Reversibility In Children Research Articles

OUTCOME OF EARLY INITIATION OF POST-SURGERY FEEDING AFTER COLOSTOMY REVERSAL IN CHILDREN

Background: Children undergoing colostomy reversal surgery often face uncertainties regarding the optimal timing for reintroducing feeding postoperatively. Early initiation of post-surgery feeding is of interest due to its potential to hasten recovery and reduce hospital stay. The impact of early feeding initiation is unclear. Objective of this study was to find out the outcome in terms of hospital stay and post-surgery complications of early initiation of post-surgery feeding after elective colostomy reversal in children. Methods: From 6 Jun 2022 to 10 Oct 2023, a non-randomized controlled trial was conducted at Bahawalpur, analyzing 93 children under 15 years with status colostomy following elective reversal. Patients were allocated to Group-A (traditional oral feeding) or Group-B (early oral feeding) at the surgeon’s discretion, with outcomes including post-surgery hospital stay duration and complications. Results: Out of a total of 93 patients, 49 (52.7%) were boys and 44 (47.3%) girls. Overall, mean age was 4.86±3.27 years. Anastomotic shock was noted among 6 (6.5%) patients while 9 (9.7%) patients had superficial surgical site infection. None of the patients needed repeat surgery for any post-surgery complications. No significant difference in terms of anastomotic leak (p=0.3983), and superficial surgical site infection (p=0.4980) were observed. Significantly shorter duration of post-surgery hospital stay was recorded among patients of Group-B when to compared to Groups-A (6.49±1.14 vs 8.90±1.27, p<0.0001). Conclusion: Early initiation of enteral feeding post elective colostomy reversal in children resulted in significantly reduced duration of post-surgery hospital stay. Pak J Physiol 2024;20(1):30-2

Experience with colostomy and colostomy reversal in children in Bauchi.

Colostomy is one of the common surgical procedures performed in pediatric surgical practice. The aim of this study was to retrospectively review our experience with colostomy and closure (reversal) in children. A retrospective review of the data of all children aged 15 years and below who had colostomy and colostomy closure in the past 5 years. Of the 67 children who had colostomy 42 (62.7%) boys and 25 (37.3%) girls, with an age range between 13 months and 8 years. Fifty-six (83.6%) of the children were <2 years. Anorectal malformation 53 (79.1%) was the common indication. Divided colostomy was performed in 62 (92.5%) patients and loop colostomy was performed in 5 (7.5%) patients. All the patients had intraperitoneal colostomy closure. A complication rate of 26.4% was seen. Duration of hospital stay ranged between 4 and 10 days. No mortality was recorded. Colostomy reversal is a safe procedure but morbidity may ensure and can easily manage.

The role of IL10 and IL17 gene polymorphisms in treatment response in children and adolescents with severe asthma.

To determine whether polymorphisms of the IL10 and IL17 genes are associated with severe asthma control and bronchodilator reversibility in children and adolescents with severe asthma. This was a cross-sectional study, nested within a prospective cohort study of patients with severe asthma. Two outcomes were evaluated: asthma control and bronchodilator reversibility. We extracted DNA from peripheral blood and genotyped three single nucleotide polymorphisms: rs3819024 and rs2275913 in the IL17A gene; and rs3024498 in the IL10 gene. For the association analyses, we performed logistic regression in three genetic models (allelic, additive, and dominant). The rs3024498 C allele in the IL10 gene was associated with failure to achieve asthma control despite regular treatment (p = 0.02). However, the G allele of the IL17A rs3819024 polymorphism was associated with failure to respond to stimulation with a b2 agonist. The rs2275913 polymorphism of the IL17A gene showed no relationship with asthma control or bronchodilator reversibility. In pediatric patients with severe asthma, the IL10 polymorphism appears to be associated with failure to achieve clinical control, whereas the IL17A polymorphism appears to be associated with a worse bronchodilator response. Knowledge of the involvement of these polymorphisms opens future directions for pharmacogenetic studies and for the implementation of individualized therapeutic management of severe asthma in pediatric patients.

Reversal of rocuronium-induced intense neuromuscular blockade by sugammadex in Korean children: A pharmacokinetic and pharmacodynamic analysis.

Sugammadex, a selective antagonist of steroidal non-depolarizing neuromuscular blocking agents, has been used in children in limited circumstances. However, neither pharmacokinetics (PKs) nor recovery profile of sugammadex for intense neuromuscular blockade reversal in children have been reported. This prospective study aimed to obtain a PK model of sugammadex and evaluate its efficacy and safety for intense neuromuscular blockade reversal in children. Forty children (age, 2-17 years) who underwent surgery that required early neuromuscular blockade reversal were enrolled. After neuromuscular blockade with 1mg∙kg-1 of rocuronium, sugammadex (2, 4, and 8mg∙kg-1 ) or a conventional dose of neostigmine (0.03 mg∙kg-1 ) was administered randomly after confirmation of zero post-tetanic count. The plasma concentrations of rocuronium and sugammadex were measured 2min after rocuronium injection; immediately before, 2, 5, 15, 60, 120, 240, and 480 min after the study drug injection. Response to train-of-four stimulation was continuously recorded. Noncompartmental analysis and population PK modeling were performed. For pharmacodynamics, the recovery profile was measured. Three-compartment PK model was established for sugammadex. The median (interquartile range [IQR]) time from injection of 8mg∙kg-1 of sugammadex to recovery of T4 /T1 greater than or equal to 0.9 at train-of-four stimulation was 1.1 (IQR: 0.88-1.8) min. No adverse events related to sugammadex were observed. We present a PK analysis of sugammadex for rocuronium-induced intense neuromuscular blockade reversal in children with its recovery profile. The time to recover T4 /T1 greater than or equal to 0.9 at train-of-four stimulation with 8mg∙kg-1 of sugammadex was less than 3min and comparable to that in adults.

Risk factors for administration of additional reversal following neuromuscular blockade with rocuronium in children: A retrospective case-control study.

BackgroundThe prevalence and risk factors for residual neuromuscular blockade in children remain poorly characterized. We hypothesize that specific patient and anesthetic risk factors may be associated with the administration of additional reversal in children following initial reversal of rocuronium with neostigmine.MethodsOur electronic health record was queried for patients <18 years of age who received rocuronium and reversal with neostigmine from 2017 through 2020. Patients receiving other nondepolarizing neuromuscular blocking drugs were excluded. The outcome of interest was defined as the administration of additional neostigmine or sugammadex following primary reversal with neostigmine. Time between the last dose of rocuronium and initial dose of neostigmine, and the cumulative dose of rocuronium were dichotomized. These were combined with other covariates including age, weight, sex, racial group, procedure type, ASA physical status, >1 rocuronium dose administered during the procedure, initial neostigmine dose <0.05 mg kg−1, use of train‐of‐four monitoring, duration of anesthesia, inpatient or outpatient, emergency case, neuromuscular disease, and extremes of weight, to assess possible associations with the primary outcome.ResultsDuring the study period, 101/6373 (1.58%) patients received rocuronium and additional reversal. Dichotomization of time between last dose of rocuronium and neostigmine yielded <28 min since the last dose of rocuronium and cumulative dose of rocuronium >0.45 mg kg−1 hr−1. These were associated with the administration of additional reversal with an OR 1.52 (95% CI, 1.08–2.35) and OR 1.71 (95% CI, 1.10–2.67), respectively. Other risk factors included an initial neostigmine dose <0.05 mg kg−1, OR 4.98 (95% CI, 2.84–6.49), and African American race, OR 1.78 (95% CI, 1.07–2.87).ConclusionRisk factors associated with the administration of additional reversal included time <28 min from the last dose of rocuronium to initial dose of neostigmine, cumulative dose of rocuronium >0.45 mg kg−1 hr−1, initial neostigmine dose <0.05 mg kg−1, and African American race.

Variation in spirometry parameters in children with and without recurrent respiratory problems

Background: Children having recurrent episodes of respiratory symptoms account for a major source of hospitalization. These children have increased morbidities and if not identified in time can have impaired lung function as adults. &#x0D; Objectives: The aim of our study was to compare the spirometry parameters and bronchodilator reversibility in children with and without recurrent respiratory problems.&#x0D; Methodology: This was a prospective observational study conducted in the Pediatric department of Manipal Teaching Hospital comparing 35 children with recurrent respiratory problems and 35 children with no history of recurrent respiratory problems. After thorough instructions, baseline spirometry was done in all children and recordings were noted. Thereafter they were given two puffs of salbutamol (100 µg) and repeat testing was done 20 minutes later. Bronchodilator reversibility was calculated according to standard formula. Various statistical tests were used to compare the findings between the two groups.&#x0D; Results: The recurrent respiratory problem group had 31 (88%) cases of bronchial asthma, two (5.7%) bronchiolitis obliterans, one (2.8%) pulmonary eosinophilia, and one (2.8%) common variable immunodeficiency syndrome. The median values of FEV1 (p=&lt;0.001), FVC (p=0.007), FEV1/FVC (p=0.005), PEF (p=0.042) and FEF25-75(p=0.026) were lower in the group with recurrent respiratory problems. Post-bronchodilator reversibility of FEV1 (p=0.001), FVC (p=&lt;0.001) and FEF25-75 (p=0.026) was higher in the groups with recurrent respiratory problems&#x0D; Conclusion: We found that lung function parameters in children with recurrent respiratory problems show features of obstructive defect. The post-bronchodilator response is higher in the group with recurrent respiratory problems as compared to normal children.

International Survey for Strategies Used for Oral Anticoagulation Reversal in Children

Background: Vitamin K antagonists (VKA) have been the main stay of oral anticoagulation (OAC) in pediatrics. However, VKA have multiple challenges. The pharmacological properties of direct oral anticoagulants (DOACs) suggest that they may have advantages particularly for children. The off-label use of DOACs is however on the rise within the pediatric population. The increasingly broad and varied use of DOACs, lack of published clinical guidance, and limited data on reversal strategies have created the imperative to identify strategies for OAC reversal in pediatrics. We conducted an online survey for strategies used for oral anticoagulants reversal in pediatrics. Study Design: Institutional review board approval was obtained and an online survey was developed using the RedCap. The survey was electronically distributed by International Society of Hemostasis and Thrombosis (ISTH) to its Pediatric/Neonatal Thrombosis and Hemostasis Subcommittee group members. The survey questions asked approach to common hypothetical clinical scenarios for OAC reversal.The data were analysed descriptively. Results: There were 76 respondents, majority from academic free-standing Children'sHospitals. Seventy-two percent reported having a hemostasis-thrombosis/anticoagulation service but only 29 % have a dedicated anticoagulation pharmacist. Approximately 40% do not have a formal protocol in place for VKA reversal. For a supra-therapeutic INR (INR &gt; 5) in a non-bleeding patient, 95% opted to manage by omitting the next dose of VKA while 18 % opted to give oral vitamin K alone or comitantly. For clinically relevant non-major bleeding, majority indicated using Vitamin K; oral (51%) or IV (37). For major bleeding on VKA, majority use either a combination of 4F-PCC and IV Vitamin K or plasma and IV Vitamin K (44/76 and 26/76 respectively). The presence of bleeding seemed to be the major driver for the choice of route (enteral versus parenteral) for Vitamin K for VKA reversal. Thirty-six of the 76 respondents indicated using DOACs; 94% used FXa inhibitors and 1/3 use dabigatran in their clinical practice. For non-urgent DOAC reversal, 97% indicated omitting the next dose. For non-major bleeding on DOAC, majority (29/36) indicated omitting the next dose/doses, some chose 4F-PCC (8/36) and only a few indicated use of specific reversal agents (3/36 and 1/36 for Dabigatran and Andexanet respectively). For major bleeding while on DOACs, the use of specific reversal agents (11/35, 6/35 for Andexanet and idarucizumab respectively) followed by 4F-PCC (9/35) was the major intervention indicated. Dilute thrombin time and partial thromboplastin time were the most commonly utilized tests to measure residual dabigatran activity. For Factor Xa inhibitors routine heparin assay rather than DOAC calibrated anti-Xa activity is utilized by most of the responders to assess presence of the plasma drug activity. Conclusion: Practices for oral anticoagulants reversal vary substantially in the pediatric population. Plasma is still used for urgent VKA reversal in many pediatric centers. The off-label use of DOACs in children is on the rise. Our results highlight the need for further studies to standardize OAC reversal in children. Disclosures Gupta: Novo Nordisk: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Takeda-Shire: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; CSL Behring: Research Funding; Novartis: Honoraria, Speakers Bureau; Octapharma: Honoraria, Membership on an entity's Board of Directors or advisory committees. Sarode:Portola: Honoraria; Octaphrarma: Consultancy; CSL Behring: Consultancy; Siemens: Research Funding. OffLabel Disclosure: The pharmacological properties of direct oral anticoagulants (DOACs) suggest that they may have advantages particularly for children. They are currently not approved in children. The off-label use of DOACs is however on the rise within the pediatric population.

Relationship between rhinitis severity and lung function in children and adolescents without asthma.

The link between upper and lower airways is recognized clinically as a “unique airway”. Subclinical spirometric abnormalities have been observed in patients with rhinitis without asthma, which could be proportional to rhinitis severity. To investigate possible subclinical alterations in lung function and bronchodilator reversibility in children and adolescents with allergic (AR) and non-allergic rhinitis (NAR) without asthma, according to the clinical grade of rhinitis classified by ARIA (Allergic Rhinitis and Its Impact on Asthma). In a cross-sectional analytical study, we included patients aged 5 to 18 years with symptoms of AR and NAR without asthma. Spirometry was performed by flow-volume curve and we analyzed the abnormalities in respiratory function and bronchodilator response in relation to clinical grade of rhinitis by ARIA using an adjusted logistic model. We studied 193 patients; 42 (21.7%) had some spirometric abnormalities. Patients with moderate-severe persistent rhinitis had greater impairment of lung function compared to the other grades of rhinitis (p=0.009). This defect was associated with both frequency (p=0.03) and severity of rhinitis (p=0.04) but not with atopic status (p=0.28). A positive bronchodilator response was more frequent in grades moderate-severe of rhinitis than in mild forms (p=0.04). Abnormalities of lung function was more prevalent in moderate-severe persistent rhinitis and was associated with the frequency and severity of rhinitis but not to atopic status. The bronchodilator reversibility was observed in patients with intermittent and persistent moderate-severe rhinitis.

Bowel preparation for colostomy reversal in children

PurposePediatric bowel preparation protocols used before colostomy reversal vary. The aim of this study is to determine institutional practices at our institution and evaluate the impact of bowel preparations on postoperative outcomes and hospital length of stay in children. MethodsThis was a retrospective review of children ≤18 years old undergoing colostomy reversal at Texas Children's Hospital (TCH) between 12/2013 and 8/2017. Preoperative bowel regimens and outcomes were collected and analyzed using descriptive statistics, Wilcoxon Rank-Sum and Fishers Exact tests. Continuous variables are presented as median [IQR]. ResultsSixty-one children underwent colostomy reversal. Thirty-eight (62%) did not receive a preoperative bowel preparation. The two cohorts were similar in age, gender, and race. The most common indication for colostomy was anorectal malformation for thirty-seven (61%). Time from admission to surgery (19 h [17, 23] vs 3 [2, 3]; p < 0.01) and HLOS (6 days [5, 8] vs 5 [4, 6]; p = 0.02) were both longer in the bowel preparation cohort. Complications (3 [13%] vs 5 [22%]; p = 0.12) and 90-day readmissions (3 [13%] vs 6 [16%]; p = 0.64) were similar in both cohorts. ConclusionForegoing bowel preparation may have the potential to improve cost and reduce morbidity in children undergoing colostomy closure. Level of evidenceIII. Study typeTreatment study.

Changes in the breath sound spectrum with bronchodilation in children with asthma.

Breath sound parameters have been suggested to be new biomarkers of airway function in patients with asthma. We investigated the effect of bronchodilation on breath sound parameters in sixty-four children (mean age, 8.9 years; range, 6-16 years) using a breath sound analyzer. The breath sound parameters included frequency limiting 50% and 99% of the power spectrum (F50 and F99), roll-off from 600-1200 Hz (slope), and spectrum curve indices such as the ratios of the third and fourth power area to the total area of the power spectrum (P3/PT and P4/PT), total area under the curve (A3/AT and B4/AT), and the ratio of power and frequency at 50% and 75% of the highest frequency of the power spectrum (RPF75 and RPF50). Lung function was assessed using spirometry and the forced oscillation technique (FOT). All variables were assessed before and after inhalation of a β2-agonist. The spectrum curve indices, A3/AT, B4/AT, RPF75, and RPF50, showed statistically significant increase following β2-agonist inhalation. The increase in RPF50 was correlated with the decrease in the difference between resistance at 5 Hz and 20 Hz, R5-R20, measured by FOT. In the multiple regression analysis adjusted for the effect of ΔRPF75, the changes in A3/AT and B4/AT were positively correlated with that in the forced expiratory volume in one second. The spectrum curve indices indicated bronchodilation, and may be useful for the assessment of bronchial reversibility in children with asthma.

ACTH deficiency and potential for reversibility in children and young people (CYP) with craniopharyngioma

ACTH deficiency and potential for reversibility in children and young people (CYP) with craniopharyngioma

Stoma Reversal in Children: Our Experience after Change of Technique

Stoma Reversal in Children: Our Experience after Change of Technique

Left Ventricular Hypertrophy in Pediatric Hypertension: A Mini Review.

Adults with arterial hypertension (HTN) have stroke, myocardial infarction, end-stage renal disease (ESRD), or die at higher rates than those without. In children, HTN leads to target organ damage, which includes kidney, brain, eye, blood vessels, and heart, which precedes “hard outcomes” observed in adults. Left ventricular hypertrophy (LVH) or an anatomic and pathologic increase in left ventricular mass (LVM) in response to the HTN is a pediatric surrogate marker for HTN-induced morbidity and mortality in adults. This mini review discusses current definitions, clinically relevant methods of LVM measurements and normalization methods, its epidemiology, management, and issue of reversibility in children with HTN. Pediatric definition of LVH and abnormal LVM is not uniformed. With multiple definitions, prevalence of pediatric HTN-induced LVH is difficult to ascertain. In addition while in adults cardiac magnetic resonance imaging is considered “the gold standard” for LVM and LVH determination, pediatric data are limited to “special populations”: ESRD, transplant, and obese children. We summarize available data on pediatric LVH treatment and reversibility and offer future directions in addressing LVH in children with HTN.

Effect of Severe Vitamin D Deficiency at Admission on Shock Reversal in Children With Septic Shock: A Prospective Observational Study

To evaluate the association of severe vitamin D deficiency with clinically important outcomes in children with septic shock. We enrolled children ≤17 years with septic shock prospectively over a period of 6 months. We estimated 25-hydroxyvitamin D [25 (OH) D] levels at admission and 72 hours. Severe deficiency was defined as serum 25 (OH) <10 ng/mL. We performed univariate and multivariate analysis to evaluate association with clinically important outcomes. Forty-three children were enrolled in the study. The prevalence of severe vitamin D deficiency was 72% and 69% at admission and 72 hours, respectively. On univariate analysis, severe vitamin D deficiency at admission was associated with lower rates of shock reversal, 74% (23) versus 25% (3); relative risk (95% confidence interval [CI]): 2.9 (1.09-8.08), at 24 hours and greater need for fluid boluses (75 vs 59 mL/kg). On multivariate analysis, nonresolution of shock at 24 hours was significantly associated with severe vitamin D deficiency after adjusting for other key baseline and clinical variables, adjusted odds ratio (95% CI): 12 (2.01-87.01); 0.01. The prevalence of severe vitamin D deficiency is high in children with septic shock admitted to pediatric intensive care unit. Severe vitamin D deficiency at admission seems to be associated with lower rates of shock reversal at 24 hours of ICU stay. Our study provides preliminary data for planning interventional studies in children with septic shock and severe vitamin D deficiency.

Longitudinal survey of ATB resistance reversibility in children with AIDS of genocide survivors in Cambodia

Background: The aim of the survey was to assess antimicrobial resistance dynamics and reversibility in the group of children with AIDS in Cambodia in 2003 2015. Patients: Correlation between antimicrobial (ATB) resistances in commonest respiratory isolates among 140 children with AIDS on antiretroviral therapy was studied from 2003 to 2015 in 586 isolates. Original Articles 8 Clinical Social Work and Health Intervention Clinical Social Work and Health Intervention Vol. 7 No. 3 2016 Results: All but 3 (98%) children showed a sustained CD4 increase after introduction of antiretroviral therapy (ART) followed by a decrease of ATB resistance. In our group of children restoration of the immune system decreased the number of infection diseases episodes and the proportion of multi-resistant bacterial strains. Conclusions: Less frequent use of antimicrobial therapy probably led to the decrease of multi-resistance and restoration of susceptibility of studied respiratory bacterial isolates. Results and discussion Table 1 presents trends in ATB resistance in major respiratory isolates from October 2003 to December 2015 (total of 586 isolates). Penicillin resistance in pneumococci decreased from 25% to 2% in 2015 (P<0.01); t-test for trends), MRSA from 33.3% in 2003 to 3% in 2014 and 2% in 2015 (P<0.01). Erythromycin resistance in Streptococcus pyogenes decreased from 10.5% in 2003 to 3.3% in 2015. At baseline extremely high proportion of ESBL producing Enterobacteriaceae decreased from 66.6% to 25% and such trend was also observed in Candida species and resistance to fluconazole (from 15% in 2003 to 6% in 2015). Reversibility of ATB resistance was documented on the hospital level (2) or on the community national level (1.3), however only in countries with small population (Finland, Denmark, Iceland) with centralized ATB policy. Reversibility time was 2-5 years per country and more (up to 5 years). Reversibility of susceptibility or antibiotic resistance was not yet sufficiently studied in pediatric population with specific immunodeficiency therefore it is deficient to assess, of 10 15 years in our group is comparable to e.g. 2 5 years on a nation level from Europe (5-8).

Character reversal in children: the prominent role of writing direction

Recent research has established that 5- to 6-year-old typically developing children in a left–right writing culture spontaneously reverse left-oriented characters (e.g., they write instead of J) when they write single characters. Thus, children seem to implicitly apply a right-writing rule (RWR: see Fischer & Koch, 2016a). In Study 1, the reversal of all asymmetrical digits and capital letters by 356 children was modeled with a simple Rasch model, which describes reversal as the outcome of two competing responses, correct writing and writing in the cultural direction of writing. It accounts for the high frequency of reversals of the left-oriented characters (3, Z, J, 1, 2, 7, 9), as predicted by the RWR. Study 2 investigated letter reversals when children spontaneously write their name from right to left. Most of the 204 children in the study radically changed the direction of the RWR by reversing mainly the right-oriented letters (B, C, D, E, F, G, K, L, N, P, R, S). Hence, a more universal formulation of the RWR would be as an implicit rule orienting characters in the writing direction. This reformulated rule is consistent with the “spatial agency bias” model (Suitner & Maas, 2016), according to which writing direction affects thoughts and actions. Visual and motoric statistical learning may favor bootstrapping of the rule. Taken together, these data demonstrate the prominent role of culture in a phenomenon—character reversal or mirror writing—which has often been presented uniquely as biologically determined.

Neural Correlates of Letter Reversal in Children and Adults

Children often make letter reversal errors when first learning to read and write, even for letters whose reversed forms do not appear in normal print. However, the brain basis of such letter reversal in children learning to read is unknown. The present study compared the neuroanatomical correlates (via functional magnetic resonance imaging) and the electrophysiological correlates (via event-related potentials or ERPs) of this phenomenon in children, ages 5–12, relative to young adults. When viewing reversed letters relative to typically oriented letters, adults exhibited widespread occipital, parietal, and temporal lobe activations, including activation in the functionally localized visual word form area (VWFA) in left occipito-temporal cortex. Adults exhibited significantly greater activation than children in all of these regions; children only exhibited such activation in a limited frontal region. Similarly, on the P1 and N170 ERP components, adults exhibited significantly greater differences between typical and reversed letters than children, who failed to exhibit significant differences between typical and reversed letters. These findings indicate that adults distinguish typical and reversed letters in the early stages of specialized brain processing of print, but that children do not recognize this distinction during the early stages of processing. Specialized brain processes responsible for early stages of letter perception that distinguish between typical and reversed letters may develop slowly and remain immature even in older children who no longer produce letter reversals in their writing.

Perspectives on Personal Pronoun Reversal in Children with ASD: A Critical Review

<p class="p1">Personal pronoun reversal (PPR), characterised by inverse use of personal pronouns (typically first and second person) is a hallmark of an autism spectrum disorder diagnosis (ASD; American Psychiatric Association, 2013). This literature review examines different theories accounting for the occurrence of PPR, in particular Kanner’s (1943) original view of PPR as echolalia, PPR as a result of impaired understanding of discourse roles (e.g. Tager-Flusberg, 1994), and PPR due to impaired theory of mind (Boucher, 2003). These existing theories are critiqued as overly simplistic, and the review argues that more complex theories are required to adequately explain the available evidence on PPR.

Bronchial obstruction and reversibility in children: inspiratory or expiratory resistance?

To the Editor: Assessing bronchial obstruction and reversibility is of help in diagnosing asthma. The forced oscillation technique (FOT) has gained popularity in children since minimal cooperation is required. Owing to the fact that measurements are performed during tidal breathing, the upper airway may significantly impact on the respiratory resistance ( R rs) [1], [2]. The glottic aperture narrows during tidal expiration [3], contributing to R rs being larger than in inspiration [2], [4], [5]. Acute bronchial obstruction promotes further laryngeal narrowing [6]–[8], which is expected to impact the R rs measured during expiration. It is not known to what extent the mechanism is present in children with stable asthma, or whether the ability of R rs to diagnose bronchial obstruction and reversibility is impeded in expiration. With a single excitation frequency, R rs may be described along the respiratory cycle and computed in expiration ( R rs,e) and inspiration ( R rs,i). The aim of this study was to compare R rs,i and R rs,e, their response to salbutamol and respective ability to separate asthmatics from controls. The hypothesis was that the diagnostic value of R rs,e and its response to bronchodilator inhalation is impeded compared with R rs,i. Patients with asthma were diagnosed in the local paediatric pulmonology clinic (Hopital d’enfants, CHU de Nancy, Nancy, France). All had discontinued their bronchodilator therapy ≥12 h prior to the study. Age-matched healthy children served as controls. Written informed consent was obtained and the study was approved by the Ethics Committee (Comite de Protection des Personnes EST III, CHU de Nancy, …

Digit reversal in children’s writing: A simple theory and its empirical validation

This article presents a simple theory according to which the left–right reversal of single digits by 5- and 6-year-old children is mainly due to the application of an implicit right-writing or -orienting rule. A number of nontrivial predictions can be drawn from this theory. First, left-oriented digits (1, 2, 3, 7, and 9) will be reversed more frequently than the other asymmetrical digits (4, 5, and 6). Second, for some pairs of digits, the correct writing of the preceding digit will statistically predict the reversal of the current digit and vice versa. Third, writing hand will have little effect on the frequency of reversals, and the relative frequencies with which children reverse the asymmetrical digits will be similar regardless of children’s preferred writing hand. Fourth, children who reverse the left-oriented digits the most are also those who reverse the other asymmetrical digits the least. An empirical study involving 367 5- and 6-year-olds confirmed these predictions.