Radiation dose to patients and personnel during intraoperative digital subtraction angiography.
BACKGROUND AND PURPOSE: The use of intraoperative angiography to assess the results of neurovascular surgery is increasing. The purpose of this study was to measure the radiation dose to patients and personnel during intraoperative angiography and to determine the effect of experience. METHODS: Fifty consecutive intraoperative angiographic studies were performed during aneurysmal clipping or arteriovenous malformation resection from June 1993 to December 1993 and another 50 from December 1994 to June 1995. Data collected prospectively included fluoroscopy time, digital angiography time, number of views, and amount of time the radiologist spent in the room. Student's t-test was used to assess statistical significance. Effective doses were calculated from radiation exposure measurements using adult thoracic and head phantoms. RESULTS: The overall median examination required 5.2 minutes of fluoroscopy, 55 minutes of operating room use, 40 seconds of digital angiographic series time, and four views and runs. The mean room time and the number of views and runs increased in the second group of patients. A trend toward reduced fluoroscopy time was noted. Calculated effective doses for median values were as follows: patient, 76.7 millirems (mrems); radiologist, 0.028 mrems; radiology technologist, 0.044 mrems; and anesthesiologist, 0.016 mrems. CONCLUSION: Intraoperative angiography is performed with a reasonable radiation dose to the patient and personnel. The number of angiographic views and the radiologist's time in the room increase with experience. (+info)
Correlating fibreoptic nasotracheal endoscopy performance and psychomotor aptitude.
We have investigated the correlation between the scores attained on computerized psychometric tests, measuring psychomotor and information processing aptitudes, and learning fibreoptic endoscopy with the videoendoscope. Sixteen anaesthetic trainees performed two adaptive tracking tasks (ADTRACK 2 and ADTRACK 3) and one information management task (MAZE) from the MICROPAT testing system. They then embarked on a standardized fibreoptic training programme during which they performed 15 supervised fibreoptic nasotracheal intubations on anaesthetized oral surgery patients. There was a significant correlation between the means of the 15 endoscopy times and both ADTRACK 2 (r = -0.599, P = 0.014) and ADTRACK 3 (r = -0.589, P = 0.016) scores. The correlation between the means of the 15 endoscopy times and MAZE scores was not significant. The ratios of the mean endoscopy time for the last seven endoscopies to the mean endoscopy time for the first seven endoscopies were not significantly correlated with ADTRACK 2, ADTRACK 3 or MAZE scores. Psychomotor abilities appeared to be determinants of trainees' initial proficiency in endoscopy, but did not appear to be determinants of trainees' rates of progress during early fibreoptic training. (+info)
Concentration and second-gas effects in the water analogue.
The water analogue provides a visual model of the process of anaesthetic exchange. In the standard version, a single pipe connects the mouth container to the lung container and the conductance of this mouth-lung pipe is proportional to alveolar ventilation. This implies that inspired and expired ventilations are equal. In fact, with high inspired concentrations of nitrous oxide, early rapid uptake of gas by solution leads to a substantial difference between inspired and expired ventilation which in turn leads to concentration and second-gas effects. It is shown that by representing inspired and expired ventilations separately, and keeping one of them constant while varying the other to compensate for rapid uptake, concentration and second-gas effects are reproduced in the water analogue. Other means of reproducing the effects are reported but we believe that the first method is the most realistic and the most appropriate for teaching. (+info)
A matter of life and death: what every anesthesiologist should know about the medical, legal, and ethical aspects of declaring brain death.
Accurate criteria for death are increasingly important as it becomes more difficult for the public to distinguish between patients who are still alive from those who, through the aid of medical technology, merely look like they are alive even though they are dead. Patients and their families need to know that a clear line can be drawn between life and death, and that patients who are alive will not be unintentionally treated as though they are dead. For the public to trust the pronouncements of medical doctors as to whether a patient is dead or alive, the criteria must be unambiguous, understandable, and infallible. It is equally important to physicians that accurate, infallible criteria define death. Physicians need to know that a clear line can be drawn between life and death so that patients who are dead are not treated as though they are alive. Such criteria enable us to terminate expensive medical care to corpses. Clear criteria for death also allow us to ethically request the gift of vital organs. Clear, infallible criteria allow us to assure families and society that one living person will not be intentionally or unintentionally killed for the sake of another. The pressure of organ scarcity must not lead physicians to allow the criteria for life and death to become blurred because of the irreparable harm this would cause to the patient-physician relationship and the devastating impact it could have on organ transplantation. As the cases presented here illustrate, anesthesiologists have an important responsibility in the process of assuring that some living patients are not sacrificed to benefit others. Criteria for declaring death should be familiar to every anesthesiologist participating in organ retrieval. Before accepting the responsibility of maintaining a donor for vital organ collection, the anesthesiologist should review data supplied in the chart supporting the diagnosis of brain death and seriously question inconsistencies and inadequate testing conditions. Knowledge of brain death criteria and proper application of these criteria could have changed the course of each of the cases presented. (+info)
Consistency, inter-rater reliability, and validity of 441 consecutive mock oral examinations in anesthesiology: implications for use as a tool for assessment of residents.
BACKGROUND: Oral practice examinations (OPEs) are used extensively in many anesthesiology programs for various reasons, including assessment of clinical judgment. Yet oral examinations have been criticized for their subjectivity. The authors studied the reliability, consistency, and validity of their OPE program to determine if it was a useful assessment tool. METHODS: From 1989 through 1993, we prospectively studied 441 OPEs given to 190 residents. The examination format closely approximated that used by the American Board of Anesthesiology. Pass-fail grade and an overall numerical score were the OPE results of interest. Internal consistency and inter-rater reliability were determined using agreement measures. To assess their validity in describing competence, OPE results were correlated with in-training examination results and faculty evaluations. Furthermore, we analyzed the relationship of OPE with implicit indicators of resident preparation such as length of training. RESULTS: The internal consistency coefficient for the overall numerical score was 0.82, indicating good correlation among component scores. The interexaminer agreement was 0.68, indicating moderate or good agreement beyond that expected by chance. The actual agreement among examiners on pass-fail was 84%. Correlation of overall numerical score with in-training examination scores and faculty evaluations was moderate (r = 0.47 and 0.41, respectively; P < 0.01). OPE results were significantly (P < 0.01) associated with training duration, previous OPE experience, trainee preparedness, and trainee anxiety. CONCLUSION: Our results show the substantial internal consistency and reliability of OPE results at a single institution. The positive correlation of OPE scores with in-training examination scores, faculty evaluations, and other indicators of preparation suggest that OPEs are a reasonably valid tool for assessment of resident performance. (+info)
Cuffed oropharyngeal airway (COPA) as an adjunct to fibreoptic tracheal intubation.
The cuffed oropharyngeal airway (COPA) was evaluated as an adjunct to oral and nasal fibreoptic tracheal intubation in 40 adult patients during general anaesthesia. Time from start to completion of intubation decreased rapidly with experience (median time 138 s). We conclude that the COPA may be a useful adjunct to fibreoptic tracheal intubation, allowing control and support of the airway during the procedure, using various anaesthetic techniques, in an acceptable amount of time. The ability to perform fibreoptic tracheal intubation while effectively supporting the airway using the COPA may be advantageous in managing the difficult airway and in trainee education. (+info)
French survey of anesthesia in 1996.
BACKGROUND: To identify the growth in the number of anesthetic procedures since 1980 and the changes in the practice of anesthesia, the present survey was designed to collect and analyze the anesthetic activity performed in France in 1996, from a representative sample collected in all French hospitals and clinics. METHODS: This study, initiated by the French Society of Anesthesia and Intensive Care, collected information that included the characteristics of patients (age, sex, American Society of Anesthesiologists status), the techniques of anesthesia, and the nature of the procedure for which anesthesia was required. All French private, public, and military hospitals were asked to participate in the survey. In each hospital in the country, all anesthetic procedures were documented and collected during 3 consecutive days, chosen at random during a 12-month period, to obtain a representative sample of the annual activity. All data were analyzed at the INSERM (National Institute of Health and MEDICAL RESEARCH: At the conclusion of the study, 5% of hospitals were randomly assigned to be audited to check for missing data and errors. The rate of anesthetic activity was calculated as the ratio between the annual number of anesthetic procedures and the number of the general population in the same age group. RESULTS: The participation rate of hospitals was 98%. The analysis of the 62,415 collected questionnaires allowed extrapolation of the anesthetic activity to 7,937,000 anesthetic procedures (95% confidence interval, +/- 387,000) performed in France in 1996. Thus, the annual rate of anesthetic procedures was 13.5 per 100 population, varying between 5.4 per 100 in girls aged 5-14 yr and 30.2 per 100 in men aged 75-84 yr. Surgery was involved in 71% of anesthesia cases. Regional anesthesia alone was performed in 20% of all surgical cases and was combined with general anesthesia in 3% of additional cases. Anesthesia for obstetric procedures represented 9% of all cases. Seventy-six percent of all anesthetic procedures started between 12:00 A.M. and 7:00 A.M. were related to obstetric activities. CONCLUSION: In comparison with a previous study, the present survey shows that the number of anesthetic procedures has increased by 120% since 1980, and the rate of anesthetic procedures increased from 6.6 to 13.5 per 100 population, the major changes being observed in patients aged > or = 75 yr and in those with an American Society of Anesthesiologists physical status of 3. In the same time period, the number of regional anesthetic procedures increased 14-fold. In obstetrics, the practice of epidural analgesia extended from 1.5% to 51% of all deliveries of the country. (+info)
Tactile evaluation of fade of the train-of-four and double-burst stimulation using the anaesthetist's non-dominant hand.
We have studied detection of fade in response to train-of-four (TOF), double-burst stimulation3,3 (DBS3,3) or DBS3,2, assessed tactilely by the anaesthetist using the index finger of the non-dominant hand and the thumb of the patient, compared with that assessed when the index finger of the dominant hand was used. The probability of detection of any fade in response to TOF or DBS3,3 using the non-dominant hand was significantly less than when the dominant hand was used (P < 0.05). The probability of identification of fade in response to DBS3,2 assessed using the non-dominant hand was comparable with that evaluated using the dominant hand when TOF ratios were 0-0.9, but when TOF ratios reached 0.91-1.00, detection using the non-dominant hand was significantly less common than with the dominant hand (12% vs 33%; P < 0.05). Using the non-dominant hand, the probability of detection of fade in response to ulnar nerve stimulation was less than that with the dominant hand and only the absence of DBS3,2 fade ensured sufficient recovery of neuromuscular block. (+info)