Optimum Positioning for Anteroposterior Pelvis Radiography: A Literature Review

AimPelvic radiography is used for the identification of hip joint changes, including pathologies such as osteoarthritis. Several studies have recommended that the position for this radiological procedure should be standing, not supine, to reflect the functional appearances of the hip joint. The aim of this review was to evaluate pelvis radiography positioning with respect to the image appearances and information provided for clinical decision-making. Aside from this, potential recommendations to the radiographic technique for an erect pelvis projection will be considered.MethodA literature search was performed using databases/abstract systems (ScienceDirect, Web of Science, PubMed, and MEDLINE). Only articles written in English were included.ResultsTwenty-five articles were identified. Findings from the review describe the effect of repositioning from supine to erect on a series of specific hip measurements. These include pelvic tilt, joint space width, and the acetabular component.ConclusionEvidence within the literature illustrates that in several studies, there were differences when repositioning from supine to standing for a number of pelvic metrics. Standing positioning is promoted by some authors since this may facilitate the early diagnosis of hip joint pathology and assist in the planning of surgical interventions. Literature is very limited on how to optimally perform erect pelvis radiography, and this should be an area for future research.     

乳腺癌根治术后三种放疗技术在模体中的剂量监测分析

目的观察分析乳腺癌术后临床常用技术的剂量分布特点,为临床治疗提供剂量学依据。方法使用高仿真非均质等效拟人体模型,模拟典型成年女子左侧乳腺癌术后患者,对患侧胸壁感兴趣区域的代表测量点及其不同深度测量点进行标记后按放疗体位行CT模拟定位。在TPS上分别为模体设计三种技术的方案．并在模体上进行模拟照射。使用金属氧化物半导体场效应管（MOSFET）对各点进行实时测量,并与TPS上各标记点计算值进行比对分析。结果三种计划方法中各深度测量点的实际测量值与TPS中的相应各点的计算值相比较发现,在皮肤表面和浅层计划值与实测值相差较大,而随着深度的增加,在lem深度测量点时计划值与实测值接近;除表皮外,三种方法照射的靶区实测剂量基本能满足l}缶床剂量学要求;IMRT照射在靶区剂量均匀性方面要好于3D．CRT和7MeV电子线照射;7MeV电子线照射时．曲面胸壁的测量点中出现低于处方剂量16％的欠剂量区。结论1．乳腺癌术后胸壁放疗时,各种方案在不加组织补偿的情况下皮肤剂量均不足,将导致胸壁复发率提高,在临床治疗中应根据不同方案选用适当厚度的补偿膜。2．电子线照射在曲面靶区的胸壁深处容易形成剂量不足区,在实际临床中应选择胸壁平坦而薄的患者进行电子线治疗。3．IMRT技术在控制靶区剂量高量、靶区剂量均匀性以及减少肺高剂量体积等方面均优于3D-CRT技术。但是由于胸壁受呼吸运动的影响较大,在逆向IMRT时．其不能考虑呼吸运动对靶区剂量范围的影响。     

Stereotactic Body Radiotherapy for the Treatment of Spinal Metastases: An Overview of the University of Toronto,Sunnybrook Health Sciences Odette Cancer Centre,Technique

Conventional low-dose radiation therapy (RT) has long been used in the treatment of patients suffering from the symptoms of metastatic cancer in and around the spine. The goals of therapy include pain control and at least short-term local disease control. Most patients are offered palliative doses such as 8 Gy in one fraction, 20 Gy in five fractions, or 30 Gy in 10 fractions, and as yet there has been no dose–response relationship within conventional RT practice. Stereotactic body radiation therapy (SBRT) is a relatively new technique that overcomes the previous limitations of conventional RT by delivering high biologically effective doses (BED), in the range of what is considered locally curative, using intensity-modulated radiotherapy (IMRT). Doses such as 16–24 Gy in a single fraction, 24–30 Gy in two or three fractions, and 30–40 Gy in four or five fractions are commonly used in spine SBRT, while sparing the surrounding normal tissues to a much lower dose that falls within tolerance. The high precision required for spine SBRT demands near-rigid patient immobilization, visualization of the target volume and spinal cord with magnetic resonance imaging, and image-guided radiotherapy. Ultimately, an overall delivery precision of approximately 1.5-2 mm is required for safe and effective treatment. The aim of this review is to discuss the technical delivery of spine SBRT with particular attention to the incorporation of robotic treatment couch technology. The HexaPOD (Elekta AB, Stockholm, Sweden) is the robotic couch in use at the University of Toronto, and it is capable of performing fine translations and rotations allowing for six degrees of freedom patient positioning. This technology is a major advancement in correcting patient setup errors.     

Trauma in pregnancy

The anatomic and physiologic changes make treatment of the pregnant trauma patient complex. The fetus is the challenge, because, in pregnancy, trauma has little effect on maternal morbidity and mortality. Aggressive resuscitation of the mother, in general, is the best management for the fetus, because fetal outcome is directly related to maternal outcome. Recent literature has attempted, with little success, to identify factors that may predict poor fetal outcomes. Cardiotocographic monitoring should be initiated as soon as possible in the emergency department to evaluate fetal well-being. Other key points include: Maternal blood pressure and respiratory rate return to baseline as pregnancy approaches term. Initial fetal health may be the best indicator of maternal health. Inferior vena cava compression in the supine patient may cause significant hypotension. Maternal acidosis may be predictive of fetal outcome. Kleihauer-Betke testing is not necessary in the emergency department. Early ultrasonographic evaluation can identify free intraperitoneal fluid and assess fetal health. Necessary radiographs should not be withheld at any period of gestation. Radiation beyond 20 weeks' gestation is safe. Patients with viable gestations require at least 4 hours of CTM monitoring after even minor trauma.     

Therapeutic positioning, wheelchair seating, and pulmonary function of children with cerebral palsy: a research synthesis.

This review analyzed research literature concerning pulmonary function and positioning of persons with cerebral palsy (CP) who lack trunk control. The search reviewed literature published from 1966 through March 2003. Twenty-eight references located by electronic database search were analyzed using Moody's Research Analysis Tool. All reflected either a physiologic or therapy-based model involving function in activities of daily living, but no health outcomes. One reference applied a nursing model to care of developmentally disabled persons, including those with CP. Existing research gaps include the need for human subjects, larger sample sizes, measurement of influence of gravity on body position, greater precision in describing independent variables of positioning, and participation by children with disabilities. This paper proposes a conceptual model using Orem's self-care theory upon which to base nursing interventions, including therapeutic positioning of persons with CP who lack trunk control. Future nursing research should explore health outcomes of various properties of wheelchair positioning.     

The influence of patient positioning on radiation dose in CT imaging: A narrative review

Background and purposeAlthough it is fundamental for optimal scanner operation, it is generally accepted that accurate patient centring cannot always be achieved. This review aimed to examine the reported knowledge of the negative impact of patient positioning on radiation dose and image quality during CT imaging. Furthermore, the study evaluated the current optimisation tools and techniques used to improve patient positioning relative to the gantry iso-center.MethodologyA comprehensive search through the databases PubMed, Ovid, and Google Scholar was performed. Keywords included patient off-centring, patient positioning, localiser radiograph orientation, radiation dose, and automatic patient positioning (including synonyms). The search was limited to full-text articles that were written in English. After initial title and abstract screening, a total of 52 articles were identified to address the aim of the review. No limitations were imposed on the year of publication.ResultsVertical off-centring was reported in up to 95% of patients undergoing chest and abdominal CT examinations, showing a significant influence on radiation dose. Depending on the scanner model and vendor, localiser orientation, bowtie filter used, and patient size, radiation dose varied from a decrease of 36% to an increase of 91%. A significant dose reduction was demonstrated when utilising an AP localiser, aligning with the trend for radiographers to off-center patients below the gantry iso-centre. Utilizing a 3D camera for body contour detection allowed for more accurate patient positioning and promoted further dose reduction.ConclusionPatient positioning has shown significant effects on radiation dose and image quality in CT. Developing a good understanding of the key factors influencing patient dose (off-centring direction, localiser orientation, patient size and bowtie filter selection) is critical in optimising CT scanning practices. Utilising a 3D camera for body contour detection is strongly recommended to improve patient positioning accuracy, image quality and to minimise patient dose.     

多点实时剂量监测在全身照射中的应用

  目的  探讨在有限条件下完成分次双侧位大野全身照射治疗时多点实时剂量监测技术用于质控的必要性。  方法  使用Varian 2300 C/D加速器6 MV射线对25例准备进行骨髓移植的患者进行全身照射治疗。治疗同时使用半导体剂量计进行多点实时剂量监测, 记录监测结果并与计划计算结果进行比对分析, 在治疗的同时进行剂量的修正, 以确保患者受照剂量误差控制在±5%以内。  结果  25例患者的12通道首次实时剂量监测结果与理论计划剂量有显著偏差。头部、胸部、腹部、盆腔、大腿、膝关节和踝关节剂量偏差中位数分别为6.10%、-1.30%、5.90%、5.05%、-4.00%、3.05%和3.30%。通过对实时监测数据的分析及时修正偏差, 所有患者的受照剂量偏差均在±5%以内, 上述部位的剂量偏差中位数分别降为0.35%、-1.05%、0.60%、0.20%、-2.55%、1.20%和0.85%。  结论  实时剂量监测是实施全身照射的必要质控手段。     

Exsanguinating hemorrhage from a caput medusae: cutaneous variceal bleeding.

We report the case of a 45-year-old female who presented to the emergency department with massive umbilical hemorrhage from a cutaneous varix. The patient had a long-standing history of alcohol-related liver disease and ascites. Her clinical course was complicated by coagulopathy and hemorrhagic shock, and she ultimately expired. Ectopic or nongastroesophageal bleeding constitutes a significant site of variceal hemorrhage. In this report we review the literature and explore methods of treatment.     

Computational dose visualization & comparison in total skin electron treatment suggests superior coverage by the rotational versus the Stanford technique

Introduction/BackgroundThe goal of Total Skin Electron Therapy (TSET) is to achieve a uniform surface dose, although assessment of this is never really done and typically limited points are sampled. A computational treatment simulation approach was developed to estimate dose distributions over the body surface, to compare uniformity of (i) the 6 pose Stanford technique and (ii) the rotational technique.MethodsThe relative angular dose distributions from electron beam irradiation was calculated by Monte Carlo simulation for cylinders with a range of diameters, approximating body part curvatures. These were used to project dose onto a 3D body model of the TSET patient's skin surfaces. Computer animation methods were used to accumulate the dose values, for display and analysis of the homogeneity of coverage.ResultsThe rotational technique provided more uniform coverage than the Stanford technique. Anomalies of under dose were observed in lateral abdominal regions, above the shoulders and in the perineum. The Stanford technique had larger areas of low dose laterally. In the rotational technique, 90% of the patient's skin was within ±10% of the prescribed dose, while this percentage decreased to 60% or 85% for the Stanford technique, varying with patient body mass. Interestingly, the highest discrepancy was most apparent in high body mass patients, which can be attributed to the loss of tangent dose at low angles of curvature.Discussion/ConclusionThis simulation and visualization approach is a practical means to analyze TSET dose, requiring only optical surface body topography scans. Under- and over-exposed body regions can be found, and irradiation could be customized to each patient. Dose Area Histogram (DAH) distribution analysis showed the rotational technique to have better uniformity, with most areas within 10% of the umbilicus value. Future use of this approach to analyze dose coverage is possible as a routine planning tool.     

Efficacy and safety of prone positioning for patients with acute respiratory distress syndrome

This article presents an overview of a literature review on how prone positioning can alleviate pathophysiological changes in ARDS and improve ventilation and perfusion. Improvement of gas exchange, efficiency of oxygenation and lung function are emphasized. Literature on the pathophysiology of ARDS, and the physiological effects of prone positioning on haemodynamics and lung function is examined. There are both advantages and disadvantages in turning a patient from the supine to the prone position. There are also contraindications in rotating between the supine and prone positions. Nevertheless, by rotating patients with ARDS, it is possible to achieve a significant improvement in A-aDO2, decrease shunting, and therefore improve oxygenation without use of expensive, invasive and experimental procedures. Placing patients with ARDS in the prone position can reduce inspiratory oxygen concentrations and peak inspiratory pressures, which minimizes the chance for barotrauma and the iatrogenic effects of hyperventilation oxygen toxicity.     

The reliability of CT numbers as absolute values for diagnostic scanning,dental imaging,and radiation therapy simulation: A narrative review

Background and purposeThe purpose of this review was to examine the reported factors that affect the reliability of Computed Tomography (CT) numbers and their impact on clinical applications in diagnostic scanning, dental imaging, and radiation therapy dose calculation.MethodsA comprehensive search of the literature was conducted using Medline (PubMed), Google Scholar, and Ovid databases which were searched using the keywords CT number variability, CT number accuracy and uniformity, tube voltage, patient positioning, patient off-centring, and size dependence. A narrative summary was used to compile the findings under the overarching theme.DiscussionA total of 47 articles were identified to address the aim of this review. There is clear evidence that CT numbers are highly dependent on the energy level applied based on the effective atomic number of the scanned tissue. Furthermore, body size and anatomical location have also indicated an influence on measured CT numbers, especially for high-density materials such as bone tissue and dental implants. Patient off-centring was reported during CT imaging, affecting dose and CT number reliability, which was demonstrated to be dependent on the shaping filter size.ConclusionCT number accuracy for all energy levels, body sizes, anatomical locations, and degrees of patient off-centring is observed to be a variable under certain common conditions. This has significant implications for several clinical applications. It is crucial for those involved in CT imaging to understand the limitations of their CT system to ensure radiologists and operators avoid potential pitfalls associated with using CT numbers as absolute values for diagnostic scanning, dental imaging, and radiation therapy dose calculation.     

Hypocalcaemia‐induced tetany secondary to total thyroidectomy: a nursing case review

Presentations to the emergency department with a diagnosis of hypocalcaemia‐induced tetany secondary to total thyroidectomy are rare. A patient presented to the emergency department of a regional Australian hospital with hypocalcaemia‐induced tetany. A case study was employed to reflect on the care provided and identify knowledge practice deficits within this unusual patient presentation. Calcium plays a central role within the nervous system and is vital for both cardiac and muscular contraction. The clinical manifestations of electrolyte disturbances such as hypocalcaemia can be life threatening, and therefore, appropriate assessment, monitoring and management are essential to ensure positive patient outcomes. Understanding the importance of calcium imbalance for the emergency and critical care nurse is paramount in preventing complications associated with cardiac conduction and muscle tone, especially the potential for airway compromise. Education is central to this and may include clinical case reviews, the application of pathophysiological presentations of electrolyte imbalance and a review of electrolyte administration guidelines. Understanding the role of calcium within the body will assist emergency and critical care nurses to assess, monitor and intervene appropriately, thereby preventing the life‐threatening manifestations of hypocalcaemia.     

Application of a modified surgical position in anterior approach for total cervical artificial disc replacement

BACKGROUND Total cervical artificial disc replacement(TDR)has been considered a safe and effective alternative surgical treatment for cervical spondylosis and degenerative disc disease that have failed to improve with conservative methods.Positioning the surgical patient is a critical part of the procedure.Appropriate patient positioning is crucial not only for the safety of the patient but also for optimizing surgical exposure,ensuring adequate and safe anesthesia,and allowing the surgeon to operate comfortably during lengthy procedures.The surgical posture is the traditional position used in anterior cervical approach;in general,patients are in a supine position with a pad under their shoulders and a ring-shaped pillow under their head.AIM To investigate the clinical outcomes of the use of a modified surgical position versus the traditional surgical position in anterior approach for TDR.METHODS In the modified position group,the patients had a soft pillow under their neck,and their jaw and both shoulders were fixed with wide tape.The analyzed data included intraoperative blood loss,position setting time,total operation time,and perioperative blood pressure and heart rate.RESULTS Blood pressure and heart rate were not significantly different before and after body positioning in both groups(P>0.05).Compared with the traditional position group,the modified position group showed a statistically significantly longer position setting time(P<0.05).However,the total operation time and intraoperative blood loss were significantly reduced in the modified position group compared with the traditional position group(P<0.05).CONCLUSION The clinical outcomes indicated that total operation time and intraoperative blood loss were relatively lower in the modified position group than in the traditional position group,thus reducing the risks of surgery while increasing the position setting time.The modified surgical position is a safe and effective method to be used in anterior approach for TDR surgery.     

Migraine aggravation caused by cephalic venous congestion

BACKGROUND: Cerebral venous distension is thought by some to serve as a source of migraine pain. Previous investigators have tried to modify pain intensity by induction of additional venous congestion via compression of both internal jugular veins (Queckenstedt's maneuver). The magnitude of blood flow within the internal jugular veins depends markedly on body position, and inconsistencies in positioning may have influenced their results. OBJECTIVE: To investigate the effect of Queckenstedt's maneuver, performed both in the upright and in the supine body position, in migraineurs during an acute attack. METHODS: Twenty-five patients (18 women, 7 men; mean age +/- SD, 35.4 +/- 13.3 years) with International Headache Society-defined migraine without aura were evaluated. Queckenstedt's maneuver was performed in both body positions during an acute migraine attack, involving constant application of manual pressure to both internal jugular veins for 30 seconds. Headache intensity was rated before, during, and after Queckenstedt's maneuver on a scale extending from 1 (mild) to 10 (intolerable). RESULTS: Seventeen patients (68%) reported an increase of headache intensity in the supine position during Queckenstedt's maneuver. In the sitting position, pain increase was observed only in 6 patients (24%). The magnitude of pain increase was significantly greater in the supine position compared to the upright position (P=.02). CONCLUSIONS: Our results support a role for cerebral venous congestion in the generation of migraine pain and suggest body position may influence the clinical expression of that process.     

A systematic review of salivary gland hypofunction and xerostomia induced by cancer therapies: prevalence, severity and impact on quality of life

Purpose

This systematic review aimed to assess the literature for prevalence, severity, and impact on quality of life of salivary gland hypofunction and xerostomia induced by cancer therapies.

Methods

The electronic databases of MEDLINE/PubMed and EMBASE were searched for articles published in English since the 1989 NIH Development Consensus Conference on the Oral Complications of Cancer Therapies until 2008 inclusive. Two independent reviewers extracted information regarding study design, study population, interventions, outcome measures, results and conclusions for each article.

Results

The inclusion criteria were met by 184 articles covering salivary gland hypofunction and xerostomia induced by conventional, 3D conformal radiotherapy or intensity-modulated radiotherapy in head and neck cancer patients, cancer chemotherapy, total body irradiation/hematopoietic stem cell transplantation, radioactive iodine treatment, and immunotherapy.

Conclusions

Salivary gland hypofunction and xerostomia are induced by radiotherapy in the head and neck region depending on the cumulative radiation dose to the gland tissue. Treatment focus should be on optimized/new approaches to further reduce the dose to the parotids, and particularly submandibular and minor salivary glands, as these glands are major contributors to moistening of oral tissues. Other cancer treatments also induce salivary gland hypofunction, although to a lesser severity, and in the case of chemotherapy and immunotherapy, the adverse effect is temporary. Fields of sparse literature included pediatric cancer populations, cancer chemotherapy, radioactive iodine treatment, total body irradiation/hematopoietic stem cell transplantation, and immunotherapy.     

光生物调节修复运动性肌肉损伤

背景：不习惯强度的运动常导致运动性肌肉损伤,光生物调节治疗运动性肌肉损伤的研究存存不同的结果,且其治疗机制及其量效关系尚不清楚。目的：总结和分析光生物调节作用的机制以及光生物调节疗法治疗运动性肌肉损伤时的剂量、强度、波长等与效应之间的关系。方法：通过PubMed数据库（1996-01／2010-04）和中国学术期刊库（2000-01／2010-04）检索了低强度激光或单色光对运动性肌肉损伤的作用及其相关机制的文献,英文检索词为“low-level laser,phototherapy,exercise-inducedmuscledamage,delayed onset muscle soreness”,中文榆索洲为“低强度激光,光疗法,运动性肌肉损伤,延迟性肌肉酸痛”。手工补充检索低强度激光疗法的专著。共收集到中、英文文献38篇,排除重复及类似性研究,纳入31篇文献进行综述。结果与结论：光生物调节作刚的机制假说主要包括线粒体机制、‘氧化氮机制、氧化还原机制和光生物信息模型理论,光生物调节疗法治疗运动性且儿肉损伤的具体机制仍不清楚。光￡削勿调节治疗运动性肌肉损伤只有在剂最和强度达到足够大情况下才有效,而阻强度町能比荆量更重要,患邮的有效照射剂量和强度受到歧肽厚度和光波波长的影响。由此推论,光生物调节疗法能有效地治疗运动性肌肉损伤,其疗效是剂量和强度依赖性的。     

Thyroid crises

In the setting of characteristic features of thyrotoxicosis, the timely diagnosis and aggressive management of thyroid storm should result in a successful outcome. However, severe storm may lead to irreversible cardiovascular collapse, especially in the older patient who may have atypical features of thyrotoxicosis. The fundamental approach is prompt and optimal treatment in the emergency department once the presenting clinical features suggest its presence. Delay in the introduction of therapy while awaiting laboratory confirmation may result in further decompensation and death. The prevention of myxedema coma entails paying special attention to certain high-risk patient groups. These groups include older women with a history of Hashimoto's thyroiditis, or previous irradiation or thyroid surgery for hyperthyroidism. Inform such patients of the symptoms and signs of hypothyroidism, and perform annual thyroid function tests, such as a serum TSH, in order to provide early, adequate treatment once the test becomes positive.     

Ventilator associated pneumonia: perspectives on the burden of illness

Objective: The objective of this narrative review is to summarize selected current concepts and clinical evidence regarding the burden of illness of VAP, including its epidemiology, diagnosis, attributable mortality and risk factors.¶Data Sources & Selection: Studies were identified through MEDLINE, EMBASE, bibliographies of primary and review articles and personal files.¶Results: While cross sectional studies inform us about VAP prevalence, longitudinal studies inform us of the cumulative risk and conditional risk of developing VAP. Reported VAP rates are modulated by factors related to case mix, causative micro-organisms, interventions that influence risk over time, and VAP definitions employed. Population-specific and organism-specific VAP rates are needed to avoid misleading benchmarking between different ICUs, and to minimize inappropriate between-study comparisons. Observational studies have shown that invasive sampling techniques versus non-invasive approaches to diagnose VAP facilitates more targeted antibiotic treatment; however, the influence of the diagnostic method on endpoints such as mortality is less clear. VAP is associated with approximately a 4 day increase in length of ICU stay and an attributable mortality of approximately 20–30 %. Fixed VAP risk factors include underlying cardiorespiratory disease, neurologic injury and trauma. Modifiable VAP risk factors include supine body position, witnessed aspiration, paralytic agents and antibiotic exposure. If modifiable risk factors tested in randomized trials lower VAP rates, such as semirecumbency versus supine positioning, these represent effective VAP prevention strategies.¶Conclusions: Ventilator-associated pneumonia is a major morbid outcome among critically ill patients. Studies evaluating more effective prevention and treatment strategies are needed.     

Effect of body position on pulmonary function

Pulmonary physical therapy has focused largely on improving ventilation. Bronchial drainage techniques have incorporated body positioning to effect gravity-assisted mucous clearance and to enhance air entry. Body position directly affects ventilation and perfusion matching and arterial oxygen levels. This article briefly describes the role of body positioning on lung function and the clinical implications of this as a treatment priority. The effect of body position on arterial oxygen levels and lung function is discussed for the following positions: erect, lean forward, supine, lateral, prone, head-down tilt, hands and knees, and upside down. The implications of these positions are discussed for both the patient who has lung dysfunction and for the individual who may be at risk for developing pulmonary complications. Research is needed to investigate the principles of therapeutic positioning for optimal gas exchange and lung function. Such work may help to refine pulmonary physical therapy procedures and to identify the role of judicious positioning in a therapeutic exercise regimen.