右美托咪定在中型颅脑损伤患者镇静治疗中的应用

目的探讨右美托咪定在中型颅脑损伤患者镇痛镇静中的疗效。方法选取2014年1月～2015年12月笔者医院收治的120例颅脑损伤患者为研究对象,其中男性81例,女性39例;平均35.1岁。按照随机数字表法随机分为右美组(n=60例)和冬眠组(n=60例),右美组给予右美托咪定(2m L:200μg,江苏恒瑞医药股份有限公司)负荷剂量为0.5～1.0μg/kg,持续泵注10min,后以0.2～0.7μg/(kg·h)速度维持3d;冬眠组肌注冬眠合剂(盐酸氯丙嗪注射液,2m L:50mg,上海禾丰制药有限公司;盐酸异丙嗪注射液,2m L:50mg,天津金耀药业有限公司;盐酸哌替啶注射液,2m L:100mg,宜昌人福药业有限责任公司),间隔8h给药1次,维持3d。对两组患者年龄、性别、体重、GCS评分、生命体征(心率、平均动脉压、血氧饱和度)、C-反应蛋白、不良反应及并发症、住院天数、预后情况等因素进行统计学分析。结果 (1)右美组患者年龄(36.2±10.8)岁、性别(男女比例38/22)、体重(68.3±13.2)kg、GCS评分(10.8±3.2)分,与冬眠组年龄(34.6±11.2)岁、性别(男女比例43/17)、体重(65.5±11.5)kg、GCS评分(10.2±2.6)分等比较差异无统计学意义(P0.05)。(2)用药后心率及血压比较,用药后1h右美组,心率(72.4±7.8)次/min,血压(87.8±8.1)mm Hg,相较于用药前无较大变化,但冬眠组心率(66.2±7.6)次/min,血压(87.8±8.1)mm Hg明显降低。而用药后两组患者血氧饱和度(右美组96.4±2.9,冬眠组96.2±2.1)均无明显变化。(3)两组患者C-反应蛋白入院后均持续升高,第3天达峰值,右美组为(32.8±7.1)mg/L,冬眠组为(41.2±7.9)mg/L,但右美组用药1d后C-反应蛋白增幅较冬眠组明显降低,用药后右美组和冬眠组的C-反应蛋白含量分别为(28.5±6.2)mg/L、(34.8±7.2)mg/L。(4)心动过缓、低血压、应激性溃疡、肺部感染发生率比较,右美组发生人次分别为13、10、7、8,冬眠组则为23、20、16、17,右美组显著低于冬眠组,而在右美组组内比较时,浅镇静组(心动过缓3人次、低血压2人次、应激性溃疡1人、肺部感染1人)明显低于深镇静组(心动过缓10人次、低血压8人次、应激性溃疡6人、肺部感染7人)。(5)右美组患者的ICU住院时间(12.8±5.5)d及总住院时间(21.2±6.5)d相较于冬眠组的ICU住院时间(15.3±6.1)d及总住院时间(28.5±7.4)d均显著缩短。(6)伤后6个月随访,两组预后,GOS评分1～5分的人数比较,右美组分别为3、5、10、15、27人,而冬眠组则分别为5、9、13、16、17人,组间比较采用Ridit分析(R值右美=0.552,R值冬眠=0.448,P=0.048),右美组好于冬眠组,但右美组与冬眠组的病死率无显著差别(5%vs.8.3%)。结论右美托咪定镇静效果满意,且对呼吸及循环系统无明显影响,还可降低C-反应蛋白水平,抑制炎性反应,改善患者预后,适用于中型颅脑损伤患者的镇静治疗。     

Anti-mitragynine monoclonal antibody-based ELISA for determination of alkaloids in the kratom cocktail

Kratom cocktail or the fatal 4 × 100 formula is defined as a mixture of boiled kratom leaves, cola drink, and cough syrup. In the present study, we focused on application of the indirect competitive enzyme-linked immunosorbent assay (ic-ELISA) using the anti-mitragynine (MG) monoclonal antibody (anti-MG mAb) to the kratom cocktail. The ic-ELISA is a rapid method for quantification of the major kratom alkaloids including MG, paynantheine, and speciogynine in kratom cocktails. Because some matrices or additives may influence the binding affinity between the alkaloids and the anti-MG mAb, a liquid–liquid extraction method using chloroform was used to clean-up samples and minimize any cross-reactivity with anti-MG mAb. The anti-MG mAb showed slight cross-reactivity to caffeine, codeine, morphine, tramadol, and dextromethorphan (<0.5 %), which are also commonly added to a kratom cocktail. When applied to eight different kratom cocktail samples, the ic-ELISA using the anti-MG mAb allowed the determination of the combined kratom alkaloid content in the range of 0.083–576 mg/L, and these values were in agreement with the results of the high-performance liquid chromatography method (R ² = 0.9689). To our knowledge, this is the first report for the quantification of total amounts of kratom alkaloids including MG in kratom cocktail by a simple immunoassay. Because of the sharp rise in kratom cocktail abuse in the world, this method will be a useful tool for detection of kratom cocktail consumption.     

不同镇痛镇静方法对急性呼吸窘迫综合征病人心脏功能的影响

目的探讨不同镇痛镇静方法对急性呼吸窘迫综合征（ARDS）机械通气病人心脏功能的早期影响。方法对我院59例ARDS患者机械通气治疗时随机分为3组,分别采用改良冬眠合剂行持续镇静镇痛治疗21例（Ⅰ组）、力月西及芬太尼持续镇静镇痛治疗19例（Ⅱ组）、力月西和芬太尼或吗啡等间断镇痛镇静19例（Ⅲ组）,监测各组血液动力学和心肌酶学改变,并进行对比分析。结果 3组入ICU时体重、急性生理和慢性健康状态评分（APACHEⅡ）、氧合指数（O I）、血液动力学、心肌酶谱指标均无显著差异（P〉0.05）。在治疗24 h后,血液动力学指标均有明显改善（P〈0.05）,但Ⅰ、Ⅱ组改善幅度相似（P〉0.05）,且均较Ⅲ组更明显（P〈0.05）。心肌损伤的相关酶学均有不同程度变化,Ⅰ、Ⅱ组LDH、Mb均有下降（P〈0.05）,而CK-MB和Tn-T仅略有上升（P〉0.05）,Ⅲ组Mb、Tn-T、CK-MB及ASL仍然有明显升高（P〈0.05）。结论镇静镇痛有利于保护ARDS病人心功能,持续镇静镇痛可能是更好的方法。     

Is administration of enteric contrast material safe before abdominal CT in children who require sedation? Experience with chloral hydrate and pentobarbital

OBJECTIVE: It has been common practice to administer enteric contrast material in preparation for abdominal CT in children who require sedation to be examined. At some institutions, the practice of administering an anesthetic or enteric contrast material before sedation is being challenged because it violates the "nothing by mouth" status that is otherwise strictly enforced before sedation. Our purpose was to review our safety record in administering enteric contrast material for CT before sedation. MATERIALS AND METHODS: Radiology reports, medical records, and department incident reports were reviewed for the past 5 years from all patients who required sedation for abdominal CT. Patient age and sex, type of sedation, and complications (defined as vomiting with aspiration) related to enteric contrast material before the sedation were recorded. For routine oral contrast material, diluted Hypaque (meglumine diatrizoate) was administered in an age-based amount 1-2 hr before scanning. For sedation, depending on the patient's age, either oral chloral hydrate (70-100 mg/kg) or IV pentobarbital (3 mg/kg with repeated doses of up to 7 mg/kg) was used. RESULTS: Three hundred sixty-seven patients who received oral contrast material before sedation for abdominal CT were identified (200 boys, 167 girls; age range, 1 month-19 years; mean age, 2.9 years). Chloral hydrate was used in 30 patients and IV pentobarbital in 337 patients. No complications related to the administration of oral contrast material before sedation were identified. CONCLUSION: The practice of administering oral contrast material in children before sedation for abdominal CT appears to be safe when using the sedation drugs and protocols in place at our institution. Further study of the safety of this practice should be undertaken.     

Fellows' Journal Club: Rate and Prognosis of Patients under Conscious Sedation Requiring Emergent Intubation during Neuroendovascular Procedures

BACKGROUND AND PURPOSE:Neuroendovascular procedures are performed with the patient under conscious sedation (local anesthesia) in varying numbers of patients in different institutions, though the risk of unplanned conversion to general anesthesia is poorly characterized. Our aim was to ascertain the rate of failure of conscious sedation in patients undergoing neuroendovascular procedures and compare the in-hospital outcomes of patients who were converted from conscious sedation to general anesthesia with those whose procedures were initiated with general anesthesia.MATERIALS AND METHODS:All patients who had an endovascular procedure initiated under general anesthesia or conscious sedation were identified through a prospective data base maintained at 2 comprehensive stroke centers. Patient clinical and procedural characteristics, in-hospital deaths, and favorable outcomes (modified Rankin Scale score, 0–2) at discharge were ascertained.RESULTS:Nine hundred seven endovascular procedures were identified, of which 387 were performed with the patient under general anesthesia, while 520 procedures were initiated with conscious sedation. Among procedures initiated with intent to be performed under conscious sedation, 9 (1.7%) procedures required emergent conversion to general anesthesia. Favorable clinical outcome and in-hospital mortality in patients requiring emergent conversion from conscious sedation to general anesthesia and in those with procedures initiated with general anesthesia were not statistically different (42% versus 50%, P = .73 and 17% versus 13%, P = 1.00, respectively).CONCLUSIONS:In our study, there was a very low rate of conscious sedation failure and associated adverse outcomes among patients undergoing neuroendovascular procedures. Proper patient selection is important if procedures are to be performed with the patient under conscious sedation. Limitations of the methodology used in our study preclude us from offering specific recommendations regarding when to use a specific anesthetic protocol.

Controversy exists regarding the type of anesthesia required in patients undergoing neuroendovascular procedures. Some operators advocate the use of local anesthesia and intravenous sedation known as conscious sedation, while others argue that these interventions are best performed with the patient under general anesthesia. One study showed that initiation of an intervention for anterior circulation stroke with the patient under general anesthesia varied widely among centers, ranging from 0% to 100%, with the average being 44%.¹ A recent survey reported that a large majority of neurointerventionalists prefer general anesthesia as the intraprocedural technique of choice.²Although such decisions depend on personal preference, experience, and institutional protocols, some studies suggest that certain modalities of sedation may prolong the hospital stay and worsen outcome. Concern for increased risk of aspiration and potential airway injury with emergent intubation³ in a procedure initiated with conscious sedation, especially if thrombolytic therapy or anticoagulation has been used, may bias operators toward general anesthesia at the onset of the procedure. However, there is insufficient evidence to suggest that such conversion is a common occurrence or that it is detrimental to the patient. We sought to determine the frequency and prognosis of patients converted from conscious sedation to general anesthesia during neurointerventional procedures at 2 academic comprehensive stroke centers.     

持续优化技术在膝关节表面置换术失血损害控制中的作用

目的评价持续优化技术对行初次单侧人工膝关节表面置换术(TKA)围术期失血损害控制的临床疗效。方法回顾性分析2016年1月-2019年7月陆军军医大学第二附属医院骨科符合纳入排除标准的177例单侧初次TKA患者,根据不同假体类型分为两组试验,每组根据采用不同手术技术及围术期管理方式分为3组,具体如下:试验1均采用后交叉韧带替代型假体(posterior stabilization,PS)及手术技术,其中对照组1使用传统鸡尾酒(肾上腺素5mg、罗哌卡因300mg、复方倍他米松7mg、吗啡10mg,使用生理盐水配制至50mL),试验组1.1采用改良鸡尾酒(氨甲环酸1g、罗哌卡因300mg、复方倍他米松7mg、吗啡10mg,使用生理盐水配制至100mL),试验组1.2采用氨甲环酸序贯疗法。试验2均采用后交叉韧带保留型假体(posterior retaining,CR)及手术技术,其中对照组2为常规CR手术技术,试验组2.1为计算机导航辅助的CR手术技术,试验组2.2为经股内侧肌下入路微创CR手术技术。分别记录各组患者的术前术后血红细胞压积(HCT)、血红蛋白(HB)、术后引流量及输血率,计算围术期失血量。结果试验1:对照组1、试验组1.1、试验组1.2的术前术后HCT、HB、术后引流量均值分别为,HCT术前:37.3%、39.3%、39.8%;HB术前:121.2 g/L、128.4 g/L、129.6 g/L;HCT术后:28.3%、31.4%、32.0%;HB术后:90.8 g/L、100.9g/L、102.1g/L;术后引流量:205.6mL、99.5mL、62.5mL。改良"鸡尾酒"组较传统"鸡尾酒"组出血量平均下降198.6mL(GROSS方程)、153.6mL(HB-balance方程);氨甲环酸序贯疗法组较传统"鸡尾酒"组出血量平均下降203.9mL(GROSS方程)、141.9mL(HB-balance方程),以上差异均有统计学意义(P<0.05)。试验2:对照组2、试验组2.1、试验组2.2的术前术后HCT、HB、术后引流量均值分别为,HCT术前:39.8%、36.6%、39.8%;HB术前:129.8 g/L、119.3 g/L、127.5g/L;HCT术后:33.2%、30.1%、34.6%;HB术后:107.0 g/L、97.0 g/L、109.3g/L;术后引流量:58.8mL、63.5mL、48.6mL。计算机导航辅助CR手术技术组较常规CR手术技术组出血量平均上升61.6mL(GROSS方程),41.3 mL(HB-balance方程),差异无统计学意义(P>0.05);试验组2.2相比对照组2出血量平均下降159.8 mL(GROSS方程)、116.0 mL(HB-balance方程),差异有统计学意义(P<0.05)。结论改良"鸡尾酒"配方、氨甲环酸序贯治疗、经股内侧肌下入路微创手术技术,对于降低初次TKA的围术期失血量作用显著,而计算机导航辅助截骨TKA未见显著差异。     

The Impact of Conscious Sedation versus General Anesthesia for Stroke Thrombectomy on the Predictive Value of Collateral Status: A Post Hoc Analysis of the SIESTA Trial

BACKGROUND AND PURPOSE:Radiologic selection criteria to identify patients likely to benefit from endovascular stroke treatment are still controversial. In this post hoc analysis of the recent randomized Sedation versus Intubation for Endovascular Stroke TreAtment (SIESTA) trial, we aimed to investigate the impact of sedation mode (conscious sedation versus general anesthesia) on the predictive value of collateral status.MATERIALS AND METHODS:Using imaging data from SIESTA, we assessed collateral status with the collateral score of Tan et al and graded it from absent to good collaterals (0–3). We examined the association of collateral status with 24-hour improvement of the NIHSS score, infarct volume, and mRS at 3 months according to the sedation regimen.RESULTS:In a cohort of 104 patients, the NIHSS score improved significantly in patients with moderate or good collaterals (2–3) compared with patients with no or poor collaterals (0–1) (P = .011; mean, −5.8 ± 7.6 versus −1.1 ± 10.7). Tan 2–3 was also associated with significantly higher ASPECTS before endovascular stroke treatment (median, 9 versus 7; P < .001) and smaller mean infarct size after endovascular stroke treatment (median, 35.0 versus 107.4; P < .001). When we differentiated the population according to collateral status (0.1 versus 2.3), the sedation modes conscious sedation and general anesthesia were not associated with significant differences in the predictive value of collateral status regarding infarction size or functional outcome.CONCLUSIONS:The sedation mode, conscious sedation or general anesthesia, did not influence the predictive value of collaterals in patients with large-vessel occlusion anterior circulation stroke undergoing thrombectomy in the SIESTA trial.

Endovascular stroke treatment (EST) is now the first choice for acute ischemic stroke in the anterior circulation caused by large-vessel occlusion.^1,2 However, selection criteria to identify patients likely to benefit from EST outside highly selective randomized trials (RCTs) are still controversial. It is also important to establish practicable selection criteria for thrombectomy failure to exclude patients prone to futility and save financial, facility, and personnel resources and, above all, avoid complications like cerebral reperfusion injuries.Current data suggest that collateral blood flow status is a strong independent predictor of therapeutic success and functional outcome after EST.^3–5 By a network of pre-existing anastomoses, compensatory cerebral collateral blood flow supplies oxygen-deprived brain areas to which the primary flow path is blocked due to large-vessel occlusion. The recently published post hoc analysis on the collateralization status from the seminal thrombectomy trial MR CLEAN (Multicenter Randomized Clinical Trial of Endovascular Treatment of Acute Ischemic Stroke in the Netherlands) showed the highest interventional therapeutic effect in patients with moderate-to-good collateral blood flow.⁶Why should the chosen sedation/airway regimen influence the impact of collateralization during EST? Collateral effects depend on cerebral perfusion pressure and vasomotor regulation of the vessel diameter. On the one hand, intubation and general anesthesia (GA) are often associated with a substantial drop in blood pressure⁷ as was shown in previous EST studies.^8–10 It is quite likely that hypotension may compromise even patients with a good collateral status, particularly if their cerebral autoregulation is impaired as is often the case in severe acute ischemic stroke. Moreover, inadvertent mechanical hyperventilation and subsequent hypocarbia can lead to cerebral vasoconstriction.^8,11 Both hypotension and hypocarbia associated with GA may have disadvantageous effects on the insufficiently supplied penumbra. Indeed, many retrospective studies have suggested worse outcome and mortality associated with GA in EST.¹² On the other hand, steering GA in ways that stabilize circulation and aim for normocarbia may theoretically serve to improve collateralization.We recently conducted the Sedation versus Intubation for Endovascular Stroke TreAtment (SIESTA) study to compare GA with conscious sedation (CS) during EST.¹³ In that first RCT on peri-interventional management, strict target values for physiologic parameters, including blood pressure and CO₂, were predefined for both treatment groups, mainly to avoid hypocarbia and hypotension. SIESTA showed no difference between GA and CS with regard to early neurologic improvement measured by the NIHSS after 24 hours,¹⁴ and unadjusted long-term outcome was even better in patients in the GA group. Of note, SIESTA was not powered and designed to primarily investigate long-term functional outcome, and slight imbalances in reperfusion grades, for example, may still have influenced that result even though the results were not statistically significant. This result was in strong contrast to most previous, yet retrospective, studies on the subject.Why was GA not inferior in SIESTA? We hypothesized that the protocolized way GA was conducted may not have compromised or even improved collateralization. In this post hoc analysis of imaging data from the SIESTA study, we mainly aimed to investigate whether the predictive value of collateral status for infarct volume and outcome is affected by the applied sedation mode (CS versus GA) and, more specifically, whether patients under a very standardized GA may have shown a favorable course despite a suboptimal collateral status at baseline.     

Regional Anesthesia as an Alternative to Moderate Sedation for Perioperative Pain Control for Percutaneous Gastrostomy Tube Placement

Percutaneous gastrostomy tube placement is typically performed under moderate sedation. However, some patients are not ideal candidates for moderate sedation because of respiratory compromise, difficult airways, or other factors. The purpose of this study was to evaluate regional anesthesia as an alternative to moderate sedation. A retrospective review of patients who underwent percutaneous gastrostomy tube placement between March 2014 and September 2020 was performed. Data on patient demographics, anesthesia type, pain scores, and opiate usage were collected. A total of 189 patients were included in the study; 35 (18.5%) received regional anesthesia and 154 received moderate sedation. Patients in the regional anesthesia group tolerated the procedure well, with lower mean immediate postprocedural and maximal pain scores of 0.7 vs 2.2 (P = .011) and 4.3 vs 6.5 (P = .003), respectively. Regional anesthesia is effective at controlling perioperative pain and is an alternative with a low complication rate for patients who cannot tolerate moderate sedation.     

Technical report: oxygen saturation monitoring during sedation for chemonucleolysis.

Pulse oximetry is widely used during anaesthetic practice to monitor heart rate and oxygenation and has been recommended as a monitor when sedative techniques are used. We monitored 25 patients receiving sedation for chemonucleolysis and showed that 17 became hypoxaemic at some stage of the procedure, none of whom had clinically detectable signs of respiratory depression. We recommend that monitoring with pulse oximetry is used in all patients receiving sedation for radiological procedures and that all radiologists administering sedation be trained in airway management.     

Conscious sedation for interventional procedures: a practical guide

Sedation is often used in interventional procedures to minimize discomfort, improve the patient's experience, and reduce the risk of procedural complications by assuring nonmobility and compliance of the patient. Sedation, however, adds a new dimension to the procedure by compromising the patients' normal protective mechanisms and carries the potential of cardiac, respiratory, and cognitive complications. Interventional procedures could be performed under local anesthesia with or without sedation, or under general anesthesia. Sedation itself could be categorized into minimal, moderate, or deep sedation. The choice generally depends on patient factors such as age, cardiovascular stability, pain tolerance, and procedural factors such as complexity, extent, and degree of induced pain. In longer and more extensive procedures on more fragile patients, the assistance of an anesthesiologist will be required. The purpose of this article is to provide a basic understanding and a practical guideline for minimal and moderate sedation for the interventionalist contemplating to administer sedation for less involved procedures.     

小儿在放射科检查治疗过程中镇静程序的建立与使用

目的 对小儿影像诊断及介入等治疗性操作中镇静药物选择和镇静程序进行探讨，以建立一个安全、高效及副作用最小的模式。材料与方法 ２０２０例单纯诊断及６８例介入等治疗性操作的小儿病例，均于放射检查或操作前经过镇静程序。从中总结出安全且成功率高的镇静模式及药物。结果 无呼吸、循环衰竭或死亡病例。４例患有重度系统性疾病需特别监护，但未发生镇静副作用。在单纯镇静组（ｎ＝２０２０）中，有５６例（２．２％）镇静失     

STOP-BANG量表用于筛查深度镇静胃结肠镜检查及评估低氧血症风险

 目的 采用STOP-BANG量表筛查深度镇静下行胃结肠镜检查术的受试者中阻塞性睡眠呼吸暂停(obstructive sleep apnea ,OSA)的患病率及对低氧血症风险的评估。方法 选择择期行无痛胃结肠镜检查患者,以STOP-BANG量表对患者进行评分,将受试者分为OSA高危组和低危组。通过靶控输注丙泊酚使患者进入深度镇静状态。比较OSA高危组和低危组发生低氧血症的发生率和辅助呼吸技术使用率。结果 共招募620例受试者,纳入614例。220例(35.8%)被划为OSA高危组,394例(64.1%)被划为低危组。85例(13.8%)在胃结肠镜检查过程当中出现低氧血症。高危组发生低氧血症的风险明显高于低危组(25.8% vs 7.3%);相对风险值(RR3.37,95% CI 2.22~5.13)。结论 深度镇静胃结肠镜检查的受试者OSA高危组发生低氧血症的风险更高, 辅助呼吸技术使用率也较高。     

The effect of vial type and cocktail quantity on tritium measurement in LSC

The effect of sample vial type and cocktail quantity on tritium measurement in liquid scintillation counting is studied in this paper. With both high and low level tritium samples, glass vials allow higher counting rates than plastic vials do. We also present detailed analysis of the way to obtain the optimal counting condition by dispensing different quantity of cocktail into sample vials. Results indicate that the optimal counting condition has little relationship with tritium concentration in the sample. The main factor which influences the counting is the quantity of cocktail added into samples. Figure of merit is employed to access the results, which increases as the quantity of cocktail increasing. But when the ratio of cocktail and sample reaches 2.0, increase of ratio makes little contribution to the counts, and the disintegrations per minute comes nearly to be a constant.     

Conscious Sedation versus General Anesthesia during Endovascular Acute Ischemic Stroke Treatment: A Systematic Review and Meta-Analysis

BACKGROUND AND PURPOSE:A number of studies have suggested that anesthesia type (conscious sedation versus general anesthesia) during intra-arterial treatment for acute ischemic stroke has implications for patient outcomes. We performed a systematic review and meta-analysis of studies comparing the clinical and angiographic outcomes of the 2 anesthesia types.MATERIALS AND METHODS:In March 2014, we conducted a computerized search of MEDLINE and EMBASE for reports on anesthesia and endovascular treatment of acute ischemic stroke. Using random-effects meta-analysis, we evaluated the following outcomes: recanalization rate, good functional outcome (mRS ≤ 2), asymptomatic and symptomatic intracranial hemorrhage, death, vascular complications, respiratory complications, procedure time, time to groin, and time from symptom onset to recanalization.RESULTS:Nine studies enrolling 1956 patients (814 with general anesthesia and 1142 with conscious sedation) were included. Compared with patients treated by using conscious sedation during stroke intervention, patients undergoing general anesthesia had higher odds of death (OR = 2.59; 95% CI, 1.87–3.58) and respiratory complications (OR = 2.09; 95% CI, 1.36–3.23) and lower odds of good functional outcome (OR = 0.43; 95% CI, 0.35–0.53) and successful angiographic outcome (OR = 0.54; 95% CI, 0.37–0.80). No difference in procedure time (P = .28) was seen between the groups. Preintervention NIHSS scores were available from 6 studies; in those, patients receiving general anesthesia had a higher average NIHSS score.CONCLUSIONS:Patients with acute ischemic stroke undergoing intra-arterial therapy may have worse outcomes with general anesthesia compared with conscious sedation. However, the difference in stroke severity at the onset may confound the comparison in the available studies; thus, a randomized trial is necessary to confirm this association.

Intra-arterial recanalization for acute ischemic stroke is commonly used in patients with large-vessel occlusion.¹ Timely recanalization of the occluded vessel with either IV-tPA or intra-arterial therapy is essential in preventing neuronal death and improving patient outcome.² A number of factors affect patient outcomes following endovascular recanalization, possibly including choice of anesthetic agent during the procedure. Moderate conscious sedation and general anesthesia with intubation are the 2 most commonly used anesthesia techniques for patients with acute ischemic stroke undergoing endovascular recanalization.³ General anesthesia is often the preferred method due to the perceptions of improved procedural safety and efficacy.³ However, conscious sedation and local anesthesia allow operators to monitor neurologic status during the procedure and avoid delays in procedure initiation.⁴ Furthermore, conscious sedation may be associated with improved hemodynamic stability compared with general anesthesia. Due to the continuing debate regarding anesthesia choices during intra-arterial treatment of acute ischemic stroke, we performed a meta-analysis of studies comparing outcomes of patients with stroke receiving general anesthesia and conscious sedation during the procedures.^5,6     

Evolution of a protocol for ketamine-induced sedation as an alternative to general anesthesia for interventional radiologic procedures in pediatric patients

PURPOSE: To establish a protocol for credentialed pediatric radiology nurses, with radiologist supervision, to administer ketamine to induce sedation and analgesia during interventional radiologic procedures. MATERIALS AND METHODS: This study was conducted in two phases. The goal of the first phase was to develop a sedation protocol to replace that of using general anesthesia for specified pediatric interventional procedures. Ketamine was administered intravenously (with intermittent bolus or continuous infusion) or intramuscularly. Sedation induction times, adverse events, doses, and sedation and recovery durations were recorded. In phase 2, the results of phase 1 were reviewed and a formal ketamine protocol was developed. RESULTS: Neither sedation failures nor substantial adverse events occurred in phase 1. Mean duration of all sedations was 52 minutes, and median recovery room time was 0 minutes. In phase 2, the results of phase 1 were reviewed and a sedation protocol was proposed to a hierarchy of hospital committees before final approval from the medical staff executive committee. Subsequently, standard order forms for radiology nurse administration of ketamine with radiologist supervision were prepared for exclusive use by the pediatric interventional radiology department. CONCLUSION: Ketamine-induced sedation may be a safe and effective alternative to general anesthesia for some interventional radiologic procedures in pediatric patients. Collaboration between anesthesia and radiology departments is important for development of a safe and successful ketamine sedation program. To the authors' knowledge, this is the first report describing the intravenous infusion of ketamine for sedation in pediatric patients and the only report describing the establishment of a protocol for ketamine administration by credentialed radiology nurses with radiologist supervision.     

Evaluation of Adult Outpatient Magnetic Resonance Imaging Sedation Practices: Are Patients Being Sedated Optimally?

Purpose

To evaluate the use of anxiolytics in adult outpatient magnetic resonance imaging (MRI) centres and to determine whether utilisation is optimal based on the pharmacology of the drugs used, who prescribes these drugs, and how patients are managed after administration.

Materials and Methods

Identical paper and Web-based surveys were used to anonymously collect data about radiologists' use of anxiolytic agents for adult outpatient MRI examinations. The survey questions were about the type of facility, percentage of studies that require sedation, the drug used and route of administration, who orders the drug, timing of administration, patient monitoring during and observation after the study, use of a dedicated nurse for monitoring, and use of standard sedation and discharge protocols. The χ² analysis for statistical association among variables was used.

Results

Eighty-five of 263 surveys were returned (32% response rate). The radiologist ordered the medication (53%) in slightly more facilities than the referring physician (44%) or the nurse. Forty percent of patients received medication 15–30 minutes before MRI, which is too early for peak effect of oral or sublingual drugs. Lorazepam was most commonly used (64% first choice). Facilities with standard sedation protocols (56%) were more likely to use midazolam than those without standard sedation protocols (17% vs 10%), to have a nurse for monitoring (P = .032), to have standard discharge criteria (P = .001), and to provide written information regarding adverse effects (P = .002).

Conclusions

Many outpatients in MRI centres may be scanned before the peak effect of anxiolytics prescribed. A standard sedation protocol in such centres is associated with a more appropriate drug choice, as well as optimized monitoring and postprocedure care.     

A method for the comparison of performance of gamma-ray spectrometry calibration cocktails.

In order to make quantitative assessments about the usefulness of different gamma-ray emitting radionuclide cocktails to carry out efficiency calibrations of gamma-ray spectrometers, a method has been developed that allows the comparison of their different performances and to optimize the choice of gamma energy lines for the radionuclides within a specific cocktail. The method has been applied to compare different cocktail configurations obtained from measurements made in the laboratory with monoenergetic radionuclides, and their relative performances are presented and discussed.     

Comparison of General Anesthesia and Conscious Sedation During Computed Tomography–Guided Radiofrequency Ablation of T1a Renal Cell Carcinoma

Purpose

Percutaneous radiofrequency ablation is so painful that this treatment requires pain control such as conscious sedation or general anesthesia. It is still unclear which type of anesthesia is better for treatment outcomes of renal cell carcinoma. This study aimed to compare general anesthesia and conscious sedation in treating patients with renal cell carcinoma with radiofrequency ablation.

Superiority of pentobarbital versus chloral hydrate for sedation in infants during imaging

PURPOSE: To compare the effectiveness and safety of oral pentobarbital and oral chloral hydrate for sedation in infants younger than 1 year during magnetic resonance (MR) imaging and computed tomography (CT). MATERIALS AND METHODS: A computerized database was used to collect information about all cases in which sedation was used. Outcomes of all infants who received oral pentobarbital or oral chloral hydrate for sedation between 1997 and 2002 were reviewed. Two study groups were compared for sedation and discharge times by using Student t test and for adverse events by using Fisher exact test and multiple logistic regression analysis. RESULTS: Infants (n = 1,316) received an oral medication for sedation. Mean doses were 50 mg/kg chloral hydrate and 4 mg/kg pentobarbital. Student t test demonstrated no difference in mean time to sedation and in time to discharge between groups. Overall adverse event rate during sedation was lower with pentobarbital (0.5%) than with chloral hydrate (2.7%) (P <.001). There were fewer episodes of oxygen desaturation with pentobarbital (0.2%) than with chloral hydrate (1.6%) (P <.01). Both medications were equally effective in providing successful sedation. CONCLUSION: Although oral pentobarbital and oral chloral hydrate are equally effective, the incidence of adverse events with pentobarbital was significantly reduced.     

Sedation/anaesthesia in paediatric radiology

Objectives

In this article we will give a comprehensive literature review on sedation/general anaesthesia (S/GA) and discuss the international variations in practice and options available for S/GA for imaging children.

Methods

The key articles were obtained primarily from PubMed, MEDLINE, ERIC, NHS Evidence and The Cochrane Library.

Results

Recently, paediatric radiology has seen a surge of diagnostic and therapeutic procedures, some of which require children to be still and compliant for up to 1 h. It is difficult and sometimes even impossible to obtain quick and high-quality images without employing sedating techniques in certain children. As with any medical procedure, S/GA in radiological practice is not without risks and can have potentially disastrous consequences if mismanaged. In order to reduce any complications and practice safety in radiological units, it is imperative to carry out pre-sedation assessments of children, obtain parental/guardian consent, monitor them closely before, during and after the procedure and have adequate equipment, a safe environment and a well-trained personnel.

Conclusion

Although the S/GA techniques, sedative drugs and personnel involved vary from country to country, the ultimate goal of S/GA in radiology remains the same; namely, to provide safety and comfort for the patients.

Advances in knowledge

Imaging children under general anaesthesia is becoming routine and preferred by operators because it ensures patient conformity and provides a more controlled environment.The main goals of paediatric sedation/general anaesthesia (S/GA) vary according to the specific imaging procedure, but generally encompass anxiety relief, pain control and control of excessive movement [1].The American Academy of Pediatrics (AAP) defines the goals of sedation in the paediatric patient for diagnostic and therapeutic procedures as follows: to guard the patient’s safety and welfare; to minimise physical discomfort and pain; to control anxiety, minimise psychological trauma and maximise the potential for amnesia; to control behaviour and/or movement to allow for the safe completion of the procedure; and to return the patient to a state in which safe discharge from medical supervision, as determined by recognised criteria, is possible [2].The target level or depth of sedation will vary according to the imaging procedure (and modality), as well as the individual patient characteristics. For CT scanning, for instance, modern multislice scanners allow for rapid image acquisition; therefore, moderate sedation can be employed. However, some children need to be asleep in order to tolerate complex or prolonged investigations such as MRI and nuclear medicine imaging, which may involve the child keeping still for up to 1 h. MRI can be particularly frightening because it is noisy and involves lying still in an enclosed space [3]. Image acquisition after the administration of the radioactive tracer becomes essential in nuclear medicine techniques in order to avoid unnecessary repeat studies and the additional radiation burden. Careful planning of S/GA is particularly important for these modalities.The rate of failure of adequate image acquisition has been reported by various investigators to be as rare as 1–3% [4], and by others to be as frequent as 10–20% [5,6]. In one large prospective study of children who underwent sedation (n=922) or were given general anaesthesia (n=140) for an MRI or CT scan [7], the sedation was inadequate in 16% of children and failed in 7% of cases. However, the procedures were successful in all of the children who were imaged under general anaesthesia. Excessive motion was noted in 12% of scans of sedated children and in only 0.7% of those completed under general anaesthesia. Malviya et al [7] also reported a clear improvement in the quality of MRI scans performed using general anaesthesia compared with those using moderate sedation.Rates of failure can be decreased dramatically when sedation is provided by a dedicated team, by implementing clear protocols [8] and when experienced anaesthesiologists themselves provide the S/GA [9].Furthermore, when movement is excessive, procedures are often rescheduled until an expert sedation service provider is available. Obviously, this leads to significant increases in the cost of the procedure as well as patient stress. It is better to assess the patients prior to the procedure, decide if S/GA might be required and employ the appropriate technique the first time around.General anaesthesia is often the best choice for children who are neurologically impaired, have global developmental delay or exhibit severe disturbances of behaviour, and also in cases where the procedure is likely to be prolonged [7].Sedation has been the method of choice for image acquisition for many years, and is routinely provided by radiological staff within the imaging department. However, owing to identified risks and overall increased cost, there is a trend towards routinely using a dedicated anaesthetics team to provide this service in paediatric cases. Because this involves a change in established service provision in most imaging departments, the funding for the anaesthetic service is often debated. Provision must be made to divert some of the funding stream for a specific imaging procedure which involves S/GA to the anaesthetics department, which sometimes involves renegotiating imaging tariffs. Also, in busy departments where lists are booked to capacity, allocating sufficient time to image children and conforming to the allocated timeslot is the key to running an efficient department.Another issue to address is the capacity and availability of anaesthetists (and their support staff, such as the operating department practitioners) who are trained in paediatric S/GA. Scheduling difficulty often arises if these personnel are required for short specified and sometimes unpredictable periods to fit around the imaging department’s and patient’s needs.