Serum concentrations of cephalosporins and the cell saver in cardiopulmonary bypass surgery

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 In each cycle, 125 mL of blood was arterially withdrawn, and washed with either normal saline (mEq/L) (sodium 154, chloride 154) or Isolyte S (mEq/L) (sodium 141, potassium 5, magnesium 3, chloride 98, phosphate 1,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.

Cell saver autologous transfusion: metabolic consequences of washing blood with normal saline

OBJECTIVE

To evaluate acid-base and electrolyte changes in high volume cell saver autologous blood transfusion when normal saline (0.9% NaCl) is used as the wash solution.

DESIGN

Open-label study.

MATERIALS AND METHODS

Nine anesthetized and anticoagulated mongrel dogs underwent 15 cycles of cell saver autologous blood transfusion. Eight percent of the circulating blood volume (125 mL) was withdrawn, washed with normal saline, and retransfused for each cycle.

MEASUREMENTS AND MAIN RESULTS

Analyses of acid-base, electrolyte, and hematologic parameters were performed on both systemic and the washed blood. The washed blood had increased levels of sodium and chloride. There were decreased levels in pH, Pco2, total CO2 (bicarbonate), lactic acid, potassium, total and ionized calcium, magnesium, inorganic phosphorus, total protein, and albumin. Systemically, in the animals, by the end of the study, there were significant increases in the levels of chloride, inorganic phosphorus, hemoglobin, and hematocrit and significant decreases in the levels of pH, total CO2, total and ionized calcium, magnesium, total protein, and albumin.

CONCLUSIONS

Acid-base, electrolyte, and hematologic changes occur when normal saline is used as the wash solution in high volume cell saver autologous blood transfusion. The washed blood with its elevation of sodium and chloride appears to reflect the constituents of the wash solution, normal saline. The depletion in the washed blood of PCO2, total CO2, potassium, total calcium, ionized calcium, magnesium, phosphorus, total protein, and albumin we feel is because of the absence of these electrolytes in the wash solution and their physical removal during salvaged blood separation and washing. The systemic acid-base and electrolyte changes primarily reflect the electrolyte pattern of the reinfused washed blood except for inorganic phosphorus. Inorganic phosphorus was maintained systemically, despite its wash out in the cell salvage process. This paradoxical finding may be caused by intracellular to extracellular inorganic phosphorus flux caused by the progressive systemic metabolic acidosis.

Effects of cardiopulmonary bypass surgery on intravenous ciprofloxacin disposition

The pharmacokinetic parameters of intravenous ciprofloxacin were examined in five adult male patients on three separate occasions of open heart surgery: the 24 h before cardiopulmonary bypass (CPB) surgery, (PRE), during surgery (SURG), and 48 to 72 h after surgery (POST). Serial blood (n = 16), urine, and SURG tissue samples were collected after intravenous administration of a single 300-mg dose of ciprofloxacin during each study period. All samples were assayed for ciprofloxacin by a specific high-performance liquid chromatographic method. Serum ciprofloxacin concentrations remained constant or continued to decline during the course of CPB surgery. A significant (P < 0.05) decrease in total body clearance was observed during the SURG and POST phases (298 and 306 ml/min/1.73 m2, respectively) compared with that during the PRE phase (364 ml/min/1.73 m2). Renal clearances and elimination half-lives were similar during all three study phases. A nonsignificant decline occurred in the apparent volume of distribution, from mean values of 2.1 and 2.0 liters/kg during the PRE and POST phases, respectively, to 1.7 liters/kg during the SURG phase. The mediastinal fat tissue ciprofloxacin concentrations ranged from 0.45 to 2.89 micrograms/g. Overall, little significant difference was noted in the disposition of intravenous ciprofloxacin during CPB surgery compared with that before and after surgery.