Fibrinogen concentrate in the treatment of severe bleeding after aortic aneurysm graft surgery

Aortic aneurysm graft surgery involving cardiopulmonary bypass is often associated with substantial coagulopathic perioperative bleeding, requiring hemostatic intervention with allogeneic blood products, such as fresh frozen plasma, platelet concentrate, and red blood cells. We conducted a pilot study to determine the effects of fibrinogen concentrate in patients with microvascular bleeding during aortic valve surgery with ascending aorta replacement. Dosing of fibrinogen concentrate was individualized based on thromboelastometry. First-line therapy with fibrinogen concentrate reduced the need for allogeneic blood product support, including transfusions of fresh frozen plasma, platelet concentrate, and red blood cells. Similar results were seen in a second cohort study conducted in patients undergoing thoraco-abdominal aortic aneurysm surgery: patients who received fibrinogen concentrate required significantly less allogeneic blood product support following surgery. These results prompted the initiation of a randomized placebo-controlled trial in patients undergoing thoraco-abdominal aortic aneurysm surgery, aortic valve surgery with ascending aorta replacement, or aortic arch surgery. Results are expected to be published soon. Larger, multicenter studies are needed to determine the exact role of fibrinogen concentrate in the management of perioperative bleeding following cardiac surgery and cardiopulmonary bypass.     

Transfusions, major bleeding, and prevention of venous thromboembolism with enoxaparin or fondaparinux in thoracic surgery

Enoxaparin 40 mg/day (E) or fondaparinux 2.5 mg/day (F) are recommended to prevent venous thromboembolism (VTE) in medical and surgical patients at risk. Over the two years after switching from E to F in our 35-bed department of pulmonology and thoracic surgery, an increase in the number of transfusions was observed. A retrospective explanatory investigation was undertaken. Hospitalised patients in the two years before and after switching from E to F were compared. The files of all transfused patients were reviewed. A blinded independent committee adjudicated major bleeding events. In the investigated time period, the overall transfusion rate increased from 1.8% of 2,989 patients to 3.1% of 3,085 patients (p=0.002). Mean ages (58.4 vs. 59.1 years), proportions of surgical patients (63.6% vs. 58.4%), cancer patients (72.1% vs. 69.5%), and treated patients (≥ 1 dose of E or F: 51.8% vs. 52.5%) were similar. The number of medical patients transfused while receiving E or F did not increase significantly (0.9% vs. 1.3%, RR=1.45 [0.66-3.17], p=0.35). The number of surgical patients transfused postoperatively while receiving E or F increased significantly (0.7% vs. 1.9% of all surgical patients, relative risk [RR]=2.75 [1.45-5.23], p=0.001), including a significant increase in transfusions for major bleeding (0.2% vs. 0.9%, RR=5.97 [1.74-20.4], p<0.001). A multivariate analysis did not find confounding factors. The incidence of symptomatic postoperative pulmonary embolism remained very low (0.05% vs. 0.17%). In conclusion, in thoracic surgery patients, switching from enoxaparin to fondaparinux to prevent VTE was associated with a significant increase in the risk of postoperative major bleeding. A causal relationship appears plausible.     

Heparin assays and bleeding complications in treatment of deep venous thrombosis with particular reference to retroperitoneal bleeding

Bleeding complications occurred in 30 (11%) out of 280 patients who received continuous heparin infusion for deep venous thrombosis (DVT). 22 (8%) had minor while 8 patients (3%) had major bleeding complications (1 intrathoracic [fatal], 2 gastrointestinal and 5 retroperitoneal). Heparin activity, in daily drawn blood samples, was determined by four assays (chromogenic substrate [CS] assay, activated partial thromboplastin time [APTT], thrombin time with citrated plasma [CiTT] and thrombin time with recalcified plasma [CaTT]). The differences in median heparin activity between patients with minor bleeding and patients with no bleeding did not reach significance for any of the tests. In patients with major bleeding, the differences were significant with the CS (p = .011) and the CaTT (p = .030) assays. Patients with retroperitoneal bleeding had significantly increased median activity judged by all four assays: CS (p = .002), CaTT (p = .003), APTT (p = .010), CiTT (p = .029). The difference was most pronounced after four days of heparin treatment, but there was a considerable overlap with patients without bleeding.     

Increased thrombin generation and fibrinogen level after therapeutic plasma transfusion: relation to bleeding

In a clinical setting, fresh frozen plasma (FFP) is transfused to diluted patients with complicated surgery or trauma, as guided by prolonged conventional coagulation times or low fibrinogen levels. However, the limited sensitivity of these coagulation tests may restrict their use in measuring the effect of transfusion and hence predicting the risk of perioperative bleeding. We used the more sensitive, calibrated automated thrombogram (CAT) method to evaluate the result of therapeutic FFP transfusion to 51 patients with dilutional coagulopathy. Thrombin generation was measured in pre- and post-transfusion plasma samples in the presence of either platelets or phospholipids. For all patients, the transfusion led to higher plasma coagulation factor levels, a shortened activated partial thromboplastin time, and a significant increase in thrombin generation (peak height and endogenous thrombin potential). Interestingly, thrombin generation parameters and fibrinogen levels were higher in post-transfusion plasmas from patients who stopped bleeding (n = 32) than for patients with ongoing bleeding (n = 19). Plasmas from 15 of the 19 patients with ongoing bleeding were markedly low in either thrombin generation or fibrinogen level. We conclude that the thrombin generation method detects improved haemostatic activity after plasma transfusion. Furthermore, the data suggest that thrombin generation and fibrinogen are independent determinants of the risk of perioperative bleeding in this patient group.     

Elective surgery on factor VIII inhibitor patients using continuous infusion of recombinant activated factor VII: plasma factor VII activity of 10 IU/ml is associated with an increased incidence of bleeding.

We examined recombinant activated factor VII (rVIIa) administered by continuous infusion to eight patients with inhibitors to factor VIII, undergoing elective surgery. rVIIa was infused at a fixed rate of 16.5 microg/kg/h for a median of 13.5 days (range 1-26). There was effective haemostasis at this infusion rate in only one of two minor procedures and two of six major operations. Three patients experienced excessive bleeding despite plasma factor VII activity around 10 IU/ml. Serious bleeding occurred in two other patients caused by procedural errors unrelated to rVIIa and required re-operation. The median rVIIa clearance on day 1 was 57 ml/h/kg (range 18-100) and on day 3 was 100 ml/h/kg (range 61-200). Clearance on the final infusion day was not significantly different from day 3. The infusion did not induce pathological activation of the coagulation mechanism. The only thrombotic adverse events were two episodes of superficial thrombophlebitis of the infused vein in one subject. In conclusion, the 16.5 microg/kg/h infusion rate reliably achieves plasma factor VII activity levels of 10 IU/ml, but this level does not provide reliable haemostasis.     

Relationship between factor XIII activity, fibrinogen, haemostasis screening tests and postoperative bleeding in cardiopulmonary bypass surgery

We investigated the relationship between factor XIII, fibrinogen, blood coagulation screening tests and postoperative bleeding in 98 patients undergoing cardiopulmonary bypass (CPB) surgery. All patients received aprotinin. Blood samples were collected preoperatively (T1),after termination of CPB (T2),12 h (T3) and 24 h (T4) after surgery to determine FXIII activity, fibrinogen, platelet count, prothrombin time (PT), activated partial thromboplastin time (APTT) and D-dimers (DD). Laboratory results were correlated with the chest tube drainage 24 h after surgery and compared between patients with 24-hour chest tube drain volumes in the lower (Group 1) with those in the upper tertile (Group 3). Median FXIII and fibrinogen levels dropped by 33.9% and 34.2%, respectively, during CPB. No association between FXIII activity and the extent of postoperative bleeding was found. However, chest tube bleeding was significantly correlated with preoperative and postoperative fibrinogen. This was confirmed by comparing Groups 1 and 3. Group 3 patients had significantly lower fibrinogen levels than Group 1 at T1 - T4, although most fibrinogen values were within or above the reference range (medians, g/l: 3.5 vs. 4.0, p = 0.043 at T1; 2.3 vs. 2.7, p = 0.015 at T2; 2.9 vs. 3.3, p = 0.008 at T3; 4.2 vs. 5.2, p = 0.002 at T4). There was also a significant relationship of platelet count, PT and APTT, as measured after CPB (T2), with postoperative chest tube drainage. In conclusion, plasma FXIII activity does not influence postoperative bleeding in patients undergoing CPB surgery. There is however an inverse association between preoperative or postoperative plasma fibrinogen levels and postoperative bleeding. These findings indicate a modulation of postoperative bleeding by fibrinogen levels.     

Clinical and economic consequences of bleeding following major orthopedic surgery

BACKGROUND: Major orthopedic surgery patients who receive antithrombotics as prophylaxis against VTE may be at higher risk of bleeding. The clinical and economic consequences of this complication may be relevant to therapeutic decision-making. OBJECTIVE: To assess the impact of major bleeding following major orthopedic surgery on length of stay (LOS) and inpatient charges. METHODS: Using a database with information on approximately 750,000 admissions annually to 100+ US acute-care hospitals, we identified all patients who underwent major orthopedic surgery between January 1, 1998 and December 13, 2000. Patients were stratified according to whether or not they experienced major postoperative bleeding prior to hospital discharge, defined as (a) fatal bleeding; (b) nonfatal bleeding at critical site; (c) re-operation due to bleeding; and (d) overt bleeding with bleeding index (BI)>or=2, where BI=number of blood units transfused plus pre-bleeding minus post-bleeding hemoglobin (g/dL) values. LOS and total inpatient charges were compared between patients with and without major bleeding. RESULTS: The incidence of major bleeding among 23,518 patients who underwent major orthopedic surgery was 2.6%. In multivariate analyses controlling for differences in baseline characteristics between patients with and without major bleeds, adjusted mean LOS was 1.8 days longer among those with major bleeding (95% CI: 1.5, 2.0) (6.1 days vs. 4.3 days for those without bleeds); adjusted mean total inpatient charges were 7,593 dollars higher (95% CI: 6,622 dollars, 8,646 dollars) (25,669 dollars vs. 18,076 dollars). CONCLUSION: Bleeding following major orthopedic surgery may increase length of stay and total hospital charges and should be an important consideration in choice of VTE prophylaxis.     

The effect of antiepileptic drugs on coagulation and bleeding in the perioperative period of epilepsy surgery: The Cleveland Clinic experience

Antiepileptic drugs (AED) are known to cause coagulation disturbances. We retrospectively analyzed the effect of AED on coagulation parameters in children who underwent craniotomy for epilepsy surgery. A total of 84 children were included. Perioperative coagulation parameters, the number and type of AED, estimated blood loss and the amount of blood products transfused were recorded. The most commonly used AED was lamotrigine. Of all patients, 7.1% were taking valproate. None of the patients showed significantly abnormal prothrombin time, activated partial thromboplastin time, or platelet count preoperatively. Thirty-eight percent of patients were transfused with allogeneic red blood cells and 4.7% of all patients showed significant coagulopathy intraoperatively and postoperatively. We concluded that the number of AED does not appear to be associated with preoperative coagulation disorders or blood transfusion requirements. However, caution should be taken in patients taking AED who undergo complex brain epilepsy surgery due to the potential for significant blood loss.     

Low PAI-1 activity in relation to the risk for perioperative bleeding complications in transurethral resection of the prostate

INTRODUCTION: Low levels of plasminogen activator inhibitor type 1 (PAI-1) have been associated with increased risk for perioperative bleeding in some case reports. The aim of this study was to investigate prospectively whether low PAI-1 activity increases the risk for perioperative bleeding in patients undergoing transurethral resection of prostate, an organ with high fibrinolytic activity. PATIENTS AND METHODS: 62 patients with benign prostatic hyperplasia planned for transurethral resection were included. Blood samples for PAI-1 were taken together with other routine preoperative blood samples 1week before surgery but analyzed after the hospitalization. The intraoperative blood loss was determined by measuring the amount of hemoglobin in the irrigating fluid. The postoperative blood loss was estimated from calculations of hemoglobin mass (Hb mass), which is a product of hemoglobin concentration and blood volume. Hb mass was calculated before surgery and on the day of discharge, and was adjusted for intraoperative blood loss and transfused Hb mass. Bleeding complications were defined as re-operation due to bleeding, more than 40ml intraoperative bleeding/g resected prostatic tissue or postoperative blood loss corresponding to more than 100g of hemoglobin. RESULTS: Bleeding complications were observed in 3 of 4 (75%) patients with low PAI-1 levels, defined as <1U/ml, and in 16 of 58 (28%) patients with PAI-1 levels >1U/ml (P=0.082). After adjustment for resection time, resected prostatic mass and systolic blood pressure this became borderline significant (odds ratio 11.8; 95% confidence interval 1.00-139; P=0.05). CONCLUSION: Low PAI-1 activity may contribute to the risk of bleeding after transurethral resection of the prostate.     

Preoperative prednisone therapy in platelet function disorders

Excessive bleeding during surgical procedures may occur in patients with disorders of platelet function. This report describes a prospective study of preoperative prednisone therapy in preventing excessive post-surgical bleeding in 14 patients with various forms of qualitative platelet defects (“aspirin-like” defect). All patients had a history of excessive bleeding, a prolonged bleeding time, and diminished platelet aggregation with epinephrine and/or collagen. A trial of prednisone therapy was instituted prior to elective surgery. In all cases, the bleeding time was corrected to the normal range of less than 10 minutes. Platelet aggregation abnormalities were, however, unchanged. Surgery performed included dental extractions, and major abdominal, orthopedic, cardiac and ophthalmologic procedures. In no instance was excessive bleeding noted during or following surgery. Platelet transfusions were not needed in these patients. It is concluded that short term prednisone therapy, monitored by the bleeding time, is effective in preventing excessive surgical bleeding in certain patients with platelet function disorders.     

Novel use of an ultrasonic bone-cutting device for endoscopic-assisted craniosynostosis surgery

Purpose

Endoscopic-assisted craniosynostosis surgery is associated with less blood loss and shorter operative times as compared to open surgery. However, in infants who have low circulating blood volumes, the endoscopic approach is still associated with significant blood loss. A major source of blood loss is the bone that is cut during surgery. We discuss the novel use of an ultrasonic bone-cutting device for craniosynostosis surgery, which decreases bone bleeding. This device, which has primarily only been used for spine and skull base surgery, may help reduce blood loss in these infants.

Methods

All patients with single suture craniosynostosis who were operated on with the use of an ultrasonic bone-cutting device were identified. The information retrospectively recorded from patient charts included patient age, suture involved, blood loss, operative times, complications, preoperative hemoglobin, postoperative hemoglobin, length of hospital stay, and follow-up times.

Results

Thirteen patients (12 males, 1 female) underwent surgery with an ultrasonic bone-cutting device during the reviewed period. The average age (±standard deviation) of the patients was 11.8 (±1.6) weeks. Four patients had metopic synostosis and nine patients had sagittal synostosis. The average surgery time was 84 (±13) min. The median (interquartile range) blood loss was 20 (10–70) cc. No patients required blood transfusions. Three patients had dural tears.

Conclusion

We demonstrate the novel use of an ultrasonic bone-cutting device for endoscopic-assisted craniosynostosis surgery. This device limited blood loss while maintaining short operative times for infants with low circulating blood volumes.     

Relationship between factor VII activity and clinical efficacy of recombinant factor VIIa given by continuous infusion to patients with factor VIII inhibitors.

A multicenter prospective study of recombinant activated factor VII (rFVIIa) given by continuous infusion (CI) to treat severe hemorrhages and to handle surgical procedures was carried out. Relations between clinical efficacy, dosages used and levels of FVII coagulant activity (FVII:C) achieved in plasma were also evaluated. Case material included 25 patients with hemophilia (9 children and 16 adults) with high-responding inhibitors and 3 patients with acquired factor VIII inhibitors. Overall, 35 CI courses were given for 10 spontaneous bleeding episodes, 11 major surgical procedures and 14 minor surgical procedures. Bolus doses of 90 to 150 microg/kg (median: 100) were followed by CI given at median rates of 20 microg/kg/h for major surgery and of 17 and 16 microg/kg/h for minor surgery and spontaneous hemorrhages. Satisfactory hemostasis was obtained in 30 of 35 courses (88%). rFVIIa CI was ineffective in 2 hemophiliacs undergoing surgical operations and in another hemophiliac with hemoperitoneum who had to be switched to other treatments (high doses of porcine or human factor VIII concentrates). rFVIIa CI was partially effective in 2 hemophiliacs who had mild local bleeding after minor surgery. The CI rates and the corresponding FVII:C levels in plasma were similar in effective, partially effective and ineffective courses (median rate: 17, 20 and 20 microg/kg/h, respectively; median FVII:C:14, 18 and 18 IU/ml, respectively). A single adverse event was observed, superficial thrombophlebitis. This study confirms that rFVIIa given by CI is effective in a high proportion of patients with factor VIII inhibitors. It also demonstrates that FVII:C levels attained in plasma do not always predict efficacy because similarly high levels were attained during successful treatments and in those that failed.     

Perioperative specific management of blood volume loss in craniosynostosis surgery

Accurate assessment and replacement of blood loss and fluid–electrolyte deficit during craniosynostosis repair is difficult owing to patient size and the diversity of surgical technique. Forty-three patients undergoing primary craniosynostosis repair over a 10-year period were studied retrospectively to determine blood loss and fluid deficit and to assess blood transfusion practices during both intraoperative and postoperative periods. Blood loss was calculated on the basis of estimated red cell mass (ERCM) and fluid-electrolyte imbalance was investigated with blood samplings. Blood transfusion was considered appropriate if the postoperative or posttransfusion ERCM was within 12% of the preoperative value. Estimated fluid requirement (EFR) was used in 4 ml kg^–1 h^–1 except for neonates. Intraoperatively, 80% of all patients were appropriately managed with respect to blood transfusion and EFR. Postoperatively only 20% of the patients receiving transfusions were transfused appropriately. In 23.3% of these patients (10/43) unexpected respiratory distress developed immediately after their recovery from the anesthesia. With the measurement of estimated blood volume and allowable blood loss, appropriate transfusion could be achieved for the successful treatment of the primary craniosynostosis. Received: 16 February 1998     

Hemispheric surgery in children with refractory epilepsy: seizure outcome, complications, and adaptive function

PURPOSE: To describe seizure control, complications, adaptive function and language skills following hemispheric surgery for epilepsy. METHODS: Retrospective chart review of patients who underwent hemispheric surgery from July 1993 to June 2004 with a minimum follow-up of 12 months. RESULTS: The study population comprised 24 children, median age at seizure onset six months and median age at surgery 41 months. Etiology included malformations of cortical development (7), infarction (7), Sturge-Weber Syndrome (6), and Rasmussen's encephalitis (4). The most frequent complication was intraoperative bleeding (17 transfused). Age <2 yr, weight <11 kg, and hemidecortication were risk factors for transfusion. Postoperative complications included aseptic meningitis (6), and hydrocephalus (3). At median follow-up of 7 yr, 79% of patients are seizure free. Children with malformations of cortical development and Rasmussen's encephalitis were more likely to have ongoing seizures. Overall adaptive function scores were low, but relative strengths in verbal abilities were observed. Shorter duration of epilepsy prior to surgery was related significantly to better adaptive functioning. CONCLUSIONS: Hemispheric surgery is an effective therapy for refractory epilepsy in children. The most common complication was bleeding. Duration of epilepsy prior to surgery is an important factor in determining adaptive outcome.     

Efficacy and safety of a prothrombin complex concentrate (Octaplex) for rapid reversal of oral anticoagulation

Bleeding is the most serious adverse event of oral anticoagulants and is a major cause of morbidity and mortality in such patients. Rapid reversal of anticoagulation in bleeding patients or prior to urgent surgery is mandatory. The therapeutic options in these situations include administration of fresh frozen plasma (FFP), and recently of prothrombin complex concentrates (PCCs). However, viral safety and thrombogenicity of PCCs remain issues of concern.

In the present study, we administered Octaplex®, a new solvent/detergent (S/D) treated and nanofiltered PCC, to excessively anticoagulated bleeding patients or to anticoagulated patients facing urgent surgery.

Ten excessively anticoagulated patients with major bleeding and 10 anticoagulated patients awaiting surgery (median age 72.5 (43–83) years, 9 females) received a median dose of 26.1 IU/kg body weight (BW) of Octaplex® for reversal of anticoagulation. Response to Octaplex® was rapid with decline of INR within 10 min after Octaplex® administration (from 6.1±2. to 1.5±0.3). Clinical response was graded as good in most patients (85%) and as moderate in the rest. Octaplex® administration was uneventful in all patients. Following Octaplex® administration, a small increase in F1+2 levels was observed in bleeding patients, whereas D-dimer level did not change significantly.

We conclude that Octaplex® is effective and safe in situations where rapid reversal of anticoagulation is needed.     

The combination of recombinant factor VIIa and fibrinogen correct clotting ex vivo in patient samples obtained following cardiopulmonary bypass surgery

Cardiac surgery involving cardio pulmonary bypass (CPB) may be associated with development of a coagulopathy that increases risk of bleeding. In the present ex vivo study we investigated the influence of fibrinogen and rFVIIa, alone or in combination, on whole blood coagulation thromboelastometry using pre- and postoperative blood samples from 18 consecutive adult patients undergoing CPB surgery. Dynamic thromboelastometric clotting profiles were recorded using citrated whole blood activated with trace amounts of tissue factor (Innovin®, final dilution 1:17000). Blood samples were collected before surgery (control) and postoperative samples were obtained following in vivo neutralization of heparin with protamine sulphate. All blood samples were treated with heparinase to ensure neutralization of possible residual heparin effect. The post-operative blood samples were spiked with buffer, rFVIIa (2 µg/mL), fibrinogen (1 mg/mL), or the combination of rFVIIa and fibrinogen. Despite neutralization of heparin, CPB surgery left a measurable coagulopathy that was thromboelastometrically characterized by prolonged onset of clotting, reduced maximum velocity of clot formation (MaxVel), and decreased maximum clot firmness (MCF). Ex vivo spiking of the postoperative samples with rFVIIa shortened the clotting time. Fibrinogen also shortened the clotting time and, in addition, improved the MaxVel, and MCF. Finally, adding the combination of rFVIIa and fibrinogen to the postoperative samples corrected all thromboelastometric parameters to the preoperative range. In conclusion, the correction of whole blood clotting abnormalities that occurs with rFVIIa and/or fibrinogen suggests that future clinical trials on treatment of bleeding during CPB surgery should study the haemostatic effect of fibrinogen or possibly the combination of rFVIIa and fibrinogen.     

3H-Imipramine binding sites in platelets of hospitalized psychiatric patients

The density of platelet 3H-imipramine binding sites has been proposed as a biological marker in psychiatry. We report the range of platelet 3H-imipramine binding in 55 psychiatric patients and 11 control subjects. All blood samples were withdrawn at 2300 h (on the day of hospital admission for patients). With the use of a slight modification of a previously described 3H-imipramine binding method, a mean B max of 1,510 fmole/mg protein (range: 390-5,560; median: 1,450) and a mean Kd of 2.0 nM (range: 0.6-17.0; median: 1.4) were determined for psychiatric patients. For the controls, a mean B max of 1,590 fmole/mg protein (range: 870-2,570; median: 1,440) and a mean Kd of 1.4 nM (range 0.8-2.4; median 1.4) were determined. When patients were subdivided based on ICD-9 psychiatric diagnoses, no significant differences between distinct subgroups of psychiatric patients with respect to B max or Kd values for platelet 3H-imipramine binding could be established. Similarly, no significant difference between psychiatric patients and controls was obtained.     

The prothrombotic paradox of severe obesity after cardiac surgery under cardiopulmonary bypass

Background

Obesity is suggested to reduce postoperative bleeding in patients undergoing cardiac surgery with cardiopulmonary bypass (CPB) but perioperative hemostasis variations have not been studied. Therefore, we investigated the effects of severe obesity (body mass index [BMI] ≥ 35 kg/m²) on chest tube output (CTO) and hemostasis in patients undergoing cardiac surgery with CPB.

Materials and Methods

We prospectively investigated 2799 consecutive patients who underwent coronary and/or valve surgery using CPB between 2008 and 2012. 204 patients (7.3%) presented a severe obesity.

Results

In the severe obesity group, the 6-h and 24-h CTO were significantly reduced by -21.8% and -14.8% respectively (P < 0.0001) compared with the control group. A significant reduction of the mean number of red blood cell units transfused at 24 h was observed in the severe obesity groups (P = 0.01). On admission to the intensive care unit, a significant increase of platelet count (+ 9.2%; P < 0.0001), fibrinogen level (+ 12.2%; P < 0.0001) and prothrombin time (+ 4.1%; P < 0.01) and a significant decrease of the activated partial thromboplastin time (-4.2%; P < 0.01) were observed in the severe obesity group compared with the control group.In multivariate analysis, severe obesity was significantly associated to a decreased risk of excessive bleeding (24-h CTO > 90th percentile; Odds ratio: 0.37, 95% CI: 0.17 to 0.82). No significant differences were observed regarding postoperative thromboembolic events between the two groups.

Conclusions

Severe obesity is associated with a prothrombotic postoperative state that leads to a reduction of postoperative blood loss in patients undergoing cardiac surgery with CPB.     

Indications for plasma in massive transfusion

The initial aim in massive transfusion (MT) is to supply crystalloids, colloids, and plasma-poor red cell concentrates (RCCs) to maintain normovolemia and oxygen supply. This frequently leads to dilution coagulopathy, which is frequently aggravated and accelerated by hypothermia, acidosis, shock-induced impairment of liver function and disseminated intravascular coagulation (DIC), and increased consumption of clotting factors and platelets at extensive wound sites. Disorders of hemostasis deteriorate the prognosis of massively transfused patients dramatically. Therefore, the second therapeutic objective is the timely administration of plasma and platelet concentrates as required to halt the microvascular bleeding (MVB) induced by impaired hemostasis. Close laboratory monitoring, to include as a minimum platelet count, prothrombin time (PT), activated partial thromboplastin time (APTT), and fibrinogen, is essential to identify hemostatic disorders requiring therapeutic intervention. Coagulopathy promoting microvascular bleeding can be assumed when PT or APTT values exceed 1.5 times mean controls and/or when fibrinogen levels fall below 1.0 g/l. Repeated rapid infusion of 10-15 ml plasma per kg of body weight will be required to raise clotting factor levels significantly and to achieve adequate hemostasis. The turnaround time for obtaining laboratory results and for readying plasma for transfusion must be taken into particular consideration in cases of rapid blood loss.     

Prevalence of claustrophobia and magnetic resonance imaging after coronary artery bypass graft surgery

BACKGROUND: The purpose of this study was to determine the prevalence of claustrophobia in patients undergoing magnetic resonance imaging (MRI) after coronary artery bypass graft (CABG) surgery. METHODS: After IRB approval, we conducted a substudy of a prospective randomized controlled clinical trial of 311 patients evaluating administration of tranexamic acid and early saphenous vein graft patency with MRI after conventional CABG surgery. Chest tube drainage was measured at 6, 12, and 24 hours after surgery. The rate of transfusion and the amount of red blood cells (RBC), fresh frozen plasma (FFP), and platelets transfused were recorded. RESULTS: A total of 237(76%) patients underwent MRI after surgery. 39 (14%, [95% CI, 10.2 to 18.0]) patients experienced severe anxiety caused by a fear of enclosed space in the MRI coil necessitating termination of the procedure. Patients with claustrophobia were on average 5 years younger. They were more likely to have diabetes mellitus and hypertension. Patients with claustrophobia had increased chest tube drainage during the postoperative period. The rate of blood product transfusion was similar between the two groups but patients with claustrophobia who were transfused received significantly more RBC and FFP than patients without claustrophobia. CONCLUSIONS: Postoperative claustrophobia and anxiety, leading to inability to undergo MRI, may be more common than previously described.