A brief, high-dose remifentanil infusion partially reverses neuropathic pain in a subgroup of post herpetic neuralgia patients

Mechanism-based therapy for chronic pain is desperately needed. Recent basic science research demonstrated that remifentanil can reverse long-term potentiation at C-fiber synapses in the dorsal horn of rats. In this exploratory, single group study, patients with chronic post-herpetic pain were treated with a single, one-hour, high-dose remifentanil infusion. The mean overall change of pain intensity seven days after treatment was -18 (-7.5; -28.5, 95%CI, p<0.001) points on the numeric rating scale (0-100) (-33 (±11) points amongst responders only). Eleven of 20 patients responded to treatment (≥30% reduction in pain), the mean relative reduction in pain from baseline amongst responders was 61.0%. These promising preliminary results suggest that a mechanism-based reversal of chronic pain may be impending.

Skin Matters: A Review of Topical Treatments for Chronic Pain. Part Two: Treatments and Applications

In Part One of this two-part series, we discussed skin physiology and anatomy as well as generalities concerning topical analgesics. This modality of therapy has lesser side effects and drug-drug interactions, and patients tolerate this form of therapy better than many oral options. Unfortunately, this modality is not used as often as it could be in chronic pain states, such as that from neuropathic pain. Part Two discusses specific therapies, local anesthetics, and other drugs, as well as how a clinician might use specific aspects of a patient's neuropathic pain presentation to help guide them in the selection of a topical agent.

Skin Matters: A Review of Topical Treatments for Chronic Pain. Part One: Skin Physiology and Delivery Systems

Chronic pain is a complex disorder with multiple etiologies for which the pathologic mechanisms are still largely unknown, making effective treatment a difficult clinical task. Achieving pain relief along with improved function and quality of life is the primary goal of pain clinicians; however, most patients and healthcare professionals consider 30% pain improvement to be clinically significant—a success level that would be unacceptable in other areas of medicine. Furthermore, patients with chronic pain frequently have multiple comorbidities, including depression and sleep apnea, and most have seen several physicians prior to being seen by a pain specialist, have more than three specific pain generators, and are taking multiple medications. The addition of further oral medications to control pain increases the risk of drug–drug interactions and side effects. However, topical analgesics have the advantage of local application with limited systemic levels of drug. Topical therapies benefit from reduced side effects, lower risk of drug–drug interactions, better patient acceptability/compliance, and improved tolerability. This two-part paper is a review of topical analgesics and their potential role in the treatment of chronic pain.

Treatment of neuropathic pain with the capsaicin 8% patch: Quantitative sensory testing (QST) in a prospective observational study identifies potential predictors of response to capsaicin 8% patch treatment

Background and aims Peripheral neuropathic pain (PNeP) is a chronic and disabling condition for which no predictors of response to treatment have yet been identified. Clinical studies show that while many patients with PNeP respond positively to treatment with the capsaicin 8% patch, others do not. This study used quantitative sensory testing (QST) to determine whether any patient characteristics can predict response to treatment with the capsaicin 8% patch. Methods This was a prospective, non-placebo-controlled, observational study. Patients used the Visual Analogue Scale (VAS) to assess their pain at baseline and then on Days 1, 7-10 (from here referred to as Day 7/10), 28 and 84 following treatment with the capsaicin 8% patch. QST was undertaken at the same timepoints on the painful area at the region of maximum PNeP and on a contralateral, control area. In addition, the size of the painful area was assessed at baseline and Days 7/10, 28 and 84. Results A total of 57 patients were treated. Among 54 evaluable patients, 19 (35.2%) achieved a ≥30% reduction in VAS pain score at Day 7/10 post-treatment compared with baseline - these were defined as 'responders'. Analysis of the QST data showed that the PNeP area in responders, but not in non-responders, had a significantly lower pressure pain threshold compared with the control area at baseline (median 320 kPa vs. 480 kPa, respectively; p = .004). Furthermore, non-responders had approximately three times greater degree of allodynia at baseline compared with responders across tests using brush, cotton wool and Q-tip. These differences were significant for tests using brush and cotton wool (p = .024 and p = .046, respectively) and approached significance in the test using Q-tip (p = .066). Following treatment with the capsaicin 8% patch, responders showed a trend towards a reduction in warm perception and also appeared to show normalization of the pinprick hyperalgesia at some stimulus levels. Responders to therapy had significantly greater reductions than non-responders in the size of the painful area at Day 28 (p = .011) and Day 84 (p = .005) following treatment. However, both responders and non-responders had meaningful reductions in the size of the painful area compared with baseline values. Conclusions This study suggests that differences can be identified in the sensory profiles of patients with PNeP who respond to the capsaicin 8% patch and those who do not, specifically pressure pain threshold and degree of allodynia. Notably, both responders and non-responders experienced meaningful reductions in the size of the painful area following treatment. Implications The findings warrant further investigation in a larger number of patients and in prospective trials.

Austrian clinical practice with anidulafungin in 2008: a multicenter survey

Anidulafungin had demonstrated favorable efficacy versus fluconazole in a randomized trial on invasive Candida infections. Since patient characteristics in the post-approval use of antifungals likely deviate from clinical trials, we surveyed the use of anidulafungin in clinical routine. We performed a retrospective survey of the post-approval use of anidulafungin in 9 Austrian clinical centers. Anidulafungin was used in 129 critically ill patients with severe comorbidities and multiple risk factors. Indications were suspected invasive fungal infections (IFI) (61%), proven candidemia (19%), and at risk for IFI (prophylaxis, 20%). Candida colonization in conjunction with other risk factors prompted treatment in many patients. predominant pathogens were C. albicans, C. glabrata and C. krusei. Anidulafungin was mostly used for pre-emptive (69%) and first-line treatment (17%) of invasive candidiasis. Treatment response, i.e. complete response/stabilization as determined by investigators (89% in the overall population; 87% for documented candidemia) and survival rates (81% and 75%, respectively) were similar to previous trial data. No breakthrough IFI and few adverse events were reported. Overall, favorable clinical experiences were documented with anidulafungin in the clinical routine setting.

Intravenous opioid testing in patients with chronic non-cancer pain

The clinical use of an intravenous opioid testing can help to predict whether opioids will be beneficial. The determination of individual opioid responsiveness justifies subsequent long-term opioid treatment and is generally recommended. An overview over current testing procedures is given with particular regard to choice of opioid, maximum dose, determination of endpoints and duration of testing and recovery. Remifentanil testing is a new approch and is studied in a randomized placebo-controlled cross-over study in 24 patients suffering from severe non-cancer pain. An ascending infusion of remifentanil and placebo respectively was titrated against endpoints. The testing allowed a disctinction between 11 opioid-responders and 13 non-responders. Complete recovery after end of infusion was rapid with a reach of baseline conditions after 25 min in all patients. Thus the complete remifentanil testing procedure required at utmost 1 h. In conclusion, remifentanil testing offers a more rapid procedure allowing the routine use in an ambulatory setting.

[Quality of postoperative pain therapy in Austria: national survey of all departments of anesthesiology]

BACKGROUND

Despite increasingly sophisticated concepts of perioperative pain therapy, such as increased use of combined regional anesthesia techniques, the renaissance of ketamine and dipyrone or the use of oral opioids, no significant improvement has been achieved in postoperative pain therapy since 1995. About 300,000 of the approximately 700,000 patients undergoing major surgery each year in Austria experience moderate to severe postoperative pain. The aim of this study was therefore to assess the nationwide status of perioperative acute pain management in postoperative recovery rooms and surgical wards in order to identify potential areas for improvement.

METHODS

In 2006 the directors of all Austrian anesthesiology departments (n=125, 100%) were contacted and asked to give detailed information on the status of acute pain management of each individual hospital in Austria using a standardized questionnaire. Data of each individual department were derived from quality control and self-assessment of each department. No patients were questioned. The return rate was 96% (n=120) due to intensive personal contact in cases of missing data.

RESULTS

In this nationwide survey 120 anesthesiology departments participated together accounting for a total of 757,895 operations per year. Of the patients 63.6% were informed preoperatively on the available regimens of acute pain management. In 81% of patients perioperative pain therapy consisted of a multimodal therapeutic approach, 58.6% of the departments used international guidelines and 39.7% worked with international guidelines adapted to local requirements. In 88% of patients a detailed prescription for postoperative pain therapy was available when transferred to the surgical ward. Surgical wards were equipped with routine pain therapy protocols in 28% another 20% of wards had special pain therapy protocols for individual operations. In 22% of cases pain assessment was repeated 3-4 times per day and in 33.9% postoperative pain was assessed only once twice per day. Pain assessments were recorded in the patient charts in 60.7% of cases. If changes to the pain therapy regimen were required anesthesiologists were involved in only 14.3% of cases. In addition an acute pain service was available only in 39.2% of Austrian anesthesiology departments.

CONCLUSIONS

Although the multimodal approach to acute pain therapy is widely used and standardized therapeutic regimens are well established in the majority of anesthesiology and surgical wards, there still remains room for improvement. Pain assessment is generally barely adequate and written documentation of pain assessment is missing almost completely. In addition, almost two thirds of hospitals in Austria are still lacking an acute pain service.

Antihyperalgesic efficacy of 5% lidocaine medicated plaster in capsaicin and sunburn pain models--two randomized, double-blinded, placebo-controlled crossover trials in healthy volunteers

OBJECTIVE

The aim of this research is to analyze analgesic efficacy of the 5% lidocaine medicated plaster in two randomized, double-blinded, placebo-controlled, crossover studies in 16 healthy volunteers using capsaicin and sunburn pain models.

METHODS

Lidocaine and placebo plasters were simultaneously applied to forearms and thighs at contralateral body sites for three alternating 12-h plaster-on/plaster-off periods. Between the second and third plaster-on period, 4.2-cm circular spots on both pretreated thighs were irradiated with three times the individual minimal erythema dose of UVB light. After the last plaster-on period, 20 μl of 0.1% capsaicin was injected intradermally into both forearms. The study was repeated using a single 12-h plaster application.

RESULTS

The area of pinprick hyperalgesia was diminished by 53% (p < 0.003) in the capsaicin model and by 84% (p < 0.0001) in the sunburn model; the intensity of mechanical hyperalgesia to rigid filaments (8 - 512 mN) was reduced in both models. Cold pain perception threshold was reduced (19.7°C ± 8.0 vs 21.8°C ± 6.8 for placebo, p < 0.05, sunburn). Similar effects were observed in the 12-h exposure study. No effect was seen on capsaicin-induced spontaneous pain and flare size, or blood flow in the sunburn area, and heat hyperalgesia in either study.

CONCLUSIONS

Lidocaine plaster effectively treats mechanical hyperalgesia and cold pain.

The anxiolytic effect of pregabalin in outpatients undergoing minor orthopaedic surgery

Preoperative anxiety can increase postoperative pain and is therefore important to avoid. Different approaches have already been tested for preoperative anxiolysis. Gabapentinoids might be a useful alternative to benzodiazepines. Pregabalin is used for treating generalized anxiety disorders and shows a favourable pharmacokinetic profile after oral administration; however, its anxiolytic effect preoperatively in healthy outpatients is still unclear. In this randomised, double-blind, placebo-controlled trial the anxiolytic effect of pregabalin in 40 outpatients undergoing standardised general anaesthesia and postoperative pain therapy for minor orthopaedic surgery was analysed. Patients received preoperatively either 300 mg pregabalin or placebo orally. The primary outcome was anxiety before anaesthesia induction, the secondary outcome the postoperative pain, both assessed using a visual analogue scale from 0 to 100. Without any side effects pregabalin reduced preoperative anxiety compared with the control group (23 ± 10 vs. 38 ± 17; p = 0.003). Pain scores did not differ between groups; however, need of piritramide in the postanaesthesia care unit was reduced to half by pregabalin compared with the control group. A single preoperative dose of 300 mg pregabalin reduces anxiety in patients undergoing minor orthopaedic surgery without any side effects like dizziness or persisting sedation resulting in a prolonged stay in the postanaesthesia care unit.

On the ropivacaine-reducing effect of low-dose sufentanil in intrathecal labor analgesia

BACKGROUND

Combining ropivacaine with sufentanil for intrathecal (i.t.) analgesia in labor is well recognized, but information on dosing is limited. This study aimed to determine the ED 50 of i.t. ropivacaine and to assess the effect of adding defined low doses of sufentanil.

METHODS

This was a two-phase, double-blind, randomized and prospective study. One hundred and fifteen parturients receiving combined spinal epidural analgesia were allocated to one of four groups to receive ropivacaine or sufentanil alone or in combination. In phase one, sufentanil dose-response was calculated using logistic regression. In phase two, ED 50 of ropivacaine and of the combination with a fixed dosage of sufentanil at ED 20 and ED 40 was evaluated using the technique of up-down sequential allocation. Analgesic effectiveness was assessed 15 min after injection using a 100 mm visual analog scale, with <10 mm lasting for 45 min defined as effective. Furthermore, side effects and duration were recorded.

RESULTS

The ED 50 of i.t. ropivacaine was 4.6 mg [95% confidence intervals (95% CI) 4.28, 5.31]. Adding sufentanil at ED 20 significantly decreased the ED 50 of i.t. ropivacaine to 2.1 mg (95%CI 1.75, 2.5) (P<0.005); at ED 40, the reduction was similar (P<0.005). Combining sufentanil with ropivacaine resulted in a dose-independent prolongation of analgesia. Besides pruritus, which was well tolerated, there were no differences in side effects.

CONCLUSION

Adding sufentanil at ED 20 results in a more than 50% dose-sparing effect of ropivacaine and considerably prolongs analgesia. Increasing dosage implicates no clinical benefit.

[Sedation and analgesia in intensive care: physiology and application]

Many therapeutic and diagnostic procedures in intensive care medicine are perceived as painful by most patients. As a consequence analgesia and sedation represent two of the main pillars in the treatment of the critically ill. Adaptation to the individual needs of the patients poses one of the biggest challenges that we are confronted with. Both morbidity and mortality can be positively influenced by adequate treatment. In the first part of this review we will discuss the physiology of sleep patterns and pain. Furthermore modes of action and side effects of the most common anesthetics and analgetics will be presented. Finally, the last part of the manuscript deals with the practical application of these therapeutics and their monitoring in intensive care medicine.

[Topical application of morphine and buprenorphine gel has no effect in the sunburn model]

BACKGROUND

The aim of this placebo-controlled double-blinded cross-over study was to investigate the antihyperalgesic effect of topical morphine and buprenorphine in the sunburn pain model.

MATERIAL AND METHODS

The study was designed as a double-blind, placebo-controlled cross-over trial, separated into 2 parts each with 16 volunteers. In part A morphine dissolved in Ultrabas-ultrasic ointment at 3 concentrations (0.1, 0.2, 0.4%) and placebo ointment were applied to 4 UVB-induced erythemas on the thighs. In part B buprenorphine at 3 concentrations (0.01, 0.02 and 0.1%) and placebo dissolved in a gel for transcutaneous application, was applied to 4 erythemas on the thighs. Thermal and mechanical hyperalgesia were assessed in the respective erythema by standardized quantitative sensory testing and opioids were compared to the placebo.

RESULTS

Neither morphine nor buprenorphine showed any significant reduction of hyperalgesia in comparison to the placebo.

CONCLUSION

The topical application of opioids in this form has no effect on inflamed skin.

Prevalence of self-reported neuropathic pain and impact on quality of life: a prospective representative survey

BACKGROUND

Data on the incidence of neuropathic pain (NeP) in Austria, its general characteristics and consequences for the quality of life (QOL) are still lacking. The prevalence in the United Kingdom is 8%.

METHODS

A representative survey (n=7707) was carried out. Patients with NeP were identified using previously validated criteria and subsequently asked to complete a questionnaire on QOL and detailed pain characteristics.

RESULTS

The prevalence of NeP was 3.3% (n=260). A higher prevalence was found in 41-50-year-olds (26%) and 51-60 year olds (24%). Pain was long lasting (>1 year: 66%; >5 years: 41%) and severe at onset (mean 6.8; numerical rating scale) as well as later (mean 4.7; 20% 8 or higher). Strong or predominant restriction of daily activities was reported in 65%, strong or predominant sleep disturbances in 60%, feelings of depression in 34% and anxiety in 25%.

CONCLUSION

For the first time, data on the prevalence of NeP in Austria are available. Pain patterns in those affected are characteristic and impact on QOL as well as pain intensity are severe.

Remifentanil for tracheal tube tolerance: a case control study

We assessed the minimal remifentanil dosage required for tracheal tube tolerance in awake and spontaneously breathing patients after major abdominal surgery. Forty postoperative patients received remifentanil 0.1 microg.kg(-1).min(-1), which was reduced in steps of 0.025 microg.kg(-1).min(-1) every 30 min. Respiratory response subscore of comfort scale (CSRR), Ramsay sedation scale (RSS), visual analogue scale (VAS), respiratory rate, and minute ventilation were recorded. Spontaneous respiration with no or little response to ventilation (CSRR 2) in co-operative, oriented and tranquil patients (RSS 2) was defined as the main outcome and study endpoint. Thirty-one patients (77.5%) reached a CSRR 2 and RSS 2 with remifentanil 0.025 microg.kg(-1).min(-1) and nine patients (22.5%) required remifentanil 0.05 microg.kg(-1).min(-1). Analgesia was sufficient in all patients (VAS = 30). Remifentanil 0.025-0.05 microg.kg(-1).min(-1) achieves satisfactory tracheal tube tolerance in awake and spontaneously breathing patients.

TENS Relieves Acute Posttraumatic Hip Pain During Emergency Transport

BACKGROUND

In Central Europe, ambulances for patients suffering from pain caused by nonlife-threatening trauma, such as hip fractures are staffed by medical personnel (medics) without physicians. Thus, there is an urgent need for nonpharmacological interventions that can be applied during the transport by basic life-support (BLS) medical personnel.

METHODS

In all, 101 patients were screened for participation in this randomized placebo-controlled double-blind study, and randomly assigned to two groups (verum and sham transcutaneous electrical nerve stimulation [TENS]). First, medic A recorded all baseline parameters and measurements, then medic B performed TENS in absence of medic A. At the end of transportation, medic A performed data collection. Each patient was asked to grade his/her pain and anxiety level on visual analog scales (VAS, 0 to 100 mm).

RESULTS

From 101 screened patients fulfilling the entry criteria, 29 declined consent and 9 had to be excluded from the analysis because of their final diagnosis. Therefore, the data from 30 patients (group 1, verum TENS) as well as from 33 patients (group 2 [control], sham TENS) were analyzed. No significant differences in potentially influencing factors were found before treatment. Pain scores upon arrival at the hospital differed significantly between group 1 and group 2 (p < 0.01). In group 1, pain reduction was observed between departure from the site of emergency and arrival at the hospital (VAS: 89 +/- 9 to 59 +/- 6 mm), whereas pain scores remained nearly unchanged in group 2 (VAS: 86 +/- 12 to 79 +/- 11 mm).

CONCLUSION

Our findings show that TENS is a valuable and fast-acting pain treatment under the difficult circumstances of "out-of-hospital rescue". Because of its lack of side effects, it could also be a valuable tool in the hospital.

Anaesthesia for brachytherapy—5½ yr of experience in 1622 procedures

BACKGROUND

Brachytherapy presents the anaesthetist with unique problems. Information on anaesthesia for brachytherapy, however, is limited. The aim of this paper is to report on our experience involving a large number of brachytherapy procedures.

METHODS

A retrospective analysis of records of 1622 anaesthetic procedures in 952 patients is presented. Records were analysed in respect of patient data, tumour localization, brachytherapy treatment and the type and duration of anaesthetic procedures.

RESULTS

More than one-third of patients were at high risk (ASA III or IV) and 40% were more than 60 yr. Repetitive treatments were performed on half of the patients. Breast cancer was the most common indication. The average duration of anaesthesia for pelvic brachytherapy was more than 3 h, with a high degree of variability. Regional anaesthesia was used in 30% of all cases and was the predominant technique for pelvic brachytherapy. Spinal catheter techniques represented a high proportion of those receiving regional anaesthesia. Complications resulting from regional and general anaesthesia were minor and no serious incidents occurred.

CONCLUSIONS

Based on a large number of procedures, this study gives an example of anaesthetic management in brachytherapy. A substantial minority of patients would be considered high risk for surgical intervention. Regional anaesthesia was the principal technique used when dealing with tumours of the lower body.

A Lack of Antinociceptive or Antiinflammatory Effect of Botulinum Toxin A in an Inflammatory Human Pain Model

Several in vitro and in vivo investigations have shown that botulinum toxin A (BoNT/A) can inhibit the release of substance P and excitatory amino acids. Recently, a marked antinociceptive effect of BoNT/A and inhibition of glutamate release was observed in an animal pain model with inflammatory sensitization. In the present study, we tested the antiinflammatory and antihyperalgetic effect of BoNT/A in a well-characterized human inflammatory pain model. Using a randomized, double-blind, paired study design, we compared the effects of 100 mouse units of BoNT/A versus pure saline. Thermal and mechanical pain testings and superficial skin blood flow measurements were performed at baseline, at 48 h (in normal skin), and at 72 h (in inflamed skin) thereafter. Ultraviolet B irradiation resulted in a local inflammation with significant primary and secondary hyperalgesia. However, despite the evidence of efficacy on sudomotor function, BoNT/A had no effect on pain measures in either normal or inflamed skin. Signs of inflammation and primary and secondary hyperalgesia were found to be unaffected by BoNT. We have confirmed that BoNT/A has no direct effect on acute, noninflammatory pain. Furthermore, despite highly promising data from animal research, we have not observed antiinflammatory or antinociceptive effects of BoNT/A in human inflammatory pain.

Long-term intrathecal S(+)-ketamine in a patient with cancer-related neuropathic pain

Neuropathic pain sometimes needs invasive pain therapy. We present the case of a patient with cancer-related neuropathic pain untreatable with conventional pain therapy after tumour-embolization. The patient was treated successfully with intrathecal (i.t.) administration of S(+)-ketamine, in addition to morphine. Plasma concentrations of S(+)-ketamine were measured regularly throughout the treatment. Continuous i.t. administration of S(+)-ketamine over a period of 3 months demonstrated low plasma levels and no unwanted side-effects.

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.

Transcutaneous electrical nerve stimulation reduces acute low back pain during emergency transport

BACKGROUND

Patients with acute low back pain may require emergency transport because of pain and immobilization. Transcutaneous electrical nerve stimulation (TENS) is a nonpharmaceutical therapy for patients with low back pain.

OBJECTIVE

To evaluate the efficacy of paramedic-administered TENS in patients with acute low back pain during emergency transport.

METHODS

This was a prospective, randomized study involving 74 patients transported to hospital. The patients were randomly assigned to two groups: group 1 (n = 36) was treated with true TENS, while group 2 (n = 36) was treated with sham TENS. The authors recorded pain and anxiety as the main outcome variables using a visual analog scale (VAS).

RESULTS

The authors recorded a significant (p < 0.01) pain reduction (mean +/- standard deviation) during transport in group 1 (79.2 +/- 6.5 mm VAS to 48.9 +/- 8.2 mm VAS), whereas pain scores remained unchanged in group 2 (75.9 +/- 16.4 mm VAS and 77.1 +/- 11.2 mm VAS). Similarly, the scores for anxiety were significantly reduced (p < 0.01) in group 1 (81.7 +/- 7.9 mm VAS to 69.2 +/- 12.1 mm VAS) after treatment. No significant change was noted (84.5 +/- 5.8 mm VAS and 83.5 +/- 8.9 mm VAS, respectively) in group 2.

CONCLUSIONS

TENS was found to be effective and rapid in reducing pain during emergency transport of patients with acute low back pain and should be considered due to its ease of use and lack of side effects in the study population.

Rofecoxib attenuates both primary and secondary inflammatory hyperalgesia: a randomized, double blinded, placebo controlled crossover trial in the UV-B pain model

The analysis of drug's influence on peripheral and central sensitisation can give useful information about its mode of action and can lead to more efficacy in the treatment of pain. Peripheral inflammation is associated with peripheral expression and up-regulation of cyclooxygenase 2 (COX-2) in the CNS. The relative contribution of COX-2 mediated central sensitisation may be prominent under inflammatory conditions. In this randomized, double blinded, placebo controlled cross-over trial the effects of multidoses of the COX-2 selective inhibitor rofecoxib on primary and secondary hyperalgesia were evaluated in the UVB pain model. Twenty-four hours after local UVB irradiation at the upper leg of 42 healthy volunteers heat pain perception (HPPT) and heat pain tolerance thresholds (HPTT) were assessed within the inflammation. The area of secondary hyperalgesia was determined by pin prick test. Subjects received oral rofecoxib 50, 250, 500 mg or placebo. Pain testing was repeated after 3 and 6 h. Compared to placebo, rofecoxib significantly increased HPPT (1.55 and 1.08 degrees C, P<0.0001 and P=0.0333), HPTT (1.74 and 1.58 degrees C, P<0.0001 and P<0.0001), and reduced the mean area of secondary hyperalgesia by 15.6% (P=0.007) and 16.8% (P<0.001) after 3 and 6 h. No significant difference between the three dosage groups was observed. These data confirm peripheral effects of rofecoxib in a human inflammatory UV-B pain model and provide circumstantial evidence that even a standard clinical dose of rofecoxib reduces central hyperalgesia in inflammatory pain. We confirm that the effect of single oral dose of rofecoxib plateaus at 50 mg.

Ultrasound-guided lumbar facet nerve block: accuracy of a new technique confirmed by computed tomography

BACKGROUND

Lumbar facet nerve (medial branch) blocks are often used to diagnose facet joint-mediated pain. The authors recently described a new ultrasound-guided methodology. The current study determines its accuracy using computed tomography scan controls.

METHODS

Fifty bilateral ultrasound-guided approaches to the lumbar facet nerves were performed in five embalmed cadavers. The target point was the groove at the cephalad margin of the transverse (or costal) process L1-L5 (medial branch T12-L4) adjacent to the superior articular process. Axial transverse computed tomography scans, with and without 1 ml contrast dye, followed to evaluate needle positions and spread of contrast medium.

RESULTS

Forty-five of 50 needle tips were located at the exact target point. The remaining 5 were within 5 mm of the target. In 47 of 50 cases, the applied contrast dye reached the groove where the nerve is located, corresponding to a simulated block success rate of 94% (95% confidence interval, 84-98%). Seven of 50 cases showed paraforaminal spread, 5 of 50 showed epidural spread, and 2 of 50 showed intravascular spread. Despite the aberrant distribution, all of these approaches were successful, as indicated by contrast dye at the target point. Abnormal contrast spread was equally distributed among all lumbar levels. Contrast traces along the needle channels were frequently observed.

CONCLUSIONS

: The computed tomography scans confirm that our ultrasound technique for lumbar facet nerve block is highly accurate for the target at all five lumbar transverse processes (medial branches T12-L4). Aberrant contrast medium spread is comparable to that of the classic fluoroscopy-guided method.

Active warming during emergency transport relieves acute low back pain

STUDY DESIGN

Prospective randomized blinded trial in a prehospital emergency system.

OBJECTIVES

To evaluate the effects of external active warming on acute back pain during rescue transport to hospital.

BACKGROUND DATA

Acute low back pain is one of the complaints that most often entails a visit to the physician or use of the emergency system. Superficial (e.g., hydrocolloid packs) and deep heating (e.g., ultrasound) can relieve acute low back pain in a clinical setting. Recent data showed significant benefit for patients in pain from minor trauma treated by active warming during emergency transport. Accordingly, we tested the hypothesis that active warming would reduce pain and anxiety in patients with acute low back pain being transported to a hospital.

METHODS

A total of 100 patients were included in our study. We selected only those suffering from acute pain > 60 mm on a visual analog scale in the lower back. Patients were randomly assigned to two groups: active warming with a carbon-fiber electric heating blanket (Group 1) versus passive warming with a woolen blanket (Group 2) during transfer to hospital. RESULTS.: Pain scores on arrival at the hospital differed significantly between Group 1 and Group 2 (P < 0.01). In Group 1, pain reduction from 74.2 +/- 8.5 mm VAS to 41.9 +/- 18.9 mm VAS (P < 0.01) was noted between departure from the emergency site and arrival at the hospital. Pain scores remained practically unchanged in Group 2 (73.3 +/- 11.9 mm VAS and 74.1 +/- 12.0 mm VAS).

CONCLUSIONS

Active warming reduces acute low back pain during rescue transport.

Ultrasound-guided lumbar facet nerve block: a sonoanatomic study of a new methodologic approach

BACKGROUND

Lumbar facet nerve (medial branch) block for pain relief in facet syndrome is currently performed under fluoroscopic or computed tomography scan guidance. In this three-part study, the authors developed a new ultrasound-guided methodology, described the necessary landmarks and views, assessed ultrasound-derived distances, and tested the clinical feasibility.

METHODS

(1) A paravertebral cross-axis view and long-axis view were defined under high-resolution ultrasound (15 MHz). Three needles were guided to the target point at L3-L5 in a fresh, nonembalmed cadaver under ultrasound (2-6 MHz) and were subsequently traced by means of dissection. (2) The lumbar regions of 20 volunteers (9 women, 11 men; median age, 36 yr [23-67 yr]; median body mass index, 23 kg/m2 [19-36 kg/m2]) were studied with ultrasound (3.5 MHz) to assess visibility of landmarks and relevant distances at L3-L5 in a total of 240 views. (3) Twenty-eight ultrasound-guided blocks were performed in five patients (two women, three men; median age, 51 yr [31-68 yr]) and controlled under fluoroscopy.

RESULTS

In the cadaver, needle positions were correct as revealed by dissection at all three levels. In the volunteers, ultrasound landmarks were delineated as good in 19 and of sufficient quality in one (body mass index, 36 kg/m2). Skin-target distances increased from L3 to L5, reaching statistical significance (*, **P < 0.05) between these levels on both sides: L3r, 45+/-6 mm*; L4r, 48+/-7 mm; L5r, 50+/-6 mm*; L3l, 44+/-5 mm**; L4l, 47+/-6 mm; L5l, 50+/-6 mm**. In patients, 25 of 28 ultrasound-guided needles were placed accurately, with the remaining three closer than 5 mm to the radiologically defined target point.

CONCLUSION

Ultrasound guidance seems to be a promising new technique with clinical relevance and the potential to increase practicability while avoiding radiation in lumbar facet nerve block.

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).

A randomized, double-blind, placebo controlled study on analgesic effects of botulinum toxin A

OBJECTIVE

Botulinum toxin type A (BTXA) is used to treat neurologic disorders associated with increased muscle tone. Its use is often associated with pain relief.

METHODS

A possible direct analgesic effect of BTXA on C and Adelta fibers was studied on 16 healthy volunteers receiving 30 U BTXA into one forearm and pure saline into the other. To exclude the secondary effect due to muscular tone reduction, BTXA was injected intradermally. Thermal sensory testing of heat pain (threshold and tolerance) and neuroselective current sensory testing of current pain threshold/tolerance were performed at baseline and 3, 14, and 28 days after treatment. Thereafter, on day 28, capsaicin was administered simultaneously into both forearms to evaluate a possible peripheral effect and central effect on pain processing and on the axon reflex flare.

RESULTS

The authors observed no significant difference in any of the perception outcome measures between BTXA and placebo pretreated areas. Flare areas as a result of the release of neuropeptides after capsaicin application showed no differences.

CONCLUSIONS

The results suggest that pain reduction after BTXA treatment is mediated through its effect on muscle tone rather than a direct analgesic effect.

The Effects of Remifentanil and Gabapentin on Hyperalgesia in a New Extended Inflammatory Skin Pain Model in Healthy Volunteers

We tested the responsiveness of measures of hyperalgesia in a model of UVB-induced inflammatory hyperalgesia with remifentanil, gabapentin, and the combination of both drugs in a double-blinded, active placebo-controlled, 4-way-crossover design in 16 volunteers. A circular skin area was irradiated with UVB-light 20 h before the application of gabapentin (600 mg) and 2 h later remifentanil (0.08 microg.kg(-1).min(-1), 40 min). In the sunburn spots we observed stable decreases of the heat pain perception thresholds (HPPT, mean difference, 4.45 degrees C; 95% confidence interval [CI], 3.32 degrees -5.59 degrees ) and heat pain tolerance thresholds (HPTT; mean difference, 5.43 degrees C; 95% CI, 4.50 degrees -6.35 degrees ) compared with normal skin. Further, large areas of mechanical hyperalgesia to pinprick adjacent to the erythema spots developed in all subjects. Overall remifentanil increased the HPPT (mean increase, 2.47 degrees C; 95% CI, 1.86 degrees -3.09 degrees, P < 0.001) and HPTT (mean increase, 3.18 degrees C; 95% CI, 2.65 degrees -3.71 degrees, P < 0.001) and reduced the area of secondary hyperalgesia by 59% (mean decrease, 5326 mm(2); 95% CI, 4233-6419 mm(2), P < 0.001) compared with placebo. In the sunburn remifentanil markedly increased the HPTT by 86% compared with normal skin (additional increase, 2.57 degrees C; 95% CI, 1.71 degrees -3.43 degrees). This different effect was not seen in the HPPT. With the exception of a small increase of HPTT in the sunburn (P = 0.02) gabapentin had no noticeable effect on either hyperalgesia. In conclusion, opioid analgesia was reliably demonstrated in this new extended pain model.

IMPLICATIONS

Opioid analgesia was reliably demonstrated in a new inflammatory model of primary and secondary hyperalgesia. Gabapentin showed no antihyperalgesic and no opioid-enhancing effect in this model.

Korean hand acupressure for motion sickness in prehospital trauma care: a prospective, randomized, double-blinded trial in a geriatric population

Patients with trauma or medical illnesses transported to the hospital by ambulance have a frequent incidence of motion sickness. Because the administration of drugs in the ambulance is prohibited by law in Austria, the noninvasive Korean hand acupressure point at K-K9 may be an alternative against nausea and vomiting. We enrolled 100 geriatric patients with minor trauma, randomizing them into a K-K9 group and a sham acupressure group. We recorded visual analog scores (VAS) for nausea and for the patient's overall satisfaction with the treatment, hemodynamic variables, and peripheral vasoconstriction. In the K-K9 group, a significant (P < 0.01) increase in nausea was recorded in all cases: from VAS of 0 mm to 25 +/- 6 mm. A similarly significant (P < 0.01) increase was registered in the sham group: from VAS of 0 mm to 83 +/- 8 mm. However, at the time of arrival in the hospital, nausea scores were significantly different between the K-K9 group and the sham group (P < 0.01). Although all patients had been vasoconstricted at the emergency site before treatment, there was a significant difference (P < 0.01) between groups with regard to the number of vasoconstricted patients at the hospital (4 and 46 constricted and dilated, respectively, in the K-K9 group versus 48 and 2 constricted and dilated, respectively, in the sham group). On arrival in the hospital, a significant difference (P < 0.01) in heart rate was noted between the K-K9 group and the sham group (65 +/- 6 bpm versus 98 +/- 8 bpm). The patients' overall satisfaction with the provided care was significantly higher (P < 0.01) in the K-K9 group (19 +/- 9 mm VAS) than in the sham group (48 +/- 12 mm VAS). Neither group experienced a significant change in blood pressure. K-K9 stimulation was an effective and simple treatment for nausea during emergency care and significantly improved patient satisfaction.

IMPLICATIONS

Korean hand acupressure at the K-K9 point was effective in reducing nausea and subjective symptoms of motion sickness in emergency trauma transport of patients at high risk of motion sickness.

Capnography in Non-Tracheally Intubated Emergency Patients as an Additional Tool in Pulse Oximetry for Prehospital Monitoring of Respiration

Victims of minor trauma transported by paramedic-based rescue systems are usually monitored with pulse oximetry. Under the difficult surroundings of prehospital trauma care, pulse oximeters show considerable periods of malfunction. We tested the hypothesis that capnography is a good, easy to use tool for monitoring in nonintubated trauma victims. Seventy nonintubated trauma victims were included in this study. Vital variables and number and time of malfunctions were sampled for oximeter and capnometer recordings. Total number of alerts (63 versus 10), number of alerts per patient (3.3 [1.9] versus 0.3 [0.9]) (mean [SD]), total time of malfunction (191.5 [216.7] s versus 11.8 [40.2] s), time of malfunction per alarm (58.3 [71.4] s versus 5.5 [14.6] s), and the percentage of malfunction time during transport (13.2% [15.3%] versus 0.8% [2.8%]) differed significantly (P < 0.01) between oximetry and capnography. Although pulse oximetry is a standard method of monitoring in emergency care, we found capnography to be helpful as a monitoring device. We consequently recommend the use of capnography on transport as an additional monitoring tool to reduce periods lacking supervision of the vital variables.

IMPLICATIONS

Capnography is a useful tool to improve respiratory monitoring in nonintubated trauma victims on emergency transport and an easy to use supplement to pulse oximetry.

The Sunburn Pain Model: The Stability of Primary and Secondary Hyperalgesia Over 10 Hours in a Crossover Setting

It was our aim to study the within-day stability and between-day repeatability of ultraviolet B (UVB) light-induced primary and secondary hyperalgesia over 10 h. Twenty hours after UVB irradiation of a skin spot (r = 2.5 cm) on the upper leg of 8 healthy volunteers the areas of secondary hyperalgesia to pinprick and pain tolerance thresholds to heat (HPTT) and electrical stimuli (5 and 250 Hz, electrical pain tolerance thresholds [EPTT]) were assessed. Measurements were repeated for 10 h at 2-h intervals and in 2 different sessions. Large areas of secondary hyperalgesia to pin prick were observed (5995 mm(2); SD, 1645). Primary hyperalgesia was evidenced by significant decreases of HPTT (mean difference, 6.5 degrees C; 95% confidence interval, 6.1-6.8; P < 0.001) and EPTT at 250 Hz (mean difference, 0.45 mA; 95% confidence interval, 0.13-0.78; P < 0.05) compared to normal skin. There was no trend within one session of either primary (P = 0.14 for HPTT) or secondary hyperalgesia (P = 0.95) and no difference between the two sessions (primary hyperalgesia, P = 0.28; secondary hyperalgesia, P = 0.07). The sunburn pain model provides a long time course of stable hyperalgesia with a high within-day stability and between-day repeatability for primary and secondary hyperalgesia.

IMPLICATIONS

The sunburn pain model provides a long time course of stable hyperalgesia with a high within-day stability and between-day repeatability for primary and secondary hyperalgesia.

Oxygenation Status of Cervical Carcinomas Before and During Spinal Anesthesia for Application of Brachytherapy

BACKGROUND AND PURPOSE

To date, no information is available concerning the impact of spinal anesthesia on the oxygenation status of carcinomas of the uterine cervix. The aim of this study was therefore to determine the influence of spinal anesthesia on the oxygenation status of cervical carcinomas.

PATIENTS AND METHODS

In ten patients with cervical carcinoma who received spinal anesthesia for a first application of brachytherapy, intratumoral pO2 measurements (pO2 histography system, Eppendorf-Netheler-Hinz, Hamburg, Germany) were performed. Systemic parameters were documented prior to and during spinal anesthesia. Patients breathed room air spontaneously. For further evaluation, all intratumoral pO2 values were pooled, and overall median pO2 values and fractions of hypoxic pO2 values < or = 5 mmHg were calculated. Overall median pO2 values in the subcutis were also calculated.

RESULTS

There were no significant changes of systemic parameters, median subcutaneous pO2 values, median intratumoral pO2 values, and the fractions of hypoxic pO2 values < or = 5 mmHg in the tumor upon administration of spinal anesthesia. The variability of measured pO2 values increased during spinal anesthesia, although substantial changes in the oxygenation status were only seen in individual cases (n = 2).

CONCLUSION

This study shows for the first time that the oxygenation status of cervical carcinomas, in general, is not influenced by spinal anesthesia prior to application of brachytherapy. To conclude, the data presented suggest that reliable pO2 measurements can be performed under spinal anesthesia. At the same time, since no substantial changes in tumor oxygenation were observed, spinal anesthesia should not affect the O2-related efficacy of high-dose-rate brachytherapy.

Local active warming: an effective treatment for pain, anxiety and nausea caused by renal colic

PURPOSE

Based on previous studies showing that warming decreases trauma pain in emergency care we hypothesized that local active warming of the abdomen and lower back region could decrease pain in acute renal colic cases during emergency transport.

MATERIALS AND METHODS

After obtaining informed consent 100 patients were divided into 2 groups, including those who received active warming of the abdomen and lower back region (42C) and those who received no warming. Pain, nausea and anxiety were rated by the patients using visual analog scales. Statistical evaluation was performed using the t test with p <0.05 considered significant.

RESULTS

In group 1 a significant pain decrease was recorded in all cases using a visual analog score (VAS) (82.7 +/- 9.5 to 36.3 +/- 16.0 mm VAS, p <0.01). In group 2 patient pain scores remained comparable (81.8 +/- 13.0 to 80.6 +/- 12.3 mm VAS). In group 1 anxiety significantly decreased (79.0 +/- 8.9 and 30.7 +/- 14.1 mm VAS before and after treatment, respectively, p <0.01). In group 2 a nonsignificant change in score was noted (79.7 +/- 20.5 to 75.2 +/- 19.7 mm VAS). In group 1 a significant decrease in nausea was recorded in all cases (85.7 +/- 11.2 to 40.6 +/- 23.0 mm VAS, p <0.01). In group 2 patient nausea scores remained comparable (79.2 +/- 22.0 to 80.3 +/- 22.4 mm VAS, respectively).

CONCLUSIONS

Local active warming is an effective and easy to learn pain treatment for patients with acute renal colic in emergency care.

Comparison of different quantitative sensory testing methods during remifentanil infusion in volunteers

BACKGROUND

The aim of this study was to compare thermal and current sensory testing stimuli with respect to opioid responsiveness.

METHODS

Eighteen healthy volunteers were randomized in a placebo-controlled, double-blind crossover study to receive an infusion of remifentanil 0.08 micro g kg(-1) min(-1) or saline for 40 min. Test procedures included determination of pain perception thresholds (PPT) and pain tolerance thresholds (PTT) to heat, cold, and current at 5, 250 and 2000 Hz, at baseline and at the end of the infusion.

RESULTS

Both current at 5 Hz (PPT 3.69 (SD 2.48) mA vs 2.01 (1.52) mA; PTT 6.42 (2.79) mA vs 3.63 (2.31) mA; P<0.001) and 250 Hz (PPT 4.31 (2.42) mA vs 2.89 (1.57) mA; PTT 7.08 (2.68) mA vs 4.81 (2.42) mA; P<0.001) and heat (PPT 47.4 (2.7) degrees C vs 45.2 (3) degrees C; PTT 51.1 (1.8) degrees C vs 49.7 (1.8) degrees C; P<0.05) detected a significant analgesic effect of remifentanil compared with placebo. No analgesic effect was shown on cold or current at 2000 Hz. The magnitude of responsiveness of current stimuli at 5 Hz and 250 Hz was superior to heat stimuli.

CONCLUSION

Both current (5 and 250 Hz) and heat sensory testing detected a significant analgesic effect of a remifentanil infusion compared with saline. There was more response to current testing.

A simple pain model for the evaluation of analgesic effects of NSAIDs in healthy subjects

AIMS

Non-steroidal anti-inflammatory drugs (NSAIDs) are believed to counteract inflammation and inflammation-induced sensitization of nociceptors by inhibiting peripheral prostaglandin synthesis. We evaluated an experimental pain model for NSAIDs, that included an inflammatory component to mimic clinical inflammatory pain conditions.

METHODS

The study was performed in a randomized, double-blind, placebo-controlled, two-way crossover design on 32 healthy volunteers. A small skin area of the proximal upper leg was irradiated with a UVB source using three times the individually estimated minimal erythema dose. Twenty hours after irradiation skin temperature, heat pain threshold and tolerance in sunburn spot were measured using a thermal sensory testing. These measurements were repeated 2 h after medication of either 800 mg ibuprofen as single oral dose or placebo capsules. Effects of ibuprofen on outcome parameters were assessed with analyses of covariance (ancova).

RESULTS

Placebo did not affect heat pain threshold or tolerance. By contrast, ibuprofen increased heat pain threshold by 1.092 degrees C [confidence interval (CI) 0.498, 1.695; P = 0.0008) compared with placebo. Heat pain tolerance also increased significantly by 1.618 degrees C (CI 1.062, 2.175; P = 0.0001).

CONCLUSION

The pain model we evaluated was well tolerated in all subjects and the effects of ibuprofen were highly significant. This model is simple, sensitive to NSAIDs' effects and therefore has potential for future experimental pain studies.

Target-controlled infusion of propofol for fibreoptic intubation

BACKGROUND AND OBJECTIVE

In a retrospective study, we examined the suitability of a departmental clinical protocol for anaesthesia induction with target-controlled infusion of propofol developed for fibreoptic intubation in spontaneously breathing patients scheduled for outpatient oral surgery at the dental clinic of the Vienna University Hospital.

METHODS

Propofol was administered using target-controlled infusion (Diprifusor) at increasing target plasma concentrations starting at 2.5 microg mL(-1). After 10 min, an intravenous dose of alfentanil (5-10 microg kg(-1)) was given for pain reduction. After a further 2 min, the patient was evaluated for response to auditory stimulation. If unresponsive, fibreoptic intubation was performed, otherwise the target concentration was increased by 0.2 microg mL(-1) every 2 min until non-responsiveness was attained.

RESULTS

Tracheal intubation was successful in all patients without any haemodynamic instability. However, one patient required facemask ventilation for 2 min. No patient was aware of intubation. The plasma concentration required for non-responsiveness was 2.8 +/- 0.4 microg mL(-1) (mean +/- SD).

CONCLUSIONS

When using a target-controlled infusion of propofol, fibreoptic intubation can be performed with complete amnesia of the procedure for the patient. However, assisted ventilation of the lungs may be necessary as spontaneous ventilation may cease.

Auricular acupressure as a treatment for anxiety in prehospital transport settings

BACKGROUND

Auricular acupuncture at the relaxation point has been previously shown to be an effective treatment for anxiety in the preoperative setting. The purpose of this prospective, randomized, blinded study was to determine whether auricular acupressure can reduce stress and anxiety during ambulance transport.

METHODS

Patients who required ambulance transport secondary to medical conditions were randomized to receive auricular acupressure at the relaxation point (n = 17) or at a sham point (n = 19). A visual analog scale was used to assess state anxiety as well as patient anticipation of hospital medical treatment (estimated waiting period for treatment, anticipated pain during treatment, attitude toward the physicians, and treatment outcomes). These variables were assessed at baseline and on arrival to the hospital.

RESULTS

Patients in the relaxation group reported significantly less anxiety than patients in the sham group on arrival to the hospital (visual analog scale mean +/- SD: 37.6 +/- 20.6 to 12.4 +/- 7.8 mm vs. 42.5 +/- 29.9 to 46.7 +/- 25.9 mm, respectively; P = 0.002). Similarly, patient perception of pain during treatment (mean visual analog scale +/- SD: 32.7 +/- 27.7 to 14.5 +/- 8.1 mm vs. 17.2 +/- 26.1 to 28.8 +/- 21.9 mm, respectively; P = 0.006) and treatment outcomes of their illnesses (mean visual analog scale +/- SD: 46.7 +/- 29.4 to 19.1 +/- 10.4 mm vs. 35.0 +/- 25.7 to 31.5 +/- 20.5 mm, respectively; P = 0.014) were significantly more positive in the relaxation group than in the sham group. No differences were found in the other variables assessed.

CONCLUSION

It was concluded that auricular acupressure is an effective treatment for anxiety in prehospital emergency settings.

Percutaneous saline-enhanced radiofrequency ablation of unresectable hepatic tumors: initial experience in 26 patients

OBJECTIVE

The purpose of our study was to evaluate the safety and efficacy of percutaneous saline-enhanced radiofrequency ablation for unresectable primary or metastatic hepatic tumors.

SUBJECTS AND METHODS

Twenty-six patients with 15 hepatocellular carcinomas and 33 hepatic metastases (maximum diameter < or = 8.6 cm) were treated; of these, seven tumors in five patients were treated twice. Thus, 44 radiofrequency treatments were performed. Saline-enhanced and impedance-controlled radiofrequency ablation (0.5-1.1 mL/min of saline, 15-mm conductive portion of the electrode tip, 25-60 W, 5-43 min) was performed using MR imaging guidance. Coagulation necrosis, volume indexes, morbidity, and complications were assessed.

RESULTS

The volume of coagulation necrosis 1-7 days after radiofrequency ablation was 1.6-126.6 cm(3) (median, 18.9 cm(3)), corresponding to coagulation diameters of 1.5-6.2 cm (median, 3.2 cm). The coagulation volume was significantly larger if there were more than four radiofrequency applications (p = 0.006). Tumors of 3 cm or less in diameter were eight times as likely to be successfully completely ablated (p = 0.01) and volume indexes of lesions treated with the patient under general anesthesia were significantly larger than those treated with the patient under conscious sedation (p < 0.001). Major complications occurred in four patients (15%). Incomplete ablation in 19 (35%) of 54 radiofrequency lesions was due to cooling by a large vessel nearby (n = 2) or to low power applied in painful (n = 11) or critical (n = 6) locations. Residual tumor was observed in 14 (58%) of 24 tumors evaluated 6-8 months after radiofrequency ablation.

CONCLUSION

Percutaneous saline-enhanced and impedance-controlled radiofrequency ablation can be effective in the treatment of unresectable hepatic tumors and minimizes potential carbonization. A greater number of radiofrequency applications, general anesthesia, and increasing experience provide significantly better results.