Introduction of universal prestorage leukodepletion of blood components, and outcomes in transfused cardiac surgery patients

A randomized control trial for evaluation of transfusion related immuno-modulation in patients with meningioma

BACKGROUND

Blood transfusion necessity in neurosurgery varies based on surgical type, blood loss, and patient anemia. Leukocytes in red blood cells (RBCs) component release pro-inflammatory cytokines during storage, contributing to transfusion-related immunomodulation (TRIM). Our aim was to examine the impact of the leukocyte content in transfused PRBCs on patients undergoing neurosurgery for meningioma tumours.

STUDY DESIGN AND METHODS

This prospective randomized controlled trial conducted from 2018 to 2020 by dividing patients randomly into non-leukoreduced (NLR) (n = 65) and leuko-reduced (LR) (n = 65) groups based on PRBCs received during surgery and hospital stay. Hospital and ICU stays, mechanical ventilation duration, and postoperative bacterial infections were observed. Hematological parameters and cytokine levels (IL-10, INF-gamma, and FAS-L) were assessed at pre-transfusion, 24 h, and 7 days post-transfusion. Data analysis included Mann-Whitney U test, Friedman test, Fisher's chi-square test, with statistical significance at p < 0.05.

RESULTS

In our study, ICU and hospital stay duration showed no significant difference (p = 0.06) between groups. However, NLR group had longer mean mechanical ventilation (18 ± 40.1 h) than the LR group (12.8 ± 8.6 h). Both groups showed statistically significant increase in Fas-L level on days 1 and 7 (p < 0.05). The IL-10 levels rose 43% in the NLR group, while and decreased by 7% the LR group on day 1. On day 7, IL-10 increased by 75% in NLR and decreased by 40% in LR, with no significance (p > 0.05).

CONCLUSION

In conclusion, leukoreduction appeared to offer some immune response protection in term of reducing mechanical ventilation timings and cytokine level changes.

Relationship between Preoperative Hemoglobin and Hospital Stays in Patients Receiving Prime Total Knee Arthroplasty

Previous evidence has shown that preoperative hemoglobin is related to poor prognosis after primary total knee arthroplasty. Reviewing cohort research was conducted at the third-level academic medical center in Singapore and involved 2,676 patients. Population statistics, complications, preoperative hemoglobin (Hb) levels, length of hospital stay (LOS), and readmission information of thirty days were obtained. Anemia was defined based on the World Health Organization (WHO). LOS extension was with the definition as no less than six days with >1/75 LOS corresponding to the data. According to the study requirements, we finally collected 2273 patients. We plotted the relationship between hemoglobin levels and length of stay. We analyzed 2273 patients, with 140 cases of Hb ≤ 11.0 g/dL, 831 cases of Hb 11.0–12.9 g/dL, and the other 1320 cases of Hb ≥ 13.0 g/dL. The mean age of patients with prolonged LOS (68.4 ± 8.2 years) was higher than that of patients with familiar LOS (65.9 ± 8.0 years). In addition, patients with extended LOS had higher ASA-PS values, a history of cerebrovascular accidents (CVA), diabetes mellitus (DM), and ischemic heart disease (IHD) (P < 0.001), repeated surgery within 30 days, HB, and operative time (min) (P < 0.01). Variables independently related to increased risk of extended LOS included general anesthesia (GA) (adjusted OR (aOR) 1.4, P=0.005, P=0.005), CVA (aOR 3.0, P < 0.001), DM (aOR 1.4, P=0.032), and HB < 11 g/dL. Variables increased LOS included HB ≥ 13 g/dL (aOR 0.4, P < 0.001) and Hb 11.0–12.9 g/dL (aOR 0.5, P=0.001). Hb was 14 g/dL, and LOS decreased by at least 0.24 days for each 1 g increase in preoperative Hb before the inflection point (95%CI 0.12 to 0.36, P=0.0001). Anemia is familiar in patients receiving elective total knee arthroplasty (TKA) in Singapore. Thus, this study describes that the preoperative hemoglobin was associated with length of stay. We found that on the left where HB was 14, length of stay decreased with increased hemoglobin values. We recommend preoperative correction of anemia to determine the diagnosis.

Effect of membrane parameters and filter structure on the efficiency of leukocyte removal by electrospun poly(ethylene-co-vinyl alcohol) membranes

Electrospinning technology is an experimentally verified tool for the generation of membranes with competing efficiency useful for leukodepletion filter, customarily used in blood banks to lessen the risks with blood transfusions. Even though a few electrospun polymers have been reported to be efficient leukodepletion filter membranes, poly(ethylene-co-vinyl alcohol) (EVAL) being one among, owe to their exceptional advantage of being electrospun from a non-toxic solvent like rubbing alcohol. Besides their excellent blood compatibility, EVAL membranes proffer a leukodepletion performance nearly as same as that of commercial leukodepletion filters. However, the role of various membrane parameters on the leukodepletion efficiency of electrospun EVAL membranes need to be disclosed in advance to their commercialization. Hence this study is an attempt to disclose the ability of electrospinning to being tuned towards the fabrication of filters with different membrane parameters including fiber diameter and pore diameter, with a typical example of EVAL. In addition, the impact of filter design upon the leukodepletion performance was also unveiled by comparing a symmetric filter where all the membranes were of uniform pores with that of an asymmetric filter where the pore sizes of upper and lower layer in the filter was different. The results of blood filtration experiments through the developed prototype filters underline the superiority of asymmetric filters over to symmetric one and, the asymmetric filters wherever the fiber diameter was 1.8 and 3 μm, offered rapid and excellent leukodepletion. Membranes with thinner fibers showed an increased flow resistance. The pore sizes of the membranes being 9 - 29 μm, larger than the size of blood cells, alludes to the direct adhesion of leukocytes to filter membranes as the major mechanism of leukocyte removal. Hence it is concluded that despite the suitability of electrospinning for fabrication of leukodepletion filter media, the use of nano-dimension fibers is not preferred for leukocyte adhesion filter when the material of choice is such a polymer with ideal surface chemistry, wettability and inherent ability for leukocyte binding.

The effect of blood transfusion on sublingual microcirculation in critically ill patients: A scoping review

PURPOSE

To investigate the effects of red blood cell (RBC) transfusion on sublingual microcirculation in critically ill patients.

METHODS

Systematic strategy was conducted to search studies that measured sublingual microcirculation before and after transfusion in critically ill patients. This review was reported according to the Preferred Reporting Items for Systematic Review and Meta-Analyses Scoping Review Extension.

RESULTS

The literature search yielded 114 articles. A total of 11 studies met the inclusion criteria. Observational evidence showed diffusive capacity of the microcirculation significantly improved in intraoperative and anemic hematologic patients after transfusion, while the convective parameters significantly improved in traumatic patients. RBC transfusion improved both diffusive and convective microcirculatory parameters in hypovolemic hemorrhagic shock patients. Most of the studies enrolled septic patients showed no microcirculatory improvements after transfusion. The positive effects of the leukoreduction were insufficiently supported. The effects of the storage time of the RBCs were not conclusive. The majority of the evidence supported a negative correlation between baseline proportion of perfused vessels (PPV) and changes in PPV.

CONCLUSIONS

This scoping review has catalogued evidence that RBC transfusion differently improves sublingual microcirculation in different populations. The existing evidence is not sufficient to conclude the effects of the leukoreduction and storage time of RBCs.

No Significant Association Between the Transfusion of Small Volumes of Leukocyte-Depleted Red Blood Cells and Mortality Over 7 Years of Follow-up in Patients Undergoing Cardiac Surgery: A Propensity Score Matched Analysis

BACKGROUND

The impact of red blood cell (RBC) transfusion on long-term clinical outcome is controversial.

METHODS

We prospectively recorded follow-up data of 6124 cardiac surgical patients who received no transfusion (RBC- group) or 1-2 units of leukocyte-depleted RBC (RBC+ group) at our institution. The primary end point was overall mortality up to 7 years after cardiac surgery; secondary end point was coronary artery revascularization during follow-up. To correct for nonrandomized group assignment, propensity score (PS) matching was performed. A subgroup analysis was also performed in patients with preoperative anemia.

RESULTS

PS matching was possible in 4118 patients. During a mean follow-up of 4.05 years (range, 0.0-7.3 years), 140 patients (14.6%) died in the RBC- group and 173 (17.2%) died in the RBC+ group. The hazard ratio for the RBC+ group versus the RBC- group was 1.00 (95% confidence interval, 0.79-1.25; P = .969). The number of revascularizations was 96 (9.9%) and 125 (10.6%), respectively, with a hazard ratio of 1.21 (95% confidence interval, 0.92-1.58; P = .166) for the RBC+ group. Preoperative anemia was not a risk factor for postoperative mortality, even when patients were transfused.

CONCLUSIONS

This PS-matched analysis does not provide evidence for an association of the transfusion of small volumes of leukocyte-depleted RBCs with an increased postoperative mortality in cardiac surgical patients. Moreover, preoperative anemia could not be identified as a risk factor for increased postoperative mortality.

Association between preoperative anaemia with length of hospital stay among patients undergoing primary total knee arthroplasty in Singapore: a single-centre retrospective study

OBJECTIVES

Studies in western healthcare settings suggest that preoperative anaemia is associated with poor outcomes after elective orthopaedic surgery. We investigated the prevalence of preoperative anaemia among patients with primary unilateral total knee arthroplasty (TKA) in Singapore and its association with length of hospital stay (LOS), perioperative blood transfusion and hospital readmission rates.

METHODS

Retrospective cohort study performed in a tertiary academic medical centre in Singapore, involving patients who underwent primary unilateral TKA between January 2013 and June 2014. Demographics, comorbidities, preoperative haemoglobin (Hb) level, LOS and 30-day readmission data were collected. Anaemia was classified according to WHO definition. Prolonged LOS was defined as more than 6 days, which corresponds to >75th centile LOS of the data.

RESULTS

We analysed 2394 patients. The prevalence of anaemia was 23.7%. 403 patients (16.8%) had mild anaemia and 164 patients (6.8%) had moderate to severe anaemia. Overall mean LOS was 5.4±4.8 days. Based on multivariate logistic regression, preoperative anaemia significantly increased LOS (mild anaemia, adjusted OR (aOR) 1.71, p<0.001; moderate/severe anaemia, aOR 2.29, p<0.001). Similar effects were seen when preoperative anaemia was defined by Hb level below 13 g/dL, regardless of gender. Transfusion proportionately increased prolonged LOS (1 unit: aOR 2.12, p=0.006; 2 or more units: aOR 6.71, p<0.001). Repeat operation during hospital stay, previous cerebrovascular accidents, general anaesthesia and age >70 years were associated with prolonged LOS. Our 30-day related readmission rate was 1.7% (42) cases.

CONCLUSION

Anaemia is common among patients undergoing elective TKA in Singapore and is independently associated with prolonged LOS and increased perioperative blood transfusion. We suggest measures to correct anaemia prior to surgery, including the use of non-gender-based Hb cut-off for establishing diagnosis.