Adherence to treatment guidelines for acute otitis media in children. The necessity of an effective strategy of guideline implementation.

OBJECTIVES: Acute otitis media is the single diagnosis responsible for most prescriptions of antibiotics in Sweden and the USA. The treatment of acute otitis media has significant impact on child health, healthcare costs, and the development of anti-microbial resistance. In the Swedish national guidelines from the year 2000, watchful waiting was recommended for most children over 2 years of age. The aims of the present study were to assess the degree of adherence to acute otitis media guidelines at a busy pediatric emergency department of a university hospital and to determine whether an information campaign changed the result. METHODS: Audit of 91 patient records before and 80 patient records after an information campaign consisting of an oral presentation, posting of flow charts, and sending of educational material to prescribing physicians. Four endpoints were studied: choosing to use antibiotics, choice of antibiotic, dosage of antibiotic, and duration of treatment. RESULTS: Before the information campaign, adherence to guidelines was between 70% (dosage) and around 90% (duration). No significant change was seen after the information campaign. The endpoint choosing to use antibiotics showed a large divergence in adherence in children under 2 years (96%) compared to older children (39%). CONCLUSIONS: Overall adherence to recommendations was 70-90% but adherence to watchful waiting was poor. Information did not improve adherence, suggesting insufficient educational power or the existence of barriers other than lack of knowledge. Specific barriers should be identified, and implementation and follow-up should be part of producing guidelines in order to achieve the desired results.

Persisting hypoxaemia is an insufficient measure of adverse lung function in very immature infants.

BACKGROUND: Bronchopulmonary dysplasia (BPD), defined as protracted neonatal hypoxaemia, is considered a risk factor for respiratory disease in adulthood. The relationship between this diagnosis and the actual lung injury appearing in very immature infants is, however, unknown. OBJECTIVES: To compare lung function at term in very immature infants and full-term infants, and to determine how degree and duration of neonatal hypoxaemia are related to other aspects of lung function. DESIGN AND METHODS: All surviving, consecutive infants with gestational age below 28 weeks from a geographically defined area were eligible. The alveolar-arterial oxygen pressure difference was assessed as a measure of oxygenation failure. At term, functional residual capacity and gas-mixing efficiency were measured by multiple-breath nitrogen washout, and compliance and conductance of the respiratory system by the occlusion method. The results were compared to those in 50 full-term controls. MAIN RESULTS: Thirty-seven of 46 eligible infants were included. The preterm infants differed markedly from the full-term infants in all lung functions tested. Infants diagnosed as having BPD had more compromised lung function than those without, but the latter group differed markedly from the full-term group in functional residual capacity, compliance and gas-mixing efficiency. Only the mechanical variables were correlated to hypoxaemia at 36 weeks postmenstrual age (PMA). CONCLUSIONS: Infants with gestational age below 28 weeks at birth have remarkably impaired lung function at term, regardless of whether they carry the diagnosis BPD or not. All very immature infants may be at risk of future respiratory disease and should be monitored appropriately.

CPAP of 4 cm H(2)O Has no short-term benefit at term in infants with BPD.

BACKGROUND: Lung development and function is compromised at term in infants with bronchopulmonary dysplasia (BPD), characterized by reduced functional residual capacity (FRC) and impaired gas-mixing efficiency in distal airways. OBJECTIVE: To determine whether continuous positive airway pressure (CPAP) improves FRC, ventilation, distal airway function, and gas exchange in spontaneously breathing infants with BPD. DESIGN/METHODS: Twenty-one infants with BPD (median birth weight 0.72 kg (range 0.50-1.27) and median gestational age 26 weeks (range 23-28)) were studied before and after CPAP of 4 cm H(2)O was applied by a facemask system. A multiple-breath nitrogen washout method was used to assess FRC, ventilation, and gas-mixing efficiency. Moment analysis and lung clearance index was calculated from the nitrogen-decay curve for assessment of gas-mixing efficiency. Transcutaneous (Tc) PO(2)/PCO(2) was monitored during stable infant conditions before each washout test. RESULTS: When CPAP was raised from 0 to 4 cm H(2)O, FRC increased significantly together with a significant increase in moment ratios (M(1)/M(0) and M(2)/M(0)). Tc PO(2) decreased significantly and the breathing pattern changed, with significantly reduced respiratory rate, minute ventilation, and alveolar ventilation. There was also an increase in tidal volume and dead space. CONCLUSIONS: CPAP of 4 cm H(2)O applied with a facemask at term to infants with BPD did not improve ventilation, gas-mixing efficiency in distal airways, or oxygenation despite an increase in FRC. We speculate that instead of promoting recruitment of unventilated lung volumes, increasing the end-expiratory pressure in infants with BPD may lead to an overexpansion of already ventilated parts of the lung, causing further compromise of lung function.

Effect of antenatal corticosteroid treatment on lung function in full-term newborn infants.

BACKGROUND: Antenatal treatment of pregnant women with corticosteroids in order to stimulate surfactant production has been shown to be effective. However, lung structure is also affected by the treatment. OBJECTIVE: We tested the hypothesis that changes within lung acini, induced by maternal corticosteroid treatment, persist during lung development. METHODS: Twenty-two healthy infants, whose mothers were treated with up to three doses of betamethasone at 25-33 weeks of pregnancy because of preterm labour, but where labour terminated and the infants were born at term, were studied at term and compared to a group of 50 healthy newborn infants without prenatal treatment with corticosteroids. Gas-mixing efficiency was measured in terms of moment ratio with a nitrogen washout method together with functional residual capacity. Mechanical parameters were assessed with the single occlusion technique. RESULTS: There were no signs of disturbed gas mixing or changed lung volume or mechanics in the treated group. CONCLUSION: The result contributes to an emerging body of evidence that antenatal treatment with corticosteroids does not permanently affect lung structure or function.

Transcutaneous blood gas monitoring during neonatal intensive care.

AIM: To evaluate the accuracy in transcutaneous (Tc) blood gas monitoring in newborn infants, including extremely low birth weight infants, during neonatal intensive care. METHODS: Tc PO(2) /PCO(2) was monitored in the neonatal intensive care unit (NICU) during stable infant conditions. In comparison, simultaneous arterial PO(2) and PCO(2) was measured. Sixty measurements were taken in 46 infants with median (range) birth weight of 0.93 (0.53-4.7) kg and at median (range) age of 8.5 (1-44) days. Comparison of measurements was performed using Bland-Altman plots, and the mean (95% CI) of the difference was calculated. Comparison was also performed in relation to body weight, postnatal age and oxygen requirement. RESULTS: The mean (95% CI) difference in PO(2) (TcPO(2)-aPO(2)) was 0.3 (-0.2-0.9) kPa, and the corresponding difference in PCO(2) (TcPCO(2)-aPCO(2)) was 0.4 (0.03-0.8, p < 0.05) kPa. Some differences were related to body weight, age and oxygen requirement, but these differences were small. CONCLUSION: There was good agreement between TcPO(2)/TcPCO(2) and corresponding arterial measurements. The mean difference between the methods was small and clinically acceptable in a current NICU. Tc blood gas monitoring could be recommended as a valuable complement for blood gas monitoring also in extremely low birth weight infants.

Fructose 1,6-bisphosphatase deficiency: enzyme and mutation analysis performed on calcitriol-stimulated monocytes with a note on long-term prognosis.

Fructose 1,6-bisphosphatase (FBPase) deficiency is an inborn error of metabolism in the gluconeogenetic pathway. During periods of low food intake or infections, a defect in FBPase can result in hypoglycemia, ketonuria and metabolic acidosis. We established a diagnostic system for FBPase deficiency consisting of enzyme activity measurement and mutation detection in calcitriol-stimulated monocytes. In healthy individuals, we showed that FBPase activity is present in monocytes but not in other leukocytes. We describe the clinical course of four individuals from two Swedish families with FBPase deficiency. Family 1: patient 1 died at the age of 6 months after a severe episode with hypoglycemia and acidosis; patients 2 and 3 were followed for >30 years and were found to have a very favorable long-term prognosis. Their FBPase activity from jejunum (residual activity 15-25% of healthy controls), mixed leukocytes (low or normal levels), and calcitriol-stimulated monocytes (no detectable activity) was compared. Mutation analysis showed they were heterozygous for two genetic alterations (c.778G>A; c.881G>A), predicting amino acid exchanges at position p.G260R and p.G294E, originating from their parents. Family 2: patient 4 had no detectable levels of FBPase in stimulated monocytes. A mutation (c.648C>G) predicting a premature stop codon at position p.Y216X was found in one allele and a large deletion of about 300 kb, where the genes FBP2, FBP1 and a part of ONPEP are located, in the other. In conclusion, we present a reliable diagnostic system to verify an FBPase deficiency and find the genetic aberration.

A novel missense mutation in SUCLG1 associated with mitochondrial DNA depletion, encephalomyopathic form, with methylmalonic aciduria.

Mitochondrial DNA depletion, encephalomyopathic form, with methylmalonic aciduria is associated with mutations in SUCLA2, the gene encoding a beta subunit of succinate-CoA ligase, where 17 patients have been reported. Mutations in SUCLG1, encoding the alpha subunit of the enzyme, have been reported in only one family, where a homozygous 2 bp deletion was associated with fatal infantile lactic acidosis. We here report a patient with a novel homozygous missense mutation in SUCLG1, whose phenotype is similar to that of patients with SUCLA2 mutations.

Immediate changes in blood-gas tensions during chest physiotherapy with positive expiratory pressure and oscillating positive expiratory pressure in patients with cystic fibrosis.

OBJECTIVE: To assess and compare immediate effects of chest physiotherapy with positive expiratory pressure (PEP) versus oscillating PEP on transcutaneously measured blood-gas tensions in patients with cystic fibrosis. METHODS: Fifteen patients (mean age 12.5 y, range 6.9-21.5 y) participated. The treatments were randomized and performed on 2 separate occasions, 8 weeks apart. Spirometry was conducted before and after each treatment. We transcutaneously measured oxygen tension (P(tO2). RESULTS: There were no changes in spirometry values. During PEP, different trends in blood-gas tension were seen, and there were no consistent changes. During oscillating PEP, P(tO2) increased and P(tCO2) decreased. During oscillating PEP, P(tCO2) was lower and the intra-individual change in P(tCO2) was more pronounced than during PEP. The results obtained immediately after oscillating PEP showed a higher P(tO2) and a lower P(tCO2) than with PEP. CONCLUSION: PEP and oscillating PEP can both cause transitory effects on blood gases in patients with cystic fibrosis. However, oscillating PEP alters blood-gas tensions more than does PEP, and hyperventilation during oscillating PEP may reduce treatment time.

Lung function at term reflects severity of bronchopulmonary dysplasia.

OBJECTIVE: To test whether infants with bronchopulmonary dysplasia (BPD) express the same functional impairments at term as healthy, preterm infants, and whether clinical severity of BPD is qualitatively or quantitatively related. STUDY DESIGN: Prospective measurements on a consecutive sample of 50 infants with BPD and 19 healthy preterm controls in a university hospital. BPD infants were classified as "severe," "moderate," or "mild," according to their need for oxygen. A multiple-breath nitrogen wash-out method was used to assess functional residual capacity (FRC) and gas mixing efficiency. Mechanical variables were estimated by the occlusion test. RESULTS: Infants with severe BPD had lower FRC, less efficient gas mixing, and higher specific conductance than those with mild and moderate BPD, and the preterm controls. Mild and moderate BPD did not differ in any property from each other but differed from controls in the same variables. The elastic properties of the respiratory system appeared unaffected by BPD. CONCLUSIONS: The ventilatory impairments in BPD were of the same nature as in healthy preterm infants when compared with term infants, but their magnitude was related to the clinical severity of the BPD. Gas mixing efficiency together with FRC appears to be useful to assess lung development in BPD.

N-acetylcysteine administration during the first week of life does not improve lung function in extremely low birth weight infants.

Oxygen toxicity is thought to be an important factor involved in development of bronchopulmonary dysplasia (BPD) in the very preterm infant. Glutathione (GSH) plays a major role in the antioxidant defense system in the preterm lung and there are theoretical implications that N-acetylcysteine (NAC) treatment could improve its function. The purpose of this study was to investigate whether NAC treatment during the first week of life to preterm infants improved neonatal lung function as a measure of lung injury. The study was part of a multi-center Nordic controlled trial with prophylactic intravenous NAC treatment (16-32 mg/kg/day) for 6 days in newborn infants with birth weights 500-999 g. Lung mechanics, with calculations of compliance and resistance of the respiratory system, together with measurements of functional residual capacity and indices of gas mixing efficiency in the lung, were performed in 33 preterm infants (18 received NAC and 15 placebo) before discharge from the NICU. Median (range) gestational age was 25 (24-28) weeks in the NAC-treated infants and 25 (24-29) in the placebo group. Corresponding mean (SD) birth weights were 0.774 (0.11) and 0.761 (0.12) kg respectively. Lung function measurements did not show any significant differences between NAC-treated infants compared to placebo when examined before discharge from the NICU. We conclude that prophylactic NAC treatment to extremely low birth weight infants during the first week of life does not improve lung function at term.

Abnormal lung function in healthy preterm infants.

The aim of this study was to assess the consequences of preterm birth for the functional development of the lungs. We studied 32 healthy preterm infants (gestational age 25 to 33 wk at birth) and 53 healthy full-term infants (37 to 42 wk) at the same mean postmenstrual age of 40 wk with a multibreath nitrogen washout technique to assess functional residual capacity (FRC), gas mixing efficiency, and dead space and with the single-breath occlusion technique to calculate compliance and resistance of the respiratory system. Twenty of the preterm infants were also assessed with the same methods at 34.2 (32 to 37) wk. At the same postmenstrual age the preterm infants had lower FRC/kg body weight, lower specific compliance, impaired gas mixing efficiency, and higher total and dead space ventilation/kg than the full-term infants. Specific compliance and specific conductance decreased but gas mixing efficiency increased from 34 to 40 wk. We conclude that premature exposure to extrauterine conditions changes lung function. Preterm infants showed signs of dysfunction of the terminal respiratory units and higher elastic recoil than infants who spent the corresponding time for development in utero. It is suggested that preterm birth per se affects alveolarization and formation of elastic tissue in the lungs.