Cost-Effectiveness of Propofol (Diprivan) Versus Inhalational Anesthetics to Maintain General Anesthesia in Noncardiac Surgery in the United States.

Abstract Objectives It is not known whether using propofol total intravenous anaesthesia (TIVA) to reduce incidence of postoperative nausea and vomiting (PONV) is cost-effective. We assessed the economic impact of propofol TIVA versus inhalational anesthesia in adult patients for ambulatory and inpatient procedures relevant to the US healthcare system. Methods Two models simulate individual patient pathways through inpatient and ambulatory surgery with propofol TIVA or inhalational anesthesia with economic inputs from studies on adult surgical US patients. Efficacy inputs were obtained from a meta-analysis of randomized controlled trials. Probabilistic and deterministic sensitivity analyses assessed the robustness of the model estimates. Results Lower PONV rate, shorter stay in the post-anesthesia care unit, and reduced need for rescue antiemetics offset the higher costs for anesthetics, analgesics, and muscle relaxants with propofol TIVA and reduced cost by 11.41 ± 10.73 USD per patient in the inpatient model and 11.25 ± 9.81 USD in the ambulatory patient model. Sensitivity analyses demonstrated strong robustness of the results. Conclusions Maintenance of general anesthesia with propofol was cost-saving compared to inhalational anesthesia in both inpatient and ambulatory surgical settings in the United States. These economic results support current guideline recommendations, which endorse propofol TIVA to reduce PONV risk and enhance postoperative recovery

Use of target controlled infusion to derive age and gender covariates for propofol clearance

BACKGROUND AND OBJECTIVE: Attempts to describe the variability of propofol pharmacokinetics in adults and to derive population covariates have been sparse and limited mainly to experiments based on bolus doses or infusions in healthy volunteers. This study aimed to identify age and gender covariates for propofol when given as an infusion in anaesthetized patients. STUDY DESIGN AND SETTING: One hundred and thirteen patients (American Society of Anesthesiologists class I or II and aged 14-92 years) were anaesthetized for elective surgical procedures with propofol using a target controlled infusion (TCI) system and with alfentanil as a baseline analgesic infusion. Frequent venous blood samples were obtained for measurement of propofol plasma concentrations. PHARMACOKINETIC AND STATISTICAL ANALYSIS: Pharmacokinetic accuracy was determined by the percentage prediction error, bias and precision, as were wobble and divergence. The clearance of propofol from the central compartment was determined for each patient using the computerized record of the infusion profile delivered to each patient, together with relevant blood propofol concentration estimations. For each patient, the nonlinear mixed-effects modelling (NONMEM) objective function was employed to determine the goodness of fit. RESULTS: The population distribution of propofol clearance was subsequently found to have a Gaussian distribution only in the log domain (mean value equivalent to 26.1 mL/kg/min). The distribution in the normal domain was consequently asymmetric, with a slight predominance of patients with high values of clearance (5% and 95% confidence limits 17.7 and 42.1 mL/kg/min, respectively). Using regression analysis, gender and age covariates were derived that optimized the performance of the target controlled infusion system. The clearance (CL) of propofol in male patients changed little with age (CL [mL/kg/min]=26.88-0.029xAge; r2=0.006) whereas that in female patients had a higher initial value but decreased progressively with age (CL [mL/kg/min]=37.87-0.198xAge; r2=0.246). CONCLUSION: We achieved a relatively simple and practical covariate model in which the variability of pharmacokinetics within the study population could be ascribed principally to variability in clearance from the central compartment. Pharmacokinetic simulation predicted an improved performance of the TCI system when employing the derived covariates model, especially in elderly female patient

[Target-controlled infusion. Clinical relevance and special features when using pharmacokinetic models],[Target-controlled infusion. Clinical relevance and special features when using pharmacokinetic models]

Contains fulltext : 79741.pdf (publisher's version ) (Closed access)Since its commercial introduction in 1996, target-controlled infusion (TCI) has become an established technique for administration of intravenous anaesthetics. Modern TCI systems, however, are characterized by an increasing number of additional options and features, such as the choice between different pharmacokinetic models and modes of application, which may confuse the less experienced user. This review describes the differences between pharmacokinetic models, modes of application and the effect of covariates as well as the consequences for dosing. The aim is to explicate for the user of modern TCI systems the underlying scientific concepts and the relevance for clinical practice

The effect of general anaesthesia on memory in children

Perioperative Medicine: Efficacy, Safety and OutcomeAnesthesiolog

[Target-controlled infusion (TCI) - a concept with a future?: state-of-the-art, treatment recommendations and a look into the future]

Contains fulltext : 69264.pdf (publisher's version ) (Closed access)Over the last 10 years the technique of target-controlled infusion (TCI) has substantially influenced the development and practice of intravenous anaesthesia. It opened the possibility of many new and exciting applications of perioperative anaesthetic care. More recent and current developments, such as open TCI (target-controlled infusion) and the availability of generic anaesthetic agents combined with modern infusion pumps, means that TCI can become a standard procedure in anaesthesia and is no longer just a research tool for specialists and enthusiasts. This review explains the fundamentals and applications of intravenous drug delivery by TCI and gives practice guidelines to successfully implement the technique into clinical practice. The aim is to provide a comprehensive reference based on clinically proven evidence

The contribution of remifentanil to middle latency auditory evoked potentials during induction of propofol anesthesia

There is a debate regarding whether opioids, as a component of general anesthesia, are adequately reflected in the assessment of anesthesia based on derivatives of the electroencephalogram. To test the hypothesis of a possible quantitative contribution of remifentanil on middle latency auditory evoked potentials, we studied its interaction with propofol anesthesia in 45 unpremedicated male patients undergoing elective lower limb orthopedic surgery. They were allocated randomly to three groups. The first two groups received remifentanil either with a high (8 ng mL(-1)) or a low (3 ng mL(-1) target concentration using target-controlled infusion (TCI). The third group received spinal anesthesia instead of remifentanil. Anesthesia was induced by a stepwise increase in propofol concentration using TCI. The auditory evoked potential index (AEPex) and calculated propofol effect site concentrations were determined at loss of consciousness and the reaction to laryngeal mask airway insertion was noted. The propofol infusion was then converted to a closed-loop TCI using an AEPex value of 40 as the target. We found no significant contribution of remifentanil alone on the auditory evoked response, whereas increasing concentrations of remifentanil led to a significant decrease of the calculated propofol effect site concentrations (P = 0.023) necessary for unconsciousness. Prediction probability for AEPex was inversely related to the remifentanil concentration and was best for the control group, which received propofol alone. These results support previous findings of a quantitative interaction between remifentanil and propofol for loss of consciousness but question the specific contribution of remifentanil to auditory evoked potentials

Comparison of Two Clinical Protocols for Total Intravenous Anesthesia (TIVA) for Breast Surgery Using Propofol Combined With Either Sufentanil or Alfentanil

BACKGROUND: Sufentanil and alfentanil have pharmacokinetic and dynamic properties which make them favourable substances for total intravenous anesthesia (TIVA) in combination with propofol. OBJECTIVES: We planned to compare two clinical protocols for TIVA with propofol, and either sufentanil or alfentanil in regards to postoperative pain, hemodynamic stability during the case and time for emergence from anesthesia. PATINETS AND METHODS: Treaty eight patients scheduled for general anesthesia for breast surgery were included in this Double-blind, randomized, controlled trial. All patients received a standardized TIVA with propofol and either 0.2 µg kg(-1) sufentanil or 20 µg kg(-1) alfentanil for induction and 0.3 µg kg(-1) h(-1) sufentanil or 30 µg kg(-1) h(-1) alfentanil for maintenance with additional propofol boluses as needed. During anesthesia, heart rate, non-invasive blood-pressure, peripheral oxygen saturation and depth of anesthesia, were recorded. In the post anesthesia care unit, pain scores, nausea and vomiting as well as medications were recorded. RESULTS: Patients in the sufentanil group required less often additional opioid and propofol boluses to maintain adequate anesthesia. We did not observe a significant difference in time to extubation. Postoperatively, patients in the sufentanil group had less pain (P = 0.03) and required less i.v. opioids (0.4 vs. 1.9 mg piritramid, P = 0.04). CONCLUSIONS: Both protocols provide excellent anesthesia, but patients receiving sufentnail had more stable anesthesia and less postoperative pain