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Competing Interests: Disclosure The authors report no conflicts of interest in this work.

The development and implementation of the hybrid operating theatre over the last decade is one of the most innovative advancements in the field of medical interdisciplinary treatment options. The hybrid operating theatre allows the combination of minimally invasive surgery and interventional procedures using the benefits of modern imaging technologies. Therefore, it will be of increasing interest for different kinds of surgical disciplines in the future. In Germany, the hybrid operating theatre is mainly used in the field of transcatheter based heart valve procedures and in the field of vascular surgery cooperating with interventional radiology. Managing this special patient population is a highly challenging task for all players in this setting, especially for the cardiac surgeon, the cardiologist, and the anaesthesiologist. Only close interdisciplinary cooperation ensures optimal treatment. The impact of recent developments in the field of transcatheter based heart valve procedures on anaesthesia management will be addressed in this article., Competing Interests: Erklärung zu finanziellen Interessen Forschungsförderung erhalten: nein; Honorar/geldwerten Vorteil für Referententätigkeit erhalten: ja, von einer anderen Institution (Pharma- oder Medizintechnikfirma usw.); Bezahlter Berater/interner Schulungsreferent/Gehaltsempfänger: nein; Patent/Geschäftsanteile/Aktien (Autor/Partner, Ehepartner, Kinder) an im Bereich der Medizin aktiven Firma: nein; Patent/Geschäftsanteile/Aktien (Autor/Partner, Ehepartner, Kinder) an zu Sponsoren dieser Fortbildung bzw. durch die Fortbildung in ihren Geschäftsinteressen berührten Firma: nein Erklärung zu nichtfinanziellen Interessen Die Autorinnen/Autoren geben an, dass kein Interessenkonflikt besteht., (Thieme. All rights reserved.)

Background: Evaluation of the nociception-anti-nociception balance during anesthesia is still challenging and routinely based on clinical criteria such as movement or vegetative response. Recently, the Analgesia Nociception Index (ANI) derived from heart rate variability and the Surgical Pleth Index (SPI) derived from photoplethysmographic signal were introduced for quantification of the analgesic component of anesthesia., Methods: After obtaining informed consent, we studied twenty-four patients (ASA I-II) scheduled for elective surgery during induction of anesthesia with sevoflurane and a stepwise increase of remifentanil effect site concentrations. Insertion of a laryngeal mask, tetanic stimulations as well as tracheal intubation were studied as nociceptive events., Results: A total of 120 events were analysed. Both ANI and SPI enabled consistent detection of nociceptive events by significant changes (∆). Further, ∆ANI and ∆SPI significantly indicated patient's movement after tetanic stimulation with a prediction probability of 0.74 and 0.84., Conclusion: Non-invasive monitoring of ANI and SPI reflected nociceptive stimulation during sevoflurane-remifentanil anesthesia and therefore may indicate the nociception - anti-nociception balance. Whether guidance of anesthesia by these variables will improve anesthesia care during surgery needs to be further evaluated.

Pharmaceutical, pharmacokinetic and pharmacodynamic drug-drug interactions (DDI) can complicate or facilitate anesthesia. Knowledge of the basic DDI mechanisms and DDI databases helps to avoid unwanted DDIs and to optimize wanted DDIs such as antidotes or desired synergism. Concerning pharmaceutical DDI (=incompatibilities) special attention must be paid to very acidic or basic drugs, polyvalent ions such as calcium and emulsions like propofol. Inducers or inhibitors of cytochrome p450 3A4 can complicate postoperative therapy of raised blood pressure or pain (pharmacokinetic DDI). Pharmacodynamik DDIs like the impact of many drugs on blood pressure are the day-to-day armamentarium for anesthetists., (© Georg Thieme Verlag Stuttgart · New York.)

Background: Measurement of the balance between nociception and anti-nociception during anaesthesia is challenging and not yet clinically established. The Surgical pleth index (SPI), derived from photoplethysmography, was proposed as a surrogate measure of nociception. Recently, the analgesia nociception index (ANI) derived by heart rate (HR) variability was developed. The aim of the present study was to challenge the ability of ANI compared with SPI to detect standardized noxious stimulation during propofol-remifentanil anaesthesia., Methods: After Ethics approval and informed consent, 25 patients were anaesthetized with propofol [bispectral index (BIS) 30-60]. A laryngeal mask (LMA) was inserted and remifentanil stepwise increased to effect-site concentrations (Ce(remi)) of 0, 2, and 4 ng ml(-1). At each step, tetanic stimulation (STIM) was applied. ANI, SPI, BIS, HR, and mean arterial pressure (MAP) were obtained before and after LMA insertion and each STIM. Analysis was performed using Wilcoxon rank tests and calculation of prediction probabilities (P(K))., Results: ANI and SPI, but not BIS, HR, or MAP, were significantly (P<0.05) changed at all examined steps. ANI response to STIM was (median [IQR]) -24 [-12-35], -30 [-20 - -40] and -13 [-5 - -27] at 0, 2 and 4 ng ml(-1) Ce(remi). However, prediction of movement to STIM was not better than by chance, as P(K) values were 0.41 (0.08) for ANI and 0.62 (0.08) for SPI., Conclusions: The two variables, ANI and SPI, enabled consistent reflection of stimulation during propofol-remifentanil anaesthesia. Nevertheless, ANI and SPI may improve detection but not prediction of a possible inadequate nociception-anti-nociception balance. Clinicaltrials.gov Identifier. NCT01522508.

The use of ultrasonography in perioperative medicine has developed rapidly within the last decade. Today ultrasonic techniques are established methods for peripheral and central venous access as well as for regional anaesthesia. However, transthoracic ultrasonography by non-cardiologists has not yet been routinely established perioperatively, in intensive care medicine or in emergency medicine. With the current module 4: Cardiosonography of the DGAI-certified seminar series in Anaesthesia Focussed Sonography (AFS) it is intended to provide a basis for a quality assured training and implementation of transthoracic sonography in anaesthesia, intensive care medicine and emergency medicine., (© Georg Thieme Verlag Stuttgart · New York.)

This study investigates the incidence of clinically relevant asymmetry in bispectral index readings from different sides of the skull (using two monitors) during ear-nose-throat surgery in 42 adults and 46 children. A unilateral increase or decrease > 10% from baseline was defined as an 'asymmetry'. Asymmetry followed by movement after stimulation was defined as a 'clinically relevant asymmetry'. Asymmetry occurred in 39 out of 42 adults (93%) and in 20 out of 46 children (44%) during surgery and in 24 out of 42 adults (57%) and in 17 out of 46 children (37%) during recovery. Clinically relevant asymmetry was observed in 5 out of 42 adults (12%) and 6 out of 46 children (13%). The incidence of asymmetry was higher in adults during surgery (p = 0.0002). In conclusion, clinically relevant bispectral index asymmetry has been observed in > 10% of paediatric and adult anaesthesia and may have clinical implications. You can respond to this article at http://www.anaesthesiacorrespondence.com., (© 2011 The Authors. Anaesthesia © 2011 The Association of Anaesthetists of Great Britain and Ireland.)

Obesity is a worldwide epidemic with increasing importance in both industrialised and developing countries. Anaesthesiologists will be increasingly challenged by the care for morbidly and super-obese patients. Prerequisites for an optimal perioperative care are a suitable and adapted environment both on the ward and in the operating theatre, the timely and comprehensive preoperative evaluation focussed on co-morbidities, such as diabetes, coronary artery disease and obstructive sleep apnoea syndrome and appropriate equipment for positioning, anaesthesia and surgery. To deliver an adequate standard of care, anaesthesiologists must consider the pharmacokinetic characteristics and pathophysiological sequelae of obesity. Careful preoxygenation, special positioning, adequate monitoring and adapted intra-operative ventilation are key issues for a successful perioperative care. While co-morbidities are frequent in the obese, overall morbidity and mortality up to a body mass index (BMI) < or = 40 kg m(-2) are not significantly increased compared with lean patients.

Obesity is a global epidemic, and approximately 20 % of the German population are obese. Therefore anaesthesiologists will be increasingly involved in the care of obese and morbidly obese patients in the near future. As a prerequisite, the hospital must focus on this patient population with respect to facilities and the availability of tailored medical equipment and supplies. Comorbidities such as diabetes, hypertension, coronary heart disease and sleep apnea considerably increase the risk of obese patients. A thorough preoperative evaluation of comorbidities, an anaesthesia induction and intraoperative ventilation tailored to the pathophysiological sequelae of obesity and a sound knowledge of pharmokocinetics are necessary to ensure optimal care for obese patients.

In vascular surgery, intraoperative monitoring of the brain is recommended when the internal carotid artery (ICA) is clamped, because brain damage by ischemia and embolism is possible. Clamping of the ICA results in embolic or ischemic brain lesions in about 7 % of all patients undergoing the procedure. Prophylactic routine insertion of an intraluminal shunt can cause brain embolism and does not reduce the occurrence of complications. Consequently, a shunt should only be inserted, if critical reduction of cerebral perfusion is evident after clamping the ICA. Measurement of carotid stump pressure is an invasive method to estimate perfusion of the brain hemisphere at the clamping side. Transcranial doppler sonography (TCD) measures the mean blood flow velocity in the ACI, but practicability is suffering from technical problems in 20% of all patients. However, TCD is useful for detecting intraoperative embolism and postoperative hyperperfusion. Changes of oxyhaemoglobine and desoxyhaemoglobine concentration in brain tissue can be measured using near-infrared spectroscopy (NIRS) with wavelengths between 700 and 1000 nm. NIRS measurement is easily performed and reacts quickly to changes of brain tissue oxygenation, but there is still lacking evidence and at present a general recommendation of its application in vascular surgery is not justified. Use of somatosensory evoked potentials (SEP) is the most widespread cerebral neuromonitoring during vascular surgery due to its high reliability and simple application. Sensitivity and specifity for ischemic lesions are 100% and 94%-99%, respectively. SEP are regarded as the gold standard for cerebral neuromonitoring in anaesthetized patients.

Anesthesiologists involved in the care of children with congenital heart disease (CHD) have to understand the pathophysiology of each cardiac lesion and anticipate the impact of the planned procedure. Often the dimished margin of hemodynamic stability determines the guidelines of care. In children with CHD maintainance of the homeostasis during anesthesia for a wide variety of procedures is the anesthesiologist's challenge. Left-to-right shunting means a volume load to the left ventricle frequently combined with pulmonary hypertension. Right-to-left shunting leads to a central cyanosis.

Diagnostic and interventional paediatric cardiology has become an increasing field of activity for anaesthesiologist in recent times. Besides a close interdisciplinary cooperation, the exact knowledge of the pathophysiology of the congenital heart diseases is essential. Especially the spectrum of interventional paediatric cardiology has extended considerably. In addition to traditionally intervention such as atrial septal defect closure and embolization of a patent ductus arteriosus, today's indications are also valvuloplasty and angioplasty as well as ventricular septal defects.

Background and Goal: For reimbursement via diagnosis-related groups (DRG), lump compensation-based payment of medical cases in German hospitals requires a case-related measuring and billing of resources that has to be consistent with DRG guidelines. Only through this, can the real costs be compared with the standard costs as calculated by the hospital reimbursment system (InEK) on a case-related basis and the DRG-specific break-even level be identified., Methods: In the present paper the authors introduce and validate two newly created alternative methods for case-related allocation of material costs in the field of anaesthesia. Method 1 allows online documentation of material costs via pre-defined anaesthesia standards. This full cost method is suitable for hospitals that have implemented an electronic hospital information system in their daily clinical documentation routine. For other hospitals method 2 could be applicable as the case-related allocation of material costs is done retrospectively based on the data collected in an electronic anaesthesia protocol record system (andoc, medlinq)., Results: Method 1 makes it possible to allocate 90.3% of anaesthesia-related material costs to a specific case corresponding to a Pearsson coefficient of 0.77. After iterative improvement through optimisation of modules the documentation quality could be raised to >98% and a Pearsson coefficient of 0.96. Although the expense for implementation and maintenance is considerable, the necessary documentation work for the clinician is low. Method 2 demands no further clinical effort in documentation and implementation and 49.1% of all material costs can be assigned on a case-related basis., Conclusions: The online documentation of material costs via predefined anaesthesia standards accounts for nearly all material costs in anaesthesia and only a negligible documentation effort is necessary for the clinician. Nevertheless, a complex and time-consuming configuration of standards and a continuous iterative alignment of the modules with the actual processes are required. Due to its process-orientated character, method 1 can also be used for workflow optimisation in terms of standard operating procedures (SOPs). Allocation of material costs with data from the electronic anaesthesia record system is a method that can be easily implemented but only a partial case relation is rendered possible.

Difficult airway management is among the key requirements in routine anaesthesia. Failures to secure the airways resulting in a "Cannot intubate, Cannot ventilate" situation can drastically increase morbidity and mortality of patients within a very short time. Therefore, an algorithm for management of the expected and unexpected difficult airway describing the sequence of various procedures, adapted to internal standards and to techniques that are available, has to be provided by each anaesthesia department. This not only facilitates the preparation of equipment and the training of personnel, but also ensures efficient decision making under time pressure.

Purpose of Review: Propofol infusion syndrome is a rare but often fatal syndrome, characterized by lactacidosis, lipaemic plasma and cardiac failure, associated with propofol infusion over prolonged periods of time. As propofol is used worldwide, knowledge of propofol infusion syndrome is essential for all anaesthesiologists and intensive care physicians. This review will provide an update on reported cases, and describe recent findings relevant to the pathophysiology and clinical presentation of propofol infusion syndrome., Recent Findings: Case reports of propofol infusion syndrome have contributed new pathophysiological evidence. Reported cases of similar syndromes may represent initial propofol infusion syndrome, and may help to identify further risk factors such as low carbohydrate supply and early warning signs such as lactacidosis. Newly identified gene defects mimicking propofol infusion syndrome may elicit the underlying genetic susceptibility. Recommendations for the limitation of propofol use have been devised by various institutions., Summary: Propofol infusion syndrome must be kept in mind as a rare but highly lethal complication of propofol use, not necessarily confined to the prolonged use of propofol. Dose limitations must be adhered to, and early warning signs such as lactacidosis should lead to the immediate cessation of propofol infusion.

The demographic trend challenges anaesthesiologists with a growing number of elderly requiring surgery. The anaesthetist needs to identify risk patients and to optimize his strategies for perioperative management. The present article gathers the current data and summarizes effective strategies for anaesthesia in patients with ischemic heart disease.

Background: Overlapping induction (OI), i.e., induction of anesthesia with an additional team while the previous patient is still in the operating room (OR), was investigated., Methods: The study period was 60 days in two followed by three ORs during surgical Block Time (7:30 am until 3:00 pm). Patients were admitted the day before surgery and were thus available and did not have surgery that day unless there was a time reduction. Facilities were already constructed. Number of cases, Nonsurgical Time (Skin Suture Finish until next Procedure Start Time), Turnover Time, and Anesthesia Control Time plus Turnover Time were studied. In addition, economic benefit was calculated., Results: Three hundred thirty-five cases were studied. Using OI, the time of care of regularly scheduled cases was shortened, and the number of cases performed within OR Block Time increased (151 to 184 cases; P < 0.05). Nonsurgical Time (in h:min) decreased (1:08 +/- 0:26 to 0:57 +/- 0:18; P < 0.001), Turnover Time decreased (0:38 +/- 0:24 to 0:25 +/- 0:15; P < 0.05), and Anesthesia Control Time plus Turnover Time decreased (0:43 +/- 0:23 to 0:28 +/- 0:18; P < 0.001). Subgroup analysis showed a significant benefit of OI only in three ORs. In three ORs, economic benefit can be gained at a case mix index greater than 0.3 besides additional costs., Conclusions: Overlapping induction increased productivity and profit despite the expense of additional staff. Subgroup analysis emphasizes the importance of the number of ORs involved in OI.

The aim of our study was to evaluate the performance of different durations of active pre-operative skin-surface warming (pre-warming) to prevent peri-operative hypothermia and postoperative shivering. We randomly assigned 200 patients, scheduled for surgery of 30-90 min under general anaesthesia, to receive passive insulation or forced-air skin surface warming for 10, 20 or 30 min. Body temperature was measured at the tympanic membrane. Shivering was graded by visual inspection. There were significant differences in changes of core temperature between the non-pre-warmed group and all the pre-warmed groups (p < 0.00001), but none between the three pre-warmed groups (p = 0.54). Without pre-warming, 38/55 (69%) patients became hypothermic (< 36 °C) at the end of anaesthesia, whereas only 7/52 (13%), 3/43 (7%) and 3/50 (6%) patients following 10, 20 or 30 min pre-warming, respectively, became hypothermic (p < 0.001 vs no pre-warming). Shivering was observed in 10 patients without, and in three, three and one patients with pre-warming in the respective groups (p = 0.02). Pre-warming of patients for only 10 or 20 min before general anaesthesia mostly prevents hypothermia and reduces shivering. [ABSTRACT FROM AUTHOR]

Respiratory variations in plethysmographic waveform amplitudes derived from pulse oximetry are believed to predict fluid responsiveness. The non-invasive pleth variability index (PVI) is a variable based on the calculation of changes in the perfusion index (PI). The aim of the following study was to examine whether the predictive power of PVI depends on different values of PI. Eighty-one patients undergoing elective coronary artery surgery were studied before operation: at baseline after induction of anaesthesia and during passive leg raising (PLR). Each patient was monitored with central venous pressure (CVP), the PiCCO monitor and the non-invasive Masimo monitoring system. Stroke volume index by transpulmonary thermodilution (SVI), pulse pressure variation (PPV), stroke volume variation (SVV) and systemic vascular resistance index (SVRI) were measured using the PiCCO monitoring system. PI and PVI were obtained by pulse oximetry. Responders were defined to increase their SVI>15% after PLR. The highest area under the curve (AUC) was found for PPV (AUC: 0.83, P<0.0001) and SVV (AUC: 0.72, P=0.002), in contrast to PVI (AUC: 0.60, P=0.11) and CVP (AUC: 0.60, P=0.13). The accuracy of PVI to predict fluid responsiveness was improved on analysing patients with higher PI values. PI of about 4% ( n=45) achieved statistical significance (AUC: 0.72, P=0.01). The PVI was not able to predict fluid responsiveness with sufficient accuracy. In patients with higher perfusion states, the PVI improved its ability to predict haemodynamic changes, strongly suggesting a relevant influence of the PI on the PVI. [ABSTRACT FROM AUTHOR]

We enrolled 114 patients, aged 65–83 years, undergoing elective surgery (duration > 2h) into a randomised, controlled study to evaluate the performance of bispectral index and spectral entropy for monitoring depth of xenon versus propofol anaesthesia. In the propofol group, bispectral index and state entropy values were comparable. In the xenon group, bispectral index values resembled those in the propofol group, but spectral entropy levels were significantly lower. Mean arterial blood pressure was higher and heart rate was lower in the xenon group than in the propofol group. Bispectral index and spectral entropy considerably diverged during xenon but not during propofol anaesthesia. We therefore conclude that these measures are not interchangeable for the assessment of depth of hypnosis and that bispectral index is likely to reflect actual depth of anaesthesia more precisely compared with spectral entropy. [ABSTRACT FROM AUTHOR]

Background: The addition of opioid to local anaesthetics has become a well-accepted practice of spinal anaesthesia for caesarean delivery. Successful caesarean delivery anaesthesia has been reported with the use of a low dose of intrathecal hyperbaric ropivacaine coadministered with sufentanil. This prospective, double-blinded study determined the median effective dose (ED50) of intrathecal hyperbaric ropivacaine with and without sufentanil for caesarean delivery, to quantify the sparing effect of sufentanil on the ED50 of intrathecal hyperbaric ropivacaine. Methods: Sixty-four parturients undergoing elective caesarean delivery with combined spinal–epidural anaesthesia were randomized into two groups: Group R (ropivacaine) and Group RS (ropivacaine plus sufentanil 5 μg). The initial dose of ropivacaine was 13 mg in Group R and 10 mg in Group RS. The effective dose was defined as a T6 level attained within 10 min and no supplemental epidural anaesthetic required during surgery. Effective or ineffective responses determined, respectively, a 0.3 mg decrease or increase of the dose of ropivacaine for the next patient using an up–down sequential allocation. Results: The ED50 of intrathecal ropivacaine was 11.2 mg [confidence interval (CI) 95%: 11.0–11.6] in Group R vs. 8.1 mg (CI 95%: 7.8–8.3) in Group RS. Motor block was markedly more intense in Group R than in Group RS, and the incidence of shivering was lower in Group RS than in Group R. There were no differences in the onset time of sensory block or motor block, in the incidence of hypotension, nausea and vomiting. Conclusion: Intrathecal sufentanil 5 μg produced a 28% reduction of ED50 of intrathecal hyperbaric ropivacaine for caesarean delivery. [ABSTRACT FROM AUTHOR]

We investigated the influence of resident training on anaesthesia workflow of three standard procedures – laparoscopic cholecystectomy, diagnostic gynaecological laparoscopy and transurethral prostate gland resection (TURP) – comparing 259 non-emergency resident vs 341 consultant cases from 20 German hospitals. Each hospital provided 10 random cases for each procedure, yielding 600 cases for analysis. Standard time intervals as documented in the hospital information system were: ‘Case Time’ (the time from the start of anaesthesia induction to discharge of the patient to the recovery area) and ‘Anaesthesia Control Time’ (which was the Case Time minus the time from the start of surgery to the end of surgical closure). Case Time was significantly shorter for consultants in all three procedures (p < 0.05, analysis of variance) and Anaesthesia Control Time shorter for consultants only in gynaecological laparoscopy and TURP. Patient comorbidity, patient age and geographical location of the hospital were not influential factors in the analysis of variance. We conclude that resident training significantly increases duration of elective operative times. [ABSTRACT FROM AUTHOR]

The aim of this study was to investigate the use of pre-operative heart rate variability analysis to predict postoperative cardiac events (identified by 24 h Holter-ECG recording and an increase of creatine kinase MB) in high-risk cardiac patients. Length of hospital stay, the incidence of postoperative cardiac ischaemia and cardiac events after discharge were recorded. Fifty patients were assigned by the presence of cardiac events and the heart rate variability in 17 patients with an event was compared with 33 patients without. Total power was identified as a predictive parameter. The usefulness of this test was assessed in a second group of 50 patients. The incidence of cardiac events detected by Holter-ECG recording or an increased creatine kinase MB was greater and the duration of hospital stay longer in the 26 patients with total power < 400 ms².Hz−1 compared with those with total power > 400 ms².Hz−1 (eight and four patients and 10 (7) days (mean (SD)), vs 1 (p < 0.05) and 0 (p < 0.05) patients and 6 (2) days (p < 0.05), respectively). The total power of high-risk cardiac patients predicted postoperative cardiac events and extended length of hospital stay. [ABSTRACT FROM AUTHOR]

Volatile anaesthetics have been shown to exert cardioprotective properties in experimental and clinical studies. However, the mode of administration may influence these cardioprotective effects. The present study was designed to compare the effect of interrupted administration of sevoflurane before cardiopulmonary bypass with continuous sevoflurane administration and with propofol-only anaesthesia, on cardioprotection as assessed by left ventricular performance and myocardial cell damage during coronary artery bypass grafting. Forty-two patients scheduled for coronary bypass surgery were randomly assigned to one of three groups: propofol-only (P; n = 14), continuous (SevoC; n = 14) and interrupted sevoflurane administration (SevoI; n = 14). Myocardial cell damage as assessed by Troponin T (cTNT) and creatine kinase MB (CK-MB) were chosen as the primary endpoints and echocardiographic myocardial performance index (MPI) measurements were also performed. Up to 48 h postoperatively, in group SevoI, postoperative cTNT values (mean (SD) 0.13 (0.04) ng.ml−1) were significantly (p < 0.05) lower than both the P (0.26 (0.31) ng.ml−1) and SevoC (0.25 (0.17) ng.ml−1) groups. CK-MB levels were also significantly (p < 0.05) lower in the SevoI group at 24 h after surgery and MPI significantly improved compared with both the P and SevoC groups. There was, however, no difference with respect to cytokine release and length of stay in either the intensive care unit or in the hospital. We conclude that prior interrupted sevoflurane administration confers some cardioprotection as compared with continuous sevoflurane administration or propofol-based anaesthesia. [ABSTRACT FROM AUTHOR]

Background: Previous studies in adult patients and animal models have demonstrated that pulse pressure variation (PPV) and stroke volume variation (SVV) can be used to predict the response to fluid administration. Currently, little information is available on the performance of these variables in infants and neonates. The aim of our study was to assess whether PPV and SVV can predict fluid responsiveness in an animal model and to investigate the influence of different tidal volumes applied. Methods: PPV and SVV were monitored by pulse contour analysis in 19 anaesthetized and paralysed piglets during ventilation with tidal volumes ( VT) of 5, 10 and 15 ml/kg both before and after fluid loading with 25 ml/kg of hydroxy-ethyl starch 6% (HES). Cardiac output was measured by pulmonary artery thermodilution and a positive response to HES infusion was defined as ≥20% increase in the stroke volume index (SVI). Results: Before HES infusion, PPV and SVV were significantly greater during ventilation with a VT of 10 and 15 ml/kg than during ventilation with a VT of 5 ml/kg ( P<0.05). After HES infusion, only ventilation with VT 15 ml/kg resulted in a significant increase in PPV and SVV. As assessed by receiver operating characteristic curve analysis, SVV during ventilation with VT 10 ml/kg was the best predictor of a positive response to fluid loading (AUC=0.87). Conclusions: In this paediatric animal model, we found that SVV during ventilation with 10 ml/kg was a sensitive and specific predictor of the response to fluid loading. [ABSTRACT FROM AUTHOR]

This study investigated whether heart rate variability predicts haemodynamic events in high risk patients, defined as Revised Cardiac Risk Index score = 3, scheduled for general anaesthesia. Fifty patients underwent baseline measurement of heart rate variability and were then assigned according to haemodynamic events (hypotension or bradycardia) after standardised induction of anaesthesia into ‘stable’ ( n = 39) and ‘unstable’ patients ( n = 11). Unstable patients had significantly lower baseline total power. Total power < 500 ms2.Hz−1 was associated with high sensitivity and specificity for the prediction of hypotension or bradycardia. Prospectively, 29 patients with total power < 500 ms2.Hz−1 were compared with 21 patients with total power > 500 ms2.Hz−1. Differences were found in the lowest mean arterial pressure and heart rate after induction of anaesthesia. We conclude that the pre-operative total power of heart rate variability in high risk patients may indicate the occurrence of haemodynamic events with high sensitivity and specificity. Heart rate variability may be a suitable tool to identify patients at high risk of a haemodynamic event and may be used to indicate need for intensive monitoring and, perhaps, prophylactic treatment. [ABSTRACT FROM AUTHOR]

Seventy-two patients undergoing routine surgical procedures under propofol-remifentanil anaesthesia were randomly assigned to receive either standard clinical practice ( n = 35) or standard practice plus monitoring of depth of anaesthesia with M-Entropy ( n = 37). Patients in the standard practice group received more propofol than the entropy group (mean (SD) 95 (14) vs 81 (22) μg.kg−1.min−1, respectively; p < 0.01), and less remifentanil (0.39 (0.08) vs 0.46 (0.08) μg.kg−1.min−1, respectively; p < 0.001). Loss of consciousness was best predicted by BIS (prediction probability (PK) 0.96) and response entropy (PK 0.93), whereas emergence was best predicted by response entropy (PK 0.94). The frequency of unwanted patient responses was higher in the standard practice group than in the entropy group (47 vs 27 total events, respectively; p < 0.01). Both regimens resulted in fast recovery with no clinical advantage for either one. There were no significant differences in haemodynamic parameters, postoperative nausea and vomiting or satisfaction with the procedure. [ABSTRACT FROM AUTHOR]

Background: To investigate if changes in low-to-high frequency ratio (LF/HF), low frequency (LF) and high frequency (HF) heart rate variability reflect autonomic regulation during spinal anaesthesia (SA) in pregnant women scheduled for elective Caesarean section. Methods: Prospective clinical trial. Systolic blood pressure (SBP) and heart rate variability were analysed at baseline, 5 min after SA and 15 min after SA. Patients were assigned by baseline LF/HF. Group LF/HF < 2.5 ( n= 52) was compared to group LF/HF > 2.5 ( n= 48). Non-parametric tests for statistical analysis. Results: Group LF/HF > 2.5 showed a significant decrease in LF/HF and LF as well as an increase in HF during SA (median, range): baseline LF/HF [4.0 (3.2/4.8)] decreased to 2.3 (1.3/3.4) at event 15 min after SA ( P < 0.001). Baseline LF = 59(43/71)% decreased to 40 (27/55)% at event 15 min after SA ( P < 0.05). Baseline HF = 15(13/22)% increased to 26(15/41)% at event 15 min after SA ( P < 0.05). In contrast, group LF/HF < 2.5 demonstrated only moderate changes in LF/HF, LF and HF during SA. SBP decreased significantly in group LF/HF > 2.5 (median and range) lowest SBP group LF/HF > 2.5: 80 (50/127 mmHg vs. group LF/HF < 2.5: 109 (104/142) mmHg, P < 0.001. Decrease of SBP before and after SA was correlated with a decrease in LF/HF, LF, and HF, respectively: LF/HF – SBP: r= 0.30, r2= 0.09, P < 0.001; LF – SBP: r= 0.25, r2= 0.06, P < 0.05, HF, NS. Conclusions: Changes in heart rate variability parameters in the course of SA may reflect a decrease in sympathetic activity and relative increase in parasympathetic activity as a result of the block. In the course of SA, the more pronounced the changes in heart rate variability were the more distinct the hypotension. [ABSTRACT FROM AUTHOR]

Background and objective: This study was performed to compare three disposable airway devices, the LMA Unique (LMA-U), the Ambu laryngeal mask (Ambu LM) and the Soft Seal laryngeal mask (Soft Seal LM) for elective general anaesthesia during controlled ventilation in non-paralysed patients. Methods: One hundred and twenty ASA I-Ill patients scheduled for routine minor obstetric surgery were randomly allocated to the LMA-U (n = 40), Ambu LM (n = 40) or Soft Seal LM (n = 40) groups, respectively. Patients were comparable with respect to weight and airway characteristics. A size 4 LMA was used in all patients and inserted by a single experienced anaesthesiologist. Oxygenation, overall success rate, insertion time, cuff pressure and resulting airway leak pressure were determined as well as a subjective assessment of handling and the incidence of sore throat, dysphagia and hoarseness. Results: Time of insertion was shortest with the Ambu LM, while failure rates were comparable with the LMA-U, the Ambu LM and the Soft Seal LM (median 1? s; range 8-57s; success rate 100% vs. 14; 8-35; 97% vs. 20; 12-46; 95%). Insertion was judged ‘excellent’ in 75% of patients in the LMA-U group, in 70% of patients in Ambu LM group and in 65% of patients in the Soft Seal LM group. There was no difference between devices with respect to postoperative airway morbidity at 6 h or 24 h following surgery. Conclusions: All three disposable devices were clinically suitable with respect to insertion times, success rates, oxygenation, airway and leak pressures, as well as to subjective handling and postoperative airway morbidity. [ABSTRACT FROM AUTHOR]

We compared the haemodynamics, emergence and recovery characteristics of total intravenous anaesthesia using propofol/remifentanil with sevoflurane/remifentanil anaesthesia, under bispectral index guidance, in 103 patients undergoing surgical procedures lasting > 3.5 h. Time to tracheal extubation was significantly shorter in the propofol group than in the sevoflurane group (mean (SD) 8.3 (3.5) min vs 10.8 (4.6) min, respectively; p = 0.0024), but further recovery was comparable in both groups. There were no significant differences in haemodynamic parameters, intensity of pain or postoperative nausea and vomiting. During and after anaesthesia of comparable depth for long lasting surgical procedures, both propofol/remifentanil and sevoflurane/remifentanil enable haemodynamic stability and fast emergence. The shorter time to extubation in the propofol group does not offer a relevant clinical advantage. [ABSTRACT FROM AUTHOR]

Even today many anaesthesiologists rely on parameters of the autonomic nervous system, such as blood pressure and heart rate to decide if a patient is adequately anaesthetized. It is thought that the electroencephalogram (EEG) may provide more information on the state of anaesthesia. Because full EEG analysis is not possible in the operating room, processed EEG parameters have been developed comprising complex information into a single value. Time and frequency domain parameters are calculated. The power spectrum results from a Fourier analysis and can be described by parameters such as median frequency, spectral edge frequency and others. It was noted, however, that anaesthetics at low doses increase frequency of the EEG, whereas at high doses the EEG is depressed. This biphasic response makes it difficult to clearly distinguish the exact anaesthetic state of a patient. Median frequency and spectral edge frequency have been studied in numerous studies. However, no sole indicator has been derived from the EEG that could serve as a descriptor of anaesthetic depth. [Copyright &y& Elsevier]

Background: The suggested induction dose of methohexital for electroconvulsive therapy (ECT) varies widely influencing efficacy of ECT and safety of anaesthesia. Bispectral index (BIS), a monitor of consciousness, may be useful to assure adequate hypnosis with optimized methohexital dose. Methods: Patients with medically resistant major depression (ICD10), scheduled for multiple ECT's, were studied. Depth of anaesthesia was BIS controlled. ECT was not performed until BIS dropped below 50. Initially anaesthesia was induced with methohexital 1.0 mg kg-1, and stepwise reduced by 0.1 mg kg-1 during consecutive treatments. If BIS did not drop below 50, the methohexital was supplemented by further boluses of 0.5 mg kg-1, until the desired level of hypnosis was reached. The adequacy of the anaesthetic recommendation for methohexital (1.0–1.5 mg kg-1) as well as the psychiatric recommendation (0.75–1 mg kg-1) was investigated. Results: One-hundred and nine ECT's in 14 patients were studied. The recommended anaesthetic dose (1.0–1.5 mg kg-1) was inadequate in 40% of the treatments, with 12% exceeding 1.5 mg kg-1, and 28% below 1.0 mg kg-1. Psychiatric recommendation (0.75–1.0 mg kg-1) was inadequate in 49%, with 39% exceeding 1.0mgkg-1 and 10% undershooting at 0.75 mg kg-1. Conclusions: Methohexital for ECT showed a great variability, exceeding as well as undershooting the dosage recommendations widely. BIS monitoring may be useful to secure adequate hypnosis during muscle relaxation and treatment and may optimize ECT efficacy. [ABSTRACT FROM AUTHOR]

Supraglottic airway devices are developed with increasing frequency following the overwhelming success of the laryngeal mask airway (LMA). Currently, the LMA, the ProSeal laryngeal mask airway (PLMA), the laryngeal tube (LT), the laryngeal tube with integrated suctioning tube (LTS) and the oesophageal tracheal combitube (OTC) are the best evaluated and most widespread devices. Both the LMA and the PLMA have been shown to be perfectly suitable for routine anaesthesia and emergency airway management. While the LMA is limited by the lack of reliable protection against aspiration, the value of the PLMA in this respect remains undetermined yet. LT and LTS are primarily intended as emergency airway devices, but have also been successfully used during controlled ventilation in adults. The OTC, though advocated for emergency as well as routine use, is limited by high airway morbidity and possible serious complications. [Copyright &y& Elsevier]

Xenon, a noble gas with anaesthetic and analgesic properties, has gained renewed interest due to its favourable physical properties which allow a rapid emergence from anaesthesia. However, high costs limit its use to a subset of patients who may benefit from xenon, thereby offsetting its costs. To date, there are only limited data available on the performance of xenon in high risk patients. We studied 39 patients with ASA physical status III undergoing aortic surgery. The patients were randomly assigned to either a xenon (Xe, n = 20) or a TIVA (T, n = 19) group. Global cardiac performance and myocardial contractility were assessed using transoesophageal echocardiography, and myocardial cell damage with troponin T and CK-MB. Echocardiographic measurements were made prior to xenon administration, following xenon administration, and after clamping of the abdominal aorta, after declamping and at corresponding time points in the TIVA group. Laboratory values were determined repeatedly for up to 72 h. Data were analysed using two-way anova factoring for time and anaesthetic agent or with ancova comparing linear regression lines. No significant differences were found in global myocardial performance, myocardial contractility or laboratory values at any time during the study period. Mean (SEM) duration of stay on the ICU (xenon: 38 ± 46 vs. TIVA 25 ± 15 h) or in hospital (xenon: 14 ± 12 vs. TIVA 10 ± 6 days) did not differ significantly between the groups. Although xenon has previously been shown to exert superior haemodynamic stability, we were unable to demonstrate an advantage of xenon-based anaesthesia compared to TIVA in high risk surgical patients. [ABSTRACT FROM AUTHOR]

Background.Brain tissue oxygen pressure (PbtO2) correlates to cerebral blood flow (CBF) during spontaneous circulation, with one important regulator being nitric oxide (NO). Although it is established that arginine vasopressin (AVP) improves CBF and global cerebral oxygenation during cardiopulmonary resuscitation, it is unknown whether similar beneficial effects are present during spontaneous circulation. The purpose of this study was to investigate the effects of AVP with and without pre-treatment with the NO synthase inhibitor N-omega-nitro-L-arginine methyl ester (L-NAME) on local brain tissue oxygenation in a beating heart model.Methods.Following approval of the Animal Investigational Committee, nine healthy piglets underwent general anaesthesia, and were instrumented with a probe in the cerebral cortex to measure PbtO2. Each animal was assigned to receive AVP (0.4?U?·?kg-1), and after a wash-out period, L-NAME (25?mg?·?kg-1 over 20?min) followed by AVP (0.4?U?·?kg-1). After each AVP administration, nitroglycerine (25?µg?·?kg-1 over 1?min) as a NO donor was infused to test the vascular reactivity independently from NOS inhibition.Findings.Three minutes after administration of AVP, PbtO2 increased significantly (P<.05; mean?±?SEM, 31?±?11 versus 43?±?14?mm?Hg, +39%), compared with baseline. After pre-treatment with L-NAME, the changes of PbtO2 after AVP were not significant (32?±?11 versus 28?±?10, -13%) when compared with the baseline.Conclusion.In this beating heart porcine model, local brain tissue oxygenation was improved after AVP alone, but not after inhibition of NO synthesis with L-NAME. [ABSTRACT FROM AUTHOR]

Cardiac output (CO) determination based on partial CO2 rebreathing has recently been introduced into clinical practice. The determination of flow is crucial for exact CO readings and the physical properties of xenon, i.e. high density and viscosity, may influence flow readings. This study compared echocardiography-derived CO measurements with the partial rebreathing method during total intravenous (TIVA) vs. xenon-based anaesthesia. Thirty-nine patients ASA physical status III undergoing aortic reconstruction were randomly assigned to receive either xenon (Xe,n = 20) or TIVA (T,n = 19) based general anaesthetic. Paired measurements were taken before xenon administration, after xenon administration, before and after clamping of the abdominal aorta and after declamping and at corresponding time points in the TIVA group. Data were analysed with a Bland-Altmann plot. Bias and precision were acceptable and comparable before xenon administration (T 0.54 ± 0.92 l.min−1 vs. Xe 0.11 ± 1.1 l.min−1), but after xenon administration CO was largely overestimated by partial CO2 rebreathing (T 0.04 ± 0.91 l.min−1 vs. Xe−4.0 ± 2.1 l.min−1). In the TIVA group, bias and precision after declamping increased significantly (P < 0.01) compared to all time points except baseline. In its current application, the NICO cardiac output monitor appears to be inappropriate for determination of CO during xenon based anaesthesia. [ABSTRACT FROM AUTHOR]

Failed tracheal intubation due to a difficult airway is an important cause of anaesthetic morbidity and mortality. This study was undertaken to evaluate the effectiveness of the Bonfils intubation fibrescope for tracheal intubation after failed direct laryngoscopy. Twenty-five patients undergoing coronary artery bypass grafting were enrolled in the study after two attempts at conventional laryngoscopy by a board certified anaesthetist had failed. Intubation with the Bonfils fibrescope was successful on the first attempt in 22 patients (88%) and on the first or second attempt in 24 patients (96%); in one patient intubation was impossible. Median (IQR[range]) time to intubation using the Bonfils intubation fibrescope was 47.5 (30–80[20–200]) s. Tracheal intubation using the Bonfils intubation fibrescope appears to be a simple and effective technique for the management of a difficult intubation. [ABSTRACT FROM AUTHOR]

Background Evaluation of analgesia and antinociception during anaesthesia is still a challenging issue and routinely based on indirect and non-specific signs such as movement, tachycardia, or lacrimation. Recently, the surgical pleth index (SPI) derived by finger plethysmography was introduced to detect nociceptive stimulation during anaesthesia. While SPI guidance reduced the number of unwanted events during total i.v. anaesthesia (TIVA), the impact of SPI during volatile-based anaesthesia with intermittent opioid administration has not yet been elucidated. Methods Ninety-four patients were randomized into either SPI-guided analgesia or standard practice (Control). In both groups, anaesthesia was maintained with sevoflurane to keep bispectral index values between 40 and 60. In the SPI group, patients received a sufentanil bolus (10 μg) whenever SPI value increased above 50, whereas in the control group, sufentanil was administered according to standard clinical practice. The number of unwanted somatic events, haemodynamics, sufentanil consumption, and recovery times were recorded. Results The incidence of intraoperative unwanted somatic events was comparable between the groups (P=0.89). No significant differences with respect to hypotensive or hypertensive events were found. The mean (95% confidence interval) sufentanil consumption was non-significantly (P=0.07) reduced in the SPI group, 0.64 (0.57–0.71) vs 0.78 (0.64–0.91) µg min−1. Recovery times were comparable between the groups. Conclusions Sufentanil administration guided by SPI during sevoflurane anaesthesia is clinically feasible. In contrast to TIVA, it did not improve anaesthesia conduct with respect to unwanted somatic events, haemodynamic stability, sufentanil consumption, emergence time, or post-anaesthesia care unit care. Therefore, we conclude that anaesthesia regimen has an impact on beneficial effects by SPI guidance. Clinical trial registration NCT01525537. (Registered at Clinicaltrials.gov.) [ABSTRACT FROM PUBLISHER]

Background Arterial pressure (AP) monitoring should be accurate, easy to use, free of risks, and ideally continuous. The continuous non-invasive arterial pressure (CNAP) device is non-invasive and provides continuous pressure readings. This study was performed to compare the agreement of CNAP and invasive AP monitoring. Methods Ninety patients undergoing surgery under general anaesthesia were enrolled. Invasive pressure monitoring was established at the radial artery. CNAP monitoring using a finger sensor recording was begun before induction of anaesthesia. Statistical analysis was conducted with the Bland–Altman method for comparisons of repeated measures. Results We obtained 16 843 valid pressure readings from 85 patients. Mean (sd) bias during maintenance of anaesthesia was: systolic AP: 4.2 (16.5) mm Hg; mean AP (MAP): −4.3 (10.4) mm Hg; and diastolic AP: −5.8 (6) mm Hg. The results of a subgroup analysis of patients who had a mean intra-arterial pressure of <70 mm Hg were as follows: systolic pressure: −0.3 (9.7) mm Hg; mean pressure: −6.8 (7.6) mm Hg; and diastolic pressure: −7.9 (7.2) mm Hg. Bias and percentage error during the induction period were greater in both the main and subgroup analyses, probably due to recalibration being omitted after induction. Conclusions The CNAP monitor showed an acceptable agreement and was interchangeable with invasive pressure monitoring for MAP during normotensive conditions. During induction of anaesthesia and when the AP was low, the agreement was less good and interchangeability was not achieved. These results suggest that CNAP is not statistically equivalent to invasive monitoring during all periods of anaesthesia but may be a useful additional AP monitor. [ABSTRACT FROM PUBLISHER]

Background: Although in modern anaesthesia, monitoring depth of anaesthesia and quality of neuromuscular block are routine, monitoring of analgesia still remains challenging. Recently, the surgical stress index (SSI), derived from finger photoplethysmographic signal, was introduced as a surrogate variable reflecting the nociception–antinociception balance. This study aimed at evaluating the SSI in patients undergoing regional anaesthesia either alone or combined with sedation compared with patients undergoing general anaesthesia (GA). [ABSTRACT FROM PUBLISHER]

Background: The surgical stress index (SSI) is a new monitoring tool for the assessment of nociception during general anaesthesia. It is calculated based on the heart beat interval and the pulse wave amplitude. Correlation of SSI with nociceptive stimuli and opioid effect-site concentrations has been demonstrated, but the influence of isolated modulation of heart rate (HR) on SSI is still unclear. The aim of this study was to evaluate the effect on SSI of atropine administration and cardiac pacing. [ABSTRACT FROM PUBLISHER]