Adding Low-Dose Propofol to Limit Anxiety during Target-Controlled Infusion of Remifentanil for Gastrointestinal Endoscopy: Respiratory Issues and Safety Recommendations.

Backgroundand Objectives: Remifentanil-based sedation is one of many protocols proposed for endoscopy procedures in spontaneous ventilation, alone or in combination with propofol. However, the effect of these small doses of propofol on the efficacy and safety of remifentanil target-controlled infusion (TCI) deserves to be examined in this context. The objective of this study was to assess the adverse respiratory and cardiovascular effects of small boluses of propofol combined with remifentanil, in comparison with remifentanil alone, and balanced with the quality of sedation and recovery. Materials andMethods: This was an observational bicenter study, representing a subgroup of a larger study describing remifentanil-based procedural sedation. In center 1, patients scheduled for gastrointestinal (GI) endoscopy had remifentanil TCI alone. In center 2, patients had a 10 mg propofol bolus before TCI and other boluses were allowed during the procedure. Remifentanil TCI was started at a target of 2 ng/mL then adapted by 0.5 ng/mL steps according to patient response to endoscopy stimulations. Results: Center 1 included 29 patients, while center 2 included 60 patients. No difference was found in the patients' characteristics, incidence of success, average remifentanil consumption, or cardiovascular variables. Light sedation was achieved when propofol was added. The incidence of respiratory events, such as bradypnea, desaturation < 90%, and apnea requiring rescue maneuvers, were significantly higher with propofol. Conclusions: Adding propofol boluses to a remifentanil TCI for GI endoscopy ensures light sedation that may be necessary for anxiolysis but increases respiratory events, even after administration of small-dose boluses. Its safety is acceptable if the procedure is performed in an equipped environment with sedation providers trained to manage respiratory events and drugs titrated to minimal doses.

Efficacy of target controlled infusion of remifentanil with spontaneous ventilation for procedural sedation and analgesia (Remi TCI PSA): A double center prospective observational study.

OBJECTIVE: Remifentanil, a rapid onset rapid offset synthetic opioid and potent analgesic, is often used for procedural conscious sedation in spontaneous ventilation, especially when delivered in target controlled infusion (TCI), which allows precise titration. We assessed efficacy, tolerance, and adverse events related with the use of remifentanil TCI during various procedures. DESIGN: Prospective, observational. SETTING: Two teaching hospitals. PATIENTS: We enrolled 434 patients undergoing procedures suitable for conscious sedation. INTERVENTIONS: The following procedures considered suitable were included: interventional radiology, gastrointestinal (GI) endoscopy, interventional cardiology, and peripheral dermatology. Sedation options were determined during the preoperative anesthesia assessment. MAIN OUTCOME MEASURES: Demographics were recorded as well as success rate, remifentanil dosage, pain scores, respiratory or cardiovascular events, and patient and operator satisfaction. RESULTS: The procedure was successful in 429 patients (99 percent), canceled in four patients because of agitation, apnea, desaturation, and converted to general anesthesia in two for major pain. The maximal remifentanil target was around 2-3 ng/ml for most procedures, but it was 3-5 ng/ml for GI endoscopy and urology. A total of 172 patients (40 percent) had bradypnea < 8 min-1, but only 26 (6 percent) had hypoxemia < 90 percent. Eighteen patients (4 percent) required mandibular luxation, and twelve needed face mask ventilation. There were no major cardiovascular adverse events. CONCLUSIONS: Remifentanil TCI is a suitable protocol for procedural sedation, but respiratory depression is a permanent concern. This risk requires equipped environment and competent medical personnel on hand to adjust the target before hypoxemia occurs. Respiratory rate monitoring, based on capnography or thoracic impedance is of a great help in anticipating this threat.

Guidelines on muscle relaxants and reversal in anaesthesia.

OBJECTIVES: To provide an update to the 1999 French guidelines on "Muscle relaxants and reversal in anaesthesia", a consensus committee of sixteen experts was convened. A formal policy of declaration and monitoring of conflicts of interest (COI) was developed at the outset of the process and enforced throughout. The entire guidelines process was conducted independently of any industrial funding (i.e. pharmaceutical, medical devices). The authors were required to follow the rules of the Grading of Recommendations, Assessment, Development and Evaluation (GRADE®) system to assess the quality of the evidence on which the recommendations were based. The potential drawbacks of making strong recommendations based on low-quality evidence were stressed. Few of the recommendations remained ungraded. METHODS: The panel focused on eight questions: (1) In the absence of difficult mask ventilation criteria, is it necessary to check the possibility of ventilation via a facemask before muscle relaxant injection? Is it necessary to use muscle relaxants to facilitate facemask ventilation? (2) Is the use of muscle relaxants necessary to facilitate tracheal intubation? (3) Is the use of muscle relaxants necessary to facilitate the insertion of a supraglottic device and management of related complications? (4) Is it necessary to monitor neuromuscular blockade for airway management? (5) Is the use of muscle relaxants necessary to facilitate interventional procedures, and if so, which procedures? (6) Is intraoperative monitoring of neuromuscular blockade necessary? (7) What are the strategies for preventing and treating residual neuromuscular blockade? (8) What are the indications and precautions for use of both muscle relaxants and reversal agents in special populations (e.g. electroconvulsive therapy, obese patients, children, neuromuscular diseases, renal/hepatic failure, elderly patients)? All questions were formulated using the Population, Intervention, Comparison and Outcome (PICO) model for clinical questions and evidence profiles were generated. The results of the literature analysis and the recommendations were then assessed using the GRADE® system. RESULTS: The summaries prepared by the SFAR Guideline panel resulted in thirty-one recommendations on muscle relaxants and reversal agents in anaesthesia. Of these recommendations, eleven have a high level of evidence (GRADE 1±) while twenty have a low level of evidence (GRADE 2±). No recommendations could be provided using the GRADE® system for five of the questions, and for two of these questions expert opinions were given. After two rounds of discussion and an amendment, a strong agreement was reached for all the recommendations. CONCLUSION: Substantial agreement exists among experts regarding many strong recommendations for the improvement of practice concerning the use of muscle relaxants and reversal agents during anaesthesia. In particular, the French Society of Anaesthesia and Intensive Care (SFAR) recommends the use of a device to monitor neuromuscular blockade throughout anaesthesia.

Peri-operative management of overweight and obese children and adolescents.

Obesity has become endemic, even in children. Systemic complications associated with obesity include metabolic syndrome, cardiovascular disease, and respiratory compromise. These comorbidities require adequate investigation, targeted optimisation, and, if surgery is required, specific management during the peri-operative period. Specific peri-operative strategies should be used for paediatric patients who are overweight or obese to prevent postoperative complications, and optimising the respiratory function during surgery is particularly crucial. This Review aims to provide up-to-date information on peri-operative management for physicians who are caring for children and adolescents (usually younger than 18 years) who are overweight or obese undergoing surgery, including bariatric surgery. We have particularly focussed on the physiological consequences of obesity-namely, obstructive sleep apnoea, respiratory compromise, and pharmacological considerations.

Prediction of movement to surgical stimulation by the pupillary dilatation reflex amplitude evoked by a standardized noxious test.

BACKGROUND: Individual assessment of the amplitude of a physiologic reflex evoked by a standardized noxious test (SNT) before surgical stimulation has been suggested to predict movement upon the forthcoming surgical stimulation. This study aimed to compare the ability of pupillary dilatation reflex amplitude (PDRA) evoked by an SNT and estimated remifentanil effect-site concentration (Ce) to predict movement upon surgical stimulation. METHODS: Eighty female patients were anesthetized for vacuum aspiration with propofol (Ce 4 µg/ml) and remifentanil. Remifentanil Ce was randomized to 0, 1, 3, or 5 ng/ml. SNT was a 60-mA, 5-s, 100-Hz tetanus applied on median nerve before cervix dilatation. PDRA was calculated as the difference in pupillary diameter after and before SNT. Movement upon cervix dilatation was recorded by an independent observer. Ability of PDRA and estimated remifentanil Ce to discriminate movers from non-movers during cervix dilatation was measured as the area under the receiver operating characteristics curve. RESULTS: Twenty-one of the 76 patients analyzed moved during cervix dilatation. Mean PDRA (±1 SD) evoked by SNT was 2.0 ± 1.2 mm in movers and 0.6 ± 0.7 in non-movers (P < 0.0001). Remifentanil Ce was 0.2 ± 0.4 ng/ml in movers and 3.0 ± 1.7 in non-movers (P < 0.0001). Area under the receiver operating characteristics curve for PDRA was 0.90 (95% CI, 0.83 to 0.96) and for remifentanil Ce 0.94 (0.89 to 0.98), without any significant difference between the two areas. CONCLUSIONS: PDRA evoked by an SNT is as accurate as the estimated remifentanil Ce to predict movement upon cervix dilatation. PDRA could be valuable when estimated opioid Ce is not available or reliable.

Is it time to re-evaluate the routines about stopping/keeping platelet inhibitors in conjunction to ambulatory surgery?

PURPOSE OF REVIEW: To assess the influence of antiplatelet drugs (APDs) in outpatients' perioperative care and to propose up-to-date management of those patients. RECENT FINDINGS: Evidence is spreading on the risk of adverse cardiovascular events (ACEs) when APD therapy is discontinued, specifically in patients with coronary stents. Conversely, maintaining such treatments throughout the operative period appears usually safe. Bridging with low-molecular-weight heparins poorly protects against ACEs. In outpatients, major surgical bleeding is rare, but sometimes a minor hemorrhage may jeopardize the success of a surgical procedure. Despite the paucity of properly sized randomized trials in this setting, recommendations have been issued by scientific societies and can be used as guidelines. Variability in APD efficiency is now better appraised, and research on versatile bedside testing of platelet function is active. New drugs are expected to be launched in the near future, all this aiming at improving individualized drug dosage and therefore both safety and efficiency of APD therapies. SUMMARY: In surgical patients APD therapy should be maintained in all situations in which the risk of surgical bleeding is low, which is usually the case in the ambulatory setting. In clearly identified cases in which bleeding might threaten either the patient's life or the success of the surgical procedure in patients at high risk of ACE, the discontinuation protocol must be established in conjunction with the cardiologist and the APD therapy resumed as soon as possible. Bridging with low-molecular-weight heparins is not recommended.

Development and feasibility of a scale to assess postoperative recovery: the post-operative quality recovery scale.

BACKGROUND: Good postoperative recovery is increasingly recognized as an important outcome after surgery. The authors created a new Post-operative Quality Recovery Scale (PQRS) that tracks multiple domains of recovery from immediate to long-term time periods in patients of varying ages, languages, and cultures. METHODS: The parameters of importance to both clinicians and patients were identified. After an initial pilot study of 133 patients, the PQRS was refined. It consists of six domains (physiologic, nociceptive, emotive, activities of daily living, cognitive, and overall patient perspective). An observational study of 701 patients was performed with the refined PQRS to assess its capacity to evaluate and track recovery and to discriminate between patients. It was conducted in eight countries and in five languages, involving patients more than or equal to 6 yr undergoing elective surgery with general anesthesia. Recovery was assessed before surgery and at multiple time periods postoperatively. Recovery was defined as return to baseline values or better. RESULTS: Seven hundred one patients completed the PQRS. Mean completion time was 4.8 (SD 2.8) min. Recovery scores improved with time. Physiologic recovery was complete in 34% of subjects by 40 min. By the third postoperative day, complete recovery was obtained in 11% of cases (all domains): 48.7% nociceptive, 81.8% emotive, 68.8% activities of daily living, and only 33.5% cognitive. Overall, 95.8% of the patients reported that they were "satisfied or totally satisfied" with their anesthetic care. CONCLUSION: The scores on the PQRS demonstrated an improvement over time, consistent with an expected recovery after surgery and anesthesia, and an ability to discriminate between individuals. Many patients had incomplete recovery by the third postoperative day.

Pharmacokinetic-pharmacodynamic modeling of propofol in children.

BACKGROUND: The aim of this study was to identify the best model to describe pharmacokinetics and pharmacodynamics in prepubertal children and therefore to calculate the corresponding pharmacodynamic parameters. In addition, and to confirm our method, a group of postpubertal subjects was also studied. METHODS: Sixteen children (9.5 yr, range 6-12) and 13 adults (22 yr, range 13-35) were included. Induction was performed by plasma target-controlled infusion of propofol (6 microg/ml) based on the Kataria model in children and on the Schnider model in adults. The relationship of bispectral index to predicted concentrations was studied during induction using the Kataria, pediatric Marsh, Schüttler, and Schnider models in children. Because the best performance was obtained, strangely enough, with the Schnider model, the two groups were pooled to investigate influence of puberty on pharmacodynamic parameters (kE0 [plasma effect-site equilibration rate constant] and Ce50 [effect-site concentration corresponding with 50% of the maximal effect]). The time-to-peak effect was calculated, and the kE0 was determined for the Kataria model (nonlinear mixed-effects modeling; pkpdtools). RESULTS: In children, the predicted concentration/effect relationship was best described using the Schnider model. When the whole population was considered, a significant improvement in this model was obtained using puberty as a covariate for kE0 and Ce50. The time to peak effect, Tpeak (median, 0.71 [range, 0.37-1.64] and 1.73 [1.4-2.68] min), and the Ce50 (3.71 [1.88-4.4] and 3.07 [2.95-5.21] microg/ml) were shorter and higher, respectively, in children than in adults. The kE0 linked to the Kataria model was 4.6 [1.4-11] min. CONCLUSIONS: In children, the predicted concentration/effect relationships were best described using the Schnider model described for adults compared with classic pediatric models. The study suggests that the Schnider model might be useful for propofol target-control infusion in children.

The effect of preoperative heart rate and anxiety on the propofol dose required for loss of consciousness.

BACKGROUND: Conflicting results have been reported on the effect of anxiety on the propofol dose required for inducing loss of consciousness (LOC). The hemodynamic effects of anxiety, increased heart rate (HR), and cardiac output may account for these discrepancies. We therefore designed this study to address, first, the effect of perioperative HR on propofol dose required for LOC and, second, the effect of perioperative anxiety on HR. METHODS: Forty-five ASA physical status I-II female patients undergoing gynecological surgery were studied. Anxiety was assessed in the operating room with the State-Trait Anxiety Inventory (STAI)-state Spielberger scale (situational anxiety). After HR recording, anesthesia was induced with a 200-mL/h 1% propofol infusion with the Base Primea pump (Fresenius-Vial, Brezins, France) until LOC. The propofol dose was recorded at the time of LOC. Relationships between STAI-state and HR versus propofol dose at LOC were tested with the Spearman test with a P value of 0.01. RESULTS: A significant relationship was observed between HR and propofol dose at LOC (rho = 0.487, P = 0.0012) but not between STAI-state and propofol dose (rho = 0.330, P = 0.0306). However, a significant relationship was observed between STAI-state and HR (rho = 0.462 and P = 0.0054). CONCLUSION: Increased perioperative HR is associated with increased propofol dose required for LOC. Perioperative anxiety accounts for increased HR.

A randomized, dose-response study of sugammadex given for the reversal of deep rocuronium- or vecuronium-induced neuromuscular blockade under sevoflurane anesthesia.

BACKGROUND: Sugammadex is the first of a new class of selective muscle relaxant binding drugs developed for the rapid and complete reversal of neuromuscular blockade induced by rocuronium and vecuronium. Many studies have demonstrated a dose-response relationship with sugammadex for reversal of neuromuscular blockade in patients induced and maintained under propofol anesthesia. However, sevoflurane anesthesia, unlike propofol, can prolong the effect of neuromuscular blocking drugs (NMBDs) such as rocuronium and vecuronium. METHODS: We designed this randomized, open-label, dose-response trial to explore the dose-response relationship of sugammadex for the reversal of deep neuromuscular blockade induced by rocuronium or vecuronium under propofol-induced and sevoflurane-maintained anesthesia. As a secondary objective, the safety variables of sugammadex were evaluated. After anesthesia induction with propofol, 102 patients aged > or = 20 and < 65 yr were randomized to receive a single bolus dose of rocuronium 0.9 mg/kg (n = 50) or vecuronium 0.1 mg/kg (n = 52), followed by maintenance doses (rocuronium 0.1-0.2 mg/kg or vecuronium 0.02-0.03 mg/kg) as needed. Neuromuscular blockade was monitored using acceleromyography. After the last dose of NMBD, at 1-2 posttetanic counts, a single bolus dose of sugammadex 0.5, 1.0, 2.0, 4.0, or 8.0 mg/kg was administered. The primary efficacy variable was time from start of sugammadex administration to recovery of the T(4)/T(1) ratio to 0.9. RESULTS: The per-protocol population consisted of 48 patients in the rocuronium group and 47 in the vecuronium group. A dose-response effect was demonstrated for decreased mean time to recovery of the T(4)/T(1) ratio to 0.9 with increasing sugammadex dose in both NMBD groups (per-protocol population): rocuronium group, 79.8 (SD 33.0) min (sugammadex 0.5 mg/kg) to 1.7 (0.7) min (4.0 mg/kg) and 1.1 (0.3) min (8.0 mg/kg subgroup); vecuronium group, 68.4 (31.9) min (0.5 mg/kg) to 3.3 (3.5) min (4.0 mg/kg), and 1.7 (0.8) min (8.0 mg/kg subgroup). Neuromuscular monitoring showed recurrent neuromuscular blockade in 5 patients, all in the rocuronium group (2 given sugammadex 0.5 mg/kg and 3 given 1.0 mg/kg), but there were no clinical events attributable to recurrent or residual neuromuscular blockade. CONCLUSION: Sugammadex at doses of > or = 4 mg/kg provides rapid reversal of deep rocuronium- and vecuronium-induced neuromuscular blockade under sevoflurane maintenance anesthesia.

Predicted propofol effect-site concentration for induction and emergence of anesthesia during early pregnancy.

BACKGROUND: Pregnancy is associated with decreased hypnotic requirement, allegedly related to progesterone. However, the effects of pregnancy and progesterone on propofol requirement have not been thoroughly investigated. We conducted this study to determine whether propofol dose and predicted effect-site concentration for loss of consciousness (LOC) during induction of anesthesia, and eye opening during emergence from anesthesia, are decreased during early pregnancy. We also investigated whether blood progesterone was correlated with propofol dose and effect-site concentration for LOC. METHODS: We studied 57 ASA I-II women patients undergoing elective termination of pregnancy and 55 control patients undergoing transvaginal oocyte puncture for in vitro fertilization. Anesthesia was induced by administration of a 1% propofol infusion at 200 mL/min. Propofol dose and calculated effect-site concentration (Schnider model) were recorded at the time of LOC during induction. We also calculated effect-site concentration at the time of eye opening upon emergence from anesthesia. Blood progesterone was measured after surgery. RESULTS: Mean (+/-1 SD) propofol dose at LOC was significantly reduced in the pregnant patients compared with the nonpregnant control patients (108.57 +/- 20.04 vs 117.59 +/- 17.98 mg, respectively; P = 0.014). Similarly, the calculated propofol effect-site concentration at LOC was significantly lower in the pregnant patients than the nonpregnant control patients (4.59 +/- 0.72 vs 5.01 +/- 0.64 microg/mL, respectively; P = 0.0014). There was no difference in the calculated effect-site concentration on eye opening upon emergence. No significant relationship was observed between blood progesterone and propofol dose or calculated propofol effect-site concentration at LOC. CONCLUSION: Propofol dose and predicted propofol effect-site concentration at LOC are decreased during early pregnancy. Progesterone does not explain this result.

Update on pharmacology of hypnotic drugs.

PURPOSE OF REVIEW: This review is intended to provide an update on pharmacology of hypnotic drugs and current state of published research for new or improved agents. RECENT FINDINGS: Albeit no completely new drugs have been launched in the last few years, research on pharmacology of existing drugs is still ongoing, and new formulations of existing drugs are proposed (propofol, isoflurane). Xenon, an old but so far unavailable drug, has elicited new interests and this review will examine the recent publications on this fascinating agent. SUMMARY: These results will improve our handling of existing drugs and open new perspectives on drug monitoring through measurement of propofol concentrations in expired air.

The relationship between bispectral index and propofol during target-controlled infusion anesthesia: a comparative study between children and young adults.

BACKGROUND: In this prospective study, we compared the relationship between propofol concentrations and bispectral index (BIS) in children versus young adults anesthetized with target-controlled infusion (TCI) of propofol. METHODS: Forty-five prepubertal subjects (children) and 45 postpubertal subjects (adults) were studied. All patients were anesthetized with TCI of propofol, based on the Kataria et al.'s model for children and on the Schnider et al.'s model for adults. All data from the BIS and the TCI system were continuously recorded using Rugloop software. Remifentanil was continuously administered throughout the study (0.25 microg x kg(-1) x min(-1)). In all patients, after the end of surgery, a 12-min period with a stable target plasma concentration (Ct) of propofol, randomly assigned at 2, 3, 4, 5, and 6 microg/mL, was performed. In addition, in most of the patients, another 12-min period was performed during which the BIS was targeted at 50 +/- 5. After each 12-min steady-state period, the Ct and BIS were noted and the plasma concentration of propofol was measured (Cm). The Ct and Cm corresponding to half maximal effect (BIS(50)) was determined by the Hill equation, and by targeting BIS at 50. RESULTS: In children, as in adults, BIS values were highly correlated with the corresponding Ct or Cm of propofol following classical E(max) dose-response curves. The ECt(50) and the ECm(50), derived from the dose-response curves, were higher in children than in adults: ECm(50): 4.0 (3.6-4.5) microg/mL vs 3.3 (3.0-3.7) microg/mL [mean (95% CI)], P < 0.001; as well were the Ct and Cm clinically obtained when BIS was targeted at 50 (Cm(50): 4.3 +/- 1.1 microg/mL vs 3.4 +/- 1.2 microg/mL, (mean +/- SD) P < 0.05, children versus adults). Cm was generally under-estimated by the Ct, and the bias was higher in children than in adults: 2.6 +/- 2.6 microg/mL vs 1.7 +/- 1.6 microg/mL (P = 0.05). CONCLUSIONS: The good relationship between propofol and BIS demonstrated in children as in adults suggested a slightly lower sensitivity to propofol in children. As the predictability of plasma propofol concentrations with the classical pharmacokinetic/pharmacodynamic models is limited in children, a cerebral pharmacodynamic feedback, such as BIS, may be useful in this population.

Does spectral entropy reflect the response to intubation or incision during propofol-remifentanil anesthesia?

BACKGROUND: Spectral entropy is an electroencephalogram-based monitoring technique with a frequency band enlarged to include the electromyogram spectrum, which is intended to help to assess analgesia. Although its correlation with hypnosis has been shown, its performance during a noxious stimulation and the influence of neuromuscular blockade have not been described. METHODS: In this prospective, open, multicenter study, 105 patients received propofol then remifentanil target-controlled infusion for induction of anesthesia, with randomized remifentanil targets ranging from 2 to 8 ng/mL. Half of the patients received neuromuscular blockade. Intubation and incision were used as standard noxious stimulations, motor or hemodynamic responses were recorded, and spectral entropy values before and after stimulations were compared between responders and nonresponders. RESULTS: No difference was found in response entropy (RE), state entropy (SE), or (RE - SE) between patients with or without hemodynamic response to stimulations. Patients with motor response to intubation had higher values of RE, SE, and (RE - SE) both before and after the intubation than patients with no response. These results were confirmed by a prediction probability analysis, showing a significant but weak predictive value of entropy for motor response only. CONCLUSIONS: Entropy predicted a motor response to noxious stimulations but not a hemodynamic response, which limits its usefulness for assessing the analgesic component of anesthesia in paralyzed patients. High values (RE >55) before the stimulation should be avoided in order to decrease the risk of motor response, but lower values might not prevent this response when the opioid concentration is insufficient, despite an adequate hypnosis.

Low-dose aspirin and clopidogrel: how to act in patients scheduled for day surgery.

PURPOSE OF REVIEW: With the increasing use of antiplatelet drug treatment, complications resulting from its interference with invasive procedures (surgery or regional anaesthesia) have become an everyday challenge to the surgical team. The purpose of this review is to examine the most recent findings and integrate them into the ambulatory surgery setting. RECENT FINDINGS: Recent studies have outlined the risks of withholding antiplatelet drug treatment, but it is now generally considered to be preferable to withhold treatment than to maintain it. The role of low molecular weight heparins or short-life NSAIDs as bridge drugs is now discussed and their usefulness challenged. SUMMARY: Most ambulatory surgical procedures present low bleeding risk. The current attitude in this setting is to maintain aspirin therapy and possible antiplatelet drug inhibitors throughout the perioperative period. High-risk patients proposed for high-risk surgery should not be treated as outpatients.

Ambulatory anesthesia for the obese patient.

PURPOSE OF REVIEW: Obese patients are more and more frequently proposed for elective surgery, including acts specifically aimed at curing this condition, i.e. bariatric surgery. Many of these acts present characteristics compatible with ambulatory treatment, but anesthesiologists are reluctant to treat the morbidly obese as outpatients due to lack of data on the safety of this approach. The purpose of this review is to present the information that could be found in the literature on the safety and feasibility of ambulatory procedures in obese patients, and outline the specificity of this population. RECENT FINDINGS: During the last few years, the risks of perioperative complications in this population have been estimated more precisely, specifically respiratory events. A better knowledge of the pharmacology of anesthetic drugs in this population allows optimization of general anesthesia protocols and the interest of regional anesthesia has also been outlined. A first study on gastric banding has demonstrated the suitability of the ambulatory setting for such a procedure. SUMMARY: Ambulatory care in the obese patient is both feasible and well suited to this population provided a few specificities are taken into account.

Posterior urethral valves in adult with Down syndrome.

Posterior urethral valves (PUVs) in patients with Down syndrome (DS) have been previously described. However, no case of PUVs has been reported in an adult patient with DS. We report on a 40-year-old man with DS, who presented with two severe urinary infections and obstructive symptoms. He was found to have type 3 PUVs associated with bladder neck sclerosis. PUV resection and bladder neck incision were done. Because PUVs seem to be more frequent in patients with DS, complete investigations should be performed, even in adults with DS, in the case of urinary infection or lower urinary tract symptoms.

A comparison of target- and manually controlled infusion propofol and etomidate/desflurane anesthesia in elderly patients undergoing hip fracture surgery.

Elderly patients have a higher risk of developing adverse drug reactions during anesthesia, especially anesthesia affecting cardiovascular performance. In this prospective randomized study we compared quality of induction, hemodynamics, and recovery in elderly patients scheduled for hip fracture surgery and receiving either etomidate/desflurane (ETO/DES) or target-controlled (TCI) or manually controlled (MAN) propofol infusion for anesthesia. Sixteen patients were anesthetized with ETO (0.4 mg/kg) followed by DES titrated from an initial end-tidal concentration of 2.5%. Eighteen patients received propofol TCI at an initial plasma concentration of 1 microg/mL and titrated upwards by 0.5-microg/mL steps. Fifteen patients received a bolus induction of propofol 1 mg/kg over 60 s followed by an infusion initially set at 5 mg . kg(-1) . h(-1). All received a bolus (20 microg/kg) followed by an infusion of 0.4 microg . kg(-1) . min(-1) alfentanil. According to hemodynamics, concentrations of DES or propofol (TCI group) and propofol infusion rate (MAN group) were respectively adjusted by a step of 20% and 50%. In the TCI and ETO/DES groups, the time spent at a mean arterial blood pressure within 15% and 30% of baseline values was more than 60% and 80% of anesthesia time, whereas in the MAN group it was <30% and 60%, respectively. In the MAN group more anesthetic drug adjustments were recorded (6.4 +/- 2.8 versus 2.5 +/- 1.2 [ETO/DES] and 2.6 +/- 1 [TCI]). TCI improves the time course of propofol's hemodynamic effects in elderly patients.

Pharmacokinetics of propofol administered by target-controlled infusion to alcoholic patients.

BACKGROUND: Chronic alcoholic patients are frequently presented for anesthesia and surgery. These patients require higher doses of propofol than control patients for induction of anesthesia, but whether this is because of changes in pharmacokinetics or pharmacodynamics is not known. This study was designed to investigate the influence of chronic ethanol intake on propofol pharmacokinetics. METHODS: Fifteen chronic alcoholic and 15 control patients, receiving propofol by target-controlled infusion for otolaryngologic surgery, were studied. Blood propofol concentrations were measured at regular intervals during and after the propofol infusion. Nonlinear mixed-effects population models (NONMEM) examining the influence of alcoholism were constructed. The influence of recovery on propofol pharmacokinetic parameters was also addressed. RESULTS: The total amount of propofol and the predicted and measured concentrations during all phases of anesthesia did not differ between the two groups. The fact that the measured concentrations at the time of opening eyes were similar further confirmed that the potency of propofol was not modified by the alcoholic status of the patients. Chronic alcoholism was associated with only mild changes in propofol pharmacokinetics (increase in rapid intercompartmental clearance and greater interindividual variability in the central volume of distribution). The rebound in concentration frequently observed during the recovery phase could be related to decreased propofol peripheral volumes of distribution despite an increase in elimination clearance. CONCLUSIONS: Chronic alcoholism induces only mild changes in the pharmacokinetics of propofol. Conversely, propofol pharmacokinetics are markedly different during anesthesia and surgery or after opening eyes in the recovery period.