Role of regional anesthesia in the ambulatory environment

Unique Considerations for Complete Surgical Analgesia for Below-the-Knee Amputations

Recent cadaver studies have suggested that posterior femoral cutaneous nerve (PFCN) may contribute to the sensory innervation of the posterior lower leg. Whether this is clinically relevant may be revealed in patients who underwent below-the-knee amputation (BKA) with monitored anesthesia care (MAC) and peripheral nerve blocks. We performed femoral and sciatic nerve blocks for a 55-year-old male patient who underwent BKA and subsequent formalization surgeries as the main surgical analgesia while providing MAC in the operating room. In both cases, the patient could not tolerate surgical incisions in the posteromedial aspect of the lower leg, despite reporting no pain in other areas of the lower leg with surgical stimulation. There may exist a small population of patients in which PFCN makes significant contribution to the sensory innervation of the posterior lower leg. For these patients, the combination of femoral and sciatic nerve blocks may not be adequate in providing surgical analgesia for BKA and related procedures.

Effect of Dexmedetomidine as an Adjuvant to 0.75% Ropivacaine in Interscalene Brachial Plexus Block Using Nerve Stimulator: A Prospective, Randomized Double-blind Study

BACKGROUND

Ropivacaine, a newer local anesthetic (LA), has been increasingly used nowadays in different concentrations for peripheral nerve blocks. It has lesser cardiac toxicity and higher safety margin when compared to bupivacaine. Dexmedetomidine, a novel α₂ agonist, is widely used as adjuvant to LA in peripheral nerve blocks to decrease the time of onset and increase the duration of the block. In this study, we evaluated the effect of dexmedetomidine as an adjuvant with 0.75% ropivacaine for interscalene brachial plexus block using nerve stimulator.

AIM

This study aims to know the effect of using dexmedetomidine as an adjuvant to 0.75% ropivacaine in interscalene brachial plexuses block using nerve stimulator.

SETTINGS AND DESIGNS

Sixty patients scheduled for elective orthopedic surgery of the upper limb under interscalene block were considered in this prospective randomized controlled double-blind study. The study population was randomly divided into two groups with thirty patients in each group by using computerized randomization.

MATERIALS AND METHODS

Group R received 30 ml of 0.75% ropivacaine with 0.5 ml normal saline and Group RD received 30 ml of 0.75% ropivacaine with 50 μg of dexmedetomidine. The onset of sensory and motor blocks, duration of sensory and motor block, and patient satisfaction score were observed.

RESULTS

Both the groups were comparable in demographic characteristics. The onset of the sensory and motor block is earlier and statistically significant in Group RD (P < 0.05) when compared to Group R. The duration of sensory and motor blockade were significantly prolonged in Group RD (P < 0.0001).

CONCLUSION

Addition of dexmedetomidine to 0.75% ropivacaine in interscalene brachial plexus block significantly shortened the time of onset of the block and prolongs the duration sensory and motor blockade.

Factors associated with postoperative nausea and vomiting in patients undergoing an ambulatory hand surgery

BACKGROUND

Patients undergoing ambulatory surgery under general anesthesia experience considerable levels of postoperative nausea and vomiting (N/V) after their discharge. However, those complications have not been thoroughly investigated in hand surgery patients yet. We investigated factors associated with postoperative N/V in patients undergoing an ambulatory hand surgery under general anesthesia and determined whether patients' satisfaction with this setting is associated with postoperative N/V levels.

METHODS

We prospectively evaluated 200 consecutive patients who underwent ambulatory hand surgeries under general anesthesia to assess their postoperative N/V visual analogue scale (VAS) levels during the first 24 hours after surgery and their satisfaction with an ambulatory surgery setting. Potential predictors of postoperative N/V were; age, sex, body mass index, smoking behavior, a history of postoperative N/V after previous anesthesia or motion sickness, preoperative anxiety level and the duration time of anesthesia. We conducted multivariate analyses to identify factors associated with postoperative N/V levels. We also conducted multivariate logistic regression analyses to determine whether the N/V levels are associated with the patients' satisfaction with this setting. Here, potential predictors for satisfaction were sex, age, postoperative pain and N/V.

RESULTS

Postoperative N/V were associated with a non-smoking history, a history of motion sickness and a high level of preoperative anxiety. Twenty-two patients (11%) were dissatisfied with the ambulatory setting and this dissatisfaction was independently associated with moderate (VAS 4-7) and high (VAS 8-10) levels of postoperative N/V and with a high level (VAS 8-10) of postoperative pain.

CONCLUSIONS

Although most of the patients were satisfied with the ambulatory surgery setting, moderate to high levels of N/V were associated with dissatisfaction of patients with this setting, suggesting a need for better identifying and managing those patients at risk. The information regarding risk factors for N/V could help in preoperative patient consultation regarding an ambulatory hand surgery under general anesthesia.

Primary payer status is associated with the use of nerve block placement for ambulatory orthopedic surgery

INTRODUCTION

Although more than 30 million patients in the United States undergo ambulatory surgery each year, it remains unclear what percentage of these patients receive a perioperative nerve block. We reviewed data from the 2006 National Survey of Ambulatory Surgery to determine the demographic, socioeconomic, geographic, and clinical factors associated with the likelihood of nerve block placement for ambulatory orthopedic surgery. The primary outcome of interest was the association between primary method of payment and likelihood of nerve block placement. In addition, we examined the association between type of surgical procedures, patient demographics, and hospital characteristics with the likelihood of receiving a nerve block.

METHODS

This cross-sectional study reviewed 6000 orthopedic anesthetics from the 2006 National Survey of Ambulatory Surgery data set, which accounted for more than 3.9 million orthopedic anesthetics when weighted. The primary outcome of this study addressed the likelihood of receiving a nerve block for orthopedic ambulatory surgery according to the patient's primary method of payment. Secondary end points included differences in demographics, surgical procedures, adverse effects, complications, recovery profile, anesthesia staffing model, and total perioperative charges in those with and without nerve block.

RESULTS

Overall, 14.9% of anesthetics in this sample involved a peripheral nerve block. Length of time in postoperative recovery, total perioperative time, and total charges were less for those receiving nerve blocks. Patients were more likely to receive a nerve block if their procedures were performed in metropolitan service areas (odds ratio [OR], 1.86; 95% confidence interval [CI], 1.19-2.91; P = 0.007) or in freestanding surgical facilities (OR, 2.27; 95% CI, 1.74-2.96; P < 0.0001) and if payment for their surgery was supported by government programs (OR, 2.5; 95% CI, 1.01-6.21; P = 0.048) or private insurance (OR, 2.62; 95% CI, 1.12-6.13; P = 0.03) versus self-pay or charity care.

CONCLUSIONS

For patients receiving ambulatory orthopedic surgery in the United States, our results suggest that geographic and socioeconomic factors are associated with different likelihoods of perioperative peripheral nerve block placement.