Episodes of spontaneous hypoxemia are frequent in V LBW(≤ 1000g) infants with CLD (FIO2 >0.21, age > 28 days, Chest X-ray changes). It has been suggested that prompt extubation in these infants may allow them to actively maintain their lung volume and therefore decrease episodes of hypoxemia (J of Ped 1995; 127:767-773). To test this hypothesis, we monitored spontaneous episodes of hypoxemia in 35 intubated VLBW infants (mean BW=748g, GA=26.3 wks, postnatal age (PNA)=38 days, study weight=1024g, FIO2=0.34, mean airway pressure=5.0 cm H2O) vs episodes of hypoxemia in 38 extubated VLBW infants with CLD (mean BW=781g, GA=26.1 wks, PNA=44 days, study weight=1228g, FIO2=0.27). Oxygen saturation (SaO2) was measured with a Nellcor N-200 oximeter for one hour time intervals with the infant supine, quietly asleep, and on the FIO2 used for patient care. The oxygenation data was quantified with a computer program (Pediatr Pulmonol 1992; 13: 136-142). The average SaO2 in the intubated infants was 92.0% versus 92.2% in the extubated (p>0.05). Values are mean ± SEM. When studied on the FIO2 used for clinical care, both intubated and extubated VLBW infants with CLD demonstrated a similar average SaO2, as well as comparable percentages of time to less than 90%, 85%, and 80% SaO2. However, the intubated infants experienced more episodes of spontaneous hypoxemia, despite continuous ventilation. Our preliminary data demonstrates that the presence of an endotracheal tube does not protect these infants from episodes of spontaneous hypoxemia. We speculate that these episodes of hypoxemia in VLBW infants with CLD may be due to sudden decreases in lung volume and/or increased intrapulmonary shunting. Prompt extubation in stable VLBW infants with CLD may indeed allow them to more adequately maintain their own lung volume and decrease these episodes of spontaneous hypoxemia.Table