Patients with acute drug poisoning and low blood pressure should be pumped with norepinephrine micropump. What should be noticed? Look at the following:~

　　Case sharing

        The patient Li * *, female, 51 years old, was admitted to the hospital with "acute amlodipine poisoning and toxic shock" at 00:16 on November 12, 2020. More than 4 hours before admission, the patient took about 112 tablets of amlodipine orally due to poor mood. After taking the medicine, nausea and vomiting occurred. The vomitus was coffee colored stomach content, with unknown amount, accompanied by unstable walking, unconsciousness, no limb convulsion, and no special treatment outside the hospital. After that, he called our hospital 120 for treatment.

        Previous history: the history of hypertension is more than 20 years, the highest blood pressure is 150 / 90mmHg, and the patient is usually treated with oral medicine. The details are unknown, and the blood pressure is not monitored regularly; Diabetes has been treated with oral medicine for more than 10 years. The details are unknown.

        Admission assessment: clear mind, poor spirit, t: 36.0 ℃, P: 74 times / min, R: 27 times / min, BP: 60 / 40mmhg, no diet, no defecation. Immediately establish venous access, apply calcium gluconate and other drugs for treatment, oxygen inhalation and ECG monitoring.

        Auxiliary examination: the blood gas analysis showed that pH 7.34, PCO Ψ 38mmhg, Po Ψ 54mmhg, potassium ion concentration 4.0mmol/l, chloride ion concentration 95mmol / L, calcium ion concentration 1.39mmol/l, blood glucose 34mmol / L, lactic acid 1.5mmol/l, and anion gap 24mmol / L.

        After admission, the patients were given symptomatic support treatment such as oxygen inhalation, electrocardiographic monitoring, electric gastric lavage, fluid replenishment and volume expansion, application of vasoactive drugs to correct blood pressure, protect gastric mucosa, and monitor blood pressure and blood glucose; In order to apply vasoactive drugs to the patients, the patients were given right subclavian vein catheterization with the consent of their families.

　　Case analysis

        Acute amlodipine poisoning may cause toxic shock and hypotension. According to the doctor's instructions, the patient shall be given rapid fluid replacement and volume expansion, and vasoactive drugs (norepinephrine micropump) shall be used to correct hypotension.

        Vasoactive drugs play an important role in the treatment of critically ill patients. Since the half-life of norepinephrine is 1-2 min, it is rapidly taken up or further metabolized by the liver after entering the human body, so it is advocated to use micro continuous pumping.

        Intravenous injection with micro injection pump can make it flow through blood vessels and achieve satisfactory results in maintaining hemodynamic stability. During clinical application, it is required to be accurate, safe and effective. So, what should be paid attention to in the process of norepinephrine micropump pumping?

　　Experience sharing

　　1. Accurately configure drugs and calculate drug infusion speed

        Noradrenalin (2 mg / ml): the required mg is: the patient's kg body weight x 0.3, and NS is added to prepare 50 ml mixed solution. For example, the patient's weight in this case is 80kg, and the required mg of noradrenaline is 80 x 0.3 = 24 mg. Therefore, 12 ml of noradrenaline (24mg) + ns 38 ml can be used to configure it, which is 1ml = 0.1 μ G/kg · min, the maximum dose was 2 μ G / kg · min, i.e. pump 20ml of mixed solution every hour.

　　2. Correctly select the infusion path

        High concentration of norepinephrine can cause strong contraction of local blood vessels and lead to tissue ischemia and necrosis when administered intravenously. Therefore, when applying norepinephrine, try to select the deep vein pipeline to ensure the drug infusion volume, enable it to exert its effect as soon as possible, and prevent the drug from damaging local skin tissue. In this case, the right subclavian vein catheter was used to inject drugs intravenously, and the pipeline nursing was done according to the routine, without skin extravasation.

　　3. Ensure stable drug infusion speed

        In order to prevent the sudden rise and fall of blood pressure, any factors that accelerate or interrupt the infusion of drugs should be avoided.

　　4. It is forbidden to mix with alkaline drugs

　　Norepinephrine is easily oxidized to pink or brown in alkaline solution and becomes ineffective, so it should not be mixed with alkaline drugs in the same channel.

　　5. When changing the medicine, the double pump method shall be adopted

　　That is, before the intravenous injection of norepinephrine diluent in channel 1 of the micropump is completed, prepare norepinephrine solution of the same dose and concentration in advance, and install it in another micropump channel (referred to as channel 2). After the syringe is connected to the extension pipe for exhaust, it is connected to the standby end of the tee joint of channel 1. When the micropump 1 is about to be pumped (the micropump is about to complete the alarm), measure the blood pressure once, To facilitate the observation of blood pressure fluctuation, open the channel 2 of the micropump, set the same speed as that of the channel 1 of the micropump, press the "start" button, and monitor the blood pressure once every 2-3 minutes. If the monitored blood pressure value is higher than the previous blood pressure of 20 mmHg, reduce the speed of the channel 1 of the micropump to half the value, and monitor the blood pressure once every 2-3 minutes. If the monitored blood pressure value is still higher than the previous blood pressure of 20 mmHg, immediately close the channel 1 of the micropump, and the channel 2 of the micropump continues to operate normally.

　　6. Patient care

　　(1) Disease observation 

　　Closely observing the changes of vital signs of patients and continuously and dynamically monitoring the changes of heart rate and blood pressure are the guarantee for the safety of norepinephrine. The doctor and the nurse shall discuss and set the target value of blood pressure monitoring according to the patient's basic blood pressure and condition. The nurse shall adjust the amount of norepinephrine according to the target value in time to avoid sudden rise or fall of blood pressure. When adjusting the dose, 0.01 ～ 0.05 μ G / kg · min. Noninvasive blood pressure was measured every 2-3 min during the adjustment of drug dosage; During the relative stable period, the blood pressure changes shall be measured every 10-15min. Before and after turning over or helping the patient change the position, the patency of the venous pipeline shall be checked and the blood pressure shall be measured in time to understand the blood pressure changes.

　　Relevant studies have confirmed that norepinephrine can improve renal perfusion and increase glomerular filtration rate. During medication, closely observe the change of urine volume, urine color and characteristics per hour, and maintain the urine volume not less than 0.5 ml / kg · H.

　　(2) Strictly implement the shift handover system

　　Each shift shall carry out strict handover, check whether the pipeline is unblocked and whether the pipeline is marked. If there is blood return in the deep venous catheter, it shall be handled correctly in time. Remember not to push the blood return into the body by pressing the "fast" button on the micropump to avoid adverse consequences. Replace the extension tube and tee tube every day to reduce the blood flow related infection of deep venous catheter.

　　(3) Skin care

　　Norepinephrine can stimulate blood vessels α Receptors, except coronary artery, almost all arterioles and venules have strong contraction, and the skin and mucous membrane have the most obvious vasoconstriction. Therefore, the skin temperature and color of the extremities should be closely observed, and warmth can be kept if necessary. Each shift shall strictly implement the turning over system and focus on the skin condition of the pressure parts. For those with unstable conditions and need to strictly restrict turning over, water glue dressing can be applied to the pressure parts to protect the skin.

　　Summary

        Norepinephrine is widely used to maintain the hemodynamic stability of critically ill patients. As the executor and observer of drugs, nurses should accurately grasp the medication nursing and precautions, so as to better ensure the medication safety of patients and achieve the purpose of treatment.