Myotonia congenita and regional anaesthesia with peripheral nerve stimulation: a case report.

Myotonia congenita is a rare disorder caused by a defect in the skeletal muscle chloride channel function, which may cause sustained membrane depolarisation. We report a case regarding a 52-year-old man affected by this muscular pathology and scheduled for shoulder surgery that was performed under sedation and peripheral nerve block. The international literature does not elucidate clear preference toward a particular anaesthesia technique, but we believe that in this setting, regional anaesthesia and complete monitoring should be preferentially utilized when possible. In any case, the anaesthesia plan should be prudent and avoid exposure to known dangerous anaesthetics.

Rheumatoid and psoriatic knee synovitis: clinical, grey scale, and power Doppler ultrasound assessment of the response to etanercept.

OBJECTIVE: To determine the effect of tumour necrosis factor alpha (TNFalpha) blockade with etanercept in refractory knee joint synovitis (KJS) in rheumatoid and psoriatic arthritis, by local and systemic disease activity assessment and combined grey scale and power Doppler ultrasonographic monitoring. METHODS: 27 knees affected by rheumatoid KJS (n = 12) and psoriatic KJS (n = 8) were assessed before receiving treatment and at 3 and 12 months' follow up. Time dependent clinical changes in disease activity were monitored by C reactive protein, erythrocyte sedimentation rate (ESR), global health status (GHS), and Ritchie (RAI) and knee joint articular (KJAI) indices; synovial changes were monitored by ultrasonographic and power Doppler indices for grey scale synovial thickening and for distinct intrasynovial vessel power Doppler flow configurations (fluid/synovium interface (F/SI-PD) and pannus/cartilage interface (P/CI-PD)). Interobserver and intraobserver variability of grey scale and power Doppler ultrasonographic was evaluated. Response to treatment was assessed by analysis of variance for repeated measures on clinical and ultrasonographic variables. RESULTS: Rapid (3 months) reduction in F/SI-PD flow (p<0.001), parallel to reductions of C reactive protein (p<0.05), ESR (p<0.001), KJAI (p<0.002), RAI, and GHS (p<0.001), was sustained at 12 months when it was accompanied by reduction in both synovial thickening and P/CI-PD flow (p<0.001). No differences (ANOVA) were noted at baseline or at 12 months in clinical and ultrasonographic variables between either the rheumatoid or the psoriatic KJS groups. CONCLUSION: Grey scale and power Doppler ultrasonography are reliable measures of long term change in rheumatoid and psoriatic KJS disease activity in response to anti-TNFalpha treatment with etanercept.

Tranexamic acid in primary CABG surgery: high vs low dose.

AIM: Prophylactic administration of tranexamic acid decreases bleeding and transfusions after cardiac procedures but it is still unclear what the best dose and the most appropriate timing to get the best results are. METHODS: We enrolled 250 patients scheduled for elective, primary coronary revascularization. They were randomly divided into 2 groups. Group H received tranexamic 30 mg x kg(-1) soon after the induction of anaesthesia and a further same dose was added to the prime solution of cardiopulmonary bypass (CPB). Group L received tranexamic acid 15 mg x kg(-1) after systemic heparinization followed by an infusion of 1 mg x kg(-1) h(-1) till the end of the operation. Transfusions of bank blood products, bleeding in the postoperative period and coagulation profile were recorded. RESULTS: We did not find any difference between the groups either with respect to transfusion requirements or with respect to blood loss. CONCLUSION: For elective, first time coronary artery bypass surgery, both dosages of tranexamic acid are equally effective. Theoretically, it seems safer to administer it when patients are protected from thrombus formation by full heparinization.

Tranexamic acid in aortic valve replacement.

OBJECTIVE: To assess the relative efficacy of tranexamic acid compared with a control group to decrease bleeding and transfusion requirements in a uniform population undergoing aortic valve replacement. DESIGN: Prospective, randomized, double-blind study. SETTINGS: University hospital. PARTICIPANTS: Adult cardiac surgery patients (n = 300). INTERVENTIONS: Patients were randomized into 2 groups to receive either a total of 5 g of tranexamic acid or a saline solution. Bleeding in the postoperative period, transfusions of bank blood products, coagulation profile, intensive care unit stay, and hospital length of stay were recorded. MEASUREMENTS AND MAIN RESULTS: Postoperative bleeding in patients treated with tranexamic acid was significantly lower compared with the control group (p < 0.0001). Packed red blood cells and fresh frozen plasma usage were reduced in the tranexamic acid group compared with the control group (p = 0.0095 and p < 0.0001). Only 24.5% of tranexamic acid patients received blood products versus 45% of control patients (p < 0.01). There was no significant difference in hematologic and coagulation profiles after the operation between the groups. CONCLUSIONS: Tranexamic acid reduces postoperative blood loss and transfusion requirements in elective aortic valve replacement.

[Alterations in left ventricular-arterial coupling and mechanical efficiency produced by remifentanil during cardiac anesthesia]. / Variazioni dell'accoppiamento ventricolo arterioso e dell'effecienza meccanica con l'impiego del remifentanil durante anestesia cardiaca.

BACKGROUND: The performance of the cardiovascular system depends on the interaction of the left ventricle and arterial system. An appropriate coupling of these two components is important to quantify the efficiency of myocardium, determined by Ea/Ees. The end-systolic elastance of the left ventricle (Ees) is an index of contractility which is independent of loading conditions, while the arterial end-systolic elastance (Ea) represents the properties of the arterial system. The aim of our study is to investigate the effects of a bolus of remifentanil (R) on myocardial efficiency. METHODS: In a period of 3 months we examined prospectively the effects of R in a group of 12 patients, ASA IV, 49-75 years old, submitted intraoperatively to cardiac anesthesia for revascularization of myocardium. After induction of anesthesia and before the beginning of surgery, a bolus of R (1 mg/kg/min) was administered and with the use of trans-esophageal echocardiography we determined both the left ventricle end-systolic volume and end-diastolic volume to assess, with different end-systolic arterial pressures, the ventricle elastance (Ees) and arterial elastance (Ea) before and after administration of R. RESULTS: The present findings indicate that R decreases the ventricular elastance from 6.07 mmHg/ml/m2 to 4.8, with a less decrease of arterial elastance from 3.69 mmHg/ml/m2 to 3.07. CONCLUSIONS: The results suggest that R preserves a good left ventricular-arterial coupling and mechanical efficiency, despite a little increase of coupling, probably because ventricular and arterial properties are so matched as to minimize the systolic work of the left ventricle.

[The value of transesophageal echocardiography during cardiac surgery]. / Ruolo dell'ecocardiografia transesofagea durante interventi cardiochirurgici.

The intraoperative use of two-dimensional transesophageal echocardiography has proved effective in the evaluation of left ventricular function after heart operations, in the assessment of adequacy of valve replacement or repair techniques, and in the detection of intracardiac air bubbles before discontinuation of cardiopulmonary bypass. We report here a patient in whom the presence of a tumor mass in the left leaflet of the aortic valve, which was missed at preoperative transthoracic echocardiogram and would have most likely been the cause of systemic embolization, was diagnosed by two-dimensional transesophageal echocardiographic monitoring. We hope that this experience may support the use of two-dimensional transesophageal echocardiography during cardiac surgery.

Postoperative sedation with propofol infusion: haemodynamics and pharmacokinetics.

OBJECTIVE: This study was designed to investigate the haemodynamic response and pharmacokinetics of a low-dose propofol continuous infusion in providing sedation in patients who required mechanical ventilation after coronary artery bypass grafting surgery. PATIENTS: 22 male patients, aged between 45 and 65 years, were evaluated in an open, uncontrolled study. INTERVENTIONS: At the end of the surgical procedure, a low-dose (1 mg/kg/h) propofol infusion was started and adjusted to optimise sedation according to the Ramsay scale. The mean propofol infusion rate was 1.42 +/- 0.4 mg/kg/h. MAIN OUTCOME MEASURES: Electrocardiogram, systemic and pulmonary arterial pressure, and central venous pressure were monitored continuously. Left ventricular shortening fraction was calculated by transoesophageal echocardiography. Propofol plasma levels were calculated in 10 patients to evaluate the pharmacokinetics. RESULTS: Throughout the duration of the study all patients were haemodynamically stable. Sedation was maintained for 363 +/- 244 minutes and was adequate in all patients. The clinical recovery time (postsedation responsiveness) was 15.7 +/- 6.2 minutes, after infusion suspension. There was no correlation between propofol plasma levels or propofol infusion rate and the depth of sedation (respectively, r = 0.39 and r = 0.23), while there was a good correlation (r = 0.62) between propofol infusion rate and plasma levels. Open two-compartment model pharmacokinetics were demonstrated. CONCLUSION: Low-dose propofol infusion (1 to 2 mg/kg/h) proved to be well tolerated and effective in maintaining sedation after cardiac surgery. Sedation was quickly obtained without a propofol loading dose; steady-state plasma concentrations of 0.6 to 0.8 mg/L were rapidly achieved. Propofol pharmacokinetics ensure rapid clearance with rapid clinical recovery.

Intraoperative plasmapheresis in cardiac surgery.

OBJECTIVE: To determine the effects of intraoperative plasmapheresis on total transfusion requirements, mediastinal drainage, and coagulation. DESIGN: The trial was prospective, randomized, and controlled. SETTING: Inpatient cardiac surgery at a university medical center. PARTICIPANTS: Two hundred ninety-three consecutive patients undergoing cardiac surgery requiring cardiopulmonary bypass. INTERVENTIONS: Intraoperative plasmapheresis (IP) was performed in 147 patients before heparinization; platelet-rich plasma was reinfused immediately after heparin reversal. MEASUREMENTS AND MAIN RESULTS: Mediastinal chest tube drainage during the first 12 postoperative hours was significantly less in the IP group (p = 0.022), but no difference was noted in total postoperative blood loss between the two groups. The amount of packed red cells and fresh frozen plasma transfused to the IP group in the intensive care unit was significantly lower (p = 0.02, p = 0.002, respectively); 51.4% of patients required no transfusion compared with the control group (34.5%) (p = 0.006). No differences were noted for data collected in the intensive care unit in terms of the mean duration of chest tube drainage, ventilator time, or any hematologic variables at baseline or at any subsequent time in the study. CONCLUSIONS: After cardiac surgery, intraoperative plasma-pheresis reduces early postoperative bleeding and decreases the need for homologous transfusions.

Propofol-fentanyl versus isoflurane-fentanyl anesthesia for coronary artery bypass grafting: effect on myocardial contractility and peripheral hemodynamics.

To avoid intraoperative awareness and postoperative respiratory depression from high-dose opioid anesthesia, propofol (P), or isoflurane (I) has been combined with moderate-dose opioid with varying results. However, the effects of both P and I on myocardial contractility and left ventricular afterload have not been completely quantified. The end-systolic pressure-diameter relationship (ESPDR) of the left ventricle (LV) is a reliable method to quantitatively assess LV contractility because it is relatively independent of changes in preload and incorporates afterload changes. The purpose of this study was to quantify the cardiodynamic effects of propofol-fentanyl (PF) anesthesia in comparison with isoflurane-fentanyl (IF) anesthesia in patients undergoing coronary artery bypass grafting (CABG). Thirty patients with normal or moderately impaired LV function (ejection fraction > or = 40% with LV end-diastolic pressure < or = 18 mmHg, no preoperative akinesia or dyskinesia) undergoing elective CABG were studied. After premedication with flunitrazepam, 2 mg orally, all patients were induced with thiopental, 1 mg/kg, fentanyl, 20 micrograms/kg, and vecuronium, 0.1 mg/kg, and were ventilated with oxygen/air (F(1)O2 0.6). Anesthesia was maintained throughout the procedure with a zero-order intravenous (IV) continuous infusion of P, 3 mg/kg/h (PF group), or with isoflurane inhalation of 0.6% (IF group), supplemented by intermittent boluses (5 micrograms/kg) of fentanyl (up to a total maintenance dose of 30 micrograms/kg). After intubation, a cross-section of the LV was visualized by two-dimensional transesophageal echocardiography and an m-mode echocardiogram was obtained at the maximum anterior-posterior diameter. The radial artery pressure tracing and the ECG were simultaneously recorded with the M mode.(ABSTRACT TRUNCATED AT 250 WORDS)