TRANSFUSION MEDICINE Original Article
Factors Associated with Successful Autologous Blood Donation for Elective Surgery PATRICIA A. McVAY, M.D.,1 M. SILVIJA HOAG, M.D.,2 SANDRA J. LEE, M.S., 3 AND PEARL T. C. Y. TOY, M.D.1
an initial hemoglobin level greater than 125 g/L (12.5 g/dL), those with higher weight, and those with more advanced age. Multiple logistic regression analysis showed that only higher initial hemoglobin levels (odds ratio, 3.3 per 10 g/L [1 g/dL] increment) and male sex (odds ratio, 2.7) were independent predictors of successful donation of 4 or more units. (Key words: Autologous blood donation; Autologous transfusion; Anemia; Transfusion in surgery) Am J Clin Pathol 1992; 97:304-308
Only some donors can donate the number of autologous blood units that their physicians request before surgery. Although some factors associated with the ability to donate the number of units requested have been examined,1 a more thorough investigation of the factors associated with successful autologous blood donation is needed. Factors associated with successful autologous donation were studied for patients whose surgeons requested four or more autologous units, a group more likely to have difficulty completing their autologous donation schedule.
of autologous blood for procedures scheduled between January 1, 1988 and June 30, 1990 were examined. Surgical procedure, diagnosis, weight at first donation, and hemoglobin (Hb) values at each donation were recorded. This blood center recommended that patients donate no more frequently than one time per week and that they do not donate closer than 1 week before surgery, except for donors who were asked to donate 6 or more units in 35 days. Donors were strongly encouraged by staff at this center to take oral iron supplements. To aid in the analysis of data, the units donated by each autologous blood donor were categorized according to donation outcome patterns listed in Table 1.
MATERIALS AND METHODS At one community blood center, all patients who were requested by their surgeons to donate at least four units
Statistical
Analysis
The Chi-square test, Fisher's exact test, or Student's ttest (all two-tailed) were used to test differences in proFrom the 'Department ofLaboratory Medicine, University of Califorportions. To determine the independence of predictors of nia, San Francisco, San Francisco, 2Blood Bank of the Alameda-Contra Costa Medical Association, Oakland, and ^Northern California outcomes Cancer by multiple logistic analysis, analysis of MaxCenter, Belmont, California. imum Likelihood Estimates was performed using the CATMOD program in PCSAS (Statistical Analysis System Received May 10, 1991; received revised manuscript and accepted for package, SAS Institute Inc., Cary, NC). publication August 7, 1991. Supported by Public Health Service Award R01 HL 36715 and Transfusion Medicine Academic Awards K07 HL01270, K07 HL01257, K07 RESULTS HL01426 from the National Heart, Lung and Blood Institute, National Institutes of Health. During the study period, 396 autologous blood donors Address reprint requests to Dr. Toy: Blood Bank, 2M6, Building NH, San Francisco General Hospital, San Francisco, California 94110. were identified who had been requested to donate at least 304
Downloaded from http://ajcp.oxfordjournals.org/ by guest on June 8, 2016
Not all donors can donate the number of autologous blood units requested by their physicians before surgery, and donors are more frequently unsuccessful as more units are requested. Therefore, 368 autologous blood donors who were requested to donate 4 or more units during the 6-week period before surgery at one community blood center were studied. More men were able to donate 4 units with no deferrals for anemia than were women (86% (181 of 211] compared to 42% [48 of 115], P < 0.001). Greater success also was observed among donors with
McVAY ET AL.
305
Factors Associated with Successful Autologous Blood Donation for Elective Surgery TABLE 1. DONATION OUTCOME PATTERNS Group
Pattern
Description
Don = Req No Hb Def Don = Req ;>1 HbDef Don < Req a l HbDef Don < Req Other Def
Donor donated as many units as requested by surgeon with no deferrals for anemia. Donor donated all units as requested by surgeon with at least one deferral for anemia. Donor donated fewer units than requested by surgeon with at least one deferral for anemia. Donor donated fewer units than requested by surgeon with no deferrals for anemia but had deferrals for out-of-range temperature, pulse, blood pressure, or feeling ill. Donor donated fewer units than requested by surgeon with no deferrals; donor did not appear for all appointments or surgery date was moved forward.
Don < Req Unknown
The numbers of patients able to donate all units requested by their surgeons by donation outcome patterns are presented in Table 2. As the number of units requested by the surgeon increased the percentage of donors able to
Table 4 presents initial Hb values and decreases in Hb from the first to fourth visit for all men and women who were requested to donate 4 units and did so at four visits without any deferrals for anemia or other causes. Men and women differed in initial Hb values, with women having lower values (P < 0.001), but they did not differ in overall decrease in Hb from first to fourth visit (P = 0.543). Men completed their donations in an average of 1.7 less days overall, which was statistically significant (P < 0.001), although not clinically significant. The average volume of red blood cells donated per unit by autologous donors in this study was 178 mL (N = 1364 total donations). To determine which underlying variables might be associated with successful donation without any deferrals for anemia, patients in Group 1 were compared to those who were not able to donate the requested number of units and had 1 or more deferrals for anemia (Group 3). (Group 2 donors were too few in number to analyze separately.) Donors in these two groups who were requested to donate 4 to 6 units were included (n = 245 and n = 59, respectively). A univariate analysis of variables associated with these donation patterns is presented in Table 5. This analysis of each variable independently revealed that the variables male sex, initial Hb < 125 g/L (12.5 g/dL), surgery for cancer, average age, average weight, and average
TABLE 2. DONATION OUTCOME PATTERNS BY UNITS REQUESTED AT ONE BLOOD CENTER Donation Pattern Number of Units Requested
Group 1 Don = Req No Hb Def
Group 2 Don = Req ill HbDef
Group 3 Don < Req izl Hb Def
Group 4 Don < Req Other Def
Group 5 Don < Req Unknown
Total
4 5 6 8 4-8
229 (70%) 13(43%) 3 (27%) 0 245 (67%)
1 (2%) 0 0 0 7 (2%)
48(15%) 7 (23%) 4 (36%) 1 (100%) 60(16%)
13(4%) 1 (3%) 3 (27%) 0 17(5%)
29 (9%) 9 (30%) 1 (9%) 0 39(11%)
326 30 11 1 368
Vol. 97 . N o . .1
Downloaded from http://ajcp.oxfordjournals.org/ by guest on June 8, 2016
four autologous blood units. After excluding 28 donors whose interval from first to last donation was longer than 35 days, 368 donors remained. Of these 28 excluded donors, only 5 donated within the last week before surgery; the other 23 donors required freezing of some autologous units. The 368 remaining donors consisted of 138 women (37%) and 230 men (63%), with an average weight of 65 ± 15 kg for the women and 83 ± 13 kg for the men. The average age was 47 ± 19 years for the women (range, 1279 years) and 55 ± 16 years for the men (range, 15-86 years). The average Hb at first donation was 135 ± 9.7 g/ L (13.5 ± 1.0 g/dL) for women and 146 ± 12 g/L (14.6 ± 1.2 g/dL) for men. The most common surgeries were spinal fusion (38%) and total hip replacement (32%) for women and radical prostatectomy (44%), total hip replacement (22%), and spinal fusion (15%) for men. Nearly one half of the male donors (48% [111 of 230]) were having surgery to remove cancer, whereas only 7% (10 of 138) of female donors were having surgery for that reason. Most donors (89%) were requested to donate 4 units within a 5-week period.
donate all units with no deferrals for anemia decreased as expected. During a 5-week period, 72% of autologous blood donors were able to donate all units if 4 units were requested (236 of 326), whereas only 43% of autologous blood donors were able to donate all units if 5 units were requested (13 of 30) and 27% of autologous blood donors were able to donate all units if 6 units were requested (3 of 11). For those donors requested to donate four or five units, the donation outcome pattern is presented by gender in Table 3. Men were more often successful than women, with 88% of men able to donate 4 units (185 of 211) compared to 44% of women who could donate 4 units (51 of 115; P < 0.001), and 69% of men were able to donate 5 units (9 of 13) compared to 24% of women who could donate 5 units (4 of 17; P = 0.025).
306
TRANSFUSION MEDICINE Original Article TABLE 3. DONATION OUTCOME PATTERNS FOR DONORS REQUESTED TO DONATE FOUR OR MORE UNITS AT ONE BLOOD CENTER BY PATIENT SEX Donation Pattern
Number of Units Requested Female patients 4 5 Male patients 4 5
Group 1 Don = Req No Hb Def
Group 2 Don = Req £ i HbDef
Group 3 Don < Req > 1 HbDef
Group 4 Don < Req Other Def
Group 5 Don < Req Unknown
Total
48 (42%) 4 (24%)
3 (3%) 0
40 (35%) 7 (41%)
5 (4%) 0
19(17%) 6 (35%)
115 17
181(86%) 9 (69%)
4 (2%) 0
8 (4%) 0
8 (4%) 1 (8%)
10 (5%) 3 (23%)
211 13
DISCUSSION During a 5-week period, 72% of autologous blood donors were able to donate all units if 4 units were requested by their physician, whereas only 43% were able to donate all units if 5 units were requested and 27% were able to donate all units if 6 units were requested. Men were more often successful than women, with 88% of men able to
TABLE 4. INITIAL HEMOGLOBIN AND HEMOGLOBIN DECREASES FOR ALL DONORS ABLE TO DONATE FOUR AUTOLOGOUS UNITS WITHOUT ANY DEFERRALS
At first visit Predonation Hb g/L (g/dL) At second visit Predonation Hb g/L (g/dL) At third visit Predonation Hb g/L (g/dL) At fourth visit Predonation Hb g/L (g/dL) From first to fourth visit Hb decrease g/L (g/dL) Time interval (days)
Female Patients (n = 45)
Male Patients (n = 170)
139 ± 9 . 0 (13.9 ±0.9)
147 ± 1 1 (14.7 ± 1.1)
126 ± 8.0 (12.6 ±0.8)
138 ± 1 1 (13.8 ± 1.1)
121 ± 8 . 0 (12.1 ±0.8)
132 ± 10 (13.2 ± 1.0)
120 ± 7.0 (12.0 ±0.7)
128 ± 10 (12.8 ± 1.0)
20 ± 9.0 (2.0 ± 0.9) 23.2 ± 3.4
19 ± 10 (1.9 ± 1.0) 21.5 ± 2.3
donate four units compared to 44% of women. Our results are similar to those of Owings,1 who found that women were unable to donate as many units as men, with only 36% of women donating 3 or more units compared to 64% of men donating 3 or more units. Few studies have included women who have tried to donate four or more autologous units. Goodnough 2 found that among unselected autologous blood donors undergoing elective orthopedic surgical procedures, only 60% (35 of 58) of patients were able to donate 4 units, although there was no differentiation of men and women in that study. In 1989 Goodnough 3 also found only 71% (17 of 24) of donors given oral iron therapy alone were able to donate at least 4 units during a 21-day period. This group included 9 men and 15 women, and thus a number between our 88% for men and 44% for women would be expected. He also found that the volume of red cells donated was greater for the 9 men (776 mL) than the 15 women (627 mL). On the other hand, Kruskall4 noted no more deferrals among female donors than male donors, but found that the average number of units ordered for female donors, who were undergoing primarily obstetric and gynecologic surgeries, was lower than that of male donors (2.9 versus 4.7 units). If we examine the decrease in Hb over time (Table 4), it is apparent that there is an equilibration of Hb levels after the first two donations. This was noted by Nicholls,5 who found a mean decrease of approximately 10 g/L (1.0 g/dL) after the first and second units followed by a plateau corresponding to a reticulocytosis of 5 to 8%. Univariate analysis of discontinuous variables revealed that male sex, an initial Hb level greater than 125 g/L (12.5 g/dL), surgery for cancer, and not taking oral iron therapy at the beginning of autologous blood donation were all factors associated with successful autologous blood donation of four to six units. (It appeared that physicians more strongly encouraged their patients with low initial Hb levels to take iron supplements.) Postmenopausal status showed a trend toward association with successful donation, but the trend was not statistically sig-
A.J.C.P. • March 1992
Downloaded from http://ajcp.oxfordjournals.org/ by guest on June 8, 2016
initial Hb were significant predictors of complete donation with no Hb deferrals. Using the Bonferroni adjustment for multiple comparisons, patients' reporting iron supplementation at time of first donation, postmenopausal status, and an age cutoff of 55 years were not significant. Multiple logistic regression analysis for the two groups described above revealed that only two variables were independently significant (Table 6): increasing initial hemoglobin, with an odds ratio of 3.3 for each increase in Hb of 10 g/L (1 g/dL), and male sex, with an odds ratio of 2.7.
307
McVAY ET Ah. Factors Associated with Successful Autologous Blood Donation for Elective Surgery
TABLE 5. ASSOCIATION OF SPECIFIC FACTORS WITH THE DONATION OUTCOME PATTERNS OF SUCCESSFUL DONATION WITH NO DEFERRALS FOR ANEMIA AND UNSUCCESSFUL DONATION WITH DEFERRALS FOR ANEMIA FOR DONORS REQUESTED TO DONATE FOUR TO SIX UNITS
Variable
Statistical Significance
51% (52/102) 96% (96/202)
49% (50/102) 4% (9/202)
P< 0.001
33% (12/36) 87% (233/268)
67% (24/36) 13% (35/268)
P< 0.001
93% (100/107) 74% (145/197)
7% (7/107) 26% (52/197)
P< 0.001
73% (82/112) 85% (163/192)
27% (30/112) 15% (29/192)
P = 0.020
43% 66% 94% 96%
57% 34% 6% 4%
(38/67) (12/35) (4/72) (5/130)
P = 0.052
45 ± 1 8 (59) 151 ± 3 6 (59) 12.8 ± 1.0(59)
P< 0.001 P< 0.001 P< 0.001
(29/67) (23/35) (68/72) (125/130)
55 ± 17 (245) 177 ± 32 (245) 14.5 ± 1.1(245)
P = 0.724
Mean ± SD (N).
nificant. Analysis of continuous variables indicated older age, greater body weight (equivalent to larger blood volume), and higher initial Hb level were all significantly associated with successful donation. However, using stepwise multiple logistic regression, we found that only increasing initial Hb level (odds ratio, 3.3 per gram of Hb increase) and male sex (odds ratio, 2.7) were significantly associated with successful outcome of autologous blood donation. Surgery for cancer, donors not taking iron, advanced age, and greater body weight are all associated with male sex, which probably is the reason why they were all independently significant. Although an initially high Hb level is an independent predictor of more successful donations, it is demonstrated in Table 4 that the average man has a higher initial Hb level.
Successful autologous blood donation among patients undergoing surgery for cancer has been reported by Lichtiger,6 who followed 235 patients during a 3-year period. Autologous blood donation for cancer patients may be especially beneficial if further studies confirm the possible harmful immunosuppressive effects of homologous blood transfusion that could lead to increased metastatic spread of cells.7 It is to be expected that fewer women are able to donate four units than men because women have lower iron reserves. In one study of the United States population, premenopausal women had an average of 309 mg total iron reserves, postmenopausal women had an average of 608 mg total iron reserves, and men had an average of 776 mg total iron reserves.8 One milliliter of red blood cells
TABLE 6. INDEPENDENT PREDICTORS OF COMPLETE DONATION PATTERN WITH NO DEFERRALS FOR ANEMIA Variable
Chi-Square
Probability Value
Odds Ratio
(95% CI)
Higher initial Hb (per 10 g/L, 1 g/dL) Male sex Higher age (10-year increments) Greater body weight (10-lb increments) Taking iron at first visit Cancer surgery
33.20 15.17 2.36 0.76 0.94 0.14
55 Male ^55 Male >55 2. Continuous Age (yrs) Weight (lb) Initial Hb
Group 3 Don < Req SLI Hb Def
Group 1 Don = Req No Hb Def
308
TRANSFUSION MEDICINE Article REFERENCES 1. Owings DV, Kruskall MS, Thurer RL, Donovan LM. Autologous blood donations prior to elective cardiac surgery, safety and effect on subsequent blood use. JAMA 1989;262:1963-1968. 2. Goodnough LT. Autologous blood transfusion. JAMA 1988; 259: 2405(letter). 3. Goodnough LT, Rudnick S, Price TH, et al. Increased preoperative collection of autologous blood with recombinant human erythropoietin therapy. N Engl J Med 1989,321:1163-1168. 4. Kruskall MS, Glazer EE, Leonard SS. Utilization and effectiveness of a hospital autologous preoperative blood donor program. Transfusion 1986;26:335-340. 5. Nichols MD, Janu MR, Davies VJ, Wedderburn CE. Autologous blood transfusion in elective surgery. Med J Australia 1986; 144: 396-399. 6. Lichtiger B, Huh YO, Armintor M, Fischer HE. Autologous transfusions for cancer patients undergoing elective ablative surgery. J Surg Oncol 1990;43:19-23. 7. van Aken WG. Does perioperative blood transfusion promote tumor growth? Transfusion Med Reviews 1989;111:243-252. 8. Cook JD, Skikne BS, Lynch SR, Reusser ME. Estimates of iron insufficiency in the US population. Blood 1986;68:726-731. 9. Walker RH, ed. Technical Manual, 10th Edition. Arlington, VA: American Association of Blood Banks, 1990, p 428. 10. Goodnough LT, Rudnick S. Iron-restricted erythropoiesis as a limitation to autologous blood donation in the maximally-stimulated bone marrow. Blood 1990; 76:400a.
Downloaded from http://ajcp.oxfordjournals.org/ by guest on June 8, 2016
contains an average of 1 mg iron9; the average autologous blood unit donated contained an average of 178 mL red blood cells or 178 mg iron in this study. Therefore, without supplemental iron, the premenopausal woman has iron reserves sufficient to donate only an average of 1.7 units (309 divided by 178), whereas a man can donate an average of 4.4 units (776 divided by 178) without iron depletion. One study of erythropoietin for autologous blood donation 10 demonstrated that 7 of 10 premenopausal women required absorption of oral iron, in contrast to none of 16 postmenopausal women and only 2 of 21 men to respond maximally to erythropoietin. In conclusion, successful autologous blood donation is significantly associated with higher predonation Hb levels and male sex. Correction of any iron deficiency in women may allow donation of more units. Because surgery is often considered several months before it is electively performed, it might be helpful to determine the Hb levels and the iron reserves of female patients. If low Hb levels and low iron stores are present, supplemental iron should be administered months before donation is anticipated.
Factors Associated with Successful Autologous Blood Donation for Elective Surgery PATRICIA A. McVAY, M.D.,1 M. SILVIJA HOAG, M.D.,2 SANDRA J. LEE, M.S., 3 AND PEARL T. C. Y. TOY, M.D.1
an initial hemoglobin level greater than 125 g/L (12.5 g/dL), those with higher weight, and those with more advanced age. Multiple logistic regression analysis showed that only higher initial hemoglobin levels (odds ratio, 3.3 per 10 g/L [1 g/dL] increment) and male sex (odds ratio, 2.7) were independent predictors of successful donation of 4 or more units. (Key words: Autologous blood donation; Autologous transfusion; Anemia; Transfusion in surgery) Am J Clin Pathol 1992; 97:304-308
Only some donors can donate the number of autologous blood units that their physicians request before surgery. Although some factors associated with the ability to donate the number of units requested have been examined,1 a more thorough investigation of the factors associated with successful autologous blood donation is needed. Factors associated with successful autologous donation were studied for patients whose surgeons requested four or more autologous units, a group more likely to have difficulty completing their autologous donation schedule.
of autologous blood for procedures scheduled between January 1, 1988 and June 30, 1990 were examined. Surgical procedure, diagnosis, weight at first donation, and hemoglobin (Hb) values at each donation were recorded. This blood center recommended that patients donate no more frequently than one time per week and that they do not donate closer than 1 week before surgery, except for donors who were asked to donate 6 or more units in 35 days. Donors were strongly encouraged by staff at this center to take oral iron supplements. To aid in the analysis of data, the units donated by each autologous blood donor were categorized according to donation outcome patterns listed in Table 1.
MATERIALS AND METHODS At one community blood center, all patients who were requested by their surgeons to donate at least four units
Statistical
Analysis
The Chi-square test, Fisher's exact test, or Student's ttest (all two-tailed) were used to test differences in proFrom the 'Department ofLaboratory Medicine, University of Califorportions. To determine the independence of predictors of nia, San Francisco, San Francisco, 2Blood Bank of the Alameda-Contra Costa Medical Association, Oakland, and ^Northern California outcomes Cancer by multiple logistic analysis, analysis of MaxCenter, Belmont, California. imum Likelihood Estimates was performed using the CATMOD program in PCSAS (Statistical Analysis System Received May 10, 1991; received revised manuscript and accepted for package, SAS Institute Inc., Cary, NC). publication August 7, 1991. Supported by Public Health Service Award R01 HL 36715 and Transfusion Medicine Academic Awards K07 HL01270, K07 HL01257, K07 RESULTS HL01426 from the National Heart, Lung and Blood Institute, National Institutes of Health. During the study period, 396 autologous blood donors Address reprint requests to Dr. Toy: Blood Bank, 2M6, Building NH, San Francisco General Hospital, San Francisco, California 94110. were identified who had been requested to donate at least 304
Downloaded from http://ajcp.oxfordjournals.org/ by guest on June 8, 2016
Not all donors can donate the number of autologous blood units requested by their physicians before surgery, and donors are more frequently unsuccessful as more units are requested. Therefore, 368 autologous blood donors who were requested to donate 4 or more units during the 6-week period before surgery at one community blood center were studied. More men were able to donate 4 units with no deferrals for anemia than were women (86% (181 of 211] compared to 42% [48 of 115], P < 0.001). Greater success also was observed among donors with
McVAY ET AL.
305
Factors Associated with Successful Autologous Blood Donation for Elective Surgery TABLE 1. DONATION OUTCOME PATTERNS Group
Pattern
Description
Don = Req No Hb Def Don = Req ;>1 HbDef Don < Req a l HbDef Don < Req Other Def
Donor donated as many units as requested by surgeon with no deferrals for anemia. Donor donated all units as requested by surgeon with at least one deferral for anemia. Donor donated fewer units than requested by surgeon with at least one deferral for anemia. Donor donated fewer units than requested by surgeon with no deferrals for anemia but had deferrals for out-of-range temperature, pulse, blood pressure, or feeling ill. Donor donated fewer units than requested by surgeon with no deferrals; donor did not appear for all appointments or surgery date was moved forward.
Don < Req Unknown
The numbers of patients able to donate all units requested by their surgeons by donation outcome patterns are presented in Table 2. As the number of units requested by the surgeon increased the percentage of donors able to
Table 4 presents initial Hb values and decreases in Hb from the first to fourth visit for all men and women who were requested to donate 4 units and did so at four visits without any deferrals for anemia or other causes. Men and women differed in initial Hb values, with women having lower values (P < 0.001), but they did not differ in overall decrease in Hb from first to fourth visit (P = 0.543). Men completed their donations in an average of 1.7 less days overall, which was statistically significant (P < 0.001), although not clinically significant. The average volume of red blood cells donated per unit by autologous donors in this study was 178 mL (N = 1364 total donations). To determine which underlying variables might be associated with successful donation without any deferrals for anemia, patients in Group 1 were compared to those who were not able to donate the requested number of units and had 1 or more deferrals for anemia (Group 3). (Group 2 donors were too few in number to analyze separately.) Donors in these two groups who were requested to donate 4 to 6 units were included (n = 245 and n = 59, respectively). A univariate analysis of variables associated with these donation patterns is presented in Table 5. This analysis of each variable independently revealed that the variables male sex, initial Hb < 125 g/L (12.5 g/dL), surgery for cancer, average age, average weight, and average
TABLE 2. DONATION OUTCOME PATTERNS BY UNITS REQUESTED AT ONE BLOOD CENTER Donation Pattern Number of Units Requested
Group 1 Don = Req No Hb Def
Group 2 Don = Req ill HbDef
Group 3 Don < Req izl Hb Def
Group 4 Don < Req Other Def
Group 5 Don < Req Unknown
Total
4 5 6 8 4-8
229 (70%) 13(43%) 3 (27%) 0 245 (67%)
1 (2%) 0 0 0 7 (2%)
48(15%) 7 (23%) 4 (36%) 1 (100%) 60(16%)
13(4%) 1 (3%) 3 (27%) 0 17(5%)
29 (9%) 9 (30%) 1 (9%) 0 39(11%)
326 30 11 1 368
Vol. 97 . N o . .1
Downloaded from http://ajcp.oxfordjournals.org/ by guest on June 8, 2016
four autologous blood units. After excluding 28 donors whose interval from first to last donation was longer than 35 days, 368 donors remained. Of these 28 excluded donors, only 5 donated within the last week before surgery; the other 23 donors required freezing of some autologous units. The 368 remaining donors consisted of 138 women (37%) and 230 men (63%), with an average weight of 65 ± 15 kg for the women and 83 ± 13 kg for the men. The average age was 47 ± 19 years for the women (range, 1279 years) and 55 ± 16 years for the men (range, 15-86 years). The average Hb at first donation was 135 ± 9.7 g/ L (13.5 ± 1.0 g/dL) for women and 146 ± 12 g/L (14.6 ± 1.2 g/dL) for men. The most common surgeries were spinal fusion (38%) and total hip replacement (32%) for women and radical prostatectomy (44%), total hip replacement (22%), and spinal fusion (15%) for men. Nearly one half of the male donors (48% [111 of 230]) were having surgery to remove cancer, whereas only 7% (10 of 138) of female donors were having surgery for that reason. Most donors (89%) were requested to donate 4 units within a 5-week period.
donate all units with no deferrals for anemia decreased as expected. During a 5-week period, 72% of autologous blood donors were able to donate all units if 4 units were requested (236 of 326), whereas only 43% of autologous blood donors were able to donate all units if 5 units were requested (13 of 30) and 27% of autologous blood donors were able to donate all units if 6 units were requested (3 of 11). For those donors requested to donate four or five units, the donation outcome pattern is presented by gender in Table 3. Men were more often successful than women, with 88% of men able to donate 4 units (185 of 211) compared to 44% of women who could donate 4 units (51 of 115; P < 0.001), and 69% of men were able to donate 5 units (9 of 13) compared to 24% of women who could donate 5 units (4 of 17; P = 0.025).
306
TRANSFUSION MEDICINE Original Article TABLE 3. DONATION OUTCOME PATTERNS FOR DONORS REQUESTED TO DONATE FOUR OR MORE UNITS AT ONE BLOOD CENTER BY PATIENT SEX Donation Pattern
Number of Units Requested Female patients 4 5 Male patients 4 5
Group 1 Don = Req No Hb Def
Group 2 Don = Req £ i HbDef
Group 3 Don < Req > 1 HbDef
Group 4 Don < Req Other Def
Group 5 Don < Req Unknown
Total
48 (42%) 4 (24%)
3 (3%) 0
40 (35%) 7 (41%)
5 (4%) 0
19(17%) 6 (35%)
115 17
181(86%) 9 (69%)
4 (2%) 0
8 (4%) 0
8 (4%) 1 (8%)
10 (5%) 3 (23%)
211 13
DISCUSSION During a 5-week period, 72% of autologous blood donors were able to donate all units if 4 units were requested by their physician, whereas only 43% were able to donate all units if 5 units were requested and 27% were able to donate all units if 6 units were requested. Men were more often successful than women, with 88% of men able to
TABLE 4. INITIAL HEMOGLOBIN AND HEMOGLOBIN DECREASES FOR ALL DONORS ABLE TO DONATE FOUR AUTOLOGOUS UNITS WITHOUT ANY DEFERRALS
At first visit Predonation Hb g/L (g/dL) At second visit Predonation Hb g/L (g/dL) At third visit Predonation Hb g/L (g/dL) At fourth visit Predonation Hb g/L (g/dL) From first to fourth visit Hb decrease g/L (g/dL) Time interval (days)
Female Patients (n = 45)
Male Patients (n = 170)
139 ± 9 . 0 (13.9 ±0.9)
147 ± 1 1 (14.7 ± 1.1)
126 ± 8.0 (12.6 ±0.8)
138 ± 1 1 (13.8 ± 1.1)
121 ± 8 . 0 (12.1 ±0.8)
132 ± 10 (13.2 ± 1.0)
120 ± 7.0 (12.0 ±0.7)
128 ± 10 (12.8 ± 1.0)
20 ± 9.0 (2.0 ± 0.9) 23.2 ± 3.4
19 ± 10 (1.9 ± 1.0) 21.5 ± 2.3
donate four units compared to 44% of women. Our results are similar to those of Owings,1 who found that women were unable to donate as many units as men, with only 36% of women donating 3 or more units compared to 64% of men donating 3 or more units. Few studies have included women who have tried to donate four or more autologous units. Goodnough 2 found that among unselected autologous blood donors undergoing elective orthopedic surgical procedures, only 60% (35 of 58) of patients were able to donate 4 units, although there was no differentiation of men and women in that study. In 1989 Goodnough 3 also found only 71% (17 of 24) of donors given oral iron therapy alone were able to donate at least 4 units during a 21-day period. This group included 9 men and 15 women, and thus a number between our 88% for men and 44% for women would be expected. He also found that the volume of red cells donated was greater for the 9 men (776 mL) than the 15 women (627 mL). On the other hand, Kruskall4 noted no more deferrals among female donors than male donors, but found that the average number of units ordered for female donors, who were undergoing primarily obstetric and gynecologic surgeries, was lower than that of male donors (2.9 versus 4.7 units). If we examine the decrease in Hb over time (Table 4), it is apparent that there is an equilibration of Hb levels after the first two donations. This was noted by Nicholls,5 who found a mean decrease of approximately 10 g/L (1.0 g/dL) after the first and second units followed by a plateau corresponding to a reticulocytosis of 5 to 8%. Univariate analysis of discontinuous variables revealed that male sex, an initial Hb level greater than 125 g/L (12.5 g/dL), surgery for cancer, and not taking oral iron therapy at the beginning of autologous blood donation were all factors associated with successful autologous blood donation of four to six units. (It appeared that physicians more strongly encouraged their patients with low initial Hb levels to take iron supplements.) Postmenopausal status showed a trend toward association with successful donation, but the trend was not statistically sig-
A.J.C.P. • March 1992
Downloaded from http://ajcp.oxfordjournals.org/ by guest on June 8, 2016
initial Hb were significant predictors of complete donation with no Hb deferrals. Using the Bonferroni adjustment for multiple comparisons, patients' reporting iron supplementation at time of first donation, postmenopausal status, and an age cutoff of 55 years were not significant. Multiple logistic regression analysis for the two groups described above revealed that only two variables were independently significant (Table 6): increasing initial hemoglobin, with an odds ratio of 3.3 for each increase in Hb of 10 g/L (1 g/dL), and male sex, with an odds ratio of 2.7.
307
McVAY ET Ah. Factors Associated with Successful Autologous Blood Donation for Elective Surgery
TABLE 5. ASSOCIATION OF SPECIFIC FACTORS WITH THE DONATION OUTCOME PATTERNS OF SUCCESSFUL DONATION WITH NO DEFERRALS FOR ANEMIA AND UNSUCCESSFUL DONATION WITH DEFERRALS FOR ANEMIA FOR DONORS REQUESTED TO DONATE FOUR TO SIX UNITS
Variable
Statistical Significance
51% (52/102) 96% (96/202)
49% (50/102) 4% (9/202)
P< 0.001
33% (12/36) 87% (233/268)
67% (24/36) 13% (35/268)
P< 0.001
93% (100/107) 74% (145/197)
7% (7/107) 26% (52/197)
P< 0.001
73% (82/112) 85% (163/192)
27% (30/112) 15% (29/192)
P = 0.020
43% 66% 94% 96%
57% 34% 6% 4%
(38/67) (12/35) (4/72) (5/130)
P = 0.052
45 ± 1 8 (59) 151 ± 3 6 (59) 12.8 ± 1.0(59)
P< 0.001 P< 0.001 P< 0.001
(29/67) (23/35) (68/72) (125/130)
55 ± 17 (245) 177 ± 32 (245) 14.5 ± 1.1(245)
P = 0.724
Mean ± SD (N).
nificant. Analysis of continuous variables indicated older age, greater body weight (equivalent to larger blood volume), and higher initial Hb level were all significantly associated with successful donation. However, using stepwise multiple logistic regression, we found that only increasing initial Hb level (odds ratio, 3.3 per gram of Hb increase) and male sex (odds ratio, 2.7) were significantly associated with successful outcome of autologous blood donation. Surgery for cancer, donors not taking iron, advanced age, and greater body weight are all associated with male sex, which probably is the reason why they were all independently significant. Although an initially high Hb level is an independent predictor of more successful donations, it is demonstrated in Table 4 that the average man has a higher initial Hb level.
Successful autologous blood donation among patients undergoing surgery for cancer has been reported by Lichtiger,6 who followed 235 patients during a 3-year period. Autologous blood donation for cancer patients may be especially beneficial if further studies confirm the possible harmful immunosuppressive effects of homologous blood transfusion that could lead to increased metastatic spread of cells.7 It is to be expected that fewer women are able to donate four units than men because women have lower iron reserves. In one study of the United States population, premenopausal women had an average of 309 mg total iron reserves, postmenopausal women had an average of 608 mg total iron reserves, and men had an average of 776 mg total iron reserves.8 One milliliter of red blood cells
TABLE 6. INDEPENDENT PREDICTORS OF COMPLETE DONATION PATTERN WITH NO DEFERRALS FOR ANEMIA Variable
Chi-Square
Probability Value
Odds Ratio
(95% CI)
Higher initial Hb (per 10 g/L, 1 g/dL) Male sex Higher age (10-year increments) Greater body weight (10-lb increments) Taking iron at first visit Cancer surgery
33.20 15.17 2.36 0.76 0.94 0.14
55 Male ^55 Male >55 2. Continuous Age (yrs) Weight (lb) Initial Hb
Group 3 Don < Req SLI Hb Def
Group 1 Don = Req No Hb Def
308
TRANSFUSION MEDICINE Article REFERENCES 1. Owings DV, Kruskall MS, Thurer RL, Donovan LM. Autologous blood donations prior to elective cardiac surgery, safety and effect on subsequent blood use. JAMA 1989;262:1963-1968. 2. Goodnough LT. Autologous blood transfusion. JAMA 1988; 259: 2405(letter). 3. Goodnough LT, Rudnick S, Price TH, et al. Increased preoperative collection of autologous blood with recombinant human erythropoietin therapy. N Engl J Med 1989,321:1163-1168. 4. Kruskall MS, Glazer EE, Leonard SS. Utilization and effectiveness of a hospital autologous preoperative blood donor program. Transfusion 1986;26:335-340. 5. Nichols MD, Janu MR, Davies VJ, Wedderburn CE. Autologous blood transfusion in elective surgery. Med J Australia 1986; 144: 396-399. 6. Lichtiger B, Huh YO, Armintor M, Fischer HE. Autologous transfusions for cancer patients undergoing elective ablative surgery. J Surg Oncol 1990;43:19-23. 7. van Aken WG. Does perioperative blood transfusion promote tumor growth? Transfusion Med Reviews 1989;111:243-252. 8. Cook JD, Skikne BS, Lynch SR, Reusser ME. Estimates of iron insufficiency in the US population. Blood 1986;68:726-731. 9. Walker RH, ed. Technical Manual, 10th Edition. Arlington, VA: American Association of Blood Banks, 1990, p 428. 10. Goodnough LT, Rudnick S. Iron-restricted erythropoiesis as a limitation to autologous blood donation in the maximally-stimulated bone marrow. Blood 1990; 76:400a.
Downloaded from http://ajcp.oxfordjournals.org/ by guest on June 8, 2016
contains an average of 1 mg iron9; the average autologous blood unit donated contained an average of 178 mL red blood cells or 178 mg iron in this study. Therefore, without supplemental iron, the premenopausal woman has iron reserves sufficient to donate only an average of 1.7 units (309 divided by 178), whereas a man can donate an average of 4.4 units (776 divided by 178) without iron depletion. One study of erythropoietin for autologous blood donation 10 demonstrated that 7 of 10 premenopausal women required absorption of oral iron, in contrast to none of 16 postmenopausal women and only 2 of 21 men to respond maximally to erythropoietin. In conclusion, successful autologous blood donation is significantly associated with higher predonation Hb levels and male sex. Correction of any iron deficiency in women may allow donation of more units. Because surgery is often considered several months before it is electively performed, it might be helpful to determine the Hb levels and the iron reserves of female patients. If low Hb levels and low iron stores are present, supplemental iron should be administered months before donation is anticipated.
