Evaluation of the predictive performance of a ‘Diprifusor’ TCI system

Swinhoe, C. F.; Peacock, J. E.; Glen, J. B.; Reilly, CS

doi:10.1111/j.1365-2044.1998.53s104.x

Cited by 145 publications

(87 citation statements)

References 16 publications

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“…In the original study by Swinhoe et al [8], blood samples were collected at suitable times to evaluate all phases of a target-controlled infusion of propofol including planned increases and decreases in target setting in patients undergoing major surgery. Thus, use of data from this study has allowed a comprehensive evaluation of the predictive performance of three models in this study.…”

Section: Discussionmentioning

confidence: 99%

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A comparison of the predictive performance of three pharmacokinetic models for propofol using measured values obtained during target‐controlled infusion

Glen

White

2014

Anaesthesia

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SummaryWe compared the predictive performance of the existing Diprifusor and Schnider models, used for target-controlled infusion of propofol, with a new modification of the Diprifusor model (White) incorporating age and sex covariates. The bias and inaccuracy (precision) of each model were determined using computer simulation to replicate the infusion profiles in an earlier study of 41 patients undergoing surgery with propofol administered by target-controlled infusion and in which timed, measured blood propofol concentrations were available. Bias with the White model (5%) was significantly less (p < 0.0001) than with the Diprifusor (16%) or Schnider (15%) models. The White model showed a significant improvement in accuracy (inaccuracy 19%, p < 0.0001) relative to the Diprifusor (26%). Temporal changes were such that with all three models, bias differed at induction and recovery. None of the models accounted fully for the extent of inter-individual variation in propofol clearance, but the improved performance with the White model suggests it has merit.

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Section: Discussionmentioning

confidence: 99%

“…This was a computer simulation study using data collected in the principal clinical study used to evaluate the predictive performance of the Diprifusor TCI system [8]. As a simulation study, this work was not reviewed by an institutional review board, but the original study was approved by the South Sheffield Research Ethics Committee.…”

Section: Methodsmentioning

confidence: 99%

A comparison of the predictive performance of three pharmacokinetic models for propofol using measured values obtained during target‐controlled infusion

Glen

White

2014

Anaesthesia

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“…The comparable intersubject levels of anesthesia due to the computer-assisted propofol application induces intraoperative SSEP changes that can be reliably predicted. [18][19][20]25 The influence of midazolam used for premedication can be neglected, as several studies showed no or only a transient effect on SSEP latencies. 22,26,27 Also the application of low doses of opioids (fentanyl) is not supposed to induce the predictable changes on SSEP latencies.…”

Section: Discussionmentioning

confidence: 99%

“…This allows longlasting anesthesia and the possibility of comparable anesthesia. 17,19,20 In the present study, the clinical reproducibility and reliability of pre-, intra-and postoperative SSEP recordings were assessed in uneventful scoliosis surgery. Firstly, the impact of anesthesia was calculated in an intersubject comparison of SSEP parameter differences between preoperative and intraoperative SSEP.…”

Section: Introductionmentioning

confidence: 99%

Reliability of perioperative SSEP recordings in spine surgery

et al. 2003

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Objective: The reproducibility and clinical reliability of perioperative somatosensory-evoked potentials (SSEP) were prospectively evaluated in uneventful scoliosis surgery. The influence of anesthesia owing to induction of total intravenous anesthesia (TIVA) upon preoperative SSEP and the variability of intraoperative SSEP were calculated. The potential effect of spine surgery was assessed by comparing pre-to postoperative SSEP. Methods: A total of 2143 pre-, intra-and postoperative tibial and median SSEP recorded in 25 patients undergoing spine surgery owing to idiopathic scoliosis were analyzed. The anesthesia protocol consisted of a computerized target controlled infusion (TCI) device for propofol and intravenous application of an opioid. Results: Anesthesia induced a significant and comparable prolongation of the tibial SSEP onset, P40 and P60 latencies, while the N50 latency was less changed. Throughout anesthesia, latencies of median (onset, N20, P25 and N35) and tibial (onset, P40, N50 and P60) SSEP showed mean variations of less than 6%. The intraoperative SSEP amplitudes were less stable with a relative standard deviation of 30-40%. In uneventful spine surgery, the postoperative tibial SSEP were not significantly changed in comparison to preoperative recordings. Conclusions: By using a standardized anesthesia protocol, the impact of anesthesia on preoperative SSEP can be predicted. Furthermore, the controlled application of sedatives and analgesics allows recording of stable SSEP parameters for intraoperative monitoring purposes. As in uneventful spine surgery pre-to postoperative SSEP are unchanged the latter comparison can be applied as an additional perioperative neuromonitoring procedure to assess the influence of spine surgery or other invasive interventions on spinal cord function.

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“…Body weight is used as an input parameter for Diprifusor™. Predicted plasma propofol concentration (Cp) and measured plasma propofol concentration (Cm) were found to be correlated, in spite of the slightly greater values of Cm compared to Cp [1][2][3][4]. If Cm is higher than Cp, arousal delay may occur; if Cm is lower than Cp, it may lead to intraoperative body movement and awakening during surgery, which may result in poor prognosis for the patient.…”

Section: Introductionmentioning

confidence: 99%

Effect of sex and polymorphisms of CYP2B6 and UGT1A9 on the difference between the target-controlled infusion predicted and measured plasma propofol concentration

et al. 2018

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Introduction: To examine whether sex and polymorphisms of cytochrome P450 (CYP) 2B6 and UDPglucuronosyltransferase (UGT) 1A9 affect the difference between predicted and measured plasma propofol concentration during continuous infusion by target-controlled infusion.Results: Blood samples of 69 patients (48 men and 21 women) were obtained at 4 h after initial propofol infusion. Percentage performance error (PE) was calculated to assess the difference between measured and predicted propofol concentration. Regression coefficients (β) and 95% confidence intervals (CI) of sex and the polymorphisms of CYP2B6 and UGT1A9 for PE were, separately and mutually, estimated with linear regression. Covariates included age and body mass index in the minimal adjusted model, and additionally included clinical factors (mean blood pressure, heart rate, volume of intravenous fluid, surgical site, surgical position, and pneumoperitoneum) in the full adjusted model. PE was higher in men than in women (28.7% versus 10.5%, p = 0.015). Female sex was inversely associated with PE: the minimal adjusted β = − 8.84 (95% CI, − 16.26 to − 1.43); however, the fully adjusted β with clinical factors became not significant. The average of PE did not differ between polymorphisms of CYP2B6 and UGT1A9, and β of CYP2B6 516G>T polymorphisms mutually adjusted with female sex was not significant. Mean blood pressure, heart rate, and volume of intravenous fluid were independently associated with PE in the full adjusted model. Conclusions: Under 4 h anesthesia with propofol target-controlled infusion in our population, sex differences appeared to exist in the propofol concentration, which might be largely mediated by clinical factors, such as hemodynamic status.

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Evaluation of the predictive performance of a ‘Diprifusor’ TCI system

Cited by 145 publications

References 16 publications

A comparison of the predictive performance of three pharmacokinetic models for propofol using measured values obtained during target‐controlled infusion

A comparison of the predictive performance of three pharmacokinetic models for propofol using measured values obtained during target‐controlled infusion

Reliability of perioperative SSEP recordings in spine surgery

Effect of sex and polymorphisms of CYP2B6 and UGT1A9 on the difference between the target-controlled infusion predicted and measured plasma propofol concentration

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