Is There a Role for Preoperative Iron Supplementation in Patients Preparing for a Total Hip or Total Knee Arthroplasty?

BACKGROUND: Several treatment modalities exist for the treatment of perioperative anemia. We determined the effect of oral iron supplementation on preoperative anemia, and the use of blood-conserving interventions before total hip arthroplasty (THA) and total knee arthroplasty (TKA). METHODS: A total of 3435 total joint arthroplasties (1461 THAs and 1974 TKAs) were analyzed during 2 phases of a blood conservation program. The first phase used erythropoietin alfa (EPO) or intravenous (IV) iron for patients at risk for perioperative anemia. The second phase included these interventions, as well as preoperative iron supplementation. The effect on preoperative hemoglobin (Hb) and serum ferritin, as well as EPO and IV iron utilization, was determined. RESULTS: Oral iron therapy increased preoperative Hb level by 6 g/L (P < .001) and 7 g/L (P < .001) in the hip and knee cohorts, respectively. Serum ferritin level rose by 80 µg/L (P < .001) and 52 µg/L (P < .001) in the hip and knee cohorts, respectively. The number of patients with an Hb level <130 g/L was significantly reduced (P < .001 for both cohorts), as were patients with serum ferritin levels <35 µg/L (P = .002 for hip and P < .001 for knee cohorts). Utilization of EPO reduced from 16% to 6% (P < .001) and 18% to 6% (P < .001) in the hip and knee cohorts, respectively. Utilization of IV iron reduced from 4% to 2% (P = .05) and 5% to 2% (P < .001) in the hip and knee cohorts, respectively. CONCLUSION: Oral iron therapy reduced the burden of perioperative anemia and reduced utilization of other blood-conserving therapies before THA and TKA. Future research should delineate the cost-effectiveness of oral iron therapy.

Cerebral Oximetry Monitoring to Maintain Normal Cerebral Oxygen Saturation during High-risk Cardiac Surgery: A Randomized Controlled Feasibility Trial.

BACKGROUND: Cerebral oxygen desaturation during cardiac surgery has been associated with adverse perioperative outcomes. Before a large multicenter randomized controlled trial (RCT) on the impact of preventing desaturations on perioperative outcomes, the authors undertook a randomized prospective, parallel-arm, multicenter feasibility RCT to determine whether an intervention algorithm could prevent desaturations. METHODS: Eight Canadian sites randomized 201 patients between April 2012 and October 2013. The primary outcome was the success rate of reversing cerebral desaturations below 10% relative to baseline in the intervention group. Anesthesiologists were blinded to the cerebral saturation values in the control group. Intensive care unit personnel were blinded to cerebral saturation values for both groups. Secondary outcomes included the area under the curve of cerebral desaturation load, enrolment rates, and a 30-day follow-up for adverse events. RESULTS: Cerebral desaturations occurred in 71 (70%) of the 102 intervention group patients and 56 (57%) of the 99 control group patients (P = 0.04). Reversal was successful in 69 (97%) of the intervention group patients. The mean cerebral desaturation load (SD) in the operating room was smaller for intervention group patients compared with control group patients (104 [217] %.min vs. 398 [869] %.min, mean difference, -294; 95% CI, -562 to -26; P = 0.03). This was also true in the intensive care unit (P = 0.02). There were no differences in adverse events between the groups. CONCLUSIONS: Study sites were successful in reversal of desaturation, patient recruitment, randomization, and follow-up in cardiac surgery, supporting the feasibility of conducting a large multicenter RCT.

Interrelationship of preoperative anemia, intraoperative anemia, and red blood cell transfusion as potentially modifiable risk factors for acute kidney injury in cardiac surgery: a historical multicentre cohort study.

PURPOSE: Acute kidney injury (AKI) is a potentially serious complication of cardiac surgery. Anemia and red blood cell (RBC) transfusion have individually been identified as potentially modifiable risk factors, but their interrelationship with AKI has not been clearly defined. The purpose of this study was to explore the interrelationship of preoperative anemia, intraoperative anemia, and RBC transfusion on the day of surgery with AKI in cardiac surgery. METHODS: This historical cohort study included 16 hospitals, each contributing data on approximately 100 consecutive patients who underwent cardiac surgery with cardiopulmonary bypass. Acute kidney injury was defined as a > 50% increase in creatinine levels during the first postoperative week. Multivariable regression was used to identify the interrelationship between preoperative anemia (hemoglobin < 130 g·L(-1) in males and < 120 g·L(-1) in females), intraoperative anemia (hemoglobin < 80 g·L(-1) during cardiopulmonary bypass), RBC transfusion on the day of surgery, and their interaction terms, after adjusting for site and baseline AKI risk. RESULTS: Of the 1,444 patients included in the study, 541 (37%) had preoperative anemia, 501 (35%) developed intraoperative anemia, 619 (43%) received RBC transfusions, and 238 (16%) developed AKI. After risk-adjustment, an individual with the combination of these three risk factors had a 2.6-fold (95% confidence interval 2.0 to 3.3) increase in the relative risk of AKI over an individual with none of these risk factors. CONCLUSIONS: Preoperative anemia, intraoperative anemia, and RBC transfusion on the day of surgery are interrelated risk factors for AKI after cardiac surgery. Targeting these risk factors may reduce the burden of AKI.

Erythropoietin and intravenous iron in PBM.

The concept of patient blood management is such that if a patient with anemia can be identified in the pre-operative period, therapeutic modalities can be targeted to that patient who might benefit from such treatment. Management strategies include the optimization of preoperative hemoglobin by maximizing hemopoiesis and RBC mass. This can best be achieved with the use of iron supplementation, either oral or intravenous, with or without the use of erythrocyte stimulating agents (ESAs) such as erythropoietin. The use of i.v. iron and ESAs is reviewed. Different i.v. iron formulations available are discussed along with current indications and contraindications for the use of ESAs.

Off-label use of recombinant activated factor VII in surgical and non-surgical patients at 16 Canadian hospitals from 2007 to 2010 (Canadian Registry Report).

PURPOSE: Recombinant activated factor VII (rFVIIa) is a pro-hemostatic drug that is approved for treatment of bleeding in hemophilia patients, but it is frequently used off-label in non-hemophiliacs. The purpose of this study was to determine if the off-label use of rFVIIa is expanding and whether this poses a net harm to patients. METHODS: For this historical cohort study, data were collected on all non-hemophilia patients who received rFVIIa from 2007 to 2010 at 16 Canadian centres, and the pattern of use was examined. Logistic regression was used to determine the prognostic importance of severity of bleeding and the presence of an rFVIIa dose-effect relationship with major adverse events. RESULTS: One thousand three hundred seventy-eight patients received rFVIIa off-label, and 987 (72%) of these patients underwent cardiac surgery. The median [interquartile range] dose was 57 [36-85] µg·kg(-1). Usage increased from 2007 to 2008 (n = 341 and 380, respectively) but decreased in 2009 and 2010 (n = 350 and 307, respectively). Dose of rFVIIa and bleeding severity were associated with measured adverse events (P < 0.05). After adjusting for bleeding severity, dose was not associated with any of the adverse events. CONCLUSIONS: The off-label use of rFVIIa in Canada remains stable. Since severity of bleeding is prognostically important, the benefits of rapidly gaining control of bleeding that is non-responsive to conventional therapies may at times warrant the use of potent hemostatic drugs with established risk profiles, such as rFVIIa.

One dose of tranexamic acid is safe and effective in revision knee arthroplasty.

Revision total knee arthroplasty (TKA) has been associated with an increased risk of perioperative blood loss. Tranexamic acid (TXA) has been proven to be safe and effective in preventing blood loss in primary TKA. The purpose of this study was to evaluate the effect of TXA on blood loss and transfusion rates in revision TKA. We performed a retrospective comparative study on 424 patients who had undergone revision TKA between January 2006 and March 2010. A total of 178 patients did not receive TXA while 246 patients received one intraoperative dose of 20mg/kg of TXA given prior to tourniquet release. There was a significant reduction in hemoglobin loss (42±16g/L vs 38±15g/L, P=0.005), transfusion rates (30.3% vs 16.7%, P=0.001) and average amount transfused (1.1±1.9units vs 0.5±1.1units, P=0.001) in the TXA group. There was no significant difference in recorded major adverse events with the administration of TXA.

Society position statement : Canadian Cardiovascular Society/Canadian Anesthesiologists' Society/Canadian Heart Rhythm Society joint position statement on the perioperative management of patients with implanted pacemakers, defibrillators, and neurostimulating devices.

PURPOSE: There are more than 200,000 Canadians living with permanent pacemakers or implantable defibrillators, many of whom will require surgery or invasive procedures each year. They face potential hazards when undergoing surgery; however, with appropriate planning and education of operating room personnel, adverse device-related outcomes should be rare. This joint position statement from the Canadian Cardiovascular Society (CCS) and the Canadian Anesthesiologists' Society (CAS) has been developed as an accessible reference for physicians and surgeons, providing an overview of the key issues for the preoperative, intraoperative, and postoperative care of these patients. PRINCIPAL FINDINGS: The document summarizes the limited published literature in this field, but for most issues, relies heavily on the experience of the cardiologists and anesthesiologists who contributed to this work. This position statement outlines how to obtain information about an individual's type of pacemaker or implantable defibrillator and its programming. It also stresses the importance of determining if a patient is highly pacemaker-dependent and proposes a simple approach for nonelective evaluation of dependency. Although the document provides a comprehensive list of the intraoperative issues facing these patients, there is a focus on electromagnetic interference resulting from electrocautery and practical guidance is given regarding the characteristics of surgery, electrocautery, pacemakers, and defibrillators which are most likely to lead to interference. CONCLUSIONS: The document stresses the importance of preoperative consultation and planning to minimize complications. It reviews the relative merits of intraoperative magnet use vs reprogramming of devices and gives examples of situations where one or the other approach is preferable.

One intraoperative dose of tranexamic Acid for patients having primary hip or knee arthroplasty.

BACKGROUND: Multiple studies suggest tranexamic acid reduces blood loss and red cell transfusions in patients undergoing THA or TKA. However, many of the dosing schedules in these studies are not ideally suited for routine application. QUESTIONS/PURPOSES: We asked whether one 20-mg per kg intraoperative dose of tranexamic acid in patients having primary THA or TKA would (1) decrease perioperative blood loss and red cell transfusion rates and (2) be a cost-effective protocol. PATIENTS AND METHODS: We retrospectively reviewed the records of 234 patients operated on from April 1 to June 30, 2007 (before our study protocol) and 259 patients from April 1 to June 30, 2008 with the single-dose protocol. We then compared change in hemoglobin, transfusion rates, hemoglobin at discharge, hospital length of stay, and complications between the two groups. No other routine patient care practices or blood conservation program strategies were altered during this time. RESULTS: We found a reduction in the decrease in hemoglobin in 2008 compared with 2007 for THA and TKA (39 from 46 g/L and 36 from 45 g/L, respectively),which led to a reduction in transfusion rates (3.6% from 13.5% and 2.0% from 13.4%, respectively) and higher hemoglobin levels at discharge [corrected].There were no recorded major adverse events associated with the introduction of this protocol. CONCLUSIONS: One 20-mg per kg intraoperative dose of tranexamic acid reduced the perioperative decrease in hemoglobin and red blood cell transfusion rates in patients having TKA and THA compared with those of a similar cohort of patients in whom the protocol was not used. This weight increment dosing facilitated pharmacy drug preparation, led to minimal dose variability and wastage, and resulted in a substantial estimated cost savings. LEVEL OF EVIDENCE: Level III, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.

Factors affecting perioperative blood loss and transfusion rates in primary total joint arthroplasty: a prospective analysis of 1642 patients.

BACKGROUND: In recent years, the use of low molecular weight heparins such as dalteparin has become attractive because of their ease of administration and superiority in preventing venous thromboembolism (VTE) compared with traditional agents. The primary purpose of our study was to evaluate the impact of dalteparin use on blood loss and transfusion rates in patients undergoing primary total joint arthroplasty. We also evaluated the effect of patient sex, releasing the tourniquet in knee arthroplasty and the turnover of house staff. METHODS: Using our hospital transfusion database, we prospectively studied the mean reduction in hemoglobin and transfusion rates of 1642 consecutive patients who underwent primary total hip arthroplasty (THA) or total knee arthroplasty (TKA) between January 2004 and December 2005. In 2004, warfarin was used exclusively for VTE prevention; however, in 2005, following the release of the 2004 American College of Chest Physicians' guidelines, our centre began using dalteparin for VTE prophylaxis. We analyzed the impact of dalteparin use and the effect of patient sex, tourniquet release in TKA and house staff turnover months on blood loss and transfusion rates. RESULTS: The use of dalteparin for postoperative VTE prevention in patients undergoing THA and TKA in 2005 was associated with a significantly greater mean reduction in hemoglobin compared with warfarin use in 2004 (p = 0.014 for patients undergoing THA, p < 0.001 for patients undergoing TKA). The use of dalteparin in 2005 was not associated with a significant increase in allogeneic blood transfusions compared with the use of warfarin in 2004, except in women (p < 0.001). Although we observed no significant differences in mean reduction in hemoglobin between men and women undergoing THA, women undergoing THA had significantly higher transfusion rates regardless of the method of VTE prophylaxis (p = 0.037 for warfarin, p < 0.001 for dalteparin). Intraoperative tourniquet release in patients undergoing TKA was associated with a significantly lower mean reduction in hemoglobin than release after wound closure (p = 0.005). Although house staff turnover months were associated with a significantly greater mean reduction in hemoglobin levels than non-turnover months (p = 0.039), these months were not associated with a significant increase in allogeneic blood transfusions (p = 0.59). CONCLUSION: Low molecular weight heparins such as dalteparin are the most common form of VTE prophylaxis in Canada. Our results suggest that dalteparin use, timing of tourniquet release and house staff turnover can all influence transfusion rates and/or blood loss in patients undergoing primary total joint arthroplasty. This study also emphasizes that women undergoing THA are at particularly high risk for blood transfusion.

Programmatic blood conservation in cardiac surgery.

Despite efforts to reduce blood transfusion rates in cardiac surgery over the past 40 years, cardiac surgery still consumes 10% to 20% of the blood transfused in the United States. This large demand has not only placed a significant pressure on the national blood supply, resulting in frequent shortages, but also has lead to many technical and pharmacological advances in blood conservation strategies in recent years. Recently, studies have shown that an organized approach to blood conservation in cardiac surgery is effective in significantly reducing the perioperative use of allogeneic blood and blood products. However, blood conservation techniques are multiple, varied, and in many situations costly and thus cannot be uniformly applied to all patients. Early preoperative planning and a coordinated perioperative plan allow the appropriate use of blood conservation modalities to ensure that their benefits span the entire perioperative period. This article describes some of the modalities currently used in patients undergoing cardiac surgery.

Randomized double-blind safety comparison of intravenous iron dextran versus iron sucrose in an adult non-hemodialysis outpatient population: A feasibility study.

BACKGROUND: Intravenous iron therapy is a treatment option for iron deficient patients who are intolerant to oral iron or where oral iron is ineffective, but with possible adverse effects. Currently, prospective studies comparing different intravenous iron formulations are needed to determine safety and efficacy of these agents. METHODS: We conducted a prospective, double-blind, randomized controlled trial (RCT) to assess the feasibility of a trial comparing the safety of high molecular weight intravenous iron dextran, Infufer®, with intravenous iron sucrose, Venofer®, in non-hemodialysis adult outpatients. Primary outcome was the occurrence of immediate severe drug reactions. RESULTS: We enrolled 143 patients in a one-year period. Overall, 45/143 (31.5 %) patients (20 iron dextran, 25 iron sucrose) developed 48 infusion reactions (14 immediate, 28 delayed, and 3 both). The risk of an immediate reaction was similar in both groups, 9/73 (12.3 %) iron dextran versus 8/70 (11.4 %) iron sucrose, RR = 0.93 (95 % CI; 0.38 to 2.27). The risk of a delayed reaction was significantly higher in the iron sucrose group 22/70 (31.4 %) versus the iron dextran group 9/73 (12.3 %), RR = 2.55 (95 % CI; 1.26 to 5.15; p = 0.0078). CONCLUSION: In this limited feasibility study, no major differences in immediate reactions were seen, but a significantly higher number of delayed reactions were seen in the iron sucrose group. Further, under our assumptions and design a full RCT to evaluate the safety of different intravenous iron preparations is not feasible. Future studies should consider modifying the clinical outcomes, utilize multiple centers, and consider other emerging parenteral iron formulations. (ClinicalTrials.gov NCT005936197 January 3, 2008).

Canadian Cardiovascular Society/Canadian Anesthesiologists' Society/Canadian Heart Rhythm Society joint position statement on the perioperative management of patients with implanted pacemakers, defibrillators, and neurostimulating devices.

There are more than 200,000 Canadians living with permanent pacemakers or implantable defibrillators, many of whom will require surgery or invasive procedures each year. They face potential hazards when undergoing surgery; however, with appropriate planning and education of operating room personnel, adverse device-related outcomes should be rare. This joint position statement from the Canadian Cardiovascular Society (CCS) and the Canadian Anesthesiologists' Society (CAS) has been developed as an accessible reference for physicians and surgeons, providing an overview of the key issues for the preoperative, intraoperative, and postoperative care of these patients. The document summarizes the limited published literature in this field, but for most issues, relies heavily on the experience of the cardiologists and anesthesiologists who contributed to this work. This position statement outlines how to obtain information about an individual's type of pacemaker or implantable defibrillator and its programming. It also stresses the importance of determining if a patient is highly pacemaker-dependent and proposes a simple approach for nonelective evaluation of dependency. Although the document provides a comprehensive list of the intraoperative issues facing these patients, there is a focus on electromagnetic interference resulting from electrocautery and practical guidance is given regarding the characteristics of surgery, electrocautery, pacemakers, and defibrillators which are most likely to lead to interference. The document stresses the importance of preoperative consultation and planning to minimize complications. It reviews the relative merits of intraoperative magnet use vs reprogramming of devices and gives examples of situations where one or the other approach is preferable.