Premature neonates with bronchopulmonary dysplasia (BPD) frequently present borderline hypoxemia and the risk for oxygen desaturation may increase in relation to the posture. Our aim was to see if ...infants with BPD experience severe hypoxemia (SaO2 < 85%) in a hammock, a 'containing' posture considered advantageous to neuromotor and relational development of the preterm. Fifteen pulse oximetry recordings (Ohmeda B105 3760 Pulse Oximeter) were obtained in 15 subjects (range of gestational age and postnatal age 27-30 and 33-48 weeks, respectively; range of birth weight and body weight at entrance to the study 0.64-1.35 and 0.97-2.24 kg, respectively) before, during and after placement in a hammock; each testing period lasted 15 min, and each baby served as his or her own control. BPD preterm infants were receiving oxygen therapy by continuous flow standard nasal cannulas (FiO2 > 25%, < 40%). The analysis of the data, that have a rough gaussian distribution, indicates a worsening of SaO2 in the hammock position. In fact, mean +/- SEM, median and range of the SaO2 values in pre- and posthammock position are comparable, but are significantly different at 99.9% confidence level (CL) in prehammock vs. hammock posture and at 98% CL in posthammock vs. hammock posture. Moreover, the percent of time with SaO2 < 85% during the periods recorded increased about 10 +/- 5% in a hammock (24 +/- 4%), in comparison to pre- (14 +/- 3%) and posthammock position (15 +/- 3%). These results suggest that oxygen-dependent BPD preterm infants in the hammock posture may experience severe hypoxemia that in part limits the possible advantages of the 'containment'.
We conducted a clinical study on the antecedents of bronchopulmonary dysplasia (BPD) in 290 premature RDS infants with < or = 1.75 kg birth weight (BW). They were enrolled in a prospective trial of ...indomethacin treatment for "silent" patent ductus arteriosus (PDA), screened by 2-D echocardiographic and pulsed Doppler evaluation on the third day of life. The trial took place at the NICU of the Pediatric Department of Padua University between January 1987 and December 1991. Out of 290 infants screened, 96 had evidence of "silent" PDA (33%) and 77 responded to indomethacin treatment (80%). Comprehensively 79 (27%) developed BPD, and from these the incidence of BPD was statistically increased in infants with "silent" PDA, 47 out of 96 (49 +/- 9%), with respect to 32 out of 194 (16 +/- 3%) preterm infants without PDA. Statistical analysis showed that in preterm infants with "silent" PDA the development of BPD was correlated at 99% C.L. to their low BWs (mean BW = 1.13 kg): in fact the mean and the mode of BW distributions were statistically lower in the presence of BPD, 1.03 kg versus 1.24 kg, and 0.88 kg versus 1.65 kg respectively. Moreover, the preterm infants with "silent" PDA unresponsive to the first course of indomethacin and/or submitted later to surgical closure, presented a statistically lower BW with respect to the early responders, 1.06 kg versus 1.18 kg, and at the same time a statistically higher incidence of BPD (63 +/- 20% versus 43 +/- 9%). From these data we conclude that, although "silent", PDA increase per se the incidence of BPD, even if benefits from an early induced closure. Furthermore, a lower BW of infants affected by "silent" PDA represents a contributing factor to the development of BPD.
Creatinine clearance and renal sodium excretion were measured consecutively in three groups of 12 premature infants (gestational age less than or equal to 35 weeks) whose mothers had received either ...steroids or aminophylline, or steroids and aminophylline before delivery. We found no significant differences for plasma and urine creatinine and its clearance in the groups considered. The steroid group presented urine osmolality and urine/plasma osmolality ratio significantly higher than among the other groups. Furthermore, urine potassium excretion increased, and urine sodium and sodium fractional excretion were reduced. Aminophylline exposure did not interfere with the hydrosaline equilibrium nor with renal function of the preterms at birth. Our results reconfirm that corticosteroid hormones play an important part in the fetal renal maturation process, inducing a precocious maturation of the tubular Na(+)-K+ ATPase enzymatic system, that is substantially unmodified by aminophylline exposure. However, due to the prolonged half-life of aminophylline in prematures, it seems reasonable to verify the coupling of tubular and glomerular functions also in the following days of life.
