[Show abstract][Hide abstract] ABSTRACT: Background Cardiopulmonary arrests are rare, high-stakes events that benefit from using crisis resource management (CRM). Simulation-based education with deliberate practice can promote skill acquisition.
Objective We assessed whether using simulation-based education to teach CRM would lead to improved performance, compared to a lecture format.
Methods We tested third-year internal medicine residents in simulated code scenarios. Participants were randomly assigned to simulation-based education with deliberate practice (SIM) group or lecture (LEC) group. We created a checklist of CRM critical actions (which includes announcing the diagnosis, asking for help/suggestions, and assigning tasks), and reviewed videotaped performances, using a checklist of skills and communications patterns to identify CRM skills and communication efforts. Subjects were tested in simulated code scenarios 6 months after the initial assessment.
Results At baseline, all 52 subjects recognized distress, and 92% (48 of 52) called for help. Seventy-eight percent (41 of 52) did not succeed in resuscitating the simulated patient or demonstrate the CRM skills. After intervention, both groups (n = 26 per group) improved. All SIM subjects announced the diagnosis compared to 65% LEC subjects (17 of 26, P = .01); 77% (20 of 26) SIM and 19% (5 of 26) LEC subjects asked for suggestions (P < .001); and 100% (26 of 26) SIM and 27% (7 of 26) LEC subjects assigned tasks (P < .001).
Conclusions The SIM intervention resulted in significantly improved team communication and cardiopulmonary arrest management. During debriefing, participants acknowledged the benefit of the SIM sessions.
[Show abstract][Hide abstract] ABSTRACT: With the increasing demand for one-lung ventilation in both thoracic surgery and other procedures, identifying the correct placement becomes increasingly important. Currently, endobronchial intubation is suspected based on a combination of auscultation and physiological findings. We investigated the ability of the visual display of airflow-induced vibrations to detect single-lung ventilation with a double-lumen endotracheal tube.
Double-lumen tubes were placed prior to surgery. Tracheal and endobronchial lumens were alternately clamped to produce unilateral lung ventilation of right and left lung. Vibration response imaging, which detects vibrations transmitted to the surface of the thorax, was performed during both right- and left-lung ventilation. Geographical area of vibration response image as well as amount and distribution of lung sounds were assessed.
During single-lung ventilation, the image and video obtained from the vibration response imaging identifies the ventilated lung with a larger and darker image on the ventilated side. During single-lung ventilation, 87.2 +/- 5.7% of the measured vibrations was detected over the ventilated lung and 12.8 +/- 5.7% over the non-ventilated lung (P < 0.0001). It was also noted that during single-lung ventilation, the vibration distribution in the non-ventilated lung had a majority of vibration detected by the medial sensors closest to the midline (P < 0.05) as opposed to the midclavicular sensors when the lung is ventilated.
During single-lung ventilation, vibration response imaging clearly showed increased vibration in the lung that is being ventilated. Distribution of residual vibration differed in the non-ventilated lung in a manner that suggests transmission of vibrations across the mediastinum from the ventilated lung. The lung image and video obtained from vibration response imaging may provide useful and immediate information to help one-lung ventilation assessment.
European Journal of Anaesthesiology 05/2008; 25(12):995-1001. DOI:10.1017/S0265021508004481 · 2.94 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: We describe the effect that inadvertent esophageal intubation has on the images and on the vibration distribution of vibration response imaging (VRI).
Vibration response imaging (VRI) is a novel, non-invasive, computer-based technology that measures vibration energy of lung sounds during respiration and displays regional intensity, in both visual and graphic format. Vibration response images, obtained prior to tracheal intubation (spontaneous breathing) and during endotracheal ventilation using a controlled mode, resulted in evenly distributed vibrations throughout the patient's lungs. During inadvertent esophageal ventilation, however, the majority of vibrations were detected in the upper regions of the image, compared to those of the lower (60% vs 8%, respectively). During spontaneous breathing and endotracheal ventilation, the midclavicular column of sensors, located over the centre of each lung, detected more vibrations compared to either the medial or the axillary column of sensors. During inadvertent esophageal ventilation, more vibrations were detected by the medial column of sensors (nearest to the midline/esophagus); and fewer were detected by the sensors that were positioned more laterally.
This report illustrates the potential for a visual image of distribution of lung vibration energy to differentiate endotracheal intubation from inadvertent esophageal intubation.
Canadian Journal of Anaesthesia 04/2008; 55(3):172-6. DOI:10.1007/BF03016092 · 2.53 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: To evaluate the effectiveness of intravenous patient-controlled analgesia (PCA) in patients after surgery.
Prospective, observational study.
University teaching hospital.
Sixty patients with American Society of Anesthesiologists physical status I-III receiving intravenous PCA for postoperative pain. The PCA was programmed to deliver morphine 1 mg or hydromorphone 0.1-0.2 mg, with a lockout interval of 10 and 6 minutes for 80% and 20% of the patients, respectively.
Patients were asked, up to 4 times during PCA use and once within 4 hours after PCA use, to describe and rate their intensity of pain at rest and after activity. During the first 12 hours of intravenous PCA use, 75% of the patients reported moderate-to-severe pain > or = 5 on a verbal numeric rating scale) at rest, 80% after activity. Corresponding values, respectively, were 33% and 72% for the 12-24-hour period, 43% and 76% for the 24-36-hour period, and 36% and 64% for the 36-48-hour period of intravenous PCA use. Within 4 hours of stopping PCA, 30% and 58% of the patients had moderate-to-severe pain at rest and after activity, respectively. In approximately 50% of patients, presence of pain was described with words signifying sensory and affective dimensions of pain. Pain control was rated as good or very good by 54% of patients during the first 12 hours of intravenous PCA. Ratings of pain control tended to improve with time.
Successful postoperative pain management using PCA is difficult to achieve on a consistent basis unless treatment is individualized. Our data support the hypothesis that small fixed doses fail to achieve adequate relief in many patients.
[Show abstract][Hide abstract] ABSTRACT: To investigate the efficacy and kinetics of bupivacaine when used for deep cervical plexus block (CPB), using either a single-injection or multiple-injections technique.
Prospective, randomized, double-blind study.
Operating room of a university hospital.
Twenty-four adult patients (16 men, 8 women) scheduled for carotid endarterectomy.
Patients were randomly assigned to receive CPB either by a single injection or after 3 injections. Patients in the multiple-injections group received a total dose of 15 mL of 0.5% bupivacaine (5 mL each deposited at C2, C3, and C4 over 2 minutes). Patients in the single-injection group received a single 15-mL injection of 0.5% bupivacaine. After the deep CPB, a superficial CPB was performed with 20 mL of 0.5% bupivacaine in all patients.
An anesthesiologist and a surgeon graded the success of the block. Arterial plasma concentrations of bupivacaine were measured using liquid chromatography-mass spectroscopy.
No significant differences were seen between the 2 groups with respect to the mean peak concentration of bupivacaine (single injection 2314 +/- 1385 ng/mL vs multiple injections 2255 +/- 1105 ng/mL) or time to reach the maximal concentration (time to maximum concentration [single injection 12.1 +/- 7.2 minutes vs multiple injections 12.5 +/- 3.9 minutes]). Furthermore, there were no significant differences in mean block scores between the single-injection and the multiple-injections groups, evaluated either by the anesthesiologists or the surgeon.
The results of this study showed that the absorption of bupivacaine is independent of the number of injections after CPB, and that anesthesia for carotid endarterectomy may be accomplished successfully using either technique.
[Show abstract][Hide abstract] ABSTRACT: To evaluate the analgesic and hemodynamic effects of a single dose of intravenous morphine 7.5 mg in patients experiencing moderate-to-severe postoperative pain, and to determine any gender differences in analgesic response.
Randomized, double-blind, parallel-group, multicenter study.
Postanesthesia care unit of a university teaching hospital.
Eighty-eight patients who underwent total abdominal hysterectomy or prostatectomy.
Thirty-seven patients received a single dose of morphine sulfate 7.5 mg and 51 patients received placebo, both administered intravenously for 1 minute.
Overall, morphine had no significant effect on systolic or diastolic blood pressure, heart rate, oxygen saturation, or respiratory rate. Compared with baseline, morphine significantly reduced pain intensity at 2, 5, and 10 minutes after administration (p<0.05). The difference in pain intensity between patients who received morphine and those who received placebo, however, was significant only at the 5-minute time point (p<0.02). Patients receiving morphine also reported mild pain relief at 2 and 5 minutes after its administration. Peak analgesic effect was reported 2 minutes after its administration in three quarters of the patients. Significant gender differences also were observed in response to analgesic effect. In women, no significant differences in pain intensity were seen at any time between the morphine and placebo groups, whereas in men receiving morphine, pain intensity was significantly less at 2, 5, and 10 minutes compared with baseline and that seen in the placebo group. Women were generally more satisfied with their pain treatment than were men.
A single 7.5-mg intravenous bolus dose of morphine did not appear to provide adequate reduction in perceived pain intensity in patients with moderate-to-severe postoperative pain. In addition, in contrast to the findings of other experimental pain studies, our data suggest that women are more tolerant of postoperative pain than are men.
[Show abstract][Hide abstract] ABSTRACT: A hypoxic rat model of halothane-induced hepatotoxicity, which is known to produce liver damage, was used to determine the effects of chronic exercise on halothane-induced hepatotoxicity and on reduced hepatic glutathione (GSH) levels. Metabolism of volatile anesthetics may generate metabolites that can cause mild and transient hepatotoxicity.
Six male Sprague-Dawley rats completed a 10-wk (5 d x wk(-1)) treadmill running protocol. Twelve age-matched animals were used as sedentary controls. After the completion of exercise training, rats were exposed for 2 h to 1% halothane in 14% O2. Twenty-four hours later, animals were anesthetized with sodium pentobarbital and sacrificed. Livers were excised, stained, and evaluated for hepatotoxicity using a histopathological 0 (normal) to 5 (severe damage) point categorical scale and for the determination of GSH levels.
Median histopathologic scores revealed significantly lower indications of hepatotoxicity in exercise animals as compared with control animals (score = 0.25 vs 1.50; P < 0.05). Liver damages scores between 1 and 5 were observed in 75% (9 of 12) of the control animals, whereas only 1 of 6 exercise animals had a score greater than 1 (P < 0.05). No significant difference was observed in reduced GSH levels.
Chronic exercise improves the detoxicant ability of the liver for halothane anesthesia as noted by the ameliorated liver damage and reduced incidence of halothane-induced hepatotoxicity in the exercise animals.
Medicine & Science in Sports & Exercise 12/2000; 32(12):2024-8. DOI:10.1097/00005768-200012000-00009 · 3.98 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: EMLA Cream (EC; Astra, Westborough, MA) has been widely used as a local anesthetic. Limited safety information is available with respect to the application of EC to the oral mucous membranes. The purpose of this pilot study was to evaluate the efficacy and safety of EC when applied to oral mucosa for fiberoptic intubation. Twenty ASA physical status I-IV patients (11 women and 9 men), 28-57 yr old, who were scheduled for awake, fiberoptic, intubation participated in this open-label study. A total of 4 g of EC was used for 5 min until the patient showed no evidence of a gag reflex (this was evaluated clinically by the patient's acceptance of the William's airway and considered the endpoint for assessing adequate topicalization of the oropharynx). The measured peak plasma concentration of lidocaine or prilocaine did not reach toxic levels in any patient. Methemoglobin levels did not exceed normal values (1.5%) in any patient, and there was no relationship between methemoglobin levels and patient weight, amount of EC used, measured peak plasma concentration, or times to measured peak concentrations of prilocaine or lidocaine. We conclude that EC provided satisfactory topical anesthesia allowing for successful oral fiberoptic intubation in all patients and should be considered a safe alternative for anesthetizing the airway of patients requiring awake oral fiberoptic intubation.
[Show abstract][Hide abstract] ABSTRACT: To determine if the new Filta-Therm filter prevents contamination and allows the reuse of breathing circuit with considerable cost and environmental savings.
52 ASA physical status I, II, III, and IV patients, aged 18 to 75 years.
Each morning a new breathing circuit was assembled. The Filta-Therm filter (Intersurgical, Inc., Liverpool, NY) elbow, and mask, but not the circuit, were changed between patients. The filter was placed between the Y-piece and the elbow of the breathing circuit. Prior to anesthesia, samples were obtained at the Y-piece, and the inspiratory and expiratory ports of breathing circuit. Following anesthesia, samples were obtained at the Murphy eye of endotrachael tube, and at the Y-piece. The samples were incubated, and the results examined at 24 and 48 hours.
Prior to anesthesia, cultures of the Y-piece and the inspired and expired ports samples showed no growth. Following anesthesia, all 52 samples obtained at the endotracheal tube were contaminated with various organisms, while all 52 Y-piece samples showed negative growth.
The single use of Filta-Therm filter prevents bacterial contamination and allows reuse of breathing circuit at least twice, resulting in significant cost savings ($50,778 per year). Further studies are needed to establish the safety of reusing breathing circuits when appropriate bacterial filters are used.
[Show abstract][Hide abstract] ABSTRACT: The anesthesiology literature does not describe entrapment of a guidewire by an inferior vena caval filter. Because anesthesiologists are involved in central access in various perioperative and intraoperative settings, consideration of this complication is important. A case of guidewire entrapment by an inferior vena caval filter and a unique technique for removal of the entrapped wire is presented.
[Show abstract][Hide abstract] ABSTRACT: Pulmonary hypertension has a diverse origin and can develop as a consequence of numerous systemic, cardiac, or pulmonary conditions or can result from disorders primarily affecting the pulmonary vascular bed. The hallmark of pulmonary hypertension is an elevation in pulmonary vascular resistance (PVR) that is primarily localized to the precapillary muscular arteries and arterioles.50 The elevation in vascular resistance may be anatomic or vasoconstrictive in origin. Mechanisms from both components, particularly in vascular disorders of long standing, have contributions from both mechanisms.23 The progressive reduction in cross-sectional area of distensibility of the pulmonary vascular bed results in a compromised pulmonary circulation. Increase in blood flow (cardiac output [CO]), such as exercise or stress, results in elevations in pulmonary artery pressure.45 As the disease progresses, smaller increases in blood flow are required to elevate the pulmonary artery pressure. Eventually, the process may be so severe that even resting CO results in an elevated pulmonary artery pressure. The elevated pulmonary artery pressure results in a dysfunctional right ventricle, which initially accommodates the increase in afterload by dilation and hypertrophy but eventually fails because of disease progression. Pulmonary hypertension is a serious disease associated with a high mortality during surgery and anesthesia.10, 32, 34 and 59 Therapeutic options with emphasis on the value of preoperative pulmonary vasodilator testing are reviewed.
Anesthesiology Clinics of North America 09/1999; 17(3):693–707. DOI:10.1016/S0889-8537(05)70125-5
[Show abstract][Hide abstract] ABSTRACT: Administration of sevoflurane in a circle absorption system generates Compound A, a nephrotoxin in rats. Reports examining the potential of Compound A to produce renal injury in humans have provided conflicting results. We tested the possibility that there is a threshold to Compound A-induced renal injury in humans and that, above this threshold, renal injury increases with increasing doses of Compound A. Eleven volunteers received 3% sevoflurane for 8 h at 2 L/min, and three volunteers received 3% sevoflurane for 8 h at 4-6 L/min. We measured inspired and expired concentrations of Compound A and urinary excretion of albumin, alpha-glutathione-S-transferase (GST), and glucose. The median urinary excretion of albumin, glucose, and alpha-GST for the first 3 days after anesthesia increased significantly from preanesthetic values in the 2-L/min group. Compound A doses < 240 ppm-h resulted in normal urinary excretion of albumin, glucose, and alpha-GST. Five of seven subjects who received doses > 240 ppm-h had abnormal excretion of albumin, and six of seven had abnormal alpha-GST urinary excretion (P < 0.05). Urinary excretion of albumin, alpha-GST, and glucose was normal by 14 days after exposure. We conclude that sevoflurane administration for 8 h at 2 L/min results in albuminuria and enzymuria when the dose of Compound A exceeds 240 ppm-h. That is, a Compound A concentration of 30 ppm breathed for > or = 8 h may produce transient renal injury. Implications: We examined the dose-response relationship of sevoflurane/Compound A and urinary excretion of albumin, glucose, and alpha-GST. Sevoflurane exposure for 8 h at a 2-L/min inflow rate produces transient albuminuria and enzymuria in healthy volunteers when the dose of Compound A exceeds 240 ppm-h (30 ppm for 8 h).