Hb, red cell transfusions and adherence
| . | Trigger<8 g/dL (n = 29) . | Trigger<9.7 g/dL (n = 29) . | Treatment effect (95% CI) . | P . |
|---|---|---|---|---|
| Hb (day 0 – 15) | ||||
| Grand mean, g/dl and GEE coefficient* | 9.46 | 10.33 | GEE coefficient: −0.45 (−0.84 to −0.07) | .022 |
| Modeled mean, g/dL† | 9.70 | 10.61 | −0.91 (−1.21 to −0.61) | <.001 |
| Hb in recovery room (day 0)‡ | ||||
| Mean, g/dl (n = 46)† | 9.17 | 10.51 | −1.35 (−1.74 to −0.95) | <.001 |
| Hb at follow-up (day 30) | ||||
| Mean, g/dL (n = 45)† | 10.75 | 11.83 | −1.07 (−1.79 to −0.36) | .004 |
| Hb below lowest trigger, n (%) | ||||
| ≥1 Hb measurement below 8 g/dL | 18 (62) | 4 (14) | 48% (27% to 70%) | <.001 |
| Red cell transfusions | ||||
| Median no. of units (interquartile range)¶ | ||||
| Overall | 1 (0 to 2) | 3 (2 to 6) | .002 | |
| During surgery§ | 0 (0 to 1) | 1 (1 to 2) | <.001 | |
| After surgery | 1 (1 to 2) | 2 (1 to 3) | .009 | |
| ≥1 unit of red cells, n (%)‖ | ||||
| Overall | 19 (66) | 29 (100) | −34% (−52% to −17%) | .002 |
| Preoperative | 0 (0) | 3 (10) | −10% (−21% to 1%) | .236 |
| Intraoperative | 10 (34) | 24 (83) | −48% (−70% to −26%) | <.001 |
| Postoperative | 16 (55) | 26 (90) | −35% (−56% to −13%) | .008 |
| Total count of red cell units transfused | 57 | 136 | ||
| Protocol suspension red cell transfusions** | ||||
| ≥1 unit of red cells, n (%)‖ | 8 (28) | 4 (14) | 14% (−7% to 34%) | .331 |
| Total count¶ | 23 | 5 | .311 | |
| Nonadherence, n (%)‖ | ||||
| ≥1 nonadherent event, overall | 8 (28) | 10 (34) | −7% (−31% to 17%) | .777 |
| ≥1 nonadherent red cell transfusion †† | 6 (21) | 4 (14) | 7% (−13% to 26%) | .728 |
| ≥1 nonadherent failure to transfuse‡‡ | 3 (10) | 10 (35) | −24% (−45% to −4%) | .059 |
| . | Trigger<8 g/dL (n = 29) . | Trigger<9.7 g/dL (n = 29) . | Treatment effect (95% CI) . | P . |
|---|---|---|---|---|
| Hb (day 0 – 15) | ||||
| Grand mean, g/dl and GEE coefficient* | 9.46 | 10.33 | GEE coefficient: −0.45 (−0.84 to −0.07) | .022 |
| Modeled mean, g/dL† | 9.70 | 10.61 | −0.91 (−1.21 to −0.61) | <.001 |
| Hb in recovery room (day 0)‡ | ||||
| Mean, g/dl (n = 46)† | 9.17 | 10.51 | −1.35 (−1.74 to −0.95) | <.001 |
| Hb at follow-up (day 30) | ||||
| Mean, g/dL (n = 45)† | 10.75 | 11.83 | −1.07 (−1.79 to −0.36) | .004 |
| Hb below lowest trigger, n (%) | ||||
| ≥1 Hb measurement below 8 g/dL | 18 (62) | 4 (14) | 48% (27% to 70%) | <.001 |
| Red cell transfusions | ||||
| Median no. of units (interquartile range)¶ | ||||
| Overall | 1 (0 to 2) | 3 (2 to 6) | .002 | |
| During surgery§ | 0 (0 to 1) | 1 (1 to 2) | <.001 | |
| After surgery | 1 (1 to 2) | 2 (1 to 3) | .009 | |
| ≥1 unit of red cells, n (%)‖ | ||||
| Overall | 19 (66) | 29 (100) | −34% (−52% to −17%) | .002 |
| Preoperative | 0 (0) | 3 (10) | −10% (−21% to 1%) | .236 |
| Intraoperative | 10 (34) | 24 (83) | −48% (−70% to −26%) | <.001 |
| Postoperative | 16 (55) | 26 (90) | −35% (−56% to −13%) | .008 |
| Total count of red cell units transfused | 57 | 136 | ||
| Protocol suspension red cell transfusions** | ||||
| ≥1 unit of red cells, n (%)‖ | 8 (28) | 4 (14) | 14% (−7% to 34%) | .331 |
| Total count¶ | 23 | 5 | .311 | |
| Nonadherence, n (%)‖ | ||||
| ≥1 nonadherent event, overall | 8 (28) | 10 (34) | −7% (−31% to 17%) | .777 |
| ≥1 nonadherent red cell transfusion †† | 6 (21) | 4 (14) | 7% (−13% to 26%) | .728 |
| ≥1 nonadherent failure to transfuse‡‡ | 3 (10) | 10 (35) | −24% (−45% to −4%) | .059 |
GEE adjusted for age, baseline Hb, and type of operation. The mean Hb values are unadjusted, as this model does not provide mean ± confidence intervals. GEE was applied on a data frame with the Hb unit in mmol/L.
Mixed model adjusted for age, baseline Hb, and type of operation. Least squared means are showed along with the mean difference. In the case of time point measurement (eg, day 0 or 30), generalized linear model was adjusted for the same covariates.
Hb in patients randomized before end of surgery.
van Elteren’s test adjusted for type of operation.
No patient received more than 5 units of red blood cell intraoperatively.
χ-square with estimated risk difference.
Reasons for protocol suspension: uncontrollable hemorrhage during surgery 5 (17%) the low-trigger group vs 4 (14%) in the high-trigger group. Protocol suspension resulting from stroke or extremity ischemia exclusively occurred in 3 (10%) patients in the low-trigger group.
Red cell transfusion at a Hb level above the allocated trigger or not preceded by a Hb measurement. No nonadherence occurred intraoperatively. Adherence proportion (number of red cell units transfused adherently divided by all red cell transfusions) is provided in the supplemental Table 2.6.
Omission of red cell transfusion despite an Hb level below the trigger. No red cell transfusions were omitted because of volume overload.