Blood Pressure Recordings During Hemodialysis Access Interventions: Implications for Acute Management

A retrospective study evaluating the pattern of blood pressure and its related complications before, during, and after percutaneous hemodialysis interventions was performed in patients presenting with asymptomatic hypertension. Hemodialysis patients undergoing percutaneous interventions including tunneled hemodialysis catheter insertion, percutaneous balloon angioplasty and thrombectomy procedure, and stage II hypertension (systolic blood pressure ≥160 mmHg) were included in this analysis. Blood pressure medications were not used while midazolam and fentanyl were routinely administered. Patients were followed for up to 4 weeks to monitor any complications. The mean blood pressure before, during, and after the procedures were 185 ± 18/96 ± 14, 172 ± 22/92 ± 15, and 153 ± 25/87 ± 14, respectively. There was a statistically significant difference between the blood pressure readings before and after the procedure (before = 185 ± 18/96 ± 14, after = 153 ± 25/87 ± 14; p = 0.001). None of the patients had a stroke, myocardial infarction, or acute pulmonary edema before, during, or after the procedure or during the 4‐week follow‐up period. A significant reduction in blood pressure was observed after the procedure without the administration of any antihypertensive medication. These results suggest that the reduction in blood pressure observed after percutaneous dialysis access interventions (particularly in the presence of midazolam and fentanyl) may make it unnecessary to treat asymptomatic hypertension prior to these procedures.     

Computerized tomography based 3D modeling of the clavicle

Previous studies have suggested clavicular morphology is highly variable, particularly in the lateral retrocurved section. Current clavicle fracture plating systems require three dimensional intra‐operative contouring to achieve adequate fit and necessitate variable soft tissue dissection placing fracture perfusion and muscular attachments at risk. The aim of this study was to search for a surgically relevant superficial shape pattern. This is a retrospective CT‐based analysis of 174 non‐pathological clavicles in 95 adults (45 females, 50 males). Using the principle of cylindrical parameterisation generated 3‐D computer models, we identified an implant preferred pathway (IPP), defined as a continuous linear region where the least possible soft tissue disruption would be necessary for plate fixation. The IPP mean form was within 3.04 mm (SD ± 1.34) on all clavicles. Clavicle length, and not shape, was found to be the biggest variable (correlation between size and form co‐ordinates r = 0.99, p < 0.05), accounting for 79% of overall variability. This length variation was mainly located in the medial antecurved section. Superior convexity and recurvatum were the main shape variables, however they only contributed 8% and 5% to the overall variation, respectively. Three IPP lengths were shown to match all clavicles when aligned at the acromial end first. In contrast to previous studies, we have shown that the IPP is fairly consistent with respect to the general shape with the exception of length variation which mainly affected the medial antecurved section. © 2015 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 34:1216–1223, 2016.

CLINICAL RELEVANCE

Future pre‐contoured fracture fixation systems should provide variable length plates with a constant lateral section retrocurve and a variable medial antecurve.     

Relationship of Right Ventricular Size and Function with Respiratory Status in Duchenne Muscular Dystrophy

The relationship between pulmonary function and right ventricle (RV) in Duchenne muscular dystrophy (DMD) has not been evaluated. Using cardiac magnetic resonance (CMR), we describe the relationship of RV size and function with spirometry in a DMD cohort. Fifty-seven boys undergoing CMR and pulmonary function testing within 1 month at a single center (2013–2015) were enrolled. Comparisons of RV ejection fraction (RVEF) and end-diastolic volume index (RVEDVI) were made across categories of percent forced vital capacity (FVC%), and relationships were assessed. Mean age was 15.5 ± 3.5 years. Spirometry and CMR were performed within 3.9 ± 4.1 days. Median FVC% was 92.0 % (67.5–116.5 %). Twenty-three (40 %) patients had abnormal FVC% (<80 %) of which 13 (57 %) had mild (FVC% 60–79 %), 6 (26 %) had moderate (FVC% 40–59 %), and 4 (17 %) had severe (FVC <40 %) reductions. Mean RVEF was 58.3 ± 3.7 %. Patients with abnormal FVC% were older and had lower RVEF and RVEDVI. Both RVEF and RVEDVI were significantly associated with FVC% (r = 0.31, p = 0.02 and r = 0.39, p = 0.003, respectively). In a large DMD cohort, RVEF and RVEDVI were related to FVC%. Worsening respiratory status may guide monitoring of cardiac function in these patients.