Mediastinal Blood Loss Research Articles

Individualized, Intraoperative Dosing of Fibrinogen Concentrate for the Prevention of Bleeding in Neonatal and Infant Cardiac Surgery Using Cardiopulmonary Bypass (FIBCON)

Background:Mediastinal bleeding is common following pediatric cardiopulmonary bypass surgery for congenital heart disease. Fibrinogen concentrate (FC) represents a potential therapy for preventing bleeding.Methods:We performed a single-center, phase 1b/2a, randomized controlled trial on infants 2.5 to 12 kg undergoing cardiopulmonary bypass surgery, aimed at (1) demonstrating the feasibility of an intraoperative point-of-care test, rotational thromboelastometry, to screen out patients at low risk of postoperative bleeding and then guide individualized FC dosing in high-risk patients and (2) determining the dose, safety, and efficacy of intraoperative FC supplementation. Screening occurred intraoperatively 1-hour before bypass separation using the rotational thromboelastometry variable fibrinogen thromboelastometry maximum clot firmness (FibTEM-MCF; fibrinogen contribution to clot firmness). If FibTEM-MCF ≥7 mm, patients entered the monitoring cohort. If FibTEM-MCF ≤6 mm, patients were randomized to receive FC/placebo (2:1 ratio). Individualized FC dose calculation included weight, bypass circuit volume, hematocrit, and intraoperative measured and desired FibTEM-MCF. The coprimary outcomes, measured 5 minutes post-FC administration were FibTEM-MCF (desired range, 8–13 mm) and fibrinogen levels (desired range, 1.5–2.5 g/L). Secondary outcomes were thrombosis and thrombosis-related major complications and postoperative 24-hour mediastinal blood loss.Results:We enrolled 111 patients (cohort, n=21; FC, n=60; placebo, n=30); mean (SD) age, 6.4 months (5.8); weight, 5.9 kg (2.0). Intraoperative rotational thromboelastometry screening effectively excluded low-risk patients, in that none in the cohort arm (FibTEM-MCF, ≥7 mm) demonstrated clinically significant early postoperative bleeding (>10 mL/kg per 4 hours). Among randomized patients, the median (range) FC administered dose was 114 mg/kg (51–218). Fibrinogen levels increased from a mean (SD) of 0.91 (0.22) to 1.7 g/L (0.41). The postdose fibrinogen range was 1.2 to 3.3 g/L (72% within the desired range). The corresponding FibTEM-MCF values were as follows: pre-dose, 5.3 mm (1.9); post-dose, 13 mm (3.2). Ten patients (8 FC and 2 placebo) exhibited 12 possible thromboses; none were clearly related to FC. There was an overall difference in mean (SD) 24-hour mediastinal drain loss: cohort, 12.6 mL/kg (6.4); FC, 11.6 mL/kg (5.2); placebo, 17.1 mL/kg (14.3; ANOVAP=0.02).Conclusions:Intraoperative, individualized dosing of FC appears feasible. The need for individualized dosing is supported by the finding that a 4-fold variation in FC dose is required to achieve therapeutic fibrinogen levels.Registration:URL:https://eudract.ema.europa.eu/; Unique identifier: 2013-003532-68. URL:https://www.isrctn.com/; Unique identifier: 50553029.

Robotic resection of posterior mediastinal lesions: indications, tips and tricks

The video-assisted thoracoscopic resection of posterior mediastinal lesions is feasible and safe in the majority of cases and is associated with a significant reduction of hospital stay, chest tube duration as well as a sensible reduction in patient’s morbidity and mortality. However, we have to consider that some of mediastinal lesions can present anatomical features that make a traditional VATS approach technically challenging or at risk of injuring surrounding structures. In these patients that could be excluded from a traditional VATS approach, the robotic assisted procedure could be effective in resecting lesions that would otherwise require an open resection. Moreover, the robotic technique, extending the ability in the surgical tissue dissection thanks to three-dimensional view and dexterity due to the use of endowrist, can reduce the risk of damage to mediastinal structures and blood loss. As happened in general surgery for upper GI, prostatectomy or low rectum resections, the robotic surgery can be indicated for procedures in narrow space like the thoracic inlet or the posterior pericardiophrenic angle, where the traditional minimally invasive surgery shows technical limitations due to the use of straight instruments.

Reduced re-exploration and blood product transfusion after the introduction of the Papworth haemostasis checklist†.

Between 2% and 8% of patients return to the theatre for mediastinal bleeding following cardiac surgery. In the majority of patients, a surgical source of bleeding is identified. Both mediastinal bleeding and re-exploration are associated with increased morbidity and mortality and the use of blood products. The aim of this study was to develop a 'haemostasis checklist' with the intention of reducing mediastinal bleeding and re-exploration following cardiac surgery. The Papworth haemostasis checklist was developed with a multidisciplinary collaboration. It consists of 2 components: surgical sites and coagulation status. The checklist is completed at a 'time-out' prior to sternal wire insertion. The analysis compared the outcomes of patients undergoing cardiac surgery in the 1 year before and after implementation. A propensity analysis assessed the impact of re-exploration on outcomes. Three thousand eight hundred and eleven patients underwent cardiac surgery during the study period. Re-exploration for bleeding was associated with inferior outcomes. Following checklist implementation, there was a significant reduction in the re-exploration rate (3.47% vs 2.08%, P = 0.01) and proportion of patients bleeding >1 l in 12 h (6.1% vs 3.49%, P < 0.001). There was a significant reduction in consumption of blood products saving £102165 ($134198). The checklist implementation was associated with reduced intensive care unit length of stay and hospital length of stay, adding to the financial benefit. The haemostasis checklist represents a simple intervention which is quick and easy to use but has had a substantial impact on clinical outcomes. We have observed a significant reduction in the mediastinal blood loss, return-to-theatre rate and consumption of blood products, which is associated with a significant clinical and financial benefit.

ACT Values after Neutralization Lower than Pre-heparinization ACT Leads to Lower Operative Times, Bleeding, and Post-Operative Transfusions in CABG Patients: an Observational Study.

ObjectiveTo evaluate if lower activated coagulation time (ACT) value after neutralization than preoperative ACT value was effective in reducing bleeding, operative times, and post-operative transfusions in patients underwent coronary artery bypass grafting (CABG).MethodsRetrospective selection of 398 patients from January 2014 to May 2017. Patients were divided into 2 groups according to final ACT after neutralization: A - final ACT lower than preoperative ACT; and B - final ACT higher than or equal to preoperative ACT. Hemostatic time, intraoperative blood loss, ACT after final neutralization, mediastinal blood loss, and transfusion requirements were observed.ResultsThe hourly blood loss in the Group A was generally lower than in the Group B at first 3 hours, which has significant difference (P<0.05). However, there was no difference after 3 hours between the two groups. Operative time, intraoperative blood loss, mediastinal blood loss, transfusion requirements, and drainage in the first postoperative 12 hours in the Group A were lower than in Group B, which has significant difference (P<0.05).ConclusionAs a result, final ACT values lower than pre-heparinization ACT values are safe and lead to lower operative times, bleeding, and post-operative transfusions.

Strategies for Prevention and Management of Bleeding Following Pediatric Cardiac Surgery on Cardiopulmonary Bypass: A Scoping Review.

We aimed to systematically describe, via a scoping review, the literature reporting strategies for prevention and management of mediastinal bleeding post pediatric cardiopulmonary bypass surgery. MEDLINE, EMBASE, PubMed, and Cochrane CENTRAL Register. Two authors independently screened publications from 1980 to 2016 reporting the effect of therapeutic interventions on bleeding-related postoperative outcomes, including mediastinal drain loss, transfusion, chest re-exploration rate, and coagulation variables. Inclusions: less than 18 years, cardiac surgery on cardiopulmonary bypass. Data from eligible studies were extracted using a standard data collection sheet. Overall, 299 of 7,434 screened articles were included, with observational studies being almost twice as common (n = 187, 63%) than controlled trials (n = 112, 38%). The most frequently evaluated interventions were antifibrinolytic drugs (75 studies, 25%), blood products (59 studies, 20%), point-of-care testing (47 studies, 16%), and cardiopulmonary bypass circuit modifications (46 studies, 15%). The publication rate for controlled trials remained constant over time (4-6/yr); however, trials were small (median participants, 51; interquartile range, 57) and overwhelmingly single center (98%). Controlled trials originated from 22 countries, with the United States, India, and Germany accounting for 50%. The commonest outcomes were mediastinal blood loss and transfusion requirements; however, these were defined inconsistently (blood loss being reported over nine different time periods). The majority of trials were aimed at bleeding prevention (98%) rather than treatment (10%), nine studies assessed both. Overall, this review demonstrates small trial sizes, low level of evidence, and marked heterogeneity of reported endpoints in the included studies. The need for more, higher quality studies reporting clinically relevant, comparable outcomes is highlighted. Emerging fields such as the use of coagulation factor concentrates, goal-directed guidelines, and anti-inflammatory therapies appear to be of particular interest. This scoping review can potentially guide future trial design and form the basis for therapy-specific systematic reviews.

A need for speed? Bypass time and outcomes after isolated aortic valve replacement surgery.

To determine in the modern era if cardiopulmonary bypass (CPB) time has a significant effect on postoperative morbidity, mortality and long-term survival in patients undergoing isolated aortic valve replacement (AVR) surgery. Analysis of a prospectively collected cardiac surgery database was performed. Uni- and multivariate analysis on the need of resternotomy for bleeding, mediastinal blood loss, intensive care unit (ICU) length of stay, hospital length of stay, in-hospital mortality and long- term survival was performed. Only patients with a cross-clamp time <90 min were analysed to exclude technical issues confounding the results. A total of 1863 isolated first-time AVR procedures were analysed, with an in-hospital mortality rate of 2.4%. The rate of long-term follow-up achieved was 100%. Univariate analysis revealed that CPB time (minutes) had no significant effect on resternotomy (P = 0.5), creatinine kinase muscle-brain isoenzyme (CKMB) release (P = 0.8) and long-term survival (P = 0.06), but was significantly associated with mediastinal blood loss (P = 0.01), ICU length of stay (P = 0.02), hospital length of stay (P = 0.03) and in-hospital mortality (P < 0.001). Multivariate analysis identified that bypass time (min) was a significant factor associated with mediastinal blood loss (P < 0.001), ICU length of stay (P = 0.01), postoperative length of stay (P < 0.001) and in-hospital mortality (odds ratio [OR] 1.02, 95% CI 1.01-1.04, P = 0.01), but not long-term survival. Multivariate analysis identified that era of surgery had no significant effect on CKMB release (P = 0.2), mediastinal blood loss (P = 0.4) and in-hospital mortality (P = 0.9), but the latter era of this study was significantly associated with a reduced postoperative length of stay (P < 0.001), reduced ICU length of stay (P < 0.001), reduced need for resternotomy for bleeding (OR 0.62, 95% CI 0.41-0.94, P = 0.02) and improved long-term survival (hazard ratio 0.76, 95% CI 0.59-0.96, P = 0.02). Adjusting for era made no difference with respect to the above study findings. Despite improvements over time with regard to morbidity, mortality and long-term survival, CPB time remains a significant factor determining mediastinal blood loss, ICU and hospital length of stay, and in-hospital mortality.

Safety and efficacy of caproamin fides and tranexamic Acid versus placebo in patients undergoing coronary artery revascularization.

Introduction: Excessive fibrinolysis contributes to post-cardiopulmonary bypass bleeding. Tranexamic Acid (TXA) and Caproamin Fides are synthetic lysine analogues that inhibit plasminogen-fibrin binding. The present study aimed to compare TXA and Caproamin Fides versus placebo in patients undergoing elective coronary artery revascularization. Methods: We analyzed perioperative data of 300 adult patients undergoing coronary artery revascularization. Patients were randomly allocated to receive TXA (n=100), Caproamin Fides (n=100) or placebo (n=100) during perioperative time. Mediastinal bleeding during the first 24 hours post-operation, transfusion requirement and post-surgical complications were assessed. Results: Most descriptive and intra-operative parameters were well comparable between the 3 study groups. Except for mean number of packed red blood cell (PRBC) units transfused during ICU stay (P=0.01), patients in the Caproamin Fides and TXA groups did not show any statistically significant differences regarding transfusion of blood products during peri-operative period. There was no evidence of a significant difference in mediastinal blood loss during the first 24 hours post-operation between the patients receiving TXA or placebo, while patients in the Caproamin Fides group had significantly lower mediastinal bleeding than the other 2 groups (Caproamin Fides vs. placebo, P=0.002, <0.001 and <0.001 at 6, 12 and 24 hours post-operation; Caproamin Fides vs. TXA, P=0.009, 0.003, <0.001 at 6, 12 and 24 hours post-operation). The incidence of postoperative complications were comparable between Caproamin Fides and TXA groups (P>0.05). Conclusion: In conclusion, Caproamin Fides seems to be superior to TXA regarding the blood saving effects in patients undergoing coronary artery revascularization.

Coagulation Effects of Hydroxyethylstarch Versus Modified Fluid Gelatin When Used as Normovolemic Hemodilution Solutions During Cardiac Surgery

summary Objective: The aim of this study to examine the effects of hydroxyethyl starch and gelatin solutions used for acute normovolemic hemodilution on coagulation during coronary artery bypass surgery. Material and Method: Seventy-two patients undergoing elective coronary artery bypass graft surgery randomly received no hemodilution (control), or 6% HES 200/0.5 (n=24) or 4% gelatin solution (n=24) for acute normovolemic hemodilution before cardiopulmonary bypass. Thromboelastography parameters were measured before (T0) and after (T1) acute normovolemic hemodilution, and one (T2) and four (T3) hours after separation from CPB. Results: The R (reaction) time in HES was significantly longer than in controls at T(2) (p=0.03). The K (coagulation) values in group HES and GEL were significantly longer than in controls at T(2) and T(3) (p=0.02 and 0.03, respectively). Rapidity of clot formation (alpha angle) was significantly smaller in HES and GEL compared to controls (p=0.01 and p=0.02, respectively). Maximum amplitudes in HES and GEL were not significantly different than cont rols at T(2) (p=0.3 and 0.9, respectively). At T2, three patients in GEL (but none in HES) showed clotlysis at 30 min (p=0.1). GEL and HES received fewer units of erythrocyts compared to controls(p<0.001); however, use of fresh frozen plasma was not significantly different than in controls. Mediastinal blood loss was greater in group HES than in controls (p<0.05). Conclusion: Performing acute normovolemic hemodilution with HES and GEL solutions caused significant change in co agulation state by thromboelastography, reduced the need for errytrocyt. Regarding the increase in mediastinal chest drainage, we concluded that HES may not be safety in patients undergoing coronary surgery.

J-shaped versus median sternotomy for aortic valve replacement with minimal extracorporeal circuit

Objectives. Minimal access Aortic Valve Replacement (AVR) has been demonstrated to have beneficial effects over median sternotomy. Minimal extracorporeal circulation (MECC) has been shown to have less deleterious effects than conventional cardiopulmonary bypass. We describe for the first time AVR via upper J-shaped partial sternotomy compared to median sternotomy using MECC. Methods. Prospectively collected pre-operative, intra-operative, post-operative and follow-up data from 104 consecutive patients who underwent minimal access AVR were compared to 72 consecutive patients undergoing median sternotomy using MECC during the same period (January 2007 to December 2009). Results. No significant differences were found in patient's characteristics or intra-operative data with the exception of pre-existing pulmonary disease. The mean cardiopulmonary bypass (86 ± 18 min vs. 78 ± 15 min, p = 0.0079) and cross-clamp times (65 ± 13 min vs. 59 ± 12 min, p = 0.0013) were significantly shorter in the median sternotomy group. Mediastinal blood loss (397 ± 257 ml vs. 614 ± 339 ml, p < 0.0001) and ventilation time (8 ± 6.9 h vs. 11 ± 16.5 h, p = 0.0054) were significantly less in the minimal access group. No differences were seen in transfusion requirements, inotropic support, intensive care unit (ICU) stay, total hospital stay, post-operative haemoglobin drop, major events or mortality. Quality of life scores after discharge demonstrated less pain with a quicker recovery and return to daily activities in patients receiving J-shaped sternotomy. Conclusions. Minimal access AVR using MECC is feasible and provides excellent clinical results. Less pain and quicker recovery was experienced among patients in this group.

Aortic Root Replacement Using a Biovalsalva Prosthesis in Comparison to a “Handsewn” Composite Bioprosthesis

The Biovalsalva aortic root prosthesis incorporates an Elan porcine stentless biological aortic valve suspended within a triple-layered vascular conduit with preformed aortic sinuses of Valsalva. This study compared implantation of the Biovalsalva prosthesis with a "handsewn" composite bioprosthetic graft (CE Perimount bovine bioprosthesis anastomosed to a gelatin-impregnated gelweave Dacron graft). Between December 2004 and January 2009, 39 patients underwent elective or urgent aortic root replacement (modified Bentall procedure with coronary button reimplantation) using a Biovalsalva (n = 21) or a handsewn bioprosthesis (n = 18) for aortic root dilatation. There was no significant difference in the preoperative variables between the two study groups including age (70.7 +/- 1.7 vs. 67.6 +/- 2.9 years, p > 0.05). There was no in-hospital mortality. Three patients in each group underwent concomitant aortic hemi-arch replacement. Patients who underwent Biovalsalva implantation had a reduced need for transfusion of blood (1.25 +/- 0.32 vs. 3.17 +/- 0.71 units, p < 0.05) and fresh frozen plasma (2.78 +/- 0.39 vs. 1.85 +/- 0.31, p < 0.05), and reduced mediastinal blood loss (416 +/- 52 vs. 583 +/- 74 mL, p < 0.05) compared to those with a handsewn bioprosthesis. Cardiopulmonary bypass time (141 +/- 6 vs. 170 +/- 17 minutes, p = NS) and aortic cross-clamp time (113 +/- 6 vs. 115 +/- 7 minutes, p = NS) were similar. Postoperative echocardiography demonstrated excellent hemodynamic function of the Biovalsalva prosthesis (mean size 25.1 +/- 0.4 mm valved conduit) with a peak pressure gradient of 26.2 +/- 1.9 mmHg and no or trivial valvular regurgitation. The Biovalsalva prosthesis should be considered for patients requiring a biological aortic root replacement. It offers an "off-the-shelf" preassembled composite biological valve conduit with excellent hemostatic and hemodynamic properties.

Effects of cell saver autologous blood transfusion on blood loss and homologous blood transfusion requirements in patients undergoing cardiac surgery on- versus off-cardiopulmonary bypass: a randomised trial☆

Off-pump CABG is potentially associated with reduced intraoperative blood loss and homologous blood transfusion in comparison to on-pump CABG. In this randomised controlled study we investigated the effects of autologous cell saver blood transfusion on blood loss and homologous blood transfusion requirements in patients undergoing CABG on- versus off-CPB. Eighty patients were randomised into one of four groups: (A) on-CPB with cell saver blood transfusion (CSBT), (B) on-CPB without CSBT, (C) off-pump with CSBT and (D) off-pump without CSBT. Volume of intraoperative autologous blood transfusion, postoperative mediastinal blood loss and homologous blood transfusion requirements were measured. Homologous blood was transfused when haemoglobin concentration fell below 8 g/dl postoperatively. Pre- and postoperatively prothrombin time and partial thromboplastin time were measured. Preoperative patient characteristics were well matched among the four groups. The amount of salvaged mediastinal blood available for autologous transfusion was significantly higher in the on-pump group (A) compared to the off-CPB group (C) (433+/-155 ml vs 271+/-144 ml, P=0.001). Volume of homologous blood transfusion was significantly higher in group B vs groups A, C and D (595+/-438 ml vs 179+/-214, 141+/-183 and 230+/-240 ml, respectively, P<0.005). The cell saver groups (A and C) received significantly less homologous blood than the groups without cell saver (160+/-197 ml vs 413+/-394 ml, respectively, P<0.005). Patients undergoing off-CPB surgery received significantly less homologous blood than those undergoing on-CPB CABG irrespective of cell saver blood transfusion (184+/-214 ml vs 382+/-397 ml, P<0.05). Postoperative blood loss was similar in the four groups (842+/-276, 1023+/-291, 869+/-286 and 903+/-315 ml in groups A to D, respectively, P>0.05). Clotting test results revealed no significant difference between the groups. There was no significant difference in postoperative morbidity between groups. Off-pump CABG is associated with significant reduction in intraoperative mediastinal blood loss and homologous transfusion requirements. Autologous transfusion of salvaged washed mediastinal blood reduced homologous transfusion significantly in the on-CPB group. Cell saver caused no significant adverse impact on coagulation parameters in on- or off-CPB CABG. Postoperative morbidity and blood loss were not affected by the use of CPB or autologous blood transfusion. We recommend the use of autologous blood transfusion in both on- and off-pump CABG surgery.

Can extra protamine eliminate heparin rebound following cardiopulmonary bypass surgery?

Abstract Objectives Heparin rebound, the reappearance of anticoagulant activity after adequate neutralization with protamine, is thought to contribute to excessive postoperative bleeding after cardiac surgery. We have previously demonstrated that a significant amount of heparin is bound nonspecifically to plasma proteins and is incompletely neutralized by protamine. The aim of this study was to investigate whether clinically important bleeding attributable to heparin rebound can be eliminated by infusion of small amounts of additional protamine for 6 hours postoperatively and whether this treatment can reduce mediastinal blood loss. Methods Three hundred patients undergoing elective cardiac surgery were randomized to receive either a continuous infusion of protamine sulphate (25 mg/h for 6 hours) postoperatively or saline placebo. Serial blood samples were obtained to measure thrombin clotting time and anti-factor Xa activity. Heparin bound nonspecifically to plasma proteins was measured after displacement with a chemically altered heparin with low affinity to antithrombin. Mediastinal blood loss and transfusion requirements were recorded. Results Heparin rebound was demonstrated in every patient in the placebo group as reflected by increased thrombin clotting time, anti-factor Xa activity, and protein-bound heparin between 1 and 6 hours after surgery. In contrast, heparin rebound was eliminated in the protamine infusion group. The thrombin clotting time was normalized and both heparin concentration and protein-bound heparin were almost undetectable ( P Conclusions Postoperative protamine infusion was able to almost totally abolish heparin rebound. In the context of this study, protamine infusion resulted in reduced postoperative bleeding but the magnitude was insufficient to alter transfusion requirements.

Can extra protamine eliminate heparin rebound following cardiopulmonary bypass surgery?

Objectives Heparin rebound, the reappearance of anticoagulant activity after adequate neutralization with protamine, is thought to contribute to excessive postoperative bleeding after cardiac surgery. We have previously demonstrated that a significant amount of heparin is bound nonspecifically to plasma proteins and is incompletely neutralized by protamine. The aim of this study was to investigate whether clinically important bleeding attributable to heparin rebound can be eliminated by infusion of small amounts of additional protamine for 6 hours postoperatively and whether this treatment can reduce mediastinal blood loss. Methods Three hundred patients undergoing elective cardiac surgery were randomized to receive either a continuous infusion of protamine sulphate (25 mg/h for 6 hours) postoperatively or saline placebo. Serial blood samples were obtained to measure thrombin clotting time and anti-factor Xa activity. Heparin bound nonspecifically to plasma proteins was measured after displacement with a chemically altered heparin with low affinity to antithrombin. Mediastinal blood loss and transfusion requirements were recorded. Results Heparin rebound was demonstrated in every patient in the placebo group as reflected by increased thrombin clotting time, anti-factor Xa activity, and protein-bound heparin between 1 and 6 hours after surgery. In contrast, heparin rebound was eliminated in the protamine infusion group. The thrombin clotting time was normalized and both heparin concentration and protein-bound heparin were almost undetectable ( P < .001). There was a modest 13% reduction in postoperative bleeding but this did not reduce blood transfusions. No adverse events were attributable to the extra protamine. Conclusions Postoperative protamine infusion was able to almost totally abolish heparin rebound. In the context of this study, protamine infusion resulted in reduced postoperative bleeding but the magnitude was insufficient to alter transfusion requirements.

A comparison of plateletworks™ and platelet aggregometry for the assessment of aspirin-related platelet dysfunction in cardiac surgical patients

Objective: To compare the assessment of aspirin-related platelet dysfunction using Plateletworks™ (Helena Laboratories, Beaumont, TX), a new point-of-care platelet function analyzer, with turbidometric platelet aggregometry, in cardiac surgical patients. Design: Prospective observational study. Setting: University-affiliated teaching hospital. Participants: Fifty consecutive adult patients undergoing elective cardiac surgery for coronary artery bypass grafting or cardiac valve replacement. Interventions: None. Measurements and Main Results: Platelet function was assessed by Plateletworks™ and turbidometric platelet aggregometry before the commencement of anesthesia. Collagen, 10 μg/mL, was used as the agonist for both techniques. The area under the receiver-operator curve for the identification of recent aspirin ingestion (≤48 hours v ≥72 hours) using Plateletworks™ was 0.58 (95% confidence interval [CI] 0.42–0.75) versus 0.77 (95% CI 0.61–0.95) for turbidometric platelet aggregometry. The Spearman correlation coefficient (ρ) between preoperative Plateletworks™ and postoperative mediastinal blood loss was 0.07 ( p = 0.58), and between preoperative turbidometric platelet aggregometry and postoperative mediastinal blood loss was −0.31 ( p = 0.03). On completion of surgery, the correlation coefficients were 0.14 ( p = 0.34) and −0.29 ( p = 0.08), respectively. Conclusion: These findings suggest that Plateletworks™ is of limited use for the detection of aspirin-related platelet defects in cardiac surgical patients.

Does the platelet function analyser (PFA-100®) predict blood loss after cardiopulmonary bypass?

This study was designed to determine if a new point-of-care test (PFA-100) platelet function analyser) that assesses platelet function predicts blood loss after cardiac surgery. and results. Blood samples from 70 patients were drawn before and after cardiopulmonary bypass (CPB) for PFA-100 measurements. The system consists of a cartridge in which a membrane and an aperture are coated with either collagen/adenosine-5'-diphosphate or collagen/epinephrine. The instrument determines the time required for full occlusion of the aperture (closure time). We observed a weak correlation between pre-CPB collagen/epinephrine closure time and second-hour mediastinal blood loss (r=0.34, P=0.01). The sensitivity and positive predictive value of the PFA-100 measurements were comparable to platelet count for predicting excessive bleeding after CPB (75 and 27% vs 100 and 25%, respectively). The PFA-100 is a logical test for detecting patients who could have excessive bleeding after CPB. However, the PFA-100 was not able to separate patients at low risk of subsequent bleeding from those who had substantial bleeding.

Low-dose postoperative aprotinin reduces mediastinal drainage and blood product use in patients undergoing primary coronary artery bypass grafting who are taking aspirin: A prospective, randomized, double-blind, placebo-controlled trial

Background: Although low-dose aprotinin administered after cardiopulmonary bypass has been reported to reduce mediastinal blood loss and blood product requirements in patients not taking aspirin, it is unknown whether low-dose postoperative aprotinin has any beneficial effects in patients undergoing coronary artery bypass operations who are at high risk of excessive postoperative bleeding and increased transfusion requirements because of aspirin use until just before the operation. Methods: Fifty-five patients undergoing primary coronary artery operations with cardiopulmonary bypass who continued taking aspirin (150 mg/d) until the day before the operation were enrolled in a prospective, randomized, double-blind trial to receive a single dose of either placebo (n = 29) or 2 × 10 6 kallikrein inhibiting units of aprotinin (n = 26) at the time of sternal skin closure. Results: Patients in the aprotinin group had a lower rate (28 ± 18 vs 43 ± 21 mL/h [mean ± standard deviation], P < .005) and total volume of mediastinal drainage (955 ± 615 vs 1570 ± 955 mL, P < .007), as well as a shorter duration of mediastinal drain tube insertion (24.4 ± 13.8 vs 31.3 ± 16.5 hours, P < .05). In addition, a smaller proportion of patients receiving aprotinin required a blood product (31% vs 62%, P = .03), resulting in a reduction in the use of packed cells by 47% ( P = .05), platelets by 77% ( P = .01), fresh frozen plasma by 88% ( P = .03), and total blood products by 68% ( P = .01) in this group. Conclusions: These results suggest that postoperative administration of low-dose aprotinin in patients taking aspirin until just before primary coronary artery operations with cardiopulmonary bypass not only reduces the rate and total amount of postoperative mediastinal blood loss but also lowers postoperative blood product use.

The Relation Between the Platelet-Activated Clotting Test (HemoSTATUS) and Blood Loss After Cardiopulmonary Bypass

Background: Platelet dysfunction is one of several major causes of bleeding after cardiopulmonary bypass. A timely, simple, point-of-care determinant of platelet function recently became available for clinical use. Adding platelet-activating factor to conventional activated clotting time methods (platelet-activated clotting test [PACT]) produces rapid results (<15 min) and may yield a measure of platelet responsiveness and whole-blood procoagulant activity. Methods: Blood samples were drawn from 100 patients after cardiac surgery on their arrival in the intensive care unit for PACT, platelet count, prothrombin time (PT), and activated partial thromboplastin time (aPTT). Cumulative blood loss at 4, 8, and 12 h after arrival in the intensive care unit and perioperative transfusion requirements were quantitated. Coagulation tests and mediastinal blood loss were compared using the Spearman rank test and Pearson correlation. The sensitivity and specificity of the laboratory tests for predicting blood loss were analyzed using the receiver operating characteristic method. Results: The PT was the only test that correlated with blood loss at 4, 8, and 12 h. The PACT did not correlate with blood loss at 4, 8, or 12 h, nor did the PACT correlate with the PT or the aPTT. The sensitivity and specificity of the PACT were less than those of the PT in predicting blood loss. Only the PT correlated with platelet and fresh frozen plasma transfusion. Conclusions: The PT correlated with blood loss and transfusion requirements and was superior to PACT, aPTT, and platelet count for predicting excessive blood loss after cardiopulmonary bypass.

Emergency coronary bypass grafting for failed percutaneous coronary artery stenting: increased costs and platelet transfusion requirements after the use of abciximab

The adjunctive use of abciximab (ReoPro), a platelet glycoprotein IIb/IIIa receptor antagonist, with aspirin as pretreatment for percutaneous coronary artery stenting (PTCS) has risen dramatically. 2 Reports on the outcomes of patients who require emergency coronary bypass grafting (CABG) for unsuccessful PTCS are scarce. This report documents three cases. Table I outlines cardiopulmonary bypass (CPB), hematologic, and coagulation assays. All patients had received aspirin (300 mg) and abciximab (0.25 mg/kg/5 min bolus and 9 mg/500 ml normal saline solution at 10 mg/min intravenous infusion) before the operation. All had a profound bleeding diathesis evident from skin incision and persisting for 4 to 5 hours after the operation. Patients PATIENT 1. A 38-year-old man had acute stent thrombosis 14 days after PTCS to the left anterior descending coronary artery. Cardiogenic shock ensued, necessitating emergency CABG. Ticlopidine (Ticlid) at 250 mg twice a day had been continued since the original PTCS. CABG with a left internal thoracic artery graft to the left anterior descending coronary artery and a saphenous vein graft to a first diagonal was performed. After reversal of heparinization, 5 units of platelets were given and the chest was closed. By 60 minutes, the mediastinal blood loss was 1500 ml. At resternotomy, no specific surgical source was evident. A 1.5 mg dose of 1-deamino-8-Darginine vasopressin (Minirim) and a 4 3 10 kallikrein activation unit (KIU) dose of aprotinin (Trasylol) were given intravenously. An additional 1900 ml blood loss occurred during the next 24 hours. The patient was discharged on postoperative day 10. PATIENT 2. A 73-year-old man in cardiogenic shock with intraaortic balloon pump support was referred for operation with a postinfarct inferior ventricular septal rupture; PTCS to the proximal right coronary artery had been performed. The operation entailed polyethylene terephthalate (Dacron) patch closure of the ventricular septal defect and placement of four venous coronary bypass grafts. Because of the previous experience, intravenous aprotinin (“high” Hammersmith dose [7 3 10 KIU]) was given at induction, and after CPB 10 units of platelets were given. This patient died of low cardiac output syndrome 96 hours after the operation. PATIENT 3. A 39-year-old woman, in cardiogenic shock from an evolving anterolateral acute myocardial infarction after PTCS to the circumflex coronary artery required emergency CABG. A left internal thoracic artery graft to the left anterior descending coronary artery and two additional venous bypass grafts were performed. “High” Hammersmith dose aprotinin was used (total 5 3 10 KIU); after CPB, 10 units of platelets were also given. The patient was discharged home 6 days after the operation. Discussion. This limited experience focuses attention on the potential impact of abciximab on patients undergoing emergency CABG; the message is sharp. In all three cases, results of history, physical examination, and hematologic and coagulation assays were normal before the operation, yet perioperative blood loss was in excess of what was expected. Aprotinin in the “high” Hammersmith dose and immediate, repeated platelet transfusions after CPB appear necessary and effective in reducing mediastinal blood loss. Abciximab use is based on the reduction in the 30-day primary end point (death, acute myocardial infarction, revascularization) reported by the EPIC (placebo 12.8% vs treated 8.5%), EPILOG (placebo 11.7% vs treated 5.2%), and CAPTURE (placebo 15.9% vs treated 11.3%) trials. 2 Only the EPIC trial reported on patients requir-

Mediastinitis after aorto-coronary bypass surgery.

To identify risk factors in 60 cases of mediastinitis amongst 2512 patients (2.3%) subjected to isolated coronary bypass surgery from March 1988 through December 1995, treated by a closed irrigation/drainage system. The mean age of the 60 patients was 56.9 +/- 6.8 years (45-81 years) and 55 (91.6%) were male. Early mediastinal reexploration was performed in all cases immediately after the diagnosis of mediastinitis, with debridement of necrosed tissues, followed by implantation of a closed-circuit irrigation system of the mediastinum constituted by irrigation catheter and drain, closure of the sternum and skin, and specific systemic antibiotic therapy. The mean interval between the original surgery and reexploration was 9.4 days (range 6-14 days). No patient required more extensive procedures, namely omental or muscular flaps. Twenty potential risk factors in patients with mediastinitis, including diabetes mellitus, obesity, coexistence of peripheral vascular disease, decreased LV function, use of inotropes, mediastinal blood drainage and utilization of double IMA, were compared with the group without mediastinitis. Mean cardiopulmonary bypass time was 74.1 +/- 8.1 min, anesthetic time 3.5 +/- 0.8 h and postoperative mechanical ventilation 18 +/- 3 h. A total of 23 patients (38.3%) received one IMA and 35 (58.3%) two IMAs. In the postoperative period, 7 of the 60 patients (11.6%) had required inotropes because of low output. Mediastinal blood loss was 1112cc +/- 452cc and 9 patients (15%) were transfused. Cultures were positive in 40 cases (66.6%) and the most frequent infecting agent was the Staph. epidermidis in 25 cases (62.5%), followed by Candida albicans and Enterobacter and Serratia species (7.5% each); 1 patient (1.7%) died and 9 (15%) had renal failure. The irrigation/drainage was maintained for a mean of 9.1 days (5-83 days). Patients with mediastinitis had a significantly higher prevalence of diabetes (41.6% vs. 18.8%; P < 0.01), obesity (48.3% vs. 15.2%; P < 0.001), peripheral vascular disease (11.6% vs. 4.0%; P < 0.05), but a lower incidence of poor LV function (18.3% vs. 32.7%; P < 0.05). A double IMA was used more frequently in patients who had mediastinitis (58.3% vs. 23.5%; P < 0.001) Diabetes mellitus, obesity, co-existence of peripheral vascular disease and use of double IMA are risk factors for mediastinitis after coronary artery surgery. The efficacy of the closed method of treatment with a mediastinal irrigation/drainage system was increased with early diagnosis and reintervention.

Does the platelet-activated clotting test (HemoSTATUS) predict blood loss and platelet dysfunction associated with cardiopulmonary bypass?

Platelet dysfunction is a major cause of bleeding after cardiopulmonary bypass (CPB). No timely, simple, point-of-care determinant of platelet function is available for clinical use. Adding platelet-activating factor to conventional activated clotting time methods (platelet-activated clotting test [PACT]) (HemoSTATUS; Medtronic, Inc., Parker, CO) produces rapid results (<3 min) and may yield a measure of platelet responsiveness and whole blood procoagulant activity. Blood samples were drawn for PACT, platelet count, prothrombin time, activated partial thromboplastin time, and thromboelastogram (TEG) from 200 patients undergoing cardiac surgery. The PACT significantly decreased from the baseline to postprotamine time interval (P < 0.001). The PACT correlated with 4-h mediastinal blood loss (r = -0.30, P = 0.014). The TEG maximum amplitude also correlated with 4-h mediastinal blood loss (r = -0.32, P = 0.003). The PACT had a sensitivity and specificity comparable to routine laboratory coagulation tests in predicting blood loss. The TEG maximum amplitude, however, was more predictive than both the PACT and routine coagulation tests in this respect. The PACT may be a useful indicator of platelet responsiveness or whole blood procoagulant activity, but we did not find it superior to other tests of coagulation function for predicting excessive blood loss after CPB.