Propofol Dose Requirement Research Articles

Propofol-sparing and hemodynamic effects of guaifenesin in sheep

ObjectiveTo evaluate the propofol-sparing and hemodynamic effects of guaifenesin administered for co-induction of anesthesia in sheep. Study designProspective, blinded, two-way crossover experimental study. AnimalsThirteen healthy adult female sheep. MethodsAnesthesia was induced without premedication with intravenous (IV) guaifenesin 5% at 100 mg kg–1 (GGE) or an equivalent volume of physiologic saline (SAL), followed by IV propofol at a controlled rate (1 mg kg–1 min–1). Heart rate (HR), respiratory rate and oscillometric noninvasive arterial blood pressure (NIBP) were recorded at baseline after co-induction administration, following endotracheal intubation and every 2 minutes thereafter for 10 minutes. Propofol doses required to achieve intubation after each co-induction treatment were compared by independent Student’s t-test. Values of p < 0.05 were considered statistically significant. ResultsThe propofol dose required (mean ± standard deviation) to achieve intubation was significantly lower (p = 0.001) in the GGE treatment (3.40 ± 0.74 mg kg–1) than in the SAL treatment (5.94 ± 1.09 mg kg–1). HR was increased after anesthetic induction compared with baseline in both treatments. HR was generally lower in the GGE treatment than in the SAL treatment. NIBP did not vary between GGE and SAL treatments. Conclusions and clinical relevanceGuaifenesin, when administered as a co-induction agent with propofol in sheep, reduces propofol dose requirements and maintains hemodynamic variables within a clinically acceptable range.

EFFECT OF VARYING TIME INTERVALS BETWEEN FENTANYL AND PROPOFOL ADMINISTRATION ON PROPOFOL REQUIREMENT FOR INDUCTION OF ANESTHESIA - AN OBSERVATIONAL STUDY

Objective: The objective of the study is to determine the dose of propofol required for induction when fentanyl was administered just before, 3 min, and 5 min before propofol administration. Furthermore, to determine changes in heart rate, systolic blood pressure (SBP), diastolic blood pressure (DBP), and mean arterial pressure (MAP), when fentanyl was given at varying time intervals. Methods: A prospective observational study was conducted in a tertiary care teaching hospital for 12 months. A total of 150 patients belonging to ASA 1 and 2 in the age group of 18–60 years scheduled for elective surgery under general anesthesia were allocated into three groups. Group 1 received propofol immediately after a 2 mcg/kg fentanyl injection and Group 2 and Group 3 received propofol 3 and 5 min, respectively, after the administration of fentanyl. The total dose of propofol required for induction is noted. Heart rate, systolic, diastolic, and MAPs after induction were also noted. Data analysis was done using SPSS version 25. Results: All three groups were comparable concerning demographic variables. The total dose of propofol required for induction was highest in Group 1, where propofol was given immediately after fentanyl, followed by Group 2, and lowest in Group 3 where propofol was given 5 min after fentanyl. Fall in heart rate, SBP, DBP, and MAP after propofol administration was highest in Group 1, followed by Group 2, and least in Group 3 where fentanyl was administered 5 min before propofol. The results were statistically significant. Conclusion: Administering fentanyl 5 min before propofol causes a marked reduction in the dose requirement of propofol along with a significantly decreased incidence of hypotension after induction.

Influence of Clinical and Genetic Factors on Propofol Dose Requirements: A Genome-wide Association Study.

Propofol is a widely used intravenous hypnotic. Dosing is based mostly on weight, with great interindividual variation in consumption. Suggested factors affecting propofol requirements include age, sex, ethnicity, anxiety, alcohol consumption, smoking, and concomitant valproate use. Genetic factors have not been widely explored. This study considered 1,000 women undergoing breast cancer surgery under propofol and remifentanil anesthesia. Depth of anesthesia was monitored with State Entropy (GE Healthcare, Finland). Propofol requirements during surgery were recorded. DNA from blood was genotyped with a genome-wide array. A multivariable linear regression model was used to assess the relevance of clinical variables and select those to be used as covariates in a genome-wide association study. Imputed genotype data were used to explore selected loci further. In silico functional annotation was used to explore possible consequences of the discovered genetic variants. Additionally, previously reported genetic associations from candidate gene studies were tested. Body mass index, smoking status, alcohol use, remifentanil dose (ln[mg · kg-1 · min-1]), and average State Entropy during surgery remained statistically significant in the multivariable model. Two loci reached genome-wide significance (P < 5 × 10-8). The most significant associations were for single-nucleotide polymorphisms rs997989 (30 kb from ROBO3), likely affecting expression of another nearby gene, FEZ1, and rs9518419, close to NALCN (sodium leak channel); rs10512538 near KCNJ2 encoding the Kir2.1 potassium channel showed suggestive association (P = 4.7 × 10-7). None of these single-nucleotide polymorphisms are coding variants but possibly affect the regulation of nearby genes. None of the single-nucleotide polymorphisms previously reported as affecting propofol pharmacokinetics or pharmacodynamics showed association in the data. In this first genome-wide association study exploring propofol requirements, This study discovered novel genetic associations suggesting new biologically relevant pathways for propofol and general anesthesia. The roles of the gene products of ROBO3/FEZ1, NALCN, and KCNJ2 in propofol anesthesia warrant further studies.

Efficacy and safety during endoscopic retrograde cholangiopancreatography (ERCP) under total intravenous anesthesia – propofol alone versus propofol supplemented with dexketa, a comparative study in medical college, Kolkata

Background: Endoscopic retrograde cholangiopancreatography (ERCP) is an invasive procedure and, hence, is distressing for awake patients, requiring an adequate level of anesthesia. Recent advancements have encouraged the use of monitored anesthesia care, that allows the patient to tolerate unpleasant experiences during procedures while maintaining cardio-respiratory function. Usually, propofol-based anesthesia is given in ERCP. The main aim of this study is to compare the effect of propofol alone and propofol with ketamine and dexmedetomidine on the hemodynamics during ERCP, recovery profile, and side effects (if any). Aims and Objectives: (1) To compare efficacy in terms of hemodynamic stability and desaturation events. (2) Recovery and quality of recovery. (3) Pain score. (4) Incidence of post-operative nausea and vomiting. Materials and Methods: This is a comparative double-blinded study. Adult patients from the age group of 18–70 years belonging to the American Society of Anesthesiologists (ASA-I) and ASA-II who had undergone ERCP under total intravenous anesthesia were taken and randomly assigned to either of the two groups. Both groups received 0.01 mg/kg glycopyrrolate, 0.1 mg/kg ondansetron, 0.05 mg/kg midazolam, 50 mcg fentanyl, and 40 mg hyoscine. Group A patients received 30 mg propofol as a bolus dose and then repeated according to requirements. Group B patients received 0.5 mcg/kg dexmedetomidine as a loading dose and 0.3 mcg/kg/h as a maintenance infusion dose. 30 mg propofol was given before negotiating scope and then 1 mL (1:1) mixture of propofol and ketamine was repeated according to requirements. Total propofol consumption, hemodynamics, quality of recovery, and side effects (if any) were recorded at regular intervals. Results: The study showed significant cases in Group A had episodes of hypotension and apneic events, whereas there were very few hemodynamic instability and almost no apneic events in Group B patients. The requirement of propofol was much higher in Group A patients. Conclusion: Dexmedetomidine when used along with propofol and ketamine in ERCP patients reduced the dose requirement of propofol and maintained hemodynamic stability without causing any apneic events.

Comparison of two sedation protocols, with and without analgesia, in pigs: Assessment of sedation end points and propofol requirements

ObjectiveTo compare the effects of intramuscular premedication with a novel nonanalgesic [alfaxalone–midazolam–acepromazine (AMA)] and an analgesic [ketamine–midazolam–detomidine (KMD)] protocol on sedation end points and propofol requirements for induction of anesthesia in swine. Study designProspective experimental study. AnimalsA total of 27 Yorkshire cross gilts weighing approximately 30 kg. MethodsTwo sedation protocols, AMA and KMD, were compared. Time from intramuscular injection to ataxia, recumbency and nonresponsiveness to tactile stimulation was recorded. The propofol dose requirement for induction of general anesthesia and tracheal intubation, and any adverse events (paddling, twitching), were recorded. Data were tested for normality using a Shapiro–Wilk test. Propofol requirements were compared using a Student’s t test. Times from injection to sedation end points were compared using a Mood’s test, and significance was confirmed using a Kaplan–Meier curve with Wilcoxon test survival analysis. ResultsSedation end points were reached significantly faster with KMD than with AMA. Nonresponsiveness occurred in 5 (0–16) and 9.5 (5–36) minutes for KMD and AMA, respectively (p = 0.011). No significant difference (p = 0.437) was found between propofol doses used in either group (KMD; 64.38 ± 5.98 mg, AMA; 72.00 ± 7.57 mg). More adverse events were noted with AMA (11/16 pigs) than with KMD (1/11 pigs). Conclusions and clinical relevanceIn pigs, AMA can be used as a reliable sedation protocol. Frequency of adverse events and time to reach sedation end points between AMA and KMD differed, but the dose of propofol needed to induce general anesthesia was not significantly different.

Effect of Classical Music on Depth of Sedation and Induction Propofol Requirements in Dogs.

The main objective of this prospective, randomized, blind, cross-over experimental study was to evaluate the effect of classical music on the depth of sedation and propofol requirements for the induction of anaesthesia in dogs. Twenty dogs were involved, and each was subjected to three different treatments with a 3-month gap: Chopin music, Mozart music, and no music, via loudspeakers. The dogs were premedicated with acepromazine and butorphanol by intramuscular injection, and anaesthesia was induced using propofol intravenously. To compare the depth of sedation and propofol requirements for the induction of anaesthesia among the different treatments, we utilized non-parametric tests (Kruskal-Wallis test) for the depth of sedation due to a slight deviation from the normal distribution and parametric (ANOVA) for propofol requirements. When exposed to music (Chopin or Mozart), dogs exhibited deeper sedation and required less propofol for their intubation compared to the no-music treatment (p < 0.05). Exposure to classical music had a positive impact on the level of sedation, and more profound central nervous system depression seemed to contribute to approximately 20% lower propofol dose requirements for tracheal intubation. Therefore, classical music during the preoperative period appeared to exert a beneficial effect, at least when applying the specific pre-anaesthetic medications used in the present study.

Effects of different dexmedetomidine doses on haemodynamic variability during laryngoscopy and intubation: A randomized double-blind study

Background: Effective airway management is vital in anesthesiology for preserving patient lives. Laryngoscopy and endotracheal intubation, commonly used procedures, can lead to undesirable outcomes due to vagal activation and sympathoadrenal reaction. This double-blind, randomized interventional study aimed to assess the impact of two different doses of dexmedetomidine on heart rate and blood pressure during laryngoscopy and intubation, which often induce tachycardia and hypertension, particularly risky for patients with hypertension, myocardial insufficiency, and cerebrovascular disease. Methods: Seventy-six participants, aged 20-60 years and classified as American Society of Anesthesiologists (ASA) Grade I &amp; II, were enrolled after Institutional Ethics Committee approval. Random allocation assigned them to two groups: Group A (0.5 µg/kg dexmedetomidine) and Group B (1.0 µg/kg dexmedetomidine) before anesthesia induction. Hemodynamic measurements were recorded at various time points: pre- and post-drug administration, before intubation, and at intervals thereafter. Results: Both groups exhibited similar age, weight, and gender distribution. Group B consistently demonstrated lower hemodynamic variables compared to Group A after laryngoscopy and intubation. Additionally, Group B required a smaller induction dose of propofol than Group A. No significant adverse effects were reported in either group during the study. Conclusion: The study suggests that intravenous administration of dexmedetomidine at a rate of 1 µg/kg is more effective than 0.5 µg/kg in attenuating the physiological response to laryngoscopy and intubation. Moreover, it reduces the required propofol dose for anesthesia induction. These findings highlight the potential benefits of higher dexmedetomidine doses in mitigating adverse physiological effects during airway management procedures

Effects of different dexmedetomidine doses on haemodynamic variability during laryngoscopy and intubation: A randomized double-blind study

Background: Effective airway management is vital in anesthesiology for preserving patient lives. Laryngoscopy and endotracheal intubation, commonly used procedures, can lead to undesirable outcomes due to vagal activation and sympathoadrenal reaction. This double-blind, randomized interventional study aimed to assess the impact of two different doses of dexmedetomidine on heart rate and blood pressure during laryngoscopy and intubation, which often induce tachycardia and hypertension, particularly risky for patients with hypertension, myocardial insufficiency, and cerebrovascular disease. Methods: Seventy-six participants, aged 20-60 years and classified as American Society of Anesthesiologists (ASA) Grade I &amp; II, were enrolled after Institutional Ethics Committee approval. Random allocation assigned them to two groups: Group A (0.5 µg/kg dexmedetomidine) and Group B (1.0 µg/kg dexmedetomidine) before anesthesia induction. Hemodynamic measurements were recorded at various time points: pre- and post-drug administration, before intubation, and at intervals thereafter. Results: Both groups exhibited similar age, weight, and gender distribution. Group B consistently demonstrated lower hemodynamic variables compared to Group A after laryngoscopy and intubation. Additionally, Group B required a smaller induction dose of propofol than Group A. No significant adverse effects were reported in either group during the study. Conclusion: The study suggests that intravenous administration of dexmedetomidine at a rate of 1 µg/kg is more effective than 0.5 µg/kg in attenuating the physiological response to laryngoscopy and intubation. Moreover, it reduces the required propofol dose for anesthesia induction. These findings highlight the potential benefits of higher dexmedetomidine doses in mitigating adverse physiological effects during airway management procedures

EFFECT OF MELATONIN ON DOSE RESPONSE OF PROPOFOL FOR INDUCTION OF GENERALANAESTHESIA USING BISPECTRAL INDEX MONITOR

Background and Aims: Anaesthesia is a balance between anaesthetic drug requirement and state of arousal of patient. Premedication has been found to decrease the requirement of intravenous anaesthetic agents like propofol for induction of anaesthesia. This study was designed to study the effect of oral melatonin on dose response of propofol used for induction of general anaesthesia, using Bispectral Index(BIS). Material and Methods: The study included 54 patients who were admitted for elective surgeries under general anaesthesia. Patients were randomized into two groups to receive tablet melatonin 6 mg or placebo 100 minutes prior to induction. At 100 minutes all the patients were induced with intravenous propofol at the rate of 4ml (40 mg/min) with Bispectral Index monitoring. Induction was stopped when BIS score reached 45. The total dose of propofol required to achieve BIS score of 45 was recorded. Heart rate and blood pressure were compared between two groups. Results: The parameters obtained was analysed using chi-square test, shapirowik test, unpaired sample t test and pearson correlation. The total propofol dose to achieve BIS score of 45 and heart rate (HR) and mean arterial pressure (MAP) were comparable. The total dose of propofol to achieve BIS of 45 was less in melatonin group with a statistical signicance (P&lt;0.05). There was a minimal change in hemodynamic parameters in the two groups without statistical signicance (P&gt;0.05). Conclusion: Melatonin premedication decreases the dose requirement of propofol required for induction without affecting haemodynamic stability

Effects of CYP2B6 Genetic Variants on the Propofol Dose and Response among Jordanian Arabic Patients Undergoing General Anesthesia.

Propofol is the most commonly used general anesthetic drug in many countries, including Jordan. However, there is a wide variation in the propofols' dose and response among the patients. Genetic variation in the cytochrome (CYP) 2B6 gene affects propofol metabolism and might affect propofol dose and response. This study aimed to determine the influence of major genetic alleles of the CYP2B6 gene, CYP2B6*2A, *6A, *3, *4A, and *5A, on the required propofol dose and response among Jordanian Arabic patients attending The University of Jordan Hospital. A total of 155 patients were administrated propofol. The propofol response was evaluated by monitoring the time to reach the bispectral index of 60 (BIS60) for every patient. The CYP2B6 genetic variants were genotyped by polymerase chain reaction followed by restriction through specific enzymes for CYP2B6 variants. It is found that patients with variant CYP2B6*2A and *4A alleles required significantly (P < 0.05) lower propofol doses, while patients with variant CYP2B6*6A, *3, and *5A alleles required higher propofol doses in comparison with patients carrying the wild CYP2B6 alleles. Patients with variant CYP2B6*2A and *3 alleles needed a significantly (P < 0.05) shorter while patients with variant CYP2B6*5A allele needed longer time of BIS60 than patients with wild CYP2B6*2A, *3, and *5A alleles. It is concluded that CYP2B6 genetic variants affect propofol dose and can explain, at least partly, the inter-individual variation in the propofol response. Further clinical studies with a larger sample size are needed to confirm the findings of this study.

Effects of Cisatracurium in Sevoflurane and Propofol Requirements in Dog-Undergoing-Mastectomy Surgery.

The purpose of the present study was to test whether the addition of cisatracurium in combination with propofol and sevoflurane would result in a change in doses of used anesthetic drugs. Ten dogs (Group A) undergoing elective unilateral mastectomy surgery were included in the study. To induce and maintain anesthesia, subjects received propofol and sevoflurane at varying doses; analgesia was performed with remifentanil. After three months, the same subjects (Group B) underwent contralateral mastectomy and received the same anesthetic protocol with the addition of cisatracurium at a dosage of 0.2 mg/kg-1. The following parameters were monitored during anesthesia: heart rate, systolic blood pressure, end-tidal CO2, oxygen saturation, halogenate requirement, and rectal temperature at baseline (T0), induction (T1), 5 (T5), 10 (T10), 15 (T15), 20 (T20), 25 (T25), 30 (T30), and 35 (T35) time points. In Group A, halogenate requirement was reduced at all the time points other than T1 (p &lt; 0.001); in Group B, the percentage of halogenate requirement was already reduced at T1 and remained constant during the experimental period, showing no significant intragroup differences. The dose requirements of sevoflurane and propofol varied significantly between the two groups, with significantly lower dosages in the Group B (the cisatracurium-treated group). Moreover, patients treated with cisatracurium showed a stable anesthetic plan. The nondepolarizing-muscle-relaxant cisatracurium besylate could be considered a useful adjunct to anesthetic protocols.

Heart rate, arterial pressure and propofol-sparing effects of guaifenesin in dogs

ObjectiveTo evaluate the heart rate (HR) and systemic arterial pressure (sAP) effects, and propofol induction dose requirements in healthy dogs administered propofol with or without guaifenesin for the induction of anesthesia. Study designProspective blinded crossover experimental study. AnimalsA total of 10 healthy adult female Beagle dogs. MethodsDogs were premedicated with intravenous (IV) butorphanol (0.4 mg kg–1) and administered guaifenesin 5% at 50 mg kg–1 (treatment G50), 100 mg kg–1 (treatment G100) or saline (treatment saline) IV prior to anesthetic induction with propofol. HR, invasive sAP and respiratory rate (fR) were recorded after butorphanol administration, after guaifenesin administration and after propofol and endotracheal intubation. Propofol doses for intubation were recorded. Repeated measures analysis of variance (anova) was used to determine differences in propofol dose requirements among treatments, and differences in cardiopulmonary values over time and among treatments with p < 0.05 considered statistically significant. ResultsPropofol doses (mean ± standard deviation) for treatments saline, G50 and G100 were 3.3 ± 1.0, 2.7 ± 0.7 and 2.1 ± 0.8 mg kg–1, respectively. Propofol administered was significantly lower in treatment G100 than in treatment saline (p = 0.04). In treatments G50 and G100, HR increased following induction of anesthesia and intubation compared with baseline measurements. HR was higher in treatment G100 than in treatments G50 and saline following induction of anesthesia. In all treatments, sAP decreased following intubation compared with baseline values. There were no significant differences in sAP among treatments. fR was lower following intubation than baseline and post co-induction values and did not differ significantly among treatments. Conclusions and clinical relevanceWhen administered as a co-induction agent in dogs, guaifenesin reduced propofol requirements for tracheal intubation. HR increased and sAP and fR decreased, but mean values remained clinically acceptable.

The effect of intravenous lidocaine on propofol dosage in painless bronchoscopy of patients with COPD.

BackgroundWe tested the hypothesis that intravenous (IV) lidocaine reduces propofol requirements in painless bronchoscopy in patients with chronic obstructive pulmonary disease (COPD).MethodsA total of 93 patients who underwent bronchoscopy were included in this randomized placebo-controlled study. The patients were randomly divided into two groups. After the IV doses of nalbuphine, patients were given a bolus of propofol, which was titrated if necessary until loss of consciousness. Then patients were given IV lidocaine (2 mg/kg then 4 mg/kg/h) or the same volume of saline. The primary endpoint was the propofol requirements. Secondary endpoints were the incidence of hypoxemia, the incidence of cough during glottis examination, the systolic blood pressure (SBP) and heart rate (HR) during bronchoscopy procedures, the bronchoscopist's comforts, and the time for wakefulness before recovery.ResultsLidocaine infusion resulted in a significant reduction in propofol requirements (p < .0001), and the incidence of hypoxemia (p = .001) and cough (p = .003) during examination decreased significantly in the lidocaine group. During the examination, the fluctuation of SBP and HR was significantly lower than that in the control group, and the difference was statistically significant (p < .05). Bronchoscopist's comforts were higher in the lidocaine group (p < .001), and time for wakefulness (p < .001) were significantly lower in the lidocaine group.ConclusionIn painless bronchoscopy in patients with COPD, IV infusion of lidocaine resulted in a reduction in propofol dose requirements and reduce the incidence of adverse events.

Cross‐sectional study of propofol dose during intravenous sedation for dental surgery in patients with long‐term oral benzodiazepine therapy: A secondary publication

ObjectivesThe amount of propofol required for intravenous sedation (IVS) in patients on long‐term oral benzodiazepine (BZD) therapy may be affected by drug interactions and central changes in sensitivity. However, there is no research on the effect of long‐term oral BZD use on the amount of propofol required for IVS. We aimed to clarify the difference between the total propofol dose required for IVS in patients with or without long‐term oral BZD therapy.Material and methodsAmong patients treated for 4 years, the total administered dose required for IVS with propofol alone and local anesthesia for the extraction of bilateral impacted mandibular wisdom teeth, was retrospectively compared between patients with continuous oral BZD use for ≥6 months (BZD group; n = 24) and those without such use (control group; n = 307). The aimed sedation level was the Ramsay sedation scale 3–4.ResultsThe amount of propofol required for IVS was significantly lower in the BZD group compared to the control group (4.83 ± 1.30 vs. 5.91 ± 1.25 mg/kg/h, p < .001; 95% confidence interval, −1.22 to −0.94 mg/kg/h; Cohen's d, 0.84). The required propofol dose was not influenced by preoperative oral BZD administration on the day of extraction (presence [n = 13] vs. absence [n = 11]: 4.9 ± 1.3 vs. 4.8 ± 1.7 mg/kg/h, p = .83). Long‐term oral BZD therapy remained a significant factor for a lower required propofol dose after adjusting for age with multiple linear regression analysis. The underlying mechanism cannot be an additive action process but might pertain to competitive inhibition via an enzyme involved in glucuronate conjugation or competitive albumin binding.ConclusionsClinicians should understand that patients on long‐term oral BZDs therapy might require less propofol for IVS than those not on BZDs, irrespective of whether BZDs were taken preoperatively on the day of surgery.

“The Induction Dose with Ketamine and Midazolam Co-Induction to Propofola”

Background: Propofol is a commonly used intravenous (IV) induction agent. The induction dose of propofol is 1.5 to 2.5 mg/kg in healthy adults producing unconsciousness, depending upon concomitant medications (i.e. opoid analgesics), the patient’s age and physical status, and the extent of surgical stimulation. Objective: To assess the induction dose with ketamine and midazolam co-induction to propofola. Methods: This was a prospective, randomized, double-blind and interventional study conducted at Department of Anesthesiology, Sher-e-bangla Medical College Hospital, Barishal, Bangladesh from January to June 2019. Sixty adult patients undergoing elective surgery to be performed under general anesthesia were randomized to receive 0.3 mg/kg of Ketamine or 0.03 mg/ kg of Midazolam intravenously as co-induction agent. A minute after administration of co-induction agent, anesthesia was induced with Propofol 40 mg bolus then 10 mg every 10 seconds until the loss of verbal response. The hemodynamic response at 0, 1, 2, 5 minutes respectively and the induction dose of Propofol were noted. Results: The mean arterial pressure heart rates were significantly lower at 1, 2 and 5 minutes in midazolam group. However, mean arterial pressure and heart were within the physiological range in both the groups. Propofol dose requirement for induction between the two groups was similar (p&gt;0.05) but co-induction significantly decreased the induction dose of Propofol as compared to standard recommended dose for induction. Conclusion: Our study showed that hemodynamic variables were maintained within the physiological range with midazolam and ketamine co-induction. However, lesser degree of decrease in mean arterial pressure was seen with ketamine but the heart rate was higher. A similar reduction of induction dose of propofol was achieved with both the drugs.

Comparison between Haemodynamic Responses of Propofol Induction between BIS Guided Dose and Sleep Dose: A Randomised Control Trial

Introduction: Propofol contributes largely in the rapid evolution of day care surgery due to its superior recovery characteristics. However, it is associated with dose-dependent systemic arterial hypotension which increases morbidity and mortality. Bispectral index or BIS is an Electroencephalographic (EEG) derived parameter used to assess the depth of anaesthesia. Titrating drugs to a specific BIS value during general anaesthesia allows to adjust the dose of anaesthetic needed by the patient thereby, reducing the dose related side-effects. Aim: To determine whether the dose of propofol guided BIS values causes less arterial hypotension than the commonly used sleep dose method. Materials and Methods: The present study was a randomised control trail conducted on 92 patients of American Society of Anesthesiologists (ASA) I and II physical status, aged 18-60 years, of both genders, scheduled for elective surgeries under general anaesthesia and were randomly divided into group A and B (46 in each). For induction of anaesthesia, Group A received propofol till the BIS values reached 50±1 for 30 seconds, while Group B received sleep dose of propofol without BIS monitoring. Haemodynamic effects Heart Rate (HR), Diastolic Blood Pressure (DBP), Systolic Blood Pressure (SBP) and Mean Arterial Pressure (MAP) were recorded at baseline, during induction and at 1, 5, 10 and 15 minutes after intubation. Total propofol consumption and secondarily, level of sedation after extubation using Ramsay Sedation Scale were also measured in both the groups. Results: The total dose requirement of propofol was reduced significantly in group A compared to group B (p&lt;0.005). Blood pressure decreased from the baseline in both the groups following induction with propofol but was insignificant. HR increased by 2.2% in group A while it decreased by 8.5% in group B but was insignificant (p&gt;0.005). On arrival to Post Anesthesia Care Unit (PACU), group A were more co-operative, oriented patients compared to group B (67.4% vs 32.6% respectively). Conclusion: BIS monitoring significantly reduces the consumption of propofol for induction of anaesthesia while the incidence of hypotension was similar in both the groups. Lower sedation level with comparatively better extubation score with the use of BIS helps in fast tracking.

The Influence of Age on Propofol Dosing Requirements During Procedural Sedation in the Emergency Department.

Propofol is a frequently used agent for procedural sedation in the emergency department (ED). Some have suggested that propofol dosing in this setting should be adjusted in elderly patients; however, limited data exist supporting this recommendation. Additional factors that may contribute to altered propofol dose requirements in this setting have not been thoroughly explored. The objective of this analysis was to ascertain the effect age may have on the propofol dose required during procedural sedation in the ED. This retrospective study was conducted at a Level 1 academic medical center ED and included patients 18 years or older who received propofol for procedural sedation from 2015 to 2017. Those patients who were 18-64 years of age were compared with those 65 years or older. Between the two groups, total and weight-based propofol requirements for sedation, opioid doses, and adverse events were compared. This analysis included 101 procedural sedations. The median induction dose and opioid requirements before or during the procedure were not significantly different between the two groups. Compared with patients 18-64 years of age, those 65 years or older had significantly less total weight-based propofol requirements (p = 0.024) and required less total propofol for sedation (p = 0.007). In addition, patients 65 years or older required fewer repeat doses of propofol during the procedure than younger patients (p = 0.043). The incidence of adverse effects, including respiratory suppression, was not significantly different between the two groups. Patients 65 years or older may have lower weight-based propofol dosing requirements than younger patients. Utilizing a reduced total dose and repeat dosing strategy for propofol in this setting may be indicated. Further investigations are recommended to clarify factors that signal the need for more tailored dosing.

Use of priming principle in the induction dose requirement of propofol and its hemodynamic stability- A cross sectional study

In anesthesia propofol induction is administered at a dose of 2mg/kg as a single bolus and when given at this dose the commonest problem faced by the anesthetist is the sudden drop in the blood pressure, as the hypotensive effect of propofol is proportional to the dose and rate of administration.To study the effect of auto co-induction (priming principle) in the requirement of induction dose of propofol and the resulting hemodynamic parameters. A prospective randomized double blinded study was conducted for a period of one year in the department of anesthesia at a government medical college hospital in TamilNadu. A total of 60 patients were selected for our study and were randomly allocated into two groups of 30 each. Group A is the study group (priming) and group B is the control group (non-priming group). In the priming group, three minutes after premedication the co induction agent was administered (25% of the calculated dose of propofol) and two minutes later the patient received propofol at a rate of 30mg/10 sec until loss of vocalization was achieved. The hemodynamic parameters along with the total dose requirement of propofol and BIS values were monitored at regular intervals after induction.The mean total dose of propofol required among the priming group patients was 78.2 mg compared to the total dose requirement in the non-priming group which was 92.5 mg and the mean difference was found to be statistically significant. A statistically significant fall in the heart rate and blood pressure was observed at 1 min and 3 mins after induction in non priming group compared to priming group. By applying priming principle the induction dose of propofol was reduced by 14.25% with a good hemodynamic stability.

A COMPARATIVE STUDY ON THE TOTAL DOSE REQUIREMENTS AND HEMODYNAMIC ALTERATIONS WITH AND WITHOUT THE APPLICATION OF PRIMING PRINCIPLE AMONG PATIENTS INDUCED WITH PROPOFOL

Background:- Propofol given at standard induction dose, is known to produce haemodynamic instability, especially hypotension. Application of “priming principle” helps to reduce the total dose of propofol. Objectives:- To study the total dose requirements of propofol and peri-intubation haemodynamic stability in patients undergoing surgery under GACV when priming principle is applied. Methodology:- This was an observational study among 54 ASA I and II patients undergoing surgery under GACV, who were randomly divided into three groups of 18 patients each. All patients received fentanyl 1 mcg/kg over 30 seconds followed by propofol. Group 1 patients received the total (100%) calculated dose of propofol. Group 2 and 3 patients received 20% and 40% of the dose respectively as priming dose, and the remaining was given 30 seconds later, until there was loss of eyelash reex. The total dose of propofol given, the heart rate, systolic and diastolic blood pressures, mean arterial pressures at various time intervals before, during and after induction and intubation, and complications observed were compared and statistically analysed using SPSS 2.0. Results:- The mean induction dose of propofol was signicantly lower in the priming groups (71.7 ± 17.2mg in group 2 and 80.0 ± 17.1mg in group 3) compared to group1 (107.9 ± 8.0mg). The fall in mean arterial pressure was signicantly lower in groups 2 and 3 (p&lt;0.05) compared to group1 at one minute post-induction. Conclusion:-Application of priming principle reduces the induction dose of propofol and is associated with better peri-intubation haemodynamic stability.

Role of priming principle in the induction dose requirement of propofol and hemodynamic stability

Aim: To study the role of priming principle in the induction dose requirement of propofol and hemodynamic stability. Methods: This observational study conducted in the, Department of Anaesthesia. 80 patients of age between 20-57 years, come under ASA-I or ASA-II category undergoing surgery which requires general anaesthesia as a mode of anaesthesia chosen to determine effect of priming principle in relation to Propofol. Results: The mean induction dose in group A was 81.22±9.68 and in group B it was 113.02±12.63. Thus we observed a 25% reduction in induction dose requirement in group A. The rise in Pulse rate was highly significant at one minute after induction, during intubation, immediately after intubation & 5 minutes later. Two groups were comparable to each other with respect to age, weight, ASA physical status. There was no significant difference in baseline pulse rate & baseline SBP, DBP & MAP, oxygen saturation between group A & Group B (p value > 0.05). Conclusion: Based on the results from this study it is concluded that application of priming principle to the induction dose of propofol will reduce the total induction dose of propofol.