Choosing the correct pain relief for extracorporeal lithotripsy

[Evaluation of protocols on the use of analgesics for pain management in patients with extracorporeal shock wave lithotripsy (ESWL)]

La douleur ressentie au cours d'une séance de lithotritie extracorporelle (LEC) est le facteur limitant le plus important de cette technique. Le but de notre travail était de comparer l'efficacité des différents types d'analgésiques utilisés pour le contrôle de la douleur pendant les séances de LEC. Nous avons mené une étude prospective colligeant 300 patients présentant une lithiase urinaire justifiant un traitement par LEC. Les patients ont été répartis de façon randomisée en trois groupes: le groupe I, incluant 100 patients ayant reçu 2cc de sérum physiologique en IM (intra musculaire) (placebo), le groupe II regroupant 100 patients ayant reçu 100mg de kétoprofène en IM tandis que le groupe III colligeant 100 patients ayant eu une application locale d'une crème contenant la lidocaïne et la prilocaïne. L'échelle visuelle analogique (EVA) a servi à évaluer la douleur à 10 minutes et à la fin de la séance. L'EVA moyenne à 10 minutes et à la fin de la LEC étaient respectivement de 3,7 et 4,91. Aucune différence significative n'a été trouvée entre les trois groupes concernant: les données épidémiologiques (âge, sexe, IMC, antécédents pathologies) et les caractéristiques du calcul (côté, taille, localisation, présence ou non de sonde double J). L'interruption précoce de la séance de LEC a été notée chez 11 patients du groupe I, avec une différence significative par rapport aux autres groupes (p=0,003). L'EVA à 10 minutes et à la fin de séance de LEC, était statistiquement plus élevée dans le groupe I par rapport aux groupes II et III (p < 0,001). Aussi, la LEC était nettement plus efficace dans les groupes (II et III) comparativement au groupe I (p<0,001). L'utilisation d'un traitement antalgique est nécessaire lors de la séance de lithotritie extracorporelle. Les deux molécules antalgiques évaluées ont montré un bon contrôle de la douleur ainsi qu'une augmentation de l'efficacité du traitement par lithotritie.

Analgesia for patients undergoing shockwave lithotripsy for urinary stones - a systematic review and meta-analysis

Background

Shock wave lithotripsy (SWL) is the first line treatment modality for a significant proportion of patients with upper urinary tracts stones. Simple analgesics, opioids and non-steroidal anti-inflammatory drugs (NSAIDs) are all suitable agents but the relative efficacy and tolerability of these agents is uncertain.

Objectives

To determine the efficacy of the different types of analgesics used for the control of pain during SWL for urinary stones.

Materials and Methods

We searched the Cochrane Renal Group’s Specialised Register, MEDLINE, EMBASE and also hand-searched reference lists of relevant articles (Figure-1). Randomised controlled trials (RCT’s) comparing the use of any opioid, simple analgesic or NSAID during SWL were included. These were compared with themselves, each-other or placebo. We included any route or form of administration (bolus, PCA). We excluded agents that were used for their sedative qualities. Data were extracted and assessed for quality independently by three reviewers. Meta-analyses have been performed where possible. When not possible, descriptive analyses of variables were performed. Dichotomous outcomes are reported as relative risk (RR) and measurements on continuous scales are reported as weighted mean differences (WMD) with 95% confidence intervals.

Results

Overall, we included 9 RCTs (539 participants from 6 countries). Trial agents included 7 types of NSAIDs, 1 simple analgesic and 4 types of opioids. There were no significant differences in clinical efficacy or tolerability between a simple analgesic (paracetamol) and an NSAID (lornoxicam). When comparing the same simple analgesic with an opioid (tramadol), both agents provided safe and effective analgesia for the purpose of SWL with no significant differences. There were no significant differences in pain scores between NSAIDs or opioids in three studies. Adequate analgesia could be achieved more often for opioids than for NSAIDs (RR 0.358; 95% CI 043 to 0.77, P=0.0002) but consumed doses of rescue analgesia were similar between NSAIDs and opioids in two studies (P=0.58, >0.05). In terms of tolerability, there is no difference in post-operative nausea and vomiting (PONV) between the groups (RR 0.72, 95% CI 0.24 to 2.17, P=0.55). One study compared outcomes between two types of NSAIDs (diclofenac versus dexketoprofen). There were no significant differences in any of our pre-defined outcomes measures.

Conclusion

Simple analgesics, NSAIDs and opioids can all reduce the pain associated with shock wave lithotripsy to a level where the procedure is tolerated. Whilst there are no compelling differences in safety or efficacy of simple analgesics and NSAIDs, analgesia is described as adequate more often for opioids than NSAIDs.

Comparison of Different Analgesia Drug Regimens for Pain Control During Extracorporeal Shock Wave Lithotripsy for Renal Stones: A Randomized Control Study

INTRODUCTION

With the increased use of extracorporeal shock wave lithotripsy (ESWL), the management of urolithiasis has become much convenient for the patients and the health care professionals alike. However, associated with the procedure is the common complaint of pain. No agreed upon pain management strategy has yet been developed for the procedure. We compared the effect of different analgesia drug regiments for pain control.

METHODOLOGY

A randomised controlled trial was carried out in Shifa International Hospital from between July 2015 to January 2016. A total of 135 patients were divided into three groups; group A received 30 g lidocaine 2% gel applied locally on corresponding lumber area 30 minutes before the procedure, group B received oral naproxen sodium 550 mg 45 minutes before the procedure, and group C received both oral naproxen and lidocaine gel. Patients were supplemented with intravenous nalbuphine during the procedure. The pain was assessed with 0-10 visual analogue scale. Both pre-procedure and post-procedure pain score was measured.

RESULTS

Among 135 patients, 105 (77.8%) were male and 29 (21.5%) were female with mean age of 38.7 ± 1.31 years. There was no difference of mean pain score or need for supplemental intravenous nalbuphine between groups B and C but there was significantly decreased mean pain score and need for supplemental intravenous nalbuphine in groups B and C in comparison with group A.

CONCLUSION

The use of oral naproxen sodium with or without the addition of lidocaine gel during ESWL is a promising option for pain management during the procedure with significant improvement in comparison with lidocaine gel alone.

[Pain evaluation during extracorporeal lithotropsy]

OBJECTIVE

The aim of this study was to demonstrate the feasibility of extracorporeal lithotripsy using lithotripter Sortz MODULITH SLK(®) without analgesics.

MATERIALS AND METHODS

An anonymous self-administered questionnaire was sent to 854 patients post-shock wave lithotripsy for urinary lithiasis. No patient had pain medication. The questionnaire included seven questions to assess the pain symptoms due to treatment. After 15 days, a reminder letter was sent.

RESULTS

The response rate was 69% (591/854). The extracorporeal lithotripsy without analgesic treatment was generally well tolerated. About 70% of patients felt just a few or no pain and average pain assessment was 3.6/10 on VAS. The pain was often considered to be multifactorial, related to the treatment itself, the duration of the session and the position on the table. Anxiety seemed to play an equally important role in pain relief with an average VAS 4.5 against 2.9 for non-anxious patients. If a new session of extracorporeal lithotripsy was necessary, 53% of patients would require no pain medication.

CONCLUSIONS

The extracorporeal lithotripsy could easily be done without systematic analgesics allowing for outpatient care. In contrast, anxiety seemed to be an important predictor of poor tolerance of sessions so the idea of a prophylactic anxiolytic treatment based on psychological profile of the patient should allow less aggressive and less costly management of urolithiasis.

Drugs for pain management in shock wave lithotripsy

Objective. With this review, we provide a comprehensive overview of the main aspects and currently used drugs for analgesia in shockwave lithotripsy. Evidence Acquisition. We reviewed current literature, concentrating on newer articles and high-quality reviews in international journals. Results. No standardized protocols for pain control in SWL exist, although it is crucial for treatment outcome. General and spinal anaesthesia show excellent pain control but are only recommended for selected cases. The newer opioids and nonsteroidal anti-inflammatory drugs are able to deliver good analgesia. Interest in inhalation anaesthesia with nitrous oxide, local anaesthesia with deep infiltration of the tissue, and dermal anaesthesia with EMLA or DMSO has recently rekindled, showing good results in terms of pain control and a favourable side effect profile. Tamsulosin and paracetamol are further well-known drugs being currently investigated. Conclusion. Apart from classically used drugs like opioids and NSARs, medicaments like nitrous oxide, paracetamol, DMSA, or refined administration techniques for infiltration anaesthesia show a good effectiveness in pain control for SWL.

Efficacy of local subcutaneous anesthesia versus intramuscular opioid sedation in extracorporeal shockwave lithotripsy: a randomized study

PURPOSE

To evaluate the analgesic efficacy of local subcutaneous (SC) anesthesia compared with intramuscular (IM) opioid sedation during extracorporeal shockwave lithotripsy (SWL) in a randomized study.

PATIENTS AND METHODS

After informed consent was obtained, 125 patients with urolithiasis who were scheduled for SWL were included in the study. The patients in each treatment session were randomized to receive either IM meperidine (group A) or SC infiltration of 10 mL 2% lidocaine and 10 mL 0.5% bupivacaine at the area of shockwave entry (group B). Degree of pain was rated by the patient using a five-point visual analogue scale (VAS).

RESULTS

The study included 88 (70.4%) men and 37 (29.6%) women with a mean age of 47.6 ± 12.5 years and a mean body mass index (BMI) of 28.16 ± 4.67 kg/m2. Of the patients, 89, 26, and 10 received a single, two, or more than two treatment sessions, respectively (176 sessions). Maximum stone length was 10.68 ± 5.12 mm. Pretreatment stent placement was performed in 17 (13.6%) patients (28 sessions). Group A comprised 89 treatment sessions while 87 were involved in group B. Both groups were similar. Supplemental intrvenous sedation was needed in two (2.5%) and four (4.6%) sessions in groups A and B, respectively. VAS was not different between both groups (P = 0.063). Patients with pretreatment stent placement had significantly lower VAS score compared with patients without stents (P = 0.012). Sex and BMI had no impact on the VAS score.

CONCLUSIONS

Local SC anesthesia alone is effective for analgesic purposes during extracorporeal SWL. Sex, age, and BMI have no relation to analgesia requirement.

Meta-analysis of the efficacy of non-steroidal anti-inflammatory drugs vs. opioids for SWL using modern electromagnetic lithotripters

PURPOSE

Clinical studies produce conflicting results on pain relief for shock wave lithotripsy (SWL). We performed a systematic review and meta-analysis to compare non-steroidal anti-inflammatory drugs (NSAIDs) and opioids in pain relief for SWL powered by an electromagnetic generator.

MATERIAL AND METHODS

A search of MEDLINE and EMBASE was performed and all randomized controlled trials comparing NSAIDs and opioids in pain relief for SWL using modern electromagnetic lithotripters were included in the analysis. Data from 3 trials (244 patients) were pooled. The primary outcome measure was adequate analgesia, defined as "if no additional pain relief was used". The difference in the proportion of patients with adequate anesthesia was compared between the NSAIDs and opioids groups as an odds ratio and odds ratio were pooled across the 3 trials with a fixed effects model.

RESULTS

There was no statistically significant difference between using NSAIDs and opioids for pain relief during SWL using modern electromagnetic lithotripters (odds ratio 0.886, 95% CI 0.446-1,760, p = 0.730).

CONCLUSIONS

Our analysis shows that in relieving pain during SWL using modern electromagnetic lithotripters NSAIDs are as effective as opioids.

[Acute pain in adults, including perioperative pain management]

The vast majority of surgical patients suffer from postoperative pain, which has an enormous influence on quality of life and the progress of the stationary stay. This article gives practical advice on perioperative pain management, taking into consideration the European Association of Urology guidelines for 2009 and the S3 guideline on the treatment of acute perioperative and traumatic pain.

Analgesia during extracorporeal shockwave lithotripsy: fentanyl citrate versus parecoxib sodium

BACKGROUND AND PURPOSE

Shockwave-induced pain may become an important issue during extracorporeal shockwave lithotripsy (SWL), although the new generation of lithotriptors generally produces less pain than previous models. The aim of the study was to compare the analgesic effect of a cyclooxygenase-2-specific inhibitor (parecoxib sodium) with that of our standard method of analgesia (fentanyl citrate) in patients who needed pain relief when undergoing SWL.

PATIENTS AND METHODS

Fifty-eight patients who were undergoing SWL for renal calculi were randomized to receive intravenously either fentanyl citrate (group A, n = 30) or parecoxib sodium (group B, n = 28) when they felt that their pain during the session became intolerable. Lithotripsy was recommenced 10 minutes after administration of analgesia. The severity of pain before and after administration of the analgesic regimens was evaluated using a five-level verbal scale. The effectiveness of each drug was evaluated with respect to degree of pain relief and ensuing tolerance of the procedure to completion, as well as the need for supplementary analgesia (half the standard dose of fentanyl citrate).

RESULTS

The patients in the two groups were comparable with regard to age, sex, body mass index, and stone size. There was no statistically significant difference in the maximum energy level achieved as well as in the total number of shock waves given in the two groups. Administration of fentanyl citrate resulted in alleviation of pain and completion of SWL in 27 patients (90%), whereas parecoxib sodium was effective in five patients (17.8%) (P < 0.01). The remaining 23 patients in group B received supplementary analgesia, and 22 completed the lithotripsy session.

CONCLUSIONS

Parecoxib sodium was not as effective as fentanyl citrate in alleviating pain during SWL. Its use, however, may lower the dose of opioid-based analgesia in this group of patients.

Comparison of Three Analgesic Regimens for Pain Control during Shockwave Lithotripsy Using Dornier Delta Compact Lithotripter: A Randomized Clinical Trial

PURPOSE

To compare the efficacy and adverse effects of oral diclofenac, topical eutectic mixture of local anesthesia (EMLA), and their combination for pain control during shockwave lithotripsy (SWL) and to investigate the need for supplemental analgesia, patient satisfaction, and overall treatment outcomes.

PATIENTS AND METHODS

A series of 240 consecutive patients with urolithiasis scheduled for SWL between May 2006 and December 2006 were randomized equally into three groups that were treated as follows: group A oral (tablet) diclofenac sodium 60 minutes prior to SWL (50 mg for body weight <70 kg; 100 mg for body weight >70 kg); group B occlusive dressing of EMLA (5 g) 60 minutes prior to SWL; group C combination of oral diclofenac sodium (in the prescribed dose) and occlusive dressing of EMLA (5 g) 60 minutes prior to SWL. A visual analog scale (VAS) was used for the subjective evaluation of pain. The various parameters were recorded and analyzed statistically.

RESULTS

The total number of shock waves delivered, the maximum voltage used, and SWL duration were statistically greater in group C (P < 0.0001). The VAS scores at 15, 30, 45, 60, and 120 minutes and the supplemental analgesia requirement were statistically less in group C (P < 0.0001). The stone fragmentation rate, stone-free rate at 3 months (88.75%), and modified Efficiency Quotient (0.64) were statistically greater in group C (P < 0.0001). The post-SWL auxiliary procedure rate (P < 0.0001) and Steinstrasse rate (P = 0.03) were statistically less in group C.

CONCLUSIONS

The use of a combination of oral diclofenac sodium and an occlusive dressing of EMLA cream during SWL provides adequate analgesia with minimal morbidity, avoids the need for parenteral analgesics and their attendant side effects, and improves the success rate of SWL.

Can prilocaine infiltration alone be the most minimally invasive approach in terms of anesthesia during extracorporeal shock wave lithotripsy?

OBJECTIVES

To evaluate the analgesic effect and utility of prilocaine infiltration alone for minimal morbidity during extracorporeal shock wave lithotripsy.

METHODS

A total of 114 patients with kidney stones, aged 18 to 69 years, were randomly separated into two groups. The 58 patients in group 1 received intramuscular diclophenac 30 minutes before extracorporeal shock wave lithotripsy, and the 56 patients in group 2 received prilocaine infiltration into the 30 cm2 area below the 12th rib right before the session. A visual analog scale (0 to 100 mm) was used to evaluate pain.

RESULTS

The visual analog scale scores for group 2 were statistically lower at 1, 10, and 20 minutes compared with the scores for group 1 (P = 0.006, P = 0.005, and P = 0.006, respectively). However, no difference was detected at the end of the procedure. The requirement for additional analgesic was less in group 2 (P = 0.007).

CONCLUSIONS

Prilocaine infiltration alone can be used for analgesic purposes efficiently and safely during extracorporeal shock wave lithotripsy with minimal morbidity.

Effectiveness of electro-acupuncture compared to sedo-analgesics in relieving pain during shockwave lithotripsy

The aim of this study was to compare the clinical efficacy of electro-acupuncture (EA) with the combination of tramadol+midazolam (TM) for pain relief during outpatient extracorporeal shockwave lithotripsy (ESWL). A total of 35 patients (20 men, 15 women) with stones located in the pelvicalyceal system of the kidney were randomized prospectively to undergo lithotripsy with a third generation lithotriptor (Stone Lith, smart PCK) after receiving either EA (n=17) or TM (n=18) for sedation and analgesia. EA treatment was applied to patients by the same licensed acupuncturist 30 min prior to ESWL in group EA. Tramadol (1.5 mg/kg) 30 min before the start of lithotripsy and midazolam (0.06 mg/kg) 5 min prior to ESWL were given as a sedo-analgesic intravenously to group TM. During ESWL, blood pressure, heart rate, pain and sedation levels were measured at baseline and every 15 min thereafter. The pain intensity perceived during lithotripsy was evaluated using a visual analog scale (VAS). There was no statistical differences in the diameters of the stones and age of the patients between groups (P=0.590; P=0.568, respectively). In the EA group, the median of maximum energy level achieved was 16.0 kV (range 10-23 kV), while it was 18.0 kV (range 10-20 kV) in the TM group. There was no statistically significant difference between the maximum energy levels applied to the patients during ESWL (P=0.613). The median numbers of shockwaves were 2,114 (range 1,100-3,800) and 2,200 (range 1,500-3,200) in the EA and TM groups, respectively. In the TM group, the numbers of shockwaves used were higher than in group EA during ESWL. However, this difference was not significant (P=0.732). VAS scores were consistently lower in the EA group compared with the TM group throughout the ESWL procedure. The median VAS score was 5.0 (range 1-10) in the EA group while it was 8.0 (range 2-10) in the TM group. The patients who underwent EA had lower median scores of VAS than patients who took only conservative treatment, but this difference was not significant (P=0.245). When both groups were compared for stone-free rates, no significant difference was found [82.3% (14/17) for group EA, 88.8% (16/18) for group TM] (P=0.658). Durations of ESWL procedures were similar in both groups [median 27.4 min (range 15.7-34.3) in group EA vs 27.1 min (range 16.1-33.6) in group TM] (P=0.517). No side effects was seen in any patient who received EA. Side effects such as mild orthostatic hypotension and dizziness occurred in patients given sedo-analgesia, but these were not severe enough to require any patient to be excluded from the study. Our study shows that EA is an effective method for inducing sedation with analgesia without any demonstrable side effects.

How painful are shockwave lithotripsy and endoscopic procedures performed at outpatient urology clinics?

Our aim was to investigate the subjective pain felt by patients during shockwave lithotripsy (SWL) and endoscopic procedures such as cystoscopy, retrograde ureteral stenting, retrograde pyelography (RGP), and ureteroscopic lithotripsy performed in an outpatient clinic, and to identify how severe pain during such procedures is. We estimated subjective pain in 984 patients after SWL (186), cystoscopy (489), retrograde ureteral stenting (127), RGP (97), and ureteroscopic lithotripsy (85) performed by a single expert in an outpatient clinic using a prospective questionnaire with a ten point visual analog scale between January 2001 and December 2003. There was no premedication in any procedure except ureteroscopic lithotripsy for which an intramuscular injection of analgesics (pethidine HCl 50 mg) was used. The pain scale score in SWL was 6.62+/-2.27, the highest among the procedures (P<0.05). Pain scores for endoscopies were 4.48+/-2.07 in retrograde ureteral stenting, 3.81+/-2.06 in ureteroscopic lithotripsy, 3.72+/-1.75 in RGP, and 3.08+/-1.95 in cystoscopy. In this study, we observed that patients feel most pain in SWL without anesthesia, and that pain during ureteroscopic lithotripsy under local anesthesia is not high, compared with other endoscopic procedures.

Bioinformatic analysis of the human mu opioid receptor (OPRM1) splice and polymorphic variants

Mu opioid receptor (OPRM1), a member of the G-protein coupled receptor superfamily, mediates the analgesic and euphoric effects of opioid drugs. The sequences of OPRM1 cDNA and reported splice variants were used to search the public and Celera genomic databases. The matched sequences were analyzed to assemble an OPRM1 genomic contig. Human OPRM1 gene was estimated to span at least 90 kb in the chromosome 6q24-25 region. Four coding exons are separated by 3 introns. While intron 2 has only 773 bp, these databases for the first time provide the precise length of and other information about long introns 1 and 3, containing 50 and 27 kb, respectively. When a consensus exon/intron splice junction at the end of the coding exon 3 was not utilized, it may have resulted in continuous translation of the exon to yield the splice variant OPRM1A. The study did not identify human orthologs of other OPRM1 variants that had been reported for mouse OPRM1, although several proposed exons were found to be included in mouse genomic clones. Single nucleotide polymorphisms in the OPRM1 gene were also analyzed and summarized, which could provide potential polymorphic markers for molecular genetic studies.

Re-auditing a regional lithotripsy service

OBJECTIVE

To assess, in a repeat audit of a regional lithotripsy service, whether changes implemented after a regional audit in 1994 (which showed disappointing results from shock wave lithotripsy, attributable to both poor patient selection and an inadequate fixed-site lithotripter) have had any effect.

PATIENTS AND METHODS

A data-collection sheet was devised to gather information on the site, size and number of stones treated, together with information on the lithotripsy treatment and outcome. Patients selected for the audit were the first 50 new patients treated with lithotripsy at each centre in 1999. As only one hospital has a fixed-site lithotripsy machine, the results of mobile lithotripsy were grouped by machine for analysis.

RESULTS

There was an overall improvement in patient selection from the previous audits. Few stones of > 16 mm or < 4 mm were treated. Two units treated more ureteric stones, thought to reflect first the influence of a fixed-site lithotripter, and second a willingness to insert a ureteric stent and await the next mobile lithotripter visit. The stone free rates were all disappointingly low (16.7-26.7%) but the results improved when fragments of < 4 mm were included as "successful" giving an "overall success rate" of 45.9-66.7%. The unit with a fixed-site lithotripter appeared to perform better (two-thirds successful) than the mobile machines (Modulith SLX, 51%; Modulith SLK, 46%). One centre visited by both mobile machines had a success rate of 65% but a high rate of auxiliary procedures (35% vs 16-19% vs the fixed-site).

CONCLUSION

Although these results show some improvement in patient selection for our regional lithotripsy service, stone-free and success rates are poorer than those reported elsewhere. This may reflect the modern lithotripsy machines that allow day-case treatment with minimal analgesia, and confirms reports by other authors who encourage a re-examination of success rates of shock wave lithotripsy.

Extracorporeal shock wave lithotripsy and percutaneous nephrolithotomy

This article reviews the basic anesthetic considerations for ESWL and PCNL. General principles governing the operation of lithotripters, elements of treatment that impinge on safety, and effective intraoperative anesthesia and complications that may be encountered in the perioperative period are discussed. Factors influencing blood loss and concerns arising from positioning patients prone are addressed in the sections devoted to PCNL.

[Extracorporeal shock-wave lithotripsy: anxiety and pain perception]

Three factors in extracorporeal shock-wave lithotripsy (ESWL) result in pain: shock wave pressure, size of focal area and pressure distribution at entry in the skin. Our Lithotripsy Unit has performed 21,000 outpatient treatments (Dornier HM-4 Lithotripter) with no sedation or anaesthetics. Pain requiring treatment discontinuation resulted in 10% instances. Anxiety-associated pain increases the perceived intensity of pain and influences the emotional response to pain.

OBJECTIVE

To determine whether the variability in the response to the pain stimulus caused by ESWL is related to the patient's status/trait of anxiety.

METHOD

Sample 20 patients; inclusion criteria: pyelic lithiasis > 2 cm, no previous SWEL and no obesity. One SWEL session (2500 pulses, 22 Kv). Anxiety was first evaluated using the status/trait of anxiety index (STAI) questionnaire; after treatment, pain was evaluated on a Numerical Analogic Scale.

RESULTS

Pain scores ranged from 2 to 8, mean score 4.1 (S.D. = 1.67); mean score for trait of anxiety 21.8 (S.D. = 8.52), and status of anxiety 29 (S.D. = 5.89). A significant correlation was found between pain-anxiety trait (R = .51; p = .02), which was higher when compared to pain-anxiety status (R = .67; p = .001).

CONCLUSIONS

SWEL is a painful therapy (95% of sample had mild-to-moderate pain); pain perception is increased by status of anxiety (45% of pain variance) more than by the trait of anxiety (26.3%); therefore, usage of sedation-analgesia in patients with high anxiety status would improve the lithotripter efficacy ratio.

Analgesia in piezoelectric SWL: comparative study of kidney and upper ureter treatments

BACKGROUND

The development of newer-generation lithotripters has reduced the pain associated with SWL, but many patients still require some form of sedation. We prospectively compared the analgesic requirements for kidney and upper ureteral treatments. Predictive factors for pain during piezoelectric SWL were also studied.

PATIENTS AND METHODS

A total of 102 consecutive patients without any previous experience of SWL were treated for renal (N = 70) or upper ureteral (N = 32) calculi using the EDAP LT02 lithotripter. The stones' largest diameter ranged from 4 to 30 mm (mean 9 mm). Patients were given an oral dose of 60 mg of dextropropoxyphene hydrochloride and 800 mg of paracetamol associated with 100 mg of ketoprofene per rectum 30 minutes before treatment. The SWL session was begun at low intensity and increased to the maximal range of energy as rapidly as could be tolerated by the patient. The amount of pain during treatment was recorded according to a visual analogue scale (VAS). Further analgesia using intravenous alfentanil was given as required by the severity of the pain. Visual analog pain scores, additional sedation requirements, and success rates after one session were analyzed.

RESULTS

The VAS scores and intravenous sedation requirements were significantly lower for patients with upper ureteral stones than for those with renal calculi (P < 0.01). The stone-free rates after one session were, respectively, 90% and 73% (P < 0.05). On the other hand, SWL tolerance was significantly lower for women presenting with renal stones (P < 0.05).

CONCLUSION

Piezoelectric SWL without intravenous sedation is suitable for the treatment of upper ureteral calculi. However, such an approach is less efficient in the management of kidney stones, especially for female patients.

The patients perspective of extracorporeal shock wave lithotripsy

We studied the effect of a single analgesic regime for outpatient lithotripsy on the patient's perception of pain and the disruption of their normal activities by sending a postal questionnaire to 200 patients. Results showed that 15% of patients received insufficient analgesia during ESWL, 25% considered treatment painful, 6.8% had side effects from analgesia, 18% had delayed return to their normal activities and 33% contacted their doctor within a week of lithotripsy with problems related to it. This study shows that analgesic requirements of patients treated with modern lithotriptors are underestimated. This can be avoided by tailoring analgesia to individual needs and better patient communication.

Piezoelectric lithotripsy of ureteral stones: influence of shockwave frequency on sedation and therapeutic efficiency

OBJECTIVE

The aim of this randomized study was to assess the relation between shockwave frequency, sedation, and efficiency in piezoelectric extracorporeal shockwave lithotripsy (SWL) for ureteral calculi.

METHODS

A random sample of 114 patients aged between 15 and 74 (mean 45) years were treated at the shockwave frequencies of 1 (N = 57) or 4 (N = 57) per second using the EDAP LT 02 lithotripter at maximum energy. The stones' largest diameter ranged from 5 to 18 mm (mean 7.6 mm). Lower ureteral stones were treated with the patient in the prone position and upper ureteral stones in supine position. The duration of SWL sessions and stone measurements were statistically similar for patients treated at low and high frequencies. The levels of required sedation (none, intramuscular analgesia, intravenous sedation-analgesia) and stone-free rates after one session were analyzed by Student's t-test or Fisher's exact test.

RESULTS

Sedation did not differ statistically with SWL frequency for mid and lower ureteral calculi. However, the use of intravenous sedation-analgesia was less common for patients with upper ureteral stones treated at low rather than high frequency (19% and 100%, respectively; P < 0.0001). The success rate was significantly lower (P = 0.04) for lower ureteral calculi treated at low v high frequency (65 % and 89%, respectively) but was not statistically affected by frequency for upper ureteral stones.

CONCLUSION

We recommend high frequency for piezoelectric SWL of lower ureteral calculi, especially for stones with a maximum diameter > or =8 mm. On the other hand, low-frequency SWL appears to be suitable for the treatment of upper ureteral stones.

Patient maintained alfentanil target-controlled infusion for analgesia during extracorporeal shock wave lithotripsy

PURPOSE

The purpose of this study was to determine whether alfentanil given by a pharmacokinetic-based target controlled infusion (TCI) system under patient control is a suitable analgesic technique for extracorporeal shock wave lithotripsy (ESWL).

METHODS

The design was an open, unblinded, noncomparative, prospective study. Forty outpatients undergoing ESWL were given patient maintained alfentanil TCI. Pain, nausea and sedation were assessed every 300 shocks. Vital signs were recorded every three minutes, pulse oximetry and electrocardiography being monitored continuously. Blood alfentanil concentration was measured for comparison with the predicted value.

RESULTS

Alfentanil consumption (median 1.34 mg, range 0.8-3.6) and measured levels following treatment (median 60 ng.ml-1, range 15.6-134.3) varied widely. The precision of the TCI system and the median prediction error (bias) were both 49%. The median of pain scores recorded during treatment was 4 (range 0-8). The median respiration rate was 15 bpm (range 10-23), three patients required oxygen (SaO2 < 92%) cardiovascular measurements were stable and there was no excessive sedation. The incidence of nausea was 15%. All patients were ready for hospital discharge within one hour following treatment.

CONCLUSIONS

Patient maintained alfentanil TCI provides good analgesia for ESWL in the majority of patients with little sedation. Respiratory depression is uncommon but supplementary oxygen should be given prophylactically. There is considerable interindividual variation in demand for alfentanil indicating the usefulness of the patient control method. The TCI system underestimated alfentanil blood concentrations but this did not affect its clinical usefulness.