Clotting and fibrinolytic disturbance during lung transplantation: effect of low-dose aprotinin. Groningen Lung Transplant Group

Incidence of Massive Transfusion and Overall Transfusion Requirements During Lung Transplantation Over a 25-Year Period

OBJECTIVE

To establish the incidence of massive transfusion and overall transfusion requirements during lung transplantation, changes over time, and association with outcome in relation to patient complexity.

DESIGN

Retrospective cohort study.

SETTING

University hospital.

PARTICIPANTS

All 514 adult patients who underwent transplantation from 1990 until 2015.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Patient records and transfusion data, divided into 5-year intervals, were analyzed. The incidence of massive transfusion (>10 units of red blood cells [RBCs] in 24 h) was 27% and did not change over time, whereas the median (interquartile range) transfusion requirement in the whole cohort decreased from 8 (5-12) to 3 (0-10) RBCs (p < 0.001). In patients transplanted from the intensive care unit, the incidence of massive transfusion increased over time from 25% to 54% (p = 0.04) and median transfusion requirements from 4.5 (3-8.5) units to 14.5 (5-26) units of RBCs (p = 0.03). Multivariable analysis showed that circulatory support, pulmonary hypertension, re-transplantation, cystic fibrosis, Eisenmenger syndrome, bilateral transplantation, and low body mass index were associated with massive transfusion. Patients with massive transfusion had more primary graft dysfunction grade III at 0, 24, 48, and 72 hours (p < 0.001), higher 30-day mortality (13% v 4%; p < 0.001), and lower 5-year survival (hazard ratio 3.67 [95% confidence interval 1.72-7.85]; p < 0.001).

CONCLUSION

The incidence of massive transfusion did not change over time, whereas transfusion requirements in the whole cohort decreased. In patients transplanted from the intensive care unit, massive transfusion and transfusion requirements increased. Massive transfusion was associated with poor outcome.

Overview of lung transplantation

Although significant gains have been made in improving lung function and survival in cystic fibrosis (CF), ultimately respiratory failure is the leading cause of mortality in these patients. For CF patients with end stage lung disease, lung transplantation is an option for treatment. The field of lung transplantation has progressed markedly in the last 20 years. Nonetheless it remains a technically complex and challenging procedure, and patients are at risk for numerous short term and long term complications. Potential transplant recipients must be physically and psychologically prepared for the arduous process involved in lung transplantation. This article will review the history of lung transplantation, indications for transplantation, surgical techniques, and complications of transplantation.

Risk factors for reperfusion injury after lung transplantation

OBJECTIVE

To assess the influence of recipient's and donor's factors as well as surgical events on the occurrence of reperfusion injury after lung transplantation.

DESIGN AND SETTING

Retrospective study in the surgical intensive care unit (ICU) of a university hospital.

METHODS

We collected data on 60 lung transplantation donor/recipient pairs from June 1993 to May 2001, and compared the demographic, peri- and postoperative variables of patients who experienced reperfusion injury (35%) and those who did not.

RESULTS

The occurrence of high systolic pulmonary pressure immediately after transplantation and/or its persistence during the first 48 h after surgery was associated with reperfusion injury, independently of preoperative values. Reperfusion injury was associated with difficult hemostasis during transplantation (p=0.03). Patients with reperfusion injury were more likely to require the administration of catecholamine during the first 48 h after surgery (p=0.014). The extubation was delayed (p=0.03) and the relative odds of ICU mortality were significantly greater (OR 4.8, 95% CI: 1.06, 21.8) in patients with reperfusion injury. Our analysis confirmed that preexisting pulmonary hypertension increased the incidence of reperfusion injury (p<0.01).

CONCLUSIONS

Difficulties in perioperative hemostasis were associated with reperfusion injury. Occurrence of reperfusion injury was associated with postoperative systolic pulmonary hypertension, longer mechanical ventilation and higher mortality. Whether early recognition and treatment of pulmonary hypertension during transplantation can prevent the occurrence of reperfusion injury needs to be investigated.

Optimal time for post-mortem heparinization in canine lung transplantation with non-heart-beating donors

BACKGROUND

We previously reported that post-mortem heparinization by closed-chest cardiac massage is beneficial in lung transplantation from non-heart-beating donors by preventing formation of microthrombi. In this study, we evaluated the optimal time for post-mortem heparinization in canine lung transplantation from non-heart-beating donors.

METHODS

Left lung transplantation was performed in 25 weight-matched pairs of mongrel dogs. Donors were killed with an intravenous injection of potassium chloride and left at room temperature for 2 hours. The cadaver donors were assigned randomly to one of five study groups. In Group H0, heparin sodium (1,000 U/kg) was given intravenously before cardiac arrest. In Groups H10, H30, H45 and H60, heparin sodium (1,000 U/kg) was given intravenously 10, 30, 45 and 60 minutes after cardiac arrest, respectively, followed by closed-chest cardiac massage for 2 minutes. After 2 hours of cardiac arrest, donor lungs were flushed with low-potassium dextran glucose solution and preserved for 60 minutes. After left lung allotransplantation, the right pulmonary artery was ligated, and recipient animals were followed up for 3 hours. Uni- and multivariate repeat analyses were utilized for statistical assessment.

RESULTS

After transplantation, gas exchange was significantly worse in Groups H45 and H60 than in Groups H0, H10 and H30. Thrombin/anti-thrombin III complex concentration during warm ischemia was significantly higher in Groups H30, H45 and H60 than in Groups H0 and H10.

CONCLUSIONS

The optimal time for post-mortem heparinization in lung transplantation from non-heart-beating donors is approximately 30 minutes after cardiac arrest.

Anesthetic Considerations for Lung Volume Reduction Surgery and Lung Transplantation

Anesthetic considerations for lung transplantation and LVRS have been reviewed, with an emphasis on critical intraoperative junctures and decision points. Cognizance of these issues promotes coordinated and optimal care and provides the potential to improve outcome in this particularly high-risk population.

Effects of postmortem heparinization in canine lung transplantation with non–heart-beating donors

OBJECTIVE

Microthrombus formation appears to be one of the major detrimental factors in lung transplantation from non-heart-beating donors. The purpose of this study was to evaluate the effects of postmortem heparinization by closed-chest cardiac massage in a canine model of left single-lung allotransplantation from non-heart-beating donors.

METHODS

Left lung transplantation was performed in 18 weight-matched pairs of mongrel dogs. Donors were killed with an intravenous injection of potassium chloride and left at room temperature for 2 hours. The cadaveric donors were assigned randomly to one of the three groups. In group 1 (n = 6), no heparin was given as a control. In group 2 (n = 6), heparin sodium (1000 U/kg) was administered intravenously before cardiac arrest. In group 3 (n = 6), heparin sodium (1000 U/kg) was administered intravenously 10 minutes after death, then closed-chest cardiac massage was performed for 2 minutes. After 2 hours of cardiac arrest, donor lungs were flushed with low-potassium dextran-glucose solution and preserved for 60 minutes. After left lung transplantation, the right pulmonary artery was ligated, and recipient animals were followed up for 3 hours. Univariate and multivariate repeated analyses were used for statistics.

RESULTS

Both groups 2 and 3 had significantly better gas exchange and lower pulmonary vascular resistance than group 1. Changes in thrombin-antithrombin III complex concentration during the warm ischemia indicated that postmortem heparinization suppressed clotting activation in the donor.

CONCLUSIONS

Postmortem heparinization by cardiac massage is beneficial in lung transplantation from non-heart beating donors by preventing microthrombus formation.

Pharmacological strategies to decrease transfusion requirements in patients undergoing surgery

Surgical procedures are inevitably associated with bleeding. The amount of blood loss may vary widely between different surgical procedures and depends on surgical as well as non-surgical factors. Whereas adequate surgical haemostasis may suffice in most patients, pro-haemostatic pharmacological agents may be of additional benefit in patients with (diffuse) surgical bleeding or in patients with a specific underlying haemostatic defect. In general, surgical haemostasis and pharmacological therapies can be complementary in controlling blood loss. The use of pharmacological therapies to reduce blood loss and blood transfusions in surgery has historically been restricted to a few drugs. Antifibrinolytic agents (aprotinin, tranexamic acid and aminocaproic acid) have the best evidence supporting their use, especially in cardiac surgery, liver transplantation and some orthopaedic surgical procedures. Meta-analyses of randomised, controlled trials in cardiac patients have suggested a slight benefit of aprotinin, compared with the other antifibrinolytics. Desmopressin is the treatment of choice in patients with mild haemophilia A and von Willebrand disease. It has also been shown to be effective in patients undergoing cardiac surgery who received aspirin up to the time of operation. However, overall evidence does not support a beneficial effect of desmopressin in patients without pre-existing coagulopathy undergoing elective surgical procedures. Topical agents, such as fibrin sealants have been successfully used in a variety of surgical procedures. However, only very few controlled clinical trials have been performed and scientific evidence supporting their use is still limited. Novel drugs, like recombinant factor VIIa (eptacog alfa), are currently under clinical investigation. Recombinant factor VIIa has been introduced for the treatment of haemophilia patients with inhibitors, either in surgical or non-surgical situations. Preliminary data indicate that it may also be effective in surgical patients without pre-existing coagulation abnormalities. More clinical trials are warranted before definitive conclusions can be drawn about the safety and the exact role of this new drug in surgical patients. Only adequately powered and properly designed randomised, clinical trials will allow us to define the most effective and the safest pharmacological therapies for reducing blood loss and transfusion requirements in surgical patients. Future trials should also consider cost-effectiveness because of considerable differences in the costs of the available pro-haemostatic pharmacological agents.

Probable allergic reaction to cyclosporin and early formation of thrombi on a pulmonary artery catheter: two unusual complications during bilateral lung transplantation

We describe a patient who had two rare complications (a probable allergic reaction to cyclosporin and the early formation of a right atrial thrombus) during bilateral sequential single lung transplantation performed under the one anaesthetic. The thrombus, discovered at the end of the procedure, was then removed under cardiopulmonary bypass. Peroperative transoesophageal echocardiography was useful in providing critical diagnostic and therapeutic information.

Aprotinin reduces postoperative bleeding and the need for blood products in thoracic surgery: results of a randomized double-blind study

OBJECTIVE

Bleeding complications have been a major concern in certain thoracic surgery operations, especially decortication and pulmonary resection for inflammatory pulmonary infection. Prevention of plasminogen activation and fibrinolysis by aprotinin administration has been shown to reduce perioperative bleeding during operations associated with high blood consumption.

METHODS

Use of blood products (packed red cells, whole blood), chest tube drainage, analgesic requirement, chest tube duration for the patients undergoing major thoracic operations were recorded. In a double blind randomized fashion, patients were assigned to two groups receiving aprotinin (n=51) at a loading dose of 10(6) kallikrein inhibitory units (KIU) followed by an infusion of the same dose during chest closure or receiving placebo (n=52). On a daily basis, red-cell percentages of total fluid from drainage bottles were recorded and using the blood hematocrit level of the patient of the day before, the corrected value for the patient's blood volume equivalent of daily drainage was calculated.

RESULTS

There was a significant reduction in perioperative use of donor blood (0.98+/-0.92 vs. 0.45+/-0.32 unit; P=0.0026), and total chest tube drainage (corrected value for the corresponding blood volume) (28.2+/-36.9 vs. 76.9+/-53.3 ml, P=0.0004) (mean+/-standard deviation) in the aprotinin group. However, aprotinin did not reduce postoperative transfusion or decrease in hematocrit level due to thoracic operations. In high transfusion-risk thoracic surgery patients (patients who underwent decortication, pulmonary resection for inflammatory lung disease and chest wall resection), the perioperative transfusion was only 0.50+/-1.08 units in aprotinin group, compared with 1.94+/-0.52 units in control group (P=0.003). Postoperative transfusion was also reduced in aprotinin administrated group (0.53+/-0.56 vs. 1.38+/-0.97 units; P=0.02). The mean total blood loss was decreased to nearly one third of the blood loss of the control group (41+/-28 ml vs. 121+/-68 ml; P=0.001).

CONCLUSION

Aprotinin significantly reduced perioperative transfusion requirement and postoperative bleeding during major thoracic operations. Aprotinin decreased perioperative transfusion needs. Moreover, patients who were at risk of greater blood loss during and after certain thoracic operations had a greater potential to benefit from prophylactic perioperative aprotinin treatment.

Pulmonary transplantation

Anesthetic technique for pulmonary transplantation varies with recipient's underlying lung disease, procedure performed and regional practice. The pulmonary allograft is vulnerable to mechanical and biochemical injury throughout the harvesting, preservation and engraftment procedures. Mechanisms of allograft injury are reviewed, with suggestions for incorporation of strategies to minimize injury into clinical practice. Particular emphasis is placed on the use of nitric oxide for treatment of reperfusion injury.

Complement activation in coronary artery bypass grafting patients without cardiopulmonary bypass: the role of tissue injury by surgical incision

STUDY OBJECTIVES

Complement activation is a trigger in inducing inflammation in patients who undergo coronary artery bypass grafting (CABG) and is usually thought to be induced by the use of cardiopulmonary bypass (CPB). In this study, we examined whether tissue injury caused by chest surgical incision per se contributes to complement activation in CABG patients.

DESIGN

Prospective study.

SETTING

Thorax center in university hospital.

PATIENTS

Twenty-two patients undergoing CABG without CPB were prospectively divided into two groups: a small chest incision via an anterolateral thoracotomy representing a minimized tissue injury (lateral group, n = 8), and a conventional median sternotomy representing a large tissue injury (median group, n = 14). Biochemical markers indicating complement activation as well as systemic inflammatory response were determined before, during, and after the operation.

MEASUREMENTS AND RESULTS

Plasma concentrations of complement 3a increased in both the lateral and median groups right after chest incision (p < 0.01 and p < 0.05, respectively) and by the end of operation increased only in the median group (p < 0.01). The terminal complement complex 5b-9 did not increase in the lateral group, but it did increase in the median group both after incision and by the end of the operation (p < 0.05 and p < 0.05, respectively). During surgery, complement 4a did not increase, suggesting that it is the alternative rather than the classic pathway that is involved in complement activation by tissue injury. Postoperatively, interleukin-6 production was greater in the median group (p < 0.01) than the lateral group (p < 0.05), suggesting a more pronounced inflammatory response to a larger chest incision.

CONCLUSIONS

Tissue injury caused by surgical incision contributes to complement activation in CABG patients who are operated on without CPB. A small anterolateral thoracotomy is associated with reduced complement activation in comparison with a median sternotomy.

The higher risk of bleeding in lung transplant recipients from bronchoscopy is independent of traditional bleeding risks: results of a prospective cohort study

STUDY OBJECTIVE

To determine whether recipients of lung transplants have a higher risk of bleeding from fiberoptic bronchoscopy (FOB) than other patients who undergo the procedure.

DESIGN

Prospective cohort study.

SETTING

Bronchoscopy services of Johns Hopkins Hospital, a tertiary referral center and Johns Hopkins Bayview Medical Center, a community hospital.

PATIENTS

All adult patients (18 years) who underwent FOB between July 1, 1996 and June 30, 1997 by the full-time pulmonary medicine staff were included. A total of 720 procedures were performed, including 38 in lung transplant recipients.

MEASUREMENTS

Bleeding was assessed by reviewing physician reports of bloody drainage after the procedure and whether the procedure was terminated early for bleeding. Patient reports of hemoptysis were assessed using questionnaires administered pre- and post-FOB. Predictor variables included patient demographics, bleeding parameters (platelets, prothrombin time, and activated partial thromboplastin time), immunosuppressive medications, aspirin use, use of transbronchial biopsy, and the time length of the procedure.

RESULTS

Lung transplant recipients were significantly more likely to have used aspirin prior to FOB (18.4 vs 7.2%, p < 0.05) and to undergo transbronchial biopsy (64.9 vs 26.8%, p < 0.001). Lung transplant patients were more likely to have new or worsened hemoptysis (53.8 vs 24.6%, p < 0.001), to have > 25 mL of blood loss (44.5 vs 17.5%, p < 0.001) and to have the procedure terminated early for bleeding (5.4 vs 1.0%, p < 0.05). In multivariate analysis, predictors of new or worsened hemoptysis included lung transplant, longer procedure time, and older patient age. Independent predictors of greater blood loss included lung transplant, performance of transbronchial biopsy, longer procedure time, and older patient age.

CONCLUSIONS

Lung transplant recipients are at higher risk of bleeding from bronchoscopy than are other patients. This propensity to bleed is independent of coagulation parameters, platelet count, immunosuppressive medication use, aspirin use, or performance of transbronchial biopsy. The higher risk of bleeding should be considered when assessing the risks and benefits of bronchoscopy in lung transplant recipients.

Use of aprotinin in pediatric organ transplantation

BACKGROUND

Pediatric thoracic organ transplantation is associated with an increased risk of perioperative bleeding. Many of these patients are undergoing repeat surgical procedures and in general require cardiopulmonary bypass.

METHODS

This article reviews the efficacy and safety of the serine protease inhibitor aprotinin in improving hemostasis in pediatric transplantation.

RESULTS

A review of the literature and investigations from Children's Hospital of Philadelphia suggest that aprotinin is beneficial in pediatric lung transplantation: high-risk patients do as well as low-risk patients. Aprotinin also appears to be of benefit in redo heart transplantations, particularly in patients who have had previous sternotomy or previous transplantation. Repeat use of aprotinin appears to be safe and does reduce blood loss in retransplantation patients. Use in the pump prime and a maintenance dose of aprotinin may be the most effective protocol. At this time, however, it is uncertain whether aprotinin is valuable in primary heart transplantation in low-risk patients.

CONCLUSIONS

Current practice at Children's Hospital of Philadelphia is to use aprotinin in all lung and heart-lung transplantations and in all redo transplantations: lung, heart-lung, and heart. The use of aprotinin in primary heart transplantations is limited to patients who have had previous sternotomies or thoracotomies.

Perioperative management of patients undergoing lung transplantation

This review focuses on recent developments in the perioperative management of patients undergoing lung transplantation. Relevant current literature and the experience of the Munich Lung Transplant Group were taken into consideration. Recent advances include the use of inhalational nitric oxide for the treatment of early graft dysfunction and the use of aerosolized cyclosporine for the treatment of recurrent and steroid-resistant acute rejection. Opportunistic infections remain a major source of morbidity and mortality in lung transplant recipients.

Aprotinin Fifteen Years Later

Aprotinin, the broad-based bovine serine protease inhibitor, was first used as an antidote against the harmful proteases released through complement-induced neutrophil activation in the early 1980s. Since then, the safety and efficacy of aprotinin have been debated. Even now, fifteen years later, aprotinin's precise mechanism of action and clear indications for use have not been defined. This article discusses what aprotinin is, its role in the contact system of blood, how it improves hemostasis, the effect of temperature on it, its use in clinical practice, and which patients should receive it. The article concludes that aprotinin's hemostatic effects are useful in patients who are at increased risk from bleeding, but that it should not be considered a substitute for surgical skill. Early claims of absolute safety were premature. Risks between high- and low-dose regimens vary significantly, and more study is required. Alternatives to aprotinin such as the less expensive antifibrinolytic agent tranexamic acid are now available, but they also require additional study.