Stable Sedation Research Articles

Intranasal Dexmedetomidine for Sedation in Acute Ischemic Stroke: A Case Report

AbstractThis case report presents the innovative use of intranasal dexmedetomidine (IN-DEX) for sedation in an 82-year-old female patient undergoing endovascular treatment (EVT) for acute ischemic stroke (AIS). The patient, with a history of chronic atrial fibrillation, arterial hypertension, and chronic kidney failure, presented with sudden left-sided weakness. IN-DEX was administered to manage her agitation, achieving stable sedation without respiratory depression, facilitating EVT, and preserving the patient's cooperative state for accurate neurological assessments. The procedure was completed successfully, with stable vital parameters and no complications. This report highlights IN-DEX's potential as a noninvasive, effective sedative alternative in emergency neurological settings, emphasizing its advantages in maintaining respiratory function and reducing stress responses in AIS patients. Further studies are recommended to validate these findings and explore the broader applicability of IN-DEX in AIS management.

Comparison of hypotension between propofol and remimazolam-propofol combinations sedation for day-surgery hysteroscopy: a prospective, randomized, controlled trial

BackgroundA combination of remimazolam and propofol could produce more stable sedation. A good medication regimen should consider not only efficacy but also safety, especially hypotension. The aim of the current study was to compare the incidence and amount of hypotension by propofol versus remimazolam-propofol combinations in day-surgery hysteroscopy.MethodsPatients were randomly assigned to receive either propofol (Group P, n = 125) or remimazolam-propofol combinations (Group RP, n = 125) at a 1:1 ratio. Intravenous injection of sufentanil 0.1ug/kg were administered before sedative medication. In group P, a bolus of 2.5 mg/kg propofol was administered. In group RP, intravenous anesthesia was commenced with 0.125 mg/kg remimazolam and 1 mg/kg propofol. After loss of consciousness, propofol was maintained at 6 mg/kg/h. The primary outcomes were the incidence and amount of hypotension during surgery. Hypotension was defined as a MAP less than 65mmHg for at least 1 min. The amount of hypotension was assessed by time-weighted average intraoperative MAP under a threshold of 65 mmHg. The secondary outcomes were various anesthesia related parameters and some adverse events.ResultsIn group P, 25 patients (20.0%) experienced hypotension during hysteroscopy compared with 9 patients (7.2%) in group RP, for a difference of 12.8% (RR 2.778, 95%CI [1.352–5.709]). The combination of remimazolam and propofol resulted in significantly lower TWA (Time Weighted Average) threshold 0.14 (0.10–0.56) mmHg in group RP compared to 0.31 (0.15–0.67) mmHg in group P. The total dose of propofol was nearly double in group P compared to group RP. A significantly higher frequency of injection pain and low oxygen saturation was observed in the group P than that of the group RP. Hiccup was observed only in group RP. The incidences of body movement, bradycardia and vomiting were no significant difference between groups.ConclusionThe incidence and amount of hypotension by remimazolam-propofol combinations was significantly less than that by propofol sedation in day-surgery hysteroscopy. The optimization of medication regimen would attenuate the harm of hypotension and contribute to patients’ rapid recovery in day surgery.Trial registration Chinese Clinical Trial Registry, ChiCTR2400079888 (date: 15/01/2024),

Comparison of bispectral index-guided endoscopic ultrasonography with continuous vs. intermittent infusion of propofol: a retrospective study in Japan.

This study aimed to evaluate the safety and efficacy of continuous propofol infusion for anesthesia during endoscopic ultrasonography (EUS). A total of 427 consecutive patients who underwent EUS between May 2018 and February 2019 were enrolled in this study. The patients were divided into two propofol infusion groups: continuous (n=207) and intermittent (n=220). The following parameters were compared: (1) propofol dose, (2) respiratory and circulatory depression, (3) body movement requiring discontinuation of the examination, (4) awakening score, and (5) patient satisfaction. The median total maintenance dose of propofol was significantly higher in the continuous group than in the intermittent group (160.0 mg vs. 130.0 mg, respectively); however, the reduction in SpO2 was significantly lower in the continuous group (2.9% vs. 13.2%). Body movements occurred less frequently in the continuous group than in the intermittent group (40.1% vs. 49.5%, respectively). The rate of complete awakening was significantly higher in the continuous group than in the intermittent group. Finally, there was a significant difference in the percentage of patients who answered "absolutely yes" when asked about receiving EUS again: 52.7% in the continuous group vs. 34.3% in the intermittent group. Continuous infusion resulted in stable sedation and reduced propofol-associated risks.

Hierarchical Deep Reinforcement Learning-Based Propofol Infusion Assistant Framework in Anesthesia.

This article aims to provide a hierarchical reinforcement learning (RL)-based solution to the automated drug infusion field. The learning policy is divided into the tasks of: 1) learning trajectory generative model and 2) planning policy model. The proposed deep infusion assistant policy gradient (DIAPG) model draws inspiration from adversarial autoencoders (AAEs) and learns latent representations of hypnotic depth trajectories. Given the trajectories drawn from the generative model, the planning policy infers a dose of propofol for stable sedation of a patient under total intravenous anesthesia (TIVA) using propofol and remifentanil. Through extensive evaluation, the DIAPG model can effectively stabilize bispectral index (BIS) and effect site concentration given a potentially time-varying target sequence. The proposed DIAPG shows an increased performance of 530% and 15% when a human expert and a standard reinforcement algorithm are used to infuse drugs, respectively.

Differential effects of four intramuscular sedatives on cardiorespiratory stability in juvenile guinea pigs (Cavia porcellus).

BackgroundNon-invasive physiological monitoring can induce stress in laboratory animals. Sedation reduces the level of restraint required, thereby improving the validity of physiological signals measured. However, sedatives may alter physiological equilibrium introducing unintended bias and/or, masking the experimental outcomes of interest. We aimed to investigate the cardiorespiratory effects of four short-acting sedatives in juvenile guinea pigs.Method12 healthy, 38 (26–46) day-old Dunkin Hartley guinea pigs were included in this blinded, randomised, crossover design study. Animals were sedated by intramuscular injection using pre-established minimum effective doses of either alfaxalone (5 mg/kg), diazepam (5 mg/kg), ketamine (30 mg/kg), or midazolam (2 mg/kg) administered in random order with a minimum washout period of 48 hours between agents. Sedative depth, a composite score comprised of five assessment criteria, was observed every 5-min from dosing until arousal. Physiological monitoring of cardiorespiratory status included measures of heart rate, blood pressure, respiratory rate, and peripheral microvascular perfusion.ResultsKetamine and alfaxalone were most effective in inducing stable sedation suitable for physiological monitoring, and diazepam less-so. Midazolam was unsuitable due to excessive hypersensitivity. All sedatives significantly increased heart rate above non-sedated control rates (P<0.0001), without altering blood pressure or microvascular perfusion. Alfaxalone and ketamine reduced respiratory rate relative to their control condition (P<0.0001, P = 0.05, respectively), but within normative ranges.ConclusionKetamine and alfaxalone are the most effective sedatives for inducing short duration, stable sedation with minimal cardiorespiratory depression in guinea pigs, while diazepam is less-so. However, alfaxalone is the most appropriate sedative for longitudinal studies requiring multiple physiological timepoints.

Dexmedetomidine versus Ketamine-Propofol for Sedation of Obese Patients Undergoing Upper Gastrointestinal Endoscopy

Abstract Background Gastrointestinal endoscopy is an uncomfortable and stressful procedure for most patients. Conscious sedation is a common strategy for improving patient comfort during this procedure. Benzodiazepines (gamma-aminobutyric acid (GABA) agonists) such as midazolam have been used for sedation of patients undergoing gastrointestinal endoscopy. The effective dose ranges of such agents differ considerably among patients, making it difficult to achieve stable sedation. Also obesity is a significant health problem that has assumed epidemic proportions. As a result, the number of obese patients requiring endoscopy is increasing. It is relatively unknown how safe the current practices of sedation for endoscopic procedures are in bariatric patients. Therefore, special consideration should be given to these patients Aim of the Work To compare the sedative properties and haemodynamic and respiratory effects of Dexmedetomidine and a Ketamine-Propofol combination (ketofol) in obese patients undergoing Upper GI Endoscopy. Patients and Methods This study was conducted in the endoscopy unit of Ain Shams University Hospital after obtaining approval from the Research Ethical Committee of Ain Shams University. A prospective, randomized controlled clinical trial was found to be the most suitable design in order to achieve the study objectives. Cases were divided into 2 groups using computer generated random list of numbers in sealed opaque envelopes. Results We found that ketamine-propofol infusion (1:3) is a better sedation regimen for upper gastrointestinal endoscopy compared to dexmedetomidine as lesser time is taken to achieve optimal sedation, with no hemodynamic unstability or postprocedure complications. Conclusion In this study, we compared a group of 40 upper GIT endoscopy obese patients (BMI 30-40) who received procedural sedation with either Dexmedetomidine or propofolketamine combination, we found that ketamine-propofol infusion (1:3) is a better sedation regimen for upper gastrointestinal endoscopy compared to dexmedetomidine as lesser time is taken to achieve optimal sedation, with no hemodynamic unstability or post procedure complications.

Does propofol mode of administration influence psychomotor recovery time after sedation for colonoscopy: A prospective randomized assessor-blinded trial.

Background:Propofol sedation has become increasingly popular for colonoscopy. Different modes of propofol administration have been described, but their influence on psychomotor recovery time remains largely unknown. This prospective randomized assessor-blinded study tested the hypothesis that target-controlled infusion system (TCI) combined with sedation depth monitoring should be associated with a more stable sedation than intermittent bolus application with clinical monitoring of sedation depth, resulting in a faster psychomotor skills recovery.Methods:One hundred sixty-four patients undergoing colonoscopy were randomized to receive propofol with the former (TCI group) or the latter (bolus group) mode of administration. Psychomotor skill recovery was assessed using the Choice Reaction Time (CRT) performed before and every ten minutes after waking up from propofol sedation. Clinical recovery was also assessed using the modified Post-anesthetic Discharge Scoring System (PADS).Results:Induction and wake up times were longer in the TCI group, where patients received more propofol than those in the bolus group. Evolution of CRT was similar in both groups. Twenty minutes after arrival in the post-anesthesia care unit, 35 (49%) of patients in the TCI group and 43 (54%) in the bolus group achieved CRT values equal or shorter than their baseline values. Interestingly, according to the PADS score, most of the patients were considered fit for discharge at that moment. Incidence of adverse event was not different between groups.Conclusion:In the conditions of our study characterized by short procedure duration, target-controlled infusion of propofol does not offer any benefit in terms of psychomotor skills recovery over intermittent bolus application.

Comparative Study of Hemodynamic Infusion of Dexmedetomidine With Alternative Sufentanil-Midazolam Injection for Sedation of Patients Undergoing Cataract Surgery

In order to induce sedation during cataract surgery, various medications with different side effects are used in separation or in combination. Dexmedetomidine has no effect on the respiratory system, but being dependent on dosage, it may cause cardiovascular disorders. The present study aims to compare the hemodynamic and sedative effects of dexmedetomidine and the combination of sufentanil-midazolam on patients undergoing cataract surgery. In a randomized clinical trial study, 60 patients were randomly divided into two dexmedetomidine and sufentanil-midazolam groups. In sufentanil-midazolam group, dexmedetomidine (DEX infusion at 0.5 μg/ kg for 10 minutes, then adjusted to 0.2 µg/kg/h) was prescribed. In the sufentanil-midazolam group, sufentanil (0.1 μg/kg for 5 minutes) and midazolam (0.2 µg/kg) were injected five minutes before the operation. Hemodynamic variables (Systolic blood pressure, diastolic blood pressure, heart rate), complications (nausea, vomiting, hypoxia), sedation level, and pain intensity were recorded (at the beginning of the study, 5, 10 minutes after anesthesia, at the start of surgery, 5, 10, 15 minutes after the surgery) as well as patient’s satisfaction, surgeon's satisfaction, and complications. Results suggest that apart from gender, other primary characteristics of patients, including age, history of blood pressure, diabetes history, ASA score, mean of systolic, diastolic blood pressure, heart rate, and SPO2 levels, were similar in both groups (P&gt;0.05). Systolic blood pressure patients receiving dexmedetomidine declined significantly more than that of patients receiving sufentanil-midazolam (P&gt;0.5). Diastolic blood pressure suddenly fell 5 minutes after the infusion of sufentanil-midazolam (P&gt;0.05), but then a relative increase and finally a relative decrease occurred, while diastolic blood pressure in patients receiving dexmedetomidine decreased steadily. The mean heart rate in patients receiving dexmedetomidine and sufentanil-midazolam declined gently (P&gt;0.05). SPO2 was reduced significantly in the sufentanil-midazolam group (P&lt;0.05). Drugs used in both groups reduced pain intensity equally (P&gt;0.05). From the beginning of the study, dexmedetomidine produced a relatively stable sedation level (score 2) based on Ramsay's criteria, while the combination of sufentanil-midazolam-medications causes deeper sedation (score 3) in patients (P&lt;0.05). Despite this fact, 23.33% of the patient receiving sufentanil-midazolam could have movements during the surgery, which was 6.66% higher in patients receiving dexmedetomidine (P=0.071). The satisfaction of patients receiving dexmedetomidine was significantly higher (P=0.044), while the surgeon's satisfaction was almost identical in both anesthesia procedures (P=0.94). In the end, the results of the present study showed that although dexmedetomidine is associated with few respiratory problems and higher satisfaction of patients, it decreases blood pressure and heart rate progressively. However, it seems that this medicine is more effective than a combination of midazolam-sufentanil because of more patient satisfaction, lack of hypoxia, fewer complications, and more suitable immobility.

Negative drift of sedation depth in critically ill patients receiving constant minimum alveolar concentration of isoflurane, sevoflurane, or desflurane: a randomized controlled trial

BackgroundIntensive care unit (ICU) physicians have extended the minimum alveolar concentration (MAC) to deliver and monitor long-term volatile sedation in critically ill patients. There is limited evidence of MAC’s reliability in controlling sedation depth in this setting. We hypothesized that sedation depth, measured by the electroencephalography (EEG)-derived Narcotrend-Index (burst-suppression N_Index 0—awake N_Index 100), might drift downward over time despite constant MAC values.MethodsThis prospective single-centre randomized clinical study was conducted at a University Hospital Surgical Intensive Care Unit and included consecutive, postoperative ICU patients fulfilling the inclusion criteria. Patients were randomly assigned to receive uninterrupted inhalational sedation with isoflurane, sevoflurane, or desflurane. The end-expiratory concentration of the anaesthetics and the EEG-derived index were measured continuously in time-stamped pairs. Sedation depth was also monitored using Richmond-Agitation-Sedation-Scale (RASS). The paired t-test and linear models (bootstrapped or multilevel) have been employed to analyze MAC, N_Index and RASS across the three groups.ResultsThirty patients were recruited (female/male: 10/20, age 64 ± 11, Simplified Acute Physiology Score II 30 ± 10). In the first 24 h, 21.208 pairs of data points (N_Index and MAC) were recorded. The median MAC of 0.58 ± 0.06 remained stable over the sedation time in all three groups. The t-test indicated in the isoflurane and sevoflurane groups a significant drop in RASS and EEG-derived N_Index in the first versus last two sedation hours. We applied a multilevel linear model on the entire longitudinal data, nested per patient, which produced the formula N_Index = 43 − 0.7·h (R2 = 0.76), showing a strong negative correlation between sedation’s duration and the N_Index. Bootstrapped linear models applied for each sedation group produced: N_Index of 43–0.9, 45–0.8, and 43–0.4·h for isoflurane, sevoflurane, and desflurane, respectively. The regression coefficient for desflurane was almost half of those for isoflurane and sevoflurane, indicating a less pronounced time-effect in this group.ConclusionsMaintaining constant MAC does not guarantee stable sedation depth. Thus, the patients necessitate frequent clinical assessments or, when unfeasible, continuous EEG monitoring. The differences across different volatile anaesthetics regarding their time-dependent negative drift requires further exploration.Trial registration: NCT03860129.

Ramsay Sedation Scale Project: Small, Easy Changes for a Big Effect on Patient Safety.

Ramsay Sedation Scale Project: Small, Easy Changes for a Big Effect on Patient Safety.

Can sedation using a combination of propofol and dexmedetomidine enhance the satisfaction of the endoscopist in endoscopic submucosal dissection?

Background and study aims The aim of this pilot randomized controlled trial was to evaluate and compare the satisfaction of the endoscopist along with the effectiveness and safety of sedation between sedation protocol using a combination of propofol (PF) and dexmedetomidine (DEX) (Combination group) and sedation protocol using PF alone (PF group) during gastric endoscopic submucosal dissection (ESD). Patients and methods Fifty-eight patients with gastric neoplasias scheduled for gastric ESD were enrolled and randomly assigned to the two groups. The satisfaction scores of the endoscopists and the parameters for the effectiveness and safety of sedation were evaluated by comparisons between the two groups. Results The satisfaction scores of the endoscopists, which were measured using a visual analogue scale, were significantly higher in the Combination group than in the PF group (88 vs. 69, P = 0.003). The maintenance dose of PF was lower in the Combination group than in the PF group (2 mg/kg/h vs. 5 mg/kg/h, P < 0.001), and the number of rescue PF injections was fewer in the Combination group than in the PF group (2 times vs. 6 times, P < 0.001). The incidence of bradycardia (defined as a pulse rate ≤ 45 bpm) in the Combination group was higher than that in the PF group (37.9 % vs. 10.3 %, P = 0.029). Conclusions This study suggests that gastroenterologist-directed sedation using a combination of PF and DEX during gastric ESD can enhance the satisfaction levels of endoscopists by providing stable sedation with an acceptable safety profile.

Propofol is a more effective and safer sedative agent than midazolam in endoscopic injection sclerotherapy for esophageal varices in patients with liver cirrhosis: a randomized controlled trial.

The efficacy of sedation during endoscopic injection sclerotherapy (EIS) for esophageal varices (EVs) in patients with liver cirrhosis remains unclear. The aim of this study is to compare the efficacy and safety between propofol- and midazolam-based sedation for EIS. Twenty-three patients with EVs were prospectively and randomly assigned to midazolam-based (Midazolam group) or propofol-based (Propofol group) sedation. All patients underwent a number connection test (NCT) to evaluate minimal hepatic encephalopathy (MHE) on the day before and at 2 and 24 hours following EIS. The primary endpoint was exacerbation of MHE after EIS, which was defined as deterioration of the NCT. The secondary endpoints were postoperative awareness, technical success rate, frequency of body movement, patient and operator satisfaction, cardiorespiratory dynamics during EIS, and adverse events. Exacerbations of MHE at 2 hours after EIS compared with those before EIS were not significantly different between the two groups. In both groups, the deterioration of NCT scores before and 2 hours after EIS was observed (Propofol group: 60.0 vs. 70.0 s, P = 0.026; Midazolam group: 42.5 vs. 67.0 s, P = 0.002). There were no significant differences in awareness, technical success rate, or patient satisfaction. However, the frequency of body movement in the Propofol group was significantly lower than that in the Midazolam group (1 vs. 4, P = 0.045), and operator satisfaction in the Propofol group was significantly higher than that in the Midazolam group (P = 0.016). No adverse events were observed. Propofol-based sedation exacerbated MHE after EIS similarly to midazolam-based sedation in patients with liver cirrhosis. However, propofol-based sedation provided stable sedation with a lower frequency of body movements and high operator satisfaction.

The Influence of Sedation Level Guided by Bispectral Index on Therapeutic Effects for Patients with Severe Traumatic Brain Injury.

Sedation therapy is vital for treating severe traumatic brain injury (TBI). Yet, types of sedation assessment tools and sedation levels that are suitable for sedation treatment have not been investigated. To investigate the influence of different sedation levels guided by the Bispectral Index (BIS) on the therapeutic effects for severe TBI. According to inclusion, exclusion, and rejection criteria, 35 patients were prospectively included and divided into Richmond Agitation Sedation Scale (RASS), BIS(I), and BIS(II) groups. The RASS group was controlled the level of sedation to within -2 or -3, and the BIS(I) and (II) groups within the range of 40-50 and 50-60, respectively. In addition to clinical data, RASS, BIS, and intracranial pressure (ICP) values were collected. RASS and ICP variability were introduced to investigate the different of sedative control effect with or without BIS monitor, and the control effect of ICP between different sedation levels. Statistical analysis was performed to estimate the effectiveness of different sedation levels guided by BIS in sedation treatment within 72 hours. There were no significant differences in demographics among the 3 groups. RASS variability of the BIS(I) and (II) groups was significantly lower than that of the RASS group (P < 0.05), and in the BIS(I) group it was insignificantly lower than in the BIS(II) group. The ICP of the BIS(I) and (II) groups declined to <13.5 mm Hg significantly earlier than that of the RASS group (P < 0.05), and the difference between BIS(I) and (II) was insignificant. ICP variability of RASS group was higher than those of the BIS(I) and (II) groups (P < 0.05), and ICP variability of the BIS(I) group was significantly lower than that of the BIS(II) group (P < 0.05). Differences in days in the neurosurgery intensive care unit and outcomes among the 3 groups were insignificant. BIS is more reliable than RASS for maintaining a stable sedation status and ICP. Deeper sedation levels (BIS 40-50) cause ICP to decrease more quickly, with lower ICP variability.

A randomised controlled trial to compare TIVA infusion of mixture of ketamine propofol (ketofol) and fentanyl-propofol (fentofol) in short orthopaedic surgeries

Background: Propofol does not possesses the analgesic properties but is a safe anaesthetic agent for day care surgeries while ketamine is an excellent analgesic but has concerns regarding recovery. Fentanyl is a short acting potent opioid with pharmacokinetics suitable for day care anaesthesia. There are many short procedures in which you need procedural sedation with good analgesia and calm patient without need of intubation and relaxation. This study was conducted to compare and find suitable sedoanalgesia regime of TIVA using Propofol- Ketamine (Ketofol) or Propofol -Fentanyl (Fentofol) mixture infusion to facilitate comfortable and stable sedation experience with rapid recovery in short orthopaedic surgeries. Settings and Design: Randomized, Double blind. Patients and Methods: This prospective, randomized, double-blind study was conducted on 100 adult patients of age 20–55 years of either sex having ASA physical status I-II, posted for short orthopaedic procedures. Patients were assigned to receive slow bolus of fresh premixed injection of either ketofol or fentofol followed by TIVA infusion to a predetermined sedation level using Ramsay sedation scale. Haemodynamics, vital signs, side effects and recovery profiles were recorded. Results: There was significant decrease (P

A target-controlled infusion system with bispectral index monitoring of propofol sedation during endoscopic submucosal dissection.

Background and study aims: Propofol administration via a target-controlled infusion system with bispectral index monitoring (BIS/TCI system) is expected to prevent complications from sedation during complex and long endoscopic procedures. We evaluated the feasibility of setting the BIS/TCI system for non-anesthesiologist administration of propofol (NAAP) during endoscopic submucosal dissection (ESD). Patients and methods: From May 2009 to February 2013, 250 patients with esophagogastric neoplasms were treated with ESD using the BIS/TCI system with NAAP. In the TCI system, the initial target blood concentration of propofol was set at 1.2 μg/mL. The titration speed of propofol was adjusted according to the BIS score and the movement of the patient. The BIS target level ranged from moderate to deep sedation, at which a stable BIS score between 60 and 80 was obtained. Results: In 80.4 % of patients, it was possible to maintain stable sedation with a blood concentration of propofol of less than 1.6 µg/mL using TCI throughout the ESD procedure. The default setting for ideal blood concentration of propofol was 1.2 μg/mL, because the medians of the lower and upper bounds of blood concentration were 1.2 μg/mL (range 0.6 – 1.8 μg/mL) and 1.4 μg/mL (range 1.0 – 3.8 μg/mL), respectively. Although hypotension occurred in 27 patients (10.8 %), oxygen desaturation occurred in only nine patients (3.6 %), and severe desaturation in only two patients (0.8 %). Conclusions: Using our settings, it is possible for a non-anesthesiologist to maintain stable sedation during a lengthy endoscopic procedure through propofol sedation with a BIS/TCI system.

The Potential Regimen of Target-Controlled Infusion of Propofol in Flexible Bronchoscopy Sedation: A Randomized Controlled Trial

ObjectivesTarget-controlled infusion (TCI) provides precise pharmacokinetic control of propofol concentration in the effect-site (Ce), eg. brain. This pilot study aims to evaluate the feasibility and optimal TCI regimen for flexible bronchoscopy (FB) sedation.MethodsAfter alfentanil bolus, initial induction Ce of propofol was targeted at 2 μg/ml. Patients were randomized into three titration groups (i.e., by 0.5, 0.2 and 0.1 μg/ml, respectively) to maintain stable sedation levels and vital signs. Adverse events, frequency of adjustments, drug doses, and induction and recovery times were recorded.ResultsThe study was closed early due to significantly severe hypoxemia events (oxyhemoglobin saturation <70%) in the group titrated at 0.5 μg/ml. Forty-nine, 49 and 46 patients were enrolled into the 3 respective groups before study closure. The proportion of patients with hypoxemia events differed significantly between groups (67.3 vs. 46.9 vs. 41.3%, p = 0.027). Hypotension events, induction and recovery time and propofol doses were not different. The Ce of induction differed significantly between groups (2.4±0.5 vs. 2.1±0.4 vs. 2.1±0.3 μg/ml, p = 0.005) and the Ce of procedures was higher at 0.5 μg/ml titration (2.4±0.5 vs. 2.1±0.4 vs. 2.2±0.3 μg/ml, p = 0.006). The adjustment frequency tended to be higher for titration at 0.1 μg/ml but was not statistically significant (2 (0∼6) vs. 3 (0∼6) vs. 3 (0∼11)). Subgroup analysis revealed 14% of all patients required no further adjustment during the whole sedation. Comparing patients requiring at least one adjustment with those who did not, they were observed to have a shorter induction time (87.6±34.9 vs. 226.9±147.9 sec, p<0.001), a smaller induction dose and Ce (32.5±4.1 vs. 56.8±22.7 mg, p<0.001; 1.76±0.17 vs. 2.28 ±0.41, p<0.001, respectively), and less hypoxemia and hypotension (15.8 vs.56.9%, p = 0.001; 0 vs. 24.1%, p = 0.008, respectively).ConclusionTitration at 0.5 μg/ml is risky for FB sedation. A subgroup of patients required no more TCI adjustment with fewer complications. Further studies are warranted to determine the optimal regimen of TCI for FB sedation.Trial RegistrationClinicalTrials.gov NCT01101477

Fluctuations in sedation levels may contribute to delirium in ICU patients

Delirium in patients admitted to the intensive care unit (ICU) is a serious complication potentially increasing morbidity and mortality. The aim of this study was to investigate the impact of fluctuating sedation levels on the incidence of delirium in ICU. A prospective cohort study of adult patients at three multidisciplinary ICUs. The Richmond Agitation and Sedation Scale (RASS) and the Confusion Assessment Method for the ICU were used at least twice a day. Delirium was detected at least once in 65% of the patients (n = 640). Delirious patients were significantly older, more critically ill, more often intubated, had longer ICU stays, and had higher ICU mortality than non-delirious patients. The median duration of delirium was 3 days (interquartile range: 1;10), and RASS was less than or equal to 0 (alert and calm) 91% of the time. The odds ratio (OR) for development of delirium if RASS changed more than two levels was 5.19 when adjusted for gender, age, severity of illness, and ICU site and setting. Continuous infusion of midazolam was associated with a decrease in delirium incidence (OR: 0.38; P = 0.002). Fluctuations in sedation levels may contribute to development of delirium in ICU patients. The risk of developing delirium might be reduced by maintaining a stable sedation level or by non-sedation.

Efficacy of Propofol Sedation for Endoscopic Submucosal Dissection (ESD): Assessment with Prospective Data Collection

The indications for endoscopic treatment in early stage cancer of the digestive tract are expanding with the emergence and technical development of endoscopic submucosal dissection (ESD). ESD requires longer term stable sedation than conventional endoscopic procedures due to the necessity of meticulous control of the devices during the procedure. Propofol has a very short half-life and can be administered continuously, which is advantageous for long-term sedation. Propofol, thus, is likely to be useful for sedation during ESD. Fifty consecutive patients who underwent ESD for early gastric cancer with propofol sedation (Group P) and those with midazolam sedation (Group M) were included in this study. Cardiorespiratory suppression rate and the condition of arousal were compared between the groups. A questionnaire survey on the satisfaction of endoscopists, anesthesiologists, endoscopy nurses, and ward nurses with the use of propofol was also carried out. Respiratory suppression was observed in 50% in Group M and in 20% in Group P (p<0.05). Hypotension was seen in 14% and 36% in Groups M and P, respectively (p<0.05). No sedation-related complications were encountered in either of the groups. Arousal rates 1 hour and 3 hours after the procedure were 23% and 60% in group M and 86% and 100% in Group P (p<0.05). As for the questionnaire survey, most respondents, in particular the ward nurses, supported the use of propofol. Our data suggest that propofol is safe and useful during ESD as compared with midazolam.

Propofol Decreases Neuronal Population Spiking Activity in the Subthalamic Nucleus of Parkinsonian Patients

Implantation of deep brain stimulation (DBS) electrodes in the subthalamic nucleus (STN) for the treatment of Parkinson disease is often performed using microelectrode recording (MER) of STN population spike activity. The extent to which sedative drugs interfere with MER is unknown. We recorded the population activity of STN neurons during propofol sedation and examined its effect on neuronal activity. The procedure was performed during DBS surgery for Parkinson disease. We administered propofol (50 μg/kg/min) at a constant electrode location in the STN until stable sedation was achieved. We recorded the electrical activity, and calculated its root mean square (RMS) before, during, and after the propofol infusions. The activity of 24 electrode trajectories was recorded in 16 patients. The RMS of STN activity decreased significantly after propofol administration in 18 of the 24 trajectories. The average normalized RMS decreased by 23.2%± 9.1% (mean ± SD) during propofol administration (P < 0.001), and returned to baseline 9.3 ± 4.0 minutes after it was stopped. Propofol administration leads to a significant decrease of STN neuronal activity. Thus, it may interfere with MER identification of the STN borders. However, activity returns to baseline shortly after administration stops. Therefore, propofol can be safely used until shortly before MER for DBS.

Anaesthesia, sedation and transportation of juvenile Menidia estor (Jordan) using benzocaine and hypothermia

Anaesthesia, sedation and transportation of the Atherinopsid, Menidia estor, were investigated using benzocaine, hypothermia and combinations of the two. The optimum dose rates of benzocaine for sedation of juvenile Chirostoma estor were 15 and 18 mg L−1. When hypothermia was used alone, stable sedation of C. estor was induced at 15 and 12°C, with no mortalities and full recovery after about 8 min. There was synergism when benzocaine and hypothermia were combined, with the optimal combination being at 15°C and 12 mg L−1 benzocaine. Successful transportation was conducted over 3.5 and 8.5 h using combined benzocaine and hypothermia. Aloe vera extract used in the transportation medium reduced scale loss. This work has, for the first time, defined a systematically derived system of safe, long distance, live transportation of this species and others of the genus Menidia.