Paraneoplastic and oncologic profiles of patients seropositive for type 1 antineuronal nuclear autoantibodies

The association of propofol with excitatory motor activity, such as myoclonic jerking and opisthotonus, in humans and in animals suggests that it may aggravate clinical seizure activity in some circumstances, although evidence suggests that under other circumstances, propofol inhibits seizure activity. In the current study, we assessed the effect of sedating doses of propofol on lidocaine-induced seizure activity in spontaneously breathing rats receiving no other anesthetics. Adult Sprague-Dawley male rats, 300-400 g, were divided into a control group and three experimental groups representing three graded levels of propofol sedation. The control rats then received a lidocaine infusion at the rate of 150 mg x kg(-1) x h(-1), resulting in a slow, progressive increase in systemic lidocaine concentrations. At the onset of electroencephalographic (EEG) seizure activity, arterial lidocaine concentrations were obtained. The treated rats received propofol according to three different dose schedules: Dose 1 = 10 mg x kg(-1) x h(-1) after a 2.5-mg/kg bolus; Dose 2 = 20 mg x kg(-1) x h(-1) after a 5-mg/kg bolus; Dose 3 = 40 mg x kg(-1) x h(-1) after a 10-mg/kg bolus. After 30 min, a steady level of sedation, dependent on the dose of propofol, was achieved. The lidocaine infusion was then started, and systemic lidocaine levels were obtained at the onset of EEG seizure activity. The lidocaine was continued until the onset of death by cardiac arrest. Plasma lidocaine was measured by gas chromatography. Analysis of variance and Dunnett's t-test were used for comparisons with the control values. Continuous propofol sedation increased the seizure dose of lidocaine from 37.7 +/- 3.5 mg/kg (mean +/- SEM) to 52.5 +/- 2.6 mg/kg (Dose 1, P < 0.05) and 67.9 +/- 8.6 mg/kg (Dose 2, P < 0.05), and completely abolished lidocaine seizures at Dose 3. The lethal dose of lidocaine, 89.4 +/- 10.5 mg/kg control versus 108.7 +/- 10.3 mg/kg (Dose 1), 98.3 +/- 10.1 mg/kg (Dose 2), and 93.5 +/- 10.4 mg/kg (Dose 3) did not differ among groups. The lidocaine levels at seizure threshold were increased in the propofol-treated rats: 16.9 +/- 0.5 microg/mL control versus 19.2 +/- 0.7 microg/mL (Dose 1, P = not significant) and 23.7 +/- 1.8 microg/mL (Dose 2, P < 0.05). Continuous propofol sedation in spontaneously breathing rats receiving no other anesthetics exerts a protective effect against lidocaine-induced seizures in a monotonic, dose-dependent fashion. The cardiac arrest dose of lidocaine is unaffected by propofol under these conditions. IMPLICATIONS: The i.v. anesthetic drug propofol, given to rats to produce sedation, was found to suppress seizure activity caused by overdosage of the local anesthetic lidocaine.     

Is patient-controlled sedation good for elderly patients?

The purpose of this study was to evaluate the safety and advantage of intra-operative patient-controlled sedation (PCS) in elderly patients. Propofol PCS was compared with anesthesiologist-controlled sedation (ACS) during knee arthroplasty under epidural anesthesia. Eleven elderly patients scheduled for unilateral knee total or partial arthroplasty were divided randomly into PCS group (n = 6) and ACS group (n = 5). Epidural anesthesia was performed to produce an appropriate level of sensory block (T 10 through S). Firstly a mixture of pentazocine 0.2 mg.kg-1 and 2% mepivacaine 6-9 ml was injected to the epidural space, and anaesthesia was maintained using 2% mepivacaine afterward. Patients in both groups received propofol 0.3 mg.kg-1 i.v. as a loading dose and 0.6 mg.kg-1.h-1 continuous infusion. Furthermore patients in PCS group received propofol PCS (bolus: 0.2 mg.kg-1, lockout time: 3 min). Patients in ACS group were administered propofol continuously and infusion rates were regulated to maintain a sedation score 3 (Wilson et al) by anesthesiologist. Respiratory rate, blood pressure, heart rate, SpO2, arterial blood gas analysis and plasma levels of propofol were measured 4 times during and after the surgery. Satisfaction of patients and surgeons was questioned. Patients in PCS group received a mean propofol dose of 1.9 +/- 0.1 mg.kg-1 during procedures with a mean duration of 147 min. On the other hand patients in ACS group received propofol 2.9 +/- 0.3 mg.kg-1 with 142 min of procedures. Satisfaction of patients and surgeons, the incidence of complication were similar between the groups. For elderly patients who undergo epidural anesthesia, PCS is a safe and effective technique providing similar good sedation as with ACS.     

Tumour cell killing using chemically engineered antibody constructs specific for tumour cells and the complement inhibitor CD59

BACKGROUND: Although beta blockers have been used primarily to decrease unwanted perioperative hemodynamic responses, the sedative properties of these compounds might decrease anesthetic requirements. This study was designed to determine whether esmolol, a short-acting beta 1-receptor antagonist, could reduce the propofol concentration required to prevent movement at skin incision. METHODS: Sixty consenting patients were premedicated with morphine, and then propofol was delivered by computer-assisted continuous infusion along with 60% nitrous oxide. Patients were randomly divided into three groups, propofol alone, propofol plus low-dose esmolol (bolus of 0.5 mg/kg, then 50 micrograms.kg-1.min-1), and propofol plus high-dose esmolol (bolus of 1 mg/kg, then 250 micrograms.kg-1.min-1). Two venous blood samples were drawn at equilibrium. The serum propofol concentration that prevented movement to incision in 50% of patients (Cp50) was calculated by logistic regression. RESULTS: The propofol Cp50 with nitrous oxide was 3.85 micrograms/ ml. High-dose esmolol infusion was associated with a significant reduction in the Cp50 to 2.80 micrograms/ml (P < 0.04). Propofol computer-assisted continuous infusion produced stable serum concentrations with a slight positive blas. Esmolol did not alter the serum propofol concentration. No intergroup differences in heart rate or blood pressure response to intubation or incision were found. CONCLUSIONS: Esmolol significantly decreased the anesthetic requirement for skin incision. The components and mechanism of this interaction remain unclear. A simple pharmacokinetic interaction between esmolol and propofol does not explain the Cp50 reduction. These results demonstrate an anesthetic-sparing effect of a beta-adrenergic antagonist in humans under clinically relevant conditions.     

Comparison of propofol and methohexital continuous infusion techniques for conscious sedation

PURPOSE: Methohexital and propofol have been shown to be effective agents for continuous intravenous infusion to produce conscious sedation during oral surgical procedures. The current study was conducted to compare these techniques for intraoperative cardiopulmonary stability, patient cooperation, amnesia, comfort, recovery time, and postoperative nausea and vomiting. METHODS: Seventy ASA Class I or Class II patients between the ages of 18 and 40 years, scheduled for surgical extraction of impacted third molars, were entered into the study. Thirty-five patients were assigned to group A (methohexital) and 35 were assigned to group B (propofol). Intravenous sedation was accomplished using premedication with 1.5 microg/kg of fentanyl and 0.05 mg/kg of midazolam followed by the continuous infusion of methohexital or propofol at a rate of 50 microg/kg/min. The infusion was then titrated to 100 microg/kg/min to accomplish a level of sedation in which the eyes were closed and the patients were responsive to verbal commands. Subjects were monitored for variability of heart rate, blood pressure, oxygen saturation, amnesia, comfort, cooperation, nausea and vomiting, and recovery time based on cognitive, perceptual, and psychomotor tests. RESULTS: There was no statistical difference between the two medication groups except for heart rate, which was found to increase by 11 beats/min for group A and only three beats/min in group B. CONCLUSION: A continuous infusion technique using either methohexital or propofol (50 to 100 microg/kg/min) was found to be safe and effective, with no clinically significant differences in cooperation, cardiopulmonary stability, recovery time, amnesia, comfort, and the incidence of nausea or vomiting. However, the cost-effectiveness of methohexital is superior to that of propofol.     

Use of Diprivan in radiology

For radiological examinations, propofol is administered, depending on the indications, at following doses: for anxiolysis: i.v. bolus of 10-20 mg, repeated as required; for sedation with maintenance of spontaneous ventilation: i.v. bolus of 0.5 mg.kg-1 or continuous infusion of 3 mg.kg.h-1. for general anaesthesia: i.v. bolus of 2 mg.kg-1 and maintenance with a continuous infusion of 6-10 mg.kg-1.h-1. These doses are modified according to the patient's reactions and painful episodes. In neuroradiology, indications for anaesthesia include vascular explorations, MRI, computerized axial tomography, as well as biopsies of organs and tumors, with the exception of explorations in patients with tight stenoses of the carotid artery. The use of propofol for cardiological explorations is questioned in adults and mainly in children with a congenital cardiopathy. For some authors this agent is contra-indicated, as during induction it decreases, sometimes excessively, the mean arterial pressure.     

Temperament and personality features in panic disorder with or without comorbid mood disorders

We treated a patient with a 30-year history of ethanol and benzodiazepine abuse who, on emerging from general anesthesia, was combative and confused. Our working diagnosis was acute ethanol withdrawal, and the patient received intravenous (i.v.) propofol, and midazolam. Initially small doses (10 to 20 mg) of propofol, combined with a midazolam infusion (50 mg/hr), produced sedation. Later, however, the patient became increasingly combative, confused, hypertensive, and tachycardic despite an i.v. propofol infusion at doses up to 1,000 micrograms/kg/min (total propofol dose: 1,755 mg). Immediate sedation was produced by thiopental bolus (500 mg) and i.v. infusion (200 mg/hr). The implication of the patient's initial appropriate response to propofol, followed by the lack of effect when much higher doses were employed, is discussed. While tachyphylaxis has been reported after long-term propofol use, we believe this to be the first case of acute tachyphylaxis.     

Propofol sedation during awake craniotomy for seizures: electrocorticographic and epileptogenic effects

This prospective study evaluated the effects of propofol sedation on the incidence of intraoperative seizures and the adequacy of electrocorticographic (ECoG) recordings during awake craniotomy performed for the management of refractory epilepsy. Thirty patients scheduled for temporal or frontal lobectomy for epilepsy under bupivacaine scalp block were randomized to receive patient-controlled propofol sedation (PCS) combined with a basal infusion of propofol (n = 15) or neurolept analgesia using an initial bolus dose of fentanyl (0.7 microg/kg) and droperidol (0.04 mg/kg) followed by a fentanyl infusion (n = 15). Propofol administration was suspended 15 min before ECoG recording in the PCS group. The occurrence of inappropriate intraoperative seizures was noted and, based on blind review, the adequacy of ECoG recordings was compared. A higher incidence of intraoperative seizures was noted among the neurolept patients (6 vs 0, P = 0.008). Intraoperatively, ECoG recordings were adequate to proceed with resection in both groups. Evidence of low spike activity on ECoG did not correlate with the type of sedation administered. Higher frequency background ECoG activity was noted among patients who received propofol, but this did not interfere with ECoG interpretation. The use of propofol sedation does not appear to interfere with ECoG during epilepsy surgery, provided administration is suspended at least 15 min before recording.     

Diprivan: sedation for difficult intubation

No study has compared anaesthetic protocols appropriate for the sedation for fiberoptic tracheal intubation. Extrapolation of results of randomised studies comparing sedation techniques for diagnostic bronchoscopy under local anaesthesia enables the following conclusions: 1. Possible hypnotic agents for this procedure are benzodiazepines, barbiturates and propofol. Fentanyl improves the conditions for bronchoscopy. 2. Sedation using propofol is a well established technique. The induction dose, given as a bolus injection is 1 mg.kg-1, followed by continuous maintenance infusion of 1 mg.kg.h-1. 3. Irrespective of the sedation protocol used, there is always respiratory depression which justifies the need for preoxygenation, continuous oxygenation and Spo2 monitoring. Reversal of benzodiazepine and opioid effects may temporarily protect against respiratory depression.     

Use of Diprivan for digestive system endoscopy

After evaluation of the patient's clinical condition and appropriate premedication is seems reasonable to suggest for: 1. Endoscopic procedures involving the gastro-intestinal tract: slow, titrated induction, using 0.5 to 1 mg.kg-1 of propofol, until the required level of sedation has been achieved; this may or not be preceded by the injection of a low dose of midazolam (0.02 to 0.03 mg.kg-1) or of alfentanil (5 micrograms.kg-1); maintenance is achieved by bolus injections of 20 mg (up to 0.5 mg.kg-1); maintenance of spontaneous ventilation, with oxygen administration is the rule; SpO2 is monitored routinely; anaesthesia has to be performed according to the recommendations of the French Society of Anaesthesia and Intensive Care (SFAR) and the anaesthetist must be prepared to manage any incident during the endoscopy and the recovery period. 2. Procedures involving the biliary tract and the oesophagus, which require deeper anaesthesia: induction should again be titrated using a very slow infusion, with doses ranging from 0.9 to 2.2 mg.kg-1); the maintenance requires a continuous infusion, doses ranging from 4 to 6 mg.kg-1.h-1 when propofol is administered alone and from 4 to 12 mg.kg-1.h-1 when combined with an opioid; continuous oxygenation is necessary using a nasal airway; the need for intubation depends on the type of procedure and the status of the patient; the same monitoring devices and similar safety measures are required during and after procedure as for any anaesthetic or sedation, especially when it is performed in day-case patients or outside the operating theatre.     

Patient-controlled sedation and analgesia, using propofol and alfentanil, during colonoscopy: a prospective randomized controlled trial

BACKGROUND AND STUDY AIMS: Patient-controlled sedation (PCS) enables titration of dosage to an individual's requirements and is potentially useful in colonoscopy. The aim was to compare the value of patient-controlled sedation, using propofol and alfentanil, with that of intravenous diazemuls and pethidine during colonoscopy. PATIENTS AND METHODS: Following randomization, 66 patients undergoing colonoscopy received either an intravenous bolus of pethidine (50 mg) and diazemuls (10-20 mg) prior to colonoscopy or were connected to an infusion pump containing propofol (10 mg/ml) and alfentanil (25 microg/ml). Patients self-administered 0.5 ml boluses as often as they required. Pain and sedation score were recorded by a nurse specialist and on a patient questionnaire. An anaesthetist was present throughout the procedure. RESULTS: PCS provided lighter sedation (median sedation score, 3 versus 4; P=0.0001), less analgesia (median pain score, 1 versus 0; P=0.004), a smaller maximum fall in systolic blood pressure (23 mmHg versus 33 mmHg; P=0.02) and a faster recovery time (median 10 min versus 40 min; P=0.0001), irrespective of the dose administered, compared with a diazemuls-pethidine combination. The duration of the procedure was unaffected. All patients were satisfied with their level of sedation. CONCLUSIONS: Patient-controlled sedation is an effective alternative to premedication with narcotic/benzodiazepine combinations during colonoscopy.     

Relationship between auditory intensity discrimination in noise and olivocochlear efferent system activity in humans

The intravenous (i.v.) steroid anesthetic, eltanolone, compares favorably to propofol with respect to its induction characteristics. This double-blind investigation was designed to compare the induction and recovery profile of eltanolone (versus propofol) when it was used for both induction and maintenance of ambulatory anesthesia. Eighty-three consenting ASA physical status I-III outpatients undergoing minor gynecologic or urologic procedures lasting 10-40 min were randomly assigned to one of three anesthetic treatment groups. All patients received midazolam, 2 mg i.v., and fentanyl, 50 micrograms i.v., before induction of anesthesia. The control group (Group 1) was induced with propofol, 2.4 mg/kg i.v. (18-60 yr or ASA physical status I or II) or 1.6 mg/kg i.v. (61-80 yr and/or ASA physical status III), followed by intermittent bolus doses of 0.6 mg/kg i.v. in combination with N2O 67% for maintenance of anesthesia. In Group 2, anesthesia was induced with eltanolone, 0.75 mg/kg i.v., (18-60 yr and/or ASA physical status I or II) or 0.5 mg/kg i.v. (61-80 yr and/or ASA physical status III), and maintained with intermittent bolus injections of 0.2 mg/kg i.v. and N2O 67%. Group 3 received eltanolone, 1.0 mg/kg i.v. (18-60 yr and/or ASA physical status I or II), or 0.75 mg/kg i.v. (61-80 yr and/or ASA physical status III), followed by intermittent bolus injections of 0.2 mg/kg i.v. and N2O 67%. In addition to recording the induction and recovery times and side effects, psychomotor testing was performed before and at 30-min intervals after anesthesia. Induction times (57 +/- 23, 67 +/- 26, and 61 +/- 22s, respectively) were similar in all three groups. Although eltanolone produced no pain on injection (versus 52% in the propofol group), 10% of the eltanolone-treated patients (versus none in the propofol group) developed transient cutaneous (rash-like) reactions. The total dose of study medication used during the anesthetic period was 9.2 +/- 3.7 mg.kg-1.h-1 in the propofol group compared with 3.3 +/- 1.4 mg.kg-1.h-1 and 3.3 +/- 1.9 mg.kg-1.h-1 in Groups 2 and 3, respectively. Early recovery times were significantly shorter after propofol anesthesia. However, times to ambulation, micturition, and being judged "fit for discharge," as well as recovery of cognitive function, were similar in all three groups. Although ethanolone seems to be a safe and effective i.v. anesthetic, these data suggest that it is unlikely to replace propofol in the ambulatory setting. Implications: Eltanolone is an investigational steroid anesthetic that causes less pain on injection and less cardiovascular depression than propofol (the most widely used intravenous anesthetic in the outpatient setting). Unfortunately, emergence from anesthesia after ambulatory surgery is slower with eltanolone compared with propofol. Therefore, it is unlikely that eltanolone will replace propofol for outpatient anesthesia.     

Use of 2% propofol to produce diurnal sedation in critically ill patients

OBJECTIVE: The assessment of propofol to produce diurnal sedation in critically ill patients. DESIGN: Prospective clinical study. SETTING: Intensive Care Unit, University Hospital. PATIENTS AND PARTICIPANTS: Thirty consecutive patients admitted to the Intensive Care Unit older than 18 years who were expected to be sedated for more than 50 h. INTERVENTIONS: The patients were randomised into two groups. All received sedation with a constant background infusion of morphine and a variable infusion rate of propofol, which was altered hourly to maintain the intended sedation score. The first group received constant light sedation (CLS) over 50 h aiming for a Ramsay score of 2-3. The second group received CLS between 0600 h and 2200 h and additional night sedation (ANS) with propofol between 2200 h and 0600 h, aiming for a sedation score of 4-5. MEASUREMENTS AND RESULTS: Patients were studied for 50 h from 1800 h on the first day of admission. Recordings of heart rate, blood pressure, sedation scores and propofol and morphine infusion rates were made hourly. An APACHE II score was recorded for each patient. Sedation scores were analysed by blind visual assessment and cosinor analysis, which is used in chronobiology to examine the correlation of data with a cosine curve. Patients in the ANS group had significantly better rhythmicity of sedation levels using cosinor analysis (r = 26% v 8%) p < 0.01. There was no difference between the CLS and ANS groups with respect to age, sex or APACHE II scores. Nine out of 15 patients in the ANS group achieved diurnal sedation. Three patients in the CLS group showed diurnal rhythmicity of sedation, which can be attributed to natural sleep, and had a median APACHE II score of 12. Five patients in the CLS group and three in the ANS group showed a deep constant sedation pattern. They had high APACHE II scores (median 21.5) and an obtunded conscious level on admission due to severe sepsis. CONCLUSION: Propofol can safely provide diurnal sedation in the critically ill when titrated against the Ramsay score. Sedation levels cannot be manipulated in some severely ill patients.     

Temperature-dependent formation of a conjugate between tris(hydroxymethyl)aminomethane buffer and the malondialdehyde-DNA adduct pyrimidopurinone

OBJECTIVE: To examine the effects of cardiopulmonary bypass (CPB) on total and unbound plasma concentrations of propofol and midazolam when administered by continuous infusion during cardiac surgery. DESIGN: Prospective clinical study. SETTING: University hospital. PARTICIPANTS: Twenty-four adult patients undergoing cardiac surgery. INTERVENTIONS: Patients received either propofol or midazolam to supplement fentanyl anesthesia. Twelve patients received a propofol bolus (1 mg/kg) followed by an infusion of 3 mg/kg/hr. A second group received midazolam, 0.2 mg/kg bolus, followed by an infusion of 0.07 mg/kg/hr. MEASUREMENTS AND MAIN RESULTS: Blood sample were collected from the radial artery cannula at 0, 2, 4, 8, 8, 10, 15, 20 minutes and then every 10 minutes before CPB, at 1, 2, 3, 4, 6, 10, 15, 20 minutes and then each 10 minutes during CPB. On weaning from CPB samples were collected at 0, 5, 10 and 20 minutes. Plasma binding, total and unbound propofol and midazolam concentrations were determined by ultrafiltration and high-pressure liquid chromatography (HPLC). CPB resulted in a fall in total propofol and midazolam plasma concentrations, but the unbound concentrations remained stable. The propofol unbound fraction increased from 0.22 +/- 0.06% to 0.41 +/- 0.17%. The midazolam unbound fraction increased from 5.6 +/- 1.0% to 11.2 +/- 2.1%. CONCLUSIONS: Unbound concentrations of propofol and midazolam are not affected by cardiopulmonary bypass. Total intravenous anesthesia algorithms do not need to be changed to achieve stable unbound plasma concentrations when initiating CPB.     

Propofol in continuous infusion for performing nuclear magnetic resonance in children: an effective alternative to sedation with other drugs

Sedation is often needed for obtaining nuclear magnetic resonance (NMR) images in children. The aim of this study was to evaluate the efficacy of propofol administered by continuous infusion to non-intubated children for whom our hospital's usual method of sedation (oral chlorohydrate 75 mg/kg at a maximum dose of 2 g plus 4 hours sleep privation the night before) had failed. Deep sedation was induced in 37 ASA I-II children aged 4 and 14 year old, with 2.5 mg/kg propofol followed by 6 mg/kg/h in continuous infusion. An additional dose of 1 mg/kg was administered if the child moved, and the perfusion was reduced to 4 mg/kg if SpO2 fell below 95%. Apnea occurred after induction in 24% (n = 9), 29% (n = 11) required additional doses of propofol, and a tendency to hypercapnia was observed as the imaging procedure progressed. Sedation failed in one child, who required general anesthesia when opisthotonos presented after the induction dose. Awakening was early and satisfactory in all patients, with a score of 2 on the Ramsay scale 15 minutes after NMR. Deep sedation with propofol is a safe and effective method of performing NMR in a child for whom other methods of sedation have failed, provided the child is ASA I-II, monitoring is exhaustive and procedure is carried out by an anesthesiologist.     

Relation between impedance and electrode temperature during radiofrequency catheter ablation of accessory pathways and atrioventricular nodal reentrant tachycardia

OBJECTIVES: To evaluate and compare the clinical efficacy, impact on hemodynamics, safety profiles, and cost of combined administration of propofol and midazolam (synergistic sedation) vs. midazolam and propofol administered as sole agents, for sedation of mechanically ventilated patients after coronary artery bypass grafting. DESIGN: Prospective, controlled, randomized, double-blind clinical trial. SETTING: Intensive care unit of SCIAS-Hospital de Barcelona. PATIENTS: Seventy-five mechanically ventilated patients who underwent coronary artery bypass graft surgery under low-dose opioid anesthesia. INTERVENTIONS: According to the double-blind method, patients were randomly assigned to receive propofol (n = 25), midazolam (n = 25), or propofol combined with midazolam (n = 25). Infusion rates were adjusted to stay between 8 and 11 points on Glasgow Coma Score modified by Cook and Palma. MEASUREMENTS AND MAIN RESULTS: Mean +/- SD duration of sedation was 14.4 +/- 1.5 hrs, 14.1 +/- 1.1 hrs, and 14.7 +/- 1.9 hrs for the propofol, midazolam, and synergistic groups, respectively. The induction dose was 0.55 +/- 0.05 mg/kg for propofol as sole agent, 0.05 +/- 0.01 mg/kg for midazolam as sole agent, and 0.22 +/- 0.03 mg/kg for propofol administered in combination with 0.02 +/- 0.00 mg/kg of midazolam (p = .001). The maintenance dose was 1.20 +/- 0.03 mg/kg/hr for propofol as sole agent, 0.08 +/- 0.01 mg/kg/hr for midazolam as sole agent, and 0.50 +/- 0.09 mg/kg/hr for propofol administered in combination with 0.03 +/- 0.01 mg/kg/hr of midazolam (p < .001). All sedative regimens achieved similar efficacy in percentage of hours of adequate sedation (93% for propofol, 88% for midazolam, and 90% for the synergistic group, respectively). After induction, both propofol and midazolam groups had significant decreases in systolic blood pressure, diastolic blood pressure, left atrial pressure, and heart rate. Patients in the synergistic group had significant bradycardia throughout the study, without impairment in other hemodynamic parameters. Patients sedated with propofol or synergistic regimen awoke sooner and could be extubated before those patients sedated with midazolam (0.9 +/- 0.3 hrs and 1.2 +/- 0.6 hrs vs. 2.3 +/- 0.8 hrs, respectively, p = .01). Synergistic sedation produced cost savings of 28% with respect to midazolam and 68% with respect to propofol. CONCLUSIONS: In the study conditions, the new synergistic treatment with propofol and midazolam administered together is an effective and safe alternative for sedation, with some advantages over the conventional regimen with propofol or midazolam administered as sole agents, such as absence of hemodynamic impairment, >68% reduction in maintenance dose, and lower pharmaceutical cost.     

Determination of plasma concentrations of propofol associated with 50% reduction in postoperative nausea

BACKGROUND: Subhypnotic doses of propofol possess direct antiemetic properties. The authors sought to determine the plasma concentration of propofol needed to effectively manage postoperative nausea and vomiting. METHODS: Patients aged 18-70 yr who were classified as American Society of Anesthesiologists physical status 1 or 2 and had surgery during general anesthesia were approached for the study. Only patients who had nausea (verbal rating score > 5 on a 0- to 10-point scale), retching, or vomiting in the postanesthetic care unit participated. Propofol was administered to these patients to achieve target plasma concentrations of 100, 200, 400, and 800 ng/ml using a computer-assisted continuous infusion device. Target concentrations were increased every 15 min until patients described at least a 50% reduction in symptoms on the verbal rating score. An arterial blood sample was obtained at each step. The measured plasma propofol concentrations were used to analyze data. Blood pressure, heart and respiratory rates, arterial blood saturation, sedation score, and overall satisfaction with treatment were recorded. RESULTS: Of the 89 patients who consented to the study, 15 patients met entry criteria and were enrolled. Five of these patients also had retching or vomiting when they entered the study. Fourteen patients responded successfully to treatment. One patient did not achieve the required response at plasma concentrations of 830 ng/ml. Hence the success rate for the treatment of postoperative nausea and vomiting was 93%. Among patients who responded, the median plasma concentration associated with an antiemetic response was 343 ng/ml. There was no difference in sedation scores from baseline and no episodes of desaturation. Hemodynamic parameters were stable during the study. CONCLUSIONS: Propofol is generally efficacious in treating postoperative nausea and vomiting at plasma concentrations that do not produce increased sedation. Simulations indicate that to achieve antiemetic plasma propofol concentrations of 343 ng/ml, a bolus dose of 10 mg followed by an infusion of approximately 10 microg x kg(-1) x min(-1) are necessary.     

1% mepivacaine and axillary block: duration of the sensory and motor blockade

Patient-controlled sedation (PCS) using propofol under spinal anesthesia in transurethral lithotripsy was carried out in a 44 year old patient with von Gierke disease accompanied with liver dysfunction, chronic renal failure, hypoglycemia and metabolic acidosis. After administering spinal anesthesia PCS was started (0.2 mg.kg-1 intravenous bolus dose of propofol; infusion at 2 mg.kg-1.h-1; a three-minute lockout time interval following an initial doses of 0.4 mg.kg-1). PCS with propofol, throughout the operation, brought about adequate sedation level for this patient with 2 or 3 on Wilson's sedation score, and the sedative effect by propofol diminished quickly within 15 minutes after the end of PCS. In addition, respiratory depression due to this sedation which would be worse in acidotic condition was not seen using PCS during the operation. This patient was much satisfied with this sedation in an interview during the postoperative period. PCS using propofol is a useful method without respiratory depression for a patient with von Gierke disease.     

Postoperative hypoxaemia: continuous extradural infusion of bupivacaine and morphine vs patient-controlled analgesia with intravenous morphine

We carried out a randomized prospective study in 60 patients who had undergone major abdominal surgery for cancer. For postoperative pain control, 30 patients received continuous extradural infusion of 0.125% bupivacaine 12.5 mg h-1 and morphine 0.25 mg h-1 (EXI group) and 30 received patient-controlled analgesia (PCA) with intravenous morphine (1 mg bolus, 5-min lock-out and maximum dose 20 mg 4h-1). Both groups had general anaesthesia. The two groups were compared for postoperative pain scores, satisfaction, sedation and oxygen saturation. Oxygen saturation was recorded continuously the night before surgery and for two consecutive postoperative nights. Episodes of moderate desaturation (90% > SpO2 85%) were more frequent in the EXI group than in the PCA group (P < 0.05). Pain scores were lower in the EXI group compared with the PCA group at rest and while coughing (P < 0.05). No significant difference was found for patient sedation and satisfaction.     

Patient-controlled versus anesthesiologist-controlled conscious sedation with propofol for dental treatment in anxious patients

In a randomized, cross-over study, we prospectively compared the efficacy and quality of two methods to achieve conscious sedation with propofol in 11 unpremedicated, anxious dental patients. Each patient underwent two dental procedures, one that was conducted under target-controlled infusion (TCI) by the anesthesiologist (ACS), and the other that used patient-controlled sedation (PCS). The initial target concentration in the ACS mode was 2.5 microg/mL, which was manipulated in both directions until the desired clinical end point was achieved. In the PCS mode, a 4-mg bolus of propofol (10 mg/mL) was delivered at each activation of the machine, infused over 7 s without a lockout interval. The anxious dental patients could induce and maintain conscious sedation with the PCS settings. The mean (range) venous blood propofol concentrations were not significantly different with either mode: ACS 1.8 (0.8-2.7) microg/mL and PCS 1.2 (0.2-2.5) microg/mL. The level of patient satisfaction, quality of sedation, and treatability were not different for either mode of sedation. The intensity of amnesia for intraoperative events was related to the blood concentrations achieved. In the ACS mode, one patient became unresponsive (sedation level 4) immediately after the start of sedation. No adverse cardiorespiratory effects resulted from either mode of propofol sedation. Five patients expressed a strong preference for PCS, and three would prefer ACS in the future. The results of the present study suggest that with these PCS settings, a satisfactory level of conscious sedation and a high level of patient satisfaction was achieved. Implications: In a randomized, cross-over study, the blood propofol concentrations necessary to achieve conscious sedation in anxious dental patients using a target-controlled infusion conducted by the anesthesiologist versus patient-controlled sedation were not different. With the patient-controlled sedation settings, a satisfactory level of conscious sedation and a high level of patient satisfaction were achieved.     

Helicobacter pylori eradication in the healing and recurrence of benign gastric ulcer: a two-year, double-blind, placebo controlled study

STUDY OBJECTIVE: To evaluate the safety and efficacy of monitored anesthesia care (MAC) in patients who undergo a novel treatment for hepatocellular cancer in which procedure-related hemodynamic instability is problematic. DESIGN: Nonrandomized open study. SETTING: University cancer center operating room. PATIENTS: Nine patients scheduled for hepatic arterial infusion of doxorubicin with complete hepatic venous isolation and extracorporeal chemofiltration (no more than 3 procedures per patient). INTERVENTIONS: Hepatic venous isolation was achieved with a dual-balloon inferior vena cava catheter connected to an extracorporeal circuit containing chemofilters. Doxorubicin was infused through the hepatic artery and filtered from the venous blood, which was returned to the patient through an internal jugular venous catheter. Each patient received a bolus of propofol (200 micrograms/kg) and one of alfentanil (2 micrograms/kg) followed by simultaneous infusions of propofol and alfentanil for percutaneous placement of the catheters and operation of the extracorporeal circuit. Drug rates were varied to maintain a sedative-analgesic state of calm, comfort, minimal movement, and adequate respiratory function. Prior to circuit initiation, patients were preloaded with crystalloid. During circuit operation, hypotension was treated with intravenous (IV) phenylephrine and crystalloid. MEASUREMENTS AND MAIN RESULTS: End-tidal CO2 (PETCO2), respiratory rate, oxygen saturation (SaO2), arterial blood pressure (BP), and heart rate (HR) were monitored. Systolic, diastolic, and mean arterial pressure (MAP), and HR were compared before, during, and after hepatic venous isolation and chemofiltration. Doses and infusion rates of propofol, alfentanil, and phenylephrine were recorded for each treatment. Hypotension occurred in 11 of 13 procedures when blood was directed through the chemofilters and was successfully treated with phenylephrine (dose range 40 to 5,733 micrograms) and crystalloid. Blood pressure returned to the baseline value on termination of the circuit. Throughout the sedation, patients were easily arousable, analgesia was adequate, and PETCO2 level of 38 +/- 4 mmHg and SaO2 greater than 94% were maintained. Mean doses and infusion rates of MAC drugs were, respectively: propofol, 261 +/- 88 mg and 23.7 +/- 3.6 micrograms/kg/min; alfentanil, 3,350 +/- 1,468 micrograms and 0.32 +/- 0.14 microgram/kg/min. CONCLUSIONS: Patients undergoing this novel cancer treatment are safely and effectively managed by MAC achieved with simultaneous infusions of alfentanil and propofol. Procedure-associated hypotension is easily treated with IV phenylephrine and crystalloid.