Plasma levels of the lipid mediators, leukotriene B4 and lyso platelet-activating factor, in intraoperative salvaged blood

Evaluation of eicosanoid concentrations in stored units of canine packed red blood cells

OBJECTIVE To evaluate eicosanoid concentrations in freshly prepared canine packed RBCs (PRBCs) and to assess changes in eicosanoid concentrations in PRBC units over time during storage and under transfusion conditions. DESIGN Prospective study. SAMPLE 25 plasma samples from 14 healthy Greyhounds. PROCEDURES Plasma samples were obtained during PRBC preparation (donation samples), and the PRBC units were then stored at 4°C until used for transfusion (≤ 21 days later; n = 17) or mock transfusion if expired (22 to 24 days later; 8). Immediately prior to use, 100 mL of saline (0.9% NaCl) solution was added to each unit and a pretransfusion sample was collected. A posttransfusion sample was collected after transfusion or mock transfusion. Concentrations of arachidonic acid, prostaglandin (PG) F_2α, PGE₂, PGD₂, thromboxane B₂, 6-keto-PGF_1α, and leukotriene B₄ were measured by liquid chromatography-mass spectrometry and analyzed statistically. RESULTS Median arachidonic acid concentration was significantly decreased in posttransfusion samples, compared with the concentration in donation samples. Median PGF_2α, 6-keto-PGF_1α, and leukotriene B₄ concentrations were significantly increased in pretransfusion samples, compared with those in donation samples. Median PGF_2α, thromboxane B₂, and 6-keto-PGF_1α concentrations were significantly increased in posttransfusion samples, compared with those in pretransfusion samples. Duration of PRBC storage had significant associations with pretransfusion and posttransfusion arachidonic acid and thromboxane B₂ concentrations. CONCLUSIONS AND CLINICAL RELEVANCE Concentrations of several proinflammatory eicosanoids increased in PRBC units during storage, transfusion, or both. Accumulation of these products could potentially contribute to adverse transfusion reactions, and investigation of the potential association between eicosanoid concentrations in PRBCs and the incidence of transfusion reactions in dogs is warranted.

Characteristics and quality of intra-operative cell salvage in paediatric scoliosis surgery

OBJECTIVE

To determine the haematological and microbiological characteristics of blood recovered by using a cell saver with a rigid centrifuge bowl (100ml) in paediatric scoliosis surgery and to determine whether it conforms to the standard expected in adult patients.

MATERIAL AND METHODS

A cross-sectional, descriptive cohort study was performed on 24 consecutive red blood cell (RBC) units recovered from the surgical field and processed by a Haemolite® 2+ (Haemonetics Corp., Braintree, MA, EE. UU.) cell saver. Data were collected regarding age, weight, surgical approach (anterior or posterior), processed shed volume and volume of autologous RBC recovered, full blood count, and blood culture obtained from the RBC concentrate, and incidence of fever after reinfusion.

RESULTS

The processed shed volume was very low (939±569ml) with high variability (coefficient of variation=0.6), unlike the recovered volume 129±50ml (coefficient of variation=0.38). A statistically significant correlation between the processed shed volume and recovered RBC concentrate haematocrit was found (Pearson, r=.659, P=.001). Haematological parameters in the recovered concentrate were: Hb 11±5.3g dl(-1); haematocrit: 32.1±15.4% (lower than expected); white cells 5.34±4.22×103 ul(-)1; platelets 37.88±23.5×103 ul(-1) (mean±SD). Blood culture was positive in the RBC concentrate recovered in 13 cases (54.2%) in which Staphylococcus coagulase (-) was isolated.

CONCLUSIONS

Cell salvage machines with rigid centrifuge bowls (including paediatric small volume) do not obtain the expected haematocrit if low volumes are processed, and therefore they are not the best choice in paediatric surgery.

Cell salvage in obstetrics

The safety of cell salvage in obstetrics has been questioned because of the presumed risk of precipitating amniotic fluid embolism and, to a lesser extent, maternal alloimmunisation. For these reasons, experience in this field is limited and has lagged far behind that in other surgical specialties. There has, however, been renewed interest in its use over recent years, mainly as a result of problems associated with allogeneic blood transfusion. Our aim was to review the medical literature to ascertain the principles of cell salvage, the ability of the process to remove contaminants, and its safety profile in the obstetric setting. The search engines PubMed and Google Scholar were used and relevant articles and websites hand searched for further references. Existing cell salvage systems differ in their ability to clear contaminants and all require the addition of a leucocyte depletion filter. Although large prospective trials of cell salvage with autotransfusion in obstetrics are lacking, to date, no single serious complication leading to poor maternal outcome has been directly attributed to its use. Cell salvage in obstetrics has been endorsed by several bodies based on current evidence. Current evidence supports the use of cell salvage in obstetrics, which is likely to become increasingly commonplace, but more data are required concerning its clinical use.

Pediatric resuscitation in the operating room

The resuscitation of pediatric patients undergoing anesthesia involves appropriate administration of fluid and blood products and stabilization of vital signs. Crystalloid is first-line therapy for fluid resuscitation, and should be given with awareness of its potential dilution of the child's hematocrit. Many alternatives to homologous blood transfusions now exist, however, when necessary for increasing oxygen-carrying capacity or treating coagulopathy benefits likely outweight the risks. The risks for such transfusion include infectious, hemolytic, metabolic, and immunologic effects. When fluid and blood administration does not stabilize the patient, the differential diagnosis of hypotension, arrest, or arrhythmias must include medication errors, anesthetic overdose, electrolyte disturbances, hypoxemia, ventilatory problems, and surgical insults, including medications given in the operative field. Resuscitation should include treatment of hypocalcemia and hyperkalemia, chest compressions, and the administration of epinephrine when necessary.

Isolyte S, a physiologic multielectrolyte solution, is preferable to normal saline to wash cell saver salvaged blood: conclusions from a prospective, randomized study in a canine model

OBJECTIVES

The purpose of this study is to compare normal saline with Isolyte S as the wash solutions during high-volume cell saver autologous blood transfusion. Normal saline, the standard wash solution in cell saver autologous blood transfusion, is associated with acid-base and electrolyte derangements. Isolyte S is a physiologic, balanced multielectrolyte crystalloid solution that approximates the electrolyte content of plasma.

DESIGN

Open-label, prospective, randomized study.

SETTING

Research laboratory in a Department of Veterans Affairs medical center.

SUBJECTS

Fourteen mongrel dogs, weighing 22 to 23 kg each.

INTERVENTIONS

Fourteen mongrel dogs were prospectively randomized to receive normal saline (n = 7) or Isolyte S (n = 7). Animals were anesthetized, received heparin for anticoagulation, and underwent 18 cycles of cell saver autotransfusion. In each cycle, 125 mL of blood was arterially withdrawn, and washed with either normal saline (mEq/L) (sodium 154, chloride 154) or Isolyte S (mEq/L) (sodium 141, potassium 5, magnesium 3, chloride 98, phosphate 1, acetate 28, and gluconate 23). The washed blood was retransfused.

MEASUREMENTS AND MAIN RESULTS

Acid-base and electrolyte analyses were performed throughout the study on the systemic blood of each group and compared. By the end of the study, the Isolyte S group had a normal pH and an increased bicarbonate concentration (mEq/L: normal values 24 to 32; normal saline 9.0 +/- 1.9 vs. Isolyte S 13.2 +/- 3.0 [p < .01]) and an increased magnesium concentration (mg/dL: normal values 1.6 to 2.4; normal saline 1.6 +/- 0.2 vs. Isolyte S 2.2 +/- 0.2 [p < .0001]). Additionally, the Isolyte S group had a lower chloride concentration (mEq/L: normal values 95 to 110; normal saline 130 +/- 9 vs. Isolyte S 117 +/- 7 [p < .02]) and a lower potassium concentration (mEq/L: normal values 3.5 to 5.0; normal saline 4.4 +/- 0.5 vs. Isolyte S 3.7 +/- 0.3 [p < .01]). There were no significant differences between normal saline or Isolyte S in the values of PCO2, lactic acid, sodium, total and ionized calcium, inorganic phosphorus, total protein, albumin, hemoglobin, and hematocrit.

CONCLUSIONS

Fewer systemic acid-base and electrolyte derangements were observed when blood was washed with Isolyte S. Differences between the normal saline and Isolyte S groups are ascribed primarily to the constituents of the wash solution. We conclude that Isolyte S, a physiologic, balanced, multielectrolyte solution, should be considered as the wash solution in high-volume autologous cell saver blood processing and transfusion.