Alain Mayné

A comparison of the training value of two types of anesthesia simulators: Computer screen-based and mannequin-based simulators

UNLABELLED In this study, we compared two different training simulators (the computer screen-based simulator versus the full-scale simulator) with respect to training effectiveness in anesthesia residents. Participants were evaluated in the management of a simulated preprogrammed scenario of anaphylactic shock using two variables: treatment score and diagnosis time. Our results showed that simulators can contribute significantly to the improvement of performance but that learning in treating simulated crisis situations such as anaphylactic shock did not significantly vary between full-scale and computer screen-based simulators. Consequently, the initial decision on whether to use a full-scale or computer screen-based training simulator should be made on the basis of cost and learning objectives rather than on the basis of technical or fidelity criteria. Our results support the contention that screen-based simulators are good devices to acquire technical skills of crisis management. Mannequin-based simulators would probably provide better training for behavioral aspects of crisis management, such as communication, leadership, and interpersonal conflicts, but this was not tested in the current study. IMPLICATIONS We compared two different training simulators (computer screen-based versus full-scale) for training anesthesia residents to better document the effectiveness of such devices as training tools. This is an important issue, given the extensive use and the high cost of mannequin-based simulators in anesthesiology.

Hemodynamic benefit of optimizing atrioventricular delay after cardiopulmonary bypass.

BACKGROUND Shortening of atrioventricular delay (AVD) by sequential cardiac pacing has been proposed to improve hemodynamics in patients with end-stage heart failure. In addition, optimization of prolonged AVD may be associated with a decrease of presystolic mitral insufficiency. The aim of this study was to explore the incidence of prolonged AVD during the early postcardiopulmonary bypass (CPB) period and to evaluate the hemodynamic benefit of its shortening by using sequential cardiac pacing. METHODS Fifty consecutive patients scheduled for coronary artery bypass grafting were prospectively screened. AVD was measured immediately after separation from CPB. Patients presenting with AVD greater than or equal to 200 ms entered the study. Sequential cardiac pacing was introduced with programmed AVD starting at 80 ms and randomly increased by steps of 20 ms until resumption of native anterograde atrioventricular node conduction. Cardiac index (CI) was derived from transesophageal echocardiographic data during each step of this procedure. RESULTS Nineteen patients were included. Median native AVD was 220 ms. Median optimal AVD was 140 ms. Mean native CI (CI-nat) was 2.59 +/- 0.42 L/min/m2. Mean optimal CI (CI-opt) was 3.12 +/- 0.45 L/min/m2. CI-opt/CI-nat was 1.20 +/- 0.07. CI-opt/CI-nat was significantly inversely correlated with preoperative left ventricular ejection fraction (r = -0.83). CONCLUSIONS Prolonged AVD is a common occurrence after CPB. Its artificial shortening by sequential cardiac pacing is always associated with a significant increase of CI. The magnitude of this hemodynamic improvement is inversely correlated with preoperative left ventricular ejection fraction.

Étude prospective comparant la technique de l’Airtraq™ et du Glidescope™ lors de l’intubation chez les patients obèses

OBJECTIVES Videolaryngoscope techniques are more and more in use and tend to modify our approach for patients difficult to intubate. We compared two techniques, Airtraq and Glidescope with direct laryngoscopy, with special emphasis on ease of access to airway (Intubation Difficulty Score - IDS score, duration and success of intubation) and the impact on hemodynamic variables among patients with a BMI of more than 30. STUDY DESIGN Prospective study randomised with minimisation technique. MATERIAL AND METHODS Eighty patients have been allocated by minimisation to four groups: two groups being intubated with Airtraq, each one with a different investigator, and two with Glidescope videolaryngoscope technique. Induction of anesthesia was standardly performed with total intravenous anesthesia with remifentanil, propofol in TCI mode and rocuronium in bolus. Following parameters were recorded : intubation success based on intubation time and desaturation level, its duration, its impact on hemodynamic variables, IDS score and possible dental lesions. RESULTS Intubation success was 100% for Glidescope and 80.6% for Airtraq (P=0.009). Airtraq allowed a better visualisation of the vocal cords (lower Cormack and Lehane score) than Glidescope. In contrast, alternative intubation techniques were significantly more often used in the Airtraq group. No difference could be detected between both systems on hemodynamic parameters. CONCLUSIONS In obese patients, Glidescope allows intubation relatively easily without rescue techniques.

Regional increment in myocardial reflectivity after aortic valve replacement: early detection of air and assessment of treatment by transesophageal echocardiography.

IR EMBOLISM during cardiac surgery is a common occurrence and may be responsible for neurologlc and cardiac complications. This case report illustrates how transesophageal echocardiography (TEE) showed the regional increment in myocardial reflectlvity secondary to coronary air embolism and how TEE momtoring aided in detecting the efficacy of maneuvers to remove the air. CASE REPORT A 56-year-old man was scheduled for an aortic valve replacement. He had a history of severe aortic valvular stenosis with a mean transaortlc gradient of 56 mmHg and an aortic valve area of 0.63 cm 2. Coronary angiogram was normal with a left ventricular ejection fraction of 60%. After induction of anesthesia, a multiplane TEE probe, operating at 5 mHz, connected to an echocardiographlc system (Hewlett Packard SONOS 1000; Andover, MA), was inserted in a routine manner. After cross-clamping of the ascending aorta, anterograde cold hyperkalemic cardioplegia was administered, followed by intermittent retrograde cold hyperkalemic cardioplegia. Cardiopulmonary bypass (CPB) was performed under mild systemic hypothermia (34.8°C). The aortic valve was replaced by a mechanical prosthetic valve (St Jude 23 ram). Before unclamping of the aorta, passive filling of the left ventricle (LV), venting through a needle inserted in the ascending aorta and manual inflation of the lungs were performed with the patient head down. The passive filling was still low, and the accumulated air in the heart was not detected by TEE at that time. Immediately after unclamping of the aorta, the TEE detected microbubbles coming from the left atrium and massively from the right pulmonary veins. Although the venting was maintained, with the heart beating, an abrupt increase in myocardial reflectivity was observed (Fig 1). This myocardial opacification involved right ventricular and septal walls and was followed by significant ST-segment elevation in inferior leads on the electrocardiogram (ECG) (Fig 2). Severe depression of the regional LV function occurred, followed by severe distention of the LV cavity and by refractory ventricular fibrillation. It was decided to clamp the ascending aorta again in order to avoid systemic air embolism and to administer crystalloid retrograde cardioplegia (300 mL) to eliminate the intracoronary air, while the heart was manipulated in