Propofol Requirements For Induction Research Articles

Effects of oral melatonin premedication on hemodynamic responses to intubation, anesthetic requirements and postoperative sedation: A randomized trial.

Sedative effects of melatonin may have an additive effect on general anesthesia (GA). We compared hemodynamic response to intubation following oral premedication with melatonin versus placebo. Induction dose of propofol, isoflurane and fentanyl consumption were also compared. This prospective, double-blinded study was conducted in fifty patients randomized into two equal groups. Group M received oral melatonin 6 mg and group P a placebo two hours before surgery. All patients were induced with intravenous propofol of 1.5-2.5mg/kg till loss of response to verbal commands, three minutes after vecuronium, laryngoscopy was done and trachea was intubated. Heart rate (HR) and mean arterial pressures (MAP) were recorded before premedication, before induction, immediately after induction and then at 1,3,5 and 10 minutes after intubation. Mean HR was comparable in both groups throughout the study period. Group M had significantly lower MAP before induction and immediately after induction (P < 0.05). At all other time points MAP remained comparable in both groups. Mean isoflurane consumption was significantly lower in group M compared to group P (14.8 ± 4.2 vs 19.7 ± 3.2 mL). Propofol requirement for induction was also significantly lower in group M (102.4 ± 19.6 vs 122.4 ± 26.3mg). Intraoperative fentanyl consumption was comparable. Oral premedication with melatonin 6mg administered two hours before surgery significantly reduced MAP before and after induction of GA with a significant reduction in dose of propofol requirement. Titrating induction dose of propofol till loss of response to verbal commands did not effectively attenuate responses to laryngoscopy and intubation following melatonin oral premedication.

Effect of Magnesium Sulphate and Clonidine on Propofol Consumption, Hemodynamics and Postoperative Recovery Using Bispectral Index (BIS) In Elective Surgeries"

The purpose of this placebo-controlled, double-blind study was to see how magnesium sulphate and clonidine affected perioperative hemodynamics, propofol consumption, and postoperative recovery. Ninety ASA I–II patients undergoing elective laparoscopic surgery were randomized into three groups. Group M Patients received Inj. magnesium sulphate (40mg/kg) in 20 ml saline infused over a period of 15 minutes before induction. Group C received Patients received Inj. Clonidine (3mcg/kg) before induction. The Group S (Control group) received 20ml normal saline over 15mind before induction. Propofol was used for induction of anaesthesia and for maintenance propofol infusion was used which was adjusted as per bispectral index along with intermittent fentanyl bolus and vecuronium as muscle relaxant According to type of data, different tests of statistical significance like Chi-square test, Kruskal Wallis test and one-way ANOVA were used. In the presence of magnesium sulphate and clonidine, propofol induction was rapid. The time it took for BIS to reach 60 was significantly shorter in groups M and C (P0.0001), and compared to clonidine and control group post-operative recovery was more delayed in magnesium sulphate group (P0.0001). There was no statistically significant difference between the groups in heart rate or arterial blood pressure. Preoperative use of magnesium sulphate and clonidine resulted in significant reduction in propofol requirements for induction as well as for maintenance (P0.0001).To conclude use of magnesium sulphate caused delayed recovery and hypotension and bradycardia was observed with clonidine, but both can be used as adjuvants with caution.

The requirement of propofol for induction of anesthesia in patients with traumatic brain injury determined using bilateral bispectral index and target controlled infusion - An observational cohort study.

Patients with traumatic brain injury (TBI) frequently require emergency surgery. There is a paucity of literature with regard to anesthetic requirements in these patients. The aim of the study was to compare the dose of propofol required for induction of anesthesia in patients with different grades of TBI. This prospective, observational study included patients with mild, moderate, and severe grades of TBI undergoing emergency surgery within 48 h of injury. Bispectral Index (BIS) values were recorded using a bilateral BIS sensor. Anesthesia was induced with a target controlled infusion (TCI) pump. Once BIS reached 40, plasma (Cp) and effect-site (Ce) concentration and total dose of propofol required were noted from the TCI pump. Of the 96 patients recruited, 27, 36, and 33 patients belonged to mild, moderate, and severe TBI (sTBI) groups, respectively. The Ce of propofol in mild, moderate, and sTBI groups was 6 ± 0.9, 5.82 ± 0.98, and 4.48 ± 1.5 μg/mL (P < 0.001), and the dose of propofol required was 1.9 ± 0.2, 1.8 ± 0.4, 1.41 ± 0.5 mg/kg, respectively (P < 0.001). Baseline BIS on the injured side was 80 ± 7.8, 71 ± 9.4, 55 ± 11.6, and on the uninjured side was 89 ± 5.5, 81 ± 8.4, and 65 ± 12 in mild, moderate, and sTBI groups, respectively. The requirement of propofol was reduced in patients with sTBI. The dose of propofol required for induction of anesthesia as determined using Ce was significantly lower only between sTBI and mild TBI and not between patients with sTBI and moderate TBI or between mild and moderate head injury. BIS values were significantly different between the groups (highest in mild TBI and lowest in sTBI) and between normal and injured sides within each group.

A Comparative Study between IV Clonidine 1.5Mcg/Kg and IV Lignocaine 1.5 Mg/Kg as Premedication for Attenuation of Hemodynamic Responses to Pneumoperitoneum in Laparoscopic Surgeries

Laparoscopy, has emerged as the main stay for most of the commonly performed surgeries. Pneumoperitoneum and different positions of the patient during laparoscopy contribute to adverse cardiovascular effects like elevated arterial pressure, increased systemic and pulmonary vascular resistance and reduced cardiac output. This randomised controlled double blind prospective study was conducted to compare the efficacy of intravenous(I.V) Lidocaine and I.V. Clonidine in providing hemodynamic stability in patients undergoing laparoscopic surgeries. Methods: Seventy five adult patients of ASA grade 1 and 2, scheduled for elective laparoscopic surgery with a mean duration of 30- 90 minutes, were randomly allocated to one of the three groups. Group A: Clonidine group (n=25) - received injection Clonidine 1.5 mcg/kg 15 minutes prior to induction of anaesthesia. Group B: Lidocaine group (n=25) - injection Lidocaine 1.5 mg/kg 90 seconds prior to induction of anaesthesia. Group C: Control group (n=25) - received 10 ml normal saline intravenously. Results: There is no statistically significant difference between lidocaine and control group regarding mean HR, SBP, DBP, MAP during the entire period of pneumoperitoneum. Whereas, there is significant increase of blood pressures (SBP, DBP, MAP) in the lidocaine and control groups compared to the clonidine group from intubation, throughout the period of pneumoperitoneum. Clonidine also decreases the requirement of propofol for induction. Conclusion: I.V Clonidine 1.5mcg/kg premedication is more effective than Lidocaine 1.5mg/kg at preventing changes in hemodynamic parameters induced by carbondioxide pneumoperitoneum. Keywords: Pneumoperitoneum, I.V Clonidine, I.V Lignocaine, Hemodynamic parameters.

Efficacy of preoperative melatonin and ramelteon (melatonin agonist) therapy on dose requirement of propofol for induction of general anaesthesia: A comparative prospective study

General anesthesia is a medically induced coma with loss of protective reflexes resulting from the administration of one or more general anesthetic agents our study is to compare the role and efficacy of preoperative oral Melatonin, Ramelteon, and Midazolam therapy on the dose requirement of induction agent (Propofol). : Were divided into Case and Control Group. Case group of people were given Oral Melatonin (6mg)/Ramelteon (8mg) as premedication 2 to 3 hours before induction in OT and the control group were given oral Midazolam (5mg). After checking all the parameters, the induction process Total number of 60 people was randomly selected from ASA grade I &amp; grade II, aged between 20 to 50 years, started with injection Propofol slowly in intravenous route and subsequently the BIS level up 60 was noted. After complete reversal of General Anesthesia, post-operative sedation level of the patient was measured using Ramsey sedation scale. Melatonin and Ramelteon shows significant reduction in preoperative anxiety state of the patient in comparison to Midazolam, measured by Hamilton Anxiety rating scale. The sedation status was measured by Ramsey Sedation Scale for each drug and it shows no significant difference between the drugs.: Considering absolute values and statistical values, all three drugs are potent premedication in general anesthesia. Among them, Melatonin is most potent in reducing the induction dose of injection Propofol. Ramelteon is also effective in reducing induction dose of Propofol. Along with, both are potent anxiolytic agent in pre-operative state.

To assess the effect of oral melatonin premedication on propofol requirement for induction in entropy guided general anaesthesia- A randomised double blind study

To assess the effect of oral melatonin premedication on propofol requirement for induction in entropy guided general anaesthesia- A randomised double blind study - IJCA- Print ISSN No: - 2394-4781 Online ISSN No:- 2394-4994 Article DOI No:- 10.18231/j.ijca.2019.079, Indian Journal of Clinical Anaesthesia-Indian J Clin

A Comparative Study between Entropy and Clinical Response to Determine the Requirement of Propofol for Induction of General Anesthesia in Geriatric Patients

AbstractBackground: Anesthesia under dosage causes awareness, while over dosage results in drug complications. Endotracheal intubation must be after an adequate level of anesthesia. Propofol is an IV short-acting anesthetic which causes hypo-tension in a dose dependent effect. With entropy, SE level 40- 60 and RE-SE difference Aim of Study: The aim of this study was to compare between the conventional clinical end-point of hypnosis and entropy on the dosage requirement of propofol and hemody-namic during propofol induction of general anesthesia in geriatric patients.Methods and Material: 60 patients, aged 60-80y, from both sexes, ASA I-II scheduled for an elective surgery required general anesthesia and endotracheal intubation were included. Group-I (control group): Propofol 30mg every 1min till loss of response to verbal commands and group-II (entropy group): Propofol 30mg every 1min till response entropy 48±2. Patient's demographic data, the total dose of propofol used for induction, (HR, MAP and entropy parameters) at baseline (T1), after induction of anesthesia (T2), during (T3), 1min and 5min after tracheal intubation (T4, T5).Results: Total dose of propofol, HR & MAP readings revealed no significant difference between two groups. After induction, both RE and SE dropped significantly in both groups when compared to baseline. There was no difference in SE & RE between the two groups.Conclusion: During intubation, usual titration of propofol until loss of verbal response, with the dose given in our study, is as good as entropy monitoring in elderly patients. So, routine use for this may not be necessary and can be used in other age groups, other anesthesia situations, medicolegal purposes and research.

Comparison of electroencephalogram entropy versus loss of verbal response to determine the requirement of propofol for induction of general anaesthesia

Background and Aims:Propofol causes dose-dependent reduction in blood pressure (BP). This study was done to evaluate the use of spectral entropy on the dose of propofol required and the haemodynamic stability during induction of general anaesthesia (GA).Methods:In this randomised controlled study, 72 American Society of Anesthesiologists’ physical status I and II patients undergoing general and orthopaedic surgeries were divided into Group S (n-36) and Group C (n-36). Patients in Group C were induced with propofol till loss of response to verbal commands and in Group S until the state entropy was <50 and state and response entropy difference was <10. The induction dose of propofol, haemodynamic parameters and the entropy values were recorded. Numerical data were expressed as a mean ± standard deviation and analysed using unpaired, two-tailed t-test. Categorical data were compared using Chi-square test. P < 0.05 value was considered significant.Results:The dose of propofol per kg was significantly more in the entropy group (1.80 ± 0.23 mg/kg in the Group C and 1.98 ± 0.217 mg/kg in the Group S [P < 0.05]). After induction, at intubation and 1 min after intubation, entropy values were lower in Group S than Group C (P < 0.05). The BP decreased significantly after induction compared with the baseline (P < 0.05), but there was no difference between the groups.Conclusion:Propofol required for induction of GA when guided by electroencephalogram entropy was significantly higher than the induction dose based on loss of verbal response. Both conventional induction and induction with entropy as the endpoint resulted in similar haemodynamic profile.

To evaluate the effects of dexmedetomidine on intraocular pressure and haemodynamic changes in response to laryngoscopy and tracheal intubation

Abstract Background: The most important prerequisites for neurosurgeries are brain relaxation, need of stable haemodynamics with less fluctuation in intracranial pressure and speedy recovery from anaesthesia. Endotracheal intubation is the major stressful stimuli that can elicit a marked pressor response. Various drugs have been used to attenuate these reflexes. Dexmedetomidine, a highly selective alpha 2-adrenoceptor agonist, have neuroprotective, cardioprotective, and sedative effects so it is potentially useful during neuroanaesthesia. This is a prospective randomised control trial carried out to see whether administration of Dexmedetomidine prior to intubation can attenuate the various haemodynamic responses, intraocular pressure (IOP) and the requirement of induction dose of propofol in control and study group. Materials and Methods: Fifty patients (ASA grade 1, 2) scheduled for intracranial tumour surgeries were divided into two groups (25 each). Group D received Dexmedetomidine 0.8 μg/kg i.v. over 10 mins and group C received 20 ml saline. Anaesthesia induced with Propofol, dose adjusted using bispectral index monitor. The groups were compared with IOP, Heart rate (HR), Mean arterial pressure (MAP), and dose of Propofol required for induction. Results: Groups were well matched for their demographic data and pre-operative. IOP in both the eyes decreases significantly after premedication and remained below baseline even after 10th min of intubation in group D while in Group C; it increased significantly after intubation and remained above baseline. The difference between groups was also statistically significant. HR and MAP decreased significantly in patients of group D compared to group C ( P&lt; 0.05). Patients were more haemodynamicaly stable at all time points after premedication in group D ( P&lt; 0.05). Propofol requirements for induction was lesser in group D (P &lt; 0.05). Bradycardia and hypotension incidences were higher in group D. Conclusion: Dexmedetomidine premedication decreases the sympathoadrenal effect on IOP and haemodynamic parameters during laryngoscopy/intubation and decreases the requirement of propofol for induction of general anaesthesia.

The effect of dexmedetomidine infusion on propofol requirement for maintenance of optimum depth of anaesthesia during elective spine surgery

Background:Maintenance of adequate depth of anaesthesia in spine surgery is vital to prevent awareness, to reduce stress response and possible autonomic instability frequently associated with spine surgery. Dexmedetomidine, a α2-adrenoceptor agonist with analgesic and sedative adjuvant property has been found to reduce dose requirement of multiple anaesthetic agents both for induction and during the maintenance of anaesthesia.Aim:The aim of this study is to observe the effect of dexmedetomidine, on the requirement of propofol for induction and maintenance of adequate depth of anaesthesia during spine surgery.Methods:It was a prospective, randomised, double-blinded, parallel group, placebo controlled and open-lebel study in tertiary care hospital. A total of 70 patients aged 20-60 years, American Society of Anaesthesiologists GradeI and II, scheduled for elective spine surgery were randomly allocated into two groups. Each patient of Group D (n=35) received an initial loading dose of dexmedetomidine at 1 μg/kg over 10 min, started 15 min before induction of anaesthesia followed by an infusion at a rate of 0.2 μg/kg/h. Patients of Group P (n=35) received the same volume of 0.9% normal saline solution as placebo. Requirement of propofol at induction and during maintenance was calculated maintaining bispectral index between 40 and 60. P<0.05 was considered to be statistically significant.Results:Mean requirement of propofol was found to be lessened by 48.08% and 61.87% for induction and maintenance of anaesthesia respectively while using dexmedetomidine.Conclusion:Administration of dexmedetomidine significantly reduces the requirement of propofol while maintaining desired depth of anaesthesia without any significant complication.

Perioperative effects of various anesthetic adjuvants with TIVA guided by bispectral index

BackgroundThis prospective, randomized, double blinded, controlled study was designed to compare effects of intravenous co-administration of clonidine, magnesium, or ketamine on anesthetic consumption, intraoperative hemodynamics, postoperative analgesia and recovery indices during Bispectral Index (BIS) guided total intravenous anesthesia (TIVA).MethodsAfter ethical committee approval and written informed consent, 120 adult patients ASA I and II scheduled for open cholecystectomy were randomly assigned to one of 4 equal groups. Group CL received clonidine 3 µg/kg and maintained by 2 µg/kg/h. Group MG received magnesium sulphate 50 mg/kg and maintained by 8 mg/kg/h. Group KET received racemic ketamine 0.4 mg/kg and maintained by 0.2 mg/kg/h. Control group (CT) received the same volume of isotonic saline. Anesthesia was induced and maintained by fentanyl, propofol and rocuronium. Propofol infusion was adjusted to keep the BIS value between 45-55. Intraoperative hemodynamics, induction time, anesthetic consumption, recovery indices, and PACU discharge were recorded.ResultsInduction time, propofol requirements for induction and maintenance of anesthesia, intraoperative fentanyl and hemodynamic values were significantly lower with Groups CL and MG compared to Groups KET and CT (P < 0.05). Patients in Group MG showed significantly lower muscle relaxant consumption, delayed recovery and PACU discharge than other groups (P < 0.05). First, analgesic requirement was significantly longer and total postoperative analgesic consumption was significantly lower in the adjuvant groups versus Group CT (P < 0.05).ConclusionsClonidine, magnesium, and ketamine can be useful adjuvant agents to BIS-guided TIVA. Pharmacokinetic studies of such drug combinations were recommended to investigate their interaction.

Influence of Atropine on the Dose Requirements of Propofol in Humans

The purpose of this study was to evaluate the effect of atropine on the dose requirement of propofol for induction of anesthesia and propofol concentrations during continuous infusion. Study 1: Forty patients were randomly allocated to the control or atropine groups. Induction of anesthesia commenced 3 min following the administration of 0.9% saline or atropine (0.01 mg kg(-1)), using a Diprifuser set to achieve propofol concentration of 6.0 microg mL(-1). The primary end point was the propofol dose per kg at the moment of loss of response to a command. Study 2: Fifteen patients undergoing elective surgery were enrolled. Propofol was administered to all subjects via target-controlled infusion to achieve a propofol concentration at 2.0 microg mL(-1) after intubation. Before and after administration of atropine (0.01 mg kg(-1)), cardiac output (CO) was measured using indocyanine green as an indicator and blood propofol concentration was determined using high-performance liquid chromatography. Study 1: The propofol dose for each group was 2.22+/-0.21 mg kg(-1) for control group and 2.45+/-0.28 mg kg(-1) for atropine, respectively (p=0.014). Study 2: After the administration of atropine, CO was significantly increased from 4.28+/-0.83 to 5.76+/-1.55 l min(-1) (p<0.0001). Propofol concentration was significantly decreased from 2.12+/-0.28 to 1.69+/-0.27 microg mL(-1) (p<0.0001). Following the administration of atropine, the propofol requirements for the induction of anesthesia were increased and propofol concentrations were decreased during continuous infusion by the administration of atropine.

Influence of landiolol on the dose requirement of propofol for induction of anesthesia

It was reported that the pharmacokinetics of propofol was influenced by cardiac output (CO). The purpose of this study was to evaluate the effect of landiolol (short-acting beta-1-adrenergic blocker) on the dose requirement of propofol for induction of anesthesia. Forty patients were randomly allocated to the control and landiolol group. Induction of anesthesia commenced 10 min after the infusion of 0.9% saline or landiolol, using a Diprifusor set to achieve propofol plasma concentration of 6.0 microg/mL. Induction of anesthesia was defined as the first lack of response to command. Propofol dose was 2.22+/- 0.21 mg/kg for the control group and 1.79+/- 0.28 mg/kg for the landiolol group (P<0.0001). The quantity of propofol required for the induction of anesthesia was reduced by the administration of landiolol.

Effects of magnesium sulphate and clonidine on propofol consumption, haemodynamics and postoperative recovery

This placebo-controlled, double-blind study was designed to assess the effects of magnesium sulphate and clonidine on peroperative haemodynamics, propofol consumption and postoperative recovery. Sixty ASA I-II patients undergoing spinal surgery were randomized into three groups. Group M received magnesium sulphate 30 mg kg(-1) as a bolus before induction and 10 mg kg(-1) h(-1) by infusion. Group CL received clonidine 3 microg kg(-1) as a bolus before induction and 2 microg kg(-1) h(-1) by infusion during the operation period. The same volume of isotonic solution was administered to the control group (group CT). Anaesthesia was induced with propofol and was maintained with propofol infusion [dose according to the bispectral index (BIS)], fentanyl and cisatracurium. Analysis of variance and the Bonferroni test were used for statistical analysis. Induction of anaesthesia with propofol was rapid in the presence of magnesium sulphate and clonidine. The time for BIS to reach 60 was significantly shorter in group M and group CL (P<0.0001) but postoperative recovery was slower with magnesium sulphate compared with the clonidine and control groups (P<0.0001). There was no statistical difference in heart rate and arterial blood pressure between the groups. Propofol requirements for induction and maintenance of anaesthesia were significantly lower with magnesium and clonidine (P<0.0001). Clonidine caused bradycardia and hypotension and magnesium sulphate caused delayed recovery, but can be used as adjuvant agents with careful management.

The Effect of Epidural Bupivacaine on Induction and Maintenance Doses of Propofol (Evaluated by Bispectral Index) and Maintenance Doses of Fentanyl and Vecuronium

The growing interest in combining local and general anesthesia has led to studies investigating possible interactions between general anesthesia and local anesthetics administered via spinal, epidural, IV, or IM routes. However, no study has evaluated the effect of local anesthetics on all three components of balanced anesthesia, i.e., hypnosis, analgesia, and muscle relaxation. In this prospective, randomized, double-blind study, we investigated the effect of epidural bupivacaine on the dose requirement of propofol (as evaluated by using the bispectral index [BIS]), fentanyl, and vecuronium for general anesthesia. This study consisted of 30 adults, ASA physical status I and II, undergoing Whipple's pancreaticoduodenectomy for periampullary carcinoma lasting >4 h. An epidural catheter was placed between T9-10. Depending on the group allocation, 10 mL of the study drug was administered as a bolus followed by an infusion at 6 mL/h via the epidural catheter. Patients were divided into 2 groups of 15 each. Patients in the control group received epidural normal saline whereas those in the bupivacaine group received epidural bupivacaine 0.1%. Induction of anesthesia was performed with IV fentanyl 2 mug/kg and propofol titrated to achieve BIS between 40-50. Endotracheal intubation was facilitated by the IV administration of vecuronium 0.1 mg/kg and patient's lungs were ventilated with 66% nitrous oxide in oxygen. After intubation, infusion of propofol 1% was titrated to maintain BIS between 40-50. Inadequate analgesia was defined as an increase in systolic blood pressure and/or heart rate by >20% of baseline values in response to surgical stimulus and was treated with bolus fentanyl 0.5 mug/kg. Neuromuscular monitoring was used to assess the need for additional doses of vecuronium. Data were analyzed by using the Student's t-test and P </= 0.05 was considered significant. The requirement of propofol for induction and maintenance of anesthesia in the bupivacaine group was 1.3 +/- 0.3 mg/kg and 2.4 +/- 0.9 mg . kg(-1) . h(-1), respectively, compared with 2.4 +/- 0.6 mg/kg and 4.4 +/- 1.6 mg . kg(-1) . h(-1) observed in the control group (P < 0.05). Significant reduction was also observed in the requirement of vecuronium and fentanyl during maintenance in the bupivacaine group (P < 0.05). We conclude that epidural bupivacaine given before induction of anesthesia reduces the requirement of propofol, fentanyl, and vecuronium during general anesthesia.

Influence of body compartments on propofol induction dose in female patients.

For induction of anaesthesia, drugs such as propofol are commonly administered according to a per weight basis. However, drugs are primarily distributed to the fat-free mass. This study was undertaken to determine the relationship between propofol requirement for induction and body mass determined by bioimpedance analysis (BIA) or by body mass index (BMI). Twenty-one ASA 1 female patients scheduled for gynaecologic surgery received propofol for induction at 133 mg.min-1. Stepwise regression analysis was used to describe the relationships between propofol requirement for loss of consciousness and age, body weight, and lean body mass measured by BIA and BMI (independent variables). Loss of consciousness was obtained with a propofol dose (Mean (SEM)) of 2.17 +/- 0.10 mg.kg-1. Stepwise analysis showed that propofol requirement (total dose) was not proportional to weight or age but related to lean body mass as determined by BIA and to body mass index (r2 = 0.447; global P- value < 0.007). BMI was the only regressor variable when the propofol dose was expressed in mg.kg-1 (r2 = 0.661; P < 0.001). Our results indicate that propofol requirements for induction are proportional to the lean body mass rather than total body weight.