Lateral popliteal sciatic nerve block compared with ankle block for analgesia following foot surgery

The purpose of this study was to compare postoperative analgesia after foot surgery in patients anaesthetised either with popliteal sciatic nerve block or ankle block. In a prospective study, 40 patients scheduled for foot surgery involving osteotomies were allocated randomly into one of two groups. Following induction of general anaesthesia, Group PS (n = 21) received a lateral popliteal sciatic nerve block and Group AB (n = 19) received an ankle block. Both groups received 20 ml bupivacaine 0.5% plain. In group PS 43% required morphine analgesia in the Post Anaesthetic Recovery Room (PAR) compared with 16% in group AB. Postoperative analgesia was assessed using VAS and a pain scale in the PAR and a questionnaire by telephone follow-up on the day after surgery. The ankle block appeared to be more reliable, providing more consistent analgesia in the PAR. Postoperative analgesia in Group PS lasted a median of 18.0 hr and in Group AB lasted 11.5 hr (P < 0.05). Both techniques provided effective analgesia after discharge home and high levels of patient satisfaction.     

EMLA® patch for intravenous cannulation in adult surgical outpatients

Purpose

The purpose of this study was to evaluate the effectiveness of a single-unt-dose package of the EMLA® Patch for dermal analgesia during intravenous cannulation in adult outpatients and in preventing vaso-vagal side effects.

Methods

After giving consent. 51 ASA I–III adult outpatients participated in a randomized, double-blind, placebo-controlled, parallel-group tnal to receive either an EMLA* or placebo patch applied to the intravenous cannula site for 60 to 90 mm. Following cannula insertion, patients and investigators rated the pain using a 100 mm VAS ruler. The incidence and seventy of vaso-vagal responses, local skin reactions, and willingness to pay for the patch were also evaluated.

Results

The median VAS pain score by patient assessment in the EMLA® patch group was lower (8 mm; range: 0–92) than in the placebo group (25 mm; range: 0–98, P < 0.05). The median VAS pain score by Investigator assessment was also lower in the EMLA® patch group (15 mm; range 1–79) than in the placebo group (23 mm; range 3–81. P < 0.05). There was a notable difference in the number of vaso-vagal reactions (17 placebo vs 4 EMLA®, P < 0.05). Eighty-eight percent of patients who received the EMLA® patch would be willing to pay for the patch in the future compared with 69% of the placebo patch patients.

Conclusion

This study showed that the EMLA® patch, applied for 60–90 min before venous cannulation reduced the pain of venepuncture and vaso-vagal side effects in adult outpatients.     

Selective spinal anesthesia for outpatient laparoscopy. II: Epinephrine and spinal cord function

PURPOSE: To compare two small-dose solutions (with and without epinephrine) for spinal anesthesia during outpatient laparoscopy and to determine spinal cord function with these low-dose solutions. METHOD: Twenty outpatients undergoing gynecological laparoscopy were randomly assigned to receive spinal anesthesia with one of two low dose solutions. Group LS-10 mg lidocaine plus 10 microg sufentanil; Group LSE-10 mg lidocaine plus 10 microg sufentanil plus epinephrine 50 microg. Solutions were diluted to three millilitres with sterile water for injection. A 27-gauge Whitacre needle was inserted at L2-3 or L3-4 in the sitting position. Operating conditions and spinal cord function (spinothalamic, dorsal column and motor) were assessed. RESULTS: Operating conditions were good-excellent in both groups. The incidence of shoulder tip discomfort, pruritus and nausea, and the amount of supplementation with alfentanil and midazolam was not different between groups. Most patients in both groups had preserved dorsal column function and normal motor power on arrival in PACU and were able to satisfy 'walk out' criteria. Recovery of pinprick sensation and discharge times were not different. Mild pruritus (VAS score < or = 5) was present in both groups. CONCLUSION: For short duration laparoscopy, addition of 50 microg epinephrine to a small dose of spinal 10 mg lidocaine with 10 microg sufentanil did not provide additional benefit in terms of intraoperative analgesia or operating conditions. Spinal cord function was preserved with small-dose techniques.     

Selective spinal anesthesia for outpatient laparoscopy. IV: Population pharmacodynamic modelling

PURPOSE: To apply a population pharmacodynamic model to small-dose hypobaric spinal anesthesia for outpatient laparoscopy. METHODS: The level of spinal analgesia after spinal blockade with small-dose (20-25 mg) hypobaric lidocaine was assessed by means of pinprick in patients undergoing outpatient laparoscopy. In 57 patients, 385 measurements were available for analysis. We first modelled the data for each patient with a mixed-effects model described by Schnider (Model 1). The population mean parameters, inter-individual variance, and residual variance were estimated. Clinically important endpoints (time to reach T10 (onset), time to maximal level, duration and maximally attained level) of each patient were calculated based on the estimated time course of analgesia level for each patient. The model was used to predict the later data with respect to level of spinal analgesia of each patient from fits based on the observed data in the first 75 min. RESULTS: The mean +/- SD onset time was 8.3 +/- 1.9 min, time to maximal level was 20.8 +/- 5.3 min, duration of effect was 37.9 +/- 13.1 min, and mean maximal level was T5. There was a good correlation (R2 = 0.90) between the observed levels of analgesia and those predicted from the model. Data from the first 75 min predicted the later observed data for each patient moderately well (R2 = 0.38). CONCLUSION: A population pharmacodynamic model was applied to low-dose hypobaric lidocaine spinal anesthesia. Clinically important endpoints were determined and forecasting of later data with respect to level of spinal analgesia was attempted. Such an approach may be useful in the management of low-dose spinal anesthetic techniques in outpatients.