Low-flow anaesthesia. Does it have potential pharmacoeconomic consequences?

Reducing Volatile Anesthetic Waste Using a Commercial Electronic Health Record Clinical Decision Support Tool to Lower Fresh Gas Flows

BACKGROUND

Volatile anesthetic consumption can be reduced by minimizing excessive fresh gas flows (FGFs). Currently, it is unknown whether decision support tools embedded within commercial electronic health record systems can be successfully adopted to achieve long-term reductions in FGF rates. The authors describe the implementation of an electronic health record-based clinical decision support tool aimed at reducing FGF and evaluate the effectiveness of this intervention in achieving sustained reductions in FGF rates and volatile anesthetic consumption.

METHODS

On August 29, 2018, we implemented a decision support tool within the Epic Anesthesia Information Management System (AIMS) to alert providers of high FGF (>0.7 L/min for desflurane and >1 L/min for sevoflurane) during maintenance of anesthesia. July 22, 2015, to July 10, 2018, served as our baseline period before the intervention. The intervention period spanned from August 29, 2018, to December 31, 2019. Our primary outcomes were mean FGF (L/min) and volatile agent consumption (mL/MAC-h). Because a simple comparison of 2 time periods may result in false conclusions due to underlying trends independent of the intervention, we performed segmented regression of the interrupted time series to assess the change in level at the start of the intervention and the differences in slopes before and after the intervention. The analysis was also adjusted for potential confounding variables. Data included 44,899 cases using sevoflurane preintervention with 26,911 cases postintervention, and 17,472 cases using desflurane with 1185 cases postintervention.

RESULTS

Segmented regression of the interrupted times series demonstrated a decrease in mean FGF by 0.6 L/min (95% CI, 0.6-0.6 L/min; P < .0001) for sevoflurane and 0.2 L/min (95% CI, 0.2-0.3 L/min; P < .0001) for desflurane immediately after implementation of the intervention. For sevoflurane, mL/MAC-h decreased by 3.8 mL/MAC-h (95% CI, 3.6-4.1 mL/MAC-h; P < .0001) after implementation of the intervention and decreased by 4.1 mL/MAC-h (95% CI, 2.6-5.6 mL/MAC-h; P < .0001) for desflurane. Slopes for both FGF and mL/MAC-h in the postintervention period were statistically less negative than the preintervention slopes (P < .0001 for sevoflurane and P < .01 for desflurane).

CONCLUSIONS

A commercial AIMS-based decision support tool can be adopted to change provider FGF management patterns and reduce volatile anesthetic consumption in a sustainable fashion.

An Accessible Clinical Decision Support System to Curtail Anesthetic Greenhouse Gases in a Large Health Network: Implementation Study

BACKGROUND

Inhaled anesthetics in the operating room are potent greenhouse gases and are a key contributor to carbon emissions from health care facilities. Real-time clinical decision support (CDS) systems lower anesthetic gas waste by prompting anesthesia professionals to reduce fresh gas flow (FGF) when a set threshold is exceeded. However, previous CDS systems have relied on proprietary or highly customized anesthesia information management systems, significantly reducing other institutions' accessibility to the technology and thus limiting overall environmental benefit.

OBJECTIVE

In 2018, a CDS system that lowers anesthetic gas waste using methods that can be easily adopted by other institutions was developed at the University of California San Francisco (UCSF). This study aims to facilitate wider uptake of our CDS system and further reduce gas waste by describing the implementation of the FGF CDS toolkit at UCSF and the subsequent implementation at other medical campuses within the University of California Health network.

METHODS

We developed a noninterruptive active CDS system to alert anesthesia professionals when FGF rates exceeded 0.7 L per minute for common volatile anesthetics. The implementation process at UCSF was documented and assembled into an informational toolkit to aid in the integration of the CDS system at other health care institutions. Before implementation, presentation-based education initiatives were used to disseminate information regarding the safety of low FGF use and its relationship to environmental sustainability. Our FGF CDS toolkit consisted of 4 main components for implementation: sustainability-focused education of anesthesia professionals, hardware integration of the CDS technology, software build of the CDS system, and data reporting of measured outcomes.

RESULTS

The FGF CDS system was successfully deployed at 5 University of California Health network campuses. Four of the institutions are independent from the institution that created the CDS system. The CDS system was deployed at each facility using the FGF CDS toolkit, which describes the main components of the technology and implementation. Each campus made modifications to the CDS tool to best suit their institution, emphasizing the versatility and adoptability of the technology and implementation framework.

CONCLUSIONS

It has previously been shown that the FGF CDS system reduces anesthetic gas waste, leading to environmental and fiscal benefits. Here, we demonstrate that the CDS system can be transferred to other medical facilities using our toolkit for implementation, making the technology and associated benefits globally accessible to advance mitigation of health care-related emissions.

Minimizing sevoflurane wastage by sensible use of automated gas control technology in the flow-i workstation: an economic and ecological assessment

Both ecological and economic considerations dictate minimising wastage of volatile anaesthetics. To reconcile apparent opposing stakes between ecological/economical concerns and stability of anaesthetic delivery, new workstations feature automated software that continually optimizes the FGF to reliably obtain the requested gas mixture with minimal volatile anaesthetic waste. The aim of this study is to analyse the kinetics and consumption pattern of different approaches of sevoflurane delivery with the same 2% end-tidal goal in all patients. The consumption patterns of sevoflurane of a Flow-i were retrospectively studied in cases with a target end-tidal sevoflurane concentration (Et_sevo) of 2%. For each setting, 25 cases were included in the analysis. In Automatic Gas Control (AGC) regulation with software version V4.04, a speed setting 6 was observed; in AGC software version V4.07, speed settings 2, 4, 6 and 8 were observed, as well as a group where a minimal FGF was manually pursued and a group with a fixed 2 L/min FGF. In 45 min, an average of 14.5 mL was consumed in the 2L-FGF group, 5.0 mL in the minimal-manual group, 7.1 mL in the AGC4.04 group and 6.3 mL in the AGC4.07 group. Faster speed AGC-settings resulted in higher consumption, from 6.0 mL in speed 2 to 7.3 mL in speed 8. The Et_sevo target was acquired fastest in the 2L-FGF group and the Et_sevo was more stable in the AGC groups and the 2L-FGF groups. In all AGC groups, the consumption in the first 8 min was significantly higher than in the minimal flow group, but then decreased to a comparable rate. The more recent AGC4.07 algorithm was more efficient than the older AGC4.04 algorithm. This study indicates that the AGC technology permits very significant economic and ecological benefits, combined with excellent stability and convenience, over conventional FGF settings and should be favoured. While manually regulated minimal flow is still slightly more economical compared to the automated algorithm, this comes with a cost of lower precision of the Et_sevo. Further optimization of the AGC algorithms, particularly in the early wash-in period seems feasible. In AGC mode, lower speed settings result in significantly lower consumption of sevoflurane. Routine clinical practice using what historically is called "low flow anaesthesia" (e.g. 2 L/min FGF) should be abandoned, and all anaesthesia machines should be upgraded as soon as possible with automatic delivery technology to minimize atmospheric pollution with volatile anaesthetics.

Reduction of greenhouse gases emission through the use of tiletamine and zolazepam

Isoflurane is an anaesthetic gas widely used in both human and veterinary medicine. All currently used volatile anaesthetics are ozone-depleting halogenated compounds. The use of total intravenous anaesthesia (TIVA) allows to induce the effect of general anaesthesia by administering drugs only intravenously without the use of anaesthetic gases. This allows you to create a protocol that is safe not only for the patient, but also for doctors and the environment. However, so far, no anaesthetic protocol based on induction of anaesthesia with tiletamine-zolazepam without the need to maintain anaesthesia with anaesthetic gas has been developed. Our study showed that the use of this combination of drugs for induction does not require the use of additional isoflurane to maintain anaesthesia. Thanks to Dixon's up-and-down method we proved that with the induction of anaesthesia with tiletamine-zolazepam at a dose of 5 mg/kg the use of isoflurane is not needed to maintain anaesthesia in minimally invasive surgical procedures. Until now, this dose has been recommended by the producer for more diagnostic than surgical procedures or for induction of general anaesthesia. The maintenance was required with anaesthetic gas or administration of another dose of the tiletamine-zolazepam. The results obtained in this study will allow for a significant reduction in the consumption of isoflurane, a gas co-responsible for the deepening of the greenhouse effect, having a negative impact on patients and surgeons. These results are certainly the first step to achieving a well-balanced and safe TIVA-based anaesthetic protocol using tiletamine-zolazepam, the obvious goal of which will be to maximize both the safety of the patient, people involved in surgical procedures, and the environment itself. Being aware of the problem of the greenhouse effect, we are committed to reducing the consumption of anaesthetic gases by replacing them with infusion agents.

Feasibility, safety, and economic consequences of using minimal flow anaesthesia by Maquet FLOW-i equipped with automated gas control

Low fresh gas flow rates are recommended because of their benefits, however, its use is limited due to associated risks. The main purpose of this study was to investigate whether 300 mL of fresh gas flow that practised with automated gas control mode is applicable and safe. The second aim is to show that automated mode can provide economic benefits. Sixty hepatectomy cases who suitable criterias were included to cohort study in three groups as prospective, sequential, observational. An operating room were allocated only for this study. 300 mL fresh gas flow with automated mode (groupA3), 600 mL fresh gas flow with automated mode (groupA6) and, 600 mL fresh gas flow with manually (groupM6) was applied. Patients’ respiratory, hemodynamic parameters (safety), number of setting changes, O₂ concentration in the flowmeter that maintained FiO₂:0.4 during the low flow anaesthesia (feasibility) and comsumption data of anaesthetic agent and CO₂ absorber (economical) were collected and compared. p < 0.05 was accepted as statistical significance level. No significant differences were detected between the groups in terms of demographic data and duration of operation. Safety datas (hemodynamic, respiratory, and tissue perfusion parameters) were within normal limits in all patients. O₂ concentration in the flowmeter that maintained FiO₂:0.4 was statistically higher in groupA3 (92%) than other groups (p < 0.001) but it was still within applicable limits (below the 100%). Number of setting changes was statistically higher in groupM6 than other groups (p < 0.001). The anaesthetic agent consumption was statistically less in groupA3 (p = 0.018). We performed fresh gas flow of 300 mL by automated mode without deviating from the safety limits and reduced the consumption of anaesthetic agent. We were able to maintain FiO₂:0.4 in hepatectomies without much setting changes, and we think that the automated mode is better in terms of ease of practise.

Feasibility, safety, and economic consequences of using low flow anesthesia according to body weight

BACKGROUND

Low flow anesthesia (LFA) provides a saving up to 75% and improves the dynamics of inhaled anesthesia gas, increases mucociliary clearance, maintains body temperature, and reduces water loss. LFA has been recommended for anesthesiologists in recent years to avoid high fresh gas flow (FGF). However, LFA use is limited due to associated risks. The main purpose of this study was to investigate whether LFA according to body weight, which is the main determinant of oxygen requirement, is feasible and safe in the normoxia range. The second aim was to show that this method can provide economic benefit.

METHODS

Eighty donor hepatectomy cases were included to study in two groups as prospective, observational. A surgery room and a team were allocated only for this study. Considering the oxygen requirement (approximately 3-3.5 mL/kg/min), for the first 40 cases, 10 mL/kg (group 10) FGF was applied; for the second 40 cases, 20 mL/kg (group 20) was applied. Desflurane (Suprane©) was used as an inhalation agent, and analgesia was achieved with remifentanil infusion. Patients' demographic, respiratory, hemodynamic, and tissue perfusion parameters (SpO₂ and NIRS), and comsumption data (anesthetic agent and CO₂ absorbent) were collected and compared.

RESULTS

No significant differences were detected between the groups in terms of demographic data, duration of surgery, and hemodynamic, respiratory, and tissue perfusion parameters. These parameters were within normal limits in all patients at all times. The maximum O₂ concentration in the FGF that maintained FiO₂:0.4 and provided adequate oxygenation during the LFA was 61% (min 56%; max 67%) in group 10, and 47% (min 43%; max 51%) in group 20. The hourly anesthetic agent consumption was significantly different in group 10 than in group 20 (12.4 ± 4 mL vs. 21.5 ± 8 mL/h, respectively (p < 0.001).

CONCLUSIONS

We performed 10 mL/kg FGF speed without deviating from the safety limits to be FiO₂:0.4 in donor hepatectomies, reducing the total costs 38% compared with 20 mL/kg FGF.

Comparison of effects of low-flow and normal-flow anesthesia on cerebral oxygenation and bispectral index in morbidly obese patients undergoing laparoscopic sleeve gastrectomy: a prospective, randomized clinical trial

Introduction

The effects of low-flow anesthesia on cerebral oxygenation in high-risk, morbidly obese patients are not well known.

Aim

In this prospective randomized study, we compared the effects of low-flow (0.75 l/min) and normal-flow (1.5 l/min) anesthesia on regional cerebral oxygen saturation (rSO₂) and the bispectral index (BIS) in morbidly obese patients undergoing laparoscopic bariatric surgery.

Material and methods

Fifty-two morbidly obese patients undergoing laparoscopic bariatric surgery (sleeve gastrectomy) were enrolled in this study. Patients were randomly allocated to two study groups: low-flow and normal-flow anesthesia groups. Heart rate, mean arterial pressure, peripheral oxygen saturation, end-tidal carbon dioxide, BIS, left and right rSO₂, and duration of anesthesia and surgery were recorded.

Results

The groups were similar with respect to age, gender, height, weight, body mass index, American Society of Anesthesiology physical status, heart rate, duration of anesthesia, and procedure. Mean arterial pressure and end-tidal carbon dioxide, both before and after insufflation of carbon dioxide and after the reverse Trendelenburg position, were significantly higher in the low-flow group. BIS values and left and right rSO₂ during the preoperative and intraoperative periods were similar. Although the difference in right rSO₂ between the two groups after awakening from anesthesia was statistically significant, the results of both groups remained within the normal range and were not clinically meaningful.

Conclusions

Low-flow anesthesia is safe regarding hemodynamic and respiratory characteristics, depth of anesthesia, and regional cerebral oxygen saturation in morbidly obese patients undergoing laparoscopic bariatric surgery.

Randomized Comparison of Isoflurane versus Sevoflurane and Desflurane for Maintenance of Ambulatory Anesthesia

Background:

Ambulatory surgeries demand safe anesthesia with faster recovery which makes it expensive due to the cost of inhalational anesthetic agents such as sevoflurane and desflurane. Isoflurane is inexpensive agent but can cause delayed recovery. The aim of this study was to evaluate cost-benefit ratio of all three agent with respect to recovery and safety profile

Materials and Methods:

Patients posted for elective ambulatory surgeries were divided into three groups. Suitable size laryngeal mask airway was inserted following induction with propofol and vecuronium. Anesthesia was maintained on low-flow anesthesia with inhalational agent as isoflurane for Group I, sevoflurane for Group II and Group III received desflurane. Patients were monitored for recovery as per modified Aldrete score and as per postanesthesia discharge scoring system for discharge from hospital. Cost analysis was done by Dion's formula. Statistical analysis was done with analysis of variance for recovery profile, Chi-square test for safety profile and Kruskal Wallis test for cost comparison between groups.

Results:

Patient characteristics and duration of anesthesia were similar in all three groups. Time to eye-opening was significantly less with desflurane than sevoflurane and isoflurane (P = 0.001). Time to home readiness was similar in all three groups (P = 0.451). The incidence of airway irritation, pain, and nausea/vomiting was similar in all three groups. Cost of Group I was statistically lower than other two groups (P = 0.00).

Conclusion:

Home readiness and safety profile were comparable between agents; the cost involved was the least with isoflurane.

A survey on the use of low flow anaesthesia and the choice of inhalational anaesthetic agents among anaesthesiologists of India

Background and Aims:

With the availability of modern workstations and heightened awareness on the environmental effects of waste anaesthesia gases, anaesthesiologists worldwide are practicing low flow anaesthesia (LFA). Although LFA is being practiced in India, hard evidence on the current practice of the same from anaesthesiologists practicing in India is lacking and hence, we conducted this survey.

Methods:

A questionnaire containing 16 questions was distributed among a subgroup of anaesthesiologists who attended the 2014 National Conference of Indian Society of Anaesthesiologists. The filled-in questionnaires were computed and analysed with SPSS version 11.

Results:

The response rate to the survey was 82%. About 73% of the respondents practiced LFA routinely, with 65% having workstations. Most of the anaesthesiologists used fresh gas flows <1.5 L/min with 45.1% using O₂ concentrations at a range of 30–40%. ETCO₂ monitoring was used routinely by most whereas use of agent analysers and bispectral index monitoring were restricted. The availability of scavenging system was also limited to only 33.5%. Majority preferred N₂ O as carrier gas and sevoflurane as volatile agent of their choice.

Conclusion:

Our survey revealed that practice of LFA in India has numerous lacunae. Provision of better monitoring facilities, workstations as well as awareness regarding the environmental issues of waste anaesthetic gases need to be addressed.

Effects of flow rate on hemodynamic parameters and agent consumption in low-flow desflurane anesthesia: An open-label, prospective study in 90 patients

BACKGROUND

In surgical patients, decreasing the fresh gas flow rate in anesthesia may minimize costs, reduce environmental pollution, and preserve heat and humidity in the respiratory system.

OBJECTIVE

The aim of this study was to investigate the effects of 3 low-flowdesflurane rates on perioperative hemodynamic stability, end-tidal desflurane concentration, emergence and recovery characteristics, and agent consumption.

METHODS

This open-label, prospective study was conducted at the Departmentof Anesthesiology and Reanimation, University of Gaziantep, Gaziantep, Turkey. Nonpremedicated adult patients scheduled to undergo surgery (ureterolithotomy, cholecystectomy, pyelolithotomy, or thyroidectomy) were enrolled. Patients were anesthetized with propofol and fentanyl and intubated after neuromuscular blockade with vecuronium. Patients were randomly allocated to 1 of 3 groups according to the fresh gas flow rate: medium flow (2 L/min), low flow (1 L/min), and minimal flow (0.5 L/min). Intraoperative fentanyl volume was recorded. Heart rate, mean arterial pressure, and end-tidal desflurane concentration were recorded before (baseline) and after anesthesia induction; immediately before incision; and 5, 10, 15, 30, 45, and 60 minutes after incision. Emergence time and desflurane consumption after extubation were recorded. Aldrete scores were recorded at 5, 15, and 30 minutes after extubation.

RESULTS

Ninety patients (46 women, 44 men; mean [SD] age, 39.74 [13.73] years; 30 patients per treatment group) participated in the study. Means of hemodynamic parameters, intraoperative volume of fentanyl, end-tidal desflurane concentration, emergence time, and Aldrete score were statistically similar between the 3 groups. Mean (SD) desflurane consumption was significantly higher in the medium-flow group compared with the low- and minimal-flow groups (110.43 [28.18] g vs 98.40 [23.62] g and 79.80 [17.54] g, respectively; both, P < 0.01). Mean (SD) desflurane consumption was also significantly higher in the low-flow group compared with the minimal-flow group (P < 0.01).

CONCLUSION

The results of the present study in adult surgical patients suggestthat desflurane may be used in low-flow anesthesia, even with the minimal fresh gas flow rate.

Inhalational anaesthesia with low fresh gas flow

During the inhalation of anaesthesia use of low fresh gas flow (0.35-1 L/min) has some important advantages. There are three areas of benefit: pulmonary - anaesthesia with low fresh gas flow improves the dynamics of inhaled anaesthesia gas, increases mucociliary clearance, maintains body temperature and reduces water loss. Economic - reduction of anaesthesia gas consumption resulting in significant savings of > 75% and Ecological - reduction in nitrous oxide consumption, which is an important ozone-depleting and heat-trapping greenhouse gas that is emitted. Nevertheless, anaesthesia with high fresh gas flows of 2-6 L/min is still performed, a technique in which rebreathing is practically negligible. This special article describes the clinical use of conventional plenum vaporizers, connected to the fresh gas supply to easily perform low (1 L/min), minimal (0.5 L/min) or metabolic flow anaesthesia (0.35 L/min) with conventional Primus Draeger^® anaesthesia machines in routine clinical practice.

The effect of low fresh gas flow rate on sevoflurane consumption

BACKGROUND

In an era of medical cost containment, cost-effectiveness has become a major focus in healthcare. The effect of a new policy on the use of low fresh gas flow during maintenance of general anesthesia with volatile anesthetics was evaluated.

METHODS

The numbers and duration of general anesthesia cases using sevoflurane 5 weeks prior to and 15 weeks after policy implementation were retrieved from the electronic medical records database. The number of sevoflurane bottles consumed was also assessed. The anesthesia hours per bottle of sevoflurane were compared before and after policy implementation.

RESULTS

The number of anesthesia hours performed per bottle of sevoflurane increased by 38.3%. The effect varied over time and tended to fade with time.

CONCLUSIONS

The implementation of a low fresh gas flow rate policy effectively reduces the amount of sevoflurane consumed for the same duration of anesthesia.

Inhaled anesthetic agents

PURPOSE

The pharmacology, bioavailability and pharmacokinetics, indications, clinical efficacy, adverse effects and toxicities, and dosage and administration of the inhaled anesthetics are reviewed.

SUMMARY

The inhaled anesthetics include desflurane, enflurane, halothane, isoflurane, and sevoflurane and are thought to enhance inhibitory postsynaptic channel activity and inhibit excitatory synaptic activity. The mechanism of action of inhaled anesthetics has not been completely defined. A number of factors can influence the pharmacokinetics of inhaled anesthetics, including solubility in blood, cardiac output, tissue equilibration, extent of tissue perfusion, metabolism, and age. All of the available inhaled anesthetics are effective for inducing or maintaining anesthesia or both. Most clinical trials of inhaled anesthetics have evaluated differences in induction and emergence from anesthesia by comparing (1) times to loss of reflex, extubation, and response to verbal commands; orientation to time and place; and ability to sit up without assistance, (2) need for post-surgical analgesia, and (3) time to discharge as measures of efficacy. Adverse effects and toxicities of the inhaled anesthetics include nephrotoxicity, hepatotoxicity, cardiac arrhythmias, neurotoxicity, postoperative nausea and vomiting, respiratory depression and irritation, malignant hyperthermia, and postanesthesia agitation. Safety issues surrounding these gases include occupational exposure and intraoperative fires within the delivery systems used with inhaled anesthetics. Drugs used for anesthesia during surgery can account for 5-13% of a hospital's drug budget.

CONCLUSION

The inhaled anesthetics have been shown to be both safe and effective in inducing and maintaining anesthesia. These agents differ in potency, adverse-effect profile, and cost. Newer anesthetic gases, such as sevoflurane and desflurane, appear to have more favorable physico-chemical properties. These factors, as well as patient characteristics and duration and type of procedure, must be considered when selecting an inhaled anesthetic.

Inhalation Anesthesiology and Volatile Liquid Anesthetics: Focus on Isoflurane, Desflurane, and Sevoflurane

Clinical pharmacists rarely are involved in the selection and dosing of anesthetic agents. However, when practicing evidence-based medicine in a cost-conscious health care system, optimizing drug therapy is imperative in all areas. Thus, we provide general information on anesthesiology, including the different types of breathing systems and the components of anesthesia machines. Modern inhalation anesthetics that are predominantly used in clinical practice include one gas--nitrous oxide--and new volatile liquid agents--isoflurane, desflurane, and sevoflurane. Desflurane and sevoflurane are the low-soluble inhalation anesthetics, and they offer some clinical advantages over isoflurane, such as fast induction and faster recovery with long procedures. However, efficient use of isoflurane can match the speed of induction and recovery of the other agents in certain cases. In addition, the patient characteristics, duration and type of procedure, type of breathing system, and efficiency in monitoring must be considered when selecting the most optimal therapy for each patient. Maximizing the clinical advantages of these agents while minimizing the waste of an institution's operating room and pharmacy budget requires an understanding of the characteristics, pharmacokinetics, and pharmacodynamics of these anesthetic agents and the collaborated effort from both the anesthesia and pharmacy departments. An anesthetic agent algorithm is provided as a sample decision-process tree for selecting among isoflurane, desflurane, and sevoflurane.

Klinischer Behandlungspfad „laparoskopische Prostatektomie“

METHODS

In this study we investigated the anesthesiological module of a clinical pathway. We chose the pathway of "laparoscopic prostatectomy" as an example for time-consuming minimally invasive surgery and 40 patients were randomly assigned to 2 groups receiving either total intravenous anesthesia (TIVA) using propofol/ remifentanil or balanced minimal flow anesthesia using desflurane/ remifentanil. During this module the indicators of quality such as vigilance, pain, postoperative nausea and vomiting (PONV) and mobilization were measured. Costs were evaluated and analyzed by a bottom-up procedure.

RESULTS

There were no anesthesia-related deviations from clinical pathways and both forms of anesthesia management were equally well tolerated by the patients. No significant difference was observed regarding hemodynamic measurements or PONV. The patients in the desflurane/ remifentanil group recovered more rapidly (p=0.037) and had more pain. The amount of analgesic agents given immediately following anesthesia was significantly higher than in the TIVA group (p=0.017). The median anesthesia costs per minute for laparoscopic prostatectomy in the propofol group were 2.79 EUR (minimum cost 2.41 EUR, maximum cost 3.21 EUR) and in the desflurane group 2.68 EUR (minimum cost 2.45 EUR, maximum cost 3.39 EUR). The total anesthesia costs for both groups were within the proceeds matrix range for diagnosis-related groups (DRG). However, the cost analysis for medication was slightly higher than the proceeds matrix range for DRGs.

CONCLUSION

Both forms of anesthesia can be implemented for time-consuming surgical procedures and allow a cost-effective anesthesia management. Anesthesiological procedures must go hand-in-hand with the type of anesthesia selected. The prophylactic use of analgetics for desflurane/ remifentanil anesthesia should be given earlier and in higher doses than in propofol/ remifentanil anesthesia. The prophylactic use of antiemetics following laparoscopic procedures of long duration is indicated. Optimizing anesthesiological procedures could lead to a continuous improvement in the quality of therapeutic pathways.

Total intravenous anaesthesia: is it worth the cost?

Total intravenous anaesthesia (TIVA) has many advocates and offers potential benefits, yet the direct costs of this technique are commonly greater than those of inhalation-based alternatives. Although many advantages are claimed for TIVA, in reality all modern anaesthetics are effective and have good safety and tolerability profiles, rendering these differences of less importance now than was perhaps once the case. The majority of direct comparisons between inhaled and intravenous anaesthetics have failed to demonstrate significant differences in recovery times, yet they have consistently shown greater direct costs associated with intravenous propofol anaesthesia. It is commonly believed that indirect costs may be offset by indirect savings achieved through more rapid recovery, reduction in adverse effects and decreased staff workloads. In some cases, these differences in outcome have not been observed, while in many where they have, indirect savings are only theoretical. Reductions in recovery time and nursing workload will only result in savings if fewer nurses are required or if the existing ones can be paid for fewer hours. Salary arrangements, peak demand for patient care, performance of multiple tasks in parallel and limitations in time accounting methodology all limit the ability to achieve such savings in reality. Drug wastage also contributes to the cost of anaesthesia and is common to both intravenous and inhaled techniques. With inhaled anaesthesia, wastage can be reduced by the use of lower fresh gas flows, which has no adverse consequences and may provide potential benefits. With intravenous anaesthesia, reducing drug wastage is difficult and potentially harmful through cross-contamination of drugs between patients. Recently, the cost of propofol has been reduced with the availability of generics, making TIVA a more attractive proposition. The costs of several inhaled anaesthetics have also decreased, however, reducing any relative benefit. Nevertheless, the net result of lowered costs is that all types of anaesthetic drugs, which typically comprise <5% of a hospital pharmacy budget, represent excellent value for money. With few new products in the immediate pipeline and most established drugs already generic or about to lose their patent protection, the expense of anaesthesia is likely to decline even further. Perhaps then we will be able to stop arguing over relatively small differences in cost and choose a technique that, in our own experienced hands, provides the best and safest patient outcomes.

Pharmacoeconomic considerations in anaesthetic use

Healthcare costs are rising in all areas of medicine, especially in high technology specialities such as anaesthesia. Therefore, cost containment and reduction have become major goals in many hospitals and anaesthesia departments. One area that has received substantial attention is the cost of pharmaceutical products, in particular the cost of newer, shorter-acting inhaled and intravenous anaesthetics, analgesics and neuromuscular blocking agents. Numerous pharmacoeconomic studies have been published on the theoretical analysis of anaesthetic drug costs and the potential benefit of various anaesthesia techniques. However, the results are not conclusive and anaesthesia departments continue to seek ways to reduce costs. In this review, we intend to discuss cost terminology, common areas of cost containment in anaesthesia and the relationship of anaesthesia care costs to total perioperative costs.

The sevoflurane saving capacity of a new anaesthetic agent conserving device compared with a low flow circle system

BACKGROUND

An anaesthetic agent conserving device (ACD) has been added to a Bain system to approach the agent-saving capacity of a low flow circle system.

METHODS

Randomly selected ASA physical status I patients received a standardized anaesthetic with sevoflurane in air/O2 through either a circle system with 1.5 l/min fresh gas flow (n = 8), or through a Bain system with an added ACD with fresh gas flow 4.4-6.4 l/min (n = 8). A target controlled infusion of remifentanil was used for analgesia.

RESULTS

The median sevoflurane consumption was 19.7 and 22.0 ml/MAC/h with the low flow circle system and the Bain system + ACD, respectively (P=0.10, Mann-Whitney U-test), or when adjusted for weight 0.25 and 0.28 ml/MAC/h/kg (P=0.26, Mann-Whitney U-test).

CONCLUSION

The expenditure of sevoflurane with a Bain system + ACD was close to that in a circle system with 1.5 l/min fresh gas flow. It is thereby possible to use sevoflurane to all its potential, performing for example rapid alterations in end-tidal concentration using high fresh gas flows by combining a Bain system with an ACD. Although the price is not decided for this not yet commercially available device, a potential for a lower cost exists. Additionally, there will be no concerns of toxic compounds produced in the absorber.

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.