Coagulation has and continues to be one of the most important elements in medicine. Issues from a lack of hemostasis range from poorer clinical outcomes to sudden death. The evolution of treatments for hemostasis have evolved from the use of Tamponade with direct pressure and bandages, the use of materials such as cobwebs and dust, the use of heat with hot oil or heated irons, to the use of suture, glues, plasmas, staplers, and electricity. This evolution has continued to bring about the prophylactic use of technology in an effort to prevent blood loss. This change from reactive treatments to proactive continue to be on a localized or superficial basis. One of the largest opportunities to proactively reduce blood loss in surgical patients is during the resection of solid organs such as the liver, kidney, and spleen. Few options have existed to help improve hemostasis short of the complete occlusion of blood supplying the tissue such as in the Pringle Maneuver. Recent studies have begun to show that practices such as this may have a significant detrimental effect on morbidity. It has been found that by applying radio frequency electrical energy in a particular way that large amounts of tissue can be pre-coagulated prior to resection. A series of animal and human clinical work has been completed to help evolve and confirm the method and the device that was created and refined during this effort. During the course of this work fifty-three patients were treated at four institutions on three continents. Average blood loss for liver resections performed with this pre-coagulation technique using the developed device in a multicenter control trail was 3.35 ml/cm2 as compared to 6.09 ml/cm2 (p < 0.05) for resections performed using standard surgical techniques alone. Additionally, the transection time necessary was also reduced from mean value of 27 minutes (2 -- 219 minutes) to 35 minutes (5 -- 65 minutes). Patients treated included those suffering from liver cirrhosis, fatty liver disease, and post chemotherapy fibrosis. From this work the use of pre-coagulation with methods and device developed was shown to be safe and effective for reducing the amount of blood loss and transection time during liver resections.

BACKGROUND: Tranexamic acid (TXA) has become highly utilized in total joint arthroplasties for its anti-fibrinolytic effect. Recently, intra-articular application of TXA has become popular for its avoidance of systemic distribution within the body. With a more direct application to the surgical site, there is interest to see if topical application will provide hemostasis without increasing rates of venous or arterial thrombotic events and infections. In particular, there is lack of published data describing the safety of TXA in patients who have a significant disposition towards thromboembolic events. METHODS: This study was a retrospective chart-review (RCR) to assess the safety and efficacy of intra-articular TXA (IA-TXA) in total knee and hip arthroplasty patients. IA-TXA 2g/50mL NS was administered to patients who were contraindicated for IV-TXA usage based on our hospital’s guidelines (history of VTE events, mitral or aortic valve replacement with additional risk factors for stroke, active cancer, genetic or acquired thrombophilia, significant cardiac disease, serum creatinine > 2.8 mg/dL). Primary efficacy outcomes were total blood loss on post-operative day 1 (POD1), overall perioperative blood loss, and changes in hemoglobin/hematocrit values over the hospital stay. Primary safety outcomes were the incidence of arterial or venous thrombosis and wound infections. The study compared patients who received IA-TXA (study group) to patients who did not receive TXA (control group). The study included TKA patients=156 (Control=72 Study=83), anterior THA patients=57 (Control=20 Study=37), and posterior THA patients=59 (Control=27 Study=32). RESULTS: TKA patients administered IA-TXA showed a significant decrease in POD1 blood loss compared to the control group [305.84 mL, p = 0.004]. Additionally, the control patients showed significantly lower levels of overall hematocrit than those who had received IA-TXA [0.9 units, p = 0.041]. However, IA-TXA did not cause a reduction in blood loss in either the anterior or posterior THA patients. No statistically significant differences existed between treatment and control groups for transfusion rates or post-operative complications (VTE events and infections). CONCLUSION: IA-TXA 2g/50mL is effective in reducing blood loss in TKA patients; however, further research is needed regarding IA-TXA use in THA patients. The lack of efficacy in THA may have been related to the dosage used, the volume instilled, the timing of administration, or technique of administration.

Fibrinogen concentrates are used widely as a sealant during and after surgery to reduce blood loss. Commercially available fibrin sealants are made from pooled human blood, which carries the risk of blood-borne diseases, and are expensive. These concerns have brought to focus the need for autologous fibrinogen concentrates. This need has been addressed by utilizing a unique approach in which fibrinogen is precipitated from plasma with protamine. The physical properties of fibrin sealant prepared from fibrinogen precipitated with protamine were evaluated. The optimal precipitation conditions included a plasma protamine concentration of 10 mg/mL at room temperature. Under these conditions 96% ± 4% of the fibrinogen present in the plasma was precipitated and 98% ± 0.9% of the precipitated fibrinogen was clottable. In addition, it was shown that almost 50% of the factor XIII in the plasma was also precipitated along with the fibrinogen. The tensile and adhesion strengths and kinetics of fibrin sealant prepared from protamine-fibrinogen concentrate were evaluated. Tensile strength and adhesion strength both increased with increasing fibrinogen concentration. Addition of calcium chloride significantly increased the tensile and adhesion strengths. The addition of aprotinin and ε-aminocaproic acid (used to inhibit natural fibrinolysis) to the fibrinogen concentrate was shown to have no effect on the mechanical properties of the sealant. Kinetic experiments showed that the clotting time decreased as the thrombin and fibrinogen concentrations were increased. A rat model with controlled renal incisions was employed to evaluate the hemostatic efficacy of the fibrin sealant made from the protamine-fibrinogen concentrate. The fibrin sealant significantly reduced the blood loss and bleeding time when compared with controls (no sealant, plasma, and a commercial product). The sealant also significantly reduced blood loss and bleeding time in rats that were anticoagulated with heparin. A mathematical model based on tensile strength and adhesion strength was developed to predict the bleeding time in the animal wound. Model predictions showed that the ability of the fibrin sealant to reduce bleeding time, and therefore blood loss, was limited by the adhesion strength.

ABSTRACTBackground: Determination of blood loss can be a crucial factor at surgical procedures, especially when the amount of blood is small and mixed with other fluids. The existing methods to measure this are still not supported with evidence enough.Aim: To validate the accuracy of the HemoCue® system (HemoCue, Ängelholm, Sweden) at estimation of blood loss in a setup where blood is mixed with saline and saliva.Materials and methods: The haemoglobin concentration of defibrinated horse blood was measured using the haematology analysers Hemocue® 201+ and Hemocue Plasma/Low Hb Photometer. Series of non-diluted blood (control) and blood diluted with saline and saliva (test) were conducted to mimic a clinical situation at oral and maxillofacial surgical treatment. Following each dilution, a new measurement of the haemoglobin concentration was performed using the appropriate haematology analyser to measure the blood loss.Results: There were no statistically significant differences regarding the measured Hb concentration in relation to the degree of dilution. The accuracy of measured blood volume in the diluted and non-diluted blood (control) was within a level of ± 11,5%.Conclusion: The measurement of haemoglobin concentrations in a mixture of blood, saline, and saliva, proved to be accurate when compared to non-diluted blood. It is suggested that the HemoCue® system can be applied in the field of oral and maxillofacial surgery to improve the accuracy of the blood loss measurement.

Blood sampling causes significant blood loss in intensive care unit (ICU) patients (up to 41 mL per day). Only 10% of the blood collected is used for testing suggesting that volumes can be reduced without compromising patient care or laboratory processes. Blood loss contributes to anemia which is highly prevalent in the ICU (>90% after 3 days) and is associated with major adverse cardiovascular outcomes and death. Diagnostic blood loss increases the likelihood of red blood cell (RBC) transfusion which is administered to about 40% of ICU patients (half are given in absence of hemorrhage) and has significant health risks. Small-volume blood collection tubes, which collect about 50% less blood, are available, but rarely used in adults. They have the same cost as standard-volume tubes and are compatible with laboratory equipment. The rationale for the continued use of standard-volume tubes is a theoretical concern about inadequate volume for testing, and the absence of data showing the benefit of small-volume tube use on an important clinical outcome. A study is needed to show that small-volume tubes reduce blood loss, anemia and RBC transfusion without harms or negative consequences on patient care and hospital procedures compared to standard-volume tubes. If this could be shown, it may lead to practice change regarding blood collection for laboratory testing. A stepped-wedge cluster randomized trial is the ideal study design for this low-risk intervention. By incorporating the small-volume tubes into routine clinical practice and using administrative and hospital electronic medical record data, this study would be a pragmatic, cost-effective way to evaluate effectiveness and implementation. However, prior to conducting a full-scale trial powered on clinical outcomes, a pilot study is needed to determine whether a larger study will be feasible. The goals of this thesis are to (i) summarize the existing evidence regarding small-volume tubes; (ii) discuss cluster randomized trial methodology;(iii) discuss the use of health care administrative data for research; (iv) discuss the role of pilot studies; and (v) present the design of a pilot stepped wedge randomized trial of small-volume versus standard-volume blood collection tubes to evaluate the feasibility of a full-scale trial. / Thesis / Master of Science (MSc) / Blood testing is a preventable cause of blood loss. Patients in the intensive care unit (ICU) have about 41 mL of blood taken per day for testing (like donating 1 unit of blood every 8 days). This contributes to anemia (low red blood cells) and transfusion, which are harmful. About 40% of ICU patients get at least one red blood cell transfusion which is a limited resource with health risks. Most of the blood sent to the laboratory is discarded (up to 90%) suggesting that volumes can be reduced without compromising care. The goals of this thesis are to (i) summarize the evidence for reducing blood loss for laboratory testing; (ii) discuss cluster randomized trials; (iii) discuss use of health care administrative data for research; (iv) discuss the role of pilot studies; and (v) present a pilot stepped wedge cluster randomized trial of small-volume versus standard-volume blood collection tubes in ICU patients.

<p>The present thesis addresses various means of reducing inflammatory responses associated with cardiopulmonary bypass (CPB) and retransfusion of pericardial suction blood (PSB) during cardiac surgery.</p><p>Four (I-IV) prospective randomised controlled clinical trials comprising 475 patients were performed in the following areas: effects of heparin coating on measures of clinical outcome and memory function (I, II), inflammatory reactions in PSB and its systemic effects after retransfusion using cardiotomy suction or cell salvage (III) and effects of retransfusion of PSB on memory function and release patterns of protein S100B (IV).</p><p>The use of heparin coated CPB-circuits was associated with a decrease of postoperative blood loss (I, II), transfusion requirements (II), shorter stay in hospital (I) decreased postoperative ventilator time (I), lower incidences of atrial fibrillation (II) and neurological deviations (I), reduction in releases of protein S100B (I, II) and lower postoperative creatinine elevation (I, II).</p><p>PSB contained high concentrations of cytokines, complements, myeloperoxidase, free plasma haemoglobin and protein S100B (III, IV). Retransfusion using cardiotomy suction increased the systemic concentrations of free plasma haemoglobin and protein S100B, whereas retransfusion using cell salvage caused no detectable systemic effects (III, IV). CPB was associated with a small but significant release of protein S100B, despite elimination of PSB-contained protein S100B using cell salvage (IV).</p><p>Subtle signs of impaired memory function were identified that were not associated with the use of heparin coated CPB-circuits (I, II) or retransfusion of PSB (IV).</p><p>Key words: cardiopulmonary bypass, oxygenators, heparin, S100 proteins, blood loss, haemostasis, memory, outcome and process assessment.</p>

The present thesis addresses various means of reducing inflammatory responses associated with cardiopulmonary bypass (CPB) and retransfusion of pericardial suction blood (PSB) during cardiac surgery. Four (I-IV) prospective randomised controlled clinical trials comprising 475 patients were performed in the following areas: effects of heparin coating on measures of clinical outcome and memory function (I, II), inflammatory reactions in PSB and its systemic effects after retransfusion using cardiotomy suction or cell salvage (III) and effects of retransfusion of PSB on memory function and release patterns of protein S100B (IV). The use of heparin coated CPB-circuits was associated with a decrease of postoperative blood loss (I, II), transfusion requirements (II), shorter stay in hospital (I) decreased postoperative ventilator time (I), lower incidences of atrial fibrillation (II) and neurological deviations (I), reduction in releases of protein S100B (I, II) and lower postoperative creatinine elevation (I, II). PSB contained high concentrations of cytokines, complements, myeloperoxidase, free plasma haemoglobin and protein S100B (III, IV). Retransfusion using cardiotomy suction increased the systemic concentrations of free plasma haemoglobin and protein S100B, whereas retransfusion using cell salvage caused no detectable systemic effects (III, IV). CPB was associated with a small but significant release of protein S100B, despite elimination of PSB-contained protein S100B using cell salvage (IV). Subtle signs of impaired memory function were identified that were not associated with the use of heparin coated CPB-circuits (I, II) or retransfusion of PSB (IV). Key words: cardiopulmonary bypass, oxygenators, heparin, S100 proteins, blood loss, haemostasis, memory, outcome and process assessment.

Conselho Nacional de Desenvolvimento Científico e Tecnológico / This study evaluated the use of bipolar electrosurgery and laparoscopic clip applier with respect to surgical time, blood loss and inflammatory response during video-assisted ovariohysterectomy with two portals. Two groups (n=10) assessed each of the hemostatic techniques during castration and a third group (GIII, n=6) evaluated changes in serum promoted only by the clinical and anesthetic protocols used in order to exclude the changes made by them. The surgical times, such as the volume of blood loss were significantly lower in Bipolar Group. The inflammatory response was significantly higher throughout the evaluation period after surgery, but no clinical manifestations different than those presented by the Clipador Group. There were no significant changes in packed cell volume between the groups, but among the times evaluated it reduced about 10% from initial value until four hours after the procedure, in the surgical groups and Group III. Both techniques have good execution by the video-assisted procedure, however, the use of bipolar forceps allows minor surgical times, minimal blood loss and shorter learning curve for the surgeon. The bleeding does not result in physiological changes and that one s on packed cell volume are presented because of the clinical and anesthetic protocols. / Este estudo avaliou a utilização da eletrocirurgia bipolar e do clipador laparoscópico em relação ao tempo cirúrgico, perda sanguínea e resposta inflamatória durante a ovariohisterectomia videoassistida com dois portais. Dois grupos (n=10) avaliaram cada uma das técnicas hemostáticas durante as castrações e um grupo (GIII, n=6) avaliou as alterações séricas promovidas somente pelo protocolo clínico e anestésico utilizado, a fim de excluir as alterações promovidas por estes. O tempo cirúrgico, assim como o volume de sangue perdido foram significativamente menores no Grupo Bipolar. A resposta inflamatória apresentou valores significativamente maiores durante todo o período de avaliação pósoperatório, sem manifestações clínicas diferentes das apresentadas pelo Grupo Clipador. Em relação ao hematócrito não houve alterações significativas entre os grupos, mas entre os tempos de avaliação reduziu cerca de 10% do valor inicial, até quatro horas do final do procedimento, tanto nos grupos cirúrgicos como no Grupo III. Ambas as técnicas são de boa execução através do procedimento videoassistido, porém, o uso da pinça bipolar permite menores tempos cirúrgicos, sangramento mínimo e menor curva de aprendizado do cirurgião. O sangramento não acarreta em alterações fisiológicas e as mudanças apresentadas no hematócrito são provenientes dos protocolos clínico e anestésico instituídos.

<p>Uvod Napredak hirur&scaron;kih i anesteziolo&scaron;kih tehnika učinio je hirur&scaron;ku intervenciju ugradnje totalne proteze kolena uspe&scaron;nom i bezbednom. Međutim, po&scaron;to spada u opsežne ortopedske intervencije, praćena je značajnim gubicima krvnog volumena, kao i značajnom potro&scaron;njom krvi i krvnih derivata. Trendovi u savremenoj medicini idu u pravcu restrikcije upotrebe krvi i krvnih derivata i čine se veliki napori u istraživanju i razvijanju metoda i tehnika koje mogu biti alternative alogenoj transfuziji krvi. Traneksamična kiselina koja ima antifibrinolitičko dejstvo, može dovesti do značajnog smanjenja perioperativnog krvarenja. Ciljevi istraživanja su bili utvrđivanje uticaja traneksamične kiseline na perioperativno krvarenje kod operacija ugradnje totalne proteze kolena, kao i utvrđivanje postojanja uticaja traneksamične kiseline na perioperativnu upotrebu alogene krvi kod operaacija ugradnje totalne proteze kolena. Matrijal i metode u studiju je bilo uključeno 96 bolesnika oba pola, starijih od 18 godina, kojima je bila ugrađivana primarna elektivna totalna proteza kolena. Oni su bili podeljeni u dve grupe, 48 u ispitivanoj grupi kod kojih je primenjivana traneksamična kiselina i 48 bolesnika koji su bili kontrolna grupa. Svi bolesnici su bili u spinalnoj anesteziji i primenjivana je pneumatska poveska na ekstremitetu koji se operisao. Ispitivana grupa je dobijala traneksamičnu kiselinu u dva navrata u dozi od 15 mg /kg i 10 mg/kg u vidu kontinuirane i.v. infuzije u trajanju od 15 minuta. Prvo davanje leka je bilo neposredno nakon uvoda u anesteziju. Drugo davanje leka je bilo 15 minuta pre otpu&scaron;tanja pneumatske poveske. Kontrolna grupa je dobijala istu količinu 0.9% fiziolo&scaron;kog rastvora koji je primenjivan na isti način. Intraoperativni gubitak krvi je beležen i meren kao gubitak u aspiratoru i gubitak na gazama. Postoperativn gubitak krvi se merio nakon 6, 12 sati i nakon 24 sata, kao gubitak na drenove Beležio se i broj primenjenih jedinica krvi i broj ukupno dobijenih mililitara krvi i ostalih krvnih produkata, kao i vreme njihove primene. Rezultati Postoji statistički značajna razlika u prosečnom intraoperativnom krvarenju između grupa (Z = -7,281; p = 000). Prosečno intraoperativno krvarenje u ispitivanoj grupi je bilo 100 &plusmn; 92,690 ml, a u kontrolnoj 447 &plusmn; 299,282 ml. U kontrolnoj grupi bolesnici imaju statistički značajno veće ukupno postoperativno krvarenje od bolesnika iz ispitivane grupe (T test, t=4,024, p&lt;0,01) ( ispitivana grupa 309,78&plusmn; 143,612 ml, kontrolna grupa 455,42 &plusmn; 201,177 ml). Razlika je bila statistički značajna nakon 6 sati (p &lt; 001) i nakon 12 sati u korist ispitivane grupe (p&lt;0,05). Postji statistički značajna razlika u ukupnom perioperativnom krvarenju među grupama i traneksamična kiselina je statistički značajno (p&lt;0,000) smanjila ukupno krvarenje од 919,36 ml (95%IP 822,083-1016,640) na 405, 32 ml (95% IP 353, 407-457, 231). Ukupno perioperativno krvarenje je u proseku iznosilo 662, 34 ml i kretalo se u intervalu od 100 do 1700 ml. U ispitivanoj grupi je samo 5 (10,4%) ispitanika primilo transfuziju, dok je u kontrolnoj grupi 39 (81,3%), &scaron;to je statistički značajna razlika (2=45,692; p=0,000). Prosečna količina date alogene krvi u ispitivanoj grupi je 33,33 &plusmn; 99,2 ml, dok je prosečna količina date alogene krvi u kontrolnoj grupi bila skoro deset puta veća i iznosila je 319,2 &plusmn; 230 ml, &scaron;to je statistički značajno veće (Z = -6,625; p = 000). Postoperativne vrednosti hemoglobina, hematokrita i trombocita bile su statistički značajno veće u isptivanoj grupi. Bolesnici iz ispitivane grupe su statistički značajno ranije postoperativno uzimali prvi obrok, sedeli i ustajali od bolesnika u kontrolnoj grupi. Zaključci Iz dobijenih rezultata o intraoperativnom, postoperativnom i ukupnom perioperativnom krvarenju može se zaključiti da je traneksamična kiselina veoma efikasan lek i da statistički značajno smanjuje krvarenje vezano za ugradnju totalne proteze kolena i da smanjuje upotrebu transfuzije alogene krvi za 66,7%. Traneksamična kiselina je uticajem na smanjenje perioperativnog krvarenja dovela do očuvanja vrednosti hemoglobina, hematokrita i trombocita. Bolesnici koji su dobijali traneksamičnu kiselinu su takođe imali brži i kvalitetniji neposredni postoperativni oporavak.</p> / <p>Uvod Napredak hirur&scaron;kih i anesteziolo&scaron;kih tehnika učinio je hirur&scaron;ku intervenciju ugradnje totalne proteze kolena uspe&scaron;nom i bezbednom. Međutim, po&scaron;to spada u opsežne ortopedske intervencije, praćena je značajnim gubicima krvnog volumena, kao i značajnom potro&scaron;njom krvi i krvnih derivata. Trendovi u savremenoj medicini idu u pravcu restrikcije upotrebe krvi i krvnih derivata i čine se veliki napori u istraživanju i razvijanju metoda i tehnika koje mogu biti alternative alogenoj transfuziji krvi. Traneksamična kiselina koja ima antifibrinolitičko dejstvo, može dovesti do značajnog smanjenja perioperativnog krvarenja. Ciljevi istraživanja su bili utvrđivanje uticaja traneksamične kiseline na perioperativno krvarenje kod operacija ugradnje totalne proteze kolena, kao i utvrđivanje postojanja uticaja traneksamične kiseline na perioperativnu upotrebu alogene krvi kod operaacija ugradnje totalne proteze kolena. Matrijal i metode u studiju je bilo uključeno 96 bolesnika oba pola, starijih od 18 godina, kojima je bila ugrađivana primarna elektivna totalna proteza kolena. Oni su bili podeljeni u dve grupe, 48 u ispitivanoj grupi kod kojih je primenjivana traneksamična kiselina i 48 bolesnika koji su bili kontrolna grupa. Svi bolesnici su bili u spinalnoj anesteziji i primenjivana je pneumatska poveska na ekstremitetu koji se operisao. Ispitivana grupa je dobijala traneksamičnu kiselinu u dva navrata u dozi od 15 mg /kg i 10 mg/kg u vidu kontinuirane i.v. infuzije u trajanju od 15 minuta. Prvo davanje leka je bilo neposredno nakon uvoda u anesteziju. Drugo davanje leka je bilo 15 minuta pre otpu&scaron;tanja pneumatske poveske. Kontrolna grupa je dobijala istu količinu 0.9% fiziolo&scaron;kog rastvora koji je primenjivan na isti način. Intraoperativni gubitak krvi je beležen i meren kao gubitak u aspiratoru i gubitak na gazama. Postoperativn gubitak krvi se merio nakon 6, 12 sati i nakon 24 sata, kao gubitak na drenove Beležio se i broj primenjenih jedinica krvi i broj ukupno dobijenih mililitara krvi i ostalih krvnih produkata, kao i vreme njihove primene. Rezultati Postoji statistički značajna razlika u prosečnom intraoperativnom krvarenju između grupa (Z = -7,281; p = 000). Prosečno intraoperativno krvarenje u ispitivanoj grupi je bilo 100 &plusmn; 92,690 ml, a u kontrolnoj 447 &plusmn; 299,282 ml. U kontrolnoj grupi bolesnici imaju statistički značajno veće ukupno postoperativno krvarenje od bolesnika iz ispitivane grupe (T test, t=4,024, p&lt;0,01) ( ispitivana grupa 309,78&plusmn; 143,612 ml, kontrolna grupa 455,42 &plusmn; 201,177 ml). Razlika je bila statistički značajna nakon 6 sati (p &lt; 001) i nakon 12 sati u korist ispitivane grupe (p&lt;0,05). Postji statistički značajna razlika u ukupnom perioperativnom krvarenju među grupama i traneksamična kiselina je statistički značajno (p&lt;0,000) smanjila ukupno krvarenje od 919,36 ml (95%IP 822,083-1016,640) na 405, 32 ml (95% IP 353, 407-457, 231). Ukupno perioperativno krvarenje je u proseku iznosilo 662, 34 ml i kretalo se u intervalu od 100 do 1700 ml. U ispitivanoj grupi je samo 5 (10,4%) ispitanika primilo transfuziju, dok je u kontrolnoj grupi 39 (81,3%), &scaron;to je statistički značajna razlika (2=45,692; p=0,000). Prosečna količina date alogene krvi u ispitivanoj grupi je 33,33 &plusmn; 99,2 ml, dok je prosečna količina date alogene krvi u kontrolnoj grupi bila skoro deset puta veća i iznosila je 319,2 &plusmn; 230 ml, &scaron;to je statistički značajno veće (Z = -6,625; p = 000). Postoperativne vrednosti hemoglobina, hematokrita i trombocita bile su statistički značajno veće u isptivanoj grupi. Bolesnici iz ispitivane grupe su statistički značajno ranije postoperativno uzimali prvi obrok, sedeli i ustajali od bolesnika u kontrolnoj grupi. Zaključci Iz dobijenih rezultata o intraoperativnom, postoperativnom i ukupnom perioperativnom krvarenju može se zaključiti da je traneksamična kiselina veoma efikasan lek i da statistički značajno smanjuje krvarenje vezano za ugradnju totalne proteze kolena i da smanjuje upotrebu transfuzije alogene krvi za 66,7%. Traneksamična kiselina je uticajem na smanjenje perioperativnog krvarenja dovela do očuvanja vrednosti hemoglobina, hematokrita i trombocita. Bolesnici koji su dobijali traneksamičnu kiselinu su takođe imali brži i kvalitetniji neposredni postoperativni oporavak.</p> / <p>Introduction: Total knee arthroplasty today is efficient and safe surgical procedure. Being extensive orthopaedic surgical procedure poses a risk from substantial perioperative bleeding and consecutive usage of blood products.&nbsp; Trends in modern medicine and surgery are in favor of restrictive usage of blood products and there are paramount efforts in researching and developing new techniques and methods of allogenic blood transfusion alternatives. Tranexamic acid as fibrinolytic agent is good example of substance that can be used to reduce preoperative bleeding in orthopaedic surgery. Aims of the study: We wanted to explore effects of tranexamic acid on perioperative bleeding reduction in total knee arthroplasty, and it&rsquo;s effect on reduction of blood product usage in this surgical population. Маterial and methods: We conducted double blind, randomized controlled trial with 96 adult patient (older than 18 years) in the study, 48 in two groups. All patients had elective, unilateral total knee arthroplasty. First group got tranexamic acid(TA), and second (control) group got normal saline. Surgery was performed in spinal anaesthesia with usage of pneumatic tourniquet in all patients. First group got tranexamic acid 15mg /kg/ bw и 10 mg/kg/bw as continuous intravenous infusion in duration of 15 min. Control group got same amount of normal saline. First dose of TA was given at the beginning of the operation and second dose 15 min before release of the tourniquet. Control group got normal saline at the same way. Intraoperative blood loss was measured as blood loss in suction bottle and blood loss on the surgical sponges. Postoperative blood loss was measured as blood loss in surgical wound drains after 6, 12, and 24 hours. Number of blood units and total amount of blood and blood products in milliliters were also recorded. Results There are statistically significant difference in average intraoperative bleeding between groups in favor tranexamic acid group (Z = -7,281; p = 000).Average intraoperative bleeding in TA group is 100 &plusmn; 92,690 mil, vs 447 &plusmn; 299,282 mil in control group. Patient in TA group has statistically significant less total postoperative bleeding (T test, t=4,024, p&lt;0,01)( TA group 309,78&plusmn; 143,612 mil vs,420 &plusmn; 201,177 mil). Blood loss was statistically significant less after 6 (p &lt; 001) and 12 hrs (p &lt;0,05). in TA group. Total perioperative bleeding was statistically significant less (p&lt; 0,000) in TA group and TA decreased total blood loss from 919,36 ml (95%IP 822,083-1016,640) to 405,32 ml (95%IP 353,407-457,231).Average total blood loss was 662,34 ml with interval from 100 to 1700 ml. In TA group only 5 (10,4%) patients received vs control group where 39 (81,3%) patients received allogenic blood transfusion and that is statistically significant (2=45,692; p=0,000).Average blood usage in TA group was 33,33 &plusmn; 99,2 ml vs 319,2 &plusmn; 230 ml in the control group (Z = -6,625; p = 000). Postoperative hemoglobin, haematocrit and platelets count values were statistically significant less in control group. Patient in TA group had earlier first postoperative meal, sitting and standing earlier than patient in the control group. Concliusions Data from this study clearly shows that intraoperative, postoperative and total perioperative blood loss in total knee arthroplasty are reduced with usage of tranexamic acid. Tranexamic acid is effective in reducing perioperative blood loss and usage of allogenic blood transfusion, which dropped for 66,7%.This reduced blood loss led to higher postoperative hemoglobin levels. Patients from TA group showed faster postoperative functional recover.</p>

Introdução: A desmopressina, análogo sintético do hormônio hipotalâmico vasopressina, é utilizada em determinadas condições hematológicas hereditárias melhorando a função plaquetária e aumentando os níveis dos fatores de von Willebrand (FvW) e Fator VIII. Entretanto, sua administração na população geral é controversa, necessitando de mais estudos para elucidar sua eficácia como agente hemostático. Objetivo: O objetivo do presente estudo foi avaliar a coagulação sanguínea, clínica e laboratorialmente, após administração profilática da desmopressina em cirurgias cardíacas valvares. Métodos: Estudo clínico prospectivo e randomizado realizado no Instituto do Coração (InCor) do Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo (HC-FMUSP). Foram incluídos 108 pacientes adultos submetidos à cirurgia cardíaca valvar, no período de fevereiro de 2015 a novembro de 2016. Os pacientes foram randomizados e alocados para a administração profilática da desmopressina ou para o grupo controle, na admissão hospitalar. Imediatamente após a reversão da heparina, administrouse a demopressina no grupo da intervenção ou solução placebo no grupo controle. O desfecho foi a análise da coagulação sanguínea e do sangramento perioperatório através dos exames laboratoriais, débito sanguíneo dos drenos cirúrgicos e do consumo de hemocomponentes em 48 horas. Resultados: Os níveis sanguíneos do Fator VIII no tempo 2h (236,5 ± 62,9 vs. 232,3 ± 66,7, P=0,015) foram estatisticamente significantes entre os dois grupos (DDAVP e controle), respectivamente. Os demais testes clássicos da coagulação, assim como a análise viscoelástica e de agregação plaquetária mantiveram-se homogêneos em todos os tempos de coleta entre os dois grupos. O débito dos drenos cirúrgicos, balanço sanguíneo e consumo de hemocomponentes não apresentaram diferenças significantes entre os grupos DDAVP e controle. O tempo de ventilação mecânica apresentou diferença relevante entre os grupos DDAVP e o controle [897 (820 - 1011) vs. 1010 (846 - 1268), em mim, P=0,031], respectivamente. Não houve diferença em relação à incidência de complicações, tempo de internação hospitalar e de UTI ou mesmo de mortalidade em 30 dias. Conclusões: A utilização profilática da desmopressina em cirurgias cardíacas valvares não se mostrou eficaz em exercer efeito hemostático em relação ao grupo controle no presente estudo / Introduction: Desmopressin, a synthetic vasopressin analogue, is used in certain hereditary hematologic conditions, improving platelet function and increasing the levels of von Willebrand factor and factor VIII. However, its use in general population is still controversial, requiring further studies to elucidate its efficacy as a haemostatic agent. Objective: To evaluate blood coagulation, through clinical and laboratorial analysis, after prophylactic use of desmopressin in heart valve surgeries. Methods: A prospective and randomized clinical study was performed in the Heart Institute (InCor) of Hospital das Clínicas, from the Faculty of Medicine, University of São Paulo (HC-FMUSP). A total of 108 adult patients undergoing heart valve surgeries were enrolled from February 2015 to November 2016. Patients were randomly assigned to the prophylactic use of desmopressin or to the control group at the time of hospital admission. Immediately after heparin reversal, demopressin was given in the intervention group or placebo solution in the control group. Blood samples were collected at three different times in all study participants. Blood coagulation and perioperative bleeding were analysed using laboratorial tests, blood flow through surgical drains and the consumption of blood components within 48 hours. Results: Blood levels of Factor VIII at Time 2h (236.5 ± 62.9 vs. 232.3 ± 66.7, P=0.015) were significantly different between the two groups (desmopressin and control), respectively. Classical coagulation tests, as well as viscoelastic and platelet aggregation tests, remained homogeneous at all collection times between the two groups. Flow rate of surgical drains, blood balance and consumption of blood components did not present significant differences between the DDAVP and control groups. Mechanical ventilation time presented a significant difference between the desmopressin and control groups [897 (820 - 1011) vs.1010 (846 - 1268), min, P=0.031], respectively. There was no difference in incidence of complications, length of hospital and ICU stay or even mortality in 30 days. Conclusions: The prophylactic use of desmopressin in heart valve surgeries was not effective in exerting haemostatic effect compared to the control group in this study