Duration of Continuous Positive Airway Pressure and Pulmonary Function Testing in Preterm Infants

Oregon Health and Science University50 enrolled

Overview

The primary aim of this study is to quantify and compare changes in lung volumes (as measured by functional residual capacity) in premature infants stable on continuous positive airway pressure (CPAP), and then randomized to two additional weeks of CPAP and room air versus room air alone. We hypothesize that infants randomized to additional CPAP will demonstrate an increased functional residual capacity (at the end of the two week study period and prior to discharge) compared to those randomized to room air.

Study Type

INTERVENTIONAL

Allocation

RANDOMIZED

Purpose

TREATMENT

Masking

SINGLE

Enrollment

Conditions

Respiratory Distress Syndrome Bronchopulmonary Dysplasia

Interventions

Stable premature infants on CPAP and room air and meeting specific stability criteria will be randomized to stay on continuous positive airway pressure and room air for an additional two weeks or will be transitioned to room air alone.

Eligibility

Sex: ALLMax age: 1 Year

Medical Language ↔ Plain English

Inclusion Criteria: * Gestational age at birth \<33 weeks * Required CPAP for a minimum of 24 hours for respiratory distress * Patient on CPAP and room air at time of randomization Exclusion Criteria: * Complex congenital heart disease other than patent ductus arteriosus or atrial septal defect * Major malformations or chromosomal anomalies * Multiple gestation greater than twins * Culture proven sepsis or unstable at time of randomization

Outcomes

Primary Outcomes

Changes in the Measurements of Functional Residual Capacity (FRC) in Randomized Premature Infants

Functional residual capacity (FRC) was measured with the nitrogen washout technique. For the nitrogen washout technique, calibration is done with 2 known volumes, and a calibration line was constructed for the system at the specific flow rate and used to correlate the nitrogen washed out to the infant's FRC. The system corrected for dead space and corrected the FRC to body temperature, pressure, and water-saturated conditions. Acceptance criteria included: 1) infant supine and quietly asleep; 2) test initiated at end expiration; 3) no evidence of leak on tracing of the washout; 4) consistent tracings; 5) at least 2-3 measurements with a coefficient of variation \<10%. These are testing and acceptance criteria outlined by the American Thoracic Society and European Respiratory Society.

Time frame: Just prior to randomization, two weeks later and at discharge (an average of 34 to 37 weeks of corrected gestational age).

Secondary Outcomes

Measurements of Passive Respiratory Compliance in Randomized Premature Infants

Measurements of passive respiratory compliance will be done with the single breath occlusion technique.

Time frame: Just before randomization, two weeks later, and at discharge at about 35-37 weeks of corrected gestational age

Passive Respiratory Resistance in Randomized Premature Infants

Measurements of passive respiratory resistance will be done with the single breath occlusion technique.

Time frame: Just prior to randomization, two weeks after randomization, and at discharge at about 35-37 weeks of corrected gestational age.

Measurements of Tidal Flow Volume Loops Will be Done in the Randomized Premature Infants.

Characteristics of tidal flow volume loops will be measured.

Time frame: Just before randomization, two weeks later, and at discharge at about 35-37 weeks of corrected gestational age.