Antecedents of respiratory pauses in extremely low birth weight infants supported by proportional assist ventilation.
OBJECTIVE
To determine characteristics of breathing patterns prior to respiratory pauses in extremely low birth weight (ELBW) infants breathing spontaneously under proportional assist ventilation (PAV).


METHODS
Thirteen infants (mean +/- SD: gestational age 25 +/- 1 weeks; birth weight 753 +/- 149 g; age 4 +/- 3 days) were studied. Recordings were obtained under PAV over two-hour periods on two consecutive days. The last 10 breaths preceding respiratory pauses were analyzed.


RESULTS
Tidal volume, inspiratory and expiratory peak flow, and mean inspiratory flow decreased in the last breaths prior to respiratory pauses compared to all other breaths (p < 0.001). Of all apneas 89% were preceded by a decrease in tidal volume of at least 33% (435/487; p < 0.001). The positive predictive value of a decrease in tidal volume to predict an apnea was 26% (435/1640; p < 0.001).


CONCLUSIONS
Decreases in tidal volume of at least 33% and in airflow are the predominant changes in the breathing pattern prior to respiratory pauses in ELBW infants, preceding 89% of all respiratory pauses. Their low positive predictive value of 26% however, indicates that further variables of breathing need to be implemented to predict cessation of breathing with higher precision.
Department of Gynecology & Obstetrics, Division of Neonatology, Klinikum Grosshadern, Ludwig Maximilian University of Munich, Munich, Germany. esther.fackeldey@med.uni-muenchen.de
Esther
E
Rieger-Fackeldey
Annegret
A
Hofmiller
Andreas
A
Schulze
D001049:Apnea / Q000503:physiopathology* / Q000628:therapy*; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D007234:Infant, Premature; D007235:Infant, Premature, Diseases / Q000503:physiopathology; D019102:Infant, Very Low Birth Weight; D007320:Inspiratory Capacity / Q000502:physiology; D008297:Male; D008991:Monitoring, Physiologic; D010366:Peak Expiratory Flow Rate / Q000502:physiology; D011175:Positive-Pressure Respiration; D011237:Predictive Value of Tests