How do we manage cardiopulmonary bypass coagulopathy?

BACKGROUND: Patients who undergo cardiopulmonary bypass (CPB) are at risk for coagulopathy. Suboptimal turnaround time (TAT) of laboratory coagulation testing results in empiric administration of blood products to treat massive bleeding. We describe our initiative in establishing the coagulation-based hemotherapy (CBH) service, a clinical pathology consultation service that uses rapid TAT coagulation testing and provides comprehensive assessment of bleeding in patients undergoing CPB. A transfusion algorithm that treats the underlying cause of coagulopathy was developed. STUDY DESIGN AND METHODS: The coagulation testing menu includes all aspects of coagulopathy with close proximity of the laboratory to the operating room to allow for rapid test results. The hemotherapy pathologist monitors laboratory results at several stages in surgery and uses a comprehensive algorithm to monitor a patient's hemostasis. The optimal number and type of blood products are selected when the patient is taken off CPB. RESULTS: The CBH service was consulted for 44 ventricular assist device implants, 30 heart transplants, and 31 other cardiovascular surgeries from May 2012 through November 2013. The TAT for laboratory tests was 15 minutes for complete blood count, antithrombin, and coagulation panel and 30 minutes for VerifyNow and thromboelastography, in comparison to 45 to 60 minutes in normal settings. The transfusion algorithms were used with optimal administration of blood components with preliminary data suggestive of reduced blood product usage and better patient outcomes. CONCLUSION: We described the successful introduction of a novel pathology consultation service that uses a rapid TAT coagulation testing menu with transfusion algorithms for improved management of CPB patients.

Comparison of the effectiveness of amitriptyline and gabapentin on chronic neuropathic pain in persons with spinal cord injury.

OBJECTIVE: To test the hypotheses that both amitriptyline and gabapentin are more effective in relieving neuropathic pain than an active placebo, diphenhydramine. DESIGN: Randomized, controlled, double blind, triple crossover 8-week trial. SETTING: Veterans Affairs medical center. PARTICIPANTS: Community dwelling adults with spinal cord injury (N=38) were recruited by telephone, letters, and flyers. INTERVENTION: Eight-week trial each of amitriptyline, gabapentin, and diphenhydramine. MAIN OUTCOME MEASURES: Pain intensity measured with a 10-cm visual analog scale (VAS) and an 11-point (0-10) numeric rating scale (NRS) and depressive symptomatology measured with the Center for Epidemiologic Studies Depression Scale-Short Form (CESD-SF). RESULTS: Baseline VAS scores for participants with low (< 10) CESD-SF scores was 4.61 and for those with high scores (> or = 10) it was 7.41. At week 8, in participants with high baseline CESD-SF scores, amitriptyline (mean, 4.21) was more effective than diphenhydramine (mean, 6.67; P=.035), and there was a nonsignificant trend suggesting that amitriptyline may be more effective than gabapentin (mean, 6.68; P=.061). Gabapentin was no more effective than diphenhydramine (P=.97). There was no significant difference among the medications for those with lower CESD-SF scores. Results could not be attributed to dropout rates, order or dose of medications, amount of medication taken for breakthrough pain, or side effects. CONCLUSIONS: Amitriptyline is more efficacious in relieving neuropathic pain than diphenhydramine at or below the level of spinal cord injury in people who have considerable depressive symptomatology.

Prediction of the effect of acute normovolemic hemodilution on the hematological constituents of sequestered autologous whole blood.

During acute normovolemic hemodilution (ANH), autologous whole blood is collected in a series of collection bags containing anticoagulant. The effect of hemodilution on the actual hematological constituents of this sequestered whole blood product has never been examined. We developed a mathematical model that predicts how whole blood bag constituents change during ANH to elucidate the theoretical basis for ANH efficacy. Formulas were derived to calculate the effect of ANH on [X], the blood constituent of interest. An exponential envelope was defined so that the projected impact of ANH on each constituent could be computed while initial blood volume and whole blood bag volume (WB(ANH)) were manipulated. Equivalency of autologous whole blood hemoglobin, platelets, and fibrinogen were determined by comparison with standard allogeneic blood products. We determined that the concentration of blood constituent X in a particular unit of collected blood ([X](n)) is provided as a fraction of the initial concentration ([X](0)). As WB(ANH) increases relative to estimated blood volume, the decrement in [X](n) increases in successive blood collection bags. Irrespective of initial blood volume, the equivalence of a 450-mL autologous whole blood bag to 1 U of packed red cells and 1 U of whole blood-derived platelet concentrate is 13.3 g/dL and 123 x 10(3)/microL, respectively. The impact of ANH on autologous whole blood constituents may be accurately predicted using this model. Conversion of WB(ANH) into equivalent allogeneic blood products could provide a useful method of comparing outcome in various ANH studies. The exponential envelope may be used to assess the actual ANH technique performed by the anesthesiologist, which in turn may impact quality assurance standards.

Autologous platelet-rich plasma reduces transfusions during ascending aortic arch repair: a prospective, randomized, controlled trial.

BACKGROUND: Blood conservation using autologous platelet-rich plasma (aPRP), a technique of whole blood harvest that separates red blood cells from plasma and platelets before cardiopulmonary bypass with retransfusion of the preserved platelets after completion of cardiopulmonary bypass, has not been studied extensively. We sought to prospectively determine whether aPRP reduces blood transfusions during ascending and transverse aortic arch repair. METHODS: We randomly assigned 80 patients undergoing elective ascending and transverse aortic arch repair using deep hypothermic circulatory arrest to receive either aPRP (n = 38) or no aPRP (n = 42). Volume of aPRP retransfused was 726 ± 124 mL. The primary end point was transfusion amount. Secondary end points were death, stroke, renal failure, pulmonary failure, and transfusion costs. Perioperative transfusion rate was defined as blood transfusions given during surgery and up to 72 hours afterward. The surgeon and intensivist were blinded to the treatment arm. Because an anesthesiologist initiated the protocol, the surgeon was not aware of aPRP collection, as this occurred only after the sterile drape was in place. In addition, because cell salvage was performed on all cases, differentiation in perfusionist activities (during spinning of aPRP) was not evident. Platelet, fresh frozen plasma, and cryoprecipitate intraoperative transfusions were performed only after heparin was reversed and the patient was judged as coagulopathic on the basis of associated criteria: cryoprecipitate transfusion for fibrinogen level less than 150 µg/dL, platelet transfusion for platelet count less than 80,000, and fresh frozen plasma when thromboelastogram test was suggestive or a partial thromboplastin time was greater than 55 seconds, and prothrombin time was greater than 1.6 seconds. RESULTS: Early mortality, stroke, and respiratory complications were similar between groups. Only acute renal failure was reduced in the aPRP group, 7% versus 0% (p < 0.014). Mean transfusion rate of packed red blood cells was reduced by 34%, fresh frozen plasma by 52.8%, cryoprecipitate by 70%, and platelets by 56.7% in the aPRP group (p < 0.02). Hospital length of stay (9.4 ± 5.3 days versus 12.7 ± 6.3 days; p < 0.014) and transfusion costs ($1,396 ± $1,755 versus $2,762 ± $2,267; p < 0.004) were reduced in the aPRP group. CONCLUSIONS: The use of aPRP reduced allogeneic transfusions during ascending and transverse aortic arch repair with deep hypothermic circulatory arrest. This translated to less acute renal failure, decreased length of stay, and lower transfusion costs. Further studies examining the coagulation factors of aPRP are required.

Impact of extracorporeal circuit prime volume reduction on whole blood sequestration during acute normovolemic hemodilution for adult cardiac surgery patients.

Acute normovolemic hemodilution (ANH) is a blood-conservation method in which whole blood (WB(ANH)) is sequestered into blood collection bags before the commencement of surgery. However, for cardiac surgery, extracorporeal circuit (ECC) priming techniques limit the amount of blood that may collected prior to the actual initiation of cardiopulmonary bypass (CPB). In this study, computational modeling was used to examine the effect of reducing extracorporeal "pump" prime volume (PPV) on WB(ANH) prior to the CPB. Increments of estimated blood volume (EBV), precardiopulmonary bypass hemoglobin concentration [Hb(Pre-CPB)], and PPV volume were manipulated to assess effects on predicted hemoglobin concentration during cardiopulmonary bypass [Hb(CPB)]. Similarly, increments of EBV and preanesthetic hemoglobin concentration [Hb(Pre-Anes)] were manipulated to examine the change in WB(ANH) volume. The impact of PPV reduction on the minimum acceptable precardiopulmonary bypass hemoglobin concentration [Hb(Pre-CPB-MA)] was then measured by computing PPV, EBV, and the minimum acceptable cardiopulmonary bypass hemoglobin [Hb(CPB-MA)]. Finally, by manipulating EBV and target hemoglobin concentration [Hb(Target)], the change in [Hb(Pre-CPB)] produced by PPV reduction was used to quantify the effect on WB(ANH) volume. The net increase in the [Hb(CPB)] produced by PPV reduction is inversely proportional to EBV. Higher [Hb(Pre-Anes)] or lower [Hb(Target)] facilitates sequestration of larger WB(ANH) volume. Although PPV and [Hb(Pre-CPB-MA)] bear a direct relationship, as EBV decreases, proportionally greater increases in [Hb(Pre-CPB-MA)] occur. The impact of PPV reduction on precardiopulmonary bypass hemoglobin concentration [Hb(Pre-CPB)] is reflected by the "excess hemoglobin" over the minimum hemoglobin threshold (designated as 7 g/dL in this study). For each 100-mL decrement in PPV, "excess hemoglobin" increases from 1% (EBV = 8000 mL) to 2% (EBV = 4000 mL). In turn, increases in "excess hemoglobin" are associated with expansion of WB(ANH) volume. In conclusion, sequential PPV reduction from 2000 mL increases the volume of WB(ANH) that potentially may be sequestered prior to initiation of CPB. Therefore, the combination of PPV reduction with ANH may represent a useful blood conservation approach in adult patients undergoing cardiac surgery with CPB.

Mobile computing platform with decision support modules for hemotherapy.

OBJECTIVES: We describe the development of a mobile computing platform (MCP) with a decision support module (DSM) for patients in our coagulation-based hemotherapy service. METHODS: The core of our MCP consists of a Microsoft Excel spreadsheet template used to gather and compute data on cardiopulmonary bypass (CPB) patients intraoperatively. The DSM is embedded into the Excel file, where the user would enter in laboratory results, and through our 45 embedded algorithms, recommendations for transfusion products would be displayed in the Excel file. RESULTS: The DSM has helped decrease the time it takes to come to a transfusion recommendation, helps double-check recommendations, and is an excellent tool for teaching. Furthermore, the problems that occur with a paper system have been eliminated, and we are now able to access this information easily and reliably. CONCLUSIONS: The development and implementation of our MCP system has greatly increased the productivity and efficiency of our hemotherapy service.

Analysis of autologous platelet-rich plasma during ascending and transverse aortic arch surgery.

BACKGROUND: Coagulopathy is a common complication after ascending and transverse arch aortic surgery with profound hypothermic circuit arrest (PHCA). Blood conservation strategies to reduce transfusion have been ongoing and involve multiple treatment modalities in modern cardiac surgery. The purpose of this study is to evaluate the effectiveness of autologous platelet-rich plasma (aPRP) as a blood conservation technique to reduce blood transfusion in ascending and arch aortic surgery. METHODS: Between 2003 and 2009, we retrospectively reviewed 685 cases of ascending aorta and transverse arch repair using PHCA. A total of 287 patients in which aPRP was used (aPRP group) were compared with 398 patients who did have aPRP (non-aPRP group). Perioperative transfusion requirements and clinical outcomes that included early mortality, postoperative stroke, renal dysfunction, prolonged ventilation, coagulopathy, and length of postoperative intensive care unit stay were analyzed. The data were analyzed by mean and frequency for continuous variables and qualitative variables. To account for potential selection bias, 2 types of propensity analysis were performed. RESULTS: In both unadjusted and adjusted analysis, perioperative transfusions were fewer in the aPRP group compared with the non-aPRP group: (3.9 units fewer packed red blood cells, 4.5 units fewer fresh frozen plasma, 7.9 units fewer platelets, and 6.8 units fewer cryoprecipitate). In all analyses, postoperative morbidity (stroke, duration of mechanical ventilation, and intensive care unit stay) were significantly improved. Hospital mortality rate was not significantly decreased. CONCLUSIONS: The utilization of aPRP was associated with a reduction in allogeneic blood transfusions as well as a decrease in early postoperative morbidity during repairs of the ascending and transverse arch aorta using PHCA.

Optimization of an EHR mobile application using the UFuRT conceptual framework.

Drchrono is an Electronic Healthcare Record (EHR) application designed specifically for the iPad. Described as portable, efficient and accessible anywhere, drchrono has several features that might be attractive to health care providers. However, EHRs have to conform to certain Federal Healthcare Information Technology Guidelines, which are evaluated in a series of 12 test procedures, defined by the Office of the National Coordinator for Health Information Technology (ONC). In this study, we evaluated Test Procedure for §170.302 (c) Maintain up-to-date problem list, in drchrono. The methodology for our evaluation was contained within Zhang's unified framework for usability, using UFuRT, i.e. user, functional, representation and task analyses. Based upon the analysis, using Adobe Flex, we then designed a prototype that corrected or improved on perceived weaknesses in the functionality served by the test procedure. We applied the test procedure taxonomy to a prototypic modification of drchrono, and then repeated the UFuRT usability analysis. We also used a 14-item heuristic evaluation by each member of our informatics team. Our findings support a conclusion that UFuRT is a valuable tool to evaluate EHR usability and that an "up-to-date problem" list may be customized, according to healthcare provider preference.

Prevalence and characteristics of chronic pain in veterans with spinal cord injury.

To assess prevalence and characteristics of individual chronic (>6 mo) pain components in the veteran spinal cord injury (SCI) population, we conducted a telephone survey with 348 (66%) of 530 veterans with SCI who received care from one regional Department of Veterans Affairs SCI center during a 3 yr period. The short-form McGill Pain Questionnaire was used to assess qualitative properties of the pain experience. Other questions were used to assess frequency, duration, intensity, exacerbating factors, and effects on daily activities. Of the participants, 75% reported at least one chronic pain component. The majority (83%) of the chronic pain components occurred daily (mean = 27.4 d/mo) and lasted most of the day (mean = 17.4 h/d). Mean pain intensity in the week before the interview averaged 6.7 (on a 0 to 10 scale), while worst pain intensity averaged 8.6. Two-thirds (67%) of the chronic pain components interfered with daily activities. The most commonly selected pain descriptors were "aching," "sharp," "hot-burning," and "tiring-exhausting." More research is needed to identify better ways to prevent, assess, and treat chronic pain in the veteran SCI population.