Indian Journal of Anaesthesia  
About us | Editorial board | Search | Ahead of print | Current Issue | Past Issues | Instructions
Home | Login  | Users Online: 909  Print this pageEmail this pageSmall font sizeDefault font sizeIncrease font size    




 
EDITORIAL
Year : 2009  |  Volume : 53  |  Issue : 3  |  Page : 265-267 Table of Contents     

Current Guidelines for Blood Conservation in Cardiac Surgery


1 Director, Deptt. Of Anaesthesiology & Critical Care, India
2 Consultant Anaesthesiology and Critical Care, India

Date of Web Publication3-Mar-2010

Correspondence Address:
Yatin Mehta
Director, Deptt. Of Anaesthesiology & Critical Care
India
Login to access the Email id

Source of Support: None, Conflict of Interest: None


PMID: 20640132

Rights and PermissionsRights and Permissions

How to cite this article:
Mehta Y, Sharma J. Current Guidelines for Blood Conservation in Cardiac Surgery. Indian J Anaesth 2009;53:265-7

How to cite this URL:
Mehta Y, Sharma J. Current Guidelines for Blood Conservation in Cardiac Surgery. Indian J Anaesth [serial online] 2009 [cited 2020 Jul 5];53:265-7. Available from: http://www.ijaweb.org/text.asp?2009/53/3/265/60288

Cardiac surgery is associated with excessive bleeding as compared to non-cardiovascular surgery. In many situations excessive bleeding is expected but unexpected bleeding may pose problem during and, or after surgery. Studies have Iound certain predictors Ior bleeding like, increased ale, emergency surely, low body surface area, prolonged cardiopulmonary bypass (CPB) time > 150 minutes, combined intracardiac and bypass surgery, num­ber of bypass grafts (> 4), reoperative surgery and preoperative antiplatelets agent. Between 3% to 14% of patients with significant bleeding require re-exploration. [1] A surgically correctable source ofbleeding is found in 50% - 67% of patients. [2] Bleeding and surgical re-exploration are both independent predictors ol'an adverse outcome. [2] Thus reducing this bleeding is a desirable clinical goal. Although the benefits of red cell blood transfu­sions for managing life-threatening bleeding are clear but allogenic blood product transfusion is consistently asso­ciated with several adverse efiects. [3]

Liberal use ofred blood cells transfusion is associated with increased nosocomial infection and mortality in critically ill patients. [4] Blood transfusion during or after coronary artery bypass graft (CABG) surbely has been shown to be associated with increased long-term mortality. [5]

Current blood conservation practice guidelines suggest that institutions strategy should start with preoperative evaluation to identify high risk patients and appropriate management ol'antiplatelet therapy. In all planned surgery thienopyridines (clopidogrel) should be stopped 5 to 7 days prior to surgeiy except in patients with drug eluting stents, in whom sudden withdrawal of antiplatelets can result in sudden stent thrombosis. Aspirin should only be discontinued in purely elective cases without acute coronary syndrome. The addition ofclopidogrel to aspirin increases postoperative haemorrhage. Yende and Wunderink demonstrated that aspirin and clopidogrel increase postoperative bleeding sevenfold. [6] Heparin is an integral component oftherapy for acute coronary events. Patients receiving low molecular weight heparin (LMWH) within 12 hours o fcardiac surgery have significantly greater blood loss and increased blood transfusion compared with patients receiving intravenous heparin or a dose of LMWH more than 12 hours before operation. Unfractionated heparin is a notable exception in that it is the only agent that may be discontinued shortly before operation or not at all.

Evidence f or transfusion trigger recommends use ofhaemoglobin level and platelets count Ior red cells and platelets transfusion respectively. More advanced measurements such as whole body oxygen-carrying capacity, oxygen consumption, oxygen extraction ratios, and oxygen delivery provide more accurate means to estimate the need for red blood cell transfusions. [7] For postoperative patients and off CPB surgeries guidelines recommend below 7-gm/dl haemoglobin level as transfusion trigger Ior red cells transfusion except in evident cardiac or non-cardiac end organ ischaemia where desirable haemoglobin level is 10 gm/dl. Patients having haemoglobin level more than 10 gm/dl should not be transfused because there is risk related to transfusion without favourable improvement in oxygen transportation. Transfusion trigger is further reduced to 6 gm/dl on CPB with moderate hypothermia except in patients with history of cerebrovascular disease, diabetes mellitus, and carotid stenosis. [8] However extracorporeal circulation is associated with a heavy fluid load that may significantly decrease haemoglo­bin concentration due to haemodilution. Thus, considering haemoglobin alone may be an inaccurate method of replacing red cell volume loss on CPB. Slight et al found that considering haemoglobin concentration alone may significantly overestimate the requirement for red cell transfusion in elective cardiac surgery patients. Patients transfused as per the red cell volume-based guideline received significantly less red cells with no associated differ­ence in clinical outcome. [9]

Intraoperative techniques in blood conservation cannot be underemphasized. Meticulous haemostasis and operative technique can play an important role in reducing blood loss. Acute normovolaemic haemodilution (ANH) has not only been shown to be more cost effective than preoperative autologous donation but also is not limited by time restraints preoperatively. The strategy behind ANH is to lower the red blood cell mass loss during surgery while preserving clotting factors. However, the efficacy of ANH is controversial. Segal et at showed that ANH was only moderately effective in reducing transfusions by 10% or 1 to 2 units less than the control group. [10] The recent ability to separate blood collected in the operating room into individual products, such as red blood cells, platelet rich plasma, and platelet poor plasma, thus allowing these products to be returned individually as indicated, may suggest that the role of ANH be revisited. [11]

To limit blood transfusions, The Society of Thoracic Surgeons(STS) and The Society of Cardiovascular Anesthesiologists(SCA) guidelines recommend use ofaprotinin and lysine analogues epsilon am inocaproic acid (EACA) and tranexamic acid (Cyclokapron) in high risk patients. Aprotinin (Trasy lop and the lysine analogues have very different modes and scope o facti on but ultimate!), inhibit fibrinolysis by limiting the action o fplasm in. A metaanalysis on aprotinin concluded significant reduction in blood transfusion in patients undergoing CABG, redo CABG and valve replacement. [12] Though aprotinin reduces blood transfusion significantly but blood conservation using antilibrinolytics randomized trial(BART) investigators found more mortality in aprotinin treated patients in high risk cardiac surgery cf. tranexamic acid. [13]

FactorVIIa is recommended for intractable bleeding, unresponsive to usual hem ostatics and non surgical means. [8] We successfully used it for reredo cardiac surgery with intractable bleeding. [14] Likewise recombinant erythropoietin can be used in patients of, autologous preoperative blood donation and anaemia, however evidence is conflicting in different trials.

Some intervention and modification during CPB are useful in blood conservation. Open reservoir membrane oxygenator system during CPB may reduce blood utilization and improve safety. Similarly activated clotting time (ACT) guided heparin dosing during prolonged CPB not only reduce blood transfusion but also haemostatic system activation, and platelets and proteins consumption as compare to fixed dose heparin supplements. Retro­grade autologous priming ofthe CPB circuit, intraoperative autotransfusion, either with blood directly from car­diotomy suction or recycled using a cell-saving device, shortly after the completion of CPB, salvage ofpump blood, either administered Nwithout washing or after washing with a cell-saving device should be used for blood conservation. [8]

Lastly, one cannot ignore importance ofa multimodality approach involving multiple stakeholders, institutional support and enforceable transfusion algorithms supplemented with point-of-care testing to prevent blood loss and blood transfusion. [8]

This becomes particularly important in a developing country like India with limited resources, variable quality of blood banking and surgical expertise with exponential growth of cardiac surgical centres. The role of anaesthesiologist is vital for implementing evidence based transfusion practices in cardiac surgery.



 
   References Top

1.Karthik S, Grayson A D, McCarron EE, et al. Reexploration for bleeding after coronary artery bypass surgery: risk factors, outcomes, and the effect of time delay. Ann Thorac Surg 2004; 78:527- 34.  Back to cited text no. 1      
2.Unsworth-White MJ, Herriot A, Valencia O, et al. Resternotomy for bleeding after cardiac operation: a marker for increased morbidity and mortality. Ann Thorac SUrg 1995; 59:664 - 7.  Back to cited text no. 2      
3.Hebert Paul C., Wells George, Morris A, et al. (Canadian Critical Care Trials Group) A multicenter, randomized, controlled clinical trial of transfusion requirements in critical care. Transfusion RCCquirenlents In Critical Care Investigators. N Engl J Mcd 1999:340:409-17  Back to cited text no. 3      
4.Taylor RW. O'Brien J. Trottier Si, et al. Red blood cell transfusions and nosocomial infections in critically ill patients. Crit Care Med 2006: 34:2302-2308.  Back to cited text no. 4      
5.Engoren MC, Habib RH. Zacharias A, et al. Effect of blood transfusion on long-term survival after cardiac operation. Ann Thorac Sure 2002; 74:1180-1186.  Back to cited text no. 5      
6.Yendc S, Wundcrink RG. Effect ofclopidogrel on bleeding after coronary artery bypass surgery. Crit Care Med 2001;29:2271-5.  Back to cited text no. 6      
7.Jan KM. Chien S. Effect of hematocrit variations on coronary hemodynanlics and oxygen Utilization. Am J Physiol 1977; 233:H106-13.  Back to cited text no. 7      
8.Ferraris A, Ferraris Suellen P. Saha S1bU P. Perioperative blood transfusion and blood conservation In cardiac surgery: The Society of Thoracic Surgeons and The Society of Cardiovascular Anesthesiologists Clinical Practice Guideline. Ann Thorac Sure 2007: 83:27-86.  Back to cited text no. 8      
9.Slight R. D, FUng A KY. Alonzi C, et al. Rationalizing blood transfusion in cardiac surgery: preliminary findings with a red cell volume-based model. Vox Sanguinis 92; 2:154-156.  Back to cited text no. 9      
10.Segal JB. Blasco-Colmenares E, Norris EJ, et al. Preoperative acute normovolemic hemodilution: a metaanalysis. Transfu­sion 2004; 44:632-644.  Back to cited text no. 10      
11.Ralley Fiona E. Programmatic Blood Conservation in Cardiac Surgery. Semin Cardiothorac VascAnesth2007: 11; 242-246.  Back to cited text no. 11      
12.Sedrakyan A, Treasure T. Elefteriades JA. Effect of aprotinin on clinical outcomes in coronary artery bypass graft surgery: a systematic review and meta-analysis of randomized clinical trials. J Thorac Cardiovasc Surg 2004;128:442- 8.  Back to cited text no. 12      
13.FergUsson Dean A., Hebert Paul C., Mazer C. David, et al (BART Investigators). A comparison of aprotinin and lysine analogues in high-risk cardiac surgery. NEJM 2008:358; 22.  Back to cited text no. 13      
14.Mehta Y, KumarA, KarlekarA, et al. Recombinant factor Vila as a rescue therapy for intractable haemorrhage after reredo cardiac surgery -A case report. Annals of Cardiac Anaesth 2006;9:132-134.  Back to cited text no. 14      




 

Top
 
  Search
 
    Similar in PUBMED
   Search Pubmed for
   Search in Google Scholar for
    Access Statistics
    Email Alert *
    Add to My List *
* Registration required (free)  

 
  In this article
    References

 Article Access Statistics
    Viewed1437    
    Printed58    
    Emailed1    
    PDF Downloaded486    
    Comments [Add]    

Recommend this journal