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Impact of bispectral index monitoring on propofol administration in patients undergoing cardiopulmonary bypass

Chiu CL, Ong G, Majid AA

Anaesth Intensive Care, 2007 Jun;35(3):342-7.
PMID: 17591126

Propofol anaesthesia using target control infusion during cardiac surgery has become more popular recently. However, without depth of anaesthesia monitoring, the standard target concentration used may be higher than necessary to maintain adequate hypnosis during hypothermic cardiopulmonary bypass. The purpose of this study was to evaluate the effect of bispectral index monitoring on propofol administration during hypothermic cardiopulmonary bypass. After ethics committee approval and written informed consent, 20 New York Heart Association class I-III patients scheduled for elective cardiac surgery requiring hypothermic cardiopulmonary bypass were studied in this prospective randomised controlled trial. In group C, routine anaesthesia was practised, where patients received propofol at target concentration between 1.5 to 2.5 microg/ml during cardiopulmonary bypass. In group B, the target concentration was titrated to a bispectral index value of 40 to 50. Mean arterial pressure and bispectral index were recorded at various time intervals. The use of propofol, phenylephrine, sodium nitroprusside and adrenaline were recorded. The median propofol administration in group B was significantly less than that in group C (2.9 mg/kg/h compared to 6.0 mg/kg/h). The bispectral index value during bypass was significantly lower in group C than in group B, reflecting a deeper state of anaesthesia. There was no difference in the use of inotropes, vasoconstrictors or vasodilators. Bispectral index monitoring enables a 50% reduction in propofol administration at this standard dose during hypothermic cardiopulmonary bypass.

Matched MeSH terms: Anesthetics, Intravenous/administration & dosage*
Fulltext Anaesthesia for a patient with long QT syndrome undergoing renal transplantation

Lim KY, Lim TA, Wong WH

Med J Malaysia, 2005 Dec;60(5):647-9.
PMID: 16515119

Anaesthetizing patients with Long QT Syndrome is a major challenge, as the potential for sudden catastrophic cardiovascular collapse is well known. We present a 15-year-old boy with Long QT Syndrome who presented for an elective renal transplant. All electrolyte concentration abnormalities were corrected preoperative and adequate beta-blockade was maintained. The patient was given a target controlled infusion of propofol, together with opioids and atracurium. Anaesthesia was uneventful and the patient was extubated at the end of the surgical procedure.

Matched MeSH terms: Anesthetics, Intravenous/administration & dosage
Predicted effect compartment concentration of thiopental at loss of eyelash reflex

Lim TA, Inbasegaran K

Br J Anaesth, 2001 Mar;86(3):422-4.
PMID: 11573534

We derived the predicted effect compartment concentration of thiopental, at loss of the eyelash reflex, following three different injection regimens. Sixty patients were given thiopental for induction of anaesthesia. Twenty patients received multiple small boluses, 20 patients received a single bolus and 20 patients received an infusion. Computer simulation was then used to derive the effect compartment concentration. The median concentration was not significantly different between the three groups. EC50, derived after combining all three groups was 11.3 microg ml(-1). The EC05-EC95 range was 6.9-18.3 microg ml(-1), suggesting wide inter-individual variation.

Matched MeSH terms: Anesthetics, Intravenous/administration & dosage*
A novel method of deriving the effect compartment equilibrium rate constant for propofol

Lim TA

Br J Anaesth, 2003 Nov;91(5):730-2.
PMID: 14570797

BACKGROUND: Calculation of the effect compartment concentration (Ce) in non-steady-state conditions requires the equilibrium rate constant, keo. Most studies of propofol derive the keo using EEG measurements. This study investigated an alternative method. Starting from a predicted concentration-time profile, a keo value was included so that the predicted Ce at a specific pharmacodynamic end-point was the same when using three different methods of injection.
METHODS: Seventy-five patients were given propofol for induction of anaesthesia. Twenty-five patients received a single bolus, 25 patients received an infusion, and 25 patients received a bolus followed by an infusion. Computer simulation was used to derive the central compartment concentration. The keo that brought about the same value for Ce at loss of the eyelash reflex using the three methods of injection was derived.
RESULTS: Keo was found to be 0.80 min(-1). Mean (SD) Ce at loss of the eyelash reflex was 2.27 (0.69) microg ml(-1).
CONCLUSIONS: The effect compartment equilibrium rate constant and concentration at loss of the eyelash reflex can be derived without the use of electronic central nervous system monitors.

Matched MeSH terms: Anesthetics, Intravenous/administration & dosage
Assessment of tracheal intubating conditions in children using remifentanil and propofol without muscle relaxant

Batra YK, Al Qattan AR, Ali SS, Qureshi MI, Kuriakose D, Migahed A

Paediatr Anaesth, 2004 Jun;14(6):452-6.
PMID: 15153205

Tracheal intubation in children can be achieved by deep inhalational anaesthesia or an intravenous anaesthetic and a muscle relaxant, suxamethonium being widely used despite several side-effects. Studies have shown that oral intubation can be facilitated safely and effectively in children after induction of anaesthesia with propofol and alfentanil without a muscle relaxant. Remifentanil is a new, ultra-short acting, selective mu-receptor agonist that is 20-30 times more potent than alfentanil. This clinical study was designed to assess whether combination of propofol and remifentanil could be used without a muscle relaxant to facilitate tracheal intubation in children.

Matched MeSH terms: Anesthetics, Intravenous/administration & dosage*
Pharmacokinetics of propofol infusion in Asian patients undergoing coronary artery bypass grafting

Lee HS, Khoo YM, Chua BC, Ng AS, Tan SS, Chew SL

Ther Drug Monit, 1995 Aug;17(4):336-41.
PMID: 7482686

The pharmacokinetics of propofol was studied in 11 Asian patients with fentanyl-isoflurane anaesthesia during cardiopulmonary bypass (CPB) and undergoing elective coronary artery bypass grafting (CABG). Instead of the usual increments of morphine and a benzodiazepine, propofol (4 mg/kg/h) was initiated at the start of CPB and ceased at CPB separation. Whole blood propofol concentrations were determined during and postinfusion using high-performance liquid chromatography with fluorescence detection. Data from four patients seemed to fit a two-compartment model, whereas those from seven patients were significantly (F test, p < 0.05) better fitted to a three-compartment model. The pharmacokinetic parameters were as follows: The mean (SD) of the initial distribution phase t1/2 pi, intermediate distribution phase t1/2 alpha, and elimination phase t1/2 beta were 2.22 (1.04) min, 42.9 (16.4) min, and 370 (138) min, respectively. The mean clearance of 1.31 (0.50) L/min was lower than those reported from other studies, whereas the mean blood concentration of 2.2 (1.0) mg/L at the 1-h infusion period was higher. The mean calculated apparent Css was 3.9 (1.5) mg/L. The low clearance is likely to be due to hemodynamic changes during CPB and CABG, thereby affecting drug distribution and blood flow to the liver.

Matched MeSH terms: Anesthetics, Intravenous/administration & dosage
Fulltext Fentanyl pre-treatment alleviates pain during injection of propofol-lipuro premixed with lignocaine

Ahmad N, Zanariah Y, Balan S

Med J Malaysia, 2008 Dec;63(5):431-3.
PMID: 19803312

We studied the effect of fentanyl pretreatment on alleviating pain during the injection of Propofol-Lipuro. One hundred and seventy patients were randomly allocated to receive either 100 mcg of intravenous fentanyl or normal saline (placebo) followed by intravenous Propofol-Lipuro premixed with 20 mg lignocaine. The incidence of injection pain was 32% and 13% in the placebo and fentanyl groups, respectively. We found a statistically significant reduction in incidence of injection pain in the fentanyl group when compared with the placebo group (p<0.003). The number needed to treat was 6 (3.2< 95% CI <15.1). In conclusion, fentanyl pretreatment is effective in alleviating pain during injection of Propofol-Lipuro.

Matched MeSH terms: Anesthetics, Intravenous/administration & dosage*
Intubation without muscle relaxant: an alternative technique for rapid tracheal intubation

Wong AK, Teoh GS

Anaesth Intensive Care, 1996 Apr;24(2):224-30.
PMID: 9133197

The quality of laryngoscopy and tracheal intubation with propofol augmented by alfentanil was investigated as an alternative technique for rapid tracheal intubation. 119 patients aged between 18 and 60 years (ASA 1 and 2) undergoing elective surgery were prospectively studied in a randomized double-blind controlled fashion. Tracheal intubation facilitated by suxamethonium 1.0 mg/kg alfentanil 15 mu g/kg alfentanil 30 mu g/kg or saline control was compared after propofol induction. The quality of laryngoscopy and intubation were graded according to jaw relaxation, ease of insertion of the endotracheal tube and coughing on intubation. Failure to intubate occurred in 4% and 17% with alfentanil 15 mu g/kg and saline control respectively Tracheal intubation was successful in all patients with alfentanil 30 mu g/kg and suxamethonium 1.0 mg/kg. Alfentanil 15 mu g/kg was not statistically significantly different from saline (P = 0.112). Alfentanil 30 mu g/kg provided similar overall intubating conditions (P = 0.5) to suxamethonium 1.0 mg/kg. Alfentanil in both dosages effectively attenuated the haemodynamic responses to laryngoscopy and tracheal intubation.

Matched MeSH terms: Anesthetics, Intravenous/administration & dosage*
Preventing the withdrawal response associated with rocuronium injection: a comparison of fentanyl with lidocaine

Ahmad N, Choy CY, Aris EA, Balan S

Anesth Analg, 2005 Apr;100(4):987-990.
PMID: 15781511 DOI: 10.1213/01.ANE.0000147790.76114.3A

We compared the efficacy of IV fentanyl with IV lidocaine as pretreatment for the prevention of withdrawal response after rocuronium injection. For this prospective, randomized, placebo-controlled, double-blind study we recruited 90 patients aged between 18 and 65 yr, ASA physical status I or II, who had undergone elective surgery requiring general anesthesia and positive pressure ventilation. Patients were randomly allocated to 1 of 3 groups: group F received 2 mL IV fentanyl 50 microg/mL (100 microg), group L received 2 mL of preservative-free lidocaine 2% (40 mg), and group P (placebo) received 2 mL of normal saline. The incidence of withdrawal response after rocuronium was 57%, 30%, and 7% in the placebo, lidocaine, and fentanyl groups, respectively. We found a significant reduction in incidence of withdrawal response in both the fentanyl and lidocaine groups when compared with the placebo group (P < 0.05), with the fentanyl group being most effective (P < 0.05). In conclusion, both fentanyl and lidocaine are effective clinical treatments to alleviate the withdrawal response associated with rocuronium injection, with fentanyl being more effective.

Matched MeSH terms: Anesthetics, Intravenous/administration & dosage