Clinical Studies
Prospective, randomized studies in radical prostatectomy,[58]
knee replacement,[59]
and hip replacement[60]
suggest that ANH can be considered equivalent to PAD as a method of autologous blood
procurement. Additional, selected clinical trials of ANH are summarized in Table
48-5
.[61]
[62]
[63]
[64]
[65]
[66]
[67]
Reviews
[68]
[69]
and commentaries
[70]
on the merits of ANH have been published.
When
ANH and reinfusion are accomplished in the operating room by on-site personnel, the
procurement and administration costs are minimized. Blood obtained during ANH does
not require the commitment of the patient's time, transportation, costs, and loss
of work time that can be associated with PAD. The wastage of PAD units (approximately
50% of units collected)[26]
also is eliminated with
ANH. Additionally, autologous blood units procured by ANH require no inventory or
testing costs. Since the blood never leaves the patient's room, ANH minimizes the
possibility of an administrative or clerical error that could lead to an ABO-incompatible
blood
TABLE 48-5 -- Selected clinical trials of acute normovolemic hemodilution (ANH)
|
Estimated Blood Loss (mL) |
Postoperative Hematocrit (%) |
Allogeneic RBC-Containing
Units or Liters ( ) Transfused |
|
|
Type of Surgery |
Control |
ANH |
P Value |
Control |
ANH |
P Value |
Control |
ANH |
P Value |
Ref. |
|
Vascular |
2250 |
2458 |
NS |
NR |
33.0 |
NR |
6.0 |
2.6 |
<0.01 |
[61]
|
|
Liver resection |
1479 |
1284 |
NS |
37.9 |
33.8 |
<0.01 |
3.8 |
0.4 |
<0.001 |
[62]
|
|
Hip arthroplasty |
1800 |
2000 |
NS |
38.4 |
32.4 |
NS |
(2.1) |
(0.9) |
NR |
[63]
|
|
Spinal fusion |
5490 |
1700 |
<0.005 |
NR |
28.7 |
NR |
8.6 |
<1 |
<0.001 |
[64]
|
|
Colectomy |
NR |
NR |
NR |
37.0 |
35.0 |
NR |
2.4 |
0 |
NR |
[65]
|
|
Prostate |
1246 |
1106 |
NS |
35.5 |
31.8 |
<0.001 |
0.16 |
0 |
NS |
[66]
|
|
Prostate |
1717 |
1710 |
NS |
29.5 |
27.9 |
<0.5 |
\0.30 |
0.13 |
NS |
[67]
|
|
NR, not reported; NS, not significant; Ref., reference number
of source. |
|
Modified from Brecher ME, Rosenfeld M: Mathematical
and computer modeling of acute normovolemic hemodilution. Transfusion 34:176–9,
1994. |
transfusion and death, as well as bacterial contamination associated with prolonged
storage at 4° C.
Some practical considerations are important regarding an ANH program.
[68]
Decisions about ANH should be based on the
surgical procedure and on the patient's preoperative blood volume and hematocrit,
target hemodilution hematocrit, and other physiologic variables. The institution's
policy and procedures and the mechanisms for educating staff should be established
and periodically reviewed.
There should be careful monitoring of the patient's circulating
volume and perfusion status during the procedure. Blood must be collected in an
aseptic manner, ordinarily into standard blood collection bags with citrate anticoagulant.
Units must be properly labeled and stored. The label must contain, at a minimum,
the patient's full name, medical record number, date and time of collection, and
the statement "For Autologous Use Only." Room temperature storage should not exceed
8 hours. If more time elapses between collection and transfusion, the blood should
be stored in a monitored refrigerator. Suggested criteria for patient selection
are listed in Table 48-6
.
