Ramiro Arellano

A triple-blinded randomized trial comparing the hemostatic effects of large-dose 10% hydroxyethyl starch 264/0.45 versus 5% albumin during major reconstructive surgery.

In Canada, hydroxyethyl starch 264/0.45 (HES 264/0.45; molar weight 264 kDa, molar substitution 0.45) has largely replaced albumin as the colloidal fluid of choice for perioperative intravascular volume expansion. The maximum recommended dose of HES 264/0.45 is 28 mL/kg; however, there are no clinical data supporting this limit. In this study we compared the hemostatic effects of HES 264/0.45 versus 5% albumin in doses up to 45 mL/kg over 24 h during major reconstructive head and neck surgery. Fifty patients were randomized to receive HES 264/0.45 or 5% human albumin from the induction of anesthesia until 24 h thereafter. Both albumin and HES 264/0.45 effectively maintained physiologic variables in the perioperative and postoperative periods. The partial thromboplastin time and international normalized ratio were significantly increased in the HES 264/0.45 group compared with the albumin group after infusion of 30 mL/kg and 45 mL/kg (P < 0.05). Factor VIII activity and von Willebrand factor level were significantly reduced in the HES 264/0.45 group compared with the albumin group after infusion of 15 mL/kg, 30 mL/kg, and 45 mL/kg (P < 0.05). Significantly more subjects in the HES 264/0.45 group received allogeneic red blood cell transfusions (P < 0.02). We conclude that HES 264/0.45 infusions >30 mL/kg over 24 h impair coagulation to a greater extent than albumin, possibly leading to more allogeneic transfusions.

Retrograde autologous priming and allogeneic blood transfusions: a meta-analysis

A literature review and meta-analysis were undertaken to assess the clinical effectiveness of retrograde autologous priming of the cardiopulmonary bypass circuit to reduce allogeneic packed red blood transfusions in adult cardiac surgery. Structured searches of Medline, Embase, Cochrane Collaboration Library, Scopus, Cumulative Index to Nursing and Allied Health Literature and Science Direct were performed to identify randomized trials comparing retrograde autologous priming to a prospective control group. A total of 21,643 studies were identified and eighteen trials were retrieved for full-text review. Six trials met eligibility criteria. Pooled estimates demonstrated that retrograde autologous priming significantly reduced the number of patients receiving intraoperative packed red cell transfusions (OR=0.36; 95% CI: 0.13, 0.94; P=0.04, I(2)=47.5%), total hospital stay packed red cell transfusions (OR=0.26; 95% CI: 0.13, 0.52; P=0.0001, I(2)=0%), and the number of units transfused of total hospital stay packed red blood cells (WMD=-0.60; 95% CI: -0.90, -0.31; P=0.0001, I(2)=0%). Retrograde autologous priming, however, did not provide a clinical benefit in reducing the number of units transfused of intraoperative packed red blood cells (WMD=-0.29; 95% CI: -0.59, 0.01; P=0.05). The combined patient population studied in the six trials was mainly primary isolated coronary artery bypass surgery. Assessing the safety of retrograde autologous priming was not possible due to limited data.

A Retrospective Analysis of Blood Loss With Combined Topical and Intravenous Tranexamic Acid After Coronary Artery Bypass Graft Surgery

OBJECTIVE Intravenous antifibrinolytics are the gold standard for blood conservation during cardiac surgery. Recent evidence suggests that topical tranexamic acid administration also is effective, although the efficacy of combined topical and intravenous administration has never been reported. Combined administration may offer superior hemostasis while decreasing side effects. The current study explores the use of combined topical and intravenous tranexamic acid as a blood conservation strategy in cardiac surgery. DESIGN Retrospective cohort. SETTING A single-center, academic, tertiary care hospital. PARTICIPANTS One hundred sixty elective coronary artery bypass graft patients. INTERVENTION A practice change allowed a retrospective comparison of postoperative chest tube drainage in patients with intravenous or combined (intravenous and topical) tranexamic acid. MEASUREMENTS AND MAIN RESULTS Chest tube drainage was decreased in the combined group at 3 (164.8 ± 102.2 v 242.7 ± 148.9 mL, p < 0.001), 6 (265.6 ± 163.7 v 358.8 ± 247.2 mL, p = 0.006), and 12 hours (374.3 ± 217.1 v 498.5 ± 336.6 mL, p = 0.006) postoperatively compared with the intravenous group. The tranexamic acid dose was higher in the combined group (5.1 ± 1.1 v 4.1 ± 1.3 g, p < 0.001), but less was administered intravenously (3.1 ± 1.1 v 4.1 ± 1.3 g, p < 0.001). No differences were observed in adverse events. CONCLUSIONS This study suggested that combined tranexamic acid administration may be superior for blood conservation, but fully powered randomized controlled trials will be required to confirm these findings and determine the safety advantage and clinical relevance of adding topical tranexamic acid to existing blood conservation strategies.

Successful Management of Cold-Induced Urticaria During Hypothermic Circulatory Arrest

Cold-induced urticaria (CIU) is a potentially life-threatening immunologic disorder characterized by swelling and edema of exposed tissue in response to a cold stimulus. We describe the successful management of a patient with a history of severe CIU who required coronary bypass and repair of an ascending aortic aneurysm using hypothermic circulatory arrest.

Point-of-care transthoracic echocardiography as an alternative to transesophageal echocardiography to confirm internal jugular guidewire position

Unintentional needle puncture of the carotid artery (CA) during internal jugular vein (IJV) cannulation occurs relatively frequently. Serious sequelae (e.g., hematoma, airway compromise, stroke, and death) usually occur when this error is not detected, and the CA is subsequently dilated with the large-bore introducer sheath. Methods employed to detect CA puncture include blood colour and flow characteristics, manometry, and pressure transduction of the needle. Ultrasonographic visualization of the IJV and CA prior to cannulation is endorsed as a method to improve safety. However, this technology does not completely eliminate accidental CA injury. Ultrasonography of the neck visualizes the guidewire for only a short distance, leaving room for posterior vein wall penetration outside the field of view. In many centres providing cardiac anesthesia, transesophageal echocardiography (TEE) is used to visualize the guidewire in the superior vena cava (SVC) or right atrium (RA) before the introducer sheath is inserted. The guidewire, seen in the bicaval view, confirms appropriate wire placement. Point-of-care ultrasonography is used increasingly by anesthesiologists, intensivists, and emergency medicine specialists to diagnose and treat hemodynamically unstable patients. Transthoracic echocardiographic (TTE) apical and subcostal four-chamber views are routinely obtained during these point-of-care assessments. We now use these TTE views to confirm appropriate IJV puncture and guidewire advancement in venous structures. During the initial venous puncture, blood is aspirated into a syringe and reinjected quickly. This produces microbubbles that are seen entering the RA, thereby confirming venous puncture (Fig. 1, Clip 1). The advanced guidewire is visualized in the SVC, RA, or inferior vena cava. In our experience, both the subcostal (Fig. 2, Clip 2) and subcostal bicaval (Fig. 3, Clip 3) views provide optimal sonographic windows. Guidewire confirmation with point-of-care TTE during IJV cannulation provides an alternative to TEE for confirming appropriate guidewire placement. Also, it may aid in reducing the incidence of CA injury associated with IJV cannulation.