Background: Open heart surgery is usually performed by connecting the heart to a cardiopulmonary bypass (CPB) machine. The use of the CPB machine may decrease the hemoglobin level and a very low hemoglobin levelcould cause seriouscomplications.This study aimed to explore the decrease in hemoglobin level after open heart surgery. Methods: A cross-sectional retrospective descriptive study was conducted on medical records of patients underwent coronary artery bypass graft (CABG) surgery and heart valve surgery in a tertiary hospital in Indonesia in 2018. The total sampling method was deployed to all medical records of patients underwent CABG surgery (n=25) and patients underwent heart valve surgery (n=3). Results: The decrease in hemoglobin level among young-adult female patients after heart valve surgery was 6.8 g/dl. The average decrease in mid-adult male and female patients after CABG surgery were 6 g/dl and 5.8 g/dl, respectively, and, after the heart valve surgery, the levels were 8.5 g/dl and 5.4 g/dl, respectively. The average decrease in Hb level among late-adult male and female patients after CABG surgery was 6.1 g/dl and 5.4 g/dl, respectively. Conclusion: Hemoglobin level decreases after an open heart surgery. Therefore, observation on the hemoglobin level to prevent complications and to facilitate early treatment is necessary.

On examination of hemoglobin with POCT generally use capillary blood. The use of capillary blood as a test sample has a deficiency, namely the possibility of dilution in capillary blood samples caused by a deep puncture so that the blood that comes out is not smooth and usually the fingers will be pressed or sequenced. This condition can cause blood dilution by tissue fluid, so the test results will tend to be low. The purpose of this study was to find out the difference in hemoglobin results with POCT in venous and capillary blood samples. This study uses descriptive analytical methods that aim to describe or describe a situation objectively, and then describe it. The results showed the average hemoglobin level in the venous blood sample was 13.2 g/dl. While in capillary blood samples 12.9 g / dl. The results of the independent t-test obtained a significance value of 0.224 (p > 0.05) so it can be concluded that there is no significant difference between the results of hemoglobin levels examination using venous blood samples and capillary blood samples.