Propofol Infusion (propofol + infusion)

Distribution by Scientific Domains

Selected Abstracts

Propofol infusion in children: when does an anesthetic tool become an intensive care liability?

Andrew R. Wolf MD FRCA
First page of article [source]

Time course of rocuronium-induced neuromuscular block after pre-treatment with magnesium sulphate: a randomised study

Background: A previously published study suggested that pre-treatment with magnesium sulphate (MgSO4) had no impact on the speed of onset of rocuronium-induced neuromuscular block. We set out to verify this assumption. Methods: Eighty patients (18,60 years) were randomly allocated to MgSO4 60 mg/kg or placebo (saline). Study drugs were given intravenously for 15 min before induction of anaesthesia with propofol, sufentanil and rocuronium 0.6 mg/kg. Anaesthesia was maintained with a target-controlled propofol infusion. Neuromuscular transmission was measured using train-of-four (TOF)-Watch SX acceleromyography. Results: Onset was analysed in 37 MgSO4 and 38 saline patients, and recovery in 35 MgSO4 and 37 saline patients. Onset time (to 95% depression of T1) was on average 77 [SD=18] s with MgSO4 and 120 [48] s with saline (P<0.001). The total recovery time (DurTOF0.9) was on average 73.2 [22] min with MgSO4 and 57.8 [14.2] min with saline (P<0.003). The clinical duration (Dur25%) was on average 44.7 [14] min with MgSO4 and 33.2 [8.1] min with saline (P<0.0002). The recovery index (Dur25,75%) was on average 14.0 [6] min with MgSO4 and 11.2 [5.2] min with saline (P<0.02). The recovery time (Dur25%TOF0.9) was on average 28.5 [11.7] min with MgSO4 and 24.7 [8.4] min with saline (P=0.28). Conclusion: Magnesium sulphate given 15 min before propofol anaesthesia reduces the onset time of rocuronium by about 35% and prolongs the total recovery time by about 25%. Trial Registration: identifier: NCT00405977. [source]

The effects of obstructive jaundice on the pharmacodynamics of propofol: does the sensitivity of intravenous anesthetics change among icteric patients?

Background Some studies suggest that certain clinical symptoms of cholestasis, such as fatigue and pruritus, result from altered neurotransmission. Patients with obstructive jaundice also have labile blood pressure and heart rate. In the present study, the authors investigated whether obstructive jaundice affects a patient's sensitivity to hypnotics and the haemodynamic profile of propofol. Methods Thirty-six ASA physical status I/II/III patients with serum total bilirubin (TBL) from 7.8 to 362.7 ,mol/l scheduled for bile duct surgery were recruited. A computer-controlled propofol infusion programmed for effect site target was used to rapidly attain and maintain sequential increase of the compartment concentration (from 1 to 3 ,g/ml). Each target-controlled concentration was maintained for about 12 min, and arterial blood samples were drawn for propofol concentration determination. The bispectral index (BIS) and mean arterial pressures (MAP) were used as indices of the propofol effect. The relation between the concentration and the effects was described by the Hill equation. The pharmacodynamic parameters were optimized using a nonlinear mixed-effect model. Results TBL was not a significant covariate of EC50 for the pharmacodynamic model. For BIS and MAP, the parameters of the pharmacodynamic model were Emax=75.77%, EC50=2.34 ,g/ml, and ,=1.82, and Emax=47.83%, EC50=1.49 ,g/ml, and ,=1.88, respectively. Conclusions We demonstrated that obstructive jaundice with serum TBL from 7.8 to 362.7 ,mol/l had no effect on propofol pharmacodynamics observed by BIS and MAP. [source]

Comparison of closed loop vs. manual administration of propofol using the Bispectral index in cardiac surgery

Background: In recent years, electroencephalographic indices of anaesthetic depth have facilitated automated anaesthesia delivery systems. Such closed-loop control of anaesthesia has been described in various surgical settings in ASA I,II patients (1,4), but not in open heart surgery characterized by haemodynamic instability and higher risk of intra-operative awareness. Therefore, a newly developed closed-loop anaesthesia delivery system (CLADS) to regulate propofol infusion by the Bispectral index (BIS) was compared with manual control during open heart surgery. Methods: Forty-four adult ASA II,III patients undergoing elective cardiac surgery under cardiopulmonary bypass were enrolled. The study participants were randomized to two groups: the CLADS group received propofol delivered by the CLADS, while in the manual group, propofol delivery was adjusted manually. The depth of anaesthesia was titrated to a target BIS of 50 in both the groups. Results: During induction, the CLADS group required lower doses of propofol (P<0.001), resulting in lesser overshoots of BIS (P<0.001) and mean arterial blood pressure (P=0.004). Subsequently, BIS was maintained within 10 of the target for a significantly longer time in the CLADS group (P=0.01). The parameters of performance assessment, median absolute performance error (P=0.01), wobble (P=0.04) and divergence (P<0.001), were all significantly better in the CLADS group. Haemodynamic stability was better in the CLADS group and the requirement of phenylephrine in the pre-cardiopulmonary bypass period as well as the cumulative dose of phenylephrine used were significantly higher in the manual group. Conclusion: The automated delivery of propofol using CLADS was safe, efficient and performed better than manual administration in open heart surgery. [source]

Reversal of rocuronium with edrophonium during propofol versus sevoflurane anesthesia

T. J. Zhou
Background: The use of volatile anesthetics for maintenance of anesthesia can enhance the action of non-depolarizing muscle relaxants and interfere with the reversal of neuromuscular blockade. In this study, we studied the antagonism of rocuronium with edrophonium-atropine during propofol- versus sevoflurane-based anesthesia. Methods: Following induction of anesthesia with propofol (2,2.5 mg kg,1, iv) and fentanyl (1,2 ,g kg,1 iv), rocuronium 0.6 mg kg,1 iv was administered to facilitate tracheal intubation. Patients were then randomized to receive either a propofol infusion (100 ,g kg,1 min,1) or sevoflurane (1.0%, end-tidal) in combination with nitrous oxide 66% for maintenance of anesthesia. Neuromuscular blockade was monitored using electromyography at the wrist, and reversed with edrophonium 1.0 mg kg,1 and atropine 0.015 mg kg,1 when the first twitch hight (T1) of the train-of-four (TOF) stimulation recovered to 25% of the baseline value. Anesthetic maintenance with propofol or sevoflurane was continued following reversal until a TOF ratio of 0.7 was attained. Results: The clinical duration of action (i.e., time to 25% T1 recovery) was similar during both propofol- (39.314.6 min) and sevoflurane-based (48.119.7 min) anesthesia. However, the reversal time from 25% T1 to TOF ratio of 0.7 was significantly longer with sevoflurane [Median 2.8 (range 0.5,18.8) min] compared with propofol [1.5 (0.75,3) min] (P<0.05). Conclusions: We conclude that the clinical duration of action after a single dose of rocuronium, 0.6 mg kg,1 iv, was similar during both propofol- and sevoflurane-based anesthesia. However, the reversal of rocuronium-induced residual blockade was slower and more variable in the presence of sevoflurane. [source]

Safety, efficacy, and long-term results of a modified version of rapid opiate detoxification under general anaesthesia: A prospective study in methadone, heroin, codeine and morphine addicts

M. Hensel
Background: In the present study a method of rapid opiate detoxification under general anaesthesia has been evaluated regarding the safety, the efficacy in preventing withdrawal symptoms, and the long-term results. In addition, it was investigated whether the profile and severity of withdrawal symptoms depend on the type of opiate abused (methadone, heroin, codeine, morphine). Methods: Seventy-two opiate addicts were detoxified in an intensive care unit (ICU). Anaesthesia was induced and maintained using propofol infusion. Patients were endotracheally intubated. The opiate receptor antagonist naltrexon was administered into the stomach via a nasogastric tube. Withdrawal symptoms before and after the detoxification treatment were assessed using an objective and a subjective opiate withdrawal scale (OOWS, SOWS). After detoxification patients entered a long-term naltrexone maintenance programme as well as a supportive psychotherapy programme. Vital organ function was monitored using haemodynamic and respiratory parameters as well as body temperature. Results: Organ function parameters were stable during the whole treatment in all patients and no anaesthetic complications were registered. Minor side effects such as bradycardia or hypotension were observed in 20 patients. Compared to patients with pre-existing heroin, codeine, or morphine abuse respectively, patients from the methadone maintenance programme had significantly higher (P<0.01) OOWS as well as SOWS values after the treatment. Twelve months after the detoxification 49 patients (68%) were abstinent from opiates whereas 17 patients had relapsed during the period of follow-up. Six patients were lost during follow-up. Conclusions: Rapid opiate detoxification under general anaesthesia is a safe and efficient method to suppress withdrawal symptoms. This treatment may be of benefit in patients who particularly suffer from severe withdrawal symptoms during detoxification and who have failed repeatedly to complete conventional withdrawal. Methadone patients have more withdrawal symptoms than other opiate addicts. [source]

Effects of dexmedetomidine on intraoperative motor and somatosensory evoked potential monitoring during spinal surgery in adolescents

Summary Background:, Dexmedetomidine may be a useful agent as an adjunct to an opioid,propofol total intravenous anesthesia (TIVA) technique during posterior spinal fusion (PSF) surgery. There are limited data regarding its effects on somatosensory (SSEPs) and motor evoked potentials (MEPs). Methods:, The data presented represent a retrospective review of prospectively collected quality assurance data. When the decision was made to incorporate dexmedetomidine into the anesthetic regimen for intraoperative care of patients undergoing PSF, a prospective evaluation of its effects on SSEPs and MEPs was undertaken. SSEPs and MEPs were measured before and after the administration of dexmedetomidine in a cohort of pediatric patients undergoing PSF. Dexmedetomidine (1 ,gkg,1 over 20 min followed by an infusion of 0.5 ,gkg,1h,1) was administered at the completion of the surgical procedure, but prior to wound closure as an adjunct to TIVA which included propofol and remifentanil, adjusted to maintain a constant depth of anesthesia as measured by a BIS of 45,60. Results:, The cohort for the study included nine patients, ranging in age from 12 to 17 years, anesthetized with remifentanil and propofol. In the first patient, dexmedetomidine was administered in conjunction with propofol at 110 ,gkg,1min,1 which resulted in a decrease in the bispectral index from 58 to 31. Although no significant effect was noted on the SSEPs (amplitude or latency) or the MEP duration, there was a decrease in the MEP amplitude. The protocol was modified so that the propofol infusion was incrementally decreased during the dexmedetomidine infusion to achieve the same depth of anesthesia. In the remaining eight patients, the bispectral index was 52 6 at the start of the dexmedetomidine loading dose and 49 4 at its completion (P = NS). There was no statistically significant difference in the MEPs and SSEPs obtained before and at completion of the dexmedetomidine loading dose. Conclusion:, Using the above-mentioned protocol, dexmedetomidine can be used as a component of TIVA during PSF without affecting neurophysiological monitoring. [source]

Subhypnotic propofol infusion plus dexamethasone is more effective than dexamethasone alone for the prevention of vomiting in children after tonsillectomy

Summary Background:, Postoperative vomiting (POV) is a common complication after tonsillectomy. Dexamethasone is known to decrease postsurgical vomiting. In this study, we compared the effects of dexamethasone alone to dexamethasone plus propofol on postoperative vomiting in children undergoing tonsillectomy. Methods:, In a randomized double-blinded study, we evaluated 80 healthy children, aged 4,12 years, who underwent tonsillectomy with or without adenoidectomy. After anesthesia was induced by inhalation of sevoflurane, 0.15 mgkg,1 dexamethasone and 2 ,gkg,1 fentanyl was administered i.v. to all patients. The patients in the dexamethasone plus propofol group received 1 mgkg,1 propofol before intubation and continuously after intubation at a rate of 20 ,gkg,1min,1 until the surgery was completed. Data for postoperative vomiting were grouped into the following time periods: 0,4 and 4,24 h. Data were analyzed using a Student's t -test and chi-squared analysis. Results:, The percentage of patients exhibiting a complete response (defined as no retching or vomiting for 24 h) increased from 37.5% in the dexamethasone-alone group to 75% in the dexamethasone plus propofol group (P = 0.001). Twenty-two patients (55%) in the dexamethasone-alone and nine patients (22.5%) in the dexamethasone plus propofol groups experienced vomited during 0,4 h (P = 0.003). Eight patients in the dexamethasone-alone group and three patients in the dexamethasone plus propofol group received ondansetron as a rescue antiemetic during the postoperative period. Conclusion:, For children undergoing tonsillectomy, intraoperative subhypnotic propofol infusion combined with dexamethasone treatment provides a better prophylaxis against postoperative vomiting than does dexamethasone alone. [source]

Use of the Bispectral Index monitor to aid titration of propofol during a drug-assisted interview

Greta M. Palmer MB
We report two drug-assisted interviews with propofol in an 18-year-old with the diagnosis of Complex Regional Pain Syndrome type 1. We describe difficulty in titration of propofol in the first interview. Consequently, in the second interview, the Bispectral Index (BIS) monitor was applied to assist adjustment of the propofol infusion. This facilitated the achievement of a prolonged sedative-hypnotic state for a successful neuropsychological evaluation. Pertinent information was obtained from this patient. However, the role of drug-assisted interviews as a technique needs to be further elucidated. [source]

A comparison of the effectiveness of dexmedetomidine versus propofol target-controlled infusion for sedation during fibreoptic nasotracheal intubation

ANAESTHESIA, Issue 3 2010
C.-J. Tsai
Summary Fibreoptic intubation is a valuable modality for airway management. This study aimed to compare the effectiveness of dexmedetomidine vs target controlled propofol infusion in providing sedation during fibreoptic intubation. Forty patients with anticipated difficult airways and due to undergo tracheal intubation for elective surgery were enrolled and randomly allocated into the dexmedetomidine group (1.0 ,,1 over 10 min) (n = 20) or the propofol target controlled infusion group (n = 20). Intubating conditions and patient tolerance as graded by a scoring system were evaluated as primary outcomes. Intubation was successful in all patients. Satisfactory intubating conditions were found in both groups (19/20 in each group). The median (IOR [range]) comfort score was 2 (1,2 [1,4]) in the dexmedetomidine group and 3 (2,4 [2,5]) in the propofol group (p = 0.027), favouring the former. The dexmedetomidine group experienced fewer airway events and less heart rate response to intubation than the propofol group (p < 0.003 and p = 0.007, respectively). Both dexmedetomidine and propofol target-controlled infusion are effective for fibreoptic intubation. Dexmedetomidine allows better tolerance, more stable haemodynamic status and preserves a patent airway. [source]

Myoclonus after cardiac arrest: pitfalls in diagnosis and prognosis,

ANAESTHESIA, Issue 8 2009
W. A. English
Summary Accurate prediction of neurological outcome in survivors of cardiac arrest may be difficult. We report the case of a 44-year-old survivor of a hypoxic cardiac arrest who repeatedly developed relentless myoclonic jerks on attempted discontinuation of his propofol infusion. These were initially thought to represent myoclonic status epilepticus before the correct diagnosis of Lance,Adams syndrome was made. Lance,Adams syndrome is a rare disorder seen in survivors of profound hypoxic episodes. It is characterised by intention myoclonus but preserved intellect. Accurate distinction between myoclonic status epilepticus and Lance,Adams syndrome is vital as they have very different prognoses. The different pathophysiology and distinguishing clinical features of these two conditions are highlighted. [source]

Effect-site concentration of remifentanil for laryngeal mask airway insertion during target-controlled infusion of propofol

ANAESTHESIA, Issue 2 2009
M. K. Kim
Summary The purpose of this study was to determine the effect-site concentration of remifentanil that would provide optimal conditions for successful laryngeal mask airway insertion during a target-controlled infusion (TCI) of propofol at 3.5 ,,1 without the use of neuromuscular blockade. Five minutes after propofol infusion, remifentanil was infused at a dose determined by a modified Dixon's up-and-down method. Five minutes after remifentanil infusion, the laryngeal mask was inserted. The effect-site concentration of remifentanil for successful laryngeal mask insertion in 50% of adults (EC50) was 3.04 (SD 0.49),1 during a TCI of 3.5 ,,1 propofol without neuromuscular blockade. From the probit analysis, the EC50 and EC95 of remifentanil were 2.84,1 (95% CI 2.09,3.57,1) and 3.79,1 (95% CI 3.26,9.25,1), respectively. [source]

Facilitation of laryngeal mask airway insertion,Effects of remifentanil administered before induction with target-controlled propofol infusion

ANAESTHESIA, Issue 9 2001
K. Grewal
Eighty-six adult day-case patients were recruited into a prospective, randomised study and allocated to one of two groups. Patients received either intravenous remifentanil 0.3,1 or an equivalent volume of sodium chloride 0.9% followed by induction of anaesthesia with propofol target-controlled infusion until the effect (brain) site calculated concentration was 2,1. Jaw opening and ease of laryngeal mask insertion were assessed immediately after mask insertion. A higher incidence of failure of induction of anaesthesia was observed in the control group compared with the remifentanil group [15 (35%) vs. 3 (7%); p < 0.01] and addition of remifentanil significantly increased the ease and success of laryngeal mask insertion, with grade 1 (no coughing/gagging) conditions observed in 29 (68%) of the remifentanil group and 21 (49%) of the control group (p < 0.01). The doses of remifentanil and propofol used were not associated with any significant cardiorespiratory instability. In conclusion, when combined with propofol target-controlled infusion, remifentanil 0.3,1 facilitates laryngeal mask insertion with minimal adverse haemodynamic changes. [source]

Regional anaesthesia and propofol sedation for carotid endarterectomy

Christopher Barringer
Background: Many surgeons now perform carotid endarterectomy under regional anaesthesia. The aim of the present study was to review a sedation technique using a computer-controlled infusion of propofol. Methods: A consecutive series of 84 carotid endarterectomies done by a single surgeon and commenced under regional anaesthesia with sedation was studied. There were 54 men and 27 women (three bilateral procedures), with a median age of 71 years (range 48,87 years). All patients had carotid stenosis >70% 80 procedures were done for symptomatic disease and three asymptomatic patients were treated before cardiac surgery (one bilateral). Results: Seventy-seven procedures were completed under regional anaesthesia and sedation alone; seven required conversion to general anaesthetic, usually for intolerance of the operation. An intraoperative shunt was required on only four occasions (5%). Postoperatively eight patients required critical care monitoring, usually for blood pressure control. The remainder were nursed on the vascular ward, and 68% were discharged home on the day after surgery. No patient died, but there were two neurological complications. One patient had a cerebellar stroke 10 days after surgery, but recovered fully after 4 months. A second developed cerebral oedema due to severe intraoperative hypertension and required intensive care for 15 days. He too recovered fully. Five patients had a further episode of transient cerebral ischaemia within 1 month of operation, but in all cases duplex imaging showed a widely patent carotid and there were no sequelae. Conclusion: Target controlled propofol infusion is an effective method of sedation in patients undergoing carotid endarterectomy. [source]