Standardization of pulmonary ventilation technique using volume-controlled ventilators in rats with congenital diaphragmatic hernia

Abstract

ABSTRACT ABSTRACT ABSTRACTObjective Objective Objective Objective Objective: To standardize a technique for ventilating rat fetuses with Congenital Diaphragmatic Hernia (CDH) using a volumecontrolled ventilator. Methods Methods Methods Methods Methods: Pregnant rats were divided into the following groups: a) control (C); b) exposed to nitrofen with CDH (CDH); and c) exposed to nitrofen without CDH (N-). Fetuses of the three groups were randomly divided into the subgroups ventilated (V) and non-ventilated (N-V). Fetuses were collected on day 21.5 of gestation, weighed and ventilated for 30 minutes using a volume-controlled ventilator. Then the lungs were collected for histological study. We evaluated: body weight (BW), total lung weight (TLW), left lung weight (LLW), ratios TLW / BW and LLW / BW, morphological histology of the airways and causes of failures of ventilation. Results Results ResultsResults Results: BW, TLW, LLW, TLW / BW and LLW / BW were higher in C compared with N-(p <0.05) and CDH (p <0.05), but no differences were found between the subgroups V and N-V (p> 0.05). The morphology of the pulmonary airways showed hypoplasia in groups N-and CDH, with no difference between V and N-V (p <0.05). The C and N-groups could be successfully ventilated using a tidal volume of 75 ìl, but the failure of ventilation in the CDH group decreased only when ventilated with 50 ìl. Conclusion Conclusion Conclusion Conclusion Conclusion: Volume ventilation is possible in rats with CDH for a short period and does not alter fetal or lung morphology.

Neonatal rodent ventilation and clinical correlation in congenital diaphragmatic hernia

“…Our findings show a slightly larger difference in lung capacity than other existing reports. Gallindo et al 20 estimated that rodents with CDH should be ventilated at a tidal volume that was 67% that of control rodents, but their data were based on estimates of ideal tidal volumes based on visualization of successful chest rise. Flemmer et al 21 used FOT and found that CDH rabbits had inspiratory capacities roughly 70% that of control rabbits.…”

“…Our lab is collaborating with industry partners to test the effect of oxygen‐carrying nanoparticles and hypoxia pathway modulators on the SpO 2 of CDH rodents. For our team and in the existing literature, neonatal rodent tracheostomy had a steep learning curve, but can be achieved reliably and reproducibly 20 . FlexiVent and other rodent ventilation systems can record a variety of measurements using different ventilation parameters.…”

Brain caspase-3 and intestinal FABP responses in preterm and term rats submitted to birth asphyxia

“…The PTV, PTAV, TV, and TAV subgroups were ventilated with a Mini-Vent type 845 mechanical mini-ventilator (Harvard Apparatus ® , Hugo Sachs Eletronik Harvard Apparatus GmbH, Germany), according to Gallindo et al ( 16 ). The newborn pups were positioned on a heated table where they were intubated with an intravascular teflon 24G Vialon™ catheter (BD Insyte Autoguard, Becton Dickinson Infusion Therapy System Inc., USA) utilizing a surgical microscope with 4.5× magnification (DFV, Vasconcellos, Brazil), with a continuous 100% oxygen (O 2 ) flow with a cycling frequency of 80 rpm, FiO 2 of 1.0, inspiratory/expiratory ratio of 1:1, and positive end expiratory pressure of 0 cmH 2 O, for 30 min.…”

Honeymoon Period in Newborn Rats With CDH Is Associated With Changes in the VEGF Signaling Pathway

“…A 24 G catheter was placed, connected to MiniVent type 845 (Hugo Sachs Elektronik-Harvard Apparatus GmbH, March-Hugstetten, Germany), with a frequency of 80 breaths per minute, FiO2 1.0, inspiration-expiration ratio 1:1, and PEEP 0 cmH2O. The tidal volume was 13.5 ml/kg in the control groups (75 µl) and 9 ml/kg (50 µl) in the groups with CDH, based on a previous study by our laboratory (18). Non-ventilated animals were delivered by cesarian section, weighted, and immediately euthanized.…”