Kathleen Williamson

Postnatal Dexamethasone (DEX) Increases Functional Residual Capacity (FRC) and Respiratory Compliance (CRS) in Both Preterm Females And Males

Postnatal Dexamethasone (DEX) Increases Functional Residual Capacity (FRC) and Respiratory Compliance (CRS) in Both Preterm Females And Males

Effect of Low-Dose Dexamethasone (Dex) on Respiratory Compliance in Very Low Birth Weight Infants (≤1250g): Racial Responses

Effect of Low-Dose Dexamethasone (Dex) on Respiratory Compliance in Very Low Birth Weight Infants (≤1250g): Racial Responses

Dexamethasone (DEX) Improves Functional Residual Capacity (FRC) and Respiratory Compliance (CRS) in Oxygen Dependent Very Low Birth Weight (VLBW) Infants: A Randomized, Blinded Trial. |[dagger]| 1072

An increasing proportion of VLBW infants developing chronic lung disease have little initial respiratory distress. In a pilot study, we documented a one week weaning course of DEX given to extubated, oxygen dependent VLBW infants to significantly increase FRC and CRS (Am Rev Respir Crit Care Med 1997;155:A235). We now report the results of a randomized, placebo controlled trial of DEX (0.5 mg/kg/day × 3 days; 0.25 mg/kg/day × 3 days; 0.1 mg/kg/day × 1 day) in VLBW infants who are extubated but oxygen dependent at greater than 5 days of age. Nine infants received DEX (mean BW=1164g; GA= 27.9 wks; FiO2=30%; age=19.9 days), while ten infants served as controls (mean BW= 1070g; GA= 28.2 wks; FiO2=31%; age=16.0 days). FRC was measured with the nitrogen washout technique. A minimum of two measurements were performed with the neonate supine and quiet. A study was acceptable if the measurements had a coefficient of variation <10%. CRS was measured using the single breath occlusion technique (SensorMedics 2600).Significantly more infants in the DEX group weaned to room air by the end of therapy. Our preliminary results demonstrate a one week course of DEX given to extubated but oxygen dependent VLBW infants significantly increases FRC (78%) and CRS(40%). We speculate that DEX may decrease the development of chronic lung disease in oxygen dependent VLBW infants. Table

TWELVE HOURS OF FETAL EXPOSURE TO ANTENATAL STEROIDS (AS) INCREASES FUNCTIONAL RESIDUAL CAPACITY (FRC) IN PRETERM INFANTS. † 969

Optimal pulmonary response to AS (two 12 mg doses of betamethasone [BMZ]) is expected to occur with dosing 24 hours prior to delivery and delivery within 7 days. Recent animal data showed an improvement in lung function after a 15 hour exposure to BMZ (Am J Obstet Gyn 1996;174:1408 -13). We have demonstrated that AS given at least 24 hours before but within 7 days of delivery significantly increases FRC and passive compliance (Crs) in treated vs. controlled infants (Pediatr Res 1995;37:224). We hypothesized fetal exposure to AS for <24 hours would improve FRC and Crs. To evaluate the effect of partial AS therapy on lung function, we measured FRC and Crs in 10 infants 25-34 weeks gestation (mean BW=1106g; GA=29.3 wks; 80% female; 80% Caucasian [Cau]) exposed to AS for a minimum of 6 hours, but less than 24 hours. 10 matched infants who received no AS (mean BW=1310g; GA=29.4 wks; 60% female; 90% Cau) served as our controls and 10 matched infants who received a full course of AS (mean BW=1309g; GA=29.8 wks; 70% female, 90% Cau) were our comparison group. FRC was meaasured with the nitrogen washout technique within 24 hours of age and prior to surfactant therapy, if needed. A minimum of 2 measurements were done with the neonate supine and quiet. Only consistent tracings started at end expiration and without evidence of a leak were accepted. A study was acceptable if the coefficient of variation was <10%. Crs was measured using a single breath occlusion (SensorMedics 2600). Values are mean ± SEM. Table

INCREASES IN FUNCTIONAL RESIDUAL CAPACITY (FRC) AT TWO DIFFERENT DOSES OF DEXAMETHASONE IN VERY LOW BIRTH WEIGHT (VLBW) INFANTS: A DOUBLE-BLIND, RANDOMIZED TRIAL. |[dagger]| 1359

We have reported a one week weaning course of 0.5 mg dexamethasone (DEX) in VLBW ventilator dependent infants 7 - 14 days of age to significantly improve pulmonary compliance (as well as subsequent CLD) when compared to controls(Pediatrics 1995; 95: 584-90). The effect of two different dose regimes of DEX on lung volume in VLBW infants at risk for CLD has not been reported. As part of an ongoing study, we measured FRC and static pulmonary mechanics (PM) in 21 infants ≤ 1000 g ventilator dependent at 7 - 14 days with a randomized, double-blind study design. Ten infants (mean BW=785 g, GA=25.7 wks, 70% male, 50% Caucasian, FIO2 at entry = 0.48, mean airway pressure (MAP) = 7.1 cmH2O) received high dose DEX (0.5mg/kg/day × 3 days; 0.25 mg/kg/day × 3 days; 0.1 mg/kg/day × 1 day) while 11 infants (mean BW=714 g, GA=25.5 wks, 64% male, 45% Caucasian, FIO2 at entry = 0.48, MAP=8.2 cm H2O received low dose DEX (0.2 mg/kg/day × 3 days; 0.1 mg/kg/day × 4 days). FRC and PM were measured at similar ventilator settings before and on days 2, 5, and 7 of DEX. FRC was measured with the nitrogen washout technique. A minimum of 2 measurements were performed with the neonate supine and quiet. Only consistent tracings initiated at end expiration and without evidence of leak were accepted. A study was acceptable if the measurements had a coefficient of variation < 10%. Respiratory compliance (Crs) was measured using the single breath occlusion technique (SensorMedics 2600). FRC is shown as ml/kg and Crs as ml/cm H2O/kg. Both groups had a significant decrease in FIO2 and MAP by day 7 of therapy (p<0.05). Although the increase is more gradual in the low dose DEX group, both high and low dose DEX had significant increases in FRC and Crs by day 7. However, the high dose DEX group had a 129% increase in FRC, while low dose DEX increased FRC by 43% (p<0.05). We speculate that this statistically significant increase in FRC with high DEX versus low DEX will also prove to be clinically significant, and supports a short course of the high dose as more effective than the low dose for infants at risk for CLD.Table

THE EFFECT OF TIDAL VOLUME (Vt) DRIVEN WEANING PROTOCOLS (WP) IN INTUBATED NEONATES WITH ACUTE RESPIRATORY DISTRESS SYNDROME (RDS) 1173

Historically, pressure limited, time cycled ventilation has been the cornerstone of neonatal ventilation. The advent of sensitive flow sensors now allows rapid, continuous measurement of Vt in small neonates. We hypothesized that an algorithm combining Vt measurements with maximal use of noninvasive monitoring would allow safe, uniform weaning of infants with RDS from mechanical ventilation with a minimum of blood draws. The primary premise of the algorithm: using Vt to modify peak inspiratory pressure (PIP) to keep Vt 5-7 ml/kg; modify rate to keep pH 7.27-7.33; modify FiO2 to maintain SaO2 89-94%. Tidal volumes were measured with the Bicore CP-100 Neonatal monitor. This uses a self calibrated transducer to measure air flow. Flow is then integrated to give the infants tidal volume. CO2 was monitored with transcutaneous CO2 (Novametrix), SaO2 with the Nellcor pulse oximeter. Arterial blood gases were drawn from the umbilical arterial line when available, or peripheral capillary blood gases were followed. Data from 33 infants (mean BW=1326g, GA=29.5 wks, 54% male, 50% Caucasian, initial mean airway pressure (MAP)=8.5 cmH2O, initial FIO2= 0.62) intubated secondary to RDS and managed as per the WP were evaluated. This was compared with data from 33 matched retrospective controls (mean BW=1274 g, GA=29.2 wks, 57% male, 66% Caucasian, initial MAP=8.7 cm H2O, FIO2=0.63). Primary outcome variables included: initial PIP (IPIP) and maximum PIP (MPIP), total blood gases (BG) for initial 72 hours of management and for first 7 days of hospitalization, and duration of mechanical ventilation. No patient managed per the weaning protocol had a pH value of <7.25. There was a significant difference between the two groups in terms of IPIP (WP=21cm H2O vs NO WP= 24 cm H2O, p<0.03), MPIP (WP = 21.8 cm H2O vs NO WP= 25.0 cmH2O, p<0.01). The infants managed with the WP had an average of 13.6 BGs drawn during the first 72 hours vs. 22.5 BGs for the NO WP (p<0.001). For the first week, the WP infants had 19.0 BG vs. 33.5 BG (p < 0.01). In terms of hospital charges for BG in the first week, the WP charges were

The Effect of a Single Remote Course Versus Weekly Courses of Antenatal Corticosteroids on Functional Residual Capacity in Preterm Infants: A Randomized Trial

1452 vs

Functional residual capacity and passive compliance measurements after antenatal steroid therapy in preterm infants

2560 for the NO WP. Actual hospital COST (therapist time and supplies per blood gas) resulted in saving

Timing of antenatal corticosteroids and neonatal pulmonary mechanics

65 per patient for the first week (

Randomized, double-blinded trial of low-dose dexamethasone: II. Functional residual capacity and pulmonary outcome in very low birth weight infants at risk for bronchopulmonary dysplasia

85 vs.