Effect of intra-operative intravenous lidocaine on opioid consumption after bariatric surgery: a prospective, randomised, blinded, placebo-controlled study.

Peri-operative lidocaine infusion warrants investigation in bariatric surgery because obese patients present different physiological and pharmacological risks. This single-centre, prospective, randomised double-blind placebo-controlled study enrolled obese patients scheduled for laparoscopic bariatric surgery using an enhanced recovery protocol. Patients received either lidocaine (bolus of 1.5 mg.kg-1 , then a continuous infusion of 2 mg.kg-1 .h-1 until the end of the surgery, then 1 mg.kg-1 .h-1 for 1 h in the recovery area) or identical volumes and rates of 0.9% saline. The primary outcome was the consumption of the equivalent of oxycodone consumption over the first 3 postoperative days. Secondary outcomes were: postoperative pain; incidence of nausea and vomiting; bowel function recovery; and lengths of stay in the recovery area and in hospital. Plasma concentrations of lidocaine were measured. On the 178 patients recruited, data were analysed from 176. The median (IQR [range]) equivalent intravenous oxycodone consumption was 3.3 mg (0.0-6.0 [0.0-14.5]) and 5.0 mg (3.3-7.0 [3.3-20.0]) in the lidocaine and saline groups, respectively (difference between medians (95%CI): 1.7 (0.6-3.4) mg; p = 0.004). Length of stay in the recovery area, postoperative pain, nausea and vomiting, day of recovery of bowel function, and length of stay in hospital were not different between groups. Mean (SD) lidocaine plasma concentrations were 2.44 (0.70) µg.ml-1 and 1.77 (0.51) µg.ml-1 at the end of surgery and 1 hour after the end of infusion, respectively. Lidocaine infusion during bariatric surgery resulted in a clinically non-relevant difference in postoperative oxycodone consumption.

Assessment of changes in lactate concentration with intravascular microdialysis during high-risk cardiac surgery using the trend interchangeability method.

Background: Blood lactate is a strong predictor of mortality, and repeated blood lactate assays are recommended during surgery in high-risk patients. We hypothesized that the use of intravascular microdialysis incorporated in a central venous catheter would be interchangeable with the reference blood gas technique to monitor changes in blood lactate. Methods: Microdialysis and central venous blood lactate measurements were recorded simultaneously in high-risk cardiac surgical patients. The correlation between absolute values was determined by linear regression, and the Bland-Altman test for repeated measurements was used to compare bias, precision, and limits of agreement. Changes in lactate measurements were evaluated with a four-quadrant plot and trend interchangeability method (TIM). Results: In the 23 patients analysed, the central venous catheter was used as part of standard care, with no complications. The correlation coefficient for absolute values ( n =104) was 0.96 ( P <0.0001). The bias, precision, and limits of agreement were -0.19, 0.51, and -1.20 to 0.82 mmol litre -1 , respectively. The concordance rate for changes in blood lactate measurements ( n =80) was 94% with the four-quadrant plot. In contrast, the TIM showed that 23 (29) changes in lactate measurements were not interpretable, and among the remaining 57 (71) interpretable changes, 18 (32) were interchangeable, 8 (14) were in the grey zone, and 31 (54) were not interchangeable. Conclusions: Microdialysis with a central venous catheter appears to provide reliable absolute blood lactate values. Although changes in blood lactate measurements showed an excellent concordance rate, changes between the two methods were poorly interchangeable with the TIM. Clinical trial registration: NCT02296593.

Spontaneous plantar vein thrombosis: state of the art.

We aim here to highlight the importance of diagnosing and treating promptly the rarely thought of diagnosis of plantar vein thrombosis. We hereby report two cases with no known thrombotic risk factors. Less than 20 cases are reported in the literature. Detection of this unusual site of involvement of the deep venous system can be easily made by ultrasound examination if searched for. Plantar vein thrombosis is a rarely evoked pathology. Knowledge of its occurrence could further improve its diagnosis especially that it could reveal an unknown neoplasia or coagulation abnormality.

Assessment of changes in cardiac index and fluid responsiveness: a comparison of Nexfin and transpulmonary thermodilution.

BACKGROUND: The Nexfin device uses non-invasive photoplethysmography to monitor cardiac output and respiratory variations in pulse pressure and stroke volume. The aim of this study was to compare rapid changes in cardiac index after fluid challenge between Nexfin and bolus transpulmonary thermodilution and the ability to predict fluid responsiveness of dynamic indices given by Nexfin. METHODS: Simultaneous comparative cardiac index were collected from transpulmonary thermodilution and Nexfin before and after fluid challenge in 45 patients following conventional cardiac surgery. Correlations, Bland-Altman analyses and percentage errors were calculated. Pulse pressure variations and stroke volume variations before fluid challenge were collected to assess their discrimination in predicting fluid responsiveness. RESULTS: Eight (18%) patients were excluded. A weak positive relationship was found between rapid changes in cardiac index after fluid challenge given by both technologies (n = 37, r = 0.39, P = 0.019). Bias, precision and limits of agreements were 0.20 l/min/m(2) (95% confidence interval (CI) 0.02-0.40), 0.57 l/min/m(2) and ± 1.12 l/min/m(2) before fluid challenge, and 0.01 l/min/m(2) (95% CI -0.24 to 0.26), 0.74 l/min/m(2) and ± 1.45 l/min/m(2) after fluid challenge. Percentage errors between Nexfin and transpulmonary thermodilution were 55% and 58% before and after fluid challenge, respectively. Pulse pressure variations and stroke volume variations given by Nexfin were not discriminant to predict fluid responsiveness: areas under receiver operating characteristics curves 0.57 (95% CI 0.40-0.73) and 0.50 (0.33-0.67), respectively. CONCLUSIONS: The Nexfin cannot be used to measure rapid changes in cardiac index following fluid challenge and to predict fluid responsiveness after cardiac surgery.

Non-invasive continuous arterial pressure and cardiac index monitoring with Nexfin after cardiac surgery.

BACKGROUND: This observational study was designed to evaluate the reliability and precision of a new digital photoplethysmographic device (Nexfin, BMEYE B.V., Amsterdam, The Netherlands) for continuous and non-invasive assessment of arterial pressure and cardiac output. METHODS: Fifty consecutive adult subjects were prospectively enrolled at admission to the intensive care unit after conventional cardiac surgery and investigated hourly from T0 to T4. Simultaneous comparative systolic, diastolic, and mean arterial pressures and cardiac index (CI) data points were collected from an invasive radial artery catheter, transpulmonary thermodilution catheter, and the Nexfin device. Correlations were determined by linear regression. The Bland-Altman analysis was used to compare bias, precision, and limits of agreement. RESULTS: Six (12%) subjects were excluded from the analysis because of the inability to obtain a reliable photoplethysmographic signal. No complications were observed. A significant relationship was found between absolute values of photoplethysmographic and radial systolic (r(2)=0.56, P<0.001), diastolic (r(2)=0.61, P<0.001), and mean (r(2)=0.77, P<0.001) arterial pressures. A significant relationship was also found between transpulmonary thermodilution and Nexfin CI absolute values (r(2)=0.33, P<0.001). Bias, precision, and limits of agreement between the mean photoplethysmographic and radial arterial pressures were 4.6 (95% confidence interval: 3.7-5.5), 6.5, and -17.3 to 8.1 mm Hg, respectively. The percentage error between transpulmonary thermodilution and the Nexfin for CI measurement was 50%. CONCLUSIONS: The Nexfin device is safe, convenient, and reliable in measuring continuous non-invasive arterial pressure but not interchangeable with transpulmonary thermodilution to monitor CI.

Effect of lipopolysaccharide, cytokines, and catecholamines on brain natriuretic peptide release from human myocardium.

BACKGROUND: During sepsis and septic shock, elevated plasma concentrations of brain natriuretic peptide (BNP) have been reported but may be related to several underlying mechanisms. The aim of the present experimental study was to investigate the effect of lipopolysaccharide (LPS), tumor necrosis factor α (TNF-α), interleukin 1ß (IL-1ß), interleukin 6 (IL-6), dobutamine (Dobu), epinephrine (Epi), and norepinephrine (Nor) on BNP synthesis by atrial human myocardium in vitro. METHODS: After the approval of local ethics committee, right atrial appendages were obtained during cannulation for cardiac surgery and pinned in a isolated organ bath containing 15 ml of Tyrode's modified solution. Preparations were oxygenated, maintained at 36 ± 0.5°C and stimulated at a frequency of 1 Hz. A 60-min equilibration period was followed by 180-min exposure to 1 µM endothelin 1 (ET-1; n = 9), 20,000 pg/ml TNF-α (n = 10), 1000 pg/ml IL-1ß (n = 10), 5000 pg/ml IL-6 (n = 10), 10,000 pg/ml LPS (n = 10), 100 µM Epi (n = 9), 100 µM Nor (n = 10), and 100 µM Dobu (n = 8). No product was added in Control group (n = 10). Two BNP dosages were performed: the first after 60 min of stabilization and the second after 180 min of stimulation. Absolute and relative changes in BNP concentration were compared between groups. RESULTS: Exposure to ET-1 significantly increased BNP release as compared with Control group. Dobu, Epi, Nor, and LPS significantly increased BNP concentration but not TNF-α, IL-1ß, or IL-6. CONCLUSIONS: In vitro, LPS, Dobu, Epi, and Nor induced BNP synthesis by human atrial myocardium.

Mechanisms involved in the desflurane-induced post-conditioning of isolated human right atria from patients with type 2 diabetes.

BACKGROUND: Desflurane triggers post-conditioning in the diabetic human myocardium. We determined whether protein kinase C (PKC), mitochondrial adenosine triphosphate-sensitive potassium (mitoK(ATP)) channels, Akt, and glycogen synthase kinase-3ß (GSK-3ß) were involved in the in vitro desflurane-induced post-conditioning of human myocardium from patients with type 2 diabetes. METHODS: The isometric force of contraction (FoC) of human right atrial trabeculae obtained from patients with type 2 diabetes was recorded during 30 min of hypoxia followed by 60 min of reoxygenation. Desflurane (6%) was administered during the first 5 min of reoxygenation either alone or in the presence of calphostin C (PKC inhibitor) or 5-hydroxydecanoate (5-HD) (mitoK(ATP) channel antagonist). Phorbol 12-myristate 13-acetate (PKC activator) and diazoxide (a mitoK(ATP) channel opener) were superfused during early reoxygenation. The FoC at the end of the 60 min reoxygenation period was compared among treatment groups (FoC(60); mean and sd). The phosphorylation of Akt and GSK-3ß was studied using western blotting. RESULTS: Desflurane enhanced the recovery of force [FoC(60): 79 (3)% of baseline] after 60 min of reoxygenation when compared with the control group (P>0.0001). Calphostin C and 5-HD abolished the beneficial effect of desflurane-induced post-conditioning (both P<0.0001). Phorbol 12-myristate 13-acetate and diazoxide enhanced the FoC(60) when compared with the control group (both P<0.0001). Desflurane increased the level of phosphorylation of Akt and GSK-3ß (P<0.0001). CONCLUSIONS: Desflurane-induced post-conditioning in human myocardium from patients with type 2 diabetes was mediated by the activation of PKC, the opening of the mitoK(ATP) channels, and the phosphorylation of Akt and GSK-3ß.

Continuous administration of remifentanil and sufentanil induces cardioprotection in human myocardium, in vitro.

BACKGROUND: Remifentanil and sufentanil are widely used opioids during general anaesthesia for cardiac and non-cardiac surgery. This study was conducted to evaluate the hypothesis that the continuous administration of remifentanil and sufentanil, at clinically relevant concentrations, could provide protection of human myocardium, in vitro, against hypoxia-reoxygenation injury. METHOD: Isometrically contracting isolated human right atrial trabeculae were exposed to 30 min of hypoxia and 60 min of reoxygenation. In separate groups, remifentanil at 10(-11), 10(-10), 10(-9), or sufentanil at 10(-11), 10(-10), 10(-9) M were administered 10 min before hypoxia until the end of the experiment. The force of contraction (FoC) of trabeculae was recorded continuously. Developed force was compared (mean ± standard deviation) between the groups using a variance analysis and post hoc tests. RESULTS: At the end of the 60-min reoxygenation, remifentanil 10(-11) M (FoC: 82 ± 7% of baseline), 10(-10) M (FoC: 78 ± 5% of baseline), 10(-9) M (FoC: 80 ± 4% of baseline) and sufentanil 10(-11) M (FoC: 78 ± 8% of baseline), 10(-10) M (FoC: 83 ± 6% of baseline), 10(-9) M (FoC: 83 ± 8% of baseline) enhanced the recovery of FoC as compared with the control group (53 ± 9% of baseline, P<0.0001). CONCLUSIONS: Remifentanil and sufentanil, at clinically relevant concentrations, confer cardioprotection of human myocardium against hypoxia reoxygenation, in vitro.

Sevoflurane- and desflurane-induced human myocardial post-conditioning through Phosphatidylinositol-3-kinase/Akt signalling.

BACKGROUND: The role of phosphatidylinositol-3-kinase (PI3K) in sevoflurane- and desflurane-induced myocardial post-conditioning remains unknown. METHODS: We recorded isometric contraction of isolated human right atrial trabeculae (oxygenated Tyrode's at 34 degrees C, stimulation frequency 1 Hz). In all groups, a 30-min hypoxic period was followed by a 60-min reoxygenation period. At the onset of reoxygenation, muscles were exposed to 5 min of sevoflurane 1%, 2%, and 3%, and desflurane 3%, 6%, and 9%. In separate groups, sevoflurane 2% and desflurane 6% were administered in the presence of 100 nM wortmannin, a PI3K inhibitor. Recovery of force after the 60-min reoxygenation period was compared between groups (mean +/- SD). RESULT: As compared with the Control group (49 +/- 7% of baseline) PostC by sevoflurane 1%, 2%, and 3% (78 +/- 4%, 79 +/- 5%, and 85 +/- 4% of baseline, respectively) and desflurane 3%, 6%, and 9% (74 +/- 5%, 84 +/- 4%, and 86 +/- 11% of baseline, respectively) enhanced the recovery of force. This effect was abolished in the presence of wortmannin (56 +/- 5% of baseline for sevoflurane 2%+wortmannin; 56 +/- 3% of baseline for desflurane 6%+wortmannin). Wortmannin alone had no effect on the recovery of force (57 +/- 7% of baseline). CONCLUSION: In vitro, sevoflurane and desflurane post-conditioned human myocardium against hypoxia through activation of phosphatidylinositol-3-kinase.

Endovenous laser procedure in a clinic room: feasibility and side effects study of 1,700 cases.

OBJECTIVES: To assess the feasibility of saphenous veins ablation by laser in a clinic room. To study immediate and short term (1 to 6 months) complications and to pinpoint those that could be directly linked to this environment. Efficacy of the technique should also be documented. METHODS: Retrospective study (22 centres) carried out in France and Switzerland. Patients with insufficiency of great saphenous vein (GSV) or small saphenous vein (SSV). Clinical stages of clinical, [corrected] aetiological, anatomical and pathophysiological classification (CEAP) C2 to C6. Endovenous laser procedures were performed outside an operating theatre, under local anaesthesia and without high ligation. Efficacy criteria: occlusion of the vein and disappearance of the pathological reflux (duplex scan assessment). The side effects and complications were studied. RESULTS: A total of 1703 procedures (1422 patients) were performed; 74% of the patients were women. [corrected] The mean age of the patients was 57. A total of 1394 GSV and 309 SSV were treated (mean diameters 7.2 mm and 6.4 mm, respectively). Overall success level was 97% and mean length of veins treated was 40 cm for GSV and 21 cm for SSV. Energy applied in joules per centimeter was homogenous (mean and median 64 for GSV and 65 for SSV). Complications were rare and 'simple' apart from one pulmonary embolism which occurred 10 days after a GSV procedure, although no deep vein thrombus was found. A total of two infections were observed: one was an infection localized at the site of access and the other was erysipelas. [corrected] CONCLUSION: Except 2 limited infections (0.1%), this large retrospective study of laser procedures performed outside the operating theatre did not reveal any significant specific complications as regards the environment required. The efficacy results were equivalent to those found in the literature. Regarding cost and constraints induced by operating theatre environment, the clinic room should be able to offer an easier and economic alternative option for saphenous veins ablation with laser [corrected]

Video recording of cardiac surgical procedures: what the surgeon needs to know.

In the past, rudimentary devices were used to record surgical operations. Currently, the introduction of technologic advances such as high-definition television and the miniaturization of high-resolution digital video cameras provides an opportunity for making significantly enhanced surgical records. These enhancements, coupled with the recent advances in telemedicine and surgical simulation, will improve cardiac surgery training and skill acquisition, decrease operative times and costs, minimize morbidity, and improve overall patient care. The present paper provides a discussion of the media technology offered to surgeons for recording a surgical procedure on video. Hardware technology, including different types of cameras and analogical or digital post processing methods, are reviewed with a surgical ''eye''. This ''how to'' paper provides practical suggestions to surgeons in order to enhance surgical video recording.

[Pulmonary mucormycosis in a multiple-trauma patient]. / Mucormycose pulmonaire chez un patient polytraumatisé.

Mucormycosis are opportunist infections occurring usually among predisposed patients. We report a case of an 18-year-old male with a severe thoracic trauma who developed an Absidia infection on his contused pulmonary parenchyma, without presenting the usual risk factors (diabetes mellitus, immunodeficiency). The early diagnosis using bronchoscopy has probably improved the outcome by allowing a faster treatment. After 18-months, the infectious process resolved thanks to a combination of a medical treatment composed of high-dose amphotericin B lipid formulation, itraconazole and a complementary surgical treatment.

[Phaeochromocytoma as an unusual aetiology of cardiogenic shock]. / Le phéochromocytome comme cause inhabituelle de choc cardiogénique.

The authors reported a case involving a young patient with a cardiogenic shock associated to an acute pulmonary oedema. According to the seriousness of the shock, an external ventricular assist device (VAD) was initially inserted and replaced thereafter because of the cardiovascular instability, by an external pneumatic biventricular assist device. A cardiogenic shock induced by an acute adrenergic myocarditis due to a phaeochromocytoma was diagnosed. The patient was weaned from the VAD on day 84 and was scheduled for elective surgery of the phaeochromocytoma on day 93. The authors discussed the time of the surgery according to the anticoagulation therapy necessary to the VAD and the necessary caution taken if a cardiogenic shock appeared around surgery.

Isoflurane may not influence postoperative cardiac troponin I release and clinical outcome in adult cardiac surgery.

BACKGROUND AND OBJECTIVE: Isoflurane has been shown experimentally to protect the myocardium against infarction but the clinical relevance of these findings is not yet well established. We therefore evaluated the effects of isoflurane administration before cardiopulmonary bypass (CPB) on postoperative cardiac troponin I (cTnI) release and clinical outcome in a large group of adult patients scheduled for cardiac surgery. METHODS: Three hundred and fifty-nine consecutive patients were included prospectively in an open observational study and divided into two groups according to whether or not isoflurane was administered before CPB. Postoperative cTnI release, in-hospital mortality, time to discharge from hospital, time to extubation and non-fatal postoperative cardiac events (number of internal cardioversions, need for inotropic support, ischaemic events, dysrhythmias and/or conduction abnormalities) were recorded. RESULTS: Two hundred and twenty-one (62%) patients did not receive isoflurane and 138 (38%) received isoflurane (1.3% [1.0-1.8%] minimum alveolar concentration over 22 [15-331 min). Postoperative cTnI release was not significantly different between the control and isoflurane groups (5.9 [1.0-336.8] vs. 6.0 [1.5-392.0] ng mL(-1), P = 0.88). No significant differences were found in non-fatal cardiac events (63% vs. 57%, P = 0.22) and in-hospital mortality (1.8% vs. 1.4%, P = 0.79) between the control and isoflurane groups. CONCLUSIONS: No significant effect was observed on postoperative cTnI release and in-hospital outcome when isoflurane was added to standardized intravenous anaesthesia before CPB in adult patients undergoing cardiac surgery.

[Feasibility of ambulatory endovenous laser for the treatment of greater saphenous varicose veins: one-month outcome in a series of 20 outpatients]. / Peut-on traiter les grandes saphènes variqueuses par laser endoveineux en ambulatoire? Résultats á l mois d'une étude de faisabilité sur 20 patients traités en salle de consultation.

The purpose of this feasibility study was to demonstrate that endovenous laser can be a useful alternative to conventional surgery for ambulatory treatment of advanced varicose veins. We assessed an open, non-randomized series of patients treated in one center by the same operator. The study protocol was approved by the local ethics committee. Twenty patients with stage II or III varicose veins in the Porter classification gave their informed consent to participate in the study. The patients were treated with endovenous laser by the first author in the outpatient clinic of the Henri Mondor University Hospital vascular surgery department. All procedures were conducted under local anesthesia. A 980 nm laser diode optic fiber was introduced into the vein percutaneously. Laser beams were fired from the sapheno-femoral junction to just under the genu, withdrawing the fiber 3 mm every 1.5 sec. Clinical evaluation with a quality-of-life questionnaire and duplex-scan was performed at days 3, 8 and 30 post-op. Complete occlusion and retraction of the treated vein was observed at day 3 and 30, from the point of introduction to the sapheno-femoral junction in 18 of the 20 patients. The branches of the greater saphenous vein remained patent with physiological flow in the stump which remained patent 1 to 2 cm upstream from the sapheno-femoral junction. The length of the patent stump dependend on the level of the anterior or posterior branch. There were no adverse effects related to the local anesthesia. Pain was low to mild during treatment and the days following the procedure, requiring 8 tablets of acetominophen at most. Hematomas were minimal and had completely resolved by the end of the first month. No work stoppage was required for the 14 patients with occupational activities. There were no cases of deep or superficial vein thrombosis. Complete occlusion and retraction of the varicose vein at one month suggests this treatment has a long-lasting effect. Long-term evaluation is required. Treatment of advanced varicose veins with endovenous laser can be an alternative to surgical treatment providing the advantage of outpatient ambulatory treatment.

Less invasive radial artery harvest.

BACKGROUND: Recent studies have sparked a renewed interest in the use of autogenous radial arteries in coronary operations. Some concerns have been found about sequelae of conventional harvesting. A less invasive technique for radial artery harvesting has been proposed by others using endoscopic devices. This technique is time consuming, needs expensive instrumentation and an important learning curve. METHODS: A new less invasive approach for radial harvesting has been developed with a light assisted retractor under direct vision. A small skin incision, median in the forearm, is followed by dissection of the proper plane of the artery. A subcutaneous tunnel is created around the vessel and all the branches are ligated or clipped. The dissection of the pedicle under the skin is completed with the aid of a modified light assisted retractor, originally designed for the saphenous vein harvesting. The incision is closed after heparin reversal with a small redon as drainage. RESULTS: A preliminary serie of 15 patients have been operated with this technique. In all patients the radial artery was patent and functional at the postoperative angiography. Morbidity included only a light hematoma at the beginning of our experience. CONCLUSION: This less invasive technique for the radial artery harvesting appears to be an excellent surgical compromise between the open technique and the endoscopic procedure; it is easy to perform, the learning curve is acceptable and it offers an excellent aesthetic result.

[Intraoperative memory. A study of its incidence in general anesthesia in 326 patients]. / Mémorisation peropératoire. Evaluation de l'incidence chez 326 patients au décours d'une anesthésie générale.

OBJECTIVES: Measuring the incidence of intraoperative recall in our hospital. STUDY DESIGN: Prospective study. PATIENTS AND METHODS: Three hundred and twenty-six patients who underwent a general anaesthesia for elective surgery on selected sites (general, urology, ORL, gynaecology and obstetrical, vascular and cardiac, thoracic) were interviewed on the first or the second postoperative day using a standard questionnaire. When recall was suspected, the anaesthetist was consulted and the anaesthetic record was looked at in order to evaluate the authenticity of any recollections. RESULTS: Four patients mentioned an anomaly evoking intra-operative recall. The reduction in the anaesthetic level would explain authentic recollection for one patient. The recollection of another patient could not be truly verified. The site was the same for these two cases and the anaesthetic protocol for digestive surgery comprised curare and droperidol. The recollections for the two other patients did not correspond to the intraoperative period. The incidence of this phenomenon on the totality of sites was 0.6 per cent. CONCLUSION: This result conforms to other studies. This phenomenon is a quality indicator, but probably under estimated. Although retrospective, this evaluation is quick and easy. This research in post-operative period should be systematic in order to find the reason and to propose an early course of action for these patients. An analysis of the anaesthetic protocol is necessary when the frequency of intraoperative recall is too high.

The in vitro effects of remifentanil, sufentanil, fentanyl, and alfentanil on isolated human right atria.

Because some clinical studies have suggested that opioids used in anesthesia may have different deleterious hemodynamic effects, we compared the direct myocardial effects of cumulative concentrations of remifentanil, sufentanil, fentanyl, and alfentanil on inotropic and lusitropic variables of isolated human myocardium in vitro. Human right atrial trabeculae, obtained from patients scheduled for coronary bypass surgery or aortic valve replacement, were suspended vertically in an oxygenated (95% oxygen/5% CO(2)) Tyrode's modified solution ([Ca(2+)](o) = 2.0 mM, 37 degrees C, pH 7.40, stimulation frequency 1 Hz). The effects of cumulative concentrations (10(-11), 10(-10), 10(-9), 10(-8), 10(-7), and 10(-6) M) of remifentanil (n = 8), sufentanil (n = 8), fentanyl (n = 8), and alfentanil (n = 8) on inotropic and lusitropic variables of isometric twitches were measured. Remifentanil, sufentanil, and fentanyl did not modify active isometric force and peak of the positive force derivative as compared with the Control group. Alfentanil induced a dose-dependent decrease in active isometric force and peak of the positive force derivative. This effect was abolished in the presence of [Ca(2+)](o) = 4.0 mM. None of these opioids altered lusitropic variables.

In vitro effects of desflurane, sevoflurane, isoflurane, and halothane in isolated human right atria.

BACKGROUND: Direct myocardial effects of volatile anesthetics have been studied in various animal species in vitro. This study evaluated the effects of equianesthetic concentrations of desflurane, sevoflurane, isoflurane, and halothane on contractile parameters of isolated human atria in vitro. METHODS: Human right atrial trabeculae, obtained from patients undergoing coronary bypass surgery, were studied in an oxygenated (95% O2-5% CO2) Tyrode's modified solution ([Ca2+]o = 2.0 mM, 30 degrees C, stimulation frequency 0.5 Hz). The effects of equianesthetic concentrations (0.5, 1, 1.5, 2, and 2.5 minimum alveolar concentration [MAC]) of desflurane, sevoflurane, isoflurane, and halothane on inotropic and lusitropic parameters of isometric twitches were measured. RESULTS: Isoflurane, sevoflurane, and desflurane induced a moderate concentration-dependent decrease in active isometric force, which was significantly lower than that induced by halothane. In the presence of adrenoceptor blockade, the desflurane-induced decrease in peak of the positive force derivative and time to peak force became comparable to those induced by isoflurane. Halothane induced a concentration-dependent decrease in time to half-relaxation and a contraction-relaxation coupling parameter significantly greater than those induced by isoflurane, sevoflurane and desflurane. CONCLUSIONS: In isolated human atrial myocardium, desflurane, sevoflurane, and isoflurane induced a moderate concentration-dependent negative inotropic effect. The effect of desflurane on time to peak force and peak of the positive force derivative could be related to intramyocardial catecholamine release. At clinically relevant concentrations, desflurane, sevoflurane, and isoflurane did not modify isometric relaxation.