External Load Fluctuations Across an Amateur Athletic Union Basketball Season

ABSTRACT

Kutson, CW, Russell, JL, Strack, D, Coutts, AJ, and McLean, BD. External load fluctuations across an Amateur Athletic Union basketball season. J Strength Cond Res 38(3): 592-598, 2024-Amateur Athletic Union (AAU) competitions are an important component of the developmental pathway for youth basketball athletes. Despite its relative importance, there is currently a paucity of research investigating the physical demands in AAU basketball. Therefore, the purpose of this study was to examine the physical demands encountered over the course of an AAU basketball season. External training load was quantified using inertial sensors (Catapult T6) from one male AAU basketball team (age: 17.5 ± 0.5 years, height: 197.3 ± 10.0 cm, and mass: 89.4 ± 11.6 kg) over the course of the 2021 AAU season and categorized post hoc into high-, medium-, and low-minute groups based on mean playing minutes. After player categorization, 2 linear mixed models were constructed, one for PlayerLoad (PL) and one for duration, to examine the differences across player category, month of the season, and activity types (practices or games). The results show that the highest training loads were encountered by high-minute players, who had total PLs of 9,766 ± 1,516 AU, 13,207 ± 2,561 AU, and 7,071 ± 2,122 AU during April, May, and June, respectively. Highly variable training loads were also evident over the course of a season, with peak PL values as high as 4,921 AU per week. Practitioners should be aware that AAU basketball players experience variable loads throughout the season, which peak around congested competition/tournament periods. In addition, players with high game minutes accumulate the most load over the course of a season. This information may be used to better inform planning and periodizing strategies during developmental phases.

Advanced fellowship training for cardiology fellows in acute care cardiology

Hospitalised children have become more medically complex and increasingly require specialised teams and units properly equipped to care for them. Within paediatric cardiology, this trend, which is well demonstrated by the expansion of cardiology-specific ICUs, has more recently led to the development of acute care cardiology units to deliver team-based and condition-focused inpatient care. These care teams are now led by paediatric cardiologists with particular investment in the acute care cardiology environment. Herein, we describe the foundation and development of an Acute Care Cardiology Advanced Training Fellowship to meet the clinical, scholarly, and leadership training needs of this emerging care environment.

Finding the Signal in the Noise-Interday Reliability and Seasonal Sensitivity of 84 Countermovement Jump Variables in Professional Basketball Players

ABSTRACT

Mercer, RAJ, Russell, JL, McGuigan, LC, Coutts, AJ, Strack, DS, and McLean, BD. Finding the signal in the noise-interday reliability and seasonal sensitivity of 84 countermovement jump variables in professional basketball players. J Strength Cond Res 37(2): 394-402, 2023-This study examined the measurement characteristics of countermovement jump (CMJ) variables in basketball athletes using different variable selection criteria. Test-retest reliability (noise) and seasonal variability (signal) CMJ data were collected from 13 professional basketball athletes playing for the same club throughout 1 competitive season. Interday reliability (coefficient of variation [CV] and intraclass correlation coefficients) were calculated over 3 preseason tests conducted on 3 consecutive days. To evaluate sensitivity, signal-to-noise ratio (SNR) was calculated by dividing seasonal variability (CV) from 8 in-season CMJ tests (collected from November to February) by preseason reliability (CV). Players performed 3 CMJs each testing day, and 3 data analysis techniques were applied: a single variable from the trial with either the best jump height (BestJH; calculated by flight time) or the best flight time to contraction time (BestFT:CT) and mean output across 3 jumps (Mean3). Mean3 was the most reliable data analysis technique, with 79 and 82 of 84 variables displaying lower interday CVs compared with BestJH and BestFT:CT, respectively. Overall, many CMJ measures display seasonal changes that are greater than the inherent noise, with 77 variables producing SNR of >1.00 for Mean3 compared with 65 and 58 variables for BestJH and BestFT:CT, respectively. To improve reliability and sensitivity, it is recommended that practitioners use the average of multiple CMJ trials and regularly reassess measurement characteristics specific to their cohort and environment.

Understanding ‘monitoring’ data–the association between measured stressors and athlete responses within a holistic basketball performance framework

This study examined associations between cumulative training load, travel demands and recovery days with athlete-reported outcome measures (AROMs) and countermovement jump (CMJ) performance in professional basketball. Retrospective analysis was performed on data collected from 23 players (mean±SD: age = 24.7±2.5 years, height = 198.3±7.6 cm, body mass = 98.1±9.0 kg, wingspan = 206.8±8.4 cm) from 2018–2020 in the National Basketball Association G-League. Linear mixed models were used to describe variation in AROMs and CMJ data in relation to cumulative training load (previous 3- and 10-days), hours travelled (previous 3- and 10-day), days away from the team’s home city, recovery days (i.e., no travel/minimal on-court activity) and individual factors (e.g., age, fatigue, soreness). Cumulative 3-day training load had negative associations with fatigue, soreness, and sleep, while increased recovery days were associated with improved soreness scores. Increases in hours travelled and days spent away from home over 10 days were associated with increased sleep quality and duration. Cumulative training load over 3 and 10 days, hours travelled and days away from home city were all associated with changes in CMJ performance during the eccentric phase. The interaction of on-court and travel related stressors combined with individual factors is complex, meaning that multiple athletes response measures are needed to understand fatigue and recovery cycles. Our findings support the utility of the response measures presented (i.e., CMJ and AROMs), but this is not an exhaustive battery and practitioners should consider what measures may best inform training periodization within the context of their environment/sport.

Quantifying Training and Game Demands of a National Basketball Association Season

Purpose: There are currently no data describing combined practice and game load demands throughout a National Basketball Association (NBA) season. The primary objective of this study was to integrate external load data garnered from all on-court activity throughout an NBA season, according to different activity and player characteristics. Methods: Data from 14 professional male basketball players (mean ± SD; age, 27.3 ± 4.8 years; height, 201.0 ± 7.2 cm; body mass, 104.9 ± 10.6 kg) playing for the same club during the 2017-2018 NBA season were retrospectively analyzed. Game and training data were integrated to create a consolidated external load measure, which was termed integrated load. Players were categorized by years of NBA experience (1-2y, 3-5y, 6-9y, and 10 + y), position (frontcourt and backcourt), and playing rotation status (starter, rotation, and bench). Results: Total weekly duration was significantly different (p < 0.001) between years of NBA playing experience, with duration highest in 3-5 year players, compared with 6-9 (d = 0.46) and 10+ (d = 0.78) year players. Starters experienced the highest integrated load, compared with bench (d = 0.77) players. There were no significant differences in integrated load or duration between positions. Conclusion: This is the first study to describe the seasonal training loads of NBA players for an entire season and shows that a most training load is accumulated in non-game activities. This study highlights the need for integrated and unobtrusive training load monitoring, with engagement of all stakeholders to develop well-informed individualized training prescription to optimize preparation of NBA players.

Successful Reduction of Postoperative Chest Tube Duration and Length of Stay After Congenital Heart Surgery: A Multicenter Collaborative Improvement Project

Background Congenital heart disease practices and outcomes vary significantly across centers, including postoperative chest tube (CT) management, which may impact postoperative length of stay (LOS). We used collaborative learning methods to determine whether centers could adapt and safely implement best practices for CT management, resulting in reduced postoperative CT duration and LOS. Methods and Results Nine pediatric heart centers partnered together through 2 learning networks. Patients undergoing 1 of 9 benchmark congenital heart operations were included. Baseline data were collected from June 2017 to June 2018, and intervention-phase data were collected from July 2018 to December 2019. Collaborative learning methods included review of best practices from a model center, regular data feedback, and quality improvement coaching. Center teams adapted CT removal practices (eg, timing, volume criteria) from the model center to their local resources, practices, and setting. Postoperative CT duration in hours and LOS in days were analyzed using statistical process control methodology. Overall, 2309 patients were included. Patient characteristics did not differ between the study and intervention phases. Statistical process control analysis showed an aggregate 15.6% decrease in geometric mean CT duration (72.6 hours at baseline to 61.3 hours during intervention) and a 9.8% reduction in geometric mean LOS (9.2 days at baseline to 8.3 days during intervention). Adverse events did not increase when comparing the baseline and intervention phases: CT replacement (1.8% versus 2.0%, P=0.56) and readmission for pleural effusion (0.4% versus 0.5%, P=0.29). Conclusions We successfully lowered postoperative CT duration and observed an associated reduction in LOS across 9 centers using collaborative learning methodology.

Image-guided chest tube drainage in the management of chylothorax post cardiac surgery in children: a single-center case series

BACKGROUND

In children, chylothorax post cardiac surgery can be difficult to treat, may run a protracted course, and remains a source of morbidity and mortality.

OBJECTIVE

To analyze the experience with percutaneous image-guided chest-tube drainage in the management of post-cardiac-surgery chylothoraces in children.

MATERIALS AND METHODS

We conducted a single-center retrospective case series of 37 post-cardiac-surgery chylothoraces in 34 children (20 boys; 59%), requiring 48 drainage procedures with placement of 53 image-guided chest tubes over the time period 2004 to 2015. We analyzed clinical and procedural details, adverse events and outcomes. Median age was 0.6 years, median weight 7.2 kg.

RESULTS

Attempted treatments of chylothoraces prior to image-guided chest tubes included dietary restrictions (32/37, 86%), octreotide (12/37, 32%), steroids (7/37, 19%) and thoracic duct ligation (5/37, 14%). Image-guided chest tubes (n=43/53, 81%) were single unilateral in 29 children, bilateral in 4 (n=8/53, 15%), and there were two ipsilateral tubes in one (2/53, 4%). Effusions were isolated, walled-off, in 33/53 (62%). In 20/48 procedures (42%) effusions were septated/complex. The mean drainage through image-guided chest tubes was 17.3 mL/kg in the first 24 h, and 13.4 mL/kg/day from diagnosis to chest tube removal; total mean drainage from all chest tubes was 19.6 mL/kg/day. Nine major and 27 minor maintenance procedures were required during 1,207 tube-days (rate: 30 maintenance/1,000 tube-days). Median tube dwell time was 21 days (range 4-57 days). There were eight mild adverse events, three moderate adverse events and no severe adverse events related to image-guided chest tubes. Radiologic resolution was achieved in 26/37 (70%). Twenty-three children (68%) survived to discharge; 11 children (32%) died from underlying cardiac disease.

CONCLUSION

Management of chylothorax post-cardiac-surgery in children is multidisciplinary, requiring concomitant multipronged approaches, often through a protracted course. Multiple image-guided chest tube drainages can help achieve resolution with few complications. Interventional radiology involvement in tube care and maintenance is required. Overall, mortality remains high.

Measuring Physical Demands in Basketball: An Explorative Systematic Review of Practices

BACKGROUND

Measuring the physical work and resultant acute psychobiological responses of basketball can help to better understand and inform physical preparation models and improve overall athlete health and performance. Recent advancements in training load monitoring solutions have coincided with increases in the literature describing the physical demands of basketball, but there are currently no reviews that summarize all the available basketball research. Additionally, a thorough appraisal of the load monitoring methodologies and measures used in basketball is lacking in the current literature. This type of critical analysis would allow for consistent comparison between studies to better understand physical demands across the sport.

OBJECTIVES

The objective of this systematic review was to assess and critically evaluate the methods and technologies used for monitoring physical demands in competitive basketball athletes. We used the term 'training load' to encompass the physical demands of both training and game activities, with the latter assumed to provide a training stimulus as well. This review aimed to critique methodological inconsistencies, establish operational definitions specific to the sport, and make recommendations for basketball training load monitoring practice and reporting within the literature.

METHODS

A systematic review of the literature was performed using EBSCO, PubMed, SCOPUS, and Web of Science to identify studies through March 2020. Electronic databases were searched using terms related to basketball and training load. Records were included if they used a competitive basketball population and incorporated a measure of training load. This systematic review was registered with the International Prospective Register of Systematic Reviews (PROSPERO Registration # CRD42019123603), and approved under the National Basketball Association (NBA) Health Related Research Policy.

RESULTS

Electronic and manual searches identified 122 papers that met the inclusion criteria. These studies reported the physical demands of basketball during training (n = 56), competition (n = 36), and both training and competition (n = 30). Physical demands were quantified with a measure of internal training load (n = 52), external training load (n = 29), or both internal and external measures (n = 41). These studies examined males (n = 76), females (n = 34), both male and female (n = 9), and a combination of youth (i.e. under 18 years, n = 37), adults (i.e. 18 years or older, n = 77), and both adults and youth (n = 4). Inconsistencies related to the reporting of competition level, methodology for recording duration, participant inclusion criteria, and validity of measurement systems were identified as key factors relating to the reporting of physical demands in basketball and summarized for each study.

CONCLUSIONS

This review comprehensively evaluated the current body of literature related to training load monitoring in basketball. Within this literature, there is a clear lack of alignment in applied practices and methodological framework, and with only small data sets and short study periods available at this time, it is not possible to draw definitive conclusions about the true physical demands of basketball. A detailed understanding of modern technologies in basketball is also lacking, and we provide specific guidelines for defining and applying duration measurement methodologies, vetting the validity and reliability of measurement tools, and classifying competition level in basketball to address some of the identified knowledge gaps. Creating alignment in best-practice basketball research methodology, terminology and reporting may lead to a more robust understanding of the physical demands associated with the sport, thereby allowing for exploration of other research areas (e.g. injury, performance), and improved understanding and decision making in applying these methods directly with basketball athletes.

Achieving Minimal Heat Conductivity by Ballistic Confinement in Phononic Metalattices

Controlling the thermal conductivity of semiconductors is of practical interest in optimizing the performance of thermoelectric and phononic devices. The insertion of inclusions of nanometer size in a semiconductor is an effective means of achieving such control; it has been proposed that the thermal conductivity of silicon could be reduced to 1 W/m/K using this approach and that a minimum in the heat conductivity would be reached for some optimal size of the inclusions. Yet the experimental verification of this design rule has been limited. In this work, we address this question by studying the thermal properties of silicon metalattices that consist of a periodic distribution of spherical inclusions with radii from 7 to 30 nm, embedded into silicon. Experimental measurements confirm that the thermal conductivity of silicon metalattices is as low as 1 W/m/K for silica inclusions and that this value can be further reduced to 0.16 W/m/K for silicon metalattices with empty pores. A detailed model of ballistic phonon transport suggests that this thermal conductivity is close to the lowest achievable by tuning the radius and spacing of the periodic inhomogeneities. This study is a significant step in elucidating the scaling laws that dictate ballistic heat transport at the nanoscale in silicon and other semiconductors.

Adaptive Shape Ripening and Interparticle Bridging of l-Arginine-Stabilized Silica Nanoparticles during Evaporative Colloidal Crystal Assembly

During evaporative self-assembly of colloidal crystal films, spherical l-arginine-stabilized silica colloids adapt to different close-packed geometries by faceting and forming bridge connections with their nearest neighbors. We systematically studied the morphological changes of 37 and 138 nm diameter colloids during evaporative assembly and compared them to 65 nm Stöber silica colloids prepared without l-arginine. Colloidal crystal films were grown from particles that had been dialyzed against water or l-arginine, and tetraethyl orthosilicate (TEOS) and/or l-arginine were added to solutions during colloidal film growth. Solid-state ²⁹Si NMR spectra showed the presence of l-arginine and incompletely condensed silica in colloids grown from silica seeds in l-arginine solutions. These colloids were especially susceptible to chemical ripening during the colloidal assembly process, adopting faceted shapes that reflected the packing symmetry of the colloidal crystal films. The addition of l-arginine and TEOS accelerated these shape changes by catalyzing the hydrolysis and olation of silica and by adding a source of silica to the solution, respectively. This chemistry provides a route to single-component and binary colloidal crystals composed of nonspherical silica building blocks.

Colloidal crystal order and structure revealed by tabletop extreme ultraviolet scattering and coherent diffractive imaging

Colloidal crystals with specific electronic, optical, magnetic, vibrational properties, can be rationally designed by controlling fundamental parameters such as chemical composition, scale, periodicity and lattice symmetry. In particular, silica nanospheres -which assemble to form colloidal crystals- are ideal for this purpose, because of the ability to infiltrate their templates with semiconductors or metals. However characterization of these crystals is often limited to techniques such as grazing incidence small-angle scattering that provide only global structural information and also often require synchrotron sources. Here we demonstrate small-angle Bragg scattering from nanostructured materials using a tabletop-scale setup based on high-harmonic generation, to reveal important information about the local order of nanosphere grains, separated by grain boundaries and discontinuities. We also apply full-field quantitative ptychographic imaging to visualize the extended structure of a silica close-packed nanosphere multilayer, with thickness information encoded in the phase. These combined techniques allow us to simultaneously characterize the silica nanospheres size, their symmetry and distribution within single colloidal crystal grains, the local arrangement of nearest-neighbor grains, as well as to quantitatively determine the number of layers within the sample. Key to this advance is the good match between the high harmonic wavelength used (13.5nm) and the high transmission, high scattering efficiency, and low sample damage of the silica colloidal crystal at this wavelength. As a result, the relevant distances in the sample - namely, the interparticle distance (≈124nm) and the colloidal grains local arrangement (≈1μm) - can be investigated with Bragg coherent EUV scatterometry and ptychographic imaging within the same experiment simply by tuning the EUV spot size at the sample plane (5μm and 15μm respectively). In addition, the high spatial coherence of high harmonics light, combined with advances in imaging techniques, makes it possible to image near-periodic structures quantitatively and nondestructively, and enables the observation of the extended order of quasi-periodic colloidal crystals, with a spatial resolution better than 20nm. In the future, by harnessing the high time-resolution of tabletop high harmonics, this technique can be extended to dynamically image the three-dimensional electronic, magnetic, and transport properties of functional nanosystems.

Confined Chemical Fluid Deposition of Ferromagnetic Metalattices

A magnetic, metallic inverse opal fabricated by infiltration into a silica nanosphere template assembled from spheres with diameters less than 100 nm is an archetypal example of a "metalattice". In traditional quantum confined structures such as dots, wires, and thin films, the physical dynamics in the free dimensions is typically largely decoupled from the behavior in the confining directions. In a metalattice, the confined and extended degrees of freedom cannot be separated. Modeling predicts that magnetic metalattices should exhibit multiple topologically distinct magnetic phases separated by sharp transitions in their hysteresis curves as their spatial dimensions become comparable to and smaller than the magnetic exchange length, potentially enabling an interesting class of "spin-engineered" magnetic materials. The challenge to synthesizing magnetic inverse opal metalattices from templates assembled from sub-100 nm spheres is in infiltrating the nanoscale, tortuous voids between the nanospheres void-free with a suitable magnetic material. Chemical fluid deposition from supercritical carbon dioxide could be a viable approach to void-free infiltration of magnetic metals in view of the ability of supercritical fluids to penetrate small void spaces. However, we find that conventional chemical fluid deposition of the magnetic late transition metal nickel into sub-100 nm silica sphere templates in conventional macroscale reactors produces a film on top of the template that appears to largely block infiltration. Other deposition approaches also face difficulties in void-free infiltration into such small nanoscale templates or require conducting substrates that may interfere with properties measurements. Here we report that introduction of "spatial confinement" into the chemical fluid reactor allows for fabrication of nearly void-free nickel metalattices by infiltration into templates with sphere sizes from 14 to 100 nm. Magnetic measurements suggest that these nickel metalattices behave as interconnected systems rather than as isolated superparamagnetic systems coupled solely by dipolar interactions.

Double Replication of Silica Colloidal Crystal Films

Inverse opals made by polymerizing vinyl monomers inside a colloidal crystal have lattice dimensions that are contracted relative to the original hard template. This effect was studied in order to investigate the possibility of making double replicas of varying pore sizes from different materials, and to gain a better understanding of the polymer contraction behavior during replication. The degree of lattice contraction was measured using colloidal crystal films formed from silica spheres with diameters in the range 33-225 nm, and polymers pEDMA [poly(1,2-ethanediol dimethacrylate)], pDVB [poly(divinylbenzene)], pHDMA [poly(1,6-hexanediol dimethacrylate)], pBDMA [poly(1,4-butanediol dimethacrylate)], and a 5:4 copolymer mixture of pEDMA/pDVB. The degree of lattice contraction depended on the alkyl chain length of the monomer, as well as the degree of cross-linking, with up to 32% contraction observed for pEDMA when the silica template was removed. However, filling the polymer inverse opals with silica or titania returned the lattice spacing closer to its original size, an effect that can be rationalized in terms of the driving forces for contraction. Double replication of both single-component and binary silica colloidal crystals therefore generated silica and titania replicas of the original lattice. Thus, double replication provides a pathway for accessing periodic structures that are difficult to synthesize directly from materials such as titania.

Chylothorax and pleural effusion in contemporary extracardiac fenestrated fontan completion

BACKGROUND

We hypothesized that chylothorax could be a sign of intolerance to the Fontan physiology, and thus patients who develop chylothorax or pleural effusion have worse medium-term to long-term survival.

METHODS

A total of 324 patients who underwent the Fontan operation between 2000 and 2013 were included. Chylothorax was defined as ≥5 mL/kg/day of chylomicron-positive chest drainage fluid no earlier than postoperative day 5 or drainage with >80% lymphocytes. Outcomes were compared between the chylothorax and non-chylothorax groups by the Kaplan-Meier method and log-rank test. Independent predictors of chylothorax and number of days of any chest drainage were analyzed with multivariable logistic regression and multivariable generalized negative binomial regression for count data, respectively.

RESULTS

Chylothorax occurred in 78 patients (24%). Compared with the non-chylothorax group, the chylothorax group had a longer duration of chest tube requirement (median, 18 days vs 9 days; P < .000) and a longer length of hospital stay (median, 19 days vs 10 days; P < .000). Eight patients (10.3%) required thoracic duct ligation. The chylothorax group had lower freedom from death (P = .013) and from composite adverse events (P = .021). No predictor was found for chylothorax. Pulmonary atresia (P = .031) and pre-Fontan pulmonary artery pressure (P = .01) were predictive of prolonged pleural effusion (>14 days).

CONCLUSIONS

Occurrence of chylothorax following the Fontan operation can be a marker of poorer medium-term clinical outcomes. It is difficult to predict occurrence of chylothorax owing to its multifactorial nature and involvement of lymphatic compensatory capacity that is unmasked only after the Fontan operation.

Incidence of infective endocarditis and its thromboembolic complications in a pediatric population over 30years

BACKGROUND

Pediatric infective endocarditis (IE) has been associated with high morbidity and mortality, mostly related to thromboembolic complications (TEC). The objective of our study was to describe the experience in children with IE and to review the changes over a thirty-year period, regarding origin of IE, incidence of vegetations, TEC and their respective morbidity and mortality rates.

METHODS

A retrospective chart review of children aged 0-18years with IE defined by the Duke Criteria and admitted to The Hospital for Sick Children, was conducted. Data were divided into three periods (P); P1 (1979-1988); P2 (1989-1998); and P3 (1999-2008).

RESULTS

The study included 113 patients, median age 7yrs.; females: 46 (41%), congenital heart defects 95 (84%), comparable in all periods. Overall, cardiac vegetations were found in 68/113 patients (60%); large vegetations (≥1cm) in 32 patients (28%). Fourty-five (45/133 [40%]) TEC were documented, 22 patients (20%) developed cerebrovascular events (CVE) and 23 patients (20%) had non-CVE. Patients diagnosed during P3 were older, had more vegetations (p<0.05), and a higher incidence of community acquired-IE (p<0.05). Overall, mortality was 15%, comparable in all periods. Significant risk factors for mortality were vegetations (HR 6.44; 95% CI: 2.07-20.01, p=0.002) and heart failure (HR 28.39; 95% CI: 10.49-76.85, p<0.001).

CONCLUSIONS

Over the study period, we report a growing incidence of community acquired pediatric IE in older children accompanied by an increasing rate of TEC. Heart failure and vegetations were associated with an increased mortality. These preliminary data need to be confirmed by prospective data.

Binary Colloidal Crystal Films Grown by Vertical Evaporation of Silica Nanoparticle Suspensions

Despite intensive research efforts in the synthesis of binary colloidal crystals, the production of well ordered binary colloidal crystal films over large areas continues to be synthetically challenging. In this paper, we investigate the phase behavior of binary mixtures of l-arginine-stabilized 36 and 22 nm silica nanoparticles deposited as centimeter-scale thin films onto a vertical substrate via evaporative assembly. By adjusting the temperature and relative colloid composition under high humidity conditions, we controlled the order of the resultant colloidal crystal films. The domain size of the AB₂ binary crystalline phase increased with an excess of small (B) particles and a very slow evaporation rate below 45 °C, with the best results obtained at 30° and 35 °C.

Oral health assessment practices and perceptions of North American paediatric cardiologists

OBJECTIVE

Children with cardiac defects should have good oral health, particularly prior to cardiac surgery to minimize risks of infective endocarditis. The aim of the study was to examine the oral health assessment practices of North American cardiologists.

METHODS

Online surveys were e-mailed to 1409 cardiologists. Cardiologists without paediatric patients or practicing in centres without cardiac surgical care were excluded. Surveys addressed oral health assessment practices for paediatric cardiac patients, and perceptions of the impact of oral health on cardiac care.

RESULTS

The centre response rate was 69%, individual response rate 20%. Most cardiologists (96%) reported oral health was assessed as part of cardiac care. The most common time for assessment was prior to cardiac surgery (44%), with a quarter assessing by age 1 (28%). While most oral assessments involved a dentist (59%), 17% of cardiologists performed the oral assessment without the aid of a dentist. Four-fifths of cardiologists (83%) reported cancellation of cardiac surgery due to oral disease. Cardiologists who deferred assessment until prior to surgery had the highest experience of cancellation (96%). Assessments were delayed despite the common belief (89%) that children on pre-surgical high-calorie diets are at increased risk of oral disease.

CONCLUSION

Assessments of oral health status were often deferred until immediately prior to cardiac surgery despite the cardiologist's perception that children with cardiac defects were at increased risk of oral disease and prior experience of surgical cancellation due to oral disease. Paediatricians may need to facilitate early oral assessment for these children.

Canadian Cardiovascular Society/Canadian Pediatric Cardiology Association Position Statement on Pulse Oximetry Screening in Newborns to Enhance Detection of Critical Congenital Heart Disease

Congenital heart disease is the most common congenital malformation and approximately 3 in 1000 newborns have critical congenital heart disease (CCHD). Timely diagnosis affects morbidity, mortality, and disability, and newborn pulse oximetry screening has been studied to enhance detection of CCHD. In this position statement we present an evaluation of the literature for pulse oximetry screening. Current detection strategies including prenatal ultrasound examination and newborn physical examination are limited by low diagnostic sensitivity. Pulse oximetry screening is safe, noninvasive, easy to perform, and widely available with a high specificity (99.9%) and moderately high sensitivity (76.5%). When an abnormal saturation is obtained, the likelihood of having CCHD is 5.5 times greater than when a normal result is obtained. The use of pulse oximetry combined with current strategies has shown sensitivities of up to 92% for detecting CCHD. False positive results can be minimized by screening after 24 hours, and testing the right hand and either foot might further increase sensitivity. Newborns with abnormal screening results should undergo a comprehensive assessment and echocardiography performed if a cardiac cause cannot be excluded. Screening has been studied to be cost neutral to cost effective. We recommend that pulse oximetry screening should be routinely performed in all healthy newborns to enhance the detection of CCHD in Canada.

Massive lindane overdose with toxicokinetics analysis

BACKGROUND

Lindane is a possible carcinogen with known teratogenicity and immunologic and neurotoxic properties. Despite reports of seizures, coma, and death associated with its use as well as banning of its environmental use by the Environmental Protection Agency (EPA), the US Food and Drug Administration (FDA) still allows treatment with lindane as a second-line scabicide and pediculicide. We present a case of a massive suicidal ingestion of lindane in which the patient survived the ingestion, though he did expire shortly thereafter from an unrelated cause pre-discharge.

METHODS

Pharmacokinetic analysis of serum lindane concentrations was performed with Phoenix® WinNONLIN®. The estimated distribution half-life for lindane was 10.3 h, and the terminal half-life was 162.9 h, much longer than the previously reported terminal half-life of 25-36 h. Because of this long half-life, repeated lindane exposures may lead to accumulation of lindane in the tissues.

RESULT

After overdose, toxicity may be delayed and full recovery may be prolonged.

Children after fontan have strength and body composition similar to healthy peers and can successfully participate in daily moderate-to-vigorous physical activity

The objective of this study was to evaluate the active lifestyle capacity (daily physical activity, strength, flexibility, body composition) of children after the Fontan procedure; hypothesized to be lower than healthy peers. Participants (n = 64, 25 females) were 9.0 ± 1.7 years of age (range 6.0-11.7 years). Fontan completion occurred at 3.3 ± 1.4 years of age (5.7 ± 2.0 years prior). Canadian Health Measures Survey protocols assessed aerobic endurance (paced walking up/down steps), strength (handgrip), flexibility (sit and reach), body composition (body mass index), and daily moderate-to-vigorous physical activity (7-day accelerometry). Difference scores compared participant data to published norms (t tests). Linear regression evaluated age/gender/demographic factor associations. Children after Fontan had strength scores similar (mean difference 1.1 kg) to their peers were less likely to be obese (mean difference of body mass index = 1.1 ± 2.5, p = 0.001) and performed 50 min of moderate-to-vigorous activity (MVPA) per day (12 ± 17 min/day below healthy peers, p < 0.001). Estimated peak endurance (61 % of expected) and flexibility (64 % of expected) were lower than peers (p < 0.001). Almost all (60/63) participants demonstrated the capacity to perform at least 20 min of MVPA per day. Difference from norms was smaller among children younger at Fontan completion (4 ± 2 min/year) and taking antithrombotic medication (7 ± 18 and 22 ± 17 min/day for taking/not taking, respectively). Children after Fontan demonstrate the capacity for the daily physical activity associated with optimal health. They have similar strength and good body composition. We recommend that children after Fontan be counselled that they can successfully participate in healthy, active lifestyles and physically active peer play.

Review of toxicity and trends in the use of tiagabine as reported to US poison centers from 2000 to 2012

BACKGROUND

Tiagabine is a novel antiepileptic that acts by increasing synaptic and extracellular gamma-aminobutyric acid concentrations. Information concerning overdose of tiagabine is limited. After introduction, an increasing number of off-label uses suggested that tiagabine use would increase. However in 2005 and 2008, warnings from the Food and Drug Administration (FDA) were issued on the risk of seizures in non-epileptic and increased suicide ideation. We evaluated the temporal trends associated with these two warnings as well as clinical outcomes from tiagabine overdose.

METHOD

A retrospective review of all single substance tiagabine exposures in National Poison Data System (NPDS) from 2000 to 2012.

RESULTS

A total of 2147 patients had ingested tiagabine, with a mean of 165 year(-1). This was disproportionally distributed, with a steep rise leading up to 2004 (max 559 year(-1)) and then a significant decline (p < 0.05) between 2005 and 2006. The number of cases reported to NPDS mirrored the sales of tiagabine. Clinical effects were predominantly neurological, with the most commonly reported effects being drowsiness (27%), agitation (19%), confusion (12%), seizures (11%), and tachycardia (10%). In all, 758 patients (35%) showed a major or moderate medical outcome, with no deaths reported. A disproportionate share of the major outcomes was in the suicide attempt group (73%). The majority of patients (75%) were treated in a health-care facility (HCF).

CONCLUSIONS

The HCF usage is likely due to high rate of symptomatic patients (59%) and the large proportion of suicide attempt cases. The frequency of tiagabine cases in NPDS mirrored pharmaceutical sales, with steep declines temporally related to the 2005 FDA warning.

Identification of N-Hydroxy-para-aminobenzoic acid in a cyanotic child after benzocaine exposure

CONTEXT

Methemoglobinemia (MetHb) after exposure to benzocaine (BZC) has been reported for more than 50 years, however the pathophysiologic mechanism has not been previously established. Direct administration of BZC to blood does not produce MetHb. After topical use, due to the lipophilicity and rapid acetylation in the tissue, little BZC reaches the liver for hepatic biotransformation. However, isolated human livers have been shown to produce MetHb forming N-hydroxyl metabolites from BZC. We report a case of BZC-induced MetHb with the first identification and quantification of the reactive metabolite responsible for the oxidative stress: N-Hydroxy-Para-amino benzoic acid (N-OH-PABA).

CASE DETAILS

An 8 year old male was admitted to a hospital for an appendectomy. Several applications of BZC spray were used during multiple attempts at nasogastric tube placement. In various attempts to achieve local anesthesia, benzocaine spray was used in both nares and through the mouth aimed at the posterior oropharynx. The patient subsequently became cyanotic with an initial MetHb level of 32.9 %. Methylene blue was administered and the patient promptly responded with resolution of cyanosis. Blood taken within 20 min of the initial symptoms contained benzocaine (5.2ug/mL), bupivacaine (740ng/mL), lidocaine (530ng/mL), acetaminophen (12ug/mL), midazolam (60ng/mL), PABA and N-OH-PABA (35ng/mL). Serum was analyzed using Liquid Chromatography- Quadrupole Time-of-Flight Mass Spectrometry. Mass spectrometry was done using an electrospray ionization source run in negative and positive polarities. A reference standard for N-OH-PABA was synthesized for confirmation and quantification.

DISCUSSION

The rare and idiopathic nature of methemoglobinemia after benzocaine use has made study of the pathophysiologic mechanism in humans difficult. Lack of understanding has brought calls for restriction of use of the widely used medication that may not be based on evidence. Our case presents several unique features: 1) benzocaine absorption after topical administration was documented with serum concentrations 2) confirmation of an in vivo formation of MetHb-forming n-hydroxyl-metabolite after benzocaine use and 3) the documentation of N-OH-PABA in humans within 20 min of MetHb post-benzocaine administration.

Enhanced physiology for submaximal exercise in children after the fontan procedure

PURPOSE

After the Fontan procedure, children exhibit reduced peak exercise capacity, yet their submaximal exercise response remains unclear. This study sought to determine the relationship between submaximal and peak exercise capacity and physical activity in Fontan patients.

METHODS

This cross-sectional study recruited 50 Fontan patients (59% males) with a median age of 9 yr (range = 6-12 yr). The median age at Fontan procedure was 2.9 yr (range = 1.6-9.1 yr). Study assessments included medical history, exercise testing, and accelerometry.

RESULTS

Significantly lower submaximal oxygen consumption (V˙O2) and HR in response to a standardized workload than published values for healthy children (mean ± SD) of -1.72 ± 5.24 (P < 0.001) and -1.45 ± 1.98 (P < 0.001), respectively, suggest enhanced submaximal work efficiency in this group of patients after Fontan. Higher submaximal V˙O2 z-score was associated with higher submaximal HR z-score (P = 0.02) and lower body mass index z-score (P = 0.01). Higher V˙O2peak was associated with higher submaximal V˙O2 z-score (P < 0.01), male sex (P = 0.03), higher RER (P = 0.02), lower submaximal HR z-score (P < 0.01), and higher chronotropic responsiveness (P < 0.0001). Exercise test duration z-score was associated with lower submaximal HR z-score (P = 0.02) and higher chronotropic responsiveness (P = 0.02).

CONCLUSIONS

Fontan patients exhibited a lower submaximal V˙O2 and HR responsiveness at a given workload than healthy controls did during standardized exercise testing. Thus, they may be better adapted to perform submaximal exercise. Although peak exercise capacity is limited, Fontan patients are able to perform submaximal physical activities at the same level as their healthy peers.

Home-based rehabilitation enhances daily physical activity and motor skill in children who have undergone the Fontan procedure

This randomized trial compared physical activity enhancing exercise prescription and education programs in 61 children (36 male) with single-ventricle physiology after Fontan. After Fontan, children are less active than recommended for optimal health. They are often geographically dispersed and unable to attend weekday programs. Participants, 5.9-11.7 years of age who were status 5.3 years post-Fontan, received 12-month, parent-delivered home programs to enhance physical activity, motor skill, fitness, and activity attitudes. Daily moderate-to-vigorous physical activity (MVPA) was measured at baseline and again at 6, 12, and 24 months. Secondary outcomes were gross motor skill, fitness, and activity attitudes. Gross motor skill (p = .01) was significantly greater at the end of the 2-year study period for both intervention groups combined. MVPA at 2 years was significantly greater (p = .03) than the predicted decrease with age. Spring season (85 ± 25 min), male sex (69 ± 21 min), greater baseline activity (0.3 ± 0.1 min/baseline minute), and better gross motor skill (1.1 ± 0.4 min/percentile) increased weekly MVPA in a multivariable repeated-measures regression model adjusted for intervention, maturation during the 2-year study, sex, season, and baseline activity. Benefits were not influenced by type of rehabilitation, compliance, or rural/urban location. Home-based, pediatric physical activity rehabilitation enhances physical activity, gross motor skill, exercise capacity, and physical fitness among preadolescent children after Fontan regardless of rural/urban location. Prescribed education and exercise programs are similarly effective for providing the important health benefits of daily physical activity. Enhanced gross motor skill is associated with increased MVPA despite exercise capacity limitations after Fontan. Rehabilitation attenuates the expected decrease in MVPA with age.

Termite fishing laterality in the Fongoli savanna chimpanzees (Pan troglodytes verus): further evidence of a left hand preference

Whether nonhuman primates show population-level handedness is a topic of much scientific debate. A previous study of handedness for termite fishing reported population-level left handedness in the chimpanzees from Gombe National Park, Tanzania. In the current study, we examined whether similar hand preferences were evident in a savanna-dwelling chimpanzee population with regards to termite fishing. Hand preference data were collected for 27 chimpanzees from February 2007 through July 2008 and November 2011 through January 2012 in southeastern Senegal. Overall, the Fongoli chimpanzees demonstrate a trend toward population-level handedness, though the results did not reach conventional levels of statistical significance likely due to the limited sample size. Fongoli chimpanzees showed the same pattern of left hand preference as reported at Gombe and the two populations did not differ significantly. When the data were combined across all studies, wild chimpanzees showed a population-level left hand preference for termite fishing.

Frequency, characteristics, and outcomes of pediatric patients readmitted to the cardiac critical care unit

PURPOSE

To describe the characteristics and outcomes of patients readmitted to a pediatric cardiac critical care unit (CCCU) from the ward within 72 h of their first discharge.

METHODS

This was a retrospective analysis of data collected on patients admitted to the CCCU between January 1, 2000 and January 31, 2007. The setting was an 18-bed pediatric CCCU in a tertiary care university hospital. No interventions were performed.

RESULTS

Among the 4,625 patients admitted to the CCCU, 112 (2.4 %) were readmitted from the ward within 72 h of their discharge. The most common cause for readmission was respiratory symptoms (42.9 %). Significant changes in the chest X-ray prior to discharge were identified retrospectively in 12.5 % of these patients. Cardiovascular symptoms were similarly frequent (40.2 %) among these patients. Nine (8 %) of the patients died during the readmission period, a rate which is considerably higher than the overall CCCU mortality rate (3.8 %) in the same period of time.

CONCLUSIONS

Respiratory reasons are the most common cause for early CCCU readmission among pediatric cardiac patients. The readmitted patients have higher rates of death compared to the overall pediatric cardiac critical care population. The development of objective predischarge scores might help planning appropriately for discharge to the ward and avoid readmission to the CCU.

Early determinants of atherosclerosis in paediatric systemic lupus erythematosus

OBJECTIVES

To assess traditional and non-traditional cardiovascular risk factors and to determine the prevalence and correlates of early vascular markers of atherosclerosis in paediatric systemic lupus erythematosus (pSLE).

METHODS

Fifty-four adolescents with pSLE had cardiovascular risk factor assessment, disease activity and vascular testing including carotid intima-media thickness (CIMT), flow-mediated dilatation (FMD), arterial stiffness measures, and myocardial perfusion studies.

RESULTS

The traditional risk factors of hypertension, elevated triglycerides, apolipoprotein B, haemoglobin A1c and insulin levels and non-traditional risk factors of elevated homocysteine and fibrinogen were present (all p<0.001). Some arterial stiffness measures, central pulse wave velocity and characteristic impedance were elevated (p<0.001), but CIMT, FMD and myocardial perfusion were normal. Cumulative prednisone dose correlated with total cholesterol (r=0.5790, p<0.001) and elevated LDL-C (r=0.4488, p=0.0012). Hydroxychloroquine treatment correlated negatively with total cholesterol (r=-0.4867, p=0.0002), LDL-C (r=-0.4805, p=0.0002) and apolipoprotein B (r=-0.4443, p=0.0011). In multivariate analysis LDL-C correlated with cumulative prednisone dose and negatively with hydroxychloroquine treatment (R2=0.40, p<0.001).

CONCLUSIONS

An increased burden of traditional and non-traditional risk factors and early evidence of insulin resistance and increased central arterial stiffness were present in paediatric SLE. Disease-specific and therapy-related factors are likely modifying these cardiovascular risk profiles warranting prospective longitudinal studies.

Factors associated with the physical activity level of children who have the Fontan procedure

BACKGROUND

Children with complex heart defects are sedentary, with activity level unrelated to exercise capacity. We sought to identify factors associated with physical activity level for children who have the Fontan procedure.

METHODS

We used a cross-sectional study, 64 children (25 female, 5-11 years) after Fontan. Measurements were weekly minutes of moderate-to-vigorous physical activity, cardiac status, resting/exercise cardiopulmonary capacity, gross motor skill, health-related endurance/strength/body composition, and parent/child activity perceptions.

RESULTS

Participants performed 361 ± 137 minutes per week of moderate-to-vigorous physical activity. Increased activity related to antithrombotic medication use (86 min/wk), lower resting heart rate (3 min/wk), higher weekday outdoor time (0.7 minutes per outside minute), lower family income (13 minutes per $10,000), and higher parent rating of child's activity relative to peers (36 min/wk). Factors related to decreased activity were winter season (-84 min/wk), history of arrhythmia (-96 min/wk), and greater child confidence in own ability to be active (-113 min/wk).

CONCLUSIONS

Physical activity after the Fontan procedure is primarily associated with factors unrelated to cardiac status. Interventions that impact these modifiable factors would be expected to enable these children to achieve the recommended activity levels associated with optimal health.

Does pain catastrophizing moderate the relationship between spinal nociceptive processes and pain sensitivity?

Existing evidence indicates that pain catastrophizing is associated with enhanced pain reports and lower pain threshold/tolerance levels, but is not significantly related to nociceptive flexion reflex (NFR) threshold in healthy and clinical pain samples. This suggests pain catastrophizing may modulate pain threshold at a supraspinal level without influencing descending modulation of spinal nociceptive inputs. To examine this issue further, the present study assessed NFR threshold, electrocutaneous pain threshold, and electrocutaneous pain tolerance, as well as subjective ratings of noxious stimuli in a sample of 105 healthy adults. Pain catastrophizing was assessed prior to testing using traditional instructions and after pain testing with instructions to report on cognitions during testing (situation-specific catastrophizing). As expected, NFR threshold was correlated with pain sensitivity measures, but uncorrelated with both measures of catastrophizing. Although situation-specific catastrophizing was correlated with some pain outcomes, neither catastrophizing measure (traditional or situation specific) moderated the relationship between NFR and pain sensitivity. These findings confirm and extend existing evidence that catastrophizing influences pain reports through supraspinal mechanisms (eg, memory, report bias, attention) without altering transmission of spinal nociceptive signals.

PERSPECTIVE

Assessing catastrophic thoughts related to a specific painful event (situation-specific catastrophizing) provides important additional information regarding the negative cognitions that influence pain-related processes. However, neither situation-specific nor traditionally measured pain catastrophizing appear to enhance pain by engaging descending controls to influence spinal nociceptive processes.

Handedness for tool use in captive chimpanzees (Pan troglodytes): Sex differences, performance, heritability and comparison to the wild

There is continued debate over the factors influencing handedness in captive and wild primates, notably chimpanzees. Previous studies in wild chimpanzees have revealed population-level left handedness for termite fishing. Here we examined hand preferences and performance on a tool use task designed to simulate termite fishing in a sample of 190 captive chimpanzees to evaluate whether patterns of hand use in captive chimpanzees differed from those observed for wild apes. No population-level handedness was found for this task; however, significant sex differences in preference and performance were found, with males showing greater left handedness and poorer performance compared to females. We also found that the hand preferences of offspring were significantly positively correlated with the hand preferences of their mothers. Lastly, older females performed more slowly on the task compared to younger individuals. The overall results neither confirm nor reject previous hypotheses claiming that raising chimpanzees in captivity induces right-handedness, but rather suggest that other factors may account for differences in hand preferences for tool use seen in wild and captive chimpanzees.

Emotional control of nociceptive reactions (ECON): do affective valence and arousal play a role?

Prior research suggests emotional picture-viewing modulates motoric (nociceptive flexion reflex), autonomic (skin conductance response, heart rate acceleration), and subjective (pain rating) reactions to noxious electrodermal stimulation. The present study sought to determine whether emotional valence and arousal contribute to nociception modulation. To do so, pictures varying in emotional content (erotica, food, neutral, loss, attack) were chosen to manipulate emotional valence (pleasant=erotic and food; unpleasant=loss and attack) and arousal (low=food and loss; moderate=erotica and attack). Pictures were presented in pseudorandom order to elicit emotional processing while noxious electric stimulations were delivered to the sural nerve. Nociceptive flexion reflex (NFR) magnitude, skin conductance response (SCR), heart rate (HR) acceleration, and subjective pain ratings to each stimulation were measured, standardized, averaged by picture content, and analyzed. Results suggested that picture-viewing explained 52% of the variance in the multivariate combination of the nociceptive reactions and modulated them in parallel. Pleasant pictures inhibited reactions, whereas unpleasant pictures enhanced them. However, only erotica and attack pictures elicited significant modulation relative to neutral pictures, suggesting arousal also contributed. An exploratory multilevel analysis also supported this conclusion. Together, these data suggest emotional control of nociceptive reactions (ECON) is associated with a valence-by-arousal interaction. Implications of these findings for how emotional picture-viewing can be used to study supraspinal modulation are discussed.

Physical activity levels in children and adolescents are reduced after the Fontan procedure, independent of exercise capacity, and are associated with lower perceived general health

OBJECTIVES

To determine physical activity levels in paediatric patients who underwent the Fontan procedure, and their relationship to functional status and exercise capacity.

STUDY DESIGN

We studied 147 patients (ages 7-18 years) at a median of 8.1 years after Fontan, as part of the Pediatric Heart Network cross-sectional study of Fontan survivors. Assessment included medical history, self-reported physical activity, parent-completed Child Health Questionnaire (CHQ), cardiopulmonary exercise testing and physical activity level measured by accelerometry (MTI Actigraph).

RESULTS

Measured time spent in moderate and vigorous activity was markedly below normal at all ages, particularly in females, and was not significantly related to self-reported activity levels, or to maximum Vo2, Vo2 at anaerobic threshold or maximum work rate on exercise testing. Lower measured activity levels were significantly related to lower perceived general health but not to self-esteem, physical functioning, social impact of physical limitations or overall physical or psychosocial health summary scores. Reduced exercise capacity was more strongly related than measured activity levels to lower scores in general health, self-esteem and physical functioning.

CONCLUSIONS

Physical activity levels are reduced after Fontan, independent of exercise capacity, and are associated with lower perceived general health but not other aspects of functional status.

Does In Vivo Catastrophizing Engage Descending Modulation of Spinal Nociception?

Prior research has found that pain catastrophizing measured before pain testing is not correlated with the nociceptive flexion reflex (NFR) threshold (a measure of spinal nociception), suggesting that catastrophizing does not alter pain through descending modulatory mechanisms. However, recent evidence suggests that in vivo catastrophizing (measured during or after pain testing) is a better predictor of pain outcomes. In the present study, NFR threshold and pain sensation ratings were assessed in 78 healthy participants by delivering electric stimulations to the sural nerve. After pain testing, participants were asked to rate their affective reaction (displeasure, arousal) to electric stimuli and to report on their pain catastrophizing. Hierarchical regression analyses controlling for participant sex, pre-experiment affect, depressive symptoms, and self-efficacy were used to predict pain-related outcomes (NFR threshold, pain sensation, displeasure ratings, arousal ratings) from in vivo catastrophizing scores. Results indicated that in vivo catastrophizing was related to pain sensation but not to NFR thresholds or arousal reactions. The relation between in vivo catastrophizing and displeasure ratings was not significant after other variables were controlled. These data support prior research suggesting that catastrophizing does not alter pain by engaging descending modulatory mechanisms.

PERSPECTIVE

Pain catastrophizing is an important psychological predictor of pain and pain-related functioning. The present study confirms prior reports suggesting that catastrophizing does not work by engaging mechanisms that alter pain transmission in the spinal cord before the signal travels to the brain.

Emotional modulation of spinal nociception and pain: The impact of predictable noxious stimulation

Recent evidence suggests that emotional picture-viewing is a reliable method of engaging descending modulation of spinal nociception. The present study attempted to replicate these findings and determine the effect of noxious stimulus predictability. Participants viewed pictures from the International Affective Picture System (IAPS), during which pain and nociceptive flexion reflexes (NFR) were elicited by electric shocks delivered to the sural nerve. For half of the participants (n=25) shocks were preceded by a cue (predictable), whereas the other half received no cue (unpredictable). Results suggested emotion was successfully induced by pictures, but the effect of picture-viewing on the NFR was moderated by the predictability of the shocks. When shock was unpredictable, spinal nociception (NFR) and pain ratings were modulated in parallel. Specifically, pain and NFR magnitudes were lower during pleasant emotions and higher during unpleasant emotions. However, when shocks were predictable, only pain was modulated in this way. NFRs from predictable shocks were not altered by pictures. Further, exploratory analyses found that pain ratings, but not NFRs, were lower during predictable shocks. These data suggest emotional picture-viewing is a reliable method of engaging descending modulation of spinal nociception. However, descending modulation could not be detected in NFRs resulting from predictable noxious stimuli. Although preliminary, this study implies that separate mechanisms are responsible for emotional modulation of nociception at spinal vs. supraspinal levels, and that predictable noxious events may disengage modulation at the spinal level. The current paradigm could serve as a useful tool for studying descending modulation.

E2F1 suppresses skin carcinogenesis via the ARF-p53 pathway

The E2F1 transcription factor, which is deregulated in most human cancers by mutations in the p16-cyclin D-Rb pathway, has both oncogenic and tumor-suppressive properties. This is dramatically illustrated by the phenotype of an E2F1 transgenic mouse model that spontaneously develops tumors in the skin and other epithelial tissues but is resistant to papilloma formation when subjected to a two-stage carcinogenesis protocol. Here, this E2F1 transgenic model was used to further explore the tumor-suppressive property of E2F1. Transgenic expression of E2F1 was found to inhibit ras-driven skin carcinogenesis at the promotion stage independent of the type of promoting agent used. E2F1 transgenic epidermis displayed increased expression of p19(ARF), p53, and p21(Cip1). Inactivation of either p53 or Arf in E2F1 transgenic mice restored sensitivity to two-stage skin carcinogenesis. While Arf inactivation impaired tumor suppression and p21 induction by E2F1, it did not reduce the level of apoptosis observed in E2F1 transgenic mice. Based on these findings, we propose that E2F1 suppresses ras-driven skin carcinogenesis through a nonapoptotic mechanism involving ARF and p53.

Postoperative Chylothorax After Cardiothoracic Surgery in Children

BACKGROUND

The purpose of this study is to determine the incidence, risk factors, and outcomes for chylothorax in children undergoing cardiothoracic surgery.

METHODS

Hospital databases were used to identify chylothorax cases. Surgical databases were used to identify all patients undergoing cardiothoracic surgery. Medical records were reviewed, including daily records of drainage volumes and management.

RESULTS

From September 2000 to December 2002, there were 48 cases of chylothorax in 1,257 surgeries--an incidence of 3.8% (95% confidence interval: 2.8% to 4.8%). Overall mortality rate was similar, but cases had longer postoperative hospital stays (median, 22 versus 8 days; p < 0.001). Incidence of chylothorax was significantly higher with heart transplantation and Fontan procedures. Diagnosis was made at a median of 6 days after surgery. Duration of drainage was a median of 15 days, with 11 patients draining more than 30 days. Longer duration of drainage was associated with cavopulmonary anastomosis procedures and longer time to diagnosis of chylothorax. Nutritional management included low fat diet, enteral feeds enriched with medium-chain triglycerides, and parenteral nutrition. Five patients were treated with octreotide, 4 with thoracic duct ligation, and 1 with pleurodesis. Octreotide was associated with a variable effect on drainage. Thoracic duct ligation reduced, but did not stop drainage.

CONCLUSIONS

Chylothorax increases duration of hospitalization after cardiovascular surgery in children. Early diagnosis may reduce the duration of chylothorax. Nutritional strategies remain the cornerstone for management of postoperative chylothorax. The impact of octreotide and surgical intervention is limited when reserved for patients with severe or prolonged drainage.

Anatomic repair of anomalous left coronary artery from the pulmonary artery by aortic reimplantation: early survival, patterns of ventricular recovery and late outcome

BACKGROUND

To determine the early and late outcomes of patients presenting with anomalous left coronary artery from the pulmonary artery who had repair by aortic reimplantation.

METHODS

From January 1952 to July 2000, 67 patients presented with anomalous coronary artery from the pulmonary artery. Forty-seven patients who had repairs performed by aortic reimplantation are the subject of this study. The median age at repair was 7.7 months. Before repair, 10 infants (21%) presented in extremis requiring ventilatory and inotropic support, and 38 infants (80%) presented in heart failure. Autologous pericardial hood coronary arterioplasty was used in 4 patients, and concomitant mitral valve repair was used in 1 patient.

RESULTS

Hospital survival was 92%. Five children required postoperative extracorporeal membrane oxygenation for a median of 4 days (range, 2 to 8 days). Patients who had extracorporeal membrane oxygenation were significantly more likely to have presented in critical condition (40% vs 3% if no extracorporeal membrane oxygenation; p = 0.006) or with ventricular arrhythmias (67% vs 7%; p = 0.027), to have presented with significantly lower preoperative repair median ejection fraction (10%, n = 5 vs 40%, n = 38; p = 0.01) or to have presented with more severe left ventricular dilatation (p = 0.03). Within a 15-year or less follow-up (mean, 4.7 years) there were no late deaths. Kaplan-Meier survival was 91% at 5 years, and freedom from reoperation was 93% at 10 years. At late follow-up, echocardiography demonstrated significant improvements in mean ejection fraction (64% +/- 9% vs 33% +/- 21% preoperatively, p < 0.0001); moderate mitral regurgitation (9% vs 38% preoperatively, p < 0.02); and wall motion abnormalities (15% vs 81% preoperatively, p < 0.002). The ratio of measured left ventricular end-diastolic dimension to the 95th percentile of normal declined from 1.4 +/- 0.3 to 1.0 +/- 0.1 (p < 0.0006). Children who had extracorporeal membrane oxygenation had normal ejection fractions and ventricular dimensions at follow-up (n = 3). Repeated measures of mixed linear regression analysis demonstrated that normalization of ejection fraction and left ventricular function occurred within 1 year of repair. Improvements in mitral regurgitation lagged behind normalization of ejection fraction and left ventricular dilatation.

CONCLUSIONS

Anatomic repair of anomalous left coronary artery from the pulmonary artery by aortic reimplantation yields excellent early survival and late functional outcomes even in critically ill infants.

Outcome following repair of sinus venosus atrial septal defects in children

The outcome of surgical repair of sinus venosus atrial septal defect was reviewed retrospectively. The operation was performed on 44 children aged 8 to 163 months, between April 1985 and November 1998. Median cardiopulmonary bypass and aortic crossclamp times were 58 minutes (range, 29 to 141 minutes) and 29 minutes (range, 4 to 67 minutes), respectively. Use of blood products decreased from 4.5 units per patient in the first period (1985 to 1989) to 0.6 units in the last period (1995 to 1998). Median intensive care and hospital stays were 2 days (range, 1 to 12 days) and 6 days (range, 4 to 16 days), respectively. There was 1 early death (2.3%). Complications included reexploration for bleeding in 2 patients (4.5%) and for superior vena cava obstruction in 1 (2.3%), and arrhythmias in 3 (6.8%), which required a pacemaker in one. During follow-up of 15 to 176 months, 83.8% of patients were in sinus rhythm. One required angioplasty for superior vena cava stenosis, hemodynamically insignificant residual shunt was found in 3, and mild superior vena cava stenosis in 3. Repair of sinus venosus atrial septal defect carries a low mortality and morbidity, but long-term follow-up is needed to monitor potential sinus node dysfunction and superior vena cava stenosis.

Surgical Closure of Secundum Atrial Septal Defects: The Cutting Edge?

Between January 1985 and November 1998, 270 patients (aged 2 to 220 months) underwent surgical closure of a secundum atrial septal defect. Cardiopulmonary bypass times ranged from 12 to 103 minutes, with aortic crossclamp times of 5 to 49 minutes. Use of blood products decreased from 2.7 units per patient in the first 5 years to 0.2 units in the last 4 years. Median intensive care unit and hospital stays were 2 days and 6 days, respectively. Complications included: bleeding in 6 patients (2%), which required reexploration in 3; air embolism in 1; and arrhythmias in 4. Postpericardiotomy syndrome occurred in 43 patients (16%), requiring drainage in 5. Follow-up (12 to 179 months) was available in 245 patients (91%). There were no early or late deaths. Most patients (94%) were in sinus rhythm, 8 had low atrial rhythm, 3 had first-degree atrioventricular block, and 1 had atrial flutter. Echocardiography in 207 patients (77%) demonstrated a residual shunt in 1 (0.5%), which was hemodynamically insignificant. Late reoperation was required in 4 patients for sternal nonunion. Surgical closure of secundum atrial septal defect remains the gold standard with which transcatheter closure should be compared, particularly with reference to morbidity and residual shunts.

Total cavopulmonary connections in children with a previous Norwood procedure

BACKGROUND

Outcomes of the Fontan operation in children initially palliated with the modified Norwood procedure are incompletely defined.

METHODS

From August 1993 to January 2000, 45 patients (mean age 2.6 +/- 1.1 years, weight 12.7 +/- 2.8 kg) who were palliated with staged Norwood procedures (hypoplastic left heart syndrome, n = 32; nonhypoplastic left heart syndrome, n = 13) underwent a modified Fontan operation. Preoperative features included moderate/severe atrioventricular valve regurgitation (n = 5, 11%), reduced ventricular function on echocardiography in 11 patients, McGoon index 1.56 +/- 0.38, and pulmonary artery distortion in 18 patients (40%).

RESULTS

A lateral tunnel (n = 16) or an extracardiac conduit (n = 29) connection with fenestration in 38 patients (84%) was used. Concomitant procedures included pulmonary artery reconstruction (n = 24, 53%), atrioventricular valve repair (n = 4, 9%) or replacement (n = 1). Before Fontan, 12 patients (27%) had an intervention to address neoaortic obstruction, and 7 patients required balloon dilation/stenting of the left (n = 5) or right pulmonary artery (n = 5). Intraoperatively, left (n = 5) or right pulmonary artery (n = 1) stenting was performed in 5 patients (11%). On follow-up, 8 patients required additional interventional procedures to address left pulmonary artery narrowing (n = 5), or venous (n = 5) or arteriopulmonary collaterals (n = 1). Perioperative mortality was 4.4% (n = 2). There were 2 late deaths at a mean follow-up of 39 +/- 20 months.

CONCLUSIONS

In relatively high-risk patients, midterm results of the Fontan operation for children initially palliated with the Norwood procedure were good. Combined interventional-surgical treatment algorithms can lead to improved outcomes.

A comparison of hydroxylapatite coated implant retained fixed and removable mandibular prostheses over 4 to 6 years

In a 6-year prospective clinical study, 181 hydroxylapatite coated endosseous dental implants were placed into the anterior mandible of 48 patients. Twenty-one patients were treated with fixed prostheses and 27 patients with an overdenture. When the implants were exposed all 181 had integrated. To date, there is 100% survival of all implants and they all retain a functioning prostheses. The initial results were very promising, in both groups the interval success was over 95% in the first 4 years of the study. However, by year 6, the interval success rates had fallen to 83% for both the fixed and removable groups. This study also compares the construction and maintenance complications for the two types of restorations. The clinical time taken, after implant exposure, to construct the prostheses was similar whether the fixed (mean of 8 visits) or removable option (mean of 7 visits) was chosen. However, the removable restoration cost less than half the price of the fixed when both technical time and implant component costs were evaluated. Maintenance for both groups was higher than expected, but patients required more appointments in the removable group both in the first year and beyond. Regarding the prostheses itself, the incidence of remakes, relines and general adjustments was higher in the removable group. This study has shown that the overdenture offers an effective and initially a more economical alternative to the fixed prostheses, in the treatment of the edentulous mandible. However, long-term maintenance of such a prosthesis can be significant.

Case report: the transmandibular implant system

This series of case reports outlines the use of the transmandibular implant system to rehabilitate 10 patients with severely resorbed mandibles. The implants were placed according to manufacturers' guidelines with the patient under a general anaesthetic and reviewed bi-annually thereafter. Three patients experienced problems: in two of these this involved the loss of integration of the distal posts, in the other patient the transmandibular implant was removed in its entirety. Distal locking screws became loose shortly after placement in three patients. Prosthetic complications included difficulty in obtaining passive fit of the superstructure in 7 patients and a high long-term maintenance commitment.

Surgical harvesting of bone graft from the ilium: point of view

Autologous bone harvested from the ilium is commonly used as a grafting material in surgical reconstructive and arthrodesis procedures to ensure a satisfactory postoperative outcome. However, operative removal of bone from the iliac crest requires an additional surgical procedure with a distinct set of postoperative complications. We provide a comprehensive literature synthesis of the incidence and severity of complications reported to be associated with this commonly practiced procedure. Most severe complications are rare, but chronic pain at the donor site exceeding three months in duration occurs frequently and can be particularly bothersome to patients. Alternative grafting materials that are safe and effective are sorely needed.

Augmenting local bone with Grafton demineralized bone matrix for posterolateral lumbar spine fusion: avoiding second site autologous bone harvest

Mineralization and integrity of the bone graft mass were evaluated among patients having posterolateral fusion. Grafting consisted of a composite of Grafton and "local" autologous bone (n=56) or iliac crest autograft alone (n=52). Mineralization was rated radiographically at baseline and at 3, 6, 12, and 24 months. Integrity was judged as fused or not fused. Mineralization ratings did not differ significantly between groups at any postoperative interval (P values of .25-1.00). The percentage of patients fused was similar in both groups (60% and 56% for Grafton and controls, respectively; P=.83). Fifteen control patients reported donor site pain. These findings warrant further evaluation of this composite.

E2F4 and E2F1 have similar proliferative properties but different apoptotic and oncogenic properties in vivo

Loss of retinoblastoma (Rb) tumor suppressor function, as occurs in many cancers, leads to uncontrolled proliferation, an increased propensity to undergo apoptosis, and tumorigenesis. Rb negatively regulates multiple E2F transcription factors, but the role of the different E2F family members in manifesting the cellular response to Rb inactivation is unclear. To study the effect of deregulated E2F4 activity on cell growth control and tumorigenesis, transgenic mouse lines expressing the E2F4 gene under the control of a keratin 5 (K5) promoter were developed, and their phenotypes were compared to those of previously generated K5 E2F1 transgenic mice. In contrast to what has been observed in vitro, ectopically expressed E2F4 was found to localize to the nucleus and induce proliferation to an extent similar to that induced by E2F1 in transgenic tissue. Unlike E2F1, E2F4 does not induce apoptosis, and this correlates with the differential abilities of these two E2F species to stimulate p19(ARF) expression in vivo. To examine the role of E2F4 in tumor development, the mouse skin two-stage carcinogenesis model was utilized. Unlike E2F1 transgenic mice, E2F4 transgenic mice developed skin tumors with a decreased latency and increased incidence compared to those characteristics in wild-type controls. These findings demonstrate that while the effects of E2F1 and E2F4 on cell proliferation in vivo are similar, their apoptotic and oncogenic properties are quite different.

Isolated origin of the left subclavian artery from the left pulmonary artery

We describe two children with isolated origin of the left subclavian artery from the left pulmonary artery detected by echocardiography during the assessment of their congenital cardiac malformations. Both patients demonstrated pre-operative evidence of subclavian steal. This entity results from persistence of the dorsal segment of the sixth left arch, with regression of the left fourth arch and interruption of the left dorsal arch distal to the origin of the seventh left intersegmental artery. The significance of this finding relates to the potential for pulmonary overcirculation, which could have significant post-operative ramifications if not detected prior to surgical repair of an associated cardiac malformation. This entity differs from cases with a right aortic arch and aberrant left subclavian artery which has the potential to form a vascular ring, unlike cases with isolated origin of the left subclavian artery from the pulmonary artery that do not cause compression of the airway.