RT Book, Section
A1 Butterworth IV, John F.
A1 Mackey, David C.
A1 Wasnick, John D.
SR Print(0)
ID 1161433520
T1 Fluid Management & Blood Component Therapy
T2 Morgan & Mikhail's Clinical Anesthesiology, 6e
YR 2018
FD 2018
PB McGraw-Hill Education
PP New York, NY
SN 9781259834424
LK accessmedicine.mhmedical.com/content.aspx?aid=1161433520
RD 2024/04/19
AB KEY  CONCEPTS  Although  the  intravascular  half-life  of  a  crystalloid  solution  is  20  to  30  min,  most  colloid  solutions  have  intravascular  half-lives  between  3  and  6  h.  Patients  with  a  normal  hematocrit  should  generally  be  transfused  only  after  losses  greater  than  10%  to  20%  of  their  blood  volume.  The  timing  of  transfusion  initiation  is  based  on  the  patient’s  surgical  procedure,  comorbid  conditions,  and  rate  of  blood  loss.  The  most  severe  transfusion  reactions  are  due  to  ABO  incompatibility;  naturally  acquired  antibodies  can  react  against  the  transfused  (foreign)  antigens,  activate  complement,  and  result  in  intravascular  hemolysis.  In  anesthetized  patients,  an  acute  hemolytic  reaction  is  manifested  by  a  rise  in  temperature,  unexplained  tachycardia,  hypotension,  hemoglobinuria,  diffuse  oozing  in  the  surgical  field,  or  a  combination  of  these  findings.  Allogeneic  transfusion  of  blood  products  may  diminish  immunoresponsiveness  and  promote  inflammation.  Immunocompromised  and  immunosuppressed  patients  (eg,  premature  infants,  organ  transplant  recipients,  and  cancer  patients)  are  particularly  susceptible  to  severe  transfusion-related  cytomegalovirus  (CMV)  infections.  Ideally,  such  patients  should  receive  only  CMV-negative  units.  The  most  common  cause  of  nonsurgical  bleeding  following  massive  blood  transfusion  is  dilutional  thrombocytopenia.  Clinically  important  hypocalcemia,  causing  cardiac  depression,  will  not  occur  in  most  normal  patients  unless  the  transfusion  rate  exceeds  1  unit  every  5  min,  and  intravenous  calcium  salts  should  rarely  be  required  in  the  absence  of  measured  hypocalcemia.  Once  normal  tissue  perfusion  is  restored,  any  metabolic  acidosis  typically  resolves,  and  metabolic  alkalosis  commonly  occurs  as  citrate  and  lactate  contained  in  transfusions  and  resuscitation  fluids  are  converted  to  bicarbonate  by  the  liver.