Biomedical subjects

W Seeling

Publications and source records attributed to W Seeling.

At least 19 recordsLinked to original sources

PubMed1996

[Epidurography: comparison with CT, spiral CT and MR epidurography].

PURPOSE: The purpose of this study was to explain the origin of image patterns demonstrated by conventional epidurography, which is a controversially discussed topic in recent literature. MATERIAL AND METHODS: After introduction of thoracic epidural catheters and iopamidol injection, conventional epidurography and CT-epidurography were performed on 25 preoperative patients. After injection of Gadolinium-DTPA MR-epidurography was performed in two patients treated for chronic pain with already introduced epidural catheters. Three volunteers also underwent identical imaging after introduction of thoracic epidural catheters and in addition helical-CT epidurography using twin-beam technology. RESULTS: 40% of the patients demonstrated the railroad track phenomenon. We were able to prove that it is a sign of a rhythmically variable filling of segments of the lateral epidural space with contrast medium 76% of the patients demonstrated no ventral epidural space at the thoracic level. 56% of the patients showed a medial area of translucence combined with a band-shaped contrasting of the epidural space in the standard ap view. This was proven in all cases to be a plica mediana dorsalis by CT. In all volunteers who underwent helical-CT and MR epidurography we observed the railroad track phenomenon and the filling defect of the anterior thoracic epidural space. CONCLUSION: CT epidurography is well suited for obtaining new insights into the interpretation of findings obtained by conventional epidurography.

Analgesia, Epidural↗

PubMed1996

[Differential administration of non-opioids in postoperative analgesia, I. Quantification of the analgesic effect of metamizole using patient-controlled analgesia].

OBJECTIVE: The aim of this study was to investigate: 1. Whether the perioperative administration of metamizol causes a significant reduction in postoperative opioid requirements within the first 24 h after surgery. 2. The opioid-sparing effect after different types of operations. 3. Whether preoperative application of metamizol causes a significant reduction of the pain-score immediately after operation. METHODS: In a double-blind, randomised, placebo-controlled study, 117 patients, scheduled for minor orthopaedic or laparoscopic surgery or other operations (mainly resection of the thyroid gland and inguinal herniotomies) received either metamizol (1 g/100 ml NaCl 0.9%) or placebo (100 ml NaCl 0.9%) intravenously over 15 min in three separate doses: the first dose was given just before induction and the others 6 h and 12 h later. After surgery all patients were allowed to self-administer buprenorphine from a PCA (patient-controlled analgesia) pump (Bolus: 30 microgram, lockout: 5 min in the recovery room, 30 min on the ward). Every hour for the first 6 h and after 24 h, cumulated doses of buprenorphine, pain scores (0-10), blood pressure, pulse and side effects were recorded. RESULTS: After minor orthopaedic and laparoscopic surgery, metamizol-treated patients had significantly less pain immediately after surgery and used a significantly lower cumulated dose of opioid in the first 24 h after surgery (-20% and -67% respectively) than patients receiving placebo. After the other types of surgery no analgesic effect could be established. CONCLUSIONS: Perioperative administration of metamizol results in better pain relief and significantly lower buprenorphine requirements particularly after laparoscopic operations. To achieve a significant pain reduction immediately after the operation, the first dose should be applied before induction.

Adolescent↗

PubMed1996

[Differential indications of non-opioid drugs for postoperative analgesia II. Quantification of the analgesic effect of a combination of metamizol plus diclofenac via patient-controlled analgesia].

OBJECTIVE: In a previous study we investigated the analgesic efficacy of metamizol. After laparoscopic operations, in particular, the reduction of postoperative opioid requirements within the first 24 h after surgery attained clinical relevance (-67%). In the present study we investigated the analgesic efficacy of supplementary diclofenac. METHODS: 86 patients, scheduled for minor orthopaedic surgery, laparoscopic cholecystectomy or resection of the thyroid gland, participated in a doubleblind, randomised, placebo-controlled study. The setting was comparable to our previous study, apart from the supplementary administration of diclofenac. Before induction of anaesthesia, verum-treated patients received a diclofenac suppository (100 mg), in addition to metamizol (1 g/100 ml NaCl 0.9% intravenous over 15 min). These infusions were repeated at 6h and 12h. In addition to the third infusion, the patients received a further diclofenac suppository (100 mg). Cumulated doses of buprenorphine (PCA, patient-controlled analgesia), pain scores (0-10), blood pressure, pulse and side effects were recorded during the first 6 h and again at 24 h. RESULTS: All verum-treated patients had significantly less pain immediately after surgery and required lower cumulated doses of buprenorphine during the first 24 h after operation (laparoscopic cholecystectomy -33%, minor orthopaedic surgery -73%, resection of thyroid gland -60%). CONCLUSIONS: Combination of metamizol and diclofenac cause a clinically relevant reduction in opioid requirements, in particular after minor orthopaedic surgery and resection of the thyroid gland. There is no need for supplementary diclofenac following laparoscopic surgery.

Adult↗

PubMed1996

Prophylactic use of epidural mepivacaine/morphine, systemic diclofenac, and metamizole reduces postoperative morphine consumption after major abdominal surgery.

BACKGROUND: Surgical trauma induces nociceptive sensitization leading to amplification and prolongation of postoperative pain. While preemptive analgesic treatment with numerous agents has been successful in experimental animals, results of human studies remain conflicting. The authors used a multimodal approach for preemptive analgesia before abdominal surgery: diclofenac and metamizole inhibit prostaglandin synthesis, thus influencing peripheral sensitization; epidural local anesthetics induce conduction block, epidural opioids inhibit nociceptive synaptic transmission, and metamizole induces descending inhibition. The interaction of these drugs might suppress spinal nociceptive sensitization and postoperative analgesic demand. METHODS: One hundred forty-two patients scheduled for major abdominal surgery were randomly assigned to one of three groups and studied prospectively. Epidural catheters in groups 1 and 2 were placed at interspaces T8-T10, the position of the catheter was confirmed by epidurography, and sensory testing after administration of 5 ml mepivacaine 1%. Group 1 received 75 mg intramuscular diclofenac, 1000 mg intravenous metamizole, 5.3 +/- 1 mg epidural morphine, and 15-20 ml mepivacaine 1% 85 +/- 41 min before skin incision. Epidural analgesia was maintained by injections of 0.1 ml.kg-1.h-1 mepivacaine 1%. Group 2 patients received the balanced analgesia regimen before wound closure (221 +/- 86 min after skin incision). Group 3 patients did not receive any study substances. General anesthesia was induced with 5 mg/kg thiopental and 2 micrograms/kg fentanyl and maintained with enflurane and nitrous oxide. Postoperative analgesia consisted of patient-controlled intravenous morphine over 5 days. RESULTS: Median visual analog scale pain intensities were < 3 cm and did not differ among the groups. Morphine consumption per hour on postoperative day 2 was 0.8 +/- 0.1 mg/h (group 1) < 1.2 +/- 0.1 mg/h (group 2) = 1.1 +/- 0.1 mg/h (group 3) and cumulative morphine consumption (in mg) on the morning of day 5 was 95 +/- 9 (group 1) < 111 +/- 11 (group 2) < 137 +/- 10 (group 3). CONCLUSIONS: A significant reduction of patient controlled analgesia requirements could be achieved by our preincisional balanced analgesia regimen compared to application before wound closure. The more distinct difference between patients receiving balanced analgesia and those in the control group is based on the analgesic action of the study substances, which lasted about 14 h.

Abdomen↗

PubMed1996

Perioperative endotoxemia and bacterial translocation during major abdominal surgery: evidence for the protective effect of endogenous prostacyclin?

OBJECTIVE: To investigate the potential role of endogenous prostacyclin (PGI2) released after mesenteric traction during major abdominal surgery on perioperative endotoxemia and bacterial translocation. DESIGN: Prospective, randomized, double-blind clinical study. SETTING: Operating room and surgical intensive care unit in a university hospital. PATIENTS: Fifty consecutive patients scheduled for major abdominal surgery (pancreas resection, abdominal aortic surgery). INTERVENTIONS: Fifteen minutes before skin incision, either 400 mg of ibuprofen or a placebo equivalent were administered intravenously. Immediately after peritoneal incision, eventration and action of the small bowel was intentionally performed in a uniform fashion. MEASUREMENTS AND MAIN RESULTS: Baseline values were obtained before induction of anesthesia. Additional measurements, along with assessments of hemodynamics and gas exchange, were performed before incision of the peritoneum and at 5, 30, and 45 mins and 3, 6, and 24 hrs after mesenteric traction. Arterial plasma concentrations of 6-keto-prostaglandin F1 alpha and thromboxane B2 (stable metabolites of PGI2 and thromboxane A2) were determined by radioimmunoassay. Endotoxin was measured by limulus amebocyte lysate test. Mesenteric lymph nodes were sampled in 31 patients (ibuprofen n = 14, placebo n = 17) and sent for culture under sterile conditions. Transient hypotension and a marked increase of plasma 6-keto-prostaglandin F1 alpha concentrations occurred up to 6 hrs after mesenteric traction in untreated patients with median peak concentrations (2243 vs. 72 ng/L [p < .0001, placebo vs. ibuprofen], observed 5 mins after mesenteric traction). Endotoxemia occurred in both study groups. However, after mesenteric traction, plasma endotoxin concentrations were significantly higher in the ibuprofen group. Median peak concentrations (0.12 vs. 0.27 EU/mL [p < .001, placebo vs. ibuprofen]) were observed 3 hrs after mesenteric traction. Gram-negative bacteria in mesenteric lymph nodes were detected exclusively in the ibuprofen group (n = 5, p < .01). CONCLUSIONS: In ibuprofen-pretreated patients, significantly higher endotoxin concentrations as well as bacterial translocation to mesenteric lymph nodes occurred, despite the absence of a transient decrease in mean arterial pressure that had been associated with PGI2 release. Therefore, we hypothesized that during major abdominal surgery, endogenous PGI2 released in response to mesenteric traction may play a crucial role in maintaining splanchnic microcirculation and thus preserving gut mucosal barrier function.

APACHE↗

PubMed1995

[CT-epidurography. A comparison of conventional and CT-epidurography with contrast medium injection through a thoracic peridural catheter].

Epidurography with contrast medium is used to verify the correct position of an epidural catheter and to detect malpositioning. There is great variability in the distribution of contrast medium according to the individual morphology of the epidural space and the way it is injected. Results of investigations of the anatomy of the spinal canal and epidural space performed with anatomic specimens, epiduroscopy, and conventional and computed tomographic (CT) epidurography are sometimes contradictory. We have performed CT epidurography in approximately 30 patients to date. Insights regarding the distribution of contrast medium in the epidural space can help to interpret conventional epidurographies and to explain special features, such as the "rail-road-track phenomenon" or the plica mediana dorsalis. METHODS. Patients scheduled for major abdominal operations were studied. Catheters were introduced into the thoracic epidural space on the day before the operation. Conventional epidurographies were performed routinely after insertion of the catheters with a mobile X-ray apparatus, usually in the recovery room, using 5 ml iopamidol (Solutrast 250 M). Selected patients (good mental state and stable psychic condition), after written consent and with approval of the local ethical committee, were investigated with CT epidurography using the same contrast medium (partly diluted). From among the CT scans performed until now, five characteristic images are presented and compared to conventional epidurographies. RESULTS. When small volumes (5 ml) of iopamidol were injected slowly, we regularly observed a railroad-track phenomenon in the AP images of conventional epidurographies. After rapid injection of larger volumes (10-15 ml), the spread was more homogeneous and sometimes outline a lighter zone of contrast distribution in the midline. CT epidurography in these cases (5 out of 30 patients) revealed a plica mediana dorsalis. In the majority of the CT scans of the thoracic epidural space its anterior (ventral) compartment was unfilled by contrast medium. According to the findings of several investigators, dura mater and ligamentum longitudinal posterius have grown together, so that an epidural space does not exist in ventral thoracic segments of the spinal canal. In lower thoracic and lumbar segments both structures are separate, and a wide anterior epidural space was present and filled with contrast medium. In other cases the dorsal and dorsolateral epidural space was completely filled, but the contrast medium stopped behind the spinal nerves and surrounding dural sheaths, as if these structures, together with the connective tissue strands between them, formed a membrane that spread in a frontal plane. A railroad-track phenomenon is interpreted in the literature as the X-ray correlate of contrast medium spread in the subdural space, indicating an incorrect catheter position. According to conventional epidurographies and confirmed by CT scans, this feature is also seen regularly in cases with correct catheter position. Small volumes of iopamidol spread preferentially into the wider parts of the epidural space between the gaps of the vertebral arcs, whereas the dura mater and periosteal layers touch at the inner side of the pedicules and laminae, allowing the existence of only a potential epidural space. This rhythmic widening and narrowing of the epidural space is the explanation of the "railroad track" in AP contrast epidurographies. CONCLUSIONS. CT epidurography is a valuable tool to provide better insight into the morphology of the epidural space when filled with fluid (contrast medium, local anaesthetics), complementing findings using epiduroscopy and anatomic specimens. It stands to reason that this time- and cost-expensive method can never replace conventional epidurographies, but can help to interpret them properly.

Adult↗

PubMed1995

[Analgesia with intra-articular morphine following knee joint arthroscopy? A double-blind, randomized study with patient-controlled analgesia].

UNLABELLED: Previous studies investigating the peripheral action of locally instilled morphine after arthroscopic knee surgery found evidence for an analgesic effect. Follow-up studies have lead to conflicting results. We used patient-controlled analgesia (PCA) to test the analgesic potency of intraarticular morphine. METHODS. Patients undergoing arthroscopic knee surgery under general anaesthesia received, after written informed consent and in double-blind and randomised manner, 1 mg morphine diluted in 10 ml saline either intraarticularly or intravenously at the end of the surgical procedure. A control injection of 10 ml saline was given at the other site. The pain intensity on a visual analogue scale (VAS) and the cumulative morphine consumption were recorded at 1, 2, 3, 4, 6, 8 and 24 h after the end of general anaesthesia. STATISTICS: Wilcoxon rank sum test with P < 0.05. RESULTS. A total of 59 patients were included in the study; 29 received morphine intraarticularly (verum group), 30 intravenously (control group). There was no difference in gender, age, duration of arthroscopy or anaesthesia. There were more than 60% diagnostic arthroscopies in both groups; other types of surgery were comparable, with the exception of cruciate band repair procedures only in the control group. We found no difference in morphine consumption or pain intensity between the two groups throughout the study period. Median overall consumption of morphine after 24 h was 14 mg in the verum group and 15 mg in the control group, with wide interindividual variation. Pain intensities were remarkably low. The peak pain intensity of both groups was found at 1 h postoperatively, with median 16/100 on the VAS in both groups. Blinding was robust. CONCLUSION. We found no reduction in postoperative morphine supplementation after 1 mg morphine intraarticularly compared to 1 mg intravenously given at the end of knee arthroscopies. There were also no differences in pain intensities on a VAS. We conclude that titration of postoperative pain with a morphine-filled PCA pump was unable to show a difference in analgesic potency between intraarticular and intravenous morphine.

Adolescent↗

PubMed1995

[Clinical randomized controlled studies in anesthesiology according to the quality guidelines of good clinical practice. 1: Basic trial design].

This article was written to give researchers and clinicians a short synopsis of ethical and thorough design, conduct, analysis, publication, and interpretation of randomised controlled clinical trials according to the European quality standards of Good Clinical Practice (GCP). The paper consists of two parts. In the first part we introduce important elements of study design, especially study hypothesis, criteria of inclusion and study population, sample size calculation, validity considerations, bias and confounding, randomisation, stratification, and masking of treatment assignment. Different treatment allocation like multiple parallel groups, factorial experiment, cross-over, and sequential design are presented. Requirements of ethical standards according to the Declaration of Helsinki are discussed for their necessity in any experimentation in humans. Principles of informed consent are demonstrated with emphasis on special conditions in anaesthesia, emergency medicine, and intensive care research. In the second part of this article we explain issues of baseline assessment, experimental intervention, data recording, and data monitoring, particularly of negative or hazardous treatment effects. Topics of data analysis and reporting of trial results in publications are illustrated with regard to their influence on subsequent interpretation.

Anesthesiology↗

PubMed1995

[Clinical randomized controlled studies in anesthesiology according to quality guidelines of good clinical practice. 2: Principles of implementation, analysis, publication and evaluation].

Anesthesiology↗

PubMed1995

Analgesic and hemodynamic effects of epidural clonidine, clonidine/morphine, and morphine after pancreatic surgery--a double-blind study.

This study characterizes analgesia an hemodynamics after epidural clonidine 8 micrograms/kg (Group C) or clonidine 4 micrograms/kg+morphine 2 mg (Group CM) in comparison to epidural morphine 50 micrograms/kg (Group M). Forty-five patients scheduled for pancreatectomy in combined general/epidural anesthesia were studied. The study drugs were administered 75 min postoperatively and for 10 h pain intensity (visual analog scale [VAS]), heart rate (HR), mean arterial pressure (MAP), and cardiac output (CO) were measured; filling pressures were kept > 5 mm Hg. Adequate analgesia could be achieved within 1 h in all patients of Groups C and CM, but only in six patients of Group M (P < 0.001). Quality of analgesia was comparable in all groups (VAS reduction 82% +/- 20%, mean +/- SD) but duration of analgesic action was longer in Groups CM (586 +/- 217 min) and M (775 +/- 378 min) compared to Group C (336 +/- 119 min) (P < 0.001). In Group M, no hemodynamic alterations occurred. In Groups C and CM, HR, CO, and MAP were reduced significantly compared to baseline within the first 15-90 min, while stroke volume and systemic vascular resistance remained stable. We conclude, that hemodynamic alteration after epidural clonidine under conditions of stable filling pressures is caused mainly by a decrease in HR. It is not an effect of analgesia but of the intrinsic antihypertensive action of clonidine.

Analgesia, Epidural↗

PubMed1994

[No better vigilance after general anesthesia with propofol in colonic surgery. A comparison of three procedures for general anesthesia (propofol, halothane and midazolam/fentanyl) in combination with catheter epidural anesthesia].

Early mental and psychomotor recovery was studied in 67 patients undergoing colorectal surgery under continuous epidural anaesthesia and light general anaesthesia using propofol, halothane, and midazolam/fentanyl. The study was approved by the local ethics committee. All patients received epidural anaesthesia with 0.25% bupivacaine and were then randomly allocated to one of three groups. In group I (halothane), light general anaesthesia was induced with thiopental 3-5 mg/kg and maintained with halothane. The propofol group (II) received 2 mg/kg for induction and a mean continuous infusion of 1.7 mg/kg.h. In group III (Mi/Fe), midazolam and fentanyl were used for induction and maintenance. All patients were intubated, received non-depolarising muscle relaxants, and were manually ventilated with nitrous oxide-oxygen (2:1.2). For postoperative analgesia, 0.05 mg/kg morphine was administrated epidurally 30 min before the end of the operation; 30, 60, 90, and 120 min after arriving in the recovery room, vigilance was assessed using a modified Steward score, the Trieger test, the ability to recall a column of numbers (KAI test), and symbol counting (CI test). Heart rate, blood pressure, arterial oxygen saturation, and blood gases were recorded. RESULTS. The three groups were comparable with regard to age, sex, ASA classification, and duration of anaesthesia and operation (Table 3). There was no difference between the groups in performance of the recovery tests (Figs. 2-5), blood pressure, heart rate, arterial blood gas analysis (Fig. 6), or oxygen saturation. Comparing pre- and postoperative values, we found severe psychomotor and mental impairment in all groups. pCO2 was slightly elevated in all groups, but only 3 patients in the propofol group and 6 in the midazolam/fentanyl group developed hypercapnia above 50 mm Hg. Patients receiving propofol or midazolam/fentanyl had significantly less postoperative nausea and vomiting than those receiving halothane (Table 5). CONCLUSION. It is concluded that propofol offers no advantage over halothane or midazolam/fentanyl where early postoperative recovery is concerned. Intraoperatively, all three techniques provided good anaesthesia. Propofol and midazolam/fentanyl caused less postoperative nausea and vomiting than halothane anaesthesia.

Adult↗

PubMed1994

[The effect of thoracic epidural anesthesia on the pathophysiology of the eventration syndrome].

Abdominal mesenteric traction (MT) results in decreased mean arterial pressure (MAP), systemic vascular resistance (SVR) and increased cardiac output (CO). This response is induced by a considerable release of prostacyclin (PGI2). Precipitous falls in systemic arterial pressure related to central and/or autonomic nervous reflex arcs also have been described during operations on the upper abdominal viscera. Those hypotensive responses to visceral traction appear to be transmitted along afferent fibres contained within the splanchnic nerves. We investigated the influence of supplementary thoracic epidural anaesthesia on mesenteric traction response during major abdominal surgery. METHODS. With the approval of the Human Investigation Review Board we studied 40 patients scheduled for major abdominal surgery (infrarenal aortic, gastrointestinal and pancreatic surgery) according to a prospective, randomized double-blinded protocol. Patients were randomized to two different anaesthetic regimens. Patients in group 1 received general anaesthesia (GA n = 20) with 0.1-0.15 mg/kg midazolam and 10 micrograms/kg fentanyl prior to skin incision. Maintenance included 65% nitric oxide in oxygen and 0.1 mg increments of fentanyl as required. Group 2 patients (EA n = 20) underwent a combined technique of dose-reduced general anaesthesia and supplementary continuous, thoracic epidural anaesthesia (bupivacaine 0.25%, sensory blockade T4 to L1-3). In both anaesthesia groups ibuprofen (400 mg i.v.) or a placebo equivalent was administered 15 min before the induction of anaesthesia. MT was applied in a uniform fashion. Baseline values preceded the incision of the peritoneum. Further assessments followed 5, 15 and 30 min after MT. The plasma concentrations of 6-keto-PGF1 alpha (stable metabolite of PGI2), TXB2 (stable metabolite of thromboxane), PGF2 alpha, KH2-PGF2 alpha (stable metabolite of PGF2 alpha) were determined by radioimmunoassay. At all assessments we recorded systolic and diastolic blood pressure, heart rate and measured arterial blood gases. Statistical analyses were performed using three-factor ANOVA for repeated measurements after log(x) transformation. A P-value of less than 0.05 was considered significant when the Bonferroni-Holm adjustment was applied. RESULTS. Patients with supplementary epidural anaesthesia demonstrated lower systolic (P = 0.0001) and diastolic (P = 0.006) blood pressure than those in the GA group. Nevertheless, in untreated patients in the EA and GA group there was a significant decrease of about 20-30% in systolic and diastolic blood pressure (P = 0.0001) after mesenteric traction. Irrespective of the anaesthetic procedure, paO2 (P = 0.0001) decreased after mesenteric traction in the placebo group. The control patients in the GA group exhibited a more pronounced increase in heart rate after MT. After traction on the mesentery a significant 20- to 30-fold increase in 6-keto-PGF1 alpha plasma concentrations occurred in the placebo group: GA group 1950/58 (5 min), 1574/59 (15 min) 858/66 (30 min) ng/l, P < 0.0001; EA group: 2002/106 (5 min), 2955/107 (15 min) 1807/70 (30 min) ng/l, P < 0.0001, for placebo vs ibuprofen. There was no statistically significant difference between the two anaesthetic procedures used. In ibuprofen-pretreated patients haemodynamics and paO2 values were stable, while 6-keto-PGF1 alpha plasma concentrations remained within the normal range. CONCLUSION. Our data clearly indicate that the mesenteric traction response consists in relevant haemodynamic alterations and a significant decrease of paO2. Stable haemodynamics and paO2 following cyclooxygenase inhibition signify an action mediated by prostacyclin. Deafferentation of the splanchnic nerves by supplementary thoracic epidural anaesthesia did not influence either prostacyclin release or the decrease in blood pressure and paO2 after traction on the mesentery root...

Abdomen↗

PubMed1994

[Analgesia and hemodynamics under 8 mu/kg clonidine for pain therapy following major abdominal surgery].

OBJECTIVE: To characterise the haemodynamic profile after epidural injection of high-dose clonidine for postoperative pain management and to establish recommendations for the therapy of haemodynamic instabilities. DESIGN: 20 patients with major surgery on pancreas, stomach or infrarenal aorta took part in the study. Anaesthesia was a combined epidural/inhalational regimen with bupivacaine 0.25%, enflurane, oxygen/nitrous oxide, fentanyl 0.1 mg and pancuronium. Postoperative analgesia consisted of morphine 50 micrograms/kg in 10 ml NaCl 0.9% for the first 12 postoperative hours; if pain > = 5 points on the VAS occurred after > 12 h postoperatively clonidine 8 micrograms/kg in 10 ml NaCl 0.9% was injected epidurally and the pain intensity (self-assessment by the patient using the visual analog scale) and circulation (invasive pressure monitoring, pulmonary artery catheter) was monitored for 60 minutes in ten minutes intervals. RESULTS: The reduction of the initial VAS score of 6 was 50% after 20 minutes and 100% after 60 minutes. We observed a significant decline in heart rate (87 +/- 11 (t0), 74 +/- 10 min-1 (t60)), mean arterial pressure (97 +/- 17 (t0), 72 +/- 15 mmHg (t60)) and cardiac output (8.7 +/- 1.3 (t0), 7.0 +/- 1.3 l.min-1 (t60)) (all p < 0.001) and no change of systemic vascular resistance. Filling pressures (CVP and PCWP) remained stable. In 9 patients the mean arterial pressure fell below 60 mmHg (always within the first 40 min); 6 of these patients responded to infusion of a colloid (500 ml of hydroxyethyl starch at > = 2 ml/kg.min) whereas the other 3 patients needed a bolus injection of a betamimetic catecholamine (theodrenaline/cafedrine, Akrinor). CONCLUSION: Epidural clonidine 8 micrograms/kg causes rapid and intense analgesia. Haemodynamic instability is a consequence of a drop in heart rate and has to be treated accordingly. The application of a pure vasopressor does not seem to be indicated taking in account the fact that the total peripheral resistance remains unchanged and in the normal range.

Abdomen↗

PubMed1994

The effect of ephedrine bolus administration on left ventricular loading and systolic performance during high thoracic epidural anesthesia combined with general anesthesia.

We investigated the effect of ephedrine on left ventricular function in patients without cardiovascular disease under high thoracic epidural anesthesia combined with general anesthesia. Because the epidural block was extended to all cardiac segments, ephedrine was assumed to be deprived of its centrally mediated actions. Left ventricular (LV) function was assessed using transesophageal echocardiography. We measured arterial pressure (AP), heart rate (HR), LV end-systolic and end-diastolic diameter and area (ESA, EDA), wall thickness, and LV ejection time before and after intravenous ephedrine bolus administration. We calculated area ejection fraction (EFA), end-systolic wall stress (ESWS), and mean velocity of circumferential fiber shortening (mVcfc). Ephedrine had a biphasic effect on left ventricular function. It transiently decreased EDA from 18.9 to 16.5 cm2 (mean), whereas EFA and mVcfc were increased from 33% to 49%, and from 1.88 to 2.67 circumferences/s, respectively. During the second phase, ephedrine increased mean arterial pressure (MAP) from a baseline value of 62 to 87 mm Hg, EDA was restored to 19.3 cm2, and EFA and mVcfc remained above baseline (52% and 2.64 circumferences/s, respectively). ESWS was not significantly increased from baseline. We conclude that ephedrine improves left ventricular contractility, even in the presence of high thoracic epidural anesthesia, without causing relevant changes of left ventricular afterload.

Adult↗

PubMed1993

Influence of high thoracic epidural anesthesia on left ventricular contractility assessed using the end-systolic pressure-length relationship.

The effect of high thoracic epidural anesthesia (TEA on left ventricular contractility was studied in a prospective clinical trial. Forty-eight patients with ASA physical status 1 and 2 and without cardiovascular disease were included in the study. Thirty-six patients scheduled for elective upper abdominal surgery were randomly assigned to Group 1 (TEA, bupivacaine 0.25%, n = 12), Group 2 (TEA, bupivacaine 0.5%, n = 12) or to Group 3 (control without TEA, n = 12). TEA induced a sensory block which extended over all cardiac segments. In order to assess the effect of systemically absorbed bupivacaine, we studied a separate group of patients who received lumbar epidural anesthesia without involvement of the cardiac segments: Group 4 (LEA, bupivacaine 0.5%, n = 10). Left ventricular contractility was assessed using the end-systolic pressure-length relationship. Left ventricular dimensions were measured by transesophageal echocardiography. All hemodynamic measurements were performed under general anesthesia. There was no significant difference in systolic or diastolic arterial pressure, heart rate, left ventricular end-systolic and end-diastolic cross-sectional areas and left ventricular wall stress between the four groups. Left ventricular maximum elastance as a measure of left ventricular contractility was significantly (P < 0.001) reduced in Groups 1 and 2 [8.1 (+/- 3.5) and 9.6 (+/- 4.4) kPa.cm-1, respectively] as compared to Groups 3 and 4 [18.4 (+/- 8.8) and 17.7 (+/- 7.7) kPa.cm-1, respectively]. No significant difference could be demonstrated between Groups 1 and 2 or between Groups 3 and 4. It is concluded that high TEA severely alters left ventricular contractility even in subjects without pre-existing cardiac disease.

Abdomen↗

PubMed1993

Effect of phenylephrine bolus administration on left ventricular function during high thoracic and lumbar epidural anesthesia combined with general anesthesia.

The effect of phenylephrine (PHE) boluses on left ventricular (LV) function was examined in patients without cardiovascular disease who developed arterial hypotension during high thoracic epidural anesthesia (TEA) combined with general anesthesia (GA) (group 1) or lumbar epidural anesthesia (LEA) combined with GA (group 2). LV function was assessed by transesophageal echocardiography (TEE) before and after central venous injection of 1 microgram/kg PHE. Fractional diameter shortening (FDS), end-systolic wall stress (ESWS), and rate-corrected velocity of circumferential fiber shortening (mVcfc) were determined. PHE effectively restored arterial blood pressure in both groups with a peak effect between 30 and 45 s after injection. FDS was reduced from 38% to 25% (mean, P < 0.01) in group 1 and remained unchanged in group 2. ESWS increased from 70 to 143 x 10(3) dyne.cm-2 (P < 0.01) and from 57 to 86 x 10(3) dyne.cm-2 (P < 0.05), in groups 1 and 2, respectively. mVcfc was significantly reduced from 1.11 to 0.80 circ/s (P < 0.05) in group 1 and was not altered in group 2. The authors conclude that PHE given as an intravenous bolus to patients under high TEA plus general anesthesia causes a transient impairment of LV function.

Abdomen↗

PubMed1992

Baroreflex control of heart rate during high thoracic epidural anaesthesia. A randomised clinical trial on anaesthetised humans.

Baroreflex control of heart rate after cardiac sympathectomy induced by thoracic epidural anaesthesia was evaluated in 30 patients who were randomly assigned to group 1 (bupivacaine 0.25%), group 2 (bupivacaine 0.5%) or group 3 (control). Plasma volume expanders were given to equalize preload conditions, as assessed using transoesophageal echocardiography. All measurements were made under general anaesthesia. Baroreflex sensitivity was determined from the heart rate response to phenylephrine and nitroglycerin. There was no difference in cardiac slowing in response to phenylephrine between the three groups. Baroreflex sensitivity, measured as cardiac acceleration in response to nitroglycerin, was significantly lower (p < 0.01) in groups 1 and 2 (1.8 and 1.5 ms.mmHg-1 respectively) compared with group 3 (3.5 ms.mmHg-1) with no differences between the two bupivacaine concentrations. The results suggest that baroreflex-mediated response to decreases in arterial pressure is dependent on the integrity of the sympathetic nervous system.

Adult↗

PubMed1991

[Patient-controlled analgesia versus epidural analgesia using bupivacaine or morphine following major abdominal surgery. No difference in postoperative morbidity].

In 1987, Yeager et al. reported that intraoperative epidural anesthesia with local anesthetics and postoperative epidural analgesia with opiates diminished postoperative morbidity. In our first clinical trial on this topic, the better postoperative analgesia with epidural bupivacaine-fentanyl failed to improve the outcome after major abdominal operations over that obtained with parenteral piritramide. This randomized controlled investigation was designed to assess whether intraoperative epidural anesthesia with bupivacaine plus light general anesthesia and postoperative epidural analgesia with morphine would diminish the overall rate of postoperative complications after major abdominal operations compared with general anesthesia (without epidural) followed by patient controlled analgesia with morphine, and with intraoperative epidural anesthesia with bupivacaine and light general anesthesia followed by postoperative bupivacaine-morphine analgesia. METHODS. A total of 292 patients undergoing infrarenal aortic bypass operation, gastric resection, gastrectomy, duodenum-preserving pancreatic resection, Whipple's operation or cystectomy and neobladder formation were randomly divided into three groups: 1. PCA group (patient controlled analgesia, n = 107): patients were operated on under general anesthesia (midazolam, fentanyl, N2O/O2, if necessary with addition of halothane, enflurane or isoflurane; muscle relaxation with pancuronium bromide). Postoperative management consisted in patient-controlled analgesia with morphine (Prominject), bolus 2 mg, lock-out 5 min (recovery room, intensive care unit) or 15 min (surgical ward). 2. EBM group (epidural bupivacaine+morphine, n = 95): operation under light general anesthesia (midazolam, low-dose fentanyl, N2O/O2, pancuronium bromide). In addition, a mixture of bupivacaine (0.25%) and morphine (60 micrograms/ml) was infused (approximately 0.1 ml/kg.h) via an epidural catheter during and after the operation (approximately 72 h). 3. EM group (epidural morphine, n = 90): operation under the same kind of general-epidural anesthesia as in the EBM group. Postoperatively, epidural injection of morphine (0.05 mg/kg in 10 ml of saline) on request up to the 3rd postoperative day. Quality of analgesia (at rest and when patients coughed vigorously), strength of cough, and rate-pressure product were recorded at 8:00 h, 12:00 noon, 16:00 h and 20:00 h on the 1st, 2nd and 3rd postoperative days. Incidence and intensity of all postoperative complications (cardiovascular, pulmonary, renal and other organ failure, reoperations, major infection, sepsis, thromboembolism, metabolic and mental disturbances) were assessed from the day of operation until discharge or death (n = 10), respectively. RESULTS AND DISCUSSION. In the PCA and EM groups analgesia was equal but of slightly inferior quality compared with the EBM group. The ability to cough was best in the EBM group and significantly worse in the PCA and EM groups, with no difference between the last two. (ABSTRACT TRUNCATED AT 400 WORDS)

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