Inter-hospital transfers and outcomes of critically ill patients with severe acute kidney injury: a multicenter cohort study

Introduction

Patients with severe acute kidney injury (AKI) who are hospitalized at centers that do not provide renal replacement therapy (RRT) are frequently subjected to inter-hospital transfer for the provision of RRT. It is unclear whether such transfers are associated with worse patient outcomes as compared with the receipt of initial care in a center that provides RRT. This study examined the relationship between inter-hospital transfer and 30-day mortality among critically ill patients with AKI who received RRT.

Methods

We conducted a retrospective cohort study of all critically ill patients who commenced RRT for AKI at two academic hospitals in Toronto, Canada. The exposure of interest was inter-hospital transfer for the administration of RRT. We evaluated the relationship between transfer status and 30-day mortality (primary outcome) and RRT dependence at 30 days following RRT initiation (secondary outcome), by using multivariate logistic regression with adjustment for patient demographics, clinical factors, biochemical indices, and severity of illness.

Results

Of 370 patients who underwent RRT for AKI, 82 (22.2%) were transferred for this purpose from another hospital. Compared with non-transferred patients who started RRT, transferred patients were younger (61 ± 15 versus 65 ± 15 years, P = 0.03) and had a higher serum creatinine concentration at RRT initiation (474 ± 295 versus 365 ± 169 μmol/L, P = 0.002). Inter-hospital transfer was not associated with mortality (adjusted odds ratio 0.61, 95% confidence interval 0.33 to 1.12) or RRT-dependence (adjusted odds ratio 1.64, 95% confidence interval 0.70 to 3.81) at 30 days.

Conclusions

Within the limitations of this observational study and the potential for residual confounding, inter-hospital transfer of critically ill patients with AKI was not associated with a higher risk of death or dialysis dependence 30 days after the initiation of acute RRT.

Electronic supplementary material

The online version of this article (doi:10.1186/s13054-014-0513-1) contains supplementary material, which is available to authorized users.     

Kisspeptins and the control of gonadotrophin secretion

Kisspeptins, the peptide products of the KiSS-1 gene, bind to the G protein coupled receptor 54 (GPR54). Since 2003, research has revealed the important role of kisspeptins in initiating puberty, timing puberty and regulating fertility in adulthood. Specific mutations in GPR54 gene cause either delayed/absent puberty or precocious puberty. The KiSS-1/GPR54 system stimulates the gonadotrophin releasing hormone (GnRH) neurons and is involved in the feedback regulation of the HPG axis by gonadal steroids. Different hypothalamic nuclei are involved in negative (arcuate nucleus; ARC) and positive (anteroventral periventricular nucleus; AVPV) feedback in mice. Continuous administration of kisspeptins down-regulates the HPG axis. During pregnancy, kisspeptins are secreted from the placenta in large amounts and are responsible for the physiological invasion of primary human trophoblast. Kisspeptins have been administered to normal male and female individuals as well as to women with hypothalamic secondary amenorrhoea. In all cases, gonadotrophin secretion was potently stimulated. Kisspeptin antagonists have been synthesized to successfully suppress GnRH and gonadotrophin release. These agonists and antagonists appear as valuable new tools for manipulating the HPG axis and are promising drugs for future treatment. The scope of this review highlights the role of kisspeptins in regulating gonadotrophin secretion and explores their possible therapeutic use.     

应用经胸超声心动图评估快速左心耳起搏心房颤动模型心脏结构及功能的变化

目的:应用经胸超声心动图观察高频率左心耳起搏致猪慢性心房颤动模型心脏结构和功能的变化。方法:实验于2005-09/2006-08在南京医科大学第一附属医院江苏省实验动物中心完成。①12只苏钟种猪随机分为实验组及对照组各6只,所有动物均开胸,将起搏电极固定在左心耳根部,高频率脉冲发生器植入左侧胸部囊袋。实验组术后恢复1周后起搏器以500次/min的频率快速起搏左心耳8周;对照组始终不起搏。②术后心电图定期监测起搏、心房颤动的发生情况;于术前、起搏后1周、起搏后4,8周超声心动图观察实验动物左房内径、心室收缩及舒张末左房面积、左房和左室射血分数、左室舒张及收缩末内径、左心室短轴缩短率等变化。结果:①实验组5只完成了实验,术后2周复查心电图,1只动物发生房颤,起搏8周3只发生阵发性房颤,1只未发生房颤;对照组则未发生任何心律失常情况。②左心房相关指标:起搏后1周,实验组左房内径、收缩末期左心房面积和舒张末期左房容积均较起搏前增加[(2.70±0.12),(2.50±0.12)cm;(6.78±0.81),(6.21±0.93)cm2;(4.66±0.53),(3.78±0.57)mL;P均<0.05],左房射血分数较起搏前下降[(55.6±6.0)%,(63.8±4.0)%,P<0.01],至起搏4,8周,左房射血分数进一步降低,左房内径等指标则继续增大。③左心室相关指标:起搏后1周,实验组左室舒张、收缩末期内径较起搏前增加[(3.64±0.13),(3.46±0.15)cm;(2.48±0.08),(2.14±0.09)cm;P均<0.01],左心室短轴缩短率和左室射血分数较起搏前下降[(31.6±2.0)%,(37.8±3.0)%;(60.8±2.0)%,(69.2±4.0)%;P均<0.01];至起搏4,8周,左心室短轴缩短率和射血分数进一步降低,左室舒张、收缩末期内径则继续增大,与对照组比较也差异显著(P<0.05,0.001)。结论:①超声心动图是监测房颤模型建立过程中心房、心室结构和功能变化的有效手段。②高频起搏左心耳是建立猪心房颤动模型的有效方法,快速心房起搏可导致左心房左心室增大及心功能减退。     

Serologic evidence that Scianna null (Sc:-1,-2) red cells lack multiple high-frequency antigens

Sera from three unrelated persons whose red cells (RBC) had the common Scianna phenotype (Sc:1,-2) contained IgG alloantibodies directed against high-frequency RBC antigens. In each case, sera or eluates or both failed to react only with Scianna null (Sc:-1,-2) cells, although an eluate from one person was compatible with a sibling's Sc:1,-2 cells. Cross-testing cells with sera or eluates, or both, from the three persons revealed no mutual compatibility. These studies show the existence of three additional RBC antigens phenotypically related to the Scianna blood group system. Sc:-1,-2 cells lack these antigens, which indicates that Scianna null cells lack multiple high-frequency antigens.     

自主研制镍钛记忆合金左心耳封堵器封闭左心耳对实验动物左心功能的影响

目的:应用经胸彩色多普勒超声技术评价自主研制的镍钛记忆合金左心耳封堵器封闭左心耳对实验动物猪左心房、左心室功能的影响。方法:实验于2005-09/2006-08在南京医科大学第一附属医院江苏省实验动物中心完成。①实验分组:选用苏钟小型种猪17只,随机分为实验组12只和对照组5只。②实验干预:实验组12只苏钟小型种猪使用自主研制的左心耳封堵器(发明专利号码:200610037789.3,公开号CN1799521,由镍钛合金骨架、多聚四氟乙烯膜和传送连接部分等构成。其外观呈单盘状,封堵器的左心房面呈圆盘状,直接连接放入心耳内的圆柱体结构)行左心耳封堵,对照组5只手术步骤相同而不采用封堵器行左心耳封堵。③实验评估:两组动物分别于术前、术后1周、2周、4周采用经胸超声心动图检查观察心功能的改变,测量左心房内径、最大及最小容积、左房射血分数、左心房搏出量、血流分数等左房功能参数以及左室射血分数、左室短轴缩短率、Tei指数、E/A比值等指标。结果:①实验动物数量分析:在施行左心耳封堵后,1头猪于术中出血过多并出现室颤后死亡,1头猪因封堵器脱入左房,卡在二尖瓣口导致死亡。其余动物封堵效果良好。②两组动物术后1,2,4周左房功能指标各参数与术前比较无明显变化(P>0.05);与术前相比,实验组术后1周、2周左室射血分数、左心室短轴缩短率、E/A比值分别由术前的0.70±0.04、0.39±0.03、1.33±0.28降低至术后1周的0.59±0.05、0.31±0.03、0.95±0.11(P<均0.01)及术后2周的0.62±0.05、0.33±0.05、0.90±0.05(P<均0.01);Tei指数由术前的0.48±0.02增加至术后1周的0.59±0.03(P<0.01)及术后2周的0.58±0.04(P<0.01)。对照组手术前后左室功能指标差异无显著性。结论:自主研制左心耳封堵器可以有效的封堵左心耳;左心耳封堵后短期内对实验动物左房功能无明显影响;封堵后短期内对左心室功能具有短期的减弱,更长期的安全性有待于进一步研究。     

Column agglutination technology: the antiglobulin test

A new system for typing and screening blood, based on the sieving effect of glass bead microparticles, has been developed. The test is performed in a microcolumn in which the red cell agglutinates are trapped in the glass bead matrix during centrifugation, and unagglutinated cells form a pellet at the bottom of the column. Anti- human globulin reagents were incorporated in the diluent and the new test system, column agglutination technology, was compared to conventional tube tests and low-ionic-strength method. Sera and plasmas (228 samples) were screened for red cell antibodies with two anti-human globulin reagents: one containing only anti-IgG and the other containing both anti-IgG and anti-C3b, -C3d. After initial testing, there was 94-percent agreement between column agglutination technology and tube tests, and after repeat testing, there was 97-percent agreement. The column agglutination technology anti-human globulin test eliminates the need to wash red cells, which decreases the overall test time. The test is easy to perform, and the results are more objective than those with tube and microplate methods.     

Fat10 is an epigenetic marker for liver preneoplasia in a drug-primed mouse model of tumorigenesis

There is clinical evidence that chronic liver diseases in which MDBs (Mallory Denk Bodies) form progress to hepatocellular carcinoma. The present study provides evidence that links MDB formation induced by chronic drug injury, with preneoplasia and later to the formation of tumors, which develop long after drug withdrawal. Evidence indicated that this link was due to an epigenetic cellular memory induced by chronic drug ingestion. Microarray analysis showed that the expressions of many markers of preneoplasia (UBD, Alpha Fetoprotein, KLF6 and glutathione-S-transferase mu2) were increased together when the drug DDC was refed. These changes were suppressed by S-adenosylmethionine feeding, indicating that the drug was affecting DNA and histones methylation in an epigenetic manner. The link between MDB formation and neoplasia formation was likely due to the over expression of UBD (also called FAT10), which is up regulated in 90% of human hepatocellular carcinomas. Immunohistochemical staining of drug-primed mouse livers showed that FAT10 positive liver cells persisted up to 4 months after drug withdrawal and they were still found in the livers of mice, 14 months after drug withdrawal. The refeeding of DDC increased the percent of FAT10 hepatocytes.