Validation of a definition of excessive postoperative bleeding in infants undergoing cardiac surgery with cardiopulmonary bypass

OBJECTIVE

To derive and validate an objective definition of postoperative bleeding in neonates and infants undergoing cardiac surgery with cardiopulmonary bypass.

METHODS

Using a retrospective cohort of 124 infants and neonates, we included published bleeding definitions and cumulative chest tube output over different postoperative periods (eg, 2, 12, or 24 hours after intensive care unit admission) in a classification and regression tree model to determine chest tube output volumes that were associated with red blood cell transfusions and surgical re-exploration for bleeding in the first 24 hours after intensive care unit admission. After the definition of excessive bleeding was determined, it was validated via a prospective cohort of 77 infants and neonates.

RESULTS

Excessive bleeding was defined as ≥7 mL/kg/h for ≥2 consecutive hours in the first 12 postoperative hours and/or ≥84 mL/kg total for the first 24 postoperative hours and/or surgical re-exploration for bleeding or cardiac tamponade physiology in the first 24 postoperative hours. Excessive bleeding was associated with longer length of hospital stay, increased 30-day readmission rate, and increased transfusions in the postoperative period.

CONCLUSIONS

The proposed standard definition of excessive bleeding is based on readily obtained objective data and relates to important early clinical outcomes. Application and validation by other institutions will help determine the extent to which our specialty should consider this definition for both clinical investigation and quality improvement initiatives.

Strategies for blood conservation in pediatric cardiac surgery

Cardiac surgery accounts for the majority of blood transfusions in a hospital. Blood transfusion has been associated with complications and major adverse events after cardiac surgery. Compared to adults it is more difficult to avoid blood transfusion in children after cardiac surgery. This article takes into account the challenges and emphasizes on the various strategies that could be implemented, to conserve blood during pediatric cardiac surgery.

Recombinant activated factor VII in cardiac surgery: single-center experience

Background

the widespread off-label use of recombinant activated factor VII for the control of refractory postoperative hemorrhage continues despite a warning from the Food and Drug Administration. Although effective in reducing the need for transfusion of blood and blood products, safety concerns still prevail.

Objective

to compare the dosing and efficacy of recombinant activated factor VII between pediatric and adult patients, and in the operating room and intensive care unit.

Methods

the records of 69 patients (33 children and 36 adults) who underwent cardiovascular surgery and received recombinant activated factor VII were reviewed retrospectively. The dose of recombinant activated factor VII, mediastinal drainage, use of blood and blood products, incidence of thrombosis, and 28-day mortality were studied.

Results

the efficacy of recombinant activated factor VII was comparable in adults and children, despite the lower dose in adults. Prophylactic use of recombinant activated factor VII decreased the incidence of mediastinal exploration and the duration of intensive care unit stay. A 4.3% incidence of thrombotic complications was observed in this study.

Conclusion

the efficacious dose of recombinant activated factor VII is much less in adults compared to children. Prophylactic use of recombinant activated factor VII decreases the dose required, the incidence of mediastinal exploration, and intensive care unit stay, with no survival benefit.

Is recombinant activated factor VII effective in the treatment of excessive bleeding after paediatric cardiac surgery?

A best evidence topic in paediatric cardiac surgery was written according to a structured protocol. The question addressed was whether recombinant activated factor VII was effective for the treatment of excessive bleeding after paediatric cardiac surgery. Altogether 150 papers were found using the reported search; 13 papers were identified that provided the best evidence to answer the question. The authors, journal, date and country of publication, patient group studied, study type, relevant outcomes and results of these studies were tabulated. A total of 311 children experienced excessive bleeding following cardiac surgery that was refractory to the conventional methods of achieving haemostasis. One hundred and ninety-two patients received the rFVIIa while 116 were in control arm from five studies. The primary end-point was on chest tube drainage, the plasma prothrombin time, the activated partial thromboplastin time after the administration of rFVIIa and the secondary end-point was reduction of blood products transfusion. Thrombosis was a complication in 8 patients (4.2%); three deaths (1.6%) but not attributable to thromboembolic events following the use of rFVIIa. Most of the studies failed to clearly state the doses but the extracted doses ranged between 30 and 180 µg/kg/dose, the interval between doses ranged between 15 and 120 min with a maximum of four doses. However, most of the patients had 180 µg/kg/dose with interval between dose of 2 h and maximum of two doses with dosage moderated with respect to weight, prior coagulopathy and responsiveness. There were two randomized studies with good sample size. One showed no significant differences in the secondary end points between the two arms and noted no adverse complications. However, the rFVIIa was used prophylactically. The other observed that there were no increase in thromboembolic events rather rFVIIa was effective in decreasing excessive bleeding that may complicate cardiac surgery in children. In conclusion, the studies were in support of the notion that the use of rFVIIa was effective in decreasing excessive bleeding which may complicate paediatric cardiac surgery, and care should be exercised when using it in the children on ECMO circuit.