Propofol Bolus Research Articles

Safety of endoscopist-directed nurse-administered sedation in an Italian referral hospital: An audit of 2 years and 19,407 procedures

Background and study aimsBalanced propofol sedation (BPS) administered by adequately trained non-anaesthesiologist personnel has gained popularity in GI endoscopy because of its shorter procedure and recovery time, high patient satisfaction, and low rate of adverse events (AEs), despite being considered controversial. We report data from an audit of endoscopist-directed (ED) nurse-administered sedation in an Italian referral hospital. Patients and methodsConsecutive endoscopic procedures performed between 2020 and 2022 were considered. Under the guidance of the endoscopist, the nurse administered midazolam/fentanyl, followed by a progressive top-up dosage of a 10–20 mg bolus of propofol to achieve moderate to deep sedation. The endoscopists and nurses were all certified in our hospital with a continuous and scheduled training from 2006. ResultsDuring the study period, a total of 19,407 examinations (7,803 EGDS, 10,439 colonoscopies, 77 PEG, 697 EUS, and 365 ERCP) and 14,415 patients were included. Of these, 29.4 % of patients were classified as ASA I, 66.5 % as ASA II, and 5.1 % as ASA III. Hypotension was recorded in 1,293 (6 %) examinations and bradycardia in 176 (0.9 %) patients. Eleven patients (0.06 %) had minor respiratory adverse events. Two patients (0.01 %) had major AEs requiring orotracheal intubation. ConclusionsED-BPS is safe in low-risk patients. Major AEs occurred in 0.01 % of procedures.

A Comparison of the Use of Propofol versus Midazolam for Pediatric Magnetic Resonance Imaging Sedation: Retrospective Cohort Study.

The aim of the present study was to do a comparison of the recovery profiles and airway-related adverse events of pediatric magnetic resonance imaging (MRI) sedation patients who received propofol alone to those who received midazolam alone. This retrospective cohort study was approved by the Mutah University Ethical Approval Committee (No. 2378). A search of the patients' medical records was performed between September 2021 and April 2022 to identify children aged 4 months-11 years who received propofol or midazolam for MRI sedation. The patients were subdivided into two groups: Those who had propofol alone (propofol group) and those who received midazolam (midazolam group) for pediatric MRI sedation. In propofol group, a 1-2 mg/kg of propofol bolus was given to have a deep sedation (Ramsay Sedation Scale score of 5). Patients in midazolam group received 0.05 mg/kg of midazolam. During the maintenance state of sedation, the patient received 150 µg/kg/min of propofol, and the infusion rate was adjusted in 25 μg/kg/min increments up or down at the discretion of the anesthesiologists to maintain a state of deep sedation. The major targets of this study were recovery profiles (time to awake and time to discharge) and airway-related intervention ratios in pediatric MRI sedation patients. Patient demographics, MRI sedation, and recovery data, including propofol induction dose, airway intervention, and sedation-related adverse events from the pediatric sedation recovery unit were also collected. The mean (standard deviation [SD]) propofol induction dose was higher compared to midazolam group (2.4 [0.7] mg vs. 1.3 [0.5] mg; mean difference, 1.1 mg; P < 0.001). The mean (SD) infusion rate was higher in propofol group compared to midazolam group (161.3 [37.6] μg/min/kg vs. 116.2 [25.6] μg/min/kg; mean difference 45.1 μg/min/kg; P < 0.001). The mean (SD) propofol total dose was higher in propofol group compared to midazolam group (236.3 [102.4] mg vs. 180.7 [80.9] mg; mean difference, 155.4 mg; P < 0.001). The mean (SD) time to awake was longer in midazolam group compared to propofol group (21.2 [5.6] min vs. 23.0 [7.1] min; mean difference, 1.8 min; P < 0.001). The mean (SD) time to discharge was longer in midazolam group compared to propofol group (34.5 [6.9] min vs. 38.6 [9.4] min; mean difference, 4.1 min; 95% confidence interval, 3.0-5.1; P < 0.001). The administration of midazolam during pediatric MRI sedation can decrease the frequency of airway complications without prolonging the clinically significant recovery profile.

Bradycardic peri-arrest after electrical cardioversion for atrial fibrillation: a case report

Electrical cardioversion can precipitate prolonged bradycardia and cardiac arrest when the sinoatrial node is dysfunctional, and the escape rhythms from the atrioventricular node and ventricles fail to take over. We report the case of an elderly male who rapidly progressed into bradycardic peri-arrest after electrical cardioversion for persistent atrial fibrillation. Despite the immediate initiation of intravenous atropine and transcutaneous pacing, 2 minutes of cardiopulmonary resuscitation with further boluses of atropine and adrenaline were required before the return of spontaneous circulation. The patient was transferred to the intensive care unit, and a permanent pacemaker was implanted before discharge. Advanced age, long duration of atrial fibrillation, previous aortic valve replacement, use of anti-arrhythmic drugs, and intravenous propofol bolus were all contributing factors to this event. We summarise the relevant clinical features, risk factors, and management considerations, in the hope of promoting awareness of this rare complication of a common procedure.

A prospective, randomized, single-blinded study comparing the efficacy and safety of dexmedetomidine and propofol for sedation during endoscopic retrograde cholangiopancreatography

BackgroundBalanced propofol sedation is extensively used in endoscopic retrograde cholangiopancreatography (ERCP), but sedation-related adverse events (SRAEs) are common. In various clinical settings, the combination of dexmedetomidine with opioids and benzodiazepines has provided effective sedation with increased safety. The aim of this investigation was to compare the efficacy and safety of dexmedetomidine and propofol for sedation during ERCP.MethodsForty-one patients were randomly divided into two groups: the dexmedetomidine (DEX) group and the propofol (PRO) group. Patients in the DEX group received an additional bolus of 0.6 μg kg−1 dexmedetomidine followed by a dexmedetomidine infusion at 1.2 μg kg−1 h−1, whereas the PRO group received 1–2 mg kg−1 of propofol bolus followed by a propofol infusion at 2–3 mg kg−1 h−1. During ERCP, the primary outcome was the incidence of hypoxemia (SpO2 < 90% for > 10 s). Other intraoperative adverse events were also recorded as secondary outcomes, including respiratory depression (respiratory rate of < 10 bpm min−1), hypotension (MAP < 65 mmHg), and bradycardia (HR < 45 beats min−1).ResultsThe incidence of hypoxemia was significantly reduced in the DEX group compared to the PRO group (0% versus 28.6%, respectively; P = 0.032). Patients in the PRO group exhibited respiratory depression more frequently than patients in the DEX group (35% versus 81%, respectively; P = 0.003). There were no significant differences in terms of hypotension and bradycardia episodes between groups. During the procedures, the satisfaction scores of endoscopists and patients, as well as the pain and procedure memory scores of patients were comparable between groups.ConclusionIn comparison with propofol, dexmedetomidine provided adequate sedation safety with no adverse effects on sedation efficacy during ERCP.Trial registrationChinese Clinical Trial Registry, ChiCTR2200061468, 25/06/2022.

Comparison of arterial hypotension incidence during general anesthesia induction – target-controlled infusion vs. bolus injection of propofol: a randomized clinical trial

BackgroundThe incidence of arterial hypotension during induction of general anesthesia is influenced by the method of propofol administration, but there is a dearth of randomized clinical trials comparing bolus injection and target-controlled infusion in relation to arterial hypotension. This study seeks to compare the incidence of arterial hypotension between these two methods of propofol administration. MethodsThis prospective, randomized, single-center, non-blinded study included 60 patients (aged 35 to 55 years), classified as ASA physical status I or II, who were undergoing non-cardiac surgeries. They were randomly allocated using a computer to two groups based on the method of propofol administration during the induction of general anesthesia: the Target Group, receiving target-controlled infusion at 4 μg.mL−1, and the Bolus Group, receiving a bolus infusion of 2 mg.kg−1. Both groups also received midazolam 2 mg, fentanyl 3 μg.kg−1, and rocuronium 0.6 mg.kg−1. Over the first 10 minutes of anesthesia induction, Mean Arterial Pressure (MAP), Heart Rate (HR), level of Consciousness (qCON), and Suppression Rate (SR) were recorded every 2 minutes. ResultsTwenty-seven patients remained in the TCI group, while 28 were in the Bolus group. Repeated measure analysis using mixed-effects models could not reject the null hypothesis for the effect of group-time interactions in MAP (p = 0.85), HR (p = 0.49), SR (p = 0.44), or qCON (p = 0.72). The difference in means for qCON (60.2 for TCI, 50.5 for bolus, p < 0.001), MAP (90.3 for TCI, 86.2 for bolus, p < 0.006), HR (76.2 for TCI, 76.9 for bolus, p = 0.93), and SR (0.01 for TCI, 5.5 for bolus, p < 0.001), irrespective of time (whole period means), revealed some significant differences. ConclusionPatients who received propofol bolus injection exhibited a lower mean arterial pressure, a greater variation in the level of consciousness, and a higher suppression rate compared to those who received it as a target-controlled infusion. However, the interaction effect between groups and time remains inconclusive.

Maternal and neonatal effects of epidural levobupivacaine combined with fentanyl or sufentanil for elective cesarean-section in brachycephalic breeds

The aim of this study was to compare the safety and clinical efficacy of epidural levobupivacaine combined with fentanyl or sufentanil for bitches undergoing elective cesarean-section and the impact of these anesthetic protocols on neonatal viability. The anesthetic protocol consisted of intramuscular morphine (0.2 mg/kg), followed by an intravenous bolus of propofol, in a dose sufficient to allowed the puncture of the lumbosacral space. The dogs were randomly allocated to receive 0.5 % levobupivacaine plus fentanyl (2.5 µg/kg; LF: n = 9) or sufentanil (1 µg/kg; LS; n = 11). Maternal cardiorespiratory parameters were monitored at specific time points during surgery. Intraoperative propofol supplementation was based on the presence of head and/or thoracic limb movements. Neonatal reflex responses and the Apgar score (range 0-10 points) were assessed at 5 and 60 minutes after birth. Puppy mortality rate was recorded until 24 hours after birth. Data were analyzed using two-way ANOVA, Tukey's test, Wilcoxon signed rank test, and Fisher's exact test (P < 0.05). Intraoperatively, maternal cardiorespiratory variables and propofol requirements were similar between groups, with no detection of anesthetic complications. The puppy reflex responses did not differ between groups at any time point. The medians (range) of Apgar scores were lower (P = 0.016) in the LF [5 (1-9)] at 5 minutes in comparison with LS [6 (2-9)], while no intergroup differences were recorded at 60 minutes [LF = 8 (2-10); LS = 9 (6-10]. The total mortality rate was 4.1 %. In the LS group, no puppies died, while in the LF 8 % of the puppies died in the first 24 hours after birth (P = 0.11). Epidural levobupivacaine combined with fentanyl or sufentanil provided minimal maternal and neonatal adverse effects, but neither protocol enabled the performance of a C-section in 100 % of the French and English bulldogs, without propofol supplementation.

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.

An unusual instance of propofol-triggered green urine in anesthesia management: A case report

Abstract Green urine is a rare and harmless side effect of propofol administration, occurring in less than 1% of cases. Urine discoloration following a single propofol bolus for induction of anesthesia is uncommon, benign, and entirely reversible upon cessation of propofol. Here, we present a case of green urine induced by a single dose (bolus) of propofol and discuss other potential endogenous and exogenous factors that could cause urine discoloration. Our case report aims to raise awareness among intensivists, physicians, and patients, helping to avoid unnecessary laboratory testing, initiating empirical broad-spectrum antibiotics, and anxiety associated with this unusual presentation.

Comparison of sedation efficacy of intravenous infusion of dexmedetomidine versus propofol in terms of opioid consumption in patients requiring postoperative mechanical ventilation after head and neck onco-surgeries – A randomized prospective study

Abstract Background: The conventional drug regimen of sedation for patients requiring mechanical ventilation in an intensive care unit (ICU) is propofol or midazolam. Dexmedetomidine is a newer drug for sedation with a better clinical profile. We conducted this study to compare the sedative efficacy of dexmedetomidine versus propofol in patients after head and neck cancer surgeries requiring mechanical ventilation. Methods: After ethics committee approval and written informed consent, 80 patients undergoing head and neck onco-surgery were recruited. The patients were randomly allocated to group I [1 mg/kg of bolus propofol over 15 minutes followed by infusion of 1 mg/kg/hour titrated by increasing or decreasing the infusion dose to Ramsay Sedation Score (RSS) 2–4] or group II (a loading dose of dexmedetomidine 1 mcg/kg over 15 minutes followed by a maintenance dose of 0.4 µg/kg/hour titrated to desired sedation level). The RSS, behavioral pain scale (BPS), heart rate, blood pressure, fentanyl consumption, additional sedative agent, extubation time, length of ICU stays, mechanical ventilation duration, side effects, and patient’s satisfaction were noted. Results: Total fentanyl required was 0.56 ± 0.13 µg/kg/hour in group II and 0.58 ± 0.18 µg/kg/hour in group I (P = 0.75). Extubation time, RSS, BPS, patient satisfaction, and ICU duration were similar in both the groups. The incidence of hemodynamic-related adverse effects were 41.67% in group II and 11.11% in group I (P = 0.006). Conclusion: The fentanyl requirement was comparable in both the groups in the postoperative period. Dexmedetomidine was associated with an increased incidence of bradycardia and hypotension as compared to the propofol group. Propofol should be the preferred sedative for postoperative mechanical ventilation after head and neck onco-surgeries.

Effectiveness and safety of an atropine/midazolam and target controlled infusion propofol-based moderate sedation protocol during percutaneous endoscopic transgastric jejunostomy procedures in Parkinson's disease: a real-life retrospective observational study.

Patients with Parkinson's disease (PD), often elderly with various comorbidities, may require a continuous intestinal infusion of carbidopa/levodopa gel by the placement of a percutaneous endoscopic gastrostomy (PEG) with a jejunal tube (PEG-J) to improve their motor outcome and quality of life. However, it is unclear what is the best procedural sedation protocol for PEG-J procedures. Fifty patients with PD and indication for PEG-J procedure (implantation, replacement, removal) underwent, from 2017 to 2022, a sedation protocol characterized by premedication with atropine (0.01 mg/Kg i.v.), midazolam (0.015-0.03 mg/Kg i.v.) and induction with bolus propofol (0.5-1 mg/Kg i.v.) as well as, finally, sedation with continuous infusion propofol (2-5 mg/Kg/h i.v.) by Target Controlled Infusion (TCI) technique. Ninety-eight per cent of patients experienced no intraprocedural or peri-procedural adverse events. All the procedures were technically successful. A good discharge time was recorded. The vital parameters recorded during the procedure did not vary significantly. A PEG-J procedure conducted within 30 min showed a significant advantage over end-tidal carbon dioxide (EtCO2). Indeed, the latter showed some predictive behavior (OR: 1.318, 95% CI 1.075-1.615, p = 0.008). In the real world, this sedation protocol showed a good safety and effectiveness profile, even with reduced doses of midazolam and a TCI propofol technique in moderate sedation.

Propofol for Anesthesia in Pediatric Patients With Epilepsy on the Ketogenic Diet: A Single-Center Experience

BackgroundPropofol use is contraindicated in patients on ketogenic diet (KD) due to higher risk of propofol infusion syndrome (PIS). This study is intended to provide a descriptive analysis of our experience with propofol bolus and short infusions for anesthetic care in patients on the KD and to evaluate if any signs of PIS were observed. MethodsAll patients on the KD who underwent anesthesia with propofol between 2012 and 2022 were reviewed. Anesthetic encounters and charts were studied for type of surgical procedure; signs of PIS, including new cardiac arrhythmias, acidosis, or rhabdomyolysis in the periprocedural period; hypoglycemia; unplanned admissions within 24 hours of the procedure; if procedure was unexpectedly aborted; and increased seizure frequency within one week. ResultsWe identified 65 patients, aged from one to 20 years who underwent 165 anesthetic encounters with propofol, of which 123 were boluses and 42 were infusions.In bolus dosing, the average dose was 2.8 mg/kg (0.7 to 12.8 ± 1.8 mg/kg). Of these, four encounters developed acidosis, one developed rhabdomyolysis, and one developed increased seizures. With infusions, the average infusion rate was 9 mg/kg/hour, with mean infusion duration of 83 minutes (10 to 352 ± 75 minutes). Of these, one developed acidosis and one increased seizures. No cases of PIS were identified. None of the adverse effects were attributed to propofol. ConclusionsBoluses and brief infusions of propofol for anesthetic use in patients on the KD did not cause PIS in our cohort.

Safety and efficacy of dexmedetomidine vs ketamine vs midazolam combined with propofol in gastrointestinal endoscopy for cancer patients: A randomized double-blinded trial

ABSTRACT Background A wide range of drugs are used for sedation in gastrointestinal (GI) endoscopy procedures, including midazolam, dexmedetomidine, and ketamine. Therefore, this study aimed to compare the effects of these drugs in combination with propofol among cancer patients undergoing GI endoscopy. Methods This randomized, double-blinded study was carried out on 75 cancer patients who underwent GI endoscopy. Patients were categorized into three equal groups. Group D: received dexmedetomidine 0.5 µg/kg bolus infusion over 10 min. Group K: received ketamine 0.5 mg/kg. Group M: received midazolam 0.05 mg/kg. With these drugs, 0.5 mg/kg propofol was administered intravenously with incremental 20 mg till achievement of Ramsey sedation score (RSS) 3–4. After that, 0.5 mg/kg propofol boluses were offered for rescue sedation. Results The endoscopy duration was comparable in the three groups. Time of RSS 3–4 achievement and total propofol dose (P < 0.05) were significantly lower in group D and group K compared to group M. Time to eye-opening were significantly lower in groups D, and K compared to group M, with insignificant difference between group K and group D. Moreover, the heart rate (HR) and mean arterial pressure (MAP) of group K at 10 min, 15 min, 20 min, 25 min, and 30 min, and PACU were significantly greater than D and M groups (P < 0.05). Incidence of hypotension and bradycardia were comparable in the three groups. Conclusions In cancer patients who underwent GI endoscopy, dexmedetomidine-propofol and ketamine-propofol had better sedation efficacy [lower achievement time of RSS 3–4, total propofol dose, and eye-opening time] compared to midazolam-propofol group with superior sedative effect of ketamine-propofol than dexmedetomidine-propofol. While ketamine-propofol had more stable HR and MAP.

Intramuscular ketamine provides better sedation and scan conditions in children undergoing magnetic resonance imaging: A single-blinded observational study.

The objectives of this study were to compare the quality of sedation provided by intravenous (i.v.) and intramuscular (im) ketamine for pediatric magnetic resonance imaging (MRI). This study was a non-randomized, single-blinded, and prospective observational study. After receiving approval from the Institutional Ethics Committee, a total of 108 children aged 2-7 years were divided into two groups, with 54 children in each group. In the i.v. group, children received ketamine at a dose of 1.5 mg/kg intravenously, while in the im group, children received ketamine at a dose of 4 mg/kg intramuscularly. If a Ramsay sedation score of 6 (RSS-6) was not achieved, half of the loading dose of ketamine was repeated. In both groups, rescue propofol boluses of 1 mg/kg intravenously were administered whenever the child moved. The primary outcome measure was the quality of sedation, which was assessed by a blinded radiologist. The time taken to reach RSS-6, the number of rescue propofol boluses, the total time wasted in taking repeat sequences, and the time required to achieve a modified Aldrete score of 9 (MAS-9) were recorded. The im group demonstrated significantly better sedation quality. In the i.v. group, the time to achieve RSS-6 was significantly shorter, but it required more rescue propofol boluses to maintain sedation. The i.v. group also experienced a notable increase in the total time wasted during repeat sequences. On the other hand, the i.v. group exhibited a shorter time to reach MAS-9 compared to the im group. The im group showed superior sedation quality when compared to the i.v. group. However, it is important to consider that the im group experienced a longer recovery time.

Hemodynamic effects of a low versus a high dose of propofol during induction of anesthesia. A randomized trial.

Hypotension is common after anesthesia induction with propofol and is associated with increased morbidity. It is important to examine the effects of the proposed interventions to limit preventable hypotension, as suggested by the reduction in the dose of propofol. Our objective was to investigate whether a high dose of propofol is inferior to a low dose with respect to changes in systolic arterial blood pressure (SAP). This randomized, double-blind, dose-controlled, non-inferiority study included 68 healthy women scheduled for gynecological surgery at the Day Surgery Unit, Haugesund Hospital, Norway. The patients were randomly allocated 1:1 to a low or high dose (1.4 mg/kg total body weight (TBW) versus 2.7 mg/kg TBW of propofol corresponding to maximal effect site concentrations (Ce) of 2.0 μg/mL versus 4.0 μg/mL. The dose of remifentanil was 1.9-2.0 μg/kg TBW, with maximal Ce of 5.0 ng/mL. The patients were observed for 450 s from the start of the infusions. The first 150 s was the sedation period, after which a bolus of propofol and remifentanil was administered. Baseline was defined as 55-5 s before the bolus doses. LiDCOplus was used for invasive beat-to-beat hemodynamic monitoring of changes in SAP, heart rate (HR), cardiac output (CO), stroke volume (SV), and systemic vascular resistance (SVR). A difference of 10 mmHg in the change in SAP was considered to be clinically important. The SAP change difference for low versus high dose was -2.9 mmHg (95% CI -9.0-3.1). The relative changes for low versus high dose were SAP -31% versus -36%, (p < .01); HR -24% versus -20%, (p = .09); SVR -20% versus -31%, (p < .001); SV -16% versus -20%, (p = .04); and CO -35% versus -32%, (p = .33). A high dose of propofol was not inferior to a low dose, and a reduction in the dose of propofol did not result in clinically important attenuation of major hemodynamic changes during induction in healthy women. ClinicalTrials.gov identifier NCT03861364, January 3, 2019.

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.

Determination of minimum infusion rate of propofol in combination with electroacupuncture in goats

Total intravenous anesthesia (TIVA) is frequently used anesthetic protocol in animals when inhalation anesthesia is not available. To date, it has not yet been known whether electroacupuncture (EA) can affect propofol-based TIVA in goats. Therefore, the present paper aims to determine the minimum infusion rate (MIR) of propofol, in combination with EA, required to preclude purposeful movement of the extremities in response to standardized noxious stimulation in goats. Twelve clinically healthy goats weighing 17.45 ± 2.15 kg were randomly allocated into two groups with six goats each. Propofol alone (P group) and propofol combined with EA (EA-P group). In the EA-P, propofol was given 30 min after EA stimulation. For induction of anesthesia, a bolus of propofol was administered at 4 mg/kg IV, and an infusion dose of 0.4 mg/kg/min was initially set for maintenance. The MIR of propofol in both groups was determined by testing for responses to stimulation (clamping on a digit with Vulsellum forceps) at 10-min intervals after inducing anesthesia until the end period of the experiment. Cardiorespiratory variables and nociceptive threshold were measured throughout anesthesia. The median propofol MIR was significantly lower in the EA-P group than the P group [0.520 (0.467–0.572) and 0.650 (0.600–0.677)], respectively; p = 0.0013). In the P group, goats anesthetized with MIR showed a significant increase in heart rate and cardiac index (p = 0.0010 and p < 0.0001, respectively), and a decrease in respiratory rate (p = 0.0001). Additionally, the EA-P showed a significant decrease in hemoglobin oxygen saturation following the initial infusion rate at 2 min (p = 0.0023) and 10 min (p = 0.0007) as compared to the P group. A significant increase in nociceptive threshold was recorded in the EA-P threshold than that of the P group (p < 0.005). EA combined with propofol provides antinociception, decreases the MIR of propofol-based TIVA, and subsequently lessens the negative cardiorespiratory consequences related to propofol anesthesia in goats.

Spectral EEG correlations from the different phases of general anesthesia.

Electroencephalography (EEG) signals contain transient oscillation patterns commonly used to classify brain states in responses to action, sleep, coma or anesthesia. Using a time-frequency analysis of the EEG, we search for possible causal correlations between the successive phases of general anesthesia. We hypothesize that it could be possible to anticipate recovery patterns from the induction or maintenance phases. For that goal, we track the maximum power of the α-band and follow its time course. We quantify the frequency shift of the α-band during the recovery phase and the associated duration. Using Pearson coefficient and Bayes factor, we report non-significant linear correlation between the α-band frequency and duration shifts during recovery and the presence of the δ or the α rhythms during the maintenance phase. We also found no correlations between the α-band emergence trajectory and the total duration of the flat EEG epochs (iso-electric suppressions) induced by a propofol bolus injected during induction. Finally, we quantify the instability of the α-band using the mathematical total variation that measures possible deviations from a flat line. To conclude, the present correlative analysis shows that EEG dynamics extracted from the initial and maintenance phases of general anesthesia cannot anticipate both the emergence trajectory and the extubation time.

Hemodynamic responses to 1 MAC desflurane inhalation during anesthesia induction with propofol bolus and remifentanil continuous infusion: a prospective randomized single-blind clinical investigation

BackgroundDesflurane is not recommended during anesthesia induction because of its sympathetic stimulation effect, particularly in patients with myocardial ischemic disease. To date, the hemodynamic response to 1 MAC desflurane inhalation in combination with remifentanil infusion during anesthesia induction has rarely been reported.MethodsThis investigation was designed to compare hemodynamic responses to 1 MAC desflurane (group D, n = 200) with sevoflurane (group S, n = 200) during anesthesia induction and endotracheal intubation in adult patients undergoing elective spine surgery. Subgroup analysis of the different age subgroups was also performed. With continuous infusion of remifentanil 0.1 μg/kg/min, anesthesia was induced with propofol bolus, and endotracheal intubation was performed after muscle relaxation. Heart rate (HR) and mean arterial blood pressure (MAP) were measured every minute for 5 min after anesthesia induction (T1-5) and after endotracheal intubation (T6-10).ResultsHR was significantly higher in group D (n = 182) than in group S (n = 173) at T3-10 except at T6 (1 min after intubation) (all P < 0.05). In the age-based subgroup analyses, which subdivided the group D and S into four subgroups based on patient’s age, the changes in HR from baseline values were significantly different between the coeval subgroups of patients in their 20–29 years and 30–39 years of age (all P < 0.05). MAP was reduced from baseline value, irrespective of group and age.ConclusionInhalation of 1 MAC desflurane during anesthesia induction with propofol bolus and remifentanil continuous infusion and during endotracheal intubation was more likely to induce elevations in HR more likely than 1 MAC sevoflurane, especially in younger patients.Trial registrationThis study was registered in the Clinical Research Information Service (CRIS, http://cris.nih.go.kr) of the Republic of Korea on Feb 12, 2016 (Registration No. KCT 0,001,813).

Evaluation of paradoxical effect of small dose ketamine as adjuvant in deep sedation for endoscopy patients

ABSTRACT Background This study tested the hypothesis that use of ketamine as an ‎adjuvant to propofol in the induction of deep sedation for ‎endoscopy patients could lead, paradoxically, to faster ‎emergence.‎ Methods We conducted a single-center, prospective randomized ‎controlled study on 154 adult ASA I or II patients‎, admitted for ‎gastrointestinal endoscopies‎. Patients were sedated with 25 µg ‎fentanyl and 1 mg/kg propofol bolus over 30 s. Patients ‎were divided into two groups: Group P (n = 77), sedated with ‎propofol only, and Group PK (n = 77), who received additionally a ‎single dose of ketamine (0.1 mg/kg) at induction. If the patient ‎moved or Ramsay Sedation Score (RSS) regressed to <4, ‎increments of 0.25 mg/kg of propofol were given. After the end ‎of the procedure, emergence from sedation was assessed with ‎modified Aldrete score, 5 and 10 m after admission to the ‎recovery room.‎ Results Adding a small dose of ketamine did not significantly achieve ‎deep sedation (RSS ≥4) more quickly or result in lesser ‎propofol increments. Patients who received ketamine showed a ‎statistically significant improvement in the Modified Aldrete ‎score when recorded 5 min after admission to the recovery ‎room (Group P 8.73 ± 1.02, Group PK 9.1 ± 0.96, P value = ‎‎0.02), but not after 10 min (Group P 9.03 ± 0.74, Group PK ‎‎9.21 ± 0.8, P value = 0.146).‎ Conclusion Inclusion of a small single dose of ketamine in the induction of sedation for gastrointestinal endoscopy significantly improves emergence from sedation.