Objective:To investigate the effect of dexmedetomidine (DEX) on reducing urethral stimulation in patients undergoing laparoscopic gastrointestinal surgery.Methods:From January 2019 to February 2020, 90 patients undergoing elective laparoscopic gastrointestinal surgery under general anesthesia in the Third Affiliated Hospital of Sun Yat-sen University were selected. They were randomly divided into 3 groups: catheterization before induction (group A), catheterization during induction (group B), and catheterization after induction (group C). In group A, patients received general anesthesia after awake catheterization. In group B, intravenous injection of DEX 0.5 μg/kg was pumped for 10 minutes, followed by catheterization and induction. In group C, patients received general anesthesia and then catheterization. Visual analogue scale (VAS) score of urethral stimulation, morphine dosage and the incidence of agitation during resuscitation were recorded. The heart rate and mean arterial pressure of the three groups were compared at the time of entering the room, catheterization, tracheal intubation, entering postanesthesia care unit (PACU), about extubation and 30 minutes after extubation.Results:The fluctuation of blood pressure and heart rate in group B was significantly less than that in group A and group C at the time of extubation and 30 minutes after extubation ( P<0.05). VAS of urethral stimulation in group B [(2.9±0.9)point] was significantly lower than that in group A [(4.4±1.8)point] when catheter was indwelling ( P<0.05). After extubation, VAS in group B [(2.8±1.1)point] was significantly lower than that in group A [(3.2±1.2)point] and C [(5.2±1.8)point] ( P<0.05). The utilization rate of morphine within 24 hours after surgery in group B (10%) was significantly lower than that in the other two groups (40%, 57%), and the incidence of postoperative agitation in group A and B was lower than that in group C within PACU ( P<0.05). The satisfaction of patients in group B (86.7%) was higher than that in group A (70%) and C (46.7%). The satisfaction of PACU personnel in group A (76.7%) and B (80%) was significantly higher than that in group C (43.3%). Conclusions:Sedation with dexmedetomidine during urethral catheterization can reduce urethral stimulation during resuscitation and improve patients' and PACU staffs' satisfaction.

Objective To demonstrate that MRI is more advantageous than ultrasound in the detection of ischemic cerebral lesions precisely in twin-twin transfusion syndrome(TTTS)fetus following fetoscopic selective laser coagulation(SLCPV).Methods The fetus with TTTS treated by SLCPV were collected.All fetuses underwent brain MRI within 1-5 days after the procedure and a follow-up MRI at 29-32 weeks'gestation.All fetuses also had frequent ultrasound evaluation until delivery.Results Twenty-five pregnancies with TTTS were included in the study.Six pregnancies resulted in survival of only one twin after the procedure(Group A),while the other 19 pregnancies resulted in the survival of both twins(Group B),as assessed at the time of initial MRI.Two fetus in Group A and three in Group B had evidence of bleeding in lateral ventricle.Two fetus in Group B had actue brain ischemia.One fetus in Group B had appeared brain atrophy and choosed to terminate pregnancy.Conclusion MRI can make a clearer diagnosis of cerebral damage of TTTS fetus in a short period after SLCPV.