Anesthetic management of patients receiving calculus therapy with a third-generation extracorporeal lithotripsy machine

Analgesia for pain control during extracorporeal shock wave lithotripsy: Current status

Purpose of Review

A cooperative patient is essential in maintaining stone targeting for optimal fragmentation during extracorporeal shock wave lithotripsy (ESWL). Therefore, it is important to choose an appropriate analgesic with minimal adverse effects. The guidelines for pain management during ESWL have not been established.

Current Status

Various analgesic agents including opioids (morphine, pethidine, and fentanyl), nonsteroidal anti-inflammatory drugs (NSAIDS - diclofenac, propofol, ketorolac, and piroxicam), local anesthetic agents and a number of combinations have been used during ESWL by various techniques (general anesthesia, regional anesthesia, subcutaneous and intravenous injections, patient-controlled analgesia, and monitored anesthesia care). Cutaneous creams like eutectic mixture of local anesthesia (EMLA) whether used alone or in combination with oral NSAIDS have also been used and are able to reduce analgesic requirements. Topical application of a combination of dimethyl sulfoxide and lidocaine has also been found to be effective.

Conclusion

The ideal analgesic, offering optimal pain control, minimal side effects, and cost-effectiveness is still elusive. Opioids administered using various techniques, provide effective analgesia, but require active monitoring of patient for potential adverse effects. Combination therapy (oral NSAID and occlusive dressing of EMLA, DMSO with lidocaine) offers an effective alternative mode for achieving analgesia with minimal morbidity. This therapy avoids the need for general anesthesia, injectable analgesics, and opioids along with their side effects.

A comparison of sedation with dexmedetomidine or propofol during shockwave lithotripsy: a randomized controlled trial

BACKGROUND

Dexmedetomidine, because it has both sedative and analgesic properties, may be suitable for conscious sedation during painful procedures. Extracorporeal shockwave lithotripsy (ESWL) is a minimal to mildly painful procedure that requires conscious sedation. We thus evaluated the utility of dexmedetomidine compared with propofol during an ESWL procedure.

METHODS

Forty-six patients were randomly allocated into two groups to receive either dexmedetomidine or propofol for elective ESWL. Dexmedetomidine was infused at 6 microg x kg(-1) x h(-1) for 10 min followed by an infusion rate of 0.2 microg x kg(-1) x h(-1). Propofol was infused at 6 mg x kg(-1) x h(-1) for 10 min followed by an infusion of 2.4 mg x kg(-1) x h(-1). Fentanyl 1 microg/kg IV was given to all patients 10 min before ESWL. Pain intensity was evaluated with a visual analog scale at 5-min intervals during ESWL (10-35 min). Sedation was determined using the Observer's Assessment of Alertness/Sedation. The Observer's Assessment of Alertness/ Sedation scores and hemodynamic and respiratory variables were recorded regularly during ESWL (35 min) and up to 85 min after.

RESULTS

Forty patients were evaluated. Visual analog scale values with dexmedetomidine were significantly lower than those with propofol only at the 25-35 min assessments (P < 0.05). During sedation, the respiratory rate with dexmedetomidine was significantly slower but Spo2 was significantly higher than with propofol (P < 0.05). Other clinical variables were similar (P > 0.05).

CONCLUSION

A combination of dexmedetomidine with fentanyl can be used safely and effectively for sedation and analgesia during ESWL.

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.

Clinical experience and results of ESWL treatment for 3,093 urinary calculi with the Storz Modulith SL 20 lithotripter at the Singapore general hospital

We study the outcome of 2,700 patients treated for 3,093 urinary calculi over a period of 60 months. All patients underwent Extracorporeal Shock Wave Lithotripsy (ESWL) treatment using the Storz Modulith SL20, predominantly on an outpatient basis (99.9% using intravenous pethidine for analgesia). The treatment outcome of 1,666 renal calculi and 1,427 ureteric calculi were analysed and stratified according to size and site. Follow-up status at 3 months was available for 91.8% of patients. For renal calculi, the overall success rate was 81% (re-treatment rate 29.7%). The majority of failures were stones larger than 2 cm and those situated in the lower pole of the renal calyces. The overall success rate for ureteric calculi is 85% with similar clearance rates throughout the ureter (re-treatment rate 22.8%). Failures were predominantly with stones larger than 2 cm. For the entire series, the morbidity rate requiring hospital admission was 2.9%, there was no mortality. The commonest cause for admission was for pain control (1.8%). To our knowledge, our experience with this lithotriptor is the largest to date. We have demonstrated that ESWL with Storz Modulith SL20 is safe, well tolerated and highly effective for the treatment of urolithiasis.

A comparison of patient-controlled sedation using either remifentanil or remifentanil-propofol for shock wave lithotripsy

Patient-controlled sedation (PCS) has been used for extracorporeal shock wave lithotripsy (SWL) because it allows for rapid individualized titration of anesthetics. Because of its sedating effects, the addition of propofol to remifentanil may improve patient tolerance of SWL with PCS. One hundred twenty patients were randomly assigned to receive remifentanil 10 microg or remifentanil 10 microg plus propofol 5 mg for PCS with zero-lockout interval. Nine patients in the Remifentanil group and three patients in the Remifentanil-Propofol group required additional sedatives to complete their SWL (P = 0.128). Compared with the Remifentanil group, the Remifentanil-Propofol group required less remifentanil, had a decreased incidence of postoperative nausea and vomiting, and had a better overall satisfaction level. However, they had an increased incidence of transient apnea and oxygen desaturation. The incidence of apnea was 15% in the Remifentanil group and 52% in the Remifentanil-Propofol group (P < 0.001). All patients were able to move themselves to the stretcher at the end of SWL, and median time to home discharge was <70 min in both groups. Both remifentanil and remifentanil-propofol were useful for PCS during SWL.

IMPLICATIONS

The addition of propofol to remifentanil improves patient satisfaction and decreases postoperative nausea and vomiting. However, it causes more respiratory depression than remifentanil alone. When remifentanil-propofol is used with patient-controlled sedation, appropriate monitoring and a minimum 1-2 min lockout interval is required.

Fast-tracking after immersion lithotripsy: general anesthesia versus monitored anesthesia care

Both monitored anesthesia care (MAC) and general anesthesia (GA) offer advantages over epidural anesthesia for immersion lithotripsy. We compared propofol-based MAC and desflurane-based GA techniques for outpatient lithotripsy. After receiving midazolam 2 mg IV, 100 subjects were randomly assigned to one of two anesthetic treatment groups. In the MAC group, propofol 50-100 microg. kg(-1). min(-1) IV was titrated to maintain an observer's assessment of alertness/sedation score of 2-3 (5 = awake/alert to 1 = asleep). Remifentanil 0.05 microg.kg(-1). min(-1) IV supplemented with 0.125 microg/kg IV boluses, was administered for pain control. In the GA group, anesthesia was induced with propofol 1.5 mg/kg IV and remifentanil 0.125 microg/kg IV and maintained with desflurane (2%-4% inspired) and nitrous oxide (60%). Tachypnea (respiratory rate >20 breaths/min) was treated with remifentanil 0.125 microg/kg IV boluses. In the GA group, droperidol (0.625 mg IV) was administered as a prophylactic antiemetic. Recovery times and postoperative side effects were assessed up to 24 h after the procedure. Compared with MAC, the use of GA reduced the opioid requirement and decreased movements and episodes of desaturation (<90%) during the procedure. Although the GA group took longer to return to an observer's assessment of alertness/sedation score of 5, discharge times were similar in both groups. We conclude that GA can provide better conditions for outpatient immersion lithotripsy than MAC sedation without delaying discharge.

IMPLICATIONS

A desflurane-based general anesthetic technique using the cuffed oropharyngeal airway device was found to be a highly acceptable alternative to propofol-based monitored anesthesia care sedation for outpatient immersion lithotripsy.

[Patient-controlled sedation with propofol for extracorporeal shock wave lithotripsy]

OBJECTIVE

Evaluation of patient-controlled sedation with propofol for extracorporeal shock wave lithotripsy (ESWL) using an EDAP LT01 lithotriptor.

STUDY DESIGN

Prospective clinical study.

PATIENTS

Fifty consecutive patients, ASA I or II, aged 18-65 years.

METHODS

Patients received 50 mg of propofol five minutes before ESWL, then they self-administered 50 mg bolus doses of propofol with a ten minutes lock-out interval. Pain (1-100 mm VAS) and sedation (four points scale) were assessed every five minutes. Patient satisfaction was recorded at the end of the procedure. Pharmacokinetic simulation was done with the Marsh's data set.

RESULTS

Three patients were excluded. Patients received a mean propofol dose of 147 +/- 68 mg during the procedure with a mean duration of 47 +/- 8 minutes. The median of the higher sedation scores was 2 (drowsy) and mean maximal VAS was 40 +/- 20 mm (10-70). No complications were recorded. Thirty-nine patients (83%) were satisfied or very satisfied by patient-controlled sedation.

CONCLUSION

Patient-controlled sedation with propofol is a safe and efficient mode of administration of an hypnotic agent for ESWL.