Assessing Propofol Induction of Anesthesia Dose Using Bispectral Index Analysis

Gürses, Ercan; Sungurtekin, Hülya; Tomatir, Erkan; Doğan, Hakan

doi:10.1213/01.ane.0000090314.43496.1d

Cited by 43 publications

(39 citation statements)

References 19 publications

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“…These values were close to those reported in previous clinical studies [21][22][23][24]. As the patients' characteristics and doses of opioids and muscle relaxants were comparable between the two groups, the lower anaesthetic requirements in patients scheduled for parathyroidectomy were most likely to be due to MB pretreatment.…”

Section: Discussionsupporting

confidence: 87%

Effects of methylene blue on propofol requirement during anaesthesia induction and surgery

Licker

Diaper²,

Robert

et al. 2008

Anaesthesia

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SummaryDelayed emergence from anaesthesia and neurological disturbances have been reported in patients undergoing parathyroidectomy who received methylene blue (MB) pre-operatively. We hypothesised that MB would decrease propofol requirements. The Bispectral index (BIS) and a target-controlled infusion of propofol were used in two groups of 11 matched patients. Patients in one group were pretreated with MB. During induction, clinical sedation scores and BIS values were significantly lower at the predicted effect-site propofol concentration of 2 lg.ml )1 in the MB compared with the control group. Intra-operatively, although similar BIS values were achieved in the two groups, patients pretreated with MB required a mean 50% lower dose of propofol compared with controls. In view of these findings, care should be taken to ensure an adequate depth of anaesthesia by titrating the administration of anaesthetic agents whenever MB is infused peri-operatively. In addition to its use as an antidote for methaemoglobinaemia, the properties of methylthioninium chloride (methylene blue, MB) as a dye, antiseptic, vasopressor and psychotropic have extended its use for many medical applications [1,2]. In surgical practice, MB is often used for localisation of parathyroid adenoma, potentially preventing surgical nerve damage and reducing the operative time [3][4][5]. Moreover, by inhibiting the nitric oxide-cyclic guanylyl monophosphate (NO-cGMP) pathway, MB has also been advocated as a second line treatment for vasodilatory hypotension associated with cardiopulmonary bypass, liver transplantation, sepsis or the hepatopulmonary syndrome [6][7][8][9]. Although considered to be safe, numerous adverse effects including nausea and vomiting, chest pain, hypertension or hypotension, dyspnoea, haemolysis and neuropsychological disturbances have been described after intravenous administration of MB in the dose range of 1-10 mg.kg )1 [1,7]. Following parathyroidectomy, 22cases of transient neurological complications in relation to MB infusion have recently been reported in the medical literature [10][11][12][13][14][15][16][17][18]. Of note, no sensorimotor deficits have been reported and brain computed tomography (CT) scans were all unremarkable. The term 'MB-associated encephalopathy' has been coined to cover clinical manifestations, lasting from a few hours up to five days and ranging from disorientation to profound lethargy and coma with cardiorespiratory depression requiring tracheal re-intubation and resuscitation.In our clinical practice, we have witnessed several cases of delayed emergence from anaesthesia and prolonged confusional state after parathyroidectomy. We hypothesised that MB could potentiate the effects of general anaesthetic agents. Therefore, we compared propofol requirements during phases of anaesthesia induction and maintenance in two groups of patients, one of which received pretreatment with MB before undergoing parathyroid or thyroid surgery. In this case-controlled study general anaesthesia was conducted with a ta...

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Section: Discussionsupporting

confidence: 87%

Effects of methylene blue on propofol requirement during anaesthesia induction and surgery

Licker

Diaper²,

Robert

et al. 2008

Anaesthesia

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“…Depth of anesthesia was evaluated with a bispectral index (BIS) monitor (model A-2000, Aspect Medical System, Natick, MA, USA) and was controlled such that BIS values were maintained in a range from 40 to 60. 24,25 Respiration rate and ventilation volume were controlled at 12-14 breaths per min and 8-10 ml kg À1 , respectively, such that the partial pressure of end-expiratory carbon dioxide was in the range of 30-35 mm Hg. Left brachial BP, heart rate (HR), arterial oxygen saturation and end-tidal CO 2 concentration as an anesthetic monitor were measured using a monitoring system (model BP608, Nippon Colin, Tokyo, Japan).…”

Section: General Anesthesiamentioning

confidence: 99%

Influence of blood pressure on cardio-ankle vascular index (CAVI) examined based on percentage change during general anesthesia

et al. 2011

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Cardio-ankle vascular index (CAVI) and brachial-ankle pulse wave velocity (baPWV) are non-invasive methods for estimating arterial distensibility. The purpose of this study is to evaluate whether CAVI as an index of true arterial stiffness is superior to baPWV based on the percentage change in hemodynamics under general anesthesia. CAVI (segment from heart to ankle), k-CAVI (heart to knee) and baPWV (brachial to ankle) in 30 oral surgery patients were measured to compare the decreased blood pressure (BP) after 10 min of tracheal intubation during general anesthesia with the control BP (after 5 min of rest). General anesthesia was performed under endotracheal intubation through intravenous injection of propofol, fentanyl and vecuronium or rocuronium. In both the elderly (X65 years) and middle-aged (o65 years) groups, CAVI and k-CAVI did not change during general anesthesia, whereas baPWV and systolic BP (SBP) showed a statistically significant decrease. Thus, the changes in CAVI (DCAVI) and k-CAVI (Dk-CAVI) showed no significant correlations with those of SBP (DSBP), whereas the changes in baPWV (DbaPWV) were significantly correlated with DSBP. DCAVI and Dk-CAVI showed no significant differences between the two groups, whereas DbaPWV and DSBP in the elderly group was much higher than that in the middle-aged group. Measurement of CAVI was not affected by the decrease in BP during general anesthesia. In contrast, baPWV was significantly influenced by changes in BP. These findings suggest that CAVI is a useful index of true arterial stiffness and is superior to baPWV.

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“…Published literature also confirms that a sample size of 20 subjects is sufficient to obtain a valid estimate of an ED 50 in most clinical scenarios. 12 16,17 A smaller reduction in propofol ED 50 (\ 25%) by pregabalin premedication could exist and be missed by our study design, although we presume that it would not be clinically significant.…”

Section: Discussionmentioning

confidence: 80%

“…We chose this starting dose based on previous estimates of the propofol induction dose. 16,17 The next patient's dose was adjusted by a fixed value (step value) depending on the preceding patient's response. A positive response (the target anesthetic depth was reached) implied a decreased dose, and a negative response implied an increased dose for the next patient.…”

Section: Conduct Of Studymentioning

confidence: 99%

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Preoperative pregabalin does not reduce propofol ED50: a randomized controlled trial

Moreau-Bussière

Gaulin

Gagnon

et al. 2013

Can J Anesth/J Can Anesth

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Background In many studies, gabapentinoids, such as pregabalin, have been shown to reduce preoperative anxiety. This anxiolysis is often accompanied by sedation, one of the most frequent side effects of pregabalin. We hypothesized that pregabalin taken preoperatively could reduce propofol requirements for induction of general anesthesia. Methods A randomized double-blind placebo-controlled trial was conducted after approval by the local ethics committee. Fifty women aged 18-40 yr, American Anesthesiologists Society physical status I and II, and scheduled to undergo elective laparoscopic gynecologic procedures were enrolled after written consent. Treatment group patients were given pregabalin 150 mg po one hour before surgery while patients in the control group received a placebo. The primary outcome was the propofol dose required to achieve a targeted anesthetic depth in 50% of the population, i.e., effective dose (ED) 50 Conclusions Preoperative pregabalin does not reduce propofol requirements in a population of healthy young women undergoing laparoscopic gynecologic procedures. This study failed to show a pre-induction anxiolytic effect of pregabalin in such a population.

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Assessing Propofol Induction of Anesthesia Dose Using Bispectral Index Analysis

Abstract: Hypotension during induction of anesthesia with propofol is common. This study has shown that propofol requirement assessed by bispectral index analysis during anesthesia induction may decrease the dose and side effects and provide for satisfactory depth of anesthesia.

Cited by 43 publications

References 19 publications

Effects of methylene blue on propofol requirement during anaesthesia induction and surgery

Effects of methylene blue on propofol requirement during anaesthesia induction and surgery

Influence of blood pressure on cardio-ankle vascular index (CAVI) examined based on percentage change during general anesthesia

Preoperative pregabalin does not reduce propofol ED50: a randomized controlled trial

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