Elimination of ventilator dead space during synchronized ventilation in premature infants

J Pediatr. 2003 Sep;143(3):315-20. doi: 10.1067/S0022-3476(03)00299-3.


Background: Mainstream airflow sensors used in neonatal ventilators to synchronize mechanical breaths with spontaneous inspiration and measure ventilation increase dead space and may impair carbon dioxide (CO(2)) elimination.

Objective: To evaluate a technique consisting of a continuous gas leakage at the endotracheal tube (ETT) adapter to wash out the airflow sensor for synchronization and ventilation monitoring without CO(2) rebreathing in preterm infants.

Design: Minute ventilation (V'(E)) by respiratory inductance plethysmography, end-inspiratory and end-expiratory CO(2) by side-stream microcapnography, and transcutaneous CO(2) tension (TcPCO(2)) were measured in 10 infants (body weight, 835+/-244 g; gestational age, 26+/-2 weeks; age, 19+/-9 days; weight, 856+/-206 g; ventilator rate, 21+/-6 beats/min; PIP, 16+/-1 centimeters of water (cmH(2)O); PEEP, 4.2+/-0.4 cmH(2)O; fraction of inspired oxygen (FIo(2)), 0.26+/-0.6). The measurements were made during four 30-minute periods in random order: IMV (without airflow sensor), IMV+Sensor, SIMV (with airflow sensor), and SIMV+Leak (ETT adapter continuous leakage).

Results: Airflow sensor presence during SIMV and IMV+Sensor periods resulted in higher end-inspiratory and end-expiratory CO(2), Tcpco(2), and spontaneous V'(E) compared with IMV. These effects were not observed during SIMV+Leak.

Conclusions: The significant physiologic effects of airflow sensor dead space during synchronized ventilation in preterm infants can be effectively prevented by the ETT adapter continuous leakage technique.

Publication types

  • Evaluation Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Blood Gas Analysis
  • Capnography
  • Humans
  • Infant, Newborn
  • Infant, Premature*
  • Intermittent Positive-Pressure Ventilation / adverse effects
  • Intermittent Positive-Pressure Ventilation / methods*
  • Intubation, Intratracheal / adverse effects
  • Intubation, Intratracheal / methods*
  • Lung Diseases / etiology*
  • Lung Diseases / physiopathology
  • Lung Diseases / prevention & control*
  • Plethysmography, Whole Body
  • Respiration Disorders / blood
  • Respiration Disorders / physiopathology
  • Respiration Disorders / therapy*
  • Respiratory Dead Space / physiology*
  • Severity of Illness Index
  • Ventilators, Mechanical / adverse effects*