Predicting postoperative haemoglobin changes after burn surgery

Abstract

Background. Burn surgery is associated with significant blood loss and fluid shifts that cause rapid haemoglobin (Hb) changes during and after surgery. Understanding the relationship between intraoperative and postoperative (day 1) Hb changes may assist in avoiding postoperative anaemia and unnecessary peri-operative blood transfusion. Objective. To describe the Hb changes into the first day after burn surgery and to identify factors predictive of Hb changes that would guide blood transfusion decisions. Methods. This was a single-institution, retrospective cohort study that included 158 patients who had undergone burn surgery. Hb was measured at the start and end of surgery, and on the first day (16 -32 hours) after surgery, and the results were analysed. Peri-operative factors (Hb at the end of surgery, total body surface area operated on (TBSA-op), fluid administration and intraoperative blood administration) were evaluated to determine their association with Hb changes on the first day after surgery. Results. The mean (standard deviation) preoperative Hb was 10.6 (2.29) g/dL, the mean postoperative Hb was 9.4 (2.01) g/dL, and the mean Hb on the first day after surgery was 9.2 (2.19) g/dL. Median total burn surface area was 7% (interquartile range 9%, min. 1%, max. 45%), with a mean body surface area operated on (debridement area plus donor area) of 9.7%. Of the 158 patients, 26 (16%) had an Hb <7 g/dL (transfusion trigger) on the first day after surgery. For patients with a high (≥9 g/dL), intermediate (≥7 -<9 g/dL), or low (<7 g/dL) Hb measurement at the end of burn surgery, those with an Hb below the transfusion trigger on the first day after burn surgery were 0%, 27%, and 75%, respectively. End-of-surgery Hb and TBSA-op strongly predicted the first day Hb level. In the intermediate group, 55% of patients with a TBSA-op ≥11% had an Hb below the transfusion trigger on the first day after surgery. Conclusion. Hb at the end of burn surgery was the best predictor of Hb on the first day after surgery. Patients with an Hb <7 g/dL remained as such on the first postoperative day. Half of the patients with an end-of-surgery Hb ≥7 -<9 g/dL and who had ≥11% TBSA-op had an Hb <7 g/dL on the first postoperative day.

Haemoglobin changes before and after packed red blood cells transfusion in burn patients: A retrospective cross‐sectional study

“…Blood transfusion in older burn patients had less effect on Hb level than in young patients. Previous studies conducted in Iran and South Africa conflicted with the findings of this study and no significant relationship was found between age and Hb level changes 60,61 . The existence of such a conflict can be caused by the criteria for entering the studies and the demographic characteristics of the participants.…”

“…In the study of Kilyewala et al, the results showed that low BMI and TBSA are more than 20% of the factors predicting the need for blood transfusion 62 . The study of Slabber et al also showed that TBSA can strongly predict Hb levels 61 . Another factor that was found to be associated with changes in Hb levels after receiving packed RBCs in the present study was the length of hospitalisation.…”

“… 62 The study of Slabber et al also showed that TBSA can strongly predict Hb levels. 61 Another factor that was found to be associated with changes in Hb levels after receiving packed RBCs in the present study was the length of hospitalisation. The results showed that in patients who are hospitalised for a longer period, the transfusion of one unit of packed RBCs can cause a greater increase in Hb level.…”

“…Previous studies conducted in Iran and South Africa conflicted with the findings of this study and no significant relationship was found between age and Hb level changes. 60 , 61 The existence of such a conflict can be caused by the criteria for entering the studies and the demographic characteristics of the participants. However, achieving such a contrast proves the need to consider other predictive factors such as BMI and TBSA.…”