OBJECTIVE: To determine whether limiting intraoperative sedation depth during spinal anesthesia for hip fracture repair in elderly patients can decrease the prevalence of postoperative delirium. PATIENTS AND METHODS: We performed a double-blind, randomized controlled trial at an academic medical center of elderly patients (>/=65 years) without preoperative delirium or severe dementia who underwent hip fracture repair under spinal anesthesia with propofol sedation. Sedation depth was titrated using processed electroencephalography with the bispectral index (BIS), and patients were randomized to receive either deep (BIS, approximately 50) or light (BIS, >/=80) sedation. Postoperative delirium was assessed as defined by Diagnostic and Statistical Manual of Mental Disorders (Third Edition Revised) criteria using the Confusion Assessment Method beginning at any time from the second day after surgery. RESULTS: From April 2, 2005, through October 30, 2008, a total of 114 patients were randomized. The prevalence of postoperative delirium was significantly lower in the light sedation group (11/57 [19%] vs 23/57 [40%] in the deep sedation group; P=.02), indicating that 1 incident of delirium will be prevented for every 4.7 patients treated with light sedation. The mean +/- SD number of days of delirium during hospitalization was lower in the light sedation group than in the deep sedation group (0.5+/-1.5 days vs 1.4+/-4.0 days; P=.01). CONCLUSION: The use of light propofol sedation decreased the prevalence of postoperative delirium by 50% compared with deep sedation. Limiting depth of sedation during spinal anesthesia is a simple, safe, and cost-effective intervention for preventing postoperative delirium in elderly patients that could be widely and readily adopted. Trial Registration: clinicaltrials.gov Identifier: NCT00590707. less...

STUDY DESIGN: A case report describing a rare perioperative complication involving the intrathoracic placement of a central venous catheter during spine surgery leading to hemodynamic instability. OBJECTIVE: To review the efficacy of central line use in perioperative spine patients and to describe the diagnosis, emergent treatment, and postoperative care of a unique case of intrathoracic extravasation of propofol. SUMMARY OF BACKGROUND DATA: Although placement of central line access is a safe procedure, complications can occur. A case in which a venous catheter delivering propofol into the thorax has never been documented. METHODS: A 48-year-old woman presented for revision spine surgery, and a central line was placed. After placement of spinal instrumentation, she became hemodynamically unstable secondary to mediastinal compression caused by pressure from intraoperative propofol and fluid insufflation. RESULTS: A chest tube was placed, and with aggressive pulmonary toilet and physical therapy, she did well and was discharged without noted symptoms. CONCLUSION: The efficacy of central line use should be carefully considered in perioperative spine surgery, and in patients with significant risk factors, placement of central venous access should be radiographically confirmed. less...

OBJECTIVE: To determine the effect of oral sodium phosphate solution, as a colon preparation agent, on the serum potassium level in patients undergoing colonoscopy under IV anesthesia. MATERIAL AND METHOD: Patients set to undergo elective colonoscopy under IV anesthesia (propofol infusion) were recruited to participate in the present study during the period between October 2008 and January 2009. All patients had normal serum potassium level prior to colon preparation, and all ingested 90 ml of sodium phosphate solution one day before colonoscopy. Blood samples for post preparation potassium level determination were taken immediately before administering IV propofol. Baseline data including age, gender, diagnosis, indication for colonoscopy, underlying illness, concurrent medications and serum potassium and creatinine levels were recorded The serum potassium levels were compared before and after colon preparation, and potentially important baseline risk factors for low potassium levels after colon preparation were determined. RESULTS: In 48 patients, there was a 0.57 mmol/L (from 4.11 to 3.54 mmol/L) average reduction in the serum potassium level after colon preparation. There were no significant adverse events during colonoscopy. No significant risk factors were identified on multivariable linear regression analysis. CONCLUSION: There was a mild reduction in serum potassium level after colon preparation with oral sodium phosphate solution, which was probably not clinically significant. Prophylactic potassium supplement or routine serum potassium monitoring after oral sodium phosphate colon preparation did not seem to be necessary for this group of patients. less...

Objective-To assess the effects of alterations in PaCO(2) and PaO(2) on blood oxygenation level-dependent (BOLD) signal intensity determined by use of susceptibility-weighted magnetic resonance imaging in brains of isoflurane-anesthetized dogs. Animals-6 healthy dogs. Procedures-In each dog, anesthesia was induced with propofol (6 to 8 mg/kg, IV) and maintained with isoflurane (1.7%) and atracurium (0.2 mg/kg, IV, q 30 min). During 1 magnetic resonance imaging session in each dog, targeted values of PaCO(2) (20, 40, or 80 mm Hg) and PaO(2) (100 or 500 mm Hg) were combined to establish 6 experimental conditions, including a control condition (PaCO(2), 40 mm Hg; PaO(2), 100 mm Hg). Dogs were randomly assigned to different sequences of conditions. Each condition was established for a period of >/= 5 minutes before susceptibility-weighted imaging was performed. Signal intensity was measured in 6 regions of interest in the brain, and data were analyzed by use of an ANCOVA and post hoc Tukey-Kramer adjustments. Results-Compared with control condition findings, BOLD signal intensity did not differ significantly in any region of interest. However, signal intensities in the thalamus and diencephalic gray matter decreased significantly during both hypocapnic conditions, compared with all other conditions except for the control condition. Conclusions and Clinical Relevance-In isoflurane-anesthetized dogs, certain regions of gray matter appeared to have greater cerebrovascular responses to changes in PaCO(2) and PaO(2) than did others. Both PaO(2) and PaCO(2) should be controlled during magnetic resonance imaging procedures that involve BOLD signaling and taken into account when interpreting findings. less...

BACKGROUND: /st> Emergence agitation (EA) in children is increased after sevoflurane anaesthesia. The efficacy of prophylactic treatment is controversial. The aim of this study was to provide a meta-analysis of the studies of the pharmacological prevention of EA in children. METHODS: /st> A comprehensive literature search was conducted to identify clinical trials that focused on the prevention of EA in children anaesthetized with sevoflurane, desflurane, or both. The data from each trial were combined using the Mantel-Haenszel model to calculate the pooled odds ratio (OR) and 95% confidence interval. I(2) statistics were used to assess statistics heterogeneity and the funnel plot and the Begg-Mazumdar test to assess bias. RESULTS: /st> Thirty-seven articles were found which included a total of 1695 patients in the intervention groups and 1477 in the control ones. Midazolam and 5HT(3) inhibitors were not found to have a protective effect against EA [OR=0.88 (0.44, 1.76); OR=0.39 (0.12, 1.31), respectively], whereas propofol [OR=0.21 (0.16, 0.28)], ketamine [OR=0.28 (0.13, 0.60)], alpha(2)-adrenoceptors [OR=0.23 (0.17, 0.33)], fentanyl [OR=0.31 (0.18, 0.56)], and peroperative analgesia [OR=0.15 (0.07, 0.34)] were all found to have a preventive effect. Subgroup analysis according to the peroperative analgesia given does not affect the results. CONCLUSIONS: /st> This meta-analysis found that propofol, ketamine, fentanyl, and preoperative analgesia had a prophylactic effect in preventing EA. The analgesic properties of these drugs do not seem to have a role in this effect. less...

PURPOSE: Rapid sequence induction (RSI) with cricoid pressure is suggested to decrease the risk of aspiration of gastric contents. However, the effectiveness of RSI has been questioned, and the technique may lead to airway and hemodynamic complications. The purpose of this study was to determine the frequency of RSI use in patients with acute appendicitis, the types of drugs administered, and the occurrence of any complications. METHODS: After approval by the Ethics Committee, the charts of patients undergoing appendectomy in a one-year period were examined retrospectively. Information was retrieved on Mallampati airway evaluation, airway device used, preoxygenation, RSI, and drugs at induction. Reported complications were noted, including airway difficulties, hypotension (systolic blood pressure < 80 mmHg) and hypertension (>160 mmHg) in the 20-min period after induction. RESULTS: General anesthesia with tracheal intubation was used in 248 of 250 cases reviewed. The Mallampati airway evaluation, preoxygenation, and RSI were recorded as performed in 95, 94, and 81% of cases, respectively. Opioids, propofol, and neuromuscular blocking agents were given in 98, 98, and 99% of patients, respectively. Succinylcholine use was common (80%), with 96% of these patients receiving rocuronium precurarization. Difficult intubation with successful alternate technique was encountered in three patients (1.2%). Hypotension and hypertension occurred in 27% and 8% of patients, respectively. There were no documented cases of aspiration. Oxygen desaturation was mentioned in one case at induction and in three cases at emergence. CONCLUSION: An RSI with opioid, induction agent, and succinylcholine is the technique of choice for appendectomies at our institution. The frequency of airway complications is too low to recommend a change in practice. less...

The objective of the current article was to review the literature and discuss the degree of evidence for various treatment strategies for status epilepticus (SE) in adults. We searched MEDLINE and EMBASE for relevant literature from 1966 to January 2005 and in the current updated version all pertinent publications from January 2005 to January 2009. Furthermore, the Cochrane Central Register of Controlled Trials (CENTRAL) was sought. Recommendations are based on this literature and on our judgement of the relevance of the references to the subject. Recommendations were reached by informative consensus approach. Where there was a lack of evidence but consensus was clear, we have stated our opinion as good practice points. The preferred treatment pathway for generalised convulsive status epilepticus (GCSE) is intravenous (i.v.) administration of 4-8 mg lorazepam or 10 mg diazepam directly followed by 18 mg/kg phenytoin. If seizures continue more than 10 min after first injection, another 4 mg lorazepam or 10 mg diazepam is recommended. Refractory GCSE is treated by anaesthetic doses of barbiturates, midazolam or propofol; the anaesthetics are titrated against an electroencephalogram burst suppression pattern for at least 24 h. The initial therapy of non-convulsive SE depends on type and cause. Complex partial SE is initially treated in the same manner as GCSE. However, if it turns out to be refractory, further non-anaesthetising i.v. substances such levetiracetam, phenobarbital or valproic acid should be given instead of anaesthetics. In subtle SE, in most patients, i.v. anaesthesia is required. less...

Objectives: To assess variability of systemic hemodynamics and its covariates following bolus propofol administration in (pre)term neonates, and to analyze the effect of propofol on cerebral tissue oxygenation index (TOI) and fractional tissue oxygen extraction measured by near-infrared spectroscopy. Methods: In (pre)term neonates, we recorded mean arterial blood pressure (MABP), saturation (SaO(2)), heart rate (HR) and TOI from 5 min before up to 60 min after intravenous bolus propofol (3 mg kg(-1)) administration during elective chest tube removal. Covariate analysis included postmenstrual age (PMA </= or >37 weeks), postnatal age (PNA </= or >10 days), comedication (fentanyl +/- midazolam) and congenital cardiopathy (yes/no). Fractional tissue oxygen extraction was calculated as (SaO(2) - TOI)/SaO(2). Results: Twenty recordings in 19 neonates were assessed. Following propofol administration, an abrupt, minor decrease in HR and SaO(2) was seen with fast recovery, while MABP decreased up to 1 h. TOI decreased during the first 3 min, reflecting an imbalance between cerebral oxygen delivery and demand. Despite sustained decrease in MABP, TOI then returned to baseline, suggesting a better balance between oxygen delivery and demand. PNA </=10 days, comedication and absence of cardiopathy were associated with more subtle decreases in cerebral oxygenation and faster recovery. Conclusions: Propofol-induced decrease in HR, SaO(2) and cerebral oxygenation is short lasting while a decrease in MABP is observed up to 60 min. The variability in the effects of propofol is influenced by PNA, comedication or cardiopathy. Near-infrared spectroscopy can be used to assess hemodynamic effects of hypnotics on the cerebral oxygenation. less...

BACKGROUND: /st> To define the pharmacokinetic profile of propofol 5% microemulsion formulation in horses. METHODS: /st> First, propofol was administered as bolus injection (2 mg kg(-1)) to six xylazine-sedated horses. Secondly, after sedation and bolus injection, propofol was maintained with continuous infusion for 3 h [8.1 (sd 3.2) mg kg(-1) h(-1)] to the same six horses. Thirdly, in two horses, a commercial propofol was used for comparison. Response to noxious stimulation was used to evaluate analgesia. Venous blood samples were obtained to measure propofol plasma concentration using liquid chromatography-mass spectrometry analysis. The plasma concentrations were related to the anaesthesia characteristics to determine the ED(50). RESULTS: /st> The pharmacokinetic profile of propofol is best characterized by a non-compartmental model. The mean (confidence interval) for area under plasma concentration-time curve, elimination half-life, mean residence time, and clearance was 41 min microg ml(-1) (+/-7.7), 44.8 min (+/-21.3), 13.7 min (+/-3.2), and 45.8 ml min(-1) kg(-1) (+/-6.5), respectively. Linear regression analysis showed a correlation between plasma concentration and infusion rate (r(2)=0.47). Most propofol infusion rates did not inhibit the response to noxious stimulation and rates above 11.9 mg kg(-1) h(-1) caused involuntary muscle contractions. Better recoveries were associated with lower propofol plasma concentrations. Propofol plasma concentration frequently increased when horses woke from anaesthesia. CONCLUSIONS: /st> Caution is warranted when propofol is used for continuous infusion due to variable kinetics, myoclonal activity, poor analgesia, and less desirable recovery quality. less...

BACKGROUND AND PURPOSE: SWI is known for its detailed visualization of the cerebral venous system and seems to be a promising tool for early detection of cerebrovascular pathologies in children, who are frequently sedated for MR imaging. Because sedation influences cerebral hemodynamics, we hypothesized that it would affect cerebral venous contrast in SWI. MATERIALS AND METHODS: SWI (125 examinations) of 26 patients (age, 2-16 years) was reviewed in this study. Images were acquired of patients sedated with propofol. Reviewers classified the images by weak or strong venous contrast. Physiologic data, such as etCO(2), BP, age, and CBF by arterial spin-labeling, were monitored and collected during MR imaging. A generalized estimating equation approach was used to model associations of these parameters with venous contrast. RESULTS: EtCO(2) and CBF were found to correlate with venous contrast, suggesting that patients with high etCO(2) and CBF have weak contrast and patients with low etCO(2) and CBF have strong contrast. BP was also found to correlate with the venous contrast of SWI, suggesting that patients with high BP have strong venous contrast. No significant correlations were found for any other physiologic parameters. CONCLUSIONS: We found that the venous contrast in SWI is affected by propofol sedation in spontaneously breathing patients. We also found that low etCO(2), low CBF, and high BP are associated with strong venous contrast. Reviewing SWI data in light of physiologic measures may therefore help prevent potential misinterpretations of weak venous contrast in SWI examinations under propofol sedation. less...