Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Propofol”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 487 records · Page 27Linked to original sources
PubMed2002

Comparison of sevoflurane-nitrous oxide and target-controlled propofol with fentanyl anesthesia for hysteroscopy.

A randomized prospective study was performed on the anesthetic induction, maintenance, and recovery characteristics of sevoflurane-nitrous oxide, compared to that of target- controlled propofol and fentanyl anesthesia, for forty day-case hysteroscopic surgery. The patients in the sevoflurane group (n = 20) received sevoflurane-nitrous oxide for both induction (8%) and maintenance (1 - 2%) of anesthesia, while the patients in the propofol group (n = 20) received target-controlled propofol (4 micro g/ml, 3-6 micro g/ml as occasion demanded) with fentanyl (1 micro g/kg). In both groups, the airway was maintained by a facemask with the patient breathing spontaneously during the surgery. The mean times to unconsciousness and readiness for surgery were similar in both groups, with those for the sevoflurane group, compared to the propofol group being 80.4 +/- 18.9 vs. 83.6 +/- 38.8 sec, and 220.1 +/- 76.9 vs. 231.0 +/- 95.4 sec, respectively. Propofol was associated with significantly higher incidences of involuntary movement (30% vs. 5%) and apnea (35% vs. 0%) during the induction period than with sevoflurane. Hemodynamic variables were similar with the exception of significantly lower blood pressures during the first 5 minutes of induction with propofol. Emergence times to eye opening, hand squeezing and orientation for sevoflurane compared to propofol were: 316.6 +/- 79.3 vs. 507.4 +/- 218.8 sec, 390.0 +/- 69.3 vs. 653.1 +/- 201.6 sec and 380.6 +/- 80.8 vs. 666.3 +/- 208.7 sec, respectively, all of these being significantly faster for sevoflurane than propofol. The postanesthetic Aldrete's recovery scores of the patients immediately after surgery were higher in the sevoflurane group. Propofol was associated with more drowsiness, with sevoflurane being associated with more nausea, in the recovery period; however, neither delayed the time to discharge (103.7 +/- 28.1 vs. 99.0 +/- 36.2 min). In conclusion, sevoflurane-nitrous oxide appears to be superior for day-case hysteroscopic surgery, than target-controlled propofol with fentanyl, with regards to the speed of recovery from anesthesia and the return to hemodynamic stability.

Adult↗
PubMed2006

Endoscopist controlled administration of propofol: an effective and safe method of sedation in endoscopic procedures.

OBJECTIVES: Propofol is a short-acting, hypnotic agent that is increasingly being used for gastrointestinal endoscopic sedation. There are concerns about the use of propofol by non anesthesiologists due to its potential for respiratory and cardiovascular depression. This report describes our experience concerning effectiveness and safety of propofol administered in endoscopic procedures by the endoscopist and the assistant nurse. METHODS: In this prospective study, a total of 102 consecutive endoscopies (60 colonoscopies and 42 upper endoscopies) performed under sedation with propofol were included. In 27 (26.47%) endoscopies propofol was administered alone and in 75 endoscopies (73.53%) it was combined with benzodiazepines and/or opioids. Seventy-six (74.51%) endoscopies were performed in patients under 65 years of age and 26 (25.49%) in patients over 65 years of age. Ninety-one (89.22%) endoscopies were performed in patients with low surgical risk (ASA I-II) and 11 (10.78%) in patients with high surgical risk. The medication was administered by the endoscopist that performed the procedure and the assistant nurse. RESULTS: The mean dose of propofol used was 72.14 mg for gastroscopies and 71.33 for colonoscopies (p = 0.92). The mean dose of propofol when infused alone was 84.81 mg whereas in combination with benzodiazepines/opioids was 66.93 mg (p = 0.06). The doses of propofol required were lower for those colonoscopies in which midazolam and/or meperidine was combined and in patients over 65 years of age (p = 0.006 y p = 0.001, respectively). Eleven (10.8%) minor complications were reported, and managed by the own endoscopist. Patients had no memories of the procedure. The tolerance rated by the endoscopist was excellent-good, fair, bad-very bad in 83, 5 and 12% of the gastroscopies and in 79, 8 and 13% of the colonoscopies respectively. Nevertheless bad tolerance did not hinder the completion of the procedure in any case. CONCLUSIONS: The administration of propofol by the endoscopist and the assistant nurse, is an effective and safe method of sedation in patients of low and high-risk as well as in elderly patients. The doses of propofol required for an adequate sedation were lower in patients over 65 years of age and for colonoscopies in which medication was combined.

Adolescent↗
PubMed1999

[Propofol sedation in endoscopic manometry of Oddi's sphincter].

Endoscopic manometry of the sphincter Oddi (SO) is a sophisticated method which requires a cooperative patient. Therefore, during endoscopic manometry sufficient i.v. sedation is crucial, and additionally must no affect SO-motility. In a pilot trial SO-motility was determined in ten patients with suspected SO-dysfunction (SOD) under initial sedation with 4.8 +/- 1 mg midazolam (baseline), and 3 min after an i.v. bolus of 50 mg of propofol. In addition, endoscopic manometry was performed in 57 consecutive patients with suspected SOD from 10/94-9/95 under sedation with midazolam (6.2 +/- 1.6 mg), and from 10/95-9/96 with propofol (268 +/- 111 mg). Sedation was always performed by an independent physician according to a standardized protocol. Neither the SO-baseline pressure nor the parameters of phasic SO-motility were significantly altered by propofol (including two patients with proven SOD). Propofol causes a more rapid onset of sedation, and the time interval to obtain successful biliary cannulation was shorter than under midazolam (p < 0.05). Successful manometric recordings could be obtained in 82% of the patients under midazolam but in 96% of the patients under propofol-sedation (p < 0.05), respectively. The patient cooperation was significantly better rated (by the endoscopist) in the propofol group than in the midazolam group (p < 0.01). The blood pressure and the heart rate were not significantly affected in both groups, however, propofol caused a significant decrease of the oxygen saturation (p < 0.05). Accordingly, an apnea episode had to be mastered by mask ventilation via ambu bag in one patient under propofol-sedation (uneventful recovery). In the midazolam group flumazenil-administration was necessary in four patients. The post-procedure recovery was faster after propofol--than after midazolam-sedation (p < 0.05). In conclusion, propofol is suitable for i.v. sedation during endoscopic manometry of the spincter of Oddi.

Adult↗
PubMed2000

Modulation of cytochrome P-450 dependent monooxygenases in streptozotocin-induced diabetic hamster: I. Effects of propofol on defluorination and cytochrome P-450 activities.

BACKGROUND: Diabetes mellitus could induce polymorphic alterations of metabolic activities of cytochrome P-450 dependent monooxygenases in chemical-induced diabetic animals. The purpose of this study is to define the functional impact of clinical concentrations of propofol on the metabolic activities of cytochrome P-450 in the diabetic animals. METHODS: In order to validate the effect of propofol on cytochrome P-450 activities, especially the cytochrome P-450 2E1 and its defluorination activity, we applied NADPH-generating system to measure the metabolizing activities of cytochrome P-450 isozymes of streptozotocin-induced diabetic hamsters within the microsomes preincubated with various concentrations of propofol. The extent of defluorination and activity of cytochrome P-450 2E1 were assessed by reacting the propofol-treated microsomes in NADPH-generating system with enflurane and aniline as substrates respectively. Drug metabolizing activities of cytochrome 1A1, 2B1, and 3A4 were evaluated by metabolizing specific substrates, benzo(a)pyrene, pentoxyresorufin and erythromycin, within the microsomes of diabetic hamsters preincubated with various concentrations of propofol. RESULTS: The hepatic and renal defluorination of enflurane was significantly inhibited by 0.05 and 0.10 mM propofol in the microsomes of diabetic hamster (P < 0.05). The activities of aniline hydroxylase (cytochrome 2E1), pentoxyresorufin O-dealkylase (cytochrome 2B1) and benzo(a)pyrene hydroxylase (cytochrome 1A1) were inhibited by propofol in a concentration-dependent manner from 0.05 to 0.10 mM. However, propofol showed no significant effect to the erythromycin N-demethylase (cytochrome 3A4) at its concentration of 0.05-0.10 mM in the diabetic hamsters. CONCLUSIONS: Our data demonstrated that propofol in therapeutic concentrations of 0.05 and 0.10 mM, could inhibit both liver and kidney defluorination and cytochrome P-450's activities of the diabetic hamsters in vitro of different extent. This should remind clinicians of propofol's potential drug-to-drug interactions in the diabetic patients.

Animals↗
PubMed2003

Propofol inhibits neuronal firing activities in the caudal ventrolateral medulla.

BACKGROUND: Propofol is a potent intravenous anesthetic. The action of propofol on the medullary depressor area, the caudal ventrolateral medulla (CVLM), has not been well established. We therefore performed extracellular recordings to study the neuronal activity of the CVLM in cats before and after intravenous propofol administration, to investigate its influence on neuronal firings. METHODS: Experiments were performed on 31 cats anaesthetized with a mixture of alpha-chloralose and urethane administered intraperitoneally. Mean systemic arterial pressure, heart rate, and the neuronal firing (NF) rate were continuously recorded before and after intravenous injection of a single dose of 2 mg x kg(-1) propofol or separate supplemental doses of 1, 2, and 4 mg x kg(-1) propofol until those parameters had returned to the premedication level. RESULTS: Propofol dose-dependently and reversibly inhibited the NF rate after the supplemental doses of 1, 2, and 4 mg x kg(-1) propofol. The control NF rate of 17.9 +/- 8.6 Hz was depressed to 15.8 +/- 8.5 Hz after the first dose of propofol (p < 0.05 vs. the control), and was further depressed to 12.8 +/- 8.3 Hz (p < 0.05 vs. the control) and 10.0 +/- 7.9 Hz (p < 0.05 vs. the control) after the second and the third doses of propofol, respectively. CONCLUSION: The dose-dependent inhibition of the spontaneous neuronal firing rate is the main pharmacological action of propofol in the caudal ventrolateral medulla of cats.

Anesthetics, Intravenous↗
PubMed1992

[Cognitive and psychomotor performance following isoflurane, midazolam/alfentanil and propofol anesthesia. A comparative study].

Mental and psychomotor abilities are impaired to varying degrees after general anaesthesia. This has important implications for the time over which patients are monitored in the recovery room and for the discharge of outpatients after day surgery. The present study was undertaken to compare recovery and mental and psychomotor skills in the first 60 min following general anaesthesia with isoflurane, midazolam/alfentanil and propofol. METHODS. A total of 45 patients undergoing microsurgical lumbar nucleotomy were randomized to three study groups. Group 1 (n = 15): anaesthesia was induced with thiopentone and maintained with isoflurane; group 2 (n = 15): anaesthesia was induced with midazolam and maintained with alfentanil; group 3 (n = 15): anaesthesia was induced and maintained with propofol. Vecuronium was used for muscle relaxation and the lungs were ventilated with a mixture of 66% nitrous oxide in oxygen. The following were checked 15, 30, 45, and 60 min after extubation: choice reaction times and critical flicker fusion for psychomotor testing; the maze test and a modification of the ball-bearing test for discrimination of motor and mental activities; and short- and long-term memory. RESULTS. Immediate recovery did not differ in the three different groups. In all patients psychomotor function was impaired compared with baseline for more than 60 min after general anaesthesia. However, impairment was significantly less pronounced after propofol, and recovery to preanaesthesia values was faster following propofol than after midazolam/alfentanil, and slowest after isoflurane-anaesthesia (Figs. 1, 2). The flicker fusion frequency, a very sensitive parameter for the persisting effects of anaesthetics, was significantly higher following propofol anaesthesia and remained so throughout the entire study period (Fig. 3). By 30 min after extubation, short-term memory was already normal in patients who had undergone propofol anaesthesia, and a statistically significant difference from the midazolam/alfentanil and isoflurane anaesthesia groups was obvious throughout the entire study period. However, no differences in long-term memory were found. At 30 min after propofol anaesthesia all patients were able to perform the ball-bearing test, as against 13 patients following midazolam/alfentanil and 10 patients following isoflurane (Table 3). The maze test was mostly impaired after midazolam/alfentanil anaesthesia. Patients who underwent isoflurane anaesthesia needed the same time for the maze test at 60 min afterwards propofol patients needed after 30 min (Table 2). Side effects, e.g., nausea, vomiting, and double vision, were observed significantly more often in groups 1 and 2 (Table 4). DISCUSSION AND CONCLUSION. The results indicate that in operations of approximately 90 min duration the return of motor and mental abilities is faster following propofol anaesthesia. At 30 min after extubation following propofol anaesthesia patients had test results that allow their transfer from the recovery room, while it took 60 min for patients in the two other groups to reach the same levels of motor and mental function. This is important for the duration of monitoring in the recovery room and, especially, for day case anaesthesia.

Adult↗
PubMed2005

Sedation and safety of propofol for therapeutic endoscopic retrograde cholangiopancreatography.

BACKGROUND: Endoscopic retrograde cholangiopancreatography (ERCP) is the most complex gastrointestinal procedure, which needs patients' cooperation. The aim of this study was to observe the quality and safety of sedation with propofol in patients undergoing therapeutic ERCP. METHODS: Seventy patients who had undergone therapeutic ERCP were randomly divided into two groups. One group,given intravenously propofol,and the other sedated with routine method,served as the control. Blood pressure,heart rate, oxygen saturation were monitored and cardiorespiratory event was observed. Patient cooperation, performance, recovery time and amnesia served as variables postoperation. RESULTS: Blood pressure elevated in four patients in the propofol group, less than in the control group (P < 0.01). Seven patients showed decreased blood pressure after administration of propofol, but none in the control group (P < 0.01). Twelve patients in the control group showed mild or significant resistance, but none in the propofol group (P < 0.01). The time for performance in the propofol group (P < 0.05) was shorter than in the control group. Patient recovery was quicker in the propofol group than in the control group (P < 0.01). The degree of amnesia better in the propofol group than in the control group (P < 0.01). The degree of amnesia was also better in the propofol group than in the control group (P<0.01). CONCLUSIONS: Propofol proves to be an excellent sedative for therapeutic ERCP. Being effective and safe, it shows a shorter ERCP duration but quick recovery and better amnesia. It is better than other routine sedatives.

Adult↗
PubMed2006

[Propofol protecting rats from paraquat induced lung injury].

OBJECTIVE: To investigate the protective efficacy of propofol against paraquat induced lung injury. METHODS: One hundred and twenty-eight male Wistar rats were randomizedly divided into three groups: the control group (n = 8), the intoxication group (n = 60) and the propofol group (n = 60). One hundred and twenty rats were once administered with 5 mg/kg paraquat (PQ) by the intragastrical injection to establish the model of PQ induced lung injury. The propofol of 10 mg/kg was administered intraperitoneally in the propofol group (60 rats) twice a day for four consecutive days one hour after the rats were intoxicated while the normal saline of the same amount as propofol in the propofol group was administered in the intoxication group (60 rats) one hour after the rats were intoxicated. The intragastrical injection of 1 mg/kg normal saline was administered once in the control group (8 rats). On the first, the third, the seventh, the 14th and the 28th day after treating, the level of malondialdehyde (MDA) in plasma, bronchoalveolar lavage fluid (BALF) and lung homogenate, and the content of hydroxyproline (HPY) in lung homogenate, the cell count of BALF were detected. Meanwhile, pathological changes of lung were examined under optical microscope. RESULTS: The level of MDA in plasma on the first, the third and the seventh day and in BALF and lung homogenate on the first and the third day in the propofol group [in plasma: (4.31 +/- 0.94), (4.04 +/- 0.87) and (3.24 +/- 1.14) nmol/ml; in BALF: (3.47 +/- 1.09) and (2.79 +/- 1.11) nmol/ml; in lung homogenate: (7.54 +/- 0.63) and (8.41 +/- 1.23) nmol/ml] were significantly lower than those in the intoxication group [in plasma: (10.15 +/- 3.15), (6.97 +/- 1.6 5) and (5.44 +/- 0.66) nmol/ml; in BALF: (5.58 +/- 1.19) and (4.86 +/- 1.89) nmol/ml; in lung homogenate: (10.20 +/- 2.43) and (10.71 +/- 171) nmol/ml, P < 0.05 or P < 0.01]. The total cell count of BALF on the first, the third and the seventh day after intoxication in the propofol group was significantly less than that in the intoxication group respectively (P < 0.05). The histological changes such as alveolar edema, hemorrhage and inflammatory cell infiltration in the propofol group were less than those in the PQ group. CONCLUSION: Propofol could reduce the level of MDA and relieve paraquat induced lung injury.

Animals↗
PubMed2006

Propofol induces growth cone collapse and neurite retractions in chick explant culture.

PURPOSE: Propofol neurotoxicity has been demonstrated in several cell culture systems. This study was undertaken to determine whether propofol has neurotoxic effects on peripheral, retinal, and autonomic neurons, and which neurons are particularly liable to injury by propofol. METHOD: Dorsal root ganglia, retinal ganglion cell layers, and sympathetic ganglion chains were isolated from day eight chick embryos and cultured for 20 hr. Thereafter, propofol was added at various concentrations [5-300 microM (0.9-53 microg x mL(-1))] to investigate its effects on these three types of neuronal tissue. Morphological changes were examined quantitatively by growth cone collapse assay. Propofol concentrations were measured using high performance liquid chromatography. RESULTS: Propofol induced growth cone collapse and neurite destruction. The three types of neurons tested exhibited significantly different dose-response relationships two hours after the application of propofol (P < 0.001) but not at 24 hr after application. The growth cone-collapsing effect was at least partially reversible in all three types of neurons after exposure to 100 microM propofol up to six hours, though reversibility was not observed after 24-hr exposure. CONCLUSION: While the clinical safety profile of propofol has been well documented, at high concentrations propofol has potential neurotoxicity on growing neurons in vitro.

Anesthetics, Intravenous↗
PubMed1985

Interaction studies and other investigations of the pharmacology of propofol ('Diprivan').

The anaesthetic properties of propofol ('Diprivan') have been described previously. This report summarizes additional studies designed to investigate some aspects of the general pharmacology of propofol. Following recovery from anaesthesia with propofol there was no evidence of any central anticholinergic or anticonvulsant effect in mice. An anti-convulsant effect followed thiopentone anaesthesia. In mice anaesthetized with propofol 24 h after the last of 4 daily doses of phenelzine, amitriptyline, diazepam or alcohol, no marked potentiation of anaesthesia was found. Pretreatment with alcohol on the day of anaesthesia potentiated thiopentone but not propofol anaesthesia. Oral doses of propofol up to 300 mg/kg failed to induce anaesthesia in mice. The acute administration of the beta-adrenoceptor antagonists, atenolol or propranolol was well tolerated during anaesthesia with propofol in pigs. In the cat the arrhythmia threshold to adrenaline was greater than that in cats anaesthetized with halothane and no ganglion blocking or alpha-adrenoceptor antagonist properties were demonstrated. No potent or specific agonist or antagonist properties were detected in the range of in vitro systems examined. Neither propofol nor thiopentone had any effect on ADP-induced platelet aggregation or whole blood clotting time. Bronchomotor tone and gastrointestinal motility were unaffected by propofol. Tests of renal function indicated only a slight reduction in sodium excretion, similar to that seen with thiopentone. A normal corticosterone response to ACTH was seen in rats anaesthetized for 90 min with an infusion of propofol.

Adrenergic beta-Antagonists↗
PubMed1993

Adverse effects of administration of propofol with various preanesthetic regimens in dogs.

The effects of propofol on anesthetic induction were evaluated in 40 dogs anesthetized with isoflurane. Propofol is a rapidly acting, nonbarbiturate drug that induces anesthesia of ultrashort duration with IV administration. Four preanesthetic regimens were used: anesthesia without preanesthetic drugs; or with preanesthetic administration of acepromazine (0.1 mg/kg of body weight, IM), diazepam (0.2 mg/kg, IV), or acepromazine (0.02 mg/kg) and butorphanol (0.4 mg/kg) IM. Heart rate, systolic arterial blood pressure (SAP), respiration, quality of induction and recovery, and adverse effects were induction and recovery, and adverse effects were recorded. Intravenous propofol administration induced a variable period of apnea in 34 of 40 dogs. Cyanosis (in 2 dogs) and signs of pain on injection (in 3 dogs) were infrequently observed during induction. One dog developed ventricular premature depolarizations after propofol administration. Venous CO2 tension increased and pH decreased immediately after propofol administration, regardless of preanesthetic regimen. The SAP significantly (P < 0.05) decreased after propofol administration in dogs treated with acepromazine (SAP, 178 mm of Hg before vs 128 mm of Hg after propofol) and with acepromazine/butorphanol (SAP, 184 mm of Hg before vs 98 mm of Hg after propofol). When used for induction, propofol induces anesthetic-related adverse effects, some of which can be minimized by preanesthetic medication. Recovery characteristics varied with preanesthetic medication, independent of propofol administration.

Anesthesia, Inhalation↗
PubMed2001

Hemodynamic stability during induction of anesthesia and tracheal intubation with propofol plus fentanyl, ketamine, and fentanyl-ketamine.

PURPOSE: This study was conducted to investigate hemodynamic and cardiac stability during anesthesia induction and intubation, using propofol plus fentanyl, propofol plus ketamine, and propofol plus fentanyl and ketamine. METHODS: Forty-five adult patients were randomly allocated to one of three groups according to the agents used for induction: propofol (2 mg/kg) plus fentanyl (3 microg/kg) (PF), propofol (2 mg/kg) plus ketamine (0.1 mg/kg) (PK), and propofol (2 mg/kg) plus fentanyl (3 microg/kg) plus ketamine (0.1 mg/kg) (PFK). Hemodynamic responses were assessed by measuring changes in blood pressure (BP), heart rate (HR), and cardiac output (CO; using dye dilution combined with pulse dye densitometry [PDD]). RESULTS: BP and HR changes during the induction of anesthesia tended to be greater in the PK group than in the PF and PFK groups. After the injection of propofol, the cardiac index (CI) fell significantly below baseline values in the PF and PFK groups, but remained unchanged in the PK group. After tracheal intubation, BP and HR increased significantly only in the PF and PK groups, and reached a level significantly above baseline values only in the PK group. The CO responses to tracheal intubation were: PK group > PF group > PFK group. CONCLUSION: A combination of propofol plus fentanyl plus ketamine would provide greater reduction of fluctuations in hemodynamic variables associated with induction of anesthesia and tracheal intubation than combinations of propofol plus fentanyl or propofol plus ketamine.

Clinical Trial↗
PubMed1989

Randomized comparison of outcome after propofol-nitrous oxide or enflurane-nitrous oxide anaesthesia in operations of long duration.

A randomized, prospective, comparative study was performed to evaluate induction characteristics, haemodynamic changes and recovery in 60 ASA I-II patients undergoing mainly gynaecological laparotomies with either propofol or thiopentone-enflurane anaesthesia. The propofol group (n = 30) received 2 mg.kg-1 propofol for induction of anaesthesia followed by propofol infusion. The thiopentone-enflurane group (n = 30) received thiopentone 4 mg.kg-1 for induction followed by enflurane (0.5-2 per cent). All patients received nitrous oxide (66 per cent] in oxygen begun one minute after tracheal intubation, and fentanyl (1.5 micrograms.kg-1) four minutes prior to induction. Other drugs administered during or after anaesthesia were similar among the groups. Haemodynamic measurements were similar between propofol and enflurane groups except after tracheal intubation when the mean arterial pressure was lower in the propofol group (P less than 0.05). The propofol group had significantly less (P less than 0.01) emesis in the recovery room than the enflurane group. The propofol group experienced significantly less (P less than 0.05) dizziness, depression/sadness and hunger than the enflurane group in the postoperative period as assessed with a visual analogue questionnaire. We conclude that propofol provided better outcome than enflurane in terms of these nonvital but annoying outcome measures after relatively long intra-abdominal operations.

Adult↗
PubMed1993

Propofol in patients with cardiac disease.

Propofol is an intravenous anaesthetic which is chemically unrelated to other iv anaesthetics. Most anaesthetists are now becoming familiar with propofol's pharmacokinetic and pharmacodynamic properties. It has proved to be a reliable drug that can be used safely for induction and maintenance of anaesthesia for most surgical procedures and unlike other anaesthetic agents, it can especially be extended into the postoperative setting or intensive care unit for sedation. Propofol's greatest attributes are its pharmacokinetic properties which result in a rapid, clear emergence and lack of cumulative effects even after prolonged administration. Compared with other iv anaesthetics, the induction dose of propofol has a relatively higher incidence of respiratory depression, short-lived apnoea and blood pressure reduction that may occasionally be marked. Possible mechanisms for the hypotension may relate to (1) its action on peripheral vasculature (vasodilatation), (2) decreased myocardial contractility, (3) resetting of the baroreflex activity and (4) inhibition of the sympathetic nervous system outflow. In vitro studies indicate that propofol depresses the immunological reaction to bacterial challenge as well as the chemotactic activity. Clinical studies, in cardiac surgery, have demonstrated that propofol, in association with an opioid, is a logical anaesthetic choice. Propofol is about to receive approval for continuous iv sedation. Comparative studies of propofol and midazolam have clearly demonstrated the superiority of propofol in terms of rapid recovery and precise control of the level of sedation.

Anesthesia, Intravenous↗
PubMed1993

Propofol anaesthesia reduces early postoperative emesis after paediatric strabismus surgery.

Propofol anaesthesia may reduce postoperative emesis. The purpose of this study was to compare the incidence of emesis after propofol anaesthesia with and without nitrous oxide, compared with thiopentone and halothane anaesthesia, in hospital and up to 24 hr postoperatively, in outpatient paediatric patients after strabismus surgery. Seventy-five ASA class I or II, unpremedicated patients, aged 2-12 yr were randomly assigned to one of three groups: Thiopentone, 6.0 mg.kg-1 i.v. induction followed by halothane and N2O/O2 for maintenance (T/H); propofol for induction, followed by propofol and oxygen for maintenance (P/O2); and propofol for i.v. induction, followed by propofol infusion and N2O/O2 for maintenance (P/N2O). All received vecuronium, controlled ventilation, and acetaminophen pr. Morphine was given as needed for postoperative analgesia. There were no differences in age, weight, number of eye muscles operated upon, duration of anaesthesia or surgery. The P/N2O group (255 +/- 80 micrograms.kg-1 x min-1) received less propofol than the P/O2 group (344 +/- 60 micrograms.kg-1 x min-1) (P < or = 0.0001) and had shorter extubation (P < 0.001) and recovery (P < 0.01) times. Emesis in the hospital, in both the P/N2O (4.0%) and P/O2 group (4.0%) was less than in the T/H group (32%) (P < 0.01). Antiemetics were required in four patients in the T/H group (16.0%). Overall emesis after surgery was not different among the groups: T/H (48%), P/O2 (28%) and P/N2O (42%). The use of propofol anaesthesia with and without N2O decreased only early emesis. This supports the concept of a short-acting, specific antiemetic effect of propofol.

Ambulatory Surgical Procedures↗
PubMed1998

Aging prolongs recovery of psychomotor functions at emergence from propofol-alfentanil anaesthesia.

PURPOSE: To compare recovery of psychomotor function in elderly and young surgical patients at emergence from propofol-alfentanil anaesthesia. METHODS: Ten elderly (> 70 yr) and 10 younger (< 40 yr) patients scheduled for orthopaedic surgery of less than three hours, were anesthetized with nitrous oxide, propofol and alfentanil. Propofol and alfentanil cumulative doses, time from cessation of propofol infusion to eye opening (EO) on verbal command and to extubation were recorded. Psychomotor performance was assessed by the Mini-Mental State (MMS) performed the day prior to surgery and postoperatively at 30, 60, and 120 min, following extubation. Propofol blood concentrations were measured at EO and at each MMS task. RESULTS: Elderly patients were comparable with young patients for preoperative MMS scores, surgery and anaesthesia duration, propofol and alfentanil cumulative doses. Postoperative MMS scores were lower at 30, 60 and 120 min, in elderly patients. Propofol blood concentrations were not different between elderly and young patients at EO, 30, 60 and 120 min. CONCLUSION: Psychomotor performance is impaired in elderly compared with young patients at emergence from propofol-alfentanil anaesthesia. These differences are not likely to be related to propofol accumulation in elderly subjects.

Adult↗
PubMed1998

Propofol enhances red cell antioxidant capacity in swine and humans.

PURPOSE: To determine the effect of an anaesthetic with antioxidant potential, propofol, on red blood cell (RBC) antioxidant enzyme activities and RBC susceptibility to peroxidative challenge. METHODS: Propofol was administered by intravenous bolus (2.5 mg.kg-1) and continuous infusion (36 and 72 ml.hr-1 in nine swine; 216 ml.hr-1 in two swine), to achieve serum concentrations between 5 and 30 micrograms.ml-1 for two hours at each rate. Arterial blood sampling was at 0, 10, 30, 60, and 120 min for each rate of infusion, for measurement of plasma propofol concentration, activities of plasma and RBC superoxide dismutase, glutathione peroxidase, glutathione reductase, RBC catalase, and RBC malondialdehyde (MDA) formation in response to ex vivo oxidative challenge with t-butyl hydrogen peroxide (tBHP; 1.5 mM). Antioxidant mechanisms were determined by in vitro study of MDA formation, GSH depletion, and oxidation of haemoglobin to methaemoglobin in human erythrocytes exposed to propofol 0-75 microM. The antioxidant potential of propofol was compared with that of alpha-tocopherol utilising the reaction with 2,4,6-tripyridyl-s-triazine (TPTZ). RESULTS: Propofol had no effect on plasma or RBC antioxidant enzyme activities. It inhibited RBC MDA production over the range of 0-20 micrograms.ml-1 (y = -18.683x + 85.431; R2 = 0.8174). Effective propofol concentrations for 25% and 50% reductions in MDA levels were 7-12 and 12-20 micrograms.ml-1, respectively. Propofol has a similar effect on human erythrocytes in vitro (R2 = 0.98). CONCLUSION: Propofol antagonises the effects of forced peroxidation of red cells at anaesthetic and sub-anaesthetic concentrations in swine. Its actions include scavenging of oxygen derived free radicals in a tocopherol-like manner.

Anesthetics, General↗
PubMed1997

Propofol inhibits medullary pressor mechanisms in cats.

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 systematic arterial pressure (MSAP), heart rate (HR) and cardiac contractility (dp/dt) were compared before and after administration of propofol the femoral vein (2, 3, or 4 mg.kg-1), vertebral artery (1 mg.kg-1) or the lateral cerebral ventricle (0.5 mg.kg-1) 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 nl) via a multibarrel-micropipette in 28 cats. One hour later, propofol (0.001%, 50 nl) was microinjected at the same site. Electrical 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 DM (59 +/- 3% vs 13 +/- 2%, n = 11, P < 0.01) or in RVLM (56 +/- 4% vs 18 +/- 2%, n = 9, P < 0.01). In CVLM, propofol slightly but not significantly increased 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.

Anesthetics, Intravenous↗