Related Experiment Video
Updated: Jan 24, 2026
Mechanical Ventilation Boot Camp Curriculum
Published on: March 12, 2018
Empirical Probability of Positive Response to PEEP Changes and Mechanical Ventilation Factors Associated With
Craig D Smallwood1,2, Brian K Walsh3, John H Arnold4
1Division of Critical Care Medicine, Department of Anesthesia, Critical Care and Pain Medicine, Boston Children's Hospital, Boston, Massachusetts and Harvard Medical School, Boston, Massachusetts. craig.smallwood@childrens.harvard.edu.
Background:
PEEP is titrated to improve oxygenation during mechanical ventilation. It is clinically desirable to identify factors that are associated with a clinical improvement or deterioration following a PEEP change. However, these factors have not been adequately described in the literature. Therefore, we aimed to quantify the empirical probability of PEEP changes having a positive effect upon oxygenation, compliance of the respiratory system (CRS), and the ratio of dead space to tidal volume (VD/VT). Further, clinical factors associated with positive response during pediatric mechanical ventilation are described.
Methods:
Mechanically ventilated pediatric subjects in the ICU were eligible for inclusion in the study. During PEEP increases (PEEPincrease), a responder was defined as having an improved SpO /FIO ratio; non-responders demonstrated a worsening SpO /FIO ratio in the following hour. When PEEP was decreased (PEEPdecrease), a responder was anyone who maintained or increased the SpO /FIO ratio; non-responders demonstrated a worsening SpO /FIO ratio. Features from continuous mechanical ventilation variables were extracted, and differences between responders and non-responders were identified.
Results:
286 PEEP change cases were eligible for analysis in 76 subjects. For PEEPincrease cases, the empirical probability of positive response was 56%, 67%, and 54% for oxygenation, CRS, and VD/VT, respectively. The median SpO /FIO increase was 13. For PEEPdecrease, the empirical probability of response was 46%, 53%, and 46% for oxygenation, CRS, and VD/VT, respectively. PEEPincrease responders had higher FIO requirements (70.8 vs 52.5%, P < .001), mean airway pressure (14.0 vs 12.9 cm H2O, P = .03), and oxygen saturation index (9.9 vs 7.5, P = .002) versus non-responders. For PEEPdecrease, VD/VT was lower in responders (0.46 vs 0.50, P = .031).
Conclusions:
In children requiring mechanical ventilation, the responder rate was modest for both PEEPincrease and PEEPdecrease cases. These data suggest that PEEP titration often does not have the desired clinical effect, and predicting which patients will manifest a positive response is complex, requiring more sophisticated means of assessing individual subjects.
Related Concept Videos
01:23Mechanical Ventilation II: Invasive Ventilation
Negative-Pressure Ventilators
Negative-pressure ventilators create a vacuum around the chest or body to draw air into the lungs, simulating breathing. This method does not require an...
01:23Mechanical Ventilation III: Noninvasive Ventilation
Noninvasive Positive-Pressure Ventilation...
01:19Factors Affecting Pulmonary Ventilation
Alveolar Surface Tension
The alveolar fluid lines the luminal surface of the alveoli and exerts a force called surface tension. This force is caused by the polar water molecules in the liquid being more strongly attracted to each...
01:29Mechanical Ventilation I: Indication and Settings
01:24Pulmonary Ventilation: Inhalation
Boyle's law becomes particularly pertinent when examining respiratory...
01:20Assessment of Ventilation I: Respiratory Rate
A Ventilation assessment is critical for monitoring a patient's health status. Respiration, one of the most accessible vital signs, provides insights into the function of numerous body systems and can indicate serious health issues, such as brainstem injuries from head trauma.
Critical Guidelines for Assessing Ventilation: