Does the application of negative suction to the chest drains increase the rate of mediastinal bleeding after coronary artery bypass graft?

ABSTRACT

There is controversy whether the institution of negative suction for cases of Coronary Artery Bypass Surgery [CABG] affects the rate of Mediastinal bleeding. Consecutive cases of CABG were studied according whether negative suction was applied [Group A] or not [Group B] from October 2003 till May 2004. The 24 hour blood loss, mortality rates, re-opening for bleeding and post-operative pericardial effusions were analyzed. 281 consecutive cases of CABG alone or in combination with other procedures were studied. Negative suction was applied in 78 cases [28%]. Male-to-female ratio was 3.21. Pure CABG was done in 92% of the cases. Concomitant procedures included Mitral valve repair and replacement and Aortic valve replacement. Re-do surgery was performed in 16 cases [5.6%]. Left Internal Thoracic Artery [LITA] was utilized in 81%. Average blood loss in group A was 870 +/- 270 ml and group B 630 +/- 215 ml giving a P value<0.05. Re-opening for bleeding occurred in 10 cases in group A [12.8%] and 9 cases in group B [4.4%] with a P value >0.05. There were 11 deaths overall [3.9%] 4 in group A [5.1%] and 7 in group B [3.4%]. Pure CABG had 7 deaths from a total of 258 cases; a mortality rate of [2.7%]. Pericardia! effusion occurred in 2 cases in group A [2.5%] and 9 in group B [4.4%] giving a P value > 0.05. Despite the limitation of not being a randomized study, nonetheless, it shows that negative suction applied to the chest drains after CABG increase Mediastinal drainage but had no effect on reopening rates, pericardial effusion and overall mortality