BLOODLOSS AND TRANSFUSION NEED IN ORTHOGNATHIC SURGERY: REVIEW OF LITERATURE
Review Article blood loss and operation time, show two outliers of blood loss, one close to 2900 mL and one at 5000 mL, in an orthognathic surgery group containing 27 Le Fort I operations and 52 bimaxillary cases. Choi et al [ 58 ], in a reported graph with the relationship between total blood loss and operation time in 61 patients, show 4 cases of blood loss in excess of 3000 mL. The mean blood loss in 11 patients who received blood transfusion included one group of 7 patients( 2,291 ± 831.7 mL) and one group of 4 patients( 1,732 ± 856.8 mL). Rummasak et al [ 43 ] reported retrospectively on 208 bimaxillary orthognathic osteotomies, and their graph depicting the regression analysis between blood loss and operative time shows one case with 2750 mL and one case with 3400 mL of estimated blood loss. Samman et al [ 44 ] reported on 291 bimaxillary and 69 single-jaw surgical cases with a range of blood loss between 50 mL and 5000 mL and 5 hemorrhagic perioperative incidents. They reported that 4 % of the 291 bimaxillary surgical cases required a transfusion greater than 2 units of blood. In the range of blood loss reported by Ash [ 9 ], we find a value of 3400 mL, which occurred in a bimaxillary osteotomy case. In the series of Böttger [ 6 ], an upper limit of 3400 mL is reported.
3.8. Criteria for transfusion The updated Cochrane review on transfusion thresholds [ 4 ] concludes that, for most patients, giving less blood is safe and blood transfusion is probably not essential until hemoglobin levels drop below 7.0 to 8.0 g / dL. In the orthognathic literature, no consensus exists regarding what constitutes a blood transfusion‘ trigger’. Fenner et al [ 13 ] performed 105 consecutive bimaxillary osteotomies without any need for transfusion and argued that in young healthy adults, hemoglobin concentrations as low as 50 g / L can be sustained. In contrast, Zellin et al [ 4 ] gave blood transfusion when arterial hemoglobin was below 100 g / L. Flood et al [ 63 ] reported overtransfusion in bimaxillary osteotomies where the postoperative hemoglobin increased after homologous transfusion. Obviously, the high rate of blood transfusion in the series of Flood et al [ 63 ] could have been avoided by more strict criteria for transfusion. The general condition of the patient and underlying diseases are taken into account when deciding on the need for blood cell transfusion, and hemoglobin concentration is one of the criteria [ 39,64 ] used the criterion of allowable blood loss. The allowable blood loss was defined as 20 % of the estimated blood volume( male 70 mL / kg, female 65 mL / kg), and once this was reached, a unit of packed red cells was transfused.
3.9. Risk of transfusion The authors report that the risk for viral transmission is very low in developed countries. An example is Canada, where the residual risk of transmission through transfusion of HIV, HCV, and HBV is estimated to be 1 per 7.8 million donations, 1 per 2.3 million donations, and 1 per 153,000 donations, respectively [ 4 ]. This reduction in risk should lead to the abandonment of the practice of autologous blood transfusion because the most important reason for an autologous blood donation is the greatly reduced risk of disease transmission. It has been reported that the availability of autologous blood increased the rate of autologous blood transfusion
[ 22,37 ]. In case strict criteria are used to‘ trigger’ blood transfusion, the availability of autologous blood did not seem to increase the rate of blood transfusion [ 25 ].
4. Preoperative donation of autologous blood Preoperative autologous blood donation has several disadvantages. It is not risk free, and human error and the administration of the wrong unit of blood still can occur. It leads to anemia and hypovolemia [ 6 ] and is more expensive than homologous blood donation. Patients waste time from work to donate. Autologous blood that is not used is discarded and constitutes waste [ 26 ]. Iwase et al [ 5 ] further reported increased intraoperative blood loss to be associated with total withdrawn blood before the operation. Retransfused autologous blood has a lower hemoglobin concentration and the erythrocyte function diminishes by 10 % per week in unused autologous blood [ 22 ]. While avoiding the risk of transfusion of homologous blood is an advantage of transfusion of autologous blood, Moennig et al [ 51 ] reported that 3 out of 4 patients needing a transfusion received the available units of autologous and additional units of homologous blood to compensate the loss. These four patients had an average estimated blood loss of 975 mL [ 51 ]. Thus, the donation of autologous blood does not entirely exclude the risk of needing a homologous blood transfusion. Meta-analyses on preoperative autologous blood donation have shown that this practice indeed reduces the use of allogeneic blood transfusion by 63 %, but at the same time increases overall red blood cell transfusions( ie, allogeneic and autologous red blood cell units) by 30 % and causes a decline in patient hemoglobin concentration by more than 1 g / dL from before commencing preoperative autologous blood donation to immediately prior to surgery [ 65 ]. The German recommendation for autologous blood donation states:“ The so-called‘ liberal’ transfusion indication for autologous blood products stands in contrast to the strict indication parameters for the therapeutic use of blood products laid down in the present guidelines and should be rejected because it is for all practical purposes equivalent to a blood transfusion without indication” [ 66 ]. Donors of autologous blood will more likely receive a transfusion because their initial hemoglobin value has been lowered by the autologous blood donation and because the availability of autologous blood influences the decision of transfusion. Puelacher [ 26 ] reports that the mean hemoglobin level of 121 patients prior to donation was 14.2 g / dL and fell to 12.7 g / dL after a mean donation of 2.3 units per patient. If then the criterion for transfusion is a certain hemoglobin level, patients with autodonation will sooner reach that level than patients without donation. Nath and Pogrel [ 24 ] report on 260 orthognathic surgery cases in which 126 patients chose autodonation and 134 patients preferred no autodonation. The transfusion rate was respectively 26 / 126 and 3 / 134 patients, indicating that the availability of autologous blood influenced the decision to use it. Obviously,‘ a perceived benefit’ must accompany this decision, which probably is influenced by the information given to the patient. Puelacher et al
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Stoma Edu J. 2018; 5( 1): 44-51 http:// www. stomaeduj. com