Reinfusion Of Blood Research Articles

Dexmedetomidine-ketamine Combination Mitigates Pulmonary Type-2 Cationic Amino Acid Transporter Isozymes Upregulation in Hemorrhagic Shock Rats

Dexmedetomidine-ketamine combination has been reported to mitigate inducible nitric oxide synthase (iNOS) upregulation in rats with hemorrhagic shock. Type-2 cationic amino acid transporter isozymes, including CAT-2 and CAT-2B, are essential in regulating iNOS activity. We sought to elucidate the effects of dexme-detomidine-ketamine combination on regulating the expression of pulmonary CAT-2 isozymes in rats with hemorrhagic shock. Forty adult male rats were randomized to one of four groups (10 rats in each group): sham-instrumentation (Sham); sham-instrumentation plus dexmedetomidine-ketamine combination (Sham-D + K); hemorrhagic shock (HS); or hemorrhagic shock plus dexmedetomidine-ketamine combination (HS-D + K). Rats in the HS and HS-D + K groups sustained controlled hemorrhagic shock (mean blood pressure was lowered to 40-45 mmHg by bloodletting for 60 minutes), followed by resuscitation with reinfusion of the shed blood mixed with saline. After close observation for 5 hours, the rats were sacrificed and the expression of CAT-2 isozymes was evaluated. Sham-instrumentation and dexmedetomidine-ketamine combination did not affect CAT-2 isozymes expression, as pulmonary CAT-2 and CAT-2B mRNA concentrations in the Sham and Sham-D + K groups were low. Hemorrhagic shock significantly upregulated CAT-2 isozymes expression as pulmonary CAT-2 and CAT-2B mRNA concentrations in the HS group were significantly higher than in the two Sham groups. Pulmonary CAT-2 and CAT-2B mRNA concentrations in the HS-D + K group were significantly lower than in the HS group, indicating that the effects of hemorrhagic shock on upregulating CAT-2 isozymes expression were attenuated by dexmedetomidine-ketamine combination. Dexmedetomidine-ketamine combination mitigates pulmonary CAT-2 isozymes upregulation in rats with hemorrhagic shock.

Current Blood Salvage Technologies during Pelvic Repair

The introduction of current technologies into traumatology and orthopedics, anesthesiology and reanimatology and the accumulation of practical experience extend the feasibilities of highly skilled care to patients with pelvic fractures. Reconstructive operations that are one of the most complex and highly traumatic types in orthopedics are accompanied by massive intra- and postoperative blood loss. Its level is as high as 800 to 6000 ml. Until recently, blood loss has been compensated for with allogenic blood preparations. However, the complications resulting from the use of donor blood are universally known. This has caused indications for the use of blood preparations to be revised and a number of alternatives associated with the use of a patient’s blood to be developed. This alternative is current blood salvage technologies. Key words: autodonation, acute hypervolemic hemodilution, instrumental washed autoerythrocyte reinfusion, drainage blood reinfusion.

Choice of an Infusion Agent for the Prevention of Multiple Organ Dysfunction in Acute Massive Blood Loss (Experimental Study)

Objective: to perform an experimental study of the effect of sterofundin isotonic on the biochemical parameters characterizing the degree of organ injury after acute massive blood loss (AMBL). Material and methods. Experiments were carried out on 36 male Wistar rats weighing 230—250 g. Hemorrhagic stroke was simulated via AMBL in a volume of 2.5 ml/100 g at a rate of 2 ml/min. An hour after AMBL, there was hypovolemia compensation within 60 minutes in a volume of 200% of the blood loss: by Ringer’s solution in a control group and by sterofundin isotonic in an experimental group. Then blood reinfu-sion was made in a volume of 70% of blood loss. The biochemical parameters of multiple organ dysfunction (glucose, lactate, urea, creatinine, bilirubin, total protein, albumin), enzymemia (aspartate aminotransferase, alanine aminotransferase, creatine phosphokinase, lactate dehydrogenase, amylase), endotoxemia (low- and medium-molecular-weight substances in the plasma and erythrocytes), acid-base condition, electrolytes of venous blood, and animal survival were determined on days 1 and 3 following AMBL. Results. There was a reduction in the time and degree of posthemorrhagic metabolic, biochemical, and electrolyte disorders, enzymemia, and endotoxemia in the experimental animals. Conclusion. The experimental studies suggest that Ringer’s solution is inadequately effective in preventing multiple organ dysfunction due to AMBL. The malate-containing blood substitute sterofundin isotonic that is used during early therapy for AMBL exerts a marked preventive effect on the development of visceral organ injuries when multiple organ dysfunction occurs in the early and late posthemorrhagic period. The experimental findings make it possible to recommend that sterofundin isotonic should be used in intensive care of hypovolemic shock arising from AMBL. Key words: acute massive blood loss, malate, sterofun dinisotonic, lactate, endotoxemia, multiple organ dysfunction.

Safety of cardiac surgery without blood transfusion: a retrospective study in Jehovah’s Witness patients

We read with interest the experience of El Azab et al. [1] of providing a cardiac surgery service to Jehovah’s Witness patients. We agree that patients who refuse allogeneic blood products present both moral and ethical challenges, especially in cardiac surgery where significant blood loss and allogeneic blood product transfusion are common. We noted that the pre-operative haemoglobin concentrations were very similar in both groups, despite 3 weeks' treatment with erythropoietin, and the number of patients in the control group who received blood product transfusion was very high. We work in a busy cardiothoracic centre with a blood product transfusion rate of 20–25% compared to 65% in the control group in their article. Knowledge of their patients’ postoperative haemoglobin concentrations would have been interesting, but this information was not provided. Cell salvage and autologous transfusion is an important component of blood conservation, but this was not part of this hospital’s protocol for managing Jehovah’s Witness patients. Cell salvage is usually acceptable to Jehovah’s Witnesses, but consent needs to be obtained on an individual basis. The 2009 Association of Anaesthetists of Great Britain and Ireland guidelines recommend the use of cell salvage in cases where patients have objections to receiving allogeneic blood product transfusions [2]. In cardiac surgery cell salvage can be used both intra- and postoperatively. The benefits of intra-operative cell salvage are the salvage of blood before and after cardiopulmonary bypass and reduction of the volume of cardiotomy blood that is returned to the patient. The re-infusion of cardiotomy blood has been implicated with the development of a coagulopathy and increased blood loss [3], increased incidence of postoperative neurocognitive dysfunction [4] and the development of systemic inflammatory response syndrome [5]. Blood can also be salvaged postoperatively from surgical drains. We feel that cell salvage is an essential component of blood conservation and should be used in all Jehovah’s Witness patients who consent to its use. No external funding and no competing interests declared. Previously posted at the Anaesthesia Correspondence website: http://www.anaesthesiacorrespondence.com.

Tourniquet use during total knee replacement in a Jehovahʼs Witness with sickle cell trait: a case report

Case presentation An 82-year-old white woman was admitted for an elective right total knee replacement. She was a Jehovah's Witness with sickle cell trait. Her preoperative haemoglobin (Hb) was 10.4 g/dl and electrophoresis revealed sickle Hb (HbS) of 35%. She also had borderline low ferritin levels and was on parenteral iron therapy. She also had hypertension, hypertension-induced renal dysfunction and chronic pulmonary disease. She refused any form of blood transfusion, including re-infusion of shed blood. After discussion with surgical team it was decided to use tourniquet intraoperatively. Prior to induction 125 μg of fentanyl was given to obtund the hypertensive response to intubation. Rapid sequence induction of anaesthesia was conducted with propofol and suxamethonium as patient was obese and had a history of gastroesophageal reflux disease. The airway was secured uneventfully. Anaesthesia was maintained with air, oxygen and sevoflurane. Her end tidal was maintained between 3.9 and 4.2 kPa. Femoral and obturator nerve blocks were performed (with 30 and 5 ml of 0.25% bupivacaine, respectively) using a nerve stimulator. Forty milligrams of atracurium was then given. She had a 300-mmHg tourniquet pressure for nearly 90 min. Her blood pressure was elevated during surgery requiring intravenous labetalol. Postoperatively she did not manifest any painful crisis and her Hb was 8.4 g/dl. She was discharged after 8 days in hospital. Discussion Sickle cell disease is a common blood disorder that has affected millions worldwide. It is caused by inappropriate substitution of valine for glutamine at the sixth position of the β-globin chain. This altered Hb has a low affinity for oxygen and polymerizes to form insoluble crystals which disrupts the structure of the erythrocytes. In the homozygous state (sickle cell anaemia, HbSS) both genes are abnormal whereas in the heterozygous state (sickle cell trait, HbAS) only one chromosome carries the gene.1 Whereas sickle cell disease is associated with significant morbidity in terms of growth and development, renal disease, cerebral infarcts, splenic infarcts and haemolytic anaemia, sickle cell trait is usually asymptomatic and affected individuals have normal life expectancy. When deoxygenated Hb (HbSS) polymerizes, it damages the red cell membrane. Although this is reversible, with repeated sickling this could lead to irreversible damage to red cell membrane. Anaesthetic techniques for patients with sickle cell disease and trait have tended to focus mainly on preventing sickling by avoiding hypoxaemia, acidosis and maintaining body temperature and intravascular volume. The use of tourniquets in sickle cell disease and trait remains controversial, as they cause hypoxaemia, hypercapnoea and lactic acidosis in the isolated limb.2 Therefore, some authorities regard both conditions as definite contraindications for tourniquet application,3 although there are case reports revealing its successful use in patients with sickle cell disease4 and a study carried out revealing no increased evidence of complications when torniquets applied in patients with sickle cell trait.5 There is a case report that has suggested the initiation of sickle cell crisis in patients with sickle cell trait after application of tourniquets,6 and as such their use should be balanced against the risks in sickle cell trait.7 Haematologists regard sickle cell trait as a benign disease with low morbidity. The incidence of sickle cell trait in African–Americans is one in 12. The occurrence under anaesthesia of cerebral thrombosis, and other mishaps including sudden death in these individuals may suggest cause-and-effect but in reality there is no proven association.8 Therefore, from the haematological viewpoint the use of tourniquets in limb surgery is regarded as safe. In our case we believe that nonapplication of tourniquet in her case could be fatal not only because of her refusal of transfusion but also because of increased bleeding risk secondary to hypertension. Furthermore as she was a carrier her risk of going into a crisis was very low. Conclusion Providing anaesthesia to sickle cell disease/trait was considered a challenge and there was currently no consensus in anaesthetics over the use of tourniquets. We believe that although the situation is less clear in sickle cell disease, sickle cell trait should not be considered a contraindication to tourniquet application.

New Measures of Heart-Rate Complexity: Effect of Chest Trauma and Hemorrhage

Traditional vital signs such as heart rate, blood pressure, and oxygen saturation are not ideal for timely and accurate assessment of physiologic status after trauma (TR) and hemorrhagic shock (HS). Analysis of the complex beat-to-beat variability present in the heart-rate time series has been proposed as a "new vital sign" in this setting. We determined the effect of chest TR and HS on heart-rate complexity (HRC) in a porcine model. Anesthetized swine in group II (n = 20) underwent blunt right chest TR with a modified captive-bolt stunner; then, 10 minutes later, hemorrhage of 12 mL/kg over 10 minutes, followed by resuscitation with lactated Ringer's solution, and reinfusion of blood. Group I (n = 15) served as time controls. Two hundred beat sections of EKG waveforms were analyzed at 7 time points: at baseline, after TR, immediately after hemorrhage (HS), and 1 hour, 2 hours, 4 hours, and 5 hours after HS. Several computationally different measures of HRC were calculated, including sample entropy, similarity of distribution, and point correlation dimension. HRC was decreased after TR, HS, and at 1 hour, manifested by decreased sample entropy and point correlation dimension and increased similarity of distribution. These HRC measures were all restored by resuscitation. Several independent measures demonstrated decreased HRC after combined TR/HS and restored HRC with resuscitation. Complexity analysis may be useful for diagnosis of TR/HS and for monitoring resuscitation.

Alterations In Vo2max By Blood Donation And Re-infusion After A 4-week Storage Period In Moderately Trained Athletes

PURPOSE: Physical performance and endurance capacity are closely related to maximal oxygen uptake (VO2max), which is - among other factors - limited by maximal oxygen transport capacity. Therefore, autologous blood doping is used to improve endurance performance prior to competition in highly endurance trained athletes. The present study investigated the effect of blood donation and autologous blood re-infusion in a heterogeneous group of moderately trained athletes from different disciplines after a 4-week period of blood storage. METHODS: 13 subjects (5 females, 8 males, 175 ± 8 cm, 24.8 ± 2.6 years, 72.2 ± 11.1 kg) participated in the study. Subjects were tested during an incremental treadmill-test until individual exhaustion (RQ > 1.1) several times prior to and after a blood donation of 500 ml, and prior to and after the re-infusion of the red-blood cell concentrate of 300 ml after a 4-week storage period. The highest measured oxygen uptake value of each test was defined as respective VO2max. RESULTS: In the subgroup of females, VO2max prior to blood donation was 47.6 ± 3.3 ml/kg/min. Immediately after blood donation, VO2max declined slightly to 44.3 ± 3.0 ml/kg/min (p<0.05) and remained reduced up to 28 days (p<0.05). Re-infusion led to a significant increase in VO2max, which remained elevated up to 7 days after re-infusion, but did not over-reach the pre-donation value. In the subgroup of males, VO2max decreased from 60.3 ± 4.4 ml/kg/min to 56.1 ± 3.2 ml/kg/min immediately after donation (p<0.05). This decline remained stable after 24 hrs and after 7 days (p<0.05). Re-infusion induced an immediate and significant increase in VO2max by 3.5 ml/kg/min, which was comparable to the prior observed decline of 4.1 ml/kg/min after blood donation. This increase in VO2max remained stable up to 3 weeks after re-infusion. CONCLUSIONS: 500 ml of blood donation decreased VO2max in both gender with a more prolonged effect in female moderately trained athletes. Re-infusion of the 300 ml red blood cell concentrate after a 4-week storage period normalized aerobic performance, however could not induce a higher level as compared to the pre-donation value. The study has been sponsored by a grant from WADA (08B05PP).

Alterations In Vo2max By Blood Donation And Re-infusion After 2-week Storage In Moderately Trained Athletes

Alterations In Vo2max By Blood Donation And Re-infusion After 2-week Storage In Moderately Trained Athletes

The Red Blood Cells NOS System After Blood Donation And Re-infusion In Moderately Trained Subjects

The Red Blood Cells NOS System After Blood Donation And Re-infusion In Moderately Trained Subjects

Changes in the Surface of Red Blood Cell Membranes after Blood Loss and Their Correction with Laser Irradiation

Objective: to reveal changes in the membrane surface microrelief during hypotension and after blood reinfusion and a possibility of correcting these impairments with laser irradiation (LI). Materials and methods. Experiments were carried out on anesthetized male rats weighing 450 g. The model of a terminal state was one-hour hypovolemic hypotension (mean blood pressure 45 mm Hg), followed by exsanguinated blood reinfusion. Two groups of experiments were made. These were control and experimental; in the latter laser irradiation was performed for 2 minutes an hour after blood reinfusion. Rat blood smears were examined on an atomic force microscope 5 and 60 minutes after blood loss and 1 and 3 hours after blood reinfusion. Results. The experiments have shown that after blood reinfusion the activated lipid peroxidation processes increase the size of a red blood cell and change its shape and its membrane surface relief. By producing an antioxidant effect, LI restores the permeability of red blood cell membranes and their surface ultrastructure. Key words: blood loss, red blood cells, membrane, lipid peroxidation, atomic force microscope.

Therapeutic Phlebotomy

In the United States, phlebotomies are most often performed for reinfusion of blood to a designated or nondesignated recipient at a later time. These are known, respectively, as autologous or allogenic donations. For a few rare blood disorders, however, phlebotomy is performed as a medical intervention for disease management. These are referred to as therapeutic phlebotomies. Four classifications of blood disorders are discussed here for which symptoms and complications can be managed by the use of therapeutic phlebotomy. The article also offers considerations for setting up a therapeutic phlebotomy program.

Effect of Sodium Oxybutyrate on Mesentery Microcirculation and Liver Metabolism in Hemorrhagic Stroke (Experimental Study)

Objective: to study the effect of sodium oxybutyrate on canine mesentery microcirculation and liver metabolism in hemorrhagic stroke. Materials and methods. The investigation was based on the examination of specimens taken from 72 dogs of both sexes, weight 15.5±1.5 kg. Hypovolemic hypotension was induced by free bloodletting via the femoral artery. Systolic blood pressure was lowered to 40 mm Hg and maintained at the same level during an hour by the Wiggers procedure. The magnitude of blood loss was 31—33 ml/kg. The dogs were divided into 4 groups: 1) intact (n=5); 2) one-hour hypovolemic hypotension (n=8); 3) control (n=31), in which physiological saline was intravenously injected at a concentration of 0.9—1.1 ml/kg an hour after hypovolemic hypotension; 4) experimental (n=28), in which 10% sodium oxybutyrate solution was intravenously injected at a concentration of 180—200 mg/kg an hour after hypovolemic hypotension. In Groups 1 and 2 dogs, as well as in the control and experimental groups, divided into 2 subgroups, in which laparotomy was carried out under local 0.25% novocaine solution in combination with intravenous sodium thiopental (15—20 mg/kg) an hour after the drug administration and an hour after blood reinfusion, then right liver lobe pieces were excised for histochemical and biochemical studies. In Groups 3 and 4, heparinized blood was reinfused an hour after administration of the agent. The animals were observed during an hour. In the dogs from the latter two groups, mesentery vascular microcirculation was evaluated at control time stages, by using biomicroscopy on a MBR-1 microscope-based unit. Results. Despite uncompensated blood loss, the use of sodium oxybutyrate in hemor-rhagic stroke improves microcirculation in the mesentery vessels. In the liver, it enhances the rate of reactions of oxida-tive phosphorylation and the pentose phosphate pathway, activates glucose uptake processes, prevents lactate accumulation, preserves glycogen stores, and elevates the content of high-energy phosphates. Conclusion. Administration of 10% sodium oxybutyrate solution at concentrations of 180-200 mg/kg an hour after hypovolemic hypotension prevents the progression of mesentery microcirculatory disorders and hepatic metabolic changes during the following hour of hemorrhagic stroke. Blood loss compensation during previous administration of sodium oxybutyrate promotes a fuller and more rapid recovery of mesentery microcirculation and hepatic metabolic processes in the early postresuscitative period. Key words: hemorrhagic stroke, sodium oxybutyrate, microcirculation, metabolism, liver.

Reinfusion of Blood within Aneurysm Sac: A Simple Method of Intraoperative Blood Conservation in Elective Abdominal Aortic Surgery

Autologous blood conservation reduces postoperative morbidity and mortality. In elective abdominal aortic aneurysm repair, the blood within the aneurysm sac is generally neglected during surgery. We present a simple method of additional blood conservation in elective abdominal aortic surgery, which involves reinfusion of autologous blood within the aneurysm sac in the perioperative period.

Neurosurgical Procedures in Jehovah’s Witnesses: The Tema Experience

On account of religious reasons, Jehovah Witnesses do not accept blood or blood products; occasionally, they accept reinfusion of autologous blood via a cell saver during surgery. The aim of this study was to document the demographics of Jehovah Witnesses undergoing neurosurgical procedures, the neurosurgical procedures undertaken in Jehovah Witnesses and to evaluate the complications of the procedures. A retrospective audit of the medical records of all Jehovah's Witnesses who underwent neurosurgical procedures at our institution, from January 1st 2000 to December 31st 2006, was carried out. The parameters investigated included demographics, pre and post operative diagnosis, type of neurosurgical procedure and complications. Nineteen patients (fifteen male, four female; male/female 3.8:1) constituted the series. The mean age was 45.8 (range: 20-65) years. A total of 21 procedures were performed; intracranial surgery (33%), spinal surgery (67%). No autotransfusion of blood was given. Lumbar laminectomy for stenosis was the commonest spine procedure, ten (71.4%); craniotomy for tumor excision was the commonest intracranial procedure, six (85.7%). With respect to the whole series, the morbidity rate was 4.7% and the mortality rate was 4.7%; both were from intracranial surgery. It is possible to perform certain types of neurosurgical procedures in Jehovah's Witnesses without increasing the mortality and morbidity rate.

Column-switching HPLC–MS/MS analysis of ropivacaine in serum, ultrafiltrate and drainage blood for validating the safety of blood reinfusion

A high-performance liquid chromatography–tandem mass spectrometry (HPLC–MS–MS) method, using back-flush column-switching was developed for total drug concentrations of ropivacaine in serum and drainage blood in the measuring range 0.1–10 μg/mL. Samples were diluted with internal standard ( 2H 7-ropivacaine) and extraction buffer, centrifuged and injected directly onto a BioTrap 500 MS extraction column. Using a time programmed six-port valve switch, ropivacaine was back-flushed onto a Zorbax SB-Aq analytical column, gradient eluted and finally detected after electro spray ionisation and multiple reaction monitoring (MRM) of the transitions m/ z 275 → m/ z 126 and m/ z 282 → m/ z 133 for ropivacaine and 2H 7-ropivacaine, respectively. Accuracy (bias-%) was −1.5 to 5.8% and intermediate precision (C.V.) was 1.4–3.1%. The low sample amount required (10 μL), high specificity and short run time (6 min) makes it very suitable for determination of ropivacaine. Using the same methodology as described above and 200 μL ultrafiltrate, the free drug concentrations of ropivacaine in serum could be precisely determined with a C.V. below 3%. The method was used to investigate the safety of reinfusion of drainage blood after knee and hip arthroplasty when ropivacaine (Naropin ®) was used for local analgesia. Data for 30 patients are summarised.

Acute Compartment Syndrome of the Forearm following Autologous Blood Reinfusion: A Case Report

Compartment syndrome is a condition with multiple reported etiologies, and permanent disability may ensue if not treated in a timely fashion. We report the first case, to our knowledge, of acute forearm compartment syndrome caused by intravenous autologous blood reinfusion. The patient underwent forearm fasciotomy, and hematoma was encountered deep to the superficial volar fascia, presumably extravasated from the reinfusion catheter. With the rise in the number of knee and hip arthroplasties, surgeons need a heightened awareness of the possible complications and morbidity associated with a presumed increase in autologous blood reinfusion.

Atomic Force Microscopy of the Structure of Red Blood Cell Membranes in Acute Blood Loss and Reinfusion

Objective: to examine the surface heterogeneities of red blood cell membranes after acute massive blood loss and blood reinfusion, by using atomic force microscopy (AFM). Materials and methods. Experiments were carried out under nembu-tal anesthesia on male rats. Hypovolemic hypotension was induced during 60 minutes, followed by blood reinfusion. The experimental phases were as follows: control before blood loss; 5 minutes after its onset; 1 hour following hypotension; and 1 and 3 hours after reinfusion. Membrane surface images were obtained by AFM in the constant scanning mode. Spatial surface spectral transformation was used. Results. The nano-surface parameters were shown to be intrinsic characteristics of membranes. The greatest changes occurred at the early stages of transient processes: blood loss and reinfusion. Conclusion. The application of AFM permitted the authors to trace the time course of changes in the red blood cell membrane surfaces during acute total blood loss and further blood reinfusion to tolerances of fractions of nanometer. Key words: blood loss, reinfusion, nanostructure, atomic force microscopy.

Blood salvage use in gynecologic oncology

Blood salvage allows for collection and processing of surgical blood loss with the eventual reinfusion of washed red blood cells (RBCs) back to the patient. The use of blood salvage in patients undergoing surgery for malignancy is off-label. Controversy exists as to the risk of potential cancer dissemination resulting from the reinfusion of the processed blood, but no data are available to confirm this risk. Recent studies have demonstrated that filtering the salvaged blood using a leukoreduction filter (LRF) significantly decreases the number of cancer cells in the recovered RBC aliquot in a variety of cancer types. Patients on the gynecologic oncology service as part of the bloodless surgery program at Englewood Hospital and Medical Center from April 1998 to April 2007 were identified. Three patients that had reinfusion of cell salvage blood (all reinfusions were performed after filtration with a LRF) were studied further with emphasis placed on long-term outcomes. Two of the three patients did not show any evidence of metastases after surgery. The only patient that developed evidence of hematogenous progression had known liver metastases at the time of her initial diagnosis and therefore had hematogenous dissemination before her index surgery. In this series of patients undergoing surgery for malignancies on the gynecologic oncology service, blood salvage with LRF was not definitively associated with hematogenous dissemination. Further large controlled studies are needed to demonstrate the clinical safety of the use of blood salvage in this setting.

Abilities of blood reinfusion in the surgical correction of scoliotic deformity

The surgical treatment of the scoliotic deformity entails a significant blood loss, which requires a careful selection of the infusion-transfusion therapy. The above therapy, including without any use of donor blood preparations, should take into account the available initial cardiopulmonary pathology.

Cardiorespiratory effects of venous lipid micro embolization in an experimental model of mediastinal shed blood reinfusion

BackgroundRetransfusion of the patient's own blood during surgery is used to reduce the need for allogenic blood transfusion. It has however been found that this blood contains lipid particles, which form emboli in different organs if the blood is retransfused on the arterial side. In this study, we tested whether retransfusion of blood containing lipid micro-particles on the venous side in a porcine model will give hemodynamic effects.MethodsSeven adult pigs were used. A shed blood surrogate containing 400 ml diluted blood and 5 ml radioactive triolein was produced to generate a lipid embolic load. The shed blood surrogate was rapidly (<2 minutes) retransfused from a transfusion bag to the right atrium under general anesthesia. The animals' arterial, pulmonary, right and left atrial pressure were monitored, together with cardiac output and deadspace. At the end of the experiment, an increase in cardiac output and pulmonary pressure was pharmacologically induced to try to flush out lipid particles from the lungs.ResultsA more than 30-fold increase in pulmonary vascular resistance was observed, with subsequent increase in pulmonary artery pressure, and decrease in cardiac output and arterial pressure. This response was transient, but was followed by a smaller, persistent increase in pulmonary vascular resistance. Only a small portion of the infused triolein passed the lungs, and only a small fraction could be recirculated by increasing cardiac output and pulmonary pressure.ConclusionInfusion of blood containing lipid micro-emboli on the venous side leads to acute, severe hemodynamic responses that can be life threatening. Lipid particles will be trapped in the lungs, leading to persistent effects on the pulmonary vascular resistance.