TRANSFUSION NEED IN ORTHOGNATHIC surgery- A REVIEW

( 2009) 53 and Rummasak et al.( 2011) 42 were not retained because they did not give a transfusion rate. The following papers were included in the no-predonation policy: Ash and Mercuri, 1985 7( 8 patients); Choi et al., 2009 54( 61 patients); Kretschmer et al., 2008 47( 36 patients); Landes et al., 2008 14( 13 patients); and Stewart et al., 2001 49( 2 patients). Three papers with a predonation policy were retained in this category: Blau et al., 1992 55( 30 patients); Moenning et al., 1995 17( 155 patients); and Posnick et al., 2010 56( 34 patients). Posnick et al.( 2010) 56 did not indicate a criterion of transfusion but believed a level below 7 g / dL( Hc = 21 %) was a definite indication for transfusion, with room for evaluation of the clinical need and transfusion before that level is reached if necessary. Blau et al.( 1992) 55 stated that they did not use uniform criteria for postoperative transfusion; indeed, many patients received transfusion postoperatively before documentation of the postoperative hemoglobin concentration. Pooling of the other data showed adherence to equal and strict transfusion criteria when considering autologous or homologous blood transfusion. The‘ arithmetic’ overall requirement of blood transfusion is 12.4 %, which signifies a figure almost double as that of a single-jaw procedure( Table 17, Table 3). However, when these figures are entered into a statistical model, the % are not the aritmethic %( 42 / 339 = 12,4) but estimated % based on the probitnormal model containing all groups(( 42 / 339; 20,6 %;( 7.1; 43.2) 95 % CI)). Statistics were done in the SAS program and 95 % exact confidence intervals were calculated for the individual studies. In Table 18 the overall transfusion rates and corresponding 95 % confidence intervals were estimated using a probit-normal model. No significant difference between the predonation and the no-predonation policy could be shown( p = 0.5047). The intra-study correlation was found to be significant. In the no-predonation policy the intrastudy correlation was 0.29( p = 0.0769). The intrastudy correlation in the predonation policy group was 0.26( p = 0.0960),( Fig. 4). Four patients in the group with the predonation policy( Table 18) received homologous blood: one in the series of Posnick et al.( 2010) 56 who did not predonate, and three in the series of Moenning et al.( 1995) 17 were patients that received both autologous and additional homologous blood. Total: 22 patients in the predonation policy group received a blood transfusion. Moenning’ s patients who received both autologous and homologous blood were classified as having received autologous blood only. One would assume that the clinical message is clear. As long as bimaxillary surgery is straightforward, the need for blood transfusion remains well defined. Once additional procedures are executed, the risk for blood transfusion increases significantly. Table 19 summarizes the findings of the transfusion rates reported in the reviewed articles. In the predonation policy centers obviously the transfusion rate reflects a policy rather than a transfusion need. In the other centers without predonation policy the increasing complexity of the surgical orthognathic procedure goes along with an increased transfusion rate. The statistical model used to study bimaxillary surgery with a predonation policy yielded no statistically significant difference between simple and complex procedures( p = 0.1257). The intrastudy correlation in the simple bimaxillary procedure group with predonation was 0.42( p = 0.0002). The intra-study correlation in the complex bimaxillary procedure group with predonation was 0.26( p = 0.1160). The statistical model used to study bimaxillary surgery with no-predonation policy yielded no statistically significant difference between simple and complex procedures( p = 0.2571), in spite of the arithmetic

Table 14. Transfusion policy according to author, in bimaxillary surgery without concomitant procedures.

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