Abstract
Purpose
Propofol, by virtue of its favourable pharmacokinetic profile, is suitable for maintenance of anesthesia by continuous infusion during neurosurgical procedures in adults. It is gaining popularity for use in pediatric patients. To determine the effects of propofol on cerebral blood flow in children, middle cerebral artery blood flow velocity (Vmca) was measured at different levels of propofol administration by transcranial Doppler (TCD) sonography.
Methods
Twelve ASA I or II children, aged one to six years undergoing elective urological surgery were randomized to receive one of two propofol dosing regimens. Half of the patients received propofol in an escalating fashion, initially targeting an estimated steady-state serum concentration of 3 μg·mL−1 which was then doubled. The other half received propofol designed initially to target the high concentration followed by the lower one. In each child anesthesia was induced and maintained with propofol according to the protocol, rocuronium was given to facilitate tracheal intubation, and a caudal epidural block was performed. A TCD probe was placed appropriately to measure Vmca. Cerebral blood flow velocity (CBFV), mean arterial pressure (MAP) and heart rate (HR) were recorded simultaneously at both levels of propofol administration.
Results
Twelve patients were studied. At the higher estimated target serum propofol concentration there were significant decreases in Vmca (17%,P < 0.001), MAP (6%,P < 0.002) and HR(8%,P < 0.05) when compared to the lower targeted concentration.
Conclusion
This study shows that a higher rate of propofol infusion is associated with lower CBFV and MAP values in children. Propofol’s cerebral vasoconstrictive properties may be responsible for this finding.
Résumé
Objectif
En vertu de son profil pharmacocinétique favorable, le propofol convient bien au maintien de l’anesthésie administrée en perfusion continue pendant des interventions neurochirurgicales chez les adultes. On l’utilise également de plus en plus en pédiatrie. Dans le but de déterminer les effets du propofol sur la vitesse circulatoire cérébrale chez les enfants, nous avons mesuré par échographie Doppler transcrânienne (DTC) la vitesse circulatoire de l’artère cérébrale moyenne (Vacm) selon différents niveaux de propofol.
Méthode
Douze enfants, de un à six ans, d’état physique ASA I ou II devant subir une intervention urologique non urgente, ont été répartis au hasard et ont reçu l’un des deux schémas posologiques de propofol. La moitié des patients a reçu du propofol de manière croissante, en visant initialement une concentration sérique estimée, à l’état d’équilibre, à 3 μg·mL−1 et qui a été ensuite doublée. Les autres enfants ont reçu du propofol de manière à atteindre d’abord une forte concentration, suivie d’une plus faible. L’anesthésie a été induite et maintenue avec du propofol d’après le protocole et du rocuronium a été administré pour faciliter l’intubation endotrachéale. Enfin, on a procédé à une anesthésie caudale. Une sonde à DTC a été placée de manière à mesurer la Vacm. La vitesse circulatoire du sang cérébral (VCSC), la tension artérielle moyenne (TAM) et la fréquence cardiaque (FC) ont été enregistrées simultanément, pour les deux concentrations de propofol administrées.
Résultats
Des baisses significatives de Vacm (17%, P < 0,001), de TAM (6 %, P < 0,002) et de FC (8%, P < 0,05) ont été notées avec la plus forte concentration sérique de propofol visée, comparée à la plus faible.
Conclusion
L’étude montre qu’une perfusion de propofol à débit élevé est associée à des valeurs de VCSC et de TAM plus faibles chez les enfants. Les propriétés vasoconstrictrices cérébrales du propofol peuvent être responsables de ce résultat.
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References
Murat I, Billard V, Vernois J, et al. Pharmacokinetics of propofol after a single dose in children aged 1–3 years with minor burns. Comparison of three data analysis approaches. Anesthesiology 1996; 84: 526.
Weir PM, Munro HM, Reynolds PI, Lewis IH, Wilton NC. Propofol infusion and the incidence of emesis in pediatric outpatient strabismus surgery. Anesth Analg 1993; 76: 760–4.
Lim TA, Gin T, Tam YH, Aun CS, Short TG. Computer-controlled infusion of propofol for long neurosurgical procedures. J Neurosurg Anesthesiol 1997; 9: 242–9.
Doyle E, McFadzean W, Morton NS. I.V. anaesthesia with propofol using a target-controlled infusion system: comparison with inhalation anaesthesia for general surgical procedures in children. Br J Anaesth 1993; 70: 542–5.
Matta BF, Heath KJ, Tipping K, Summors AC. Direct cerebral vasodilatory effects of sevoflurane and isoflurane. Anesthesiology 1999; 91: 677–80.
Vandesteene A, Trempont V, Engelman E, et al. Effect of propofol on cerebral blood flow and metabolism in man. Anaesthesia 1988; 43(Suppl): 42–3.
Eng C, Lam AM, Mayberg TS, Lee C, Mathisen T. The influence of propofol with and without nitrous oxide on cerebral blood flow velocity and CO2 reactivity in humans. Anesthesiology 1992; 77: 872–9.
McFarlan CS, Anderson BJ, Short TG. The use of propofol infusions in paediatric anaesthesia: a practical guide. Paediatr Anaesth 1999; 9: 209–16.
Karsli C, Luginbuehl I, Farrar MW, Bissonnette B. Cerebrovascular carbon dioxide reactivity in children anaesthetised with propofol. Paediatr Anaesth 2002 (in press).
McAuliffe G, Bissonnette B, Cavalle-Garrido T, Boutin C. Heart rate and cardiac output after atropine in anaesthetised infants and children. Can J Anaesth 1997; 44: 154–9.
Strebel S, Kaufmann M, Guardiola PM, Schaefer HG. Cerebral vasomotor responsiveness to carbon dioxide is preserved during propofol and midazolam anesthesia in humans. Anesth Analg 1994; 78: 884–8.
Marsh B, White M, Morton N, Kenny GN. Pharmacokinetic model driven infusion of propofol in children. Br J Anaesth 1991; 67: 41–8.
Jones RD, Chan K, Andrew LJ. Pharmacokinetics of propofol in children. Br J Anaesth 1990; 65: 661–7.
Short TG, Aun CS, Tan P, Wong J, Tam YH, Oh TE. A prospective evaluation of pharmacokinetic model controlled infusion of propofol in paediatric patients. Br J Anaesth 1994; 72: 302–6.
Kataria BK, Ved SA, Nicodemus HF, et al. The pharmacokinetics of propofol in children using three different data analysis approaches. Anesthesiology 1994; 80: 104–22.
Roberts FL, Dixon J, Lewis GT, Tackley RM, Prys-Roberts C. Induction and maintenance of propofol anaesthesia. A manual infusion scheme. Anaesthesia 1988; 43: 14–7.
Spelina KR, Coates DP, Monk CR, Prys-Roberts C, Norley I, Turtle MJ. Dose requirements of propofol by infusion during nitrous oxide anaesthesia in man. I: patients premedicated with morphine sulphate. Br J Anaesth 1986; 58: 1080–4.
Turtle MJ, Cullen P, Prys-Roberts C, Coates D, Monk CR, Faroqui MH. Dose requirements of propofol by infusion during nitrous oxide anaesthesia in man. II: patients premedicated with lorazepam. Br J Anaesth 1987; 59: 283–7.
Reed MD, Yamashita TS, Marx CM, Myers CM, Blumer JL. A pharmacokinetically based propofol dosing strategy for sedation of the critically ill, mechanically ventilated pediatric patient. Crit Care Med 1996; 24: 1473–81.
Leon JE, Bissonnette B. Cerebrovascular responses to carbon dioxide in children anaesthetized with halothane and isoflurane. Can J Anaesth 1991; 38: 817–25.
Bishop CC, Powell S, Rutt D, Browse NL. Transcranial Doppler measurement of middle cerebral artery blood flow velocity: a validation study. Stroke 1986; 17: 913–5.
Kochs E, Hoffman WE, Werner C, Albrecht RF, Schulte am Esch J. Cerebral blood flow velocity in relation to cerebral blood flow, cerebral metabolic rate for oxygen, and electroencephalogram analysis during isoflurane anesthesia in dogs. Anesth Analg 1993; 76: 1222–6.
Sudikoff S, Banasiak K. Techniques for measuring cerebral blood flow in children. Curr Opin Pediatr 1998; 10: 291–8.
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Karsli, C., Luginbuehl, I., Farrar, M. et al. Propofol decreases cerebral blood flow velocity in anesthetized children. Can J Anesth 49, 830–834 (2002). https://doi.org/10.1007/BF03017417
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DOI: https://doi.org/10.1007/BF03017417