Fluid and electrolyte balance during the first week of life and risk of bronchopulmonary dysplasia in the preterm neonate

A Systematic Review: Is Early Fluid Restriction in Preterm Neonates Going to Prevent Bronchopulmonary Dysplasia?

Preterm birth causes constant challenges, with bronchopulmonary dysplasia (BPD) being a major concern. Immediately after birth, it takes time to establish feeding between the mother and the premature baby. During this time, the telological shifting of fluid from extracellular space to intracellular space will help the baby; this transition should be smooth. Both normal physiologic changes and pathophysiologic events are capable of disrupting this delicate fluid shifting that occurs in very low-birth-weight infants during the first week of life. The immaturity of the renal system and evaporative losses complicate this process. This lack of fluid displacement can be associated with an increased amount of water in the lungs and reduced lung compliance. This can lead to the need for more ventilatory support and a higher oxygen requirement, which, in turn, leads to lung damage. The fluid restriction is also associated with complications such as severe dehydration, intracranial hemorrhage, and bilirubin toxicity. However, the administration of large amounts of fluid and salt is associated with an increased incidence of patent ductus arteriosus, BPD, necrotizing enterocolitis, and intraventricular hemorrhage. There were studies conducted in both the pre-surfactant and surfactant eras that were inconclusive regarding fluid restriction in BPD. We only included very recent studies. This systematic review attempts to summarize the current evidence, focusing on the efficacy and safety of early fluid management in preterm infants. This reduces the risk of BPD and improves outcomes for premature infants. As we know, intact survival is very important. Our review supported the early fluid restriction.

Risk factors and machine learning prediction models for bronchopulmonary dysplasia severity in the Chinese population

BACKGROUND

Bronchopulmonary dysplasia (BPD) is a common chronic lung disease in extremely preterm neonates. The outcome and clinical burden vary dramatically according to severity. Although some prediction tools for BPD exist, they seldom pay attention to disease severity and are based on populations in developed countries. This study aimed to develop machine learning prediction models for BPD severity based on selected clinical factors in a Chinese population.

METHODS

In this retrospective, single-center study, we included patients with a gestational age < 32 weeks who were diagnosed with BPD in our neonatal intensive care unit from 2016 to 2020. We collected their clinical information during the maternal, birth and early postnatal periods. Risk factors were selected through univariable and ordinal logistic regression analyses. Prediction models based on logistic regression (LR), gradient boosting decision tree, XGBoost (XGB) and random forest (RF) models were implemented and assessed by the area under the receiver operating characteristic curve (AUC).

RESULTS

We ultimately included 471 patients (279 mild, 147 moderate, and 45 severe cases). On ordinal logistic regression, gestational diabetes mellitus, initial fraction of inspiration O2 value, invasive ventilation, acidosis, hypochloremia, C-reactive protein level, patent ductus arteriosus and Gram-negative respiratory culture were independent risk factors for BPD severity. All the XGB, LR and RF models (AUC = 0.85, 0.86 and 0.84, respectively) all had good performance.

CONCLUSIONS

We found risk factors for BPD severity in our population and developed machine learning models based on them. The models have good performance and can be used to aid in predicting BPD severity in the Chinese population.

Neurodevelopmental consequences of early plasma sodium changes in very preterm infants

BACKGROUND

Sodium fluctuations in very preterm neonates and their neurodevelopmental consequences are not well described.

METHODS

We assessed the changes in plasma sodium and glucose in the first days of life in very preterm neonates and studied the association of glucose-corrected plasma sodium fluctuations on neurodevelopmental outcomes. We included 147 consecutive neonates born before 29 weeks of gestation in our center and retrospectively obtained plasma sodium, glucose, and glucose-corrected sodium levels. Neurodevelopmental assessment was obtained from the Canadian Neonatal Follow-Up Network.

RESULTS

Mean ± standard deviation of plasma sodium changes within the first 10 days of life were 16.2 ± 6.0, 14.8 ± 5.3, and 11.1 ± 5.2 mmol/l in neonates born ≤25, 25-26, and 26-27 weeks of gestation, respectively (p < 0.001). Non-steroidal anti-inflammatory drug administration was associated with larger plasma sodium fluctuation. Eighty-six percent had a known neurological status at 18 months. Higher fluctuations in glucose-corrected plasma sodium were associated with death or neurodevelopmental impairment at 18 months corrected age (B = 3.19, 95% CI [1.24, 5.14]), and this association remained after adjustment for gestational age (B = 2.1, 95% CI [0.16, 4.04]).

CONCLUSIONS

Neonates born very preterm show fluctuations in glucose-corrected plasma sodium during the first days of life, which may increase the risk of death or developmental impairment.

IMPACT

Risk factors and neurodevelopmental consequences of plasma sodium changes in early neonatal life of preterm infants are not well characterized. This study shows for the first time that glucose-corrected plasma sodium fluctuations within the first days of life are more severe in preterm infants receiving non-steroidal anti-inflammatory drugs (NSAIDs) and are associated with death or neurodevelopmental impairment at 18 months corrected age. Large plasma sodium and glucose fluctuations should be expected more often in preterm infants receiving NSAIDs and should be avoided.

Fluid status in the first 10 days of life and death/bronchopulmonary dysplasia among preterm infants

OBJECTIVE

To investigate the association between fluid and sodium status in the first 10 postnatal days and death/bronchopulmonary dysplasia (BPD) among infants born <29 weeks' gestation.

STUDY DESIGN

Single center retrospective cohort study (2015-2018) of infants born 23-28 weeks'. Three exposure variables were evaluated over the first 10 postnatal days: cumulative fluid balance (CFB), median serum sodium concentration, and maximum percentage weight loss. Primary outcome was death and/or BPD. Multivariable logistic regression adjusting for patient covariates was used to assess the association between exposure variables and outcomes.

RESULTS

Of 191 infants included, 98 (51%) had death/BPD. Only CFB differed significantly between BPD-free survivors and infants with death/BPD: 4.71 dL/kg (IQR 4.10-5.12) vs 5.11 dL/kg (IQR 4.47-6.07; p < 0.001). In adjusted analyses, we found an association between higher CFB and higher odds of death/BPD (AOR 1.56, 95% CI 1.11-2.25). This was mainly due to the association of CFB with BPD (AOR 1.60, 95% CI 1.12-2.35), rather than with death (AOR 1.08, 95% CI 0.54-2.30).

CONCLUSION

Among preterm infants, a higher CFB in the first 10 days after delivery is associated with higher odds of death/BPD.

IMPACT

Previous studies suggest that postnatal fluid status influences survival and respiratory function in neonates. Fluid balance, serum sodium concentration, and daily weight changes are commonly used as fluid status indicators in neonates. We found that higher cumulative fluid balance in the first 10 days of life was associated with higher odds of death/bronchopulmonary dysplasia in neonates born <29 weeks. Monitoring of postnatal fluid balance may be an appropriate non-invasive strategy to favor survival without bronchopulmonary dysplasia. We developed a cumulative fluid balance chart with corresponding thresholds on each day to help design future trials and guide clinicians in fluid management.

Do Calcium and Potassium Levels Influence Ductal Patency in Preterm Infants?

OBJECTIVE

We investigated the relationship of serum potassium (K⁺) and ionized calcium (iCa²⁺) levels with the persistence of ductus arteriosus.

STUDY DESIGN

This retrospective cohort study included infants with birth weight < 1,500 g and gestational age < 32 weeks. Serum K⁺ and iCa²⁺ levels at the 1st and 48th hour of life were measured from samples. The difference between the two levels was calculated for both serum K⁺ (ΔK⁺) and iCa²⁺ (ΔCa²⁺). These values were compared between hemodynamically significant patent ductus arteriosus (hsPDA) and non-hsPDA.

RESULTS

Of 1,322 hospitalized preterm nonates, 1,196 were included in the study. Mean serum K⁺ levels at the 1st and 48th hour were higher and iCa²⁺ levels at the 1st and 48th hour were lower in hsPDA and non-hsPDA, respectively (p < 0.001). Ionized ΔCa²⁺ (-0.06 ± 0.13 vs. -0.02 ± 0.12 mmol/L) was higher in hsPDA (p < 0.001).

CONCLUSION

We demonstrated that serum K⁺ and iCa²⁺ level might play a role in ductal constriction.

Assessment and Optimization of the Pediatric Parenteral Nutrition Preparation Process in a Hospital Pharmacy

BACKGROUND

Parenteral nutrition (PN) is associated with risks that could threaten the clinical condition of premature neonates hospitalized in the neonatal intensive care unit. In this work, risk-analysis methodology was implemented to contain the risks associated with the PN production process and improve PN safety.

METHODS

The Failure Modes, Effects, and Criticality Analysis was performed by a multidisciplinary team. All potential failure modes of the PN preparation process were recorded, and associated risks were scored based on their severity, occurrence, and detectability, with a risk priority number (RPN). All identified failure scenarios and the respective work stages were ranked in descending order of criticality. Corrective actions were proposed to address critical points, and the safety of the process was reassessed by the same method in a prospective manner.

RESULTS

The highest RPN scores were obtained with the PN composition calculation performed manually (RPN: 530) or electronically (RPN: 478), completion of the PN medical order form (RPN: 354), manual compounding of PN admixtures (RPN: 258), and the structure/organization/maintenance of the PN preparation unit (RPN: 133). The quality and safety of PN admixtures could be compromised by many critical factors, such as the increased particle-microbial load in the unit and the inadequate training/experience of the involved health professionals and their incompliance with the given instructions. The implementation of the proposed corrective measures is expected to reduce the risks of the overall PN production process by 67.5%.

CONCLUSIONS

Improvement of the PN production process through risk-analysis methodologies enhances safety for premature neonates.

Changes in Serum Creatinine Levels and Natural Evolution of Acute Kidney Injury with Conservative Management of Hemodynamically Significant Patent Ductus Arteriosus in Extremely Preterm Infants at 23-26 Weeks of Gestation

Changes in kidney function in extremely preterm infants (EPT) with conservatively managed hemodynamically significant (HS) patent ductus arteriosus (PDA) are not known well. We aimed to present the postnatal course in serum creatinine levels (sCr), prevalence of acute kidney injury (AKI), then relevance between AKI and adverse outcomes in EPT with conservatively managed HS PDA. By review of medical records, we analyzed the postnatal course of sCr and prevalence of stage 3 AKI defined by the modified Kidney Disease Improving Global Outcome (KDIGO) in EPT at gestational age of 23 to 26 weeks with conservatively treated HS PDA. We investigated if the presence and/or prolonged duration of stage 3 AKI elevated the risk of adverse outcomes. The results showed that, neither factor was associated with adverse outcomes. While the average PDA closure date was at postnatal day (P) 41 and 53, sCr peaked at P 10 and 14 and the cumulative prevalence of stage 3 AKI was 57% and 72% in the EPT of 25–26 and 23–24 weeks’ gestation, respectively. The high prevalence of stage 3 AKI without adverse outcomes in EPT with conservatively managed HS PDA suggests that it might reflect renal immaturity rather than pathologic conditions.

Acute Kidney Injury is Associated with Poor Lung Outcomes in Infants Born ≥32 Weeks of Gestational Age

OBJECTIVE

This study aimed to evaluate the association between acute kidney injury (AKI) and lung outcomes in infants born ≥32 weeks of gestational age (GA).

STUDY DESIGN

Secondary analysis of infants ≥32 weeks of GA in the assessment of worldwide acute kidney injury epidemiology in neonates (AWAKEN) retrospective cohort (n = 1,348). We used logistic regression to assess association between AKI and a composite outcome of chronic lung disease (CLD) or death at 28 days of age and linear regression to evaluate association between AKI and duration of respiratory support.

RESULTS

CLD occurred in 82/1,348 (6.1%) infants, while death occurred in 22/1,348 (1.6%); the composite of CLD/death occurred in 104/1,348 (7.7%). Infants with AKI had an almost five-fold increased odds of CLD/death, which remained after controlling for GA, maternal polyhydramnios, multiple gestations, 5-minute Apgar's score, intubation, and hypoxic-ischemic encephalopathy (adjusted odds ratio [OR] = 4.9, 95% confidence interval [CI]: 3.2-7.4; p < 0.0001). Infants with AKI required longer duration of respiratory support (count ratio = 1.59, 95% CI: 1.14-2.23, p = 0.003) and oxygen (count ratio = 1.43, 95% CI: 1.22-1.68, p < 0.0001) compared with those without AKI.

CONCLUSION

AKI is associated with CLD/death and longer duration of respiratory support in infants born at ≥32 weeks of GA. Further prospective studies are needed to elucidate the pathophysiologic relationship.

Association of Chorioamnionitis With Bronchopulmonary Dysplasia Among Preterm Infants: A Systematic Review, Meta-analysis, and Metaregression

Importance

Bronchopulmonary dysplasia (BPD), a chronic lung disease of prematurity, remains one of the major and most common complications of very preterm birth. Insight into factors associated with the pathogenesis of BPD is key to improving its prevention and treatment.

Objective

To perform a systematic review, meta-analysis, and metaregression of clinical studies exploring the association between chorioamnionitis (CA) and BPD in preterm infants.

Data Sources

PubMed and Embase were searched without language restriction (last search, October 1, 2018). Key search terms included bronchopulmonary dysplasia, chorioamnionitis, and risk factors.

Study Selection

Included studies were peer-reviewed studies examining preterm (<37 weeks' gestation) or very low-birth-weight (<1500 g) infants and reporting primary data that could be used to measure the association between exposure to CA and the development of BPD.

Data Extraction and Synthesis

The Meta-analysis of Observational Studies in Epidemiology (MOOSE) guideline was followed. Data were independently extracted by 2 researchers. A random-effects model was used to calculate odds ratios (ORs) and 95% CIs. Heterogeneity in effect size across studies was studied using multivariate, random-effects metaregression analysis.

Main Outcomes and Measures

The primary outcome was BPD, defined as supplemental oxygen requirement on postnatal day 28 (BPD28) or at the postmenstrual age of 36 weeks (BPD36). Covariates considered as potential confounders included differences between CA-exposed and CA-unexposed infants in gestational age, rates of respiratory distress syndrome (RDS), exposure to antenatal corticosteroids, and rates of early- and late-onset sepsis.

Results

A total of 3170 potentially relevant studies were found, of which 158 met the inclusion criteria (244 096 preterm infants, 20 971 CA cases, and 24 335 BPD cases). Meta-analysis showed that CA exposure was significantly associated with BPD28 (65 studies; OR, 2.32; 95% CI, 1.88-2.86; P < .001; heterogeneity: I2 = 84%; P < .001) and BPD36 (108 studies; OR, 1.29; 95% CI, 1.17-1.42; P < .001; heterogeneity: I2 = 63%; P < .001). The association between CA and BPD remained significant for both clinical and histologic CA. In addition, significant differences were found between CA-exposed and CA-unexposed infants in gestational age, birth weight, odds of being small for gestational age, exposure to antenatal corticosteroids, and early- and late-onset sepsis. Chorioamnionitis was not significantly associated with RDS (48 studies; OR, 1.10; 95% CI, 0.92-1.34; P = .24; heterogeneity: I2 = 90%; P < .001), but multivariate metaregression analysis with backward elimination revealed that a model combining the difference in gestational age and the odds of RDS was associated with 64% of the variance in the association between CA and BPD36 across studies.

Conclusions and Relevance

The results of this study confirm that among preterm infants, exposure to CA is associated with a higher risk of developing BPD, but this association may be modulated by gestational age and risk of RDS.

Long-term outcomes of saline boluses in very preterm infants

BACKGROUND

Normal saline bolus is commonly used in clinical practice for treating hypotension in very preterm infants during resuscitation at an early age despite the paucity of high quality evidence supporting this practice.

OBJECTIVES

To determine the effects of early (<7 days after birth) saline boluses given to very preterm infant (VPI) from 23 to 31 weeks GA.

METHOD

This is a population-based cohort analysis of the use of normal saline boluses given to VPI. The outcomes were extracted from the Perinatal Follow-Up Program Database which included all VPI from Halifax County admitted to the NICU at the IWK Health Centre, Halifax, Nova Scotia, Canada between January 2006 to December 2010. We excluded infants with major congenital anomalies and those not offered resuscitation in the delivery room. Our primary outcome was the composite of death or disability by 18-36 months while secondary outcomes were neonatal death, BPD, CP, IVH, PVL, ROP, BSITD III (Bayley Scales of Infant and Toddler Development®, Third Edition) Cognitive, Motor and Language score.

RESULTS

Death or disability in those who received saline bolus occurred in 15 (53.6%) compared with 9 (32.1%) in non saline group. Significantly higher rates of CP (p = 0.04), lower scores on the BSITDIII for motor (p = 0.04) and language scales (p = 0.03) were noted for infants who received saline boluses. Cognitive scores approached significance (p = 0.05) with lower scores in the saline bolus group.

CONCLUSION

Significant differences were found between the two groups in terms of long term neurodevelopmental outcome and one of the short-term outcome (i.e. BPD). Given the limitations of this retrospective study and the small sample size, a larger cohort from Canadian Neonatal Network database is warranted to evaluate the effects of using normal saline boluses during early life on neurodevelopmental.

Natural evolution of ductus arteriosus with noninterventional conservative management in extremely preterm infants born at 23-28 weeks of gestation

This study aimed to determine the natural course of patent ductus arteriosus (PDA) with noninterventional conservative management and whether the presence and/or prolonged duration of hemodynamically significant (HS) PDA increased the risk of mortality and morbidities in extremely preterm (EPT) infants. We retrospectively reviewed the medical records of EPT infants born at 23-28 weeks of gestation (n = 195) from January 2011 to June 2014, when PDA was managed with noninterventional conservative treatment. We stratified infants into three subgroups of 23-24, 25-26, and 27-28 weeks and analyzed the prevalence and natural evolution of HS PDA, defined as ventilator dependency and PDA size ≥2 mm. Multivariate regression analyses determined if the presence and/or prolonged duration of HS PDA increased the risk for mortality and/or morbidities. The overall incidence of HS PDA was 57% (111/195) at the end of the first postnatal week. In subgroup analyses, infants with 23-24 weeks of gestation had the highest incidence (93%, 50/54), with 64% (47/74) for 25-26 weeks and 21% (14/67) for 27-28 weeks. Six (5%) of 111 infants with HS PDA were discharged without ductus closure, 4 had spontaneous PDA closure on follow up, and device closure was performed for 2 infants. In the multivariate analyses, the presence or prolonged duration (per week) of HS PDA was not associated with the risk of mortality and/or morbidities. Spontaneous closure of HS PDA was mostly achieved, even in EPT infants, with a noninterventional conservative approach. In conclusion, our data showed the incidence and natural course of HS PDA in EPT infants and suggested that the presence or prolonged duration of HS PDA might not increase the rate of mortality or morbidities.

Do early postnatal body weight changes contribute to neonatal morbidities in the extremely low birth weight infants

BACKGROUND

The implications of early postnatal body weight changes (Δbw) in the morbidities related to body fluid metabolism in sick preterm infants in not well investigated. The extremely low birth weight infants (ELBW, birth weight <1000 g) have the highest incidence of such morbidities among all neonates.

AIM

To determine the relationships between Δbw and neonatal morbidities associated with body fluid metabolism in the ELBW infants.

METHODS

In an observational study, the associations between daily weight changes from birth weight (DΔ bw) and oxygen dependence on postnatal day 28 (BPD28), patent ductus arteriosus (PDA), intraventricular-periventricular hemorrhage (IVH), antenatal steroid (ANS) and gestational age (GA) were evaluated. Maximum weight loss (MΔ bw) was correlated with GA, BPD28 and BPD36 (oxygen dependence on postmenstrual 36 weeks). Pearson's correlation co-efficient and multivariate logistic regressions were performed for analysis.

RESULTS

DΔ bw correlated inversely with GA on days 1-8 of life (p <  0.01 for all, 0.06 for DOL 2). DΔ bw was associated with a lower risk of BPD28 on days 6 (OR 0.87, 95% CI 0.76-1), 10 (OR 0.86, 95% CI 0.76-0.98) and 11 (OR 0.87, 95% CI 0.77-0.99); with PDA on days 8-11 (OR ranging between 0.89 to 0.92 for the 4 days, 95% CI 0.83 to 0.99) and with IVH on day 5 (OR 0.93, 95% CI 0.86-1) after controlling for GA. DΔ bw was not identified as risk factor for the tested morbidities. ANS decreased DΔ bw on days 4 (OR 0.88, 95% CI 0.78-1) and 10 (OR 0.9, 95% CI 0.84-1). MΔbw correlated directly with BPD28 (r = 0.3, p = 0.004), which declined after controlling for GA (r = 0.2, p = 0.2).

CONCLUSIONS

DΔ bw is protective for PDA, BPD28 and IVH, independent of gestational age, whereas, the effects of MΔ bw on BPD are governed by maturation in ELBW infants. ANS decreases DΔbw, which correlates inversely with GA during the first week of life.

Acute kidney injury is associated with bronchopulmonary dysplasia/mortality in premature infants

BACKGROUND

Acute kidney injury (AKI) impairs electrolyte balance, alters fluid homeostasis and decreases toxin excretion. More recent data suggest it also affects the physiology of distant organs.

METHODS

We performed a prospective cohort study which invloved 122 premature infants [birth weight (BW) ≤1200 g and/or gestational age (GA) <31 weeks] to determine relationships between AKI and bronchopulmonary dysplasia (BPD)/mortality. Days until oxygen discontinuation was compared between those with and without AKI in survivors who received oxygen for ≥24 h.

RESULTS

Acute kidney disease, defined by a rise in serum creatinine (SCr) of ≥0.3 mg/dl or an increase in SCr of ≥150%, occurred in 36/122 (30%) of the premature infants. Those with AKI had a 70% higher risk of oxygen requirement or of dying at 28 days of life [relative risk (RR) 1.71, 95% confidence interval (CI) 1.22-2.39; p < 0.002]. This association remained after controlling for GA, pre-eclampsia, 5 min Apgar score and percentage maximum weight change (max % weight Δ) in the first 4 days (RR 1.45, 95% CI 1.07-1.97); p < 0.02). Similar findings were noted for receipt of mechanical ventilation/death by day 28 (adjusted RR 1.53, 95% CI 1.05-2.22; p < 0.03). Those without AKI were 2.5-fold more likely to come off oxygen [hazard ratio (HR) 1.3-5; p < 0.02) than those with AKI, even when controlling for GA, pre-eclampsia, 5 min Apgar and max % weight Δ (multivariate HR 2.0, 95% CI 0.9-4.0; p < 0.06).

CONCLUSIONS

In premature infants, AKI is associated with BPD/mortality. As AKI could lead to altered lung physiology, interventions to ameliorate AKI could improve long-term BPD.

Major enzymes controlling the androgenic pressure in the developing lung

A sex difference is observed in the incidence and morbidity of respiratory distress syndrome (RDS) of the neonate and in bronchopulmonary dysplasia (BPD). The involvement of androgens is well evidenced in RDS and it is suspected in BPD. Interestingly, the developing lung is not an inert tissue just exposed to circulating androgens, but is rather an active androgen metabolizing tissue, expressing enzymes involved in both androgen synthesis and inactivation. The present review focuses on the major enzymes involved in androgen metabolism within the developing lung. Testosterone synthesis and inactivation by AKR1C3/Akr1c6 (human/mouse 17β-hydroxysteroid dehydrogenases (HSDs) type 5) and HSD17B2 (17β-HSD type 2), respectively, play an important role in the developing lung. Akr1c14 (3α-HSD) shows a strong increase in expression according to developmental time. The canalicular stage of lung development corresponding to the surge of surfactant lipid synthesis, which is linked to RDS, as well as saccularization/alveolarization, which are linked to BPD, are covered by this review for the mouse and human species. The androgen metabolizing enzymes expressed within the developing lung can become potential pharmaceutical targets in the objective of accelerating lung maturation by specific treatments. The classic deleterious effects of androgens on lung maturation and the surge of surfactant synthesis in males are well known. Conversely, androgens also have positive impacts on the development of both male and female lungs. Steroidogenic enzymes are key regulators of these positive effects. This article is part of a Special Issue entitled 'CSR 2013'.

What is the safe approach for neonatal hypernatremic dehydration? A retrospective study from a neonatal intensive care unit

OBJECTIVES

The aims of this study were to evaluate the prevalence, complications, and mortality of hypernatremic dehydration in neonates and to compare the effect of correction rate at 48 hours on mortality and on neurological outcome in the short term.

METHODS

This retrospective study was conducted between January 2007 and 2011 in the neonatal intensive care unit. Term neonates were included. The patients were grouped as follows: group 1 = 150 to 160 mmol/L, group 2 = 161 to 170 mmol/L and group 3 = 171 to 189 mmol/L.

RESULTS

Among 4280 neonates, 81 cases (1.8%) had hypernatremic dehydration. Groups 1, 2, and 3 consisted of 55, 23, and 3 patients, respectively. Mortality rates were as follows: 3.6%, 17.3%, and 66.6%. Mean serum sodium (Na) correction rates at 0 to 24 hours and 24 to 48 hours were 0.48 ± 0.2 versus 0.38 ± 0.31 mmol/L per hour (group 1) and 0.49 ± 0.21 versus 0.52 ± 0.28 mmol/L per hour (group 2), respectively. In 32 patients (58.1%) from group 1 and in 13 patients (56.5%) from group 2, correction rate of 0.5 mmol/L per hour or less was achieved. Twenty-two patients developed convulsions, which was the most common complication during therapy. Serum Na greater than 160 mmol/L at admission (odds ratio, 1.9; 95% confidence interval, 1.3-3.7) and serum Na correction rate of greater than 0.5 mmol/L per hour (odds ratio, 4.3; 95% confidence interval, 1.2-6.5) were independent risk factors for death or convulsion. There was a significant difference between groups 1 and 2 in Denver Developmental Screening Test II results (64.1% vs 30.7 %, P = 0.001).

CONCLUSION

Hypernatremic dehydration is an important problem that should be managed properly to avoid adverse outcomes.

Pulmonary research recently published in Brazilian journals

We reviewed original articles in the field of pulmonary medicine that had been recently published in 12 Brazilian journals--general or specialty journals--excluding the Brazilian Journal of Pulmonology. All were journals indexed for the Institute for Scientific Information Web of Knowledge. The selection of articles was based on the "continuously variable rating" concept. We have organized the articles by category.

Regional variation on rates of bronchopulmonary dysplasia and associated risk factors

Background. An abnormally high incidence (44%) of bronchopulmonary dysplasia with variations in rates among cities was observed in Colombia among premature infants. Objective. To identify risk factors that could explain the observed high incidence and regional variations of bronchopulmonary dysplasia. Study Design. A case-control study was designed for testing the hypothesis that differences in the disease rates were not explained by differences in city-of-birth specific population characteristics or by differences in respiratory management practices in the first 7 days of life, among cities. Results. Multivariate analysis showed that premature rupture of membranes, exposure to mechanical ventilation after received nasal CPAP, no surfactant exposure, use of rescue surfactant (instead of early surfactant), PDA, sepsis and the median daily FIO(2), were associated with a higher risk of dysplasia. Significant differences between cases and controls were found among cities. Models exploring for associations between city of birth and dysplasia showed that being born in the highest altitude city (Bogotá) was associated with a higher risk of dysplasia (OR 1.82 95% CI 1.31-2.53). Conclusions. Bronchopulmonary dysplasia was manly explained by traditional risk factors. Findings suggest that altitude may play an important role in the development of this disease. Prenatal steroids did not appear to be protective at high altitude.