Diaphragmatic muscle function in term and preterm infants.

We aimed to assess the determinants of diaphragmatic function in term and preterm infants. 149 infants (56 term; 93 preterm, of whom 14 were diagnosed with bronchopulmonary dysplasia-BPD) were studied before discharge. Diaphragmatic function was assessed by measurement of the maximum transdiaphragmatic pressure (Pdimax)-a measure of diaphragmatic strength, and the pressure-time index of the diaphragm (PTIdi)-a measure of the load-to-capacity ratio of the diaphragm. The Pdimax was higher in term than preterm infants without BPD (90.1 ± 16.3 vs 81.1 ± 11.8 cmH2O; P = 0.001). Term-born infants also had lower PTIdi compared to preterms without BPD (0.052 ± 0.014 vs 0.060 ± 0.017; P = 0.006). In term and preterm infants without BPD, GA was the most significant predictor of Pdimax and PTIdi, independently of the duration of mechanical ventilation and oxygen support. In infants with GA < 32 weeks (n = 30), the Pdimax was higher in infants without BPD compared to those with BPD (76.1 ± 11.1 vs 65.2 ± 11.9 cmH2O; P = 0.015). Preterms without BPD also had lower PTIdi compared to those with BPD (0.069 ± 0.016 vs 0.109 ± 0.017; P < 0.001). In this subgroup, GA was the only significant independent determinant of Pdimax, while BPD and the GA were significant determinants of the PTIdi.  Conclusions: Preterm infants present lower diaphragmatic strength and impaired ability to sustain the generated force over time, which renders them prone to diaphragmatic fatigue. In very preterm infants, BPD may further aggravate diaphragmatic function. What is Known: • The diaphragm of preterm infants has limited capacity to undertake the work of breathing effectively. • The maximum transdiaphragmatic pressure (a measure of diaphragmatic strength) and the pressure-time index of the diaphragm (a measure of the load-to-capacity ratio of the muscle) have not been extensively assessed in small infants. What is New: • Preterm infants have lower diaphragmatic strength and impaired ability to sustain the generated force over time, which renders them prone to diaphragmatic fatigue. • In very preterm infants, bronchopulmonary dysplasia may further impair diaphragmatic function.

Flow-resistive loading and diaphragmatic muscle function in term and preterm infants.

PURPOSE: We aimed to assess diaphragmatic function in term and preterm infants with and without history of bronchopulmonary dysplasia (BPD), before and after the application of inspiratory flow resistive loading. METHODS: Forty infants of a median (range) gestational age of 34 (25-40) weeks were studied. BPD was defined as supplemental oxygen requirement for >28 days of life. Seventeen infants were term, 17 preterm without history of BPD, and six preterm with a history of BPD. The diaphragmatic pressure-time index (PTIdi) was calculated as the mean to maximum trans-diaphragmatic pressure ratio times the inspiratory duty cycle. The PTIdi was calculated before and after the application of an inspiratory-flow resistance for 120 s. Airflow was measured by a pneumotachograph and the transdiaphragmatic pressure by a dual pressure catheter. RESULTS: The median (interquartile range [IQR]) pre-resistance PTIdi was higher in preterm infants without BPD (0.064 [0.050-0.077]) compared with term infants (0.052 [0.044-0.062], p = .029) and was higher in preterm infants with BPD (0.119 [0.086-0.132]) compared with a subgroup of preterm infants without BPD (0.062 [0.056-0.072], p = .004). The median (IQR) postresistance PTIdi was higher in preterm infants without BPD (0.101 [0.084-0.132]) compared with term infants (0.067 [0.055-0.083], p < .001) and was higher in preterm infants with BPD [0.201(0.172-0.272)] compared with the preterm subgroup without BPD (0.091 [0.081-0.108],p = .004). The median (IQR) percentage change of the PTIdi after the application of the resistance was higher in preterm infants without BPD (65 [51-92] %) compared with term infants (34 [20-39] %, p < .001). CONCLUSIONS: Preterm infants, especially those recovering from BPD, are at increased risk of diaphragmatic muscle fatigue under conditions of increased inspiratory loading.

Early Diagnosis of Late-Onset Neonatal Sepsis Using a Sepsis Prediction Score.

Sepsis represents a common cause of morbidity in the Neonatal Intensive Care Unit (NICU). Our objective was to assess the value of clinical and laboratory parameters in predicting septicemia (positive blood culture) in NICU infants. In the first part of the present study (derivation cohort) we retrospectively reviewed the clinical files of 120 neonates with symptoms of suspected sepsis and identified clinical and laboratory parameters associated with proven sepsis on the day the blood culture was taken, as well as 24 h and 48 h earlier. These parameters were combined into a sepsis prediction score (SPS). Subsequently (validation study), we prospectively validated the performance of the SPS in a cohort of 145 neonates. The identified parameters were: temperature instability, platelet count < 150,000/mm3, feeding volume decrease > 20%, changes in blood glucose > 50%, CRP > 1 mg/dL, circulatory and respiratory deterioration. In the retrospective cohort, on the day the blood culture was obtained, a SPS ≥ 3 could predict sepsis with 82.54% sensitivity, 85.96% specificity, 5.88 PLR (Positive Likelihood Ratio), 0.20 NLR (Negative Likelihood Ratio), 86.67% PPV (Positive Predictive Value), 81.67% NPV (Negative Predictive Value) and 84.17% accuracy. In the prospective cohort, on the day the blood culture was obtained, a SPS ≥ 3 could predict sepsis with 76.60% sensitivity, 72.55% specificity, 2.79 PLR, 0.32 NLR, 83.72% PPV, 62.71% NPV and 75.17% accuracy. We concluded that this combination of clinical and laboratory parameters may assist in the prediction of septicemia in NICUs.

Effect of prone and supine positioning on the diaphragmatic work of breathing in convalescent preterm infants.

OBJECTIVES: To compare the work of breathing in the prone and supine positions in convalescent prematurely born infants. WORKING HYPOTHESIS: The work of breathing would be lower in the prone compared to the supine position. STUDY DESIGN: Prospective observational cohort study. PATIENT-SUBJECT SELECTION: Consecutive preterm infants breathing unsupported in room air with a gestational age of 28-34 weeks in a tertiary neonatal intensive care unit were studied before discharge from neonatal care. METHODOLOGY: The diaphragmatic pressure time product (PTPdi) was used to assess the work of breathing, calculated as the integration of transdiaphragmatic pressure over the inspiratory time. The PTPdi was measured in prone, supine, and supine with 45° head-up tilt (supine-tilt) positions. RESULTS: The mean (SD) PTPdi was lower in the prone (259 [68] cm H2 O*s/min) compared with the supine position (320 [78] cm H2 O*s/min, p= .005). The mean (SD) PTPdi was lower in the supine-tilt position (262 [76] cm H2 O*s/min) compared with the supine position (p = .032). The PTPdi was not different between the prone and supine-tilt positions (p = .600). The difference in PTPdi between prone and supine was not independently associated with gestational age (standardized coefficient = 0.262, adjusted p= .335), birth weight (standardized coefficient = -0.249, adjusted p= .394) or postmenstrual age at study (standardized coefficient = -0.025, adjusted p= .902). CONCLUSIONS: In convalescent preterm neonates, the work of breathing may be lower in the prone and supine-tilt positions, compared with supine.

Nutrition of neonates with congenital heart disease: existing evidence, conflicts and concerns.

Introduction: Congenital heart disease is one of the most of the groups of congenital anomalies with an incidence of about 1 per 100 live births. Almost one-third of these infants require some type of intervention, usually in the first year of life and increasingly often in the neonatal period. Innovative reparative and palliative surgical procedures and advanced medical support in the Neonatal Intensive Care Unit have significantly reduced the mortality related to congenital heart disease. Achieving survival is not the only target of clinicians for these patients. Appropriate growth, development, and improved quality of life are also very important. Growth failure is a very common problem of these children and nutritional support and management are a challenge for health care providers. Early intervention and identification of at-risk patients have the potential to decrease morbidity and mortality related to malnutrition.Aim/methods: The purpose of this article is to analyze the existing evidence and common concerns about perioperative and postdischarge nutritional management of neonates with congenital heart disease based on the special issues or complications that may arise. Furthermore, we reviewed the recent literature about current practices and proposed policies that could prevent malnutrition and improve the outcomes of neonates with congenital heart disease.Results/conclusion: A standardized institutional protocol and clear guidelines referring to feeding initiation, prompt estimation of caloric needs and provision of adequate and appropriate nutrient intake is likely to benefit these patients. Clear definitions for the nutritional approach in the setting of medical complications and close assessment of growth by pediatricians and specialized nutritionists are crucial for the long-term outlook and quality of life of these infants.

Extensively-drug resistant Acinetobacter baumannii bacteremia in neonates: effective treatment with the combination of colistin and ampicillin/sulbactam.

Acinetobacter baumannii has evolved as a major pathogen of outbreaks in the healthcare setting with increased morbidity and mortality. In neonates, treatment can be quite challenging due to the resistance profile of A. baumannii as well as limited data on pharmakokinetics and pharmakodynamics of antibiotics in this age group. We present an outbreak of eight cases of extensively-drug resistant (XDR) A. baumannii bacteremias successfully managed with the combination of colistin with high dose ampicillin/sulbactam.

Hymenoptera sting-induced Kounis syndrome: effects of aspirin and beta-blocker administration.

Kounis syndrome is the concurrence of acute coronary syndromes with conditions associated with activation of interacting inflammatory cells including allergic or hypersensitivity and anaphylactic or anaphylactoid insults. It is caused via inflammatory mediators released during inflammatory cell activation. A variety of conditions, drugs, and environmental exposures can induce Kounis syndrome. A patient suffering from coronary artery disease and taking metoprolol and aspirin was stung by wasps and developed cutaneous allergic signs including rash, urticaria and orbital oedema. This was followed by retrosternal pain, chest discomfort and electrocardiographic changes compatible with acute myocardial ischemia. Cardiac enzymes, troponins and blood pressure remained normal but serum tryptase was raised. The clinical implications and pathophysiology of this rare association are discussed.