The Study Of Dexmedetomidine Used By Patients With Mechanical Ventilation In The ICU

ObjectiveTo evaluate the safety and efficacy of dexmedetomidine for sedation and analgesia of patients with mechanical ventilation., and to compare the prevalence of delirium , the time to weaning,the time to extubation ,the duration of mechanical ventilation and the length of staying in the ICU of the patients with mechanical ventilation using dexmedetomidine and midazolam respectively.Method40 postoperative patients with general anesthesia into ICU to get ventilation for respiratory support for less than 24 hours maybe were collected for the study. All the patients were parted into two groups(dexmedetomidine group with 20 patients, midazolam groups with 20patients).Two groups were used loading dose to get effective blood concentration quickly and then maintained sedation by maintenance dose(dexmedetomidine group ,1μg/kg for 30 minutes and following0.2～0.7μg/kg/h by micro-pump;midazolam group , 0.03mg/kg iv slowly and following 0.03～0.13mg/kg/h by micro-pump)Observe the patients'state , evaluate the sedation depth by SAS (sedation-agitation scale )every 2 hours and evaluate the analgesia level by NRS every 3 hours. Adjust the pumping speed according to the sedation state, inject midazolam or morphine (5mg per time)while the patients showing irritability ,against the ventilator or painful expression in order to get the proper sedation level(SAS 3～4degrees,NRS 0～3 degrees).Observe and record the sedation depth, the times and dosage of using morphine and midazolam, the change of patients'heart rate and blood pressure ,the occurrence of Cardiovascular adverse events, the occurrence of delirium during the therapy. Stop using dexmedetomidine or midazolam before weaning the ventilator according to the patients'state, record the time of weaning and extubation, and record the duration of ventilation and staying in the ICU of each group. ResultAll the patients can get target sedation level(SAS 3～4degrees)(P>0.05),the times and dosage of using midazolam have no significant difference (P>0.05),the effect of analgesia in dexmedetomidine group is better than the other (P<0.05),the times of using morphine in dexmedetomidine group is less(P<0.05). the occurrence of Cardiovascular adverse events in dexmedetomidine group(15%) has no significant difference with that in midazolam group (10%) (P>0.05), the occurrence of delirium in dexmedetomidine group(10%)is significantly lower than that in midazolam group (40%) (P<0.05).the time of weaning and extubation in dexmedetomidine group is significantly shorter than that in midazolam group (P<0.05),while the duration of Mechanical ventilation and staying in the ICU in two groups has no significant difference .Conclusion1. It is safe and effective to use dexmedetomidine for sedation and analgesia in patients with mechanical ventilation.2.Compare to midazolam, dexmedetomidine can shorten the time of weaning and extubation and lessen the occurrence of delirium.3. Dexmedetomidine can lessen the occurrence of Cardiovascular adverse events just as hypotention and bradycardia by prolong the time of loading dose to prevent severe complications.