The World Federation of Societies of Anaesthesiologists Minimum Capnometer Specifications 2021-A Guide for Health Care Decision Makers.

Capnometry, the measurement of respiratory carbon dioxide, is regarded as a highly recommended safety technology in intubated and nonintubated sedated and/or anesthetized patients. Its utility includes confirmation of initial and ongoing placement of an airway device as well as in detecting gas exchange, bronchospasm, airway obstruction, reduced cardiac output, and metabolic changes. The utility applies prehospital and throughout all phases of inhospital care. Unfortunately, capnometry devices are not readily available in many countries, especially those that are resource-limited. Constraining factors include cost, durability of devices, availability of consumables, lack of dependable power supply, difficulty with cleaning, and maintenance. There is, thus, an urgent need for all stakeholders to come together to develop, market, and distribute appropriate devices that address costs and other requirements. To foster this process, the World Federation of Societies of Anaesthesiologists (WFSA) has developed the "WFSA-Minimum Capnometer Specifications 2021." The intent of the specifications is to set the minimum that would be acceptable from industry in their attempts to reduce costs while meeting other needs in resource-constrained regions. The document also includes very desirable and preferred options. The intent is to stimulate interest and engagement among industry, clinical providers, professional associations, and ministries of health to address this important patient safety need. The WFSA-Minimum Capnometer Specifications 2021 is based on the International Organization for Standardization (ISO) capnometer specifications. While industry is familiar with such specifications and their presentation format, most clinicians are not; therefore, this article serves to more clearly explain the requirements. In addition, the specifications as described can be used as a purchasing guide by clinicians.

The Origins, Evolution, and Spread of Anesthesia Monitoring Standards: From Boston to Across the World.

In the mid-1980s, the anesthesia departments at hospitals affiliated with Harvard Medical School were faced with a challenge: mounting medical malpractice costs. Malpractice insurance was provided by the Controlled Risk Insurance Company (CRICO), a patient safety and medical malpractice insurance company owned by and providing service to the Harvard medical community. CRICO spearheaded an effort to reduce these costs and ultimately found a way to decrease the risks associated with anesthesia. Here, we chronicle events that led to the dramatic changes in medical practice that resulted from the activities of a small group of concerned anesthesiologists at Harvard-affiliated hospitals. We place these events in a historical perspective and explore how other specialties followed this example, and end with current strategies that minimize the risk associated with anesthesia. We conducted interviews with principals who formulated original standards of patient monitoring. In addition, we consulted documents in the public domain and primary source material. Efforts of these pioneers resulted in the establishment of the seminal Harvard-based anesthesia monitoring standards for minimal monitoring. What followed was an unprecedented transformation of the entire field. After the implementation of these standards at Harvard-affiliated hospitals, the American Society of Anesthesiologists (ASA) adopted "Standards for Basic Anesthetic Monitoring" for use during the administration of all anesthetics in the United States. Other nations have since adopted similar guidelines and these practices have resulted in significant improvements in patient safety. Currently, we estimate mortality due to anesthesia in healthy patients to be 1:400,000-perhaps as much as 10 times lower since the early 1980s. What began as an attempt to lower medical malpractice costs in a group of university hospitals became a worldwide effort that resulted in improvements in patient safety. Other specialties have adopted similar measures. Currently, an attitude and appreciation of safety are exemplified by several practices that include among others-the adherence to these patient safety guidelines, simulator training, the promulgation of standards and guidelines by ASA, and the use of a safety checklist before induction of anesthesia.

World Health Organization-World Federation of Societies of Anaesthesiologists (WHO-WFSA) International Standards for a Safe Practice of Anesthesia.

The International Standards for a Safe Practice of Anesthesia were developed on behalf of the World Federation of Societies of Anaesthesiologists (WFSA), a non-profit organization representing anesthesiologists in 150 countries, and the World Health Organization (WHO). The recommendations have been approved by WHO and the membership of WFSA. These Standards are applicable to all anesthesia providers throughout the world. They are intended to provide guidance and assistance to anesthesia providers, their professional organizations, hospital and facility administrators, and governments for maintaining and improving the quality and safety of anesthesia care. The Standards cover professional aspects; facilities and equipment; medications and intravenous fluids; monitoring; and the conduct of anesthesia. HIGHLY RECOMMENDED standards, the functional equivalent of mandatory standards, include (amongst other things): the continuous presence of a trained and vigilant anesthesia provider; continuous monitoring of tissue oxygenation and perfusion by clinical observation and a pulse oximeter; intermittent monitoring of blood pressure; confirmation of correct placement of an endotracheal tube (if used) by auscultation and carbon dioxide detection; the use of the WHO Safe Surgery Checklist; and a system for transfer of care at the end of an anesthetic. The International Standards represent minimum standards and the goal should always be to practice to the highest possible standards, preferably exceeding the standards outlined in this document.

Assessment of interchangeability rate between 2 methods of measurements: An example with a cardiac output comparison study.

The Bland-Altman (BA) and percentage error (PE) methods have been previously described to assess the agreement between 2 methods of medical or laboratory measurements. This type of approach raises several problems: the BA methodology constitutes a subjective approach to interchangeability, whereas the PE approach does not take into account the distribution of values over a range. We describe a new methodology that defines an interchangeability rate between 2 methods of measurement and cutoff values that determine the range of interchangeable values. We used a simulated data and a previously published data set to demonstrate the concept of the method. The interchangeability rate of 5 different cardiac output (CO) pulse contour techniques (Wesseling method, LiDCO, PiCCO, Hemac method, and Modelflow) was calculated, in comparison with the reference pulmonary artery thermodilution CO using our new method. In our example, Modelflow with a good interchangeability rate of 93% and a cutoff value of 4.8 L min, was found to be interchangeable with the thermodilution method for >95% of measurements. Modelflow had a higher interchangeability rate compared to Hemac (93% vs 86%; P = .022) or other monitors (Wesseling cZ = 76%, LiDCO = 73%, and PiCCO = 62%; P < .0001). Simulated data and reanalysis of a data set comparing 5 CO monitors against thermodilution CO showed that, depending on the repeatability of the reference method, the interchangeability rate combined with a cutoff value could be used to define the range of values over which interchangeability remains acceptable.

Assessment of Paravalvular Leak After Transcatheter Aortic Valve Replacement: Transesophageal Echocardiography Compared With Transthoracic Echocardiography.

OBJECTIVES: Determine whether moderate or greater paravalvular leak (PVL) after transcatheter aortic valve replacement quantified using intraoperative transesophageal echocardiography (TEE) is associated with mortality and investigate the correlation between PVL grading using intraoperative TEE and postoperative transthoracic echocardiography (TTE). DESIGN: Retrospective, observational study. SETTING: Single academic institution. PARTICIPANTS: The study comprised adult patients undergoing elective transcatheter aortic valve replacement between April 2011 and February 2014. INTERVENTIONS: Patients were grouped by amount of PVL on intraoperative TEE into "significant" (moderate or greater) and "nonsignificant" (no, trivial, or mild) PVL groups. Demographics and patient characteristics were compared. Continuous variables were assessed with t-tests or Wilcoxon rank sum tests and categorical variables with the chi-square or Fisher exact test. A Cox proportional hazards model adjusted for EuroSCORE was used to test the independent association of PVL with late mortality, and covariate-adjusted survival curves were constructed. A Fleiss-Cohen-weighted kappa value was used to assess agreement between PVL grading using intraoperative TEE and postoperative TTE. MEASUREMENTS AND MAIN RESULTS: One hundred ninety-six patients were grouped into the "significant" (n = 22) or "nonsignificant" (n = 174) PVL group. Twenty patients (10%) died during the follow-up period. Significant PVL on either TTE (p = 0.62, hazard ratio 1.68, 95% confidence interval [CI] 0.22-12.85) or TEE (p = 0.49, hazard ratio 0.49; 95% CI 0.06-3.68) was not associated with a survival difference. Modest agreement was found between PVL on intraoperative TEE and postoperative TTE (kappa = 0.47, CI 0.37-0.57, p < 0.0001). CONCLUSIONS: Larger studies are needed to evaluate the association of PVL graded on intraoperative TEE with survival. There is modest agreement between the degree of PVL found on TEE and TTE.

Assessment of a smartphone app (Capstesia) for measuring pulse pressure variation: agreement between two methods: A Cross-sectional study.

BACKGROUND: Less invasive and noninvasive methods are emerging for haemodynamic monitoring. Among them is Capstesia, a smartphone app that, from photographs of a patient monitor showing invasive arterial pressure, estimates advanced haemodynamic variables after digitising and analysing the pressure curves. OBJECTIVE: The aim of this study was to compare the level of agreement between the analysis of the signals obtained from the patient monitor and a photograph of the same images using the Capstesia app. DESIGN: Cross-sectional study. SETTING: Araba University hospital (Txagorritxu), Vitoria-Gasteiz, Alava, Spain, from January to February 2015. PATIENTS: Twenty patients (229 images) who had an arterial catheter (radial or femoral artery) inserted for haemodynamic monitoring. INTERVENTION: Snapshots obtained from the patient monitor and a photograph of these same snapshots using the Capstesia application were assessed with the same software (MATLAB, Mathworks, Natick, Massachusetats, USA) for evaluating the level of concordance of the following variables: pulse pressure variation (PPV), cardiac output (CO) and maximum slope of the pressure curve (dP/dt). Comparison was made using interclass correlation coefficients with corresponding 95% confidence intervals, and Bland-Altman plots with the corresponding percentages of error. MAIN OUTCOME MEASURES: (PPV). Secondary outcome: CO and maximum slope of the pressure curve [dP/dt]. RESULTS: The interclass correlation coefficients for PPV, CO and max dP/dt were 0.991 (95% confidence interval 0.988 to 0.993), 0.966 (95% confidence interval 0.956 to 0.974) and 0.962 (95% confidence interval 0.950 to 0.970), respectively. In the Bland-Altman analysis, bias and limits of agreement of PPV were (0.50% ±â€Š1.42) resulting in a percentage of error of 20% for PPV. For CO they were 0.19 ±â€Š0.341, with a 13.8% of error. Finally bias and limits of agreement for max dP/dt were 1.33 ±â€Š77.71, resulting in an error of 14.20% CONCLUSIONS: Photograph of the screenshots obtained with the Capstesia app show a good concordance with analysis of the original screenshots. Either approach could be used to monitor the haemodynamic variables assessed.

Determination of loss of consciousness: a comparison of clinical assessment, bispectral index and electroencephalogram: An observational study.

BACKGROUND: Computer-processed algorithms of encephalographic signals are widely used to assess the depth of anaesthesia. However, data indicate that the bispectral index (BIS), a processed electroencephalography monitoring system, may not be reliable for assessing the depth of anaesthesia. OBJECTIVE: The aim of this study was to evaluate the ability of the BIS monitoring system to assess changes in the level of unconsciousness, specifically during the transition from consciousness to unconsciousness, in patients undergoing total intravenous anaesthesia with propofol. We compared BIS with the electroencephalogram (EEG), and clinical loss of consciousness (LOC) defined as loss of verbal commands and eyelash reflex. DESIGN: This was an observational cohort study. SETTING: University Hospital Linköping, University Hospital Örebro, Finspång Hospital and Kalmar Hospital, Sweden from October 2011 to April 2013. PATIENTS: A total of 35 ASA I patients aged 18 to 49 years were recruited. INTERVENTIONS: The patients underwent total intravenous anaesthesia with propofol and remifentanil for elective day-case surgery. Changes in clinical levels of consciousness were assessed by BIS and compared with assessment of stage 3 neurophysiological activity using the EEG. The plasma concentrations of propofol were measured at clinical LOC and 20 and 30 min after LOC. MAIN OUTCOME MEASURES: The primary outcome was measurement of BIS, EEG and clinical LOC. RESULTS: The median BIS value at clinical LOC was 38 (IQR 30 to 43), and the BIS values varied greatly between patients. There was no correlation between BIS values and EEG stages at clinical LOC (r = -0.1, P = 0.064). Propofol concentration reached a steady state within 20 min. CONCLUSION: There was no statistically significant correlation between BIS and EEG at clinical LOC. BIS monitoring may not be a reliable method for determining LOC. CLINICAL TRIALS REGISTRY: This trial was not registered because registration was not mandatory at the time of the trial.

Validity of Thromboelastometry for Rapid Assessment of Fibrinogen Levels in Heparinized Samples During Cardiac Surgery: A Retrospective, Single-center, Observational Study.

OBJECTIVE: To assess the validity of fibrinogen assay of rotational thromboelastometry (FIBTEM)-derived estimates of fibrinogen in samples collected during cardiopulmonary bypass in cardiac surgical patients by comparison to Clauss method fibrinogen concentration. DESIGN: Retrospective observational study. SETTING: Single university hospital center. PARTICIPANTS: Human participants. INTERVENTIONS: Retrospectively obtained laboratory assays including rotational thromboelastometry (ROTEM) and Clauss fibrinogen assay. MEASUREMENTS AND MAIN RESULTS: A retrospective review was performed of anesthesia records at a single university teaching hospital during a 1-year period. From paired samples taken near the end of cardiopulmonary bypass, fibrinogen concentrations (Clauss method) were compared with FIBTEM-derived measures of maximal clot firmness (MCF) and clot amplitude at 10 minutes (A10) using Spearman's rank correlation, linear regression, and receiver operating characteristic curve analysis. The study included 1,077 patients. Clauss fibrinogen was correlated strongly with FIBTEM amplitudes (r = 0.78 for MCF and A10; p<0.01). The correlation was related inversely to hemoglobin concentration (p<0.01). The area under the receiver operating characteristic curve was 0.95; the optimal FIBTEM A10 cutoff for diagnosis of a fibrinogen concentration of<1.5 g/L was ≤8 mm. CONCLUSIONS: The FIBTEM was a valid point-of-care method for estimating the fibrinogen concentration during cardiopulmonary bypass and may be used for prediction of hypofibrinogenemia before separation from the extracorporeal circuit.

Bispectral Index Monitoring: validity and utility in pediatric dentistry.

Reliable and safe provision of sedation and general anesthesia is dependent on continuous vigilance of patient's sedation depth. Failure to do so may result in unintended oversedation or undersedation. It is a common practice to observe sedation depth by applying subjective sedation scales and in case of general anesthesia, practitioner is dependent on vital sign assessment. The Bispectral Index System (BIS) is a recently introduced objective, quantitative, easy to use, and free from observer bias, and clinically useful tool to assess sedation depth and it precludes the need to stimulate the patient to assess his sedation level. The present article is an attempt to orient the readers towards utility and validity of BIS for sedation and general anesthesia in pediatric dentistry. In this article, we attempt to make the readers understand the principle of BIS, its variation across sedation continuum, its validity across different age groups and for a variety of sedative drugs.

Review article: the evolving role of information technology in perioperative patient safety.

PURPOSE: The adoption of new technologies in medicine is frequently met with both enthusiasm and resistance. The universal adoption of health information technology (IT) and anesthesia information management systems (AIMS) remains low despite the potential benefits. Electronic medical records, and hence AIMS, are at the intersection of patient safety. This article highlights advantages and barriers to adoption and implementation of IT in general and AIMS in particular, with a focus on clinical decision support systems (CDSS) and computerized physician order entry (CPOE) as hallmarks that may lead to improvement in patient safety and quality in the perioperative setting. PRINCIPAL FINDINGS: The advantages of health IT and AIMS include improved legibility of documentation; the ability to integrate new scientific evidence into practice; enhanced management and exchange of complex health information; the ability to standardize order sets, incorporate computerized physician order entry, and provide clinical decision support; and the ability to capture data for management, research, and quality monitoring and reporting. While not foolproof, AIMS have been shown to improve safety, quality, and patient outcomes. Barriers to the adoption of health IT and AIMS include costs, lack of truly interoperable AIMS components in health-system IT solutions, and lack of clinician involvement in implementation, planning, design, and installation of many IT or AIMS products. CONCLUSIONS: Health IT and AIMS are at the intersection of patient safety and technology. Anesthesiologists are perfectly positioned to be the physician leaders of adoption, design, implementation, and integration, not only for AIMS but also for health-system IT solutions in general.

Intraoperative neurophysiological monitoring in spine surgery: indications, efficacy, and role of the preoperative checklist.

Spine surgery carries an inherent risk of damage to critical neural structures. Intraoperative neurophysiological monitoring (IONM) is frequently used to improve the safety of spine surgery by providing real-time assessment of neural structures at risk. Evidence-based guidelines for safe and efficacious use of IONM are lacking and its use is largely driven by surgeon preference and medicolegal issues. Due to this lack of standardization, the preoperative sign-in serves as a critical opportunity for 3-way discussion between the neurosurgeon, anesthesiologist, and neuromonitoring team regarding the necessity for and goals of IONM in the ensuing case. This analysis contains a review of commonly used IONM modalities including somatosensory evoked potentials, motor evoked potentials, spontaneous or free-running electromyography, triggered electromyography, and combined multimodal IONM. For each modality the methodology, interpretation, and reported sensitivity and specificity for neurological injury are addressed. This is followed by a discussion of important IONM-related issues to include in the preoperative checklist, including anesthetic protocol, warning criteria for possible neurological injury, and consideration of what steps to take in response to a positive alarm. The authors conclude with a cost-effectiveness analysis of IONM, and offer recommendations for IONM use during various forms of spine surgery, including both complex spine and minimally invasive procedures, as well as lower-risk spinal operations.

Cost-effectiveness of confirmatory techniques for the placement of lumbar pedicle screws.

OBJECT: There is considerable variation in the use of adjunctive technologies to confirm pedicle screw placement. Although there is literature to support the use of both neurophysiological monitoring and isocentric fluoroscopy to confirm pedicle screw positioning, there are no studies examining the cost-effectiveness of these technologies. This study compares the cost-effectiveness and efficacy of isocentric O-arm fluoroscopy, neurophysiological monitoring, and postoperative CT scanning after multilevel instrumented fusion for degenerative lumbar disease. METHODS: Retrospective data were collected from 4 spine surgeons who used 3 different strategies for monitoring of pedicle screw placement in multilevel lumbar degenerative disease. A decision analysis model was developed to analyze costs and outcomes of the 3 different monitoring strategies. A total of 448 surgeries performed between 2005 and 2010 were included, with 4 cases requiring repeat operation for malpositioned screws. A sample of 64 of these patients was chosen for structured interviews in which the EuroQol-5D questionnaire was used. Expected costs and quality-adjusted life years were calculated based on the incidence of repeat operation and its negative effect on quality of life and costs. RESULTS: The decision analysis model demonstrated that the O-arm monitoring strategy is significantly (p < 0.001) less costly than the strategy of postoperative CT scanning following intraoperative uniplanar fluoroscopy, which in turn is significantly (p < 0.001) less costly than neurophysiological monitoring. The differences in effectiveness of the different monitoring strategies are not significant (p = 0.92). CONCLUSIONS: Use of the O-arm for confirming pedicle screw placement is the least costly and therefore most cost-effective strategy of the 3 techniques analyzed.

Availability of anesthesia equipment in Chinese hospitals: is the safety of anesthesia patient care assured?

Availability of physiologic monitoring equipment to ensure the safe administration of anesthesia is an expected standard in many parts of the world. Many hospitals in China may not have an adequate quantity and variety of anesthesia delivery and patient monitoring equipment to assure safe administration of anesthesia patient care. We present some typical cases of hospitals of different sizes and located in regions with different economic levels; our data demonstrate that there is a lack of available anesthesia administration and patient monitoring equipment in small hospitals and hospitals in economically underdeveloped regions.

The accuracy of intraoperative O-arm images for the assessment of pedicle screw postion.

STUDY DESIGN: Human cadaveric study. OBJECTIVE: The objective of the study was to determine the accuracy of intraoperative O-arm images in determining pedicle screw position using open dissection as the gold standard. SUMMARY OF BACKGROUND DATA: Pedicle screws are widely used in the treatment of various spinal disorders. Postoperative computed tomographic scans are the imaging gold standard to detect pedicle screw malposition. However, a second procedure is necessary if such malpositioned screws have to be revised. The O-arm is an intraoperative scanner that allows revision of a screw without having to return the patient to the operating room for a separate procedure. No previous studies have looked at the accuracy of intraoperative O-arm images in determining pedicle screw position. METHODS: This factorial validation study utilized 9 cadavers in a comparison of intraoperative O-arm images and the dissection gold standard. Four hundred sixteen screws were inserted using 3-dimensional image (O-arm) guidance from C2 to S1. The screw positions were randomized into 3 groups: "IN" (fully contained within the pedicle), "OUT-lateral," or "OUT-medial." After screw insertion, O-arm images were obtained and reviewed in a blinded fashion by 3 independent observers. Dissection identified the true position of the screws. Specificity, sensitivity, positive predictive value (PPV), and negative predictive value (NPV) were calculated using dissection results as the gold standard. The interobserver reliability was also determined. RESULTS: The overall accuracy, specificity, sensitivity, PPV, and NPV of O-arm images for the thoracic and lumbar spine were 73%, 76%, 71%, 74%, and 72%, respectively. Accuracy of surgeon perception in the cervical spine was significantly less than in the thoracic and lumbosacral spine. There was substantial interobserver agreement between the 3 readers. CONCLUSION: Intraoperative O-arm images accurately detect significant pedicle screw violations in the thoracic and lumbosacral spine but are less accurate for the cervical spine.

[Perioperative coagulation monitoring - medical and economic aspects]. / Perioperative Gerinnungsdiagnostik - Medizinische und ökonomische Perspektiven.

For preoperative haemostatic assessment a structured questionnaire for the bleeding history of the patient should be primarily used. Only in case of abnormalities an additional laboratory coagulation testing is recommended. Such a test set must include functional testing of platelets as defects of the primary haemostasis are frequent. In the event of acute acquired perioperative coagulopathy laboratory coagulation testing is a prerequisite for sophisticated and precise diagnosis and therapy. Points of care techniques like thrombelastography are capable to provide fast and extensive information.

The evidence for intraoperative neurophysiological monitoring in spine surgery: does it make a difference?

OBJECTIVE: The objective of this article was to undertake a systematic review of the literature to determine whether IOM is able to sensitively and specifically detect intraoperative neurologic injury during spine surgery and to assess whether IOM results in improved outcomes for patients during these procedures. SUMMARY AND BACKGROUND DATA: Although relatively uncommon, perioperative neurologic injury, in particular spinal cord injury, is one of the most feared complications of spinal surgery. Intraoperative neuromonitoring (IOM) has been proposed as a method which could reduce perioperative neurologic complications after spine surgery. METHODS: A systematic review of the English language literature was undertaken for articles published between 1990 and March 2009. MEDLINE, EMBASE, and Cochrane Collaborative Library databases were searched, as were the reference lists of published articles examining the use of IOM in spine surgery. Two independent reviewers assessed the level of evidence quality using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) criteria, and disagreements were resolved by consensus. RESULTS: A total of 103 articles were initially screened and 32 ultimately met the predetermined inclusion criteria. We determined that there is a high level of evidence that multimodal IOM is sensitive and specific for detecting intraoperative neurologic injury during spine surgery. There is a low level of evidence that IOM reduces the rate of new or worsened perioperative neurologic deficits. There is very low evidence that an intraoperative response to a neuromonitoring alert reduces the rate of perioperative neurologic deterioration. CONCLUSION: Based on strong evidence that multimodality intraoperative neuromonitoring (MIOM) is sensitive and specific for detecting intraoperative neurologic injury during spine surgery, it is recommended that the use of MIOM be considered in spine surgery where the spinal cord or nerve roots are deemed to be at risk, including procedures involving deformity correction and procedures that require the placement of instrumentation. There is a need to develop evidence-based protocols to deal with intraoperative changes in MIOM and to validate these prospectively.

Speckle tracking for the intraoperative assessment of right ventricular function: a feasibility study.

OBJECTIVES: Speckle tracking is an ultrasound method that assesses B-mode features to measure tissue displacement and derive deformation parameters. The objective of this study was to assess the feasibility of using speckle tracking in the measurement of right ventricular (RV) longitudinal strain during cardiac surgery using transesophageal echocardiography (TEE). DESIGN: This was a prospective, observational cohort study. SETTING: A single university hospital setting. PARTICIPANTS: Twenty-one patients without valvular disease referred for coronary artery bypass graft surgery were studied. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: After the induction of anesthesia and mechanical ventilation, transthoracic echocardiography (TTE) and transesophageal echocardiography (TEE) were used to obtain tricuspid annular plane systolic excursion (TAPSE), RV fractional area of change (FAC), and 2-dimensional strain analysis (speckle tracking) on 3 consecutive heart beats. There was a larger percentage of measurable segments achieved when using TEE. All segments could be analyzed per cardiac cycle in 73% of loops when using TEE and 38% when using TTE. The global strain value was similar using both methods (TEE: -20.4%, TTE: -20.1%). The TAPSE could be measured in only 52% of the segments using TTE and 100% using TEE. The FAC could be measured in 90.5% of the loops using TEE and in only 33.3% of the loops using TTE. CONCLUSIONS: Perioperative measurements of RV strain using TEE in ventilated patients is feasible. The success rate was higher using TEE in ventilated patients under anesthesia. Differences between the 2 methods were likely the result of differences in 2-dimensional image quality.

Comparison of contemporary EEG derived depth of anesthesia monitors with a 5 step validation process.

During the last decennium, a growing number of depth of anesthesia monitors, extracting information from the spontaneous electroencephalogram (EEG) have been developed and commercialized. The growing interest in depth of anesthesia monitoring resulted in an intensified technological progress. Innovations on both hardware and mathematical algorithms were introduced for improving the extraction of data. Because of the abundance of monitors now commercially available, it becomes increasingly important to develop a standardized reproducible methodology for comparing depth of anesthesia monitors. In this review, the authors present a strategy to compare monitors of the hypnotic component of anesthesia, based on the available literature and their own experience with validation studies. They also discuss the level of validation of the most commonly used EEG derived depth of anesthesia monitors.