Impact of dexmedetomidine-assisted anesthesia in elderly patients undergoing radical resection of colon cancer

BACKGROUND Radical resection of colon cancer under general anesthesia is one of the main treatment methods for this malignancy.However,due to the physiological charac-teristics of elderly patients,the safety of perioperative anesthesia needs special attention.As anα2-adrenergic receptor agonist,dexmedetomidine(Dex)has attracted much attention from anesthesiologists due to its stabilizing effect on heart rate and blood pressure,inhibitory effect on inflammation,and sedative and analgesic effects.Its application in general anesthesia may have a positive impact on the quality of anesthesia and postoperative recovery in elderly patients undergoing radical resection of colon cancer.METHODS A total of 165 colon cancer patients who underwent radical surgery for colon cancer under general anesthesia at Qingdao University Affiliated Haici Hospital,Qingdao,China were recruited and divided into two groups:A and B.In group A,Dex was administered 30 min before surgery,while group B received an equivalent amount of normal saline.The hemodynamic changes,pulmonary compliance,airway pressure,inflammatory factors,confusion assessment method scores,Ramsay Sedation-Agitation Scale scores,and cellular immune function indicators were compared between the two groups.RESULTS Group A showed less intraoperative hemodynamic fluctuations,better pulmonary compliance,and lower airway resistance compared with group B.Twelve hours after the surgery,the serum levels of TLR-2,TLR-4,IL-6,and TNF-αin group A were significantly lower than those of group B(P<0.05).After extubation,the Ramsay Sedation-Agitation Scale score of group A patients was significantly higher than that of group B patients,indicating a higher level of sedation.The incidence of delirium was significantly lower in group A than in group B(P<0.05).CONCLUSION The use of Dex as an adjunct to general anesthesia for radical surgery in elderly patients with colon cancer results in better effectiveness of anesthesia.

Clinical effect of ultrasound-guided nerve block and dexmedetomidine anesthesia on lower extremity operative fracture reduction

BACKGROUND Lower extremity fractures are mainly treated by surgical reduction,but this operation is often affected by the patient’s level of agitation and the type of anesthesia used.The main treatment for lower-extremity fractures is operative reduction.However,operations can often be affected by both agitation and the degree of anesthesia.Therefore,it is of great importance to develop an effective anesthesia program to effectively ensure the progress of surgery.AIM To discuss the effect of ultrasound-guided nerve block combined with dexmedetomidine anesthesia in lower extremity fracture surgery.METHODS A total of 120 hospital patients with lower extremity fractures were selected for this retrospective study and divided into an observation group(n=60)and a control group(n=60)according to the anesthesia scheme;the control group received ultrasound-guided nerve block;the observation group was treated with dextromethomidine on the basis of the control group,and the mean arterial pressure,heart rate(HR),and blood oxygen saturation were observed in the two groups.RESULTS The mean arterial pressure of T1,T2 and T3 in the observation group were 94.40±7.10,90.84±7.21 and 91.03±6.84 mmHg,significantly higher than that of the control group(P<0.05).The observation group’s HR at T1 was 76.60±7.52 times/min,significantly lower than that of the control group(P<0.05);The observation group’s HR at T2 and T3 was 75.40±8.03 times/min and 76.64±7.11 times/min,significantly higher than that of the control group(P<0.05).The observation group’s visual analog score at 2 h,6 h and 12 h after operation was 3.55±0.87,2.84±0.65 and 2.05±0.40.the recovery time was 15.51±4.21 min,significantly lower than that of the control group(P<0.05).Six hours post-anesthesia,epinephrine and norepinephrine in the observation group were 81.10±21.19 pg/mL and 510.20±98.27 pg/mL,significantly lower than that of the control group(P<0.05),and the mini-mental state exam score of the observation group was 25.51±1.15,significantly higher than that in the control group(P<0.05).CONCLUSION Ultrasound-guided nerve block combined with dexmedetomidine has a good anesthetic effect in the operation of lower limb fractures and has little effect on the hemodynamics of patients.

Observation on the Anesthesia Effect of Ultrasound-Guided Nerve Block for Elderly Patients with Lower Limb Fractures

Objective:To explore the anesthesia effect of ultrasound-guided nerve block in elderly patients with lower limb fractures.Methods:From November 2017 to November 2020,50 elderly patients with lower limb fractures in our hospital were divided into experimental group(25 cases,general anesthesia+femoral nerve and sciatic nerve block)and control group(25 cases,general body anesthesia).Compare the MAP,HR,anesthesia effect,and adverse reactions between the two groups at each time period.Results:Before induction,the difference in MAP and HR between the two groups of patients did not form,p>0.05;the MAP and HR of the experimental group were compared with the control group at the time of skin incision,1 hour during the operation,and removal of the laryngeal mask,P<0.05;the time of extubation in the experimental group(14.28±3.18)min,awake time(5.57±1.32)min,orientation recovery time(11.89±2.23)min,propofol dosage(191.36±22.48)mg,remifentanil dosage(0.23±0.04)mg,Compared with the control group,P<0.05;the adverse reaction rate of the experimental group(8%,2/25)was lower than that of the control group(32%,8/25),P<0.05.Conclusion:The use of ultrasound-guided femoral nerve and sciatic nerve block for elderly patients with lower limb fractures can enhance the effect of anesthesia,effectively reduce the use of anesthetics,and have fewer adverse reactions.It is worthy of promotion.

Effect of continuous spinal anesthesia with ropivacaine on the ultrastructure of spinal cord and nerve roots in rats

To investigate the effects of continuous spinal anesthesia with different concentrations and doses of ropivacaine on the ultrastructure of the spinal cord and nerve roots.Methods Twenty-four male SD rats weighing 220～280 g were anesthetized with intraperitoneal 10% chloral hydrate 300～350 mg/kg.A polyurethane microcatheter was inserted into the lumbar subarachnoid space according to the technique described by Yaksh.An 8 cm catheter segment was left in the subarachnoid space.The animals were randomized to receive normal saline,0.5%,0.75% or 1.0% ropivacaine 40 μl intrathecally 3 times at 1.5 h interval.Six hours after the first intrathecal administration the animals were decaptiated and L 1,2 segment of the spinal cord and nerve roots were immediately removed for electron microscopic examination.Results Electron microscopic examination revealed that in animals which received intrathecal (i.t.) normal saline,0.5% or 0.75% ropivacaine the neurolemma of the nerve roots and the mitochondria and endoplasmic reticulum of the neurons in the spinal cord were intact,while in animals which received i.t. 10.% ropivacaine the neurolemma was stratified and partly disrupted and there were swelling of endoplasmic reticulum and vacuole degeneration.Conclusion Six hours continuous spinal anesthesia with 10.% ropivacaine may be injurious to the spinal cord and nerve roots.12 refs,8 figs,1 tab.

Effects of urethane on the response properties of visual cortical neurons in young adult and old cats

Previous studies have shown that visual cortical neurons in old mammals exhibit higher spontaneous activity,higher responsiveness to visual stimuli,and lower selectivity for stimulus orientations and motion directions than did neurons in young adult counterparts.However,whether the responsive difference in cortical neurons between young and old animals resulted from different effects induced by anesthetics has remained unclear.To clarify this issue,we recorded the response properties of individual neurons in the primary visual cortex of old and young adult cats while systematically varying the anesthesia level of urethane,a widely used anesthetic in physiology experiments.Our results showed that cumulatively administrating 50 mg and 100 mg of urethane upon the minimal level of urethane required to anesthetize an old or young adult cat did not significantly alter the degree of neuronal response selectivity for stimulus orientations and motion directions nor significantly change the visually-driven response and spontaneous activity of neurons in old and young adult cats.Cumulatively administrating 150 mg of urethane decreased neuronal responsiveness similarly in both age groups.Therefore,urethane appears to exert similar effects on neuronal response properties of old and young adult animals.