Ronald Morton
University of Louisville, KY, Pediatrics, Faculty Member
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Primary spontaneous pneumothorax (PSP) in pediatric patients is less common than in adults. Tall, thin adolescent males are most commonly affected. While clinical guidelines exist for the adult pop...
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Medicine and Pneumothorax
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Neuroendocrine cell hyperplasia of infancy (NEHI) is a diffuse lung disease which presents in infancy and improves during childhood. Long-term outcomes have not previously been described. In one familial cohort, we have reported that NEHI... more
Neuroendocrine cell hyperplasia of infancy (NEHI) is a diffuse lung disease which presents in infancy and improves during childhood. Long-term outcomes have not previously been described. In one familial cohort, we have reported that NEHI is associated with a heterozygous variant of NKX2.1/TTF1. Our objective was to determine whether pulmonary abnormalities persist in adults with NEHI, to aid in elucidating the natural history of this disease. Four adult relatives with heterozygous NKX2.1 mutation and with clinical histories compatible with NEHI enrolled in a prospective study that included questionnaires, pulmonary function tests, and chest computed tomography scans. Mild radiologic abnormalities including mosaicism were seen in all four cases. Three individuals had obstruction on pulmonary function tests, two had marked air-trapping, and three had symptomatic impairments with exercise intolerance. Although clinical improvement occurs over time, NEHI may result in life-long pulmona...
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Copyright © 2012 Adrian R. O’Hagan et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work... more
Copyright © 2012 Adrian R. O’Hagan et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Recent asthma recommendations advocate the use of long-acting beta-agonists (LABAs) in uncontrolled asthma, but also stress the importance of stepping down this therapy once asthma control has been achieved. The objective of this study was to evaluate downtitration of LABA therapy in pediatric patients who are well-controlled on combination-inhaled corticosteroid (ICS)/LABA therapy. Clinical and physiologic outcomes were studied in children with moderate-to-severe persistent asthma after switching from combination (ICS/LABA) to monotherapy with ICS. Of the 54 patients, 34 (63%) were determined to have stable asthma after the switch, with a mean followup of 10.7 weeks. Twenty (37%) had loss of asthma control leading to addition of ...
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Pediatrics and Medicine
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Pleuropulmonary blastomas (PPBs) represent a rare, malignant neoplasm in infants and children. Despite their overall rarity, they are the most common primary lung malignancy in young children. Typically originating as cystic lesions that... more
Pleuropulmonary blastomas (PPBs) represent a rare, malignant neoplasm in infants and children. Despite their overall rarity, they are the most common primary lung malignancy in young children. Typically originating as cystic lesions that are amenable to easy resection, PPBs can progress to solid masses prone to metastases if not identified and treated early enough. In their early cystic form, PPBs are often difficult to distinguish from congenital pulmonary airway malformations based on clinical and radiographic findings. We report on an eight-month-old girl who presented to our institution with a large, right-sided, cystic lung lesion, which had not been apparent on a chest radiograph shortly after birth. After excision of the lesion, pathology demonstrated it to be a type I PPB, which was unique for its apparent extra lobar origin. We review the relevant literature concerning PPBs, as well as the debate surrounding resection of cystic lung lesions in infants and children.
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The premature primate exposed to hyperoxia provides a useful model of bronchopulmonary dysplasia. A critical target in hyperoxic injury is the mitochondrial matrix enzyme aconitase. We hypothesized that this enzyme’s activity would... more
The premature primate exposed to hyperoxia provides a useful model of bronchopulmonary dysplasia. A critical target in hyperoxic injury is the mitochondrial matrix enzyme aconitase. We hypothesized that this enzyme’s activity would decline in the premature baboon lung during exposure to hyperoxia. Total aconitase activity was significantly decreased in the lungs of premature baboons of 140 days gestation with exposure to 100% oxygen for 6–10 days compared with as needed [pro re nada (PRN)] oxygen exposure and fetal controls ( P = 0.0001). In activity gels, lungs from 100% oxygen-exposed animals (6–10 days) showed a nearly complete loss of mitochondrial aconitase activity relative to lungs from animals exposed only to PRN oxygen. Decreased lung aconitase activity was not a nonspecific effect of hyperoxia, causing mitochondrial damage or loss, because the activity of the mitochondrial respiratory enzyme cytochrome oxidase was not different in lungs of 100% oxygen-exposed relative to P...
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We describe the case of an infant who presented to our institution with tachypnea, cough, and hypoxemia. The baby had been diagnosed with complete heart block (heart rate 50-60 beats/min) in utero and had a pacemaker placed at birth. The... more
We describe the case of an infant who presented to our institution with tachypnea, cough, and hypoxemia. The baby had been diagnosed with complete heart block (heart rate 50-60 beats/min) in utero and had a pacemaker placed at birth. The mother was found to have both anti-Ro and anti-La antibodies. At age 3 months, the chest radiograph showed diffuse bilateral interstitial infiltrates. A lung biopsy confirmed the presence of necrotizing capillaritis and alveolar hemorrhage, which is an infrequent complication in pediatric patients with systemic lupus erythematosus. The patient did well after recognition and aggressive treatment of this previously unrecognized complication of neonatal lupus.
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OBJECTIVES To evaluate the impact of a payor-initiated formulary change in inhaled corticosteroid coverage on lung function in patients with asthma and on provider prescribing practices. This formulary change, undertaken in August 2016 by... more
OBJECTIVES To evaluate the impact of a payor-initiated formulary change in inhaled corticosteroid coverage on lung function in patients with asthma and on provider prescribing practices. This formulary change, undertaken in August 2016 by a Medicaid payor in Kentucky, eliminated coverage of beclomethasone dipropionate (BDP), a metered dose inhaler (MDI), in favor of mometasone furoate, available as MDI and dry powder inhaler (DPI). STUDY DESIGN A retrospective chart review was conducted on children with asthma ages 6 to 18 covered by the relevant payor from a university-based pediatric practice who were seen before the formulary change (February to July 2016) and after (February to July 2017). Spirometry data from each visit was compared using the paired Student t-test. RESULTS Fifty-eight patients were identified who were initially on BDP and had spirometry available at both visits. Those who switched from an MDI to a DPI (n=24) saw a decline in median predicted FEV1 from 98.5% to 91% (P = .013). A decline was also seen in FEF25-75, from 89.5% predicted to 76% predicted (p=0.041). No significant changes were observed in children remaining on an MDI. Seven patients discontinued ICS therapy. CONCLUSION This study suggests insurance formulary changes leading to use of a different inhaler device may have a detrimental impact on pediatric lung function, which may be a surrogate measure for overall asthma control. This could be due to a lack of adequate timely educational intervention as well as the inability of some children to use DPIs.
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Prolonged mechanical ventilation (PMV) in medically fragile children is commonly used in pediatric long term extended care facilities (P-LTEC). Currently, PMV weaning is performed in an unstandardized fashion. Without an official... more
Prolonged mechanical ventilation (PMV) in medically fragile children is commonly used in pediatric long term extended care facilities (P-LTEC). Currently, PMV weaning is performed in an unstandardized fashion. Without an official protocol, patients are subjected to delayed weaning, infection, increased mortality, and difficulty obtaining placement at adult group homes. A step-wise approach may help these children wean from PMV effectively. A retrospective chart review of five tracheostomized children with bronchopulmonary dysplasia was conducted. A 5-step weaning protocol was created using data collected retrospectively. First, pressure control ventilator settings were decreased until rate = 10, fraction of inspired oxygen = 30% and pressure support = 6-10. Second, continuous positive airway pressure (CPAP) was trialed while awake with ventilator at night. Third, CPAP was continued for 24 hours. Fourth, tracheostomy collar (TC) was trialed while awake, with CPAP at night. Lastly, TC...
The availability of cysteine for glutathione synthesis is low in premature infants with respiratory distress. The effects of gestational age, oxygen delivery, and cysteine infusion or glutathione infusion, or both, on plasma total... more
The availability of cysteine for glutathione synthesis is low in premature infants with respiratory distress. The effects of gestational age, oxygen delivery, and cysteine infusion or glutathione infusion, or both, on plasma total cysteine and other methionine metabolites were studied in a baboon model of severe premature birth with respiratory distress. Premature baboons were studied as part of the multiinvestigator National Institutes of Health Collaborative Project on Bronchopulmonary Dysplasia. Premature baboons, 125 d (69% of term) or 140 d (78% of term) of gestational age, were maintained in neonatal intensive care units for </=14 d. Parenteral feeding with or without supplemental cysteine and glutathione infusions was given. Plasma total cysteine, methionine, N:-methylglycine, cystathionine, and the other methionine metabolites were monitored by capillary gas chromatography-mass spectrometry. Cord blood plasma total cysteine was the lowest in the 125-d-old premature baboon...
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Intrinsic enzymatic and non-enzymatic pulmonary antioxidant defense mechanisms undoubtedly protect the lung against oxidant-mediated environmental stresses and diseases. In addition, new ways of augmenting pulmonary antioxidant defenses... more
Intrinsic enzymatic and non-enzymatic pulmonary antioxidant defense mechanisms undoubtedly protect the lung against oxidant-mediated environmental stresses and diseases. In addition, new ways of augmenting pulmonary antioxidant defenses are being developed which can be used to bolster disease-overwhelmed intrinsic lung defense mechanisms. Improved understanding of antioxidant defense mechanisms will increase our knowledge of the causes and suggest rational approaches for treating oxidant-induced lung injury.
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We present a rare case of hemoptysis secondary to isolated unilateral pulmonary vein atresia. Isolated pulmonary vein atresia is a rare condition in which patients typically acquire a diagnosis in infancy and early childhood [Mataciunas... more
We present a rare case of hemoptysis secondary to isolated unilateral pulmonary vein atresia. Isolated pulmonary vein atresia is a rare condition in which patients typically acquire a diagnosis in infancy and early childhood [Mataciunas et al.; Pourmoghadam et al.]. Our patient presented during puberty with several previous episodes of hemoptysis prior to her admission and diagnosis. The initial diagnosis was suspected in our patient from chest computerized tomography (CT), and confirmed with cardiac catheterization and pulmonary angiography. Treatment aim is to preserve lung function and minimize irreversible pulmonary remodeling [Pourmoghadam et al.; Harrison et al.]. Conservative monitoring can be considered with milder or asymptomatic cases, while others may require preoperative collateral artery banding, surgical anastomosis between the pulmonary vein (PV) & left atrium (LA) and even pneumonectomy [Pourmoghadam et al.].
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INTRODUCTION: Ivacaftor has been used successfully in patients with cystic fibrosis to help reverse the underlying gating defect associated with the G551D mutation. There is limited data with regards to ivacaftor’s impact on chest CT... more
INTRODUCTION: Ivacaftor has been used successfully in patients with cystic fibrosis to help reverse the underlying gating defect associated with the G551D mutation. There is limited data with regards to ivacaftor’s impact on chest CT imaging in young pediatric patients. CASE PRESENTATION: We report on a 6 year old girl with cystic fibrosis (CF) (deltaF508/G551D) with a history of severe, progressive lung disease, complete collapse of her left lung, and subsequent improvement after starting therapy with ivacaftor. At the time of initiating therapy, the patient had 14 prior admissions for CF exacerbations. A chest CT scan done 4 months prior to starting ivacaftor revealed collapse of the entire left lung with corresponding overexpansion of the right lung and mediastinal shift. The left lung was reduced to a small crescent shape object, sandwiched between the overinflated right lung, which filled the entire left chest cavity, and the thoracic cage. A thoracic surgery consult found no v...
BACKGROUND: Theophylline has been used in asthma for over 80 years. While initially used in high doses as a bronchodilator, it has been more recently used in lower doses for its anti-inflammatory properties. Specifically, theophylline has... more
BACKGROUND: Theophylline has been used in asthma for over 80 years. While initially used in high doses as a bronchodilator, it has been more recently used in lower doses for its anti-inflammatory properties. Specifically, theophylline has been recognized for its ability to restore histone deacetylase-2 (HDAC2). We hypothesized that since in severe asthma, airway inflammation downregulates HDAC2 expression, low dose Theophylline, by increasing HDAC2 expression in these patients, would result in improved steroid responsiveness and thus improve clinical outcome. METHODS: The current study investigated whether theophylline is associated with improved outcomes in hospitalized children with severe asthma. To realize this goal we conducted a retrospective, observational study of 166 hospitalized children who were stratified into receiving theophylline (n=57, 34.5%) and not receiving theophylline (n=109, 65.5%). Low dose theophylline (5-7mg/kg/day) PO was used during acute status asthmaticu...
Introduction Impulse oscillometry (IOS) is an effort-independent pulmonary function test based on the forced oscillatory technique using sound waves to detect airway changes. As it only requires tidal breathing, it can be an optimal test... more
Introduction Impulse oscillometry (IOS) is an effort-independent pulmonary function test based on the forced oscillatory technique using sound waves to detect airway changes. As it only requires tidal breathing, it can be an optimal test in those who cannot do spirometry. Additionally, IOS has been found to be a sensitive marker for small airway disease. While increasingly used in asthma, there remains an overall lack of data in patients with cystic fibrosis (CF). We report on our institution’s use of IOS in patients with CF and its impact on clinical decision making. Methods A roster of all patients with CF who had IOS testing done between January 2012 and April 2014 was compiled into a retrospective database. Charts were reviewed to determine if patients were symptomatic at the time of testing, if they were on inhaled corticosteroids (ICS), and if any management changes were made based on IOS results. All testing was conducted in the same pulmonary function laboratory, using stand...
INTRODUCTION: Severe asthma is frequently characterized by extensive mucus plugging which is often viscous in nature. It is postulated that some specific asthma phenotypes are more prone to mucus hypersecretion and thus may be at risk for... more
INTRODUCTION: Severe asthma is frequently characterized by extensive mucus plugging which is often viscous in nature. It is postulated that some specific asthma phenotypes are more prone to mucus hypersecretion and thus may be at risk for developing sequela such as bronchiectasis and recurrent pneumonia that is not routinely seen in other asthma patients. CASE PRESENTATION: We report on a 14 year old African-American male with history of asthma since 6 months of age. He was originally referred for evaluation of persistent left lower lobe pneumonia. He had an extensive workup for immunodeficiency, allergic bronchopulmonary aspergillosis, histoplasmosis, cystic fibrosis and mycoplasma which were all unyielding. A chest CT scan demonstrated bilateral basilar bronchiectasis. He underwent flexible bronchoscopy which showed a large mucus plug adhering to the bronchial mucosa in the apical segment of the left lower lobe. Multiple attempts with various techniques were unable to dislodge it....
BACKGROUND: While theophylline has traditionally been used in high dose as a bronchodilator, more recently it has increasingly been used in lower doses for anti-inflammatory properties. Specifically, theophylline has been recognized for... more
BACKGROUND: While theophylline has traditionally been used in high dose as a bronchodilator, more recently it has increasingly been used in lower doses for anti-inflammatory properties. Specifically, theophylline has been recognized for its ability to restore histone deacetylase-2 (HDAC2) activity which leads to improved steroid responsiveness and thus improve clinical outcome. While we have previously established the medical soundness of this management strategy, its economic soundness has not been examined. In the current study we look at the cost-effectiveness of using theophylline in the treatment of status asthmaticus in children. METHODS: We conducted a retrospective, observational study of 166 hospitalized status asthmaticus children who were stratified into receiving theophylline (n=57, 34.5%) and not receiving theophylline (n=109, 65.5%). Low dose theophylline (5-7mg/kg/day) PO was used during acute status asthmaticus when patients did not respond to standard inpatient asth...
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In an observational long-term study, we followed 62 children (37 males, 25 females; mean age: 11.6 +/- 2.9 years) with moderate-to-severe asthma for 2 years and studied the effects of fluticasone propionate (176-1320 microg/day) on the... more
In an observational long-term study, we followed 62 children (37 males, 25 females; mean age: 11.6 +/- 2.9 years) with moderate-to-severe asthma for 2 years and studied the effects of fluticasone propionate (176-1320 microg/day) on the function of the hypothalamic-pituitary-adrenal axis. Morning cortisol levels were monitored after patients had been on fluticasone for a mean of 8.0 +/- 5.2 months. Patients who had abnormal low morning cortisol levels (&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;5.5 microg/dL) were then switched either to lower fluticasone dosage or to other inhaled steroid formulation. Exact methods based on the binomial distribution were used to construct a 95% confidence interval for the true proportion of abnormal readings among those treated, and the Wilcoxon signed rank test was used to test for a significant difference between cortisol levels taken before and after the switch. Twenty-two patients (36%) had abnormal morning cortisol levels while on fluticasone. Of the patients on a low dose (176 microg/day), 17% had abnormal values, whereas 43% of patients on a high dose (&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt; or =880 microg/day) were abnormal. Patients with abnormal results (17/22) had their morning cortisol levels repeated 3 months after the switch. Thirteen of these patients (77%) had normal levels. A stratified analysis of the difference in morning cortisol levels before and after the switch showed significant increase in morning cortisol levels in the group receiving 440 microg/day or less of fluticasone (median difference: 5.25; confidence interval: 3.60-8.15), as well as in the group receiving 440 microg/day or more (median difference: 3.85; confidence interval: 1.00-7.60). Inhaled fluticasone, even at conventional doses, may have greater effects on the adrenal function than previously recognized, but the clinical significance of this suppression still remains to be established.
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Pneumonia with pleuritis is a rare presentation of histoplasmosis infection. We present a 12-year old previously healthy boy in whom histoplasmosis presented with pleuritis, confirmed by detection of antigen in empyema fluid.
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Asthma, Humans, Child, Chronic Disease, Female, and 4 moreMale, Lung, Pediatric Pulmonology, and Retrospective Studies
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... Article. Persistent tachypnea of infancy (PTI)-A New Entity. Dr. Robin R. Deterding 1,* ,; Leland L. Fan 2 ,; Ron Morton 3 ,; Tom C. Hay 4 ,; Claire Langston 5. Article first published online: 10 MAR 2007. DOI:... more
... Article. Persistent tachypnea of infancy (PTI)-A New Entity. Dr. Robin R. Deterding 1,* ,; Leland L. Fan 2 ,; Ron Morton 3 ,; Tom C. Hay 4 ,; Claire Langston 5. Article first published online: 10 MAR 2007. DOI: 10.1002/ppul.1950262330. ...