A close-in giant planet escapes engulfment by its star.

When main-sequence stars expand into red giants, they are expected to engulf close-in planets1-5. Until now, the absence of planets with short orbital periods around post-expansion, core-helium-burning red giants6-8 has been interpreted as evidence that short-period planets around Sun-like stars do not survive the giant expansion phase of their host stars9. Here we present the discovery that the giant planet 8 Ursae Minoris b10 orbits a core-helium-burning red giant. At a distance of only 0.5 AU from its host star, the planet would have been engulfed by its host star, which is predicted by standard single-star evolution to have previously expanded to a radius of 0.7 AU. Given the brief lifetime of helium-burning giants, the nearly circular orbit of the planet is challenging to reconcile with scenarios in which the planet survives by having a distant orbit initially. Instead, the planet may have avoided engulfment through a stellar merger that either altered the evolution of the host star or produced 8 Ursae Minoris b as a second-generation planet11. This system shows that core-helium-burning red giants can harbour close planets and provides evidence for the role of non-canonical stellar evolution in the extended survival of late-stage exoplanetary systems.

A temperate Earth-sized planet with tidal heating transiting an M6 star.

Temperate Earth-sized exoplanets around late-M dwarfs offer a rare opportunity to explore under which conditions planets can develop hospitable climate conditions. The small stellar radius amplifies the atmospheric transit signature, making even compact secondary atmospheres dominated by N2 or CO2 amenable to characterization with existing instrumentation1. Yet, despite large planet search efforts2, detection of low-temperature Earth-sized planets around late-M dwarfs has remained rare and the TRAPPIST-1 system, a resonance chain of rocky planets with seemingly identical compositions, has not yet shown any evidence of volatiles in the system3. Here we report the discovery of a temperate Earth-sized planet orbiting the cool M6 dwarf LP 791-18. The newly discovered planet, LP 791-18d, has a radius of 1.03 ± 0.04 R⊕ and an equilibrium temperature of 300-400 K, with the permanent night side plausibly allowing for water condensation. LP 791-18d is part of a coplanar system4 and provides a so-far unique opportunity to investigate a temperate exo-Earth in a system with a sub-Neptune that retained its gas or volatile envelope. On the basis of observations of transit timing variations, we find a mass of 7.1 ± 0.7 M⊕ for the sub-Neptune LP 791-18c and a mass of [Formula: see text] for the exo-Earth LP 791-18d. The gravitational interaction with the sub-Neptune prevents the complete circularization of LP 791-18d's orbit, resulting in continued tidal heating of LP 791-18d's interior and probably strong volcanic activity at the surface5,6.

How useful is pre-referral pediatric spine imaging?

PURPOSE: Primary care physicians rely on radiology reports to confirm a scoliosis diagnosis and inform the need for spine specialist referral. In turn, spine specialists use these reports for triage decisions and planning of care. The objectives were to determine (1) the adequacy of index images to inform treatment decisions at the initial consultation and (2) the utility of index radiology reports for appropriate triage decisions. METHODS: A retrospective chart review was conducted including all idiopathic scoliosis patients seen for initial consultation, aged three to 18 years, between January 1 and April 30, 2021. A score out of five was generated based on the adequacy of index images to provide accurate Cobb angle measurements and determine skeletal maturity. Index images were considered inadequate if repeat imaging was necessary. Index radiology reports, associated imaging, and new imaging, if obtained at the initial consultation, were compared. RESULTS: Of the 94 patients reviewed, 79% (n = 74) required repeat imaging at the initial consultation, of which 74% (n = 55) were due to insufficient quality and/or limited field of view. Of index images available for review at the initial consult (n = 80), 41.2% scored five out of five, and 32.5% scored two or below. Comparing index radiology reports to initial visit evaluation with ≤ 60 days between imaging (n = 49), discrepancies in Cobb angle were found in 24.5% (95% CI 14.6, 38.1) of patients. The Risser stage was reported in 14% of index radiology reports. CONCLUSION: Although pre-referral pediatric spine radiographs serve a diagnostic purpose, most are inadequate for comprehensive idiopathic scoliosis evaluation. LEVEL OF EVIDENCE: III.

A Comparison of 2 Abbreviated Methods for Assessing Adolescent Bone Age: The Shorthand Bone Age Method and the SickKids/Columbia Method.

BACKGROUND: Radiographic assessment of bone age is critically important to decision-making on the type and timing of operative interventions in pediatric orthopaedics. The current widely accepted method for determining bone age is time and resource-intensive. This study sought to assess the reliability and accuracy of 2 abbreviated methods, the Shorthand Bone Age (SBA) and the SickKids/Columbia (SKC) methods, to the widely accepted Greulich and Pyle (GP) method. METHODS: Standard posteroanterior radiographs of the left hand of 125 adolescent males and 125 adolescent females were compiled, with bone ages determined by the GP method ranging from 9 to 16 years for males and 8 to 14 years for females. Blinded to the chronologic age and GP bone age of each child, the bone age for each radiograph was determined using the SBA and SKC methods by an orthopaedic surgery resident, 2 pediatric orthopaedic surgeons, and a musculoskeletal radiologist. Measurements were then repeated 2 weeks later after rerandomization of the radiographs. Intrarater and interrater reliability for the 2 abbreviated methods as well as the agreement between all 3 methods were calculated using weighted κ values. Mean absolute differences between methods were also calculated. RESULTS: Both bone age methods demonstrated substantial to almost perfect intrarater reliability, with a weighted κ ranging from 0.79 to 0.93 for the SBA method and from 0.82 to 0.96 for the SKC method. Interrater reliability was moderate to substantial (weighted κ: 0.55 to 0.84) for the SBA method and substantial to almost perfect (weighted κ: 0.67 to 0.92) for the SKC method. Agreement between the 3 methods was substantial for all raters and all comparisons. The mean absolute difference, been GP-derived and SBA-derived bone age, was 7.6±7.8 months, as compared with 8.8±7.4 months between GP-derived and SKC-derived bone ages. CONCLUSIONS: The SBA and SKC methods have comparable reliability, and both correlate well to the widely accepted GP methods and to each other. However, they have relatively large absolute differences when compared with the GP method. These methods offer simple, efficient, and affordable estimates for bone age determination, but at best provide an estimate to be used in the appropriate setting. LEVEL OF EVIDENCE: Diagnostic study-level III.

The effectiveness of booster seat use in motor vehicle collisions.

BACKGROUND: Alberta remains the only province in Canada without booster seat legislation. To date, analyses of booster seat effectiveness compared with seatbelt only use have demonstrated mixed findings using observational data. METHODS: This study uses Alberta police collision report data for the years 2010-2016, inclusive. Using a case-control study design, children aged four to eight years, who were reported by police to be injured (cases), were compared with uninjured controls for restraint use (seatbelt, booster seat or no restraint). Logistic regression was used to estimate the relation between booster seat use and injury with adjusted odds ratios (aORs) and 95% confidence intervals (CI), stratified by collision types. RESULTS: There were 12,922 children involved in collisions, of whom 570 were injured. Approximately 62% of all children included in the analysis were in a booster seat or safety seat at the time of collision. Crude analysis indicates higher odds of injury for seatbelt wearers compared with booster seat use (OR = 1.21; 95% CI: 1.02-1.44). Front-end vehicle-vehicle collisions, demonstrated higher odds of injury for seatbelt wearers relative to those in booster seats (aOR = 1.46; 95% CI: 1.03-2.07). CONCLUSION: This analysis indicates a protective effect of booster seats that varies depending on the type of collision and impact location. These regionally-specific injury data may encourage and inform policy on the use of booster seats. Moreover, stratification by collision type may be necessary to inform analyses on booster seat effectiveness.

Supracondylar Humerus Fractures in Older Children: Success of Closed Reduction and Percutaneous Pinning.

BACKGROUND: The incidence of supracondylar humerus (SCH) fracture declines and fracture types change as children grow. Optimal treatment method is unclear in older children. The aim of the study was to determine if fracture type and configuration of distal humerus fractures changes as patients approach skeletal maturity, and to assess the success of closed reduction and percutaneous pin (CRPP) in extra-articular SCH fractures in this transitional age group. METHODS: Inclusion criteria for this retrospective review were (1) distal humerus fractures with extension types 2 and 3, flexion type, T-type; (2) surgically managed, and (3) modified Sauvegrain score ≥1. Reviewed parameters included fracture type and configuration, grade of skeletal maturity, fixation technique, and loss of reduction. Primary analysis was to determine the distribution of fracture type and configuration with age or grade of skeletal maturity. Secondary analysis was used to determine the factors affecting treatment success of CRPP in extra-articular fractures. RESULTS: A total of 142 patients were included (58 males and 84 females). Fracture types revealed significant changes with increased age (P=0.031) and skeletal maturity grade (P<0.005). Skeletal maturity was a better predictor of changing fracture type than chronological age. T-type fractures were only seen in patients with modified Sauvegrain score ≥6 and flexion-type fractures were only seen in patients with modified Sauvegrain score ≤4. Loss of reduction rate after CRPP was 5%. The success of CRPP was not affected by age, sex, modified Sauvegrain score, fracture type, direction of displacement, coronal fracture pattern, number of pins or medial pin use. Fracture obliquity in the sagittal plane (P=0.05), suboptimal pin spread (P<0.01), and lack of bicolumnar fixation (P<0.01) were found as statistically significant factors associated with failed CRPP. CONCLUSION: The distribution of fracture type changed with increased age and skeletal maturity. CRPP of extra-articular fractures in older children is a reliable option regardless of the stage of skeletal maturity. Determinants of a good outcome include optimal pinning technique with adequate pin spread at the fracture site and bicolumnar fixation. LEVEL OF EVIDENCE: Level IV-retrospective case series.

Publisher Correction: A planet within the debris disk around the pre-main-sequence star AU Microscopii.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

A planet within the debris disk around the pre-main-sequence star AU Microscopii.

AU Microscopii (AU Mic) is the second closest pre-main-sequence star, at a distance of 9.79 parsecs and with an age of 22 million years1. AU Mic possesses a relatively rare2 and spatially resolved3 edge-on debris disk extending from about 35 to 210 astronomical units from the star4, and with clumps exhibiting non-Keplerian motion5-7. Detection of newly formed planets around such a star is challenged by the presence of spots, plage, flares and other manifestations of magnetic 'activity' on the star8,9. Here we report observations of a planet transiting AU Mic. The transiting planet, AU Mic b, has an orbital period of 8.46 days, an orbital distance of 0.07 astronomical units, a radius of 0.4 Jupiter radii, and a mass of less than 0.18 Jupiter masses at 3σ confidence. Our observations of a planet co-existing with a debris disk offer the opportunity to test the predictions of current models of planet formation and evolution.

Very regular high-frequency pulsation modes in young intermediate-mass stars.

Asteroseismology probes the internal structures of stars by using their natural pulsation frequencies1. It relies on identifying sequences of pulsation modes that can be compared with theoretical models, which has been done successfully for many classes of pulsators, including low-mass solar-type stars2, red giants3, high-mass stars4 and white dwarfs5. However, a large group of pulsating stars of intermediate mass-the so-called δ Scuti stars-have rich pulsation spectra for which systematic mode identification has not hitherto been possible6,7. This arises because only a seemingly random subset of possible modes are excited and because rapid rotation tends to spoil regular patterns8-10. Here we report the detection of remarkably regular sequences of high-frequency pulsation modes in 60 intermediate-mass main-sequence stars, which enables definitive mode identification. The space motions of some of these stars indicate that they are members of known associations of young stars, as confirmed by modelling of their pulsation spectra.

Consumption of Cow's Milk in Early Childhood and Fracture Risk: A Prospective Cohort Study.

Cow's milk is consumed by most North American children, yet the relationships between the volume and fat content of cow's milk consumed and childhood fracture risk are unclear. Our primary objectives in this study were to evaluate whether the volume or fat content of cow's milk consumed at 1-3 years of age was associated with the risk of fracture between 3 and 10 years of age. This was a prospective cohort study of 2,466 children enrolled in Toronto, Ontario, Canada, between 2008 and 2016. The primary exposure was volume of cow's milk consumed between the ages of 1 and 3 years, and the secondary exposure was average percentage of milk fat consumed by each child during the same period. The primary outcome was a parental report of child fracture at ages 3-10 years. In the primary and secondary adjusted analyses, no association between milk volume and fracture risk (adjusted relative risk = 1.04, 95% confidence interval: 0.87, 1.26) or between milk-fat content and fracture risk (adjusted relative risk = 1.05, 95% confidence interval: 0.84, 1.31) was observed. In this study, we did not identify a protective association of early childhood cow's milk volume or fat consumption with fracture risk in later childhood. Future prospective research is needed to understand whether cow's milk is beneficial for fracture prevention through the life course.

A wide star-black-hole binary system from radial-velocity measurements.

All stellar-mass black holes have hitherto been identified by X-rays emitted from gas that is accreting onto the black hole from a companion star. These systems are all binaries with a black-hole mass that is less than 30 times that of the Sun1-4. Theory predicts, however, that X-ray-emitting systems form a minority of the total population of star-black-hole binaries5,6. When the black hole is not accreting gas, it can be found through radial-velocity measurements of the motion of the companion star. Here we report radial-velocity measurements taken over two years of the Galactic B-type star, LB-1. We find that the motion of the B star and an accompanying Hα emission line require the presence of a dark companion with a mass of [Formula: see text] solar masses, which can only be a black hole. The long orbital period of 78.9 days shows that this is a wide binary system. Gravitational-wave experiments have detected black holes of similar mass, but the formation of such massive ones in a high-metallicity environment would be extremely challenging within current stellar evolution theories.

Identifying motorist characteristics associated with youth bicycle-motor vehicle collisions.

Objective: The objective of this study was to identify driver characteristics associated with youth bicycle-motor vehicle collisions in Alberta, Canada. Methods: Edmonton and Calgary police collision report data from the years 2010-2014 were used. From these data, motor vehicle collisions involving youth (<18 years old) were identified (cases). The controls were drivers who, over the same period, were involved in separate motor vehicle-only collisions but deemed not at fault using an automated culpability analysis. Control selection used the quasi-induced exposure method, assuming that not-at-fault drivers in collisions are representative of the typical driver (source population). Descriptive statistics, including proportions, medians, and interquartile ranges (as appropriate) were used to describe the characteristics of the case and control drivers. Purposeful variable selection techniques were used to inform multivariable logistic regression models and results are presented as adjusted odds ratios (aORs) and 95% confidence intervals (CIs). Results: Four hundred twenty-three drivers involved in youth bicycle-motor vehicle collisions were identified, as were 243,927 not-at-fault control drivers. Drivers >54 years old had higher odds of involvement in youth bicycle-motor vehicle collisions than drivers between 25 and 39 years old (aOR = 1.37; 95% CI, 1.03, 1.82). Compared to driving between 3:01 p.m. and 6:00 p.m., driving between 12:01 a.m. and 6:00 a.m. (aOR = 0.27; 95% CI, 0.11, 0.66), between 6:01 a.m. and 9:00 a.m. (aOR = 0.61; 95% CI, 0.44, 0.85), or between 9:01 a.m. and 12:00 p.m. (aOR = 0.26; 95% CI, 0.16, 0.41) had lower odds of bicyclist collision, whereas driving between 6:01 p.m. and 12:00 a.m. had higher odds (aOR = 1.34; 95% CI, 1.01, 1.79). Driving a truck/van had lower odds of bicyclist collision compared to driving a passenger car (aOR = 0.67; 95% CI, 0.48, 0.94). Conclusions: Culpability analysis is typically applied to motorists to identify transient exposures; however, this study used culpability analysis to select control drivers who could be compared with drivers involved in youth bicycle-motor vehicle collisions. This study highlights motorist characteristics in youth bicycle-motor vehicle collisions. In doing so, we hope to inform primary prevention strategies for motorists and the environment that will reduce collisions.

Risk of Recurrent Fracture: A Population-Based Study.

OBJECTIVES: To determine if children who sustain a fracture in childhood had an increased rate of fracture later in childhood or early adulthood. The a priori null hypothesis was that children who sustained a fracture would not have an increased rate of future fractures compared with children who did not sustain a fracture when controlling for important covariates. METHODS: This is a population-based retrospective cohort study using health care databases in Ontario. Approximately 2.5 million healthy children aged 0 to 15 years living in Ontario, Canada between April 1, 2003, and March 31, 2004, were included and followed for 7 years. The exposure was occurrence of any fracture during a 1-year baseline period. The main outcome was any fractures during a 7-year follow-up period. RESULTS: A total of 43 154 children suffered a fracture during the baseline year (17.5 fractures per 1000 child years). Children with a baseline fracture had a 60% higher rate of fracture (incidence rate ratio: 1.60; 95% confidence interval: 1.46-1.75; P < .0001) during the follow-up period after adjustment for sex, rurality, history of previous fracture, and the occurrence of other injuries (head and soft-tissue). CONCLUSIONS: The occurrence of a fracture during childhood was associated with an increased rate of future fractures compared with children who did not suffer a fracture. Attempting to improve childhood bone health by targeting children who present to a fracture clinic with multiple fracture risk factors may be a useful strategy for secondary prevention of fractures and may have beneficial effects on long-term bone health.

Child and adolescent bicycling injuries involving motor vehicle collisions.

BACKGROUND: Bicycle-related injuries are among the most common recreational injuries for children in Canada; moreover, bicycle-motor vehicle collisions often result in serious injuries. This study seeks to examine environmental, motorist, and bicyclist characteristics of bicycle-motor vehicle collisions that resulted in police reported severe injuries in youth (< 18 years old) bicyclists, in Alberta, Canada. FINDINGS: Using Calgary and Edmonton police collision reports, 423 youth bicycle-motor vehicle collisions were identified from 2010 to 2014. Forty-three (10.2%) of these collisions resulted in major/fatal (severe) injuries. These severe injury cases were compared with the 380 youth bicycle-motor vehicle collisions resulting in minor or no injury (controls) using classification tree and logistic regression analyses. There were no driver or bicyclist characteristics with a significant effect on the odds of severe injury to youth bicyclists; however, lower odds were found on each of: divided roads with no barrier (aOR = 0.36; 95% CI: 0.13-0.97) or during peak traffic time (aOR = 0.44; 95% CI: 0.16-0.99). CONCLUSION: Personal and environment characteristics should be considered in future research and interventions focused on reducing severe youth bicycle-motor vehicle collision injuries.

Adaptation of a Canadian culpability scoring tool to Alberta police traffic collision report data.

Objective: The objective of this study was to adapt a previously validated Canadian Culpability Scoring Tool (CCST) to Alberta police report data. Methods: Police traffic collision reports from motor vehicle (MV) collisions in Calgary and Edmonton (Alberta, Canada) from 2010 to 2014 were used. Adaptation of the CCST was completed with input from personnel within Alberta Transportation, contributing to face and content validity. Two research assistants, given only the information necessary for scoring, evaluated 175 randomly selected MV-MV collisions. Interrater agreement was estimated using kappa (k) and reported with 95% confidence intervals (CIs). Discussion of disagreements between the research assistants and consultation from Alberta Transportation informed the algorithm used in the Alberta Motor Vehicle Collision Culpability Tool (AMVCCT). The AMVCCT was automated and applied to all motorists involved in collisions. Binary logistic regression was used to examine characteristics of the culpable and nonculpable drivers and their effects were reported using odds ratios (ORs) with 95% CIs. Results: Interrater agreement for the random sample was excellent (k = 0.95; 95% CI, 0.92-0.99). Of those drivers hospitalized, 1,130 (37.54%) were rated not culpable and 1,880 (62.46%) were rated culpable. The odds of being culpable were higher for males than for females (OR = 1.43; 95% CI, 1.23-1.66). The odds of being culpable were higher in those impaired by alcohol than those considered "apparently normal" (OR = 61.10; 95% CI, 22.66-164.75). The odds of being deemed culpable, when compared with drivers >54 years old, were higher for those <25 years old (OR = 1.72; 95% CI, 1.35-2.20) and lower for those in the 40- to 54-year-old age group (OR = 0.78; 95% CI, 0.63-0.96). Driving between 12 a.m. and 6 a.m. resulted in higher odds of being culpable compare with all other 6-h time blocks. Direction and statistical significance remained consistent when applying the tool to all MV collisions. Sensitivity analysis including the removal of single vehicle collisions did not affect the direction or statistical significance of the main results. Conclusions: The AMVCCT identified a culpable group that exhibited characteristics expected in drivers who are at fault in collisions. The age groups 25-39 and 40-54 demonstrated different results than the CCST. However, this is the only difference that exists in the findings of the AMVCCT compared to the CCST and could exist due to differences between the driving populations in Alberta and British Columbia. It is possible to adapt the CCST to provinces outside British Columbia and, in doing so, we can identify risk factors for collision contribution and not-at-fault drivers who represent the driving population.

A giant planet undergoing extreme-ultraviolet irradiation by its hot massive-star host.

The amount of ultraviolet irradiation and ablation experienced by a planet depends strongly on the temperature of its host star. Of the thousands of extrasolar planets now known, only six have been found that transit hot, A-type stars (with temperatures of 7,300-10,000 kelvin), and no planets are known to transit the even hotter B-type stars. For example, WASP-33 is an A-type star with a temperature of about 7,430 kelvin, which hosts the hottest known transiting planet, WASP-33b (ref. 1); the planet is itself as hot as a red dwarf star of type M (ref. 2). WASP-33b displays a large heat differential between its dayside and nightside, and is highly inflated-traits that have been linked to high insolation. However, even at the temperature of its dayside, its atmosphere probably resembles the molecule-dominated atmospheres of other planets and, given the level of ultraviolet irradiation it experiences, its atmosphere is unlikely to be substantially ablated over the lifetime of its star. Here we report observations of the bright star HD 195689 (also known as KELT-9), which reveal a close-in (orbital period of about 1.48 days) transiting giant planet, KELT-9b. At approximately 10,170 kelvin, the host star is at the dividing line between stars of type A and B, and we measure the dayside temperature of KELT-9b to be about 4,600 kelvin. This is as hot as stars of stellar type K4 (ref. 5). The molecules in K stars are entirely dissociated, and so the primary sources of opacity in the dayside atmosphere of KELT-9b are probably atomic metals. Furthermore, KELT-9b receives 700 times more extreme-ultraviolet radiation (that is, with wavelengths shorter than 91.2 nanometres) than WASP-33b, leading to a predicted range of mass-loss rates that could leave the planet largely stripped of its envelope during the main-sequence lifetime of the host star.

The impact of pedestrian countdown signals on single and two vehicle motor vehicle collisions: a quasi-experimental study.

The objective of this study was to examine the impact of pedestrian countdown signals (PCS) on the rate of motor vehicle collisions (MVCs) in Toronto, Canada. A quasi-experimental design was used to compare rates of single and two vehicle MVCs before and after installation of PCS in Toronto, Canada between January 2005 and December 2009. Collision incidence rates were compared using Poisson regression analyses with adjustment for relevant cofounders and reported as incidence rate ratios (IRR) with 95% confidence intervals (CI). Secondary analyses were performed on subsets of collisions by collision type and injury severity. A total of 94,175 MVCs occurred at or near 1965 intersections at which PCS were installed over the five-year study period. Overall, the MVC incidence rate increased 7.5% (IRR = 1.075; 95% CI: 1.042-1.109; p < 0.0001) after installation of PCS. The installation of PCS led to an increase in MVCs. PCS may have an unintended consequence of increasing the rate of MVCs.

Identifying High-Risk Medications Associated with Acute Kidney Injury in Critically Ill Patients: A Pharmacoepidemiologic Evaluation.

BACKGROUND: Nephrotoxic medications are a common cause of acute kidney injury (AKI). Critically ill children receive more medication than other inpatients; however, the risk of nephrotoxic medication-induced AKI in these children is not well understood. OBJECTIVE: The aim of this study was to determine the association between exposure to nephrotoxic medications in the intensive care unit (ICU) and the development of AKI amongst critically ill children, adjusting for differences in underlying risk. METHODS: We conducted a nested case-control study among a cohort of patients admitted to a paediatric intensive care unit between January 2006 and June 2009. Cases were identified according to the RIFLE criteria. Using incidence density sampling, controls were matched 1:1 according to pre-ICU nephrotoxic drug exposure. Administration of nephrotoxic medications and other known risk factors of AKI were evaluated during the ICU stay prior to the diagnosis of AKI. RESULTS: A total of 914 patients in the cohort developed AKI and had an identifiable matched control. Eighty-seven percent of cases and 74% of controls were exposed to one or more nephrotoxic medications in the ICU during the study period. Furosemide (administered to 67.8% of patients), vancomycin (28.7%), and gentamicin (21.4%) were the most frequently administered nephrotoxic drugs. Patients who developed AKI were more likely to be exposed to at least one nephrotoxic medication and risk increased with increasing number of nephrotoxic medications. Ganciclovir (adjusted odds ratio [AOR] 4.7; 95% CI 1.7-13.0), furosemide (AOR 1.9; 95% CI 1.4-2.4), and gentamicin (AOR 1.8; 95% CI 1.4-2.4) significantly increased the odds of developing AKI after adjusting for underlying differences in risk factors of AKI. CONCLUSION: This is the first study to assess the association between risk-adjusted nephrotoxic medication exposure and the development of AKI in critically ill children. Nephrotoxic medication exposure was common amongst children in the ICU and we found AKI was associated with the administration of specific drugs after adjustment for important risk factors.

Temperament and fracture in preschool-aged children.

OBJECTIVES: Approximately one-half of all children will sustain a fracture before adulthood. Understanding the factors that place a child at increased risk of fracture is necessary to inform effective injury prevention strategies. The purpose of this study was to examine the association between temperament and fracture risk in preschool-aged children. METHODS: Children aged 3 to 6 years who were diagnosed with a fracture were recruited from the Hospital for Sick Children Fracture Clinic. Using a retrospective case-control study design, the 148 cases were frequency-matched by age and sex to 426 controls from the TARGet Kids primary care paediatric cohort. The Childhood Behaviour Questionnaire, a 36-item caregiver response questionnaire was used to assess three of the following temperament factors: surgency (e.g., high activity level), negative affect (e.g., anger, fear, discomfort) and effortful control (e.g., attentional focusing). RESULTS: Unadjusted logistic models demonstrated no association between children with previous fracture and higher scores of surgency (unadjusted odds ratio [OR]=1.06, 95% confidence interval [CI]: 0.84, 1.34), negative affect (unadjusted OR=1.15, 95% CI: 0.93, 1.42) or effortful control (unadjusted OR=0.80, 95% CI: 0.63, 1.03). Further, models adjusted for covariates also demonstrated no significant association with surgency (1.00, 95% CI: 0.78, 1.29), negative affect (1.09, 95% CI: 0.86, 1.37) and effortful control (0.80, 95% CI: 0.61, 1.05). CONCLUSION: None of the three main temperament types identified by the Childhood Behaviour Questionnaire were associated with an increase in fracture risk.

Risk Factors of Acute Kidney Injury in Critically Ill Children.

OBJECTIVES: Acute kidney injury may be promoted by critical illness, preexisting medical conditions, and treatments received both before and during ICU admission. We aimed to estimate the frequency of acute kidney injury during ICU treatment and to determine factors, occurring both before and during the ICU stay, associated with the development of acute kidney injury. DESIGN: Cohort study of critically ill children. SETTING: University-affiliated PICU. PATIENTS: Eligible patients were admitted to the ICU between January 2006 and June 2009. We excluded those admitted with known primary renal failure, chronic renal failure or postrenal transplant, conditions with known renal complications, or metabolic conditions treated with dialysis. Patients were also excluded if they had a short ICU stay (< 6 hr) and those who had no creatinine or urine output measurements during their ICU stay. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Of the 3,865 pediatric patients who met the inclusion criteria, 915 (23.7%) developed acute kidney injury, as classified by the Risk, Injury, Failure, Loss of kidney function, and End-stage kidney disease criteria, during their ICU stay. Patients at high risk for development of acute kidney injury included those urgently admitted to the ICU (adjusted odds ratio, 1.88), those who developed respiratory dysfunction during their ICU care (adjusted odds ratio, 2.90), and those who treated with extracorporeal membrane oxygenation (adjusted odds ratio, 2.72). The single greatest risk factor for acute kidney injury was the administration of nephrotoxic medications during ICU admission (adjusted odds ratio, 3.37). CONCLUSIONS: This study, the largest evaluating the incidence of RIFLE-defined acute kidney injury in critically ill children, found that one-quarter of patients admitted to the ICU developed acute kidney injury. We identified a number of potentially modifiable risk factors, the largest of which was the administration of nephrotoxic medication. The results of this study may be used to inform targeted interventions to reduce acute kidney injury and improve the outcomes of critically ill children.