[Delta(9)-tetrahydrocannabinol and the opioid receptor agonist piritramide do not act synergistically in postoperative pain]. / Keine synergistische Wirkung der Kombination von Delta(9)-Tetrahydrocannabinol und Piritramid bei postoperativen Schmerzen.

BACKGROUND: It is concluded from animal experiments that cannabinoid receptor and mu-opioid receptor agonists act synergistically with respect to antinociception. In order to demonstrate this effect under clinical conditions, we conducted a randomized double blind trial with patients after radical prostatectomy. PATIENTS AND METHODS: From the evening before the operation until the morning of the second postoperative day, all patients received eight oral doses of either placebo or 5 mg Delta(9)-tetrahydrocannabinol (dronabinol). Postoperatively patients had access to patient-controlled analgesia with the micro-opioid agonist piritramide for 48 h. We expected patients receiving dronabinol to require significantly less piritramide compared to patients on placebo. RESULTS: The consumption of piritramide was recorded in 100 patients after radical retropubic prostatectomy with regional lymphadenectomy. Patients in the placebo group consumed 74 mg (median), interquartile range (IQR) 44-90 mg, patients in the verum group consumed 54 mg (median) IQR 46-88 mg. The difference between groups was not statistically significant. Plasma concentrations of Delta(9)-THC were measurable in all patients in the verum group. The levels (median) were 1.5 ng/ml (IQR 0.6-2.3), 1.3 ng/ml (IQR 0.5-2.2) and 1.9 ng/ml (IQR 0.8-2.7) on the day of operation, the first and second postoperative day, respectively. CONCLUSION: We found neither a synergistic nor even an additive antinociceptive interaction between Delta(9)-tetrahydrocannabinol and the micro-opioid agonist piritramide in a setting of acute postoperative pain.

Ibuprofen does not impair renal function in patients undergoing infrarenal aortic surgery with epidural anaesthesia.

OBJECTIVE: To investigate the effect of preoperative ibuprofen administration on renal function during and after infrarenal aortic surgery under thoracolumbar epidural anaesthesia (EPA). DESIGN: A prospective randomised, double-blinded clinical study. SETTING: Operation room and intensive care unit in a university hospital. PATIENTS: Twenty-six consecutive patients scheduled for elective infrarenal aortic surgery. INTERVENTIONS: The patients were prospectively randomised to receive 400 mg ibuprofen intravenously (i.v.) or a placebo aliquot before surgery. MEASUREMENTS AND RESULTS: We assessed renal function by calculating creatinine clearance, and fractional sodium excretion before surgery (baseline), 1 h after cross-clamping (intraoperative), 6 h after cross-clamping (postoperative) and 24 h after cross-clamping (on the 1 st postoperative day). At each point in time, we additionally registered haemodynamics and determined the plasma concentration of 6-keto-PGF1alpha (stable metabolite of prostacyclin, PGI2), bicyclic PGE2 (stable metabolite of PGE1 E2), active renin, aldosterone and vasopressin by radioimmunoassays. Throughout the observation period the renal function parameters mostly remained within the normal range without a significant difference between ibuprofen- and placebo-treated patients (creatinine clearance: baseline 41 +/- 3 vs 38 +/- 6, intraoperative 57 +/- 8 vs 64 +/- 11, postoperative 64 +/- 9 vs 56 +/- 9, first postoperative day 43 +/- 5 vs 47 +/- 6 ml x min x m(-2), means +/- SEM). The plasma levels of 6-keto-PGF1alpha (68 +/- 8 vs 380 +/- 71* ng x l(-1)), bicyclic PGE2 (57 +/- 5 vs 88 +/- 9* ng x l(-1)) and vasopressin (14 +/- 7 vs 45 +/- 10* ng x l(-1), p < 0.0125), however, were significantly higher during the intraoperative period in the placebo-treated patients. CONCLUSION: The inhibition of endogenous prostaglandin release by ibuprofen does not substantially impair renal function during infrarenal aortic surgery under EPA.

[Epidurography: comparison with CT, spiral CT and MR epidurography]. / Die Epidurographie: Vergleich mit CT-, Spiral-CT- und MR-Epidurographie.

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.

[Postoperative analgesia after endoscopic abdominal operations. A randomized double-blind study of perioperative effectiveness of metamizole]. / Postoperative Analgesie nach endoskopischen abdominellen Operationen. Eine randomisierte Doppelblindstudie zur perioperativen Wirksamkeit von Metamizol.

In comparison to conventional operating technique endoscopic surgery reveals numerous advantages, particular rapid mobilisation and earlier discharge from observation. For a effective utilization of these advantages, it is desirable to have a efficient postoperative analgesic scheme, which can be continued into the period after discharge from hospital. In a randomised, prospective double-blind study we investigated the analgesic efficacy of dipyrone in 40 patients, scheduled for endoscopic abdominal surgery (mainly endoscopic cholecystectomy). Patients received before induction of anesthesia either dipyrone (1 g/100 ml NaCl i.v.) or placebo (100 ml NaCl i.v.). These infusions were repeated 6 h and 12 h after first application. After surgery all patients were allowed to self-administer buprenorphine intravenously from a PCA-pump (Bolus 30 micrograms, 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), pulse, blood pressure and side effects were recorded. Dipyrone-treated patients had significantly less pain immediately after surgery and used a significantly lower cumulated dose of buprenorphine (-67%; 90 micrograms vs. 270 micrograms buprenorphine) in the first 24 h after surgery.

[Imbalances of the water and electrolyte status]. / Imbalanzen im Wasser- und Elektrolytstatus.

Nutritional therapy can be impaired if imbalances in water and electrolyte status have led to gross disorders of the cardiovascular, pulmonary, renal, metabolic, and central nervous systems. Restauration and maintenance of the functional extracellular fluid volume is the primary therapeutic goal in water and electrolyte resuscitation. Hyper- and hypoosmolar disturbances are automatically corrected by intrinsic regulatory mechanisms. Potassium deficiency or overload, or potassium disequilibrium between the intracellular and extracellular space can lead to dangerous cardiac arrhythmias. Hyper- and hypokalemia usually develop within days or even weeks and should not be corrected within a few hours. If life threatening hyperkalemia develops during acute renal failure, 20 ml 10% calcium gluconate solution can be given intravenously in order to avoid ventricular fibrillation or cardiac arrest. The discrimination between prerenal disease, acute tubular necrosis and other causes of acute renal failure is based on special investigations, such as urinary osmolality, urinary sodium concentration, clearance of creatinine, osmolar solutes, free water, and fractional sodium excretion. The clinical examination of a patient should be the basis of assessing his water and electrolyte state. Laboratory findings which are in disagreement with the clinical state have to be repeated, critically interpreted, but not completely rejected. Third space losses make fluid balance difficult.

[Unexpected intravenous penetration of an epidural catheter]. / Versehentlich intravasale Lage eines Periduralkatheters.

The tip of an epidural catheter inserted by the lumbar route, penetrated into the inner vertebral venous plexus. After the position of the catheter tip had been corrected, blood neither returned spontaneously nor could any be aspirated, suggesting that it was in the correct position. A low dose (3.5 ml) of 0.75% bupivacaine was given as a test injection whereupon no signs of a systemic reaction were observed. When the entire initial dose of 10 ml was given, the patient developed tonic clonic seizures. The fit could be controlled by giving oxygen and thiobarbital. The patient was given succinylcholine and then intubated and ventilated. As no signs of cardiac depression were noted, the operation (open mobilisation of a joint) was performed under general anaesthesia. The patient recovered normally. If the position of an epidural catheter which has penetrated an epidural vein has been corrected, this does not ensure that the tip has been removed from the vein, even if blood cannot be aspirated. This incorrect position can be detected by injection of a small volume of epinephrine-containing local anaesthetic, but this procedure cannot be recommended in cases of coronary insufficiency. The anaesthesist is best advised to remove the catheter completely and place a fresh epidural at a different level.

[Subarachnoid placement of a peridural catheter with high spinal anesthesia. The advantage of 0.25 % bupivacaine]. / Subarachnoidale Lage eines Periduralkatheters mit hoher Spinalanaesthesie. Der Vorteil von 0.25%igem Bupivacain.

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.

[Unilateral epidural anesthesia]. / Die einseitige Epiduralanaesthesie.

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.

[Malignant hyperthermia in a 41-year-old woman]. / Maligne Hyperthermie bei einer 41jährigen Patientin.

Malignant hyperthermia is one of the most devastating crises encountered in anaesthesia and it frequently occurs unexpectedly. Although malignant hyperthermia develops in young individuals (mean age approximately 22 years), older people can also be affected. The case of a 41-year-old woman with a history of several previously uneventful general anaesthetics is described. She developed the complete symptomatology of malignant hyperthermia triggered by halothane anaesthesia, with tachycardia, cardiac arrhythmia, cyanosis, combined respiratory and metabolic acidosis and hyperpyrexia. Because treatment with dantrolene and hyperventilation with 100% O2 was started immediately, the symptoms of malignant hyperthermia were stopped within a short time. It should always be remembered, that the life threatening crises which can be caused by malignant hyperthermia can occur at any age and even after several uneventful anaesthetics.

[Influence of postoperative pain on morbidity and mortality.]. / Beeinflußt die Schmerztherapie postoperative Morbidität und Letalität?

Postoperative pain can intensify the sympathoadrenergic reaction, which is commonly seen after surgery, and thus possibly pave the way for certain complications, such as coronary ischemia, bronchopneumonia, intestinal stasis, thromboembolism, infection, sepsis, and metabolic disturbances. Investigations of cardiovascular, respiratory, gastrointestinal, metabolic, and immunologic function indicate that high-quality pain relief can diminish postoperative organ impairment and failure. Some aspects of the improvements attributed to the quality of analgesia, such as prevention of tachycardia and hypertension, attenuation of hyperglycemia and catabolism, improvement of gastrointestinal motility and cellular immunity cannot be definitely distinguished from the effects of sympathetic blockade due to epidural analgesia with local anesthetics, however. There is another aspect of the problem. The better the quality of postoperative pain relief, the more likely it is that analgesia-related complications, such as respiratory depression (opioids), cardiovascular depression (epidural local anesthetics), renal failure (NSAIDs) and bladder dysfunction (epidural opioids and local anesthetics) will occur. The question of whether postoperative morbidity and mortality can be reduced by effective analgesia has been investigated in the past few years. Some studies indicate that better analgesia is advantageous for the patient, especially with respect to postoperative complications, hospital stay, long-term well being, and costs. In other clinical trials incorporating more patients, however, this hypothesis had to be rejected. At present, therefore, we cannot state that effective pain relief influences postoperative morbidity and mortality.

Spinal epidural abscess: a meta-analysis of 915 patients.

Spinal epidural abscess (SEA) was first described in the medical literature in 1761 and represents a severe, generally pyogenic infection of the epidural space requiring emergent neurosurgical intervention to avoid permanent neurologic deficits. Spinal epidural abscess comprises 0.2 to 2 cases per 10,000 hospital admissions. This review intends to offer detailed evaluation and a comprehensive meta-analysis of the international literature on SEA between 1954 and 1997, especially of patients who developed it following anesthetic procedures in the spinal canal. In this period, 915 cases of SEA were published. This review is the most comprehensive literature analysis on SEA to date. Most cases of SEA occur in patients aged 30 to 60 years, but the youngest patient was only 10 days old and the oldest was 87. The ratio of men to women was 1:0.56. The most common risk factor was diabetes mellitus, followed by trauma, intravenous drug abuse, and alcoholism. Epidural anesthesia or analgesia had been performed in 5.5% of the patients with SEA. Skin abscesses and furuncles were the most common source of infection. Of the patients, 71% had back pain as the initial symptom and 66% had fever. The second stage of radicular irritation is followed by the third stage, with beginning neurological deficit including muscle weakness and sphincter incontinence as well as sensory deficits. Paralysis (the fourth stage) affected only 34% of the patients. The average leukocyte count was 15,700/microl (range 1,500-42,000/microl), and the average erythrocyte sedimentation rate was 77 mm in the first hour (range 2-50 mm). Spinal epidural abscess is primarily a bacterial infection, and the gram-positive Staphylococcus aureus is its most common causative agent. This is true also for patients who develop SEA following spinal anesthetics. Magnetic resonance imaging (MRI) displays the greatest diagnostic accuracy and is the method of first choice in the diagnostic process. Myelography, commonly used previously to diagnose SEA, is no longer recommended. Lumbar puncture to determine cerebrospinal fluid protein concentrations is not needed for diagnosis and entails the risk of spreading bacteria into the subarachnoid space with consequent meningitis; therefore, it should not be performed. The therapeutic method of choice is laminectomy combined with antibiotics. Conservative treatment alone is justifiable only for specific indications. Laminotomy is a therapeutic alternative for children. The mortality of SEA dropped from 34% in the period of 1954-1960 to 15% in 1991-1997. At the beginning of the twentieth century, almost all patients with SEA died. Parallel to improvements in the mortality rate, today more patients experience complete recovery from SEA. The prognosis of patients who develop SEA following epidural anesthesia or analgesia is not better than that of patients with noniatrogenic SEA, and the mortality rate is also comparable. The essential problem of SEA lies in the necessity of early diagnosis, because only timely treatment is able to avoid or reduce permanent neurologic deficits. The problem with spinal epidural abscesses is not treatment, but early diagnosis - before massive neurological symptoms occur" (Strohecker and Grobovschek 1986).

[Postoperative pulmonary function following abdominal surgery. Comparison of continuous, segmental thoracic peridural anesthesia and intramuscular piritramide injections]. / Untersuchungen zur postoperativen Lungenfunktion nach abdominellen Eingriffen. Vergleich zwischen kontinuierlicher, segmentaler, thorakaler Periduralanaesthesie und intramuskulär injiziertem Piritramid.

Respiratory function was studied in 35 patients after upper abdominal surgery, who had been randomized into two groups. 15 patients (median age: 59 years) were operated on using neuroleptanalgesia and received intramuscular piritramide as postoperative analgesic. A continuous thoracic epidural was placed prior to surgery in 20 patients (median age 52 years). A light general anaesthesia was additionally given when these patients were operated on. Postoperatively, epidural analgesia was continued by infusion of 0.25-0.3 ml/kg X h 0.125% bupivacaine via epidural catheter over a period of 4 days. If pain prevention during coughing and getting up was not complete, top-ups of 6-10 ml 0.25% bupivacaine were given additionally. Respiratory function (FVC, peak expiratory flow, VT, VD/VT, RR, MV, VA, AaDO2(0.21), PaO2 and PaCO2) was investigated before surgery, and on the 1st, 3rd and 5th postoperative day, the patients breathing room air. Results (the median of each groups is plotted, the values of the epidural group being in brackets. 0: preop., 1: first, 3: third, 5: fifth postop. day): FVC 0: 3.05 (3.16) 1: 1.42 (1.40) 3: 1.64 (1.42) 5: 1.39 (2.27) 1. Peak expiratory flow 0: 310 (287) 1: 118 (113) 3: 130 (127) 5: 153 (194) 1/min. Respiratory rate 0: 16 (14.5) 1: 20 (18.5) 3: 16 (18.5) 5: 17 (17) min-1.(ABSTRACT TRUNCATED AT 250 WORDS)

[Postoperative peridural analgesia via catheter following abdominal surgery. Peridural bupivacaine versus buprenorphine]. / Postoperative Katheterperiduralanalgesie nach abdominellen Eingriffen. Bupivacain versus Buprenorphin peridural.

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...

Spinal hematoma: a literature survey with meta-analysis of 613 patients.

Spinal hematoma has been described in autopsies since 1682 and as a clinical diagnosis since 1867. It is a rare and usually severe neurological disorder that, without adequate treatment, often leads to death or permanent neurological deficit. Epidural as well as subdural and subarachnoid hematomas have been investigated. Some cases of subarachnoid spinal hematoma may present with symptoms similar to those of cerebral hemorrhage. The literature offers no reliable estimates of the incidence of spinal hematoma, perhaps due to the rarity of this disorder. In the present work, 613 case studies published between 1826 and 1996 have been evaluated, which represents the largest review on this topic to date. Most cases of spinal hematoma have a multifactorial etiology whose individual components are not all understood in detail. In up to a third of cases (29.7%) of spinal hematoma, no etiological factor can be identified as the cause of the bleeding. Following idiopathic spinal hematoma, cases related to anticoagulant therapy and vascular malformations represent the second and third most common categories. Spinal and epidural anesthetic procedures in combination with anticoagulant therapy represent the fifth most common etiological group and spinal and epidural anesthetic procedures alone represent the tenth most common cause of spinal hematoma. Anticoagulant therapy alone probably does not trigger spinal hemorrhage. It is likely that there must additionally be a "locus minoris resistentiae" together with increased pressure in the interior vertebral venous plexus in order to cause spinal hemorrhage. The latter two factors are thought to be sufficient to cause spontaneous spinal hematoma. Physicians should require strict indications for the use of spinal anesthetic procedures in patients receiving anticoagulant therapy, even if the incidence of spinal hematoma following this combination is low. If spinal anesthetic procedures are performed before, during, or after anticoagulant treatment, close monitoring of the neurological status of the patient is warranted. Time limits regarding the use of anticoagulant therapy before or after spinal anesthetic procedures have been proposed and are thought to be safe for patients. Investigation of the coagulation status alone does not necessarily provide an accurate estimate of the risk of hemorrhage. The most important measure for recognizing patients at high risk is a thorough clinical history. Most spinal hematomas are localized dorsally to the spinal cord at the level of the cervicothoracic and thoracolumbar regions. Subarachnoid hematomas can extend along the entire length of the subarachnoid space. Epidural and subdural spinal hematoma present with intense, knife-like pain at the location of the hemorrhage ("coup de poignard") that may be followed in some cases by a pain-free interval of minutes to days, after which there is progressive paralysis below the affected spinal level. Subarachnoid hematoma can be associated with meningitis symptoms, disturbances of consciousness, and epileptic seizures and is often misdiagnosed as cerebral hemorrhage based on these symptoms. Most patients are between 55 and 70 years old. Of all patients with spinal hemorrhage, 63.9% are men. The examination of first choice is magnetic resonance imaging. The treatment of choice is surgical decompression. Of the patients investigated in the present work, 39.6% experienced complete recovery. The less severe the preoperative symptoms are and the more quickly surgical decompression can be performed, the better are the chances for complete recovery. It is therefore essential to recognize the relatively typical clinical presentation of spinal hematoma in a timely manner to allow correct diagnostic and therapeutic measures to be taken to maximize the patient's chance of complete recovery.

[Epidural and intrathecal administration of alpha 2-adreno-ceptor agonists for postoperative pain relief]. / Epidurale und intrathekale Anwendung von alpha2-Adrenozeptor-Agonisten zur postoperativen Analgesie.

Spinal clonidine interacts with pre- and postsynaptic alpha(2)-adrenoceptors on afferent neurons in the superficial dorsal horn of the spinal cord: it causes analgesia by inhibition of the synaptic and electrotonic neurotransmission of nociceptive impulses. Epidural doses higher than 4 microg/kg have an analgesic onset time of less than 30 min, reduce pain by more than 70 %; these effects last for 4-5 h. Epidural clonidine analgesia is accompanied by a reduction in heart rate, cardiac output and blood pressure of approximately 20 % compared with baseline. The haemodynamic side effects mean close supervision is needed during the first hour after epidural application and limit the use of epidural clonidine to patients who are refractory to the analgesic effects of epidural opioid or local anaesthetics. In these patients excellent results can be achieved either with clonidine alone or with a combination of clonidine and an opioid or a local anaesthetic to exploit the additive or supra-additive interactions of these drugs.

[Complications of the postoperative use of lumbar epidural catheters in place for surgery]. / Komplikationen bei der postoperativen Verwendung von zur Operation gelegten, lumbalen Epidural-Kathetern.

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.

[Early postoperative mobilization of the knee joint following arthrolysis with continuous catheter peridural anesthesia]. / Postoperative Frühmobilisation des Kniegelenks nach Arthrolyse mit kontinuierlicher Katheterperiduralanaesthesie.

21 patients with stiffness of the knee were operated on, for mobilisation under epidural analgesia. As soon as the patients returned to the ward the leg was placed on a mobilisation-splint driven by an electric motor. Epidural analgesia was continued by infusion of 0.25 ml/kg . h of 0.125% bupivacaine via epidural catheter for a period of four to six days whereafter the catheter was removed. Analgesia during mobilisation was complete or almost complete in 15 patients. In 5 cases loss of sensitivity was present predominantly or selectively in the contralateral extremity, in one patient segmental extension of epidural analgesia did not include the knee. The bladder had to be catheterized in 9 patients, three suffered from decubital ulcers which disappeared after removal of the epidural catheter. In spite of the frequency of side effects, which can be diminished by further experience, continuous epidural analgesia is advantageous for early mobilisation of the knee after arthrolysis. The patients must be informed about side effects and possible complications before giving their consent for this method of long lasting analgesia.