒症的典型病理组织损伤,符合进一步研究的需要。3、在研究中发现相同造模程度下异氟醚麻醉组CLP大鼠死亡率为25%;水合氯醛麻醉组CLP大鼠死亡率达68.75%。     

The use of vasopressin for treating vasodilatory shock and cardiopulmonary arrest

Objective – To discuss 3 potential mechanisms for loss of peripheral vasomotor tone during vasodilatory shock; review vasopressin physiology; review the available animal experimental and human clinical studies of vasopressin in vasodilatory shock and cardiopulmonary arrest; and make recommendations based on review of the data for the use of vasopressin in vasodilatory shock and cardiopulmonary arrest. Data Sources – Human clinical studies, veterinary experimental studies, forum proceedings, book chapters, and American Heart Association guidelines. Human and Veterinary Data Synthesis – Septic shock is the most common form of vasodilatory shock. The exogenous administration of vasopressin in animal models of fluid‐resuscitated septic and hemorrhagic shock significantly increases mean arterial pressure and improves survival. The effect of vasopressin on return to spontaneous circulation, initial cardiac rhythm, and survival compared with epinephrine is mixed. Improved survival in human patients with ventricular fibrillation, pulseless ventricular tachycardia, and nonspecific cardiopulmonary arrest has been observed in 4 small studies of vasopressin versus epinephrine. Three large studies, though, did not find a significant difference between vasopressin and epinephrine in patients with cardiopulmonary arrest regardless of initial cardiac rhythm. No veterinary clinical trials have been performed using vasopressin in cardiopulmonary arrest. Conclusion – Vasopressin (0.01–0.04 U/min, IV) should be considered in small animal veterinary patients with vasodilatory shock that is unresponsive to fluid resuscitation and catecholamine (dobutamine, dopamine, and norepinephrine) administration. Vasopressin (0.2–0.8 U/kg, IV once) administration during cardiopulmonary resuscitation in small animal veterinary patients with pulseless electrical activity or ventricular asystole may be beneficial for myocardial and cerebral blood flow.     

牛产后败血症及脓毒血症防治

牛产后败血症以全身症状表现为主,体温高热稽留,死亡率较高;脓毒血症以组织器官化脓为主要特征表现。预防该病需做好母牛疾病防控及产后护理,科学助产;抗生素是治疗该病的最佳药物,治疗该病建议采用局部和全身相结合的方案进行用药,同时,为加速疾病康复还应配合保健用药。     

Lactate: physiology and clinical utility

Objective: To review the physiology of lactate production and metabolism, the causes of lactic acidosis, and the current applications of lactate monitoring in humans and animals. Data sources: Human and veterinary studies. Summary: Lactate production is the result of anaerobic metabolism. Tissue hypoxia due to hypoperfusion is the most common cause of lactic acidosis. Studies in critically ill humans have shown that serial lactate monitoring can be used to assess the severity of illness and response to therapy. Several veterinary studies have also shown lactate as a useful tool to assess severity of illness. Conclusions: Lactate measurement in critically ill veterinary patients is practical and can provide information to assess severity of illness. Further veterinary studies are needed to establish the value of serial lactate measurements for prognostic and therapeutic purposes. Information regarding lactate measurement in cats is limited, and further studies are warranted.