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Byline: Hendrik S. Fischer (1), Charles C. Roehr (1), Hans Proquitte (1), Hannes Hammer (1), Roland R. Wauer (1), Gerd Schmalisch (1) Keywords: CPAP; Air leak; Tidal volume; Equipment; Neonate Abstract: Objective To investigate tidal volume (V .sub.T) and leak measurements during continuous positive airway pressure (CPAP) in neonates using a commercial ventilatory device equipped with a flow sensor at the Y-piece. Design Randomized cross-over trial. Setting Neonatal intensive care unit level III. Patients Thirty-two infants, median (range) birth weight 1,435 (710--2,730) g, gestational age 30 (24--38) weeks. Interventions During nasopharyngeal CPAP, leak and V .sub.T were measured with and without occlusion of the contralateral nostril using the Leoni ventilator (Heinen & Lowenstein, Germany) and a recently developed algorithm to correct measured V .sub.T in the presence of leaks. The measuring range of the Leoni is limited to leaks Main results Analyzable measurements with leaks Conclusions Leak and corrected V .sub.T could be determined in the presence of leaks of up to 69%, but leaks during CPAP often exceeded the measuring range. Reliable volume and leak monitoring was not possible with the tested equipment during nasopharyngeal CPAP. Advanced equipment is necessary to further investigate the effects of leaks on neonatal CPAP therapy. Author Affiliation: (1) Clinic of Neonatology CCM, Charite University Medicine Berlin, Chariteplatz 1, 10117, Berlin, Germany Article History: Registration Date: 28/08/2009 Received Date: 12/04/2009 Accepted Date: 04/08/2009 Online Date: 22/09/2009

Perfluorocarbons (PFC) reduce the production of various inflammatory cytokines, including TNF-[alpha]. The anti-infammatory effect is not entirely understood. If anti-inflammatory properties are caused by a mechanical barrier, PFC in the alveoli should have no effect on the inflammatory response to intravenous LPS administration. To test that hypothesis, rats (n = 31) were administered LPS intravenously and were either spontaneously breathing (Spont), conventionally ventilated (CMV), or receiving partial liquid ventilation (PLV). Serum concentration of TNF-[alpha] was measured. The pulmonary expressions of TNF-[alpha] and TNF-[alpha] receptor 1 protein and of TNF-[alpha] and ICAM-1 mRNA were determined. LPS caused a significant (P < 0.001) increase in serum TNF-[alpha]. Serum TNF-[alpha] concentration was similar in LPS/Spont (525 [+ or -] 180 pg/ml) and LPS/CMV (504 [+ or -] 154 pg/ml) but was significantly (P < 0.001) lower in animals of the LPS/PLV group (274 [+ or -] 101 pg/ml). Immunohistochemical data on TNF-[alpha] protein expression showed a LPSinduced increase in TNF-[alpha] and TNF-[alpha] receptor 1 expression that was diminished by partial liquid ventilation. PCR measurements revealed a lower expression of TNF-[alpha] and ICAM-1 mRNA in LPS/PLV than in LPS/CMV or LPS/Spont animals. Semiquantitative histological evaluation revealed only minor alveolar inflammation with no significant differences between the groups. Low serum TNF-[alpha] concentration in PFC-treated animals is most likely explained by a decreased production of TNF-[alpha] in the lung. fluorocarbons; tumor necrosis factor-[alpha]; lipopolysaccharide; liquid ventilation; anti-inflammatory agents

Abstract Objective: Chylothorax is a rare but life-threatening condition in children. To date, there is no commonly accepted treatment protocol. Somatostatin and octreotide have recently been used for treating chylothorax [...]

Byline: Wolfram Burkhardt (1), Hans Proquitte (1), Susann Krause (1), Roland R. Wauer (1), Mario Rudiger (1) Keywords: Animal model; Fluorocarbons; Liquid ventilation; Near-infrared spectroscopy; Oxygen; Artificial ventilation Abstract: Objective To measure the impact of changes in the fraction of inspired oxygen (FiO.sub.2) on systemic and cerebral oxygen supply in gas and liquid ventilated healthy animals. Design Interventional prospective animal study. Setting University research laboratory. Participants Ten healthy, new-born piglets. Interventions Variations in FiO.sub.2 during conventional mechanical ventilation (CMV) followed by partial liquid ventilation (PLV) with two different filling volumes of PF 5080 (10 vs. 30 ml/kg). Measurements and results Arterial blood gases were obtained 15 min after changing FiO.sub.2 and concentrations of cerebral oxygenated and total hemoglobin were determined with near infrared spectroscopy. During CMV an increase in FiO.sub.2 1.0 was associated with a constant rise in PaO.sub.2 but only a small increase in the cerebral concentration of oxygenated Hb. Initiation of PLV (at FiO.sub.2 of 1.0) caused a rapid drop in PaO.sub.2 towards values that were similar to CMV at FiO.sub.2 of 0.5. At FiO.sub.2 of 0.5 a reduction in oxygenated Hb was found in the 30 ml/kg filling group. Complete filling of the lungs with PFC caused a significant drop in total cerebral Hb concentration. Conclusions According to our data, PLV in healthy lungs should be performed with a FiO.sub.2 of 1.0 and a small filling volume to avoid deterioration in cerebral oxygen supply. Author Affiliation: (1) Clinic of Neonatology, Charite-Mitte, Schumannstrasse 20, 10098, Berlin, Germany Article History: Registration Date: 06/11/2003 Received Date: 28/03/2003 Accepted Date: 31/10/2003 Online Date: 14/01/2004 Article note: Financial support: The study was supported by a grant of German Ministry of Education and Research (BMBF 'Perinatale Lunge-01ZZ9511). NIRO 300 was kindly supplied by Hamamatsu Germany.

Byline: Tobias Gregor (1), Gerd Schmalisch (1), Wolfram Burkhardt (1), Hans Proquitte (1), Roland R. Wauer (1), Mario Rudiger (1) Keywords: Fluorocarbons; Nebulizers; Respiration, artificial; Aerosols Abstract: Objective Inhalation of perfluorocarbons (PFC) has been suggested as a new and promising technique of PFC delivery in animal models of severe lung injury. However, no in vitro data were available on the efficacy of PFC aerosolization during mechanical ventilation. Therefore, the aim of the in vitro study was to investigate the influence of physical properties of PFC and the ventilatory settings on the amount of PFC delivered into the lung. Design In vitro lung model study. Setting University research laboratory. Measurements and results Two different PFC (PF 5080 and PFOB) were aerosolized with a PariBoy jet nebulizer. Using a PFC selective adsorber, the effect of endotracheal tube size (2 mm and 3 mm diameter) on delivery of PFC was investigated. PFC delivery was estimated by continuous measurement of weight gain of the adsorber (adsorption rate). Finally, the influence of respiratory rate and tidal volume on adsorption rate (AR) was studied. AR was significantly reduced by a decreasing tube diameter and ranged from 1.45+-0.03 ml/min (no tube) to 0.93+-0.03 ml/min (2.0 mm) for PF 5080 (vapor pressure 51 mmHg) and from 0.49+-0.06 ml/min to 0.32+-0.04 ml/min for PFOB (11 mmHg). PFC-aerosolization into a ventilatory circuit with simulation of spontaneous tidal breathing (minute volume 600 ml) reduced AR to 0.16+-0.02 ml/min. During mechanical ventilation, changes in respiratory rate and tidal volume, which reduce minute ventilation, caused a decrease in AR. Conclusion The amount of PFC that can be delivered into the lung by aerosolization is very small and is influenced by PFC properties, tube size, and ventilatory settings. Author Affiliation: (1) Clinic for neonatology, Charite Campus Mitte, Schumannstrasse 21, 10098, Berlin, Germany Article History: Received Date: 29/08/2002 Accepted Date: 21/02/2003 Online Date: 16/04/2003

Background: Randomized controlled trials have indicated reduced mortality rates in very preterm infants assigned to high compared to low oxygen saturation (SpO 2 ) target levels, accompanied by higher rates of retinopathy of prematurity and bronchopulmonary dysplasia. However, the benefit-to-harm ratio may depend on the local background mortality risk. We therefore aimed to quantify the risk-benefit ratios of different SpO 2 target ranges in 10 tertiary newborn intensive care units (NICUs) in East Germany., Methods: In a retrospective multicenter study, 1,399 infants born between 2008 and 2012 at a gestational age between 24 0/7 and 27 6/7 weeks and with a birthweight below 1,250 g were grouped according to the hospital's target SpO 2 range [high oxygen saturation group (HOSG) above 90%], low oxygen saturation group (LOSG) below 90%] and the compliance of units with their target SpO 2 range. The association between neonatal morbidities, neurodevelopmental outcomes, selected treatment strategies, and target SpO 2 ranges was calculated using chi-squared and Mann Whitney U tests., Results: Nine of the ten participating NICUs met their SpO 2 target ranges. Five units were considered as HOSG, and five units were considered as LOSG. Necrotizing enterocolitis and intraventricular hemorrhage grade ≥ 2 occurred significantly more frequently in the HOSG than in the LOSG (8.4% vs. 5.1%, p  = 0.02; and 26.6% vs. 17.7%, p  < 0.001). No significant differences in the mortality rate and the rate of retinopathy of prematurity were found., Conclusion: In our patient population, a lower SpO 2 target range was not associated with increased safety risks in extremely preterm infants. We cannot be sure that our outcome differences are associated with differences in oxygen saturations due to the retrospective study design and the differences in site practices., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (© 2023 Willgerodt, Bührer, Rossi, Kühn, Rüdiger, Avenarius, Böttger, Olbertz, Proquitte, Bittrich, Haase, Fröhlich, Höhne and Thome.)