Insulin does not stimulate ß-alanine transport into human skeletal muscle.

To test whether high circulating insulin concentrations influence the transport of ß-alanine into skeletal muscle at either saturating or subsaturating ß-alanine concentrations, we conducted two experiments whereby ß-alanine and insulin concentrations were controlled. In experiment 1, 12 men received supraphysiological amounts of ß-alanine intravenously (0.11 g·kg-1·min-1 for 150 min), with or without insulin infusion. ß-Alanine and carnosine were measured in muscle before and 30 min after infusion. Blood samples were taken throughout the infusion protocol for plasma insulin and ß-alanine analyses. ß-Alanine content in 24-h urine was assessed. In experiment 2, six men ingested typical doses of ß-alanine (10 mg/kg) before insulin infusion or no infusion. ß-Alanine was assessed in muscle before and 120 min following ingestion. In experiment 1, no differences between conditions were shown for plasma ß-alanine, muscle ß-alanine, muscle carnosine and urinary ß-alanine concentrations (all P > 0.05). In experiment 2, no differences between conditions were shown for plasma ß-alanine or muscle ß-alanine concentrations (all P > 0.05). Hyperinsulinemia did not increase ß-alanine uptake by skeletal muscle cells, neither when substrate concentrations exceed the Vmax of ß-alanine transporter TauT nor when it was below saturation. These results suggest that increasing insulin concentration is not necessary to maximize ß-alanine transport into muscle following ß-alanine intake.

Effects of ß-alanine and sodium bicarbonate supplementation on the estimated energy system contribution during high-intensity intermittent exercise.

The effects of ß-alanine (BA) and sodium bicarbonate (SB) on energy metabolism during work-matched high-intensity exercise and cycling time-trial performance were examined in 71 male cyclists. They were randomised to receive BA + placebo (BA, n = 18), placebo + SB (SB, n = 17), BA + SB (BASB, n = 19), or placebo + placebo (PLA, n = 18). BA was supplemented for 28 days (6.4 g day-1) and SB (0.3 g kg-1) ingested 60 min before exercise on the post-supplementation trial. Dextrose and calcium carbonate were placebos for BA and SB, respectively. Before (PRE) and after (POST) supplementation, participants performed a high-intensity intermittent cycling test (HICT-110%) consisting of four 60-s bouts at 110% of their maximal power output (60-s rest between bouts). The estimated contribution of the energy systems was calculated for each bout in 39 of the participants (BA: n = 9; SB: n = 10; BASB: n = 10, PLA: n = 10). Ten minutes after HICT-110%, cycling performance was determined in a 30-kJ time-trial test in all participants. Both groups receiving SB increased estimated glycolytic contribution in the overall HICT-110%, which approached significance (SB: + 23%, p = 0.068 vs. PRE; BASB: + 18%, p = 0.059 vs. PRE). No effects of supplementation were observed for the estimated oxidative and ATP-PCr systems. Time to complete 30 kJ was not significantly changed by any of the treatments, although a trend toward significance was shown in the BASB group (p = 0.06). We conclude that SB, but not BA, increases the estimated glycolytic contribution to high-intensity intermittent exercise when total work done is controlled and that BA and SB, either alone or in combination, do not improve short-duration cycling time-trial performance.

Feasibility and Impact of Focused Intraoperative Transthoracic Echocardiography on Management in Thoracic Surgery Patients: An Observational Study.

OBJECTIVES: Intraoperative focused transthoracic echocardiography (TTE) is feasible and has an effect on the management of hemodynamically unstable surgical patients. Furthermore, in noncardiac thoracic surgery, TTE might provide additional information for hemodynamic treatment. Transthoracic accessibility during thoracic surgical interventions is assumed to be difficult. For patients positioned on their right side, a modified subcostal transthoracic view might be helpful. DESIGN: A prospective observational study. SETTING: Single-center university hospital. PARTICIPANTS: The study comprised 105 consecutive patients undergoing noncardiac thoracic surgery. INTERVENTIONS: Focused TTE was performed during anesthetic induction after intubation for mechanical ventilation. Intraoperative focused TTE, after positioning and draping for surgery, was attempted again for all 105 patients. Changes in patient management due to the results of the TTE were documented and analyzed. MEASUREMENTS AND MAIN RESULTS: Presurgical TTE with mechanical ventilation was applied successfully in 98.1% of 105 patients. Intraoperative imaging was successful in 90 patients (85.7%). Results of intraoperative TTE led to the modification of perioperative management in 39 patients (37.1%), 20 (22.0%) of these during surgery. CONCLUSIONS: TTE in noncardiac thoracic surgery is feasible using a modified subcostal view and has an effect on hemodynamic management in a considerable number of patients.

Impact of Focused Intraoperative Transthoracic Echocardiography by Anesthesiologists on Management in Hemodynamically Unstable High-Risk Noncardiac Surgery Patients.

OBJECTIVES: Focused transthoracic echocardiography (TTE) is used perioperatively for surgical patients. Intraoperative application of TTE is feasible, but its benefits remain unclear. The intention of this study was to investigate the effect of intraoperative TTE on the management of high-risk noncardiac surgery patients. DESIGN: A prospective interventional study. SETTING: Single-center university hospital. PARTICIPANTS: Fifty consecutive hemodynamically unstable high-risk patients anesthetized for noncardiac surgery. INTERVENTIONS: Focused TTE was performed on hemodynamically unstable anesthetized patients whenever circulatory instability (defined as hypotension or low cardiac output) occurred intraoperatively. A cardiac output monitoring system using pulse contour analysis was established before induction of anesthesia. The intended therapy for stabilizing the patient was documented; however, the management actually administered was guided by the results of the TTE. Differences between the 2 lines of management were documented and analyzed. MEASUREMENTS AND MAIN RESULTS: Intraoperative TTE was applied successfully in all 50 unstable patients. In 33 patients (66%, 95% confidence interval, 52.11-77.61) TTE led to a change of management. Altogether, 82 episodes of hemodynamic instability were recorded, including 38 episodes (46.34%, 95% confidence interval, 35.95-57.06) in which TTE led to a change of treatment. The most common pathologic finding was hypovolemia (66%); in contrast, in 22%, right-heart overload or right-heart failure (4%) was detected. CONCLUSIONS: Focused TTE by anesthesiologists can provide new information that may alter the hemodynamic management of unstable high-risk noncardiac surgery patients in the operating room.

Beta-alanine supplementation enhances judo-related performance in highly-trained athletes.

OBJECTIVES: In official judo competitions, athletes usually engage in 5-7 matches in the same day, performing numerous high-intensity efforts interspersed by short recovery intervals. Thus, glycolytic demand in judo is high and acidosis may limit performance. Carnosine is a relevant intracellular acid buffer whose content is increased with beta-alanine supplementation. Thus, we hypothesized that beta-alanine supplementation could attenuate acidosis and improve judo performance. DESIGN: Twenty-three highly-trained judo athletes were randomly assigned to receive either beta-alanine (6.4gday-1) or placebo (dextrose, same dosage) for 4 weeks. METHODS: Performance was assessed before (PRE) and after (POST) supplementation through a 5-min simulated fight (randori) followed by 3 bouts of the Special Judo Fitness Test (SJFT). Blood samples were collected for blood pH, bicarbonate (HCO3-) and lactate determination. RESULTS: Beta-alanine supplementation improved the number of throws per set and the total number of throws (both p<0.05). Placebo did not change these variables (both p>0.05). Blood pH and HCO3- reduced after exercise (all p<0.001), with no between-group differences (all p>0.05). However, the lactate response to exercise increased in the beta-alanine group as compared to placebo (p<0.05). CONCLUSIONS: In conclusion, 4 weeks of beta-alanine supplementation effectively enhance judo-related performance in highly-trained athletes.

Implementation and effects of pulse-contour- automated SVV/CI guided goal directed fluid therapy algorithm for the routine management of pancreatic surgery patients.

BACKGROUND: Goal directed fluid management in major abdominal surgery has shown to reduce perioperative complications. The approach aims to optimize the intravascular fluid volume by use of minimally invasive devices which calculate flow-directed variables such as stroke volume (SV) and stroke volume variation (SVV). OBJECTIVE: We aimed to show the feasibility of routinely implementing this type of hemodynamic monitoring during pancreatic surgery, and to evaluate its effects in terms of perioperative fluid management and postoperative outcomes. METHODS: All patients undergoing pancreatic surgery at a university hospital during two successive 12 months periods were included in this retrospective cohort analysis. Twelve months after the implementation of a standard operating procedure for a goal directed therapy (GDT, N = 45) using a pulse contour automated hemodynamic device were compared with a similar period before its use (control, N = 31) regarding mortality, length of hospital and ICU stay, postoperative complications and the use of fluids and vasopressors. RESULTS: Overall, 76 patients were analysed. Significantly less crystalloids were used in the GDT group. Patients receiving GDT showed significantly fewer severe complications (insufficiency of intestinal anastomosis: 0 vs. 5 (P = 0.0053) and renal failure: 0 vs. 4 (P = 0.0133). Mortality for pancreatic surgery was 1 vs. 3 patients, (P = 0.142), and length of stay (LOS) in the intensive care unit (ICU) was 4.38 ± 3.63 vs. 6.87 ± 10.02 (P= 0.0964) days. Use of blood products was significantly less within the GDT group. CONCLUSIONS: Implementation of a SOP for a GDT in the daily routine using flow-related parameters is feasible and is associated with better outcomes in pancreatic surgery.

Postoperative analgesia and functional recovery after total-knee replacement: comparison of a continuous posterior lumbar plexus (psoas compartment) block, a continuous femoral nerve block, and the combination of a continuous femoral and sciatic nerve block.

BACKGROUND AND OBJECTIVES: Continuous femoral nerve block is a well-accepted technique for regional analgesia after total-knee replacement. However, many patients still experience considerable pain at the popliteal space and at the medial aspect of the knee. The goal of this study is to evaluate whether a psoas compartment catheter provides better postoperative analgesia than a femoral nerve catheter does and whether it is as effective as the combination of a femoral and a sciatic nerve catheter and, thus, improves functional outcome. METHODS: Ninety patients who underwent total-knee replacement under standardized general anesthesia participated in this prospective randomized study. Group FEM received a continuous femoral nerve block, group FEM/SCI received a combination of a femoral and a sciatic continuous nerve block, and group PSOAS received a continuous psoas compartment block. Patient-controlled analgesia with piritramide was available for 48 hours. Maximal bending and extending of the knee and walking distance was assessed during the first 7 days. A standardized telephone survey was conducted after 9 to 12 months to evaluate residual pain and functional outcome. RESULTS: Postoperative opioid consumption during 48 hours was significantly less in the FEM/SCI group (median: 18 mg; 25th/75th percentile: 6/40) compared with the FEM group (49 mg; 25/66) and the PSOAS group (44 mg; 30/62) (P =.002). Postoperative pain scores were not different, and no differences occurred with respect to short-term or long-term functional outcome. CONCLUSION: The FEM/SCI catheter is superior to FEM and PSOAS catheter with respect to reduced analgesic requirements after total-knee replacement, but functional outcome does not differ with those 3 continuous regional analgesia techniques.

Pharmacoeconomic considerations of tropisetron for prophylaxis and treatment of CINV and PONV.

Postoperative nausea and vomiting has been described as the big little problem in anesthesia, with the overall incidence after anesthesia using volatile anesthetics remaining between 20 and 30%. In patients who receive ambulatory surgery, postoperative nausea and vomiting may lead to delayed discharge or unplanned overnight admission to hospital which is counterproductive to the primary goal of saving costs in healthcare by undergoing day-surgery. The same economic factors apply to patients who experience nausea and vomiting after chemotherapy. Drugs today are judged by their ability to cure a condition with as few adverse reactions as possible. There remains the question of whether a certain medication meets expectations from a pharmacoeconomic point of view. 5-HT3 antagonists are a comparatively new class of drugs that seem to perform satisfactory in the treatment of different forms of nausea and vomiting with few adverse reactions. However, these drugs are comparatively expensive. Studies on the efficacy and pharmacoeconomic comparisons have been conducted. Tropisetron is one of the newest 5-HT3 antagonists. While its efficacy has been shown in several studies, there are few studies on its pharmacoeconomic benefits. There are several antiemetic measures, such as total intravenous anesthesia, using antiemetic prophylaxis or omitting the nitrous oxide with proven effectiveness. Most are roughly equivalent but differ with respect to costs and side effects Routine antiemetic prophylaxis is not indicated due to economic and medical reasons (potential side effects of antiemetics). Patients at high risk can be identified using validated risk scores and should receive antiemetic drugs.