Mortality of Pediatric Surgical Lung Biopsies in Ontario, Canada, 2000-2019.

Rationale: Surgical lung biopsies are often required for the definitive diagnosis of nonmalignant pediatric diffuse lung diseases; however, the literature on mortality after surgical lung biopsy in pediatric patients is sparse. Objectives: To determine the 30-day postoperative mortality rate after surgical lung biopsies for nonmalignant lung disease in pediatric patients in Ontario, Canada, and to identify risk factors associated with mortality. Methods: We performed an observational cohort study using population-based health administrative data available from ICES in Ontario, Canada, from 2000 to 2019. Cases were identified using the Canadian Classification of Health Interventions. Inclusion criteria were first surgical lung biopsies between 2000 and 2019 and age <18 years. Individuals with lung cancer, lung transplant, or missing data were excluded. A multivariable logistic regression model with generalized estimating equation was used to estimate the 30-day odds of mortality after surgical lung biopsy and to identify patient characteristics associated with increased mortality while accounting for clustering by hospital. Results: We identified 1,474 pediatric patients who underwent surgical lung biopsy in Ontario between 2000 and 2019. The overall mortality rates decreased over the study duration from 6.6% (2000-2004) to 3.0% (2015-2019). The study cohort for multivariate analyses consisted of 1,342 patients who had complete data. The pediatric mortality 30 days after surgical lung biopsy was 5.1% but was <1% in elective cases. Risk factors for increased mortality included open surgical lung biopsy (vs. video-assisted) (odds ratio [OR], 13.13; 95% confidence interval [CI], 3.76, 45.87; P < 0.001), nonelective procedure (OR, 11.74; 95% CI, 3.51, 39.27; P < 0.001), younger age (<3 mo) (OR, 6.04; 95% CI, 2.40, 15.22; P < 0.001), and higher comorbidity score (OR, 1.15; 95% CI, 1.05, 1.26; P = 0.003). Conclusions: Pediatric mortality postsurgical lung biopsy is not insignificant, particularly in nonelective procedures. Other important risk factors to consider when pursuing pathologic diagnosis include surgical approach, younger age, and higher comorbidity.

Situs Ambiguus Is Associated With Adverse Clinical Outcomes in Children With Primary Ciliary Dyskinesia.

BACKGROUND: Primary ciliary dyskinesia (PCD) is a rare disorder of motile cilia associated with situs abnormalities. At least 12% of patients with PCD have situs ambiguus (SA), including organ laterality defects falling outside normal arrangement (situs solitus [SS]) or mirror image inversion (situs inversus totalis [SIT]). RESEARCH QUESTION: Do patients with PCD and SA achieve worse clinical outcomes compared with those with SS or SIT? STUDY DESIGN AND METHODS: This cross-sectional, multicenter study evaluated participants aged 21 years or younger with PCD. Participants were classified as having SA, including heterotaxy, or not having SA (SS or SIT). Markers of disease severity were compared between situs groups, adjusting for age at enrollment and severe CCDC39 or CCDC40 genotype, using generalized linear models and logistic and Poisson regression. RESULTS: In 397 participants with PCD (mean age, 8.4 years; range, 0.1-21), 42 patients were classified as having SA, including 16 patients (38%) with complex cardiovascular malformations or atrial isomerism, 13 patients (31%) with simple CVM, and 13 patients (31%) without cardiovascular malformations. Of these, 15 patients (36%) underwent cardiac surgery, 24 patients (57%) showed an anatomic spleen abnormality, and seven patients (17%) showed both. The remaining 355 participants did not have SA, including 152 with SIT and 203 with SS. Overall, 70 participants (17%) harbored the severe CCDC39 or CCDC40 genotype. Compared with participants without SA, those with SA showed lower median BMI z scores (P = .03), lower FVC z scores (P = .01), and more hospitalizations and IV antibiotic courses for acute respiratory infections during the 5 years before enrollment (P < .01). Participants with cardiovascular malformations requiring surgery or with anatomic spleen abnormalities showed lower median BMI z scores and more hospitalizations and IV therapies for respiratory illnesses compared with participants without SA. INTERPRETATION: Children with PCD and SA achieve worse nutritional and pulmonary outcomes with more hospitalizations for acute respiratory illnesses than those with SS or SIT combined. Poor nutrition and increased hospitalizations for respiratory infections in participants with SA and PCD are associated with cardiovascular malformations requiring cardiac surgery, splenic anomalies, or both. TRIAL REGISTRY: ClinicalTrials.gov; Nos.: NCT02389049 and NCT00323167; URL: www. CLINICALTRIALS: gov.

Efficacy of Antibiotic Eradication Therapy of Early Pseudomonas aeruginosa Infection in Children with Primary Ciliary Dyskinesia.

Rationale: Chronic infection with Pseudomonas aeruginosa (PsA) negatively impacts lung disease in patients with primary ciliary dyskinesia (PCD). There is currently limited evidence regarding the efficacy of PsA antibiotic eradication therapy (AET) in children with PCD. Objectives: To assess the effectiveness of AET of early PsA infection in children with PCD. Methods: This retrospective study included pediatric patients with a confirmed PCD diagnosis according to the American Thoracic Society guidelines at the Hospital for Sick Children between 2010 and 2022. Children with newly acquired PsA infection underwent AET using a stepwise protocol. The protocol included the following steps: step 1, 28 days of tobramycin inhalation solution (TIS); step 2, repeat TIS if culture positive after step 1; and step 3, 14 days of intravenous antibiotics followed by 28 days of TIS if culture positive after step 2. Step 3 was also used for patients who presented with pulmonary exacerbation symptoms. The main outcome was a PsA-negative culture result based on the microbiological results of the first culture after completion of each step of treatment. Results: During the study period, 31 children had a new PsA infection and underwent AET. Of the 27 children who had been asymptomatic at the time of the PsA infection, negative PsA culture results were achieved in 20 (74%) of 27, 1 (14%) of 7, and 5 (83%) of 6 after steps 1, 2, and 3 of AET, respectively. All four symptomatic patients who initially were treated with step 3 had successful clearance of PsA. The overall cumulative success rate of the protocol for negative culture results after AET was 97% (30 of 31). For patients in whom AET was successful, the probability of staying PsA free for at least 1 year was 70%. Conclusions: AET for early PsA infection is highly effective in PCD, with sustained efficacy in most individuals. These data suggest that AET should be considered in all children with PCD who have early PsA infection.

Inter- and intravisit repeatability of free-breathing MRI in pediatric cystic fibrosis lung disease.

PURPOSE: The purpose of this study is to assess the intra- and interscan repeatability of free-breathing phase-resolved functional lung (PREFUL) MRI in stable pediatric cystic fibrosis (CF) lung disease in comparison to static breath-hold hyperpolarized 129-xenon MRI (Xe-MRI) and pulmonary function tests. METHODS: Free-breathing 1-hydrogen MRI and Xe-MRI were acquired from 15 stable pediatric CF patients and seven healthy age-matched participants on two visits, 1 month apart. Same-visit MRI scans were also performed on a subgroup of the CF patients. Following the PREFUL algorithm, regional ventilation (RVent) and regional flow volume loop cross-correlation maps were determined from the free-breathing data. Ventilation defect percentage (VDP) was determined from RVent maps (VDPRVent ), regional flow volume loop cross-correlation maps (VDPCC ), VDPRVent ∪ VDPCC , and multi-slice Xe-MRI. Repeatability was evaluated using Bland-Altman analysis, coefficient of repeatability (CR), and intraclass correlation. RESULTS: Minimal bias and no significant differences were reported for all PREFUL MRI and Xe-MRI VDP parameters between intra- and intervisits (all P > 0.05). Repeatability of VDPRVent , VDPCC , VDPRVent ∪ VDPCC , and multi-slice Xe-MRI were lower between the two-visit scans (CR = 14.81%, 15.36%, 16.19%, and 9.32%, respectively) in comparison to the same-day scans (CR = 3.38%, 2.90%, 1.90%, and 3.92%, respectively). pulmonary function tests showed high interscan repeatability relative to PREFUL MRI and Xe-MRI. CONCLUSION: PREFUL MRI, similar to Xe-MRI, showed high intravisit repeatability but moderate intervisit repeatability in CF, which may be due to inherent disease instability, even in stable patients. Thus, PREFUL MRI may be considered a suitable outcome measure for future treatment response studies.

Granulomatosis with polyangiitis in an adolescent male with chronic cough and pulmonary nodules.

Granulomatosis with polyangiitis (GPA) is a small to medium vessel vasculitis that is uncommon in paediatrics. However, with chronic cough often being the initial symptom, a common complaint and a median age of diagnosis of 14 years, it is nevertheless an important condition for paediatricians to consider as it can otherwise go undiagnosed for a long period of time. In this case report, we discuss a paediatric patient with GPA that presented with non-specific respiratory symptoms for several months and was then found to have pulmonary nodules on chest imaging once a broader differential diagnosis was considered. We will review the common presentation of GPA, the classification criteria and its management. This will ultimately assist any providers in identifying and managing GPA cases.

Measurement of forces applied using a Macintosh direct laryngoscope compared with a Glidescope video laryngoscope in patients with predictors of difficult laryngoscopy: A randomised controlled trial.

BACKGROUND: In patients with predictive features associated with easy direct laryngoscopy, videolaryngoscoy with the GlideScope has been shown to require less force when compared with Macintosh direct laryngoscopy. OBJECTIVE: The aim of this study was to compare forces applied with Glidescope vs. Macintosh laryngoscopes in patients with predictive features associated with difficult direct laryngoscopy. DESIGN: A randomised study. SETTING: Toronto General Hospital, a university tertiary centre in Canada. PATIENTS: Forty-four patients aged over 18 years, with one or more features of difficult intubation, undergoing elective surgery requiring single-lumen tracheal intubation. INTERVENTION: We measured the force applied to oropharyngeal tissues by attaching three FlexiForce Sensors (A201-25) to the concave surface of Macintosh and GlideScope laryngoscope blades.Anaesthetists or experienced anaesthesia residents performed laryngoscopies with both devices in a randomised sequence. MAIN OUTCOME MEASURES: The primary outcome was peak force. The secondary outcomes were average force and impulse force. The latter is the integral of the force over the time during which the force acted. RESULTS: Complete data were available for 40 individuals. Peak and average forces decreased with GlideScope (17 vs. 21 N, P = 0.03, and 6 vs. 11 N, P < 0.001, respectively). Laryngoscopy time increased with the GlideScope (30 vs. 18 s, P < 0.001), resulting in similar median impulse forces (206 vs. 175 N, P = 0.92). CONCLUSION: GlideScope laryngoscopy resulted in reduced peak and average forces, but as the laryngoscopy duration increased, the product of force and time (impulse force) was similar with both devices. TRIAL REGISTRATION: Clinicaltrials.gov Identifier: NCT01814176.

Modeling breath-enhanced jet nebulizers to estimate pulmonary drug deposition.

BACKGROUND: Predictable delivery of aerosol medication for a given patient and drug-device combination is crucial, both for therapeutic effect and to avoid toxicity. The gold standard for measuring pulmonary drug deposition (PDD) is gamma scintigraphy. However, these techniques expose patients to radiation, are complicated, and are relevant for only one patient and drug-device combination, making them less available. Alternatively, in vitro experiments have been used as a surrogate to estimate in vivo performance, but this is time-consuming and has few "in vitro to in vivo" correlations for therapeutics delivered by inhalation. An alternative method for determining inhaled mass and PDD is proposed by deriving and validating a mathematical model, for the individual breathing patterns of normal subjects and drug-device operating parameters. This model was evaluated for patients with cystic fibrosis (CF). METHODS: This study is comprised of three stages: mathematical model derivation, in vitro testing, and in vivo validation. The model was derived from an idealized patient's respiration cycle and the steady-state operating characteristics of a drug-device combination. The model was tested under in vitro dynamic conditions that varied tidal volume, inspiration-to-expiration time, and breaths per minute. This approach was then extended to incorporate additional physiological parameters (dead space, aerodynamic particle size distribution) and validated against in vivo nuclear medicine data in predicting PDD in both normal subjects and those with CF. RESULTS: The model shows strong agreement with in vitro testing. In vivo testing with normal subjects yielded good agreement, but less agreement for patients with chronic obstructive lung disease and bronchiectasis from CF. CONCLUSIONS: The mathematical model was successful in accommodating a wide range of breathing patterns and drug-device combinations. Furthermore, the model has demonstrated its effectiveness in predicting the amount of aerosol delivered to "normal" subjects. However, challenges remain in predicting deposition in obstructive lung disease.