Bolus Dose Of Propofol Research Articles

Dexmedetomidine as an Adjunct to Propofol in Patients Undergoing Elective Endoscopic Retrograde Cholangio-Pancreaticography - A Double-blind Randomized Controlled Study.

Propofol is the drug of choice for procedural sedation. The addition of α2 agonist dexmedetomidine may improve the safety profile of the procedure by providing stable hemodynamics, better sedation quality, and decreasing the side effects of each drug during elective endoscopic retrograde cholangio-pancreaticography (ERCP). Eighty patients aged between 18 and 60 years were distributed randomly into two groups. The dexmedetomidine + propofol group (group DP) received an injection of dexmedetomidine at the dose of 1 mcg/kg in 100 mLsaline, and the propofol group (group P) received plain 100 mL normal saline over 10 min. Subsequently, both groups received a bolus dose of injection propofol 1 mg/kg as sedation, and a modified observer's assessment of alertness/sedation score (MOASS) score was assessed, followed by infusion at the rate of 50 mcg/kg/min during the procedure. A rescue bolus dose (20 mg) of propofol was administered when the patient showed signs of inadequate sedation or analgesia in both groups. Cardiovascular and respiratory parameters were recorded every 10 min throughout the procedure. Post-procedure modified Aldrete score was evaluated for 30 min, and the endoscopist's score was noted at the end of the procedure. There was a significant difference (P = 0.001) in the additional number of rescue doses of propofol administered in group DP (3.47 ± 0.77) as compared to group P (8.78 ± 1.11). The total dose of propofol was lower in group DP (316.59 ± 43.29 mg) than in group P (443 ± 41.1 mg) with P value = 0.001. Statistically significant differences in the hemodynamic values were observed in group DP during infusion (P value < 0.05) of dexmedetomidine and throughout the procedure (P < 0.05) when compared with group P. Endoscopists graded the satisfaction score as very high (3.477 ± 0.77) in group DP. The addition of dexmedetomidine to propofol during ERCP provided better and safer sedation.

Comparison of airway collapsibility following single induction dose ketamine with propofol versus propofol sedation in children undergoing magnetic resonance imaging: A randomised controlled study.

Adequate sedation is essential for children undergoing magnetic resonance imaging (MRI) console. Propofol is commonly used for sedation, but it has the drawback of upper airway collapse at higher doses, which may be overcome by ketamine. This study was designed to evaluate the beneficial effect of ketamine on propofol in preventing airway collapse. Fifty-eight children undergoing MRI were randomised to Group P (propofol bolus dose followed by infusion or Group KP (bolus dose of ketamine and propofol followed by propofol infusion). The primary aim is to compare the upper airway cross-sectional area (CSA) and diameters (transverse diameter [TD] and anteroposterior diameter [APD]) obtained from MRI during inspiration and expiration. Upper airway collapse as measured by delta CSA in mean (SD) [95% confidence interval] was statistically more significant between the two groups [at the soft palate level, 16.9 mm2 (19.8) [9.3-24.4] versus 9.0 mm2 (5.50) [6.9-11.1] (P = 0.043); at the base of the tongue level, 15.4 mm2 (11.03) [11.2-19.6] versus 7.48 mm2 (4.83) [5.64-9.32] (P < 0.001); at the epiglottis level, 23.9 (26.05) [14.0-33.8] versus 10.9 mm2 (9.47) [7.35-14.5] (P = 0.014)]. A significant difference was obtained for TD at all levels and for APD at the soft palate and base of tongue level. Adding a single dose of ketamine to propofol reduced the upper airway collapse significantly, as evidenced by the MRI-based measurements of upper airway dimensions, compared to propofol alone.

Dose-dependent changes in orientation amplitude maps in the cat visual cortex after propofol bolus injections

A general intravenous anesthetic propofol (2,6-diisopropylphenol) is widely used in clinical, veterinary practice and animal experiments. It activates gamma- aminobutyric acid (GABAa) receptors. Though the cerebral cortex is one of the major targets of propofol action, no study of dose dependency of propofol action on cat visual cortex was performed yet. Also, no such investigation was done until now using intrinsic signal optical imaging. Here, we report for the first time on the dependency of optical signal in the visual cortex (area 17/area 18) on the propofol dose. Optical imaging of intrinsic responses to visual stimuli was performed in cats before and after propofol bolus injections at different doses on the background of continuous propofol infusion. Orientation amplitude maps were recorded. We found that amplitude of optical signal significantly decreased after a bolus dose of propofol. The effect was dose- and time-dependent producing stronger suppression of optical signal under the highest bolus propofol doses and short time interval after injection. In each hemisphere, amplitude at cardinal and oblique orientations decreased almost equally. However, surprisingly, amplitude at cardinal orientations in the ipsilateral hemisphere was depressed stronger than in contralateral cortex at most time intervals. As the magnitude of optical signal represents the strength of orientation tuned component, these our data give new insights on the mechanisms of generation of orientation selectivity. Our results also provide new data toward understanding brain dynamics under anesthesia and suggest a recommendation for conducting intrinsic signal optical imaging experiments on cortical functioning under propofol anesthesia.

Subanesthetic-dose propofol infusion for preventing emergence agitation in children: a retrospective observational study.

Anesthesia maintenance using propofol and a propofol bolus dose at the end of surgery have been shown to prevent emergence agitation (EA).However, the preventive effect of subanesthetic propofol infusion during sevoflurane anesthesia on EA remains unknown. We aimed toevaluate the effect of subanesthetic propofol infusion on EA in children. We retrospectively compared the incidences of severe EA requiring pharmacological intervention in children who underwent adenoidectomy, tonsillectomy with or without adenoidectomy, or strabismus surgery between maintenance with sevoflurane alone (sevoflurane group) and maintenance with subanesthetic propofol with sevoflurane (combination group). A multivariable logistic regression model adjusted for confounders was used to assess the association between anesthesia methods and the occurrence of EA. Additionally, we estimated the direct effect of anesthesia methods by a mediation analysis, excluding the indirect effects of intraoperative fentanyl and droperidol administration. Among 244 eligible patients, 132 and 112 were in the sevoflurane and combination groups, respectively. The crude incidence of EA was significantly lower in the combination group (17.0% [n = 19]) than in the sevoflurane group (33.3% [n = 44]) (P = 0.005).After adjusting for confounders, the incidence of EA was still significantly lower in the combination group (adjusted odds ratio [aOR]: 0.48, 95% confidence interval [CI] 0.25-0.91). The mediation analysis revealed a direct association of anesthesia methods with a lower EA incidence in the combination group (aOR: 0.48, 95% CI 0.24-0.93) than in the sevoflurane group. Subanesthetic propofol infusion may effectively prevent severe EA requiring the administration of opioids or sedatives.

1023: IMPACT OF OBESITY ON HEMODYNAMICS IN CRITICALLY ILL PATIENTS RECEIVING PROPOFOL

Introduction: Propofol is a commonly used sedative in the ICU, but data on optimal dosing in obese patients is lacking. As propofol is a lipophilic medication, a relatively higher dose based on actual body weight (ABW) may lead to accumulation and increase risk of adverse events. The purpose of this research project is to evaluate the rate of hypotension and bradycardia in critically ill patients receiving propofol for sedation. Methods: This single center, retrospective cohort study examined mechanically ventilated, adult patients receiving continuous sedation with propofol in the ICU from 8/1/16-8/1/21. Patients were excluded if they met the any of the following criteria: propofol dosing not based on ABW, on concomitant vasopressors at time of initiation of propofol, received a bolus dose of propofol, on propofol for < 4 hours, and history of heart block or permanent pacemaker. The primary outcome was the percent of hemodynamic instability during the first 72 hours of propofol administration as defined as hypotension (MAP < 65 mmHg or SBP < 90 mmHg) and bradycardia (heart rate < 60 bpm). Secondary outcomes evaluated include the total dose of propofol (mg) and the degree of hemodynamic instability, defined by the need for intervention (administration of atropine, fluid bolus, vasopressor). All continuous data was expressed as an interquartile range or mean (+/-) standard deviation and analyzed using the independent T-test. Categorical data was expressed as a percent and analyzed using the Chi-Squared test. Results: 331 patients met inclusion criteria (n=171 obese patients, n=160 nonobese patients). Baseline characteristics were similar between the groups, apart from age (61.1±13.9 vs 66.7±13.7, p=< 0.001) and SOFA score (4.3 ± 2.8 vs 2.4 ± 2.5, p< 0.001) More patients in the obese patient group required administrations of a fluid bolus than the non-obese patient group (43.3% vs 28.8%, p< 0.006). Conclusions: The use of ABW in the obese population did not result in a significant association between the occurrence of bradycardia and hypotension, though more obese patients required fluids. Additional studies are needed to confirm this relationship and further explore whether clinical significance exists.

Comparison of Quantium Consciousness Index and Richmond Agitation Sedation Scale in Mechanically Ventilated Critically Ill Patients: An Observational Study.

BackgroundThe quantium consciousness index (qCON), an electroencephalography (EEG)-based modality, has no studies regarding intensive care unit (ICU) sedation, though very few studies describe its use for assessing depth of anesthesia in the operation theater. In this study, we evaluated qCON for assessing sedation compared with Richmond Agitation Sedation Scale (RASS) in patients on a mechanical ventilator in the ICU.Materials and methodsEighty-seven mechanically ventilated patients aged between 18 and 60 years were investigated over a 12-hour period. They were given a standardized dosage of sedation comprised of a bolus dose of propofol 0.5 mg/kg and fentanyl 1 µg/kg, and then infusions of propofol 2–5 mg/kg/hour and fentanyl 0.5–2 µg/kg/hour. These drug infusions were adjusted to achieve a RASS score between 0 and −3. Using the qCON monitor, the investigator recorded the qCON values and then assessed the RASS score.ResultsA total of 1,218 readings were obtained. After contrasting each qCON value correspondingly with time to each RASS value, we found their correlation to be statistically significant (ρ = 0.288, p <0.0001). With the help of receiver operating characteristic (ROC) curves, we were able to differentiate appropriate from inappropriate levels of sedation. A qCON value of 80 had a sensitivity of 72.67% and a specificity of 67.42% (AUC 0.738 with SE 0.021).ConclusionqCON can be used for assessing sedation levels in mechanically ventilated critically ill patients.Clinical trial registrationCTRI/2019/07/020064.How to cite this articleHarsha MS, Bhatia PK, Sharma A, Sethi P. Comparison of Quantium Consciousness Index and Richmond Agitation Sedation Scale in Mechanically Ventilated Critically Ill Patients: An Observational Study. Indian J Crit Care Med 2022;26(4):491–495.

Anesthetic Stability of Propofol, Dexmedetomidine, and Isoflurane by Measuring Bispectral Index (BIS) and Hemodynamic Indices: A Comparative Study

BackgroundHemodynamic changes and anesthetic awareness occurring during surgery under general anesthesia is a great concern for both surgeon and anesthesiologist. Maintenance of the adequate depth of anesthesia throughout the intraoperative period is important in maintaining hemodynamic stability, preventing intraoperative awareness, and avoiding postoperative recall.AimThis study aims to predict the anesthetic stability of propofol, dexmedetomidine, and isoflurane by measuring bispectral index (BIS) and hemodynamic indices.Materials and methodsThis is a prospective comparative study. Sixty patients of either sex, aged 18-60 years, with American Society of Anesthesiologist (ASA) physical status classification I and II, undergoing elective surgical procedures requiring general anesthesia were allocated into three groups of 20 each. Patients in each group were administered standard general anesthesia with routine hemodynamic monitoring along with BIS, and values were recorded at baseline and thereafter at every five-minute interval for the duration of surgery. Anesthesia was maintained in Group P using a bolus dose of propofol 1 milligram.kg-1 for 10 minutes followed by propofol infusion 50-75 microgram.kg-1.minute-1, Group D with a bolus dose of dexmedetomidine 1 microgram.kg-1 for 10 minutes followed by infusion 0.2-0.7 microgram.kg-1.hour-1, and Group I with isoflurane at 1 minimum alveolar concentration (MAC) for 10 minutes and then maintained between 0.5 MAC and 1.5 MAC until the duration of surgery. To maintain the surgical plane of anesthesia, the BIS score was monitored between 40 and 65. The quantitative variables were expressed as mean±SD and compared between groups using Student’s unpaired t-test. Data analysis was done using SPSS Statistics for Windows version 20.0 (IBM Corp., Armonk, NY, USA). A p-value of <0.05 was considered statistically significant.ResultsDuring intergroup comparison among study drugs, the mean BIS values were statistically significant among the groups (p<0.05). Hemodynamic indices were significantly better maintained in the dexmedetomidine group as compared to the isoflurane and propofol groups throughout the intraoperative period (p<0.05).ConclusionDexmedetomidine is better than propofol and isoflurane in maintaining the BIS score and hemodynamic parameters during the intraoperative period.

Impact of vaginal delivery history on anesthesia management of hysteroscopic surgery under intravenous general anesthesia: a cohort study of 99 patients

To evaluate the impact of a history of vaginal delivery on anesthesia management of patients undergoing hysteroscopic surgery under intravenous general anesthesia without tracheal intubation. Ninety-nine patients undergoing hysteroscopic surgery under intravenous general anesthesia were enrolled in this study, including 43 patients with (VD group) and 56 patients without a history of vaginal delivery (NVD group). For all the patients, blood pressure, heart rate (HR), blood oxygen saturation (SpO2) and bispectral index (BIS) were recorded before anesthesia (T1), after anesthesia (T2), after cervical dilation (T3), and at 3 min after cervical dilation (T4). Propofol and etomidate doses during anesthesia induction, the total dose of propofol administered, additional intraoperative bolus dose and times of propofol, intraoperative body movement, total operation time and surgeons' satisfaction feedback scores were compared between the two groups. The postoperative awake time, recovery time, VAS score at 30 min after operation, and postoperative nausea and vomiting (PONV) were also compared. There was no significant differences in SBP, DBP, HR, SpO2, or BIS between the two groups at T1 and T2, but at T3 and T4, SBP and DBP were significantly higher in NVD group than in VD group (P < 0.01); HR was significantly higher in NVD group only at T3 (P < 0.01). The application of vasoactive drugs did not differ significantly between the two groups. The total dose of propofol, additional intraoperative dose and times of propofol were all greater in NVD group than in VD group (P < 0.01). More body movements of the patients were observed in NVD group (P < 0.01), which also had lower surgeons' satisfaction score for anesthesia (P < 0.01), higher postoperative VAS score (P < 0.05), and shorter postoperative awake time (P < 0.05) and recovery time (P < 0.01). A history of vaginal delivery has a significant impact on anesthesia management of patients undergoing hysteroscopic surgery under intravenous general anesthesia without tracheal intubation in terms of hemodynamic changes, anesthetic medication, and postoperative recovery quality, suggesting the necessity of individualized anesthesia management for these patients.

Different behaviour of target-controlled infusion pumps despite apparently using the same Schnider pharmacokinetic model

BACKGROUND Target-controlled infusion (TCI) pumps deliver an initial bolus of drug to achieve a preset drug target concentration quickly. OBJECTIVE We investigated whether differences exist in the initial bolus dose between different TCI pumps despite apparently using the same pharmacokinetic (PK) model. DESIGN Observational study. SETTING Laboratory data from a German University Hospital. Experiments were performed between February 2019 and September 2020. PARTICIPANTS Four TCI pumps set to the Schnider model in effect-site mode with a target propofol concentration of 3.5 μg ml−1 were studied. The algorithms of two pumps employed a fixed equilibration rate constant (k e0) of 0.456 min−1 (Perfusor® Space® and Injectomat TIVA Agilia®), while the other two used a fixed time to peak concentration (t peak) of 1.6 min (Alaris® PK and Syramed® μSP6000). Pump performance was assessed on 13 virtual patients with different combinations of age, sex, height and weight: the initial propofol dose injected was measured on a high precision scale. MAIN OUTCOME MEASURES Propofol bolus dose, as if delivered for anaesthesia induction. RESULTS A small difference in propofol bolus doses was observed for some simulations: for example, 56.4 ± 1.2 and 59.7 ± 0.2 mg with a Syramed μSP6000 and an Alaris pharmacokinetic pump, respectively, in a virtual 54-year old man with a height of 170 cm and a weight of 74 kg. In contrast, significant differences were found in other simulated patients: for example, 72.0 ± 1.0 and 111.9 ± 1.2 mg (P &lt; 0.001) using a Perfusor Space and an Alaris TCI pump in a virtual 60-year-old, obese man with a height of 182 cm and a weight of 139 kg. CONCLUSIONS Discrepancies in the initial bolus dose can be explained by differences in k e0. Anaesthetists should be aware that differences exist in the implementation of the Schnider model between manufacturers, which could lead to disparities in the initial propofol bolus in some patients.

Comparison of Nalbuphine and Dexmedetomidine versus Nalbuphine and Propofol for Monitored Anaesthesia Care in Tympanoplasty: A Randomised Double-blind Study

Introduction: Tymanoplasty, a middle ear surgery, is done either under Local Anaesthesia (LA), General Anaesthesia (GA) or sedation with local anaesthesia. It is usually performed under Monitored Anesthesia Care (MAC) providing advantages of rapid onset, allowing hearing test intraoperatively and early mobilisation of the patient. Aim: To study the effect of nalbuphine/dexmedetomidine with nalbuphine/propofol on sedation and analgesia in tympanoplasties performed under MAC. Materials and Methods: This randomised, double-blind, clinical study was conducted from June 2020 to June 2021 in the Department of Anaesthesiology at Mahatma Gandhi Memorial Medical College and MY Hospital, Indore, Madhya Pradesh, India. Total 60 adult patients, of American Society of Anesthesiologists (ASA) grade I and II undergoing tympanoplasty under MAC, were randomly allocated into two groups. All patients received injection nalbuphine 50 μg/kg intravenously. Group D received a bolus dose of injection dexmedetomidine 1 μg/kg i.v. over 10 min followed by an infusion at 0.3 μg/kg/h i.v. Group P received a bolus dose of injection propofol 0.75 mg/ kg followed by an infusion at 0.025 mg/kg/min i.v. Sedation and analgesia were titrated to Ramsay Sedation Score (RSS) and Visual Analog Scale (VAS) of 3 each. The vital parameters and need for intraoperative rescue sedation/analgesia were recorded and compared. Results: Mean RSS was significantly more in group D (3.11±0.055) than group P (2.80±0.350). Overall, VAS score was significantly less in group D (1.60±0.670) than group P (2.70±0.691). In group D, 2 (6%) patients and in group P, 4 (12%) patients required inj. midazolam. Similarly, the requirement of inj. paracetamol in group D was in 3 (10%) patients, and in Group P it was 10 (33%) patients. Bradycardia (23.3% in group D and 13.3% in group P) and hypotension (20% in group D and 13.3% in group P) were the major side-effects seen in the study. Conclusion: Nalbuphine/dexmedetomidine is superior to nalbuphine/propofol in producing sedation and decreasing VAS in patients undergoing tympanoplasty under MAC.

Comparison between Sevoflurane and Isoflurane for Controlled Hypotensive Anaesthesia in Patients undergoing Craniotomy for Supratentorial Intracranial Surgery: A Randomised Single-blinded Study

Introduction: The controlled hypotensive anaesthesia technique is widely used for decades to create a bloodless surgical field and decrease intraoperative blood loss during neurosurgical procedures. Inhalation agents like isoflurane and sevoflurane provide the benefit of being hypnotic and hypotensive agents at clinical concentrations and predictable dose-dependent effects made them popular in neurosurgery. Aim: To compare the effects of sevoflurane and isoflurane for producing controlled hypotensive anaesthesia in surgeries for supratentorial brain tumours. Materials and Methods: Sixty-six patients of either sex in the age group of 20-60 years, with American Society of Anaesthesiologists (ASA) Grade I and II posted for elective craniotomy for supratentorial brain tumour under general anaesthesia were enrolled for this study. Patients were randomly allocated to two aesthetic regimens: Group I received isoflurane 1 Minimum Alveolar Concentration (MAC), and Group S received sevoflurane 1 MAC. The Systolic Blood Pressure (SBP) was lowered to less than 100 mmHg before the skin incision and was maintained throughout the surgery.If the blood pressure was not maintained within the above-mentioned range, then injection propofol bolus dose of 20 mg was given intravenously. The quality of the surgical field, brain relaxation, blood loss, duration of surgery, and postoperative complications were compared. Time taken for onset and recovery of controlled hypotension and the requirement of propofol for maintaining controlled hypotension in both groups were also compared. Results: The group S had better brain relaxation (N=26 vs N=20), less blood loss (241.5±61.62 vs 380.65±203.9 mL), and a shorter duration of surgery (135.45±25.6 vs 171.4±60.5 minutes) than group I. Group S had a few patients who required propofol (5 vs 17) to maintain controlled hypotension. The mean time to achieve the target Mean Arterial Pressure (MAP) and time to recovery was faster in group S (10.55±2.54 minutes) vs 15.35±0.99 minutes in group I and 12.95±3.24 minutes in Group S vs 17.85±2.21 minutes in Group I, respectively; p&lt;0.001). Conclusion: Sevoflurane is a safer and more potent drug than isoflurane to achieve controlled hypotension during surgery for a supratentorial brain tumour.

Effects of Fentanyl and Remifentanil on intraoperative hemodynamics and postoperative recovery in percutaneous nephrolithotomy cases

Objective: To compare the effects of fentanyl or remifentanil on intraoperative hemodynamic effects and postoperative recovery in patients undergoing percutaneous nephrolithotomy (PCNL).Material and Methods: Randomized and prospective study was conducted. Forty patients who underwent PCNL with the American Society of Anaesthesiologists (ASA) I-II enrolled into the study. All patients were divided into 2 groups according to administered anaesthesiology technique and drugs, which are remifentanil and fentanyl. Induction of anesthesia was same in both groups. Induction of anesthesia was obtained with a bolus dose of propofol (1-2 mg/kg), maintenance was achieved with sevoflurane (MAC2). Muscle relaxation was achieved with rocuronium. Group 1 was consisted of patients who were administered remifentanil and they received 1 μgr/kg of remifentanil as a single dose during the induction of anaesthesia Group 2 was received fentanyl 2 μg/kg as a single dose during the induction of anaesthesia. Group 1 received remifentanil 0.05 μgr/kg per minute as an infusion throughout the procedure for providing intraoperative hemodynamic stability, in group 2 fentanyl was given at a dose of 0.5 μg/kg iv bolus every 45 minutes. Intraoperative hemodynamic parameters and recovery data were recorded. Aldrete score, Ramsay sedation scale 15, 60, 360 minutes were noted after surgery. Visual analogue scale (VAS0-10) was used for pain evaluation.Results: Intraoperative hemodynamic measurements were more stable in Group 1. The need for nitro-glycerine was significantly increased in Group 2 (p&amp;lt;0.05). The Aldrete scores, Ramsay sedation scales and VAS did not differ significantly between the groups. Immediate recovery was significiantly earlier in Group 1 than Group 2 (p&amp;lt;0.05).Conclusion: Stable hemodynamic status and safer recovery can be provided with remifentanil compared to fentanyl during PCNL.

Deepening of sedation with propofol has limited effect on intra-abdominal pressure - An interventional study in mechanically ventilated adult patients with intra-abdominal hypertension.

To evaluate the effect of deepening of sedation on intra-abdominal pressure (IAP). 37 adult mechanically ventilated ICU patients with intra-abdominal hypertension received a bolus dose and subsequent infusion of propofol (bolus: 1 mg/kg, infusion: 3 mg/kg/h). IAP, mean arterial pressure (MAP), abdominal perfusion pressure (APP), depth of sedation according to Richmond Agitation-Sedation Scale (RASS), respiratory parameters, and vasopressor dose were assessed after bolus and at 15, 30 and 60 min of infusion of propofol. Median IAP at baseline was 15 (13-16) mm Hg. During the intervention, median IAP decreased by 1 mm Hg at all time points. In 24% of patients IAP decreased by ≥3 mm Hg. Compared to baseline, MAP and APP were reduced at all time points. Deepening of sedation per RASS was achieved in 70% of patients at all time points. No changes in respiratory tidal volumes nor plateau pressures were observed. Vasopressor therapy with noradrenaline was started or increased in 43% of patients, whereas the increase in patients already receiving noradrenaline prior to the intervention was not significant. Deepening of sedation with propofol results in a small decrease in IAP and greater simultaneous decrease in MAP and APP, requiring increased vasopressor support in some cases.

Observer's Assessment of Alertness/Sedation-based titration reduces propofol consumption and incidence of hypotension during general anesthesia induction: A randomized controlled trial.

Administration of a single propofol bolus dose for anesthesia induction causes hypotension. We included 160 patients (74 males and 86 females; mean age, 42.4 ± 10.7 [range: 18-60] years) with the American Society of Anesthesiologists status I-II undergoing elective surgery under general anesthesia. Using simple randomization, the patients were divided into a conventional group (n = 80; received 2 mg/kg propofol at a rate of 250 mg/min) and titrated group (n = 80; received propofol at a rate of 1 mg/kg/min until the Observer's Assessment of Alertness/Sedation scale score reached 1 point). Fentanyl (4 µg/kg) and cisatracurium (0.2 mg/kg) were administered, as appropriate. Systolic blood pressure, diastolic blood pressure, mean blood pressure, and heart rate were recorded at different time points. Propofol consumption, hypotension, and other adverse events were recorded. All the patients were intubated without awareness. Compared with the conventional group, the titrated group showed more stable blood pressure (p < 0.05), as well as a lower decrease in systolic blood pressure, mean blood pressure at 1 and 3 min, and diastolic blood pressure at 1 min after propofol administration (p < 0.01). Moreover, compared with the conventional group, the titrated group showed a lower post-intubation hypotension incidence (9 vs. 19 cases; p = 0.04), as well as lower total propofol dosage and propofol dose per kilogram of body weight (93.57 ± 14.40 mg vs. 116.80 ± 22.37 mg and 1.73 ± 0.27 mg/kg vs. 2.02 ± 0.08 mg/kg, respectively, p < 0.01). Compared with conventional propofol usage, titrated propofol administration can reduce the incidence of hypotension and propofol consumption during anesthesia induction.

Safety of Propofol When Used for Rapid Sequence Intubation in Septic Patients: A Multicenter Cohort Study.

Septic patients are at risk for hypotension, and this risk may increase during rapid sequence intubation (RSI). Sedatives such as propofol must be used carefully due to its ability to reduce vascular sympathetic tone. Since the safety of propofol for RSI is not well described in sepsis, this was a study evaluating propofol and its effects on hemodynamics when used for RSI in a septic population. We conducted a multicenter, retrospective, cohort study of patients with sepsis or severe sepsis requiring sedation for RSI. Patients receiving a propofol bolus for RSI were compared to patients undergoing RSI without a propofol bolus. The safety profile of propofol was evaluated according to the rates of post-intubation hypotension and vasopressor utilization between groups. A total of 179 patients (79 propofol, 100 non-propofol) were evaluated. There were no differences in hypotension (81% vs 78%; P = .62) or vasopressor utilization between the propofol and non-propofol groups (43% vs 49%; P = .43). Patients in the non-propofol group had increased APACHE II scores and healthcare-associated infections. In this cohort study, administration of propofol for RSI in patients with sepsis and severe sepsis did not increase incidence of hypotension or vasopressor use, but acute illness may have introduced provider selection bias causing less propofol use in the non-propofol group. Larger prospective studies are needed to better characterize the adverse hemodynamic effects of propofol, before propofol bolus doses for RSI can be considered for safe use in this population.

Variation in propofol induction doses administered to surgical patients over age 65.

Advanced age is associated with increased susceptibility to acute adverse effects of propofol. The present study aimed to describe patterns of propofol dosing for induction of general anesthesia before endotracheal intubation in a nationwide sample of older adults presenting for surgery. Retrospective observational study using the Multicenter Perioperative Outcomes Group data set. Thirty-six institutions across the United States. A total of 350,766 patients aged over 65 years who received propofol for general anesthetic induction and endotracheal intubation between 2014 and 2018. None. Total induction bolus dose of propofol administered. The mean (SD) weight-adjusted propofol dose was 1.7 (0.6) mg/kg. The mean prevalent propofol induction dose exceeded the upper bound of what has been described as the typical geriatric dose requirement across every age category examined. The percent of patients receiving propofol induction doses above the described typical geriatric range was 64.8% (95% CI 64.6-65.0), varying from 73.8% among patients aged 65-69 to 45.8% among patients aged 80 and older. The present study of a large multicenter cohort demonstrates that prevalent propofol dosing commonly falls above the published typically required dose range for patients aged ≥65 in nationwide anesthetic practice. Widespread variability in induction dose administration remains incompletely explained by known patient variables. The nature and clinical consequences of these unexplained dosing decisions remain important topics for further study. Observed discordance between expected and actual induction dosing raises the question of whether there should be reconsideration of widespread provider practice or, alternatively, whether what is published as the typical propofol induction dose range should be revisited.

CONSCIOUS SEDATION FOR MIDDLE EAR SURGERIES: COMPARISON BETWEEN PROPOFOLAND MIDAZOLAM WITH RESPECT TO HEMODYNAMIC EFFECTS

Background and aims: Middle ear surgeries can be done under local anesthetic infiltration and titrated dose of sedation. Use of supplemental intravenous sedative hypnotic drugs for these surgeries under local anesthesia can enhance patient comfort and increase acceptance of this technique. Our study was aimed to compare Propofol and Midazolam in equipotent doses for conscious sedation in middle ear surgeries Methods and material: After approval from the Institutional Ethics committee, 60 patients from ASA grade 1 and 2 scheduled for middle ear surgery (Tympanoplasty, mastoidectomy) under local anesthesia were randomly allocated into two groups to receive either Propofol (Group I) or Midazolam (Group II) for conscious sedation. Both the groups received premedication and sedation with 1.5 mcg /kg Fentanyl, Group 1 received Inj. Propofol bolus dose of 0.5-1 mg/Kg I.V, followed by infusion at the rate of 1.5-4.5 mg/kg/hour, to attain a sedation score of 3 and additional bolus doses were given as and when required to maintain a sedation score of 3. Group 2 received Inj. Midazolam bolus dose 0.03 to 0.05 mg/kg I.V followed by infusion at the rate of 0.03 to 0.06 mg/kg/hour to attain a sedation score of 3 and additional bolus doses as and when required to maintain a sedation score of 3. All the patients in both the groups received oxygen by nasal prongs at the flow rate of 4L/min from the start of sedation. Heart rate, systolic blood pressure, diastolic blood pressure, respiratory rate, oxygen saturation was noted at basal level and at an interval of 2 minutes and later every 5 mins for 30 mins then every 15 mins till end of surgery. Result: The results were analyzed using student’s 't’ test and chi square test wherever appropriate. Results: Pulse rate at 30th minute of sedation was not significantly different from the basal value among both the groups. Mean systolic blood pressure (SBP) in Propofol group was 121.33mmHg and 117.27mmHg among Midazolam group at basal which was comparable and the difference was not significant. Mean diastolic blood pressure was 78.47mmHg in Propofol group and 78.07mmHg among Midazolam group at basal which was comparable and the difference was not significant. Mean respiratory rate (breaths/min) among Propofol and Midazolam group were 16.83 and 16.70 respectively at basal which was comparable and the difference was not significant. Mean arterial oxygen saturation (%) among Propofol and Midazolam group were and 98.0 and 98.07 respectively at basal which was comparable and the difference was not significant. Conclusions: After the start of sedation mean diastolic blood pressure did not show any significant change in both the groups throughout the procedure. After the start of sedation mean respiratory rate and arterial oxygen saturation did not show any significant change in both the groups. Both Propofol and Midazolam are equally safe with respect to hemodynamic effects when used in titrated doses.

The Effect of Propofol Infusion Before Administration of Its Bolus Dose on Propofol Injection Pain and Serum Complement C3 Levels; A Randomized Clinical Trial.

BackgroundPain on injection with propofol is still a major problem associated with anesthesia. Several factors involved in this event have been studied with respect to their pain attenuating effects.ObjectivesThe purpose of this study was to evaluate the effect of propofol infusion before administration of its bolus dose of propofol on the resulted pain at its induction dose and on serum complement C3 levels.MethodsThis clinical trial was performed on patients undergoing surgery under general anesthesia divided into three groups, including A (without intervention), B (propofol infusion at a dose of 50 µg/kg/min before anesthesia induction), and C (propofol infusion at a dose of 100 µg/kg/min 100 before anesthesia induction). During anesthesia induction by propofol, the presence, absence or severity of pain was determined using the Numerical Rating Pain Scale. Serum complement C3 levels were measured and their relationships with pain scores were compared between three groups. The data were analyzed using SPSS V. 22 software.ResultsThere were significant differences in the mean pain scores between three groups (P < 0.05). However, no significant difference in the mean pain scores was observed between the groups B and C (P > 0.05). The mean and standard deviation of the differences in complement C3 values in the three groups before and after injection were 72.15 ± 14.9, 27.65 ± 9.82, and 18.95 ± 4.68, respectively, which demonstrated a significant difference between three groups (P < 0.05). However, the difference in complement C3 values between the groups B and C was not significant (P > 0.05).ConclusionsAccording to the obtained results, the low doses of infused propofol, 2 minutes before administration of its bolus dose, seems to have a considerable attenuating effect on its pain score.

Proof of principle: Preoperative cognitive reserve and brain integrity predicts intra-individual variability in processed EEG (Bispectral Index Monitor) during general anesthesia.

BackgroundPreoperative cognitive reserve and brain integrity may explain commonly observed intraoperative fluctuations seen on a standard anesthesia depth monitor used ubiquitously in operating rooms throughout the nation. Neurophysiological variability indicates compromised regulation and organization of neural networks. Based on theories of neuronal integrity changes that accompany aging, we assessed the relative contribution of: 1) premorbid cognitive reserve, 2) current brain integrity (gray and white matter markers of neurodegenerative disease), and 3) current cognition (specifically domains of processing speed/working memory, episodic memory, and motor function) on intraoperative neurophysiological variability as measured from a common intraoperative tool, the Bispectral Index Monitor (BIS).MethodsThis sub-study included participants from a parent study of non-demented older adults electing unilateral Total Knee Arthroplasty (TKA) with the same surgeon and anesthesia protocol, who also completed a preoperative neuropsychological assessment and preoperative 3T brain magnetic resonance imaging scan. Left frontal two-channel derived EEG via the BIS was acquired preoperatively (un-medicated and awake) and continuously intraoperatively with time from tourniquet up to tourniquet down. Data analyses used correlation and regression modeling.ResultsFifty-four participants met inclusion criteria for the sub-study. The mean (SD) age was 69.5 (7.4) years, 54% were male, 89% were white, and the mean (SD) American Society of Anesthesiologists score was 2.76 (0.47). We confirmed that brain integrity positively and significantly associated with each of the cognitive domains of interest. EEG intra-individual variability (squared deviation from the mean BIS value between tourniquet up and down) was significantly correlated with cognitive reserve (r = -.40, p = .003), brain integrity (r = -.37, p = .007), and a domain of processing speed/working memory (termed cognitive efficiency; r = -.31, p = .021). Hierarchical regression models that sequentially included age, propofol bolus dose, cognitive reserve, brain integrity, and cognitive efficiency found that intraoperative propofol bolus dose (p = .001), premorbid cognitive reserve (p = .008), and current brain integrity (p = .004) explained a significant portion of intraoperative intra-individual variability from the BIS monitor.ConclusionsOlder adults with higher premorbid reserve and less brain disease were more stable intraoperatively on a depth of anesthesia monitor. Researchers need to replicate findings within larger cohorts and other surgery types.

The Effect of Three Different Bolus Doses of Propofol Using Total Intravenous Anaesthesia (TIVA) in Patients Undergoing Transvaginal Oocyte Retrieval with Regard to Total Propofol Consumption

Background: Total intravenous anaesthesia (TIVA) using propofol is one of the commonest techniques used for TVOR as a day care procedure by virtue of its adequate sedation and speedy clear headed recovery. Monitors like BIS or entropy help us to effectively titrate the drug so as to maintain optimal depth of anaesthesia and minimise drug consumption. Subjects and Methods: After obtaining Institutional Review Board approval, this prospective randomised controlled study was conducted in the Department of Anaesthesiology and Intensive care, Medical College Hospital. All ASA Grade I and II female patients of reproductive age group coming for oocyte retrieval under general anaesthesia who can understand the informed consent form were included in the study. Results: There is a statistically significant difference observed between group P1 and P3 with regard to Proportion of patients not requiring rescue boluses. No significant difference was observed between P1 – P2 and P2-P3 groups. There was a statistically significant difference observed between groups P1 and P3 in respect to total propofol consumption. No significant difference observed between P1-P2 and P2-P3. &nbsp;Conclusion: Bolus dose of propofol can be an induction dose of choice in oocyte retrieval patients as it requires less rescue boluses compared to 1.0mg/kg and and overall propofol consumption was less than 2 mg/kg but more than1 mg/kg.