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W Seeling

Publications and source records attributed to W Seeling.

At least 55 records · Page 3Linked to original sources
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].

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

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)

Abdomen↗
PubMed1991

[Subarachnoid placement of a peridural catheter with high spinal anesthesia. The advantage of 0.25 % bupivacaine].

A 72-year-old female patient was scheduled for abdominal surgery with epidural block in combination with general anesthesia. An 18 G epidural catheter was inserted through an 18 G Tuohy needle between T12 and L1 using the midline approach and the 'loss of resistance' technique. A test dose of 13 ml bupivacaine 0.25% showed no effect and a bolus of 12 ml bupivacaine 0.25% was added 8 min later. Bilateral analgesia between S5 and C4 developed over the following 17 min but was not accompanied by any cardiovascular or respiratory depression. The patient became sleepy and was finally intubated after the administration of thiopentone 175 mg and pancuronium 6 mg. There were no objections to surgery, so the hemicolectomy was continued as planned. Intraoperatively the systolic blood pressure dropped twice, to a minimum of 105 mm Hg, coinciding with eventration of the intestine, but this was reversed immediately on administration of a vasoconstrictor. Extubation of the patient was possible 90 min later on the termination of surgery, when the level of anesthesia had reached T2. A spinal X-ray with radiopaque dye showed a typical intrathecal distribution. Most remarkable in this case is the stability of the cardiovascular function which in our opinion is related to the 0.25% solution. Serious complications of an inadvertent dural puncture can be avoided or alleviated with this concentration if the epidural block is to be combined with general anesthesia.

Aged↗
PubMed1990

[Postoperative peridural analgesia via catheter following abdominal surgery. Peridural bupivacaine versus buprenorphine].

Seventy-five patients scheduled for major abdominal operations were randomly divided into four groups, each with a different postoperative analgesic regime. Group I: buprenorphine 4 micrograms/kg was injected i.v. every 4 h. Groups II-IV: all patients were preoperatively supplied with a thoracic epidural catheter that, however, was not used during the operation. Group II: bupivacaine 0.15 ml/kg was injected epidurally every 2 h, the first dose being 0.5%, the top-ups 0.25%. Group III: buprenorphine 4 micrograms/kg in 10 ml saline was given via the catheter and repeated on request. Group IV: these patients received a combined regime. Bupivacaine was injected as in group II, and in addition buprenorphine was added epidurally in the doses and time intervals of group I. After extubation the patients categorized the intensity of postoperative pain twice, first while lying immobile and then after coughing vigorously, using a rating scale with pain scores from 0 to 10. Thereafter, the analgesic regime described above commenced. One hour later the patients' pain scores were again determined. In addition to pain scores, heart rate (HR), mean arterial pressure (MAP) and paCO2 were recorded at the same points in time. The investigation was then interrupted overnight. The analgesic regime continued as described for groups I and II. Patients in group III received 0.15 mg buprenorphine on request i.v., and in group IV bupivacaine was given as in group II with no further buprenorphine. The study recommenced the next morning at 7:00 a.m. After the initial values (pain scores, HR, MAP, paCO2) had been recorded the analgesic program, as scheduled for each patient, restarted. In group IV buprenorphine was again added to bupivacaine and repeated every 4 h, whereas bupivacaine was injected every 2 h. All values were registered hourly until 7:00 p.m., when the investigation was terminated. RESULTS. On the day of operation and during the first few hours on the morning thereafter, analgesia in groups II and IV was considerably better compared to groups I and III (P less than 0.001). We could not statistically demonstrate, however, that analgesia in group IV was superior to that in group II despite the fact that pain scores were lowest in this group, with a median at rest of 0 throughout the study time. In group III (n = 20), epidural buprenorphine failed to produce any acceptable analgesic effect in 6 patients despite correct catheter position. For this reason they were dropped from the study. No patient in any of the other groups, however, was dropped (P less than 0.01). Later in the 1st postoperative day analgesia in groups II and IV lost its superiority at rest, but coughing continued to be less painful in comparison to groups I and III. We noticed that the duration of action of 0.25% bupivacaine, injected as a bolus, was considerably shorter than expected (less than 2 h) and that several patients experienced pain before the next top-up was given...

Abdomen↗
PubMed1990

[Unilateral epidural anesthesia].

Four cases of unilateral spread of epidural anesthesia are presented. All were documented by X-ray epidurography. In two patients the catheter had passed immediately into one of the intervertebral foramina so that the local anesthetic had almost totally been injected into the paravertebral space. In the third and fourth cases a membrane was present in the dorsal epidural space that had prevented bilateral spread of the local anesthetic. This article discusses the fact that strands of the dorsomedian connective tissue band of the lumbar epidural space can cause catheters to coil up, be diverted, and not infrequently be directed into the next intervertebral foramen. These strands sometimes form a dense membrane, which together with the plica mediana of the dura mater prevent symmetrical spreading of epidurally injected fluids. When informing a patient about epidural anesthesia, the anesthesiologist should mention that anatomical variations in the epidural space can cause epidural anesthesia to spread unilaterally.

Adult↗
PubMed1990

[Complications of the postoperative use of lumbar epidural catheters in place for surgery].

Two cases of secondary subarachnoidal dislocation of lumbar epidural catheters are reported. The first catheter was placed, tested, and injected with 20 ml local anesthetic in order to achieve intraoperative anesthesia up to the T4 level. On the 2nd postoperative day the test dose produced paralysis of the lower extremities; liquor now could be aspirated. The second catheter had been introduced into the epidural space immediately after injection of 15 ml local anesthetic through the needle. Use of this catheter for postoperative analgesia led to total spinal anesthesia in spite of negative aspiration and test dose prior to injection of 7 ml local anesthetic. Implications of these two cases concerning placement procedures and monitoring during reuse of catheters placed some time before are discussed.

Aged↗