Related Experiment Video
Updated: May 3, 2026

Expired CO2 Measurement in Intubated or Spontaneously Breathing Patients from the Emergency Department
Published on: January 29, 2011
The value of Pa(CO2) in relation to outcome in congenital diaphragmatic hernia
Ariel A Salas1, Ramachandra Bhat1, Katarzyna Dabrowska1
1Department of Pediatrics, University of Alabama at Birmingham, Birmingham, Alabama.
Background:
Postnatal assessment of disease severity is critical for analysis of mortality rates and development of future interventions in congenital diaphragmatic hernia (CDH).
Objective:
The objective of this study was to stratify the risk of mortality based on arterial Paco 2.
Methods:
Retrospective analysis of infants (n = 133) with CDH admitted to a regional extracorporeal membrane oxygenation (ECMO) center in two different periods: period I (1987-1996; n = 46) and period II (2002-2010; n = 87).
Results:
The mortality rate (37%) was similar in both periods (p = 0.98). Paco 2 < 60 mm Hg in the first arterial blood gas (ABG) was an independent predictor of survival in both periods (p = 0.03). The predicted survival rate was 84% if initial Paco 2 was < 55 mm Hg. For infants with initial Paco 2 > 55 mm Hg treated with ECMO (n = 83), the predicted survival rate was 11% if the Paco 2 was > 88 mm Hg before the initiation of ECMO.
Conclusion:
Paco 2, a surrogate of lung hypoplasia, may be useful for risk stratification in CDH. Paco 2 < 60 mm Hg in the first ABG may indicate milder pulmonary hypoplasia. A Paco 2 > 80 mm Hg in the first ABG and/or before ECMO may indicate severe pulmonary hypoplasia.
Related Concept Videos
Assessment of Diffusion and Perfusion
The Role of Diffusion in Respiration
Diffusion is the process by which molecules move from an area of higher concentration to an area of lower concentration. In the respiratory system, this...
Diagnosing Acidosis and Alkalosis
First, the pH level is assessed to determine whether the blood pH is normal (7.35–7.45), low (acidosis), or high (alkalosis).
Next, the PCO2 and...
Acute Respiratory Failure-III
Pneumothorax II: Pathophysiology
Atelectasis II: Pathophysiology
Factors 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...

