Plasmin generation and fibrinolysis in pediatric patients undergoing cardiopulmonary bypass surgery

Predictive role of cardiopulmonary bypass exposure indexed to body surface area on postoperative organ dysfunction: a retrospective cohort study

OBJECTIVES

Long cardiopulmonary bypass times are associated with adverse postoperative outcomes and increased healthcare resource use. It is likely that this effect is pronounced in smaller patients. Previous studies have been criticized for not taking into consideration that prolonged bypass times are often due to higher complexity. The purpose of this study was to investigate the relationship between bypass index (bypass time/body surface area) and adverse postoperative events.

METHODS

Single-centre, retrospective cohort study including 2413 patients undergoing cardiac surgery on cardiopulmonary bypass from June 2018 to April 2020. Length of hospital stay, as surrogate marker of postoperative morbidity, was selected as primary outcome. The strength of association between bypass index and the primary outcome was assessed with linear regression analysis. Secondary outcomes included new onset renal, pulmonary or cardiac rhythm dysfunction. The predictive value of bypass index was assessed with linear regression analysis; univariate and multiple regression were used to assess the strength of association between Bi and the secondary outcomes.

RESULTS

Bypass index was predictive for length of stay at univariate (Relative Risk (RR): 1.004, P < 0.001) and at multivariable (RR: 1.003, P < 0.001) analysis. The association between bypass index and new renal (mean difference: 14.1 min/m2, P < 0.001) and cardiac rhythm dysfunction (mean difference: 12.6 min/m2) was significant. This was not true of postoperative lung dysfunction (mean difference: -1.5 min/m2, P = 0.293).

CONCLUSIONS

Bypass index, calculated as total bypass time/patient body surface area, is predictive of postoperative morbidity and resource utilization after cardiac surgery on pump.

Post-operative blood loss is higher among African American neonates undergoing open-heart surgery with cardiopulmonary bypass for CHD

BACKGROUND

Neonates are at high risk of bleeding after open-heart surgery. We sought to determine pre-operative and intra-operative risk factors for increased bleeding after neonatal open-heart surgery with cardiopulmonary bypass.

METHODS

We conducted a retrospective cohort study of neonates (0-30 days old) who underwent open-heart surgery with cardiopulmonary bypass from January, 2009, to March, 2013. Cardiac diagnosis; demographic and surgical data; and blood products, haemostatic agents, and anti-thrombotic agents administered before, during, and within 24 hours after surgery were abstracted from the electronic health record and anaesthesia records. The outcome of interest was chest tube output (in ml/kg body weight) within 24 hours. Relationships between chest tube output and putative associated factors were evaluated by unadjusted and adjusted linear regression.

RESULTS

The cohort consisted of 107 neonates, of whom 79% had a Society of Thoracic Surgeons-European Association for Cardio-Thoracic Surgery (STAT) Mortality Category of 4 or 5. Median chest tube output was 37 ml/kg (range 9-655 ml/kg). Age, African-American race, and longer durations of surgery and cardiopulmonary bypass each had statistically significant associations with increased chest tube output in unadjusted analyses. In multivariable analysis, African-American race retained an independent, statistically significant association with increased chest tube output; the geometric mean of chest tube output among African-American neonates was 71% higher than that of Caucasians (95% confidence interval, 29-125%; p = 0.001).

CONCLUSION

Among neonates with CHD undergoing open-heart surgery with cardiopulmonary bypass, African-American race is independently associated with greater chest tube output over the first 24 hours post-operatively.

The association of preoperative atrial fibrillation with post-cardiopulmonary bypass hyperfibrinolysis in rheumatic valvular heart disease patients

OBJECTIVE

The purpose of this study was to assess the fibrinolytic status after cardiopulmonary bypass in rheumatic valvular heart disease patients, and detect the associated factors of post-cardiopulmonary bypass hyperfibrinolysis.

METHODS

According to the fibrinolytic status after cardiopulmonary bypass, 203 rheumatic valvular heart disease patients were divided into two groups: hyperfibrinolysis group (H group, n = 78) and non-hyperfibrinolysis group (NH group, n = 125). The demographic characteristics, operative variables, and postoperative follow-ups were compared between these two groups.

RESULTS

The incidence of hyperfibrinolysis was 38.4% after cardiopulmonary bypass. Patients in the H group had a significant higher incidence of preoperative atrial fibrillation than patients in the NH group (92.3% vs. 55.2%, P < 0.01). Furthermore, postoperative daily drainage (655.3 ± 131.5 ml vs. 535.4 ± 161.4 ml, P < 0.01), transfusion volume of fresh frozen plasma (621.8 ± 220.2 ml vs. 455.2 ± 208.5 ml, P < 0.01), and red blood cells (5.9 ± 2.2 u vs. 4.7 ± 2.8 u, P < 0.01) was greater in the H group than in the NH group. Moreover, the logistic regression analysis revealed that preoperative atrial fibrillation was associated with post-cardiopulmonary bypass hyperfibrinolysis (OR = 19.691, 95% CI = 6.849-56.612; P < 0.05).

CONCLUSION

Preoperative artial fibrillation is associated with post-cardiopulmonary bypass hyperfibrinolysis in rheumatic valvular heart disease patients.

Impact of Heparin- or Nonheparin-Coated Circuits on Platelet Function in Pediatric Cardiac Surgery

BACKGROUND

Extracorporeal circuit coating has been shown to improve coagulation derangements during pediatric cardiopulmonary bypass (CPB). This study compared platelet function and hemostasis activation in pediatric cardiac surgery conducted with nonheparin coating (Balance; Medtronic, Minneapolis, MN) versus heparin-based coating (Carmeda; Medtronic) circuits.

METHODS

A prospective, randomized, double-center trial was conducted in children older than 1 month undergoing congenital heart disease treatment. Blood samples were collected at baseline (T0), 15 minutes after the start of CPB (T1), and 15 minutes (T2) and 1 hour after the conclusion of CPB (T3). The primary end point of the study was to detect potential differences in β-thromboglobulin levels between the two groups at T2. Other coagulation and platelet function indicators were analyzed as secondary end points.

RESULTS

The concentration of β-thromboglobulin increased significantly at T2 in both groups. However, there was no significant difference between the groups across all time points. There was no difference in the secondary end points between the groups.

CONCLUSIONS

The two circuits showed similar biological effects on platelet function and coagulation. This observation may be useful in optimizing the conduct of CPB and in rationalizing its cost for the treatment of congenital heart disease.