Targeting Effect Compartment or Central Compartment Concentration of Propofol 

1999 ◽  
Vol 90 (1) ◽  
pp. 92-97 ◽  
Author(s):  
Howard G. Wakeling ◽  
John B. Zimmerman ◽  
Scott Howell ◽  
Peter S. A. Glass
Keyword(s):  
Central Compartment ◽  
Pharmacokinetic Parameters ◽  
Effect Compartment ◽  
Effect Site ◽  
Anesthetic Drugs ◽  
Effect Site Concentration ◽  
American Society ◽  
Target Effect ◽  
American Society Of Anesthesiologists ◽  
To Receive

Background An effect compartment has been postulated, and the ke0 has been quantified for several intravenous anesthetic drugs using electroencephalography (EEG) as the measure of effect. The authors wanted to validate that loss of responsiveness (LOR) was related to targeting an effect compartment concentration rather than a central compartment (plasma) concentration. Methods Twenty American Society of Anesthesiologists physical status I and II patients were randomized to receive propofol administered to a target central compartment or target effect compartment site concentration of 5.4 microg/ml propofol administered by a target-controlled infusion (TCI) using a previously validated set of pharmacokinetic parameters and a ke0 of 0.63 min(-1). Every 30 s for the first 5 min and every minute for the second 5 min the patients were asked to open their eyes. The time to LOR was measured by a blinded investigator. The authors also simulated the time to reach the desired target effect site concentration using varying ke0 values. Results The median time to LOR in the group targeted to a predicted plasma propofol concentration was 3.02 min and 1.23 min in the group targeted to a predicted effect compartment propofol concentration (P < 0.05). LOR to command in both groups occurred at a predicted median effect compartment concentration of 4.55 microg/ml. Simulations demonstrated that the time predicted to LOR targeting an effect site concentration of 5.4 microg/ml is markedly altered by the value chosen for the ke0. Conclusions This study confirms the utility of the ke0 value to describe the effect compartment for propofol. The authors also illustrate the importance of selecting the correct ke0 value for the pharmacokinetic parameters used within the TCI system.

Estimation of the Plasma Effect Site Equilibration Rate Constant (ke0) of Propofol in Children Using the Time to Peak Effect

2004 ◽  
Vol 101 (6) ◽  
pp. 1269-1274 ◽  
Author(s):  
Hernán R. Muñoz ◽  
Luis I. Cortínez ◽  
Mauricio E. Ibacache ◽  
Fernando R. Altermatt
Keyword(s):  
Rate Constant ◽  
Peak Effect ◽  
Auditory Evoked Potential ◽  
Pharmacokinetic Parameters ◽  
Time To Peak ◽  
Effect Site ◽  
Effect Site Concentration ◽  
Target Effect ◽  
Equilibration Rate ◽  
Plasma Effect

Background Targeting the effect site concentration may offer advantages over the traditional forms of administrating intravenous anesthetics. Because the lack of the plasma effect site equilibration rate constant (ke0) for propofol in children precludes the use of this technique in this population, the authors estimated the value of ke0 for propofol in children using the time to peak effect (tpeak) method and two pharmacokinetic models of propofol for children. Methods : The tpeak after a submaximal bolus dose of propofol was measured by means of the Alaris A-Line auditory evoked potential monitor (Danmeter A/S, Odense, Denmark) in 25 children (aged 3-11 yr) and 25 adults (aged 35-48 yr). Using tpeak and two previously validated sets of pharmacokinetic parameters for propofol in children, Kataria's and that used in the Paedfusor (Graseby Medical Ltd., Hertfordshire, United Kingdom), the ke0 was estimated according to a method recently published. Results The mean tpeak was 80 +/- 20 s in adults and 132 +/- 49 s in children (P < 0.001). The median ke0 in children was 0.41 min(-1) with the model of Kataria and 0.91 min(-1) with the Paedfusor model (P < 0.01). The corresponding t1/2 ke0 values, in minutes, were 1.7 and 0.8, respectively (P < 0.01). Conclusions : Children have a significantly longer tpeak of propofol than adults. The values of ke0 of propofol calculated for children depend on the pharmacokinetic model used and also can only be used with the appropriate set of pharmacokinetic parameters to target effect site in this population.

scholarly journals Remifentanil Alleviates Propofol-Induced Burst Suppression without Affecting Bispectral Index in Female Patients: A Randomized Controlled Trial

2019 ◽  
Vol 8 (8) ◽  
pp. 1186
Author(s):  
Dahye Jung ◽  
Sungwon Yang ◽  
Min Soo Lee ◽  
Yoonki Lee
Keyword(s):  
Bispectral Index ◽  
Suppression Ratio ◽  
Controlled Trial ◽  
Burst Suppression ◽  
Remifentanil Infusion ◽  
Female Patients ◽  
Effect Site ◽  
Effect Site Concentration ◽  
American Society ◽  
American Society Of Anesthesiologists

The bispectral index is affected by various factors, such as noxious stimuli and other drugs, such as muscle relaxants. The burst suppression ratio from bispectral index monitoring is correlated with electroencephalographic burst suppression, which is associated with deep anesthesia, metabolic disorders, and brain injury. We assessed patients undergoing total intravenous anesthesia and examined the effects of remifentanil on the bispectral index, burst suppression ratio, and hemodynamic changes immediately after loss of consciousness with propofol. Seventy American Society of Anesthesiologists physical status class I and II Korean female patients scheduled for general anesthesia were administered propofol with an effect-site concentration of 5 μg/mL, using a target-controlled infusion (TCI). After losing consciousness, patients received either saline or remifentanil at an effect-site concentration of 5 ng/mL for 10 min. During this period, we recorded the bispectral index values, including burst suppression ratio, blood pressure, and heart rate. With remifentanil infusion, burst suppression ratios were lower (p < 0.01) but bispectral values were not different. The burst suppression ratio was significantly different at 6, 7, 8, and 10 min after remifentanil infusion (p < 0.05). In female patients with propofol-induced unconsciousness, remifentanil alleviated the burst suppression ratio without affecting the bispectral value.

Epidural Neostigmine versus Fentanyl to Decrease Bupivacaine Use in Patient-controlled Epidural Analgesia during Labor

2017 ◽  
Vol 127 (1) ◽  
pp. 50-57 ◽  
Author(s):  
Jessica L. Booth ◽  
Vernon H. Ross ◽  
Kenneth E. Nelson ◽  
Lynnette Harris ◽  
James C. Eisenach ◽  
...  
Keyword(s):  
Epidural Analgesia ◽  
Local Anesthetic ◽  
Primary Outcome ◽  
A Priori ◽  
Regulatory Compliance ◽  
Epidural Bupivacaine ◽  
American Society ◽  
American Society Of Anesthesiologists ◽  
Labor Epidural ◽  
To Receive

Abstract Background The addition of opioids to epidural local anesthetic reduces local anesthetic consumption by 20% but at the expense of side effects and time spent for regulatory compliance paperwork. Epidural neostigmine also reduces local anesthetic use. The authors hypothesized that epidural bupivacaine with neostigmine would decrease total hourly bupivacaine use compared with epidural bupivacaine with fentanyl for patient-controlled epidural analgesia. Methods A total of 215 American Society of Anesthesiologists physical status II, laboring parturients requesting labor epidural analgesia consented to the study and were randomized to receive 0.125% bupivacaine with the addition of either fentanyl (2 μg/ml) or neostigmine (2, 4, or 8 μg/ml). The primary outcome was total hourly local anesthetic consumption, defined as total patient-controlled epidural analgesia use and top-ups (expressed as milliliters of 0.125% bupivacaine) divided by the infusion duration. A priori analysis determined a group size of 35 was needed to have 80% power at α = 0.05 to detect a 20% difference in the primary outcome. Results Of 215 subjects consented, 151 patients were evaluable. Demographics, maternal and fetal outcomes, and labor characteristics were similar among groups. Total hourly local anesthetic consumption did not differ among groups (P = 0.55). The total median hourly bupivacaine consumption in the fentanyl group was 16.0 ml/h compared with 15.3, 14.6, and 16.2 ml/h in the 2, 4, and 8 μg/ml neostigmine groups, respectively (P = 0.55). Conclusions The data do not support any difference in bupivacaine requirements for labor patient-controlled epidural analgesia whether patients receive epidural bupivacaine with 2 to 8 μg/ml neostigmine or epidural bupivacaine with 2 μg/ml fentanyl.

scholarly journals Management of Pain During Propofol Injection Using Intravenous Nitroglycerine

KYAMC Journal ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 202-205
Author(s):  
Muhammad Sazzad Hossain ◽  
Mohammad Mamunur Rashid ◽  
Md Anisur Rahman Babu ◽  
Afsana Sultana ◽  
Md Sirajul Islam Mahfuz ◽  
...  
Keyword(s):  
Placebo Group ◽  
Venous Occlusion ◽  
Saline Group ◽  
Injection Pain ◽  
Group A ◽  
American Society ◽  
Group B ◽  
Double Blinded ◽  
American Society Of Anesthesiologists ◽  
To Receive

Background: Propofol is an intravenous (IV) anesthetic agent, can irritate the skin, mucous membrane and venous intima. The main drawback is the pain at injection site following its intravenous injection. Objectives: This study was performed to evaluate the effect of intravenous nitroglycerine on pain in patients following propofol injection. Materials and Methods: Eighty adult patients of both sexes, aged 20-50 years, according to American Society of Anesthesiologists (ASA) physical status were divided into two equal groups (n=40) to receive 200 mcg intravenous nitroglycerine diluted in 10 ml saline (group A) and 10 ml normal saline as placebo (group B) at an ambient operating room temperature in a randomized and double blinded fashion to compare the pain-relieving effects of the drugs during propofol injection before the patients lost consciousness. The pain on propofol injection was assessed according to the Mc Crirrick and Hunter scale. Results: The overall incidence and severity of pain were significantly less in Groups A (nitroglycerine group) than group B (placebo group) (p< 0.05). The incidence of mild and moderate pain in Group A versus group B was 25% vs 45% and 15% vs 30% respectively (p<0.05). The incidence of score '0' (no pain) was higher in Group A (60%) than Group B (25%) (p<0.05). Conclusion: Pretreatment with 200 mcg nitroglycerine with venous occlusion for one minute is effective pretreatment in alleviating propofol injection pain when compared to placebo. KYAMC Journal Vol. 10, No.-4, January 2020, Page 202-205

scholarly journals Intraoperative anaphylaxis

2018 ◽  
Vol 5 (2) ◽  
pp. 62-65
Author(s):  
Sujita Manandhar
Keyword(s):  
Standard Protocol ◽  
Recurrent Tonsillitis ◽  
Upper Eyelid ◽  
Anesthetic Agents ◽  
Anesthetic Drugs ◽  
Eyelid Swelling ◽  
History Of ◽  
Facial Area ◽  
American Society ◽  
American Society Of Anesthesiologists

A 24 years lady was scheduled for tonsillectomy for recurrent tonsillitis had anaphylaxis and asystole before extubation, she was revived successfully.She had no known history of allergy and exposure to anesthetic agents and was classified as an American Society of Anesthesiologists, ASA I. In the operating theatre, her baseline vitals were unremarkable and remained hemodynamically stable on receiving antibiotic and anesthetic drugs. The anesthetic course remained uneventful throughout the surgery. Upon removal of surgical drapes, upper eyelid swelling was noted, that rapidly progressed to facial area within minutes, and she developed cardiac arrest which was managed with standard protocol and resuscitated successfully.  

Performance of the ARX-derived Auditory Evoked Potential Index as an Indicator of Anesthetic Depth

2002 ◽  
Vol 96 (4) ◽  
pp. 803-816 ◽  
Author(s):  
Michel M. R. F. Struys ◽  
Erik Weber Jensen ◽  
Warren Smith ◽  
N. Ty Smith ◽  
Ira Rampil ◽  
...  
Keyword(s):  
Bispectral Index ◽  
Evoked Potential ◽  
Auditory Evoked Potential ◽  
Noxious Stimulus ◽  
Gynecologic Surgery ◽  
Effect Compartment ◽  
Loss Of Consciousness ◽  
Anesthetic Depth ◽  
Effect Site ◽  
Effect Site Concentration

Background Autoregressive modeling with exogenous input of middle-latency auditory evoked potential (A-Line autoregressive index [AAI]) has been proposed for monitoring anesthetic depth. The aim of the current study was to compare the accuracy of this new index with the Bispectral Index (BIS), predicted effect-site concentration of propofol, and hemodynamic measures. Methods Twenty female patients scheduled for ambulatory gynecologic surgery received effect compartment controlled infusion of propofol. Target effect-site concentration was started at 1.5 microg/ml and increased every 4 min by 0.5 microg/ml. At every step, sedation level was compared with monitoring values using different clinical scoring systems and reaction to noxious stimulus. Results Bispectral Index, AAI, and predicted propofol effect-site concentration were accurate indicators for the level of sedation and loss of consciousness. Hemodynamic variables were poor indicators of the hypnotic-anesthetic status of the patient. BIS correlated best with propofol effect-site concentration, followed by AAI. Hemodynamic measurements did not correlate well. No indicators predicted reaction to noxious stimulus. Poststimulus, BIS and AAI showed an increase as a result of arousal. This reaction occurred more rapidly with the AAI than with BIS. Conclusion Bispectral Index, AAI, and predicted propofol effect-site concentration revealed information on the level of sedation and loss of consciousness but did not predict response to noxious stimulus.

A Method to Compare Costs of Drugs and Supplies among Anesthesia Providers 

1998 ◽  
Vol 88 (5) ◽  
pp. 1350-1356 ◽  
Author(s):  
Franklin Dexter ◽  
David A. Lubarsky ◽  
Bill C. Gilbert ◽  
Christine Thompson
Keyword(s):  
Tertiary Hospital ◽  
Demographic Variables ◽  
Drug Supply ◽  
Anesthetic Drugs ◽  
Anesthesia Providers ◽  
Relative Value ◽  
American Society ◽  
The Cost ◽  
American Society Of Anesthesiologists ◽  
Pearson Correlations

Background Comparison of costs among anesthesia providers using "cost per case" does not adjust for variations in casemix (such as the type of procedure and patient condition). The authors propose an alternative method for comparing costs using the American Society of Anesthesiologists' Relative Value Scale (ASARVS) system, which incorporates basic units (for the procedure), modifier units (for the patient's physical condition), "other" units (such as for the placement of invasive monitors), and time units (proportional to the case duration). Methods Data were obtained from a series of 3,340 anesthetics performed at a tertiary hospital. Administered and discarded drug, supply, and fluid costs were used. Results Costs expressed as dollars per ASARVS unit had 54% less variability than costs expressed as dollars per case (P &lt; 0.0001). Pearson correlations between demographic variables and cost per ASARVS unit ranged from -0.10 to 0.13. Total (e.g., quarterly) costs for simulated sets of cases were predicted within 0.0 +/- 2.3% by multiplying (1) their sum of units and (2) a like set of case's sum of costs divided by sum of units. Conclusions Costs of anesthetic supplies and drugs of a case were more accurately reported as "cost per unit" than as "cost per case." This method of calculating the cost of anesthetic drugs and supplies has several applications, including (1) comparison of costs among anesthesia providers and (2) benchmarking costs among hospitals and anesthesia groups. By design, anesthesia providers' time is quantified by their ASARVS units. Together anesthesia costs (personnel, supplies, and drugs) are better reported as "cost per unit" than as "cost per case."

Comparison of Plasma Compartment versus  Two Methods for Effect Compartment–controlled Target-controlled Infusion for Propofol

2000 ◽  
Vol 92 (2) ◽  
pp. 399-399 ◽  
Author(s):  
Michel M. R. F. Struys ◽  
Tom De Smet ◽  
Birgit Depoorter ◽  
Linda F. M. Versichelen ◽  
Eric P. Mortier ◽  
...  
Keyword(s):  
Time Course ◽  
Drug Effect ◽  
Peak Effect ◽  
Effect Compartment ◽  
Loss Of Consciousness ◽  
Group Iii ◽  
Time To Peak ◽  
Effect Site ◽  
Effect Site Concentration ◽  
Plasma Effect

Background Target-controlled infusion (TCI) systems can control the concentration in the plasma or at the site of drug effect. A TCI system that targets the effect site should be able to accurately predict the time course of drug effect. The authors tested this by comparing the performance of three control algorithms: plasmacontrol TCI versus two algorithms for effect-site control TCI. Methods One-hundred twenty healthy women patients received propofol via TCI for 12-min at a target concentration of 5.4 microg/ml. In all three groups, the plasma concentrations were computed using pharmacokinetics previously reported. In group I, the TCI device controlled the plasma concentration. In groups II and III, the TCI device controlled the effect-site concentration. In group II, the effect site was computed using a half-life for plasma effect-site equilibration (t1/2k(eo)) of 3.5 min. In group III, plasma effect-site equilibration rate constant (k(eo)) was computed to yield a time to peak effect of 1.6 min after bolus injection, yielding a t1/2keo of 34 s. the time course of propofol was measured using the bispectral index. Blood pressure, ventilation, and time of loss of consciousness were measured. Results The time course of propofol drug effect, as measured by the bispectral index, was best predicted in group III. Targeting the effect-site concentration shortened the time to loss of consciousness compared with the targeting plasma concentration without causing hypotension. The incidence of apnea was less in group III than in group II. Conclusion Effect compartment-controlled TCI can be safely applied in clinical practice. A biophase model combining the Marsh kinetics and a time to peak effect of 1.6 min accurately predicted the time course of propofol drug effect.

scholarly journals Intraoperative Tranexamic Acid Reduces Blood Transfusion in Children Undergoing Craniosynostosis Surgery

2011 ◽  
Vol 114 (4) ◽  
pp. 856-861 ◽  
Author(s):  
Christophe Dadure ◽  
Magali Sauter ◽  
Sophie Bringuier ◽  
Michelle Bigorre ◽  
Olivier Raux ◽  
...  
Keyword(s):  
Blood Transfusion ◽  
Blood Loss ◽  
Tranexamic Acid ◽  
Surgical Correction ◽  
Intraoperative Bleeding ◽  
Significant Difference ◽  
Surgical Data ◽  
American Society ◽  
American Society Of Anesthesiologists ◽  
To Receive

Background Surgical correction of craniosynostosis in children is associated with substantial intraoperative bleeding. Tranexamic acid (TXA) decreases intraoperative blood loss during cardiac or orthopedic surgery in children. We hypothesized that intraoperative TXA would reduce blood transfusion relative to placebo in patients pretreated with erythropoietin. Methods Forty consecutive children, American Society of Anesthesiologists status 1 or 2, scheduled to undergo surgical correction of craniosynostosis were randomly assigned to receive either intravenous TXA or saline, 0.9%, intraoperatively. All children received preoperative erythropoietin (600 U/kg once a week for 3 weeks before surgery). Perioperative blood loss, number and volume of transfusions, percentage of children who underwent transfusion, and side effects were noted after surgery and at the end of the study. Surgeon satisfaction and cost of treatment were also recorded. Results There was no significant difference between groups in demographic or surgical data. In the TXA group, the volume of packed erythrocytes transfused was significantly reduced by 85% (from 11 to 1.6 ml/kg) intraoperatively and by 57% (from 16.6 to 7.2 ml/kg) throughout the study period (P &lt; 0.05). Compared with the placebo group, the percentage of children requiring blood transfusion was lower in the TXA group during surgery (9 [45%] of 20 vs. 2 [11%] of 19 children; P &lt; 0.05) and during the whole study period (14 [70%] of 20 vs. 7 [37%] of 19; P &lt; 0.05). Preoperative and postoperative hematologic parameters were comparable in both groups. There were no adverse events. Conclusion In children undergoing surgical correction of craniosynostosis and pretreated with erythropoietin, intraoperative TXA reduces the transfusion requirement.

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