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

The Optimal Cell Salvage Settings to Maximize Hematocrit and Minimize Potassium Using the Cobe BRAT2 Autologous Blood Recovery Unit

OBJECTIVE

The objective was to determine the optimal cell saver device settings (infusion rate and wash rate) at which hematocrit is preserved and potassium and lactate are removed from banked red blood cells (RBC).

DESIGN

Red cells were washed using the Cobe BRAT 2 Autologous Blood Recovery Unit and sampled for electrolyte composition and hematocrit pre- and postwash.

SETTING

This was a single-center study.

INTERVENTIONS

Red cells were washed using six infusion rates (100-1,000 mL/min) and six wash rates (100-1,000 mL/min) for a total of 36 combinations. Hematocrit, potassium, glucose, and lactate were evaluated before and after washing.

MEASUREMENTS AND MAIN RESULTS

At wash rates ≤400 mL/min, hematocrit increased independent of infusion rate. At wash rates ≥400 mL/min, slower infusion rates were associated with higher hematocrit compared to faster infusion rates (p < 0.0001 for a wash rate 400-800 mL/min, p < 0.0005 for a wash rate 1,000 mL/min). Maximal wash speeds were associated with decreasing hematocrit. Infusion and wash rate were both independent predictors of potassium change; slower rates were associated with a larger decrease in potassium. Glucose decreased proportionally as infusion and wash rate decreased. Lactate did not show an association with either infusion or wash rate.

CONCLUSION

Red-cell washing produces higher hematocrit and lower potassium as infusion rate and wash rate decrease. A 340-mL unit of RBC can be processed in 4.26 minutes without loss of hematocrit or an increase in potassium when both infusion and wash rates are set to 400 mL/min.

Intraoperative Cell Saving: Is the Solution the Actual Problem?

Allogenic blood is a scarce, precious, and expensive resource that is not always available on demand. After termination of cardiopulmonary bypass, a large amount of residual pump blood remains in the extracorporeal circuit. The cell saver washes and concentrates this blood with .9% normal saline (NS), making autologous blood available and reducing the demand for allogenic blood. To quantify the quality of residual pump blood it was washed with either NS or a bicarbonate-buffered solution (Balsol). A qualitative in vitro analysis was conducted. Residual cardiopulmonary bypass blood from forty bypass circuits was processed with a cell saver device, using NS or Balsol solution. Measurements made compared the pH, electrolytes, metabolites, hematocrit, hemoglobin, osmolality, albumin, total protein, and strong ion difference. There were significant differences between the NS and Balsol groups. In the Balsol group, osmolality, electrolytes, and strong ion difference were similar to the constitution of Balsol solution after washing, but not with the normal saline group. Washing residual cardiopulmonary bypass pump blood with Balsol solution results in a resuspended red cell concentrate with a superior electrolyte profile and a strong ion difference similar to that of residual pump blood.

Comparison of bicarbonate-buffered fluid and isotonic saline solution as Cell Saver washing fluids for packed red blood cells

OBJECTIVES

Massive transfusion (MT) can cause severe electrolyte and acid-base disturbances in neonates and infants due to the unphysiological composition of packed red blood cells (PRBCs). Washing of the PRBCs using Cell Saver systems prior to MT is recommended for this reason.

AIM

The composition of normal saline (NaCl), the standard wash fluid for Cell Saver systems, is considerably different from that of physiological plasma. The aim of the study presented here was to investigate the effect of washing the PRBCs with a bicarbonate-buffered hemofiltration solution (BB-HS) in comparison with washing with NaCl and to evaluate the impact on electrolyte concentrations, acid-base balance and the stability of PRBCs.

METHODS

In an experimental in vitro setting, PRBCs were washed with Cell Saver systems prepared with NaCl or BB-HS as washing solutions. Before and after the washing procedure, electrolyte concentrations, acid-base parameters, adenosine triphosphate (ATP) and free hemoglobin (fHb) concentrations were measured.

RESULTS

In both groups, the potassium concentrations decreased (baseline: 18.4 ± 5.17 mmol·l(-1), end of study: NaCl 2.71 ± 1,81 mmol·l(-1), BB-HS 2.50 ± 1.54 mmol·l(-1), P < 0.05) while the acid-base balance improved only in the BB-HS-group (baseline: base excess -21.6 ± 3.52 mmol·l(-1), end of study: NaCl -30.2 ± 1.42 mmol·l(-1), BB-HS -7.51 ± 2.49 mmol·l(-1) , P < 0.05). Furthermore, markers of erythrocyte stability such as fHb and ATP concentrations were improved in the BB-HS-group.

CONCLUSIONS

Washing of PRBCs with BB-HS rather than NaCl results in a more physiological composition with improvements of electrolyte concentrations, acid-base balance and erythrocyte stability.

Washing of irradiated red blood cells prevents hyperkalaemia during cardiopulmonary bypass in neonates and infants undergoing surgery for complex congenital heart disease

OBJECTIVE

High concentrations of potassium and lactate in irradiated red cells transfused during cardiopulmonary bypass may have detrimental effects on infants and neonates undergoing cardiac surgery. The effects of receiving washed and unwashed irradiated red cells from the cardiopulmonary circuit on serum potassium and lactate concentrations were compared.

METHODS

The study population included neonates and infants undergoing heart surgery for complex congenital heart disease. A control group (n=11) received unwashed irradiated red cells and the study group (n=11) received irradiated red cells washed in a cell saver (Dideco Electa) using 900ml of 0.9% saline prior to pump priming. Potassium and lactate concentrations were compared before, during and after bypass.

RESULTS

Washing irradiated red cells reduced donor blood [potassium] from>20 to 0.8+/-0.1mmol/l, and [lactate] from 13.7+/-0.5 to 5.0+/-0.3mmol/l (p<0.001). The resulting prime had significantly lower [potassium] and [lactate] than the unwashed group (potassium 2.6+/-0.1 vs 8.1+/-0.4mmol/l, p<0.001; lactate 2.6+/-0.2 vs 4.6+/-0.3mmol/l, p<0.001). Peak [potassium] in the unwashed group occurred 3 minutes after going on bypass (4.9+/-0.3mmol/l) and during rewarming (4.9+/-0.4mmol/l). These were significantly higher than the washed group (3.1+/-0.1, p<0.001 and 3.0+/-0.1mmol/l, p<0.001). The [potassium] was greater than 6.0mmol/l for 4 out of these 11 unwashed patients compared with none of the washed group. Immediately post-bypass the washed group had significantly lower serum [potassium] (3.2+/-0.1 vs 4.2+/-0.2mmol/l, p=0.002). There was no significant difference in [lactate] between groups during and after cardiopulmonary bypass.

CONCLUSIONS

The washing of irradiated red cells reduces potassium and lactate loads and prevents hyperkalaemia during cardiopulmonary bypass. The washing of irradiated red cells should be considered in neonates and infants undergoing cardiac surgery for complex congenital heart disease.

Red blood cell recovery and reinfusion

This article describes the intraoperative washed cell salvage process and principles of cell salvage technology and addresses the parameters that can maximize the effectiveness of the process. Used appropriately, this technique can be used to recover and readminister several blood volumes of red cells.

Hypophosphatemia after 95 right-lobe living-donor hepatectomies for liver transplantation is not a significant source of morbidity

BACKGROUND

Hypophosphatemia appears to be a universal event after right hepatic lobectomy for live-donor adult liver transplantation according to one report. Because hypophosphatemia appears to contribute to increased postoperative complications, routine hyperalimentation with supratherapeutic levels of phosphorus was advocated.

METHODS

From July 2000 to May 2002, we performed 95 right-lobe living-donor hepatectomies for 95 adult liver-transplant recipients, the largest single institutional experience. We reviewed our data that were collected prospectively.

RESULTS

We did not find profound hypophosphatemia (<1.0 mg/dL) to be prevalent in our donors. At least six (6.3%) donors did not have postoperative hypophosphatemia. In addition, there appears to be no increased morbidity related to hypophosphatemia when aggressively corrected with intravenous or oral phosphates in our group of donors that underwent right-lobe hepatectomies.

CONCLUSIONS

We, therefore, cannot endorse the routine administration of hyperalimentation with supratherapeutic phosphorus because of its potential morbidity.

Planning for hemorrhage. Steps an anesthesiologist can take to limit and treat hemorrhage in the obstetric patient

Obstetric hemorrhage continues to be a significant cause of maternal mortality and morbidity. Blood transfusion in such circumstances may be life saving but involves exposing the patient to additional risks. Limiting blood transfusion and using autologous blood when possible may reduce some of these risks. This article outlines the techniques that may be used to limit and more effectively treat hemorrhage in the obstetric patient, with particular attention paid to reducing the use of allogeneic blood transfusion.

Acid-base, electrolyte and metabolite concentrations in packed red blood cells for major transfusion in infants

METHODS

Acid-base, electrolyte and metabolite concentrations were determined in 100 U of packed red blood cells (RBC) preserved in extended-storage media to be used for major transfusion in paediatric and cardiac surgery.

RESULTS

In fresh RBC, low pH, bicarbonate (cHCO3-), base excess (BE) and high glucose values were observed all outside the physiological range. With lengthening storage duration, values of pH, cHCO3-, BE, sodium and glucose decreased and carbon dioxide, potassium and lactic acid concentrations increased [mean +/- SD (range): storage duration 6.7 +/- 3.8 (1-17) days, pH 6.79 +/- 0.1 (6.53-6.99); mmol.l-1: cHCO3- 11.1 +/- 1.5 (6.2-14.5), BE - 29.2 +/- 4.1 ([-39.4] - [-20.9]), potassium 20.5 +/- 7.8 (4.2-43.6), glucose 24.1 +/- 6.1 (16.7-29.2), lactic acid 9.4 +/- 4 (4.3-21.4)].

CONCLUSION

Massive and rapid transfusion of RBC may lead to a severe burden of hydrogen ions, carbon dioxide, potassium, glucose and lactic acid and this can be avoided by cell saver blood processing, when autologous erythrocytes from the operative field are saved and substrate load and storage lesions from packed red blood cells are minimized in one step by washing.