Growth of Escherichia coli in propofol, lidocaine, and mixtures of propofol and lidocaine

BACKGROUND: Microorganisms grow rapidly in propofol. Extrinsic contamination of propofol is thought to be a source of postoperative sepsis and wound infection. We studied growth of a strain of Escherichia coli in thiopental, propofol, lidocaine, and mixtures of propofol and lidocaine. METHODS: The pathogen was exposed to 2.5% thiopental; 1.0% propofol; 1.0%, 2.0% and 4.0% preservative-free lidocaine; and propofol solutions containing 0.25%, 0.5%, 1.0%, 2.0%, or 4.0% lidocaine for 2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, and 24 h at room temperature, respectively. The inocula from these suspensions were cultured for 48 h at 37 degrees C after the antimicrobial activity of the local anesthetics in the inocula was inactivated by a 1:1000 dilution with distilled water. RESULTS: No organisms grew after exposure to 2.5% thiopental. The exposure of E. coli to propofol increased the colony count to approximately 90 times the control count. The colony counts of E. coli after exposure to 1.0%, 2.0% and 4.0% lidocaine and 0.25%, 0.5%, 1.0%, 2.0% and 4.0% lidocaine in 1.0% propofol were lower than the counts after exposure to 1.0% propofol (P = 0.0048, 0.0027, 0.0003, 0.0503, 0.0188, 0.0080, 0.0044, and 0.0001, respectively). The growth rate of the microorganism was significantly higher in cultures exposed to 1.0% propofol than that in cultures exposed to lidocaine alone or lidocaine-propofol mixtures (P < 0.0001, respectively). CONCLUSION: Lidocaine possesses bacteriostatic activity against E. coli. Addition of lidocaine to propofol confers its bacteriostatic activity to the mixture and may decrease the hazard of infection associated with the extrinsic contamination of propofol.     

Interactive web simulation for propofol and fospropofol, a new propofol prodrug

Using pharmacokinetic and pharmacodynamic data published in the scientific literature, we have developed interactive on-line simulations to model administration of propofol and fospropofol, a new water-soluble prodrug formulation of propofol. The prodrug formulation of fospropofol leads to a delayed onset to peak concentrations of propofol. A comparison simulation that overlays administration of fospropofol and propofol allows clinicians to understand the differences of administering fospropofol and traditional propofol. The simulations have the added advantage of allowing for differences among patients documented in test studies and the use of different models.     

Convulsions, ataxia and hallucinations following propofol

A 6-year-old fit girl experienced convulsions 44 h after an otherwise uneventful anaesthesia with propofol, alfentanil and nitrous oxide. As an underlying pathology was suspected, the child was kept sedated for 6.5 h for further investigations. During this period she received a continous infusion of propofol amounting in total to 1600 mg. After having regained consciousness, she was strikingly ataxic and remained so for 5 days. During this period she also experienced two episodes of hallucinations lasting about 2 h. Investigations including lumbar puncture, EEG, cerebral CT and MR scan could not explain the neurological symptoms. She recovered without long-term sequelae.     

Intra-arterial injection of metoclopramide,midazolam, propofol and pethidine

A case is reported in which metoclopramide, midazolam, propofol, and pethidine were injected arterially during the course of anaesthesia, resulting in oedema and discolouration of the hand initially, but no long-term sequelae. An AVI 470 pump (3M Corporation) was used to control the infusion, andprevented backflow through a cannula which was unintentionally sited in an artery rather than a vein. Few anaesthetic drugs have their effects well documented when given arterially, and in particular, there were no previous reported cases involving metoclopramide in this context. The pharmacology of metoclopramide is discussed with reference to the drug's known effects on vascular beds and platelet function.     

Recovery after anesthesia for short pediatric oncology procedures: propofol and remifentanil compared with propofol, nitrous oxide, and sevoflurane

Anesthesia techniques in children undergoing short painful oncology procedures should allow rapid recovery without side effects. We compared the recovery characteristics of two anesthetic techniques: propofol with sevoflurane and nitrous oxide and a total IV technique using propofol and remifentanil. Twenty-one children, undergoing two similar painful procedures within 2 wk were studied in a single-blind manner within patient comparison. The order of the techniques was randomized. Propofol and remifentanil involved bolus doses of both propofol 3-5 mg/kg and remifentanil 1-4 microg/kg. Propofol with sevoflurane and nitrous oxide involved propofol 3-5 mg/kg with 2%-8% sevoflurane and 70% nitrous oxide. The primary outcome variable was the time taken to achieve recovery discharge criteria; other recovery characteristics were also noted. The mean age of the children was 6.5 yr (range, 2.5-9.8 yr). Nineteen had lymphoblastic leukemia and two had lymphoma. All children had intrathecal chemotherapy and one had bone marrow aspiration. Most procedures lasted <4 min. The mean time to achieve recovery discharge criteria was appreciably shorter after propofol and remifentanil than propofol with sevoflurane and nitrous oxide by nearly 19 min (P = 0.001). All other time comparisons had similar trends and statistical differences. Seven parents expressed a preference for the propofol and remifentanil technique compared with one preferring propofol with sevoflurane and nitrous oxide. Children are apneic during the procedure and require respiratory support from an anesthesiologist. Discharge readiness from the recovery ward was achieved on average 19 min earlier after propofol with remifentanil compared with the combination of propofol, sevoflurane and nitrous oxide. Parents more often preferred propofol with remifentanil.     

A controlled investigation of propofol,thiopentone and methohexitone

This was a randomized study of 180 ASA physical status I and II patients, 60 in each group who received propofol (PROP), 2.5 mg . kg-1, thiopentone (THIO), 4 mg . kg-1, or methohexitone (METH), 1.5 mg . kg-1. Control values, followed by changes after induction and during a 3-min delay before intubation were recorded for the following parameters: heart rate (HR), systolic and diastolic blood pressures (SBP, DBP), respiratory rate (RR), end-tidal CO2 (PETCO2), and induction time (IT). In addition, the incidence of adverse reactions and time for recovery from anaesthesia were noted. The IT (mean +/- SE) was 35 +/- 1 sec for propofol, 35 +/- 1.2 sec for thiopentone and 34 +/- 1.4 sec for methohexitone. Ninety-three per cent of the PROP group fell asleep with one dose and required no additional doses. Fifty per cent of each of the THIO and METH groups required additional agents (p less than 0.05). METH was associated with the highest elevation in HR, PROP the least (p less than 0.05). PROP was associated with the most decrease in SBP and DBP and in addition respiratory depression (p less than 0.05). The incidence of injection pain or excitatory activity was equal in the three groups with the exception that 14 patients who received METH developed hiccoughs while none did in the other groups. PROP was associated with the most rapid recovery, particularly with respect to the orientation time. We conclude that PROP is an effective alternative to barbiturate induction and that the published recommended doses of THIO and METH are often ineffective.     

Dreams, images and emotions associated with propofol anaesthesia

One hundred and twelve patients scheduled for day case varicose vein surgery were randomly allocated to one of three groups: total intravenous anaesthesia with propofol, propofol induction followed by inhalational anaesthesia with nitrous oxide and isoflurane or thiopentone induction followed by inhalational anaesthesia with nitrous oxide and isoflurane. Assessments were made in the recovery room of the incidence of dreaming, the content of the dreams and the emotional status of the patients. The groups differed significantly in reporting that they had been dreaming: patients who underwent total intravenous anaesthesia reported the most dreaming and patients who received thiopentone the least. However, despite the large number of case reports of sexual imagery following propofol anaesthesia and despite the two groups who had received propofol experiencing significantly greater happiness upon recovery than the thiopentone group, there were no appreciable differences in the sexual content of the dreams. Each group had only a small number of dreams even remotely related to sex.     

Induction and recovery characteristics of propofol, thiopental and etomidate

Propofol, thiopental and etomidate, with 20 patients in each group, were compared for anesthesia of short duration in women undergoing termination of pregnancy, with respect to: 1: pain on injection (equally often after propofol and etomidate, but more rarely after thiopental); 2: apnea following induction (no difference); 3: involuntary muscular movements more frequent after etomidate); 4: blood pressure (larger drop after propofol); 5: heart rate (greater increase after thiopental); 6: time to eye opening on command (longer after propofol); 7: Steward score on eye opening (no difference); 8: coin counting after 15, 30 and 60 min (performance better after propofol at 15 and 30 min, producing even shorter times than preoperatively at 60 min); 9: reaction time after 15, 30 and 60 min (performance better after propofol, producing even shorter times than preoperatively at 60 min. It is concluded that the faster recovery gives propofol an advantage over thiopental and etomidate in outpatient anesthesia.     

Complement activation by propofol and its effect during propofol anaesthesia

We have examined whether propofol activates complement. In the first study, blood was mixed with saline, propofol or the lipid solvent for propofol, and the activated complement 3 (C3a) and 4 (C4a) concentrations in the supernatant were assayed. In the second study, blood and propofol were mixed with various levels of nafamostat mesilate (anti-complement agent) up to 0.3 mmol/l and the C3a was assayed. In the third study, the time course of plasma C3a concentration in patients during propofol anaesthesia was examined. The results showed that the lipid solvent activated complement and produced similar levels of C3a to propofol, probably via both the classical and alternative pathways. This activation was not inhibited by any of the nafamostat concentrations used. There was no significant change in plasma C3a concentration during propofol anaesthesia. These results suggest that C3a is generated by the lipid solvent, but its accumulation during propofol anaesthesia is minimal.     

Intravenous lidocaine and ephedrine, but not propofol, suppress fentanyl-induced cough

PURPOSE: The aim of this study was to evaluate the effectiveness of lidocaine, propofol and ephedrine in suppressing fentanyl-induced cough. METHODS: One hundred and eighteen patients were randomly assigned into four groups and the following medications were given intravenously: patients in Group I (n = 31) received normal saline 2 mL, Group II (n = 29) received lidocaine 2 mg.kg(-1), Group III (n = 30) received propofol 0.6 mg.kg(-1) and Group IV (n = 28) received ephedrine 5 mg. At one minute after the study medication, fentanyl 2.5 microg.kg(-1) was given intravenously within two seconds. The occurrence of cough and vital sign profiles were recorded within two minutes after fentanyl bolus by an anesthesiologist blinded to study design. RESULTS: Sixty-five percent of patients in the placebo group had cough, whereas the frequency was significantly decreased in Groups II (14%) and IV (21%). Although a numerically lower frequency of cough was noted in Group III (37%), it was not statistically different from that of the placebo group. SpO(2) decreased significantly in patients of Group III compared to placebo; one patient experienced hypoxemia necessitating mask ventilation. Patients in Group III showed a decrease in heart rate and systolic blood pressure (2 beats.min(-1) and 8 mmHg vs baseline). Patients in Group IV showed an increase in both measurements (5 beats.min(-1) and 8 mmHg vs baseline). No truncal rigidity was observed throughout the study. CONCLUSIONS: Intravenous lidocaine 2 mg.kg(-1) or ephedrine 5 mg, but not propofol 0.6 mg.kg(-1), was effective in preventing fentanyl-induced cough. The results provide a convenient method to decrease fentanyl-induced cough.     

Renal responses to low-flow desflurane, sevoflurane, and propofol in patients

BACKGROUND: The contributing factors that result in significant, postoperative proteinuria and glucosuria after low-flow isoflurane and sevoflurane anesthesia are unknown. The present study compared renal responses after anesthesia with desflurane (negligible metabolism), sevoflurane, or intravenous propofol. METHODS: Informed consent was obtained from 52 patients with American Society of Anesthesiologists physical status I-III (aged 36-81 yr). Patients with diabetes or renal insufficiency were excluded. Desflurane (n = 20) or sevoflurane (n = 22), without nitrous oxide, was given at 1 l/min fresh gas flow for elective surgical procedures lasting more than 2 h; 10 patients received propofol without nitrous oxide as the primary anesthetic. Blood and urine chemistries were obtained before surgery. Blood and 24-h urine collections were obtained for 3 days after surgery and were analyzed for liver and renal indices. RESULTS: Length of surgery averaged approximately 300 min (range, 136-750 min), minimum alveolar concentration-hour averaged 4.3 (range, 1.2-11.0), and infusion rates of propofol were 99-168 microg x kg(-1) x min(-1). Plasma creatinine concentration did not change, plasma blood urea nitrogen decreased significantly, and significant increases in urine glucose, protein, and albumin occurred similarly in all groups. Mean (+/- SD) postoperative urine glucose values for day 1 after desflurane, sevoflurane, and propofol were 1.4 +/- 3.0, 1.1 +/- 2.1, and 1.9 +/- 2.6 g/d (normal, < 0.5 g/d). The average daily protein/creatinine ratios for postoperative days 2-3 after desflurane, sevoflurane, and propofol were 240 +/- 187, 272 +/- 234, and 344 +/- 243 (normal, < 150 mg/g). Regardless of anesthetic, there were significantly greater urine protein concentrations after surgical procedures in central versus peripheral regions. CONCLUSIONS: Alterations in postoperative renal function were common and unrelated to the choice of anesthetic. These findings implicate nonanesthetic factors in producing changes in biochemical indices of renal excretory function.