Optimizing the surgical field in pediatric functional endoscopic sinus surgery: a new evidence-based approach. Comparative effects of propofol versus fentanyl on cerebral oxygenation state during normothermic cardiopulmonary bypass and postoperative cognitive dysfunction. [The effect of encephalogram bispectral index monitoring during total intravenous anesthesia with propofol in outpatient surgery]. Target-controlled versus manually-controlled infusion of propofol for direct laryngoscopy and bronchoscopy. Impact of bispectral index monitoring on propofol administration in patients undergoing cardiopulmonary bypass. Comparison of closed-loop controlled administration of propofol using Bispectral Index as the controlled variable versus "standard practice" controlled administration. Propofol anaesthesia via target controlled infusion or manually controlled infusion: effects on the bispectral index as a measure of anaesthetic depth. [Bispectral index monitoring is useful to reduce total amount of propofol and to obtain immediate recovery after propofol anesthesia]. Double-blind, placebo-controlled, randomized trial of prophylactic metoprolol for reduction of hospital length of stay after heart surgery: the beta-Blocker Length Of Stay (BLOS) study.
To conduct the first prospective randomized controlled study 1) evaluating the possibility of improving the quality of the operative field and to provide a bloodless functional endoscopic sinus surgery (FESS) in children through total intravenous anesthesia (TIVA) using remifentanil combined with propofol, and 2) testing the safety and efficacy of remifentanil in propofol-TIVA in inducing controlled hypotension in children at a target mean arterial blood pressure of 50 mm Hg.
                Randomized controlled trial.
                General hospital.
                Seventy children underwent FESS under hypotensive general anesthesia with equal randomization into two groups. Group I received TIVA with remifentanil, whereas group II had balanced anesthesia (BA) with esmolol. Heart rate, blood pressure, operative time, blood loss, and quality of the surgical conditions were recorded.
                Intraoperative blood loss in the TIVA group was less than in the BA group. The quality and dryness of the surgical field in both the visual analogue scale and the six-point scale was significantly better in the TIVA group than in the BA group. Hypotension was sustained at the target mean arterial blood pressure of 50 mm Hg in the two groups, without any significant difference.
                Improving the quality of the surgical field and providing a bloodless FESS in children is attainable with TIVA. TIVA using a combination of remifentanil and propofol is superior to BA, even with the use of additional potent hypotensive agents such as esmolol. Both techniques are safe and effective in inducing controlled hypotension in children at a target mean arterial blood pressure of 50 mm Hg. The purpose of this study was to examine the comparative effects of propofol and fentanyl on cerebral oxygenation during normothermic cardiopulmonary bypass and postoperative cognitive dysfunction.
                One hundred eighty patients scheduled for elective coronary artery bypass grafting were randomly divided into two groups: propofol group (n = 90) and fentanyl group (n = 90). After induction of anesthesia, a fiberoptic oximetry oxygen saturation catheter was inserted into the right jugular bulb to monitor jugular venous oxygen hemoglobin saturation continuously. Hemodynamic measurements and arterial and jugular venous blood gases were measured at seven time points. All patients underwent a battery of neurologic and neuropsychological tests on the day before the operation and at 6 months after the operation.
                Cerebral desaturation (defined as a jugular venous oxygen hemoglobin saturation value less than 50%) during cardiopulmonary bypass was more frequent in the fentanyl group than in the propofol group. Cerebral desaturation time (duration when jugular venous oxygen hemoglobin saturation was less than 50%) and the ratio of cerebral desaturation time to total cardiopulmonary bypass time in the fentanyl group differed significantly from those in the propofol group (fentanyl group: 27 +/- 14 minutes, 20% +/- 9%; propofol group: 18 +/- 11 minutes, 14% +/- 7%, respectively, p < 0.05). There was no significant difference in postoperative cognitive dysfunction at 6 months after operation between the two groups (propofol group: 5 of 77, 6%; fentanyl group: 5 of 75, 7%).
                Propofol preserved cerebral oxygenation state estimated by jugular venous oxygenation during cardiopulmonary bypass compared with the fentanyl group. However, propofol did not affect postoperative cognitive dysfunction. To assess the effect of monitoring the encephalogram bispectral index (BIS) during outpatient surgery. Outcome measures were amount of propofol administered, awakening and discharge.
                Forty consecutive outpatient surgery patients were studied. The patients gave informed consent and received general intravenous anesthesia with propofol administered through a laryngeal mask using a computerized system (Diprifusor(R)). Two groups were formed: in group A, BIS was monitored, although the information was hidden from the anesthesiologists, who used the usual signs (loss of blinking reflex, pupil size and hemodynamic response) to guide anesthesia; in group B the anesthesiologists used BIS monitoring to guide propofol administration. Measurements were blood pressure, heart rate and BIS at six times during the procedure (T1-T6). Other data recorded were age, weight, height, propofol consumption in relation to weight and duration of procedure, consumption of rocuronium and alfentanil, duration of propofol infusion, time from withdrawal of propofol until eye opening, duration of stay in the post-anesthesia intensive care unit and time until total recovery. A questionnaire assessed the presence of intraoperative awareness and degree of satisfaction. The data were analyzed by Student's t and a chi square tests, with statistical significance at p < 0.05.
                Demographic variables (age, weight and height) were similar, as were duration of propofol infusion, total dose of alfentanil and rocuronium, evolution of blood pressure and heart rate. Statistically significant differences in BIS were observed at two times, T4 and T5; total propofol administered was 32.6% lower in group B; and time until eye opening was significantly shorter in group B. No significant differences were observed for time until full recovery. No instances of intraoperative awareness were reported and satisfaction was high in both groups.
                BIS monitoring allows for propofol titration that leads to a mean reduction of 32.6% in consumption, shortening the time until eye opening without causing intraoperative awareness or reducing patient satisfaction. Few studies have compared the clinical profile of target-controlled infusions of propofol with that of manually-controlled infusions. Fifty-four ASA physical status I or II patients scheduled for an elective otorhinolaryngology endoscopy performed under general anesthesia with spontaneous ventilation were enrolled in this prospective randomized study to compare the clinical outcome of such administrations. Before induction, all patients received a single alfentanil bolus dose (10 microg/kg). Propofol administration was adapted to maintain absence of movement, hemodynamic stability, and efficient spontaneous ventilation. When compared with the Manually-Controlled Infusion group, in the Target-Controlled Infusion group there were fewer movements at insertion of the laryngoscope (14.8% vs. 44.4%), improved hemodynamic stability (largest variations of mean arterial blood pressure <10% of control values, versus 20%), fewer episodes of apnea, and less respiratory acidosis after endoscopy (pH = 7.37 +/- 0.05 and PaCO(2) = 50 +/- 7 mm Hg versus pH = 7.28 +/- 0.06 and PaCO(2) = 58 +/- 9 mm Hg); the recovery was also shorter (time to opening eyes or verbal response, 4.6 +/- 2.0 min and 6.8 +/- 2.5 min versus 10.8 +/- 7.3 min and 15.7 +/- 7.1 min). Propofol consumption was comparable in the two groups. Targeting the effect-site concentration improved the time course of the propofol drug effect during direct laryngoscopy performed during spontaneous ventilation when compared with manual infusion.
                This study compares the clinical profile of propofol anesthesia for direct laryngoscopy with spontaneous ventilation when the drug is administered either as a manually controlled infusion or by targeting the effect-site concentration through a target-controlled infusion (TCI) device. TCI improves the time course of propofol effects. Propofol anaesthesia using target control infusion during cardiac surgery has become more popular recently. However, without depth of anaesthesia monitoring, the standard target concentration used may be higher than necessary to maintain adequate hypnosis during hypothermic cardiopulmonary bypass. The purpose of this study was to evaluate the effect of bispectral index monitoring on propofol administration during hypothermic cardiopulmonary bypass. After ethics committee approval and written informed consent, 20 New York Heart Association class I-III patients scheduled for elective cardiac surgery requiring hypothermic cardiopulmonary bypass were studied in this prospective randomised controlled trial. In group C, routine anaesthesia was practised, where patients received propofol at target concentration between 1.5 to 2.5 microg/ml during cardiopulmonary bypass. In group B, the target concentration was titrated to a bispectral index value of 40 to 50. Mean arterial pressure and bispectral index were recorded at various time intervals. The use of propofol, phenylephrine, sodium nitroprusside and adrenaline were recorded. The median propofol administration in group B was significantly less than that in group C (2.9 mg/kg/h compared to 6.0 mg/kg/h). The bispectral index value during bypass was significantly lower in group C than in group B, reflecting a deeper state of anaesthesia. There was no difference in the use of inotropes, vasoconstrictors or vasodilators. Bispectral index monitoring enables a 50% reduction in propofol administration at this standard dose during hypothermic cardiopulmonary bypass. This report describes a new closed-loop control system for propofol that uses the Bispectral Index (BIS) as the controlled variable in a patient-individualized, adaptive, model-based control system, and compares this system with manually controlled administration of propofol using hemodynamic and somatic changes to guide anesthesia.
                Twenty female patients, American Society of Anesthesiologists physical status I or II, who were scheduled for gynecologic laparotomy were included to receive propofolremifentanil anesthesia. In group I, propofol was titrated using a BIS-guided, model-based, closed-loop system. The BIS target was set at 50. In group II, propofol was titrated using classical hemodynamic signs of (in)adequate anesthesia. Performance of control during induction and maintenance of anesthesia were compared between both groups using BIS as the controlled variable in group I and the reference variable in group II, and, conversely, the systolic blood pressure as the controlled variable in group II and the reference variable in group I. At the end of anesthesia, recovery profiles between groups were compared.
                Although patients undergoing manual induction of anesthesia in group II at 300 ml/h reached a BIS level of 50 faster than patients undergoing open-loop, computer-controlled induction in group I, manual induction caused a more pronounced initial overshoot of the BIS target. This resulted in a more pronounced decrease in blood pressure in group II. During the maintenance phase, better control of BIS and systolic blood pressure was found in group I compared with group II. Recovery was faster in group I.
                A closed-loop system for propofol administration using the BIS as a controlled variable together with a model-based controller is clinically acceptable during general anesthesia. Target controlled infusions (TCI) of propofol allow anaesthetists to target constant blood concentrations and respond promptly to signs of inappropriate anaesthetic depth. Studies comparing propofol TCI with manually controlled infusion (MCI) reported similar control of anaesthesia, but did not use an objective measure of anaesthetic depth. We therefore tested whether the Bispectral Index (BIS), an electroencephalographic (EEG) variable, is more stable during propofol TCI or MCI. Forty patients received midazolam and fentanyl before induction and were randomized to TCI or MCI. Target propofol concentrations in the TCI group were 3 to 8 microg/ml. The MCI group received propofol bolus (approximately 2 mg/kg) and infusion (3 to 10 mg/kg/h). Neuromuscular blockade was achieved with rocuronium. Following endotracheal intubation, nitrous oxide (66%) in oxygen was delivered and propofol infusion and fentanyl boluses were titrated against clinical signs. Blood pressure, heart rate and EEG were recorded, although the anaesthetist was blind to BIS values. The ideal BIS for general anaesthesia was defined as 50. Performance error, absolute performance error, wobble and divergence of BIS, and maximum changes in blood pressure and heart rate were compared using two-sample t-tests or rank-sum tests where appropriate. There was no difference in absolute performance errors during maintenance of anaesthesia with propofol TCI or MCI (23 +/- 11% vs 23 +/- 9%; P=0.97). The two groups did not differ significantly in performance error, wobble, divergence on haemodynamic changes. We conclude that TCI and MCI result in similar depth of anaesthesia and haemodynamic stability when titrated against traditional clinical signs. Bispectral index (BIS) is a processed EEG parameter for assessment of hypnotic effects of anesthetics. We studied whether BIS monitoring can improve recovery from propofol anesthesia and decrease the total amount of propofol needed. Forty-six patients without hypertension and obesity were studied. In the BIS group (n = 20), propofol infusion rate was adjusted to achieve a target BIS value between 40-60, increasing to 65 during the final 10 min of the surgical procedure. In the control group (n = 19), propofol infusion rate was adjusted based only on standard clinical signs. Compared with the control group, patients in the BIS group required lower propofol infusion rates(4.3 +/- 1.1 vs 4.9 +/- 0.8 mg.kg-1.h-1; P < 0.05), and the total amount of propofol decreased significantly (709 +/- 210 vs 914 +/- 326 mg; P < 0.05). BIS monitoring led to immediate recovery after propofol anesthesia. There were no significant differences in the incidence of intraoperative responses between the two groups. BIS monitoring decreased the total amount of propofol and led to immediate recovery after propofol anesthesia. These findings indicate that the use of BIS monitoring may be useful in controlling the infusion rate of propofol during surgery. Atrial fibrillation (AF) is a common complication of heart surgery. Previous studies have shown that there is an association between postoperative AF and prolongation of hospital length of stay. No previous trials have been primarily directed at demonstrating that the use of drugs that prevent AF would shorten length of stay and reduce the costs of postoperative care.
                A randomized, double-blind, placebo-controlled trial of metoprolol was performed in patients immediately after nonemergent heart surgery. Metoprolol was given orally at a dose of 100 mg per day after the patient's arrival in the intensive care unit until hospital discharge or 14 days, whichever was sooner. This dose was increased to 150 mg per day after the enrollment of 411 patients. The primary outcome measure of the study was hospital length of stay from admission to intensive care unit until hospital discharge. There were 1000 patients enrolled, evenly distributed to the metoprolol and placebo groups.
                There was a 20% reduction in the risk of AF developing with metoprolol, from 39% of patients to 31% of patients (P =.01). There was no effect of treatment on hospital length of stay, which was 152 +/- 61 hours for placebo and 155 +/- 90 hours for metoprolol (P = 0.79). The cost of postoperative care in the 2 treatment groups was similar.
                Prophylactic metoprolol reduces the risk of AF after heart surgery. It does not reduce hospital length of stay. Although it is cost effective for the reduction of AF, it did not reduce the overall cost of care.
Using propofol to achieve deliberate hypotension may improve the surgical field, but the effect is small. Deliberate hypotension with propofol did not decrease TBL and operation time. RCTs with good quality methodology and large sample size are required to investigate the effectiveness of deliberate hypotension with propofol for FESS.