Browsing by Author "Araneda, Andrea"

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    Pharmacokinetic modelling and simulation for prolonged infusion of levobupivacaine with or without epinephrine in transversus abdominis plane and erector spinae plane blocks: a randomised controlled trial and analysis of pooled data
    (2025) Araneda, Andrea; De La Cuadra Fontaine, Juan Carlos; Corvetto Aqueveque, Marcia Antonia; Balde Sepúlveda, Detlef Peter Mario; De La Fuente Sanhueza, Rene Francisco; Ibacache Figueroa, Mauricio Enrique; Contreras, Víctor; Solari Gajardo, Sandra; Cortinez Fernández, Luis Ignacio
    Background: Interfacial blocks often require large volumes of local anaesthetic, raising concerns about systemic absorption and potential toxicity. This study examined the pharmacokinetics of levobupivacaine with and without epinephrine during thoracic erector spinae plane (ESP) or transversus abdominis plane (TAP) blocks, simulating reported 48-h dosing regimens to evaluate safety. Methods: Data from three studies were analysed. Study 1 included 38 patients receiving an ESP block before video-assisted thoracoscopy, whereas Study 2 analysed published data on TAP blocks. Both studies used 20 ml of levobupivacaine 0.25% with or without epinephrine (5 μg ml−1), measuring arterial concentrations over 90 min. Study 3 involved intravenous bupivacaine administration in 10 healthy volunteers. Pharmacokinetic analysis used NONMEM software, with significance set at P<0.05. Results: We analysed 258 ESP samples, 150 TAP samples, and 190 bupivacaine i.v. samples. A one-compartment model described the data, with a mean distribution volume of 41.9 L (coefficient of variation, 47%) and clearance rate of 0.288 L min−1 (coefficient of variation, 38%). Epinephrine reduced bioavailability (54.3% vs 32.8%) and prolonged absorption half-life (0.84 min vs 1.55 min; P<0.05). Simulated doses of 50 mg plus 300 mg per 24 h over 48 h remained below toxic thresholds. Conclusions: Similar dosing regimens for ESP and TAP blocks are supported by this pharmacokinetic analysis, with epinephrine effectively reducing systemic drug concentrations by prolonging absorption half-life and lowering bioavailability. The findings suggest that extended 300 mg per 24 h dosing for 48 h is likely to be safe. Further studies in broader patient populations are warranted to evaluate safety.
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    Simulated-based training for ultrasound-guided popliteal block: determining the learning curve and transference to real patient
    (2024) Miranda, Pablo; Araneda, Andrea; Molina, Natalia; Miranda, Felipe; Morrison Corrales, Christopher Joseph; Corvetto Aqueveque, Marcia Antonia; Altermatt Couratier, Fernando René
    Background and Aims: This study aimed to determine the learning curve for an ultrasound-guided popliteal block and the transference of this training to a real patient situation. Methods: After approval by the ethics committee, ten first-year anesthesia residents were recruited to participate in a simulated-based training program to perform a single shot in plane popliteal block. (NCT06081790) Training consisted of 10 individual sessions, with direct feedback from the instructor, with a specific Laerdal® sciatic popliteal block phantom, lasting one hour and distributed weekly. At the end of each session, the resident’s performance was assessed. Residents were videotaped while performing the block, which was to be evaluated using a validated global rating scale (GRS). Additionally, a tracking motion device (ICSAD) attached to the operator’s hands recorded the total distance traveled by both hands (Total Path Length=TPL) and total procedure time (TPT). One week later, the same assessment was done on a real patient. Results: Ten residents completed the training and the assessments. Median values of GRS scores significantly improved from 14 to 28 through the training (p=0.02) (figure 1). Regarding ICSAD scores, TPT improved from 126 to 59.5 seconds (p=0.004), and TPL improved from 11.06 to 9.3 meters (p=0.432). We found no significant differences between the last simulated session and the subsequent measurement in an actual patient.