Clinical application and research progress of Sodium Lactate Ringer Injection
1. Development process and physiological basis of crystalloid fluid
Physiological saline, as the earliest isotonic crystalloid fluid used in clinical practice, although labeled as "physiological", has significant differences in its actual composition from human plasma.
. Traditional physiological saline only contains sodium chloride, lacking essential electrolytes such as potassium, calcium, and magnesium, and does not have the function of buffering acid-base balance. The defects in this component make it significantly limited in clinical applications, especially in critically ill patients who need to maintain complex electrolyte balance.
To compensate for these shortcomings, the medical community developed the first generation of improved balancing fluid - Ringer's solution. The solution was supplemented with potassium chloride and calcium chloride on the basis of physiological saline, which initially improved the electrolyte composition. However, Ringer's solution still lacks a critical buffering system and cannot effectively regulate plasma pH. This defect is particularly prominent in patients with metabolic disorders, prompting researchers to further optimize the formula.
The breakthrough in the second-generation equilibrium crystal solution lies in the introduction of sodium lactate as a buffering agent. Sodium lactate can be converted into bicarbonate through liver metabolism in the body, which endows it with the ability to regulate acid-base balance. This improved solution is named Sodium Lactate Ringer Injection, also known as Hartmann's Solution. Its composition design is closer to extracellular fluid, containing various electrolytes such as sodium, potassium, calcium, chlorine, etc. Its pH value is also closer to plasma, making it one of the closest crystal fluids to physiological state in clinical practice.
2、 Detailed explanation of drug ingredients and mechanism of action
2.1 Main ingredients and ratios: Sodium lactate Ringer injection is a compound preparation, containing 1.55g of sodium lactate, 3.00g of sodium chloride, 0.15g of potassium chloride, and 0.1g of calcium chloride (calculated as CaCl2 · 2H2O) per 500ml. These ingredients are accurately proportioned to ensure that their osmotic pressure is isotonic with plasma (about 274-310mOsm/L), and the pH value is maintained within the physiological range of 6.5-7.5.
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2.2 Pharmacological effects of each component Sodium lactate, as a key buffering component, is metabolized into bicarbonate ions (HCO3-) through glycolysis in the liver, which requires the consumption of hydrogen ions to effectively correct metabolic acidosis. Sodium ions are the main cations that maintain extracellular fluid volume and osmotic pressure, and their concentration directly affects neuromuscular excitability and fluid distribution. Potassium ions, as the most important cation in cells, play an irreplaceable role in maintaining myocardial electrophysiological stability and nerve conduction. Calcium ions participate in the coagulation cascade, muscle contraction, and activation of various enzyme systems. 2.3 Comprehensive therapeutic effect: This solution exerts therapeutic effects through multiple mechanisms: firstly, its electrolyte composition can quickly supplement circulating blood volume and improve tissue perfusion; Secondly, the buffering system generated by sodium lactate metabolism can effectively correct acid-base imbalances; Furthermore, a balanced ion concentration helps to restore cell membrane potential and maintain important organ function. Clinical observations have shown that in cases of acute blood loss, severe dehydration, etc., sodium lactate Ringer injection can stabilize hemodynamic parameters faster and reduce the incidence of complications.
3、 Clinical Application Guidelines and Expert Consensus
3.1 Scope of Indications Sodium Lactate Ringer Injection is suitable for various clinical scenarios: Perioperative fluid management is its classic indication, especially for patients undergoing major abdominal surgeries. Research has shown that compared to traditional saline, the use of sodium lactate Ringer injection can reduce the incidence of postoperative nausea and vomiting and promote gastrointestinal function recovery. In the field of trauma first aid, this solution is recommended as a first-line choice for shock resuscitation as it can simultaneously correct electrolyte imbalances and metabolic acidosis.

Non operative indications include dehydration caused by acute gastroenteritis, adjuvant treatment of diabetes ketoacidosis, early fluid resuscitation of burns, etc. It is worth noting that caution should be exercised when using in patients with severe liver function impairment, as lactate metabolism may be affected.
3.2 Optimization of dosing regimen: The standard dosage for adults is 500-1000ml per dose, 1-2 times a day. It is recommended to control the infusion rate at 300-500ml/h, and for elderly patients or those with heart failure, it should be appropriately slowed down. Children's medication should be accurately calculated based on body weight (usually 20-30ml/kg/d), and electrolyte changes should be closely monitored. In special circumstances such as severe acidosis or massive bleeding, the dosage may be increased as appropriate, but fluid overload should be avoided. 3.3 Multidisciplinary Expert Consensus: The 2014 Expert Consensus on Fluid Therapy during Anesthesia Surgery clearly states that Sodium Lactate Ringer Injection can effectively prevent intraoperative hypotension and maintain hemodynamic stability. In 2015, the Expert Consensus on Perioperative Fluid Therapy for Surgical Patients listed it as one of the two equilibrium fluids closest to extracellular fluid components, and it is particularly recommended for elective abdominal surgery. The Chinese National Formulary recommends it as a key medication, covering multiple clinical departments such as surgery, ICU, and emergency.
4、 Clinical advantages and precautions
4.1 Analysis of therapeutic advantages Compared with traditional crystalloid solution, Sodium Lactate Ringer Injection has multiple advantages: its electrolytic mass spectrometry is more in line with physiological needs and can reduce iatrogenic electrolyte disorders; Calcium containing formula is beneficial for postoperative coagulation function recovery; The buffer system design enables it to actively correct acid-base imbalances. Long term clinical observations have confirmed that patients who use this solution have a significantly reduced incidence of postoperative complications and shorter hospital stays. 4.2 Precautions for use

Despite its high safety, the following issues should still be noted during clinical application: patients with severe liver dysfunction may not be able to effectively metabolize lactate and may need to switch to other buffering systems;
; Patients with hyperlipidemia should avoid using it; Rapid and large infusion may lead to volume overload, especially in patients with cardiac and renal dysfunction, where infusion speed needs to be strictly controlled. In addition, this solution has compatibility contraindications with certain antibiotics and should be used with caution according to the drug instructions.
4.3 Special population medication: Elderly patients with reduced regulatory function are more prone to electrolyte imbalance. It is recommended to strengthen monitoring. There are no clear contraindications for pregnant women to use it, but the pros and cons should be weighed. The dosage of medication for children should be accurately calculated based on body weight to avoid electrolyte imbalance. Patients with renal insufficiency need to adjust the infusion rate and amount to prevent sodium and water retention.
5、 Research progress and future prospects
In recent years, large-scale clinical studies on balanced crystalloid fluid have been continuously deepening. Multiple randomized controlled trials have confirmed that Sodium Lactate Ringer Injection is superior to physiological saline in reducing the incidence of acute kidney injury and improving patient prognosis. Future research directions include optimizing the concentration of sodium lactate to adapt to different pathological states, developing novel buffering systems, and exploring individualized infusion plans. With the development of precision medicine, customized balancing fluids for specific patient populations may become a new research direction.