Cell salvage is a process whereby the bloodshed from the operative field is collected and returned to the patient. It can be especially useful when allogeneic red blood cell (RBC) units are not readily available such as when the recipient has multiple alloantibodies. We report on the anesthesia and transfusion strategies for managing a pregnant patient with sickle cell disease (SCD) with HELLP (Hemolysis, Elevated Liver enzymes and Low Platelets) syndrome. A pregnant patient with twins at 30 weeks of gestation was admitted in an SCD crisis. She subsequently developed HELLP syndrome and required urgent cesarean delivery; however, she had multiple RBC antibodies complicating the immediate provision of crossmatched RBC units. Cell salvage was used to capture the blood shed during her procedure while the blood bank was searching for compatible RBCs units. Despite multiple interventions designed to optimize the cell salvage procedure for the unique challenges of a patient with SCD, the salvaged RBCs hemolyzed and could not be reinfused. Cell salvage in an obstetric patient with SCD in an acute crisis and superimposed HELLP was unable to recover intact and useable RBCs. Further studies into methods of optimizing the procedure for use in this context are warranted. Close communication between the clinical teams treating the patient and the transfusion service is required so that the RBC transfusion requirements can be anticipated; this is especially important when the patient has multiple antibodies.
sickle cell disease; HELLP syndrome; cell salvage; thromboelastogram; anticoagulation
The objective of this study was to determine if tranexamic acid (TXA) applied topically reduced postoperative bleeding and transfusion rates after primary total hip arthroplasty (THA) and primary total knee arthroplasty (TKA).
Two hundred and ninety consecutive patients from a single surgeon were enrolled. In TKA, TXA solution was injected into the knee after closure of the arthrotomy. In THA, the joint was bathed in TXA solution at three points during the procedure. In both THA and TKA the TXA solution was at a concentration of 3gm TXA per 100mL saline.
The mean blood loss was significantly higher in the non-TXA patients in both TKA and THA groups. Postoperative transfusions decreased dramatically with TXA, dropping from 10% to 0%, and from 15% to 1%, in the TKA and THA groups, respectively.
Topical application of TXA significantly reduces postoperative blood loss and transfusion risk in TKA and THA.
Blood Transfusion; Tranexamic Acid; Antifibrinolytic; Total Knee Arthroplasty; Total Hip Arthroplasty
Accurate measurement of intraoperative blood loss is an important clinical variable in managing fluid resuscitation and avoiding unnecessary transfusion of blood products. In this study, blood lost onto laparotomy sponges during surgical cases was measured using a tablet computer programmed with a unique algorithm modeled after facial recognition technology. In this study we assessed the accuracy and performance of the system in surgical cases.
In this prospective, multicenter study, 46 patients undergoing surgery with anticipated significant blood loss contributed laparotomy sponges for hemoglobin (Hb) loss measurement using the Triton System with Feature Extraction Technology (Gauss Surgical, Inc., Los Altos, USA). The Hb loss measured by the new system was compared to Hb loss measured by manual rinsing of the sponges. Accuracy was evaluated using linear regression and Bland-Altman analysis. In addition, the new system’s calculation of blood volume loss was compared with the gravimetric method of estimating blood loss from intraoperative sponge weights.
A significant positive linear correlation was noted between the new system’s measurements and the rinsed Hb mass (r = 0.93, p < 0.0001). Bland-Altman analysis revealed a bias of 9.0 g and narrow limits of agreement (−7.5 g to 25.5 g) between the new system’s measures and the rinsed Hb mass. These limits were within the clinically relevant difference of +/−30 g, which is approximately half of the Hb content of a unit of allogeneic whole blood. Bland-Altman analysis of the estimated blood loss on sponges using the gravimetric method demonstrated a bias of 466 ml (overestimation) with limits of agreement of −171 ml and 1103 ml, due to the presence of contaminants other than blood on the laparotomy sponges.
The novel mobile monitoring system provides an accurate measurement of Hb mass on surgical sponges as compared with manual rinsing measurements and is significantly more accurate than the gravimetric method. Further study is warranted to assess the clinical utility of the technology.
Accurate measurement of intraoperative blood loss is an important clinical variable in managing fluid resuscitation and avoiding unnecessary transfusion of blood products. In this study, we measured surgical blood loss using a tablet computer programmed with a unique algorithm modeled after facial recognition technology. The aim of the study was to assess the accuracy and performance of the system on surgical laparotomy sponges in vitro.
Study Design and Methods
Whole blood samples of pre-measured hemoglobin (Hb) and volume were reconstituted from units of human packed red blood cells and plasma and distributed across surgical laparotomy sponges. Normal saline was added to simulate the presence of varying levels of hemodilution and/or irrigation use. Soaked sponges from four different manufacturers were scanned using the Triton System with Feature Extraction Technology (Gauss Surgical, Inc., Palo Alto, USA) under three different ambient light conditions in an operating room. Accuracy of Hb loss measurement was evaluated relative to the pre-measured values using linear regression and Bland-Altman analysis. Correlations between studied variables and measurement bias were analyzed using nonparametric tests.
The overall mean percent error for measure of Hb loss for the Triton System was 12.3% [95% CI 8.2 to 16.4%]. A strong positive linear correlation between the pre-measured and actual Hb masses was noted across the full range of intraoperative lighting conditions, including (A) high (r = 0.95 [95% CI 0.93–0.96]), (B) medium (r = 0.94 [95% CI 0.93–0.96]), and (C) low (r = 0.90 [95% CI 0.87–0.93]) mean ambient light intensity. Bland-Altman analysis revealed a bias of 0.01 g [95% CI −0.03 to 0.06 g] of Hb per sponge between the two measures. The corresponding lower and upper limits of agreement were −1.16 g [95% CI −1.21 to −1.12 g] per sponge and 1.19 g [95% CI 1.15 to 1.24 g] per sponge, respectively. Measurement bias of estimated blood loss and Hb mass using the new system were not associated with the volume of saline used to reconstitute the samples (p = 0.506 and p = 0.469, respectively), suggesting that the system is robust under a wide range of sponge saturation conditions.
Mobile blood loss monitoring using the Triton system is accurate in assessing Hb mass on surgical sponges across a range of ambient light conditions, sponge saturation, saline contamination, and initial blood Hb. Utilization of this tool could significantly improve the accuracy of blood loss estimates.
The objective of this study was to determine if there are differences in common red blood cell (RBC) indices and platelet concentrations during pregnancy and to establish if any observed differences in these parameters were based on the patient's ethnicity.
From an electronic perinatal database which stores laboratory and clinical information on a large number of births at a regional hospital specializing in obstetrical care, RBC index and platelet concentration data were retrospectively analyzed at various time points throughout pregnancy. RBC index data was collected from 8,277 pregnant women (5,802 Caucasian pregnant women and 2,475 non-Caucasian pregnant women). Platelet concentration data was available from 8252 pregnant women (5,784 Caucasian pregnant women and 2,468 non-Caucasian pregnant women).
Hemoglobin (HGB) levels were significantly higher amongst Caucasian women compared to non-Caucasian women (P at least <0.01) starting at 27 weeks gestation and proceeding until term. There was no significant difference in the mean PLT counts between Caucasian and non-Caucasian pregnant women at any point during gestation.
There are ethnic differences in HGB levels, but not the platelet concentrations, during pregnancy. Based on this finding it would be reasonable to conduct formal prospective studies to determine the clinical significance of this difference and to establish the threshold for diagnosing gestational anemia, especially in pregnant non-Caucasian women.
Anemia; Complete blood count; Hemoglobin; Pregnancy; Reference Ranges
autotransfusion; cell salvage; erythrocytes; allogeneic transfusion; blood conservation
Warming of IV administered fluids and blood products is routinely performed in the operating room to help maintain normothermia. Current guidelines recommend against the warming of platelets (PLTs), although there is no evidence for this prohibition in the literature. Our goal in this pilot study was to determine if the warming of stored PLTs had any effect on their function.
Ten units of three-day-old PLT rich plasma-derived whole blood PLTs were acquired from the transfusion service. A 5 mL aliquot was taken from each unit before warming (control samples). The remainder of the unit was then passed into a blood warming device and held there for two minutes. Post-warming (warmed) PLT samples were then collected from the effluent end of the warming device. PLT aggregometry assays with adenosine diphosphate, collagen, and arachidonic acid as agonists were performed on the control and warmed samples. Thromboelastrography (TEG®) tests were also performed on the control and warmed samples from six of the 10 PLT units.
The mean temperature of the control and warmed samples was 22.4 ± 0.5°C and 37.8 ± 2.3°C, respectively. There was no significant difference (all P ≥ 0.13) in any of the PLT aggregometry assays or in the maximum amplitude of the TEG® test between the control and the warmed samples. The observed mean of only one parameter decreased (PLT aggregometry with 5 µM adenosine diphosphate), by 5% (95% CI: −115% to 105%). The maximum change observed was PLT aggregometry with arachidonic acid as agonist, which increased by 116% (95% CI: −91% to 323%).
Although small in size, the results of this study do not support the prohibition against mechanical PLT warming. Studies of PLT activation after warming are also warranted.
Plasma is used to correct coagulopathies, but not all coagulation abnormalities are clinically significant enough to require correction before an invasive procedure. We report an 82-year-old female who, in response to a mildly prolonged INR of unknown etiology, was unnecessarily transfused with plasma in advance of elective surgery. The patient suffered a moderately severe transfusion reaction, including hives and voice hoarseness, which caused a 4-week delay in her surgery. This delay and adverse reaction could have been avoided had the principles of evidence based plasma therapy, which we herein review, been followed and if the etiology of the mildly elevated INR been investigated before the day of her surgery.
Allergic reaction; guidelines; plasma; transfusion
Autologous blood; Autotransfusion; Blood salvage; Cell salvage; Red blood cells; Transfusion
There is concern that salvaged blood has the potential to activate the coagulation system, which might place patients at risk of thrombotic complications. The aim of this study was to determine whether transfusion of salvaged blood after total knee arthroplasty (TKA) would lead to procoagulopathic changes as measured by thromboelastography (TEG), and furthermore if washing would reduce this risk.
STUDY DESIGN AND METHODS
Twenty two patients undergoing TKA were enrolled. Control samples were venous blood samples taken before surgery. Test samples were created by mixing the control samples with postoperatively salvaged blood, either washed or unwashed. TEG profiles were measured, noting the time to initiate clotting (R), the time of clot formation (K), the angle of clot formation (α-angle), and the maximum strength of clot (MA).
The changes in the coagulation profile from control samples to test samples were consistent for both the washed and unwashed groups: R time decreased, MA decreased, and K and alpha-angle remained the same. However, the changes were more pronounced in the unwashed group than the washed group, with a 61% decrease in R time as compared with 14%, and a 26% drop in MA as compared with 6%.
The addition of salvaged blood to the patient’s preoperative blood resulted in decreased clot strength as well as decreased time to initial clot formation. This suggests that the reinfusion of postoperatively salvaged washed or unwashed blood after TKA favors a change towards a more hypocoagulable state, and washing appears to reduce this effect.
Autotransfusion; Blood transfusion; Coagulation; Salvaged blood; Thromboelastography; Total knee arthroplasty
The rising costs, limited supply, and clinical risks associated with allogeneic blood transfusion have prompted investigation into autologous blood management strategies, such as post-operative red cell salvage. This study provides a cost comparison of transfusing washed post-operatively salvaged red cells using the OrthoPat device versus unwashed shed blood and banked allogeneic blood.
Study Design and Methods
Cell salvage data was retrospectively reviewed for a sample of 392 patients who underwent primary hip or knee arthroplasty. Average unit costs were calculated for washed salvaged red cells, equivalent units of unwashed shed blood, and therapeutically equivalent volumes of allogeneic packed red cells.
No initial capital investment was required for the establishment of the post-operative cell salvage program. For patients undergoing total knee arthroplasty (TKA), the average unit cost for washed post-operatively salvaged cells, unwashed shed blood, and allogeneic banked blood was $758.80, $474.95, and $765.49, respectively. In patients undergoing total hip arthroplasty (THA), the average unit cost for washed post-operatively salvaged cells, unwashed shed blood, and allogeneic banked blood was $1827.41, $1167.41, and $2609.44, respectively.
This analysis suggests that transfusing washed post-operatively salvaged cells using the OrthoPat device is more costly than using unwashed shed blood in both THA and TKA. When compared to allogeneic transfusion, washed post-operatively salvaged cells carry a comparable cost in TKA, but potentially represent a significant savings in patients undergoing THA. Sensitivity analysis suggests that in the case of TKA, however, cost comparability exists within a narrow range of units collected and infused.
blood salvage; autologous transfusion; allogeneic transfusion; cost study analysis
Since a study in orthopedic hip fracture patients demonstrated that a liberal hemoglobin (Hb) threshold does not improve patient morbidity and mortality relative to a restrictive Hb threshold, the standard of care in total joint arthroplasty (TJA) should be examined to understand the variability of red blood cell (RBC) transfusion following TJA.
The study aimed to answer the following questions: (1) What is the blood utilization rate after primary TJA for individual surgeons within a large hospital network? (2) What is the comparison of hospital charges, length of stay (LOS), and discharge locations among TJA patients who were and were not transfused?
A retrospective study was conducted on 3,750 primary total knee arthroplasties (TKAs) and 2,070 primary total hip arthroplasties (THAs), and data was retrospectively collected over a 15-month period on the number of RBCs transfused per patient, along with demographic and cost details. The number of patients who received at least 1 RBC unit and the number of RBCs transfused per patient was calculated and stratified by surgeon.
In the postoperative period, 19.3% TKA patients and 38.5% THA patients received a RBC transfusion. Transfusion rates following TJA varied widely between surgeons (TKA 4.8–63.8%, THA 4.3–86.8%). Transfused TKA patients received an average of 1.65 ± 0.03 RBCs, and THA patients received an average of 1.97 ± 0.14 RBCs. LOS and hospital charges for blood transfusion patients were higher than nontransfused patients.
Blood utilization after primary TJA varies greatly among surgeons, suggesting that resources may be misallocated. These findings highlight the need to standardize RBC transfusion practice following TJA.
Electronic supplementary material
The online version of this article (doi:10.1007/s11420-013-9327-y) contains supplementary material, which is available to authorized users.
total joint arthroplasty; blood utilization; transfusion rate; blood management; red blood cell (RBC) transfusion; intervention
Plasma is used to correct coagulopathies, but not all coagulation abnormalities are clinically significant enough to require correction before an invasive procedure. We report an 82 year old female who, in response to a mildly prolonged INR of unknown etiology, was unnecessarily transfused with plasma in advance of elective surgery. The patient suffered a moderately severe transfusion reaction, including hives and voice hoarseness, which caused a 4-week delay in her surgery. This delay and adverse reaction could have been avoided had the principles of evidence based plasma therapy, which we herein review, been followed and if the etiology of the mildly elevated INR been investigated before the day of her surgery.
Plasma; FFP; Transfusion; Allergic; Reaction; Complication
Modified ultrafiltration (MUF) is available for the salvage of post-cardiopulmonary bypass circuit blood. This study evaluated the extent of hemolysis, the mechanical fragility index (MFI), and the amount of plasma free hemoglobin (PFHb) created after processing with the MUF device. Several RBC parameters were measured on pre- and post-MUF device processed samples of blood from 12 patients undergoing cardiac surgery. The MFI and total amount of PFHb did not change significantly between the pre- and post-processing samples: MFI, pre: .19 ± .06 versus post: .19 ± .06, p = .76; total amount of PFHb, pre: .24 ± .21 g versus post: .20 ± .12 g, p = .42. There was significantly more hemolysis in the post-processing samples compared with the pre-processing samples, .33 ± .24% versus .96 ± .48%, respectively, p < .001. Although percent hemolysis was increased following processing with the MUF device, the total amount of PFHb and RBC sublethal injury were not increased. The clinical significance of these findings needs to be determined.
modified ultrafiltration; cardiac surgery; hemolysis; cell salvage; red blood cell
Patients with Klippel-Feil Syndrome (KFS) have congenital fusion of their cervical vertebrae due to a failure in the normal segmentation of the cervical vertebrae during the early weeks of gestation and also have myriad of other associated anomalies. Because of limited neck mobility, airway management in these patients can be a challenge for the anesthesiologist. We describe a unique case in which a dexmedetomidine infusion was used as sedation for an awake fiber-optic intubation in a parturient with Klippel-Feil Syndrome, who presented for elective cesarean delivery. A 36-year-old female, G2P1A0 with KFS (fusion of cervical
vertebrae) who had prior cesarean section for breech presentation with difficult airway management was scheduled for repeat cesarean delivery. After obtaining an informed consent, patient was taken in the operating room and non-invasive monitors were applied. Dexmedetomidine infusion was started and after adequate sedation, an awake fiber-optic intubation was performed. General anesthetic was administered after intubation and dexmedetomidine infusion was continued on maintenance dose until extubation. Klippel-Feil Syndrome (KFS) is a rare congenital disorder for which the true incidence is unknown, which makes it even rare to see a parturient with this disease. Patients with KFS usually have other congenital abnormalities as well, sometimes including the whole thoraco-lumbar spine (Type III) precluding the use of neuraxial anesthesia for these patients. Obstetric patients with KFS can present unique challenges in administering anesthesia and analgesia, primarily as it relates to the airway and dexmedetomidine infusion has shown promising result to manage the airway through awake fiberoptic intubation without any adverse effects on mother and fetus.
Klippel-Feil syndrome; dexmedetomidine; awake fiberoptic intubation; cesarean section.
Intraoperative cell salvage exerts shear stress upon RBCs, particularly as they are suctioned from the surgical field. Shear stress can result in overt hemolysis or it can cause sublethal injury to the suctioned RBCs. The mechanical fragility (MF) test uses shear stress to measure the extent of RBC sublethal injury. RBCs that have sustained sublethal injury are more susceptible to shear stress induced hemolysis. In this study we suctioned whole blood samples from an artificial surgical field to determine if pre-menopausal female RBCs would demonstrate greater resistance to hemolysis and less sublethal injury compared to that of males and post-menopausal females.
Ten CPD-preserved whole blood units from these 3 donor groups were obtained and samples suctioned at -150 mmHg from a simulated surgical field. The MF test was then performed and the % hemolysis calculated. In addition the MF test was serially performed on these whole blood units during the 21 days of storage.
There were no differences in the extent of hemolysis or RBC shear stress resistance after suctioning between the 3 donor groups. During storage the pre-menopausal female RBCs demonstrated higher shear stress tolerance compared to the males or post-menopausal females at all of the time points.
Although during static storage pre-menopausal female RBCs in CPD-preserved whole blood demonstrated higher shear stress tolerance, this enhanced resistance was not observed after suctioning from a simulated surgical field.
Red blood cell; Mechanical fragility; Suctioning; Cell salvage; Hemolysis; Storage lesion; Peri-operative