Sascha S. Beutler

Transpulmonary thermodilution curves for detection of shunt

PurposeMonitoring using transpulmonary thermodilution (TPTD) via a single thermal indicator technique allows measurement of cardiac output, extravascular lung water (EVLW) and volumetric variables.Methods and resultsThis report describes two cases of systemic-venous circulation shunt generating early recirculation of thermal indicator with overestimation of EVLW.ConclusionIn the case of recirculation of thermal indicator, the observed overestimated EVLW in absence of gas exchanges abnormality could be an indicator suggesting the search for a circulatory shunt.

Providing Initial Transthoracic Echocardiography Training for Anesthesiologists: Simulator Training Is Not Inferior to Live Training

OBJECTIVE Transthoracic echocardiography (TTE) is finding increased use in anesthesia and critical care. Efficient options for training anesthesiologists should be explored. Simulator mannequins allow for training of manual acquisition and image recognition skills and may be suitable due to ease of scheduling. The authors tested the hypothesis that training with a simulator would not be inferior to training using a live volunteer. DESIGN Prospective, randomized trial. SETTING University hospital. PARTICIPANTS Forty-six anesthesia residents, fellows, and faculty. INTERVENTIONS After preparation with a written and video tutorial, study subjects received 80 minutes of TTE training using either a simulator or live volunteer. Practical and written tests were completed before and after training to assess improvement in manual image acquisition skills and theoretic knowledge. The written test was repeated 4 weeks later. MEASUREMENTS AND MAIN RESULTS Performance in the practical image-acquisition test improved significantly after training using both the live volunteer and the simulator, improving by 4.0 and 4.3 points out of 15, respectively. Simulator training was found not to be inferior to live training, with a mean difference of -0.30 points and 95% confidence intervals that did not cross the predefined non-inferiority margin. Performance in the written retention test also improved significantly immediately after training for both groups but declined similarly upon repeat testing 4 weeks later. CONCLUSIONS When providing initial TTE training to anesthesiologists, training using a simulator was not inferior to using live volunteers.

Left Atrial Dissection and Intramural Hematoma After Aortic Valve Replacement

Fig 1. LA dissection, left ventricle (LV), LVOT, and aorta (Ao) are visualized in the midesophageal long-axis view after the first AVR. The LA is compressed by the intramural hematoma (white arrows) leading to hypotension. The image is recorded in the process of re-establishing cardiopulmonary bypass. (Color version of figure is available online.)

Practice patterns in the intraoperative use of bispectral index monitoring

Assessing the depth of anesthesia and reducing intraoperative awareness has become a focus of much technology development and research in the field of anesthesia. Bispectral index (BIS) is the most widely utilized technology that uses electroencephalogram to provide a measurement of anesthetic depth. There are no definitive guidelines on when BIS should be used. Our aim was to assess actual patterns of intraoperative use of BIS by anesthesia professionals. We retrospectively collected intraoperative data on 55,210 surgical cases at a tertiary care hospital. Variables collected included: age, sex, body mass index (BMI), American Society of Anesthesiologists (ASA) physical status, anesthesia provider type and level of training, use of inhalational anesthetics versus total intravenous anesthesia (TIVA), utilization of nitrous oxide, utilization of non-depolarizing neuromuscular blockade, emergency status of surgery, airway type, case duration, and surgical subspecialty. A univariate logistic regression model was fitted. Subsequently, a multivariate logistic regression model was applied. Covariates utilized for the model included age, anesthesia provider level, and length of case. Factors associated with BIS use included increased age, greater ASA physical status, extremes of BMI, use of TIVA, use of a long-acting paralytic agent, use of an endotracheal tube (ETT), emergency surgery, increasing length of case, and certain surgical services. BIS use was associated with previously documented risk factors for intraoperative awareness. These factors are also indicators of case complexity, which may be a major factor among providers deciding when to apply BIS monitoring in the operating room.

Pharmacologic Properties of Novel Local Anesthetic Agents in Anesthesia Practice

Therapeutic duration of traditional local anesthetics when used in peripheral nerve blocks is normally limited. This article describes novel approaches to extend the duration of peripheral nerve blocks currently available or in development. Three newer approaches on extending the duration of peripheral nerve blocks include site-1 sodium channel blockers, novel local anesthetics delivery systems, and novel adjuvants of local anesthetics. Compared with plain amide-based and ester-based local anesthetics, alternative approaches show significant promise in decreasing postoperative pain, rescue opioid requirement, hospital length-of-stay, and overall health care cost, without compromising the established safety profile of traditional local anesthetics.

New Hypnotic Drug Development and Pharmacologic Considerations for Clinical Anesthesia

Since the public demonstration of ether as a novel, viable anesthetic for surgery in 1846, the field of anesthesia has continually sought the ideal anesthetic-rapid onset, potent sedation-hypnosis with a high therapeutic ratio of toxic dose to minimally effective dose, predictable clearance to inactive metabolites, and minimal side effects. This article aims to review current progress of novel induction agent development and provide an update on the most promising drugs poised to enter clinical practice. In addition, the authors describe trends in novel agent development, implications for health care costs, and implications for perioperative care.

Education and training for nonanesthesia providers performing deep sedation.

Purpose of review There has been a significant increase in the number and types of procedures performed outside of the operating room with nonanesthesia providers administering sedation. This review describes current recommendations for training nonanesthesiologists involved in administering deep sedation, summarizes best practices and highlights select patient outcomes. Recent findings There are numerous guidelines and standards related to the administration of deep sedation. However, there are no universally accepted guidelines regarding the necessary educational and skill competencies needed for nonanesthesiologists to provide deep sedation. The American Society of Anesthesiologists has published a position statement and guidelines on these educational requirements, yet the extent to which these are adhered to remains unknown. As evidence-based guidelines continue to evolve, more research is needed to describe how current practices affect patient outcomes. Summary The American Society of Anesthesiologists publishes recommendations regarding the essential educational components for nonanesthesiologist providers who administer deep sedation. The available data support the need for formal educational programmes to prevent adverse events associated with deep sedation. Competencies should include preprocedural evaluation, understanding sedation levels, airway management, documentation, emergency life support skills, teamwork and quality improvement.

Analysis of Unplanned Intensive Care Unit Admissions in Postoperative Pediatric Patients

Background: Currently, there are only a few retrospective, single-institution studies that have addressed the prevalence and risk factors associated with unplanned admissions to the pediatric intensive care unit (ICU) after surgery. Based on the limited amount of studies, it appears that airway and respiratory complications put a child at increased risk for unplanned ICU admission. A more extensive and diverse analysis of unplanned postoperative admissions to the ICU is needed to address risk factors that have yet to be revealed by the current literature. Aim: To establish a rate of unplanned postoperative ICU admissions in pediatric patients using a large, multi-institution data set and to further characterize the associated risk factors. Methods: Data from the National Anesthesia Clinical Outcomes Registry were analyzed. We recorded the overall risk of unplanned postoperative ICU admission in patients younger than 18 years and performed univariate and multivariate logistic regression analysis to identify the associated patient, surgical, and anesthetic-related characteristics. Results: Of the 324 818 cases analyzed, 211 reported an unexpected ICU admission. There was an increased likelihood of unplanned postoperative ICU in infants (age <1 year) and children who were classified as American Society of Anesthesiologists physical status classification of III or IV. Likewise, longer case duration and cases requiring general anesthesia were also associated with unplanned ICU admissions. Conclusion: This study establishes a rate of unplanned ICU admission following surgery in the heterogeneous pediatric population. This is the first study to utilize such a large data set encompassing a wide range of practice environments to identify risk factors leading to unplanned postoperative ICU admissions. Our study revealed that patient, surgical, and anesthetic complexity each contributed to an increased number of unplanned ICU admissions in the pediatric population.

GlideScope® Tracheal Intubation with and without Muscle Relaxation: A Prospective, Randomized Clinical Trial

Purpose: GlideScope ® videolaryngoscope (GVL, Verathon Medical Inc., Bothell, WA, USA) assisted orotra- cheal intubation is a useful technique for patients who are difficult to intubate, but who can be mask ventilated. The effect of muscle relaxants on the success of GVL intubation has not been evaluated. The authors conducted a prospective, pla- cebo-controlled study to assess the effectiveness and incidence of complications of GVL-assisted tracheal intubation per- formed during general anesthesia with and without the use of a muscle relaxant in patients with seemingly normal airway anatomy. Material and Methods: 52 patients who required orotracheal intubation were prospectively included. Anesthesia was in- duced using midazolam (0.01-0.03 mg/kg), fentanyl (1-3 µg/kg) and propofol (1-3 mg/kg). Patients were randomly as- signed to one of two groups to receive rocuronium 0.6 mg/kg (n = 26 for rocuronium group) or saline intravenously (n = 26 for placebo group). GVL-assisted intubation was initiated after 90 s. The number of successful intubations, the number of attempts and their duration were recorded. Events during the procedure, such as airway trauma, blood pressure changes and movements were also recorded. Results: The success rate of GVL intubation was 100% in the placebo group and 100% in the rocuronium group. Patients in both groups received the same number of intubation attempts and the intubation time were alike (53± 15 vs. 55 ± 18 s; p=0.63). The Placebo group experienced a greater incidence of events during intubation (81 vs. 35%; P < 0.001) than pa- tients in the rocuronium group. Conclusions: Omitting muscle relaxants in patients with apparently normal airways is not associated with a higher failure rate, increased intubation attempts or intubation time when performing GVL assisted orotracheal intubation, but is associ- ated with a higher rate of patient movement.

Intubation with simultaneous use of the GlideScope and the Trachlight

Despite careful airway assessment, GVL laryngoscopy occasionally yields unexpectedly poor laryngeal views, thus leading to inability to intubate the trachea in 2%–15% of patients [1,3,4]. Angling a stylet with a 60° or a 90° curvature has been recommended [4,5]. Hung et al. [6,7] have recommended bending the TL stylet 70° to 90°. Therefore, the preferred intubation shape of the TL meets the criteria for GVL use [4–7]. The combination of the GVL and TL has not been assessed. Because of the high success rates of both devices [8], it can be assumed that using both instruments together would lead to a higher success rate of tracheal intubation, should one device alone fail. We chose the TL and not a fi beroptic bronchoscope, because the TL was more quickly assembled. In addition, it can be more easily transported and cleaned. In this patient the GVL produced a poor laryngeal view. The light source of the TL was too bright for the GVL monitor and an adequate image was seen only after turning off the TL. Video guidance helped to direct the TL underneath the epiglottis, where the light was not affecting the video camera, since the epiglottis was blocking the light. In conclusion, when using a combination of the GVL and TL, the latter should be inserted and the light turned on only if needed and after the tip of the lighted stylet has passed underneath the epiglottis, in order to avoid the light affecting the GLV monitor.