Transfusion requirement and length of stay of anaemic surgical patients associated with a patient blood management service: a single-Centre retrospective study.

OBJECTIVE: To assess the value of patient blood management (PBM) in the detection and management of preoperative anaemia before elective surgery. BACKGROUND: PBM is recognised as the standard of care, with diagnosis and management of preoperative anaemia being the key components of PBM. No formal assessment of the value of PBM anaemia screening and correction before scheduled surgery had been made at our hospital. METHODS: We conducted a retrospective study in a tertiary-care, academic hospital of consecutive records of elective surgery (n = 25 641). We excluded minor surgeries. We identified anaemic patients who had been assessed by PBM or not (non-PBM). We calculated transfusion incidence and hospital length of stay (LOS) across all surgical specialities. RESULTS: During the 1-year study period, 15 245 patients were eligible for inclusion; 311 patients (2·0%) were transfused, and 83·3% of transfusions were in anaemic patients. Transfusion incidence was 9·2% in anaemic PBM-assessed patients and 17·4% in non-PBM patients. For haemoglobin (Hb) <100 g L-1 , the transfusion incidence was 22·1% [95% confidence interval (CI) 15·5-30·6%] in PBM and 40·0% (95% CI 35·1-45·0%) in non-PBM patients, and for Hb 100-119 g L-1 , it was 4·7% (95% CI 2·8-7·5%) and 7·9% (95% CI 6·3-9·8%), respectively. Overall mean LOS was 2·1 days [standard deviation (SD) 6·0]. Mean LOS with Hb <100 g L-1 was 6·7 days (SD 14·8) in PBM-assessed patients and 12·4 days (SD 19·5) in non-PBM patients and was 3·1 (SD 5·2) and 6·2 (SD 9·5) days, respectively, for Hb 100-119 g L-1 . CONCLUSION: Anaemic elective surgery patients assessed by patient blood management (PBM) had a markedly lower transfusion risk and shorter LOS than anaemic patients not assessed by PBM.

Assessment of intra-operative cell salvage haemolysis in the obstetric and orthopaedic clinical setting, in comparison with allogeneic blood.

OBJECTIVES/BACKGROUND: Haemolysis is still a re-occurring theme in intra-operative cell salvage (ICS) with further haemolysis possibly caused by suction pressure, washing/centrifuging process and aspiration method. Previous investigations, along with manufacturer's reports, state that between 75 and 95% of free haemoglobin (Hb) is removed by the washing and centrifugation process; however, if these results are above the expected levels, excess free Hb may remain after washing. The aim of this article was to quantify haemolysis levels whilst employing different aspiration methods from skimmed (orthopaedics) and pooled (obstetrics) surgery types and comparing this to allogeneic blood. METHODS/MATERIALS: Samples obtained from 50 allogeneic units and 50 ICS cases (25 obstetric and 25 orthopaedic) were tested for plasma free Hb levels. RESULTS: Free Hb testing as a marker of haemolysis was greatest in orthopaedic 17·2 g L(-1) (range: 1·7-57·0 g L(-1) ), obstetric 2·8 g L(-1) (range: 1·0-13·5 g L(-1) ) and allogeneic 0·95 g L(-1) (range: 0·2-4·8 g L(-1) ) cases. CONCLUSION: ICS involving skimming collection techniques (orthopaedics) had significantly more haemolysis than pooled collections (obstetrics) (P < 0·001). Further analysis of orthopaedic data highlighted a difference between the three machines used with the Haemonetics OrthoPat (Haemonetics Ltd., Watford, UK) significantly higher with a free Hb of 29·8 g L(-1) compared with the other two machines 6·7 g L(-1) (P < 0·001). On comparison of ICS blood to allogeneic blood, free Hb levels obtained from ICS were significantly higher (P < 0·001).

Lactate dehydrogenase and Haemolysis Index as quality control markers of haemolysis in intra-operative cell salvage.

OBJECTIVES: The aim of this investigation was to explore the potential use of the tests lactate dehydrogenase (LDH) and Haemolysis Index as haemolysis markers in intra-operative cell salvage (ICS) blood in comparison to plasma free haemoglobin levels. BACKGROUND: Quality control (QC) should be seen as a fundamental part of any ICS blood conservation programme, however, due to lack of available knowledge, familiarity and experience, QC is still a comparatively new subject. A QC pilot scheme is currently being undertaken by the Royal Cornwall Hospital in association with the UK Cell Salvage Action Group to explore potential markers that can be used to assess the quality of blood obtained from ICS. This test list should be available to all ICS users and achievable within financial budgets. Currently this proposed test list includes a full blood count, a protein marker such as urine albumin/microalbumin and heparin monitoring. Haemolysis testing is another key marker. METHODS/MATERIALS: Samples were collected from ICS processed blood and allogeneic SAGM leucodepleted red cell units and processed for plasma free haemoglobin, LDH and Haemolysis Index. RESULTS: There was a very strong correlation between plasma free haemoglobin and LDH (0.960), and plasma free haemoglobin and the Haemolysis Index (0.944). CONCLUSION: We have shown that the LDH and Haemolysis Index tests are suitable and reliable alternatives for measuring haemolysis from samples obtained from ICS or allogeneic blood. We have incorporated the LDH test into our Hospital's ICS QC package and recommend that this test is considered for all ICS QC samples.

A modified thrombin clotting time test as a quality control marker for heparin contamination in obstetric intraoperative cell salvage.

OBJECTIVE: To assess if a modified thrombin clotting time test could be used as a simple quality control (QC) method to screen for unfractionated heparin in the product obtained from obstetric intraoperative cell salvage cases before re-infusion. BACKGROUND: A national QC scheme has recently been piloted to monitor the quality of autologous blood being returned to the patient. Laboratory tests include full blood count and microalbumin. Unfractionated heparin testing should be performed to ensure that there is no gross contamination of heparin in the final product; however, presently, there is no quick cheap test available suitable for heparin detection. MATERIALS AND METHODS: Samples were collected into plain non-anticoagulated tubes and centrifuged at 2500 × g for 5 min. Supernatant was mixed with commercially available coagulated normal plasma and a thrombin clotting time test performed. RESULTS: Calibration runs demonstrated that our system was sensitive up to 0 · 14 IU mL(-1) heparin, linear between 0 · 08 and 0 · 14 IU mL(-1). CONCLUSION: We have shown that the thrombin clotting time test can be modified and used as a cheap and reliable marker for heparin contamination. We have successfully incorporated this modified test into our hospital's obstetric QC scheme.

Intraoperative cell salvaged blood as part of a blood conservation strategy in Caesarean section: is fetal red cell contamination important?

BACKGROUND: Cell salvage is used in obstetric surgery as part of a blood conservation strategy in our Trust. This carries a theoretical risk of amniotic fluid embolism and also a risk of fetal red cells being present in the re-infusion, resulting in alloimmunization. In this study, we attempted to quantify the risk of antibody formation from re-infusion of autologous blood after Caesarean section. METHODS: Women presenting for elective Caesarean section were routinely requested to consent for collection of blood by cell salvage, using one suction device. If an adequate volume of blood was collected, it was processed and, if clinically appropriate, re-infused via a leucodepletion filter. Women who received a re-infusion were followed up to test for antibody formation. RESULTS: Seventy women consented for re-infusion and follow-up. The median volume re-infused was 324 ml (range 118-1690 ml). The median fetal red cell contamination was 0.8 ml (range 0.2-12.9 ml). All re-infusions were given without adverse clinical signs. No antibodies were detected in 48 follow-up samples. One positive anti-S antibody was detected. CONCLUSIONS: The implementation of a blood conservation strategy which includes the use of intraoperative cell salvage appears safe and can contribute to a reduction in the number of blood transfusions to the obstetric population. We remain uncertain of the significance of fetal red cell contamination.

Contamination of salvaged maternal blood by amniotic fluid and fetal red cells during elective Caesarean section.

BACKGROUND: Cell salvage in obstetrics is still a controversial subject and has yet to be fully embraced. The aim of this exploratory study was to measure amniotic fluid (AF), heparin, and fetal red cell contamination of washed filtered salvaged maternal blood and to investigate differences based on the number of suction devices used. METHODS: Patients undergoing elective Caesarean section were assigned alternately to one of two groups. In Group 1, all blood and AF was collected with one suction. In Group 2, AF was aspirated to waste with a second separate suction device before collection of any blood. RESULTS: In both groups, alpha-fetoprotein (AFP), squames cells, and heparin were significantly reduced (P<0.001) by the washing and filtering process. Mean AFP levels post-filtration were 2.58 IU ml(-1) in Group 1 and 3.53 IU ml(-1) in Group 2. Squames cells were completely removed in all but two cases. Fetal red blood cells were still present in the final product, range 0.13-4.35%. In Group 1, haemoglobin and haematocrit were higher than in Group 2, with lower white blood cell, AFP, and fetal red cell counts. CONCLUSIONS: This study adds to the growing body of evidence that there is little or no possibility for AF contamination to enter the re-infusion system when used in conjunction with a leucodepletion filter.