The burden of heat-related mortality attributable to recent human-induced climate change.

Climate change affects human health; however, there have been no large-scale, systematic efforts to quantify the heat-related human health impacts that have already occurred due to climate change. Here, we use empirical data from 732 locations in 43 countries to estimate the mortality burdens associated with the additional heat exposure that has resulted from recent human-induced warming, during the period 1991-2018. Across all study countries, we find that 37.0% (range 20.5-76.3%) of warm-season heat-related deaths can be attributed to anthropogenic climate change and that increased mortality is evident on every continent. Burdens varied geographically but were of the order of dozens to hundreds of deaths per year in many locations. Our findings support the urgent need for more ambitious mitigation and adaptation strategies to minimize the public health impacts of climate change.

The effects of hot nights on mortality in Barcelona, Spain.

Heat-related effects on mortality have been widely analyzed using maximum and minimum temperatures as exposure variables. Nevertheless, the main focus is usually on the former with the minimum temperature being limited in use as far as human health effects are concerned. Therefore, new thermal indices were used in this research to describe the duration of night hours with air temperatures higher than the 95% percentile of the minimum temperature (hot night hours) and intensity as the summation of these air temperatures in degrees (hot night degrees). An exposure-response relationship between mortality due to natural, respiratory, and cardiovascular causes and summer night temperatures was assessed using data from the Barcelona region between 2003 and 2013. The non-linear relationship between the exposure and response variables was modeled using a distributed lag non-linear model. The estimated associations for both exposure variables and mortality shows a relationship with high and medium values that persist significantly up to a lag of 1-2 days. In mortality due to natural causes, an increase of 1.1% per 10% (CI95% 0.6-1.5) for hot night hours and 5.8% per each 10° (CI95% 3.5-8.2%) for hot night degrees is observed. The effects of hot night hours reach their maximum with 100% and lead to an increase by 9.2% (CI95% 5.3-13.1%). The hourly description of night heat effects reduced to a single indicator in duration and intensity is a new approach and shows a different perspective and significant heat-related effects on human health.

Winter circulation weather types and hospital admissions for respiratory diseases in Galicia, Spain.

The link between various pathologies and atmospheric conditions has been a constant topic of study over recent decades in many places across the world; knowing more about it enables us to pre-empt the worsening of certain diseases, thereby optimizing medical resources. This study looked specifically at the connections in winter between respiratory diseases and types of atmospheric weather conditions (Circulation Weather Types, CWT) in Galicia, a region in the north-western corner of the Iberian Peninsula. To do this, the study used hospital admission data associated with these pathologies as well as an automatic classification of weather types. The main result obtained was that weather types giving rise to an increase in admissions due to these diseases are those associated with cold, dry weather, such as those in the east and south-east, or anticyclonic types. A second peak was associated with humid, hotter weather, generally linked to south-west weather types. In the future, this result may help to forecast the increase in respiratory pathologies in the region some days in advance.

Assessment of quality of life in adolescent patients with orthopaedic problems: are adult measures appropriate?

New pressures of accountability brought on by a rapidly evolving system of health care financing have underscored the need for standardized, valid measures of patient outcome that reflect the effect of clinical intervention on all aspects of quality of life. In response, there has been a burgeoning interest in the area of outcomes assessment and measurement of quality of life after orthopaedic intervention in adults, but less attention has been focused on the assessment of broadly defined outcomes in children. In an effort to borrow from the broader adult experience in this area, the authors sought to examine whether the Medical Outcomes Study Short Form 36 (SF-36) or the EuroQol questionnaire, widely accepted adult health status measures, would be valid in this setting. These two measures were administered to 196 adolescent patients (10-18 years old) seeking orthopaedic evaluation. Tests of scale properties and construct validity show that these properties are maintained in this population, but neither instrument reflected known differences in health status among this cohort. Most importantly, both the SF-36 and the EuroQol exhibited serious ceiling effects (most respondents scored at the top of their scales), despite evidence indicating those patients often had suboptimal health status. Thus, neither the SF-36 nor the EuroQol is valid for use in this population. The assessment of pediatric health status demands outcomes measures specifically designed to reflect the unique needs of this population.

Capturing quality of life in pediatric orthopaedics: two recent measures compared.

There is a clear need for standardized measures to assess health status that are valid and appropriate to the needs of children with orthopaedic problems. The Child Health Questionnaire and the American Academy of Orthopaedic Surgeons Pediatric Outcomes Data Collection Instrument, two new pediatric health status measures, were assessed for their ability to detect differences in health states in a pediatric orthopaedic population. The instruments have a range of scales designed to measure various aspects of physical and psychosocial health. Two hundred forty-two patients with wide-ranging diagnoses were enrolled in this cross-sectional study. The instruments exhibited ceiling effects in some domains but generally performed as they were intended in this large cohort. Using secondary factor analysis, it was shown that the domains of the instruments appropriately distinguish physical and psychosocial health. Several domains from each instrument discriminated between diagnosis groups and patients with varying numbers of comorbidities. Both of these measures show significant promise and have an important role in helping define the outcomes of children with orthopaedic problems.

Patient-based outcomes after clubfoot surgery.

Despite decades of experience in the area of clubfoot repair, considerable uncertainty remains regarding indications, surgical technique, and long-term results of treatment. Much of this uncertainty is due to the lack of a standardized and valid method for assessing postoperative outcomes of clubfoot repair. The current study used various end points to compare traditional and patient-based outcome measures and to develop a disease-specific instrument that is both meaningful to the patient and statistically valid. A cohort of 46 patients was identified, and several types of outcomes data were collected, including traditional end points of outcome (range of motion and radiographic criteria, qualitative patient-based data) and a previously validated instrument measuring pediatric functional status (FSIIr). At an average follow-up of 45 months, radiographic measures and range of motion were comparable to values published in previous studies. Postoperative functional status, as measured by the FSIIr, did not differ from that of age-matched controls. Psychometric analysis of these data allowed us to generate a 10-item disease-specific instrument (DSI), which conveyed patient-based attitudes toward outcome.

Surgical treatment of the child's and adolescent's flexible flatfoot.

Operative intervention for juvenile flexible flatfoot is considered after a protracted course of orthotics and shoe modifications have failed to relieve associated symptoms. Surgical treatment options include hindfoot fusion, soft tissue procedures, calcaneal osteotomies, limited midtarsal arthrodeses, combination techniques, and subtalar arthroereisis. Long-term, high success rates have been documented with use of combination procedures and the anterior calcaneal osteotomy of Evans.

Extent of surgery for intermediate-risk well-differentiated thyroid cancer.

BACKGROUND: Methods of assigning patients with papillary or follicular thyroid cancer (well-differentiated thyroid cancer) to risk groups for the purpose of determining appropriate therapy have been developed. Despite these efforts, the optimal extent of surgery for intermediate-risk patients remains controversial. METHODS: A retrospective study was conducted of 208 patients with well-differentiated thyroid cancer (DTC) from two institutions. Univariate and multivariate analysis of patient- and tumor-related variables was performed. A regression model was obtained, three risk groups (low, intermediate, and high) were defined, and survival curves were generated. RESULTS: Prognostic variables were age (P <0.001), distant metastases (P <0.001), tumor size (P <0.001) and an aggressive growth pattern (P = 0.03) by univariate analysis and age (P <0.001) and distant metastases (P <0.001) by multivariate analysis. Tumor size (P = 0.07) was included in the regression model. Total thyroidectomy appeared to provide a survival advantage for intermediate risk patients. High-risk patients treated by lobectomy had a poorer prognosis. CONCLUSIONS: Total thyroidectomy may provide a survival advantage for intermediate-risk patients with DTC. A prospective randomized trial with 200 such patients is required to confirm this finding.

Superior mesenteric artery syndrome after segmental instrumentation: a biomechanical analysis.

Superior mesenteric artery (SMA) syndrome is a rare complication that occurs after correction of scoliosis. A review of the literature suggests that the incidence of this syndrome may be decreasing, as methods for the correction of scoliosis have improved. We present the first report of SMA syndrome that occurred after segmental 'derotational' instrumentation. Computerized axial tomography was helpful in suggesting the diagnosis of this condition. The risk factors and pathophysiology of SMA syndrome are reviewed with respect to the biomechanical effects of casting and Harrington and segmental instrumentation systems on the spine. Attention to the three-dimensional nature of the scoliotic deformity, particularly in the sagittal plane, may help to predict those at risk for the development of this potentially fatal syndrome.

Valproate therapy: predisposition to bone fracture?

A 13-year-old girl on valproate therapy had 20 fractures over a 4-year period between the ages of 5 years and 9 years. Once valproate was withdrawn, no further fractures occurred over the ensuing 4 years. Three other children manifested at least two fractures while on valproate antiepileptic therapy. These reports suggest that valproate, along with other known causes of demineralization (e.g., lack of exercise, diet, and genetic factors), predisposes patients to fractures.

The effectiveness of preoperative erythropoietin in averting allogenic blood transfusion among children undergoing scoliosis surgery.

Concerns about the transmission of the human immunodeficiency virus (HIV) have driven the evolution of surgical transfusion practices including the use of preoperative erythropoietin (rhEPO). Although there is significant experience documenting the efficacy of preoperative rhEPO in reducing transfusion requirements for adult patients, there is little experience in the pediatric population. With 178 pediatric patients who underwent surgery for spinal deformity, a retrospective cohort study was performed using patient charts, administrative records, and blood bank computer data. Of these patients, 44% received erythropoietin and 55% did not. From the entire population, 17.5% were in the rhEPO treatment group that received homologous blood transfusion compared with 30.6% in the untreated group (p < 0.05). Among the children with idiopathic scoliosis, this effect was more pronounced, with 3.9% of rhEPO patients receiving blood transfusion compared with 23.5% of nontreated patients (p = 0.006). Additionally, rhEPO treatment was associated with a significantly decreased length of stay only for patients in the idiopathic group (9.3 vs. 6.7, p = 0.02). Use of preoperative erythropoietin in pediatric patients undergoing scoliosis surgery resulted in higher preoperative hematocrit levels. Significantly lower rates of transfusion were noted only in the idiopathic group, however. Although there is a possibility of erythropoietin "resistance" in the neuromuscular and congenital patients, alternative explanations for the lack of effect on transfusion rates may include underdosing and biases existent in this nonrandomized retrospective study.

The sagittal pelvic tilt index as a criterion in the evaluation of spondylolisthesis. Preliminary observations.

STUDY DESIGN: Radiographic analysis of a pediatric population with spondylolisthesis was performed to examine sagittal plane pelvic rotation and degree of slip over time. OBJECTIVES: To determine whether the degree of standing sagittal offset of L5 with respect to the acetabulum correlated with slip progression and symptoms. SUMMARY OF BACKGROUND DATA: The natural history of isthmic spondylolisthesis remains unclear. Attempts to predict slip progression in the clinical setting, and thus the possible need for eventual surgical intervention, remain imprecise. Predicting slip progression based on sagittal alignment of the L5 vertebra with respect to the acetabulum has been proposed by some investigators. METHODS: Fifty-two children and adolescents were followed clinically and radiographically for an average of 5.6 years. Serial lateral standing radiographs that included the hips and lumbar spine were measured to compute a sagittal pelvic tilt index. The latter value is a ratio of relative distances from the center of S2 to the projection of L5 and the center of the femoral heads on the horizontal. RESULTS: Of the 52 patients studied, 38 have remained asymptomatic without significant slip progression or change in sagittal pelvic tilt index ratio. Of the original group, 13 patients had significant symptoms and revealed a decrease in the sagittal pelvic tilt index over time. Eight of the 13 stabilized at the end of adolescence, whereas 5 had continued decrease in the sagittal pelvic tilt index ratio. These five required operative treatment for pain and progressive slip. CONCLUSIONS: The sagittal pelvic tilt index gives the examiner an objective measure of the stability of the lumbosacral junction by quantifying the relationship between S2, the center of the hip, and L5. A decreasing sagittal pelvic tilt index ratio in this preliminary series correlated with slip progression and risk of conservative treatment failure, whereas those patients with a stable sagittal pelvic tilt index did not progress and remained clinically asymptomatic.

Lumbar gibbus in storage diseases and bone dysplasias.

OBJECTIVE: The objective of this study was to review the problem of lumbar gibbus in children with storage diseases and bone dysplasias utilizing plain films and MR imaging. MATERIALS AND METHODS: Clinical histories and radiographic images in five patients with storage diseases [four mucopolysaccharidosis (MPS) and one mucolipidosis] and two with achondroplasia were reviewed. The International Skeletal Dysplasia Registry (Los Angeles, Calif.), surveyed for all patients with lumbar gibbus and skeletal dysplasias, provided 12 additional cases. RESULTS: All patients had localized gibbus of the upper lumbar spine, characterized by anterior wedging and posterior displacement of the vertebrae at the apex of the curve, producing a beaked appearance. The curve, exaggerated in the sitting or standing position, was most severe in the two patients with MPS-IV (one of whom died). Both developed severe neurologic signs and symptoms requiring surgical intervention. In four patients, MR images demonstrated the apex of the curve to be at or below the conus. Two patients demonstrated anterior herniation of the intervertebral discs at the apex of the curve, though the signal intensity of the intervertebral discs was normal. CONCLUSION: Lumbar gibbus has important neurologic and orthopedic implications, and is most severe in patients with MPS. The etiology of the gibbus with vertebral beaking is multifactorial and includes poor truncal muscle tone, weight-bearing forces, growth disturbance and anterior disc herniation. The curve is generally at or below the conus. Neurologic complications are unusual, although orthopedic problems can arise. Due to their longer survival, patients with achondroplasia or Morquio's disease are more vulnerable to eventual gibbus-related musculoskeletal complications.

Intraoperative monitoring of motor evoked potentials: a review of 116 cases.

We reviewed the results of motor evoked potential (MEP) and somatosensory evoked potential (SEP) monitoring during 116 operations on the spine or spinal cord. We monitored MEPs by electrically stimulating the spinal cord and recording compound muscle action potentials from lower extremity muscles and monitored SEPs by stimulating posterior tibial or peroneal nerves and recording both cortical and subcortical evoked potentials. We maintained anesthesia with an N2O/O2/opioid technique supplemented with a halogenated inhalational agent and maintained partial neuromuscular blockade using a vecuronium infusion. Both MEPs and SEPs could be recorded in 99 cases (85%). Neither MEPs nor SEPs were recorded in eight patients, all of whom had preexisting severe myelopathies. Only SEPs could be recorded in two patients, and only MEPs were obtained in seven cases. Deterioration of evoked potentials occurred during nine operations (8%). In eight cases, both SEPs and MEPs deteriorated; in one case, only MEPs deteriorated. In four cases, the changes in the monitored signals led to major alterations in the surgery. We believe that optimal monitoring during spinal surgery requires recording both SEPs and MEPs. This provides independent verification of spinal cord integrity using two parallel but independent systems, and also allows detection of the occasional insults that selectively affect either motor or sensory systems.

Supracondylar femoral osteotomies for the correction of angular deformity about the knee in children. A follow-up study.

The results of 18 supracondylar osteotomies of the femur performed for angular deformity about the knee joint on 14 patients under the age of 18 years were reviewed. The mean follow-up was 46 months. Twelve of 18 osteotomies had a successful outcome. Six were considered failures due to recurrence of angular deformity despite bony union at the osteotomy site. Four of the six failures occurred in patients with metabolic bone disease. Special care needs to be taken when planning supracondylar osteotomies in patients with metabolic disease.

Severe mid-cervical kyphosis with cord compression in Larsen's syndrome and diastrophic dysplasia: unrelated syndromes with similar radiologic findings and neurosurgical implications.

Mid-cervical kyphosis in diastrophic dysplasia (DD) with cord compression and weakness has been recognized for the last three decades. A strikingly similar situation exists in Larsen's syndrome (LS), an otherwise unrelated problem of weakness with lay joints and dislocations with typical facies. Forty patients with DD were studied of whom seven had cervical spine kyphosis: one patient had spontaneous correction over the ensuing two decades. Seven patients with LS were studied of whom four had cervical spine changes with cord compression. There was one sudden death among the patients with LS and no cases of spontaneous correction. Muscle weakness in DD and LS should lead to evaluation of cervical spine kyphosis with cord compression. Plain films, CT and recently MRI are useful.

Non-union of pediatric fibula fractures: easy to overlook, painful to ignore.

Fracture non-union in the pediatric population may span the age range from childhood to adolescence. Fracture non-union in children and adolescents is often due to an underlying cause such as affliction with neurofibromatosis or osteogenesis imperfecta. Although less commonly seen, non-union may occur in the otherwise healthy pediatric population. We report three cases of fracture non-union of the distal end of the fibula in the pediatric age group. All three were characterized by persistent local pain and tenderness following injury with radiographic evidence of fracture non-union. All three had undergone conservative treatment with extended periods of immobilization. Following surgery, all three had marked improvement of their local symptomatology. One patient's course was complicated by reflex sympathetic dystrophy syndrome. In two patients, resection of the un-united fragment at the distal fibula resulted in marked relief from pain without any increase in ankle instability. We postulate that the fracture non-union resulted in a fibrotic reaction that was so extensive that ankle stability was maintained even after removal of the fracture fragment.