Aim-To investigate the eYcacy of nasal high frequency ventilation (nHFV) in newborn infants with moderate respiratory insuYciency. Method-Twenty one preterm and term neonates were treated with nHFV for respiratory insuYciency. Criteria for starting nHFV were: deterioration on nasal CPAP expressed by a median pH of 7.24 and pCO 2 of 8.3 kPa, or increasing FIO 2 . nHFV was delivered using the Infant Star ventilator. Ventilator setting amplitude was 35 cm H 2 O; mean airway pressure 7 cm H 2 O; and frequency 10 Hz. Results-pCO 2 decreased significantly from 8.3 kPa to 7.2 kPa after nHFV was started. In five patients nHFV was discontinued after a median period of 6 1 ⁄2 hours due to CO 2 retention and high oxygen need, and endotracheal mechanical ventilation was started. Conclusions-nHFV can reduce pCO 2 in neonates with moderate respiratory insufficiency and, therefore, could be used to decrease the need for endotracheal mechanical ventilation. (Arch Dis Child Fetal Neonatal Ed 1998;79:F61-F63) Keywords: nasal high frequency ventilation; idiopathic respiratory distress syndrome Over the past two decades assisted mechanical ventilation has been used to manage respiratory insuYciency in newborn infants. However, complications such as airleaks occur in 15 to 48% of the infants who need ventilator support, 1 2 and 5 to 25% develop bronchopulmonary dysplasia (BPD).3 Both these complications contribute substantially to morbidity in preterm infants. Therefore, a less invasive approach such as nasal continuous positive airway pressure (nCPAP) is frequently used in the initial management of respiratory insuYciency.4-6 But 43 to 80% of the neonates with moderate to severe respiratory insuYciency, initially treated with nasal CPAP, will need subsequent mechanical ventilation.
7Nasal CPAP has also been used after extubation to facilitate weaning from mechanical ventilation. [8][9][10][11] However, extubation failed in 16 to 40% of cases. In both events subsequent endotracheal mechanical ventilation was needed because of CO 2 retention or increased oxygen need and apnoea of prematurity.High frequency ventilation (HFV) is a new method of mechanical ventilation based on the delivery of small tidal volumes at a supraphysiological respiratory frequency of 10 Hz.
13This technique is very eVective in eliminating carbon dioxide and is independent of dead space.We hypothesised that HFV applied on a single nasopharyngeal tube (nHFV) might reduce pCO 2 by augmenting CO 2 diVusion in the pharynx and larynx area and, therefore, decreasing the need for subsequent mechanical ventilation. To test this hypothesis we performed a non-controlled observational study and tested the eYcacy of nHFV in infants with moderate respiratory insuYciency.
MethodsTwenty one newborn infants were oVered nHFV. All patients were initially treated with nasal CPAP applied via a single nasopharyngeal tube positioned at a depth of 3-4 cm. nHFV was started due to CO 2 retention (median value 8.3 kPa), acidosis (median pH value 7.24), and/or increasing oxyge...
We conclude that defective deacetylation during human female meiosis increases with maternal age and is correlated with misaligned chromosomes. As chromosome misalignment predisposes to segregation errors, our data imply that defective regulation of histone deacetylation could be an important factor in age-related aneuploidy.
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