[Challenges to endoprosthetic reconstruction after tumor resection around the knee : Management of intra- and postoperative complications]. / Herausforderungen in der Tumorendoprothetik des Kniegelenks : Management von intra- und postoperativen Komplikationen.

BACKGROUND: The good functional outcomes of endoprosthetic knee reconstructions combined with modern oncosurgical concepts have resulted in a decreased rate of primary amputations following tumor resection in the region of the knee, thereby improving the quality of life of affected patients. OBJECTIVE: This study aimed to reappraise complications which are more common than in conventional arthroplasties performed for arthritis or trauma due to the complexity of the surgical procedures, the size of the endoprosthetic reconstructions, and neo-/adjuvant therapies. MATERIAL AND METHODS: Possible intra- and postoperative complications and treatment options are presented. RESULTS: Typical intraoperative complications include malalignment (axis, length, rotation) in implant positioning, unplanned soft tissue defects, impaired implant fixation due to poor bone stock, periprosthetic fractures, vessel/nerve injuries, and lesions/defects of the extensor mechanism. The relevant postoperative complication profile is characterized by local recurrences, periprosthetic infections, thromboembolic events, and mechanical failures (loosening, failure of the constraining mechanism). CONCLUSION: Depending on anatomic conditions and the systemic oncological status of the patient, these complications represent tremendous challenges to reconstructive management. Knowledge of the potential problems enables them to be avoided. This requires profound experience in oncosurgery and tumor endoprosthesis revisions.

Incidence of severe critical events in paediatric anaesthesia in the United Kingdom: secondary analysis of the anaesthesia practice in children observational trial (APRICOT study).

The anaesthesia practice in children observational trial of 31,127 patients in 261 European hospitals revealed a high (5.2%) incidence of severe critical events in the peri-operative period and wide variability in practice. A sub-analysis of the UK data was undertaken to investigate differences compared with the non-UK cohort in the incidence and nature of peri-operative severe critical events and to attempt to identify areas for quality improvement. In the UK cohort of 7040 paediatric patients from 43 hospitals, the overall incidence of peri-operative severe critical events was lower than in the non-UK cohort (3.3%, 95%CI: 2.9-3.8 vs. 5.8%, 95%CI: 5.5-6.1, RR 0.57, p < 0.001). There was a lower rate of bronchospasm (RR 0.22, 95%CI: 0.14-0.33; p < 0.001), stridor (RR 0.42, 95%CI: 0.28-0.65; p < 0.001) and cardiovascular instability (RR 0.69, 95%CI: 0.55-0.86; p = 0.001) than in the non-UK cohort. The proportion of sicker patients where less experienced teams were managing care was lower in the UK than in the non-UK cohort (10.4% vs. 20.4% of the ASA physical status 3 and 9% vs. 12.9% of the ASA physical status 4 patients). Differences in work-load between centres did not affect the incidence and outcomes of severe critical events when stratified for age and ASA physical status. The lower incidence of cardiovascular and respiratory complications could be partly attributed to more experienced dedicated paediatric anaesthesia providers managing the higher risk patients in the UK. Areas for quality improvement include: standardisation of serious critical event definitions; increased reporting; development of evidence-based protocols for management of serious critical events; development and rational use of paediatric peri-operative risk assessment scores; implementation of current best practice in provision of competent paediatric anaesthesia services in Europe; development of specific training in the management of severe peri-operative critical events; and implementation of systems for ensuring maintenance of skills.

Airway management in paediatric anaesthesia in Europe-insights from APRICOT (Anaesthesia Practice In Children Observational Trial): a prospective multicentre observational study in 261 hospitals in Europe.

BACKGROUND: Critical respiratory events are common in children in the peri-anaesthetic period and are caused by airway and ventilation management difficulties. We aimed to analyse current European paediatric airway management practices and identify the incidence and potential consequences of difficult airway management. METHODS: We performed a secondary analysis of airway and ventilation management details of the European multicentre observational trial (Anaesthesia PRactice in Children Observational Trial, APRICOT) of children from birth to 15 yr of age. The primary endpoint was the incidence of difficult airway management. Secondary endpoints were the associations between difficult airway management, known pre-existing respiratory risk factors, and the occurrence of critical respiratory events. RESULTS: Details for 31 024 anaesthetic procedures were available for analysis. Three or more tracheal intubation attempts were necessary in 120 children (0.9%) and in 40 children (0.4%) for supraglottic airways insertions. The incidence (95% confidence interval) for failed tracheal intubation and failed supraglottic airway insertions was 8/10 000 (0.08%; 0.03-0.13%) and 8.2/10 000 (0.08%; 0.03-0.14%) children, respectively. Difficulties in securing the airway increased the risk for a critical respiratory event for tracheal tube (2.1; 1.3-3.4) and supraglottic airway (4.3; 1.9-9.9) placement. History of pre-existing respiratory risk factors was significantly associated with critical respiratory events independently of the airway device used. CONCLUSIONS: Airway management practices vary widely across Europe. Multiple airway device insertion attempts and pre-existing respiratory risk factors increase the likelihood of critical respiratory events in children and require further stratification during preoperative assessment and planning. This study highlights areas where education, research, and training may improve perioperative care. CLINICAL TRIAL REGISTRATION: NCT01878760.

Drug safety in paediatric anaesthesia.

Life-threatening drug errors are more common in children than in adults. This is likely to be because of their variations in age and weight, combined with the occasional exposure of most anaesthetists to paediatric patients. Drug administration in anaesthesia is mostly undertaken by a single operator and thus represents a potentially greater risk compared with other areas of medicine. This increased risk is believed to be offset by anaesthetists working with only a limited number of drugs on a very frequent and repetitive basis. However, high rates of errors continue to be reported. Paediatric anaesthesia practice requires individual age- and weight-specific drug dose calculations and is therefore without a 'familiar' or 'usual' dose. The aim of this narrative systematic review of existing recommendations and current evidence of preventive strategies is to identify measures to enhance the safety and quality of drug administration in paediatric anaesthesia. This review collates and grades the evidence of such interventions and recommendations and assesses their feasibility. Most highly effective available measures require low or limited costs and labour. The presented solutions should, therefore, achieve a high level of acceptance and contribute significantly to safety and quality of care in paediatric anaesthesia.

Emergence delirium or pain after anaesthesia--how to distinguish between the two in young children: a retrospective analysis of observational studies.

BACKGROUND: Early postoperative negative behaviour in preschool children after general anaesthesia is a common problem. The distinction between emergence delirium (ED) and pain is difficult, but management differs between the two. The aim of the current analysis was to identify individual observational variables that can be used to diagnose ED and allow distinction from postoperative pain. METHODS: This retrospective analysis of data from three previous prospective observational studies included children undergoing general anaesthesia for elective adeno-tonsillectomy, sub-umbilical surgery, and MRI scanning. Two trained observers simultaneously applied the Face, Legs, Activity, Cry, Consolability Scale; the Children's Hospital Eastern Ontario Pain Scale; the Children's and Infants' Postoperative Pain Scale or the Paediatric Anaesthesia Emergence Delirium (PAED) scale. Data from each domain of the scales were available at awakening and at five, 10, and 15 min after anaesthesia. Each patient was analysed over time, and subsequently, each evaluation was considered as a single event. The descriptive behaviour items overlapping in the assessed scales were identified as dichotomous variable ('true/false') and then were applied for each evaluation. RESULTS: Children (n=512) were assessed for a total of 2048 evaluations. Most children (69%) displayed at least one episode of ED and/or pain. Almost 15% of children demonstrated both ED and pain. Children with ED showed 'no eye contact' and 'no awareness of surroundings'. Children with pain displayed 'abnormal facial expression', 'crying', and 'inconsolability'. CONCLUSIONS: 'No eye contact' and 'no awareness of surroundings' identifies ED. 'Abnormal facial expression', 'crying', and 'inconsolability' indicate acute pain in children in the early postoperative period.

Population pharmacokinetics of single-dose intravenous paracetamol in children.

BACKGROUND: To determine the pharmacokinetics (PK) of a new i.v. formulation of paracetamol (Perfalgan) in children ≤15 yr of age. METHODS: After obtaining written informed consent, children under 16 yr of age were recruited to this study. Blood samples were obtained at 0, 15, 30 min, 1, 2, 4, 6, and 8 h after administration of a weight-dependent dose of i.v. paracetamol. Paracetamol concentration was measured using a validated high-performance liquid chromatographic assay with ultraviolet detection method, with a lower limit of quantification (LLOQ) of 900 pg on column and an intra-day coefficient of variation of 14.3% at the LLOQ. Population PK analysis was performed by non-linear mixed-effect modelling using NONMEM. RESULTS: One hundred and fifty-nine blood samples from 33 children aged 1.8-15 yr, weight 13.7-56 kg, were analysed. Data were best described by a two-compartment model. Only body weight as a covariate significantly improved the goodness of fit of the model. The final population models for paracetamol clearance (CL), V(1) (central volume of distribution), Q (inter-compartmental clearance), and V(2) (peripheral volume of distribution) were: 16.51×(WT/70)(0.75), 28.4×(WT/70), 11.32×(WT/70)(0.75), and 13.26×(WT/70), respectively (CL, Q in litres per hour, WT in kilograms, and V(1) and V(2) in litres). CONCLUSIONS: In children aged 1.8-15 yr, the PK parameters for i.v. paracetamol were not influenced directly by age but were by total body weight and, using allometric size scaling, significantly affected the clearances (CL, Q) and volumes of distribution (V(1), V(2)).

Surgical management of recurrent thoracolumbar spinal sarcoma with 4-level total en bloc spondylectomy: description of technique and report of two cases.

INTRODUCTION: The descriptions of total spondylectomy and further development of the technique for the treatment of vertebral sarcomas offered for the first time the opportunity to achieve oncologically sufficient resection margins, thereby improving local tumor control and overall survival. Today, single level en bloc spondylectomies are routinely performed and discussed in the literature while only few data are available for multi-level resections. However, due to the topographic vicinity of the spinal cord and large vessels, the multisegmental resections are technically demanding, represent major surgery and only few case reports are available. Surgical options are even more limited in cases of revision surgery and local recurrences when en bloc spondylectomy was considered to be not feasible due to high risk of vital complications in expanding resection margins. Deranged anatomy, implants in situ and extensive intra-/paraspinal scar tissue formation resulting from previously performed approaches and/or radiation are considered the principal complicating factors that usually hold back spine surgeons to perform revision for resection leaving the patient to palliative treatment. METHODS: We present two patient cases with previously performed piecemeal vertebrectomy in the thoracic spine due to a solitary high-grade spinal sarcoma. After extensive re-staging, both patients underwent a multi (4)-level en bloc spondylectomy in our department (one patient with combined en bloc lung resection). Except a local wound disturbance, there was no severe intra- or postoperative complication. RESULTS: After multilevel en bloc spondylectomy both patients showed a good functional outcome without neurological deficits, except those resulting from oncologically scheduled resection of thoracic nerve roots. After a median follow-up of 13 months, there was no local recurrence or distant metastasis. The reconstruction using a posterior screw rod system that is interconnected to an anterior vertebral body replacement with a carbon composite cage showed no implant failure or loosening. In summary, the approach of a multilevel en bloc surgery for revision and oncologically sufficient resection in cases of spinal sarcoma recurrences seems possible. However, interdisciplinary decision making in a tumor board, realistic evaluation of surgical resectability to attain tumor free margins, advanced experiences in spinal reconstructions and involvement of vascular, visceral and thoracic surgical expertise are essential preconditions for acceptable oncological and functional outcome.

Functional resurfacing of the palm: flap selection based on defect analysis.

Extensive defect coverage of the palm and anatomical reconstruction of its unique functional capacity remains difficult. In manual laborers, reconstruction of sensation, range of motion, grip strength but also mechanical stability is required. Sensate musculo-/fasciocutaneous flaps bear disadvantages of tissue mobility with shifting/bulkiness under stress. Thin muscle and fascial flaps show adherence but preclude sensory nerve coaptation. The purpose of this review is to present our algorithm for reliable selection of the most appropriate procedure based on defect analysis. Defect analysis focusing on units of tactile gnosis provides information to weigh needs for sensation or soft tissue stability. We distinguish radial unit (r)-thenar, ulnar unit (u)-hypothenar and unit (c)-central plus distal palm. Individual parameters need similar consideration to choose adequate treatment. Unit (r) and unit (u) are regions of secondary touch demanding protective sensation. Restoration of sensation using neurovascular, fasciocutaneous flaps is recommended. In unit (c), tactile gnosis is of less, mechanical resistance of greater value. Reconstruction of soft tissue resistance is suggested first in this unit. In laborers, free fascial- or muscle flaps with plantar instep skin grafts may achieve near to anatomical reconstruction with minimal sensation. Combined defects involving unit (c) require correlation with individual parameters for optimal flap selection. Defect coverage of the palm should not consist of merely providing sensate vascularized tissue. The most appropriate procedure should be derived from careful defect analysis to achieve near to anatomical reconstruction. In laborers, defect related demands need close correlation with sensation and mechanical stability to be expected.

[Definition of the quality of hand surgery]. / Definition von Qualität in der Handchirurgie.

The quality of treatment within the total concept of the healthcare system is subject to multifactorial influences. With the intention to improve the quality of hand surgery the German Society for Hand Surgery (DGH) has initiated a number of projects. These include the S3 guidelines codeveloped by the DGH, the hand trauma register of the DGH, the definition of criteria for hand surgical procedures to be performed in an outpatient setting within the framework of a consensus recommendation as well as participation in a large epidemiological study with the special documentation of pathological alterations of the hand to determine the prevalences (study of health in Pomerania, SHIP); however, within these projects the quality of treatment itself is not assessed. In the attempt to document the quality, the currently available quality indicators in hand surgery probably only evaluate the aspects really relevant for the patients to a limited extent. Therefore, the DGH participated at an early stage in the development of assessments within the international study named by the WHO as a lighthouse project. These developed and validated assessments are intended to include all aspects of the results including the individual patient view in order to precisely relate the quality of treatment to an exactly defined pattern of hand injury. The use of these assessments should permanently enable a prediction of outcome quality for each individual patient. All these projects require the largest involvement possible to collect as much data as possible. With this intention the DGH further coordinates and develops these projects within the committees of the extended executive board and attempts to motivate as many surgeons as possible to participate.

Advanced ASDEX Upgrade pellet guiding system design.

Cryogenic pellet injection will be the prime candidate to fuel future fusion power plants. In order to harvest optimum fueling performance, it is essential to inject pellets from the magnetic high field side of the tokamak. The pellet launching system of the tokamak ASDEX Upgrade injects cryogenic hydrogen pellets with a speed of up to 1000 m/s from the magnetic high field side via curved guiding tubes. Pellets passing the guiding tube are sliding on a gas cushion, generated by the Leidenfrost effect. The actual track has a rectangular cross section and is composed of a series of ellipses in order to generate the required 270° looping type turn; the path length is 17 m. The last part of this track is marked by strong geometrical constraints from the vacuum vessel port. The previous design was composed of a sequence of three sections of ellipses too, tangentially constant but discontinuous with regard to the curvature. It had been in operation for almost 20 years. Its steps in the curvature are supposed to limit the system performance. A novel and advanced geometry concept, adopting a method well-known from civil engineering (e.g., for the railroad track design), has been applied to develop an improved design. It relies on clothoid shape sections keeping the track curvatures continuous and, thus, provides a smooth transition between all the elements. The new design presented improves the pellet launching system performance on ASDEX Upgrade and provides knowledge for an advanced design of pellet guiding tubes in future fusion devices.

Fluoroscopic guidance of Arndt endobronchial blocker placement for single-lung ventilation in small children.

BACKGROUND: Thoracoscopic surgery may require single-lung ventilation (SLV) in infants and small children. A variety of balloon-tipped endobronchial blockers exist but the placement is technically challenging if the size of the tracheal tube does not allow the simultaneous passage of the fibreoptic scope and the endobronchial blocker. This report describes a technique for endobronchial blocker insertion using fluoroscopic guidance in children undergoing SLV. METHODS: After approval from the local Medical Ethics Committee and parental consent, 18 patients aged 2 years or younger scheduled for thoracic surgery requiring SLV were prospectively included. Following induction of anesthesia, a 5 Fr endobronchial blocker (Cook) Arndt endobronchial blocker) was inserted first into the trachea under direct laryngoscopy. Correct placement in the main bronchus was assessed by fluoroscopy and tracheal intubation next to the endobronchial blocker. Optimal position and balloon inflation was verified using a fibreoptic scope. The duration and number of insertion attempts as well as age, weight and size of the tracheal tube were recorded. RESULTS: Eighteen patients were studied. Median (range) age and weight were 12 (0.2-24) months and 11.2 (4-15) kg, respectively. SLV was successfully achieved in all patients using a 5 Fr endobronchial blocker outside a 3.5-4.5 mm ID tracheal tube within 11.2 (+/-2.2) min. No side effects were observed during the procedure. CONCLUSION: Fluoroscopic-guided insertion of extraluminal endobronchial blocker is an effective and reliable tool to place Arndt endobronchial blockers in small children.

[About the self-reported quality of life after amputation of the hand in patients with upper extremity tumors]. / Zur Selbsteinschätzung der Lebensqualität von Tumorpatienten nach Amputation der Hand.

PURPOSE/BACKGROUND: Amputation proximal to the wrist may be oncologically dictated in cases of upper extremity soft tissue sarcoma and aggressive fibromatosis. Literature on functional long-term results and patient-oriented assessment is sparse. Our study is concerned with subjective impressions of quality of life and upper extremity health status and their importance in the evaluation and interpretation of results after amputation of the hand. PATIENTS/METHODS: Between 1999 and 2007, 14 patients (6 females/8 males; average age: 25 years) were operated because of a soft tissue sarcoma (n = 11) or aggressive fibromatosis (n = 3). Ten patients underwent limb-sparing surgery. There were two amputations at the level of the forearm. Local recurrence following forequarter amputation due to aggressive fibromatosis required reoperation in another patient. A heterotopic replantation after resection was carried out in one patient. In patients with amputations, the self-reported upper extremity-specific health status and quality of life were measured with the DASH score. Disturbances in body image and symptoms of depression were assessed psychiatrically. RESULTS: In two cases with amputations, minimal impairments in everyday life and a high reported quality of life were observed (DASH scores: 3,5). CONCLUSION: Self-reported upper extremity health status and quality of life following amputation of the hand can be in contrast to the objective pathology. In patient-oriented assessment of results, individual psychosocial factors that may affect results must be taken into consideration. They also must not be neglected when determining whether patients are suitable candidates for prosthetic devices.