Use, applicability and reliability of depth of hypnosis monitors in children - a survey among members of the European Society for Paediatric Anaesthesiology.

BACKGROUND: To assess the thoughts of practicing anaesthesiologists about the use of depth of hypnosis monitors in children. METHODS: Members of the European Society for Paediatric Anaesthesiology were invited to participate in an online survey about their thoughts regarding the use, applicability and reliability of hypnosis monitoring in children. RESULTS: The survey achieved a response rate of 30% (N = 168). A total of 138 completed surveys were included for further analysis. Sixty-eight respondents used hypnosis monitoring in children (Users) and 70 did not (Non-users). Sixty-five percent of the Users reported prevention of intra-operative awareness as their main reason to apply hypnosis monitoring. Among the Non-users, the most frequently given reason (43%) not to use hypnosis monitoring in children was the perceived lack or reliability of the devices in children. Hypnosis monitoring is used with a higher frequency during propofol anaesthesia than during inhalation anaesthesia. Hypnosis monitoring is furthermore used more frequently in children > 4 years than in younger children. An ideal hypnosis monitor should be reliable for all age groups and any (combination of) anaesthetic drug. We found no agreement in the interpretation of monitor index values and subsequent anaesthetic interventions following from it. CONCLUSIONS: Prevention of intraoperative awareness appears to be the most important reason to use hypnosis monitoring in children. The perceived lack of reliability of hypnosis monitoring in children is the most important reasons not to use it. No consensus currently exists on how to adjust anaesthesia according to hypnosis monitor index values in children.

Intraoperative Completion Studies, Local Anesthesia, and Antiplatelet Medication Are Associated With Lower Risk in Carotid Endarterectomy.

BACKGROUND AND PURPOSE: In Germany, all surgical and endovascular procedures on the carotid bifurcation must be documented in a statutory nationwide quality assurance database. We aimed to analyze the association between procedural and perioperative variables and in-hospital stroke or death rates after carotid endarterectomy. METHODS: Between 2009 and 2014, overall 142 074 elective carotid endarterectomy procedures for asymptomatic or symptomatic carotid artery stenosis were documented in the database. The primary outcome of this secondary data analysis was in-hospital stroke or death. Major stroke or death, stroke, and death, each until discharge were secondary outcomes. Adjusted relative risks (RRs) were assessed by multivariable multilevel regression analyses. RESULTS: The primary outcome occurred in 1.8% of patients, with a rate of 1.4% in asymptomatic and 2.5% in symptomatic patients, respectively. In the multivariable analysis, lower risks of stroke or death were independently associated with local anesthesia (versus general anesthesia: RR, 0.85; 95% confidence interval [CI], 0.75-0.95), carotid endarterectomy with patch plasty compared with primary closure (RR, 0.71; 95% CI, 0.52-0.97), intraoperative completion studies by duplex ultrasound (RR, 0.74; 95% CI, 0.63-0.88) or angiography (RR, 0.80; 95% CI, 0.71-0.90), and perioperative antiplatelet medication (RR, 0.83; 95% CI, 0.71-0.97). No shunting and a short cross-clamp time were also associated with lower risks; however, these are suspected to be confounded. CONCLUSIONS: Local anesthesia, patch plasty compared with primary closure, intraoperative completion studies by duplex ultrasound or angiography, and perioperative antiplatelet medication were independently associated with lower in-hospital stroke or death rates after carotid endarterectomy.

Retrospective Cohort Study to Compare Anesthesia in Living Donor Liver Transplantation Recipients Who Received Single and Dual Liver Grafts.

OBJECTIVE: Dual graft living donor liver transplantation (LDLT) is an alternative way to overcome small-for-size syndrome in LDLT. Surgical technique and outcome of using dual grafts have been reported, but there are no reports regarding anesthetic management. The aim of the current study is to compare the anesthetic management of single graft and dual graft liver transplantation. METHODS AND PATIENTS: Anesthesia records of 24 single graft liver transplantation recipients (GI) and 6 dual graft recipients (GII) were reviewed, analyzed, and compared retrospectively. Patient characteristics and intraoperative data between groups were compared with Mann-Whitney t test and Fisher's exact test where appropriate. P value less than .05 was regarded as significant. RESULTS: Patient characteristics and most of the intraoperative data were similar between groups. Significant difference was noted in the total anesthesia time and the anhepatic time. Both times were significantly longer in GII compared to GI. CONCLUSION: Dual graft living donor liver transplantation is surely a technically more challenging and demanding procedure. Therefore the total anesthesia time is longer, especially the anhepatic phase, because there are more graft vessels to be reconstructed before reperfusion. Overall the anesthetic management in terms of blood transfusion, fluid administration, sodium bicarbonate, calcium supplement, and the number of patients requiring fractional diluted noradrenaline support for maintenance of acceptable hemodynamic were not much different between the 2 groups.

Control Law Design for Propofol Infusion to Regulate Depth of Hypnosis: A Nonlinear Control Strategy.

Maintaining the depth of hypnosis (DOH) during surgery is one of the major objectives of anesthesia infusion system. Continuous administration of Propofol infusion during surgical procedures is essential but increases the undue load of an anesthetist in operating room working in a multitasking setup. Manual and target controlled infusion (TCI) systems are not good at handling instabilities like blood pressure changes and heart rate variability arising due to interpatient variability. Patient safety, large interindividual variability, and less postoperative effects are the main factors to motivate automation in anesthesia. The idea of automated system for Propofol infusion excites the control engineers to come up with a more sophisticated and safe system that handles optimum delivery of drug during surgery and avoids postoperative effects. In contrast to most of the investigations with linear control strategies, the originality of this research work lies in employing a nonlinear control technique, backstepping, to track the desired hypnosis level of patients during surgery. This effort is envisioned to unleash the true capabilities of this nonlinear control technique for anesthesia systems used today in biomedical field. The working of the designed controller is studied on the real dataset of five patients undergoing surgery. The controller tracks the desired hypnosis level within the acceptable range for surgery.

Risks factors and regression model for risk calculation of anesthesiologic intervention in topical and intracameral cataract surgery.

PURPOSE: To determine risk factors for anesthesiologist intervention during routine cataract surgery performed with topical and intracameral anesthesia and establish a regression model to identify high-risk patients. SETTING: Department of Ophthalmology, Clínica Universidad de Navarra, Pamplona, Spain. DESIGN: Prospective case series. METHODS: After cataract surgery at an ambulatory surgical center, anesthesia personnel completed a questionnaire to determine adverse medical events and risk factors related to anesthesiologist intervention. A Poisson regression model was used to calculate the interventional risks. Bootstrapping was performed for internal model validation. RESULTS: Of the 1010 cases, 50 (4.95%) required anesthesiologist intervention. Univariate analysis identified an association between anesthesiologist intervention and hypertension (P<.001), psychiatric history (P=.002), initial systolic blood pressure (P<.001), surgical duration (P=.001), and diabetes (P=.018). Scores were obtained using the following proposed regression model equation: (-8.68 + 0.33 × sex [men, 0; women, 1] + -0.02 × age [years] + 0.68 × hypertensive history [no, 0; yes, 1] + 1.18 × psychiatric background [no, 0; yes, 1] + 0.04 × initial systolic blood pressure [mm Hg]). The area under the receiver-operating curve was 0.803 (95% confidence interval [CI], 0.721-0.886). The area under the curve found in the validation method was 0.813 (95% CI, 0.727-0.887). CONCLUSION: Hypertension was the main risk factor for anesthesiologist intervention. The regression model discriminated between patients at lower and higher risk for intraoperative intervention for monitored anesthesia care. The probability of anesthesiologist intervention was 11.7 times higher when the model obtained a high score. FINANCIAL DISCLOSURE: No author has a financial or proprietary interest in any material or method mentioned.

A randomized-controlled pilot study comparing ICD implantation with and without intraoperative defibrillation testing in patients with heart failure and severe left ventricular dysfunction: a substudy of the RAFT trial.

INTRODUCTION: The need to perform defibrillation testing (DT) at the time of implantable cardioverter defibrillator (ICD) insertion is controversial. In the absence of randomized trials, some regions now perform more than half of ICD implants without DT. METHODS: During the last year of enrolment in the Resynchronization for Ambulatory Heart Failure Trial, a substudy randomized patients to ICD implantation with versus without DT. RESULTS: Among 252 patients screened, 145 were enrolled; 75 randomized to DT and 70 to no DT. Patients were similar in terms of age (65.9 ± 9.3 years vs 67.9 ± 8.9 years); LVEF (24.7 ± 4.6% vs 23.6 ± 4.6%), QRS width (154.8 ± 23.5 vs 155.8 ± 23.6 ms), and history of atrial fibrillation (5% vs 6%). All 68 patients in the DT arm tested according to the protocol achieved a successful DT (≤25 J); 96% without requiring any system modification. No patient experienced perioperative stroke, myocardial infarction, heart failure (HF), intubation or unplanned ICU stay. The length of hospital stay was not prolonged in the DT group: 20.2 ± 26.3 hours versus 21.3 ± 23.0 hours, P = 0.79. One patient in the DT arm had a failed appropriate shock and no patient suffered an arrhythmic death. The composite of HF hospitalization or all-cause mortality occurred in 10% of patients in the no-DT arm and 19% of patients in the DT arm (HR = 0.53, 95% CI: 0.21-1.31, P = 0.14). CONCLUSIONS: In this randomized trial, perioperative complications, failed appropriate shocks, and arrhythmic death were all uncommon regardless of DT. There was a nonsignificant increase in the risk of death or HF hospitalization with DT.

[Is the determination of the defibrillation threshold in patients with an implantable cardioverter-defibrillator still required?]. / Wird die Bestimmung der Defibrillationsschwelle bei Patienten mit implantierbarem Kardioverter/Defibrillator noch benötigt?

BACKGROUND: Intraoperative testing of implantable cardioverter-defibrillators (ICDs) is time consuming and associated with risks. In the present study, we elucidated whether the initial implantation of an ICD with high energy output makes intraoperative defibrillation threshold testing (DFTT) unnecessary even though antiarrhythmic (AA) therapy is needed in the future. METHODS: A total of 111 patients (94 men, 17 women) receiving an ICD with subsequent AA therapy (mexiletine, amiodarone, sotalol, flecainide) were analyzed retrospectively. DFT was performed during ICD implantation and after AA drug therapy. In a second step, DFT results from the study cohort were analyzed for implantation of virtual ICDs with either low (≤ 30 J, LOD), intermediate (34 J, IOD), or high energy output (36 J, HOD). RESULTS: In the study cohort, all patients reached the safety margin (SM) of 10 J between DFT and maximal shock energy of the ICD. After loading of AA agents, 6 patients (12%) with a LOD, 3 patients (11%) with an IOD, and 3 (13%) patients with a HOD failed the 10 J SM. Using virtual ICDs, 6 (5.5%) patients with a LOD, 1 patient (1%) with an IOD, and no patients with a HOD would have failed the 10 J SM. After loading of AA agents, 18 patients (16%) with a virtual LOD, 12 patients (10.8%) with an IOD, and still 9 patients (8%) with a HOD would have failed the 10 J SM. CONCLUSION: Our results demonstrate that the 10 J SM would have been achieved intraoperatively in all patients with virtual HOD ICDs. Thus, determination of the DFT during implantation does not seem to be obligatory. However, in patients receiving AA agents, DFT testing is still required.

Intraoperative mapping of language functions: a longitudinal neurolinguistic analysis.

OBJECT: This prospective longitudinally designed study was conducted to evaluate language functions pre- and postoperatively in patients who underwent microsurgical treatment of tumors in close proximity to or within language areas and to detect those patients at risk for a postoperative aphasic disturbance. METHODS: Between 1991 and 2005, 153 awake craniotomies with subsequent cortical mapping of language functions were performed in 149 patients. Language functions were assessed using a standardized test battery. Risk factors were obtained from multivariate logistic regression models. RESULTS: Language mapping was able to be performed in all patients, and complete tumor resection was achieved in 48.4%. Within 21 days after surgery a new language deficit (aphasic disturbance) was observed in 41 (32%) of the 128 cases without preoperative deficits. There were a total of 60 cases involving postoperative aphasic disturbances, including cases both with and without preoperative disturbances. Risk factors for postoperative aphasic disturbance were preoperative aphasia (p<0.0002), intraoperative complications (p<0.02), language-positive sites within the tumor (p<0.001), and nonfrontal lesion location (p<0.001). In patients without a preoperative deficit, a normal (yet submaximal) naming performance was a powerful predictor for an early postoperative aphasic disturbance (p<0.0003). Seven months after treatment 10.9% of the 128 cases without preoperative aphasic disturbances continued to demonstrate new postoperative language disturbances. A total of 17.6% of all cases demonstrated new postoperative language disturbances after 7 months. Risk factors for persistent aphasic disturbance were increased age (>40 years, p<0.02) and preoperative aphasia (p<0.001). CONCLUSIONS: Every attempt should be undertaken to preserve language-relevant areas intraoperatively, even when they are located within the tumor. New postoperative deficits resolve in the majority of patients, which may be a result of cortical mapping as well as functional reorganization.

Patient perceptions of "awake" brain tumour surgery.

BACKGROUND: Awake brain tumour surgery allows intraoperative patient assessment and is done to optimise safe tumour removal. It is an established technique but little is known about patient perceptions of the procedure. METHOD: Fifteen adult patients filled out a dedicated questionnaire to assess 10 aspects of patient perceptions of the procedure. FINDINGS: All patients, who were awake for a median of 45 minutes (range 10-105), stated they were adequately prepared for the operation. Most recollected various aspects of the procedure, although 3 patients (20%) had little memory of actually being awake during the surgery despite being cooperative. A minority reported more than minor discomfort (20%), fear (15%) or anxiety (29%), and most felt they coped with the cortical stimulations and functional testing well. Sources of discomfort and pain were the cranial pin holding device, operative position, inadequate infiltration of the cranial wound with local anesthetic, a full bladder causing a desire to micturate and a hard and uncomfortable operating table. CONCLUSIONS: These results, are very similar to a previous American report using a different anesthetic technique, in that most patients tolerate awake craniotomy remarkably well if the procedure is explained to them and some simple precautions are taken. Additionally between 8%-37% of patients (95% Confidence Interval, summing data from the two studies, n = 35) will have no recollection of being awake. Ways of minimising discomfort and problems of anxiety in this patient cohort are discussed.

The National Survey of Local Anaesthesia for Ocular Surgery. I. Survey methodology and current practice.

PURPOSE: To describe the current usage of the various techniques of local anaesthesia (LA) in the United Kingdom, and safety precautions taken. METHODS: An observational study of practice of LA in the whole of the United Kingdom was carried out over 3 months in late 1996. Staff in all ophthalmology theatres in the National Health Service were invited to report every LA given for the purpose of intraocular surgery during the first week, and thereafter to report adverse events only. RESULTS: Participation during the first week was calculated to be 72.8% overall. Anaesthesia techniques for intraocular surgery were: 70% LA alone, 5.8% LA with sedation and 24.2% general anaesthesia. LA techniques were: 65.6% peribulbar, 16.9% retrobulbar, 6.7% sub-Tenon's, 4.4% subconjunctival, 2.9% topical and 2.3% combinations. Of patients who were given LA, 96% were monitored, 84% had an anaesthetist available in theatres in case of a problem and intravenous access was established in 60%. CONCLUSION: Local anaesthesia is frequently used for intraocular surgery in the United Kingdom. A variety of techniques are used, and safety precautions are taken in most cases.

Effectiveness of monitored anesthesia care in cataract surgery.

OBJECTIVE: To determine the need for monitored anesthesia care in cataract surgery by evaluating the incidence of intervention by anesthesia personnel and by looking for associated risk factors. DESIGN: Nonrandomized, prospective case series with analysis of consecutive cataract surgery cases. PARTICIPANTS: A total of 1006 consecutive cataract surgery patients at an ambulatory surgery center over a 6-month period. METHODS: Routine cataract surgery was performed with the patient under local anesthesia. A detailed questionnaire was completed by the anesthesia personnel at the conclusion of each phase (before, during, and after) of cataract surgery. MAIN OUTCOME MEASURES: Age, medical history, and preoperative electrocardiogram (EKG) were analyzed as predictors for intervention by anesthesia personnel. The nature of the patient's problem and the type of intervention by anesthesia personnel were recorded. RESULTS: In 1006 consecutive cataract surgery cases, intervention by anesthesia personnel was required in 376 (37.4%) cases. No preoperative identifying characteristics were found to be reliable predictors of the need for intervention. There were no statistically significant differences in preoperative EKG and some medical conditions such as heart disease, diabetes, and thyroid disease between patients who received intervention and those who did not. Certain subgroups of patients did show a statistically significantly greater incidence of intervention, including systemic hypertensives (41.4%) versus nonhypertensives (34.5%) (P = 0.030), patients with pulmonary disease (49.3%) versus no pulmonary disease (36.5%) (P = 0.043), patients with renal disease (68.8%) versus no renal disease (36.9%) (P = 0.019), and patients with cancer (61.9%) versus no cancer (36.3%) (P = 0.001). Intervention was also required in 61.1 % of patients younger than 60 years of age compared to 36.5% of those patients 60 years of age and older (P = 0.005). CONCLUSIONS: Because intervention is required in more than one third of cataract surgery cases and the authors cannot reliably predict those patients at risk, monitored anesthesia care seems justified in cataract surgery with the patient under local anesthesia.

Audit of neurophysiological recording during movement disorder surgery.

Sixty-two cases of thalamic pallidal and subthalamic surgery in Dundee were audited to assess the influence of physiological localisation on the procedure. Methods included microelectrode recording, evoked potential and stimulation techniques. Although anatomical localisation is improving with modern techniques, the physiological information is still modifying the surgery in 67% of cases.

[The hemodynamic effects of the in-vivo administration of insulin-like growth-factor I]. / Effetti emodinamici della somministrazione in vivo dell'Insulin-like Growth Factor-I.

BACKGROUND: Recent studies have demonstrated that IGF-I has several biological activities that correlate with the GH axis, by acting as a cell protecting factor and a promoting compound in different tissues and organs. Our latest findings have demonstrated a potential application of IGF-I in the treatment of postischemic renal injury, which frequently appears after a kidney transplant. The beneficial effect of the renal postoperative recovery probably correlates with the regulation of the vascular tone, in which IGF-I plays a role with other cytokines. However, this rises the question whether IGF-I has any effect on the general hemodynamic status. This study was designed to underline the intraoperative hemodynamic effect of exogenous IGF-I in an experimental setting of renal transplantation in swine. METHODS: Twelve female swine underwent a left renal autotransplantation. At the reperfusion the animals were separated in two groups. Group one served as control. Group two received 400 micrograms of IGF-I (added to the flushing solution). The animals were kept under complete hemodynamic monitoring over the operation. RESULTS: Among the different parameters studied (mean arterial pressure, mean pulmonary arterial pressure, pulmonary wedge pressure, central venous pressure, cardiac output, oxygen extraction ratio, systemic vascular resistance, oxygen delivery and oxygen consumption), any statistically significant difference between group one and two were observed. CONCLUSIONS: While the clinical administration of IGF-I requires further studies, the in vivo administration of this peptide is apparently well tolerated, and does not cause any hemodynamic instability to the operation.

[Intraoperative tonal-threshold audiometry in the surgery of otosclerosis]. / L'audiometria tonale liminare intraoperatoria nella chirurgia dell'otosclerosi.

At the end of stapedioplasty, performed under local anesthesia, the surgeon usually tests the hearing function making questions to the patient turning his voice from a soft whisper to a loud tone. At the ENT Department, University of Parma Italy, a more precise method is employed in order to measure the air conduction threshold of the patient at the beginning and at the end of surgery. From April 1996 to October 1996, intraoperative pure-tone audiometry was performed in 36 patients who underwent stapedioplasty. A portable audiometer "Amplaid 161/C Amplifon" was used in the operating room. Air conduction thresholds were measured at 125-8000 Hz. Intraoperative pure-tone audiometry allows an instantaneous and a more accurate evaluation of the surgical functional results.