Haim Berkenstadt

Stroke volume variation as a predictor of fluid responsiveness in patients undergoing brain surgery.

Changes in arterial blood pressure induced by mechanical ventilation allow assessment of cardiac preload. In this study, stroke volume variation (SVV), which is the percentage change between the maximal and minimal stroke volumes (SV) divided by the average of the minimum and maximum over a floating period of 30 s, continuously displayed by the PiCCO continuous cardiac output monitor, was evaluated as a predictor of fluid responsiveness. Fifteen patients undergoing brain surgery were included. During surgery, graded volume loading was performed with each volume loading step (VLS) consisting of 100 mL of 6% hydroxyethylstarch given for 2 min. Successive responsive VLSs were performed (increase in SV > 5% after a VLS) until a change in SV of <5% was reached (nonresponsive). A total of 140 VLSs were performed. Responsive and nonresponsive VLSs differed in their pre-VLS values of systolic blood pressure, SV, and SVV, but not in the values of heart rate and central venous pressure. By using receiver operating characteristic analysis, the area under the curve for SVV (0.870, 95% confidence interval [CI]: 0.809 to 0.903) was statistically more than those for central venous pressure (0.493, 95% CI: 0.397 to 0.590, P = 7 × 10−10), heart rate (0.593, 95% CI: 0.443 to 0.635, P = 5.7 × 10−10), and systolic blood pressure (0.729, 95% CI: 0.645 to 0.813, P = 4.3 × 10-3). An SVV value of 9.5% or more, will predict an increase in the SV of at least 5% in response to a 100-mL volume load, with a sensitivity of 79% and a specificity of 93%.

Novel, compact, intraoperative magnetic resonance imaging-guided system for conventional neurosurgical operating rooms.

OBJECTIVEPreliminary clinical experience with a novel, compact, intraoperative magnetic resonance imaging (MRI)-guided system that can be used in an ordinary operating room is presented. DESCRIPTION OF INSTRUMENTATION The system features an MRI scanner integrated with an optical and MRI tracking system. Scanning and navigation, which are operated by the surgeon, are controlled by an in-room computer workstation with a liquid crystal display screen. The scanner includes a 0.12-T permanent magnet with a 25-cm vertical gap, accommodating the patient’s head. The field of view is 11 × 16 cm, encompassing the surgical area of interest. The magnet is mounted on a transportable gantry that can be positioned under the surgical table when not in use for scanning, thus rendering the surgical environment unmodified and allowing the use of standard instruments. The features of the integrated navigation system allow flap planning and intraoperative tracking based on updated images acquired during surgery. OPERATIVE TECHNIQUE Twenty patients with brain tumors were surgically treated using craniotomy or transsphenoidal approaches. One patient underwent conscious craniotomy with cortical mapping, and two underwent electrocorticography. EXPERIENCE AND RESULTS Planning was accurate. Resection control images were obtained for all patients during surgery, with precise localization of residual tumor tissue. There were no surgical complications related to the use of the system. CONCLUSIONThis intraoperative MRI system can function in a normal operating room modified only to eliminate radiofrequency interference. The operative environment is normal, and standard instruments can be used. The scanning and navigation capabilities of the system eliminate the inaccuracies that may result from brain shift. This novel type of intraoperative MRI system represents another step toward the introduction of the modality as a standard method in neurosurgery.

Improving Handoff Communications in Critical Care: Utilizing Simulation-Based Training Toward Process Improvement in Managing Patient Risk

BACKGROUND A patient admitted to the medical step-down unit experienced severe hypoglycemia due to an infusion of a higher-than-ordered insulin dose. The event could have been prevented if the insulin syringe pump was checked during the nursing shift handoff. METHODS Risk management exploration included direct observations of nursing shift handoffs, which highlighted common deficiencies in the process. This led to the development and implementation of a handoff protocol and the incorporation of handoff training into a simulation-based teamwork and communication workshop. A second round of observations took place 6 to 8 weeks following training. RESULTS The intervention demonstrated an increase in the incidence of nurses communicating crucial information during handoffs, including patient name, events that had occurred during the previous shift, and treatment goals for the next shift. However, there was no change in the incidence of checking the monitor alarms and the mechanical ventilator. CONCLUSIONS Simulation-based training can be incorporated into the risk management process and can contribute to patient safety practice.

Incorporating simulation-based objective structured clinical examination into the Israeli National Board Examination in Anesthesiology.

We describe the unique process whereby simulation-based, objective structured clinical evaluation (OSCE) has been incorporated into the Israeli board examination in anesthesiology. Development of the examination included three steps: a) definition of clinical conditions that residents are required to handle competently, b) definition of tasks pertaining to each of the conditions, and c) incorporation of the tasks into hands-on simulation-based examination stations in the OSCE format, including 1) trauma management, 2) resuscitation, 3) crisis management in the operating room, 4) regional anesthesia, and 5) mechanical ventilation. Members of the Israeli Board of Anesthesiology Examination Committee assisted by experts from the Israel Center for Medical Simulation and from Israels National Institute for Testing and Evaluation were involved in this process and in the development of the assessment tools, orientation of examinees, and preparation of examiners. The examination has been administered 4 times in the past 2 yr to 104 examinees and has gradually progressed from being a minor part of the oral board examination to a prerequisite component of this test. The pass rate ranged from 70% in resuscitation to 91% in regional anesthesia. The mean inter-rater correlations for all the checklist items, for the score based on the critical checklist items only, and for the general rating were 0.89, 0.86, and 0.76, respectively. The overall Kappa coefficients (the inter-rater agreement coefficient) for the total score and the critical checklist items were 0.71 and 0.76, respectively. The correlation between the total score and the general score was 0.76. According to a subjective feedback questionnaire, most (70%–90%) participants found the difficulty level of the examination stations reasonable to very easy and prefer this method of examination to a conventional oral examination. The incorporation of OSCE-driven modalities in the certification of anesthesiologists in Israel is a continuing process of evaluation and assessment.

Using advanced simulation for recognition and correction of gaps in airway and breathing management skills in prehospital trauma care

In this prospective study, we used two full-scale prehospital trauma scenarios (severe chest injury and severe head injury) and checklists of specific actions, reflecting essential actions for a safe treatment and successful outcome, were used to assess performance of postinternship physician graduates of the Advanced Trauma Life Support (ATLS) course. In the first 36 participants, simulated training followed basic training in airway and breathing management, whereas in the next 36 participants, 45 min of simulative training in airway management using the Air-Man simulator (Laerdal, Norway) were added before performing the study scenarios. The content of training was based on common mistakes performed by participants of the first group. After the change in training, the number of participants not performing cricoid pressure or not using medication during intubation decreased from 55% (20 of 36) to 8% (3 of 36) and from 42% (15 of 36) to 11% (4 of 36), respectively (P < 0.05). The number of participants not holding the tube properly before fixation decreased from 28% (10 of 36) to 0% (0 of 36) (P < 0.05). In the severe head trauma scenario, performed by 15 of 36 participants in each group, the incidence of mistakes in the management of secondary airway or breathing problems after initial intubation decreased from 60% (9 of 15) to 0% (0 of 15) (P < 0.05). The present study highlights problems in prehospital trauma management, as provided by the ATLS course. It seems that graduates may benefit from simulation-based airway and breathing training. However, clinical benefits from simulation-based training need to be evaluated.

Monitored anesthesia care using remifentanil and propofol for awake craniotomy.

Adequate analgesia and sedation with adequate respiratory and hemodynamic control are needed during brain surgery in awake patients. In this study, a protocol using clonidine premedication, intraoperative propofol, remifentanil, and labetalol was evaluated prospectively in 25 patients (aged 50 ± 16). In all but one patient, no significant problems regarding cooperation, brain swelling, or loss of control were noticed, and it was not necessary to prematurely discontinue any of the procedures. One patient, who was uncooperative and hypertensive, became apneic with increasing sedation, and needed a laryngeal mask airway inserted. Patients were hemodynamically stable; elevated systolic blood pressure (≥ 150 mm Hg) was measured infrequently, and there were no events of significant hypotension, tachycardia, or bradycardia. Events of hypoxemia (SAO2 ≤ 95%), severe hypoxemia (SaO2 ≤ 90%), or hypoventilation (respiratory rate ≤8 minute), were frequent in the first ten patients, but the incidence decreased significantly in subsequent patients (P < .001). Three patients developed a focal neurologic deficit, and two patients experienced intraoperative seizures. Nausea and vomiting were not recorded in any of the patients. Although these findings attest to the safety of awake craniotomy, they demonstrate the difficulty of achieving adequate sedation without compromising ventilation and oxygenation. The learning curve of using a new protocol and a new potent anesthetic drug is emphasized.

The Israel Center for Medical Simulation: a paradigm for cultural change in medical education.

Simulation-based medical education (SBME) is a rapidly growing field, as is illustrated by the increased development of simulation centers worldwide. SBME is becoming a powerful force in addressing the need to increase patient safety through quality-care training. Recognizing the benefits of SBME, increasing numbers of bodies involved in medical and health care education and training are establishing simulation centers worldwide. The general model of most facilities focuses on a single simulation modality or a specific branch of medicine or health care, limiting their overall impact on patient safety and quality of care across the health care systems. MSR, the Israel Center for Medical Simulation, is a comprehensive, national, multimodality, multidisciplinary medical simulation center dedicated to enhancing hands-on medical education, performance assessment, patient safety, and quality of care by improving clinical and communication skills. The center uses an “error-driven” educational approach, which recognizes that errors provide an opportunity to create a unique beneficial learning experience. The authors present the Israeli experience as an alternative model, and describe the impact of the MSR model on the Israeli medical community during four years of activity. They also describe the opportunities this model has opened towards changing the culture of medical education and patient safety within Israel Although this model may require modification when implemented in other medical systems, it highlights important lessons regarding the power of SBME in triggering and bringing about cultural changes in traditional medical education.

Propofol/remifentanil versus propofol alone for bone marrow aspiration in paediatric haemato-oncological patients

Background: This prospective randomized study was designed to evaluate the effects of adding remifentanil to the standard propofol‐based technique in the setting of paediatric haematology‐oncology outpatient clinic.

Supplemental Oxygen Compromises the Use of Pulse Oximetry for Detection of Apnea and Hypoventilation During Sedation in Simulated Pediatric Patients

OBJECTIVE. The goal was to assess the time to recognition of apnea in a simulated pediatric sedation scenario, with and without supplemental oxygen. METHODS. A pediatric human patient simulator mannequin was used to simulate apnea in a 6-year-old patient who received sedation for resetting of a fractured leg. Thirty pediatricians participating in a credentialing course for sedation were randomly assigned to 2 groups. Those in group 1 (N = 15) used supplemental oxygen, and those in group 2 (N = 15) did not use supplemental oxygen. A third group (N = 10), consisting of anesthesiology residents (postgraduate years 2 and 3 equivalent), performed the scenario with oxygen supplementation, to ensure validity and reliability of the simulation. The time interval from simulated apnea to bag-mask ventilation was recorded. Oxygen saturation and Paco2 values were recorded. All recorded variables and measurements were compared between the groups. RESULTS. The time interval for bag-mask ventilation to occur in group 1 (oxygen supplementation) was significantly longer than that in group 2 (without oxygen supplementation) (173 ± 130 and 83 ± 42 seconds, respectively). The time interval for bag-mask ventilation to occur was shorter in group 3 (anesthesiology residents) (24 ± 6 seconds). Paco2 reached a higher level in group 1 (75 ± 26 mmHg), compared with groups 2 and 3 (48 ± 10 and 42 ± 3 mmHg, respectively). There was no significant difference between the groups in oxygen saturation values at the time of clinical detection of apnea (93 ± 5%, 88 ± 5%, and 94 ± 7%, respectively). CONCLUSIONS. Hypoventilation and apnea are detected more quickly when patients undergoing sedation breathe only air. Supplemental oxygen not only does not prevent oxygen desaturation but also delays the recognition of apnea.

The Use of Advanced Simulation in the Training of Anesthesiologists to Treat Chemical Warfare Casualties

Training anesthesiologists to treat nerve gas intoxication in a mass casualty scenario is a complicated task. The scenario is an unfamiliar medical situation involving the need to decontaminate patients before providing definitive medical treatment, and the need for physical protection to the medical team before decontamination. We describe the development of a simulation-based training program. In one site of a virtual hospital, anesthesiologists were trained in initial airway and breathing resuscitation before decontamination while wearing full protective gear. In another site, they were trained in the treatment of critically-ill patients with combined conventional and chemical injuries or severe intoxication. Intubation simulators of newborn, pediatric, and adult patients, advanced full-scale simulators, and actors simulating patients were used. Initial airway, breathing, and antidotal treatment were performed successfully, with or without full protective gear. The gas mask did not interfere with orotracheal intubation, but limited effective communication within the medical team. Chemical protective gloves were the limiting factor in the performance of medical tasks such as fixing the orotracheal tube. Twenty-two participants (88%) pointed out that the simulated cases represented realistic problems in this scenario, and all 25 participants found the simulated-based training superior to previous traditional training they had in this field. Using advanced simulation, we were able to train anesthesiologists to treat nerve gas intoxication casualties and to learn about the limitations of providing medical care in this setting. IMPLICATIONS: Advanced medical simulation can be used to train anesthesiologists to treat nonconventional warfare casualties. The limitations of medical performance in full protective gear can be learned from this training.