Recently, a doctor in the department changed sodium nitroprusside, which is being used to reduce blood pressure, to urapidil. As the antihypertensive effect of urapidil is not as significant as that of sodium nitroprusside, it cannot well inhibit the rise of blood pressure when using the same dose. Nurses have to rely on experience to constantly explore the regulation, and need to closely observe the changes in blood pressure.

As a result, some nurses complained that they could not use sodium nitroprusside all the time? Why use urapidil?

So, why did the doctor replace sodium nitroprusside with urapidil? With this problem, the author carefully read the instructions of sodium nitroprusside, checked its relevant information, and had a deep understanding of the drug.

1. Adverse reaction of sodium nitroprusside:

Short term use of appropriate amount will not cause adverse reactions. The toxic reaction of this product comes from its metabolite * * * and thiocyanate. * * * is an intermediate metabolite, and thiocyanate is the final metabolite. If * * * cannot be converted to thiocyanate normally, poisoning can occur even though the blood concentration of thiocyanate is normal.

In other words, short-term use will generally not lead to drug accumulation and poisoning. However, with the extension of use time, attention should be paid to its accumulation.

The liver and kidney functions of the patients should be monitored regularly during normal treatment. If possible, the concentration of thiocyanate in blood can be monitored. After being used for more than 48~72 hours, especially for those with renal insufficiency, the plasma levels of * * * or thiocyanate must be determined every day, and the thiocyanate should not exceed 100 μ G/mL, * * * not more than 3 μ Mol/mL, if it exceeds the limit, the drug should be stopped.

2. In the process of treatment, what kind of situation should we be alert to drug poisoning?

Thiocyanate poisoning or overdose may cause dyskinesia, blurred vision, delirium, dizziness, headache, loss of consciousness, nausea, vomiting, tinnitus and shortness of breath.

***In case of poisoning or overdose, there may be disappearance of reflex, coma, distant heart sounds, hypotension, disappearance of pulse, pink skin, shallow breathing and dilated pupils.

3. What patients are prone to poisoning?

Patients with renal function impairment are more likely to suffer from thiocyanate poisoning.

Sodium nitroprusside is quickly metabolized in the blood, and the maximum effect is achieved in 1-2 minutes. The effect disappears in 2-15 minutes after drug withdrawal, with a half-life of 2-30 minutes. Thiocyanate is the final metabolite of sodium nitroprusside. When renal function is normal, the elimination half-life of thiocyanate is 3-7 days.

Clinical studies abroad have shown that there is a linear relationship between the plasma thiocyanate concentration and the total intravenous infusion of sodium nitroprusside and the level of renal function. Generally, people with normal liver and kidney functions will not cause * * * and thiocyanate accumulation if they are not used for a long time, so they will not be poisoned. However, if a large amount of sodium nitroprusside enters the body in a short time, a large amount of free cyanide will rapidly accumulate in the body. Thiocyanate synthetase in the liver is relatively reduced and it will definitely decrease when liver function is damaged. * * poisoning is caused by the obstacle in the process of converting * * into thiocyanate.

4. Use with caution and disable:

Disable:

(1) There is no human body study on the carcinogenesis, teratogenicity, and effects on pregnant women and nursing mothers. Research on the application in children has not been carried out.

(2) When using this product for the elderly, attention should be paid to the influence of the decline of renal function on the excretion of this product. The elderly are also sensitive to the hypotensive reaction, so the dosage should be reduced accordingly.

Use with caution in the following cases:

(1) The tolerance to hypotension is reduced when the blood supply of cerebrovascular or coronary artery is insufficient.

(2) If anemia or hypovolemia occurs during the control of hypotension during anesthesia, it should be corrected before administration.

(3) In case of encephalopathy or other intracranial hypertension, the expansion of cerebral vessels can further increase the intracranial pressure.

(4) When the liver function is damaged, this product may aggravate the liver damage.

(5) When the thyroid function is too low, thiocyanate, the metabolite of this product, can inhibit the uptake and binding of iodine, which may aggravate the disease.

(6) In case of pulmonary insufficiency, this product may aggravate hypoxemia.

(7) Use this product when vitamin B12 is deficient, which may aggravate the disease.

5. Usage:

(1) Intravenous drip: Dissolve 50mg of this product in 5ml of 5% glucose injection before use, then dilute it in 250ml~1000ml of 5% glucose injection, and drip it intravenously in a dark infusion bottle.

Common dosage for adults: intravenous drip, starting with 0.5g/kg body weight per minute. According to the treatment response, the dose is gradually adjusted by increasing 0.5g/kg per minute. The commonly used dose is 3g/kg per minute and the maximum dose is 10g/kg per minute.

Common dosage for children: intravenous drip, 1.4? Per minute according to weight? G/kg, gradually adjust the dosage according to the effect.

(2) Micro pumping: Dissolve 50mg of this product in 50ml of 5% glucose injection before use, start pumping at the rate of 2mg/h, and adjust the pumping amount according to the blood pressure.

6. Precautions:

(1) This product is sensitive to light, and the stability of the solution is poor. The solution should be freshly prepared and protected from light. The author has seen with his own eyes that the liquid in the whole 50ml syringe turns dark green because the light proof paper of sodium nitroprusside in use falls off. The newly prepared solution is light brown. If there is any abnormality, it should be discarded immediately. The storage and application of solution shall not exceed 24 hours. Other drugs should not be added into the solution.

(2) Interference to diagnosis: partial pressure of blood carbon dioxide, pH value and bicarbonate concentration may decrease when using this product; The concentration of plasma * * * and thiocyanate may increase due to the production of this product after metabolism. The concentration of lactate in arterial blood may increase when this product is overdosed, indicating metabolic acidosis.

(3) The liquid medicine is local irritant, so beware of extravasation.

(4) When young male patients use this product for controlled hypotension during anesthesia, they need to use a large amount, even close to the maximum amount.

(5) If the intravenous drip has reached 10? Per minute? G/kg. If the blood pressure is still unsatisfactory after 10 minutes, it should be considered to stop using this product and use or add other antihypertensive drugs.

(6) In case of left heart failure, the application of this product can restore the pumping function of the heart, but in case of hypotension, myocardial positive inotropic drugs such as dopamine or dobutamine must be added at the same time.

(7) In the process of using this product, obvious drug resistance may occasionally occur, which should be regarded as a precursor of poisoning. At this time, the drop rate will be reduced and disappear.

7. Do a good job of nursing and health education on the use of sodium nitroprusside.

Since sodium nitroprusside takes effect after entering the human body for 1~2 min, and disappears after stopping the infusion for 1~10 min, patients often need to maintain the medication for a long time. Therefore, during the use process, patients and their families should be actively introduced about the purpose and precautions of sodium nitroprusside, and told not to adjust the infusion rate by themselves. For those who use the micro pump to pump in, they do not need to change the adjustment key on the micro pump by themselves, so as to prevent self adjustment of the infusion rate or excessive changes in body position, And affect the efficacy or the occurrence of adverse reactions. During use, closely observe the change of blood pressure and timely record it. Patients with hypertensive intracerebral hemorrhage should lower their blood pressure slowly. They should not lower their blood pressure to normal or below normal in a short time to avoid insufficient cerebral perfusion. When the blood pressure is obstinately not falling, be alert to the phenomenon of increased intracranial pressure, find out the reason in time, and replace the antihypertensive drug if necessary.

Adverse reactions:

Occasionally, headache, dizziness, nausea, fatigue, palpitation, arrhythmia, itching, insomnia, etc. Postural hypotension was less than prazosin, and there was no first dose reaction.

matters needing attention:

1. Before this product is used in combination with other antihypertensive drugs, a certain interval of time should be allowed, and the dosage of this product should be adjusted if necessary.

2. Sudden drop in blood pressure may cause bradycardia or even cardiac arrest, and the treatment period generally does not exceed 7 days.

3. Those who drive or operate machinery shall use it with caution, as it may affect their ability to drive or operate.

4. Excess can cause hypotension, lower limbs can be raised and blood volume can be increased. If necessary, antihypertensive drugs can be added.

5. It should be noted that the elderly and those with impaired liver function can enhance the effect of this product.

From the adverse reactions and side effects of the two drugs, urapidil is significantly safer than sodium nitroprusside, which is why doctors should replace it in time.