Bispectral Index Research Articles

SQI-DOANet: electroencephalogram-based deep neural network for estimating signal quality index and depth of anaesthesia.


Monitoring the depth of anaesthesia (DOA) during surgery is of critical importance. However, accurate and real-time estimation of DOA remains a challenging task. In this paper, we proposed a signal quality index (SQI) network (SQINet) for assessing the electroencephalogram (EEG) signal quality and a DOA network (DOANet) for analyzing EEG signals to precisely estimate DOA. The two networks are termed SQI-DOANet.
Approach:
The SQINet contained a shallow convolutional neural network to quickly determine the quality of the EEG signal. The DOANet comprised a feature extraction module for extracting features, a dual attention module for fusing multi-channel and multi-scale information, and a gated multilayer perceptron module for extracting temporal information. The performance of the SQI-DOANet model was validated by training and testing the model on the large VitalDB database, with the bispectral index (BIS) as the reference standard.
Main results:
The proposed DOANet yielded a Pearson correlation coefficient with the BIS score of 0.88 in the 5-fold cross-validation, with a mean absolute error (MAE) of 4.81. The mean Pearson correlation coefficient of SQI-DOANet with the BIS score in the 5-fold cross-validation was 0.82, with an MAE of 5.66.
Significance:
The SQI-DOANet model outperformed three compared methods. The proposed SQI-DOANet may be used as a new deep learning method for DOA estimation. The code of the SQI-DOANet will be made available publicly at https://github.com/YuRui8879/SQI-DOANet.&#xD.

Comparison of sevoflurane and propofol in combination with remifentanil on the quality of postoperative recovery in patients undergoing laparoscopic bariatric surgery.

This study aimed to evaluate and compare the effects of sevoflurane + remifentanil (Sev + Rem) and propofol + remifentanil (Pro + Rem) on the postoperative recovery quality of patients undergoing laparoscopic bariatric surgery to determine which anesthesia regimen provides a better overall recovery experience. Sixty patients were divided into two groups based on the treatments they underwent: Sev + Rem (n = 30) and Pro + Rem (n = 30). The Sev + Rem group received sevoflurane inhalation (0.5%, increasing to 0.5-4%) and remifentanil via target-controlled infusion. The Pro + Rem group received propofol [4-8 mg/(kg·h)] and remifentanil via target-controlled infusion. Anesthesia depth was maintained at a bispectral index of 40-60 in both groups. Perioperative data, hemodynamic parameters, and postoperative recovery quality were assessed. Compared to the Pro + Rem group, the dose of remifentanil in the Sev + Rem group was significantly lower (1693.67 ± 331.75 vs. 2,959 ± 359.77, p < 0.001), the proportion of patients used norepinephrine was markedly higher [16 (53.33) vs. 8 (26.67), p = 0.035], and the time of extubation was earlier (356.33 ± 63.17 vs. 400.3 ± 50.11, p = 0.004). The Hemodynamic results showed the HR in the Sev + Rem group was faster than that in the Pro + Rem group at the beginning of surgery and 1 h post-surgery (67.37 ± 4.40 vs. 64.33 ± 4.44, p = 0.010, 69.07 ± 4.23 vs. 66.40 ± 5.03, p = 0.030). In regard to the assessment of postoperative recovery quality, the emotional state scores in the Sev + Rem group were significantly lower than the Pro + Rem group (36.83 ± 2.79 vs. 39.50 ± 4.64, p = 0.009). The two anesthesia modalities (Sev + Rem and Pro + Rem) have their advantages and disadvantages for patients undergoing laparoscopic bariatric surgery and have comparable effects on postoperative recovery quality.

Anesthesia Management in a Low Weight Patient with Parkinson&amp;apos;s Disease: A Case Report

&amp;lt;i&amp;gt;Background&amp;lt;/i&amp;gt;: Parkinson&amp;apos;s disease (PD) is a progressive neurological disease related to the destruction of dopaminergic neurons in the substantia nigra, basket spot and other brain regions, which is mainly characterized by motor neurological disorders and non-motor neurological disorders. Middle-aged and elderly people are more common, with more women than men. Polypharmacy in PD patients may lead to potential interactions with anesthetic drugs, so perioperative management is very important. &amp;lt;i&amp;gt;Case presentetion&amp;lt;/i&amp;gt;: An 80-year-old female with a medical history of PD weighing 28kg, planed to undergo elective peritoneoscopically assisted transvaginal uterine abdominal wall suspension under general anesthesia. Antiparkinsonian medications continued until just before the induction of anesthesia. Preoperative examinations were completed and they showed no obvious abnormality. Vital signs, train-of-four (TOF) and bispectral index (BIS) were monitored to guide the administration of anesthesia. Appropriate sedatives, analgesics, muscle relaxants and antiemetics were selected after fully assessed the patient&amp;apos;s condition and drug interactions during the perioperative period. The patient successfully completed the surgery and discharged from hospital. &amp;lt;i&amp;gt;Conclusions&amp;lt;/i&amp;gt;: General anesthesia (GA) is the main anesthesia method for patients with Parkinson&amp;apos;s disease undergoing surgery. When patients with PD undergo surgery, the anesthesiologists should fully and carefully evaluate the patient&amp;apos;s status and preoperative combination of medications. Perioperative drugs that aggravate Parkinson&amp;apos;s disease should be avoided in order to facilitate a smooth recovery after surgery.

Comparison of opioid-free and opioid-inclusive propofol anaesthesia for thyroid and parathyroid surgery: arandomised controlled trial.

Postoperative nausea and vomiting occur frequently following thyroid and parathyroid surgery and are associated with worse patient outcomes. We hypothesised that opioid-free propofol anaesthesia would reduce the incidence of postoperative nausea and vomiting compared with opioid-inclusive propofol anaesthesia in patients undergoing these procedures. We conducted a randomised, double-blinded controlled trial in adult patients scheduled to undergo thyroid and parathyroid surgery at two medical centres in mainland China. Patients were allocated randomly (1:1, stratified by sex and trial site) to an opioid-free anaesthesia group (esketamine, lidocaine, dexmedetomidine and propofol) or an opioid-inclusive group (sufentanil and propofol). Propofol infusions were titrated to bispectral index 45-55. Patients received prophylaxis for nausea and vomiting using dexamethasone and ondansetron and multimodal analgesia with paracetamol and flurbiprofen axetil. The primary outcome was the incidence of postoperative nausea and vomiting in the first 48 h after surgery. We assessed 557 patients for eligibility and 394 completed this trial. The incidence of postoperative nausea and vomiting in the first postoperative 48 h was lower in the opioid-free anaesthesia group (10/197, 5%) compared with opioid-inclusive group (47/197, 24%) (OR (95%CI) 0.17 (0.08-0.35), p < 0.001), yielding a number needed to treat of 5.3. Additionally, opioid-free propofol anaesthesia was associated with a reduced need for rescue anti-emetics, lower rates of hypotension and desaturation after tracheal extubation, and higher patient satisfaction. Time to tracheal extubation was prolonged slightly in the opioid-free group. The two groups had similar postoperative pain scores and 30-day outcomes. Opioid-free propofol anaesthesia reduced postoperative nausea and vomiting in patients undergoing thyroid and parathyroid surgery. An opioid-free anaesthetic regimen can optimise anaesthetic care during thyroid and parathyroid surgery.

Intraoperative microelectrode recording during asleep deep brain stimulation of subthalamic nucleus for Parkinson Disease. A case series with systematic review of the literature

The use of microelectrode recording (MER) during deep brain stimulation (DBS) for Parkinson Disease is controversial. Furthermore, in asleep DBS anesthesia can impair the ability to record single-cell electric activity.The purpose of this study was to describe our surgical and anesthesiologic protocol for MER assessment during asleep subthalamic nucleus (STN) DBS and to put our findings in the context of a systematic review of the literature. Sixty-three STN electrodes were implanted in 32 patients under general anesthesia. A frameless technique using O-Arm scanning was adopted in all cases. Total intravenous anesthesia, monitored with bispectral index, was administered using a target controlled infusion of both propofol and remifentanil. A systematic review of the literature with metanalysis on MER in asleep vs awake STN DBS for Parkinson Disease was performed. In our series, MER could be reliably recorded in all cases, impacting profoundly on electrode positioning: the final position was located within 2 mm from the planned target only in 42.9% cases. Depth modification > 2 mm was necessary in 21 cases (33.3%), while in 15 cases (23.8%) a different track was used. At 1-year follow-up we observed a significant reduction in LEDD, UPDRS Part III score off-medications, and UPDRS Part III score on medications, as compared to baseline. The systematic review of the literature yielded 23 papers; adding the cases here reported, overall 1258 asleep DBS cases using MER are described. This technique was safe and effective: metanalysis showed similar, if not better, outcome of asleep vs awake patients operated using MER. MER are a useful and reliable tool during asleep STN DBS, leading to a fine tuning of electrode position in the majority of cases. Collaboration between neurosurgeon, neurophysiologist and neuroanesthesiologist is crucial, since slight modifications of sedation level can impact profoundly on MER reliability.

Comparing the haemodynamic effects of high- and low-dose opioid anaesthesia: a secondary analysis of a randomised controlled trial.

This is a secondary analysis of a randomised controlled trial wherein four groups (A-D) of patients received one out of four different combinations of propofol and remifentanil, titrated to a predicted equipotency in probability of tolerance to laryngoscopy (PTOL) according to the Bouillon interaction model. In group A, a high dose of propofol and a low dose of remifentanil was administered, and across the groups this ratio was gradually changed until it was reversed in group D. Mean and systolic arterial blood pressure (MAP, SAP) were compared at four time points (Tbaseline, Tpost-bolus, T3min, Tnadir) within and between groups Heart rate, bispectral index (BIS) and the incidence of hypotension were compared. Data from 76 patients was used. At Tpost-bolus a statistically significant lower MAP and SAP was found in group A versus D (p = 0.011 and p = 0.002). A significant higher heart rate was found at T3min and Tnadir between groups A and B when compared to groups C and D (p = < 0.001 and p = 0.002). A significant difference in BIS value was found over all groups at T3min and Tnadir (both p < 0.001). All other outcomes did not differ significantly between groups. Induction of anaesthesia with different predicted equipotent combinations of propofol and remifentanil did result in statistically different but clinically irrelevant differences in haemodynamic endpoints during induction of anaesthesia. Our study could not identify preferable drug combinations that decrease the risk for hypotension after induction, although they all yield a similar predicted PTOL.

Bispectral Index Monitoring and Combinations in Anesthesia Safety

Anesthesia should ideally provide an adequate level of hypnosis (sleep, unawareness/non-recall), analgesia and a suitable environment for surgery (immobility, muscle relaxation). Monitoring of the depth of anesthesia is recommended to reduce awareness during anesthesia and to improve the administration of anesthetic drugs. The bispectral index (BIS) is a numerical scale based on the analysis of EEG parameters and can reduce the adverse effects associated with over- or under-dosing of anesthetic drugs. BIS is the most studied and best documented method of cerebral monitoring This summary is based on selected literature on BIS monitoring and its combination with other monitoring modalities over the last 20 years.

Comparison of Propofol and Sevoflurane Anaesthesia in Terms of Postoperative Nausea-Vomiting Complication in Cardiac Surgery Patients Undergoing Enhanced Recovery After Surgery Protocol: A Prospective Randomized Study.

Postoperative nausea (PN) and vomiting (PONV) in cardiac surgery increases adrenergic stimulation, limits mobilization and oral intake, and can be distressing for patients. The primary aim of our study was to investigate the effect of sevoflurane and propofol anaesthesia on the incidence of PONV in cardiac surgery patients undergoing Enhanced Recovery After Surgery (ERAS) protocol. Following ethics committee approval, 62 patients undergoing elective coronary artery bypass surgery with ERAS protocol were included in this prospective randomized study. After standard induction of anaesthesia, Group S received 1.5-2% sevoflurane and Group P received 50-100 μg kg-1 min-1 propofol infusion as maintenance anaesthetic agent with a bispectral index of 40-50. The incidence of PN and PONV between 0-6 hours (early) and 6-24 hours (late) after extubation was compared as the primary outcome. The incidence of delirium was analyzed as a secondary outcome for similar periods. In the propofol group, 3 patients were excluded due to postoperative tamponade revision and prolonged mechanical ventilation. PN in the early post-extubation period (29% vs. 7.1%, P=0.031) was significantly higher in Group S. The incidence of delirium was similar between the groups in both periods. Propofol may reduce the incidence of PN in the first 6 hours after extubation compared with sevoflurane. We believe that this period will be beneficial for gastrointestinal tolerance as it is the period when oral intake is initiated in patients. In conclusion, propofol maintenance in cardiac surgery patients may facilitate patient rehabilitation as part of the ERAS protocol.

Potential increased propofol sensitivity in cognitively impaired elderly: a controlled, double-blind study.

Cognitive impairment in the elderly may lead to potential increased sensitivity to anesthetic agents targeting receptors associated with cognition. This study aimed to explore the effect of cognitive status on propofol consumption during surgery in elderly patients. Sixty elderly patients scheduled for laparoscopic radical prostatectomy were allocated to either a cognitively normal [CogN, Montreal Cognitive Assessment (MoCA) score ≥26] or cognitively impaired (CogI, MoCA <26) group. Propofol was administered via target-controlled infusion to maintain a bispectral index (BIS) between 55-65 during surgery. Propofol consumption was recorded at three time points: T1 (abolished eyelash reflex), T2 (BIS = 50), T3 (extubation). BIS values at eyelash reflex abolition were also recorded. Postoperative MoCA, Visual Analogue Scale (VAS) scores, and remifentanil/sufentanil consumption were assessed. BIS values before induction were similar between CogN and CogI groups. However, at eyelash reflex abolition, BIS was significantly higher in CogI than CogN (mean ± SD: 65.3 ± 7.2 vs. 61.1 ± 6.8, p = 0.031). Propofol requirement to reach BIS 50 was lower in CogI vs. CogN (1.24 ± 0.19 mg/kg vs. 1.46 ± 0.12 mg/kg, p = 0.003). Postoperative MoCA, VAS scores, and remifentanil/sufentanil consumption did not differ significantly between groups. Compared to cognitively intact elderly, those with cognitive impairment exhibited higher BIS at eyelash reflex abolition and required lower propofol doses to achieve the same BIS level, suggesting increased propofol sensitivity. Cognitive status may impact anesthetic medication requirements in the elderly.

Comparison of remimazolam tosilate and propofol during induction and maintenance of general anesthesia in patients undergoing laparoscopic cholecystectomy: a prospective, single center, randomized controlled trial

BackgroundRemimazolam tosilate (RT) is a new, ultrashort-acting benzodiazepine. Here, we investigated the efficacy and safety of RT for general anesthesia in patients undergoing Laparoscopic Cholecystectomy (LC).MethodsIn this study, 122 patients undergoing laparoscopic cholecystectomy were randomly allocated to receive either remimazolam tosilate (Group RT) or propofol group (Group P). RT was administered as a slow bolus of 0.3 mg kg− 1 for induction, followed by 1.0–2.0 mg kg− 1 h− 1 for maintenance of general anesthesia. Propofol was started at 2 mg kg− 1 and followed by 4–10 mg kg− 1 h− 1 until the end of surgery. The primary outcome was the time to bispectral index (BIS) ≤ 60. The secondary outcome included the time to loss of consciousness (LoC), and the time to extubation. Adverse events were also assessed.ResultsA total of 112 patients were recruited for study participation. Among them, the time to BIS ≤ 60 in Group RT was longer than that in Group P (Group RT: 89.3 ± 10.7 s; Group P: 85.9 ± 9.7 s, P > 0.05). While the time to LoC comparing remimazolam and propofol showed no statistical significance (Group RT: 74.4 ± 10.3 s; Group P: 74.7 ± 9.3 s, P > 0.05). The time to extubation in Group RT was significantly longer than that in Group P (Group RT: 16.0 ± 2.6 min; Group P: 8.8 ± 4.3 min, P < 0.001). Remimazolam tosilate had more stable hemodynamics and a lower incidence of hypotension during general anesthesia.ConclusionsRemimazolam tosilate can be safely and effectively used for general anesthesia in patients undergoing Laparoscopic Cholecystectomy. It maintains stable hemodynamics during induction and maintenance of general anesthesia compared with propofol. Further studies are needed to validate the findings.Trial registrationChictr.org.cn ChiCTR2300071256 (date of registration: 09/05/2023).

Comparison of dexmedetomidine dosing strategies based on Bispectral Index (BIS) and Ramsay Sedation Scale (RSS) in patients undergoing infraumbilical surgeries under spinal anesthesia: A prospective comparative study

Comparison of dexmedetomidine dosing strategies based on Bispectral Index (BIS) and Ramsay Sedation Scale (RSS) in patients undergoing infraumbilical surgeries under spinal anesthesia: A prospective comparative study

Can Bispectral Index be Used in the Diagnosis and Treatment of Non-convulsive Status Epilepticus in Children?

Can Bispectral Index be Used in the Diagnosis and Treatment of Non-convulsive Status Epilepticus in Children?

Comparison of propofol versus dexmedetomidine sedation for awake C-MAC® D-Blade video laryngoscopic nasotracheal intubation in patients with difficult airway: A randomised clinical study.

Awake intubation is the preferred method for securing difficult airways. We compared intravenous (IV) propofol and dexmedetomidine for C-MAC® D-blade-guided anticipated difficult nasotracheal intubation under conscious sedation. This randomised study included 60 patients with difficult airway (El-Ganzouri Score 4-9). After adequate airway preparation with IV midazolam 0.03 mg/kg and IV fentanyl 1 µg/kg, in Group P, propofol was infused at 250 µg/kg/min and in Group D, dexmedetomidine was infused at 1 μg/kg over 10 min, then at 0.5 μg/kg/h till a bispectral index (BIS) value 65-70 was achieved. Patients underwent C-MAC® D-blade video laryngoscope-guided nasotracheal intubation. The intubation score was the primary outcome measure. Secondary outcome measures included haemodynamic parameters, intubation time, number of attempts, the incidence of failed awake intubation, glottic view, time to achieve desired BIS, complications, study drug consumption and patient-reported satisfaction with the awake intubation technique. Quantitative variables were compared between groups using unpaired t-test/Welsch test/Mann-Whitney Test. Qualitative variables were correlated using the Chi-square test/Fisher's exact test. A P value of <0.05 was considered statistically significant. The intubation score was significantly higher in Group D versus Group P (P = 0.007). Patient reaction to intubation, haemodynamic parameters and percentage of glottis opening score were more favourable in Group P. Coughing and vocal cord movement were comparable between the groups (P > 0.05). The time to target BIS was four times longer, and the time to intubate was 6 seconds longer in Group D. Successful awake C-MAC® D-blade video laryngoscopic intubation can be performed under dexmedetomidine/propofol conscious sedation, with propofol giving a better intubation score.

Safety of propofol sedation administered by interventional radiologists for radiofrequency ablation in patients with hepatocellular carcinoma.

To evaluate the safety of propofol sedation administered by interventional radiologists during radiofrequency ablation (RFA) for hepatocellular carcinoma (HCC). Propofol sedation was administered by interventional radiologists in 72 patients (85 procedures, 93 tumors) during RFA for HCC between August 2018 and December 2020. Interventional radiologists equipped with adequate knowledge and skills in sedation and respiratory management were responsible for sedation. Sedation was carefully assessed based on vital signs, including end-tidal carbon dioxide, consciousness status, and bispectral index. The primary endpoint was the incidence of sedation-related complications, which were evaluated separately as respiratory and cardiovascular complications. Secondary endpoints were technical success rate, ablation-related complications, and local tumor control rate. Technical success was defined as completion of ablation in the planned area. Complications were evaluated using the Clavien-Dindo classification. Sedation-related complications, technical success rate, and ablation-related complications were evaluated on a procedure basis, and local tumor control was evaluated on a tumor basis. Respiratory and cardiovascular complications were observed in eight (8/85, 9.4%) and two (2/85, 2.4%) patients, respectively. Four patients required the jaw thrust maneuver due to glossoptosis, whereas a decrease in oxygen saturation to < 90% was recorded in the other four patients. However, these were temporary, and none required manual ventilation or endotracheal intubation. Bradycardia (< 50bpm) was detected in two patients; one recovered immediately without treatment, whereas the other rapidly improved after atropine sulfate administration. No severe hypotension (< 80mmHg) was observed. The technical success rate was 100% (85/85). Grade 3 ablation-related complications were identified in three patients (3/85, 3.5%). The local tumor control rate was 95.7% (89/93). Propofol sedation can be safely administered by interventional radiologists during RFA for HCC. Although it requires special safety considerations, it may be a sedation option during hepatic RFA.

Determining the Target Concentration of Propofol for Sedation in Patients Undergoing Endoscopic Retrograde Cholangiopancreatography: A Target-Controlled Infusion Approach.

Introduction Endoscopic retrograde cholangiopancreatography (ERCP) is vital for diagnosing and treating biliary and pancreatic diseases, necessitating deep sedation typically achieved through total intravenous anesthesia. Propofol, with its favorable pharmacokinetic profile, is the preferred sedative, but conventional administration methods of mg/kg boluses or infusion rates pose challenges. Target-controlled infusion (TCI) systems offer a solution that ensures precise dose delivery of propofol. Despite its widespread use, the literature lacks specific guidance on the target plasma concentration (Cp) of propofol for sedation in patients undergoing ERCP. Methods A prospective interventional study was conducted at the Institute of Liver and Biliary Sciences, Delhi, India to determine the target Cp of propofol for sedation during ERCP. The study enrolled 86 American Society of Anesthesiologists (ASA) grade I and II patients aged 18-70 years. The primary objective was to establish the optimal propofol concentration for sedation as guided by a bispectral index (BIS) value of 60-70. Secondary outcomes included induction time, recovery time, total propofol consumption, and the occurrence of adverse events (if any). The Marsh pharmacokinetic model guided the TCI pump, adjusting Cp until the target sedation was achieved. Results The mean Cp of propofol to maintain the BIS value 60-70 was 2.21 ± 0.42 µg/ml. Age-wise analysis revealed variations, emphasizing the need for individualized dosing. Induction time was 4.21 ± 0.68 minutes; recovery times were seven minutes (median, IQR: 5-10 minutes) for BIS >80 and seven minutes (median, IQR: 5-10 minutes) for achieving a Modified Observer's Assessment of Alertness/Sedation score of ≥5. The mean propofol consumption was 6.24 mg/kg/hr. Side effects were minimal, with 1.16% experiencing transient hypoxia and hypotension. Conclusion The study establishes a mean target propofol concentration of 2.21 ± 0.42 µg/ml for sedation in ASA I and II patients undergoing ERCP.

Comparing Bispectral Index Monitoring vs Clinical Assessment for Deep Sedation in the ICU: Effects on Delirium Reduction and Sedative Drug Doses—A Randomized Trial

BackgroundSedative overdoses pose a delirium risk among Intensive Care Unit (ICU) patients, with potential mitigation through the use of a processed EEG monitor (BIS) to guide depth of sedation. Research QuestionCan BIS-guided deep sedation (RASS -4, -5) reduce sedative dosage and increase delirium-free and coma-free (DFCF) days? Study Design and MethodsA randomized controlled trial was conducted in a tertiary mixed ICU, enrolling patients requiring deep sedation for >8 hours. Patients were randomly assigned to either the Clinical Assessment (CA) or BIS groups (BIS range of 40-60). Both groups utilized a BIS sensor, while the CA group's screen remained covered. After deep sedation, BIS sensors were removed, and delirium was assessed twice daily by researchers blinded to the randomization. The primary outcome was the number of DFCF days within 14 days after deep sedation. Additionally, we compared doses of sedative drugs and BIS values during deep sedation. ResultsNinety-nine patients were included in the study. We found no significant difference in DFCF (p=0.1) between CA and BIS arms, but propofol doses were significantly lower in the BIS group (CA group 1.77 mg/kg/hr [95% CI 1.60, 1.93] vs. BIS group 1.44 mg/kg/hr [95% CI 1.04, 1.83]; p=0.03). During deep sedation, the CA group spent 46% of the total hours (95% CI 35, 57%) with BIS values below 40, whereas the BIS group spent 32% (95% CI 25, 40%), (p=0.03). Subgroup analysis focusing on patients sedated for more than 24 hours revealed an increase in DFCF in the BIS group (CA group median of 1 day [IQR 0, 9] vs. BIS group 8 days [IQR 0, 13]; p=0.04). InterpretationBIS-guided deep sedation did not improve DFCF days but reduced sedative drug use. In patients requiring sedation for more than 24 hours, it showed an improvement in DFCF days.

Pharmacologic Sleep Aids in the Intensive Care Unit: A Systematic Review.

Background: Patients in the intensive care unit (ICU) often experience poor sleep quality. Pharmacologic sleep aids are frequently used as primary or adjunctive therapy to improve sleep, although their benefits in the ICU remain uncertain. This review aims to provide a comprehensive assessment of the objective and subjective effects of medications used for sleep in the ICU, as well as their adverse effects. Methods: PubMed, Web of Science, Scopus, Embase, and Cochrane Central Register of Controlled Trials were systematically searched from their inception until June 2023 for comparative studies assessing the effects of pharmacologic sleep aids on objective and subjective metrics of sleep. Results: Thirty-four studies with 3498 participants were included. Medications evaluated were melatonin, ramelteon, suvorexant, propofol, and dexmedetomidine. The majority of studies were randomized controlled trials. Melatonin and dexmedetomidine were the best studied agents. Objective sleep metrics included polysomnography (PSG), electroencephalography (EEG), bispectral index, and actigraphy. Subjective outcome measures included patient questionnaires and nursing observations. Evidence for melatonin as a sleep aid in the ICU was mixed but largely not supportive for improving sleep. Evidence for ramelteon, suvorexant, and propofol was too limited to offer definitive recommendations. Both objective and subjective data supported dexmedetomidine as an effective sleep aid in the ICU, with PSG/EEG in 303 ICU patients demonstrating increased sleep duration and efficiency, decreased arousal index, decreased percentage of stage N1 sleep, and increased absolute and percentage of stage N2 sleep. Mild bradycardia and hypotension were reported as side effects of dexmedetomidine, whereas the other medications were reported to be safe. Several ongoing studies have not yet been published, mostly on melatonin and dexmedetomidine. Conclusions: While definitive conclusions cannot be made for most medications, dexmedetomidine improved sleep quantity and quality in the ICU. These benefits need to be balanced with possible hemodynamic side effects.

A Comparative Study of Fixed-Dose Dexmedetomidine and Propofol Infusions on Intraoperative Desflurane Consumption During Bispectral Index-Guided Laparoscopic Surgeries: A Randomized Controlled Study.

Background Desflurane is an excellent but expensive volatile anesthetic agent. Dexmedetomidine and propofol may decrease intraoperative desflurane consumption. This study aimed to compare the desflurane-sparing effect of dexmedetomidine and propofol in patients undergoing laparoscopic surgeries under bispectral index (BIS)-guided general anesthesia (GA). Methods Sixty-two adult patients, ASA (American Society of Anesthesiologists) physical status I or II, of either sex, aged between 18 and 60 years, were randomly allocated into group D or group P. Only group D patients received an intravenous (IV) bolus of dexmedetomidine (1 mcg/kg) over 15 minutes before induction. In both groups, GA was induced following the standard protocol with propofol infusion (0.5 mg/kg/min) until the BIS value dropped below 60. For maintenance, group D and group P patients received IV dexmedetomidine infusion (0.5 mcg/kg/h) and propofol infusion (50 mcg/kg/min), respectively. In both groups, desflurane dial concentration was adjusted between 3 and 8% to maintain the BIS within the range of 45-55. An hourly bolus of IV fentanyl (0.5 mcg/kg) and a half-hourly bolus of IV vecuronium (0.02 mg/kg) were administered. The total amount of desflurane consumed, duration of pneumoperitoneum, extra aliquots of propofol used during maintenance, number of boluses of IV atropine, fentanyl, and esmolol, time to attain Ramsay Sedation Score of 2 after extubation, time to first postoperative analgesic request at Numerical Rating Scale (NRS) score ≥ 4, time to reach a Modified Aldrete Score of ≥9, and incidence of any side effects were recorded. All the data were analyzed and compared using appropriate statistical tests, and a p-value of <0.05 was considered significant. Results The final data analysis was performed on 60 patients. The mean desflurane consumption was clinically higher in group P patients than in group D, but the difference was statistically insignificant (p-value > 0.05). The mean induction dose of propofol was significantly less in group D than in group P (p-value < 0.05). After extubation, the difference in time to the first analgesic request (NRS ≥ 4) between the groups was statistically significant (p-value < 0.05). Group D patients had a residual intraoperative analgesic effect. Conclusion The effects of dexmedetomidine and propofol infusions on desflurane consumption in laparoscopic surgeries are comparable, with minimal effects on intraoperative hemodynamics and postoperative recovery profiles.

Bispectral Index monitoring of palliative sedation for home withdrawal of tracheostomy ventilation: A case report.

Tracheostomy ventilation in motor neurone disease is an uncommon life-sustaining treatment. Best practice is having a plan for ventilation withdrawal, but the literature to guide practice is limited. Case reports have documented standard doses of opioids and benzodiazepines used for sedation in such cases. A 49-year-old man was diagnosed with motor neurone disease in 2016. He commenced tracheostomy ventilation in 2018. In 2022 and 2023, planning was undertaken, at the patient's request, for withdrawal of tracheostomy ventilation at home, when he was no longer able to communicate with technology. Planning included Bispectral Index monitoring prior to cessation of ventilation, ensuring this only occurred when deep sedation was achieved. After ventilation withdrawal in 2023, a retrospective review of medications given and his level of sedation on monitoring was undertaken, with family consent. Ventilation withdrawal was initiated after deep sedation was achieved, 6 h after commencing subcutaneous infusions of morphine, midazolam, clonazepam and phenobarbital. Doses required to achieve acceptable sedation exceeded literature reports. Achieving deep sedation was a longer than expected process. More research using an objective measure of sedation is required, as clinical assessment of sedation in this context is compromised.

Effect of bispectral index on intra-operative awareness: A meta-analysis of randomized controlled studies.

Randomized controlled trials (RCTs) investigating the efficacy of bispectral index (BIS) to reduce intra-operative awareness (IOA) have reported conflicting results. The purpose of this meta-analysis is to consolidate results from RCTs to assess the efficacy of BIS in reducing IOA when compared to controls. Secondary outcomes included time to extubation, time to spontaneous and/or verbal eye opening, PACU discharge time, and utilization of inhaled anesthetics. RCTs which reported on one of the primary and/or secondary outcomes were included. Literature search utilized keywords "randomized control trial" and "intraoperative awareness." Meta-analysis was performed using RevMan 5. Twenty-seven RCTs were included in the study with a total of 35,585 patients, with 18,146 patients in the BIS and 17,439 in the control group. Eighteen of 14,062 patients (0.12%) and 42 of 16,765 (0.25%) reported definite IOA in the BIS and control group, respectively, with no statistically significant difference. BIS was effective in reducing the time to spontaneous eye opening by an average of 1.3 minutes and the time to extubation by an average of 1.97 minutes. There was no difference in PACU discharge times among the groups. There was a significant decrease in consumption of sevoflurane but no difference in desflurane and propofol compared to the control group. While BIS monitoring results in decreased incidence of intra-operative awareness by half, it was not statistically significant. BIS provides modest benefits with regard to reducing the time to extubation, the time to spontaneous eye opening, and consumption of sevoflurane.Level of evidence: I.