Aerosol Delivery Efficiency With High-Flow Nasal Cannula Therapy in Neonatal, Pediatric, and Adult Nasal Upper-Airway and Lung Models.

BACKGROUND: High-flow nasal cannula (HFNC) systems employ different methods to provide aerosol to patients. This study compared delivery efficiency, particle size, and regional deposition of aerosolized bronchodilators during HFNC in neonatal, pediatric, and adult upper-airway and lung models between a proximal aerosol adapter and distal aerosol circuit chamber. METHODS: A filter was connected to the upper airway to a spontaneously breathing lung model. Albuterol was nebulized using the aerosol adapter and circuit at different clinical flow settings. The aerosol mass deposited in the upper airway and lung was quantified. Particle size was measured with a laser diffractometer. Regional deposition was assessed with a gamma camera at each nebulizer location and patient model with minimum flow settings. RESULTS: Inhaled lung doses ranged from 0.2-0.8% for neonates, 0.2-2.2% for the small child, and 0.5-5.2% for the adult models. Neonatal inhaled lung doses were not different between the aerosol circuit and adapter, but the aerosol circuit showed marginally greater lung doses in the pediatric and adult patient models. Impacted aerosols and condensation in the non-heated HFNC and aerosol delivery components contributed to the dispersion of coarse liquid droplets, high deposition (11-44%), and occlusion of the supine neonatal upper airway. In contrast, the upright pediatric and adult upper-airway models had minimal deposition (0.3-7.0%) and high fugitive losses (∼24%) from liquid droplets leaking out of the nose. The high impactive losses in the aerosol adapter (56%) were better contained than in the aerosol circuit, resulting in less cannula sputter (5% vs 22%), fewer fugitive losses (18% vs 24%), and smaller inhaled aerosols (5 µm vs 13 µm). CONCLUSIONS: The inhaled lung dose was low (1-5%) during HFNC. Approaches that streamline aerosol delivery are needed to provide safe and effective therapy to patients receiving aerosolized medications with this HFNC system.

Physiologic Effects of Nasal Aspiration and Nasopharyngeal Suctioning on Infants With Viral Bronchiolitis.

BACKGROUND: There is limited evidence supporting an optimum method for removing mucus from the airways of hospitalized infants with bronchiolitis. This study was designed to evaluate short-term physiologic effects between nasal aspiration and nasopharyngeal suctioning in infants. METHODS: Sixteen infants requiring hospitalization for supportive management of bronchiolitis were instrumented with transcutaneously measured partial pressure of carbon dioxide ([Formula: see text]) and [Formula: see text] monitoring. Electrical impedance tomography (EIT) was used to estimate changes in inspiratory and end-expiratory lung volume loss and recovery. Subjects were suctioned with both nasal aspiration and nasopharyngeal suctioning methods in a randomized order (8 received nasal aspiration followed by nasopharyngeal suctioning, and 8 received nasophayrgeal suctioning followed by nasal aspiration). Noninvasive gas exchange and EIT measurements were obtained at baseline (pre-suction) and at 10, 20, and 30 min following each suctioning intervention. Sputum mass was obtained following suctioning, and clinical respiratory severity scores, before and after suctioning, were computed. RESULTS: There were no differences in inspiratory EIT (P = .93), change in end-expiratory lung impedance (ΔEELI; P = .53), [Formula: see text] (P = .41), [Formula: see text] (P = .88), heart rate (P = .31), or breathing frequency (P = .15) over the course of suctioning between nasal aspiration and nasopharyngeal suctioning. Sputum mass (P = .14) and clinical respiratory score differences before and after suctioning (P = .59) were not different between the 2 suctioning interventions. Sputum mass was not associated with ΔEELI at 30 min for nasal aspiration (ρ = 0.11, P = .69), but there was a moderate positive association for nasopharyngeal suctioning (ρ = 0.50, P = .048). CONCLUSIONS: Infants with viral bronchiolitis appeared to tolerate both suctioning techniques without adverse short-term physiologic effects, as indicated by the unchanged gas exchange and estimated lung volumes (EIT). Nasopharyngeal suctioning recovered 36% more sputum than did nasal aspiration and there was moderate correlation between sputum mass and end-expiratory lung impedance change at 30 minutes post-suction with nasopharyngeal that was not present with nasal aspiration. It is possible that a subset of patients may benefit from one type of suctioning over another. Future research focusing on important outcomes for suctioning patients with bronchiolitis with varying degrees of lung disease severity is needed.

Determining Interrater Reliability of the Cornell Assessment of Pediatric Delirium Screening Tool Among PICU Nurses.

OBJECTIVES: To determine the interrater reliability of the Cornell Assessment of Pediatric Delirium Screening Tool amount PICU nurses. DESIGN: The design was setup as a cross-sectional study and conducted over the course of a year. SETTING: This study setting was a PICU and a pediatric cardiac ICU at Seattle Children's Hospital, a tertiary freestanding university-affiliated hospital in Seattle, Washington. PATIENTS: A total sample of 108 patients were included in this study. Patients were selected using a convenience sample. Inclusion in this study involved all patients eligible for a Cornell Assessment of Pediatric Delirium assessment, reflecting practice standards. Exclusion criteria included patients who had a Richmond Agitation and Sedation Score of (-4) or (-5), based on the Cornell Assessment of Pediatric Delirium procedure. There were 113 patients screened, but five were excluded from the final sample size due to missing information. INTERVENTIONS: The research nurse would screen the patient using the Cornell Assessment of Pediatric Delirium during the 12:00 noon hour, which coincided with the clinical nurse Cornell Assessment of Pediatric Delirium assessment. The clinical and research nurse were kept blind to each other's assessment. Scores were then analyzed to determine the kappa coefficient. MEASUREMENTS AND MAIN RESULTS: The kappa coefficient between nurses was found to be 0.60 (95% CI, 0.44-0.76), indicating moderate agreement. Age was found to have a higher association with agreement. In children 2 years old or greater, the kappa coefficient was 0.85 (95% CI, 0.68-1.00). Children whose raters did not agree on scoring were more likely to be younger than those who had raters that agreed (p < 0.01). CONCLUSIONS: Evaluating the interrater reliability of clinical tool, such as the Cornell Assessment of Pediatric Delirium, may be important to more accurately identify patients at high risk of delirium in a PICU or pediatric cardiac ICU. The evaluation of the tool's performance in practice may also be helpful to ensure ongoing consistency among the clinical nurses that complete these assessments on a daily basis.