Editor's key points † The effect of pulmonary oedema on reliability of transpulmonary thermodilution cardiac output measurement was investigated. † Cardiac output was measured in newborn lambs in the presence of increased extravascular lung water. † Measurement of cardiac output by transpulmonary thermodilution is not affected by severe pulmonary oedema in a newborn lamb model. Background. The transpulmonary thermodilution (TPTD) technique is widely used in clinical practice for measuring cardiac output (CO). This study was designed to investigate the influence of various levels of pulmonary oedema on the reliability of CO measurements by the TPTD method
