Amount of rehydration fluid
1.Adjust according to body weight [2ml/(kg?h) i.e. 48ml/(kg?day)], generally 2500-3000ml.
2.According to the body temperature, greater than 37 degrees Celsius, each degree of increase, 3-5ml/kg more supplement.
3.Special loss: gastrointestinal decompression; diarrhea; intestinal fistula; bile drainage; various drains; ventilator support (increased evaporation through the airway)
Rehydration fluid
Sugar: generally glucose, 250-300g (5% glucose injection: 100ml: 5g, 250ml: 12,5g, 500ml: 25g; 10% glucose injection: 100ml: 10g, 250ml: 25g, 500ml: 50g).
2.Salt: generally refers to sodium chloride, 4-5g (0.9% sodium chloride injection: take 0.9g of sodium chloride, dissolve in a small amount of distilled water and dilute to 100ml. 0, 9% sodium chloride injection Specification 100ml: 0, 9g, 250ml: 2, 25g, 500ml: 4, 5g ).
When serum sodium <130 mmol/L, rehydrate. First, supplement by 1/3-1/2 of the total amount.
Formula: should be supplemented with Na+ (mmol) = [142 – patient’s blood Na+ (mmol/L)] × weight (kg) × 0, 6 (0, 5 for women)
Saline = [142 – patient’s blood Na+ (mmol/L)] × body weight (kg) × 3, 5 (3, 3 for women)
The ratio of sugar to salt in complete parenteral nutrition is about 5:1.
3, potassium: generally refers to potassium chloride, physiological amount of 3-4g (10% potassium chloride solution, specification: 10ml: 1g. Generally 10-15ml of 10% potassium chloride injection is added to 500ml of electroglucose injection).
Low potassium.
For mild potassium deficiency of 3,0-3,5 mmol/l, the amount of potassium supplementation is 6-8g throughout the day.
For moderate potassium deficiency of 2, 5-3, 0mmol/l, the amount of potassium should be 8-12g for the whole day.
For severe potassium deficiency <2, 5 mmol/l, the amount of potassium supplementation should be 12-18g for the whole day.
Potassium supplementation formula: (4, 5 – measured blood potassium) * weight (kg) * 0, 4 = potassium deficiency (mmol)
Note: 1g of potassium chloride = 13,6 mmol of K+ Daily potassium supplementation is: physiological amount + potassium deficiency
4, general fasting time within 3 days, do not need to supplement protein, fat. Greater than 3 days, daily protein, fat should be supplemented.
Principles of rehydration
First fast and then slow, first gel and then crystal, first thick and then shallow, first salt and then sugar, see urine and potassium, what is lacking.
Note: In case of shock, first crystal and then gel.
The amount of rehydration = 1/2 cumulative loss, additional loss of the day, normal daily requirement.
Rough calculation of rehydration = urine volume + 500ml. if febrile patients + 300ml × n
1. Potassium replenishment.
Principles of potassium supplementation.
① It is safer to take oral potassium supplementation.
② The speed of potassium supplementation should not be fast. Generally <20 mmol/h.
③Concentration should not exceed 3g in 1000ml of liquid.
④See urine for potassium supplementation. The urine volume is >30 ml/h.
The total extracellular fluid potassium ion content is only about 60 mmol, the input should not be too fast, and must see urine for potassium supplementation.
⑤ Low potassium should not be given to sugar, because potassium is consumed during glycolysis. 100g of sugar = 2,8g of potassium consumed.
For mild potassium deficiency of 3.0-3.5 mmol/L, the amount of potassium should be 6-8g throughout the day.
For moderate potassium deficiency of 2, 5 – 3, 0mmol/l, the amount of potassium supplementation is 8-12g for the whole day.
For severe potassium deficiency <2,5 mmol/l, the amount of potassium supplementation is 12-18g for the whole day.
2. Sodium supplementation: If the serum sodium is <130 mmol/L, rehydrate. First, add 1/3-1/2 of the total amount.
Formula.
Should be supplemented with Na+ (mmol) = [142 – patient’s blood Na+ (mmol/L)] × weight (kg) × 0,6 <0,5 for women>
Saline = [142 – patient’s blood Na+ (mmol/L)] × body weight (kg) × 3, 5 <3, 3 for women
Sodium chloride = [142 – patient’s blood Na+ (mmol/L)] × body weight (kg) × 0,035 <0,03 for women
Or = weight (kg) × [142 – patient blood Na+ (mmol/L)] × 0, 6 < 0, 5> for women ÷ 17
3.Infusion rate determination
Input volume per hour (ml) = number of drops per minute × 4
Number of drops per minute (gtt/min) = total ml of fluid input ÷ [total infusion time (h) × 4]
Infusion time required (h) = total number of ml of fluid input ÷ (number of drops per minute × 4)
4.The number of intravenous infusion drops into the calculation method
5. 5% NB (ml) = [normal value of CO2CP – patient CO2CP] × weight (kg) × 0,6.
The normal value of CO2CP is 22%-29%.
If the CO2 binding capacity is not measured, it can be calculated as 5ml/kg of 5% sodium bicarbonate per solution
(This dosage can be increased by 10 volume%). If necessary, the application can be repeated after 2-4 hours.
Note
1.Adjust the quantity and quality of rehydration fluid according to the patient’s combined other medical diseases, important ones such as diabetes, cardiac insufficiency, renal insufficiency, hepatic insufficiency, etc. Of course, if you are not sure, you should call the internal medicine specialist for consultation.
2, according to the patient’s actual condition, the need for fluid, insufficient volume. Such as hypotension, low urine output, and other low-volume conditions. Pay attention to improve circulation.
3.According to the laboratory results: albumin, sodium, potassium, calcium, etc., the lack of how much to make up (can be calculated according to the formula), make up to the laboratory review of the basic normal.
4, hemorrhagic shock expansion should pay attention to the ratio of crystalloid, not only transfusion of whole blood, crystal is appropriate to choose saline, crystalloid ratio of 3:1.
5, fasting greater than 3 days, daily supplementation of 20% fat milk 250ml.
6, diabetes, high blood glucose, rehydration must remember to add RI. according to different situations: a: post-operative and trauma elderly, even if there is no diabetes, RI should be added, according to 5:1 to give, because surgery is a stress, there will be insulin resistance blood glucose rise. b diabetic patients, according to the specific blood glucose situation. RI4:1 can completely offset the sugar, and then rise, such as 3:1 can lower the sugar. Of course when you can’t get it yourself, you still call for endocrine consultation.
The following is a simple plan for the rehydration of a standard 50kg patient, except for all other factors of fasting: 10% GS 1500ml, 5% GNS 1000ml, 10% Kcl 30ml.
Specific plan
The rehydration plan should include three elements based on the patient’s clinical presentation and laboratory findings
① Estimate the cumulative amount of water that the patient may have lost before admission (only l/2 amount in the first 24 hours).
② estimate the amount of fluid lost by the patient yesterday, such as: vomiting, diarrhea, gastrointestinal alkaline pressure, intestinal fistula, etc. loss of fluid; heat loss of fluid < every 1 degree increase in body temperature, per kg of body weight should be replenished 3 to 5m / fluid). The amount of fluid dissipated by tracheotomy expiration: the amount of fluid lost by heavy sweating, etc. < p="">
③ Normal daily physiological fluid requirement, calculated as 2000ml
What to rehydrate?
The specific contents of rehydration fluids are chosen according to the patient’s specific situation.
① Crystalloids (electrolytes) are commonly used: glucose saline, isotonic saline solution, balanced saline solution, etc;
② Colloid fluids: blood, plasma, dextrose, etc;
(③) caloric supplementation is commonly used: l0% glucose saline;
④ Alkaline fluids such as 5% sodium bicarbonate or 11 2% sodium lactate are often used to correct acidosis.
How to make up?
Specific rehydration methods.
① Rehydration procedure: first expand the volume, then adjust the electrolyte and acid-base balance; when expanding the volume, use crystals first and then limbs.
② Rehydration speed: first fast and then slow. Usually 60 drops per minute, equivalent to 250m1 per hour Note: rehydration should be slow for cardiac, cerebral and renal dysfunction, and slow for potassium rehydration; fast for resuscitation of shock, and fast for application of mannitol for dehydration.
Monitoring indicators of safe rehydration
① Central venous pressure (CVP): normal is 5 ~ l0cm water column CVP and blood pressure decrease at the same time, indicating insufficient blood volume, should speed up rehydration; CVp increase, blood pressure decrease indicates cardiac insufficiency, should slow down rehydration and knot and cardiac drugs; CVP normal, blood pressure decrease, indicating insufficient blood volume or cardiac insufficiency, should do rehydration test Intravenous injection of saline 250m1 within 10 minutes, if blood pressure rises, CVP remains unchanged, which means insufficient blood volume; if blood pressure remains unchanged, but CVP rises, which means cardiac insufficiency.
② degree of jugular vein filling: when lying down, the two veins are not obviously filled, indicating insufficient blood volume; if the filling is obvious and even in a state of anger, indicating cardiac insufficiency or too much replenishment.
③ Pulse: the pulse rate gradually returns to normal after rehydration, indicating appropriate rehydration: if it becomes faster and weaker, it indicates aggravation of the disease or cardiac insufficiency.
④ Urine volume: normal urine volume (more than 50ml per hour) indicates appropriate rehydration.
⑤ Other: observe whether there is any relief of dehydration status, whether pulmonary edema occurs, whether cardiac insufficiency manifests, etc.
One point to emphasize is that any formula is for reference only and should not be implemented mechanically. It is important to avoid too little or too much rehydration. Too little often makes it difficult to control shock and can lead to acute renal failure; too much can cause excessive circulatory burden and cerebral and pulmonary edema, and contribute to increased local exudation of burns, which is conducive to bacterial reproduction and infection.
For this reason, the following infusion indicators can be adjusted according to.
① Appropriate amount of urine. When the renal function is normal, the urine volume mostly reflects the circulatory situation. Generally, adults are required to maintain a uniform urine volume of 30-40 ml per hour. rehydration should be accelerated below 20 ml; above 50 ml, it should be slowed down. If you have hemoglobinuria, the urine volume requirement is high; if you have cardiovascular disease, compound brain trauma or elderly patients, the requirement is low.
② Quiet, clear and cooperative, as a sign of good circulation. If the patient is agitated, it is mostly due to insufficient blood volume and cerebral hypoxia, and rehydration should be accelerated. If the amount of rehydration has reached or exceeded the general level and irritability occurs, the possibility of cerebral edema should be alerted.
③Good peripheral circulation and strong pulse and heartbeat.
④No obvious thirst. If there is irritability and thirst, rehydration should be accelerated.
⑤ Maintain blood pressure and heart rate at a certain level. It is generally required to maintain systolic blood pressure above 90 mmHg, pulse pressure above 20 mmHg, and heart rate below 120 beats per minute. The change of pulse pressure is earlier and more reliable.
(6) No significant hemoconcentration. However, in severe large burns, early hemoconcentration is often difficult to correct completely. If the hemoconcentration is not obvious and the circulation is good, it should not be forcibly corrected to normal in order to avoid overfeeding.
(7) Breathing is stable. If there is increased respiration, identify the causes, such as hypoxia, metabolic acidosis, pulmonary edema, acute pulmonary insufficiency, etc., and adjust the infusion amount in time.
(8) Maintain central venous pressure at normal level. Generally speaking, low blood pressure, low urine output and low central venous pressure indicate insufficient cardiac blood return and should be accelerated; when central venous pressure is high and blood pressure is still low and there is no other explanation, it mostly indicates poor cardiac output capacity. Rehydration should be done with caution and the reasons need to be studied. Since there are many factors affecting the central venous pressure, especially for those with high volume of rehydration, measurement of pulmonary artery pressure (PAP) and pulmonary wedge pressure (PWAP) can be considered to further understand the cardiac function and take corresponding measures.
The systemic condition is the first priority among the infusion indicators. The condition must be closely observed and the treatment must be adjusted promptly and accurately. Intravenous infusion channels must be good, and two can be established if necessary, so that the infusion rate can be adjusted at any time and evenly replenished to prevent interruption.