[Intractable cancer pain as a reason for referral : Analysis of pain etiology and previous drug treatment.]

Many studies have demonstrated that cancer pain can be relieved in most cases by suitable analgesic medication. Patients with a diagnosis of "intractable cancer pain", however, are referred to our pain clinic nearly every day. A retrospective study of 1140 patients was therefore performed to evaluate the pain mechanisms and whether analgesic pretreatment had been adequate. Half of the patients (53%) were suffering from pain at more than one site. The most frequent locations were the back (36% of the patients), abdomen (30%), and the thoracic (22%) region. The main pain etiologies were compression or infiltration of pain-sensitive structures by the tumor (84% of the patients), and less frequently oncological treatment (18%), debilitating disease (10%), or causes unrelated to tumor or therapy (9%). Pain could be classified with almost equal frequency as neuropathic, visceral, soft tissue-related, or bone-related. Upon admission to our pain clinic, most patients (86%) indicated pain of severe intensity. The principal causes for the inadequacy of the analgesic pretreatment were: failure to prescribe analgesics (10% of the patients), irregular intake schedule or prolonged intervals between applications (66%), underdosage of nonopioid analgesics (27%) or opioids (42%), and withholding of nonopioid analgesics (30%), strong opioids (14%), or co-analgesic drugs (17%), although their prescription was indicated. The severe pain was thus caused in many patients by simple mistakes in the prescription of analgesics. Terms like "intractable" should be used with caution when referring to cancer pain because they are often unreflected and can make patients and physicians feel helpless or insecure.

[Postoperative pain therapy with piritramide and metamizole. A randomized study in 120 patients with intravenous on-demand analgesia after abdominal surgery.]

In this randomized study, the efficacy of i.v. patient-controlled analgesia (PCA) was determined for the opioid piritramide (a pure mu-receptor agonist) and the antipyretic analgesic metamizole (Dipyrone) in three groups of patients following abdominal surgery. The doses of piritramide were 1.5 mg (40 patients) and 3 mg (40 patients) on demand. In addition, we studied the effect of 71 mg metamizole in combination with on-demand boluses of 1.5 mg piritramide in 40 patients. During PCA we estimated the degree of analgesia (verbal gain rating scale, visual analog scale) and monitored the ventilation, vigilance, and typical drug side effects over a period of 24 h. The individual demand for analgesic drugs varied markedly. The mean consumption of piritramide during the study was 46.5 mg in the group with 1.5 mg per bolus and 68.6 mg in the group with 3.0 mg. The resulting pain relief was satisfactory in both groups. The combination of piritramide 1.5 mg and metamizole 71 mg per bolus resulted in a reduction of mean Piritramide-consumption to 44.1 mg, and the pain relief was similar to that produced in the group treated with 3 mg piritramide per bolus. The intensity of typical side effects of opioids and antipyretic analgesics (nausea, vomiting, lowering of respiratory frequency, sweating) was low and always easily controlled. The acceptance by patients, nurses, and physicians of PCA was high. PCA with on-demand intravenous injection of the combination of piritramide and metamizole improved the degree of analgesia and concomitantly reduced the opioid dose.

[Postoperative pain therapy with hydromorphone and metamizole. A prospective randomized study in intravenous patient-controlled analgesia (PCA)]

Most potent opioid analgesics available in Germany have been investigated for use in postoperative patient-controlled analgesia (PCA). To conclude an older comparative series, it was the aim of the present study to define analgesic potency, side effects and patient acceptance of hydromorphone and its interaction with the non-opioid analgesic metamizole. A total of 120 patients recovering from elective abdominal or orthopaedic surgery, performed under standardised general anaesthesia, were randomised into 3 double-blind treatment groups to receive intravenous PCA demand doses of hydromorphone 283 micrograms (low dose, LD), 566 micrograms (high dose, HD) or a combination of hydromorphone 283 micrograms and metamizole 50 mg (low dose hydromorphone + metamizole, LM). Demand-independent low-dose background infusions were added to deliver hydromorphone at 67.9 micrograms/h in all groups, with additional metamizole at 12 mg/h in group LM. Lockout times were set to 2 min. After an average observation time of 24.5 +/- 2.6 h (mean, SD) since start of PCA, cumulative PCA hydromorphone doses in groups LD, HD and LM were 7.8 +/- 3.3, 12.1 +/- 4.8 and 7.5 +/- 2.0 mg, respectively, with the well known large inter-individual variability in all groups. Although hydromorphone consumption was significantly higher in group HD, self-reported pain intensities (VAS, retrospective pain scores) were quite comparable between the groups. Low dose, PCA bolus-linked metamizole did not significantly reduce hydromorphone consumption nor improve patient acceptance. Side-effects were typical for potent postoperative opioids, but never required special treatment; haemodynamic or respiratory complications were not observed in any patient. It can be concluded by comparison with other PCA opioid investigations performed under the same study protocol that hydromorphone is about 3-4 times as potent an analgesic as morphine under the conditions of intravenous postoperative PCA. Due to a favourable patient acceptance, hydromorphone can be recommended as a suitable alternative to other opioids for the treatment of postoperative pain.

[Development and state of the in-patient palliative care institutions in Germany]

In April 1999 altogether 114 inpatient units providing palliative care (50 palliative care units, 64 inpatient-hospices) offered a total of 989 beds. Compared to 1993 this has been an increase of 256%, compared to 1997 of 60%. The number of available beds, compared to 1997, increased markedly (58%), with a availability of 12 beds per one million residents. However, there are still major deficits: the distribution of the units is very irregular and the number of available beds is still to low, compared to the estimated need of 50 inpatient beds per one million residents. The quality of palliative care shows significant deficits (e. g. the availability of nursing staff, cooperation with pain clinics, standardised documentation, education). Differences between palliative care wards and hospices were huge. According to the definition of the German Society for Palliative Care, a palliative care ward should provide a ratio of at least 1.4 nursing staff per bed, however, only 18% of the palliative care units fulfil this definition. Only few hospices and half of the palliative care units worked in close cooperation with pain clinics. Despite a significant increase in units and inpatient beds providing palliative care, there still is a major deficit in the overall number of beds and the quality of palliative care.

[Lack of pre-emptive analgesic effect of low-dose ketamine in postoperative patients. A prospective, randomised double-blind study]

NMDA receptors are assumed to play an important role for neuronal plasticity. In vitro and animal experiments confirmed that NMDA antagonistic drugs can prevent hyperexitability of dorsal root neurons after strong pain stimuli. Clinical data, however, are more or less controversial in this respect. It was the aim of the present prospective, randomised, double-blind study to verify if low-dose preoperative ketamine, an NMDA antagonist, provides relevant postoperative analgesia in surgical patients and to re-examine positive results published by other investigators. 80 ASA I-II patients undergoing elective laparoscopic or proctologic surgery received at induction of general anaesthesia a single i.v. bolus dose of either ketamine 0.15 mg/kg or placebo (0.9% NaCl). Postoperative analgesia was provided by i.v. patient-controlled analgesia (PCA) using the opioid piritramide. Cardiovascular parameters, respiration, sedation, cumulative piritramide consumption and pain scores (visual analogue scale 1-10, verbal rating scale 0-4) were monitored at 1, 2, 3, 4, 5, 6, 12 and 24 hours after surgery. Additionally, a retrospective pain score was documented after the 24 hours observation period. There was no statistically significant difference in any study parameter. Cumulative PCA piritramide consumption after 24 hours was 25.0+/-16.2 mg in the ketamine group and 29.5+/-20.4 mg in the placebo group. Ketamine-specific side effects such as hallucinations or bad dreams were not observed. It is concluded that under the study conditions used, low dose ketamine, contrary to previously reported results [30], does not provide a clinically relevant pre-emptive analgesic effect in postoperative patients.

Transdermal fentanyl for the management of cancer pain: a survey of 1005 patients

Transdermal fentanyl was released in Germany in 1995. From October 1996 to February 1998 transdermal treatment was documented for 1005 patients (506 men and 499 women with a mean age of 60 years, range 20-92 years) with chronic pain in an open survey including 290 physicians from hospitals and general practitioners throughout Germany. Most patients suffered from cancer pain and only 11 patients had chronic pain from non-malignant disease. Physicians were asked to complete a questionnaire for patients treated with transdermal fentanyl on initiation of therapy (day 0), and days 3, 6, 18, 30 thereafter, followed by monthly follow-up intervals. Patients were asked to complete a pain diary. Transdermal therapy was documented from day 0 for 824 patients, while 181 patients had been treated with transdermal fentanyl before admission in the survey. Most of the other 824 patients had been treated with other step 3 opioids (55% of the patients) or step 2 opioids (23%) before conversion to transdermal fentanyl, whereas 8% had been treated only with non-opioids and 14% had received analgesics only as required or not at all before initiation of transdermal therapy. The most important reasons for switching to transdermal opioid therapy were insufficient pain relief with the previous medication followed by a variety of gastrointestinal symptoms impeding oral analgesic therapy. Initial fentanyl doses ranged from 0.6 to 9.6 mg/day (25 to 400 microg/h) with a median of 1.2 mg/day (50 microg/h). Median doses slowly increased throughout the observation period to 2.4 mg/day (100 microg/h) after 4 months of treatment. Most patients continued transdermal therapy until the time of death (47% of patients). Other reasons for discontinuation were inadequate pain relief (10%), pain relief with other analgesic regimens (10%), other symptoms than pain (5%), rejection of transdermal therapy by the patient (6%) or miscellaneous (16%). Adverse events were documented as the reason for discontinuation of transdermal therapy in 49 patients (5%). Dyspnoea was documented for seven patients as the reason for discontinuation. One of these patients, as well as another patient with an episode of apnoea, had to be treated with artificial respiration for several hours, but both patients recovered without sequelae. Transdermal therapy with fentanyl was safe and efficient in this national survey. Transdermal fentanyl can be recommended for treatment of moderate to severe cancer pain and probably may even be used as a first-line drug on step 3 of the World Health Organization recommendations in selected patient groups.

[Anesthesiology education and training in Germany. Results from a representative questionnaire]

The aim of the present investigation, initiated by the German Academy of Education in Anaesthesiology (DAAF), was to obtain valid information about education and training strategies of German anaesthetists, in order to highlight weaknesses and strengths for better planning and performance of future efforts in this area. For this reason, a questionnaire with 23 items was distributed to 2000 German anaesthetists during the years 1993-1995 and of these 1290 questionnaires could then be evaluated (response rate 64.5%). The most important means of education and training were classical media such as text books and journals. Modern techniques such as videos, tapes or computer-assisted anaesthesia simulators were poorly used. Refresher courses, repetitoria and hospitations in other departments were, despite infrequent use, considered to be effective means of education and training and should be made more available. Systematic theoretical education was provided particularly seldom in most hospitals. Respondents considered anaesthetic complications and mishaps, intensive care and pain medicine to be the main top topics for continuing medical education. German anaesthetists seem highly motivated for education and training and spend on average about 5.5 h per week for personal learning and refreshing, a figure that is quite comparable to international standards. Hospital and department heads are mostly believed to have positive attitudes to education and training. Most respondents were in favour of strict rules for education and training measures, which includes the obligation to prove their certified attendance (as yet not required in Germany). On the other hand, the majority voted against making the continued recognition as a specialist in anaesthesiology dependent on completion of a performance control.

Double-stranded RNA adenosine deaminases ADAR1 and ADAR2 have overlapping specificities

Adenosine deaminases that act on RNA (ADARs) deaminate adenosines to produce inosines within RNAs that are largely double-stranded (ds). Like most dsRNA binding proteins, the enzymes will bind to any dsRNA without apparent sequence specificity. However, once bound, ADARs deaminate certain adenosines more efficiently than others. Most of what is known about the intrinsic deamination specificity of ADARs derives from analyses of Xenopus ADAR1. In addition to ADAR1, mammalian cells have a second ADAR, named ADAR2; the deamination specificity of this enzyme has not been rigorously studied. Here we directly compare the specificity of human ADAR1 and ADAR2. We find that, like ADAR1, ADAR2 has a 5' neighbor preference (A approximately U > C = G), but, unlike ADAR1, also has a 3' neighbor preference (U = G > C = A). Simultaneous analysis of both neighbor preferences reveals that ADAR2 prefers certain trinucleotide sequences (UAU, AAG, UAG, AAU). In addition to characterizing ADAR2 preferences, we analyzed the fraction of adenosines deaminated in a given RNA at complete reaction, or the enzyme's selectivity. We find that ADAR1 and ADAR2 deaminate a given RNA with the same selectivity, and this appears to be dictated by features of the RNA substrate. Finally, we observed that Xenopus and human ADAR1 deaminate the same adenosines on all RNAs tested, emphasizing the similarity of ADAR1 in these two species. Our data add substantially to the understanding of ADAR2 specificity, and aid in efforts to predict which ADAR deaminates a given editing site adenosine in vivo.

[Morphine dose and side effects: a comparison of older and younger patients with tumor pain]

BACKGROUND AND GOAL OF STUDY: Older patients are said to be more sensitive to analgesics and to have a higher risk of side effects due to pharmacokinetic changes developing with old age. On account of this many elderly patients with cancer pain are denied adequate analgesic treatment. We compared efficacy and side effects of cancer pain management in different age groups.

METHODS

From 1994 to April 1996 577 cancer patients were treated in our pain clinic according to WHO-Guidelines. Efficacy and side effects were evaluated for 508 patients (< 65 years = G1: 323 patients, 65-74 years = G2: 127 patients, > 74 years = G3: 58 patients) with a computerised documentation system.

RESULTS

508 patients were treated on 42,123 days and revisited on 5572 controls. 30 patients were treated longer than 1 year (G1 21 patients, G2 6 patients, G3 3 patients). 143 patients were treated until death. 286 patients were treated on 19,448 days with oral morphine. (G1: 1712 days; G2: 3645 days; G3: 2364 days). Geriatric patients (G3) received significantly higher doses of morphine than younger patients. Adjuvant drugs were given on 81% of treatment days (G1 84%, G2 75%, G3 75%). Incidence and intensity of side effects were not increased in older patients with the exception of urinary disorders.

CONCLUSIONS

Geriatric patients with cancer pain can be treated as effectively according to WHO-Guidelines as younger patients. In our study patients in the old age group received significantly higher doses of oral morphine. When analgesic drugs are titrated according to individual needs, side effects are not more frequent or severe than in younger patients.

Modifiers of Patient-Controlled Analgesia Efficacy in Acute and Chronic Pain

Patient-controlled analgesia (PCA) is widely used as an effective tool for the treatment of acute and chronic pain. Its greatest advantage seems to be the easily achieved individualization of therapy, allowing optimum titration of analgesic dose to analgesic needs. This short review summarizes some predictors of PCA efficacy.

Patient-controlled analgesia: An efficient therapeutic tool in the postoperative setting

Patient-controlled analgesia (PCA) is one of the newer techniques for pain management. It was developed in reaction to the large number of unsatisfied postoperative patients suffering from moderate to severe pain despite the availability of potent analgesic drugs. With PCA, patients are allowed to self-administer small analgesic doses into a running intravenous infusion, intramuscularly, subcutaneously or even into the spinal space. Clinical experience soon demonstrated that individual variability in pain intensity and analgesic needs was extremely large. Psychological factors seem to be as important as the surgical trauma. Opioid consumption is usually higher than with conventional regimens, but without serious side effects. Although patients generally prefer self-control, pain relief is not necessarily better than with well-conducted conventional techniques. In addition to routine clinical pain management, PCA has proven its importance in research, e.g. for pain measurement, to determine predictors of postoperative pain, to evaluate drug interactions and the concept of pre-emptive analgesia, or for pharmacokinetic designs. PCA has been extremely important in order to change the mind of physicians and nursing staff with respect to individual pain management strategies.

Current concepts and practice in postoperative pain management: need for a change?

Despite a growing trend in acute pain management, many deficiencies still account for the high incidence of moderate to severe postoperative pain to date. Patients nowadays continue to receive inadequate doses of analgesics, but additionally the identification and treatment of those patients with pain still remains a significant health care problem. Advanced techniques are available including epidural or intrathecal administration of local anaesthetics and opioids, various opioid administration techniques such as patient-controlled analgesia and infusions via sublingual, oral-transmucosal, nasal, intra-articular and rectal routes. Nonopioid analgesics such as nonsteroidal anti-inflammatory drugs and newer nonopioid drugs such as alpha2-adrenergic agonists, calcium channel antagonists and various combinations of the above are possible. However, the solution to the problem of inadequate pain relief lies not so much in the development of new drugs and new techniques, but in the effective strategy of delivering these to patients through the introduction of acute pain management services on surgical wards.

Cognitive impairment and its influence on pain and symptom assessment in a palliative care unit: development of a Minimal Documentation System

Symptom assessment in the palliative care unit must consider the reduced physical and mental status of the patients. Standardized instruments are often not completed by patients with cognitive impairment. We tried to combine minimal burden for patients and staff with sufficient information content in a Minimal Documentation System (MIDOS) for pain and symptom assessment in palliative care patients. From January to July 1998, 108 patients (123 consecutive admissions) with a mean age of 63 years (range 32-87 years) were admitted to the palliative care unit. Pain was reported as the reason for admission in 70% of the patients, and 71% were treated with opioids. Using a cut-off point of 20/21, 35% of the patients were impaired in the Mini Mental State Examination (MMSE). The number of missing values in the Brief Pain Inventory (BPI) and the quality-of-life questionnaire SF-12 correlated highly with each other and with the MMSE sum score, but not with the summary scores of BPI or SF-12. Only 31 patients completed the SF-12 quality-of-life questionnaire. Age was not correlated to MMSE scores, and neither were opioid doses for 26 patients with slow-release oral morphine or for 20 patients with transdermal fentanyl. Only a minority of patients was able to use the numerical scale for symptoms other than pain, though most patients were able to score symptom intensity on the verbal categorical scale. Pain and symptom assessments were performed by the physician for 17% of the patients at admission, and for 16% of the follow-up controls because self-assessment was not possible. In this study, cognitive impairment prevented symptom assessment with longer and more complicated instruments such as the SF-12 in a large number of the patients admitted to the palliative care unit. Assessment instruments for patients with advanced disease must provide simple categorical scales and the possibility of being administered by interview.

Constipation and the use of laxatives: a comparison between transdermal fentanyl and oral morphine

Constipation and the use of laxatives were investigated in patients with chronic cancer pain treated with oral morphine and transdermal fentanyl in an open sequential trial. Forty-six patients were treated with slow-release morphine 30-1000 mg/day for 6 days and 39 of these patients were switched to transdermal fentanyl 0.6-9.6 mg/day with a conversion ratio of 100:1. Median fentanyl doses increased from 1.2 to 3.0 mg/day throughout the 30-day transdermal treatment period. Twenty-three patients completed the study. Two patients died from the basic disease while treated with transdermal fentanyl, 12 patients were excluded for various reasons, and not enough data for evaluation were available for two patients. Mean pain intensity decreased slightly after conversion although the number of patients with breakthrough pain or requiring immediate-release morphine as a rescue medication was higher with transdermal fentanyl. The number of patients with bowel movements did not change after the opioid switch but the number of patients taking laxatives was reduced significantly from 78-87% of the patients per treatment day (morphine) to 22-48% (fentanyl). Lactulose was used mainly and was reduced most drastically, but other laxatives were also used less frequently. In this study transdermal fentanyl was associated with a significantly lower use of laxatives compared to oral morphine. The difference in the degree of constipation between the two analgesic regimens should be confirmed in a randomized double-blind study that takes into account both constipation and use of laxatives.

Clinical pharmacokinetics of transdermal opioids: focus on transdermal fentanyl

Transdermal delivery allows continuous systemic application of opioids through the intact skin. This review analyses the pharmacokinetic properties of transdermal opioid administration in the context of clinical experience, with a focus on fentanyl. A transdermal therapeutic system (TTS) for fentanyl has been developed. The amount of fentanyl released is proportional to the surface area of the TTS, which is available in different sizes. After the first application of a TTS, a fentanyl depot concentrates in the upper skin layers and it takes several hours until clinical effects are observed. The time from application to minimal effective and maximum serum concentrations is 1.2 to 40 hours and 12 to 48 hours, respectively. Steady state is reached on the third day, and can be maintained as long as patches are renewed. Within each 72-hour period, serum concentrations decrease gradually over the second and third days. When a TTS is removed, fentanyl continues to be absorbed into the systemic circulation from the cutaneous depot. The terminal half-life for TTS fentanyl is approximately 13 to 25 hours. The interindividual variability of serum concentrations, partly caused by different clearance rates, is markedly larger than the intraindividual variability. The effectiveness of TTS fentanyl was first demonstrated in acute postoperative pain. However, the slow pharmacokinetics and large variability of TTS fentanyl, together with the relatively short duration of postoperative pain, precluded adequate dose finding and led to inadequate pain relief or, especially, a high incidence of respiratory depression; such use is now contraindicated. Conversely, in cancer pain, TTS fentanyl offers an interesting alternative to oral morphine, and its effectiveness and tolerability in this indication has been demonstrated by a number of trials. Its usefulness in chronic pain of nonmalignant origin remains to be confirmed in controlled trials. In general, TTS fentanyl produces the same adverse effects as other opioids, mainly sedation, nausea, vomiting and constipation. In comparison with oral morphine, TTS fentanyl causes fewer gastrointestinal adverse events. The risk of hypoventilation is comparatively low in cancer patients. Sufentanil and buprenorphine may also be suitable for transdermal delivery, but clinical results are not yet available. Transdermal morphine is only useful if applied to de-epithelialised skin. However, iontophoresis may allow transdermal administration of opioids, including morphine, with a rapid achievement of steady state concentrations and the ability to adjust delivery rates. This would be beneficial for acute and/or breakthrough pain, and initial clinical trials are in progress.

High-dose tramadol in comparison to low-dose morphine for cancer pain relief

Cancer pain treatment following the World Health Organization guidelines is effective and feasible. However, the evidence supporting the use of opioids for mild to moderate pain on the second step of the analgesic ladder is widely discussed. The present evaluation compares the efficacy and safety of high doses of oral tramadol (> or = 300 mg/d) with low doses of oral morphine (< or = 60 mg/d). Patients were included in this nonblinded and nonrandomized study if the combination of a nonopioid analgesic and up to 250 mg/d of oral tramadol was inadequate. 810 patients received oral tramadol for a total of 23,497 days, and 848 patients received oral morphine for a total of 24,695 days. The average dose of tramadol was 428 +/- 101 mg/d (range 300-600 mg/d); the average dose of morphine was 42 +/- 13 mg/d (range 10-60 mg/d). Additional nonopioid analgesics were given on more than 95% of days. Antiemetics, laxatives, neuroleptics, and steroids were prescribed significantly more frequently in the morphine group; the use of other adjuvants was similar in both groups. The mean pain intensity on a 0-100 numerical rating scale (NRS) was 27 +/- 21 (95% CI 26-29) in the tramadol and 26 +/- 20 (95% CI 24-27) in the morphine group (NS). The analgesic efficacy was good in 74% and 78%, satisfactory in 10% and 7%, and inadequate in 16% and 15% of patients receiving tramadol and morphine, respectively (NS). Constipation, neuropsychological symptoms, and pruritus were observed significantly more frequently with low-dose morphine; other symptoms had similar frequencies in both groups. These data suggest that tramadol can be used for the treatment of cancer pain, when nonopioids alone are not effective. High doses of tramadol are effective and safe.

Intravenous titration with morphine for severe cancer pain: report of 28 cases

BACKGROUND

In a multicenter study, 28 patients with cancer pain and insufficient pain relief with analgesic treatment according to step II of the guidelines of the World Health Organization (WHO) were switched to oral slow-release morphine.

METHODS

Patients received intravenous morphine through a patient-controlled pump (PCA) for the first 24 hours (bolus = 1 mg, lockout interval = 5 minutes, maximum dose = 12 mg/hour). From day 2 patients were treated with oral slow-release morphine. Daily doses were calculated from the requirements of the day before. Breakthrough pain was treated with PCA until stable doses were reached (<2 boluses/day) and then with oral immediate-release morphine solution. Pain intensity was reported in a diary four times a day, in addition to mood, activity, and quality of sleep once daily.

RESULTS

Mean duration until adequate pain relief reported (<30 on a 101-step numerical scale; NRS) was 5 hours (range = 80-620 minutes). Mean pain intensity was reduced from 67 NRS to 22 NRS. Mean doses of oral morphine were 133 mg/day initially and then 154 mg/day on day 14. Serious adverse events such as respiratory depression were not observed. Two patients terminated the study due to progressive symptoms of gastrointestinal obstruction. Seventy-five percent of the patients evaluated the effectiveness of the analgesic regime as good.

CONCLUSIONS

Dose finding with intravenous PCA may be appropriate for a small minority of patients with severe pain. Higher treatment costs and the risk of complications are drawbacks of this method compared with conventional oral titration.

Validation of the German version of the Brief Pain Inventory

The Brief Pain Inventory is a comprehensive instrument for pain assessment and has been validated in several languages. A validated German version was not available until now. From March to May 1995 all outpatients of the pain clinic of the Department of Anesthesiology completed a questionnaire with the German versions of the Brief Pain Inventory (BPI) and the SF-36 quality-of-life questionnaire. The BPI was repeated after the consultation. The physician assessed the performance status score of the Eastern Cooperative Oncology Group (ECOG). The questionnaire was completed by 151 patients. Forty-two patients were excluded from evaluation for methodological reasons, so 109 patients were evaluated. As in the original version of the BPI, factor analysis showed a common factor for pain intensity and a second factor for pain-related interference with function. The comparative fit index of 0.86 confirmed this model. Responses before and after consultation correlated closely for the sum scores of the pain intensity items (Perarson correlation r = 0.976) as well as for the interference with function items (r = 0.974). Pain intensity in the BPI correlated with bodily pain in the SF-36 (r = 0.585). Sum scores of the pain interference items were higher in patients with deteriorated ECOG performance status, whereas sum scores of the intensity items were not changed. Validity and reliability of the German BPI were comparable to the original version. The BPI may be advantageous for palliative care patients, as it places only a small burden on the patient and offers easy criteria for evaluation. However, further research is needed to differentiate the impact of pain-related and disease-related interference with function on the BPI, and to find an algorithm for the evaluation of the BPI when values are missing.

[WHO recommendations for treatment of tumor pain. Development of an evaluation system]

AIM OF THE STUDY

Evaluation of the observance of the World Health Organization guidelines for cancer pain management is a prerequisite for further research into the effectiveness and acceptability of the guidelines.

METHODS

In a nationwide survey 172 physicians in pain management and oncological units documented transdermal therapy with fentanyl. From October 1996 to May 1997, 591 patients were included. A total of 148 patients had already received transdermal fentanyl before inclusion in the survey, and no data on previous analgesic management were available for 7 patients. For 436 patients analgesic therapy before initiation of transdermal fentanyl was evaluated. The last analgesic regimen documented by the treating physician was rated by three physicians from our pain clinic independently of each other. A rating system with four items (potency of analgesic according to the analgesic ladder of the WHO guidelines, prescription of a rescue medication, combination of nonopioids with opioids, inadequate combinations of analgesics) and a global rating (the analgesic regimen is considered adequate, sufficient or inadequate) was used.

RESULTS

Good agreement was reached for classification according to the analgesic ladder, prescription of rescue medication and for inadequate drug combinations. The ratings on combinations with nonopioids showed more differences. The scores for the global assessment showed a wide difference between raters, with agreement on the same score for only 36.2% (raters 1 and 3), 36.7% (raters 2 and 3) and 55.5% of the patients (raters 1 and 3).

CONCLUSIONS

A global assessment score is not useful for evaluation of guideline acceptance. A more differentiated scoring system was developed for further studies that includes the analgesic ladder and other aspects of the WHO guidelines in a 10-point score.

The importance of internal loops within RNA substrates of ADAR1

Adenosine deaminases that act on RNA (ADARs) are a family of RNA editing enzymes that convert adenosines to inosines within double-stranded RNA (dsRNA). Although ADARs deaminate perfectly base-paired dsRNA promiscuously, deamination is limited to a few, selected adenosines within dsRNA containing mismatches, bulges and internal loops. As a first step in understanding how RNA structural features promote selectivity, we investigated the role of internal loops within ADAR substrates. We observed that a dsRNA helix is deaminated at the same sites whether it exists as a free molecule or is flanked by internal loops. Thus, internal loops delineate helix ends for ADAR1. Since ADAR1 deaminates short RNAs at fewer adenosines than long RNAs, loops decrease the number of deaminations within an RNA by dividing a long RNA into shorter substrates. For a series of symmetric internal loops related in sequence, larger loops (>/=six nucleotides) acted as helix ends, whereas smaller loops (</=four nucleotides) did not. Our work provides the first information about how secondary structure within ADAR substrates dictates selectivity, and suggests a rational approach for delineating minimal substrates for RNAs deaminated by ADARs in vivo.

Serum concentrations of tramadol enantiomers during patient-controlled analgesia

AIMS

Tramadol, a centrally acting analgesic, is used as a racemate containing 50% of a (+)- and 50% of a (-)-enantiomer. This paper presents the pharmacokinetic results of postoperative patient-controlled analgesia using (+)-tramadol, (-)-tramadol or the racemate.

METHODS

Ninety-eight patients recovering from major gynaecological surgery were treated in a randomised, double-blind study with (+)-tramadol, (-)-tramadol or the racemate. Following an i.v. bolus up to a maximum of 200 mg, patient-controlled analgesia with demand doses of 20 mg was made available for 24 h. Prior to each demand, the serum concentrations of the enantiomers of tramadol and its metabolite M1 were measured in 92 patients.

RESULTS

The mean concentrations of tramadol during the postsurgery phase were 470+/-323 ng ml-1, 590+/-410 ng ml-1 and 771+/-451 ng ml-1 in the (+)-, racemate- and (-)-group, respectively ((+) vs (-), P<0.05); the mean concentrations of the metabolite M1 were 57+/-18 ng ml-1, 84+/-34 ng ml-1 and 96+/-41 ng ml-1 in the (+)-, racemate- and (-)-group, respectively ((+) vs (-) and (+) vs racemate, P<0.05). The mean concentrations of (+)-tramadol and (+)-M1 were lower in the racemate- than in the (+)-group (P<0.05), those of (-)-tramadol and (-)-M1 were lower in the racemate than in the (-)-group (P<0.05). In the racemate group, the mean serum concentrations of (+)-tramadol were higher than those of (-)-tramadol (P<0.05), whereas the mean serum concentrations of (-)-M1 were higher than those of (+)-M1 (P<0. 05).

CONCLUSIONS

The therapeutic serum concentration of tramadol and M1 showed a great variability. The lowest mean concentrations were measured in the (+)-group and the highest in (-)-group. This is in agreement with the clinical finding that (+)-tramadol is a more potent analgesic than (-)-tramadol.

[Ketorolac and butylscopolamine in combination with alfentanil for renal lithotripsy]

BACKGROUND

Patient-controlled analgesia (PCA) using intravenous alfentanil provides adequate pain relief during extracorporal shock wave lithotripsy (ESWL) of renal stones. Occasional disadvantages of opioid analgesia include nausea, sedation and respiratory depression. This double-blind, placebo-controlled study examined whether the alfentanil requirements and thereby the frequency of side effects could be reduced by preemptive analgesia with the non-opioid analgesic ketorolac or the spasmolytic butylscopolamine.

METHODS

90 patients scheduled for ESWL of renal stones received 1 hour prior to ESWL ketorolac 30 mg, butylscopolamine 20 mg or placebo intramusculary. 10 mg of metoclopramide and 6.6 microg/kg of alfentanil were given intravenously at the beginning of ESWL (Philips/Dornier MFL 5000). Intravenous PCA was started (demand dose: 0.25 mg of alfentanil, lockout time: 1 minute). Pain intensity (NRS 0-100), sedation score (VRS 0-4), respiratory rate (min(-1)) and partial oxygen saturation (SO(2)) were measured every 5 minutes. Statistical analysis included ANOVA and Chi-square-test (p<0,05).

RESULTS

Demographic and ESWL data were comparable between the study groups. However, patients of the ketorolac group were statistically significantly younger than those in the other groups. Alfentanil doses, pain scores and frequency of respiratory depression, sedation and nausea were lower subsequent to ketorolac than subsequent to butylscopolamine or placebo (not statistically significant). Signs of respiratory depression were only seen during ESWL.

CONCLUSIONS

The present study confirms that PCA using alfentanil is effective during ESWL of renal stones. However, because of the possibility of respiratory depression, adequate monitoring is mandatory. Preemptive analgesia with 30 mg of ketorolac or 20 mg of butylscopolamine cannot reduce alfentanil requirements or improve efficacy and safety.

[Out-patient hospice services--their importance for palliative care in Germany]

Hospice services can be divided into three groups. Few institutions deliver the full scope of palliative home care, most of the others can provide considerably less. The third group of services are those that do not support patients but aim to establish a home care service or a hospice. In February, 1997 396 home care services were working in Germany. 48 of these services provided palliative home care, 69 services were hospice initiatives. The scope of services rendered is very broad and reaches from psychosocial support to complex medical tasks. In the last year, 13,700 patients have been supported at home by hospice services in Germany. Palliative care services usually have professional staff, but they would not be able to work without honorary help. Beside of support for patients and relatives tasks of the home care service are the coordination and exchange between in-patient units, general physicians and social care ward. By cooperation with all institutions for out-patient and home care as well as with general physicians, they contribute to avoid in-patient treatment for their patients. Another important function is to spread the hospice idea and work as multipliers for knowledges and attitudes in palliative care. The number of home care services available in Germany is not sufficient. Only 48 institutions can be ranked as palliative care services. The distribution of the hospice services in Germany is very irregular, and providers of home care services are even more scarce in the eastern part of Germany.

[Anesthesia for cesarean section in Germany. A survey]

AIM OF STUDY

Goal of this survey is to give an overview of anaesthesia for caesarean section in Germany.

METHOD

In 1994 and 1995, we sent a questionnaire to the chief-anaesthetists of all German hospitals with departments of gynaecology/obstetrics to find out the routine anaesthetic procedures for caesarean section.

RESULTS

We obtained data from 409 hospitals (response rate 46.4%) with 321,816 births--50,123 of which were sections (mean caesarean section rate 16.6%). The mean general anaesthesia rate for elective caesarean sections was 66.5%, for non-elective sections 90.8%. The mean epidural anaesthesia rate for caesarean section was 22.6% and the mean spinal anaesthesia rate was 9.8%. For general anaesthesia most hospitals used antacids and/or histamine2-receptor antagonists (64.6% of responding hospitals). Anaesthesia was induced with intravenous barbiturates (82%), succinylcholine for intubation (98.2%) and no opioids before clamping of the cord (94.8%). For regional anaesthesia bupivacaine was the most common local anaesthetic (spinal 84.0%, epidural 96.8%). Opioids were added to local anaesthetics for epidural anaesthesia at 21.4% of the hospitals.

CONCLUSIONS

General anaesthesia is the commonest practice for caesarean sections at German hospitals. Nowadays regional anaesthesia gains more importance compared to previous German surveys and in agreement with foreign data.

Opioids: overview on action, interaction and toxicity

The history of opioid use in briefly reviewed, and the presently accepted indications are discussed with reference to dosage, modes of administration, efficacy, duration of effect and speed of onset, and possible side effects. Physicians' fears about dependence and addiction are also touched upon.

Tramadol in the management of post-operative pain: a double-blind, placebo- and active drug-controlled study

A double-blind, randomized, placebo- and drug-controlled study in which the analgesic efficacy and safety of intravenous (i.v.) tramadol in patients with post-operative pain is reported. One hundred and eighty patients recovering from gynaecological or abdominal surgery were assigned to one of three treatment groups. After titration of an individual loading dose, patients could self-administer tramadol 20 mg, morphine 2 mg or placebo using a patient-controlled analgesia (PCA) device throughout a 48-h period. Criteria of efficacy were a decrease in pain intensity within the first 30 min of at least 20 on a visual analogue scale (VAS) (0 denotes no pain, 100 worst pain imaginable) and satisfactory analgesia in the patient's opinion during the study period. Patients treated with tramadol, morphine and placebo were assessed as responders at 66.7%, 75.0% and 18.3% (P < 0.0001). VAS after the initial bolus were 39.2 +/- 22.1, 35.9 +/- 21.6 and 50.0 +/- 24.2 (P = 0.002), the initial loading dose amounted to tramadol 144.9 +/- 51.2 mg, morphine 12.3 +/- 5.1 mg and placebo 17.2 +/- 4.9 mL. No serious opioid-related adverse events occurred in the patients given tramadol while two patients given morphine developed an impaired respiratory rate and a decreased oxygen saturation to 80% or less. Tramadol proved to be efficacious for PCA treatment of post-operative pain following gynaecological and abdominal surgery.

[The current standing of obstetrical analgesia and anesthesia. A survey of North Rhein-Westfalia]

BACKGROUND

The purpose of this study was to determine obstetrical pain management practices for labour for spontaneous and operative vaginal deliveries since there were no comparative German data available for the past 10 years.

METHODS

A mail survey was sent to the chief anaesthetists of all hospitals in North Rhine-Westfalia designated to have obstetrical beds. The confidential and standardised questionnaire consisted of 24 mainly multiple-choice questions relating to general issues and methods of analgesia and anaesthesia for vaginal deliveries.

RESULTS

In all, 118 completed replies to 258 sent questionnaires were received, giving a response rate of 46%. Among the 118 hospitals there were 79,157 vaginal deliveries annually. All participating hospitals practiced either systemic analgesics/spasmolytics and/or regional-anaesthetic methods (Table 2). Perineal local infiltration (23.7% of vaginal deliveries, in 99% of cases performed by the obstetrician) and epidural analgesia (23.2% of vaginal deliveries, in 81% of cases performed by an anaesthetist) were the commonest regional-anaesthetic methods. Pudendal nerve blocks were performed in 18.5% of vaginal deliveries (Table 1). Of all participating hospitals, 97% provided a 24-h epidural service. The method of epidural anaesthesia was widely homogeneous in all 118 hospitals (Table 3). Other methods of regional analgesia (i.e., epidural infusions or patient-controlled epidural analgesia) were performed only rarely.

CONCLUSIONS

The methods of obstetrical analgesia and anaesthesia are on a high level and show a broad homogeneity in all hospitals. Overall, the results indicate, in comparison to former studies and in common with other countries, steadily increasing use of regional anaesthesia performed by anaesthetists in contrast to decreasing numbers of local infiltrations performed by obstetricians.

[Tramadol in acute pain]

Tramadol has been in clinical use in Germany since the late 1970s and has proven effective in both experimental and clinical pain without causing serious cardiovascular or respiratory side effects. Moreover, the negligible abuse potential of tramadol has meant that it has never been a restricted drug, and it therefore very quickly became the most popular analgesic of its class in Germany. Although tramadol has been used in myocardial emergencies, in trauma and obstetric pain, or to supplement balanced anaesthesia, most studies have investigated postoperative patients. The focus of this article is to review clinical experience with tramadol in the treatment of acute postoperative pain. Tramadol, a synthetic opioid of the aminocyclohexanol group, is a centrally acting analgesic with weak opioid agonist properties, and effects on noradrenergic and serotonergic neurotransmission. In addition, these opioid and nonopioid modes of action appear to act synergistically. Tramadol has been shown to provide effective analgesia after both intramuscular and intravenous administration for the treatment of postoperative pain. The drug is available in formulations suitable for oral, rectal and parenteral administration. Clinically effective analgesic doses of tramadol were comparable to those of pethidine (meperidine) and about 10 times higher than those of morphine. While it is not recommended as a supplement to general anaesthesia because of its insufficient sedative activity, tramadol has been successful in the treatment of postoperative pain. A randomised double-blind study reported acceptable analgesia with postoperative intravenous tramadol 50mg, repeated once if required after 30 minutes. It produced an effect similar to that of morphine 5mg or the alpha 2 agonist, clonidine 150 micrograms. In another study, it was shown that the 50mg dose of tramadol fulfilled the requirements of an analgesic for the treatment of moderate postoperative pain, whereas for severe pain a higher dose was recommended. Tramadol is generally well tolerated, the most common adverse events being nausea and vomiting. In contrast to agents such as morphine and pethidine, clinically relevant respiratory depression is rarely observed during tramadol administration at equipotent doses and consequently it can be recommended for first-line management of postoperative pain instead of morphine. It is also associated with a low incidence of cardiac depression and significantly less dizziness and drowsiness than morphine. Finally, the dependence and abuse potential with tramadol is negligible. Comparative studies have generally shown that tramadol is more effective than NSAIDs for controlling post operative pain. Use of a combination of tramadol and NSAIDs allows the tramadol dose to be reduced and results in a lower incidence of adverse effects. Patient controlled analgesia (PCA) with tramadol has been frequently used and is well accepted by patients. Wide individual variations exist with regard to analgesic requirements and, nowadays, it is generally accepted that adequate pain management implies systematic individualisation of the therapy, i.e. titration of the analgesic effect to individual needs. Demand and loading doses play a decisive role in the success of PCA. Analgesic failures requiring rescue medication are rare, but it should be stressed that these can always occur with weak opioids. In conclusion, tramadol can be recommended as a basic analgesic for the treatment of moderate to severe pain. In the event of analgesic failure with tramadol, there is no reason not to switch to more potent opioids. Although no studies are available regarding its use in the management of postoperative pain after day case surgery, tramadol is frequently administered with good results in such patients. The most important side effects of tramadol are nausea and emesis, which can often be prevented by slow injection and administration of a prophylactic antiemetic such as metoclopramid

Transdermal fentanyl in the long-term treatment of cancer pain: a prospective study of 50 patients with advanced cancer of the gastrointestinal tract or the head and neck region

This open prospective study evaluated the combination of initial dose titration with patient-controlled analgesia (PCA) and long-term treatment with transdermal fentanyl in 50 cancer patients requiring opioids for severe pain. The delivery rate of the first transdermal therapeutic system (TTS) was calculated from the self-administered intravenous fentanyl dose during the first 24 h. TTS were changed every 48-72 h, and a different patch size was chosen if necessary. Pain intensity (101-step numeric analog scale) and side-effects were assessed daily. The patients were treated for 66 +/- 101 days (range 3-535 days). The average delivery rate was 5.9 +/- 4.1 mg/d. Mean pain intensity decreased from initially 45 +/- 21 to 19 +/- 15 in the titration phase and 15 +/- 11 during long-term treatment. Three patients showed moderate respiratory depression. Other severe side-effects were not observed. Patient compliance and acceptance were excellent. The results suggest that intravenous PCA is useful for initial dose finding, and transdermal fentanyl is effective and safe during long-term treatment of cancer pain.

A risk-benefit assessment of tramadol in the management of pain

Tramadol is a cyclohexanol derivative with mu-agonist activity. It has been used as an analgesic for postoperative or chronic pain since the late 1970s, and became one of the most popular analgesics of its class in Germany. International interest has been renewed during the past few years, when it was discovered that tramadol not only acts on opioid receptors, but also inhibits serotonin (5-hydroxytryptamine; 5-HT) and noradrenaline (norepinephrine) reuptake. This review aims to provide a risk-benefit assessment of tramadol in the management of acute and chronic pain syndromes. Tramadol has been used intraoperatively as part of balanced anaesthesia. Such use is under discussion, however, as it was associated with a high incidence of intraoperative recall and dreaming, and postoperative respiratory depression has been described after intraoperative administration of high doses. Postoperatively, intravenous and intramuscular tramadol has been used with good efficacy. Analgesic doses were comparable with pethidine (meperidine) and 10 times higher than morphine. Nausea and vomiting were the most frequently reported adverse effects. In controlled studies, haemodynamic and respiratory parameters were only minimally impaired. The risk of severe respiratory depression in typical dosages is negligible in comparison with other opioids used for postoperative pain management. Tramadol has been used with good results for the management of labour pain without respiratory depression of the neonate. It was also effective for the treatment of pain from myocardial ischaemia, ureteric colic and acute trauma. Good results have been published for cancer pain management with tramadol in several studies. The potential for abuse or addiction seems to be minimal, and serious complications have not been reported. For patients with severe pain, the efficacy of morphine is superior, and most patients with adequate analgesia from tramadol had to be changed to a more potent opioid after a few weeks due to increased nociceptive input during tumour progression. Tramadol can be recommended as a safe and efficient drug for step II according to the World Health Organization guidelines for cancer pain management.

Comparison of ondansetron and droperidol in the prevention of nausea and vomiting after inpatient minor gynecologic surgery

Ondansetron and droperidol are both effective in the prevention of postoperative nausea and vomiting (PONV). In this randomized, double-blind study, 80 inpatients scheduled for minor gynecologic surgery received either ondansetron 8 mg intravenously (i.v.) or droperidol 2.5 mg i.v. 5 min prior to induction of isoflurane-narcotic anesthesia. PONV was absent in 68% of the patients after ondansetron and in 88% after droperidol (P < 0.05). The respective times of complete arousal from anesthesia were 171 min and 229 min (P < 0.001). After ondansetron and droperidol, the incidence of severe drowsiness, restlessness, anxiety, or dizziness was 5% and 28%, respectively (P < 0.01). Thus after minor gynecologic surgery, droperidol 2.5 mg i.v. was superior to ondansetron 8 mg i.v. in the prevention of PONV. However, relative to ondansetron, droperidol entailed an average 1-h delay in recovery from anesthesia.

Transdermal fentanyl in combination with initial intravenous dose titration by patient-controlled analgesia

Two studies including a total of 70 patients evaluated the efficacy and side effects of a combination of initial patient-controlled analgesia (PCA) for dose finding with transdermal fentanyl administration. Patients, requiring strong opioids for severe cancer pain, received intravenous (i.v.) fentanyl on an on-demand basis over a 24 h period. The amount of fentanyl administered was then used for selecting a suitable transdermal therapeutic system (TTS), which remained in place for 72 h. The size of the second TTS was adjusted according to the amount of supplementary i.v. fentanyl required on day 3. Beginning on day 4, oral or subcutaneous morphine was made available as a rescue medication. The use of TTS fentanyl in combination with initial dose titration using PCA resulted in rapid and statistically significant pain relief in both studies. A respiratory rate below 8 per minute was observed in three patients. Due to adequate symptomatic treatment, other moderate and severe symptoms were relatively rare. TTS fentanyl was shown to be an effective, safe and simple method for long-term pain relief in cancer patients and presents an interesting novel option in the treatment of cancer pain.

New developments in patient-controlled postoperative analgesia

Patient-controlled analgesia (PCA) is a newer technique for pain management. Patients are allowed to self-administer small analgesic bolus doses into a running intravenous infusion, intramuscularly, subcutaneously or even into the epidural space. Demands are usually controlled by computer-driven infusion pumps, but can also be delivered by disposable devices. Clinical experience demonstrates that individual variability in pain sensitivity and analgesic needs are of utmost importance. In contrast to earlier expectations, opioid consumption is usually higher than with restrictive conventional dosing regimes, but without an increase in serious side effects. Patients' acceptance is generally enthusiastic because of the possibility of self-control. PCA has proved its importance for pain studies, e.g. for algesimetry, to determine predictors of postoperative pain, to describe drug interactions, to evaluate the concept of pre-emptive analgesia or for pharmacokinetic designs. It is concluded that PCA results have been urgently required in order to change the mind of physicians and nursing staff with respect to individual pain management strategies. Once this goal is achieved, PCA concepts should also be used for the improvement of more conventional techniques.

A new orphan member of the nuclear hormone receptor superfamily closely related to Rev-Erb

We have isolated complementary DNA clones encoding a novel orphan member of the nuclear receptor superfamily, termed BD73. This protein shows strong amino acid sequence similarity to the previously described Rev-ErbA alpha. Unlike Rev-Erb, in which the opposite strand of the C-terminal coding region encodes the C-terminal portion of a variant thyroid hormone receptor isoform, the opposite strand of the C-terminal coding region of BD73 does not have any extensive open reading frames. BD73 messenger RNA is expressed in a wide variety of tissues and cell lines. In quiescent HepG2 cells, BD73 messenger RNA levels are strongly induced by planar aromatic antioxidants. Like Rev-Erb, BD73 binds as a monomer to a DNA sequence which consists of a specific A/T-rich sequence upstream of the consensus hexameric half-site specified by the P box of the DNA-binding domain. Amino acid sequence comparisons suggest that the A box sequence, which has been suggested to mediate monomer binding by other superfamily members, lies closer to the DNA-binding domain in BD73 and Rev-Erb than in other receptors. Under the conditions examined, neither BD73 nor Rev-Erb activated reporters containing multiple copies of their common binding site. Thus, these two orphans may require an as yet unidentified ligand or other signal for such activation. Together, BD73 and Rev-Erb define a subgroup of orphan receptors that bind as monomers to a half-site flanked by a specific and extended A/T-rich sequence.

Tramadol for the management of acute pain

This paper reviews the use of tramadol in the management of acute pain. Tramadol is a weak opioid analgesic with a potency comparable to that of pethidine. While it is not recommended as a supplement to general anaesthesia because of its insufficient sedative activity, tramadol has been successful in the treatment of postoperative pain. Several studies have demonstrated its analgesic efficacy after intramuscular and intravenous application, both in adults and children. Moreover, negligible respiratory depressant activity and only minor side effects have consistently been shown. Patient-controlled analgesia with tramadol has been frequently employed and was well accepted by the patients. There have been only a few studies of oral or spinal application of tramadol in acute pain states. Tramadol has also been used for the control of pain associated with labour and acute myocardial infarction, as well as for the management of trauma pain. In summary, tramadol can be recommended as a basic analgesic for the treatment of patients with moderate to severe pain.

[Continuous monitoring of spontaneous respiration in the postoperative phase. 4. The effect of postoperative pain therapy on cutaneous oxygen and carbon dioxide partial pressure following gynecologic surgery with neuroleptanalgesia]

METHODS

Cutaneous O2 and CO2 pressures were monitored for 16 h in 55 female patients recovering from major gynaecological surgery performed under neurolept anaesthesia. Postoperative pain was managed either with an antipyretic analgesic (i.m. or i.v. metamizol up to 2.5 g/4 h; group NLA) or with i.v. patient-controlled analgesia using fentanyl (demand dose 34 micrograms, infusion rate 4 micrograms/h, hourly maximum dose 0.25 mg, lock-out time 1 min; group NLA/PCA). In addition, 11 patients received a single i.v. bolus injection of 150 mg amiphenazole, a respiratory stimulant, at the beginning of PCA treatment (group NLA/PCA/AMI). Data were collected and stored by a personal computer, using the TCM3 system with a combination electrode for simultaneous measurement of cutaneous oxygen and carbon dioxide partial pressures (TINA, Radiometer) at 30-s intervals. The overall observation period was four times 240 min; patients from the NLA group who required additional opioids were excluded from the analysis. Means and standard deviations were calculated for individual data and data pooled for 15- or 60-min intervals. Groups were compared by means of the chi-square test, Student's t-test or analysis of variance (level of significance, P < or = 0.05).

RESULTS

The 55 patients were classified as ASA I-II. The study groups were comparable with respect to demographic and anaesthesiological data, except that those in the NLA group were younger and had received less intraoperative fentanyl (Table 1). Mean PCA fentanyl consumption was 0.6-0.7 mg in the 16-h observation period (Table 2). In all groups, pctO2 levels were decreased and pctCO2 levels elevated in the first observation hours and slowly returned to normal within the first observation period (Figs. 1, 2, Tables 3, 4). Episodes of hypercapnia (pct-CO2 > 50 or > 55 mm Hg) were frequent in the first 2 h (8-29% of individual values for pctCO2 > 50, up to 5% of values recorded for pctCO2 > 55; Table 4). There were no statistically significant differences between patients treated with metamizol and those treated with fentanyl. Amiphenazole did not significantly improve postoperative respiration. PCA patients had occasional episodes of hypercapnia (up to 19% of all values for pctCO2 > 50, up to 5% for pctCO2 > 55) even in the last observation period (13-16 h after surgery), indicating the need for close monitoring of spontaneous ventilation during PCA following neurolept anaesthesia.

DISCUSSION AND CONCLUSIONS

The present study confirmed that spontaneous respiration in the early postoperative period can be monitored non-invasively by measuring cutaneous partial pressures of carbon dioxide and, less precisely owing to wide individual variations, oxygen. It showed that spontaneous respiration is less effective immediately after termination of surgery under neurolept anaesthesia and recovers slowly over the next 4 h. During the first observation period, ventilation was no worse with i.v. PCA using fentanyl than with conventional pain management using the antipyretic analgesic metamizol, confirming the hypothesis that opioid-induced respiratory depression occurs only at overdosage (which is not a problem with individualized dose titration using PCA). Since all patients in the NLA group required additional opioids after the first observation period and had to be excluded from further analysis, it cannot be decided from the present data whether late hypercapnia was due to PCA or to residual effects of surgery and anaesthesia. The respiratory stimulant amiphenazole (150 mg i.v.) was not helpful in improving ventilation; there was no indication of analgesic effects or interactions of amiphenazole.

Validation of World Health Organization guidelines for pain relief in head and neck cancer. A prospective study

In a prospective study of 167 patients with head and neck cancer, we assessed the causes and mechanisms of pain, as well as the efficacy and side effects of analgesic treatment, along World Health Organization (WHO) guidelines. The majority of patients had pain caused by cancer (83%) and/or treatment (28%), 4% had pain due to debility, and 7% had pain unrelated to cancer. Palliative antineoplastic treatment was performed in 32% of patients. Systemic analgesics were administered on 97% of a total of 8,106 treatment days, and coanalgesics or adjuvant drugs on 100%. The treatment proved to be very successful, as severe pain was experienced only during 5% of the observation period. In the absence of serious side effects, the most frequent symptoms observed were insomnia, dysphagia, anorexia, constipation, and nausea. The use of analgesic and adjuvant drugs along WHO guidelines to treat pain in head and neck cancer is highly effective and relatively safe.

[Continuous monitoring of spontaneous postoperative respiration. 3. The effect of amiphenazole on cutaneous oxygen and carbon dioxide partial pressure following gynecologic surgery under halothane anesthesia]

METHODS

In an attempt to verify non-invasive respiratory monitoring for patients in the early postoperative period, cutaneous O2 and CO2 pressures were monitored in 30 female patients recovering from major gynaecologic surgery under halothane anaesthesia. In a double-blind and randomized fashion, in the recovery room the patients received a single intravenous bolus injection of placebo or 150 mg amiphenazole, a respiratory stimulant. The data were collected and stored in a personal computer, using the TCM3 system with a combination electrode for simultaneous measuring of cutaneous oxygen and carbon dioxide partial pressures (TINA, Radiometer) at 30-s intervals. The overall observation period was 240 min. Means and standard deviations were calculated for individual data and for data pooled at 15- or 60-min intervals. Groups were compared by means of the chi 2 test, Student's t-test, Wilcoxon rank sum test or analysis of variance (level of significance P < or = 0.05).

RESULTS

The study groups were comparable with respect to demographic and anaesthesiological data. The partial pressures for both O2 and CO2 were not statistically significant between groups. Electrode heating was slightly higher with amiphenazole (n.s.), indicating a trend for peripheral vasodilation without a true improvement of spontaneous ventilation. pctO2 and pctCO2 levels were decreased or elevated, respectively, in the first observation hours and slowly returned to normal within the 240-min observation period. Episodes of hypercapnia (pct-CO2 > 50 or > 55 mm Hg) were frequent in the first 2 h (10-30% of individual data for pctCO2 > 50, 2-7% for pctCO2 > 55, respectively), indicating the need for close monitoring of spontaneous respiration after general anaesthesia with halothane.

DISCUSSION AND CONCLUSION

The present study confirmed that spontaneous respiration in the early postoperative period can be monitored non-invasively by measuring transcutaneous partial pressures of carbon dioxide and, less precisely due to large individual variations, oxygen. It showed that spontaneous respiration deteriorates after gynaecological surgery under halothane anaesthesia and recovers slowly during the next 4 h. The respiratory stimulant amiphenazole (150 mg i.v.) was of no significant value with respect to the improvement of ventilation.

Pharmacokinetics of sufentanil in general surgical patients under different conditions of anaesthesia

The pharmacokinetics of sufentanil were studied in 56 surgical patients after an intravenous bolus of 2 micrograms kg-1, in association with neurolept analgesia or volatile anaesthetics (halothane, enflurane and isoflurane). Plasma concentrations of sufentanil were measured by radioimmunoassay. The kinetics of sufentanil were comparable under neurolept analgesia and under anaesthesia with halothane, enflurane or isoflurane. The overall mean elimination half-life was 182 min, Vdss 169 l and the plasma clearance 910 ml min-1. Except for the isoflurane subgroup, there was no significant correlation between half-life, the volume of distribution or clearance with age (24-77 years) or body weight (45-95 kg).