Continuous positive airway pressure care for pediatric obstructive sleep apnea: A long-term quality improvement initiative

Successful treatment of pediatric obstructive sleep apnea syndrome (OSAS) with continuous positive airway pressure (CPAP) is challenging due to behavioral, technical, medical, and systems factors. We undertook a quality improvement (QI) initiative involving physicians, nurses, psychologists, and respiratory therapists to improve CPAP outpatient care and processes. We aimed to: (1) increase the proportion of patients with a follow-up visit within 4 months of initiation of CPAP, (2) reduce the median time to first follow-up visit to under 4 months, and (3) increase the proportion of patients obtaining a post-initiation polysomnogram within 1 year to >50%. We also explored healthcare utilization (HCU) in a subsample of patients. Interventions focused on developing a tracking system and standardizing interdisciplinary clinical care. The proportion of patients returning to clinic within 4 months improved from 38.2% to 65.5% and median time to first follow-up visit improved from 133 to 56 days. The percentage of patients who returned for a post-initiation polysomnogram within 1 year was 71.1%. Subsample analyses showed significant reductions in the length of stay for emergency department visits from pre-CPAP initiation (Mdn = 3.00 h; interquartile range [IQR] = 7.00) to post-initiation (Mdn = 2.00 h, IQR = 5.00). The length of hospitalizations was also significantly shorter from pre (Mdn = 48.00 h, IQR = 243.00) to post-CPAP initiation (Mdn = 0.00 h, IQR = 73.00). A standardized, tracked approach to interdisciplinary outpatient CPAP care can improve follow-up care and potentially HCU.

Clinical utility of repeated positive airway pressure titrations in children with obstructive sleep apnea syndrome

STUDY OBJECTIVES

Positive airway pressure (PAP) is the second line of treatment for OSAS in children. It is common practice following initiation of PAP to perform repeat titration polysomnography (PSG) to re-evaluate the patient's therapeutic pressure, however data supporting this practice is lacking. We hypothesized that repeat PAP titration would result in significant setting changes in children with OSAS.

METHODS

We retrospectively analyzed demographic, polysomnographic and PAP data of children with OSAS aged 0-18 years who were initiated on PAP and underwent two titration studies over a two-year period. PAP mode and recommended pressure differences between the two titrations were compared.

RESULTS

64 children met inclusion criteria. The median (IQR) baseline obstructive apnea hypopnea index (OAHI) and SpO₂ nadir were 14.8 (8.7-32.7) events/h and 88.5% (85-92%), respectively. The mean differences in OAHI, SpO₂ nadir, and %TST with SpO₂ < 90% between both titrations were negligible, including children with obesity, adenotonsillar hypertrophy, and Trisomy 21. Additionally, there was no significant difference in mean PAP pressure between two separate titration studies for those on continuous PAP or bilevel PAP.

CONCLUSION

Overall, repeat PAP titration in children with OSAS within the timeframe here described did not result in significant changes in PAP mode, continuous PAP pressure or OAHI. Based on these data, repeat PAP titration within two years of an initial titration does not appear to be necessary.

Auto-titrating CPAP for the treatment of obstructive sleep apnea in children: a good beginning

Khaytin I, Tapia IE, Beck SE. Auto-titrating CPAP for the treatment of obstructive sleep apnea in children: a good beginning. J Clin Sleep Med . 2020;16(10):1825–1826.

Positive Airway Pressure for the Treatment of OSA in Infants

BACKGROUND

Positive airway pressure (PAP) is a standard therapy for the treatment of OSA in children, but objective data on the effectiveness of PAP in infants are sparse. The aim of this study was to compare the effectiveness of PAP in infants younger than 6 months of age with that in school-aged children.

RESEARCH QUESTION

Compared with PAP in school-aged children, can PAP be titrated as successfully in infants, and is adherence to PAP similar in both age groups?

STUDY DESIGN AND METHODS

Single-center retrospective study. For consecutive infants younger than 6 months of age and school-aged children 5 to 10 years of age with OSA treated with PAP, baseline and titration polysomnography data, PAP adherence data, and parent-reported barriers to adherence were compared between groups.

RESULTS

Forty-one infants and 109 school-aged children were included. Median obstructive apnea hypopnea index (OAHI) in infants was 25.7/h (interquartile range [IQR], 17.8-35.9/h) and was greater than that in school-aged children (12.1/hr; IQR, 7.6-21.5/h; P < .0001). After PAP titration, OAHI was reduced by a median of 92.1% in infants, similar to the median 93.4% reduction in school-aged children (P = .67). PAP was used in infants on 94.7% of nights, which was more than the 83% in school-aged children (P = .003). No differences were found in barriers to adherence between infants and school-aged children, with behavioral barriers being most common in both groups.

INTERPRETATION

Objective data demonstrate that PAP is both highly effective at treating OSA and well-tolerated in infants. Like older patients, PAP should be considered along with other therapies for the treatment of OSA in even the youngest children.

Auto-titrating CPAP for the treatment of obstructive sleep apnea in children

STUDY OBJECTIVES

In-laboratory titration polysomnography (PSG) is standard to determine optimal therapeutic continuous positive airway pressure (CPAP) in children with obstructive sleep apnea (OSA). The use of auto-titrating CPAP devices (autoCPAP) as an alternative to CPAP titration has not been well studied in children. We hypothesized that autoCPAP-derived pressures (PMEAN, PPEAKMEAN, P90) would be similar to titration PSG pressure (PPSG).

METHODS

This is a retrospective study of children with OSAS initiated on autoCPAP between 2007 and 2017, who used autoCPAP for at least 2 h/night and who had adequate titration PSG were included in the analysis. AutoCPAP-derived pressures were obtained from use downloads and compared with PPSG. PPSG predictive factors were analyzed by median regression. Nonparametric methods were used for analysis.

RESULTS

Of 110 children initiated on autoCPAP, 44 satisfied the inclusion criteria. Age (median (interquartile range)) was 13.01 (9.98-16.72) years, and 63.6% were obese. PPSG median (interquartile range) was 8 (7-11) cmH₂O, mean autoCPAP-derived pressure (PMEAN) was 6.2 (5.6-7.6) cmH₂O, peak mean pressure (PPEAKMEAN) was 9.4 (7.7-11.1) cmH₂O, and average device pressure ≤ 90% of the time (P90) was 8.1 (7.2-9.7) cmH₂O. AutoCPAP-derived pressures correlated with PPSG (P < .05). PMEAN was lower than the other 3 pressures (P < .0002). Median regression analysis demonstrated that after adjusting for patient characteristics such as age, sex, and obesity status, autoCPAP-derived pressures remained significant predictors of PPSG (P < .05). There were no significant interactions between these patient characteristics and autoCPAP-derived pressures.

CONCLUSIONS

This study demonstrates that autoCPAP-derived pressures correlate with the titration PSG-derived pressures. These results indicate that autoCPAP can be used in the pediatric population and can determine pressures that are close to the titration pressures.

0885 Reduction in Emergency Department and Inpatient Hospitalization Visits and Length of Stay in a Cohort of Pediatric Patients Initiated on Positive Airway Pressure for Obstructive Sleep Apnea Syndrome

Introduction

Positive Airway Pressure (PAP) is an efficacious treatment of pediatric obstructive sleep apnea syndrome (OSAS). However, it is unknown whether PAP initiation is associated with reduced healthcare utilization, an important metric of care management. We hypothesized that healthcare utilization would be reduced after initiation of PAP in a cohort of pediatric patients prescribed PAP for OSAS.

Methods

Data were extracted from electronic medical records of 475 patients (Mean±SD age at PAP initiation=7.7±5.7 years; 58.7% male; 40.6% White; 38.3% Black; 18.1% multiracial/other; 12.1% Hispanic/Latinx) prescribed PAP for OSAS and followed in our Sleep Center quality improvement program. We extracted the total number of emergency department (ED) visits and hospitalizations and computed the related average length of stay (LOS) in hours for these visits in the 18 months prior to and 18 months following PAP initiation.

Results

Paired samples t-tests showed that number of ED visits and hospitalizations, and the related visit LOS, were significantly reduced following PAP initiation. The average number of visits reduced from 2.20 pre-PAP to 1.77 post-PAP initiation [t(474) = 3.48, p&lt;.001, effect size = 0.16], while average LOS reduced from 185.14 hours pre-PAP to 42.94 hours post-PAP initiation [t(474) = 4.81, p&lt;.001, effect size = 0.29]. Findings for the significant reduction in LOS held after adjusting for the number of pre and post-PAP ED visits and hospitalizations, average pre-PAP LOS, and patient demographics (age at the time of initiation; sex; race/ethnicity) using multiple linear regression.

Conclusion

PAP initiation was associated with fewer and shorter ED visits and hospitalizations in a large sample of pediatric patients. We speculate that PAP initiation could help reduce morbidity associated with pediatric OSAS, as well as improve healthcare utilization, capacity management and care in this population.

Support

K23HD094905 and Sleep Research Foundation (AAW)

The role of polysomnography in tracheostomy decannulation of children with bronchopulmonary dysplasia

BACKGROUND

Patients with bronchopulmonary dysplasia (BPD) may require tracheostomy for long-term mechanical ventilation. Polysomnography (PSG) may predict successful decannulation in children, however it is unclear how this success compares with children without a PSG. To better evaluate this role, we compared decannulation outcomes between tracheostomy-dependent children with BPD who underwent PSG before decannulation to those who did not.

METHODS

This is a retrospective cohort study between 1 January 2007 and 1 June 2017 of tracheostomy-dependent children with BPD who were clinically considered for decannulation. Patient demographics, PSG results, and medical comorbidities were abstracted from medical records and compared between groups. Decannulation outcomes were compared between children with BPD who underwent PSG before decannulation and those who did not.

RESULTS

One hundred twenty-five patients with BPD were considered for tracheostomy decannulation. Forty-six (37%) had a pre-decannulation PSG while 79 (63%) did not. Nineteen (41%) patients did not undergo decannulation within 6 months of the PSG. One (3%) patient with pre-decannulation PSG failed decannulation. Four (5%) patients without pre-decannulation PSG failed decannulation. Nineteen patients with PSG and no decannulation had significantly higher obstructive apnea-hypopnea index (OAHI) (13.62 vs 2.68 events per hour, P = 0.004), higher end-tidal CO ₂ max (52.84 vs 48.03 mm Hg, P = 0.035), and were older at PSG (median age, 6.04 vs 4.04 years, P = 0.008).

CONCLUSIONS

While successful decannulation can be achieved without a PSG in some patients, PSG is a valuable tool to identify BPD patients undergoing clinical evaluation for decannulation who would benefit from treatment of OSA before decannulation.

Adherence to Positive Airway Pressure for the Treatment of Obstructive Sleep Apnea in Children With Developmental Disabilities

STUDY OBJECTIVES

To determine whether adherence to positive airway pressure (PAP) differs in children with developmental disabilities (DD) compared to typically developing (TD) children.

METHODS

PAP adherence of 240 children initiated on PAP for obstructive sleep apnea (OSA) was retrospectively analyzed. Adherence between groups, expressed as percentage of nights used and hours of usage on nights used at 3 and 6 months, was compared. Predictive factors of adherence were studied using a median regression model.

RESULTS

A total of 103 children with DD (median [interquartile range] age = 7.9 [3.2-13.1] years) and 137 TD (11.0 [5.5-16.1], P = .005) children were included. Percentage of nights used was significantly higher in children with DD at 3 (DD = 86.7 [33.9-97.9], TD = 62.9 [30.8-87.8] P = .01) and 6 months (DD = 90.0 [53.3-100], TD = 70.7 [29.2-90.8], P = .003). Hours of usage on nights used at 3 and 6 months were similar between groups (DD = 5.0 [1.4-7.9], TD = 4.6 [1.9-7.2], P = .715; DD = 6.4 [1.8-8.3], TD = 5.7 [2.5-7.3], P = .345, respectively). This adherence measure improved over time in both groups (DD, P = .007; TD, P = .005). At 6 months, higher median neighborhood income and titration at or before 6 months were significantly predictive for percentage of nights used; higher PAP pressure was significantly predictive for hours of usage in both groups.

CONCLUSIONS

Children with DD had better PAP adherence expressed as percentage of nights used than TD children. Hours of usage on nights used at 3 and 6 months were similar between groups and improved over time. Higher income and titration at or before 6 months were predictive of adherence in all children. These findings indicate that children with DD can successfully wear PAP.

Financial Analysis of an Intensive Pediatric Continuous Positive Airway Pressure Program

Study Objectives

Continuous positive airway pressure (CPAP) is effective in treating obstructive sleep apnea in children, but adherence to therapy is low. Our center created an intensive program that aimed to improve adherence. Our objective was to estimate the program's efficacy, cost, revenue and break-even point in a generalizable manner relative to a standard approach.

Methods

The intensive program included device consignment, behavioral psychology counseling, and follow-up telephone calls. Economic modeling considered the costs, revenue and break-even point. Costs were derived from national salary reports and the Pediatric Health Information System. The 2015 Medicare reimbursement schedule provided revenue estimates.

Results

Prior to the intensive CPAP program, only 67.6% of 244 patients initially prescribed CPAP appeared for follow-up visits and only 38.1% had titration polysomnograms. In contrast, 81.4% of 275 patients in the intensive program appeared for follow-up visits (p < .001) and 83.6% had titration polysomnograms (p < .001). Medicare reimbursement levels would be insufficient to cover the estimated costs of the intensive program; break-even points would need to be 1.29-2.08 times higher to cover the costs.

Conclusions

An intensive CPAP program leads to substantially higher follow-up and CPAP titration rates, but costs are higher. While affordable at our institution due to the local payer mix and revenue, Medicare reimbursement levels would not cover estimated costs. This study highlights the need for enhanced funding for pediatric CPAP programs, due to the special needs of this population and the long-term health risks of suboptimally treated obstructive sleep apnea.

Sleep Patterns in Children with Cystic Fibrosis

This study examined sleep patterns and the association between sleep and perceived health for children with and without CF. Ninety families (45 CF) completed questionnaires about the child's sleep and health. Significant group differences were found for sleep patterns (bedtime, wake time, total sleep time), symptoms of sleep disordered breathing, and sleep disturbances. Poorer perceived health was associated with sleep disturbances among children with CF, but not for children without CF. This study highlights the importance of including sleep in the evaluation of children with CF, as both medical and behavioral interventions can improve the sleep of children with CF.

Predictors of positive airway pressure therapy adherence in children: a prospective study

STUDY OBJECTIVES

Children with obstructive sleep apnea are increasingly being treated with positive airway pressure (PAP), particularly if they have underlying medical conditions. Although PAP is an effective treatment, its use is challenging due to poor adherence. We hypothesized that demographic, psychosocial, and polysomnographic parameters would be related to PAP adherence. We therefore prospectively collected data potentially pertaining to PAP adherence, and correlated it with PAP use.

METHODS

Fifty-six patients and their parents completed a series of psychosocial questionnaires prior to PAP initiation. Objective adherence data were obtained after 1 and 3 months of PAP use.

RESULTS

The population was primarily obese; 23% had neurodevelopmental disabilities. PAP adherence varied widely, with PAP being worn 22 ± 8 nights in month-1, but mean use was only 3 ± 3 h/night. The greatest predictor of use was maternal education (p = 0.002 for nights used; p = 0.033 for mean h used/night). Adherence was lower in African American children vs other races (p = 0.021). In the typically developing subgroup, adherence correlated inversely with age. Adherence did not correlate with severity of apnea, pressure levels, or psychosocial parameters other than a correlation between family social support and nights of PAP use in month-3.

CONCLUSIONS

PAP adherence in children and adolescents is related primarily to family and demographic factors rather than severity of apnea or measures of psychosocial functioning. Further research is needed to determine the relative contributions of maternal education, socioeconomic status and cultural beliefs to PAP adherence in children, in order to develop better adherence programs.

Randomized, double-blind clinical trial of two different modes of positive airway pressure therapy on adherence and efficacy in children

STUDY OBJECTIVES

To determine the effects of bilevel positive airway pressure with pressure release technology (Bi-Flex) on adherence and efficacy in children and adolescents compared to standard continuous positive airway pressure (CPAP) therapy. We hypothesized that Bi-Flex would result in improved adherence but similar efficacy to CPAP.

METHODS

This was a randomized, double-blinded clinical trial. Patients with obstructive sleep apnea were randomized to CPAP or Bi-Flex. Repeat polysomnography was performed on pressure at 3 months. Objective adherence data were obtained at 1 and 3 months.

RESULTS

56 children and adolescents were evaluated. There were no significant differences in the number of nights the device was turned on, or the mean number of minutes used at pressure per night for CPAP vs Bi-Flex (24 ± 6 vs 22 ± 9 nights, and 201 ± 135 vs 185 ± 165 min, respectively, for Month 1). The apnea hypopnea index decreased significantly from 22 ± 21/h to 2 ± 3/h on CPAP (p = 0.005), and 18 ± 15/h to 2 ± 2/h on Bi-Flex (p < 0.0005), but there was no significant difference between groups (p = 0.82 for CPAP vs Bi-Flex). The Epworth Sleepiness Scale decreased from 8 ± 5 to 6 ± 3 on CPAP (p = 0.14), and 10 ± 6 to 5 ± 5 on Bi-Flex (p < 0.0005; p = 0.12 for CPAP vs Bi-Flex).

CONCLUSIONS

Both CPAP and Bi-Flex are efficacious in treating children and adolescents with OSAS. However, adherence is suboptimal with both methods. Further research is required to determine ways to improve adherence in the pediatric population.

Effects of positive airway pressure therapy on neurobehavioral outcomes in children with obstructive sleep apnea

RATIONALE

Positive airway pressure therapy is frequently used to treat obstructive sleep apnea in children. However, it is not known whether positive airway pressure therapy results in improvements in the neurobehavioral abnormalities associated with childhood sleep apnea.

OBJECTIVES

We hypothesized that positive airway pressure therapy would be associated with improvements in attention, sleepiness, behavior, and quality of life, and that changes would be associated with therapy adherence.

METHODS

Neurobehavioral assessments were performed at baseline and after 3 months of positive airway pressure therapy in a heterogeneous group of 52 children and adolescents.

MEASUREMENTS AND MAIN RESULTS

Adherence varied widely (mean use, 170 ± 145 [SD] minutes per night). Positive airway pressure therapy was associated with significant improvements in attention deficits (P < 0.001); sleepiness on the Epworth Sleepiness Scale (P < 0.001); behavior (P < 0.001); and caregiver- (P = 0.005) and child- (P < 0.001) reported quality of life. There was a significant correlation between the decrease in Epworth Sleepiness Scale at 3 months and adherence (r = 0.411; P = 0.006), but not between other behavioral outcomes and adherence. Behavioral factors also improved in the subset of children with developmental delays.

CONCLUSIONS

These results indicate that, despite suboptimal adherence use, there was significant improvement in neurobehavioral function in children after 3 months of positive airway pressure therapy, even in developmentally delayed children. The implications for improved family, social, and school function are substantial. Clinical trial registered with www.clinicaltrials.gov (NCT 00458406).

Pediatric polysomnography: the patient and family perspective

STUDY OBJECTIVES

The gold-standard test used to diagnose childhood obstructive sleep apnea is polysomnography. However, this test requires an overnight stay at a sleep laboratory and the attachment of multiple sensors to the patient. The long-term impact of this testing on the child and family are not known. We hypothesized that polysomnography does not precipitate acute or chronic psychological effects in children.

METHODS

A consecutive cohort of children who had undergone sleep studies 2 to 4 months prior to the interview were administered a standardized questionnaire via telephone.

RESULTS

Of the 118 families that were eligible to participate, 67% could be contacted and agreed to participate; 87% of respondents reported the experience to have been satisfactory (mean Likert score of 8.6 ± 2.0 [SD] on a scale of 1-10). Similar levels of satisfaction were reported by parents of children with developmental delay or those who were younger than 3 years. The night's sleep was considered typical in 68% of cases. Sleep was less likely to be typical in children younger than 3 years (47%, p = 0.043). Eight percent of children experienced pain during the study. By caregiver report, of those children who remembered the sleep study, memories were positive in 84%. No child had evidence of serious long-term psychological issues.

CONCLUSIONS

The vast majority of children and families found the polysomnography experience to be satisfactory, with no psychological sequelae. However, many children, especially those younger than 3 years, demonstrated sleep patterns different from their usual sleep. The clinical relevance of this finding merits further study. Further research evaluating the generalizability of this study is also needed.

Effect of low pH on single skeletal muscle myosin mechanics and kinetics

Acidosis (low pH) is the oldest putative agent of muscular fatigue, but the molecular mechanism underlying its depressive effect on muscular performance remains unresolved. Therefore, the effect of low pH on the molecular mechanics and kinetics of chicken skeletal muscle myosin was studied using in vitro motility (IVM) and single molecule laser trap assays. Decreasing pH from 7.4 to 6.4 at saturating ATP slowed actin filament velocity (V(actin)) in the IVM by 36%. Single molecule experiments, at 1 microM ATP, decreased the average unitary step size of myosin (d) from 10 +/- 2 nm (pH 7.4) to 2 +/- 1 nm (pH 6.4). Individual binding events at low pH were consistent with the presence of a population of both productive (average d = 10 nm) and nonproductive (average d = 0 nm) actomyosin interactions. Raising the ATP concentration from 1 microM to 1 mM at pH 6.4 restored d (9 +/- 3 nm), suggesting that the lifetime of the nonproductive interactions is solely dependent on the [ATP]. V(actin), however, was not restored by raising the [ATP] (1-10 mM) in the IVM assay, suggesting that low pH also prolongs actin strong binding (t(on)). Measurement of t(on) as a function of the [ATP] in the single molecule assay suggested that acidosis prolongs t(on) by slowing the rate of ADP release. Thus, in a detachment limited model of motility (i.e., V(actin) approximately d/t(on)), a slowed rate of ADP release and the presence of nonproductive actomyosin interactions could account for the acidosis-induced decrease in V(actin), suggesting a molecular explanation for this component of muscular fatigue.

Hypertrophic and dilated cardiomyopathy mutations differentially affect the molecular force generation of mouse α-cardiac myosin in the laser trap assay

Point mutations in cardiac myosin, the heart's molecular motor, produce distinct clinical phenotypes: hypertrophic (HCM) and dilated (DCM) cardiomyopathy. Do mutations alter myosin's molecular mechanics in a manner that is predictive of the clinical outcome? We have directly characterized the maximal force-generating capacity (Fmax) of two HCM (R403Q, R453C) and two DCM (S532P, F764L) mutant myosins isolated from homozygous mouse models using a novel load-clamped laser trap assay. Fmaxwas 50% (R403Q) and 80% (R453C) greater for the HCM mutants compared with the wild type, whereas Fmaxwas severely depressed for one of the DCM mutants (65% S532P). Although Fmaxwas normal for the F764L DCM mutant, its actin-activated ATPase activity and actin filament velocity ( Vactin) in a motility assay were significantly reduced (Schmitt JP, Debold EP, Ahmad F, Armstrong A, Frederico A, Conner DA, Mende U, Lohse MJ, Warshaw D, Seidman CE, Seidman JG. Proc Natl Acad Sci USA 103: 14525–14530, 2006.). These Fmaxdata combined with previous Vactinmeasurements suggest that HCM and DCM result from alterations to one or more of myosin's fundamental mechanical properties, with HCM-causing mutations leading to enhanced but DCM-causing mutations leading to depressed function. These mutation-specific changes in mechanical properties must initiate distinct signaling cascades that ultimately lead to the disparate phenotypic responses observed in HCM and DCM.

Nuclear markers confirm taxonomic status and relationships among highly endangered and closely related right whale species

Right whales (genus: Eubalaena) are among the most endangered mammals, yet their taxonomy and phylogeny have been questioned. A phylogenetic hypothesis based on mitochondrial DNA (mtDNA) variation recently prompted a taxonomic revision, increasing the number of right whale species to three. We critically evaluated this hypothesis using sequence data from 13 nuclear DNA (nuDNA) loci as well as the mtDNA control region. Fixed diagnostic characters among the nuclear markers strongly support the hypothesis of three genetically distinct species, despite lack of any diagnostic morphological characters. A phylogenetics analysis of all data produced a strict consensus cladogram with strong support at nodes that define each right whale species as well as relationships among species. Results showed very little conflict among the individual partitions as well as congruence between the mtDNA and nuDNA datasets. These data clearly demonstrate the strength of using numerous independent genetic markers during a phylogenetics analysis of closely related species. In evaluating phylogenetic support contributed by individual loci, 11 of the 14 loci provided support for at least one of the nodes of interest to this study. Only a single marker (mtDNA control region) provided support at all four nodes. A study using any single nuclear marker would have failed to support the proposed phylogeny, and a strong phylogenetic hypothesis was only revealed by the simultaneous analysis of many nuclear loci. In addition, nu DNA and mtDNA data provided complementary levels of support at nodes of different evolutionary depth indicating that the combined use of mtDNA and nuDNA data is both practical and desirable.

Pulmonary capillaritis with hemorrhage due to propylthiouracil therapy in a child

We report on a case of pulmonary capillaritis with diffuse alveolar hemorrhage in a child due to propylthiouracil (PTU). PTU treatment is a rare cause of pulmonary capillaritis in adults; we report on the first case in a pediatric patient. The treatment of pulmonary capillaritis often requires corticosteroid therapy, other immunosuppressive medications, or withdrawal of the causative agent. Our patient recovered completely after treatment with a limited course of corticosteroids and removal of PTU.

Successful transgene expression with serial doses of aerosolized rAAV2 vectors in rhesus macaques

Bronchoscopic microspraying of recombinant adeno-associated viral (rAAV) vectors targets high doses of vector directly to pulmonary epithelium. Single-dose endobronchial gene therapy trials have been accomplished in cystic fibrosis patients; however, repeated dosing strategies are likely essential for lifetime correction. These studies address whether serial redosing with rAAV2 vectors results in an antiserotypic response and, furthermore, whether it triggers an inflammatory response prohibitive to transgene expression. Serial redosing of 9 x 10(11) infectious units of aerosolized rAAV2 vectors to rhesus macaques resulted in successful gene transfer by quantitative PCR (1.43 x 10(9) copies/g tissue) and transgene expression. Additionally, confocal microscopy and immunohistochemical analysis demonstrated in situ expression localized to the pulmonary epithelium. Although serial redosing did induce a heightened anti-neutralizing antibody response in sera, gene transfer prevailed with resultant expression. This study is the first to demonstrate successful gene transfer subsequent to repeated aerosolized doses of rAAV2 in immunocompetent nonhuman primates without associated inflammatory responses prohibitive to transgene expression.

Deposition and expression of aerosolized rAAV vectors in the lungs of Rhesus macaques

The goals of these experiments were to efficiently deliver aerosolized adeno-associated virus (AAV) vector to the lungs of Rhesus macaques and to measure gene transfer and expression. To determine optimal lung deposition, we compared four techniques of delivering aerosolized saline admixed with the radioisotope (99m)technetium ((99m)Tc) nebulized through a mouthpiece (Neb Oral), a laryngeal airway mask (Neb LMA), or an endotracheal tube (Neb ETT), or bronchoscopically delivered by Microsprayer (PennCentury). Total lung deposition fraction, as indicated by gamma scintigraphy, averaged 0.5% (Neb Oral), 1.2% (Neb LMA), 1.8+/-0.4% (Neb ETT), and 62.3+/-11.3% (Microsprayer). Because microspraying was the most efficient method of delivery, we used it to administer saline with (99m)Tc-labeled diethylene-triamine penta-acetic acid (DTPA) admixed with 9 x 10(11) infectious units (i.u.) of AAV serotype 2 (rAAV2) vector encoding green fluorescent protein (GFP; rAAV2-GFP). Initial total and regional lung depositions were quantified by scintigraphy. We analyzed the tissue three weeks later for vector-specific DNA transduction and RNA expression. Radioisotope was detected in all lung regions, reflecting an average dose of 1.33 x 10(10)+/-9.5 x 10(9) i.u. per region. Regional data indicated an increase in expression when the dose exceeded 3 x 10(9) i.u. (P=0.030). We conclude that expression of rAAV2-GFP in lungs appears to be related to depositing a regional threshold dose greater than 3 x 10(9) i.u., easily achieved by bronchoscopic microspraying.

Repeated delivery of adeno-associated virus vectors to the rabbit airway

Efficient local expression from recombinant adeno-associated virus (rAAV)-cystic fibrosis (CF) transmembrane conductance regulator (CFTR) vectors has been observed in the airways of rabbits and monkeys for up to 6 months following a single bronchoscopic delivery. However, it is likely that repeated administrations of rAAV vectors will be necessary for sustained correction of the CF defect in the airways. The current study was designed to test the feasibility of repeated airway delivery of rAAV vectors in the rabbit lung. After two doses of rAAV-CFTR to the airways, rabbits generated high titers of serum anti-AAV neutralizing antibodies. Rabbits then received a third dose of a rAAV vector containing the green fluorescent protein (GFP) reporter gene packaged in either AAV serotype 2 (AAV2) or serotype 3 (AAV3) capsids. Each dose consisted of 1 ml containing 5 x 10(9) DNase-resistant particles of rAAV vector, having no detectable replication-competent AAV or adenovirus. Three weeks later, GFP expression was observed in airway epithelial cells despite high anti-AAV neutralizing titers at the time of delivery. There was no significant difference in the efficiency of DNA transfer or expression between the rAAV3 and rAAV2 groups. No significant inflammatory responses to either repeated airway exposure to rAAV2-CFTR vectors or to GFP expression were observed. These experiments demonstrate that serum anti-AAV neutralizing antibody titers do not predict airway neutralization in vivo and that repeated airway delivery rAAV allows for safe and effective gene transfer.

Jewish beliefs, values, and practices: implications for culturally sensitive nursing care

Providing culturally sensitive nursing care for the Jewish patient is a challenge for the non-Jewish nurse. Understanding the major values, ethics, and practices of Judaism that have relevance to nursing and medical care will give the advanced practice nurse the ability to provide care that is individualized to the patient and family.

A fluorescence video-endoscopy technique for detection of gene transfer and expression

The green fluorescent protein (GFP) has previously been adapted as a reported for gene transfer and expression in mammalian cells in culture and in tissue sections. Herein is described a new method for detecting GFP in situ within epithelia accessible to fiberoptic endoscopy by incorporating fluorescent filters for detection of GFP into an existing fiberoptic endoscopy system. This device was used to detect expression of GFP from adeno-associated virus (AAV; does of 3 x 10(7) IU) and adenovirus (Ad; does of l x 10(9) to 1 x 10(10) p.f.u.) vectors within the bronchial epithelium of New Zealand white rabbits. GFP expression was confirmed by fluorescence-activated cell sorting (FACS), direct fluorescence microscopy of cytospin preparations of brushed cells, and by fluorescence microscopy of fixed tissue sections. This reporter gene/detection system was then used to track the time course of expression of the AAV vector in the bronchial epithelium over the first 30 days after administration. The transduction frequency in the treated region of the epithelium peaked at around 50% at 21 days after transduction. Vector expression was still present at around 20% efficiency at 30 days after administration. This example indicates how this method could be used to reliably track gene transfer in living animals or patients.

Safety of single-dose administration of an adeno-associated virus (AAV)-CFTR vector in the primate lung

Gene therapy for cystic fibrosis (CF) would ideally be accomplished with a vector capable of long-term expression of the cystic fibrosis transmembrane conductance regulator (CFTR) in the absence of a host inflammatory response. Recombinant adeno-associated virus (AAV)-CFTR vectors possess these characteristics in rabbits. Because the utility of AAV vectors as gene transfer agents has only been recognized recently, AAV vector-mediated transduction has never been modeled in a primate host, which is an important step before its use in humans. In order to test the safety and biological activity of AAV-CFTR, single doses of AAV-CFTR vector were administered by fiberoptic bronchoscopy to the posterior basal segment of the right lower lobe (RLL) of the lungs of 10 rhesus macaques with four matched vehicle-treated controls. Animals were followed for 10, 21, 90 or 180 days following vector instillation. Vector DNA transfer occurred in bronchial epithelial cells in the RLL of each animal that received vector as assessed by in situ DNA PCR. Vector mRNA was detectable for 180 days after administration as detected by RT-PCR and by RNase protection assay. Safety of vector administration was determined by measurements of pulmonary mechanics, arterial blood gas analysis, chest radiographs, and bronchoalveolar lavage (BAL) fluid analysis including cell count and quantification of inflammatory cytokines. Gross and microscopic pathologic examination were also performed. There was no evidence of inflammation or other toxicity, although vector DNA was found in extrapulmonary organs of some animals. These results indicate that transduction of the primate airway epithelium with the AAV-CFTR mediates long-term CFTR cDNA transfer and is relatively safe.

Cooperative Learning and Feminist Pedagogy-A Model for Classroom Instruction in Nursing Education

This article reports on a research study conducted as part of a doctoral dissertation on the development of a cooperative learning teaching model in nursing education. The subjects for the study were a convenience sample of registered nurses who were pursuing a baccalaureate degree in nursing at an urban university. Principles of feminist pedagogy were incorporated as part of the cooperative learning model. The teacher/researcher taught two sections of the same course and, through the use of action research, developed a model for using cooperative learning strategies as the primary teaching modality. End of class and end of semester evaluations provided feedback that suggested that this was an exciting and effective alternative to traditional classroom teaching.

Levels of beta-trace protein and lysozyme in human amniotic fluids

The levels of beta-trace protein and lysozyme were estimated in amniotic fluids from normal fetuses and from fetuses with neuraltube defects. The values of these proteins in normal amniotic fluids were found to be similar to those detected in fetuses with anencephaly and spina bifida. The levels of lysozyme were shown to be correlated with gestational age.

Human complement C7 and C9 in fetal and newborn sera

Using specific immune sera, C7, C9, and C3 activator were detected in sera from human fetuses more than 16 weeks old and in newborn samples. Levels of C9 in cord sera ranged between 10 and 30% of those present in sera from adult subjects. The mean value of Ce activator was about half that in maternal blood. The mean level of C7 in newborns was nearly 70% of the amount in normal adults.