Dexmedetomidine has been used in clinical applications for many years, and we must have accumulated a lot of experience and encountered many problems, and even some adverse events. The use of dexmedetomidine in neurosurgery and neurocritical care medicine does have many advantages and benefits. However, some problems do occur with the use of this drug. We only started using it last year, and as the drug has been used more and more, some problems have been observed that were rarely seen before. For example, severe bradycardia, occasional cardiac arrest, severe hypotension, etc. Common problems we encounter when using dexmedetomidine: 1. hypotension, some patients with preoperative hypertension may experience hypotension after pumping dexmedetomidine alone, and only after the use of norepinephrine there is barely some recovery.
2. Severe bradycardia, even cardiac arrest. After simple compressions immediately recovered.
The clearance rate of dexmedetomidine is significantly reduced in patients with severe hepatic and renal impairment, so the dose should be reduced. The pharmacokinetic parameters of dexmedetomidine in patients with severe renal impairment are not significantly different from those in healthy subjects, but close attention should be paid to the patient’s reaction during long-term infusion.
2.Patients with withdrawal syndrome caused by opioid or alcohol addiction Dexmedetomidine can be used to prevent and treat withdrawal syndrome caused by long-term opioid or alcohol addiction. For the treatment of withdrawal syndrome, dexmedetomidine can be administered intravenously at a rate of 0.2 to 0.7 μg/kg/h after 1 μg/kg (10-15 min), and the dose can be continued for 3 days depending on the patient’s condition. Prevention of withdrawal syndrome should be preceded by an intravenous infusion of dexmedetomidine 1 μg/kg (10-15 min) as a loading dose before discontinuing the opioid, and the maintenance phase should be used as before.
Dexmedetomidine can significantly shorten the duration of postoperative delirium and reduce clinical symptoms in elderly patients. The usage of dexmedetomidine is as follows: after a loading dose of 0.5~1 μg/kg by intravenous pumping, continue intravenous infusion at a rate of 0.2~0.7 μg/kg/h, with the maximum dose not exceeding 1.5 μg/kg/h until the condition is relieved. Special attention was paid to keeping the patient’s airway open and maintaining hemodynamic stability during the high-dose administration. Intraoperative continuous intravenous infusion of dexmedetomidine can prevent postoperative agitation in patients with Alzheimer’s disease.
Regardless of whether a loading dose is given or not, 2ml of this product must be diluted to 50ml with 0.9% sodium chloride solution or 5% glucose solution, i.e. 4μg/ml, before administration. 2. Dexmedetomidine should be given by microinfusion pump, and the infusion dose should be adjusted individually according to the clinical efficacy.
3. This product should not be given simultaneously with blood or plasma through the same line.
Precautions 1. After dexmedetomidine is administered, the general onset of action is 10-15 min, and the peak time is 25-30 min, so the infusion dose should not be increased frequently within 30 min to avoid excessive sedation.
2. The most common adverse reactions are hypotension, bradycardia and dry mouth. Patients with high vagal tone, diabetes, hypertension, advanced age, hepatic or renal impairment are more likely to experience bradycardia or even sinus arrest. In case of hypotension or bradycardia, reduce or stop giving dexmedetomidine, speed up the infusion, elevate the lower limbs, and inject atropine or ephedrine by sedation.
3. Excessive administration of loading dose may cause transient hypertension and bradycardia, which can be relieved by slowing down the rate of administration without special treatment. 4. Prepare relevant equipment for maintaining upper airway patency when dexmedetomidine is given for sedation.