Less invasive ventilation in extremely low birth weight infants from 1997 to 2011: survey versus evidence

Evidence for target values of arterial oxygen saturation (SaO2), CO2, and pH has changed substantially over the last 20years. A representative survey concerning treatment strategies in extremely low-birth-weight infants (ELBW) was sent to all German neonatal intensive care units (NICUs) treating ELBW infants in 1997. A follow-up survey was conducted in 2011 and sent to all NICUs in Germany, Austria, and Switzerland. During the observation period, NICUs targeting SaO2 of 80, 85, and 90% have increased, while units aiming for 94 and 96% decreased (all p < 0.001). Similarly, NICUs aiming for pH7.25 or lower increased, while 7.35 or higher decreased (both p < 0.001). Furthermore, more units targeted a CO2 of 50mmHg (7.3 kPa) or higher (p < 0.001), while fewer targeted 40 or 35mmHg (p < 0.001). Non-invasive ventilation (NIV) was used in 80.2% of NICUs in 2011. The most frequently used ventilation modes were synchronized intermittent mandatory ventilation (SIMV) (67.5%) and intermittent positive pressure ventilation (IPPV) (59.7%) in 1997 and SIMV (77.2%) and synchronized intermittent positive pressure ventilation (SIPPV) (26.8%) in 2011. NICUs reporting frequent or always use of IPPV decreased to 11.0% (p < 0.001). SIMV (77.2%) and SIPPV (26.8%) did not change from 1997 to 2011, while high-frequency oscillation (HFO) increased from 9.1 to 19.7% (p = 0.018). Differences between countries, level of care, and size of the NICU were minimal. Conclusions: Target values for SaO2 decreased, while CO2 and pH increased significantly during the observation period. Current values largely reflect available evidence at time of the surveys. What is Known: • Evidence concerning target values of oxygen saturation, CO 2 , and pH in extremely low-birth-weight infants has grown substantially. • It is not known to which extent this knowledge is transferred into clinical practice and if treatment strategies have changed. What is New: • Target values for oxygen saturation in ELBW infants decreased between 1997 and 2011 while target values for CO 2 and pH increased. • Similar treatment strategies existed in different countries, hospitals of different size, or university versus nonuniversity hospitals in 2011