ABC of Blood transfusion

Hemorrhage is the leading    cause   of intensive   care unit   admission   and one of the leading causes of death in the obstetric population .  This  emphasizes   the importance of  a working    knowledge of the indications  for and  complications associated  with blood product    replacement    in obstetric   practice. This article   provides  current information  regarding  preparation  for the administration of blood   products  discusses   alternatives   to banked  blood in the obstetric   population and introduces   pharmacological   strategies for treatment of hemorrhage  ,

Preparing   for transfusion  step 1: How to recheck the group / type a blood of recipient  : Your own pt at ward:  : Preparing   for an obstetric   hemorrhage   requires   the drawing    of a blood   sample from the patient   to obtain   cross matched blood. The first  step in the process of preparing    blood is determining    ABO   type and the presence   or absence  of Rh factor. To  determine ABO type the blood  is mixed  with commercially available antibodies   that react   with A or B  antigens   on the patient’s   erythrocytes     causing  agglutination  . The Rh   factor status    is also classified by this method. Then  the blood type is confirmed   by mixing   the patient’s  blood with cells that contain    A or B   antigens. Because   most people   have antibodies to antigens    that they lack    agglutination   will occur   when antigen   antibody complexes are present.  

Step 2: Verify & check the pts blood &   screened   her serum for common antibodies  . Screening involves   mixing   the recipient’s   blood with   commercially available   antigens. If red blood  cell agglutination or hemolysis  occurs   antibodies are present  and must be  characterized  .

Step 3: You are anxious as PPH is continuing  : You are constantly loitering outside the   blood bank:: This initial type  and  screen  takes approximately 45 minutes  and is best for patients at low  risk for   requiring blood transfusion . The most recent American Society of Anesthesilogists  Practice Guidelines  for Obstetric  Anesthesia state that  a   routine   blood cross match  is not necessary for healthy and uncomplicated    parturients   for vaginal  or operative   delivery . 

 The decision    whether   to order to require   a blood type  and screen   or crossmatch  should be   based on maternal history   anticipated   hemorrhagic  complications    and local   institutional   policies.

What is cross matching?? Patients   should undergo blood   cross matching when blood transfusion    is imminent or likely To cross match blood the recipient’s   blood is mixed   with the donor’s   to mimic the transfusion   . This   process detects antibodies   in the Kell   Duffy   Kidd   and MN  groups   as well as   antibodies that are present    in low   titers   and that do not   agglutinate easily.    Blood   cross matching   typically  takes   an additional 15-45  minutes  after the blood   has been    typed and screened.

 In   an emergency  where    the patient   requires   transfusion   before type   specific   or cross  matched blood  can be obtained , type – O  blood   can be   administered. In obstetric patients    it is especially   important    to administer type – O   Rh  negative blood    because of the risk   of Rh    sensitization  . Cross  matched blood should be   administered as soon as    it is   available    because   the estimated   risk  of a hemolytic    transfusion   reaction  with this  emergency   blood has  been reported   to be    as high    as 5%   although   publications with trauma   patients   report   much lower   complication  rates.

The American Society   of Anesthesiologists   Task  Force   on Obstetric  Anesthesia   and the American College  of Obstetricians   and Gynecologists   recommend    that all facilities providing   obstetric  care be  prepared   to manage hemorrhagic    emergencies. Immediate  availability  of such    equipment    as hand inflated  pressure bags , an  automatic rapid infusion system  a fluid warmer  and a forced air warming  device is   recommended. Knowledge     of blood bank   capability    is paramount and resources    vary depending   on the hospital . Therefore   it is essential  to know the time required for   obtaining type- O , type – specific , and cross matched blood    as well as   platelet    and clotting      factor   availability . Response   to massive   hemorrhage takes   a coordinated effort    between   clinicians  and the blood bank   , it is    helpful  to have a massive   hemorrhage   protocol    outlined   before  an emergency occurs  . Facilities   should also   consider    writing  and posting   such a protocol   in addition  to running   clinical drills on    obstetric    hemorrhage   scenarios