Long-term outcomes of pulmonary embolism in children and adolescents

ABSTRACT

Knowledge regarding the long-term consequences of pulmonary embolism (PE) in children is limited. This cohort study describes the long-term outcomes of PE in children who were followed-up at a single-center institution using a local protocol that included clinical evaluation, chest imaging, echocardiography, pulmonary function tests, and cardiopulmonary exercise tests at follow-up, starting 3 to 6 months after acute PE. Children objectively diagnosed with PE at age 0 to 18 years, who had ≥6 months of follow-up were included. Study outcomes consisted of PE resolution, PE recurrence, death, and functional outcomes (dyspnea, impaired pulmonary or cardiac function, impaired aerobic capacity, and post-PE syndrome). The frequency of outcomes was compared between patients with/without underlying conditions. In total, 150 patients were included; median age at PE was 16 years (25th-75th percentile, 14-17 years); 61% had underlying conditions. PE did not resolve in 29%, recurrence happened in 9%, and death in 5%. One-third of patients had at least 1 documented abnormal functional finding at follow-up (ventilatory impairments, 31%; impaired aerobic capacity, 31%; dyspnea, 26%; and abnormal diffusing capacity of the lungs to carbon monoxide, 22%). Most abnormalities were transient. When alternative explanations for the impairments were considered, the frequency of post-PE syndrome was lower, ranging between 0.7% and 8.5%. Patients with underlying conditions had significantly higher recurrence, more pulmonary function and ventilatory impairments, and poorer exercise capacity. Exercise intolerance was, in turn, most frequently because of deconditioning than to respiratory or cardiac limitation, highlighting the importance of physical activity promotion in children with PE.

Study of the ^{22}Mg Waiting Point Relevant for X-Ray Burst Nucleosynthesis via the ^{22}Mg(α,p)^{25}Al Reaction

The ^{22}Mg(α,p)^{25}Al reaction rate has been identified as a major source of uncertainty for understanding the nucleosynthesis flow in Type-I x-ray bursts. We report a direct measurement of the energy- and angle-integrated cross sections of this reaction in a 3.3-6.9 MeV center-of-mass energy range using the MUlti-Sampling Ionization Chamber (MUSIC). The new ^{22}Mg(α,p)^{25}Al reaction rate is a factor of ∼4 higher than the previous direct measurement of this reaction within temperatures relevant for x-ray bursts, resulting in the ^{22}Mg waiting point of x-ray burst nucleosynthesis flow to be significantly bypassed via the (α,p) reaction.

Unraveling the pathophysiology of lower-limb postthrombotic syndrome in adolescents: a proof-of-concept study

A better understanding of the pathophysiology of pediatric postthrombotic syndrome (PTS) is needed to develop strategies to treat this condition. We investigated calf pump function, exercise capacity, balance in power output, and changes in limb muscle oxygen saturation (SmO2) and fluid content during exercise in 10 pediatric patients with unilateral lower-limb PTS, and in age- and sex-matched controls (1:1-1:2 ratio). Outcomes were investigated using bioimpedance spectroscopy, torque-sensing pedals, and near-infrared spectroscopy during incremental- and constant-load cycling tests. The median age at participation was 17 years (25th-75th percentile, 15-18 years); 68% of participants were females. The median CAPTSure score in the affected leg of affected participants was 35 points (25th-75th percentile, 24-46 points), indicating moderate/severe PTS; 20% of patients had a history of central venous catheter-related thrombosis. Increasing PTS severity was associated with higher calf pump venous volume and higher ejection volume, leading to compensated calf pump performance. We found no evidence of PTS impact on exercise capacity. Leg contribution to power output was similar in affected and unaffected legs. However, the PTS-affected legs showed lower SmO2 during active cycling and recovery with increasing PTS severity, indicating impaired microvascular function in the muscle. These findings suggest that PTS severity is associated with impaired blood flow, presumably from elevated venous pressure during and after exercise. The fact that microvascular function is impaired in young patients with PTS underscores the relevance of developing strategies to mitigate the effects of this chronic vascular disease to minimize its deleterious effects as children grow older.

Physical Activity for Children with Deep Vein Thrombosis and Pulmonary Embolism on Anticoagulation: A Scoping Review

Context

There are no clear pediatric guidelines on the return to physical activity following deep vein thrombosis (DVT) or pulmonary embolism (PE), particularly while being treated with anticoagulation.

Objective

This scoping review aimed to examine the current literature on physical activity beyond simple ambulation for patients with DVT/PE being treated with anticoagulation.

Data Sources

An electronic search for articles in MEDLINE, Epub Ahead of Print, In-Process, and Other Non-Indexed Citations, Daily (1946 to April 4, 2022), and Embase+Embase Classic (1946 to 2022, week 13) was conducted.

Study Selection

(1) Patients of any age with DVT/PE, treated with anticoagulation; (2) studies of any design providing information on physical activity (ie, sport, exercise) while on anticoagulation; and (3) studies in English.

Data Extraction

Data from eligible studies obtained included the study design, population, disease characteristics, and information on physical activity participation.

Results

A total of 26 eligible studies were included. Only 2 studies were specific to children. Studies recommend a gradual return to participation in noncontact or low-risk activities after the first 3-4 weeks of anticoagulation, with close monitoring of symptoms. Participation in contact sports and activities is typically delayed until after anticoagulants are discontinued. However, personalized anticoagulation with intermittent dosing schedules has been proposed for athletes after the first 3 months of anticoagulation treatment.

Conclusions

Physical activity participation guidelines for children with DVT/PE being treated with anticoagulation are needed, and the evidence currently available is limited. Largely based on evidence from adult patients, we present evidence-informed options to facilitate clinician recommendations for returning to activity.

Functional impact of pediatric postthrombotic syndrome

BACKGROUND

Postthrombotic syndrome (PTS) is the most common complication of deep vein thrombosis (DVT) in children.

OBJECTIVES

We aimed to assess the impact of pediatric PTS on functioning as assessed by movement ability, mobility, functional disability, and physical activity levels in children after diagnosis of limb DVT.

METHODS

Patients aged 8-21 years in follow-up care after objectively documented limb DVT were prospectively recruited in this cross-sectional study. Measures of functioning (outcomes) included self-reported questionnaires that assessed: 1) movement ability, measured with the Movement Ability Measure-Computer Adaptive Test version; 2) mobility, evaluated with the Computer Adaptive Test version of the Patient-Reported Outcomes Measurement Information System Pediatric Physical Functioning, Mobility domain; 3) functional disability, evaluated with the Functional Disability Inventory; and 4) physical activity levels, evaluated with the Godin Leisure-Time Exercise Questionnaire. The main predictor was PTS severity, which was assessed using the index for the Clinical Assessment of PTS in children. The association between PTS and outcomes was analyzed using linear models.

RESULTS

Eighty-seven patients (median age, 16 years; 25th-75th percentile, 15-18 years; 56% boys) were enrolled. Adjusted for age, sex, and underlying condition, increasing PTS severity was associated with lower current movement ability, a wider gap between current vs preferred movement ability, lower mobility, and slightly higher functional disability scores. There was a nonsignificant effect of PTS severity on moderate-strenuous physical activity.

CONCLUSION

In children, increased PTS severity is associated with lower movement ability and impaired mobility. Reducing the gap between the patients' current vs preferred movement ability is a relevant aspect of PTS management in children.

Stellar ^{36,38}Ar(n,γ)^{37,39}Ar Reactions and Their Effect on Light Neutron-Rich Nuclide Synthesis

The ^{36}Ar(n,γ)^{37}Ar (t_{1/2}=35  d) and ^{38}Ar(n,γ)^{39}Ar (269 yr) reactions were studied for the first time with a quasi-Maxwellian (kT∼47  keV) neutron flux for Maxwellian average cross section (MACS) measurements at stellar energies. Gas samples were irradiated at the high-intensity Soreq applied research accelerator facility-liquid-lithium target neutron source and the ^{37}Ar/^{36}Ar and ^{39}Ar/^{38}Ar ratios in the activated samples were determined by accelerator mass spectrometry at the ATLAS facility (Argonne National Laboratory). The ^{37}Ar activity was also measured by low-level counting at the University of Bern. Experimental MACS of ^{36}Ar and ^{38}Ar, corrected to the standard 30 keV thermal energy, are 1.9(3) and 1.3(2) mb, respectively, differing from the theoretical and evaluated values published to date by up to an order of magnitude. The neutron-capture cross sections of ^{36,38}Ar are relevant to the stellar nucleosynthesis of light neutron-rich nuclides; the two experimental values are shown to affect the calculated mass fraction of nuclides in the region A=36-48 during the weak s process. The new production cross sections have implications also for the use of ^{37}Ar and ^{39}Ar as environmental tracers in the atmosphere and hydrosphere.

Probing the Single-Particle Character of Rotational States in ^{19}F Using a Short-Lived Isomeric Beam

A beam containing a substantial component of both the J^{π}=5^{+}, T_{1/2}=162  ns isomeric state of ^{18}F and its 1^{+}, 109.77-min ground state is utilized to study members of the ground-state rotational band in ^{19}F through the neutron transfer reaction (d,p) in inverse kinematics. The resulting spectroscopic strengths confirm the single-particle nature of the 13/2^{+} band-terminating state. The agreement between shell-model calculations using an interaction constructed within the sd shell, and our experimental results reinforces the idea of a single-particle-collective duality in the descriptions of the structure of atomic nuclei.

Study of the ^{26}Al^{m}(d,p)^{27}Al Reaction and the Influence of the ^{26}Al 0^{+} Isomer on the Destruction of ^{26}Al in the Galaxy

The existence of ^{26}Al (t_{1/2}=7.17×10^{5}  yr) in the interstellar medium provides a direct confirmation of ongoing nucleosynthesis in the Galaxy. The presence of a low-lying 0^{+} isomer (^{26}Al^{m}), however, severely complicates the astrophysical calculations. We present for the first time a study of the ^{26}Al^{m}(d,p)^{27}Al reaction using an isomeric ^{26}Al beam. The selectivity of this reaction allowed the study of ℓ=0 transfers to T=1/2, and T=3/2 states in ^{27}Al. Mirror symmetry arguments were then used to constrain the ^{26}Al^{m}(p,γ)^{27}Si reaction rate and provide an experimentally determined upper limit of the rate for the destruction of isomeric ^{26}Al via radiative proton capture reactions, which is expected to dominate the destruction path of ^{26}Al^{m} in asymptotic giant branch stars, classical novae, and core collapse supernovae.

Development of CAPTSureTM - a new index for the assessment of pediatric postthrombotic syndrome

Essentials We developed a discriminative and evaluative index for pediatric postthrombotic syndrome (PTS). A Delphi-survey was used for item reduction and multi-criteria decision analysis for item weighting. The new index assesses limb PTS based on the relative severity of each sign and symptom. Higher scores related to higher odds of parental dissatisfaction with their child's condition.

SUMMARY

Background Postthrombotic syndrome (PTS) is a complication of deep vein thrombosis defined by the presence of characteristic signs and symptoms. We developed a discriminative and evaluative index for the assessment of upper extremity (UE) and lower extremity (LE) pediatric PTS. Methods The items to be included in the index were voted for by 26 pediatric thrombosis experts invited to participate in a Delphi survey. Subsequent item weighting was based on item importance elicited by the use of multicriteria decision analysis (MCDA); 122 healthcare providers and patients/parents were invited to participate in item weighting. The implications of the overall scores were explored by comparison with PTS diagnosis (independently assessed by two clinical experts) and parental satisfaction/dissatisfaction with their child's current condition. Results Items voted for inclusion by at least 70% of the Delphi survey respondents (81% response rate) were pain, paresthesia, swelling, heaviness, endurance, collateral circulation and arm circumference difference for the UE, and pain, paresthesia, swelling, heaviness, tightness, tired limb, redness/purple or blotchy skin, endurance, ulcers and thigh/calf circumference difference for the LE. Items were then weighted by the use of MCDA (82% response rate). The index had excellent discrimination for patients with/without PTS. For every 10-point increase in index scores (with higher scores being indicative of worse PTS), the odds of parental dissatisfaction increased by 75% and 92% in the UE and LE, respectively. Conclusion We report the development of the CAPTSure™ (index for the Clinical Assessment of Postthrombotic Syndrome in children), which reflects collective judgement of the severity of pediatric PTS. We also provide information on the meaning of the scores.

Timing of low bone mineral density and predictors of bone mineral density trajectory in children on long-term warfarin: a longitudinal study

We studied bone mineral density (BMD) of children exposed to long-term warfarin. BMD Z-scores ≤ -2.0 were estimated to occur in less than one fifth of the patients after 10 years of warfarin exposure, and BMI and growth hormone deficiency predicted BMD changes over time. These predictors can help identify high-risk patients.

INTRODUCTION

Children with chronic diseases are at increased risk of developing thrombosis, which may require long-term warfarin therapy. Warfarin could further jeopardize the bone health of a population already at risk for bone fragility. Our objective was to investigate the occurrence and timing of low bone mineral density (BMD) and the predictors that influence BMD trajectory in children receiving warfarin for >1 year.

METHODS

We analyzed the results of an institutional protocol that includes dual-energy X-ray absorptiometry, with or without spinal X-rays and laboratory biomarkers, as required.

RESULTS

Low BMD (age, sex, race, and height-for-age-Z-score adjusted BMD Z-score ≤ -2.0) was detected in 13 % (9/70) of the patients at some point during their follow-up; these patients were more likely to have complex underlying medical conditions and low body mass index (BMI) percentile. BMD Z-scores remained within normal range in 87 % of children. Survival analysis showed that the estimated 10-year abnormal BMD-free rate for the entire group was 81 % (95 % confidence interval [CI] 69 to 93 %). Trajectory analysis revealed that BMI percentiles at baseline and growth hormone deficiency (GHD) were associated with lower BMD Z-scores at the first assessment, whereas baseline BMI percentile was the only predictor of BMD Z-score over time.

CONCLUSIONS

Our findings identified BMI and GHD as risk factors influencing BMD in children exposed to long-term warfarin, creating an opportunity for early detection and intervention in these patients.

Constraining the 6.05 MeV 0+ and 6.13 MeV 3- cascade transitions in the 12C(α,γ)16O reaction using the asymptotic normalization coefficients

The 12C(α,γ)^16O reaction plays a fundamental role in astrophysics and needs to be known with accuracy better than 10%. Cascade γ transitions through the excited states of 16 O are contributing to the uncertainty. We constrained the contribution of the 0+ (6.05 MeV) and 3- (6.13 MeV) cascade transitions by measuring the asymptotic normalization coefficients for these states using the α-transfer reaction 6 Li(12C,d)^16O at sub-Coulomb energy. The contribution of the 0+ and 3- cascade transitions at 300 keV is found to be 1.96 ± 0.3 and 0.12 ± 0.04  keV b for destructive interference of the direct and resonance capture and 4.36 ± 0.45 and 1.44 ± 0.12  keV b for constructive interference, respectively. The combined contribution of the 0+ and 3- cascade transitions to the 12C(α,γ)16O reaction cross section at 300 keV does not exceed 4%. Significant uncertainties have been dramatically reduced.

Systematic review on heparin-induced thrombocytopenia in children: a call to action

BACKGROUND

Heparin-induced thrombocytopenia (HIT) has increasingly been reported in children as an indication for use of new alternative anticoagulant drugs (NAADs).

OBJECTIVES

To systematically review the literature regarding: (i) the incidence and prevalence of seroconversion and HIT and (ii) the clinical/laboratory findings and management of HIT in children.

DESIGN/METHODS

MEDLINE and EMBASE databases were searched for studies that reported pediatric cases of HIT. Methodological reliability assessment of studies was performed with the Loney scale.

RESULTS

The incidence of seroconversion in neonates ranged between 0% and 1.7%. There were no cases of neonatal HIT in the included cohorts. The incidence range of seroconversion in the non-neonatal population was 1.3-52%. The incidence of HIT in non-neonates after cardiopulmonary bypass was 0.33% (95%CI, < 0.01-2.04). Whereas more than half of pediatric cases labeled as HIT (30/52) did not include pivotal features of this syndrome, 80% of them received NAADs.

CONCLUSION

The incidence of HIT is likely to have been overestimated in children, leading to potential misuse of NAADs in many cases. Clinical findings and laboratory assessment of pediatric cases are poorly described in the literature at present. Thorough laboratory investigation, proper reporting of cases and adequate design of studies are mandatory to elucidate the clinical/laboratory picture of pediatric HIT.

Assessment of cervical involvement in endometrial carcinoma by hysteroscopy and directed biopsy

The objective of this study was to assess the diagnostic validity of hysteroscopy and directed biopsy for assessing cervical involvement in endometrial carcinoma. We conducted a study of 240 hysteroscopies and 44 cervical biopsies performed on 240 patients with endometrial carcinoma between 2000 and 2005. Hysteroscopy results suggested cervical involvement in 55 cases, of which only 31 were confirmed (a subtotal hysterectomy was performed in two cases, and the resection margins were examined for tumor invasion). In the 31 patients with confirmed cervical involvement, 19 of the hysteroscopy-directed biopsies were positive, 3 were negative, and 3 provided insufficient material. Six patients did not undergo biopsy. In the 24 patients with hysteroscopy false positive, 10 directed biopsies were positive and 9 were negative. Five patients did not undergo biopsy. Hysteroscopy suggested an absence of cervical involvement in 185 patients. Diagnosis was confirmed in 177 cases, and there were eight false negatives. In our case, office hysteroscopy proved to be a valid means of ruling out cervical involvement in endometrial carcinoma. However, it was not a valid means of detecting tumor involvement, even when combined with directed biopsy.

Establishment of Paediatric and Neonatal Intensive Care Units at Patan Hospital, Kathmandu: Critical Determinants and Future Challenges

Introduction: Although preventive medicine and primary care are priorities in developing countries, they must be supported by appropriate care of sick and extremely sick children in the medical facilities. Lack of resources and absence of skilled physicians and nurses may lead to poor outcomes in critically ill patients. Intensive care of newborns and children is thought to be very expensive with a low cost-benefit ratio. This presentation discusses the critical factors that facilitated the establishment of PICU and NICU in an urban public hospital in Nepal, where a good standard of Level 2 care was already provided. Aims and objectives: A cooperative model of creation and transfer of technology from the West to a resource-poor country was envisaged. PICU and NICU with six beds each were established. Design and setting: The Nick Simons Foundation, USA provided financial support for design, building and furnishing of a new Mother and Child Wing at Patan Hospital. A generous grant of $300,000 again by the Nick Simons Foundation helped equip the units. Donated equipments also included procedures, medication and storage carts. Methodology: A total of 22 volunteers, 21 from USA and one from Netherlands, were recruited to complete the three months of training. An extensive curriculum was prepared. The trainer team had monthly teleconferences and regular communications with the Chief of Paediatric Services and Nursing Director of Patan Hospital via e-mails and telephone. Responsibilities of volunteers and the host hospital were identified. Results: After 3 years of preparation, the project started in June 2009. All day lectures on topics in critical care, mock case scenarios, practical equipment training and simulated procedures led to the graduation of 60 nurses. Twenty five physicians were trained for three months. The expert team worked with the locals in preparing the units, arranging furniture and equipment, stocking carts, making inventory and preparing protocols. A protocol handbook was developed on topics such as mechanical ventilation, sedation, admission/discharge criteria, procedures and management of different disease states. Various charts such as nurse observation charts, notes by residents, procedure hand offs at change of shifts were designed and printed. Infection control practices and methods of sterilizing non disposable articles were identified and protocols written. At the end of three months the units were functioning with trained local manpower and reasonable modern equipment. Conclusion: Developing nations may not have enough resources to establish much needed critical care facilities. Developed countries can help by funding basic infrastructure and providing expertise in order to transfer knowledge and technology. Involvement in planning from the beginning and training at the host site is a preferred model of transfer of technology. Key words: Paediatric Intensive Care Unit (PICU); Neonatal Intensive Care Unit (NICU); Patan Hospital DOI: 10.3126/jnps.v31i1.4161J Nep Paedtr Soc 2010;31(1):49-56