Postoperative outcome of neonatal emergency surgeries in a tertiary care institute-A prospective observational study.

AIMS: Neonatal surgical mortality continues to be high in developing countries. A better understanding of perioperative events and optimization of causative factors can help in achieving a favorable outcome. The present study was designed to evaluate the perioperative course of surgical neonates and find out potential factors contributing to postoperative mortality. METHODS: This prospective observational study enrolled neonates, undergoing emergency surgical procedures in a tertiary care institute. Primary outcome was 6 weeks postsurgical mortality. The babies were observed till discharge and subsequently followed up telephonically for 6 weeks after surgery. Multivariable logistic regression analysis of various parameters was performed. RESULTS: Out of the 324 neonates who met inclusion criteria, 278 could be enrolled. The median age was 4 days. Sixty-two (27.7%) neonates were born before 37 weeks period of gestation (POG), and 94 (41.8%) neonates weighed below 2.5 kg. The most common diagnoses was trachea-esophageal fistula (29.9%) and anorectal malformation (14.3%). The median duration of hospital stay for survivors was 14 days. The in-hospital mortality was 34.8%. Mortality at 6 weeks following surgery was 36.2%. Five independent risk factors identified were POG < 34 weeks, preoperative oxygen therapy, postoperative inotropic support postoperative mechanical ventilation, and postoperative leukopenia. In neonates where invasive ventilation was followed by non-invasive positive pressure ventilation in the postoperative period, risk of postoperative surgical mortality was significantly reduced. CONCLUSION: Present study identified preterm birth, preoperative oxygen therapy, postoperative positive pressure ventilation, requirement of inotropes, and postoperative leukopenia as independent predictors of 6-week mortality. The possibility of early switch to noninvasive positive pressure ventilation was associated with a reduction in neonatal mortality.

Assessment of potential predictors affecting preoperative anxiety in Indian children- A prospective observational study.

Background and Aims: Preoperative anxiety is a common problem among children undergoing surgery. The aim of the study was to assess the incidence and identify various predictors of preoperative anxiety in Indian children. Material and Methods: A prospective, observational study was conducted on 60 children of the American Society of Anesthesiologists Physical status 1/2, aged 2-6 years and scheduled for elective surgery under general anesthesia in a tertiary care teaching hospital. Preoperative parental anxiety was assessed using the State-Trait Anxiety Inventory questionnaire. The children's anxiety was assessed in the preoperative room, at the time of parental separation, and at the induction of anesthesia using modified Yale Preoperative Anxiety Scale (mYPAS) scoring by an anesthesiologist and a psychologist. Sedative premedication was employed prior to parental separation. Logistic regression analysis was carried out to identify the possible predictors of anxiety. Results: The incidence of high preoperative anxiety among the studied children was 76% in the preoperative room, 93% during parental separation, and 96% during anesthetic induction. Among the nine possible predictors identified on univariate regression, the presence of siblings was found to be a significant independent predictor on multivariate regression analysis (P = 0.04). The inter-rater agreement was excellent for the assessment of preoperative anxiety using mYPAS by the anesthesiologist and psychologist (weighted Kappa, k = 0.79). Conclusion: The incidence of preoperative anxiety in Indian children in the age group of 2-6 years is very high. The preop anxiety escalates progressively at parental separation and induction of anesthesia despite sedative premedication. The presence of siblings is a significant predictor of preoperative anxiety.

Evaluation of indigenously developed closed-loop automated blood pressure control system (claps): a preliminary study.

Closed-loop systems have been designed to assist anesthetists in controlling anesthetic drugs and also maintaining the stability of various physiological variables in the normal range. In the present study, we describe and clinically evaluated a novel closed-loop automated blood pressure control system (CLAPS) in patients undergoing cardiac surgery under cardiopulmonary bypass. Forty ASA II-IV adult patients undergoing elective cardiac surgery were randomly allocated to receive adrenaline, noradrenaline, phenylephrine and nitroglycerine (NTG) adjusted either through CLAPS (CLAPS group) or manually (Manual group). The desired target mean arterial blood pressure (MAP) for each patient in both groups was set by the attending anesthesiologist. The hemodynamic performance was assessed based on the percentage duration of time the MAP remained within 20% of the set target. Automated controller performances were compared using performance error criteria of Varvel (MDPE, MDAPE, Wobble) and Global Score. MAP was maintained a significantly longer proportion of time within 20% of the target in the CLAPS group (79.4% vs. 65.5% p < 0.001, 't' test) as compared to the manual group. Median absolute performance error, wobble, and Global score was significantly lower in the CLAPS group. Hemodynamic stability was achieved with a significantly lower dose of Phenyepherine in the CLAPS group (1870 µg vs. 5400 µg, p < 0.05, 't' test). The dose of NTG was significantly higher in the CLAPS group (3070 µg vs. 1600 µg, p-value < 0.05, 't' test). The cardiac index and left ventricular end-diastolic area were comparable between the groups. Automated infusion of vasoactive drugs using CLAPS is feasible and also better than manual control for controlling hemodynamics during cardiac surgery. Trial registration number and date This trial was registered in the Clinical Trial Registry of India under Registration Number CTRI/2018/01/011487 (Retrospective; registration date; January 23, 2018).

Oral melatonin as part of multimodal anxiolysis decreases emergence delirium in children whereas midazolam does not: A randomised, double-blind, placebo-controlled study.

BACKGROUND: Pre-operative anxiety is a risk factor for emergence delirium in children and a multimodal approach including sedatives and nonpharmacological measures is the current strategy to tackle this anxiety. The efficacy of oral melatonin as a component of multimodal anxiolytic strategy to decrease emergence delirium is not well studied. OBJECTIVE: The aim of this study was to evaluate the efficacy of a multimodal anxiolytic strategy including oral melatonin or midazolam to decrease emergence delirium after sevoflurane anaesthesia. DESIGN: A randomised, double-blind, parallel arm, placebo-controlled trial. SETTING: Tertiary care teaching hospital from July 2019 till January 2020. PARTICIPANTS: Children in the age group of 3 to 8 years who received sevoflurane anaesthesia for elective ambulatory procedures. INTERVENTIONS: Children were randomised to receive oral premedication with either melatonin 0.3 mg kg-1, midazolam 0.3 mg kg-1 or honey as placebo. All the children received standardised nonpharmacological measures involving multiple techniques to allay anxiety. The anaesthetic plan was also standardised. MAIN OUTCOME MEASURES: The primary outcome was the incidence of emergence delirium as assessed by the Watcha scale in the postanaesthesia care unit. The secondary outcomes were pre-operative anxiety assessed using a modified Yale Preoperative Anxiety scale, patient compliance with mask induction using the Induction Compliance Checklist and postoperative sedation. RESULTS: Data from 132 children were analysed. Melatonin significantly reduced the incidence of emergence delirium compared to placebo: 27 vs. 50%, respectively, an absolute risk reduction of 23.3 [95% confidence interval 3.7 to 42.9), P = 0.03]. Melatonin also significantly reduced the risk of emergence delirium compared with midazolam: 27 vs. 56%, respectively, an absolute risk reduction of 29.2 (95% CI 9.5 to 48.8). The midazolam group had a similar incidence of emergence delirium as placebo. Sedation scores were similar in the three groups postoperatively. The incidence and score of pre-operative anxiety as well as the compliance with mask induction were similar in the three groups. CONCLUSIONS: A multimodal anxiolytic approach including oral melatonin, as opposed to oral midazolam, significantly reduced emergence delirium after sevoflurane anaesthesia. TRIAL REGISTRATION: CTRI/2019/06/019850 in Clinical Trial Registry of India (www.ctri.nic.in).

Prospective audit of sedation/anesthesia practices for children undergoing computerized tomography in a tertiary care institute.

BACKGROUND AND AIMS: The aim of the study was to enumerate the sedative drugs used, assess the efficacy of sedative drugs, and determine the incidence of adverse events. MATERIAL AND METHODS: A prospective audit of children sedated for computerized tomography (CT) by anesthesiology team was conducted for a period of 4 months. The data included patient demographic variables, fasting period, medications administered, adequacy of sedation, imaging characteristics, adverse events, and requirement for escalated care. RESULTS: A total of 331 children were enrolled for sedation by the anesthesia team. The drugs used for sedation were propofol, ketamine, and midazolam. Twenty-two percent children received one sedative drug, 60% children were administered two drugs, and 5% children required a combination of all three drugs for successful sedation. Sedation was effective for successful conduct of CT scan in 95.8% patients without the requirement of a repeat scan. Twelve (5%) children experienced adverse events during the study period. However, none of the adverse events necessitated prolonged postprocedural hospitalization or resulted in permanent neurologic injury or death. CONCLUSIONS: The current practice of sedation with propofol, ketamine, and midazolam, either single or in combination was efficacious in a high percentage of patients. The incidence of adverse events during the study period was low.

Incentive-Based Game for Allaying Preoperative Anxiety in Children: A Prospective, Randomized Trial.

BACKGROUND: Induction of anesthesia can be distressing both for children and their parents. Nonpharmacological behavioral interventions can reduce the anxiety of children without significant adverse effects as seen with sedative medications. We hypothesized that the use of incentive-based game therapy in conjunction with parental involvement would be a simple and cost-effective intervention in reducing the preoperative anxiety in children. METHODS: Eighty children between the age group of 4 and 8 years scheduled to undergo surgery were randomly assigned to a control group (n = 40) and intervention group (n = 40). Children in the intervention group participated in an incentive-based game in the preoperative room. Anesthesia was induced with parental presence in both the groups. The modified Yale Preoperative Anxiety Scale (mYPAS) score to measure the anxiety of the children during induction was taken as the primary outcome. Induction Compliance Checklist score and parental satisfaction were assessed as secondary outcomes. RESULTS: The mYPAS score of children in the intervention group was significantly less than the control group during anesthesia induction. The mean difference (95% confidence interval [CI]) of the mYPAS at induction between the 2 groups was 20 (95% CI, 16-24; P < .001). Fourteen (35%) children in the intervention group and 2 (5%) children in control group displayed no anxiety (mYPAS score <30) (difference of -30%; 95% CI, -11% to -49%; P < .001). Children in the intervention group were more compliant with mask induction and had a significantly less Induction Compliance Checklist score compared to the control (P < .001). Thirty (75%) parents in the intervention group were satisfied at the end of surgery compared to 6 (15%) in the control group (difference of -60%; 95% CI, -39% to -73%; P < .001). CONCLUSIONS: The use of incentive-based game therapy reduces the anxiety scores during induction of anesthesia and improves the compliance to facemask induction in children undergoing surgery. It can form a simple, cost-effective, and easy-to-administer technique that can be easily applied in low-income settings.

A Multicenter Evaluation of a Closed-Loop Anesthesia Delivery System: A Randomized Controlled Trial.

BACKGROUND: Closed-loop systems for anesthesia delivery have been shown to outperform traditional manual control in different clinical settings. The present trial was aimed at evaluating the feasibility and efficacy of Bispectral Index (BIS)-guided closed-loop anesthesia delivery system (CLADS) in comparison with manual control across multiple centers in India. METHODS: Adult patients scheduled for major surgical procedures of an expected duration of 1 to 3 hours were randomized across 6 sites into 2 groups: a CLADS group and a manual group. In the manual control group, propofol infusion was titrated manually by the attending anesthesiologist to a BIS of 50 during induction and maintenance. Analgesia was maintained with fentanyl infusion and nitrous oxide in both groups. In the CLADS group, both induction and maintenance of anesthesia were performed automatically using CLADS. The primary outcome measure was the performance of the system as assessed by the percentage of total anesthesia time BIS remained ±10 of target BIS. The secondary outcome measures were a percentage of anesthesia-time heart rate and mean arterial pressure within 25% of the baseline, median absolute performance error, wobble, and global score. Wobble indicates intraindividual variability in the control of BIS, and global score reflects the overall performance; lower values indicate superior performance for both parameters. The performance parameters of the system also were compared among the participating sites. RESULTS: Two hundred forty-two patients were randomized. BIS was maintained within ±10 of target for significantly longer time in the CLADS group (81.4% ± 8.9 % of anesthesia duration) than in the manual group (55.34% ± 25%, P < 0.0001). The indices that assess performance were significantly better in the CLADS group than the manual group as follows: median absolute performance error was 10 (10, 12) (median [interquartile range]) in the CLADS group versus 18 (14, 24) in the manual group, P < 0.0001; wobble was 9 (8, 10) in CLADS group versus 10 (8, 14) in the manual group, P = 0.0009; and Global score, which reflects overall performance, was 24 (19, 30) in the CLADS group versus 51 (31, 99) in the manual group, P < 0.0001. The percentage of time heart rate was within 25% of the baseline was significantly greater in the CLADS group (heart rate of 95 [87, 99], median [interquartile range], in the CLADS group versus 90 [75, 98] in the manual group P = 0.0031). On comparison of data between the centers, the performance parameters did not differ significantly among the centers in the CLADS group (P = 0.94), but the parameters differed significantly among the centers in the manual group (P < 0.001). CONCLUSIONS: Our study in a multicenter setting proves the consistently better performance of automated anesthesia drug delivery compared with conventional manual control. This highlights an important advantage of an automated system for delivering standardized anesthesia, thereby overcoming differences in practices among anesthesiologists.

Early versus late removal of the laryngeal mask airway (LMA) for general anaesthesia.

BACKGROUND: The laryngeal mask airway (LMA) is a safe and effective modality to maintain the airway for general anaesthesia during surgical procedures. The LMA is removed at the end of surgery and anaesthesia, when the patient maintains an adequate respiratory rate and depth. This removal of the LMA can be done either when the patient is deep under anaesthesia (early removal) or only after the patient has regained consciousness (late removal). It is not clear which of these techniques is superior. OBJECTIVES: The objective of this review was to compare the safety of LMA removal in the deep plane of anaesthesia (early removal) versus removal in the awake state (late removal) for participants undergoing general anaesthesia. SEARCH METHODS: We searched the Cochrane Central Register of Controlled Trials (CENTRAL; 2014, Issue 8); MEDLINE (1966 to August 2014); EMBASE (1980 to August 2014); LILACS (1982 to August 2014); CINAHL (WebSPIRS; 1984 to August 2014); and ISI Web of Science (1984 to August 2014). We searched for ongoing trials through various trial registration websites. In addition, we searched conference proceedings and reference lists of relevant articles. SELECTION CRITERIA: We included randomized controlled trials (RCTs) on adults and children undergoing elective general anaesthesia using the LMA, that compared early removal of the LMA (defined as removal of the LMA in the deep plane of anaesthesia) versus late removal of the LMA (defined as removal of the LMA after the patient is awake). DATA COLLECTION AND ANALYSIS: Two authors independently assessed trial quality and extracted data. We contacted study authors for additional information. We used a random-effects model to generate forest plots from the data. MAIN RESULTS: We identified a total of 9188 citations and included 15 RCTs conducted on 2242 participants in this review. All trials used the LMA Classic in American Society of Anesthesiologists (ASA) physical status I or II for patients undergoing elective general anaesthesia. Children were enrolled in 11 trials and adults in five trials. None of the trials were of high methodological quality. Eight of the 15 studies had adequate generation of random sequence, whereas only one trial had adequate concealment of random sequence. Three trials had blinded the outcome assessor. Thus, the majority of the studies appeared to have a high risk of bias in the study design.Using the GRADE approach, we found low quality evidence that the risk of laryngospasm was similar with early removal of the LMA (3.3%) versus late removal (2.7%): risk ratio (RR) 1.23, 95% confidence interval (CI) 0.74 to 2.03; 11 trials, 1615 participants. The quality of evidence was very low that the risk of coughing was less after early removal (13.9%) than late removal (19.4%): RR 0.52, 95% CI 0.29 to 0.94; 11 trials, 1430 participants. The quality of evidence for the risk of desaturation was also very low; there was no difference between early removal (7.9%) and late removal (10.1%): RR 0.68, 95% CI 0.4 to 1.16; 13 trials, 2037 participants. We found low quality evidence that the risk of airway obstruction was higher with early removal (15.6%) compared to late removal of the LMA (4.6%): RR 2.69, 95% CI 1.32 to 5.5; eight trials, 1313 participants. AUTHORS' CONCLUSIONS: This systematic review suggests that current best evidence comparing early versus late removal of the LMA in participants undergoing general anaesthesia does not demonstrate superiority of either intervention. However, the quality of evidence available is either low or very low. There is a paucity of well designed RCTs and a need for large scale RCTs to demonstrate whether early removal or late removal of the LMA is better after general anaesthesia.

Scope of artificial intelligence in airway management.

The evolution of artificial intelligence (AI) systems in the field of anaesthesiology owes to notable advancements in data processing, databases, algorithmic programs, and computation power. Over the past decades, its accelerated progression has enhanced safety in anaesthesia by improving the efficiency of equipment, perioperative risk assessments, monitoring, and drug administration systems. AI in the field of anaesthesia aims to improve patient safety, optimise resources, and improve the quality of anaesthesia management in all phases of perioperative care. The use of AI is likely to impact difficult airway management and patient safety considerably. AI has been explored to predict difficult intubation to outperform conventional airway examinations by integrating subjective factors, such as facial appearance, speech features, habitus, and other poorly known features. This narrative review delves into the status of AI in airway management, the most recent developments in this field, and its future clinical applications.

Evaluation of closed-loop anesthesia delivery for propofol anesthesia in pediatric cardiac surgery.

OBJECTIVE: The objective of this study was to compare the feasibility of closed-loop anesthesia delivery with manual control of propofol in pediatric patients during cardiac surgery. METHODS: Forty ASA II-III children, undergoing elective cardiac surgery under cardiopulmonary bypass (CPB) in a tertiary care hospital, were randomized to receive propofol either through a closed-loop anesthesia delivery system (CL group) or through traditional manual control (manual group) to achieve a target BIS of 50. Patients were induced and subsequently maintained with a propofol infusion. The propofol usage and the efficacy of closed-loop system in controlling BIS within ±10 of the target were compared with that of manual control. RESULTS: The maintenance of BIS within ±10 of target and intraoperative hemodynamic stability were similar between the two groups. However, induction dose of propofol was less in the CL group (2.06 ± 0.79 mg·kg(-1) ) than the manual group (2.95 ± 1.03 mg·kg(-1) ) (P = 0.006) with less overshoot of BIS during induction in the closed-loop group (P = 0.007). Total propofol used in the off-CPB period was less in the CL group (6.29 ± 2.48 mg·kg(-1) h(-1) vs 7.82 ± 2.1 mg·kg(-1) h(-1) ) (P = 0.037). Phenylephrine use in the pre-CPB period was more in the manual group (16.92 ± 10.92 µg·kg(-1) vs 5.79 ± 5.98 µg·kg(-1) ) (P = 0.014). Manual group required a median of 18 (range 8-29) dose adjustments per hour, while the CL group required none. CONCLUSION: This study demonstrated the feasibility of closed-loop controlled propofol anesthesia in children, even in challenging procedures such as cardiac surgery. Closed-loop system needs further and larger evaluation to establish its safety and efficacy.

Goal-directed fluid therapy guided by Plethysmographic Variability Index (PVI) versus conventional liberal fluid administration in children during elective abdominal surgery: A randomized controlled trial.

BACKGROUND: PVI has been shown to be an accurate predictor of fluid responsiveness in paediatric patients. Evidence regarding the role of PVI to guide intraoperative fluid therapy in paediatric abdominal surgery is lacking. We aimed to assess the effect of PVI-guided fluid therapy on the volume of intraoperative fluids administered and post-operative biochemical and recovery profile in children undergoing elective abdominal surgery. METHODS: 42 children, 6 months-3 years scheduled for elective open bowel surgery were randomised to receive either 'conventional liberal intraoperative fluids' (liberal group) or 'goal-directed intraoperative fluids' (GDT group). PVI <13 was targeted in the GDT group. The primary outcome was the volume of intraoperative fluids administered. Postoperative serum lactate, base excess, hematocrit, recovery of bowel function and duration of postoperative hospital stay were the secondary outcomes. RESULTS: The mean fluid administered intra-operatively was significantly lower in the GDT group as compared to the liberal group (24.1 ± 9.6 mL/kg vs 37.0 ± 8.9 mL/kg, p < 0.001). The postoperative hemoglobin concentration (g%) was significantly lower in the liberal group as compared to the GDT group (8.1 ± 1.3 vs 9.2 ± 1.4, p = 0.008). Recovery of bowel function (hours) was significantly delayed in the liberal group as compared to the GDT group (58.2 ± 17.9 vs 36.5 ± 14.1, p < 0.001). CONCLUSION: Intraoperative PVI-guided fluid therapy significantly reduces the volume of intravenous crystalloids administered to children undergoing open bowel surgery. These children also had faster recovery of bowel function and less hemodilution in the immediate postoperative period, compared to those who received liberal intraoperative fluid therapy. TYPE OF STUDY: Randomized Clinical Trial. LEVEL OF EVIDENCE: Treatment Study (LEVEL 1).

Bi-spectral index, entropy and predicted plasma propofol concentrations with target controlled infusions in Indian patients.

OBJECTIVE: Many processed electroencephalographic signals are used now to help the anaesthesiologist titrate the depth of sedation. We investigated the relationship between target plasma propofol concentration and objective end-points of sedation- Bispectral Index (BIS), State Entropy (SE) and Response Entropy (RE)-at clinical end-points as assessed by Modified Observer Assessment of Alertness/sedation Scale (MOAAS) in Indian patients. METHODS: Eighteen ASA 1 and 2 Indian adult patients scheduled to undergo elective surgery were included. The target control infusion (TCI) of propofol was administered using 'Diprifusor'. The level of sedation was assessed using MOAAS by the anaesthesiologist. BIS, SE, RE were recorded throughout. TCI was started at 0.5 µg/ml and increased by 0.5 µg/ml every 6 min till MOAAS scores reached 0 or there was sustained BIS value less than 30. RESULTS: The EC(50) and EC(95) of predicted plasma propofol concentration for loss of consciousness (assessed by loss of response to verbal command), were 2.3 and 2.8 µg/ml respectively and for loss of response to painful stimuli (trapezius squeeze) were 4.0 and 5.0 µg/ml respectively. The BIS and entropy values (EC(50) and EC(95)) for loss of consciousness and response to painful stimuli in Indian patients were estimated. The preliminary relation of target plasma propofol concentration with BIS was found to be BIS = 100.5-16.4 × (Target concentration). CONCLUSIONS: The target plasma propofol concentrations required to produce unconsciousness and loss of response to painful stimuli in Indian patients have been estimated. Also, the relations between target plasma concentration and objective measures of different levels of anaesthesia have been established.

Efficacy of dexmedetomidine as an adjunct to ropivacaine in transversus abdominis plane block for paediatric laparoscopic surgeries: A double-blinded randomised trial.

BACKGROUND AND AIMS: α2 agonists have been utilised in regional blocks, but very little data is available for their use in transversus abdominis plane (TAP) block in paediatric laparoscopic (LAP) surgeries. This study investigated the analgesic effect of ropivacaine alone versus its combination with dexmedetomidine for TAP block in children undergoing LAP surgery. METHODS: A randomised, double-blind trial was conducted in 50 American Society of Anesthesiologists (ASA) 1 and 2 children of 2-8 years undergoing LAP abdominal surgery. Children were randomised to receive a total volume of 0.5 ml/kg of 0.2% ropivacaine (LA group) or 0.2% ropivacaine with 1 µg/kg dexmedetomidine (LAD group) for performing ultrasound-guided bilateral TAP block postoperatively (PO). Patients were monitored PO for vital signs, pain, sedation, time to first rescue analgesic and total analgesic consumption for 24 h. Time to first rescue analgesic was expressed as mean ± standard deviation (SD) and analysed using Kaplan-Meier survival analysis. Pain and sedation scores were expressed as median [interquartile range (IQR)] and analysed using Mann-Whitney U test. RESULTS: First rescue analgesic demand was significantly longer (P = 0.001) in LAD (474.8 min) versus LA group (240.9 min) but total analgesics consumption in first 24 h was comparable. Pain scores were significantly lower (P < 0.05) in LAD compared to LA group at all times PO. Each group had comparable but significantly lower sedation scores up to 24 h PO. CONCLUSION: Addition of dexmedetomidine to ropivacaine in TAP block prolongs the time to first analgesic requirement without a difference in the total analgesic consumption.

Bispectral index-controlled postoperative sedation in cardiac surgery patients: a comparative trial between closed loop and manual administration of propofol.

BACKGROUND AND OBJECTIVE: Postoperative cardiac surgery patients are usually sedated according to clinical sedation scores. Electrophysiological data derived from electroencephalography, such as the bispectral index (BIS), have been reported to assess and quantify the level of sedation, although experience in these patients is limited. In the current study, we evaluated a closed-loop system - closed-loop anaesthesia delivery system (CLADS) - for postoperative sedation after open heart surgery using BIS. METHODS: Forty-one postoperative cardiac surgery patients in the age group 18-65 years were included. In the postanaesthesia care unit, they were randomly allocated to two groups: a CLADS group, which received a continuous infusion of propofol using CLADS, and a manual group, which received propofol at a rate manually adjusted by the clinician. Propofol was administered in both groups to maintain the BIS at a target of 70 for adequate sedation. Patients were weaned from mechanical ventilation and the trachea extubated after confirmation of haemodynamic stability, haemostasis, normothermia and mental orientation. RESULTS: The percentage of total sedation time during which BIS remained within +/-10 of the target value (BIS of 70 during sedation) was significantly higher in the CLADS group than in the manual group (P = 0.002). The assessment of performance parameters using median performance error and median absolute performance error indicated better performance in the CLADS group. Manual control required the propofol infusion rate to be changed frequently, taking up considerable time and attention of the clinician. CONCLUSION: Closed-loop delivery of propofol to control BIS for postoperative sedation is feasible and efficient after cardiac surgery.