Gerd Schmalisch

The effect of maternal anthropometric characteristics and social factors on gestational age and birth weight in Sudanese newborn infants

BackgroundIn Africa low birth weight (LBW) (<2500 g), is the strongest determinant of infant morbidity and mortality. The aim of this study was to quantify the effect of maternal anthropometry, education and socio-economic status on gestational age and birth weight.MethodsIn 1000 Sudanese mothers with singleton births, anthropometric measurements (weight, height, mid-arm circumference) and newborn birth weight were taken within 24 hours of delivery. Furthermore, maternal education and socio-economic status were recorded. The effect of these maternal variables on gestational age and birth weight was investigated by receiver operating characteristic (ROC) curves and by multivariate logistic regression analysis.ResultsAlthough maternal height was significantly correlated (p = 0.002) with gestational age, we did not find maternal characteristics of value in determining the risk for preterm birth. Birth order was the strongest determinant of birth weight compared to other maternal characteristics. The LBW rate of first born babies of 12.2% was nearly twice that of infants of multiparous mothers. Maternal age and all maternal anthropometric measurements were positively correlated (p < 0.001) with birth weight. A maternal height of <156 cm, a maternal weight of <66 kg, a maternal mid arm circumference of <27 cm and years of education of ≤ 8 years were found to increase the relative risk of LBW but this was statistically significant only in the case of maternal height. Maternal age and BMI had no statistically significant effect on determining the risk for LBW. The social class did not affect the birth weight, while the number of years of education was positively correlated with birth weight (p = 0.01). The LBW rate decreased from 9.2% for ≤ 8 years of education to 6.0% for >12 years of education.ConclusionBirth order and maternal height were found to be the most important maternal parameters which influences birth weight and the risk for LBW. The duration of maternal education and not social class was found to significantly affect the risk for LBW.

Accuracy of Volume Measurements in Mechanically Ventilated Newborns: A Comparative Study of Commercial Devices

Objective. Ventilatory measurements in ventilated newborns are increasingly used to monitor and to optimize mechanical ventilation. The aim of this study was to compare the accuracy of volume measurements by different instruments using standardized laboratory conditions. Methods. The accuracy of displayed volume values of different commercial devices (Bicore CP-100, Ventrak 1500, Ventrak 1550, Babylog 8000, PEDS IV and SensorMedics 2600) was investigated using adjustable calibration syringes (volume range 2–60 ml, breathing rates 30/min–60/min) and humidified (>95%), heated (35 °C) breathing gas with adjustable FIO2 (0.21–1.0). The pneumotach and also the tubes were placed within an incubator (37 °C). Results. The relative volume error of all devices was in conformity with clinically allowed tolerances (Bicore CP-100 6.4 ± 0.5% (mean ± SD), Ventrak 1500 3.6 ± 4.2%, Ventrak 1550 6.5 ± 2.7%, Babylog 8000 −5.5 ± 1.5%, PEDS IV −4.0 ± 1.4%, SensorMedics 2600 3.5 ± 1.75%) for the measuring range studied (10 ml < V < 60 ml, rate 30–60/min, FIO2 = 0.21). Unacceptable errors were obtained for volumes lower than 10 ml with Bicore CP-100 (−28.5 ± 26%) and PEDS IV (−10.3 ± 3.4%). Changes in FIO2 had an important influence on volume measurements and only the SensorMedics 2600 and the PEDS IV corrected properly for FIO2 changes. Conclusion. Most of the currently available neonatal spirometry devices allow sufficiently accurate volume measurements in the range of 10–60 ml and at frequencies between 30–60/min provided that an increased FIO2 is taken into account.

Current methods of non-invasive ventilatory support for neonates.

Non-invasive ventilatory support can reduce the adverse effects associated with intubation and mechanical ventilation, such as bronchopulmonary dysplasia, sepsis, and trauma to the upper airways. In the last 4 decades, nasal continuous positive airway pressure (CPAP) has been used to wean preterm infants off mechanical ventilation and, more recently, as a primary mode of respiratory support for preterm infants with respiratory insufficiency. Moreover, new methods of respiratory support have been developed, and the devices used to provide non-invasive ventilation (NIV) have improved technically. Use of NIV is increasing, and a variety of equipment is available in different clinical settings. There is evidence that NIV improves gas exchange and reduces extubation failure after mechanical ventilation in infants. However, more research is needed to identify the most suitable devices for particular conditions; the NIV settings that should be used; and whether to employ synchronized or non-synchronized NIV. Furthermore, the optimal treatment strategy and the best time for initiation of NIV remain to be identified. This article provides an overview of the use of non-invasive ventilation (NIV) in newborn infants, and the clinical applications of NIV.

Manual ventilation devices in neonatal resuscitation: Tidal volume and positive pressure-provision

BACKGROUND Excessive peak inspiratory pressures (PIP) and high tidal volumes (Vt) during manual ventilation can be detrimental to the neonatal lung. We compared the influence of different manual ventilation devices and individual professional experience on the extent of applied Vt and PIP in simulated neonatal resuscitation. MATERIAL AND METHODS One hundred and twenty medical professionals were studied. An intubated mannequin (equivalent to 1.0 kg neonate) was ventilated using two different devices: a self-inflating bag and a T-piece resuscitator. Target value was a PIP of 20 cm H(2)O. Applied PIP and the resulting Vt were recorded continuously using a respiratory function monitor (CO(2)SMO(+), Novametrix, USA). RESULTS Vt and PIP provision was significantly higher in SI-bags, compared to T-piece devices: median (interquartile range) PIP 25.6 (18.2) cm H(2)O vs 19.7 (3.2) cm H(2)O (p<0.0005), and Vt 5.1(3.2) ml vs Vt 3.6 (0.8) ml (p<0.0005) respectively. The intersubject variability of Vt and PIP provision was distinctly higher in SI-bags, compared to T-piece devices. Professional experience had no significant impact on the level and the variability of Vt or PIP provided. CONCLUSION Use of T-piece devices guarantees reliable and constant Vt and PIP provision, irrespective of individual, operator dependent variables. Methods to measure and to avoid excessive tidal volumes in neonatal resuscitation need to be developed.

Differences in tidal breathing between infants with chronic lung diseases and healthy controls

BackgroundThe diagnostic value of tidal breathing (TB) measurements in infants is controversially discussed. The aim of this study was to investigate to what extent the breathing pattern of sleeping infants with chronic lung diseases (CLD) differ from healthy controls with the same postconceptional age and to assess the predictive value of TB parameters.MethodsIn the age of 36–42 postconceptional weeks TB measurements were performed in 48 healthy newborns (median age and weight 7d, 3100 g) and 48 infants with CLD (80d, 2465 g)) using the deadspace-free flow-through technique. Once the infants had adapted to the mask and were sleeping quietly and breathing regularly, 20–60 breathing cycles were evaluated. Beside the shape of the tidal breathing flow-volume loop (TBFVL) 18 TB parameters were analyzed using ANOVA with Bonferroni correction. Receiver-operator characteristic (ROC) curves were calculated to investigate the discriminative ability of TB parameters.ResultsThe incidence of concave expiratory limbs in CLD infants was 31% and significantly higher compared to controls (2%) (p < 0.001). Significant differences between CLD infants and controls were found in 11/18 TB parameters. The largest differences were seen in the mean (SD) inspiratory time 0.45(0.11)s vs. 0.65(0.14)s (p < 0.0001) and respiratory rate (RR) 55.4(14.2)/min vs. 39.2(8.6)/min (p < 0.0001) without statistically significant difference in the discriminative power between both time parameters. Most flow parameters were strongly correlated with RR so that there is no additional diagnostic value. No significant differences were found in the tidal volume and commonly used TB parameters describing the expiratory flow profile.ConclusionThe breathing pattern of CLD infants differs significantly from that of healthy controls. Concave TBFVL and an increased RR measured during quiet sleep and under standardized conditions may indicate diminished respiratory functions in CLD infants whereas most of the commonly used TB parameters are poorly predictive.

Reliability of two common PEEP-generating devices used in neonatal resuscitation.

BACKGROUND Approximately 15% of neonates require respiratory support at birth, the demand of which increases with decreasing gestational age. Positive end-expiratory pressure (PEEP) stabilizes the airways and improves both pulmonary functional residual capacity and compliance. Self-inflating bags, which can be used with and without a PEEP-valve, are most commonly used for neonatal resuscitation, pressure limited T-piece resuscitators are becoming increasingly popular. The aim of the study was to investigate the reliability of PEEP provision of both systems. MATERIAL AND METHODS An intubated, leak free mannequin (equivalent to 1 kg neonate, pulmonary compliance 0.2 ml*cmH (2)O (-1)) was used for testing both devices. Eleven PEEP-valves attached to a 240 ml self-inflating bag and 5 T-piece resuscitators were investigated. Provision of a PEEP of 5 cmH (2)O (gas flow of 8l/min) at manual ventilation at breaths 40/min was investigated. Data were recorded using a standard pneumotachograph. RESULTS Only 1/11 PEEP-valves provided a PEEP of 5 cmH (2)O (mean (SD) 2.95 (1.82) cmH (2)O, CV 0.62%), in 5/11 (45%) PEEP was <3 cmH (2)O, in 2 of the PEEP-valves produced a PEEP below 0.3 cmH (2)O. All T-piece resuscitators provided a PEEP >5 cmH (2)O (mean 5.59 (0.32) cmH (2)O, CV 0.06%). Significant differences in individual performance per device (p<0.05) and between systems (p=0.007) were found. CONCLUSION Self-inflating bags did not reliably provide the desired PEEP of 5 cmH (2)O, whereas T-piece resuscitators did reliably provide the set PEEP-level, with less variability. When using self-inflating bags with PEEP-valves, neonatologists should check the equipment regarding the reliability of PEEP provision.

Persistently Elevated Right Ventricular Index of Myocardial Performance in Preterm Infants with Incipient Bronchopulmonary Dysplasia

Objectives Elevated pulmonary vascular resistance occurs during the first days after birth in all newborn infants and persists in infants at risk for bronchopulmonary dysplasia (BPD). It is difficult to measure in a non-invasive fashion. We assessed the usefulness of the right ventricular index of myocardial performance (RIMP) to estimate pulmonary vascular resistance in very low birth weight infants. Study Design Prospective echocardiography on day of life (DOL) 2, 7, 14, and 28 in 121 preterm infants (median [quartiles] gestational age 28 [26]–[29] weeks, birth weight 998 [743–1225] g) of whom 36 developed BPD (oxygen supplementation at 36 postmenstrual weeks). Results RIMP derived by conventional pulsed Doppler technique was unrelated to heart rate or mean blood pressure. RIMP on DOL 2 was similar in infants who subsequently did (0.39 [0.33–0.55]) and did not develop BPD (0.39 [0.28–0.51], p = 0.467). RIMP declined steadily in non-BPD infants but not in BPD infants (DOL 7: 0.31[0.22–0.39] vs. 0.35[0.29–0.48], p = 0.014; DOL 14: 0.23[0.17–0.30] vs. 0.35[0.25–0.43], p<0.001; DOL 28: 0.21[0.15–0.28] vs. 0.31 [0.21–0.35], p = 0.015). Conclusions In preterm infants, a decline in RIMP after birth was not observed in those with incipient BPD. The pattern of RIMP measured in preterm infants is commensurate with that of pulmonary vascular resistance.

Immature platelet fraction as novel laboratory parameter predicting the course of neonatal thrombocytopenia

Thrombocytopenia occurs in up to 30% of neonates admitted to neonatal intensive care units (NICUs). In preterm neonates, severe thrombocytopenia is associated with increased risk of intracerebral bleeding. Thus, diagnosis of thrombocytopenia often leads to repeated subsequent analysis of blood cell counts and transfusion of platelets. However, no evidence has been provided that current practice for platelet transfusion prevents bleeding complications and improves clinical outcome. A rapid automated method to assess reticulated platelets, the immature platelet fraction (IPF), is available (Briggs et al, 2000). The aim of this study was to investigate the diagnostic value of IPF as a marker for megakaryopoietic activity in neonates. All 612 neonates admitted to our NICUs over a 6-month period were included in the study. Written parental consent and organisational approval were obtained. During the first postnatal week, blood samples were obtained as clinically indicated. To generate reference values for the IPF, patients were divided in two groups: The control group (n = 456) always displayed normal platelet counts (150–450 · 10/l). In the thrombocytopenic group (n = 156), platelet counts dropped below 150 · 10/l at least once. Blood samples obtained after platelet transfusion were excluded from analysis. Platelet counts were optically measured with the automated analyser XE-2100 (Sysmex, Kobe, Japan) equipped with the software xe-ipf-master. Determination of IPF is based on fluorescence flow cytometry using a nucleic acid specific dye that stains RNA in erythrocytic and platelet reticulocytes. The computed algorithm discriminates mature and immature platelet populations applying a preset gate (fluorescent intensity = RNA-content; forward scatter = cell volume). The IPF is normally expressed as a percentage of the platelet count to indicate the rate of platelet production; additionally, absolute values may be used to differentiate between insufficient platelet production and increased consumption as cause of thrombocytopenia. Regression analysis was used to calculate the correlation between platelet counts and IPF. Student’s t-test was applied to compare group means. Statistical analysis was performed using the software statgraphics (Manugistics Inc., Rockville, MD, USA). A P-value < 0Æ05 was considered to indicate statistical significance. In 1045 out of 1339 blood specimens IPF was routinely determined in addition to platelet counts. Four hundred and fifty-six patients (838 specimens) were assigned to the control group, 25Æ5% of patients (n = 156; 501 specimens) to the thrombocytopenic group. The mean [standard deviation (SD)] birth weight in the control group was significantly higher than in the thrombocytopenic group [2717 g, (SD ± 849) vs. 2188 g, (SD ± 105), P < 0Æ001]; this also refers to mean gestational age [36Æ3 weeks, (SD ± 3Æ7) vs. 34Æ2 weeks, (SD ± 5Æ0), P < 0Æ001]. In controls, the mean IPF value was 4Æ3% [95% confidence interval (CI) 0Æ7–7Æ9%] during the first postnatal week. In the thrombocytopenic group, the mean IPF (SD) during the first postnatal week was always significantly higher than in the control group [e.g. day 1: IPF 8Æ7% (9Æ3) vs. 4Æ53% (1Æ8); P < 0Æ001; Fig 1). 36% of thrombocytopenic neonates displayed an IPF above 7Æ9%. We found no significant correlation between gestational age and IPF. Using simultaneous IPF and platelet measurements of both groups, a significant negative correlation between IPF and platelet counts was found with an exponential decay (r = )0Æ62, P < 0Æ001). Increasing platelet counts were anticipated by an increased IPF, reflecting enhanced platelet production (Fig 1). According to the study aim, we analysed whether the platelet counts on the following day were somehow predicted by means of previous IPF values. In patients whose blood samples were analysed on two subsequent days, the difference in platelet counts was plotted against the corresponding IPF value (Fig 2). In this scatter plot, specimens (n = 398) were divided in to four quadrants according to IPF (>8%, which is outside CI > 95% of controls) and difference in platelet counts (severe

DELIVERY ROOM MANAGEMENT OF VERY LOW BIRTH WEIGHT INFANTS IN GERMANY, AUSTRIA AND SWITZERLAND ― A COMPARISON OF PROTOCOLS

BackgroundSurveys from the USA, Australia and Spain have shown significant inter-institutional variation in delivery room (DR) management of very low birth weight infants (VLBWI, < 1500 g) at birth, despite regularly updated international guidelines.ObjectiveTo investigate protocols for DR management of VLBWI in Germany, Austria and Switzerland and to compare these with the 2005 ILCOR guidelines.MethodsDR management protocols were surveyed in a prospective, questionnaire-based survey in 2008. Results were compared between countries and between academic and non-academic units. Protocols were compared to the 2005 ILCOR guidelines.ResultsIn total, 190/249 units (76%) replied. Protocols for DR management existed in 94% of units. Statistically significant differences between countries were found regarding provision of 24 hr in house neonatal service; presence of a designated resuscitation area; devices for respiratory support; use of pressure-controlled manual ventilation devices; volume control by respirator; and dosage of Surfactant. There were no statistically significant differences regarding application and monitoring of supplementary oxygen, or targeted saturation levels, or for the use of sustained inflations. Comparison of academic and non-academic hospitals showed no significant differences, apart from the targeted saturation levels (SpO2) at 10 min. of life. Comparison with ILCOR guidelines showed good adherence to the 2005 recommendations.SummaryDelivery room management in German, Austrian and Swiss neonatal units was commonly based on written protocols. Only minor differences were found regarding the DR setup, devices used and the targeted ranges for SpO2 and FiO2. DR management was in good accordance with 2005 ILCOR guidelines, some units already incorporated evidence beyond the ILCOR statement into their routine practice.

Randomized double blind trial of Ambroxol for the treatment of respiratory distress syndrome

In order to test the ability of Ambroxol to improve the clinical course of respiratory distress syndrome and to reduce the incidence of complications a multicentre, randomized, placebo-controlled double-blind trial was conducted. Entry was limited to infants with a birth weight below 1500g. A total of 179 neonates were enrolled, but 31 were later excluded because they had other diseases. Of the remaining 148 babies, 74 received Ambroxol (birth weight 1190±216g; gestational age 29.1±1.9 weeks) and 74 placebo (birth weight 1168±216g; gestational age 28.9±1.9 weeks). In the Ambroxol group 23 (31%) and in the placebo group 27 (37%) infants died during the first 5 months of life. In 28 day-survivors Ambroxol was able to significantly improve the PaO2/FiO2 ratio, mean airway pressure, phospholipid profile of tracheal effluent and pulmonary mechanics of spontaneously breathing infants. In addition, the incidences of bronchopulmonary dysplasia (29% vs 54%), intraventricular haemorrhage (25% vs 44%) and postnatally acquired pneumonia (15% vs 36%) were significantly reduced in the Ambroxol group as compared to the control group. No adverse events attributed to the Ambroxol treatment were reported.