Use Of Anesthetic Drugs Research Articles

Applying animal learning theory: training captive animals to comply with veterinary and husbandry procedures

AbstractAnimals within zoo environments are learning continuously: they learn signals that predict when food is going to arrive or that the presence of a certain person means that something unpleasant may happen. They may learn to control their environment and caregivers: for example, they may learn that if they perform a particular behaviour (eg repetitive behaviour) they will receive a reward (ie food or attention from a caregiver). Using standard operant conditioning and classical conditioning techniques we can easily modify the behaviour of animals in zoos. Animals can be trained to comply with almost all minor veterinary procedures and examinations, such as injection, the measurement of heart rate, the cleaning of teeth and the treatment of superficial injuries. Compliance can be achieved using standard animal learning abilities without the need for punishment type I (ie physical punishment) or immobilisation (chemical or physical). In this paper we discuss how we apply learning theory to such procedures, the dangers associated with such programs (eg injury to the trainer) and the benefits (eg the treatment of large endangered animal species without the use of anaesthetic drugs). Additionally, we briefly discuss the selection and management of animal trainers. The methods we describe here are equally applicable to laboratory, farm and pet animals. Finally, as with all management processes applied to animals, a written policy on animal training needs to be produced by any institution training animals.

Cost considerations in the use of anaesthetic drugs

Measuring the direct drug costs of an anaesthetic is relatively easy, but assessing increased expenditure in relation to clinical benefits and indirect costs is not. This review examines a number of papers that have attempted just such a task and tries to illustrate some of the difficulties inherent in this important area of cost-effective analyses.

Postoperative Coma in a Child with Carnitine Palmitoyltransferase I Deficiency

Postoperative Coma in a Child with Carnitine Palmitoyltransferase I Deficiency

General anaesthesia for supratentorial neurosurgery.

Anaesthesia for the surgical treatment of supratentorial tumours requires an understanding of: the pathophysiology of a localised or generalised increase in intracranial pressure (ICP), the regulation and maintenance of intracerebral perfusion, avoidance of secondary systemic insults to the brain, and the effects of anaesthetic drugs on ICP, cerebral perfusion and cerebral metabolism. Knowledge of the therapeutic options available for decreasing ICP, brain bulk and brain tension perioperatively is also essential. Potential complications which may present during supratentorial neurosurgery include massive intraoperative haemorrhage and seizures. The fact that the surgeon is operating on a tensed brain is also a potential source of difficulty. The need to monitor brain function and environment during surgery poses a challenge to the anaesthesiologist, as does the achievement of rapid emergence from anaesthesia with the adequate use of anaesthetic drugs.

Cost considerations in the use of anaesthetic drugs.

Anaesthetic drugs typically comprise approximately 5% or less of a hospital pharmacy budget, yet they are a common target for cost reduction measures. In particular, there is considerable pressure to use less costly products where alternatives exist and to limit the introduction of expensive new items. In considering strategies to reduce a departmental drug budget, or in defending against restrictions imposed from outside, it is important to consider all of the costs associated with anaesthetic drug delivery. These costs comprise not only the expense of the anaesthetic drugs themselves, but also fixed and variable costs associated with their delivery and related to their effects. Elimination of drug waste will always be beneficial, since it has no direct effect on the patient yet clearly reduces cost. Waste is by no means confined to anaesthetic drugs, however. Using less expensive drugs may appear an attractive option and can reduce costs, provided that patient outcome is in no way affected. Rarely is this the case. Once patient care is modified, through changes in recovery times or complication rates, determining the true cost of the intervention becomes essential; there may be increases in indirect costs which dwarf the apparent savings. Sometimes indirect costs will rise by a lesser amount than savings in direct costs, such that there is still an overall benefit but less than that originally anticipated. Exactly how indirect effects result in indirect costs is highly variable. The requirement for additional drugs or supplies to treat an adverse event, such as emesis, will always have an associated cost. Delayed recovery or prolonged hospital stay will waste operating room time or increase the amount of time that a patient requires nursing care, but whether this carries an associated cost depends on what the staff would otherwise have been doing. Depending on the employment method, staff may have been sent home early (with less pay) or employed at identical cost but with less to do. Many studies which purport to consider all costs either ignore such issues, or make invalid assumptions. These issues are complex, but anyone involved with decisions concerning anaesthetic costs should be familiar with the underlying principles and be able to make a rational assessment of the likely indirect costs in their own institution.

THE IMPACT OF EEG-BISPECTRAL INDEX MONITORING ON DRUG USAGE AND RECOVERY DURING AMBULATORY ANESTHESIA

S51 INTRODUCTION: The Bispectral Index (BIS) is a processed EEG parameter that has been validated as a measure of the sedative-hypnotic effects of anesthetic drugs. Controlled studies have shown that BIS use facilitates the administration of intravenous and inhaled anesthetics, resulting in decreased propofol use and improved recovery. [1,2] These studies, however, involved only limited number of patients and included a specific requirement to titrate the sedative-hypnotic drug according to a predetermined target BIS values. The impact of BIS monitoring on drug usage in routine clinical practice remains to be confirmed. Therefore, we evaluated the effect of BIS monitoring on propofol use and on patient recovery during standard ambulatory anesthesia. METHODS: Following IRB approval, the hospital records of 1043 patients who had undergone orthopedic surgery under general anesthesia at our outpatient surgical facility during a 45 month period were reviewed. Patient demographic, anesthesia and recovery data were obtained for two groups of patients, namely, those treated during a 30 month period "Prior to BIS use", and those treated during the 15 month period of "BIS use". Anesthesia providers received only a standard instruction in the use of BIS (A-1050, Aspect Medical, Inc.). Patient management was according to routine clinical practice. After premedication with midazolam, 1-2 mg i.v., anesthesia was induced with 2-2.5 mg/kg propofol and maintained with a variable rate infusion of propofol supplemented with sufentanil, 2.5-5 [micro sign] g boluses, as needed, and 65% nitrous oxide in oxygen. Data on neuromuscular blocking and reversal agents were not included. Data were analyzed using Student t-and Chi-square tests, as appropriate. P values < 0.05 were considered statistically significant (*). Data are presented as mean +/- SD. RESULTS: There were no significant demographic differences between the two study groups (Table 1). All procedures were conducted by the same small group of surgeons and anesthesia provides. A difference in propofol use was not evident in the grand total propofol dose. However, the introduction of BIS monitoring was associated with a significant reduction in the normalized total propofol dose (total propofol dose divided by weight and case duration), (p<0.001). Likewise, there was a reduction in the average maintenance rate of propofol during the anesthesia maintenance period of 8.9 [micro sign] g/kg/min (p<0.001). There was a small but significant increase in the average intraoperative opioid dosage (p<0.001). The difference in recovery times was minimal but the incidence of postoperative nausea and vomiting (PONV) was reduced (p<0.01).Table 1DISCUSSION: These results suggest that BIS has a significant impact on the use of anesthetic drugs in routine clinical practice. Titration of propofol using BIS resulted in decreased maintenance rates. The reduction in propofol use for the "average" case in this study was approximately 77 mg/case. Contrary to previous reports, [1] we found an increase in the use of intraoperative opioids. This may relate to the ability to maintain "lighter" planes of anesthesia with BIS. Thus, in addition to its influence on the amount of hypnotics used, BIS monitoring also affects the choice of drugs during outpatient anesthesia.

Using an Anesthesia Information Management System as a Cost Containment Tool

Background- Medical informatics provide a new way to evaluate the practice of medicine. Anesthesia automated record keepers have introduced anesthesiologists to computerized medical records. To derive useful information from the stored data requires programming that is not currently commercially available. The authors describe how they custom-programmed an automated record keeper's database to perform cost calculations, how they validated the programming, and how they used the data in a successful pharmaceutical cost-containment program. Methods: The Arkive® (San Diego, CA) automated record keeper database was programmed at Duke University Medical Center as an independent noncommercial project to calculate costs according to standard formulae and to follow adherence to Duke University Department of Anesthesiology's prescribing guidelines for anesthetic drugs. Validation of that programming (including analysis of discarded drugs) was accomplished by comparing database calculated costs with actual pharmacy distribution of drugs during a 1-month period. Results: Validation data demonstrated a 99% accuracy rate for total costs of the drugs studied (atracurium, vecuronium, rocuronium, propofol, midazolam, fentanyl, and isoflurane). The study drugs represented approximately 67% of all drug costs for the period studied. Conclusions: Programming of an anesthesia automated record keeper's database yields essential information for management of an anesthetic practice. Accurate economic evaluation of anesthetic drug use is now possible. In the future, as definitive identification of best anesthetic practices that yield optimal patient outcomes and higher measures of patient satisfaction is pursued, large numbers of patients should be studied. This is only possible through database analysis and complete computerization of the perioperative medical record.

The successful implementation of pharmaceutical practice guidelines. Analysis of associated outcomes and cost savings. SWiPE Group. Systematic Withdrawal of Perioperative Expenses.

Although approximately 2,000 medical practice guidelines have been proposed, few have been successfully implemented and sustained. We hypothesized that we could develop and institute practice guidelines to promote more appropriate use of costly anesthetics, to generate and sustain widespread compliance from a large physician group, and to decrease costs without adversely affecting clinical outcomes. A prospective before and after comparison study was performed at a tertiary care medical center. Clinical outcomes data and times indicative of perioperative patient flow were collected on the first of two sets of patients 1 month before discussion of practice guidelines. Practice guidelines were developed by the physicians and their associated care team for the intraoperative use of anesthetic drugs. A drug distribution process was developed to aid compliance. Clinical outcomes data and times indicative of perioperative patient flow were collected on the second set of patients 1 month after institution of practice guidelines. Hospital drug costs and adherence to guidelines were noted throughout the study period and for each of the following 9 months by querying the database of an automated anesthesia record keeper. A total of 1,744 patients were studied. Drug costs decreased from 56 dollars per case to 32 dollars per case as a result of adherence to practice guidelines. Perioperative patient flow was minimally affected. Time (mean +/- SD) from end of surgery to arrival in the post-anesthesia care unit (PACU) increased from 11 +/- 7 min before the authors instituted practice guidelines to 14 +/- 8 min after practice guidelines (P < 0.0001). Admission of inpatients to the PACU receiving monitored anesthesia care increased from 6.5 to 12.9% (P < 0.02). Perioperative patient flow and clinical outcomes were not otherwise adversely affected. Compliance and cost savings have been sustained. This study is an example of a successful physician-directed program to promote more appropriate utilization of health care resources. Cost savings were obtained without any substantial changes in clinical outcomes. Institution of similar practice guidelines should result in pharmaceutical savings in the range of 50% at tertiary care centers around the country, with a slightly smaller degree of savings expected at institutions with more ambulatory surgery.

Using an anesthesia information management system as a cost containment tool. Description and validation.

Medical informatics provide a new way to evaluate the practice of medicine. Anesthesia automated record keepers have introduced anesthesiologists to computerized medical records. To derive useful information from the stored data requires programming that is not currently commercially available. The authors describe how they custom-programmed an automated record keeper's database to perform cost calculations, how they validated the programming, and how they used the data in a successful pharmaceutical cost-containment program. The Arkive (San Diego, CA) automated record keeper database was programmed at Duke University Medical Center as an independent noncommercial project to calculate costs according to standard formulae and to follow adherence to Duke University Department of Anesthesiology's prescribing guidelines for anesthetic drugs. Validation of that programming (including analysis of discarded drugs) was accomplished by comparing database calculated costs with actual pharmacy distribution of drugs during a 1-month period. Validation data demonstrated a 99% accuracy rate for total costs of the drugs studied (atracurium, vecuronium, rocuronium, propofol, midazolam, fentanyl, and isoflurane). The study drugs represented approximately 67% of all drug costs for the period studied. Programming of an anesthesia automated record keeper's database yields essential information for management of an anesthetic practice. Accurate economic evaluation of anesthetic drug use is now possible. In the future, as definitive identification of best anesthetic practices that yield optimal patient outcomes and higher measures of patient satisfaction is pursued, large numbers of patients should be studied. This is only possible through database analysis and complete computerization of the perioperative medical record.

Transcranial Doppler ultrasonography in neurosurgery: Effects of intracranial tumour on right middle cerebral artery flow velocity during induction of anaesthesia

The right middle cerebral artery flow velocity (MCAFV) was measured by transcranial Doppler ultrasonography in neurosurgical patients with and without intracranial tumours during anaesthetic induction and endotracheal intubation. With institutional and patient consent, 20 non-tumour and 85 tumour-bearing neurosurgical patients were enlisted. The right middle cerebral artery was insonated with a pulsedwave range-gated transcranial Doppler at 2 MHz, and MCAFV was recorded via a video graphics printer. The mean MCAFV, pulsatility index, use of anaesthetic drugs, heart rate, mean arterial pressure, and endtidal CO 2 were recorded on preinduction, postinduction, intubation, and 90 to 180 s postintubation. There was no demographic, Systemic haemodynamic, or anaesthetic difference between groups except for a predominance of women in the tumour group. In all patients, mean arterial pressure and MCAFV demonstrated with time a significant decrease with anaesthetic induction, increase with endotracheal intubation, and decrease post intubation. The right MCAFV was significantly higher in both tumour and right-sided tumour patients compared to non-tumour patients. There was no difference in left-sided tumour patients compared to non-tumour patients. These data indicate that intracranial tumours have cerebrovascular effects, causing either hyperaemia or vasoconstriction, and that the effects of anaesthetic induction and intubation agree with previously reported effects on cerebral blood flow and intracranial pressure.

Factors modifying the use of anaesthetic drugs in the elderly

The elderly are forming an ever greater proportion of our hospital population. The process of ageing produces a gradual erosion of all the body's margins of safety coupled with a decreasing ability to adapt. This has significant effects on the physiological responses to the surgical and pharmacological trespass encountered during anaesthesia. In addition elderly people often suffer from multiple pathology and polypharmacy, both of which play important roles in the selection of the optimal anaesthetic regimen.

Myocardial Protection: Role of Anesthetic Drugs

Summary and Conclusion Most anesthetic techniques can conceivably have favorable effects on myocardial ischemia in certain circumstances by reducing the hemodynamic and neurohumoral stress response to pain, anxiety, and surgical trauma.12,14 There is no one ideal anesthetic drug or technique for all situations and there are many complicating factors that may influence whether or not a specific drug has the potential to protect against ischemia. These include interactions with other drugs,88 the magnitude of the stress response to surgery, the degree of myocardial damage, the presence of coronary spasm, and the degree of collateral coronary circulation. Of the inhalation anesthetics, halothane and enflurane demonstrate protective effects on the nonfailing ischemic heart in animals when excessive hypotension is avoided. In patients with coronary artery disease they are associated with a low incidence of myocardial ischemia when sensitive methods of detection are used. Isoflurane may not be the drug of choice for patients with ischemic heart disease because of its potential for causing the adverse redistribution of coronary flow. Because they either decrease or have minimal effects on myocardial oxygen consumption, fentanyl, sufentanil, diazepam, midazolam, and etomidate are the intravenous agents most likely to favorably influence myocardial ischemia. None are complete anesthetics by themselves and thus have the potential to inadequately blunt the stress response to surgery or laryngoscopy. They are probably more effectively used in combinations with each other or with an inhalation anesthetic during periods of stimulation. We currently have a great deal of knowledge about how the anesthetic agents affect hemodynamic determinants of myocardial oxygen consumption and supply. It is well recognized that the use of anesthetic drugs to limit myocardial oxygen consumption while avoiding excessive decrements in supply has the potential to reduce the incidence of and improve tolerance to myocardial ischemia. Further work needs to be done to determine how anesthetic agents affect the occurrence of coronary vasospasm, how they influence intracellular metabolism during myocardial ischemia, and whether they have any effect on coronary thrombosis.

Mysterious deaths at Ann Arbor

AnaesthesiaVolume 33, Issue 8 p. 752-753 Free Access Mysterious deaths at Ann Arbor JOHN W. DUNDEE, JOHN W. DUNDEE Professor J.W. Dundee, MD, PhD, FFARCS, MRCP. Professor of Anaesthetics, The Department of Anaesthetics, The Queen's University of Belfast, Whitla Medical Building, 97 Lisburn Road, Belfast BT9 7BL, Northern Ireland.Search for more papers by this author JOHN W. DUNDEE, JOHN W. DUNDEE Professor J.W. Dundee, MD, PhD, FFARCS, MRCP. Professor of Anaesthetics, The Department of Anaesthetics, The Queen's University of Belfast, Whitla Medical Building, 97 Lisburn Road, Belfast BT9 7BL, Northern Ireland.Search for more papers by this author First published: September 1978 https://doi.org/10.1111/j.1365-2044.1978.tb08475.xCitations: 3AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat No abstract is available for this article. References 1 Wilcox, R.H. (1977) The Mysterious Deaths at Ann Arbor. Popular Library, New York . 2 Maltby, J.R. (1977) Criminal use of anaesthetic drugs. Anaesthesia, 32, 212. Citing Literature Volume33, Issue8September 1978Pages 752-753 ReferencesRelatedInformation

Criminal use of anaesthetic drugs

Criminal use of anaesthetic drugs