A Nationwide Analysis of the Use and Outcomes of Epidural Analgesia in Open Colorectal Surgery

Introduction

Epidural analgesia has demonstrated superiority over conventional analgesia in controlling pain following open colorectal resections. Controversy exists regarding cost-effectiveness and postoperative outcomes.

Methods

The Nationwide Inpatient Sample (2002–2010) was retrospectively reviewed for elective open colorectal surgeries performed for benign and malignant conditions with or without the use of epidural analgesia. Multivariate regression analysis was used to compare outcomes between epidural and conventional analgesia.

Results

A total 888,135 patients underwent open colorectal resections. Epidural analgesia was only used in 39,345 (4.4 %) cases. Epidurals were more likely to be used in teaching hospitals and rectal cancer cases. On multivariate analysis, in colonic cases, epidural analgesia lowered hospital charges by US$4,450 (p?<?0.001) but was associated with longer length of stay by 0.16 day (p?<?0.05) and a higher incidence of ileus (OR?=?1.17; p?<?0.01). In rectal cases, epidural analgesia was again associated with lower hospital charges by US$4,340 (p?<?0.001) but had no effect on ileus and length of stay. The remaining outcomes such as mortality, respiratory failure, pneumonia, anastomotic leak, urinary tract infection, and retention were unaffected by the use of epidurals.

Conclusion

Epidural analgesia in open colorectal surgery is safe but does not add major clinical benefits over conventional analgesia. It appears however to lower hospital charges.     

Inhibition of platelet function by cis-unsaturated fatty acids

The uptake of free fatty acids has previously been shown to affect the capping of lymphocytes, and there is evidence that different types of fatty acids may partition into separate lipid domains in cell surface membranes. In studies of gel-filtered human platelets, we found that cis-unsaturated fatty acids (1-35 microM) inhibited platelet shape change, aggregation, and secretion of 5-hydroxytryptamine induced by thrombin, adenosine diphosphate (ADP), collagen, U46619 (a thromboxane A2 analog), or plant lectins, but not that induced by A23187, a calcium ionophore. Trans-unsaturated and saturated fatty acids had little or no inhibitory effect. The inhibitory effects of cis-unsaturated fatty acids were not affected by inhibition of adenylate cyclase or cyclooxygenase. 14C-labeled fatty acids were taken up into platelet lipids. The maximum platelet-inhibitory effect of cis-unsaturated fatty acids was seen when over 90% of the platelet label was still in the form of free fatty acids. Platelet inhibition could be reversed by washing the platelets by gel filtration. Binding of platelet agonists to the platelet was not inhibited by the fatty acids. Cis-unsaturated fatty acids, but not trans-unsaturated or saturated fatty acids, decreased fluorescence polarization of platelets or isolated platelet membranes monitored with 1,6-diphenyl- 1,3,5-hexatriene. The potency of the fatty acids as inhibitors of platelet aggregation was inversely correlated with their melting points. These data suggest that inhibition of receptor-mediated platelet responses by cis-unsaturated fatty acids results from perturbation of the platelet membrane in specific lipid domains.     

Tooth root dentin mineralization defects in a mouse model of hypophosphatasia

Tissue‐nonspecific alkaline phosphatase (TNAP) is expressed in mineralizing tissues and functions to reduce pyrophosphate (PP_i), a potent inhibitor of mineralization. Loss of TNAP function causes hypophosphatasia (HPP), a heritable disorder marked by increased PP_i, resulting in rickets and osteomalacia. Tooth root cementum defects are well described in both HPP patients and in Alpl^?/? mice, a model for infantile HPP. In Alpl^?/? mice, dentin mineralization is specifically delayed in the root; however, reports from human HPP patients are variable and inconsistent regarding dentin defects. In the current study, we aimed to define the molecular basis for changes in dentinogenesis observed in Alpl^?/? mice. TNAP was found to be highly expressed by mature odontoblasts, and Alpl^?/? molar and incisor roots featured defective dentin mineralization, ranging from a mild delay to severely disturbed root dentinogenesis. Lack of mantle dentin mineralization was associated with disordered and dysmorphic odontoblasts having disrupted expression of marker genes osteocalcin and dentin sialophosphoprotein. The formation of, initiation of mineralization within, and rupture of matrix vesicles in Alpl^?/? dentin matrix was not affected. Osteopontin (OPN), an inhibitor of mineralization that contributes to the skeletal pathology in Alpl^?/? mice, was present in the generally unmineralized Alpl^?/? mantle dentin at ruptured mineralizing matrix vesicles, as detected by immunohistochemistry and by immunogold labeling. However, ablating the OPN‐encoding Spp1 gene in Alpl^?/? mice was insufficient to rescue the dentin mineralization defect. Administration of bioengineered mineral‐targeting human TNAP (ENB‐0040) to Alpl^?/? mice corrected defective dentin mineralization in the molar roots. These studies reveal that TNAP participates in root dentin formation and confirm that reduction of PP_i during dentinogenesis is necessary for odontoblast differentiation, dentin matrix secretion, and mineralization. Furthermore, these results elucidate developmental mechanisms underlying dentin pathology in HPP patients, and begin to explain the reported variability in the dentin/pulp complex pathology in these patients. © 2013 American Society for Bone and Mineral Research     

Tracheobronchial tree: expandable metallic stents used in experimental and clinical applications. Work in progress

An expandable stainless steel stent was formulated for use in the treatment of tracheobronchial stenosis, tracheomalacia, and airway collapse following tracheal reconstruction. The stents were placed through an endotracheal tube into the trachea and bronchi of 11 healthy dogs. The stents expanded over time, substantially increasing the diameter of the lumen. Slight migration occasionally occurred, while an inflammatory reaction was noted in each animal. The stents were successfully used in the treatment of two cancer patients to dilate a postoperative bronchial stenosis that caused pneumonia and to support a tracheal graft that collapsed with respiration. Because of the stent migration in experimental studies, designs are being tested to develop stents with greater stability. These stents may be effective in overcoming stenosis caused by scarring, extrinsic compression, and collapse of reconstructed tracheobronchial structures.     

Partial anomalous pulmonary venous drainage of the right lower lobe shown by CT scans

A case is reported in which the diagnosis of partial anomalous pulmonary venous return was first suggested on computed tomographic (CT) scans. Abnormal pulmonary vessels could be seen on serial CT sections to drain into the superior vena cava. The diagnosis was confirmed at angiographic study.     

Mediastinal lesions in children: comparison of CT and MR

Magnetic resonance (MR) imaging was compared with computed tomography (CT) in 13 children with mediastinal abnormalities. CT and MR provided comparable information regarding the presence and size of the mediastinal lesions. The MR imaging technique that was most reliable in detecting a mass was a T1-weighted spin-echo pulse sequence. MR better discriminated mediastinal masses and enlarged nodes from vascular structures and was more sensitive than CT in detecting intraspinal extension. However, CT demonstrated calcification and bronchial abnormalities not seen on MR images. It is concluded that MR may be more helpful than CT in evaluating posterior mediastinal tumors, since there is a likelihood of intraspinal extension. In other cases, however, CT continues to be the procedure of choice to supplement plain radiography in children with suspected mediastinal neoplasms.     

Comparison of laparoscopic versus open appendectomy for acute nonperforated and perforated appendicitis in the obese population

Background

Use of laparoscopic appendectomy (LA) has been increasing in obese patients. We evaluated the outcomes of LA compared with open appendectomy (OA) in obese patients.

Methods

By using the Nationwide Inpatient Sample database, clinical data of obese patients who underwent LA and OA for suspected acute appendicitis (perforated or nonperforated) from 2006 to 2008 were examined.

Results

A total of 42,426 obese patients underwent an appendectomy during this period. In acute nonperforated cases, LA had a lower overall complication rate (7.17% vs 11.72%; P < .01), mortality rate (.09% vs .23%; P < .01), mean hospital charges ($25,193 vs $26,380; P = .04), and shorter mean length of stay (2.0 vs 3.1 d; P < .01) compared with OA. Similarly, in perforated cases, LA was associated with a lower overall complication rate (22.34% vs 34.65%; P < .01), mortality rate (.0% vs .50%; P < .01), mean hospital charges ($36,843 vs $43,901; P < .01), and a shorter mean length of stay (4.4 vs 6.5 d; P < .01) compared with OA.

Conclusions

LA can be performed safely with superior outcomes compared with OA in obese patients and should be considered the procedure of choice for perforated and nonperforated appendicitis in these patients.     

Utilization of laparoscopy in colorectal surgery for cancer at academic medical centers: does site of surgery affect rate of laparoscopy?

Use of laparoscopy in colorectal cancer surgery is still limited. The aim of this study was to determine the rate of use of laparoscopic colorectal surgery for cancer at academic medical centers and to evaluate if the site of surgery influences the rate of use. Clinical data of patients who underwent laparoscopic or open colon and rectal resections for cancer from 2007 to 2009 were obtained from the University HealthSystem Consortium database. Data concerning rate of laparoscopy, length of stay, morbidity, and risk-adjusted mortality were obtained. During the 36-month study period, 22,780 operations were performed. The overall rate for use of laparoscopy was 14.8 per cent. Laparoscopy was most often used for total colectomy (22.6%), sigmoid colectomy (17.3%), cecectomy (17.1%), and right hemicolectomy (17.0%). Laparoscopy was most infrequently used for abdominoperineal resection (8.0%), transverse colectomy (10.0%), and left hemicolectomy (13.1%). Length of stay for laparoscopic colon and rectal procedures was 3.2 days shorter than for open surgery. Although the benefits of laparoscopic colorectal surgery for cancer have been demonstrated, the use of laparoscopy for colorectal resection remains under 20 per cent for colon cancer and under 10 per cent for rectal cancer. Further studies are needed to determine the factors limiting the use of laparoscopy in colorectal surgery.     

多孔钽假体治疗早期股骨头坏死的生物力学和临床评价

简介 股骨头坏死是因股骨头血运破坏所导致的一种影响功能的疾病。其主要在年轻人中发病。病因包括酗酒、激素药物应用史、创伤、血液系统病、放射治疗以及气压1-30在美国，估计每年有10,000到30,000例发生。其中5％到10％须用人工关节置换术治疗。对股骨头和软骨下板塌陷前的早期坏死进行手术治疗似更有效。早期阶段，病理改变通常局限于股骨头上方负重部位的楔形坏死区。随着疾病的进展。坏死区将塌陷并在存活骨和坏死骨接合处发生骨折。     

A comparative study of the effective radiation doses from cone beam computed tomography and plain radiography for sialography

Objectives

As a first step in developing a protocol for multidimensional sialography using cone beam CT (CBCT), the objective of this study was to compare the effective radiation doses from sialography of the parotid and submandibular glands using plain radiography and CBCT.

Methods

The effective doses were calculated from dose measurements made at 25 selected locations in the head and neck of a radiation analogue dosimeter (RANDO) phantom, using International Commission on Radiological Protection 2007 tissue weighting factors.

Results

The effective dose (E) changed in relationship to changes in CBCT field of view (FOV), peak kilovoltage (kVp) and milliamperage (mA). Specifically, E decreased from a maximum of 932 μSv (30 cm FOV, 120 kVp, 15 mA) to 60 μSv (15 cm FOV, 80 kVp, 10 mA) for a parotid gland study and to 148 μSv (15 cm FOV, 80 kVp, 10 mA) for a submandibular study. The collective series of plain radiographs made during sialography of the parotid and submandibular glands yielded effective doses of 65 μSv and 156 μSv, respectively. The plain parotid gland series included one panoramic, two anterior–posterior skull and four lateral skull radiographs, whereas the submandibular gland series included one panoramic, one standard mandibular occlusal and four lateral skull radiographs.

Conclusion

The effective doses from CBCT examinations centred on the parotid and submandibular glands were similar to those calculated for plain radiograph sialography when a 15 cm FOV was chosen in combination with exposure conditions of 80 kVp and 10 mA.