BACKGROUND Several techniques of nasogastric tube(NGT)insertion have been described in the literature with different success rates.AIM To systematically search the literature and conduct a meta-analysis comparing the ...BACKGROUND Several techniques of nasogastric tube(NGT)insertion have been described in the literature with different success rates.AIM To systematically search the literature and conduct a meta-analysis comparing the success rates,insertion time and complications associated with different techniques of NGT insertion in anesthetized and intubated patients.METHODS An electronic search of the PubMed,Scopus,CENTRAL(Cochrane Central Register of Controlled Trials),and Google Scholar databases were performed up to October 31,2019.We included 17 randomized controlled trials with 2500 participants in the meta-analysis.RESULTS As compared to the conventional method,successful insertion of the NGT on first attempt was higher with modified techniques such as the reverse Sellick’s maneuver[relative risk(RR)1.94;95%confidence interval(CI):1.62-2.31],use of a frozen NGT(RR 1.55;95%CI:1.13-2.13),inserting the NGT with neck flexion and lateral neck pressure(RR 1.64;95%CI:1.10-2.45),endotracheal tube-assisted(RR 1.88;95%CI:1.52-2.32)and video-assisted placements(RR 1.60;95%CI:1.31-1.95).All the modified techniques also led to comparatively higher insertion success rates than the conventional technique.CONCLUSION The use of modified techniques of NGT insertion such as the reverse Sellick’s maneuver,neck flexion with lateral neck pressure,frozen NGT,endotracheal tube-guided or video-assisted methods result in a significantly better chance of successful tube insertion at first attempt as compared to the conventional technique.All modified techniques also significantly improve the overall chance of successful NGT placement as compared to the conventional method.展开更多
BACKGROUND: Generally speaking, anesthesia is often used in gravid body and it has been already proved that many kind of medicine can result in malformation. OBJECTIVE: To explore embryonic skeleton development and ne...BACKGROUND: Generally speaking, anesthesia is often used in gravid body and it has been already proved that many kind of medicine can result in malformation. OBJECTIVE: To explore embryonic skeleton development and neonatal learning and memory of rats anesthetized with pentobarbital sodium in gravid rats. DESIGN: A randomized control trial. SETTING: Laboratory Animal Center of Xuzhou Medical College. MATERIALS: A total of 80 adult female SD rats, of clean grade and weighing 220-240 g, were selected in this study. The main reagents were detailed as follows: pentobarbital sodium (Shanghai Xingzhi Chemical Plant, batch number: 921019); MG-2 maze test apparatus (Zhangjiagang Biomedical Instrument Factory); somatotype microscope (Beijing Taike Instrument Co., Ltd.). METHODS: ① A total of 160 SD rats of half males and females were selected in this study. All rats were copulated. The day that the plug was checked out in the vagina next day was looked as the first day of pregnancy. Gravid rats were divided randomly into four groups, including early anesthesia group, second anesthesia group, late anesthesia group and control group with 20 in each group. Rats in the early anesthesia group were injected with 25 mg/kg soluble pentobarbitone on the 7th day of pregnancy for once; rats in the second anesthesia group were anesthetized with 25 mg/kg soluble pentobarbitone on the 7th and the 14th days of pregnancy for once; rats in the late anesthesia group were anesthetized with 25 mg/kg soluble pentobarbitone on the 14th day of pregnancy for once; rats in the control group did not treat with anything. The time of anesthetizing was controlled in 3 to 4 hours and ether was absorbed while the time was not enough. ② Half of each group was sacrificed on day 20th of pregnancy and the fetus was taken out to be stained with alizarin red S. After stained, the fetal skeleton was examined. The learning and memorizing of one-month rats that were given birth by the rest gravid rats were tested through electric mare method. Determine their study ability according to their correct rate of 90% or above of arrival at the safe area in 20 s. After they finally learned to arrive at the safe area correctly, test them once more in 24 hours and record the correct rate of 15 times. MAIN OUTCOME MEASURES: The rate of malformation in fetus and ability of learning and memory in one-month rats. RESULTS: A total of 80 female rats were anesthetized in this experiment. Totally 490 immature rats were tested with maze testing machine and 196 fetuses were stained with alizarin red S to observe the development of their skeleton. However, one of the 80 female rats was led to death because of overdose. ① Malformation experiment: Learning ability of second anesthesia group was evidently different from the control group while the other two groups were not in the electric mare method. The fetal skeleton malformation rate of three experimental groups was 87.0%, 60.9% and 17.9%, respectively, while it was 5.6% in the control group. ② Electric mare method: Times of rats which arrived at the safe regions were respectively 49.0±31.0, 68.0±35.0, 47.0±31.0 and 44.0±21.0 in early anesthesia group, second anesthesia group, late anesthesia group and control group; and then, there was significant difference between the second anesthesia group and the control group (P < 0.05). Exact rates of memory of rats were respectively (64.36±14.35)%, (62.15±18.33)%, (54.19±12.28)% and (68.24±15.91)% in early anesthesia group, second anesthesia group, late anesthesia group and control group; and then, there were no significant differences as compared with the control group (P > 0.05). CONCLUSION: The influence of anesthesia with pentobarbital sodium is obvious in fetal skeleton development and learning and memory ability.展开更多
P2X_(1) receptors and adrenoceptors are mainly responsible for vasoconstriction in a variety of blood vessels.However,previous studies have shown that α,β-methylene adenosine 5'-triphosphate(α,β-MeATP),a stabl...P2X_(1) receptors and adrenoceptors are mainly responsible for vasoconstriction in a variety of blood vessels.However,previous studies have shown that α,β-methylene adenosine 5'-triphosphate(α,β-MeATP),a stable analogue of ATP,can induce both pressor and depressor responses in la boratory animals.In this study,the effects of increasing intravenous doses of α,β-MeATP and noradrenaline(NA)(0-30 nmol/kg)administered at 20 min intervals on systolic(SBP),diastolic(DBP)and mean(MBP)blood pressure in groups of anesthetized mice(n=6)were compared.Both α,β-MeATP and NA caused transient,dose-dependent increases in SBP,DBP and MBP but the effect of α,β-MeATP was more rapid and significantly larger at doses of 10 and 30 nmol/kg(P<0.01).At the dose of 30 nmol/kg,α,β-MeATP increased SBP,DBP and MBP by 65.8±7.0,65.7±5.0 and 65.7±5.5 mmHg,respectively,compared to increases of 36.8±4.6,33.3±4.9 and 34.5±4.7 mmHg,respectively,produced by NA.These results indicate P2X_(1) receptors play an important role in BP regulation although purinergic vasoconstriction alone may not explain the more potent pressor response to α,β-MeATP in the anesthetized mouse.展开更多
Debates regarding the specific effects of general anesthesia on developing brains have persisted for over 30 years.A consensus has been reached that prolonged,repeated,high-dose exposure to anesthetics is associated w...Debates regarding the specific effects of general anesthesia on developing brains have persisted for over 30 years.A consensus has been reached that prolonged,repeated,high-dose exposure to anesthetics is associated with a higher incidence of deficits in behavior and executive function,while single exposure has a relatively minor effect on long-term neurological function.In this review,we summarize the dose-dependent neuroprotective or neurotoxic effects of gamma-aminobutyric acid type A receptor agonists,a representative group of sedatives,on developing brains or central nervous system diseases.Most preclinical research indicates that anesthetics have neurotoxic effects on the developing brain through various signal pathways.However,recent studies on low-dose anesthetics suggest that they may promote neurodevelopment during this critical period.These findings are incomprehensible for the general“dose-effect”principles of pharmacological research,which has attracted researchers'interest and led to the following questions:What is the threshold for the dual effects exerted by anesthetics such as propofol and sevoflurane on the developing brain?To what extent can their protective effects be maximized?What are the underlying mechanisms involved in these effects?Consequently,this issue has essentially become a“mathematical problem.”After summarizing the dose-dependent effects of gamma-aminobutyric acid type A receptor agonist sedatives in both the developing brain and the brains of patients with central nervous system diseases,we believe that all such anesthetics exhibit specific threshold effects unique to each drug.These effects range from neuroprotection to neurotoxicity,depending on different brain functional states.However,the exact values of the specific thresholds for different drugs in various brain states,as well as the underlying mechanisms explaining why these thresholds exist,remain unclear.Further in-depth exploration of these issues could significantly enhance the therapeutic translational value of these anesthetics.展开更多
Researchers have discovered that mice instinctively exhibit rescue-like behavior towards anesthetized companions-a finding that suggests a biological basis for prosociality.The study,published in PNAS on April 23,2025...Researchers have discovered that mice instinctively exhibit rescue-like behavior towards anesthetized companions-a finding that suggests a biological basis for prosociality.The study,published in PNAS on April 23,2025,was led by Dr.HU Li from the Institute of Psychology of the Chinese Academy of Sciences(IPCAS)and Dr.CHEN Zhoufeng from Washington University School of Medicine and the Shenzhen Medical Academy of Research and Translation.展开更多
The primary intravenous anesthetics employed in clinical practice encompass dexmedetomidine(Dex),propofol,ketamine,etomidate,midazolam,and remimazolam.Apart from their established sedative,analgesic,and anxiolytic pro...The primary intravenous anesthetics employed in clinical practice encompass dexmedetomidine(Dex),propofol,ketamine,etomidate,midazolam,and remimazolam.Apart from their established sedative,analgesic,and anxiolytic properties,an increasing body of research has uncovered neuroprotective efects of intravenous anesthetics in various animal and cellular models,as well as in clinical studies.However,there also exists conficting evidence pointing to the potential neurotoxic efects of these intravenous anesthetics.The role of intravenous anesthetics for neuro on both sides of protection or toxicity has been rarely summarized.Considering the mentioned above,this work aims to ofer a comprehensive understanding of the underlying mechanisms involved both in the central nerve system(CNS)and the peripheral nerve system(PNS)and provide valuable insights into the potential safety and risk associated with the clinical use of intravenous anesthetics.展开更多
Cancer,potentially the second leading cause of mortality globally,poses a significant health challenge.The conventional treatment for solid tumors typically involves surgical intervention,followed by chemotherapy,radi...Cancer,potentially the second leading cause of mortality globally,poses a significant health challenge.The conventional treatment for solid tumors typically involves surgical intervention,followed by chemotherapy,radiotherapy,and targeted therapies.However,cancer recurrence and metastasis remain major issues.Anesthesia is essential for ensuring patient comfort and safety during surgery.Despite its crucial role in surgery,the precise effect of anesthesia on cancer patients'outcomes has not been clearly understood.This comprehensive review aims to elucidate perioperative anesthesia strategies for cancer patients and their potential effects on prognosis.Given the complexity of cancer treatments,understanding the relationship between anesthesia and cancer outcomes is crucial.By examining potential implications of anesthesia strategies for cancer prognosis,this review may help better understand treatment efficacy and risk factors for cancer recurrence and metastasis.Ultimately,a detailed analysis of anesthesia practices in cancer surgery may provide insights to refine existing anesthesia protocols and reduce risk factors for poor patient outcomes.展开更多
Anesthetic pharmacology,a specialized branch of pharmacology,differs significantly from the foundational pharmacology taught in undergraduate medical programs.A key challenge lies in effectively distinguishing and int...Anesthetic pharmacology,a specialized branch of pharmacology,differs significantly from the foundational pharmacology taught in undergraduate medical programs.A key challenge lies in effectively distinguishing and integrating these two courses to enhance students’theoretical understanding and foster their clinical anesthesia skills.This paper explores strategies for optimizing lesson preparation and delivery in anesthetic pharmacology,focusing on course positioning,student knowledge assessment,clinical integration,objective setting,content development,instructional design,innovative teaching tools,and classroom management.The ultimate aim is to enhance teaching effectiveness and train anesthesiology professionals with robust theoretical knowledge and practical competence.展开更多
Dear Editor,General anesthetics play a pivotal role in inducing a safe and reversible loss of consciousness in patients,the importance of which cannot be overstated[1].Among the intravenous anesthetics,propofol stands...Dear Editor,General anesthetics play a pivotal role in inducing a safe and reversible loss of consciousness in patients,the importance of which cannot be overstated[1].Among the intravenous anesthetics,propofol stands out for its rapid onset and swift systemic clearance,effectively eliminating the prolonged sedation associated with earlier agents[2].展开更多
[Objective] The aim of the study is to seek a good anesthetic to Fenneropenaeus chinensis. [Method] The anesthetic effect of eugenol to juvenile Fenneropenaeus chinensis was investigated. [Result] The juveniles could ...[Objective] The aim of the study is to seek a good anesthetic to Fenneropenaeus chinensis. [Method] The anesthetic effect of eugenol to juvenile Fenneropenaeus chinensis was investigated. [Result] The juveniles could be effectively anaesthetized by 50-400 mg/L eugenol aqueous solution with temperature of 24 ℃. Within the concentration range of 50-400 mg/L, the increase of the eugenol concentration could shorten the time required for anesthesia, meanwhile could prolong the time for recovery. The recovered rate of prawn reached 100% when the eugenol concentration was lower than 200 mg/L, while the recovered rate of prawn was just 66.67% when the eugenol concentration was higher than 400 mg/L. The survival rate of prawns in test group was 100% from the observation of three consecutive days. For the specific dose, the anesthetic effect enhanced with the increase of water temperature (18-27℃). [Conclusion] Eugenol is a safe and efficient anesthetics that can be applied in genetic breeding of prawn.展开更多
Intramedullary pressure increases after spinal cord injury, and this can be an important factor for secondary spinal cord injury. Until now there have been no studies of the dynamic changes of intramedullary pressure ...Intramedullary pressure increases after spinal cord injury, and this can be an important factor for secondary spinal cord injury. Until now there have been no studies of the dynamic changes of intramedullary pressure after spinal cord injury. In this study, telemetry systems were used to observe changes in intramedullary pressure in the 72 hours following spinal cord injury to explore its pathological mechanisms. Spinal cord injury was induced using an aneurysm clip at T10 of the spinal cord of 30 Japanese white rabbits, while another 32 animals were only subjected to laminectomy. The feasibility of this measurement was assessed. Intramedullary pressure was monitored in anesthetized and conscious animals. The dynamic changes of intramedullary pressure after spinal cord injury were divided into three stages: stage I(steep rise) 1–7 hours, stage Ⅱ(steady rise) 8–38 hours, and stage Ⅲ(descending) 39–72 hours. Blood-spinal barrier permeability, edema, hemorrhage, and histological results in the 72 hours following spinal cord injury were evaluated according to intramedullary pressure changes. We found that spinal cord hemorrhage was most severe at 1 hour post-spinal cord injury and then gradually decreased; albumin and aquaporin 4 immunoreactivities first increased and then decreased, peaking at 38 hours. These results confirm that severe bleeding in spinal cord tissue is the main cause of the sharp increase in intramedullary pressure in early spinal cord injury. Spinal cord edema and blood-spinal barrier destruction are important factors influencing intramedullary pressure in stages Ⅱ and Ⅲ of spinal cord injury.展开更多
Response features of mitral cells in the olfactory bulb were examined using principal component analysis to determine whether they contain information about odorant stimuli.Using microwire electrode array to record fr...Response features of mitral cells in the olfactory bulb were examined using principal component analysis to determine whether they contain information about odorant stimuli.Using microwire electrode array to record from the olfactory bulb in freely breathing anesthetized rats,we recorded responses of different mitral cells to saturated vapor of anisole(1 M),carvone(1 M),isobutanol(1 M),citral(1 M)and isoamyl actate(1 M).The responses of single mitral cells to the same odorant varied over time.The response profiles showed similarity during certain amount of period,which indicated that the response was not only depended on odor itself but also associated with context.Furthermore,the responses of single mitral cell to different odorants were observed with difference in firing rate.In order to recognize different odorant stimuli,we apply four cells as a sensing group for classification using principal component analysis.Features of each cell’s response describing both temporal and frequency characteristics were selected.The results showed that five different single molecular odorants can be distinguished from each other.These data suggest that action potentials of mitral cells may play a role in odor coding.展开更多
Objective The present study was aimed to investigate the pharmacological modulatory effects of ropivacaine,an amide-type local anesthetic,on rat Nav1.2（rNav1.2）and rNav1.5,the two Na＋channel isoforms heterologously...Objective The present study was aimed to investigate the pharmacological modulatory effects of ropivacaine,an amide-type local anesthetic,on rat Nav1.2（rNav1.2）and rNav1.5,the two Na＋channel isoforms heterologously expressed in Xenopus oocytes and in HEK293t cell line,respectively.Methods Two-electrode voltage-clamp（TEVC）and whole-cell patchclamp recordings were employed to record the whole-cell currents.Results Ropivacaine induced tonic inhibition of peak Na＋ currents of both subtypes in a dose-and frequency-dependent manner.rNav1.5 appeared to be more sensitive to ropivacaine.In addition,for both Na＋channel subtypes,the steady-state inactivation curves,but not the activation curves,were significantly shifted to the hyperpolarizing direction by ropivacaine.Use-dependent blockade of both rNav1.2 and rNav1.5 channels was induced by ropivacaine through a high frequency of depolarization,suggesting that ropivacaine could preferentially bind to the 2 inactivated Na＋channel isoforms.Conclusion The results will be helpful in understanding the pharmacological modulation by ropivacaine on Nav1.2 subtype in the central nervous system,and on Nav1.5 subtype abundantly expressed in the heart.展开更多
Background： Spinal hyperbaric ropivacaine may produce more predictable and reliable anesthesia than plain ropivacaine for cesarean section. The dose-response relation for spinal hyperbaric ropivacaine is undetermined...Background： Spinal hyperbaric ropivacaine may produce more predictable and reliable anesthesia than plain ropivacaine for cesarean section. The dose-response relation for spinal hyperbaric ropivacaine is undetermined. This double-blind, randomized, dose-response study determined the ED50 （50% effective dose） and ED95 （95% effective dose） of spinal hyperbaric ropivacaine for cesarean section anesthesia. Methods： Sixty parturients undergoing elective cesarean section delivery with use of combined spinal-epidural anesthesia were enrolled in this study. An epidural catheter was placed at the L1-L2 vertebral interspace then lumbar puncture was performed at the L3-L4 vertebral interspace, and parturients were randomized to receive spinal hyperbaric ropivacaine in doses of 10.5 mg, 12 mg, 13.5 mg, or 15 mg in equal volumes of 3 ml. Sensory levels （pinprick） were assessed every 2.5 min until a T7 level was achieved and motor changes were assessed by modified Bromage Score. A dose was considered effective if an upper sensory level to pin prick of T7 or above was achieved and no intraoperative epidural supplement was required. ED50 and ED95 were determined with use of a logistic regression model. Results： ED50 （95% confidence interval） of spinal hyperbaric ropivacaine was determined to be 10.37 （5.23-11.59） mg and ED95 （95% confidence interval） to be 15.39 （13.81-23.59） mg. The maximum sensory block levels and the duration of motor block and the rate of hypotension, but not onset of anesthesia, were significantly related to the ropivacaine dose. Conclusion： The ED50 and ED95 of spinal hyperbaric ropivacaine for cesarean delivery under the conditions of this study were 10.37 mg and 15.39 mg, respectively. Ropivacaine is suitable for spinal anesthesia in cesarean delivery.展开更多
AIM: To compare deep sedation with propofol-fentanyl and midazolam-fentanyl regimens during upper gastrointestinal endoscopy. METHODS: After obtaining approval of the research ethics committee and informed consent, 20...AIM: To compare deep sedation with propofol-fentanyl and midazolam-fentanyl regimens during upper gastrointestinal endoscopy. METHODS: After obtaining approval of the research ethics committee and informed consent, 200 patients were evaluated and referred for upper gastrointestinal endoscopy. Patients were randomized to receive propofol-fentanyl or midazolam-fentanyl (n = 100/group).We assessed the level of sedation using the observer's assessment of alertness/sedation (OAA/S) score and bispectral index (BIS). We evaluated patient and physician satisfaction, as well as the recovery time and complication rates. The statistical analysis was performed using SPSS statistical software and included the MannWhitney test, χ 2 test, measurement of analysis of variance, and the κ statistic. RESULTS: The times to induction of sedation, recovery, and discharge were shorter in the propofolfentanyl group than the midazolam-fentanyl group. According to the OAA/S score, deep sedation events occurred in 25% of the propofol-fentanyl group and 11% of the midazolam-fentanyl group (P = 0.014). Additionally, deep sedation events occurred in 19% of the propofol-fentanyl group and 7% of the midazolamfentanyl group according to the BIS scale (P = 0.039). There was good concordance between the OAA/S score and BIS for both groups (κ = 0.71 and κ = 0.63, respectively). Oxygen supplementation was required in 42% of the propofol-fentanyl group and 26% of the midazolam-fentanyl group (P = 0.025). The mean time to recovery was 28.82 and 44.13 min in the propofolfentanyl and midazolam-fentanyl groups, respectively (P < 0.001). There were no severe complications in either group. Although patients were equally satisfied with both drug combinations, physicians were more satisfied with the propofol-fentanyl combination. CONCLUSION: Deep sedation occurred with propofolfentanyl and midazolam-fentanyl, but was more frequent in the former. Recovery was faster in the propofol-fentanyl group.展开更多
AIM: To assess the use of dezocine combined with propofol for the anesthetization of patients undergoing indolent colonoscopy.METHODS: A cross-sectional survey of patients undergoing indolent colonoscopy in the Xinjia...AIM: To assess the use of dezocine combined with propofol for the anesthetization of patients undergoing indolent colonoscopy.METHODS: A cross-sectional survey of patients undergoing indolent colonoscopy in the Xinjiang people's Hospital was conducted from April 1 to April 30, 2015. The survey collected patient general information and anesthesia data, including overall medical experience and pain management. Thirty minutes after colonoscopy surgery, samples of venous blood were collected and the biochemical indicators of gastrointestinal function were analyzed. RESULTS: There were 98 female and 62 male respondents. Indolent colonoscopy was found to be more suitable for mid to older-aged patients. The necessary conditions for the diagnosis of digestive diseases were required in 65 of the 73 inpatients. Adverse reactions to the intraoperative process included two cases of body movement and two cases of respiratory depression. Gastrin and vasoactive intestinal peptide levels were slightly increased. However, somatostatin and endothelin levels were slightly decreased. CONCLUSION: This study revealed that dezocine combined with propofol can be successfully used for the anesthetization of indolent colonoscopy patients without pain and should be widely used.展开更多
Ischemic preconditioning and postconditioning distinctly attenuate ventricular arrhythmia after ischemia without affecting the severity of myocardial stunning. Therefore, we report the effects of sevofiurane precondit...Ischemic preconditioning and postconditioning distinctly attenuate ventricular arrhythmia after ischemia without affecting the severity of myocardial stunning. Therefore, we report the effects of sevofiurane preconditioning and postconditioning on stunned myocardium in isolated rat hearts. Isolated rat hearts were underwent 20 min of global ischemia and 40 min of reperfusion. After an equilibration period （20 min）, the hearts in the preconditioning group were exposed to sevoflurane for 5 min and next washout for 5 min before ischemia. Hearts in the sevoflurane postconditioning group underwent equilibration and ischemia, followed immediately by sevoflurane exposure for the first 5 min of reperfusion. The control group received no treatment before and after ischemia. Left ventricular pressure, heart rate, coronary flow, electrocardiogram, and tissue histology were measured as variables of ventricular function and cellular injury, respectively. There was no significant difference in the duration of reperfusion ventricular arrhythmias between control and sevoflurane preconditioning group （P=0.195）. The duration of reperfusion ventricular arrhythmias in the sevoflurane postconditioning group was significantly shorter than that in the other two groups （P〈0.05）. ＋（dPIdt）max in the sevoflurane preconditioning group at 5, 10, 15, 20, and 30 min after reperfusion was significantly higher than that in the control group （P〈0.05）, and there were no significant differences at 40 min after reperfusion among the three groups （P〉0.05）. As expected, for a 20-min general ischemia, infarct size in heart slices determined by 2,3,5-triphenyltetrazolium chloride staining among the groups was not obvious. Sevofiurane postconditioning reduces reperfusion arrhythmias without affecting the severity of myocardial stunning. In contrast, sevoflurane preconditioning has no beneficial effects on reperfusion arrhythmias, but it is in favor of improving ventricular function and recovering myocardial stunning. Sevoflurane preconditioning and postconditioning may be useful for correcting the stunned myocardium.展开更多
Although beneficial in acute and chronic pain management, the use of local anaesthetics is limited by itsduration of action and the dose dependent adverse effects on the cardiac and central nervous system. Adjuvants o...Although beneficial in acute and chronic pain management, the use of local anaesthetics is limited by itsduration of action and the dose dependent adverse effects on the cardiac and central nervous system. Adjuvants or additives are often used with local anaesthetics for its synergistic effect by prolonging the duration of sensory-motor block and limiting the cumulative dose requirement of local anaesthetics. The armamentarium of local anesthetic adjuvants have evolved over time from classical opioids to a wide array of drugs spanning several groups and varying mechanisms of action. A large array of opioids ranging from morphine, fentanyl and sufentanyl to hydromorphone, buprenorphine and tramadol has been used with varying success. However, their use has been limited by their adverse effect like respiratory depression, nausea, vomiting and pruritus, especially with its neuraxial use. Epinephrine potentiates the local anesthetics by its antinociceptive properties mediated by alpha-2 adrenoreceptor activation along with its vasoconstrictive properties limiting the systemic absorption of local anesthetics. Alpha 2 adrenoreceptor antagonists like clonidine and dexmedetomidine are one of the most widely used class of local anesthetic adjuvants. Other drugs like steroids(dexamethasone), anti-inflammatory agents(parecoxib and lornoxicam), midazolam, ketamine, magnesium sulfate and neostigmine have also been used with mixed success. The concern regarding the safety profile of these adjuvants is due to its potential neurotoxicity and neurological complications which necessitate further research in this direction. Current research is directed towards a search for agents and techniques which would prolong local anaesthetic action without its deleterious effects. This includes novel approaches like use of charged molecules to produce local anaesthetic action(tonicaine and n butyl tetracaine), new age delivery mechanisms for prolonged bioavailability(liposomal, microspheres and cyclodextrin systems) and further studies with other drugs(adenosine, neuromuscular blockers, dextrans).展开更多
文摘BACKGROUND Several techniques of nasogastric tube(NGT)insertion have been described in the literature with different success rates.AIM To systematically search the literature and conduct a meta-analysis comparing the success rates,insertion time and complications associated with different techniques of NGT insertion in anesthetized and intubated patients.METHODS An electronic search of the PubMed,Scopus,CENTRAL(Cochrane Central Register of Controlled Trials),and Google Scholar databases were performed up to October 31,2019.We included 17 randomized controlled trials with 2500 participants in the meta-analysis.RESULTS As compared to the conventional method,successful insertion of the NGT on first attempt was higher with modified techniques such as the reverse Sellick’s maneuver[relative risk(RR)1.94;95%confidence interval(CI):1.62-2.31],use of a frozen NGT(RR 1.55;95%CI:1.13-2.13),inserting the NGT with neck flexion and lateral neck pressure(RR 1.64;95%CI:1.10-2.45),endotracheal tube-assisted(RR 1.88;95%CI:1.52-2.32)and video-assisted placements(RR 1.60;95%CI:1.31-1.95).All the modified techniques also led to comparatively higher insertion success rates than the conventional technique.CONCLUSION The use of modified techniques of NGT insertion such as the reverse Sellick’s maneuver,neck flexion with lateral neck pressure,frozen NGT,endotracheal tube-guided or video-assisted methods result in a significantly better chance of successful tube insertion at first attempt as compared to the conventional technique.All modified techniques also significantly improve the overall chance of successful NGT placement as compared to the conventional method.
文摘BACKGROUND: Generally speaking, anesthesia is often used in gravid body and it has been already proved that many kind of medicine can result in malformation. OBJECTIVE: To explore embryonic skeleton development and neonatal learning and memory of rats anesthetized with pentobarbital sodium in gravid rats. DESIGN: A randomized control trial. SETTING: Laboratory Animal Center of Xuzhou Medical College. MATERIALS: A total of 80 adult female SD rats, of clean grade and weighing 220-240 g, were selected in this study. The main reagents were detailed as follows: pentobarbital sodium (Shanghai Xingzhi Chemical Plant, batch number: 921019); MG-2 maze test apparatus (Zhangjiagang Biomedical Instrument Factory); somatotype microscope (Beijing Taike Instrument Co., Ltd.). METHODS: ① A total of 160 SD rats of half males and females were selected in this study. All rats were copulated. The day that the plug was checked out in the vagina next day was looked as the first day of pregnancy. Gravid rats were divided randomly into four groups, including early anesthesia group, second anesthesia group, late anesthesia group and control group with 20 in each group. Rats in the early anesthesia group were injected with 25 mg/kg soluble pentobarbitone on the 7th day of pregnancy for once; rats in the second anesthesia group were anesthetized with 25 mg/kg soluble pentobarbitone on the 7th and the 14th days of pregnancy for once; rats in the late anesthesia group were anesthetized with 25 mg/kg soluble pentobarbitone on the 14th day of pregnancy for once; rats in the control group did not treat with anything. The time of anesthetizing was controlled in 3 to 4 hours and ether was absorbed while the time was not enough. ② Half of each group was sacrificed on day 20th of pregnancy and the fetus was taken out to be stained with alizarin red S. After stained, the fetal skeleton was examined. The learning and memorizing of one-month rats that were given birth by the rest gravid rats were tested through electric mare method. Determine their study ability according to their correct rate of 90% or above of arrival at the safe area in 20 s. After they finally learned to arrive at the safe area correctly, test them once more in 24 hours and record the correct rate of 15 times. MAIN OUTCOME MEASURES: The rate of malformation in fetus and ability of learning and memory in one-month rats. RESULTS: A total of 80 female rats were anesthetized in this experiment. Totally 490 immature rats were tested with maze testing machine and 196 fetuses were stained with alizarin red S to observe the development of their skeleton. However, one of the 80 female rats was led to death because of overdose. ① Malformation experiment: Learning ability of second anesthesia group was evidently different from the control group while the other two groups were not in the electric mare method. The fetal skeleton malformation rate of three experimental groups was 87.0%, 60.9% and 17.9%, respectively, while it was 5.6% in the control group. ② Electric mare method: Times of rats which arrived at the safe regions were respectively 49.0±31.0, 68.0±35.0, 47.0±31.0 and 44.0±21.0 in early anesthesia group, second anesthesia group, late anesthesia group and control group; and then, there was significant difference between the second anesthesia group and the control group (P < 0.05). Exact rates of memory of rats were respectively (64.36±14.35)%, (62.15±18.33)%, (54.19±12.28)% and (68.24±15.91)% in early anesthesia group, second anesthesia group, late anesthesia group and control group; and then, there were no significant differences as compared with the control group (P > 0.05). CONCLUSION: The influence of anesthesia with pentobarbital sodium is obvious in fetal skeleton development and learning and memory ability.
文摘P2X_(1) receptors and adrenoceptors are mainly responsible for vasoconstriction in a variety of blood vessels.However,previous studies have shown that α,β-methylene adenosine 5'-triphosphate(α,β-MeATP),a stable analogue of ATP,can induce both pressor and depressor responses in la boratory animals.In this study,the effects of increasing intravenous doses of α,β-MeATP and noradrenaline(NA)(0-30 nmol/kg)administered at 20 min intervals on systolic(SBP),diastolic(DBP)and mean(MBP)blood pressure in groups of anesthetized mice(n=6)were compared.Both α,β-MeATP and NA caused transient,dose-dependent increases in SBP,DBP and MBP but the effect of α,β-MeATP was more rapid and significantly larger at doses of 10 and 30 nmol/kg(P<0.01).At the dose of 30 nmol/kg,α,β-MeATP increased SBP,DBP and MBP by 65.8±7.0,65.7±5.0 and 65.7±5.5 mmHg,respectively,compared to increases of 36.8±4.6,33.3±4.9 and 34.5±4.7 mmHg,respectively,produced by NA.These results indicate P2X_(1) receptors play an important role in BP regulation although purinergic vasoconstriction alone may not explain the more potent pressor response to α,β-MeATP in the anesthetized mouse.
文摘Debates regarding the specific effects of general anesthesia on developing brains have persisted for over 30 years.A consensus has been reached that prolonged,repeated,high-dose exposure to anesthetics is associated with a higher incidence of deficits in behavior and executive function,while single exposure has a relatively minor effect on long-term neurological function.In this review,we summarize the dose-dependent neuroprotective or neurotoxic effects of gamma-aminobutyric acid type A receptor agonists,a representative group of sedatives,on developing brains or central nervous system diseases.Most preclinical research indicates that anesthetics have neurotoxic effects on the developing brain through various signal pathways.However,recent studies on low-dose anesthetics suggest that they may promote neurodevelopment during this critical period.These findings are incomprehensible for the general“dose-effect”principles of pharmacological research,which has attracted researchers'interest and led to the following questions:What is the threshold for the dual effects exerted by anesthetics such as propofol and sevoflurane on the developing brain?To what extent can their protective effects be maximized?What are the underlying mechanisms involved in these effects?Consequently,this issue has essentially become a“mathematical problem.”After summarizing the dose-dependent effects of gamma-aminobutyric acid type A receptor agonist sedatives in both the developing brain and the brains of patients with central nervous system diseases,we believe that all such anesthetics exhibit specific threshold effects unique to each drug.These effects range from neuroprotection to neurotoxicity,depending on different brain functional states.However,the exact values of the specific thresholds for different drugs in various brain states,as well as the underlying mechanisms explaining why these thresholds exist,remain unclear.Further in-depth exploration of these issues could significantly enhance the therapeutic translational value of these anesthetics.
文摘Researchers have discovered that mice instinctively exhibit rescue-like behavior towards anesthetized companions-a finding that suggests a biological basis for prosociality.The study,published in PNAS on April 23,2025,was led by Dr.HU Li from the Institute of Psychology of the Chinese Academy of Sciences(IPCAS)and Dr.CHEN Zhoufeng from Washington University School of Medicine and the Shenzhen Medical Academy of Research and Translation.
基金supported by the National Key Research and Development Program of China(2018YFC2001802)the National Natural Science Foundation of China(82303765 and 82071251)+4 种基金Hubei Province Key Research and Development Program(2021BCA145)Open Foundation of Hubei Key Laboratory of Regenerative Medicine and Multi-disciplinary Translational Research(2022zsyx008)Program of Scientifc and Technological Project in Guizhou Province(Qian Ke He Ji Chu ZK[2022]Yi Ban 516 and Qian Ke He Ji Chu ZK[2021]Yi Ban 559)the Science and Technology Talents Growth Project in Education Department of Guizhou Province(Qian Jiao He KY Zi[2021]4Y211)Research project of Guizhou Administration of Traditional Chinese Medicine(QZYY-2021-082).
文摘The primary intravenous anesthetics employed in clinical practice encompass dexmedetomidine(Dex),propofol,ketamine,etomidate,midazolam,and remimazolam.Apart from their established sedative,analgesic,and anxiolytic properties,an increasing body of research has uncovered neuroprotective efects of intravenous anesthetics in various animal and cellular models,as well as in clinical studies.However,there also exists conficting evidence pointing to the potential neurotoxic efects of these intravenous anesthetics.The role of intravenous anesthetics for neuro on both sides of protection or toxicity has been rarely summarized.Considering the mentioned above,this work aims to ofer a comprehensive understanding of the underlying mechanisms involved both in the central nerve system(CNS)and the peripheral nerve system(PNS)and provide valuable insights into the potential safety and risk associated with the clinical use of intravenous anesthetics.
基金Innovative and Entrepreneurial Team of Jiangsu Province(Grant No.JSSCTD202144)Nanjing Postdoctoral Program(Grant No.BSHNJ2023006)National Natural Science Foundation of China(Grant No.82201380)。
文摘Cancer,potentially the second leading cause of mortality globally,poses a significant health challenge.The conventional treatment for solid tumors typically involves surgical intervention,followed by chemotherapy,radiotherapy,and targeted therapies.However,cancer recurrence and metastasis remain major issues.Anesthesia is essential for ensuring patient comfort and safety during surgery.Despite its crucial role in surgery,the precise effect of anesthesia on cancer patients'outcomes has not been clearly understood.This comprehensive review aims to elucidate perioperative anesthesia strategies for cancer patients and their potential effects on prognosis.Given the complexity of cancer treatments,understanding the relationship between anesthesia and cancer outcomes is crucial.By examining potential implications of anesthesia strategies for cancer prognosis,this review may help better understand treatment efficacy and risk factors for cancer recurrence and metastasis.Ultimately,a detailed analysis of anesthesia practices in cancer surgery may provide insights to refine existing anesthesia protocols and reduce risk factors for poor patient outcomes.
基金supported by Collaborative Education Project of the Ministry of Education of China(250101414020206)Planning Project of Shanghai Higher Education Association(2QYB24158).
文摘Anesthetic pharmacology,a specialized branch of pharmacology,differs significantly from the foundational pharmacology taught in undergraduate medical programs.A key challenge lies in effectively distinguishing and integrating these two courses to enhance students’theoretical understanding and foster their clinical anesthesia skills.This paper explores strategies for optimizing lesson preparation and delivery in anesthetic pharmacology,focusing on course positioning,student knowledge assessment,clinical integration,objective setting,content development,instructional design,innovative teaching tools,and classroom management.The ultimate aim is to enhance teaching effectiveness and train anesthesiology professionals with robust theoretical knowledge and practical competence.
基金supported by grants from the National Natural Science Foundation of China(82101273)the Second Affiliated Hospital of the Army Medical University Incubation Program for Young Doctoral Talents(2023YQB007).
文摘Dear Editor,General anesthetics play a pivotal role in inducing a safe and reversible loss of consciousness in patients,the importance of which cannot be overstated[1].Among the intravenous anesthetics,propofol stands out for its rapid onset and swift systemic clearance,effectively eliminating the prolonged sedation associated with earlier agents[2].
文摘[Objective] The aim of the study is to seek a good anesthetic to Fenneropenaeus chinensis. [Method] The anesthetic effect of eugenol to juvenile Fenneropenaeus chinensis was investigated. [Result] The juveniles could be effectively anaesthetized by 50-400 mg/L eugenol aqueous solution with temperature of 24 ℃. Within the concentration range of 50-400 mg/L, the increase of the eugenol concentration could shorten the time required for anesthesia, meanwhile could prolong the time for recovery. The recovered rate of prawn reached 100% when the eugenol concentration was lower than 200 mg/L, while the recovered rate of prawn was just 66.67% when the eugenol concentration was higher than 400 mg/L. The survival rate of prawns in test group was 100% from the observation of three consecutive days. For the specific dose, the anesthetic effect enhanced with the increase of water temperature (18-27℃). [Conclusion] Eugenol is a safe and efficient anesthetics that can be applied in genetic breeding of prawn.
基金supported by the National Natural Science Foundation of China,No.81272164(to JJL)the Special Fund for Basic Scientific Research of Central Public Research Institutes in China,No.2016CZ-4(to JJL),2018CZ-1(to JJL)+1 种基金the Beijing Institute for Brain Disorders in China,No.0000-100031(to JJL)the Basic Scientific Research Foundation of China Rehabilitation Research Center,No.2017ZX-22,2017ZX-20(to JJL)
文摘Intramedullary pressure increases after spinal cord injury, and this can be an important factor for secondary spinal cord injury. Until now there have been no studies of the dynamic changes of intramedullary pressure after spinal cord injury. In this study, telemetry systems were used to observe changes in intramedullary pressure in the 72 hours following spinal cord injury to explore its pathological mechanisms. Spinal cord injury was induced using an aneurysm clip at T10 of the spinal cord of 30 Japanese white rabbits, while another 32 animals were only subjected to laminectomy. The feasibility of this measurement was assessed. Intramedullary pressure was monitored in anesthetized and conscious animals. The dynamic changes of intramedullary pressure after spinal cord injury were divided into three stages: stage I(steep rise) 1–7 hours, stage Ⅱ(steady rise) 8–38 hours, and stage Ⅲ(descending) 39–72 hours. Blood-spinal barrier permeability, edema, hemorrhage, and histological results in the 72 hours following spinal cord injury were evaluated according to intramedullary pressure changes. We found that spinal cord hemorrhage was most severe at 1 hour post-spinal cord injury and then gradually decreased; albumin and aquaporin 4 immunoreactivities first increased and then decreased, peaking at 38 hours. These results confirm that severe bleeding in spinal cord tissue is the main cause of the sharp increase in intramedullary pressure in early spinal cord injury. Spinal cord edema and blood-spinal barrier destruction are important factors influencing intramedullary pressure in stages Ⅱ and Ⅲ of spinal cord injury.
基金This research is supported by the National Natural Science Foundation of China(Grant 60725102).
文摘Response features of mitral cells in the olfactory bulb were examined using principal component analysis to determine whether they contain information about odorant stimuli.Using microwire electrode array to record from the olfactory bulb in freely breathing anesthetized rats,we recorded responses of different mitral cells to saturated vapor of anisole(1 M),carvone(1 M),isobutanol(1 M),citral(1 M)and isoamyl actate(1 M).The responses of single mitral cells to the same odorant varied over time.The response profiles showed similarity during certain amount of period,which indicated that the response was not only depended on odor itself but also associated with context.Furthermore,the responses of single mitral cell to different odorants were observed with difference in firing rate.In order to recognize different odorant stimuli,we apply four cells as a sensing group for classification using principal component analysis.Features of each cell’s response describing both temporal and frequency characteristics were selected.The results showed that five different single molecular odorants can be distinguished from each other.These data suggest that action potentials of mitral cells may play a role in odor coding.
基金supported by the National Basic Research Development Program of China(No. 2006CB500801,2010CB529806)the National Natural Science Foundation of China(No.30900422)+2 种基金the Natural Science Foundation of Shanghai Municipality,China(No.08JC1409500)State Key Laboratory of Medical Neurobiology,Fudan University(No.09-02)National Laboratory of Biomacro-molecules,Institute of Biophysics,Chinese Academy of Sciences(No.O5SY021097)
文摘Objective The present study was aimed to investigate the pharmacological modulatory effects of ropivacaine,an amide-type local anesthetic,on rat Nav1.2（rNav1.2）and rNav1.5,the two Na＋channel isoforms heterologously expressed in Xenopus oocytes and in HEK293t cell line,respectively.Methods Two-electrode voltage-clamp（TEVC）and whole-cell patchclamp recordings were employed to record the whole-cell currents.Results Ropivacaine induced tonic inhibition of peak Na＋ currents of both subtypes in a dose-and frequency-dependent manner.rNav1.5 appeared to be more sensitive to ropivacaine.In addition,for both Na＋channel subtypes,the steady-state inactivation curves,but not the activation curves,were significantly shifted to the hyperpolarizing direction by ropivacaine.Use-dependent blockade of both rNav1.2 and rNav1.5 channels was induced by ropivacaine through a high frequency of depolarization,suggesting that ropivacaine could preferentially bind to the 2 inactivated Na＋channel isoforms.Conclusion The results will be helpful in understanding the pharmacological modulation by ropivacaine on Nav1.2 subtype in the central nervous system,and on Nav1.5 subtype abundantly expressed in the heart.
文摘Background： Spinal hyperbaric ropivacaine may produce more predictable and reliable anesthesia than plain ropivacaine for cesarean section. The dose-response relation for spinal hyperbaric ropivacaine is undetermined. This double-blind, randomized, dose-response study determined the ED50 （50% effective dose） and ED95 （95% effective dose） of spinal hyperbaric ropivacaine for cesarean section anesthesia. Methods： Sixty parturients undergoing elective cesarean section delivery with use of combined spinal-epidural anesthesia were enrolled in this study. An epidural catheter was placed at the L1-L2 vertebral interspace then lumbar puncture was performed at the L3-L4 vertebral interspace, and parturients were randomized to receive spinal hyperbaric ropivacaine in doses of 10.5 mg, 12 mg, 13.5 mg, or 15 mg in equal volumes of 3 ml. Sensory levels （pinprick） were assessed every 2.5 min until a T7 level was achieved and motor changes were assessed by modified Bromage Score. A dose was considered effective if an upper sensory level to pin prick of T7 or above was achieved and no intraoperative epidural supplement was required. ED50 and ED95 were determined with use of a logistic regression model. Results： ED50 （95% confidence interval） of spinal hyperbaric ropivacaine was determined to be 10.37 （5.23-11.59） mg and ED95 （95% confidence interval） to be 15.39 （13.81-23.59） mg. The maximum sensory block levels and the duration of motor block and the rate of hypotension, but not onset of anesthesia, were significantly related to the ropivacaine dose. Conclusion： The ED50 and ED95 of spinal hyperbaric ropivacaine for cesarean delivery under the conditions of this study were 10.37 mg and 15.39 mg, respectively. Ropivacaine is suitable for spinal anesthesia in cesarean delivery.
文摘AIM: To compare deep sedation with propofol-fentanyl and midazolam-fentanyl regimens during upper gastrointestinal endoscopy. METHODS: After obtaining approval of the research ethics committee and informed consent, 200 patients were evaluated and referred for upper gastrointestinal endoscopy. Patients were randomized to receive propofol-fentanyl or midazolam-fentanyl (n = 100/group).We assessed the level of sedation using the observer's assessment of alertness/sedation (OAA/S) score and bispectral index (BIS). We evaluated patient and physician satisfaction, as well as the recovery time and complication rates. The statistical analysis was performed using SPSS statistical software and included the MannWhitney test, χ 2 test, measurement of analysis of variance, and the κ statistic. RESULTS: The times to induction of sedation, recovery, and discharge were shorter in the propofolfentanyl group than the midazolam-fentanyl group. According to the OAA/S score, deep sedation events occurred in 25% of the propofol-fentanyl group and 11% of the midazolam-fentanyl group (P = 0.014). Additionally, deep sedation events occurred in 19% of the propofol-fentanyl group and 7% of the midazolamfentanyl group according to the BIS scale (P = 0.039). There was good concordance between the OAA/S score and BIS for both groups (κ = 0.71 and κ = 0.63, respectively). Oxygen supplementation was required in 42% of the propofol-fentanyl group and 26% of the midazolam-fentanyl group (P = 0.025). The mean time to recovery was 28.82 and 44.13 min in the propofolfentanyl and midazolam-fentanyl groups, respectively (P < 0.001). There were no severe complications in either group. Although patients were equally satisfied with both drug combinations, physicians were more satisfied with the propofol-fentanyl combination. CONCLUSION: Deep sedation occurred with propofolfentanyl and midazolam-fentanyl, but was more frequent in the former. Recovery was faster in the propofol-fentanyl group.
文摘AIM: To assess the use of dezocine combined with propofol for the anesthetization of patients undergoing indolent colonoscopy.METHODS: A cross-sectional survey of patients undergoing indolent colonoscopy in the Xinjiang people's Hospital was conducted from April 1 to April 30, 2015. The survey collected patient general information and anesthesia data, including overall medical experience and pain management. Thirty minutes after colonoscopy surgery, samples of venous blood were collected and the biochemical indicators of gastrointestinal function were analyzed. RESULTS: There were 98 female and 62 male respondents. Indolent colonoscopy was found to be more suitable for mid to older-aged patients. The necessary conditions for the diagnosis of digestive diseases were required in 65 of the 73 inpatients. Adverse reactions to the intraoperative process included two cases of body movement and two cases of respiratory depression. Gastrin and vasoactive intestinal peptide levels were slightly increased. However, somatostatin and endothelin levels were slightly decreased. CONCLUSION: This study revealed that dezocine combined with propofol can be successfully used for the anesthetization of indolent colonoscopy patients without pain and should be widely used.
基金Project supported by the National Natural Science Foundation of China (No. 30772090)the Natural Science Foundation of Zhejiang Province (No. Y204141)+1 种基金the Foundation from Science and Tech-nology Department of Zhejiang Province (No. 2007R10034)the Foundation from the Health Bureau of Zhejiang Province (No. 2007QN007), China
文摘Ischemic preconditioning and postconditioning distinctly attenuate ventricular arrhythmia after ischemia without affecting the severity of myocardial stunning. Therefore, we report the effects of sevofiurane preconditioning and postconditioning on stunned myocardium in isolated rat hearts. Isolated rat hearts were underwent 20 min of global ischemia and 40 min of reperfusion. After an equilibration period （20 min）, the hearts in the preconditioning group were exposed to sevoflurane for 5 min and next washout for 5 min before ischemia. Hearts in the sevoflurane postconditioning group underwent equilibration and ischemia, followed immediately by sevoflurane exposure for the first 5 min of reperfusion. The control group received no treatment before and after ischemia. Left ventricular pressure, heart rate, coronary flow, electrocardiogram, and tissue histology were measured as variables of ventricular function and cellular injury, respectively. There was no significant difference in the duration of reperfusion ventricular arrhythmias between control and sevoflurane preconditioning group （P=0.195）. The duration of reperfusion ventricular arrhythmias in the sevoflurane postconditioning group was significantly shorter than that in the other two groups （P〈0.05）. ＋（dPIdt）max in the sevoflurane preconditioning group at 5, 10, 15, 20, and 30 min after reperfusion was significantly higher than that in the control group （P〈0.05）, and there were no significant differences at 40 min after reperfusion among the three groups （P〉0.05）. As expected, for a 20-min general ischemia, infarct size in heart slices determined by 2,3,5-triphenyltetrazolium chloride staining among the groups was not obvious. Sevofiurane postconditioning reduces reperfusion arrhythmias without affecting the severity of myocardial stunning. In contrast, sevoflurane preconditioning has no beneficial effects on reperfusion arrhythmias, but it is in favor of improving ventricular function and recovering myocardial stunning. Sevoflurane preconditioning and postconditioning may be useful for correcting the stunned myocardium.
文摘Although beneficial in acute and chronic pain management, the use of local anaesthetics is limited by itsduration of action and the dose dependent adverse effects on the cardiac and central nervous system. Adjuvants or additives are often used with local anaesthetics for its synergistic effect by prolonging the duration of sensory-motor block and limiting the cumulative dose requirement of local anaesthetics. The armamentarium of local anesthetic adjuvants have evolved over time from classical opioids to a wide array of drugs spanning several groups and varying mechanisms of action. A large array of opioids ranging from morphine, fentanyl and sufentanyl to hydromorphone, buprenorphine and tramadol has been used with varying success. However, their use has been limited by their adverse effect like respiratory depression, nausea, vomiting and pruritus, especially with its neuraxial use. Epinephrine potentiates the local anesthetics by its antinociceptive properties mediated by alpha-2 adrenoreceptor activation along with its vasoconstrictive properties limiting the systemic absorption of local anesthetics. Alpha 2 adrenoreceptor antagonists like clonidine and dexmedetomidine are one of the most widely used class of local anesthetic adjuvants. Other drugs like steroids(dexamethasone), anti-inflammatory agents(parecoxib and lornoxicam), midazolam, ketamine, magnesium sulfate and neostigmine have also been used with mixed success. The concern regarding the safety profile of these adjuvants is due to its potential neurotoxicity and neurological complications which necessitate further research in this direction. Current research is directed towards a search for agents and techniques which would prolong local anaesthetic action without its deleterious effects. This includes novel approaches like use of charged molecules to produce local anaesthetic action(tonicaine and n butyl tetracaine), new age delivery mechanisms for prolonged bioavailability(liposomal, microspheres and cyclodextrin systems) and further studies with other drugs(adenosine, neuromuscular blockers, dextrans).
