Regional anesthesia in diabetic peripheral neuropathy

Foot Drop Following a Popliteal Sciatic Nerve Block with Ropivacaine, A Case Report and Literature Review

Although peripheral nerve blocks are deemed very safe, a significant number of patients for whom this anesthetic technique may be particularly appealing to apply may present with preexisting peripheral neuropathies, putting them at risk for further nerve damage. We present a case with a 74-year-old male with several risk factors for peripheral neuropathy who developed a foot drop following a popliteal sciatic nerve block with ropivacaine. We suggest that the vasoconstrictive properties of ropivacaine may have contributed to a preexisting neuronal ischemia, thus further damaging an already compromised nerve.

Do you mind the role of spinal sensory block duration in a crucial endocrine disorder of diabetes mellitus? A prospective observational study

OBJECTIVE

Diabetes mellitus, per se, is a global health concern, which is often accompanied by complications such as diabetic neuropathy. This prospective observational study purposed to assess the durations of spinal sensory block and motor blocks in individuals with and without diabetes mellitus who had undergone spinal anesthesia.

METHODS

This study incorporated 80 cases, which were evenly divided into spinal sensory block without diabetes mellitus and spinal sensory block with diabetes mellitus. Various parameters were recorded at different time points, including heart rate, mean arterial blood pressure, SpO2, and spinal block characteristics. Notable measures included maximum spinal sensory block onset time, time to reach the 10th thoracic vertebra (T10), maximal spinal sensory block, time for Bromage scores, and block regression while controlling for age-related variations.

RESULTS

Patients in the diabetic group exhibited extended block durations, with significant differences in heart rate noted at specific time points. Regarding the spinal block characteristics, the "maximum onset of SSB" and the "time to reach the T10" were more prolonged in the SSBwDM without significance. Maximum sensory spinal sensory block did not differ. However, some cases in the SSBwDM displayed blocks extending up to the T6. The times to achieve Bromage motor block scores 1-3 were shorter in SSBwDM and lost significance regarding age. Notably, the regression time was longer in SSBwDM, which held significance for both parameters.

CONCLUSION

Diabetic cases commonly encounter prolonged block durations post-subarachnoid intervention, potentially linked to nerve sensitivity, age-related changes, and glycemic control. As such, attenuated local doses for diabetic neuropathic cases may enhance early mobilization, attenuate thromboembolic events, and expedite gastrointestinal recovery.

Diabetic Neuropathy and Minimum Effective Anesthetic Concentration of Mepivacaine for Axillary Brachial Plexus Block: A Prospective Observational Study

Nerves in patients with diabetic neuropathy (DN) show increased susceptibility to local anesthetics, potentially requiring a decreased dose. We investigated whether the minimum effective anesthetic concentration (MEAC) of mepivacaine for successful axillary block is lower in patients with DN than in those without. This prospective observational study included patients with DN (n = 22) and without diabetes (n = 22) at a tertiary care center. Patients received an ultrasound-guided axillary block with 30 mL of mepivacaine for anesthesia. The mepivacaine concentration used in each patient was calculated using Dixon's up-and-down method. A block was considered successful if all four sensory nerves had a score of 1 or 2 within 30 min with no pain during surgery. The primary outcome was the MEAC of mepivacaine, and the secondary outcomes included the minimal nerve stimulation intensity for the musculocutaneous nerve and the occurrence of adverse events. The MEAC50 was 0.55% (95% CI 0.33-0.77%) in patients without diabetes and 0.58% (95% CI 0.39-0.77%) in patients with DN (p = 0.837). The MEAC90 was 0.98% (95% CI 0.54-1.42%) in patients without diabetes and 0.96% (95% CI 0.57-1.35%) in patients with DN (p = 0.949). The stimulation threshold for the musculocutaneous nerve was significantly different between groups (0.49 mA vs. 0.19 mA for patients with vs. without diabetes; p = 0.002). In conclusion, the MEAC of mepivacaine for a successful axillary block is not lower in patients with DN.

Prevalence of diabetic foot amongst adults with diabetes mellitus in northern Sudan: A cross-sectional study

OBJECTIVE

The aim of this study was to determine the prevalence and associated factors for diabetic foot (DF) amongst patients with diabetes Mellites (DM) in Nahr an Nil State (River Nile State), Sudan.

METHODS

We conducted a cross-sectional study between May and August 2018. DM patients were examined for DF, and clinical data were collected through a questionnaire.

RESULTS

A total of 2048 DM patients were enrolled in the study. Their median (interquartile range) age was 58 (15) years. Over half (54.2%) of the patients were female. The median (interquartile range) of the duration of diabetes was 5 (6) years. In this sample, 70.1% of the patients had type 2 DM and 47.6% had hypertension as well. Of all enrolled patients, 21.2% had normal weight, 1.2% were underweight, 37.2% were overweight and 40.4% were obese. Two hundred and sixty (12.7%) patients had DF. Multivariate regression analyses showed that age [adjusted odds ratio (AOR) = 1.21; 95% confidence interval (CI): 1.18-1.24] and duration of DM (AOR = 1.09; 95% CI: 1.05-1.14) were positively associated with DF. Moreover, type 2 DM (AOR = 1.77; 95% CI: 1.17-2.68), family history of DM (AOR = 1.5; 95% CI: 1.07-2.09), hypertension (AOR = 2.93; 95% CI: 2.07-4.16) and obesity (AOR = 2.86; 95% CI: 1.70-4.81) were associated with DF. There was no significant association between DF and gender or overweight status.

CONCLUSION

This study found a high prevalence of DF. Older age, type 2 DM, duration of DM, family history of DM and hypertension are associated with DF.

[Treatment of diabetes mellitus in perioperative medicine-an update]

Patients with diabetes who undergo a surgical intervention have an increased risk of metabolic derailment, anesthesiological complications, postoperative infections and cardiovascular events. The treatment of diabetes mellitus is subject to a continuous further development due to pharmaceutical and technical innovations. This article presents the implications of the current concepts of diabetes treatment for perioperative medicine, particularly the changes due to new oral antidiabetic agents and insulin pump treatment. Some of the currently available guidelines are discussed with respect to the care of diabetes patients in childhood and adulthood in connection with an operation. Finally, possible perspectives in the field of monitoring and treatment of diabetes patients are discussed.

Challenges in diabetic foot treatment during pandemic of COVID-19

Objectives:

To avoid hospital spread of Coronavirus-2019 (COVID-19) and to analyze out of hospital outcomes after amputation.

Methods:

Prospective analysis of data obtained from 60 diabetic patients in 2020 was performed at Cantonal Hospital Zenica, Zenica, Bosnia and Herzegovina. Personal protection equipment included double surgical mask, glasses, disposable surgical coats, and surgical masks for patients. Swabs were used to take samples from wounds. We randomly divided patients in 2 groups of 30 patients each. In pre-operative treatment, we used local anesthesia lidocaine hydrochloride 2% (Belupo, Koprivnica, Croatia) in group A and systemic analgesia intravenous tramadol chloride 100 mg intravenous (Krka, Novo Mesto, Slovenia) in group B. Wounds were surgically treated each day and heal spontaneously. Periodical control exams were performed.

Results:

Wound healing did not present any statistically significant differences between groups (group A: 69±21.97 and B: 61±22.13 days, t=−1.22; p=0.11). No statistically significant differences (p<0.05) between groups A and B in wound healing regarding to gender or cigarette use was noted.

Conclusion:

No significant differences in amputation treatment between the 2 comparative groups were noted. No confirmed COVID-19 infections in medical staff who performed surgical interventions or in treated patients were detected.

Regional anaesthesia in patients with diabetes

Diabetes is the most common metabolic condition worldwide and about 20% of surgical patients will have this condition. It is a major risk-factor for worse outcomes after surgery including mortality; infective and non-infective complications; and increased length of stay. However, diabetes is a modifiable risk-factor, and programs to improve medical management have the potential to reduce peri-operative complications and the risk of harm. Regional anaesthesia has well-documented benefits in promoting the restoration of function but there are legitimate concerns that the incidence of complications of regional anaesthesia in patients with diabetes is higher. The aim of this review is to explore in detail the various potential advantages and disadvantages of regional anaesthesia in patients with diabetes. This, in turn, will allow practitioners to undertake more informed shared decision-making and potentially modify their anaesthetic technique for patients with diabetes.

Effects of adding a combined femoral and sciatic nerve block with levobupivacaine and clonidine to general anaesthesia in femoropopliteal bypass surgery: A randomised, double-blind, controlled trial

BACKGROUND

Adding a regional block to general anaesthesia can prevent postoperative pain and improve peripheral circulation.

OBJECTIVE

To seek improved postoperative analgesia and care due to a long-acting combined femoral and sciatic nerve block in patients undergoing femoropopliteal bypass surgery.

DESIGN

A randomised, double-blind, controlled trial.

SETTING

Vascular surgery unit of a French university hospital.

PATIENTS

Forty-four adults scheduled for bypass surgery under general anaesthesia.

INTERVENTION

Patients were allocated to receive either an active nerve block with 20 ml of 0.375% levobupivacaine and clonidine 0.5 μg kg, or a simulated (sham) block only, but with local anaesthesia of the skin, before general anaesthesia. General anaesthesia was standardised with propofol, then sevoflurane and sufentanil adjusted according to clinical need. Postoperative analgesia was standardised with paracetamol 1 g every 6 h, and intravenous morphine, initially titrated in the postanaesthesia care unit and then patient-controlled. Oral analgesics were repeated up to day 3.

MAIN OUTCOME MEASURES

The primary outcome was morphine consumption during the first 24 postoperative hours. In a subgroup of postoperative patients distal tissue oxygen saturation was recorded at the lateral side of the blocked calf.

RESULTS

Patients in the active group received less intra-operative sufentanil (median dose 25 vs. 41 μg), needed less morphine during the first 24 h (15 vs. 27 mg) and 72 (20 vs. 35 mg) postoperative hours, than in the control group. They also had less pain on movement, but pain at rest, the tissue oxygen saturation and other rehabilitation outcomes were unaffected by the treatment. Tolerance outcomes were also similar between groups.

CONCLUSION

Combining the two regional blocks improves the quality of postoperative care in this frail population, probably by reducing the amount of peri-operative opioid.

TRIAL REGISTRATION

ClinicalTrials.gov (ref. NCT01785693).

Neurotoxicity of bupivacaine and liposome bupivacaine after sciatic nerve block in healthy and streptozotocin-induced diabetic mice

Background

Long-acting local anaesthetics (e.g. bupivacaine hydrochloride) or sustained-release formulations of bupivacaine (e.g. liposomal bupivacaine) may be neurotoxic when applied in the setting of diabetic neuropathy. The aim of the study was to assess neurotoxicity of bupivacaine and liposome bupivacaine in streptozotocin (STZ) - induced diabetic mice after sciatic nerve block. We used the reduction in fibre density and decreased myelination assessed by G-ratio (defined as axon diameter divided by large fibre diameter) as indicators of local anaesthetic neurotoxicity.

Results

Diabetic mice had higher plasma levels of glucose (P < 0.001) and significant differences in the tail flick and plantar test thermal latencies compared to healthy controls (P < 0.001). In both diabetic and nondiabetic mice, sciatic nerve block with 0.25% bupivacaine HCl resulted in a significantly greater G-ratio and an axon diameter compared to nerves treated with 1.3% liposome bupivacaine or saline (0.9% sodium chloride) (P < 0.01). Moreover, sciatic nerve block with 0.25% bupivacaine HCl resulted in lower fibre density and higher large fibre and axon diameters compared to the control (untreated) sciatic nerves in both STZ-induced diabetic (P < 0.05) and nondiabetic mice (P < 0.01). No evidence of acute or chronic inflammation was observed in any of the treatment groups.

Conclusions

In our exploratory study the sciatic nerve block with bupivacaine HCl (7 mg/kg), but not liposome bupivacaine (35 mg/kg) or saline, resulted in histomorphometric indices of neurotoxicity. Histologic findings were similar in diabetic and healthy control mice.

Schwann cells apoptosis is induced by high glucose in diabetic peripheral neuropathy

Diabetic peripheral neuropathy (DPN) is a common complication of diabetes mellitus that affects approximately half of patients with diabetes. Current treatment regimens cannot treat DPN effectively. Schwann cells (SCs) are very sensitive to glucose concentration and insulin, and closely associated with the occurrence and development of type 1 diabetic mellitus (T1DM) and DPN. Apoptosis of SCs is induced by hyperglycemia and is involved in the pathogenesis of DPN. This review considers the pathological processes of SCs apoptosis under high glucose, which include the following: oxidative stress, inflammatory reactions, endoplasmic reticulum stress, autophagy, nitrification and signaling pathways (PI3K/AKT, ERK, PERK/Nrf2, and Wnt/β-catenin). The clarification of mechanisms underlying SCs apoptosis induced by high glucose will help us to understand and identify more effective strategies for the treatment of T1DM DPN.

Diabetes Mellitus: Preoperative Concerns and Evaluation

Diabetes is an important cause of morbidity in the adult population resulting in blindness, renal dysfunction, cardiovascular events, and amputation. Such morbidities may have an impact on perioperative anesthetic care and outcomes. In this review, the authors discuss the preoperative considerations in managing patients with diabetes as well as those without diabetes albeit hyperglycemic. They propose a plan for managing preoperative diabetes pharmacotherapy, including the use of a subcutaneous insulin pump to avoid both hypoglycemia and hyperglycemia. The authors also discuss the decision whether to proceed or cancel surgery for a given hemoglobin A1c percentage or blood glucose concentration.

Chronic pain following thoracotomy for lung surgeries: It's risk factors, prevalence, and impact on quality of life - A retrospective study

Background and Aims:

Chronic post thoracotomy pain (CPTP) is a nagging complication and can affect quality of life (QOL). Studies conducted across globe have found a wide variability in the risk factors predisposing to chronic pain following thoracotomy. As no study on CPTP is available from India, we aim to detect the prevalence of CPTP, assess the predisposing factors implicated in its causation and study the impact of CPTP on QOL.

Methods:

After obtaining clearance from Institutional ethics committee, medical records of patients who underwent open posterolateral thoracotomy between January 2012 and December 2015 were reviewed. Data on perioperative variables, address, and contact number were collected from the patient records. All patients were mailed the Telugu translation of medical outcome study short form -36(MOS-SF-36) QOL questionnaire and were contacted telephonically to enquire about presence of CPTP and QOL. A univariate analysis was done to assess factors associated with CPTP and a multivariate logistic regression analysis was done subsequently to identify independent risk factors of CPTP. QOL indices were compared between those patients who suffered from CPTP and those who did not.

Results:

The prevalence of pain in our study was 40.86% (85/208). The factors implicated in the causation of CPTP were diabetes mellitus, preoperative pain, rib resection, and duration of chest tube drainage with odds ratio of 9.8, 2.6, 6.7, and 1.03, respectively. The health-related QOL showed poor scores in all domains in patients suffering from CPTP.

Conclusion:

The prevalence of CPTP was high. It significantly impacts health-related QOL.

Dexmedetomidine enhances ropivacaine-induced sciatic nerve injury in diabetic rats

BACKGROUND

Previous studies suggest that dexmedetomidine has a protective effect against local anaesthetic-induced nerve injury in regional nerve blocks. Whether this potentially protective effect exists in the context of diabetes mellitus is unknown.

METHODS

A diabetic state was established in adult male Sprague-Dawley rats with intraperitoneal injection of streptozotocin. Injections of ropivacaine 0.5%, dexmedetomidine 20 μg kg^-1 (alone and in combination), or normal saline (all in 0.2 ml) were made around the sciatic nerve in control and diabetic rats (n=8 per group). The duration of sensory and motor nerve block and the motor nerve conduction velocity (MNCV) were determined. Sciatic nerves were harvested at post-injection day 7 and assessed with light and electron microscopy or used for pro-inflammatory cytokine measurements.

RESULTS

Ropivacaine and dexmedetomidine alone or in combination did not produce nerve fibre damage in control non-diabetic rats. In diabetic rats, ropivacaine induced significant nerve fibre damage, which was enhanced by dexmedetomidine. This manifested with slowed MNCV, decreased axon density, and decreased ratio of inner to outer diameter of the myelin sheath (G ratio). Demyelination, axon disappearance, and empty vacuoles were also found using electron microscopy. An associated increase in nerve interleukin-1β and tumour necrosis factor-α was also seen.

CONCLUSIONS

Ropivacaine 0.5% causes significant sciatic nerve injury in diabetic rats that is greatly potentiated by high-dose dexmedetomidine. Although the dose of dexmedetomidine used in this study is considerably higher than that used in clinical practice, our data suggest that further studies to assess ropivacaine (alone and in combination with dexmedetomidine) use for peripheral nerve blockade in diabetic patients are warranted.