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Mobile devices, such as smartphones, have become powerful enough to implement efficient speech-based and multimodal interfaces, and there is an increasing need for such systems. This chapter gives an overview of design and development issues necessary to implement mobile speech-based and multimodal systems. The chapter reviews infrastructure design solutions that make it possible to distribute the user interface between servers and mobile devices, and support user interface migration from server-based to distributed services. An example is given on how an existing server-based spoken timetable application is turned into a multimodal distributed mobile application.

Spinal surgery in adults can vary from simple to complex and can also have variable anticipated surgical blood loss. There are several factors that can put patients at increased risk for greater intraoperative blood loss. These factors, including a review of the literature, will be discussed.

This article reviews the extent of blood loss in spine surgery for scoliosis corrections in the pediatric age group. An extensive literature review presents blood loss values in surgery for adolescent idiopathic scoliosis, cerebral palsy, Duchenne muscular dystrophy, spinal muscular atrophy, and myelomeningocoele. The underlying disorder plays a major role in determining the extent of blood loss. Blood loss is considerably higher in those patients with a neuromuscular scoliosis compared with adolescent idiopathic scoliosis. Within the neuromuscular group those with Duchenne muscular dystrophy demonstrate the highest mean levels of blood loss. Blood loss is also shown to be progressively greater with increasing numbers of vertebral levels incorporated into the fusion, with posterior fusions compared to anterior fusions, and in those patients having both anterior and posterior fusions.

The problems linked to blood loss and blood-sparing techniques in spine surgery have been less studied than in other fields of orthopedics, such as joint-replacement procedures. Decreasing bleeding is not only important for keeping the patient’s hemodynamic equilibrium but also for allowing a better view of the surgical field. In spine surgery the latter aspect is especially important because of the vicinity of major and highly fragile neurologic structures. The techniques and agents used for hemostasis and blood sparing in spinal procedures are mostly similar to those used elsewhere in surgery. Their use is modulated by the specific aspects of spinal approach and its relation to the contents of the spinal canal. Blood-sparing techniques can be divided into two categories based on their goals: either they are aimed at decreasing the bleeding itself, or they are aimed at decreasing the need for homologous transfusion. Various hemodynamic techniques, as well as systemic and local drugs and agents, can be used separately or in combination, and their use in the field of spine surgery is reported. The level of evidence for the efficacy of many of those methods in surgery as a whole is limited, and there is a lack of evidence for most of them in spine surgery. However, several blood-saving procedures and drugs, as well as promising new agents, appear to be efficient, although their efficacy has yet to be assessed by proper randomized controlled trials.

The pharmacological methods used to achieve systemic hemostasis have generated much discussion due to concerns of serious adverse effects (e.g., thromboembolic complications) and costs of therapy in addition to efficacy considerations. There are a limited number of well-controlled trials involving pharmacological hemostasis for spine surgery. In the largest doubleblinded randomized controlled trial to date involving spine surgery, there was a trend toward reduced homologous transfusion in patients receiving aprotinin, but the only statistically significant result (<0.001) was a reduction in autologous red cell donations. The findings of this trial are important, since the investigators used a number of restrictive transfusion strategies (e.g., autologous donation, low hematocrit trigger for transfusion, blood-salvaging procedures with the exception of no cell saver) that were not always employed in earlier trials involving hemostatic agents. Smaller studies involving antifibrinolytic agents other than aprotinin have demonstrated reductions in blood loss and transfusion requirements in patients undergoing spine surgery, although the results were not always statistically significant. A very large randomized trial would be required to address comparative medication- and transfusion-related adverse events; such a trial involving patients undergoing cardiac surgery is currently being performed. Additionally, cost-effectiveness analyses are needed to help define the role of these agents based on the data that is available.

. Allogeneic blood transfusions (ABT) are often necessary in elective spine surgery because of perioperative blood loss. Preoperative autologous blood donation (PABD) has emerged as the principal means to avoid or reduce the need for ABT. Consequently, a multicentre study was conducted to determine the yield and efficacy of PABD in spine surgery and the possible role of recombinant human erythropoietin (EPO) in facilitating PABD.

. We retrospectively reviewed the hospital charts and blood bank records from all consecutive spine surgery patients who were referred for PABD. Data were obtained from two A-category hospital blood banks and one general hospital. Although we collected data from 1994, the analytic study period was from the last quarter of 1995 to December 2003. Fifty-four (7%) out of 763 patients referred for PABD were rejected, and medical records were available for 680 patients who were grouped into spinal fusion (556; 82%) and scoliosis surgery (124;18%). EPO was administered to 120 patients (17.6%). From 1999 to 2003, PABD steadily increased from 60 to 209 patients per year. . Overall, 92% of the patients were able to complete PABD, 71% were transfused, and almost 80% avoided ABT. PABD was more effective in fusions (86%) than in scoliosis (47%). Blood wastage was 38%, ranging from 18% for scoliosis to 42% for fusions. EPO allowed the results in the anaemic patients to be improved.

. Therefore, despite the limitations of this retrospective study, we feel that PABD is an excellent alternative to ABT in spine surgery. However, the effectiveness of PABD may be enhanced if associated with other blood-saving techniques.

Spine surgery may be associated with profuse intraoperative bleeding that often requires blood transfusions. In recent years several techniques have been developed to avoid allogenic transfusions and their potential complications to surgical patients. In this study we review and analyse the role of preoperative recombinant human erythropoietin (rHuEPO) administration in spine surgery as a blood conservation strategy. Between 1998 and 2002, a total of 250 patients scheduled for spine surgery were included in our bloodsparing program: 114 patients (group 1), operated on before rHuEPO approval (2000), underwent preoperative autologous blood donation (ABD) alone, and 136 patients operated on after rHuEPO approval (groups 2 and 3) received rHuEPO while undergoing ABD. Adding rHuEPO to ABD resulted in higher haemoglobin and haematocrit values the day of surgery, more ABD units retrieved per patient and, consequently, reduced allogenic transfusion requirements. The effectiveness of rHuEPO as the only preoperative blood conservation technique was evaluated in ten patients with a predicted blood loss of less than 30% of their total volume, scheduled for lumbar surgery. Data from these patients were matched with those from a similar group of patients who had undergone ABD. Patients receiving rHuEPO alone had higher haemoglobin levels the day of surgery than did patients in the ABD program. Neither group required allogenic transfusions. Conclusions: preoperative rHuEPO is useful for reducing allogenic blood requirements in elective spine surgery. In patients with an expected blood loss of around 50% of blood volume, rHuEPO improves ABD, minimising preoperative anaemia and increasing the number of ABD units collected. In patients with expected blood loss below 30% of total volume, rHuEPO administration may replace ABD.

Positioning on the surgical table is one of the most important steps in any spinal surgical procedure. The “prone position” has traditionally been and remains the most common position used to access the dorsolumbar-sacral spine. Over the years, several authors have focused their attention on the anatomy and pathophysiology of both the vascular system and ventilation in order to reduce the amount of venous bleeding, as well as to prevent other complications and facilitate safe posterior approaches. The present paper reviews the pertinent literature with the aim of highlighting the advantages and disadvantages of various frames and positions currently used in posterior spinal surgery.

Aprotinin is a potent pharmacological agent that reduces bleeding and limits blood transfusion requirements in current surgical practice. Many studies have been conducted in orthopedic surgery. In several trials performed in total hip replacement (THR) and total knee replacement (TKN) patients, aprotinin only moderately decreased blood-loss-replacement requirements. Conversely, when aprotinin was used in patients at high risk for bleeding (cancer, sepsis, redone surgery), it developed a potent hemostatic activity and decreased blood transfusion significantly. No increase in deep vein thrombosis and pulmonary embolism was observed. The only major side effect could be the potential occurrence of an anaphylactoid reaction. Prophylactic administration of aprotinin should be considered in extensive spine surgery and in high-risk major orthopedic operations. The decision to use aprotinin should be guided by a risk/ benefit analysis.

Patients who undergo major spinal surgery often require multiple blood transfusions. The antifibrinolytics are medications that can reduce blood-transfusion requirements in cardiac surgery and total knee arthroplasty. The present role of synthetic antifibrinolytics, especially tranexamic acid, in reducing perioperative blood-transfusion requirements in spine surgery is still unclear. The majority of studies exploring the role of these drugs in spine surgery have limited patient enrolment and report mixed results. The goal of the present review is to discuss the pharmacology of tranexamic acid briefly. A brief synopsis of the studies using the synthetic antifibrinolytics for spine surgery is presented. Finally, the potential risks and the benefits of antifibrinolytics are discussed.