Unexpected values of mixed venous blood analysis: Back to basics before sampling.

This article discusses a case study of a 62-year-old man who experienced low-cardiac-output syndrome after heart surgery. The study focused on the analysis of mixed venous blood samples taken from the pulmonary artery catheter to assess cardiac output and oxygen delivery. The results showed unexpected values in the mixed venous blood sample compared to the arterial blood sample, indicating the importance of checking the position and waveform of the catheter during blood withdrawal. The article also references previous studies that found similar discrepancies in blood gas values and suggests that prolonged, unintentional migration of the catheter can lead to complications. [Extracted from the article]