Perioperative use of erythropoietin

Exploring the effects of post operative hyperoxic intermittent stimuli on reticulocyte levels in cancer patients: a randomized controlled study

BACKGROUND

Anemia is common among hospitalized critically ill and surgical oncological patients. The rising incidence of cancer and aggressive treatments has increased the demand for blood products, further strained by a dwindling donor pool. The normobaric oxygen paradox (NOP) has emerged as a potential avenue to increase EPO levels. While some studies support its efficacy, research remains limited in clinical settings. This study aims to assess the effectiveness of a NOP protocol in stimulating erythropoiesis, as measured by changes in reticulocyte counts, in cancer patients undergoing abdominal surgeries.

METHODS

This is a post hoc analysis of a prospective, single-center, controlled, randomized study. A total of 49 patients undergoing abdominal surgery were analyzed at the Institut Jules Bordet. Adult patients admitted to the intensive care unit (ICU) for at least 24 h were enrolled, excluding those with severe renal insufficiency or who received transfusions during the study period. Participants were randomized into two groups: a normobaric oxygen paradox (OXY) group who received 60% oxygen for 2 h on days 1, 3, and 5 post-surgery and a control (CTR) group who received standard care. Data on baseline characteristics, surgical details, and laboratory parameters were collected. Statistical analysis included descriptive statistics, chi-square tests, t-tests, Mann-Whitney tests, and linear and logistic regression.

RESULTS

The final analysis included 33 patients (median age 62 [IQR 58-66], 28 (84.8%) males, with no withdrawals or deaths during the study period. No significant differences were observed in baseline surgical characteristics or perioperative outcomes between the two groups. In the OXY group (n = 16), there was a significant rise (p = 0.0237) in the percentage of reticulocyte levels in comparison to the CTR group (n = 17), with median values of 36.1% (IQR 20.3-57.8) versus - 5.3% (IQR - 19.2-57.8), respectively. The increases in hemoglobin and hematocrit levels did not significantly differ between the groups when compared to their baselines' values.

CONCLUSIONS

This study provides preliminary evidence supporting the potential of normobaric oxygen therapy in stimulating erythropoiesis in cancer patients undergoing abdominal surgeries. While the OXY group resulted in increased reticulocyte counts, further research with larger sample sizes and multi-center trials is warranted to confirm these findings.

TRIAL REGISTRATION

The study was retrospectively registered under NCT number 06321874 on The 10th of April 2024.

Organ function, sphingolipid levels and inflammation in tunicamycin induced endoplasmic reticulum stress in male rats

Disorders of the endoplasmic reticulum (ER) lead to cellular damage but can cause cell death if ER dysfunction is prolonged. We aimed to examine liver/kidney functions, neutral sphingomyelinase (N-SMase) activity, sphingolipid levels, cytosolic phospholipase A2 (cPLA2) and cyclooxygenase-2 (COX-2) protein expression in rats under ER stress. ER stress was induced by tunicamycin (TM) and the ER stress inhibitor taurodeoxycholic acid (TUDCA) was injected before induction of ER stress. ER stress was confirmed by increased tissue levels of GRP78. Hematological and biochemical profiles were measured by autoanalyzers while hepatic and renal injury was evaluated via microscopy and histopathological scoring. Tissue levels of C16-C24 sphingomyelins (SM), C16-C24 ceramides (CERs) and sphingosine-1-phosphate (S1P) were determined by LC-MS/MS. Tissue cPLA2 and COX-2 were measured by western blot and activity assays. Tunicamycin treatment caused kidney and liver function test abnormalities, increased hematocrit and hemoglobin levels but decreased white blood cell counts. Histopathological findings showed hepatic necroinflammation and renal tubular damage in rats treated with TM. TUDCA administration attenuated WBC abnormalities and TM- induced hepatic/renal functional impairment in ER stress, as evident by significantly restored serum ALT, AST, creatinine, and total bilirubin levels. A significant increase was observed in N-SMase activity, tissue levels of C16-C24 CERs, cPLA2 and COX-2 expression in liver and kidney tissue under ER stress. TUDCA administration decreased tissue CER levels, cPLA2 and COX-2 expression as well as prostaglandin E2 (PGE2) formation. These results signify that ER stress causes hepatic and renal toxicity as well as CER-induced PGE2 formation in liver and kidney.

Maternal mortality from hemorrhage

Hemorrhage remains as one of the top 3 obstetrics related causes of maternal mortality, with most deaths occurring within 24-48 hours of delivery. Although hemorrhage related maternal mortality has declined globally, it continues to be a vexing problem. More specifically, the developing world continue to shoulder a disproportionate share of hemorrhage related deaths (99%) compared with industrialized nations (1%). Given the often preventable nature of death from hemorrhage, the cornerstone of effective mortality reduction involves risk factor identification, quick diagnosis, and timely management. In this monograph we will review the epidemiology, etiology, and preventative measures related to maternal mortality from hemorrhage.

Possibility of enhanced risk of retinal neovascularization in repeated blood donors: blood donation and retinal alteration

Repeated blood donors manifest clinical, subclinical, and biochemical signs of iron deficiency anemia, have significantly higher erythropoietin and vascular endothelial growth factor (VEGF) concentrations, and decreased tissue oxygen saturation, oxygenated tissue hemoglobin, and regional cerebral oxygen saturation. Erythropoietin and VEGF are potent retinal angiogenic factors which may initiate and promote the retinal angiogenesis process independently or simultaneously. Increases in circulating levels of erythropoietin and VEGF are proportionate to the levels of hematocrit, hypoxemia, and tissue hypoxia. It is suggested that higher erythropoietin production following iron deficiency anemia-induced chronic hypoxemia/ hypoxia may, hypothetically, enhance the risk of retinal angiogenesis and/or neovascularization, possibly by inducing hypoxia inducible factor-1 alpha, which consequently upregulates genes stimulating angiogenesis, resulting in formation of a new vasculature, possibly by modulation of signal transducer and activator of transcription 3 signaling in the retina. Implications of this hypothesis cover erythropoietin doping, chronic hypoxia, and hypoxemic situations, such as angiogenesis-related cardiac and pulmonary diseases.

Perioperative blood conservation

This review examines the science and methodology of blood conservation in modern anaesthetic and surgical practice. Blood transfusion is associated with increased morbidity and mortality in all surgical patients, and the reduction or even elimination of transfusion has been and continues to be the subject of much research. Blood substitutes, despite extensive investigation, have not been proved successful in trials to date, and none have entered clinical practice. Pharmacological treatments include antifibrinolytic drugs (although aprotinin is no longer in clinical use), recombinant factor VIIa, desmopressin, erythropoietin and topical haemostatic agents, and the role of each of these is discussed. Autologous blood transfusion has recently fallen in popularity; however, cell salvage is almost ubiquitous in its use throughout Europe. Anaesthetic and surgical techniques may also be refined to improve blood conservation. Blood transfusion guidelines and protocols are strongly recommended, and repetitive audit and education are instrumental in reducing blood transfusion.

Does the Use of Erythropoietin Reduce the Risk of Exposure to Allogeneic Blood Transfusion in Cardiac Surgery? A Systematic Review and Meta-Analysis

BACKGROUND

The use of blood conservation techniques is important in cardiac surgery as postoperative bleeding is common and allogeneic blood transfusion carries the risk of transfusion reactions and infection transmission. Erythropoietin with and without preoperative autologous blood donation is one of the modalities to avoid allogeneic blood transfusion. The objective of this review was to assess the effectiveness of erythropoietin in reducing the risk of exposure to allogeneic blood transfusion during or after cardiac surgery.

METHODS

A meta-analysis of 11 identified randomized controlled trials, reporting comparisons between erythropoietin and control, was undertaken. The primary outcome was the number of patients exposed to allogeneic blood transfusion during or after cardiac surgery.

RESULTS

Eleven studies, involving 708 patients, met the inclusion criteria for this review. In total, 471 patients were given erythropoietin, and 237 patients formed the control group. The administration of erythropoietin with and without preoperative autologous blood transfusion prior to cardiac surgery is associated with a significant risk reduction: RR = 0.28 (95% CI 0.18-0.44, P < 0.001) and RR = 0.53 (95% CI 0.32-0.88, P < 0.01), respectively.

CONCLUSION

The administration of erythropoietin before cardiac surgery is associated with a significant reduction in the risk of exposure to allogeneic blood transfusion. Further studies are warranted to define the patients' subgroups that may benefit the most from EPO administration.

IL-6 and IL-8 response to erythropoietin therapy in radical hysterectomy

BACKGROUND

The use of recombinant human erythropoietin (rHuEPO) improves autologous blood donation before elective surgery. However, there are other studies indicating that rHuEPO may suppress postoperative endogenous production of erythropoietin and stimulate inflammatory mediator release. Weekly donations generate only a moderate increase in endogenous erythropoietin production. We scheduled patients with cancer to predeposit three units of blood in 2 weeks, with or without rHuEPO therapy. The aim was to determine whether rHuEPO therapy and/or an aggressive donation schedule alter perioperative erythropoietin concentrations and whether rHuEPO therapy leads to the release of the pro-inflammatory cytokines IL-6 and IL-8.

METHODS

Thirty women scheduled for radical hysterectomy and pelvic lymphadenectomy were randomly assigned to either a control group with no rHuEPO therapy or to receive rHuEPO. Three units of whole blood were collected from each patient before the operation. Concentrations of haemoglobin, erythropoietin (s-EPO) and cytokines (IL-6 and IL-8) were repeatedly analyzed before and after the operation.

RESULTS

During the preoperative donation period, median s-EPO levels in the control group increased from 7 to 14 IU l(-1). There was a great increase in s-EPO concentrations 1 h postoperatively in the rHuEPO group compared with the control group (P < 0.001). IL-6 and IL-8 were not significantly changed after intravenous administration of rHuEPO.

CONCLUSION

The use of rHuEPO therapy to optimise autologous blood donation does not influence IL-6 and IL-8 release. 1 h postoperatively rHuEPO therapy resulted in elevated s-EPO concentrations. There was, however, no difference in s-EPO between the groups from day 1 postoperatively and until the end of the study.