[Life-threatening complication of schizophrenia]

The Wernicke Encephalopathy (WE) as a result of a (sub)acute thiamine deficiency remains, unfortunately, still under-diagnosed, especially among non-alcoholics. It should be considered in each occurrence of delirium as well as in any ocular motor disorder and ataxia, in particular if there is a history of weight loss with or without gastrointestinal symptoms. In cases with suspected WE an immediate intravenous substitution of 3×200 mg/d is recommended.

[Continuous intrathecal administration of medication. Special features in anaesthesiology and intensive care]

In anaesthesiological and intensive care practice patients are increasingly being treated with implanted medication pumps. Basic knowledge on the special aspects of this form of therapy is therefore important. During the preanasthesiology visit, information on the pump, the intrathecal catheter, type and dosage of the medication as well as the next scheduled refilling must be collected and documented. Needle punctures near the pump and the catheter must be avoided. During intensive care treatment any possible interaction and overdosing or underdosing of the intrathecally administered medication must be considered. Information on the schedule and punctual organisation of refilling are important to avoid complications.

Die präklinische Diagnose der traumatischen Querschnittlähmung - eine prospektive Studie an 100 Patienten

OBJECTIVE

To avoid neurological deterioration, traumatic spinal cord injury has to be recognized as early as possible. Aim of the study was to analyze alterations of the neurological level of injury in the preclinical interval.

METHODS

In a prospective observational study the clinical diagnoses of 100 patients referred to the Swiss Paraplegic Centre in Nottwil, Switzerland, were compared to the preclinical diagnoses.

RESULTS

In 12 patients we observed neurological deterioration for more than 2 spinal segments. Six of these patients had been diagnosed preclinically with paraplegia at a neurological level of T4 or T5, whereas the evaluation in the hospital showed cervical spinal cord injury and tetraplegia.

CONCLUSION

Possible reasons for this neurological deterioration can be secondary damages of the nervous tissue due to vascular, metabolic or biochemical mechanisms, transportation trauma or insufficient preclinical diagnostics. There is no evidence for a higher risk of secondary tissue damage for patients with cervical spinal cord injury. None of the six patients had additional injuries of the spinal cord or the vertebral column in the thoracic region, therefore transportation trauma is also unlikely. It is more likely that preclinical diagnoses were incorrect, what could have been avoided by consequent sensory and motor testing at the upper extremities.

Einsatz der WHO-Leitlinien für die Tumorschmerztherapie vor Zuweisung in eine Schmerzklinik

In 1986 the World Health Organization (WHO) released guidelines for cancer pain relief. Since then, several controlled studies on effectiveness and practicability of these guidelines have been published. Various authors described inadequate use of these guidelines. We analysed, whether the pain medication of 160 cancer patients referred to the anesthesiological pain clinic at the university hospital of Vienna corresponded to the WHO guidelines or not. Adequacy of pain treatment was assessed using the pain management index (PMI). Multiple criteria were chosen to assess the conformity of the treatment with the guidelines. Furthermore we studied the effect of a strict use of the WHO guidelines in these patients. The average pain intensity of the referred patients was 75 mm (VAS). Negative PMI scores, indicating inadequate pain therapy, were found in 39 % of cases. A violation of the rules was found in 38% of the therapy schedules. Pain medication was then modified by switching to fixed time intervals, escalation of the steps of the WHO ladder, increasing the dosage or treating neuropathic pain with adjuvant drugs. Two weeks later the average pain score of the patients was reduced to 27 mm (VAS). At that time 72% of the patients quoted an adequate reduction of pain. Inadequate knowledge or disregard of the WHO guidelines for cancer pain relief are common and result in unnecessary and prolonged suffering in these patients.

CT-gesteuerte perkutane Nukleotomie mit dem Dissektor zur Therapie chronischer Rückenschmerzen mit radikulärer Ausstrahlung

Percutaneous disc decompression using the Decompressor system is another treatment option for patients suffering from chronic discogenic leg pain. This is the first report on a patient undergoing this procedure under CT-control. A 49 year old man with radicular leg pain showed significant pain reduction after percutaneus decompression of a discal herniation at the L4/5 level. The new system enables qualitative and quantitative measures of the removed disc material. CT-control ensures exact positioning of the device.

Comparison between bupivacaine 0.125% and ropivacaine 0.2% for epidural administration to outpatients with chronic low back pain

BACKGROUND AND OBJECTIVE

Epidural blocks should provide good analgesia for the treatment of chronic low back pain without any motor block to allow active physiotherapy. Epidural ropivacaine is known to produce less motor block compared to bupivacaine at anaesthetic concentrations. This prospective, randomized double blind study compares the analgesic, motor block, and haemodynamic effects of single shot epidural injections of ropivacaine 0.2% 10 mL with bupivacaine 0.125% in outpatients suffering from chronic low back pain.

METHODS

Forty patients were assigned to receive either ropivacaine 0.2% (n = 20) or bupivacaine 0.125% (n = 20) within a series of eight single shot epidural blocks.

RESULTS

Thirty-six patients received either ropivacaine 0.2% (n = 18) or bupivacaine 0.125% (n = 18) within a series of eight single shot epidural blocks. Both groups showed no significant differences either in analgesia, or in motor blockade or haemodynamic changes. Thus ropivacaine 0.2% did not reduce the incidence of motor block (9.0% of patients with motor block Bromage scores 1, 2 or 3 in ropivacaine or bupivacaine). The combination of repeated epidural analgesia and physiotherapy reduced the median pain-scores (visual analogu scale, 0-10) from 7 (SD +/- 1.6) at the beginning of the study to 4.1 (SD +/- 1.7) at the end of the series.

CONCLUSIONS

Both bupivacaine 0.125% and ropivacaine 0.29% appear suitable for epidural administration to outpatients with chronic low back pain attending for epidural analgesia associated with physiotherapy (physical therapy).

Multicentre evaluation of in vitro contracture testing with bolus administration of 4-chloro-m-cresol for diagnosis of malignant hyperthermia susceptibility

BACKGROUND AND OBJECTIVE

The in vitro contracture test with halothane and caffeine is the gold standard for the diagnosis of susceptibility to malignant hyperthermia (MH). However, the sensitivity of the in vitro contracture test is between 97 and 99% and its specificity is 78-94% with the consequence that false-negative as well as false-positive test results are possible. 4-Chloro-m-cresol is potentially a more specific test drug for the in vitro contracture test than halothane or caffeine. This multicentre study was designed to investigate whether an in vitro contracture test with bolus administration of 4-chloro-m-cresol can improve the accuracy of the diagnosis of susceptibility to MH.

METHODS

Three hundred and fifty-two patients from 11 European MH laboratories participated in the study. The patients were first classified as MH susceptible, MH normal or MH equivocal by the in vitro contracture test according to the European MH protocol. Muscle specimens surplus to diagnostic requirements were used in this study (MH susceptible = 103 viable samples; MH equivocal = 51; MH normal = 204). 4-Chloro-m-cresol was added to achieve a concentration of 75 micromol L(-1) in the tissue bath. The in vitro effects on contracture development and muscle twitch were observed for 60 min.

RESULTS

After bolus administration of 4-chloro-m-cresol, 75 micromol L(-1), 99 of 103 MH-susceptible specimens developed marked muscle contractures. In contrast, only two of 204 MH-normal specimens showed an insignificant contracture development following 4-chloro-m-cresol. From these results, a sensitivity rate of 96.1% and a specificity rate of 99.0% can be calculated for the in vitro contracture test with bolus administration of 4-chloro-m-cresol 75 micromol L(-1). Forty-three patients were diagnosed as MH equivocal, but only specimens from 16 patients developed contractures in response to 4-chloro-m-cresol, indicating susceptibility to MH.

CONCLUSIONS

The in vitro contracture test with halothane and caffeine is well standardized in the European and North American test protocols. However, this conventional test method is associated with the risk of false test results. Therefore, an improvement in the diagnosis of MH is needed. Regarding the results from this multicentre study, the use of 4-chloro-m-cresol could increase the reliability of in vitro contracture testing.

Inverse relation between stimulus intensity and seizure duration: implications for ECT procedure

A retrospective analysis of the effects of electroconvulsive therapy (ECT) was performed for two groups of 11 patients matched according to age (mean age, 52 years), sex, and diagnosis. Group 1 received ECT according to the age-dose protocol; group 2 was treated according to the titration method. A higher dose relative to the seizure threshold appeared to shorten the seizure duration. At the first treatment, the correlation between stimulus intensity and seizure duration was negative. In the titration group, the initial mean charge of 91 mC resulted in a seizure duration of 51 s, whereas in the age-dose group the seizure duration of 31 s was significantly shorter despite a higher mean charge of 312 mC. Seizure duration decreased during the ECT course in the group treated first at low dose (titrated) and then at 2.5 times the initial threshold. High stimulus intensity represented adequate treatment, although it produced short seizures. Thus, seizure duration proved to be an unreliable guideline for effective treatment. Furthermore, focus on seizure duration led to frequent high-dose restimulation in the elderly. The titration method obviates inadequate or excessive charges because the seizure threshold must first be determined.

The effect of remifentanil on the heat pain threshold in volunteers

Remifentanil offers a wide range of clinical uses and has been successfully combined with general anesthetics. However, there are few human experimental studies demonstrating the analgesic property of remifentanil. It was our aim to determine the analgesic effect of remifentanil with regard to dose-dependent increments in a human model of heat pain threshold assessment. Twenty healthy volunteers were randomized in a double-blinded cross-over design to receive an infusion of remifentanil or saline. The stepped infusion was increased every 5 min by 0.01 microg. kg(-1). min(-1) up to 0.17 microg. kg(-1). min(-1)and terminated in case of defined safety limits. Thermal sensory testing of the heat pain threshold was performed every 5 min at the left forearm. The dose-response relationship and the effective dose for at least 50% of the subjects (ED(50)) were determined. Remifentanil led to a clear dose-dependent increase of the heat pain threshold differing significantly from placebo (P < 0.0007). The ED(50) of remifentanil equals 0.05 microg. kg(-1). min(-1) (first quartile 0.025 microg. kg(-1). min(-1) and third quartile 0.06 microg. kg(-1). min(-1)) in this experimental setting. In conclusion, an opioid-mediated analgesic effect of remifentanil was determined in a human heat pain threshold model. The dose of 0.05 microg. kg(-1). min(-1) is an effective and safe increment in healthy volunteers.

A multicenter study of 4-chloro-m-cresol for diagnosing malignant hyperthermia susceptibility

Standardization of the in vitro contracture test (IVCT) for malignant hyperthermia (MH) susceptibility has resulted in very rare false negative tests. However, false positive results stigmatizing the patient seem to be more frequent than false negative results and make supplementary tests desirable. This multicenter approach studied the usefulness of an IVCT with 4-chloro-m-cresol (4-CmC), a ryanodine receptor-specific agonist for a better definition of MH susceptibility. Diagnosis made by the standard IVCT was compared with the results of this 4-CmC test on muscle specimens of 202 individuals from 6 European MH centers. In the 4-CmC test, the results of the MH susceptible group differed significantly from both the MH normal and the MH equivocal group. 4-CmC revealed a qualitatively dose response-curve similar to caffeine. A correlation index of r = 0.79 for the concentration thresholds underlined the strong concordance of the caffeine and the 4-CmC effects. The optimal threshold concentration was determined to be 75 microM in the pooled data of all centers and is much lower than that of caffeine (2 mM), suggesting a more than 25-fold higher affinity of 4-CmC. The predictive value of 4-CmC is as high as that of caffeine and consequently higher than that of halothane. 4-CmC seems to be a suitable drug to refine diagnosis of MH susceptibility and could be used as an additional test substance.

IMPLICATIONS

Although in vitro contracture testing for malignant hyperthermia diagnosis is well standardized, with a relatively high sensitivity and specificity, false test results cannot be excluded and may be associated with serious disabilities for the concerned individuals. In this multicenter study, 4-chloro-m-cresol was evaluated as a new test substance for the in vitro contracture testing. Its use improves the accuracy of in vitro diagnosis of malignant hyperthermia susceptibility.

[Use of electrocardiographic placement control of central venous catheters in Austria]

After placement of a central venous catheter the correct position of the catheter tip has to be verified. The use of intravascular ECG tracing via a guide-wire or via the saline-filled lumen of the catheter enables immediate and safe control of the position. Only if complications (e.g. pneumothorax) are suspected, further clinical and radiological diagnostics are necessary. Up to now, no data on the routine clinical use of this method are available. In April 1998, a semi-structured questionnaire was sent to the 518 heads of anaesthesiological, surgical and medical departments in Austria (33% of the questionnaires were returned). The subclavian (56%) and internal jugular veins (35%) are most frequently used for catheter insertion in Austria. Verification of the catheter tip placement by ECG-guidance is used in only 8% of cases, while radiographs are performed in most cases. Uncertainty with respect to forensic consequences of using the ECG-guidance for control of the catheter tip placement and the possible necessity of an additional radiograph are the main problems seen by the heads of the departments. After placement of a central venous line, measures for the verification of the catheter tip and measures for the control of possible complications have to be considered separately. Intravascular ECG tracing is unable to detect complications. Concerning the verification of the catheter tip position many studies confirm the easy handling, relevance of results and cost savings for this method. Its use for the control and documentation of the tip location is considered a standard. In Austria the consequent use of the method would offer the chance for significant reductions of treatment costs.

Ropivacaine and bupivacaine for long-term epidural infusion in a small child

Ropivacaine is assumed to be less toxic than bupivacaine but there are no reports concerning its long-term use in paediatric anaesthesia. We report the use of ropivacaine for long-term epidural anaesthesia in a 21-month-old girl. In two consecutive periods of 3 days each, 0.5% bupivacaine and 0.5% or 0.75% ropivacaine were administered to facilitate painful vaginal brachytherapy. The mean dose of bupivacaine increased from 1.05 to 1.32 mg kg-1 h-1 and that of ropivacaine increased from 1.40 to 3.86 mg kg-1 h-1. No toxic side effects were observed. We conclude that both epidural ropivacaine and bupivacaine were effective and safe during long-term epidural anaesthesia in this particular case. However, the doses were potentially toxic and should therefore be used with extreme caution.

[Pain therapy near the spinal marrow. Status survey in Germany and Austria]

OBJECTIVE

The objective of this survey was to investigate the current status of the epidural and intrathecal management in patients with chronic cancer and non-cancer pain in Germany and Austria.

METHODS

In June 1997 a questionnaire was sent to 598 German and Austrian anaesthesiologists specialized in pain therapy. Questions concerning the use of medicaments for epidural and intrathecal treatment of chronic pain were asked.

RESULTS

The response rate was 23%. The data show that 78% of the anaesthesiologists use epidural or intrathecal analgesia in the therapy of chronic pain. Local anaesthetics are used by 85% of these anaesthesiologists, followed by morphine (72%), clonidine (48%), buprenorphine (34%), baclofen (20%), fentanyl (13%) and sufentanil (10%). For most of the treatments local anaesthetics are used, again followed by opioids und clonidine. In the 137 answering pain clinics 79.821 epidural and intrathecal analgetic treatments are performed per year.

DISCUSSION

Epidural and intrathecal pain therapy is frequently used in Germany and Austria, either as a complementary or alternative treatment to systemic pain therapy. Local anaesthetics followed by opioids are the most commonly used medicaments for this treatment. For some of the applied substances neurotoxicological data are lacking. The use of these substances has to be considered very carefully.

[Occupational exposure to inhalation anesthetics at the work-place of veterinary surgery]

In a prospective study we evaluated the work-place pollution by isoflurane and nitrous oxide during various anaesthetic procedures in animal surgery. The study was conducted during one working week at an University Animal Department. Trace concentrations of isoflurane and nitrous oxide were directly measured every minute in the breathing zone by means of a photoacoustic infrared spectrometer in two different operating rooms (OR) with an air turnover of 17 changes per hour. In one OR the 8-hour time-weighted average (mean +/- SEM) was calculated to be 12.3 +/- 9.9 ppm nitrous oxide and 1.9 +/- 2.5 ppm isoflurane. The other OR, where only isoflurane was used, was contaminated with 5.3 +/- 8.1 ppm isoflurane. In the first OR, the trace gas concentrations were low and comparable to values obtained under human anaesthesia in adults and children. The higher contamination in the second OR resulted from performing inhalational anaesthesia with an open mask system in birds and small animals. Although the mean values were below the recommended occupational exposure standards, some high peak values (> 300 ppm isoflurane) violated these threshold limits. We recommend the use of a local scavenging device, if other alternatives such as total intravenous anaesthesia are not possible.

[Interscalene plexus block for mobilizing chronic shoulder stiffness]

INTRODUCTION

After mobilisation of a frozen shoulder, patients should work with a physiotherapist one to two times a day. In the remaining time patients must exercise on their own: otherwise, the shoulder is likely to become less mobile. Exercise is only possible in the absence of pain. Therefore, adequate analgesic therapy for four to five days after the first mobilisation is of great importance. We used interscalene blockade of the brachial plexus to achieve mobilisation in patients suffering from a painful frozen shoulder. We investigated the efficacy of this technique by registering the use of additional analgesics and documenting the patient's assessment. The observation time was 18 months.

METHODS

Thirty-seven patients were treated with a plexus block using a catheter inserted at the affected side. Catheter location was verified with electric nerve stimulation. In all patients a bolus of 20 ml bupivacaine 0.375% was given for initial mobilisation, followed by 10 ml bupivacaine 0.25% every 6 hours.

RESULTS

In 34 of 37 (92%) patients, the shoulder could be mobilised without general anaesthesia. Thirty-three of 37 (89%) patients did not need any additional analgesics during the following mobilizations. The mean duration of catheter treatment was 4 days; no infections occurred. The following side effects were observed at the first mobilisation: Horner's syndrome in 20 patients (54%), paresis of the recurrent nerve in 9 patients (24%) and paresis of the phrenic nerve in 6 patients (16%). During subsequent treatment, Horner's syndrome was observed in 15 patients (41%) and a paresis of the recurrent nerve in 8 patients (22%). In an interview after the end of the treatment period all patients stated that they would use this method again if necessary.

CONCLUSIONS

With the use of this regional anaesthesia technique it was possible to provide comfortable pain therapy during the mobilisation period. In order to achieve sufficient analgesia with only a mild motor blockade of the motoneurons, the exact location of the catheter tip is important. The latter can be verified by electrical stimulation.

Data processing in prehospital emergency medicine

Information about the use of data processing systems in prehospital emergency medicine were collected, using a questionnaire sent to all German rescue helicopter bases. Twenty-seven of the 42 German rescue helicopter bases returned the questionnaire. At present, only 15 of them take advantage of electronic data processing. All of them enter their data manually by keyboard, automatic data transfer by means of a bar code reader is available at one base only. The stored data are used for statistical analysis (n = 15), quality assessment (n = 10), administration (n = 10), research (n = 9) and education (n = 7). Based on the data of this survey, one fifth of those who replied use their computer only for administrative purposes, the other also manage patient and mission data with their computer systems. Today, documentation of a rescue mission consists of patient data, vital data, mission data and information about the procedures carried out. The use of a computer system, however, requires more time and work than a handwritten record, when most of the data have to be entered manually using a keyboard. Future developments may include automated data transfer and digitization of handwritten documents to decrease the workload of the staff. For the automation of data transfer, configuration and synchronisation a standardized interface in all medical devices is required. There is a clear need for the use of data processing systems in emergency medicine.