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Biomedical subjects

C Baillard

Publications and source records attributed to C Baillard.

At least 19 recordsLinked to original sources

[Anaesthetic preoperative assessment of chronic medications and herbal medicine use: a multicenter survey].

OBJECTIVE: This study was undertaken to quantify the use of chronic medication and herbal remedies in the presurgical population. STUDY DESIGN: Prospective multicenter survey. PATIENTS AND METHODS: Adult patients presenting for anaesthesia were directly asked if they were currently using chronic medication or herbal remedies. RESULTS: Among 1057 patients (age 54+/-17 yrs, woman 54%, ASA 2 [1-4], 74%) were taking one or more chronic medication. The most commonly used treatments were, in descending order angiotensin-converting enzyme inhibitors and angiotensin-II receptor blockers (15%), beta blockers (11%) and platelet inhibitors (10%). Also, 9% were taking one or more of the following herbal remedies known to interact with the perioperative period: valeriane, ginseng, ginkgo, St John's wort, echinacea and ephedra. Women and patients aged 40-70 yr were most likely to be taking a herbal product (p<0.001 and p<0.01 respectively). CONCLUSION: Chronic medication and herbal remedies are common in patients presenting for anaesthesia. Because of the potential interactions between anaesthetic drugs or techniques and such medication it is important for anaesthetists to be aware of their use.

Adrenergic beta-Antagonists↗

Postoperative residual neuromuscular block: a survey of management.

BACKGROUND: To avoid postoperative residual neuromuscular block there is a need for a change in clinician's attitude towards monitoring and reversal. This study aims to evaluate changes of perioperative neuromuscular block management during the last decade in our institution and to quantify the incidence of postoperative residual neuromuscular block. METHODS: Patients receiving intermediate-acting neuromuscular blocking agents for scheduled surgical procedures during 3-month periods in 1995 (n=435), 2000 (n=130), 2002 (n=101), and in 2004 (n=218) were prospectively and successively enrolled in our study. The management of neuromuscular block in the operating room and the adequacy of the recovery were at the discretion of the anaesthesiologist. An attempt was made between each study period to promote a change in the management of neuromuscular block. In the post-anaesthesia care unit, train-of-four (TOF) stimulations were used to assess the presence of a residual neuromuscular block. RESULTS: Between 1995 and 2004 quantitative measurement and reversal of neuromuscular block in the operating room increased from 2 to 60% and from 6 to 42%, respectively (P<0.001). During the same time, the incidence of residual neuromuscular block defined as a TOF ratio less than 0.9 decreased from 62 to 3% (P<0.001). Use of objective neuromuscular monitoring and/or anticholinesterase drugs was less likely in patients with an inadequate recovery (P<0.001). CONCLUSIONS: During the last decade the incidence of residual neuromuscular block strongly decreased in our institution. It confirms the positive impact of neuromuscular monitoring and reversal of neuromuscular block in routine anaesthetic practice.

Adult↗

[Preoperative management of chronic medications].

This review focuses on potential drug interactions between anaesthetic drugs or techniques and chronic medications in patients scheduled for surgery. The vast majority of therapeutics can be continued until the morning of surgery. However, for some drugs such as ACE inhibitors, there is strong evidence to recommend their discontinuation prior to surgery. When juged necessary, interruption of chronic therapeutic needs to be anticipated and planned. In the other hand, for other drugs such as beta-blockers or L-Dopa, acute withdrawal is associated with documented adverse outcome. As a result, such drugs have to be continuing throughout the operative period. Although a general consensus exists for many medications, there are still controverses as to the management of antithrombotic drugs and some central nervous system agents. Advances in anaesthesia include knowledge on the mechanisms involved in drug interactions, which allows us to improve the preoperative management of chronic therapeutics.

Anesthetics↗

[Remifentanil-midazolam compared to sufentanil-midazolam for ICU long-term sedation].

OBJECTIVE: Remifentanil has a unique metabolic pathway that holds potential benefits for long-term sedation. We compared remifentanil-midazolam to sufentanil-midazolam in 41 critically ill adults requiring mechanical ventilation. STUDY DESIGN: Randomized double-blind trial. PATIENTS AND METHODS: Infusion rates were titrated every 4 hours to achieve the desired Ramsay score. Five fold increases in dose requirement was considered as the development of tolerance. Drugs requirement, development of tolerance and weaning time of ventilation were compared. RESULTS: The study was stopped after an interim analysis. The remifentanil and sufentanil groups were comparable regarding IGS II: 56+/-22 vs 64+/-26, mean+/-SD, ICU length of stay: 26 (8-45) vs 19 (11-34) days, and sedation duration: 6 (4-19) vs 6 (3-16)days, median [interquartile range, IQR]). There was a shorter weaning time in the remifentanil group as compared to sufentanil group: 22 h (12-53) vs 96 (47-142) h, median [IQR], p=0.04). The daily opioid infusion rate needed to be decreased over time only in sufentanil group, p < 0.001. Tolerance occurred in 6 (30%; CI(95), 10 to 40%) remifentanil and no sufentanil patients (P=0.02). CONCLUSION: Sufentanil infusion needed to be reduced over time and prolonged the weaning time when compared to remifentanil.

Adult↗

Tracheal intubation in routine practice with and without muscular relaxation: an observational study.

BACKGROUND AND OBJECTIVE: The ease of endotracheal intubation has been recently shown to affect the incidence of laryngeal injury. There remains controversy as to whether or not a muscle relaxant is routinely required for tracheal intubation. This study examined conditions of intubation in our routine practice, which employs a relaxant-sparing approach. METHODS: All adult patients scheduled for surgery with general anaesthesia were prospectively included. A muscle relaxant was used to facilitate intubation when it was required for the surgical procedure and/or otherwise regarded as necessary by the anaesthesiologist. In the remaining patients, a relaxant-free intubation was performed. Intubating conditions were evaluated in all the patients as well as the post-intubation laryngeal symptoms. RESULTS: Between March and July 2003, 612 patients were consecutively included. A muscle relaxant was used in 32% of patients and no relaxant in the remaining patients (68%). Clinically acceptable intubating scores were observed in 98.4% overall with no significant difference between the two groups. Excellent conditions occurred more frequently in the relaxant group as compared to the relaxant-free group, 87% vs. 72%, P = 0.005. Laryngeal symptoms occurred in 184 (33%) patients with no difference between the two groups. CONCLUSIONS: Our relaxant-sparing approach did not increase the incidence of poor conditions of intubation nor laryngeal symptoms. However, excellent conditions occurred more frequently in the relaxant group. A more flexible approach to the issue of the need for neuromuscular blockade prior to intubation is proposed.

Adult↗

Anaphylaxis to rocuronium.

Reports about anaphylactic and anaphylactoid reactions to rocuronium have increased recently. We report two new cases of documented grade III anaphylaxis, leading to death in one patient. The first case occurred in an 81-year-old ASA II woman scheduled for emergency abdominal surgery. Severe hypotension and tachycardia were observed after rocuronium, without bronchospasm. Neosynephrine allowed rapid resuscitation, and the patient recovered fully. The second patient was a 64-year-old ASA II man scheduled for abdominal surgery. Severe haemodynamic instability and bronchospasm occurred after rocuronium. Despite immediate life support, the postoperative period was complicated by persistent low systolic pressure, acute respiratory distress syndrome, acute renal failure, disseminated intravascular coagulation and pancreatitis, leading to the death of the patient.

Aged↗

Use of time frequency analysis to follow transitory modulation of the cardiac autonomic system in clinical studies.

Heart rate variability (HRV) can be assessed through a time frequency analysis, the smoothed pseudo Wigner-Ville transformation (SPWVT). Such an analysis has allowed the calculation of ICF, a frequential index, extremely sensitive to the modulation of the sympatho-vagal balance. The use of ICF has been applied in the present study to two clinical situations for which a role of this balance was probable, brain death and atrial fibrillation (AF). The use of the time frequency analysis immediately identified the timing of brain death. No difference could be found in the analysis of the 30 min preceding an atrial fibrillation episode. It is suggested that a time frequency analysis should be used in clinical situations in which transitory fluctuations of the sympatho-vagal balance are expected and crucial to the well being of the patients.

Atrial Fibrillation↗

[Patient's perspectives with regard to anesthesia services].

PURPOSE: Whereas patients most often select their surgeon, they don't usually select their anesthesiologist. Further, anesthesia frequently involves different physicians at different stages perioperatively. This inability to choose and the multiplicity of interveners may reduce patient satisfaction. Our study examined patients' willingness to choose their anesthesiologist for the operation, as well as their opinion on the way anesthesia is practiced presently. CLINICAL FEATURES: Nine hundred and twelve patients (mean age 51 +/- 16 yr, 58% moles) were requested, immediately after the preoperative visit, to choose their anesthesiologist for the operation. The request was formuled by a nurse, in the absence of the anesthesiologist, in order to avoid a courteous response. After surgery, prior to leaving the hospital, patients were invited to give their opinion on the anesthesia core received and to name the anesthesiologist(s) and surgeon involved. RESULTS: Women chose an anesthesiologist more frequently than men, but only 34% of patients overall elected to do so. Eighty percent of patients were cared for by an anesthesiologist other than the one seen at the preoperative visit. Four percent of patients regretted the change. Patients recalled the surgeon's name more frequently (60%) than the attending anesthesiologist's (4%). CONCLUSION: In France, the preoperative visit is required by law and must precede the operation by at least 48 hr. Despite this preoperative interview, patients were unwilling to choose the anesthesiologist responsible for surgery, did not object to multiple interveners and seldom remembered their anesthesiologist's name. Efforts to improve the image of the profession are required.

Adolescent↗

[Locoregional neuraxial anesthesia as used in vascular surgery].

OBJECTIVES: Neuraxial blockade (spinal or epidural anesthesia) is still widely used in patients undergoing vascular surgery. However, the combined administration of anticoagulants and antiplatelet agents may compromise the safety of this technique with regards to the potential occurrence of a spinal or of an epidural hematoma. We review the benefits and risks of neuraxial blockade in light of the evolution of anticoagulation for vascular surgery. MAIN FINDINGS: Vascular surgery generally requires a high level of intraoperative anticoagulation. An increasing number of patients are also treated pre and post-operatively with antiplatelet agents. Their administration cannot be interrupted without serious risks to the patients' cardiovascular system and, further their continued use during surgery may improve graft permeability. Recent reports have emphasized the danger of neuraxial anesthesia in patients receiving low dose anticoagulation. So, high doses of heparins should carry an ever higher risk of serious complications in patients undergoing neuraxial blockade. Furthermore, no published data has ever demonstrated convincingly the benefit of either epidural or spinal anesthesia over general anesthesia. No differences have ever been documented in terms of cardio-vascular morbidity, graft patency, and mortality. CONCLUSION: Routine neuraxial blockade cannot be recommended in patients undergoing vascular surgery. The decision to perform a neuraxial block in such a patient may only be taken on a case by case basis, after careful consideration of expected benefits and potential risks.

Anesthesia, Conduction↗

Segmentation of brain 3D MR images using level sets and dense registration.

This paper presents a strategy for the segmentation of brain from volumetric MR images which integrates 3D segmentation and 3D registration processes. The segmentation process is based on the level set formalism. A closed 3D surface propagates towards the desired boundaries through the iterative evolution of a 4D implicit function. In this work, the propagation relies on a robust evolution model including adaptive parameters. These depend on the input data and on statistical distribution models. The main contribution of this paper is the use of an automatic registration method to initialize the surface, as an alternative solution to manual initialization. The registration is achieved through a robust multiresolution and multigrid minimization scheme. This coupling significantly improves the quality of the method, since the segmentation is faster, more reliable and fully automatic. Quantitative and qualitative results on both synthetic and real volumetric brain MR images are presented and discussed.

Algorithms↗

The continuous recording of blood pressure in patients undergoing carotid surgery under remifentanil versus sufentanil analgesia.

UNLABELLED: We compared the hemodynamic stability during carotid endarterectomy of remifentanil with that of sufentanil anesthesia. Fifty-six patients were randomly assigned into Remifentanil (n = 27) or Sufentanil (n = 29) groups. In the Remifentanil group, IV propacetamol (2 g) and morphine (0.1 mg/kg) were infused 30 min before skin closure. In the Sufentanil group, patients received 2 g propacetamol. Beat-to-beat recordings of systolic arterial blood pressure (SBP) and heart rate (HR) were stored on a computer. The maximum and minimum values of BP and HR after induction, at intubation, during the surgical procedure, and after the operation and the coefficients of variation of SBP and HR were used as indices of hemodynamic stability. The coefficients of variation of SBP and HR were similar in both groups during and after surgery. However, at intubation, maximal SBP was higher in the Sufentanil group (P < 0.05). Decreased propofol doses and isoflurane end-tidal concentrations were used in the Remifentanil group. At recovery, a similar profile of SBP and HR was found in both groups. We conclude that intra- and posthemodynamic stability was similar with remifentanil or sufentanil in patients undergoing carotid endarterectomy. However, remifentanil was more effective for blunting the increase in SBP at intubation without increasing the blood pressure-decreasing effect of induction. Intraoperative remifentanil use was associated with a decreased amount of hypnotic drug administered. IMPLICATIONS: Beat-to-beat recordings of heart rate and blood pressure in patients undergoing carotid surgery revealed that hemodynamic stability was similar with remifentanil or sufentanil anesthesia both during and after surgery. Remifentanil was more effective in limiting the increase in blood pressure associated with intubation without increasing the blood pressure-lowering effect of induction or the blood pressure response to recovery.

Aged↗

Randomized study comparing the "sniffing position" with simple head extension for laryngoscopic view in elective surgery patients.

BACKGROUND: The "sniffing position" is recommended for optimization of glottic visualization under direct laryngoscopy. However, no study to date has confirmed its superiority over simple head extension. In a prospective, randomized study, the authors compared the sniffing position with simple head extension in orotracheal intubation. METHODS: The study included 456 consecutive patients. The sniffing position was obtained by placement of a 7-cm cushion under the head of the patient. The extension position was obtained by simple head extension. The anesthetic procedure included two Laryngoscopies without paralysis: the first was used for topical glottic anesthesia. During the second direct laryngoscopy, intubation of the trachea was performed. The head position was randomized as follows: group A was in the sniffing position during the first Laryngoscopy and the extension position during the second, group B was in the extension position during the first laryngoscopy and the sniffing position during the second. Glottic exposure was assessed by the Cormack scale. RESULTS: The sniffing position improved glottic exposure (decreased the Cormack grade) in 18% of patients and worsened it (increased the Cormack grade) in 11% of patients, in comparison with simple extension. The Cormack grade distribution was not significantly modified between the two groups. Multivariate analysis showed that reduced neck mobility and obesity were independently related to improvement in laryngoscopic view with application of the sniffing position. CONCLUSIONS: Routine use of the sniffing position appears to provide no significant advantage over simple head extension for tracheal intubation in this setting. The sniffing position appears to be advantageous in obese and head extension-limited patients.

Adult↗

Cardiac troponin I is reliable with immediate but not medium-term cardiac complications after abdominal aortic repair.

BACKGROUND: The diagnosis of cardiac complications is particularly challenging in the postoperative course of non-cardiac surgery. Follow-up of patients suggests that silent or symptomatic postoperative myocardial infarction have similar short-term outcomes. Cardiac troponin I (cTnI) has been reported as being a sensitive and specific marker of these complications. METHODS: We conducted a prospective study to determine the cut-off values of cTnI which may predict cardiac complications, i: in the postoperative period until discharge, and ii: during a 1-year period after aortic surgery. Three hundred and twenty-nine consecutive patients undergoing infrarenal aortic surgery were included over a 2-year period in a single center. cTnI was measured at recovery and on the 1st, 2nd and 3rd postoperative days. The presence or absence of cardiac complications was classified by reviewers who had no knowledge of cTnI. For evaluation of the ideal discrimination value of cTnI between the complicated and uncomplicated patient groups, we calculated receiver-operator characteristics for the mean values of the peak of cTnI. RESULTS: Thirteen patients (4%) developed 19 postoperative cardiac complications. Thirteen patients (4%) died in the postoperative period. Nine patients (3%) developed 10 cardiac complications during the 1-year follow-up in 316 patients. In 280 patients, cTnI was below 0.5 ng/ml, in 22 patients between 0.5 and 1.5 ng/ml and the 27 remaining patients had a cTnI higher than 1.5 ng/ml. The area under the curve for postoperative cardiac complications was 0.84 (SD=0.21). A limit value of 0.54 ng/ml yielded a sensitivity of 75% and a specificity of 89%. The area under the curve for late cardiac complications was 0.45 (SD= 0.13). CONCLUSION: A cTnI level greater than 0.54 ng/ml appears to be correlated with the occurrence of cardiac complications in the period until discharge, but no value of cTnI is predictive of late cardiac complications occurring in the 1st year after aortic surgery.

Aged↗

Residual curarization in the recovery room after vecuronium.

We have investigated residual block after anaesthesia which included the use of the neuromuscular blocking agent vecuronium but no anticholinesterase, in 568 consecutive patients on admission to the recovery room. The ulnar nerve was stimulated submaximally using TOF stimulation (30 mA). Postoperative residual curarization was defined as a TOF ratio < 0.7. Of the 568 patients, 239 (42%) had a TOF < 0.7 in the recovery room. These patients had received a larger cumulative dose of vecuronium than patients who had full recovery (mean 7.7 (SD 3.6) mg vs 6.2 (2.7) mg; P < 0.05) and a shorter time had elapsed since the last vecuronium dose (117 (70) min vs 131 (80) min; P < 0.05). Of 435 patients whose trachea was extubated, 145 (33%) exhibited inadequate recovery from neuromuscular block. Six of these had one or no response to TOF stimulation and were reintubated. In the remaining 139 patients, neuromuscular block was successfully antagonized. Only 20 patients (3.5%) remembered TOF stimulation when questioned 2 h later in the recovery room, and discomfort associated with it was assessed using a visual analogue scale before discharge. We conclude that it is necessary to antagonize residual block produced by vecuronium.

Adolescent↗

Biology of hypertensive cardiopathy.

Available data suggest that hypertensive cardiopathy is principally determined by the phenoconversion that allows the myocyte to adapt to the new working conditions by re-expressing a fetal program. Nevertheless, in clinical conditions, the scheme is different. The above phenotype is modified by trophic factors, which originate from ischemia, senescence, diabetes, genetics, or neurohormonal reactions. This review only focuses on some of the most recent advances concerning the permanent changes in the myocyte. Changes in extracellular matrix have been excluded. Recently, emphasis has been on the kinetic basis of the myocardial dysfunction at the myosin level, the potential therapeutic utilization of transferring the adrenergic receptor gene, the participation of NO synthases in the adaptational process, the existence of an abnormal excitation-contraction coupling due to a redistribution of Ca2+ sparks, the role of the microtubule as a determinant of sarcomere motion, and the multifactorial origin of cell death by apoptosis.

Adenosine Triphosphate↗

Converting enzyme inhibition normalizes QT interval in spontaneously hypertensive rats.

We quantified the repolarization time (so-called QT interval) in a rat, an animal species that does not show a well-characterized T wave on surface ECG. We used spontaneously hypertensive rats (SHR) and converting enzyme inhibition to demonstrate a reversible increase in QT interval in pressure-overloaded hearts in the absence of ischemia. An implanted telemetry system recording ECG data in freely moving rats was used to automatically calculate the RR interval. The QT duration was manually determined by use of a calibrated gauge, and a time-frequency domain analysis was used to evaluate heart rate variability. Left ventricular mass was sequentially assessed by echocardiography. Before treatment, 12-month-old SHR had higher left ventricular mass, QT and RR intervals, and unchanged heart rate variability compared with age-matched Wistar rats. A 2-month converting enzyme inhibition treatment with trandolapril reduces systolic blood pressure, left ventricular mass, and QT interval. The RR interval and heart rate variability remains unchanged. There is a positive correlation between the QT interval and left ventricular mass. The SHR is suitable for longitudinal studies on the QT interval. Thus, the detection of the QT interval reflects the phenotypic changes that occur during mechanical overload and, on the basis of these criteria, allows an in vivo determination of the adaptational process.

Age Factors↗

Haemodynamic measurements (continuous cardiac output and systemic vascular resistance) in critically ill patients: transoesophageal Doppler versus continuous thermodilution.

Ten critically ill patients underwent this prospective study to assess the reliability of the continuous thermodilution versus transoesophageal Doppler techniques in the determination of continuous cardiac output (CO) and systemic vascular resistance (SVR). A total of 145 pairs of CO and SVR measurements were obtained by both a pulmonary artery catheter with a heated filament and a transoesophageal Doppler apparatus (ODM II). Total CO ranged from 2.4 and 13 l.min-1; the bias of all measurements was 0.01 +/- 0.48 l.min-1, and the 95% confidence limits (mean difference +/- 2 SD) were 0.97/0.96 l.min-1. Total SVR ranged from 309 and 2643 dyn.s.cm-5; the bias of all measurements was 18 +/- 127 dyn.s.cm-5, and the 95%, confidence limits were 272/236 dyn.s.cm-5. Transoesophageal Doppler accurately measures continuous CO and SVR in critically ill patients. It should be viewed as complementary to pulmonary catheterization.

Aged↗