Influence of acute non-isovolemic hemodilution plus tranexamic acid on coagulation factors and hemorrhage / 实用医学杂志

Objective To study the effect of acute non-isovolemic hemodilution (ANIH) plus tranexamic acid on bleeding and coagulation factors. Methods Forty-two patients with brain tumor under general anesthesia were randomly divided into group N and group T with 21 patients in each group. Group N was given ANIH , while group T was given tranexamic acid and ANIH. Bleeding, transfusion, urine volume were recorded. Coagulation factors and D-dimer were detected one day before and after surgery. Hemoglobin was recorded before and after ANIH and after auto-blood was transfused. Results There was less bleeding in group T. Hemoglobin in group T was higher after transfusion. No significant difference was found in Group T and group N in terms of urine volume and transfusion rate. Both the two groups had no difference on variation of coagulation factors. Conclusion ANIH with tranexamic acid has no significant effect on coagulation but produces synergetic effect on decreasing bleeding. They can be applied in surgery of brain tumor safely.

Effect of acute non-isovolemic hemodilution in combination with tranexamic acid on cycle function blood gas and electrolytes with brain tumor surgery / 实用医学杂志

Objective To investigate the effect of acute non-isovolemic hemodilution in combination with tranexamic acid on cycle function blood gas and electrolytes with brain tumor surgery. Methods Forty-two patients undergoing brain tumor were randomly divided into two groups. Patients in group A received ANIH plus tranexamic acid , while patients in group B received ANIH alone. Collected blood was transfused before the end of surgery. HR、CVP、MAP,hemoglubin, blood gas and plasma electrolytes were respectively recorded before ANIH(T1), at 0 min (T1) and 1 h (T2) after ANIH, and at the end of operation (T4). Results There were no significant changes in HR, CVP, MAP. At T2, T3, T4, Hb, Hct in both two groups lower than those at T1(P <0.05); at T4, Hb, Hct in group A were higher than those in group B. There were no significant changes in pH , PaO2, PaCO2, BE between the both two groups. There were no significant changes in Na +, Cl-, Ca2+and K+between the both two groups. Conclusion ANIH has little effect on the cycle function and blood gas electrolyte. ANIH in combination with TA has a section blood effect. It can be used in the brain tumor operation with TA security.

The Effect of Acute Hemodilution on Carotid Blood Flow, Arterial Blood Gas Analysis and Acid-Base Balance in Rabbits / 대한마취과학회지

BACKGROUND: Hemodilution is known to increase cerebral blood flow, but it is not known why it is. We tried to investigate about these question like above. METHODS: Blood flow were checked on carotid artery after hemodilution by using electromagnetic blood flow-meter in 10 rabbits. Hemodilution was induced as 15 ml of lactated Ringers solution (LR) was infused after removing 5 ml of blood. Hemodilution was done 5 times in each rabbit. At 15 minutes after each hemodilution procedure, blood flow was checked and arterial blood gas analysis, and they compared with control data. The Sigma STAT and one way repeated measured ANOVA in Bonfferoni correction and regression analysis with DBSTAT PC application were used for statical analysis. RESULTS: Hemoglobin concentration and hematocrit in blood according to each hemodilution step decreased. At the same time, carotid blood flow increased following hemodilution. Though PaO2 level was not changed, CaO2 and pH, bicarbonate, and base excess in accordance with hemodilution were decreased. Also carotid blood flow calculated as increase 2.5 ml/min whenever hematocrit decreased 1%. CONCLUSIONS: We concluded as follow. Carotid blood flow increased to 2.5 ml/min (4.7%) whenever hematocrit decreased 1% by hemodilution. Whenever 15 ml of L/R solution was infused for acute hemodilution, carotid blood flow increased, on the contrary, hematocrit and arterial oxygen content decreased. Metabolic acidosis was induced by the large amount of L/R solution and it may be affected to carotid blood flows.

The Effect of Isovolemic Hemodilution on the Autoregulation of Cerebral Blood Flow / 대한마취과학회지

BACKGROUND: Hemodilution may increase cerebral blood flow (CBF) but the mechanism(s) remain controversal. Autoregulation is easily modified or disturbed by several conditions. The aim of this study was to evaluate the effects of isovolemic hemodilution on the autoregulation of cerebral blood flow in a rabbit model. METHODS: Stepwise hemodilution was accomplished by incrementally removing whole blood from the animals in amounts of 8-12 ml and replacing this with an equal volume of 6% hetastarch in saline. This procedure was continued until the target content values of approximately Hct -18% were achieved. To evaluate the influence of pressure changes on CBF, mean arterial pressure (MAP) was increased from a baseline pressure (approximately 78 mmHg) to 145 mmHg by infusing methoxamine, and cerebral blood flow was measured at each MAP level using the hydrogen clearence method after MAP had been stabilized for 15 min. RESULTS: Stepwise hespen replacement caused a sudden drop of Hct from 37.4% to 18.5% and a simultaneously a significant increase in local CBF of 161% in the hemodilution group. Hemodilution significantly reduced CaO2 in the hemodilution group (9.45 +/- 1.7 ml O2/dl) versus the control group (18.34 +/- 1.3 ml O2/dl). However, despite these decrease in CaO2, calculated cerebral oxygen delivery (DO2) was as well maintained in the hemodilution group (22.47 +/- 7.28 ml O2/100 gm/min) as in the control group (24.14 +/- 8.67 ml O2/100 gm/min). MAP increases from 78 mmHg to 145 mmHg produced a significant increase in CBF from 122.4 +/- 32.8 ml/100 gm/min to 170.9 +/- 23.7 ml/100 gm/min in control group (39.6%) and from 218.4 +/- 75.6 ml/100 gm/min to 268.4 +/- 106.5 ml/100 gm/min in the hemodilution group (44.6%) (P<0.001). These CBF increases were not significantly different in the two groups. CONCLUSIONS: The present study demonstrates that in the normal brain the decrease in CaO2 caused by hemodilution is well compensated for by an increase CBF, and that oxygen transport to the brain is also well maintained during at a Hct value of 20%. Although the present study did not show the tight CBF control within the MAP range from 78 mmHg to 145 mmHg, hemodilution did not alter the response of the cerebral circulation to increased MAP.

The Effects of Isovolemic Hemodilution on Hemodynamic Changes in Myocardial Ischemia-Induced Dogs / 대한마취과학회지

BACKGROUND: Anesthesiologists often encounter patients who have acute, massive blood loss and severe hemodilution as the result of fluid therapy in the operating room. It is known that patients with normal heart function survive at hemoglobin 4 6 g/dl. Recently, the incidence of elderly patients with ischemic heart disease have been increasing progressively but studies about critical hematocrit level in patients with ischemic heart disease are rare. This study, therefore, was designed to evaluate the hemodynamic response of isovolemic hemodilution in myocardial ischemia-induced dogs. METHODS: In 12 anesthetized dogs, a Swan-Ganz catheter and left ventricle catheter were inserted and hemodynamic parameters were measured as control values. Myocardial ischemia was induced with a left anterior descending (LAD) coronary artery ligation. Thereafter, isovolemic hemodilutions were done several times to set the hematocrit levels of 36%, 31%, 26%, 21%, 16%, and 11%. Records and samples for hemodynamic parameters were obtained after LAD ligation and at each hematocrit level. RESULTS: There were significant decreases in diastolic blood pressures in hematocrits 21%, 16%, 11%, in mean arterial pressures in hematocrits 16%, 11% and in systolic blood pressure in hematocrit 11% (P < 0.05). Oxygen delivery progressively decreased in hematocrits 36%, 31%, 26%, 21%, 16% and 11% (P < 0.05). Oxygen extraction ratios progressively increased and were statistically significant in hematocrits 21%, 16% and 11% (P < 0.05). Arterial blood gases showed metabolic acidosis in hematocrits 16% and 11%. There was decreased PCO2 in hematocrit 11% (P < 0.05). Mixed venous blood oxy-hemoglobin saturation decreased in hematocrit 16% and 11% (P < 0.05). Other variables were not significant. CONCLUSIONS: Blood pressure decreased at hematocrit 16% so it is necessary to maintain a hematocrit level above 21% at least in cardiac depressed dogs.

Cardiovascular Effects of Acute Isovolemic Hemodilution / 대한마취과학회지

Acute normovolemic hemodilution is widely used to conserve blood and to minimize the need for homologous blood transfusion during operation. To evaluate the effects of aeute isovolemic hemodilution on hemodynamics and oxygen transport, pulmonary artery catheter and radial artery catheter were introduced in 8 patients in whom maxillofacial or Wertheim's operation were performed. Blood(estimated from allowable blood loss) was withdrawn from radial artery, and simultaneously replaced by intravenous administration of 5% plasmanate and Hartmann solution. Acute isovolemic hemodilution decreased the hematocrit level from 33.2+/-3.7% to 29.6+/-2.9%. Cardiac output increased significantly, which was associated with decreased systemic vaacular resistance. Oxygen transport and oxygen consumption increased despite a decrease in oxygen carrying capacity. Heart rate, mean arterial perssure, mean pulmonary arterial pressure, central venous pressure, and pulmonary capillary wedge pressure did not change significantly during hemodilution. The results indicate that blood perfusion and oxygenation to tissue were well maintained in the hemodilution of the magnitude used in this study. Therfore it could be concluded that acute isovolemic hemodilution is a safe and relatively simple method of conserving blood and minimizing homologous blood transfusion.

Cardiovascular Effects of Acute Isovolemic Hemodilution / 대한마취과학회지

Acute normovolemic hemodilution is widely used to conserve blood and to minimize the need for homologous blood transfusion during operation. To evaluate the effects of aeute isovolemic hemodilution on hemodynamics and oxygen transport, pulmonary artery catheter and radial artery catheter were introduced in 8 patients in whom maxillofacial or Wertheim's operation were performed. Blood(estimated from allowable blood loss) was withdrawn from radial artery, and simultaneously replaced by intravenous administration of 5% plasmanate and Hartmann solution. Acute isovolemic hemodilution decreased the hematocrit level from 33.2+/-3.7% to 29.6+/-2.9%. Cardiac output increased significantly, which was associated with decreased systemic vaacular resistance. Oxygen transport and oxygen consumption increased despite a decrease in oxygen carrying capacity. Heart rate, mean arterial perssure, mean pulmonary arterial pressure, central venous pressure, and pulmonary capillary wedge pressure did not change significantly during hemodilution. The results indicate that blood perfusion and oxygenation to tissue were well maintained in the hemodilution of the magnitude used in this study. Therfore it could be concluded that acute isovolemic hemodilution is a safe and relatively simple method of conserving blood and minimizing homologous blood transfusion.

The Effect of Calcium Channel Blockers on Acute Hemodilution in Hypoxic Dogs / 대한마취과학회지

Hemodilution, which is usually induced by autotransfusion, cardiopulmonary bypass and replace-ment therapy for blood loss, has some advantages in saving blood, improving blood flow and reducing the work-load of myocardium. But the safety and compensatory mechanism can be jeopardized by multiple factors, such as changes in inspired oxygen fraction (FIO,), cardiovascular diseases and drugs with potent cardiovascular actions, because of the disadvantageous hemodynamic changes and reduction of oxygen carrying capacity during hemodilution. Calcium channel blockers (CCB), which have recently gained a great popularity in treating several cardiovascular diseases, can affect cardiovascular system and compensatory mechanism during hemodilution. Therefore, to evaluate the effect of CCB on acute isovolemic hemodilution under the condition of hypoxia, we observed the parameters of hemodynamics and oxygen transport during acute isovolemic hemodilution after bleeding (20 ml/kg) in 16 experimentally induced hypoxic (FIO 0.15) dogs divided into verapamil and diltiazem treated groups. The results were as follows; 1) Hemodynamics; (a) In verapamil treated group, mean arterial pressure (MAP) was lower during experiment, but after hemodilution, central venous pressure (CVP) and pulmonary capillary wedge pressure (PCWP) increased greater than in diltiazem treated group. Verapamil showed a greater negative inotropic effect. (b) Verapamil brought more vasodilatory effect than diltiazem. A significant increase of pul-monary vascular resistance (PVR) appeared after hypoxia, which meant hypoxic pulmonary vasocon-striction in diltiazem treated group. (c) In both groups, cardiac output (CO) was maintained well but heart rate (HR), MAP and rate pressure product (RPP) were decreased afrter hypoxia, bleeding and hemodilution. CCB reduce the work load of heart and myocardial oxygen consumption, thereby protect the myocardium. This effect was greatest after bleeding. 2) Oxygen transport; (a) Arterial oxygen tension (PaO2) was increased after hypoxia, bleeding and hemodilution in both groups and arterial carbon dioxide tension (PaCO2) was decreased after hemodilution in verapamil treated group. Ventilation-perfusion mismatch was improed in both groups, more prominently in verapamil treated group. (b) Oxygen flux (O2Flux) and oxygen consumption (VO2) were maintained well in both groups but oxygen extraction ratio (O2ER) after hypoxia and bleeding, and arterial and mixed venous oxygen content difference (Ca-vO2) after hypoxia were increased in diltiazem treated group. After hemodilu-tion, O2ER was decreased in both groups and Ca-VO2, was decreased in verapamil treated group. In diltiazem treated group, pH of arterial blood (pHa) and mixed venous oxygen tension (PvO2) were decreased after hypoxia, and PvO2 were decreased after hypoxia, and , was also decreased after hemodilution. Oxygen deficit was not seen in either group and oxygen utilization was more satisfactory in verapamil treated group. 3) After hemodilution with dextran-40, colloid osmotic pressure (COP) increased and ionized calcium (Ca++) decreased in both groups. The above findings indicated that use of CCB during acute isovolemic hemodilution in hypoxic dogs is safe because CCB showed adequate maintenance of cardiac output without any sign of heart failure or reduction of myocardial work despite a negative inotropic effect and vasodilatory effect hemodynamically, and also revealed improvement of ventiltion-perfusion mismatch and smooth maintenance of oxygen transport. Both of the effects were more prominent with verapamil than diltiazem in an equimolar dose.

Circulatory Responses to Acute Isovolemic Hemodilution in Hypoxic Dogs / 대한마취과학회지

The circulatory responses to acute isovolemic hemodilution were studied in nine mongrel dogs in hypoxic(FIO2=0.15) environment. The animals were bled 20ml/kg of blood. The shed blood was replaced by equivalent amounts of low molecular weight extran(LMWD). Hemodynamic measurements and calculations were performed in control normoxic period, hypoxic period before bleeding, hypoxic period after fleeding and after hemodilution with LMWD. By hemodilution, Hb and Hct were decreased from 13.6+/-0.8gm/dl and 41+/-2% to 12.9+/-0.9gm/dl and 21+/-2%, respectively. Hypoxia itself did not cause any hemodynamic changes. Bleeding caused significant increases in SVR(60%) and PVR(77.9%), and resulted in decreases in CI(40.0%), TI(32.7%) and PCWP(2.0%) compared with the data in control period. Hemodilution reversed hemodynamic changes induced by bleeding. PVR returned to normal and SVR was rather decreased by 24.2%, CI, PCWP and CVP were increased by 25.4%, 6.0%, and 37.5%, respectively. The parameters such as HR and RPP which might be related to oxygen consumption were decreased by 10.6%, compared with control data. This study demonstrated that, in spite of lowered arterial oxygen content during hemodilution, tissue oxygen supply and cardiac performance might be well maintained by combined effects of decreased afterload and oxygen consuming factors, and increased preload. In conclusion, acute isovolemic hemodilution with LMWD might be a safe tolerable method in the aspects of circulatory response in hypoxic dogs.