儿童感染性休克的血流动力学评价及治疗策略

虽然儿童重症抢救技术有了长足进展,但无论是在发达国家还是在发展中国家,儿童感染性休克仍然有很高的发病率及病死率。在欧美国家其病死率达2 0 %～40 %。我院PICU统计,感染性休克占所有休克患儿的38 5 %,居于首位,病死率高达40 %[1 ] 。目前对感染性休克的治疗仍以综合治疗措施为主,目的是改善脏器的灌注,主要包括三个方面:一是液体复苏及心血管活性药物的使用;二是清除感染病灶及有效的抗生素治疗;三是针对引起休克的病理生理机制进行的治疗,如针对炎症介质的治疗或针对凝血机制障碍等的治疗。其中补液及心血管活性药物仍然是感染性休…     

The effects of milrinone on hemodynamics in an experimental septic shock model.

OBJECTIVE: To investigate the specific hemodynamic effects of the phosphodiesterase inhibitor milrinone in a rabbit model of septic shock in the absence of any other treatment. DESIGN: A prospective, controlled, interventional study. Animal Model: Fourteen sedated New Zealand rabbits. SETTING: Research laboratory of a health sciences university. INTERVENTIONS: Rabbits were anesthetized and vascular catheters inserted in femoral artery and jugular vein. After a stabilization period and the recording of baseline measurements (H0), all animals received a 10-mL infusion of Pseudomonas aeruginosa. Two hours later (H2rabbits were randomly assigned to receive 5% dextrose (control group) or milrinone (milrinone group). MEASUREMENTS AND MAIN RESULTS: Mean arterial blood pressure (MAP) was monitored continuously, and a cardiac index (CI) was determined every 30 mins by a transpulmonary thermodilution technique using an integrated monitoring device (PICCO). No differences were detected between the two groups after stabilization (H0) or before the treatment (H2) for either CI (mL/min(-1)/kg(-1)) or MAP (mm Hg). CI decreased progressively in the control group during the following 4 hrs, but not in the treated group (at H6: 122 +/- 4 vs. 207 +/- 16 mL/min(-1)/kg(-1); p < .05). No drop of MAP occurred after milrinone infusion. A comparison of the treated and control group reveals that milrinone improved tissue perfusion as evidenced by measurements of central venous saturation (at H4: 0.59 +/- 0.05 vs. 0.71 +/- 0.03, p = .04), lactacidemia (at H6: 10.3 +/- 2.4 vs. 3.9 +/- 0.9 mmol/L, p = .03), creatinemia (at H6: 95 +/- 11 vs. 60 +/- 5 micromol/L, p = .02) and survival (at H6: 5 vs. 7, not significant). CONCLUSION: Milrinone improves cardiac output and tissue perfusion in a rabbit model involving severe septic shock.     

Pneumococcal pneumonia and septic shock in the newborn infant

Pneumococcal sepsis and pneumonia in the neonate are rarely reported. They appear either as an early-onset respiratory distress with a high mortality rate or as a delayed infection. The authors describe 3 term neonates with an early respiratory distress syndrome and recall the main points of this severe foeto-maternal infection. Neonatal pneumococcal sepsis is strikingly similar to early-onset group B streptococcal infection. The isolation of the germ in the mother's vaginal flora is hazardous. Such cases suggest that early respiratory support and intensive circulatory resuscitation lead only to a slight decrease in the mortality rate, and thus preventive antibiotherapy is a necessity.     

亚甲蓝对小儿感染性休克血液动力学和氧代谢影响的临床观察

目的　 观察亚甲蓝在小儿感染性休克中的疗效。 方法 　 44例小儿感染性休克患儿随机分成实验组和对照组 ,对照组按休克常规治疗。实验组除按休克常规治疗外 ,早期应用亚甲蓝治疗 ,并对两组患儿进行血液动力学及氧代谢指标监测。 结果　实验组患儿总治愈率、重型休克治愈率明显高于对照组 ;血液动力学指标改善较对照组明显 ;氧代谢变化两组患儿大致相同。 结论 　亚甲蓝能改善感染性休克患儿血液动力学方面异常 ,提高感染性休克治愈率。     

高容量血液滤过对脓毒性休克患儿血流动力学及血管内皮通透性的影响

目的 比较分析高容量血液滤过对脓毒性休克患儿血流动力学、血管活性因子及血管内皮通透性的影响。方法 2013 年1 月至2014 年9 月确诊为脓毒性休克的36 例患儿被随机分为对照组和观察组,每组18 例。对照组采用常规容量血液滤过进行治疗,观察组采用高容量血液滤过进行治疗。比较两组患儿治疗前后的血流动力学指标及血管活性因子[6-酮-前列腺素F1α(6-keto-PGF1α)、血栓素B2(TXB2)、可溶性E-选择素(sE-selectin)和血管内皮舒张因子(EDRF)]的变化情况,分析超滤液对血管内皮细胞通透性的影响。结果 与对照组相比,治疗后观察组平均动脉压和血氧饱和度显著升高,心率显著下降(PPP结论 与常规容量血液滤过治疗相比,高容量血液滤过治疗能更有效改善脓毒性休克患儿的血流动力学及血管活性因子水平,降低血管内皮细胞的通透性。     

纳洛酮与硫酸镁治疗新生儿缺氧缺血性脑病疗效对比

目的　比较纳洛酮与 2 5 %硫酸镁治疗新生儿缺氧缺血脑病 (HIE)疗效。方法　将 79例HIE患儿随机分为A组 (39例 )和B组 (4 0例 ) ,A组肌注 2 5 %硫酸镁 ,B组静滴纳洛酮。治疗后检测其红细胞游离钙、血浆钙、镁及 β 内啡肽浓度变化。 结果　A组患儿红细胞游离钙浓度和血浆钙、镁浓度改善较B组快 ,而B组患儿β 内啡肽降低幅度大于A组。 结论　 2 5 %硫酸镁对HIE急性期治疗效果较好 ,而纳洛酮有利于受损神经细胞功能恢复。     

The effect of blood glucose concentration on postasphyxia cerebral hemodynamics in newborn lambs

The effect of preasphyxia blood glucose concentration on postasphyxia (PA) cerebral hemodynamics was examined in 21 newborn lambs. Glucose was unregulated in one group (n = 7), and controlled throughout the study by glucose clamp in hyperglycemic (n = 7) and hypoglycemic (n = 7) groups. Cerebral blood flow, determined using radiolabelled microspheres, and arterial and sagittal sinus O2 contents were measured at control, 5 min, 1, 2, and 4 h after resuscitation from an asphyxial insult. Preasphyxia blood glucoses were 6.48 +/- 0.55 mM (mean +/- SEM), 12.08 +/- 0.80, and 2.66 +/- 0.14 in the three study groups. In all three groups, 5 min PA cerebral blood flow was significantly increased from control. In the late period after asphyxia, the unregulated group had decreased cerebral blood flow compared with control, 53.2 +/- 3.8 mL.100 g-1.min-1, mean +/- SEM, p less than 0.01; 49.6 +/- 2.0, p less than 0.005; 53.4 +/- 3.0, p less than 0.01, at 1, 2, and 4 h PA, respectively, versus 85.7 +/- 6.9 at control, whereas both the hyper- and hypoglycemic groups did not differ significantly from control measurements. Cerebral oxygen consumption (CMRO2) was significantly decreased in all three groups 5 min PA and remained decreased in the late period after asphyxia in both the unregulated and hypoglycemic groups. In the unregulated group, CMRO2 was 191 +/- 14 microM.100 g-1.min-1, mean +/- SEM, p less than 0.05; 200 +/- 4; and 181 +/- 10, p less than 0.05 at 1, 2, and 4 h, respectively, PA versus 251 +/- 12 at control.(ABSTRACT TRUNCATED AT 250 WORDS)     

The effect of arterial PCO2-variations on ocular and cerebral blood flow in the newborn piglet

The response of ocular and cerebral blood flow to different arterial PCO2 levels was studied in ventilated paralyzed newborn piglets with the radionuclide-labeled microsphere method. The retina and the choroid have different blood flow responses to variations in arterial PCO2 levels. Retinal blood flow (ml/g/min) was increased during hypercarbia, from 0.26 +/- 0.03 at baseline to 0.51 +/- 0.07 (PaCO2 8.7 +/- 0.2 kPa) and 0.62 +/- 0.07 (PaCO2 11.0 +/- 0.2 kPa). However, no significant change was found in choroidal blood flow during hypercarbia. Cerebral blood flow was more responsive to PaCO2 than retinal blood flow, increasing from 0.71 +/- 0.03 at baseline to 2.25 +/- 0.25 (PaCO2 8.7 +/- 0.2) and 1.77 +/- 0.13 (PaCO2 11.0 +/- 0.2). Hypocarbia did not influence either retinal or choroidal blood flow.     

Intestinal apolipoprotein synthesis in the newborn piglet

To determine the effects of dietary and biliary lipid absorption on intestinal apo B-48 and apo A-I synthesis in the newborn piglet, 2-d-old female piglets were prepared with a duodenal infusion catheter. After recovery, animals were given either low triglyceride (Vivonex; VIV group) or high triglyceride (Intralipid; FAT group) diets by continuous intraduodenal infusion for 24 h. A bile-diverted group was also studied. Segments of proximal jejunum and distal ileum were then pulse-radiolabeled in vivo with 3H-leucine. Mucosal apo B-48 and apo A-I were immunoprecipitated, and apoprotein synthesis was expressed as percentage of total protein synthesis. Mucosal apoprotein content (ng apoprotein/microgram total protein) was measured by competitive ELISA assays. In jejunum and ileum, apo B-48 synthesis was not different in the three groups. However, apo B content increased 2.4-fold in jejunum and 1.7-fold in ileum in the FAT group compared with the VIV group. Immunoblotting revealed the majority of jejunal apo B to be apo B-48, not apo B-100 from contaminating plasma lipoproteins, in all three experimental groups. Bile-diverted animals had decreased jejunal apo B content compared with the VIV group. Jejunal apo A-I synthesis and content were approximately 2-fold higher in FAT animals compared with the VIV group. Although ileal apo A-I synthesis was also 2-fold higher in the FAT group, apo A-I content was not different from the VIV group. Neither jejunal nor ileal apo A-I synthesis was significantly affected by bile diversion, even though jejunal apo A-I content was decreased by over two thirds compared with the VIV animals. In the newborn piglet, intestinal synthesis of apo B-48 and apo A-I is differentially regulated by luminal lipid absorption. Although fat feeding and bile diversion regulate mucosal apo B-48 content, synthesis is unchanged, indicating a posttranslational regulatory mechanism.(ABSTRACT TRUNCATED AT 250 WORDS)     

Oxygen-induced lung injury in the newborn piglet

Oxygen-induced lung toxicity was studied in artificially fed newborn miniature piglets. Paired littermates of newborn piglets were exposed to either 96–98% oxygen or air for 2, 4, 7 or 10 days. Development of pulmonary edema, as monitored by both the lung wet weight to dry weight ratio and the lung wet weight to body weight ratio, was evident 4 days after the start of oxygen exposure. Examination of light and electron micrographs showed that pulmonary edema was located mainly in the perivascular and interstitial spaces. Endothelial and type I cells were normal in appearance throughout the oxygeh exposure. After exposure to 10 days of oxygen, type II cells appeared to show a decrease in the size of lamellar bodies and an increase in the number and size of mitochondria. The activity of pulmonary antioxidant defenses, as measured by the activity of superoxide dismutase (SOD), glutathione peroxidase (GP) and glutathione reductase (GR), and the level of reduced glutathione (GSH), showed a progressive increase in activity with duration of oxygen exposure, culminating in a significantly higher SOD, GP and GSH level in 7-day oxygen-exposed piglets. It is concluded that the newborn piglet is less susceptible to oxygen-induced lung injury compared to adults of other species, and the increase in the lung complement of SOD, GR, GP and GSH may contribute to the apparent resistance to oxygen toxicity.     

Effects of asphyxia on renal function in the newborn piglet

This investigation was undertaken to determine the nature of acute alterations in renal function following the production of hypoxemia, hypercarbia, and acidosis in newborn piglets 6-96 hr of age. After completion of the surgical procedure piglets were allowed to recover from the effects of anesthesia. When respiratory dead space was increased arterial oxygen tension decreased whereas arterial carbon dioxide tension and hydrogen ion concentration increased. There was little change in glomerular filtration rate. Total renal blood flow decreased and renal vascular resistance increased significantly (504 +/- 78 mm Hg/liter/mm/m2 to 1422 +/- 504). There was no change in distribution of intrarenal blood flow. Sodium excretion and urinary flow rate demonstrated significant parallel increases following the increase in dead space. Plasma renin concentration increased from 67 to 110 ng/ml.     

Current perspectives on septic shock

Although septic shock may be initiated by invading microbes, it is the metabolic and immunologic host responses that determine the true pathophysiology of this common critical care illness. Currently, septic shock therapeutics emphasize empiric and symptomatic treatment. Biochemical elucidation of the septic process will ultimately result in specific interventions for this ominous intensive care syndrome.     

血乳酸清除率在小儿脓毒性休克中的应用

血乳酸是反映全身组织灌注情况和细胞内是否缺氧的敏感标志物.近年来研究发现,脓毒性休克时血乳酸明显增高,当休克得到改善,血乳酸可很快下降.因此,测定体内乳酸的清除率可准确提示脓毒性休克的血流动力学改变情况并对其预后作出有效评估.该文就血乳酸清除率在小儿脓毒性休克中的研究进展作一概述.     

Response to resistive loading in the newborn piglet

The diaphragmatic force generation and electromyographic response to long-term (1 h) inspiratory resistive loading was examined in the newborn piglet during the 3rd postnatal wk of life. Minute ventilation decreased to approximately 50% of baseline level within 5 min of imposition of a severe resistive load and remained at this level for the duration of loading. The decrease in ventilation was secondary to a fall in tidal volume at a constant frequency. There was a significant increase in central nervous system output to the diaphragm as manifested by integrated diaphragmatic electromyogram. Progressive augmentation of this index of central drive continued throughout the period of loading. Functional residual capacity fell significantly by 60 min of inspiratory resistive loading. This strategy should allow greater force generation by placing the diaphragm at a more optimal length-tension relationship. However, the force generating capability of the diaphragm was compromised as assessed by force-frequency curve analysis. These results suggest that the diaphragm of the neonatal piglet fatigues during prolonged inspiratory resistive loading.     

血清CRP在小儿感染性休克中临床意义的探讨

目的　探讨血清C反应蛋白 (CRP)在感染性休克患儿中诊断及疗效观察中的临床意义。方法　选择符合诊断标准的 5 1例感染性休克患儿为实验组 ,其中好转存活患儿 2 5例 ,死亡患儿 2 6例 ;2 5例一般感染患儿为对照组。测定各组患儿入院及经治疗 3d、7d的血清CRP水平 ,进行回顾性研究。结果　入院时CRP值 ,死亡组、存活组与一般感染组相比有显著性差异 (P <0 0 1 ) ;存活组入院治疗 3d与入院时比较无显著性差异 ,而治疗 7d较前均明显降低 ,有显著性差异 (P <0 0 1 ) ;死亡组治疗 3dCRP水平与入院时相比有显著性差异 (P <0 0 1 )。结论　血清CRP值的高低与感染性休克危重症严重程度有关 ,CRP越高 ,病情越重 ,预后越差。血清CRP水平可作为感染性休克病情发展及疗效评价的指标。