Comparing outcomes in renal replacement therapy: how should we correct for case mix?

The need to evaluate the effectiveness of clinical practice to justify expensive therapy in the face of financial constraints in all areas of health care delivery makes it necessary to identify groups of patients who are likely to benefit most from treatment. Various risk stratification methods have been used for analyzing survival probabilities for patients receiving renal replacement therapy. Complicated risk stratification methods produce large numbers of risk groups of small sizes, which makes comparison between individual centers difficult. We compared three simple methods of risk stratification, that divided patients into low-, medium-, and high-risk groups, in a cohort of 1,407 patients who commenced renal replacement therapy in five European countries during a 7-year period. Method 1 considered age (>55 years) and diabetes alone; method 2 used a higher age limit (>70 years) and comorbid illnesses, including those other than diabetes; and method 3 used only the number of comorbidities (none, 1, or > or =2) for stratification. Kaplan-Meier survival curves were constructed for comparison between risk groups and Cox's regression model used to assess strength of relationship with mortality. Although patient survival was significantly different between the low-, medium-, and high-risk groups using all three methods, Cox's regression analysis showed that method 2 provided the greatest discrimination between risk groups. In predicting mortality, method 2 (based on comorbidities and age) showed the highest sensitivity and specificity (84% and 80%, respectively) compared with method 1 (80% and 74%) and method 3 (64% and 82%). Validation of this approach in other populations in a prospective study is required before this method, which takes into account the influences of both age and comorbidity for risk stratification, can be used for comparing survival data and for presenting results of renal replacement therapy.     

Consequences of candidemia for pediatric patients

The hospital records of 45 infants and children with one or more blood cultures positive for Candida species were studied retrospectively in an attempt to define the risk of Candida-related complications. Death of eight of the patients (18%) was related to Candida infection, and five additional patients (11%) had metastatic foci of infection but survived. No characteristics were identified that would predict patients who were at high risk for complications of candidemia. Eleven patients were treated with amphotericin B for longer than a week and were examined for evidence of nephrotoxicity. None had persistent abnormalities of blood urea nitrogen or serum creatinine concentrations develop during treatment; two patients had hypokalemia.     

Pseudoaneurysm: a complication of faulty technique in femoral arterial puncture

Pseudoaneurysm is a well-documented but rare complication of retrograde femoral arterial puncture. We present six patients in whom pseudoaneurysm complicated this procedure. The pseudoaneurysm arose from the superficial femoral artery in five patients and from the profunda femoris artery in one. An arteriovenous fistula also arose from the superficial femoral artery in one patient. In no patient did the pseudoaneurysm arise from the common femoral artery. Two mechanisms are postulated as to why pseudoaneurysms rarely complicate puncture of the common femoral artery.     

Teenage pregnancy in type 1 diabetes mellitus

Carmody D, Doyle A, Firth RGR, Byrne MM, Daly S, Mc Auliffe F, Foley M, Coulter‐Smith S, Kinsley BT. Teenage pregnancy in type 1 diabetes mellitus Younger maternal age at delivery has been linked to adverse reproductive outcomes. Pregnancy complicated by type 1 diabetes mellitus (T1DM) is also associated with adverse pregnancy outcomes. Optimising diabetic glycaemic control prior to pregnancy is known to reduce the rate of congenital abnormalities and improve pregnancy outcomes. Teenage pregnancies are not usually planned and little data exist on teenage pregnancy complicated by T1DM. We sought to identify the glycemic control achieved in teenage pregnancy with T1DM and to clarify if there is an associated increase in adverse pregnancy outcomes compared to those seen in older women with T1DM. We compared outcomes in 18 teenagers (TG) with 582 older women with T1DM (CON) from 1995–2007. TG booked to the combined diabetes‐obstetrical service at a median gestational age of 11 weeks (range 6–22) compared to 7 weeks in CON (range 4–40, p < 0.02). Glycaemic was worse in TG compared to CON at 13, 26 and 35 weeks gestation, despite higher insulin doses. First trimester miscarriage rate did not differ between groups. Major congenital anomaly rate was 6.2% (1/16) compared to 3.2% in CON. This preliminary study has demonstrated that pregnant teenage women with T1DM book later to specialised care and have worse glycaemic control in pregnancy compared to older women with T1DM. This group also appear to be more insulin resistant than older women in early pregnancy. Our data would suggest that teenagers with type 1 diabetes mellitus may constitute a high‐risk group for adverse pregnancy outcomes.     

Myocardial deformation abnormalities in patients with aortic regurgitation: a strain rate imaging study

Aims: Early left ventricular (LV) dysfunction in asymptomatic patientswith severe aortic regurgitation (AR) may go undetected dueto the lack of a sufficiently sensitive diagnostic tool. Ultrasonicstrain/strain rate (S/SR) imaging should now provide such sensitivityin detecting early dysfunction in regional LV systolic deformation.The aim of this study was to understand and define the changesin LV regional systolic deformation based on S/SR imaging inpatients with asymptomatic or minimally symptomatic AR. Methods and results: Eighty-one individuals were studied: 59 asymptomatic patientswith isolated non-ischaemic AR who were divided into three sub-groupssuch as mild, moderate, and severe AR and 22 age-matched healthysubjects. All patients underwent standard echocardiographicexaminations including a tissue Doppler imaging study. For LVradial deformation, the posterior wall (LVPW) was examined.To assess LV longitudinal deformation, S and SR data were acquiredfrom the LV lateral wall and septum. Radial as well as longitudinalpeak systolic SRs were significantly decreased in patients withboth moderate AR (LVPW, P = 0.0009; septum, P = 0.03; LV lateralwall, P = 0.0009) and severe AR (P < 0.0001) compared withhealthy subjects. Changes in regional LV deformation correlatedinversely both with LV end-diastolic volume and with end-systolicvolume. Conclusions: Strain rate imaging is a sensitive tool in detecting the spectrumof changes in radial and longitudinal deformation in asymptomaticor minimally symptomatic patients with AR. The index where volumewas corrected by deformation should form the basis for predictingsubclinical LV dysfunction in patients with increasing LV dilatation.     

Polarized distribution of key membrane transport proteins in the rat submandibular gland

 Immunofluorescence labelling and confocal microscopy were employed to examine the polarized distribution of several membrane transport proteins believed to be essential for salivary secretion in the rat submandibular gland. The Na⁺/K⁺-ATPase, Na⁺/H⁺ exchanger isoform 1 (NHE1), and the secretory Na⁺/K⁺/2Cl^–cotransporter isoform were all found in the basolateral membranes of acinar and intralobular duct cells. Anion exchanger isoform 2 (AE2) was found only in the basolateral membranes of acinar cells, while AE1 was absent from glandular epithelial cells. Aquaporin 5 was detected in the apical membranes of acinar cells, while the cystic fibrosis transmembrane conductance regulator was found only in apical membranes of intralobular duct cells. NHEs 2 and 3 were found in the apical membranes of both acinar and intralobular duct cells. Our results are generally consistent with the expected distribution of most transporters based on previous physiological and pharmacological experiments. However, the apical localization of NHEs 2 and 3, and the presence of the secretory isoform of the Na⁺/K⁺/2Cl^–cotransporter in intralobular duct cells were not predicted. Received: 10 June 1996 / Received after revision: 9 September 1996 / Accepted: 17 September 1996     

培养心肌细胞牵张刺激装置的建立及应用

1　方法　牵张刺激装置的制作如模式图 1.制作实验模型采用材料为有机玻璃板、2 4孔培养板、硅胶膜 (厚度 0 .2 2 μｍ) .硅胶膜从平面圆形变为球形时 ,面积扩大的百分比 =(Ｓ球 -Ｓ园 ) /Ｓ园 ,其中Ｓ球 =ＡＤ2 ,Ｓ园 =ｒ2 ,而ＡＤ2 =ｈ2 +ｒ2 ,其中ｒ为孔的半径 ,ｈ为膜升高的高度图 2 .通过控制ｈ的大小 ,可控制膜被牵拉的强度 .本实验采用使膜面积扩大 2 0 %的强度 ,故ｈ =4ｍｍ[1] .参照Ｋａｓｓｉｒｉ等[2 ,3 ] 方法进行心肌细胞的分离培养 .生长有贴壁心肌细胞的 2 4孔板被固定于牵张装置 ,缓慢充气使硅胶膜向上凸起 4ｍｍ ,分别维持…     

Meniscal injuries: detection using MR imaging

Both retrospective and blinded analyses of thin-section, high-resolution magnetic resonance (MR) images of the knee joint, produced using a solenoid surface coil, indicate that MR imaging is an effective technique for evaluating meniscal injuries. Images of 49 patients were evaluated, and the results were correlated with those of subsequent arthroscopy. A grading scale was developed to rate the index of suspicion of a meniscal tear based on the MR images. Overall, approximately 80% of menisci rated grade 4 (definite tear) or 3 (probable tear) were found to have corresponding tears at arthroscopy. In many other patients with a grade 4 or 3 meniscus in whom a corresponding tear was not found arthroscopically, meniscal tears at other sites or other abnormalities were correctly diagnosed using MR. A majority of the false-positive MR images involved the posterior horns of the menisci, the sites of most false-negative arthroscopic diagnoses. The predictive value of a negative MR image was almost 100%. Even in patients with moderate-to-large effusions, the menisci were accurately evaluated. The results imply that MR imaging is useful in the preoperative evaluation of suspected meniscal tears.