Retrospective analysis of mepivacaine, prilocaine and chloroprocaine for low-dose spinal anaesthesia in outpatient perianal procedures

[Feasibility and structural prerequisites for conversion to outpatient treatment in proctology]

BACKGROUND

Despite the introduction of the diagnosis-related groups (DRG) system, costs in the German healthcare system have risen continuously for years. In order to reduce costs the federal government is aiming to shift inpatient services to the outpatient sector. Outpatient services affect many areas of medicine, including proctological operations as these are common and can often be carried out on an outpatient basis.

OBJECTIVE

The aim of the present work is to discuss which areas of proctology are suitable for outpatient treatment and which structural requirements are necessary.

MATERIAL AND METHODS

The present article is intended to provide a narrative overview with reference to the literature on the topic of outpatient care in proctology. A literature search was carried out using the following keywords: outpatient care, selective sector-level remuneration, day care, proctological operations, AOP catalog and hybrid DRG.

RESULTS

In proctology, outpatient surgical care is implementable in many cases; however, not every patient is suitable for this. In addition to previous illnesses, patient compliance and the possibility of postoperative care from relatives must also be taken into account. In addition, emergency treatment must be guaranteed. Contraindications include severe heart and circulatory diseases as well as severe coagulation or organ dysfunction. Extensive abscesses, complex fistulas or sphincter reconstructions should be surgically treated in an inpatient setting. The prerequisite for successful outpatient care is to make the sector boundaries between outpatient and inpatient patient care more permeable and to adequately remunerate the interventions.

CONCLUSION

In addition to the surgical indications, the prerequisites for successful proctological operations are the correct assessment of the operational capability and compliance. From an organizational and economic perspective, better networking between outpatient and inpatient treatment and equal remuneration across the sector boundaries are crucial.

Comparison of Different Local Anesthetic Volumes for Saddle Block Anesthesia in Ambulatory Surgery: A Prospective Randomized Trial

INTRODUCTION

Saddle block anesthesia (SBA) is a frequently preferred method for ambulatory anorectal surgery. This study aimed to observe the effects of two different dose SBAs on discharge times and perioperative block characteristics in patients undergoing ambulatory anorectal surgery.

METHODS

The study was conducted as a prospective, randomized controlled study. Patients over the age of 18 who were scheduled for ambulatory anorectal surgery and had American Society of Anaesthesiologists (ASA) physical status I and II were included in the research. Patients were divided into two groups: 5 mg hyperbaric bupivacaine 0.5% (Group I; n=34) and 3 mg hyperbaric bupivacaine 0.5% (Group II; n=34). The primary outcome was discharge time. Characteristics of the spinal block like time to reach S4 blockade, maximum blocked dermatome, regression time of sensorial, first analgesic need time, voiding time, mobilization time, and side effects were the secondary outcomes.

RESULTS

Sixty-eight patients were included in the study. The groups were similar in terms of demographic and surgical characteristics (p > 0.05). In Group II, S4 sensory dermatome blockade time was statistically longer (p: 0.007) and the time to the disappearance of the sensory block was statistically shorter (p < 0.001). Also, voiding time and discharge times were statistically shorter in Group II (p: 0.049, p < 0.001, respectively).

CONCLUSION

SBA provided adequate anesthesia, and the complication rates were limited. Saddle block can be considered an advantageous technique because of conditions that adversely affect recoveries, such as postoperative cognitive problems, nausea, and vomiting due to general anesthesia. In addition, better recovery results and optimal surgical condition with 3 mg hyperbaric bupivacaine in our study suggest that this dose may be a good alternative.

Spinal anesthesia in ambulatory surgery

Spinal anesthesia is a safe alternative to general anesthesia but remains underrepresented in the ambulatory setting. Most concerns relate to low flexibility of spinal anesthesia duration and the management of urinary retention in the outpatient setting. This review focuses on the characterization and safety of the local anesthetics that are available to adapt spinal anesthesia very flexibly to the needs of ambulatory surgery. Furthermore, recent studies on the management of postoperative urinary retention provide evidence for safe, but report wider discharge criteria and much lower hospital admission rates. With the local anesthetics that have current approval for usage in spinal anesthesia, most requirements for ambulatory surgeries can be met. The reported evidence on local anesthetics without approval supports clinically established off-label use and can improve the results even further.

Regional anaesthesia: what surgical procedures, what blocks and availability of a “block room”?

PURPOSE OF REVIEW

With an expected rise in day care procedures with enhanced recovery programs, the use of specific regional anaesthesia can be useful. In this review, we will provide insight in the used regional block and medication so far known and its applicability in a day care setting.

RECENT FINDINGS

Regional anaesthesia has been improved with the aid of ultrasound-guided placement. However, it is not commonly used in the outpatient setting. Old, short acting local anaesthetics have found a second life and may be especially beneficial in the ambulatory setting replacing more long-acting local anaesthetics such as bupivacaine.To improve efficiency, a dedicated block room may facilitate the performance of regional anaesthesia. However, cost-efficacy for improved operating time, patient care and hospital efficiency has to be established.

SUMMARY

Regional anaesthesia has proven to be beneficial in ambulatory setting. Several short acting local anaesthetics are favourable over bupivacaine in the day care surgery. And if available, there are reports of the benefit of an additional block room used in a parallel (monitored) care of patients.

Saddle block anesthetic technique for benign outpatient anorectal surgery

BACKGROUND

Current American Society of Colorectal Surgery Clinical Practice Guidelines for Ambulatory Anorectal Surgery endorse use of monitored anesthesia care, general anesthesia, or spinal anesthesia based on physician and patient preference. Although several studies support the use of monitored anesthesia care over general anesthesia, the literature regarding spinal anesthesia is limited and heterogenous due to small sample sizes and disparate spinal anesthesia techniques. Saddle block anesthesia is a form of spinal anesthesia that localizes to the lowermost sacral spinal segments allowing for preservation of lower extremity motor function and faster recovery. We accrued one of the largest reported cohort of anorectal procedures using saddle block anesthesia, as such, we sought to evaluate our institutional 12-year experience.

METHODS

Patients who underwent a benign anorectal procedure at our outpatient surgery center between July 2008-2020 were retrospectively reviewed. Demographics, surgical factors, perioperative times, and adverse events were collected from the electronic medical records. Saddle block anesthesia was generally performed in the preoperative area using a spinal needle (25-27 gauge) and a single injection technique of a 1:1 ratio local anesthetic mixed with 10% dextrose solution. Between 2.5-5 mg of hyperbaric anesthetic was injected intrathecally in the sitting position and the patient remained upright for 3-10 minutes. This technique of saddle block anesthesia provides analgesia for approximately 1-3 hours.

RESULTS

In the study, 859 saddle block anesthesia patients were identified, with a mean age of 44.6 years and American Society of Anesthesia score of 1.9; 609 (70.9%) were male. Surgical indications included lesion removal (27.1%), anal fistula (25.8%), hemorrhoidectomy (24.7%), pilonidal disease (6.3%), anal fissure (5.8%), and a combination of prior (10.2%). Prone jackknife positioning was used in 91.6% of procedures. Saddle block anesthesia most often was performed with bupivacaine (48.9%) or ropivacaine (41.7%). The median procedural saddle block anesthesia time was 11 minutes, surgery time was 17 minutes, anesthesia time was 42 minutes, and recovery time was 91 minutes. Patients spent a median of 3 hours and 53 minutes in the facility. Adverse events included urinary retention (1.9%), conversion to general anesthesia (1.8%), spinal headache (1.5%), hemodynamic instability (0.9%), and injection site reaction (0.3%).

CONCLUSION

Demonstrated using the largest known cohort of anorectal patients with saddle block anesthesia, saddle block anesthesia provides an effective method of analgesia to avoid general anesthesia with a low rate of adverse events.

Non-Doppler hemorrhoidal artery ligation and hemorrhoidopexy combined with pudendal nerve block for the treatment of hemorrhoidal disease: a non-inferiority randomized controlled trial

BACKGROUND

In this study, we proposed a combined outpatient treatment modality for hemorrhoidal disease.

METHODS

This study was a prospective non-inferiority randomized controlled trial (RCT). The experimental group included the dearterialization and hemorrhoidopexy under pudendal nerve block, whereas the comparator consisted of the standard Doppler guided hemorrhoidal artery ligation and hemorrhoidopexy, under spinal anesthesia. As primary hypothesis, we considered the non-inferiority of the proposed modality in terms of the presenting symptom remission rate (non-inferiority margin: 10%). Randomization was based on a 1:1 ratio. Blinding was confined to the patient and the investigator.

RESULTS

Overall, 60 patients were enrolled. The primary hypothesis of this RCT (96.7% vs 73.3%) was validated. The experimental group was associated with a lower operation duration and an expedited onset of mobilization and feeding. Moreover, a favorable profile regarding short-term morbidity and analgesia was identified. The control group displayed a higher pile recurrence rate and a suboptimal patient satisfaction. A significant effect of the treatment modality in most of the SF-36 components was confirmed.

CONCLUSIONS

The proposed treatment modality was associated with favorable short and long-term outcomes. Due to specific limitations, further RCTs, with a larger sample size, are required. Trial Registration ClinicalTrials.gov : NCT03298997.

Optimal local anesthetic regimen for saddle block in ambulatory anorectal surgery: an evidence-based systematic review

BACKGROUND

Ambulatory anorectal surgery requires an anesthetic of short duration but profound depth. Saddle block anesthesia (SBA) can provide dense sacral anesthesia with minimal motor blockade, but the ideal local anesthetic agent remains undefined. This systematic review aims to identify the optimal SBA regimen for ambulatory anorectal surgery.

METHODS

We sought randomized trials examining SBA for ambulatory anorectal surgery and stratified patients into four subgroups according to local anesthetic type and dose: (1) longer acting, higher dose; (2) longer acting, lower dose; (3) shorter acting, higher dose; and (4) shorter acting, lower dose. Longer acting agents included bupivacaine and levobupivacaine; shorter acting agents included chloroprocaine, mepivacaine, and prilocaine. Lower dose was defined as ≤5 mg and ≤20 mg for longer and shorter acting local anesthetics, respectively. The primary outcome was time to discharge; secondary outcomes included times to sensory and motor block regression, urine voiding, and ambulation, as well as block success.

RESULTS

A total of 11 trials (1063 patients) were included. Overall study quality and reporting consistency was poor. Doses ranged from 1.5-7.5 mg to 3-30 mg of longer and shorter acting local anesthetics, respectively. Hyperbaric local anesthetics were used in eight trials (953 patients, 86%). The median time to discharge appeared similar across all subgroups with an overall time of 182 (IQR 102) min. The use of long-acting, lower dose regimens was associated with a faster median time to motor block regression. Block success approached 99% among all trials.

CONCLUSIONS

There is presently insufficient qualitative and quantitative evidence to identify an optimal SBA regimen for ambulatory anorectal surgery. Nonetheless, we found that doses as low as 1.5 and 3 mg of longer and shorter acting hyperbaric local anesthetics, respectively, can achieve effective and reliable SBA with timely hospital discharge. Despite similar discharge times, longer acting, lower dose local anesthetics may produce faster motor block regression following SBA for ambulatory anorectal surgery.

In vitro and in vivo quantification of chloroprocaine release from an implantable device in a piglet postoperative pain model

Background

The pharmacokinetic properties and clinical advantages of the local anesthetic chloroprocaine are well known. Here, we studied the pharmacokinetic profile of a new hydrogel device loaded with chloroprocaine to investigate the potential advantages of this new strategy for postoperative pain (POP) relief.

Materials and methods

We performed both in vitro and in vivo analyses by considering plasma samples of four piglets receiving slow-release chloroprocaine. To quantify chloroprocaine and its inactive metabolite 4-amino-2-chlorobenzoic acid (ACBA), a HPLC–tandem mass spectrometry (HPLC-MS/MS) analytical method was used. Serial blood samples were collected over 108 hours, according to the exposure time to the device.

Results

Chloroprocaine was consistently found to be below the lower limit of quantification, even though a well-defined peak was observed in every chromatogram at an unexpected retention time. Concerning ACBA, we found detectable plasma concentrations between T₀ and T_12h, with a maximum plasma concentration (C_max) observed 3 hours after the device application. In the in vitro analyses, the nanogel remained in contact with plasma at 37°C for 90 minutes, 3 hours, 1 day, and 7 days. Chloroprocaine C_max was identified 1 day following exposure and C_min after 7 days, respectively. Additionally, ACBA reached the C_max following 7 days of exposure.

Conclusion

A thorough review of the literature indicates that this is the first study analyzing both in vivo and in vitro pharmacokinetic profiles of a chloroprocaine hydrogel device and is considered as a pilot study on the feasibility of including this approach to the management of POP.