Liquid therapy is a common clinical treatment method in pediatrics, especially the preparation of mixed liquids is very commonly used in the clinic, but the conventional preparation method in textbooks is more complex, the composition of the liquid is not easy to remember, the simple preparation method are 500ml as an example, in addition to the lack of accuracy, the application of the clinical application of not easy to implement, and some physicians even have to copy the simple preparation method in a small notebook, and then read it again when you are using it, which is extremely inconvenient for the clinical application, especially in the emergency department and rescue of emergency patients, and the need to prepare special tensions of the liquid appears to be more passive for this reason. Extremely inconvenient, especially in the emergency department and rescue emergency patients, and the need to formulate a special tension of the liquid appears to be more passive for this reason, the author according to their own clinical experience, combined with the relevant information, summed up the mixture of liquid preparation of the rapid calculation formula for teaching and clinical reference. Zhang Jiankui, Department of Pediatrics, The First Affiliated Hospital of Henan College of Traditional Chinese Medicine 1 Extrapolation process It is well known that the sodium-chlorine ratio of plasma is 3:2, therefore, the mixture prepared in this ratio is most in line with human physiology, which is the theoretical basis for the author’s summarized rapid calculation formula for the preparation of mixture. The general preparation of the mixture follows the principle that the tension of the composition of the liquid is tension-free or isotonic, commonly used tension-free liquid is 5% or 10% glucose, isotonic sodium-containing liquid is 0.9% sodium chloride, 1.4% sodium bicarbonate, 1.87% sodium lactate, the preparation of the general use of tension-free liquid and high tensile sodium-containing liquid, commonly used high tensile liquid is 10% sodium chloride, 5% sodium bicarbonate or 11.2% sodium lactate. To get the sodium-chloride ratio of 3:2 mixture, need to use 2 copies of 0.9% sodium chloride, 1 copy of 1.4% sodium bicarbonate or 1.87% sodium lactate, i.e., 0.9% sodium chloride accounted for the amount of equal tensile sodium liquid 2 / 3, 1.4% sodium bicarbonate or 1.87% sodium lactate accounted for the amount of equal tensile sodium liquid 1 / 3. Therefore: equal tensile sodium liquid amount = the total amount of mixture × tension, so 0.9% sodium chloride liquid amount = mixture of liquid, so the amount of 0.9% sodium chloride liquid = mixture, so the amount of 0.9% sodium chloride liquid = mixture, the amount of 0.9% sodium chloride liquid = mixture, the amount of 0.9% sodium chloride liquid = mixture, the amount of 1/3. The amount of sodium chloride = the total amount of mixture × tension × 2/3, according to “C dilute × V dilute = C thick × V thick”, the amount of 10% sodium chloride = the total amount of mixture × tension × 2/3 × 0.9% ÷ 10% = the total amount of mixture × tension × 6% Similarly, the amount of 1.4% sodium bicarbonate = the total amount of mixture × tension × 1/3 According to “C dilution × V dilution = C concentration × V concentration”, the amount of 5% sodium bicarbonate = total mixture × tension × 1/3 × 1.4% ÷ 5% ≈ total mixture × tension × 9.3%. By analogy, 11.2% sodium lactate ≈ total mixture × tension × 6%. The remaining fluid is prepared with a tension-free fluid, i.e., 5% or 10% dextrose. 2 Formulas for Preparation Therefore, any mixture with a sodium-chlorine ratio of 3:2 can be prepared as follows: Formula 1: 10% sodium chloride liquid volume (ml) = total mixture × tension × 6% Formula 2: 5% sodium bicarbonate liquid volume (ml) = total mixture × tension × 9.3% or 11.2% sodium lactate liquid volume (ml) = total mixture × tension × 6% Formula 3: 5% or 10% glucose liquid volume (ml) = total mixture – 10% sodium chloride liquid volume – 5% sodium bicarbonate or 11.2% sodium lactate liquid volume 3 Example Preparation Example 1, the preparation of isotonic solution (2:1 liquid) 200ml, the required 10% sodium chloride = 200 × 1 × 6% = 12ml, 5% sodium bicarbonate = 200 × 1 × 9.3% ≈ 19ml, 10% glucose = 200- 12-19=169 ml; Example 2, to prepare 1/2 sheet of sodium-containing liquid (:2:1 liquid) 300 ml, required 10% sodium chloride = 300 × 1/2 × 6% = 9 ml, 11.2% sodium lactate = 300 × 1/2 × 6% = 9 ml, 10% dextrose = 300 – 9-9 = 282 ml; Example 3, to prepare 2/3 sheet of sodium-containing liquid (4:3:2 liquid) 300 ml, 10% sodium chloride = 300 × 2/3 × 6% = 12 ml, 5% sodium bicarbonate = 300 × 2/3 × 9.3% = 19 ml, 10% dextrose = 300-12-19 = 269 ml; Example 4, to prepare 1/3 sheet of sodium-containing solution (6:2:1 solution) 300 ml, 10% sodium chloride = 300 × 1/3 × 6% = 6 ml. 5% sodium bicarbonate = 300 × 1/3 × 9.3% ≈ 9 ml, 10% dextrose = 300-6-9 = 285 ml; Example 5, the preparation of 1/5 sheet containing sodium solution 300 ml, the required 10% sodium chloride = 300 × 1/5 × 6% = 3.6 ml, 5% sodium bicarbonate = 300 × 1/5 × 9.3% ≈ 5.6 ml, 10% dextrose = 300 – 3.6 – 5.6 = 290 ml. 5.6 = 290 ml. The author believes that the formula is simple to calculate, easy to use, rapid calculation, accurate and practical, very consistent with human physiology, and can be used without memorizing its composition, if applied to the simple preparation, plus simple, especially suitable for grass-roots level. The formula not only makes up for the lack of simple formula calculation in the mixture preparation, but also has clinical practical value, worth home application and promotion.