Effect of Different Rates of Infusion of Propofol for Induction of Anaesthesia in Elderly Patients

Peacock, J. E.; Lewis, Roger; Reilly, C.S.; Nimmo, W.S.

doi:10.1097/00132586-199104000-00037

Cited by 41 publications

(52 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…In some elderly or critically ill patients, however, propofol may decrease cardiac output, and cause hypotension and bradycardia. 1 The mechanism responsible for the propofol-induced hypotension has not been well-defined. The following may contribute to these actions of propofoh direct peripheral vasodilatation, 2,3 decrease in sympathetic tone, 4,s resetting ofbaroreflex sensitivity, 4 and direct negative chronotropic and inotropic actions.…”

mentioning

confidence: 99%

Propofol inhibits medullary pressor mechanisms in cats

et al. 1997

View full text Add to dashboard Cite

Purpose: Propofol may cause hypotension and the mechanism is complex. The present study was designed to determine the direct actions of propofol in medulla of cats.Methods: Mean systemic arterial pressure (MSAP), heart rate (HR) and cardiac contractility (dp/dt) were compared before and after administration of propofol through the femoral vein (2, 3 or 4 mg.kg ~), vertebral artery (I mg.kg ') or the lateral cerebral ventricle (0.5 mg.kg ~) in eight anaesthetized cats. To study the direct effect of propofol in medulla, pressor areas of the dorsomedial medulla (DM) and rostral ventrolateral medulla (RVLM), or the depressor area of the caudal ventrolateral medulla (CVLM) were first identified with electrical stimuli and then confirmed by pressure microinjection of glutamate (Glu, 0.25M, 30 hi) via a multibarrel-micropipette in 28 cats. One hour later, propofol (0.001%, 50 hi) was microinjected at the same site. Electncal stimulation and Glu were applied again to compare changes of SAP, HR and dp/dt with that of the control.Results: Propofol dose-dependently decreased SAP, HR and cardiac contractility. The percent increase of MSAP induced by Glu were reduced by propofol in DN (59 +_ 3 % r 13 • 2 %, n = I I, P < 0.0 I) or in RVLM (56 _+ 4 % vs 18 • 2 %, n = 9, P < 0.01 ). In CVLN, propofol slightly but not significantly increased the depressor responses elicited by Glu (-27 • 2 % vs -33 _+ 3 %, n = 5, P > 0.05).Conclusion: Our results show that propofol principally inhibits the vasomotor mechanism in the dorsomedial and ventrolateral medulla to effect its hypotensive actions.Objectif : Le propofol produit de I'hypotension par un m&anisme complexe. Cette Etude avait pour object~f de delimiter sur le bulbe du chat I'activit6 directe du propofol.M&hodes : La pression artErielle systEmique moyenne (PASM), la frEquence cardiaque (FC) et la contractilitE cardiaque (dp/dt) ont ErE comparEes avant et apr& I'injection de propofol dans la veine fEmorale (2,3 et 4 mg.kg '), I'art&e vertEbrale (I mg-kg -~) et le ventricule cErEbral lateral (0,5 mg'kg -~ ) chez six chats anesthEsiEs. Pour &udier les effets bulbalres directs du propofol, les zones vasopressives dorsomEdiane (DM) et ventrolatErale rostrale (BVLR) bulbaires, ou la zone vasodEpressive ventrolatErale caudale (BVLC) bulbalre ont d'abord ErE identifiEes par stimulation Electrique et confirmEes par micro-injection sous pression de glutamate (Glu 0.25M, 30 ml) I'aide d'une micropipette ,~ plusieurs barillets chez 28 chats. Une heure plus tard, du propofol (0,001%, 50 hi) Etait injectE au m~me site. I'Electrostimulation et Glu Etaient appliques encore une lois pour comparer les changements de PAS, le FC et de dp/dt avec ceux du contrEle.REsultats : DEpendamment de la dose, le propofol diminue PAS, FC et alp~tit. En pourcentage, I'augmentation de PASM induite par Glu Etait rEduite par le propofol dans DM 159 • 3 % vs 13 • 2 %, n = I I, P < 0,01 ) ou dans BLVR (56 -+ 4 % vs 18 • 2%, n = 9, P < 0,01 ). Dans BLVM, le propofol a augmentE IEg&ement mais non significativement les...

show abstract

mentioning

confidence: 99%

Propofol inhibits medullary pressor mechanisms in cats

et al. 1997

View full text Add to dashboard Cite

show abstract

“…Although the original (smaller) study of Skues et al [2] suggested that this technique might be valuable, this has not been borne out by closer investigation and the only valid reason for anticholinergic pretreatment would now appear to be as prophylaxis against bradycardia in selected patients. Reducing the rate of administration of propofol during induction decreases the dose required and minimises the haemodynamic disturbance [4] without compromising the quality of induction. If the hypotensive effect of propofol is primarily due to increased venous capacitance IS], then other rational antihypotensive strategies might include fluid preloading o r the use of vasopressors.…”

Section: Discussionmentioning

confidence: 99%

The effect of pre‐induction glycopyrronium on the haemodynamic response of elderly patients to anaesthesia with propofol

Sneyd

Mayall

1992

Anaesthesia

View full text Add to dashboard Cite

SummaryThis study investigated whether pretreatment with glycopyrronium can attenuate the hypotension caused by anaesthesia of the elderly with propofol. Twenty elderly patients (77.1 k2.44 years, mean SEM) of ASA physical status 2 or 3 scheduled for elective urological procedures were given glycopyrronium 0 ( n = 10) or 5 pg.kg-' ( n = 10) in a randomised, double-blind manner, 5 rnin before induction of anaesthesia with propofol infused at 600 ml.h-' (average induction dose 1.7f0.06 mg.kg-', mean f SEM) followed by maintenance with a propofol infusion at 10 mg.kg-'.h-'. Although glycopyrronium significantly increased heart rate ( p < 0.01, A NO V A ) , the decrease in blood pressure 2 and 5 min after induction was similar in both groups.The study had a power of 80% to detect a 20 mmHg diference in systolic arterial pressure between treatment groups with p < 0.05. Key wordsAnaesthetics, intravenous; propofol. Parasympathetic nervous system, glycopyrronium. Complications; hypotension.Propofol anaesthesia often causes hypotension and this may be particularly severe in the elderly [I]. When glycopyrronium 5 pg.kg-l, atropine 10 pg.kg-' and placebo were compared as pretreatments given 5 min before total intravenous anaesthesia with propofol and alfentanil, the two anticholinergic agents caused equivalent increases in heart rate but those patients who received glycopyrronium suffered less hypotension than those receiving atropine or saline [2]. This apparent antihypotensive effect was attributed to differences in affinity of atropine and glycopyrronium for the MI and M, muscarinic receptor subtypes. Subsequently, a larger study compared placebo, 2.5, 5 and 7.5 pg.kg-l of glycopyrronium as pretreatments before anaesthesia with propofol and a small dose of fentanyl [3]. The average ages of the patients in these two studies were 42.5 years [2] and 39 years [3] respectively.We have compared the effects of glycopyrronium 5 pg.kg-' and placebo on the haemodynamic consequences of induction and early maintenance anaesthesia with propofol in elderly patients. MethodsThe study was approved by the South Manchester District Ethics Committee and all patients gave informed consent in writing. Twenty patients of ASA physical status 2-3 weighing 35-80 kg and aged 65-85 years who were scheduled for urological procedures (usually check cystoscopy) were recruited into the study. Day surgery patients received no premedication; patients expected to stay overnight received oral temazepam 10-20 mg 100 min pre-operatively .An anaesthetist who was not otherwise involved in the study mixed glycopyrronium injection and 0.9% saline solution to give a solution containing glycopyrronium 0 or 400pg in 8 ml, and 0.1 ml.kg-' of this solution was administered intravenously in a randomised, double-blind manner 5 min before the start of induction giving a glyco-

show abstract

“…There is justifiable concern that such hypotension may compromise myocardial perfusion in patients with heart disease. Stokes and Hutton [5] suggested that the hypotension is related to the rate of injection of propofol and this was confirmed by Peacock et al [6] in elderly patients. The majority of studies investigating infusions of propofol during cardiac surgery have been in patients with ischaemic heart disease and good left ventricular function .…”

mentioning

confidence: 88%