Administration and monitoring of clofazimine for NTM infections in children with and without cystic fibrosis.

Few studies have evaluated clofazimine (CLOF) drug monitoring and safety in children. We treated 10 children, 8 with CF, for NTM infection with multiple antimicrobials, including CLOF. All had serial blood CLOF concentrations measured and were followed for adverse events. Despite CLOF dose escalation, most children with CF did not reach a target CLOF concentration. Our data suggest that children with CF may require earlier initiation of CLOF at higher doses than is currently recommended.

Alternative models for telephone response to pediatric poisonings.

BACKGROUND: Poison Control Centers (PCCs) provide telephone consultations to manage poisonings. They are threatened with funding loss. Policy decision-makers have requested an evaluation of alternate models for telephone management of poisonings. OBJECTIVE: We examined the feasibility of alternative models for the telephone management of poisonings from the public. METHODS: Alternative models evaluated included emergency medical dispatchers (EMDs), advice nurses (RNs), and poison information providers (PIPs) to manage real and hypothetical poisonings with protocols or computerized references (Poisindex) with and without PCC backup. RESULTS: EMDs and RNs with a structured protocol and access to a PCC specialist were able to manage a small subset of poisoning calls. EMDs and RNs managed 6% and 12% of poisoning calls respectively. Non-protocol management of hypothetical cases using Poisindex resulted in mismanagement of cases and longer periods of time to manage cases. PIPs within a PCC were able to manage a substantially greater proportion of calls, but had a significant portion of non-productive time waiting for a PCC call. CONCLUSION: EMDs, RNs, and technician-level PIPs can manage a subset of poisoning cases using structured protocols. Alternative providers were dependent on PCC staff for consultation of the majority of poisoning calls. There are several obstacles to these models and their cost-effectiveness needs to be determined. These studies were the basis of a new staffing model with the integration of PIPs into the call response system in California.

Early pulmonary infection, inflammation, and clinical outcomes in infants with cystic fibrosis.

A thorough understanding of the early natural history of cystic fibrosis (CF) lung disease is critical for the development of effective interventions in the youngest patients. We assessed the evolution of pulmonary infection, inflammation, and clinical course among 40 infants over a 2-year period through annual bronchoalveolar lavage (BAL) for culture and measurements of pro- and anti-inflammatory cytokines, semiannual infant pulmonary function testing, and quarterly clinical evaluations. Both the prevalence of CF pathogens and their density in BAL fluid increased with age. Infants had neutrophilic lower airway inflammation and elevated IL-8 concentrations independent of whether CF pathogens were recovered. Total leukocyte and neutrophil densities and IL-8 concentrations increased with density of CF pathogens in BAL fluid, whether the isolated organism was P. aeruginosa or another pathogen. IL-10 concentrations were similar in CF subjects and non-CF historical controls. Infants generally had suboptimal growth (low weight and height percentiles) and obstructive lung disease (decreased expiratory flows and air trapping). Subjects from whom CF pathogens were isolated at > 10(5) cfu/mL had the worst air trapping and lowest Brasfield chest X-ray scores. Our findings provide a foundation for future studies of early intervention in CF lung disease, including antimicrobial and anti-inflammatory therapy.

A sword for the left hand: an unusual case of left-sided scimitar syndrome.

Scimitar syndrome is a rare anomaly involving abnormalities of the heart and lung which classically involves the right side. A rare case of left-sided scimitar syndrome is described in an asymptomatic child, with a review of the literature.

Respiratory diseases in the first year of life in children born to HIV-1-infected women.

Our objective was to describe the respiratory complications, clinical findings, and chest radiographic changes in the first year of life in infected and uninfected children born to HIV-1-infected women. We prospectively followed a cohort of 600 infants born to HIV-1-infected women from birth to 12 months in a multicenter study. Of these, 93 infants (15.5%) were HIV-1-infected, 463 were uninfected, and 44 were of unknown status prior to death or loss to follow-up. The cumulative incidence ( +/- SE) of an initial pneumonia episode at 12 months was 24.1 +/- 4.7% in HIV-1-infected children compared to 1.4 +/- 0.6% in HIV-1-uninfected children (P < 0.001). The rate of Pneumocystis carinii pneumonia (PCP) was 9.5 per 100 child-years. The HIV-1 RNA load was not higher in the group that developed pneumonia in the first year vs. those who did not. Children who developed lower respiratory tract infections or PCP had increased rates of decline of CD4 cell counts during the first 6 months of life. Lower maternal CD4 cell counts were associated with higher rates of pneumonia, and upper and lower respiratory tract infections. The rates of upper respiratory tract infection and bronchiolitis/reactive airway disease in infected children were not significantly different than in uninfected children. At 12 months, significantly more HIV-1-infected than uninfected children had tachypnea and chest radiographs with nodular and reticular densities. There was no relationship between cytomegalovirus infection in the first year of life and radiographic changes or occurrences of pneumonia. In conclusion, despite a low incidence of PCP, rates of pneumonia remain high in HIV-infected children in the first year of life. The incidence of pneumonia in uninfected infants born to HIV-1-infected mothers is low. Chest X-ray abnormalities and tachypnea suggest that subacute disease is present in infected infants. Further follow-up is warranted to determine its nature.

Forced expiratory flow in uninfected infants and children born to HIV-infected mothers.

The Pediatric Pulmonary and Cardiovascular Complications of Vertically Transmitted HIV (P(2)C(2) HIV) Study is a multicenter study examining pulmonary and cardiac outcomes in offspring of HIV-infected mothers. This portion of the P(2)C(2) study tests the hypothesis that infants exposed to, but uninfected by, maternal HIV have normal maximal expiratory flow at functional residual capacity (V'max,(FRC)). We obtained 500 measurements of V'max,(FRC) by rapid thoracic compression in 285 children ages 6-30 mo in five U.S. centers. The data were compared with those from a healthy cohort of children described elsewhere. V'max,(FRC) rose with height in a linear relationship. The slope of the regression line in the exposed infants did not differ statistically from the slope in the comparison group, but the intercept was about 20% lower (p < 0.001). Height and weight were comparable in the two cohorts, and the differences between intercepts persisted after adjusting for birth weight and gestational age. However, maternal HIV infection cannot be assumed to be the cause as the cohorts may have differed in other variables, such as socioeconomic status and frequency of maternal smoking and drug use. Also, measurements varied substantially within and between our five centers, probably in part because of different racial and ethnic distributions. In summary, maternal HIV infection probably has only a modest effect, if any, on maximal expiratory flow at functional residual capacity in uninfected infants.

Longitudinal assessment of Pseudomonas aeruginosa in young children with cystic fibrosis.

Pseudomonas aeruginosa lung infection is an important cause of morbidity and mortality in cystic fibrosis (CF). Longitudinal assessment of the phenotypic changes in P. aeruginosa isolated from young children with CF is lacking. This study investigated genotypic and phenotypic changes in P. aeruginosa from oropharynx (OP) and bronchoalveolar lavage fluid (BALF) in a cohort of 40 CF patients during the first 3 years of life; antibody response was also examined. A high degree of genotypic variability was identified, and each patient had unique genotypes. Early isolates had a phenotype distinct from those of usual CF isolates: generally nonmucoid and antibiotic susceptible. Genotype and phenotype correlated between OP and BALF isolates. As determined by culture, 72.5% of patients demonstrated P. aeruginosa during their first 3 years. On the basis of combined culture and serologic results, 97.5% of patients had evidence of infection by age 3 years, which suggests that P. aeruginosa infection occurs early in CF and may be intermittent or undetectable by culture.

Thoracoabdominal compression and respiratory system compliance in HIV-infected infants.

The thoracoabdominal compression technique (TAC) is used to measure expiratory flow in infants. We investigated whether TAC caused a change in total thoracic compliance (Crs), resistance (Rrs), and respiratory system time constant (Trs). We studied 41 infants (mean age, 12.4 mo; SD, 7.5) from five centers studying longitudinal lung and cardiovascular function of infants from HIV-infected mothers. We measured Crs, Rrs, and Trs before and after TAC. Changes in Crs, Rrs, and Trs after TAC were not dependent on the length of time since TAC. Crs and Trs were reduced after TAC, p = 0.013 and p = 0.003, respectively, whereas Rrs did not change. When compared with uninfected infants, HIV-infected infants had a larger post-pre TAC percent decline in Crs (p = 0.003) and a post-pre TAC rise in mean Rrs (p = 0.03). These differences remained significant after adjusting for sex and age. When performing infant pulmonary function testing, TAC itself produces a temporary decrease in Crs and Trs that is more significant in infants at risk for abnormal lung volume or compliance. Therefore, the sequence of performing the infant lung function parameters should be the same each time the testing is repeated with TAC as the last parameter tested at each testing session.

T-tube ileostomy for meconium ileus: four decades of experience.

BACKGROUND/PURPOSE: The T-tube ileostomy was first used at Texas Children's Hospital in 1959. The purpose of this study is to update the experience since the initial report of this technique in 1981. METHODS: A database of 448 patients with cystic fibrosis (CF) seen in the authors' institution was used to identify 83 patients (18.5%) who presented with meconium ileus. The clinic and hospital charts of these patients were reviewed retrospectively to identify patients who had undergone placement of a T-tube ileostomy. RESULTS: Surgery was performed in 60 of 83 patients for complications of meconium ileus or failure to evacuate the meconium after a contrast enema. Of these patients, 21 of 60 (35%) underwent placement of a T-tube ileostomy. An additional 8 patients were identified who underwent placement of a T-tube ileostomy but were not included in the CF database, for a total of 29 patients who have been treated with T-tube ileostomy since 1959 at Texas Children's Hospital. Five patients were excluded from analysis because of insufficient data or misdiagnosis. One of the 24 patients in the series died of complications of prematurity. A total of 20 of 23 patients had resolution of their meconium ileus after T-tube irrigation with n-acetylcysteine or pancreatic enzymes. Three patients required additional surgery to relieve persistent bowel obstruction. All patients had the T-tube removed within the first 8 weeks after surgery. Two patients required subsequent repair of an incisional hernia. There were otherwise no complications of this procedure, with an average follow-up of 11.5 years. CONCLUSION: In patients with uncomplicated meconium ileus unrelieved by contrast enema, the T-tube ileostomy is an effective and safe treatment.

Diagnostic accuracy of oropharyngeal cultures in infants and young children with cystic fibrosis.

The objective of this study was to assess the diagnostic accuracy of oropharyngeal (OP) cultures relative to simultaneous bronchoalveolar lavage (BAL) cultures in very young children with CF, and to examine the effects of bacterial density, age, and study cohort on diagnostic accuracy. Respiratory culture data were analyzed from three independent, prospective studies involving simultaneous collection of 286 OP and BAL cultures from 141 children with CF <5 years of age. For predicting any growth of Pseudomonas aeruginosa (Pa) from the lower airway in subjects /=10(3) or >/=10(5) cfu/mL. Specificity for Pa declined significantly with increasing age. In children with CF <5 years of age, the specificity and negative predictive value of OP cultures for Pa are high, while the sensitivity and positive predictive value are poor. Thus, in this age range, a negative throat culture is helpful in "ruling out" lower airway infection with Pa. However, a positive culture does not reliably "rule in" the presence of Pa in the lower respiratory tract. These findings may have implications for study design and interpretation as well as clinical management of young children with CF.

Effects of viral lower respiratory tract infection on lung function in infants with cystic fibrosis.

OBJECTIVE: To determine the effect of respiratory viral infections on pulmonary function in infants with cystic fibrosis (CF) after the respiratory virus season (October through March). METHODS: Recruitment was for one respiratory virus season during a 3-year span, 1988 to 1991, with reenrollment allowed; 22 infants <2 years of age with CF (30 patient-seasons) and 27 age-matched controls (28 patient-seasons) participated. Primary outcome variables were preseason and postseason pulmonary function tests and serology for viral antibodies. Twice-weekly telephone calls screened for respiratory symptoms. The presence of respiratory symptoms triggered a home visit and an evaluation for upper or lower (LRTI) respiratory tract infection. A nasopharyngeal sample for viral culture was performed with each visit. RESULTS: Controls and CF infants each had a mean of 5.3 acute respiratory illnesses; CF infants were four times more likely to develop an LRTI compared with controls (odds ratio, 4.6; 95% confidence interval, 1.3 and 16.5). Three of 7 (43%) CF infants with respiratory syncytial virus infection (documented by culture) required hospitalization. Controls had no association between respiratory illness and postseason pulmonary function. For CF infants, reduced postseason maximal flow at functional residual capacity (V'maxFRC) was associated with two interactions, ie, respiratory syncytial virus infection and LRTI, and male sex and LRTI; increased gas trapping (FRC) was associated with an interaction between respiratory syncytial virus and LRTI and day care. Postseason pulmonary function tests were obtained a mean of 3. 2 months after final LRTI. CONCLUSIONS: Infants with CF incurring respiratory virus infection are at significant risk for LRTI, for hospitalization, and for deterioration in lung function that persists months after the acute illness.

Incidence and prevalence of neutralizing antibodies to the common adenoviruses in children with cystic fibrosis: implication for gene therapy with adenovirus vectors.

OBJECTIVE: Defining the infection rate and prevalence of the common adenoviruses (Ads) in cystic fibrosis (CF) children may aid in formulation of strategies for gene therapy with Ad vectors. We undertook this study to determine the incidence and prevalence of infection with the common Ads in children with CF. METHODOLOGY: Thirty newly diagnosed CF children mean age 1.1 years (Group 1), 48 CF children mean age 4.6 years (Group 2), and 47 mothers of CF children (Group 3) were followed for a mean of 13 months. Group 4 consisted of 33 adult volunteers seen once. Throat and stool specimens for virus culture, and blood samples were obtained every 3 months from CF children in Group 1. Blood samples from CF children (Group 2) and their mothers (Group 3) were obtained every 6 months, and once from adults in Group 4. Neutralizing antibody to Ad serotypes 1 through 7 (Ad 1 to Ad 7) was evaluated with a microneutralization assay. RESULTS: Five (16.7%) CF children in Group 1 were culture-positive for an Ad; 4 of these CF children developed a fourfold or greater rise in antibody titer. Ad 3 infection occurred frequently based on serology; seronegative (< 3.5 log 2) CF children had a higher infection rate compared with seropositive CF children (7/11 vs 1/34). The prevalence of neutralizing antibodies in CF children in order of decreasing frequency was 91.1% to Ad 3, 37.5% to Ad 2, 27.1% to Ad 1, 26.1% to Ad 7, 16.7% to Ad 5, 8.5% to Ad 4, and 2.0% to Ad 6. The neutralizing antibody titers in seropositive CF children were comparable to those in adults except to Ad 3, which was significantly greater in mothers of CF children. CONCLUSIONS: CF children had a normal antibody response after Ad infection, preexisting antibody may protect against reinfection and antibody prevalence was low to the common Ads.

The costs and outcomes of restricting public access to poison control centers. Results from a natural experiment.

OBJECTIVES: The authors examined the costs and outcomes resulting from a natural experiment during which direct public access to poison control centers was restricted and then restored. METHODS: Both societal and health care purchaser perspectives were used. Probability data were obtained from a natural experiment during which public callers from a large county in California were electronically blocked from directly accessing the poison control center. Callers were referred to 911, which had direct access to the poison control center, if they thought they had a poisoning emergency. We conducted telephone interviews of: (a) persons who attempted to call the poison control center for a child's poisoning exposure but who did not have direct access (n = 270) and (b) persons who called the poison control center after direct access was restored (n = 279). Cost data were obtained from primary data collection and from other sources. The outcome measure was the appropriateness of the treatment location (at home or at a health care facility). Caller-reported outcomes were also examined. RESULTS: The average additional cost per blocked call was $10.89 from a societal perspective, or $33.14 from a health care purchaser perspective. Fourteen percent of callers with restricted access were treated at an inappropriate location, compared with only 2% of callers with direct poison control center access. Also, 14% did not obtain any professional advice after they attempted to call the poison control center, although 66% of these cases involved potentially toxic substances. Results were robust across a range of sensitivity analyses. CONCLUSION: Restricting direct public access to poison control centers created additional costs to society, the health care sector, and callers.

Sequential annual administration of purified fusion protein vaccine against respiratory syncytial virus in children with cystic fibrosis.

BACKGROUND: We recently showed the clinical benefit of the PFP-2 vaccine for respiratory syncytial virus (RSV) for children with cystic fibrosis (CF). OBJECTIVE: To determine the safety and immunogenicity of yearly sequential administration of the PFP-2 vaccine in CF children. STUDY DESIGN: Twenty-nine of the 34 CF children who participated in the previous study were enrolled in this open label vaccine study. All of the CF children ages 2.6 to 8.9 years received the PFP-2 vaccine, the PFP/PFP group received the PFP-2 vaccine in 1993 and 1994 and the saline/PFP group received the vaccine for the first time in 1994. At entry demographic data and measurements of lung function and nutrition were collected. Microneutralization test, enzyme-linked immunosorbent assay to F protein and Western blot assay were performed on plasma drawn before and 4 weeks after vaccination and at the end of the RSV season. During the study weekly telephone calls were made and acute respiratory illnesses were evaluated. RESULTS: Baseline measurements were similar between groups. Systemic and local vaccine reactions were mild and similar for both groups. A 4-fold or greater neutralizing antibody rise to RSV occurred in 4 of 14 (28.6%) and 9 of 14 (64.3%) in PFP/PFP and saline/PFP groups (P = 0.13), respectively. Four children in the PFP/PFP group and 7 in the saline/PFP group were infected with RSV. A reduction in lower respiratory illnesses (1.0 vs. 2.0), antibiotic courses (2.5 vs. 5.6) and days of illnesses (37.3 vs. 93.1) was observed in the PFP/PFP vaccinees infected with RSV compared with the saline/PFP group (t test; P < or = 0.05). One death occurred in the PFP/PFP group; the cause of death was consistent with septic shock and unrelated to vaccination or RSV infection. CONCLUSION: Sequential annual PFP-2 vaccination was safe and not associated with exaggerated respiratory disease.

Willingness to pay for poison control centers.

We used the willingness-to-pay (WTP) method to value the benefits of poison control centers when direct access was blocked, comparing WTP among: (1) blocked callers (n = 396), (2) callers after access was restored (n = 418), and (3) the general population (n = 119). Mean monthly WTP was $6.70 (blocked callers), $6.11 (non-blocked callers), and $2.55 (general population). Blocked and non-blocked callers had a significantly higher WTP than general population respondents (p < 0.001). We conclude that the WTP method measured benefits that are difficult to quantify; however, WTP surveys need to be carefully conducted to minimize bias. We discuss how this approach could be useful for other health care services.

Purified fusion protein vaccine protects against lower respiratory tract illness during respiratory syncytial virus season in children with cystic fibrosis.

OBJECTIVE: To test in a double blind, placebo-controlled study a purified fusion protein (PFP-2) vaccine against respiratory syncytial virus (RSV) in RSV-seropositive children with cystic fibrosis (CF). METHODS: Seventeen CF children, mean age 4.5 years, received PFP-2 vaccine and 17 CF children, mean age 5.8 years, received a saline vaccine. At enrollment the Shwachman clinical score, Brasfield radiographic score, oxygen saturation (SpO2), anthropometric indices and other variables were recorded. After vaccination the reactions were assessed daily for 7 days. During the RSV season weekly telephone interviews were performed and children with an acute respiratory illness were evaluated and cultured for RSV. Serum was drawn before vaccination, 1 month after vaccination and at the end of the RSV season and tested for antibodies to RSV. RESULTS: Other than age the baseline measurements at enrollment were similar between groups. The PFP-2 vaccine produced mild local reactions and induced a significant neutralizing antibody response in two-thirds of the vaccinees and a significant enzyme-linked immunosorbent assay-fusion glycoprotein antibody response in nearly all the PFP-2 vaccinees. Vaccine-enhanced disease was not observed in PFP-2 vaccines infected with RSV. Protection against RSV infection was not observed; however, a significant reduction (t test, P < 0.01) in mean number of lower respiratory tract illnesses (0.8 vs. 2.1), antibiotic courses (2.2 vs 4.5) and days ill (30.5 vs. 67) occurred among RSV-infected PFP-2 vaccinees. CONCLUSIONS: Efficacy of the PFP-2 vaccine against lower respiratory tract illness during the RSV season was shown in RSV-seropositive children with CF.

High-dose, short-duration ribavirin aerosol therapy compared with standard ribavirin therapy in children with suspected respiratory syncytial virus infection.

Children with suspected respiratory syncytial virus infection were examined prospectively in a randomized evaluation of standard ribavirin aerosol therapy (6 gm/300 ml water for 18 hours daily) compared with high-dose, short-duration ribavirin aerosol therapy (6 gm/100 ml water given for a period of 2 hours three times a day) by means of an oxygen hood (n = 20) or a ventilator (n = 12). Viral shedding was quantitated daily; clinical observations were recorded daily by 2 physicians aware and one unaware of treatment assignments. Study characteristics evaluated at entry were not significantly different in the high-dose and the standard-dose groups. Viral titers and clinical scores decreased similarly in both groups during the study; pulmonary function test results were also similar at discharge in children not receiving mechanical ventilation. Potential complications related to aerosol therapy were noted in three patients (one hood patient who was receiving standard therapy; two patients with an endotracheal tube in place who were receiving high-dose therapy); substantial crystallization was noted in the tubing of the patients undergoing intubation and receiving high-dose therapy. Environmental sampling revealed that ribavirin was nearly undetectable near patients supported by mechanical ventilation who were receiving either form of therapy, and was significantly decreased on a daily basis in patients without an endotracheal tube who were receiving high-dose therapy compared with those receiving standard therapy. The effects of high-dose, short-duration aerosol ribavirin therapy were similar to those of standard-dose therapy in our study patients and resulted in a decreased release of ribavirin into the room of patients receiving therapy by means of an oxygen hood.

Symptoms, lung function, and airway responsiveness following irritant inhalation.

STUDY OBJECTIVE: To estimate the incidence of respiratory symptoms and physiologic abnormalities after inhalation of common irritant chemicals. DESIGN: Structured interview of 12 months of poison control center (PCC) inhalation cases. Follow-up measurement of pulmonary function and airway responsiveness in a subgroup with symptoms 12 to 24 h postexposure. SETTING: A regional PCC and clinical pulmonary function laboratory. PATIENTS: Consecutive sample of 547 inhalation cases. Interviews of 299 subjects. Lung function follow-up in 10 subjects. MEASUREMENTS AND MAIN RESULTS: Immediate respiratory symptoms were reported by 262 (88 percent) subjects; 12 to 24 h postexposure symptoms were reported by 130 (44 percent). Cigarette smoking was significantly related to immediate onset of cough (relative risk [RR] = 1.3; 95 percent confidence interval [CI], 1.1 to 1.5); both smoking (RR = 1.6; 95 percent CI, 1.1 to 2.1) and prior asthma (RR = 1.3; 95 percent CI, 1.1 to 1.6) were associated with wheeze, exhibiting multiplicative combined risk (RR = 2.8; 95 percent CI, 1.9 to 4.3). Of 10 subjects studied, none had abnormal airflow or lung volumes 8 +/- 4 days postexposure; 8 demonstrated increased airway responsiveness to methacholine. By three months, only one subject's increased responsiveness reversed; in three others, symptoms resolved but increased responsiveness remained. CONCLUSIONS: Respiratory symptoms following irritant exposure are associated with smoking and asthma and typically resolve quickly. Continuing symptoms are associated with persistent increased airway responsiveness without other pulmonary function abnormalities. This may reflect newly induced airway changes or, alternatively, could represent underlying increased responsiveness in subjects symptomatic after irritant exposure.

A lamb model for human respiratory syncytial virus infection.

Respiratory syncytial virus (RSV) is the most important cause of bronchiolitis and pneumonia in young children. The development of an animal model of RSV disease serves to better understanding the pathophysiology of airway disease from RSV infection in infants and children. Groups of six lambs were inoculated intratracheally (IT) or intranasally (IN) with a human strain of RSV (H-RSV). For controls 8 lambs received IT virus-free cell lysate. Tachypnea and fever were observed significantly more often following IT than following IN inoculation of H-RSV or IT placebo (for tachypnea: 20 of 69 days, 5 of 63 days, and 3 of 89 days, respectively, P < 0.001; for fever: 6 of 69 days, 0 of 63 days, and 1 of 89 days, respectively, P < 0.02). Nasal fluid production was significantly more frequent in both IT (14 of 69 days) and IN (15 of 63 days) groups than in the placebo group (2 of 87 days, P < 0.001). Postvaccination geometric mean titers (GMT, arithmetic transformation of log 2) of RSV-specific neutralizing antibody were significantly increased in the IT H-RSV group compared with postplacebo GMTs at 1 week (72 vs. 6.7, P < 0.03). By the second week postinoculation both H-RSV-infected groups had comparable levels of RSV-specific neutralizing antibody titers and had significantly greater GMTs for the second through to the fourth week than the placebo group (144, 128, and 4.8, respectively P < 0.0008). Bacterial isolates of the upper airway were comparable among the three groups. Histopathology at day 28 postinoculation was unremarkable for the three study groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Oxygen desaturation during sleep in infants and young children with congenital heart disease.

Oxygen saturation (SaO2) during sleep and pulmonary functions were evaluated in 19 infants with congenital heart disease, aged 6 +/- 4 months, and in 11 normal infants, aged 8 +/- 5 months, to determine whether infants with congenital heart disease have more frequent oxygen desaturation during sleep and, if so, its relationship to underlying pulmonary function. Infants with congenital heart disease were classified as acyanotic (n = 11) or cyanotic (n = 8) on the basis of their aortic SaO2 at the time of cardiac catheterization (greater or less than 90% SaO2). Pulmonary function tests included respiratory rate, functional residual capacity, total respiratory system compliance, and maximal flows at functional residual capacity. Significant differences were found in the values for the lowest SaO2 of each 5-minute epoch (SaO2L) averaged during the entire sleep time (normal 94% +/- 2%, acyanotic 90% +/- 3%, and cyanotic 74% +/- 4%; p less than 0.01). The three groups also differed significantly in frequency distributions of percentage of total sleep time with SaO2L less than 90% (SaO2%T) (normal 10% +/- 17%, acyanotic 36% +/- 34%, and cyanotic 97% +/- 4%; p less than 0.05). Compared with the control group, the acyanotic group had a higher respiratory rate (66 +/- 19 breaths/min vs 35 +/- 6 breaths/min; p less than 0.01), a lower tidal volume (65% +/- 29% predicted vs 105% +/- 18% predicted; p less than 0.01), and a lower total respiratory compliance (59% +/- 18% predicted vs 106% +/- 30% predicted; p less than 0.01). A negative correlation existed between SaO2%T and aortic SaO2 (R2 = 0.64; p less than 0.01). We conclude that oxygen desaturation occurs during sleep in infants with congenital heart disease; the presence of desaturation appears to be related to the initial degree of hypoxemia and the presence of abnormal pulmonary function.