Effects of sodium acetate, bicarbonate and lactate on acid-base status in anaesthetized dogs

Bicarbonate Ringer's solution for early resuscitation in hemorrhagic shock rabbits

Background

Fluid resuscitation is important for correcting hypovolemia. Isotonic crystalloids are the preferred solution for the initial clinical management of patients with multiple traumas. Bicarbonated Ringer’s solution (BRS), offering physiological levels of bicarbonate ions and electrolyte ions, can be used for supplementing missing extracellular fluid and correcting metabolic acidosis. We here investigated the effects of BRS on the resuscitation of hemorrhagic shock models and compared the resuscitation performance of three crystalloids, including BRS, acetated Ringer’s solution (ARS), and normal saline.

Methods

Thirty adult male New Zealand rabbits were randomly divided into five groups (n=6): a sham operation group (Sham group), an operation without fluid therapy group (Shock group), a BRS group, an ARS group, and a normal saline group (Saline group). The New Zealand rabbits experienced rapid bloodletting to shock status and maintained for 20 minutes except Sham group. The status of shock was maintained in the Shock group. The fluid was infused at a rate of 60 mL/kg per hour for 1.5 hours in three fluid therapy group. Measurement of vital signs, arterial blood gas tests, blood biochemistry, hematoxylin and eosin (HE) staining of lung tissue, TUNEL staining of the liver and kidney tissues, and analysis of intestinal flora were performed.

Results

The reduction in both base excess (BE) and bicarbonate ion (HCO₃^-) caused by acidosis in rabbits with hemorrhagic shock was significantly improved in the BRS group when compared with the Saline group at infusion for 30 minutes (T3) and 30 minutes after infusion (T5) (BRS group vs. Saline group, BE: at T3, −4.83±3.60 vs. −12.50±3.27 mmol/L, P<0.01; at T5, −3.67±4.37 vs. −11.00±2.76 mmol/L, P<0.01; HCO₃^-: at T3, 22.15±2.63 vs. 15.42±3.03 mmol/L, P<0.01; at T5, 23.15±2.9 vs. 16.23±3.07 mmol/L, P<0.01). Compared with Shock group, liver cell apoptosis due to hemorrhagic shock was relieved in both the BRS group and ARS group (BRS group vs. Shock group: 19.1±3.3 vs. 28.1±6.1, P<0.05; ARS group vs. Shock group: 19.8±5.4 vs. 28.1±6.1, P<0.05).

Conclusions

During resuscitation of hemorrhagic shock, BRS, a novel perioperative balanced crystalloid, is more effective than normal saline in maintaining acid-base balance and in protecting tissues and organs.

Safety of resuscitation with Ringer's acetate solution in severe burn (VolTRAB)--an observational trial

BACKGROUND

A variety of crystalloids are available during fluid resuscitation of the severely burnt patient. There is a paucity of literature evidence on the comparative influence of these with regard to clinical outcomes. Significant differences in crystalloids may be clinically relevant given the large volumes employed during shock resuscitation.

METHODS

The study compared two groups of severely burnt patients (TBSA 20-70%). Prospectively 40 consecutive patients treated with Ringer's acetate (RA group) against a retrospective control group of 40 patients treated with Ringer's lactate (RL group). Outcome parameters analysed included Sequential Organ Failure Assessment (SOFA)-scores at Days 3 and 7 after injury, mortality at 28 and 60 days, electrolyte and renal function, infection rates, cumulative volume administration and duration of ventilator support.

RESULTS

Groups RA and RL were comparable w.r.t. age, total body surface area burn size and ABSI. SOFA-scores on Day 1 of admission also showed no significant difference but were significantly lower in RA group between the 3rd and 6th day. By Day 7 these differences could be attributed as a group effect (P=0.019). In particular low cardiovascular organ function scores contributed to this. Total crystalloid use within the first 28 days were equal in both but differed within the RA group having lower observed volumes of colloid and incidence of blood transfusion. Furthermore group RA had distinctly higher levels of platelets throughout treatment. Elevated lactate levels were noted in RL group during the initial three days. Survival rates at 28 days and 60 days showed no significant difference.

CONCLUSION

Ringer's acetate solution is a suitable medium for the initial fluid management of the acutely burnt patient. In comparison to Ringer's lactate solution the study revealed lower SOFA-scores for Ringer's acetate solution (ClinicalTrials.gov number, NCT00609700).

Acid-base and electrolyte balance following administration of three crystalloid solutions in dogs undergoing elective orthopaedic surgery

OBJECTIVE

To compare acid-base balance and incidence of hyperchloraemic metabolic acidosis following administration of three crystalloid solutions to dogs undergoing anaesthesia for orthopaedic surgery.

STUDY DESIGN

Prospective, randomised, clinical study.

ANIMALS

Sixty dogs.

METHODS

During a non-standardised anaesthetic, 0.9% saline (S), Hartmann's solution (H) or a polyionic glucose-free maintenance solution (M) was administered IV at 10 mL kg(-1)  hour(-1) . Venous blood pH, PCO2 , PCV, total protein, urea, sodium, potassium and chloride concentrations were measured at induction of anaesthesia (T0) and after 2 hours of fluid therapy (T2). Base excess (BE), bicarbonate, corrected chloride concentration (corrCl), osmolality, change in plasma volume (PV) and strong ion gap (SIG) were calculated. Changes in variables within groups (1-sample Student's t-test/Wilcoxon signed rank test) and between groups (1-way anova/Kruskal-Wallis) were assessed. Data are presented as median (interquartile range). Significance was set at p < 0.05.

RESULTS

No significant differences existed between groups for pH, PCO2 , PCV, total protein, urea, potassium, corrCl, PV and SIG. Potassium significantly increased in all groups. Significant differences existed between groups S and M for BE, sodium, chloride, bicarbonate and osmolality, and between groups H and M for sodium and osmolality. Chloride concentration significantly changed from 116 (114-117) to 117 (116-119) mmol L(-1) in group S, 116 (115-118) to 115 (113-117) mmol L(-1) in group H and 116 (115-118) to 114 (113-118)  mmol L(-1) in group M. In groups H and M, sodium and osmolality decreased, and BE and bicarbonate concentration increased significantly. Plasma volume increased by 28 (14-44)%, 25 (5-40)% and 24 (13-33)% in groups S, H and M, respectively.

CONCLUSION AND CLINICAL RELEVANCE

Hyperchloraemic metabolic acidosis did not develop after intraoperative 0.9% saline, Hartmann's solution or maintenance solution at 10 mL kg(-1)  hour(-1) for 2 hours in dogs undergoing elective orthopaedic surgery. Bicarbonate and BE increased after Hartmann's and maintenance solutions. Increases in potassium concentration were unexplained.

Comparison of the effects of intravenous administration of isotonic and hypertonic sodium bicarbonate solutions on venous acid-base status in dehydrated calves with strong ion acidosis

OBJECTIVE-To compare the effects of IV administration of isotonic (1.3%) and hypertonic (8.4%) sodium bicarbonate (NaHCO(3)) solutions on acid-base status in dehydrated calves with strong ion (metabolic) acidosis. DESIGN-Randomized controlled clinical trial. ANIMALS-50 calves with diarrhea and severe dehydration. PROCEDURES-Calves were randomly assigned to receive isotonic NaHCO(3) solution (65 mL/kg [29.5 mL/lb], IV) over 3 hours (n = 30) or hypertonic NaHCO(3) solution (10 mL/kg [4.5 mL/lb], IV) over 20 minutes (20). Blood samples were collected at 0 hours (immediately prior to solution administration) and at 0.5, 1, 2, and 4 hours after administration began. Samples were submitted for blood gas analysis, serum biochemical analysis, and determination of blood Na(+), K(+), and Cl(-) concentrations and percentage change in plasma volume. RESULTS-Calves that received isotonic NaHCO(3) solution had an increase in venous blood pH, HCO(3) concentration, and base excess; a small, transient increase in Po(2); and no change in Pco(2) within 4 hours after administration began. Calves that received hypertonic NaHCO(3) solution had an immediate increase in venous blood pH, HCO(3) concentration, and base excess; a small, transient increase Pco(2); and no change in Po(2) within 0.5 hours after treatment began. Plasma volume increased to a greater extent following administration of isotonic solution than after administration of hypertonic solution. CONCLUSIONS AND CLINICAL RELEVANCE-IV administration of 8.4% NaHCO(3) solution in small volumes provided fast and effective improvement of severe acid-base abnormalities in calves with severe strong ion acidosis but did not improve hydration status as well as administration of a larger volume of isotonic NaHCO(3) solution.

Effects of hypertonic sodium bicarbonate solution on electrolyte concentrations and enzyme activities in newborn calves with respiratory and metabolic acidosis

OBJECTIVE

To determine concentrations of electrolytes, total bilirubin, urea, creatinine, and hemoglobin; activities of some enzymes; and Hct and number of leukocytes and erythrocytes of newborn calves in relation to the degree of acidosis and treatment with a hypertonic sodium bicarbonate (NaHCO(3)) solution.

ANIMALS

20 acidotic newborn calves with a blood pH < 7.2 and 22 newborn control calves with a blood pH > or = 7.2.

PROCEDURES

Approximately 10 minutes after birth, acidotic calves were treated by IV administration of 5% NaHCO(3) solution. The amount of hypertonic solution infused was dependent on the severity of the acidosis.

RESULTS

Treatment resulted in a significant increase in the mean +/- SEM base excess from -8.4 +/- 1.2 mmol/L immediately after birth to 0.3 +/- 1.1 mmol/L 120 minutes later. During the same period, sodium concentration significantly increased from 145.3 +/- 0.8 mmol/L to 147.8 +/- 0.7 mmol/L. Mean chloride concentration before NaHCO(3) administration was significantly lower in the acidotic calves (99.6 +/- 1.1 mmol/L) than in the control calves (104.1 +/- 0.9 mmol/L). Calcium concentration in acidotic calves decreased significantly from before to after treatment. Concentrations of potassium, magnesium, and inorganic phosphorus were not affected by treatment.

CONCLUSIONS AND CLINICAL RELEVANCE

Administration of hypertonic NaHCO(3) solution to acidotic neonatal calves did not have any adverse effects on plasma concentrations of several commonly measured electrolytes or enzyme activities. The treatment volume used was smaller, compared with that for an isotonic solution, which makes it more practical for use in field settings.

Pharmacological study of BRS, a new bicarbonated Ringer's solution, in haemorrhagic shock dogs

BACKGROUND AND OBJECTIVES

Sodium bicarbonate is the most physiological alkalinizing agent. The effect of a new bicarbonated Ringer's solution (BRS) containing Mg2+, on metabolic acidosis and serum magnesium abnormality were evaluated and compared with those of acetated Ringer's (ARS), lactated Ringer's (LRS) and Ringer's (RS) solutions in an experimental haemorrhagic shock model with dogs.

METHODS

Animals were randomly divided into six groups (n = 6 in each group), a sham-operated group, an operated group without infusion, and 4 operated groups with infusion (BRS, ARS, LRS and RS groups). Each RS was intravenously administered at 60 mL kg(-1) h(-1) for 1.5 h. Arterial blood gases, plasma electrolytes and cardiovascular parameters were analysed.

RESULTS

BRS significantly improved blood base excess values, which were decreased by blood-letting, faster and more markedly than did LRS and RS (BRS--6.3 +/- 0.5 mEq L(-1); LRS--9.2 +/- 1.1 mEq L(-1); RS--12.4 +/- 1.0 mEq L(-1) at the end of infusion). The alkalinizing effect of BRS tended to be better than that of ARS but not significantly so. The serum Mg2+ concentration was well-maintained by BRS as compared to other RS (BRS 1.5 +/- 0.0 mgdL(-1); ARS 1.2 +/- 0.0mgdL(-1); LRS 1.1 +/- 0.0mgdL(-1); RS 1.3 +/- 0.1 mgdL(-1), at the end of infusion).

CONCLUSIONS

These results suggest that BRS is a suitable perioperative solution for metabolic acidosis and serum electrolyte balance among RS tested.

Pharmacological study of BRS, a new bicarbonated Ringer's solution, in partially hepatectomized rabbits

BACKGROUND AND OBJECTIVE

The effects of bicarbonated Ringer's solution were evaluated and compared with those of acetated Ringer's, lactated Ringer's and Ringer's solutions in partially hepatectomized rabbits.

METHOD

Animals were randomly divided into six groups (n = 6 in each group): a sham-operated group, an operated group without infusion, and four operated groups with infusions of each of the four Ringer's solutions. Each Ringer's solution was intravenously administered at 40 mL kg(-1) h(-1) for 1.5 h. Arterial blood gases, plasma magnesium concentrations and cardiovascular parameters were analysed.

RESULTS

The partial hepatectomy-induced decrement of base excess was inhibited by bicarbonated Ringer's solution more remarkably than by either lactated or plain solutions (P < 0.01). The alkalinizing effect of bicarbonated Ringer's solution tended to be more marked than that of the acetated solution but not significantly so. Plasma magnesium concentrations were well maintained by bicarbonated solution as compared to the other solutions (P < 0.01).

CONCLUSIONS

These results suggest that bicarbonated Ringer's solution is the most suitable perioperative solution for metabolic acidosis and plasma electrolyte balance among the Ringer's solutions tested.