Sedation in hypoalbuminemic geriatric patients under spinal anesthesia in hip surgery: Midazolam or Propofol?

Objectives:

To compare midazolam and propofol sedation in hypoalbuminemic geriatric patients under spinal anesthesia in hip surgery with bispectral index monitoring.

Methods:

This prospective and randomized study was completed in the Department of Anesthesiology, Okmeydani Training and Research Hospital, Istanbul, Turkey between February 2013 and December 2014. Sixty patients undergoing elective hip surgery under spinal anesthesia in the geriatric age group with albumin levels below 3 g/dl were randomly divided into Group I and Group II. After administration of spinal block, Group I were given 0.05 mg/kg bolus midazolam, and then 0.02-0.1 mg/kg/hr dose infusion was begun. In Group II, 1 mg/kg bolus propofol was given within 10 minutes, and then 1-3 mg/kg/hr infusion was begun. The systolic arterial pressure, diastolic arterial pressure, mean arterial pressure, heart rate, peripheral oxygen saturation values, respiratory rate, and Wilson’s 5-stage sedation score were recorded at 15-minute intervals. At the end of the operation, the recovery time and surgeon satisfaction were recorded.

Results:

The recovery times for patients in Group I were found to be longer than in Group II (p<0.05). The respiration rate in patients in Group I at the start of surgery, 15th minute of surgery, and after surgery were lower than in Group II (p<0.05).

Conclusion:

We conclude that propofol is more reliable in terms of hemodynamic stability than midazolam, as it causes less respiratory depression and faster recovery in the propofol group.Spinal anesthesia is used at very high rates in elderly patients, and is a well-tolerated anesthetic method. Even in geriatric patients with left ventricle failure and in spite of a clear reduction in systemic vascular resistance linked to spinal anesthesia, it is proven that stroke volume and cardiac output do not decrease much.1 Sedation is a very important component of patient management during regional anesthesia. As the patient is conscious during operation under regional anesthesia, the surgical environment may negatively affect the patient. These effects may be more obvious during orthopedic interventions due to the noise of tools used, long duration of tourniquet use, position given, and manipulation of patient extremities during the surgery. To remove the possibility of such effects, the most appropriate method is to administer sedation to the patient.2 It is very important that sedation administration be appropriate for the patient’s characteristics, as well as reliable, and effective. As a result, the appropriate dose of the correct sedative agent should be administered. In elderly patients especially, there is an increased sedative response to centrally effective agents.3,4 Midazolam and propofol are agents frequently used for sedation. Midazolam binds to plasma proteins, especially albumin at a rate of 98%. The free fraction increases in hypoalbuminemic patients.5,6 Propofol is significantly lipophilic and like medications, such as midazolam, 98% is carried bound to plasma proteins. As a result of pharmacokinetic changes due to advanced age, the same dose provides higher plasma concentrations, and this increase reduces the dose requirements. As maximal plasma concentrations are higher in the elderly, a situation occurs where the possibility of cardiorespiratory effects like hypotension, apnea, airway obstruction and/or oxygen desaturation is higher in these patients. Higher plasma levels reduce the distribution volume linked to age, and shows reduced clearance between compartments. As a result, lower doses of propofol are recommended for use in elderly patients at the start, and for maintenance, of sedation/anesthesia.7 In the elderly, hypoalbuminemia may occur linked to acute phase reaction, inflammation and trauma, in addition to malnutrition. Hypoalbuminemia is a frequent finding in geriatric hip surgery patients. Although there are many studies comparing propofol and midazolam sedation administered with spinal anesthesia,8-10 there is no study comparing the efficacy and reliability of midazolam and propofol for hypoalbuminemic geriatric patients. This study primarily aimed to prospectively and randomly compare the effects of midazolam and propofol on hemodynamic parameters and side effects in hypoalbuminemic geriatric patients undergoing hip surgery under spinal anesthesia. The secondary end points of this study were to compare the sedation levels of patients, postoperative recovery duration, and patient and surgeon satisfaction.     

七氟烷吸入联合丙泊酚-芬太尼复合静脉麻醉用于小儿气管异物取出术的麻醉效果观察

目的探讨七氟烷吸入联合丙泊酚-芬太尼复合静脉麻醉应用于小儿气管异物取出术的麻醉效果。方法选取行气管异物取出术患儿45例,随机分为两组。观察组24例采用七氟烷吸入联合丙泊酚-芬太尼复合静脉麻醉,对照组21例采用丙泊酚复合芬太尼麻醉。观察手术前后相关指标的变化。结果两组患儿插气管镜后和清醒后平均动脉压、心率、呼吸频率均有所下降（P〈0．05）。观察组患儿术中呛咳、屏气及术后恶心呕吐、躁动的发生率低于对照组（P〈0．05）。且观察组的出入镜次数、手术时间以及麻醉恢复时间均短于对照组（P〈0．05）。结论七氟烷吸入联合丙泊酚-芬太尼复合静脉麻醉应用于小儿气管异物取出术效果显著,且安全有效．无严重不良反应发生,值得临床进一步推广研究。     

喉罩用于静脉复合麻醉下颅骨修补术的气道管理体会

目的:观察喉罩应用于瑞芬太尼复合丙泊酚静脉麻醉下行颅骨修补术的临床效果及安全性。方法:选择ASAⅠ~Ⅱ级,行择期颅骨修补术患者20例。麻醉诱导为缓慢静注丙泊酚2 mg/kg,瑞芬太尼1μg/kg。诱导后3~5 min后待患者意识消失、无明显对抗时置入喉罩,保留自主呼吸。麻醉维持为丙泊酚5 mg/(kg.h),瑞芬太尼0.1μg/(kg.h)。手术开始时,由手术者采用0.5%利多卡因在手术区域行局部浸润麻醉。严密观察并记录患者心率(HR)、血压(BP)、脉搏血氧饱和度(SpO2)、呼吸频率(RR)的变化及术毕患者苏醒时间。结果:20例患者麻醉效果均满意。麻醉期间各时间点HR、BP、SpO2及RR值无显著性差异(P>0.05)。术毕至患者OAA/S评分≥4分的时间为(7.53±2.56)min。麻醉期间4例患者出现一过性呼吸抑制(SpO2<93%),无低血压,无恶心、呕吐,无心动过缓。1例女性患者术毕苏醒后烦躁。结论:瑞芬太尼复合丙泊酚加局麻配合使用喉罩应用于颅骨修补术,是一种安全、可靠的麻醉方法。     

异丙酚与芬太尼复合静脉麻醉在小儿气管异物取出术中的应用

目的：探讨异丙酚与芬太尼复合静脉麻醉用于小儿气管异物取出术的应用效果、血流动力学变化及并发症情况。方法：40例气管异物的患儿,芬太尼0．004mg/kg,异丙酚2mg／kg静脉诱导,咽喉部表麻后置入直达喉镜;经直达喉镜的吸氧孔接高频喷射通气管,术中根据患儿体动情况静注异丙酚1～1．5mg／kg,异物取出后停止给药,记录入室、麻醉后、手术开始、及术毕时的MAP、HR、SPO2,记录术中喉痉挛、分泌物、手术操作满意度情况,术后患儿苏醒时间、有无惊厥、躁动,恶心、呕吐等并发症。结果：40例患儿麻醉成功,均顺利完成异物取出术,术中血流动力学变化稳定,术后苏醒快,并发症少。结论：异丙酚与芬太尼复合静脉麻醉可满足小儿气管异物取出的手术,麻醉安全、平稳,并发症少。     

右美托咪定对小儿全麻苏醒期的影响

目的 观察右美托咪定预防小儿全麻苏醒期躁动的效果.方法 选择ASA分级Ⅰ～Ⅱ级在丙泊酚复合瑞芬太尼静脉全麻行腹股沟疝行常规手术的患儿60例.随机分为对照组(C组)和右美托咪定(D组)组各30例,麻醉前对照组注射生理盐水10mL,右美托咪定组注射右美托咪定0.5μg/kg,两组患儿静脉注射瑞芬太尼0.5μg/kg和丙泊酚2mg/kg麻醉诱导,麻醉维持采用静脉输注丙泊酚5mg/kg·h和瑞芬太尼0.2μ g/kg·min,在手术结束前15min静脉注射芬太尼0.1μ g/kg.记录小儿苏醒时(T0)、小儿苏醒后10 min(T1)、小儿苏醒后30 min(T2)、小儿苏醒后60 min(T3)的HR、Sp02.记录小儿苏醒时间、躁动评分及躁动例数.结果 两组小儿苏醒后各时间点Sp02比较无统计学意义,但苏醒后各时间点右美托咪定组患儿的HR比对照组低,比较具有统计学意义.D组比C组的苏醒时间延长,具有统计学意义.美托咪定组患儿躁动评分比对照组低,两组间比较有统计学意义,躁动例数D组比C组明显少比较,比较有统计学意义(P＜0.05).结论 术前静脉注射右美托咪定0.5μg/kg能有效预防小儿全麻术后躁动,且没有呼吸抑制作用,是预防小儿全麻术后躁动的一个很好选择.     

Effect of preemptive intravenous oxycodone on low-dose bupivacaine spinal anesthesia with intrathecal sufentanil

Objectives:

To evaluate the efficacy of preemptive intravenous oxycodone on low-dose bupivacaine spinal anesthesia with intrathecal sufentanil in patients undergoing transurethral resection of the prostate (TURP).

Methods:

In this randomized, double-blinded, placebo-controlled trial, 60 patients undergoing TURP were allocated into 2 groups: oxycodone group (group O, n=30) and a normal saline group (group N, n=30). Oxycodone 0.1 mg/kg, or normal saline 0.1 ml/kg was administered intravenously 10 minutes before surgical procedures in group O, or in group N. All patients received sufentanil 5 µg + bupivacaine 0.5% (0.8 ml) + normal saline 0.7 ml - in total, bupivacaine 0.25% (1.6 ml) intrathecally. Spinal block characteristics, hemodynamic values, the perioperative analgesic requirements, visual analogue scale (VAS) scores, Ramsay sedation scale, and side effects were assessed. The study was carried out at the First Hospital of Jilin University, Jilin, China between March and September 2014.

Results:

The time to 2-segment regression of sensory block, full recovery of sensory block, and first analgesic request was longer in group O. Fewer patients required postoperative analgesics, and the VAS pain scores at 4, 8, 16, and 24 hour after operation were significantly lower in group O.

Conclusion:

Preemptive intravenous oxycodone was an efficient and safe method to decrease postoperative pain and reduce tramadol analgesia in patients under low-dose dilute bupivacaine spinal anesthesia combined with intrathecal sufentanil.Intrathecal anaesthesia is preferred for transurethral resection of the prostate (TURP) for early recognition of transurethral resection syndrome. Low-dose bupivacaine with intrathecal 5 µg sufentanil can yield adequate anaesthesia with minimal hemodynamic instability for TURP.1 Most patients undergoing TURP are elderly and frequently present with cardiac or pulmonary conditions. Therefore, it is important to decrease and delay postoperative pain to reduce stress reactions, and furthermore to prevent the occurrence of severe adverse effects.2,3 Preemptive analgesia has been shown to be effective in control of postoperative pain by protecting the CNS from deleterious effects of noxious stimuli, which can result in allodynia and increased pain. Oxycodone, a type of opioid, was previously reported to have a preemptive analgesic effect on general anesthesia.4 However, there is a scarcity of information on an association with preemptive analgesic efficacy of intravenous oxycodone on spinal anesthesia. In this prospective, randomized, placebo-controlled, double-blinded clinical trial, the hypothesis was tested that preemptive intravenous oxycodone would enhance this method of spinal anesthesia, reduce postoperative pain, and decrease and delay postoperative analgesic requirement.     

The pattern of plasma sodium abnormalities in an acute elderly care ward: A cross-sectional study

Introduction

The combination of ageing, illness, and medications can lead to hyponatraemia or hypernatraemia.

Aims

To describe the distribution of plasma sodium levels in older patients admitted to hospital.

Methods

We carried out a hospital based cross-sectional study examining 1,511 serum sodium concentrations ([Na⁺]) among 336 elderly patients and attempted to elucidate the cause(s) of the abnormal serum [Na⁺].

Results

The study population had a mean age of 81.4. Ninety-two (27.4%) patients had hyponatraemia and seven patients (2.1%) had hypernatraemia during their hospitalisation. The distribution of [Na⁺] results was towards the lower end of the normal range. The mortality rate of patients with hyponatraemia was 14.1% and that of patients with normal serum [Na⁺] was 8.9%. Six patients with hypernatraemia died in hospital. Lower respiratory tsuract infection and medication accounted for the majority of cases.

Conclusions

Deranged [Na⁺] is common among elderly patients admitted to hospital.     

利多卡因胶浆表面麻醉复合小剂量丙泊酚在老年无痛胃镜检查中的应用

目的 探讨利多卡因胶浆表面麻醉复合小剂量丙泊酚静脉麻醉用于老年患者无痛胃镜检查及治疗的可行性.方法 156例自愿接受无痛胃镜检查的65岁以上老年患者采用数字表法随机分为：复合表面麻醉组（LP组,n=78）,胃镜检查前患者含服2%盐酸利多卡因胶浆10 mL,表面麻醉后缓慢静脉注射小剂量丙泊酚（0.8～1.5 mg/kg）,使患者进入麻醉状态,再进行胃镜检查;单纯丙泊酚麻醉组（P组,n=78）,静脉缓慢注射丙泊酚（1～1.8 mg/kg）,待患者进入麻醉状态后进行胃镜检查.记录胃镜检查前、检查中和检查后的血氧饱和度（oxyhemoglobin saturation,SpO2）、血压（blood pressure,BP）、心率（heart rate,HR）的变化,记录检查中呛咳反应和体动的发生率,以及检查后询问患者是否愿意接受再次检查（复检率）.结果 所有患者均顺利完成检查及治疗,未出现明显恶心呕吐、体动等症状,无呼吸抑制发生.2组患者检查前、检查中、检查后的血流动力学比较,差异无统计学意义（P〉0.05）;LP组患者检查中出现呛咳反应和咽部不适明显少于P组（P〈0.05）;LP组愿意接受再次胃镜检查的患者数,明显高于P组（P〈0.05）;LP组丙泊酚用量明显低于P组（P〈0.05）.结论 利多卡因胶浆表面麻醉复合小剂量丙泊酚静脉麻醉用于老年患者无痛胃镜检查,安全、舒适,是一种较为可行的麻醉方法.     

老年人腹腔镜胆囊切除术麻醉的临床研究

为观察异丙酚全凭静脉麻醉在老年人腹腔镜胆囊切除术 (LC)围麻醉期呼吸循环功能的变化 ,以评价其实用性和安全性 ,将 30例ASAⅠ～Ⅱ级患者 ,择期行LC手术 ,以微量泵持续静注异丙酚维持麻醉 (剂量递减法 10～ 8～ 6mg/kg·h-1) ,控制呼吸频率 16～ 2 5 /min ,人工气腹后保持轻度过度通气状态 ,连续监测呼吸循环功能各参数的变化。结果显示 :本组异丙酚平均总用量为 5 6 0± 12 8mg( 8.0 5± 2 .16mg/kg·h-1) ,麻醉诱导后SBP、DBP、MAP一过性降低 (P <0 .0 1) ,于插管后迅速恢复 ;CO2 气腹后PETCO2 开始上升并于 15min后达最高值但在正常范围 ,86 .6 7%的病例于拔管后 5～ 10min麻醉苏醒并能简单答话。认为异丙酚全凭静脉维持麻醉用于老年人LC并于气腹期轻度过度通气能维持呼吸循环功能的相对稳定 ,且苏醒快 ,术后恢复良好 ,具有实用性和安全性     

Oral administration of cilnidipine to patients with hypertensive intracerebral hemorrhage in the acute stage: significance and role of an N-type calcium channel blocker

Background

Elevated blood pressure (BP) causes re-bleeding or enlargement of intracerebral hematomas.

Aims

How a long-acting oral calcium channel blocker, cilnidipine, could control BP in the acute stage of cerebral hemorrhage was evaluated.

Methods and results

Cilnidipine given within 3 days of hospitalization has more benefit than cilnidipine given after 4 days of hospitalization; it can reduce the amount of intravenous nicardipine, and it can help to maintain the BP below 80% of the initial BP. Surgical removal of the hematoma has no benefit in reducing the amount of intravenous nicardipine and maintaining the BP below 80% of the initial BP.

Conclusion

In order to reduce the total amount of intravenous nicardipine and to maintain the BP below 80% of the initial BP, oral administration of a long-acting N-type calcium channel blocker, cilnidipine, is useful and important, independent of whether the hematomas are surgically removed.     

In-situ emergency pediatric surgery in the intensive care unit

Background

The role of surgery in the intensive care unit (ICU) remains unclear. Although previous studies have not shown any increase in morbidity when operating on patients in the ICU for surgical procedures; there remains a reluctance to operate on sick patients in the ICU.

Aim

We did a retrospective study of critically ill children and neonates who underwent in-situ surgery (ISS) to further evaluate its safety and potential. Surgery was aided with the use of operative loupes and high-intensity headlight.

Methods

The medical records of all patients who had undergone surgical procedures in the pediatric ICU over an 11-year period from January 1998 till December 2008 were retrospectively reviewed. We reviewed our experience looking specifically at wound infection rates along with other morbidities in 543 patients.

Results

Our morbidities were comparable with that of operations performed in the operating theater, with low wound infection rates (1 %) for all surgeries undertaken in the pediatric ICU.

Conclusion

ISS avoids the risks of transfer to the operative theater and the potential delays in theater access. Our results suggest that ISS in a tertiary-level pediatric surgical hospital is safe and does not impact adversely on clinical outcome.     

异丙酚加小剂量芬太尼麻醉在人工流产术中的应用

目的 在30例人工流产手术病人观察异丙酚加小剂量芬太尼的麻醉效果及其对呼吸、循环功能的影响.方法 先静注芬太尼1ug/kg,接着静注异丙酚2mg/kg,并继以0.1～0.2mg/kg/min的速度持续输注.结果 麻醉效果满意,对循环功能影响较轻.但对呼吸功能仍有明显抑制,呼吸频率减慢发生率为56.7%,SPO2下降发生率为60%,但在5min内均能自行恢复.结论 异丙酚配合小剂量芬太尼用于人工流产手术简便易行,诱导迅速舒适,苏醒快而完全,但应注意其对呼吸、循环功能的抑制.     

Not written, not done: are we identifying elderly at-risk patients for pneumococcal vaccination?

Background

Pneumococcal disease, especially in its invasive form, is a significant cause of morbidity and mortality worldwide. However, with the advent of vaccination, invasive disease is potentially avoidable. This study aimed to assess the documentation of pneumococcal vaccination status in elderly patients by healthcare professionals in a busy teaching hospital environment.

Methods

One hundred and fifty-seven open (active) medical records of inpatients and outpatients aged over 65 years were reviewed, to examine for evidence of documentation of pneumococcal vaccination status.

Results

From the medical records, 338 patient encounters were studied. Overall, there was a mean of 2.4 ± 1.2 indications for pneumococcal vaccination, with more indications in medical than in surgical patients (P = 0.04). The rate of recording in respiratory outpatient clinics was 71.4 % in comparison to 0 % in other medical and surgical outpatient clinics. Overall the documentation rate was 2.1 %.

Conclusions

Only respiratory physicians had demonstrable evidence of actively asking about pneumococcal vaccination on a regular basis. There is considerable need for increased awareness among healthcare professionals and improvement in methods of recording vaccination status.     

A Time Series Observation of Chinese Children Undergoing Rigid Bronchoscopy for an Inhaled Foreign Body: 3149 Cases in 1991–2010

Background:

In China, tracheobronchial foreign body (TFB) aspiration, a major cause of emergency episode and accident death in children, remains a challenge for anesthetic management. Here, we share our experience and discuss the anesthetic consideration and management of patients with TFB aspiration.

Methods:

This was a single-institution retrospective study in children with an inhaled foreign body between 1991 and 2010 that focused on the complications following rigid bronchoscopy (RB). Data including the clinical characteristics of patients and TFB, anesthetic method, and postoperative severe complications were analyzed by different periods.

Results:

During the 20-year study period, the charts of 3149 patients who underwent RB for suspected inhaled TFB were reviewed. There were 2079 male and 1070 female patients (1.94:1). A nut (84%) was the most commonly inhaled object. The study revealed a 9% (n = 284) overall rate of severe postoperative complications related to severe hypoxemia, laryngeal edema, complete laryngospasm, pneumothorax, total segmental atelectasis, and death with incidences of 3.2%, 0.9%, 1.3%, 0.3%, 0.3%, and 0.1%, respectively. The rates of preoperative airway impairment, negative findings of TFB, and adverse postoperative events have been on the rise in the past 5 years.

Conclusions:

The survey results confirmed that hypoxemia remains the most common postoperative complication in different periods. Both controlled ventilation and spontaneous ventilation were effective during the RB extraction of the foreign body at our hospital in the modern technique period. An active respiratory symptom was commonly seen in the groups with negative findings.     

Submental intubation: a retrospective review of 45 cases

Background

Airway management in patients undergoing maxillofacial surgery requires special consideration. A number of options including oro- or naso-tracheal intubation and tracheostomy are available. Submental intubation is now a recognised method of airway control during maxillofacial surgery. It provides a secure airway and does not interfere with maxillomandibular fixation or access to naso-orbito-ethmoid fractures. It avoids potential complications associated with nasotracheal intubation and tracheostomy in patients with multiple facial fractures, and obviates the need to alternate between oral and nasal intubation intra-operatively.

Methods

This is a ten year retrospective review of patients who underwent submental intubation in a Regional Oral and Maxillofacial Surgery Department. The following variables were recorded: patient gender and age, preoperative diagnosis, duration of intubation, and complications associated with the intubation technique.

Results

Submental intubation was performed 45 times on 45 patients. There were no complications relating to the submental intubation procedure.

Conclusion

Submental intubation should be considered as an option for airway management in selected cases of craniomaxillofacial surgery. It is a quick and safe technique with minimal morbidity and a low complication rate. It allows access to the maxillofacial skeleton intra-operatively and does not preclude the use of intermaxillary fixation.     

丙泊酚复合瑞芬太尼和氯胺酮用于小儿非插管全麻的临床观察

目的观察丙泊酚-瑞芬太尼麻醉与丙泊酚-氯胺酮麻醉用于小儿非插管全麻短小手术的临床效果和安全性。方法选择40例短小手术患儿平分为瑞芬太尼组和氯胺酮组。两组麻醉诱导和维持分别选用微量泵输注丙泊酚-瑞芬太尼和丙泊酚-氯胺酮，记录两组患儿围手术期心率（HR）、平均动脉压（M AP）、呼吸频率（RR）和脉搏氧饱和度（SpO2）的变化，并同时记录术后清醒时间、麻醉恢复时间以及术后恶心呕吐发生情况。结果与术前相比，手术期间瑞芬太尼组HR、RR和M AP均有下降，而氯胺酮组无变化。瑞芬太尼组患儿出现恶心呕吐。结论微量泵注丙泊酚-氯胺酮麻醉在维持患儿血流动力学稳定、减少呼吸抑制和术后恶心呕吐发生率等方面优于复合瑞芬太尼，使小儿非插管全身麻醉更平稳安全。     

Medical complications and outcomes at an onsite rehabilitation unit for older people

Background

The rehabilitation of older patients in Ireland after an acute medical event occurs at dedicated onsite hospital units or at offsite centres. Information on medical complications and outcomes is inadequate.

Aims

Enumeration of medical complications of patients admitted to a dedicated onsite rehabilitation unit for older people, and the extent of co-morbidity in the population with the effects that this had on the evolution of medical complications.

Methods

A retrospective analysis of patients admitted to a 58-bed onsite unit over a 1-year period was performed. Information collating co-morbidities, medical complications and functional outcomes was recorded.

Results

Medical complications occurred in almost 95 % of patients, where full data were available. Over one-third required intravenous therapy.

Conclusion

Twenty-four hour medical cover is required for older patients managed at onsite rehabilitation units. Further studies on offsite medical rehabilitation facilities for older patients are required.     

Changes in the Bispectral Index in Response to Loss of Consciousness and No Somatic Movement to Nociceptive Stimuli in Elderly Patients

Background:

Bispectral index (BIS) is considered very useful to guide anesthesia care in elderly patients, but its use is controversial for the evaluation of the adequacy of analgesia. This study compared the BIS changes in response to loss of consciousness (LOC) and loss of somatic response (LOS) to nociceptive stimuli between elderly and young patients receiving intravenous target-controlled infusion (TCI) of propofol and remifentanil.

Methods:

This study was performed on 52 elderly patients (aged 65–78 years) and 52 young patients (aged 25–58 years), American Society of Anesthesiologists physical status I or II. Anesthesia was induced with propofol administered by TCI. A standardized noxious electrical stimulus (transcutaneous electrical nerve stimulation, [TENS]) was applied (50 Hz, 80 mA, 0.25 ms pulses for 4 s) to the ulnar nerve at increasing remifentanil predicted effective-site concentration (Ce) until patients lost somatic response to TENS. Changes in awake, prestimulus, poststimulus BIS, heart rate, mean arterial pressure, pulse oxygen saturation, predicted plasma concentration, Ce of propofol, and remifentanil at both LOC and LOS clinical points were investigated.

Results:

BIS_LOC in elderly group was higher than that in young patient group (65.4 ± 9.7 vs. 57.6 ± 12.3) (t = 21.58, P < 0.0001) after TCI propofol, and the propofol Ce at LOC was 1.6 ± 0.3 μg/ml in elderly patients, which was significantly lower than that in young patients (2.3 ± 0.5 μg/ml) (t = 7.474, P < 0.0001). As nociceptive stimulation induced BIS to increase, the mean of BIS maximum values after TENS was significantly higher than that before TENS in both age groups (t = 8.902 and t = 8.019, P < 0.0001). With increasing Ce of remifentanil until patients lost somatic response to TENS, BIS_LOS was the same as the BIS_LOC in elderly patients (65.6 ± 10.7 vs. 65.4 ± 9.7), and there were no marked differences between elderly and young patient groups in BIS_awake, BIS_LOS, and Ce of remifentanil required for LOS.

Conclusion:

In elderly patients, BIS can be used as an indicator for hypnotic-analgesic balance and be helpful to guide the optimal administration of propofol and remifentanil individually.

Trial Registration:

CTRI Reg. No: ChiCTR-OOC-14005629; http://www.chictr.org.cn/showproj.aspx?proj=9875.     

两种麻醉方法用于恒河猴急性脑梗死模型麻醉效果的比较

目的 比较两种麻醉方法用于恒河猴急性脑梗死模型的麻醉效果。方法 选择拟行大脑中动脉M2段栓塞建立急性脑梗死模型的健康成年恒河猴16只,雄性,采用数字表法随机分为2组（n=8）：丙泊酚组（P组）、丙泊酚+右美托咪定组（PD组）。所有恒河猴采用0.1 mL/kg氯胺酮及速眠新的混合液肌内注射进行基础麻醉。待动物入睡后行气管内插管,接呼吸机行机械通气,P组麻醉维持采用持续输注丙泊酚,PD组麻醉维持采用持续输注丙泊酚及右美托咪定,两组必要时均追加上述氯胺酮与速眠新的混合液。大脑中动脉M2段栓塞模型制备结束后,停止输注麻醉维持药物,待恒河猴恢复自主呼吸,行头部磁共振成像（magnetic resonance imaging,MRI）检查。记录术中血流动力学变化、自主呼吸恢复时间、建模术中追加氯胺酮与速眠新混合液容量、丙泊酚用量、麻醉合并症发生情况。结果 16只恒河猴全部存活超过24 h。实验中16只恒河猴未发生躁动、呼吸抑制、心律失常等严重合并症。血流动力学指标、体温、动脉血气分析均在正常范围。两组不同时刻血流动力学指标、体温、动脉血气分析比较差异无统计学意义（P>0.05）。全部恒河猴均在实验结束停药后30 min内恢复自主呼吸,两组自主呼吸恢复时间比较,差异无统计学意义（P>0.05）。PD组术中丙泊酚用量、术中追加氯胺酮与速眠新混合液容量低于P组（P<0.05）。结论 两种麻醉方法用于恒河猴大脑中动脉M2段栓塞建立急性脑梗死模型麻醉效果良好,麻醉深度可控、安全性高。右美托咪定可减少建模术中丙泊酚、氯胺酮与速眠新混合液用量。