This study examined whether propofol and aminophylline affect the mobilization of intracellular calcium in human umbilical vein endothelial cells. Intracellular calcium was measured using laser scanning confocal microscopy. Cultured and serum-starved cells on round coverslips were incubated with propofol or aminophylline for 30 min, and then stimulated with lysophosphatidic acid, propofol and aminophylline. The results were expressed as relative fluorescence intensity and fold stimulation. Propofol decreased the concentration of intracellular calcium, whereas aminophylline caused increased mobilization of intracellular calcium in a concentration-dependent manner. Propofol suppressed the lysophosphatidic acid-induced mobilization of intracellular calcium in a concentration-dependent manner. Propofol further prevented the aminophylline-induced increase of intracellular calcium at clinically relevant concentrations. However, aminophylline reversed the inhibitory effect of propofol on the elevation of intracellular calcium by lysophosphatidic acid. Our results suggest that propofol and aminophylline antagonize each other on the mobilization of intracellular calcium in human umbilical vein endothelial cells at clinically relevant concentrations. Serious consideration should be given to how this interaction affects mobilization of intracellular calcium when these two drugs are used together.
Aminophylline/*antagonists & inhibitors/pharmacology ; Anesthetics, Intravenous/*antagonists & inhibitors/pharmacology ; Bronchodilator Agents/*antagonists & inhibitors/pharmacology ; Calcium/*metabolism ; Cells, Cultured ; Endothelial Cells/*drug effects/metabolism ; Endothelium, Vascular/cytology ; Humans ; Lysophospholipids/pharmacology ; Microscopy, Confocal ; Propofol/*antagonists & inhibitors/pharmacology ; Umbilical Veins/cytology

BACKGROUND: Monitored anesthetic care can provide patient safety and optimal surgical conditions. However, propofol and fentanyl decrease the hypoxic ventilatory response and heart rate. Ketamine has less respiratory depression and blocks bradycardia. Furthermore, ketamine can reduce the amount of opioid use but it delays discharge in the outpatient anesthesia. Therefore, this study retrospectively examined the effects of combined fentanyl and ketamine administered during monitored anesthetic care on the use of opioids, cardiorespiratory side effects, and patient discharge. METHODS: The anesthetic room, the recovery room and day surgery center records of ambulatory strabismus surgery with monitored anesthetic care was reviewed by anesthesiologists from Oct. 2004 to July 2005. The patients were classified as those receiving either fentanyl (F group: n = 32) or fentanyl and ketamine (FK group: n = 19) with a propofol infusion. The fentanyl dose used, the need for airway support, anticholinergics and naloxone were compared. The stay in the recovery room and the day surgery center was also examined. RESULTS: The FK group used significantly less fentanyl than the F group (P < 0.05). Although airway support was needed, there was less anticholinergics and naloxone used in the FK group, but this difference was not significant. The stay in recovery room and the day surgery center were similar. CONCLUSIONS: Co-administered ketamine reduces the amount of fentanyl-needed, but it does not reduce the need for airway support and anticholinergics. In addition, co-administered ketamine does not affect the number of days in the recovery room and day surgery center.
Ambulatory Surgical Procedures ; Analgesics, Opioid ; Anesthesia ; Bradycardia ; Cholinergic Antagonists ; Fentanyl* ; Heart Rate ; Humans ; Ketamine* ; Naloxone ; Outpatients ; Patient Discharge ; Patient Safety ; Propofol ; Recovery Room ; Respiratory Insufficiency ; Retrospective Studies ; Strabismus*

BACKGROUND: Bradycardia frequently occurs in intravenous anesthesia with propofol. Patients with sinus bradycardia have increased vagal tone at rest. The purpose of this study is to evaluate the effect of propofol on blood pressure and heart rate during induction of anesthesia in patients with sinus bradycardia. METHODS: Sixteen adult patients were studied. No anticholinergics were used before induction. Anesthesia was induced intravenously with midazolam 0.03 mg/kg, propofol 2 mg/kg, lidocaine 1 mg/kg and vecuronium 0.12 mg/kg. Anesthesia was maintained with continuous infusion of propofol 150 microgram/ kg/min and 100% O2. Hemodynamic data were recorded 3 minutes after midazolam injection, immediately after propofol injection, 1 and 2 minutes after propofol continuous infusion, and immediately, 1, 3 and 5 minutes after intubation. RESULTS: Heart rate significantly increased after intravenous injection of propofol (P < 0.05) and was maintained during the study. There was no incidence of bradycardia. CONCLUSIONS: Anesthesia induction and maintenance with propofol could be a suitable and safe ansethetic method for patients with sinus bradycardia.
Adult ; Anesthesia* ; Anesthesia, Intravenous ; Blood Pressure* ; Bradycardia* ; Cholinergic Antagonists ; Heart Rate* ; Heart* ; Hemodynamics ; Humans ; Incidence ; Injections, Intravenous ; Intubation ; Intubation, Intratracheal* ; Lidocaine ; Midazolam ; Propofol* ; Vecuronium Bromide

Many sedatives are used clinically and include benzodiazepines, barbiturates, antihistamines, propofol, and alpha-2-agonist. Benzodiazepines activate GABA neuronal receptors in the brain and present sedating, hypnotic, anxiolytic, amnestic, and anticonvulsant effects, but low analgesic effects. Propofol induce sedative, anxiolytic, and amnestic effects but no analgesic effects. However, risks such as cardiopulmonary instability and hypotension must be considered during administration. Dexmedetomidine is a high selective alpha-2 agonist and has many advantages as a sedative. Patients under dexmedetomidine sedation awaken easily and are more likely to be cooperative. Risk of respiratory depression and cardiopulmonary instability is low as well. Additionally, dexmedetomidine decreases amount of analgesic needed during and after surgery, presenting analgesic effects. Dexmedetomidine also decreases risk of delirium. However, bradycardia may occur and biphasic effects on blood pressure may be observed during beginning of administration. Because of lengthy symptom onset and offset time, physicians should carefully control administration at the beginning and end of dexmedetomidine administration. The purpose of this review is to evaluate the efficacy and availability of dexmedetomidine in various clinical fields including sedation for critically ill patients, regional anesthesia, monitored anesthesia care for some invasive procedures, stabilization of heart in cardiac surgery or endoscopic procedures.
Anesthesia* ; Anesthesia, Conduction ; Barbiturates ; Benzodiazepines ; Blood Pressure ; Bradycardia ; Brain ; Critical Illness ; Delirium ; Dexmedetomidine* ; GABAergic Neurons ; Heart ; Histamine Antagonists ; Humans ; Hypnotics and Sedatives ; Hypotension ; Propofol ; Respiratory Insufficiency ; Thoracic Surgery

Many sedatives are used clinically and include benzodiazepines, barbiturates, antihistamines, propofol, and alpha-2-agonist. Benzodiazepines activate GABA neuronal receptors in the brain and present sedating, hypnotic, anxiolytic, amnestic, and anticonvulsant effects, but low analgesic effects. Propofol induce sedative, anxiolytic, and amnestic effects but no analgesic effects. However, risks such as cardiopulmonary instability and hypotension must be considered during administration. Dexmedetomidine is a high selective alpha-2 agonist and has many advantages as a sedative. Patients under dexmedetomidine sedation awaken easily and are more likely to be cooperative. Risk of respiratory depression and cardiopulmonary instability is low as well. Additionally, dexmedetomidine decreases amount of analgesic needed during and after surgery, presenting analgesic effects. Dexmedetomidine also decreases risk of delirium. However, bradycardia may occur and biphasic effects on blood pressure may be observed during beginning of administration. Because of lengthy symptom onset and offset time, physicians should carefully control administration at the beginning and end of dexmedetomidine administration. The purpose of this review is to evaluate the efficacy and availability of dexmedetomidine in various clinical fields including sedation for critically ill patients, regional anesthesia, monitored anesthesia care for some invasive procedures, stabilization of heart in cardiac surgery or endoscopic procedures.
Anesthesia* ; Anesthesia, Conduction ; Barbiturates ; Benzodiazepines ; Blood Pressure ; Bradycardia ; Brain ; Critical Illness ; Delirium ; Dexmedetomidine* ; GABAergic Neurons ; Heart ; Histamine Antagonists ; Humans ; Hypnotics and Sedatives ; Hypotension ; Propofol ; Respiratory Insufficiency ; Thoracic Surgery

The present study was designed to investigate the inhibitory effects of intravenous general anesthetic propofol (0.1-3.0 mmol/L) on excitatory synaptic transmission in supraoptic nucleus (SON) neurons of rats, and to explore the underlying mechanisms by using intracellular recording technique and hypothalamic slice preparation. It was observed that stimulation of the dorsolateral region of SON could elicit the postsynaptic potentials (PSPs) in SON neurons. Of the 8 tested SON neurons, the PSPs of 7 (88%, 7/8) neurons were decreased by propofol in a concentration-dependent manner, in terms of the PSPs' amplitude (P < 0.01), area under curve, duration, half-width and 10%-90% decay time (P < 0.05). The PSPs were completely and reversibly abolished by 1.0 mmol/L propofol at 2 out of 7 tested cells. The depolarization responses induced by pressure ejection of exogenous glutamate were reversibly and concentration-dependently decreased by bath application of propofol. The PSPs and glutamate-induced responses recorded simultaneously were reversibly and concentration-dependently decreased by propofol, but 0.3 mmol/L propofol only abolished PSPs. The excitatory postsynaptic potentials (EPSPs) of 7 cells increased in the condition of picrotoxin (30 µmol/L, a GABA(A) receptor antagonist) pretreatment. On this basis, the inhibitory effects of propofol on EPSPs were decreased. These data indicate that the presynaptic and postsynaptic mechanisms may be both involved in the inhibitory effects of propofol on excitatory synaptic transmission in SON neurons. The inhibitory effects of propofol on excitatory synaptic transmission of SON neurons may be related to the activation of GABA(A) receptors, but at a high concentration, propofol may also act directly on glutamate receptors.
Anesthetics, Intravenous ; pharmacology ; Animals ; Excitatory Postsynaptic Potentials ; drug effects ; GABA-A Receptor Antagonists ; pharmacology ; Glutamic Acid ; pharmacology ; In Vitro Techniques ; Neurons ; drug effects ; Propofol ; pharmacology ; Rats ; Receptors, Glutamate ; metabolism ; Supraoptic Nucleus ; cytology

OBJECTIVETo investigate the antioxidant and anti-endotoxin effects of propofol on endothelial cells and the possible mechanisms.

METHODSCultured endothelial cells were treated with hydrogen peroxide (H(2)O(2)), propofol + H(2)O(2), lipopolysaccharide (LPS) and propofol + LPS, respectively. Endothelial cell damage was monitored for possible lactic dehydrogenase (LDH) release. The transcription and the protein expression levels of endothelial nitric oxide synthase (eNOS) were measured.

RESULTSLDH release was higher in groups treated with H(2)O(2) or LPS than in the control group. After pretreatment with propofol, the effects induced by H(2)O(2) were attenuated, but propofol did not decrease the LDH release induced by LPS. Both H(2)O(2) and LPS significantly increased the eNOS transcript levels and the increases were significantly attenuated after pretreatment with propofol. Both H(2)O(2) and LPS significantly increased the eNOS protein expression and the increase was attenuated after pretreatment with propofol.

CONCLUSIONPropofol could protect endothelial cells against oxidative stress by inhibiting eNOS transcription and protein expression, but could not antagonise endotoxin induced cell injuries.

Antioxidants ; pharmacology ; Endothelium, Vascular ; cytology ; drug effects ; metabolism ; Endotoxins ; antagonists & inhibitors ; Free Radical Scavengers ; pharmacology ; Humans ; In Vitro Techniques ; Lipopolysaccharides ; pharmacology ; Nitric Oxide ; pharmacology ; Nitric Oxide Synthase ; biosynthesis ; Nitric Oxide Synthase Type III ; Propofol ; pharmacology

To investigate the effects of novel intravenous general anesthetic propofol on membrane electrophysiological characteristics and action potential (AP) of the supraoptic nucleus (SON) neurons and possible ionic mechanisms, intracellular recordings were conducted in SON neurons from the coronal hypothalamic slice preparation of adult male Sprague Dawley (SD) rats. The results showed that bath application of 0.1 mmol/L propofol induced a significant decline in resting potential (P < 0.01), and higher concentrations of propofol (0.3 and 1.0 mmol/L) decreased time constant and slope resistance of cell membrane (P < 0.01). Under the hyperpolarizing current pulses exceeding 0.5 nA, an anomalous rectification was induced by hyperpolarization-activated cation channel (I(h) channel) in 11 out of 18 tested SON neurons. Bath of propofol reversibly decreased the anomalous rectification. Moreover, 0.1 mmol/L propofol elevated threshold level (P < 0.01) and decreased Max L. slope (P < 0.05) of the spike potential in SON neurons. Interestingly, 0.3 and 1.0 mmol/L propofol nullified APs in 6% (1/18) and 71% (12/17) tested SON neurons, respectively. In the SON neurons where APs were not nullified, propofol (0.3 mmol/L) decreased the amplitude of spike potential (P < 0.05). The higher concentrations of propofol (0.3 and 1.0 mmol/L) decreased firing frequencies evoked by depolarizing current pulses (0.1-0.7 nA), and shifted the current intensity-firing frequency relation curves downward and to the right. These results suggest that propofol decreases the excitability of SON neurons by inhibiting I(h) and sodium channels.
Action Potentials ; drug effects ; Anesthetics, Intravenous ; pharmacology ; Animals ; Cyclic Nucleotide-Gated Cation Channels ; antagonists & inhibitors ; Hyperpolarization-Activated Cyclic Nucleotide-Gated Channels ; Hypothalamus ; drug effects ; physiology ; In Vitro Techniques ; Male ; Potassium Channels ; Propofol ; pharmacology ; Rats ; Rats, Sprague-Dawley ; Sodium Channel Blockers ; pharmacology ; Supraoptic Nucleus ; drug effects ; physiology

OBJECTIVETo investigate the efficacy of continuous propofol infusion via the common carotid artery for general anesthesia.

METHODSForty adult patients scheduled for abdominal surgery were randomly assigned into 2 groups to receive propopol via the common carotid artery (IC group, n=20) or via the median cubital vein (IV group, n=20). Anesthesia was induced with intravenous administration of drugs and maintained with continuous propofol infusion via the common carotid artery or the median cubital vein, with the CSI stabilized at 40-/+5 till the end of the operation. During the anesthesia, intravenous injection of fentanyl (3 microg.kg(-1).h(-1)) and vecuronium (50 microg.kg(-1).h(-1)) were given intermittently to maintain the analgesia and muscular relaxation. The dose of propofol used, hemodynamics and recovery of the patients were observed.

RESULTSThe dose of propofol used during the surgery to maintain a CSI of 40-/+5 was significantly lower in group IC and than in group IV (2.57-/+0.67 vs 5.72-/+1.37 mg.kg(-1).h(-1), P<0.01). In group IC, the blood pressure was elevated in more than half of the patients and in some cases, the elevation exceeded one third of baseline value and needed intervention with hypotensive drugs. In the IV group, the patients' blood pressure remained stable and varied within the amplitude of 15% of the baseline level. Recovery of spontaneous breathing and consciousness was more quickly in group IC than in group IV (P<0.05).

CONCLUSIONLoss of consciousness and nervous reflex can be achieved with propofol infusion via the common carotid artery, which reduces propofol dose by about 50% in comparison with intravenous infusion and allows more rapid recovery of spontaneous breath and consciousness.

Abdomen ; surgery ; Adult ; Aged ; Analgesics, Opioid ; administration & dosage ; Anesthesia, General ; methods ; Carotid Artery, Common ; Female ; Fentanyl ; administration & dosage ; Humans ; Hypnotics and Sedatives ; administration & dosage ; Infusions, Intra-Arterial ; Male ; Middle Aged ; Nicotinic Antagonists ; administration & dosage ; Propofol ; administration & dosage ; Treatment Outcome ; Vecuronium Bromide ; administration & dosage