Evaluation of anesthetic skills acquisition in pre-graduate veterinary students with different grades of anesthetic experience using veterinary simulation exercises.

Background: Anesthetic skills are usually learned through continuous supervision by experienced trainers who observe, advise and challenge students. Current educational techniques rely less on live animal training and include the use of simulations and models for teaching and assessment of surgical and anesthetic skills. Objective: To evaluate the development of anesthetic skills of veterinary students having different levels of previous experience using simulation. An additional aim was to evaluate the impact of the simulation training on students with no anesthesia experience. Study design: Single group periinterventional and postinterventional study. Methods: Initial and final anesthesia simulation training recording were obtained from 53 randomly selected veterinary students. Seven faculty members blinded to previous student anesthesia experience reviewed the simulation recording and scored student performance using a rubric, results were recorded and analyzed. Results: All students participating in an anesthesia and surgery course reached higher proficiency levels on fundamental anesthesia skills regardless of their previous amount of experience with anesthesia. Simulation based learning positively influenced the final score in veterinary students having no previous anesthesia training, suggesting that it is possible for veterinary students to achieve a level of competence in anesthesia skills with simulation-based training. Main limitations: Sample size, group simulation, multiple reviewers bias. Conclusion: Students having no experience with clinical anesthesia demonstrated remarkable improvement in their skills, achieving a score that was similar to students having extensive prior clinical anesthesia experience. Despite this clear improvement students having no prior clinical anesthesia experience required more time to complete all anesthesia tasks and may require more training sessions to acquire the speed demonstrated by peers who had significant prior clinical anesthesia experience. Overall, all participants reached a higher proficiency level performing fundamental anesthesia skills at the end of the course.

Use of a simulation of the ventilator-patient interaction as an active learning exercise: comparison with traditional lecture.

Research suggests that simulation technology has potential to enhance student achievement, particularly for students having a preference for hands-on learning. The aim of this study was to compare ventilation learning outcomes in students attending traditional lecture versus students using an active learning ventilation simulation. A computer simulation was developed to advance students' learning of mechanical ventilation. Forty-one students were divided into upper and lower strata based on performance rankings and were then randomly assigned to first complete a simulation scenario or view a lecture. Two distinct ventilation topics, controls and clinical, were developed for each instructional method. Students completed examinations three weeks following each respective instructional intervention (lecture or simulation scenarios) as well as one long-term examination and survey six weeks following the second examination. Upper-ranking students who learned the clinical topic through the simulation scenarios outperformed students who learned by traditional lecture. In addition, upper-ranking students scored higher than lower-ranking students in both the clinical and long-term composite examinations. No differences in student scores attributed to instructional method or class rank were identified for the controls topic. Survey results indicated that students were more engaged as learners when using the simulation and wished to have the simulation available during their clinical intensive care unit (ICU) rotations. Use of the simulation was associated with improved performance of upper-ranking students on the clinical-topic exam and was equivalent to lecture as an instructional intervention on the controls-topic exam. The simulation was perceived as an engaging, desirable tool providing immediate feedback.

Comparing measles with previous eradication programs: enabling and constraining factors.

BACKGROUND: Five major disease eradication initiatives were initiated during the second half of the 20th century. The enabling and constraining factors-political, social, economic, and other-for these previous and current eradication programs can inform decision making regarding a proposed measles eradication initiative. METHODS: We reviewed the literature on the yaws, malaria, smallpox, guinea worm, and polio eradication programs and compared enabling and constraining factors for each of these programs with the same factors as they relate to a possible measles eradication initiative. RESULTS: A potential measles eradication program would enjoy distinct advantages in comparison with earlier eradication programs, including strong political and societal support, economic analyses demonstrating a high level of cost-effectiveness, and a rigorous upfront process, compared with previous eradication initiatives, that has validated the feasibility of achieving measles eradication. However, increasing population density, urbanization, and wars/civil conflicts will pose serious challenges. CONCLUSIONS: Measles eradication will be very challenging but probably not as difficult to achieve as polio eradication. Measles eradication should be undertaken only if the commitments and resources will be adequate to meet the political, social, economic, and technical challenges.

Effects of 6% hetastarch (600/0.75) or lactated Ringer's solution on hemostatic variables and clinical bleeding in healthy dogs anesthetized for orthopedic surgery.

OBJECTIVE: To evaluate and compare hemostatic variables and clinical bleeding following the administration of 6% hetastarch (600/0.75) or lactated Ringer's solution (LRS) to dogs anesthetized for orthopedic surgery. STUDY DESIGN: Randomized blinded prospective study. ANIMALS: Fourteen, healthy adult mixed-breed hound dogs of either sex, aged 11-13 months, and weighing 20.8±1.2 kg. METHODS: The dogs were randomly assigned to receive a 10 mL kg(-1) intravenous (i.v.) bolus of either 6% hetastarch (600/0.75) or LRS over 20 minutes followed by a maintenance infusion of LRS (10 mL kg(-1)  hour(-1)) during anesthesia. Before (Baseline) and at 1 and 24 hours after bolus administration, packed cell volume (PCV), total protein concentration (TP), prothrombin time (PT), activated partial thromboplastin time (APTT), von Willebrand's factor antigen concentration (vWF:Ag), factor VIII coagulant activity (F VIII:C), platelet count, platelet aggregation, colloid osmotic pressure (COP) and buccal mucosal bleeding time (BMBT) were measured. In addition a surgeon who was blinded to the treatments assessed bleeding from the incision site during the procedure and at 1 and 24 hours after the bolus administration. RESULTS: Following hetastarch or LRS administration, the PCV and TP decreased significantly 1-hour post-infusion. APTT did not change significantly compared to baseline in either treatment group, but the PT was significantly longer at 1-hour post-infusion than at 24 hours in both groups. No significant change was detected for vWF:Ag, FVIII:C, platelet aggregation or clinical bleeding in either group. The BMBT increased while platelet count decreased significantly at 1-hour post-infusion in both groups. The COP decreased significantly in both treatment groups 1-hour post-infusion but was significantly higher 1-hour post-infusion in the hetastarch group compared to the LRS group. CONCLUSIONS AND CLINICAL RELEVANCE: At the doses administered, both hetastarch and LRS can alter hemostatic variables in healthy dogs. However, in these dogs undergoing orthopedic surgery, neither fluid was associated with increased clinical bleeding.

Evaluating a Multimodal Clinical Anesthesia Course Integrated Into an Existing Veterinary Curriculum.

INTRODUCTION: This study evaluated a multimodal, simulation-based course in veterinary anesthesia integrated into an existing veterinary curriculum. METHODS: A simulation-based, multimodal training course in clinical anesthesia was evaluated using outcomes from multiple levels of the Kirkpatrick Model of Training Evaluation. Cognitive and affective outcomes were evaluated before and after instruction. Head-mounted cameras were used to record clinical performance during students' first live patient anesthesia experience in the curriculum. RESULTS: Pretest-posttest analysis of cognitive and affective outcomes for course participants revealed significant increases in knowledge and self-efficacy. Course participants received higher ratings on clinical task performance and professional skills (ie, communication and collaboration) compared with a matched control group when evaluated by blinded, external raters using a standardized rubric. CONCLUSIONS: These findings indicate that implementing a multimodal anesthesia simulation-based course directly into the curriculum can enhance cognitive and affective outcomes and prepare students for subsequent anesthesia-related patient care experiences.

Hemodynamic changes during laparoscopic radiofrequency ablation of normal adrenal tissue in dogs.

OBJECTIVE: To determine the hemodynamic response to radiofrequency ablation (RFA) of normal adrenal tissue in dogs. STUDY DESIGN: Experimental study. ANIMALS: Healthy adult mixed-breed dogs (n=6). METHODS: During general anesthesia a Swan-Ganz thermodilution catheter was flow directed into the pulmonary artery and used to quantify cardiac output. An arterial catheter was used for direct blood pressure measurements. An RFA device was introduced into the left adrenal gland under observation through laparoscopic instrumentation. Blood samples were collected and hemodynamic variables studied after a stable surgical anesthetic depth was achieved (time 1), during CO(2) insufflation of the abdomen (time 2), during adrenal RFA (time 3), and after completed RFA (time 4). Catecholamine determinations were performed with a human enzyme immunoassay. Histopathology was performed to verify medullary necrosis. RESULTS: Arterial, pulmonary arterial and central venous pressure, and plasma norepinephrine increased more during RFA than during abdominal insufflation. Heart rate and cardiac index did not differ between time points. High baseline epinephrine was present and significant differences between time points were not detected. Systemic vascular resistance had very high individual variation and differences were not detected. CONCLUSIONS: RFA of normal adrenal tissues is associated with severe hemodynamic alterations. Further studies of the optimal blockage of catecholamine-induced hypertension in dogs are warranted. CLINICAL RELEVANCE: Clinicians should prepare for potential hypertensive crisis during RFA of adrenal masses, especially if treating a margin of normal tissue.

Use of the virtual ventilator, a screen-based computer simulation, to teach the principles of mechanical ventilation.

Examination scores from 109 students enrolled in the professional veterinary program at Washington State University were evaluated to determine the effectiveness and utility of the Virtual Ventilator computer simulation for teaching the principles of mechanical ventilation in an anesthesia course. Students were randomly assigned to either a live-animal mechanical ventilation laboratory (LIVE-1st) or a computer laboratory using the mechanical ventilation simulation (SIM-1st) in week 1. During week 2, students in the LIVE-1st group participated in the ventilation simulation while students in the SIM-1st group participated in the live-animal laboratory. Student knowledge was evaluated using two similar written quizzes administered following each laboratory. Student opinions concerning the value of the simulation were assessed using an online survey. Differences in quiz scores within and between groups were compared using t-tests while survey results were tabulated. A p value of less than 0.05 was considered significant. Within the LIVE-1st group, scores for the second quiz, which was taken after the students had completed the simulation exercise, were significantly higher than those obtained from the first quiz. Accordingly, the Virtual Ventilator simulation was at least equivalent to the live-animal laboratory in the ability to present information that was subsequently tested for on the quizzes. Students in the SIM-1st group reported that use of the simulation prior to a live-animal ventilation laboratory enhanced their understanding of and ability to provide mechanical ventilation to anesthetized patients. The Virtual Ventilator simulation appears to be a useful and well-received teaching tool.

Comparison of Fick and thermodilution cardiac output determinations in standing horses.

The Fick and thermodilution (TD) methods are two currently popular techniques for determination of cardiac output (CO) in adult horses. To our knowledge, a comparison of these two techniques has not been reported. Six healthy, resting, fit, adult horses of either sex and weighing 516.5+/-33.2 kg (mean+/-SD) were instrumented to enable measurement of cardiac output. Resting CO was determined by the Fick method and by thermodilution while the horses stood quietly in the stocks. Fick and thermodilution CO measurements were repeated under conditions of increased cardiac output achieved with the use of a dobutamine infusion (5 microg kg(-1) min(-1), IV), and again under conditions of decreased CO induced by administration of xylazine (0.5 mg/kg, IV). Fick and thermodilution cardiac outputs were compared using Bland-Altman analysis for repeated measures. The mean of the differences+/-1.96SD (bias and precision) between the two techniques was 1.88+/-24.17 L/min. Variability between measurements with the two techniques was decreased to 3.41+/-46.78 mL kg(-1) min(-1) when CO was normalized for body size by calculation of cardiac index.

Cardiovascular effects of desflurane in mechanically ventilated calves.

OBJECTIVE: To determine cardiovascular effects of desflurane in mechanically ventilated calves. ANIMALS: 8 healthy male calves. PROCEDURE: Calves were anesthetized by face mask administration of desflurane to permit instrumentation. Administration of desflurane was temporarily discontinued until mean arterial blood pressure increased to >or= 100 mm Hg, at which time baseline cardiovascular values, pulmonary arterial temperature, end-tidal CO(2) tension, and end-tidal desflurane concentration were recorded. Cardiac index and systemic and pulmonary vascular resistances were calculated. Arterial blood gas variables were measured and calculated. Mean end-tidal concentration of desflurane at this time was 3.4%. After collection of baseline values, administration of 10% end-tidal concentration of desflurane was resumed and calves were connected to a mechanical ventilator. Cardiovascular data were collected at 5, 10, 15, 30, and 45 minutes, whereas arterial blood gas data were collected at 15 and 45 minutes after collection of baseline data. RESULTS: Mean +/- SD duration from beginning desflurane administration to intubation of the trachea was 151 +/- 32.8 seconds. Relative to baseline, desflurane anesthesia was associated with a maximal decrease in arterial blood pressure of 35% and a decrease in systemic vascular resistance of 34%. Pulmonary arterial blood temperature was decreased from 15 through 45 minutes, compared with baseline values. There were no significant changes in other measured variables. All calves recovered from anesthesia without complications. CONCLUSIONS AND CLINICAL RELEVANCE: Administration of desflurane for induction and maintenance of general anesthesia in calves was smooth, safe, and effective. Cardiopulmonary variables remained in reference ranges throughout the study period.

Use of a Mobile Device Simulation as a Preclass Active Learning Exercise.

BACKGROUND: Research shows that preclass activities introducing new material can increase student performance. In an effort to engage students in an active learning, preclass activity, the authors developed a mobile application. METHOD: Eighty-four nursing students were assigned a preclass reading exercise, whereas 32 students completed the preclass simulation scenario on their mobile device. All students completed the same electronic fetal monitoring (EFM) quiz 1 week following the lecture. The effects of reading or simulation on student quiz performance was evaluated with a student's paired t test, using an alpha of .05. RESULTS: Students completing the preclass simulation scored higher on the EFM quiz, compared with students assigned the preclass reading (85% versus 70% correct answers, p = .01). Student survey data indicated that the mobile device simulation was perceived as an engaging and desirable instructional tool. CONCLUSION: Nursing students completing the mobile device EFM preclass simulation outperformed the students who were given the traditional reading assignment.

Effects of a polymerized ultrapurified bovine hemoglobin blood substitute administered to ponies with normovolemic anemia.

The development of ultrapurified hemoglobin-based oxygen carriers has eliminated many problems associated with whole-blood transfusions in other species. We hypothesized that the administration of polymerized ultrapurified bovine hemoglobin (PUBH) would result in improved hemodynamic parameters in ponies with normovolemic anemia without adverse effects on renal function or coagulation times. Normovolemic anemia was induced in 6 healthy adult ponies. Over a 3-day period, at least 45 mL/kg of whole blood was withdrawn from each pony until a target PCV of <12% was attained. Plasma was separated from the red blood cells via centrifugation and readministered to the ponies on each day. After the final plasma transfusion, 15 mL/kg of hetastarch (control, n = 6) or 15 mL/kg of PUBH (treatment, n = 6) was administered at 10 mL/kg/h IV. Administration of PUBH at a rate of 10 mL/kg/h was not associated with any adverse effects in 5 of the 6 ponies. One pony experienced an anaphylactoid reaction during infusion of PUBH. The reaction, characterized by intense pruritus, tachycardia, and tachypnea resolved shortly after stopping the infusion. Ponies receiving PUBH had significantly lower cardiac indices (P = .03) and heart rates (P = .002) than control animals. A significantly greater increase in central venous pressure was observed in the PUBH group compared to the hetastarch group (P = .02). No adverse renal or coagulation effects were observed with PUBH infusion. These results suggest that PUBH improves hemodynamics and oxygen transport parameters in horses experiencing normovolemic anemia. Patients should be monitored closely during infusion for any adverse reactions.

Comparative cardiovascular, analgesic, and sedative effects of medetomidine, medetomidine-hydromorphone, and medetomidine-butorphanol in dogs.

OBJECTIVE: To compare sedative, analgesic, and cardiopulmonary effects after IV administration of medetomidine (20 microg/kg), medetomidine-hydromorphone (20 microg of medetomidine/kg and 0.1 mg of hydromorphone/kg), and medetomidine-butorphanol (20 microg of medetomidine/kg and 0.2 mg of butorphanol tartrate/kg) in dogs. ANIMALS: 6 dogs healthy mixed-breed dogs. PROCEDURE: Instruments were surgically inserted, and heart rate (HR), respiratory rate (RR), systolic arterial pressure (SAP), mean arterial pressure (MAP), diastolic arterial pressure (DAP), mean pulmonary arterial pressure (MPAP), pulmonary capillary wedge pressure (PCWP), central venous pressure (CVP), core body temperature, and cardiac output (CO) were measured 0, 5, 10, 15, 30, 45, and 60 minutes after injection. Cardiac index (CI), stroke volume (SV), stroke index (SI), systemic vascular resistance (SVR), and pulmonary vascular resistance (PVR) were calculated. Arterial samples for blood gas analysis were collected 0, 15, and 45 minutes after injection. Intensity of analgesia, degree of sedation, and degree of muscle relaxation were evaluated at aforementioned time points and 75, 90, 120, 150, 180, and 210 minutes after injection. RESULTS: Administration of medetomidine, medetomidine-hydromorphone, and medetomidine-butorphanol was associated with increases in SAP, MAP, DAP, MPAP, PCWP, CVP, SVR, PVR, core body temperature, and PaCO2 and decreases in HR, CO, CI, SV, SI, RR, pH, and PaO2. Clinically important differences were not detected among treatments. Medetomidine-hydromorphone and medetomidine-butorphanol provided a longer duration of sedation and better quality of analgesia, compared with medetomidine alone. CONCLUSIONS AND CLINICAL RELEVANCE: Medetomidine-hydromorphone or medetomidine-butorphanol is associated with improved analgesia and sedation but has cardiopulmonary effects comparable to those for medetomidine alone.

Intracranial pressure and cardiopulmonary variables during isoflurane or sevoflurane anesthesia at various minimum alveolar concentration multiples in normocapnic dogs.

OBJECTIVE: To compare effects of isoflurane and sevoflurane on intracranial pressure and cardiovascular variables at 1.0, 1.5, and 2.0 times the minimum alveolar concentration (MAC) in mechanically ventilated normocapnic dogs. ANIMALS: 6 healthy male Beagles. PROCEDURES: The individual MAC was determined for each agent with an electrical stimulus. After a minimum of 1 week, anesthetic induction by use of a mask with one of the inhalation anesthetics selected randomly was followed by mechanical ventilation and instrumentation for measurement of intracranial pressure and cardiovascular variables. Heart rate; systolic, mean, and diastolic arterial blood pressures; central venous pressure; mean pulmonary arterial pressure; pulmonary artery occlusion pressure; cardiac output; intracranial pressure (ICP); core body temperature; end-tidal inhalation anesthetic and carbon dioxide concentration; and arterial blood gas values were measured after attaining equilibrium at 1.0, 1.5, and 2.0 MAC of each inhalation anesthetic. Cardiac index, systemic vascular resistance, pulmonary vascular resistance, and cerebral perfusion pressure (CPP) were calculated. RESULTS: Mean ICP did not differ within and between anesthetics at any MAC. Compared with equipotent concentrations of isoflurane, the CPP and mean values for systolic, mean, and diastolic arterial blood pressures were increased at 2.0 MAC for sevoflurane, whereas mean values for mean and diastolic arterial blood pressures and systemic vascular resistance were increased at 1.5 MAC for sevoflurane. CONCLUSIONS AND CLINICAL RELEVANCE: Although ICP was similar in healthy normocapnic dogs, CPP was better maintained during 2.0 MAC for sevoflurane, compared with isoflurane.

Effects of tepoxalin and medetomidine on glomerular filtration rate in dogs.

The objective of this study was to evaluate glomerular filtration rate (GFR) and the cardiovascular effects of the combination of tepoxalin (TPX) and medetomidine (MED) in dogs. Six healthy dogs of either sex (5 males and 1 female), aged 2.5 ± 2.2 years and weighing 14.7 ± 4.4 kg, were studied. Each dog received four randomized treatments with a minimum of 1 week between treatments: no medication as the control group (C); MED (750 µg/m(2), intravenously [IV]); TPX (10 mg/kg orally for 3 days); and MT (TPX 10 mg/kg orally for 3 days plus MED 750 µg/m(2), IV). Iohexol (300 mg iodine/kg, IV) was injected in all dogs in each treatment as an indicator of GFR. Blood samples for serum iohexol clearance analysis were collected before and 1, 2, 5, 10, 15, 20, 60, 120, 240 and 360 min after the iohexol administration. Rectal temperature, heart rate, respiratory rate and direct arterial pressure (AP) were obtained before and 5, 10, 15, 20, 60, 120, 240 and 360 min after the iohexol injection. GFR did not differ between treatments. Heart rate was significantly lower in the MED and MT groups than in C or TPX. Mean AP was significantly higher with MT than TPX, but only at 5 min after the iohexol injection. TPX, MED and the combination of these two drugs do not alter GFR. The combination has minimal effect on cardiovascular variables at these doses in healthy dogs.

Effects of intravenous butorphanol on cardiopulmonary function in isoflurane-anesthetized alpacas.

OBJECTIVE: To determine the effects of intravenous (IV) butorphanol on the cardiopulmonary system and on the bispectral index (BIS) in isoflurane-anesthetized alpacas. STUDY DESIGN: Randomized, blinded cross-over experimental trial. ANIMALS: Eight healthy, young (3 +/- 1 SD years) adult female alpacas weighing 64 +/- 9 SD kg. METHODS: Alpacas were anesthetized with isoflurane by mask followed by tracheal intubation and maintenance of anesthesia with isoflurane in oxygen and intermittent positive pressure ventilation. Animals were assigned to two treatments, butorphanol (0.1 mg kg(-1), IV) and saline (0.01 mL kg(-1), IV) in a randomized manner allowing a 2-week interval between treatments. Cardiovascular variables included systolic, diastolic, and mean arterial blood pressure, heart rate, pulmonary arterial pressure, pulmonary arterial occlusion pressure (PAOP), central venous pressure, cardiac output, and pulmonary temperature (TEMP). Cardiac index, systemic vascular resistance (SVR), and pulmonary vascular resistance (PVR) were calculated. Bispectral index was also measured. Arterial and mixed venous blood samples were collected for blood gas analysis. All variables were recorded at baseline (time 0) and at 5, 10, 15, 30, 45 and 60 minutes following injection and were analyzed by using repeated-measures ANOVA (p < 0.05). PAOP, PVR, and BIS were analyzed by paired t-tests. RESULTS: Butorphanol decreased SVR at all times when compared with the baseline, but no difference was detected between treatments. TEMP decreased with time in both treatments, but they were not different from each other. Other cardiovascular, BIS, and blood gas variables were not different between groups. CONCLUSION AND CLINICAL RELEVANCE: We conclude that butorphanol had minimal effects on the cardiovascular system of the alpacas, causing a mild decrease in SVR.