ELECTIVE SURGERY, PREADMISSION TESTING and
THE TRANSFUSION SERVICE
Ileana Lopez-Plaza, M.D., Associate
Medical Director, Transfusion Services
Increasingly, admissions for elective surgical procedures are occurring
the same day of surgery. Most preoperative laboratory testing is completed days in advance
of the scheduled procedure. This often does not include blood bank testing,
creating a logistic challenge for the transfusion service when patients are admitted when
patients are admitted.
Typically, patients must present to the preop holding areas a few hours
before a scheduled procedure. For surgical cases requiring the use of blood, a sample is
drawn at this time for compatibility testing. Often this provides less than two hours of
turn-around-time to complete testing before a scheduled surgery. Any delay in blood
availability can impact the patient and operating room schedule significantly.
PREADMISSION BLOOD BANK TESTING
Samples for compatibility testing can be collected up to 14 days prior
to a scheduled procedure. Typing, screening, and crossmatching must be performed by the
blood bank servicing the facility where the procedure is to be done. Blood needed for
surgery can be crossmatched the night before surgery, preventing delays in blood
availability the day of the procedure. Further, it allows time to evaluate a positive
antibody screen and obtain compatible blood for these patients. Samples drawn at
preadmission are tracked to the patient the day of the surgery by comparing a unique
numeric identifier present on both the band that the patient was provided with at the time
the sample was drawn, as well as on the blood sample itself. This identification band
provides the only link between the patient and the sample.
In order to perform preadmission testing, patients need to meet the
following criteria: a) the patient has not been transfused or pregnant in the past three
months; b) the band provided to the patient at time of the sample was drawn is present on
the patient, the day of surgery. Patients, who do not meet these criteria, must have their
sample drawn within three days before surgery. Samples drawn the day of surgery, must be
collected a minimum of two hours beforehand in order to complete testing once the sample
has reached the blood bank. Patients with positive antibody screens will require
additional time for antibody identification and blood availability. Depending on antibody
specificity, it may take hours or more for blood availability. Patients drawn in advance,
who do not have the band on them the day of the surgery will need to be redrawn, and all
testing repeated prior to the release of crossmatched blood.
SUPPLEMENTARY PREOPERATIVE BLOOD BANK FEATURES
Preoperative services that
the blood bank provides include preoperative autologous blood donations and the Maximum
Surgical Blood Ordering Schedule (MSBOS).
MSBOS is based on data collected from surgical records of blood usage
at an institution. The MSBOS provides recommendations on the maximum number of units to
order for common elective procedures. Options for testing include no blood required,
type and screen required, or type and crossmatches, stating the number of
units to be crossmatched. It is recommended that surgeons, who routinely require less than
one unit of blood, should only order a type and screen. Once the MSBOS is established, the
transfusion service will follow these guidelines to meet blood requirements for each
patient undergoing that particular procedure.
MSBOS facilitates the availability of blood for surgery by minimizing
the amount of blood tied up in the crossmatch inventory. Also, it prevents patients from
going to the OR without sufficient blood ordered.
PREOPERATIVE AUTOLOGOUS BLOOD COLLECTIONS
Autologous blood collection
should be attempted for every medically eligible patient undergoing an elective surgical
procedure who will require transfusion. Contraindications for autologous donations
generally include cardiovascular disease with compromised hemodynamic reserves or risk of
bacterial contamination of the collected blood.
Unnecessary collection of autologous blood is not without risks to the
donor. The decrease in hemoglobin levels put the patient at risk for transfusion. Units
are typically collected on a weekly basis and no less than 72 hours prior to surgery.
Blood ABO and Rh typing are the only required tests for an autologous
unit collected and transfused in the same facility. However, autologous units that are
collected by a blood center need to be fully tested (including viral markers) in order to
be distributed to the hospital facilities. Autologous blood donation is best ordered as
packed red cells versus whole blood, in order to extend the shelf life of that unit up to
six weeks after collection.
Most transfusion services provide options that facilitate blood
availability for surgery. Physicians (surgeons, primary care), medical institutions, and
health insurance companies should maximize the use of these benefits provided by