The intraoperative therapeutic equivalence of balanced vs saline-based 6% hydroxyethyl starch 130/0.4 and their influence on perioperative acid-base status and renal functions

Intra-operative intravascular effect of the difference in colloid solutions during acute normovolemic hemodilution

Background

Acute normovolemic hemodilution (ANH) is used to reduce the risk of peri-operative allogeneic blood transfusion. Although crystalloid and/or colloid solutions have been used for volume replacement during ANH, no studies have examined the differences among solutions on the volume status, electrolytes, acid-base balance, and hemodynamic status during surgery with ANH.

Methods

We retrospectively compared the effect of Ringer’s lactate with 3% dextran-40 (Saviosol®, DEX group) and 6% hydroxyethyl starch 130/0.4 in 0.9% sodium chloride (Voluven®, HES group) on blood hemoglobin serum electrolytes and estimated blood volume before induction of anesthesia (baseline), after ANH and after blood transfusion following surgery in patients undergoing open gynecological surgery (n = 111 and 67, respectively). The primary outcomes were the changes in hemoglobin and electrolytes after ANH.

Results

There were no differences in hemoglobin or electrolytes between the two groups at baseline. Postoperative hemoglobin was significantly higher (11.0 ± 1.5 g/dL vs 9.9 ± 1.3 g/dL) (mean ± SD) in the DEX group than in the HES group (p = 0.03). Postoperative potassium was significantly decreased from the baseline both in the DEX group (137.9 ± 2.5 mmol/L vs 136.3 ± 2.7 mmol/L) and in the HES group (138.3 ± 2.0 mmol/L vs 137.8 ± 2.5 mmol/L) (p < 0.001 for both); however, it was significantly higher than in the DEX group after surgery (p < 0.001). Estimated blood volume after surgery was significantly increased after ANH in both groups; however, it was larger in the HES group than in the DEX group.

Conclusions

Postoperative hemoglobin and potassium were significantly higher, and estimated blood volume was significantly smaller in the DEX than in the HES group.

Comparing the Effects of Pre-loading with Gelatine 4% Plasma Volume Expander and 6% Hydroxyethyl Starch Solution Before Spinal Anaesthesia for Lower Limb Orthopaedic Surgery

BACKGROUND

Hypotension is a common complication following spinal anaesthesia. The administration of intravenous fluids prior to spinal anaesthesia, known as pre-loading, has been used to offset the hypotension effect; however, the ideal fluid for pre-loading is still a matter of debate. The objective of this study was to compare the effects of Gelaspan 4% and Volulyte 6% as pre-loading fluids.

METHODS

A total of 93 patients with American Society of Anaesthesiologists (ASA) physical status I or II having lower limb orthopaedic surgery under spinal anaesthesia were randomised into two groups that received either Volulyte (n = 47) or Gelaspan (n = 46). Before the spinal anaesthesia, these patients were pre-loaded with 500 mL of the fluid of their respective group. Blood samples were taken before pre-loading and again after spinal anaesthesia and sent for venous blood gas and electrolyte level measurement. Baseline and intraoperative records of systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial pressure (MAP), heart rate (HR) and the requirement of ephedrine to treat hypotension were also recorded.

RESULTS

Both fluids could not prevent significant reductions in SBP (P = 0.011), DBP (P = 0.002) and MAP (P = 0.001). There was also significant reduction in HR over time (P < 0.001). There was no significant difference in terms of ephedrine usage between both groups. Neither Volulyte 6% nor Gelaspan 4% caused significant changes in acid-base status.

CONCLUSION

The use of 500 mL of either Gelaspan 4% or Volulyte 6% as pre-loading fluids did not significantly prevent the incidence of post-spinal anaesthesia hypotension following orthopaedic lower limb surgery; however, both were useful in the maintenance normal acid-base balance.

Acid/base alterations during major abdominal surgery: 6% hydroxyethyl starch infusion versus 5% albumin

BACKGROUND

To compare the effects of intraoperative infusions of balanced electrolyte solution (BES)-based hydroxyethyl starch (HES) and saline-based albumin on metabolic acidosis and acid/base changes during major abdominal surgery conducted using Stewart's approach.

METHODS

Forty patients, aged 20-65 years, undergoing major abdominal surgery, were randomly assigned to the HES group (n = 20; received 500 ml of BES-based 6% HES 130/0.4) or the albumin group (n = 20; received 500 ml of normal saline-based 5% albumin). Acid-base parameters were measured and calculated using results obtained from arterial blood samples taken after anesthesia induction (T1), 2 hours after surgery commencement (T2), immediately after surgery (T3), and 1 hour after arriving at a postanesthetic care unit (T4).

RESULTS

Arterial pH in the HES group was significantly higher than that in the albumin group at T3 (7.40 ± 0.04 vs. 7.38 ± 0.04, P = 0.043), and pH values exhibited significant intergroup difference over time (P = 0.002). Arterial pH was significantly lower at T3 and T4 in the HES group and at T2, T3, and T4 in the albumin group than at T1. Apparent strong ion difference (SIDa) was significantly lower at T2, T3, and T4 than at T1 in both groups. Total plasma weak nonvolatile acid (ATOT) was significantly lower in the HES group than in the albumin group at T2, T3 and T4 and exhibited a significant intergroup difference over time (P < 0.001).

CONCLUSIONS

BES-based 6% HES infusion was associated with lower arterial pH values at the end of surgery than saline-based 5% albumin infusion, but neither colloid caused clinically significant metabolic acidosis (defined as an arterial pH < 7.35).

Lactated Ringer' Solution may be Superior to Saline-Based 6% Hydroxyethyl Starch 130/0.4 for Early Resuscitation within 12 hours from Hemorrhagic Shock

Purpose: To compare the effects of fluid resuscitation with lactated Ringer's solution (LR) and saline-based 6% hydroxyethyl starch 130/0.4 (HES) on the inflammatory response and oxidative stress in the small intestine as well as on bacterial translocation to the liver. Methods: Sprague-Dawley rats were subjected to blood pressure-controlled hemorrhagic shock and then resuscitated with LR or HES. At 1, 3, 6, 12, and 24 hr after resuscitation, liver tissues were collected to count the bacterial colonies, and small intestines were harvested to analyze the levels of inflammatory (TNF-α and HO-1) and oxidative stress (MPO) mediators as well as the intestinal injury by immunohistochemistry, colorimetry and hematoxylin & eosin staining, respectively. Results: The expression level of TNF-α in the LR group was stable from 1 to 6 hr but decreased at 12 hr and then abruptly increased at 24 hr. The expression level of TNF-α in the LR group was significantly lower than that in the HES group, especially during the first 12 hr post-fluid infusion. MPO activity decreased to its lowest level at 3 hr but increased from 6 to 12 hr, with no difference at 24 hr between the two groups. Although a decreasing tendency was observed from 6 hr, HO-1 expression levels remained higher in the LR group than in the HES group at 12 and 24 hr, particularly at 12 hr. During the initial 12 hr, the LR group exhibited significantly lower colony-forming units in the liver tissues than the HES group. Chiu's score in the intestine decreased regardless of which resuscitative fluids were used. Conclusions: During early resuscitation (within 12 hr), LR may be superior to HES in reducing intestinal injuries by suppressing inflammatory and oxidative mediators.

Comparison of acid-base and electrolyte changes following administration of 6% hydroxyethyl starch 130/0.42 in a saline and a polyionic solution in anaesthetized dogs

OBJECTIVE

To evaluate the effects of a 6% hydroxyethyl starch (130/0.42) in either a buffered, electrolyte-balanced (HES-BAL) or saline (HES-SAL) carrier solution on electrolyte concentrations and acid-base parameters in healthy anaesthetized dogs.

STUDY DESIGN

Prospective randomised clinical study.

ANIMALS

A group of 40 client-owned dogs undergoing general anaesthesia for elective surgical procedures or diagnostic imaging.

METHODS

During anaesthesia, dogs were intravenously administered 15 mL kg^-1 of either HES-SAL (n = 20) or HES-BAL (n = 20) over 30-40 minutes. Jugular blood samples were analysed before (T₀) and 5 minutes (T₅), 1 hour (T₆₀) and 3 hours (T₁₈₀) after fluid administration. Sodium, potassium, chloride, ionised calcium, phosphate, albumin, pH, venous pCO₂, base excess (BE), bicarbonate and anion gap were determined and strong ion difference (SID) and total quantity of weak nonvolatile acids were calculated for each time point.

RESULTS

Chloride was significantly increased at T₅, T₆₀ and T₁₈₀ compared with T₀ after HES-SAL, and was significantly greater after HES-SAL than after HES-BAL at T₅ (p = 0.042). Ionised calcium was significantly decreased at T₅ compared with T₀ after HES-SAL, and was significantly lower after HES-SAL than after HES-BAL at T₅ (p < 0.001). Bicarbonate was significantly lower after HES-SAL than after HES-BAL at T₅ (p = 0.004) and T₆₀ (p = 0.032). BE was significantly lower after HES-SAL than after HES-BAL at T₅ (p < 0.001) and T₆₀ (p = 0.007). SID was significantly decreased after HES-SAL at T₅ and T₆₀ compared with T₀, and was significantly lower after HES-SAL than after HES-BAL at T₅ (p = 0.027). Mean electrolyte and acid-base parameters remained within or marginally outside of reference intervals.

CONCLUSIONS AND CLINICAL RELEVANCE

Changes in both groups were minor and short-lived with either fluid in healthy individuals, but might become clinically relevant with higher fluid doses or in critically ill dogs.

Influence of saline-based hydroxyethyl starch on umbilical cord blood electrolytes

Hydroxyethyl starch (HES) is widely used to prevent and treat spinal anesthesia-induced hypotension during cesarean section. However, the use of saline-based HES may lead to hyperchloremia. This study aimed to clarify the effects of saline-based HES on umbilical cord chloride level at delivery. We retrospectively analyzed 93 consecutive single-pregnancy patients who underwent cesarean section with combined spinal-epidural anesthesia. The patients were divided into two groups, depending on the use of 6% HES 130/0.4: group A (461 ± 167 ml of saline-based HES was administered; 43 patients) and group B (HES not administered; 50 patients). The major outcome was umbilical cord chloride level at delivery. The volume infused from operating room admission until delivery was not significantly different between groups. The umbilical cord chloride level at delivery was statistically significantly higher in group A than in group B, but clinically similar (108 ± 2 vs. 107 ± 2 mmol/l, P = 0.02). No differences were observed in the Apgar score or other umbilical cord laboratory data at delivery (Na⁺, K⁺, pH, base excess). In conclusion, we suggest that although the use of up to 500 ml of saline-based HES during cesarean section influences umbilical cord blood electrolytes, the effect is not of a clinically significant magnitude.