Ventilatory management in extremely low birth weight infants.

Area of Science:

• Neonatology
• Pediatric Pulmonology
• Critical Care Medicine

Background:

• Mechanical ventilation improves survival in premature infants but increases the risk of ventilator-induced lung injury (VILI) and chronic lung disease (CLD).
• High-frequency ventilation (HFV) has shown promise in reducing VILI and CLD in very low birth weight infants.
• Understanding optimal ventilator strategies for conventional mechanical ventilation (CMV) is crucial for minimizing CLD in neonates, especially after surfactant administration.

Purpose of the Study:

• To investigate whether optimizing lung volumes on CMV can minimize CLD in neonates.
• To evaluate the impact of evolving ventilatory strategies on mortality and CLD incidence in extremely low birth weight infants.

Main Methods:

• Retrospective review of medical charts of 51 extremely low birth weight infants from two distinct epochs (1990-1991 and 1999-2000).
• Analysis of ventilatory strategies, including peak inspiratory pressure (PIP), mean airway pressure (MAP), and mode of ventilation (e.g., synchronous intermittent mandatory ventilation - SIMV).
• Comparison of outcomes (mortality and CLD rates) between different eras and in relation to surfactant therapy and ventilation management.

Main Results:

• Surfactant therapy improved pulmonary compliance but necessitated adjustments in ventilatory management to prevent lung damage.
• In the pre-surfactant era, mortality was 30% and CLD was 40%. Post-surfactant, mortality decreased to 18%, but CLD increased to 78%.
• In the most recent era, with 10 years of experience, mortality was 17% and CLD was 21%, associated with lower PIP/MAP and increased SIMV use in the first 24 hours post-surfactant.

Conclusions:

• Ventilator strategies, particularly in the immediate period following surfactant administration, significantly impact long-term morbidity in premature infants.
• Lowering peak inspiratory pressure and mean airway pressure, alongside increased use of synchronous intermittent mandatory ventilation, is associated with improved outcomes.
• Further research is needed to optimize conventional ventilation modes for protecting the immature lung and managing lung volumes effectively.