Biomedical subjects

Thomas Standl

Publications and source records attributed to Thomas Standl.

27 records · Page 2Linked to original sources

PubMed2003

Systemic intravenous infusion of bovine hemoglobin significantly reduces microcirculatory dysfunction in experimentally induced pancreatitis in the rat.

OBJECTIVE: To evaluate the effectiveness of bovine hemoglobin on pancreatic microcirculation and outcome in experimental acute rodent pancreatitis. SUMMARY BACKGROUND DATA: Stasis of the pancreatic microcirculation initiates and aggravates acute pancreatitis. Hydroxyethyl-starch (HES) has been shown to improve pancreatic microcirculation. Similarly, bovine hemoglobin might improve rheology due to its colloid effect, but additionally supplies oxygen to oxygen depleted pancreatic tissue. METHODS: In Wistar rats, severe acute pancreatitis was induced by administration of glucodeoxycholic acid i.d. and cerulein i.v. Pancreatic microcirculation was continuously monitored by fluorescence microscopy. Fifteen minutes after the initiation of acute pancreatitis, animals received either 0.8 mL bovine hemoglobin (Oxyglobin), HES, or 2.4 mL 0.9% NaCl i.v. at random. After 6 hours, animals were killed and histopathological damage of the pancreas was assessed using a validated histology score (0-16). RESULTS: In comparison to controls, pancreatic microcirculation improved significantly in the HBOC group (mean difference of capillary density 31.4%; standard error 5.6%; P < 0.001; 95% confidence interval for difference 17.5-45.3). HES was not as effective as HBOC substitution. The histology score revealed less tissue damage in the HBOC group [6.25 vs. 9.25 (3-8.5 vs. 8-10.75, P < 0.001)] in comparison to controls and also in comparison to the HES group [6.25 vs. 8 (3-8.5 vs. 6.5-10.25, P < 0.006)]. CONCLUSIONS: In severe acute pancreatitis, single i.v. injection of bovine hemoglobin improves pancreatic microcirculation and reduces tissue damage.

Acute Disease↗

PubMed2003

Hydroxyethyl starch (HES) 130/0.4 provides larger and faster increases in tissue oxygen tension in comparison with prehemodilution values than HES 70/0.5 or HES 200/0.5 in volunteers undergoing acute normovolemic hemodilution.

UNLABELLED: Stable hemodynamics and improved rheology are important effects of hemodilution with hydroxyethyl starch (HES) infusions. One clinical indicator of improved rheology is increased tissue oxygen tension (tpO(2)). In this prospective, randomized, double-blinded, crossover study, we examined the effects of acute normovolemic hemodilution with HES 130/0.4 on hemodynamics and skeletal muscle tpO(2) in comparison with conventional HES solutions. Twelve healthy volunteers were randomly enrolled in each group. At an interval of >8 days, volunteers donated 18% of their calculated blood volume within 30 min and randomly received 6% HES 130/0.4, 6% HES 70/0.5, or 6% HES 200/0.5 (crossover design) in a 1:1.2 ratio to their blood loss. Hemodynamic variables, tpO(2) in the quadriceps muscle, hematocrit, plasmatic HES concentrations, plasma viscosity, colloid osmotic pressures, and platelet aggregation were measured until 6 h after the infusion of HES. No differences were found among groups with respect to changes of hemodynamics, hematocrit, or platelet aggregation. With HES 200, colloid osmotic pressures and plasma viscosities were larger than after HES 70 (P < 0.05). HES 130 in comparison with HES 70 and 200 caused the fastest (30 min versus 90 min and 150 min after hemodilution; P < 0.05) and largest increase of tpO(2) in comparison to baseline (+93% versus +33% and 40%; P < 0.05). In healthy volunteers undergoing acute normovolemic hemodilution, the newly designed HES 130/0.4 showed a more pronounced and earlier increase of skeletal muscle tpO(2) in comparison with prehemodilution values than HES 70/0.5 or 200/0.5. IMPLICATIONS: The effects of three different hydroxyethyl starch (HES) solutions on hemodynamics, rheology, and skeletal muscle tissue tension after acute normovolemic hemodilution were examined in awake volunteers. With HES 130/0.4, increases of tissue oxygen tension in comparison to baseline were larger and more rapid than with HES 70/0.5 or HES 200/0.5.

Adult↗

PubMed2003

ARX-derived auditory evoked potential index and bispectral index during the induction of anesthesia with propofol and remifentanil.

UNLABELLED: A new commercial auditory evoked potential (AEP) monitor (A-line AEP monitor) was developed to calculate an index (ARX AEP index; AAI) by automatically using the amplitudes and latencies of the AEP. We investigated 30 patients before spine surgery. AAI; bispectral index (BIS); relative (%) delta, theta, alpha, and beta; spectral edge frequency; median frequency; mean arterial blood pressure; heart rate; and oxygen saturation were obtained simultaneously during stepwise (1.0 micro g/mL) induction of target-controlled propofol concentration until 5.0 micro g/mL, followed by an infusion of 0.3 micro g. kg(-1). min(-1) of remifentanil. Every minute, the patients were asked to squeeze the observer's hand. Prediction probability (Pk), receiver operating characteristic, and logistic regression were used to calculate the probability to predict the conditions AWAKE, UNCONSCIOUSNESS (first loss of hand squeeze), and steady-state ANESTHESIA (5.0 micro g/mL of propofol and 0.3 micro g. kg(-1). min(-1) of remifentanil). Although a statistically significant difference among the conditions was observed for AAI, BIS, mean arterial blood pressure, median frequency, and %alpha, only AAI and BIS were able to distinguish UNCONSCIOUSNESS versus AWAKE and ANESTHESIA versus AWAKE with better than Pk = 0.90. The modern electroencephalographic variables AAI and BIS were superior to the classic electroencephalographic and hemodynamic variables to distinguish the observed anesthetic conditions. IMPLICATIONS: The modern electroencephalographic ARX-derived auditory evoked potential index and the bispectral index were superior to the classic electroencephalographic and hemodynamic variables for predicting anesthetic conditions. Variables derived from the auditory evoked potential did not provide an advantage over variables derived from spontaneous electroencephalogram.

Adolescent↗

PubMed2003

Continuous wound infiltration with ropivacaine reduces pain and analgesic requirement after shoulder surgery.

UNLABELLED: After achieving a reduction of pain scores for 10 h with a single dose wound infiltration after shoulder surgery, we examined in a prospective, placebo-controlled and double-blinded study the analgesic effects of continuous wound infiltration with different concentrations of ropivacaine. Forty-five patients undergoing shoulder surgery were randomly assigned into three groups to receive single dose wound infiltration with 30 mL saline (group S) or ropivacaine 7.5 mg/mL (groups R2 and R3.75) after skin closure. Postoperatively, patients received a continuous wound infiltration with saline (group S), ropivacaine 2 mg/mL (group R2) or ropivacaine 3.75 mg/mL (group R3.75) for 48 h. Supplemental pain relief was provided by IV patient-controlled analgesia with the opioid piritramide. At 1, 2, 3, 4, 24, and 48 h postoperatively visual analogue scale (VAS) values (0-100 mm), piritramide requirements and side effects were registered. Plasma levels of ropivacaine were measured preoperatively and at 24 h and 48 h after surgery. Until 48 h VAS values were smaller in group R3.75 compared with group S (group R3.75, 8 +/- 9 mm; group S, 31 +/- 14 mm; P < 0.005), whereas 4 h and 48 h postoperatively VAS values were even smaller in group R3.75 compared with group R2 (P < 0.05). Cumulative piritramide consumption was always smaller in groups R2 and R3.75 compared with group S (1-24 h, P < 0.005; 48 h, P < 0.05). Plasma ropivacaine levels remained less than the toxic threshold. We conclude that continuous postoperative wound infiltration with ropivacaine, especially using 3.75 mg/mL, provides smaller VAS values and opioid requirement in comparison with saline after shoulder surgery. IMPLICATIONS: The continuous postoperative wound infiltration after shoulder surgery with different concentrations of ropivacaine, 2 mg/mL and 3.75 mg/mL, results in lower pain scores and opioid requirement compared with infiltration with placebo. Plasma levels of ropivacaine remained less than the toxic threshold.

Adult↗

PubMed2002

Influence of early defibrillation on the survival rate and quality of life after CPR in prehospital emergency medical service in a German metropolitan area.

Early defibrillation by emergency medical personnel has been shown to improve survival in patients suffering from out-of-hospital cardiac arrest with ventricular fibrillation. Due to organisational differences it is difficult to compare results in various studies. Comparison of studies has been simplified by introduction of the Utstein template. After introduction of an early defibrillation program in Hamburg, we compared the patients being treated with early defibrillation by emergency medical technicians (EMTs) with patients being defibrillated by physicians in an out-of-hospital emergency service in a prospective study. All patients suffered from non EMT-witnessed ventricular fibrillation of cardiac origin. During 1 year, 103 patients were analyzed with respect to survival rate and quality of life. Of the 53 patients in the early defibrillation group (G1) 11 regained a palpable pulse at physicians' arrival, whereas all patients of the control group (G2) showed ventricular fibrillation. More patients treated with early defibrillation regained sinus rhythm without antiarrhythmics in the prehospital phase (G1: n=43 (86%); G2: n=32 (60%); P<0.05) and had a shorter in-hospital stay (G1: median, 23 days; range 5-51 days; G2: median 39, range 15-88 days; P<0.05). Twelve patients in G1 and 16 in G2 were discharged from hospital. The survival rate was similar in both groups (after 6 months G1: n=12; G2: n=14, after 12 months G1: n=10; G2: n=13 and after 24 months G1: n=9; G2: n=10), and the quality of life according to Glasgow-Pittsburgh Cerebral Performance Category (CPC) and Overall Performance Category (OPC) scores also was comparable between groups. We conclude that early defibrillation provides a higher incidence of return of a spontaneous circulation, a reduced need for antiarrhythmics and shorter in-hospital treatment times in patients with out-of-hospital ventricular fibrillation.

Aged↗

PubMed2002

Active warming during cesarean delivery.

UNLABELLED: We tested the hypothesis that 15 min of forced-air prewarming, combined with intraoperative warming, prevents hypothermia and shivering in patients undergoing elective cesarean delivery. We simultaneously tested the hypothesis that maintaining maternal normothermia increases newborn temperature, umbilical vein pH, and Apgar scores. Thirty patients undergoing elective cesarean delivery were randomly assigned to forced-air warming or to passive insulation. Warming started 15 min before the induction of epidural anesthesia. Core temperature was measured at the tympanic membrane, and shivering was graded by visual inspection. Patients evaluated their thermal sensation with visual analog scales. Rectal temperature and umbilical pH were measured in the infants after birth. Results were compared with unpaired, two-tailed Student's t-tests and chi(2) tests. Core temperatures after 2 h of anesthesia were greater in the actively warmed (37.1 degrees C +/- 0.4 degrees C) than in the unwarmed (36.0 degrees C +/- 0.5 degrees C; P < 0.01) patients. Shivering was observed in 2 of 15 warmed and 9 of 15 unwarmed mothers (P < 0.05). Babies of warmed mothers had significantly greater core temperatures (37.1 degrees C +/- 0.5 degrees C vs 36.2 degrees C +/- 0.6 degrees C) and umbilical vein pH (7.32 +/- 0.07 vs 7.24 +/- 0.07). IMPLICATIONS: Perioperative forced-air warming of women undergoing cesarean delivery with epidural anesthesia prevents maternal and fetal hypothermia, reduces maternal shivering, and improves umbilical vein pH.

Adult↗

PubMed2002

Narcotrend, bispectral index, and classical electroencephalogram variables during emergence from propofol/remifentanil anesthesia.

UNLABELLED: The aim of this study was to investigate modern and classical electroencephalographic (EEG) variables in response to remifentanil and propofol infusions. We hypothesized that modern EEG variables may indicate the effects of propofol but not of remifentanil. Twenty-five patients were included in the study after the end of elective spine surgery without any surgical stimulation. Baseline values were defined with remifentanil 0.3 microg. kg(-1). min(-1) and target-controlled infusion of propofol 3.0 microg/mL. EEG changes were evaluated 1, 3, 5, 7, and 9 min after the stop of remifentanil infusion, followed by a step-by-step reduction (0.2 microg/mL) every 3 min of target-controlled infusion propofol. Narcotrend (NT; classifying EEG stages from awake to deep anesthesia), bispectral index (BIS), EEG spectral frequency bands (%), 50% (Median) and 95% percentiles (spectral edge frequency), mean arterial blood pressure, heart rate, and oxygen saturation were detected at every time point. The end of remifentanil application resulted in significant increases in %alpha, spectral edge frequency, mean arterial blood pressure, and %theta and decreases in %delta (P < 0.05). NT, BIS, Median, heart rate, and oxygen saturation were unchanged. Decreases in propofol concentration were associated with statistically significant increases in NT and BIS (P < 0.05). Thus, the sedative-hypnotic component of propofol could be estimated by modern EEG variables (NT and BIS), whereas the analgesic component provided by remifentanil was not indicated. However, during conditions without surgical stimulation, neither NT nor BIS provided an adequate assessment of the depth of anesthesia when a remifentanil infusion was used. IMPLICATIONS: We investigated modern and classical electroencephalographic (EEG) variables during emergence from propofol/remifentanil anesthesia. Modern EEG variables indicate changes of infusion in propofol, but not in remifentanil. Thus, modern EEG variables did not provide an adequate assessment of depth of anesthesia when remifentanil was used.

Adolescent↗

PubMed2002

Use of perflubron emulsion to decrease allogeneic blood transfusion in high-blood-loss non-cardiac surgery: results of a European phase 3 study.

BACKGROUND: This single-blind randomized study in general surgery evaluated the efficacy of perflubron emulsion (PFC) as an artificial oxygen carrier being used to augment preoperative acute normovolemic hemodilution to reduce and avoid transfusion of both allogeneic erythrocytes and erythrocytes from preoperative autologous donation compared with standard of care. METHODS: Subjects (N = 492) with hemoglobin concentrations of 12-15 g/dl undergoing noncardiac surgical procedures with 20 ml/kg or greater expected blood loss were randomized into two groups. Control patients were transfused intraoperatively at a hemoglobin concentration less than 8.0 +/- 0.5 g/dl or at protocol-defined, physiologic triggers. PFC-treated patients first underwent acute normovolemic hemodilution to hemoglobin of 8.0 +/- 0.5 g/dl, followed by dosing with perflubron emulsion (1.8 g/kg). When hemoglobin reached less than 6.5 +/- 0.5 g/dl, an additional 0.9-g/kg dose was given. PFC patients were transfused at hemoglobin less than 5.5 +/- 0.5 g/dl or at predefined physiologic triggers. After surgery, hemoglobin was maintained at 8.5 +/- 0.5 g/dl or greater in all patients until discharge. Efficacy endpoints included the number of allogeneic and preoperative autologous donation units transfused and the percentage of subjects avoiding transfusion. RESULTS: Both groups had similar hemoglobin concentrations at screening (13.5 +/- 1.0 g/dl) and at discharge: 10.8 +/- 1.2 g/dl (PFC) and 11.1 +/- 1.3 g/dl (control). At 24 h, more patients in the PFC group avoided allogeneic and preoperative autologous donation erythrocyte transfusions (53% vs. 43%, < 0.05), and fewer erythrocytes were transfused (1.5 +/- 4.8 vs. 2.1 +/- 3.9 units; median, 0 vs. 1 unit; P = 0.013). By day of discharge, these differences were not significant in the intent-to-treat population, but overall there were less allogeneic and preoperative autologous donation erythrocyte transfusions in the PFC group (696 vs. 846 units). In the protocol-defined target population (n = 330 subjects with blood loss > or = 20 ml/kg), significantly greater avoidance of any erythrocyte transfusion was maintained through day of hospital discharge (26% vs. 16% in the PFC and control groups, respectively; P < 0.05), and there was also a significant reduction in the number of erythrocyte units transfused (3.4 +/- 2.9 vs. 4.9 +/- 2.4 units; median 2 vs. 4 units; P < 0.001). Adverse events rates were similar in the PFC (86%) and control (81%) groups; however, more serious adverse events were reported in the PFC group (32%) than in controls (21%; P < 0.05). Overall mortality was 3%, and the difference between groups (PFC, 4% vs. controls, 2%) was not statistically significant. CONCLUSIONS: Augmented acute normovolemic hemodilution with PFC reduces transfusion needs in patients undergoing noncardiac surgical procedures with blood loss 20 ml/kg or greater.

Adult↗

PubMedDate not supplied

Patient-controlled thoracic epidural infusion with ropivacaine 0.375% provides comparable pain relief as bupivacaine 0.125% plus sufentanil after major abdominal gynecologic tumor surgery.

BACKGROUND AND OBJECTIVES: We tested the hypothesis that an opioid-free local anesthetic alone is able to provide comparable analgesia to the opioid supplemented epidural application of local anesthetics using thoracic epidural catheters after major abdominal surgery. METHODS: In a prospective, randomized, and double-blind study, we have compared the analgesic efficacy and side effects of ropivacaine 0.375% (group R) versus bupivacaine 0.125% in combination with sufentanil 0.5 microg/mL(-1) (group B/S) via a thoracic epidural catheter for a duration of 96 hours after major abdominal surgery in 30 gynecologic tumor patients. Piritramide was given for breakthrough pain. Assessments were performed every 12 hours after start of the epidural infusion using continuous (first 24 hours) and patient-controlled epidural analgesia (PCEA) (24 to 96 hours). RESULTS: No differences were seen in demographic and perioperative data. Dynamic pain scores (visual analog scale [VAS] values) were comparable between groups during mobilization (group R v group B/S: 24 hours: 40 +/- 30 v 36 +/- 14, P =.9; 48 hours: 46 +/- 33 v 42 +/- 25, P =.93; 72 hours: 42 +/- 24 v 48 +/- 26, P =.78; 96 hours: 42 +/- 25 v 29 +/- 28, P =.49) and on coughing during the whole study period. Hemodynamics, intensity of motor block (Bromage scale), and side effects like nausea, vomiting, pruritus, and bladder disfunction also did not differ between groups. CONCLUSION: The present study shows that thoracic epidural infusion of ropivacaine 0.375% provides comparable pain relief and incidence of side effects after major abdominal gynecologic surgery as bupivacaine 0.125% in combination with 0.5 microg/mL(-1) sufentanil and may therefore represent an alternative in epidural pain management.

Adult↗