Search

Purpose of review Sustained inflation performed shortly after birth to help clear lung fluid and establish functional residual capacity in preterm infants is gaining popularity, but definitive evidence for its effectiveness is lacking. Although there is a sound physiologic basis for this approach, and much preclinical experimental evidence of effectiveness, the results of recent animal studies and clinical trials have been inconsistent. Recent findings The most recent data from a multicenter randomized trial suggest a modest benefit of sustained inflation in reducing the need for mechanical ventilation in extremely-low-birth-weight infants. However, the impact may be more modest than earlier retrospective cohort comparisons suggested. The trend toward more airleak and a higher rate of intraventricular hemorrhage is worrisome. Sustained inflation may be ineffective unless some spontaneous respiratory effort is present. Several on-going trials should further clarify the putative benefits of sustained inflation. Summary Delivery room sustained inflation is an attractive concept that holds much promise, but widespread clinical application should await definitive evidence from on-going clinical trials.

Severe respiratory distress is the major cause of perinatal mortality associated with congenital urinary tract anomalies or severe obstructive uropathy, and is often accompanied by oligohydramnios. In the past the prognosis in these high risk cases was extremely poor. We review our recent experience in 3 neonates with severe respiratory distress and congenital urinary tract anomalies who were successfully managed with extracorporeal membrane oxygenation, of whom 2 had posterior urethral valves and 1 had bilateral solid renal dysplasia. The use of extracorporeal membrane oxygenation for life threatening respiratory distress in the neonate associated with congenital uropathy is not limited to our experience. A review of the National Neonatal Extracorporeal Membrane Oxygenation Registry for neonates with urological indications for extracorporeal membrane oxygenation revealed 10 interventions with 9 survivors, for a survival rate of 90%. Extracorporeal membrane oxygenation may provide cardiopulmonary support during a period of immature circulation, allowing pulmonary parenchymal and vascular maturation as well as preventing iatrogenic barotrauma.

Traditional lung management during extracorporeal membrane oxygenation (ECMO) calls for low inspiratory and expiratory pressures with low ventilator rate to achieve lung rest. However, rapid weaning of pressures to severely injured lungs commonly leads to marked increase in pulmonary opacification as seen on chest x-ray and loss of volume. We postulated that a sufficiently high level of PEEP could prevent this deterioration. Forty-six newborns, who required ECMO therapy for refractory respiratory failure, were maintained on 8 to 14 cm H2O PEEP. The peak pressure was 20 to 24 cm H2O, rate 10 to 15 breath/min, and FIO2 0.21. Forty-one (89%) of 46 patients survived to discharge. The duration of ECMO was significantly decreased compared to the national average (82.4 +/- 43 vs. 117.5 +/- 59 h). The lungs of most patients remained adequately expanded and free of severe pulmonary opacification. Eleven of 40 patients did show significant worsening of chest x-ray compared to baseline, but only one of 18 who were on PEEP of greater than or equal to 12 cm H2O showed such deterioration. No unexpected complications were encountered. These data suggest that the use of high PEEP during ECMO safely prevents deterioration of lung function and promotes more rapid lung recovery. PEEP levels of 12 to 14 cm H2O appear to be most effective.

Despite the increasing acceptance of high frequency jet ventilation (HFJV), very little work has been done to determine if lung damage results from its use. We performed an experimental study to compare the effects of conventional ventilation with those of HFJV on the lung parenchyma of anesthetized dogs. Thirteen animals were studied for periods ranging from 2-24 h. Using a double-lumen Carlen's endotracheal tube, each animals's lungs were ventilated simultaneously but independently, one with conventional ventilation, the other with HFJV. No gross or microscopic evidence of atelectasis or barotrauma was noted in either group. Less hyperaeration was seen in the majority of jet ventilated lungs compared to the conventionally ventilated. In no case did the jet ventilated side show more damage than the control. We concluded that it is possible to use HFJV for 24 h without apparent parenchymal lung damage. Reduced hyperaeration is identified as a possible advantage of HFJV over conventional methods.