How to Restart the Interventional Activity in the COVID-19 Era: The Experience of a Private Pain Unit in Spain.

INTRODUCTION: The situation generated in the health system by the COVID-19 pandemic has provoked a crisis involving the necessity to cancel non-urgent and oncologic activity in the operating room and in day-to-day practice. As the situation continues, the need to reinstate attention for patients with chronic pain grows. The restoration of this activity has to begin with on-site appointments and possible surgical procedures. On-site clinical activity has to guarantee the safety of patients and health workers. OBJECTIVES: The objective of this review was to evaluate how to manage activity in pain units, considering the scenario generated by the pandemic and the implications of chronic pain on the immune system and proposed pharmacological and interventional therapies. METHODS: Besides the established general recommendations (physical distance, surgical masks, gloves, etc.), we established specific recommendations that will allow patient treatment and relieve the disruption of the immune response. It is important to highlight the use of opioids with the least influence in the immune system. Further, individualized corticoid use, risk assessment, reduced immune suppression, and dose adjustment should take patient needs into account. In this scenario, we highlight the use of radiofrequency and neuromodulation therapies, techniques that do not interfere with the immune response. CONCLUSIONS: We describe procedures to implement these recommendations for individual clinical situations, the therapeutic possibilities and safety guidelines for each center, and government recommendations during the COVID-19 pandemic.

Is the introduction of another variable to the strength-duration curve necessary in neurostimulation?

INTRODUCTION: Neurostimulation is the process and technology derived from the application of electricity with different parameters to activate or inhibit nerve pathways. Pulse width (Pw) is the duration of each electrical impulse and, along with amplitude (I), determines the total energy charge of the stimulation. OBJECTIVES: The aim of the study was to test Pw values to find the most adequate pulse widths in rechargeable systems to obtain the largest coverage of the painful area, the most comfortable paresthesia, and the greatest patient satisfaction. MATERIAL AND METHODS: A study of the parameters was performed, varying Pw while maintaining a fixed frequency at 50 Hz. Data on perception threshold (Tp ), discomfort threshold (Td ), and therapeutic threshold (Tt ) were recorded, applying 14 increasing Pw values ranging from 50 µsec to 1000 µsec. Lastly, the behavior of the therapeutic range (TR), the coverage of the painful area, the subjective patient perception of paresthesia, and the degree of patient satisfaction were assessed. RESULTS: The findings after analyzing the different thresholds were as follows: When varying the Pw, the differences obtained at each threshold (Tp , Tt , and Td ) were statistically significant (p < 0.05). The differences among the resulting Tp values and among the resulting Tt values were statistically significant when varying Pw from 50 up to 600 µsec (p < 0.05). For Pw levels 600 µsec and up, no differences were observed in these thresholds. In the case of Td , significant differences existed as Pw increased from 50 to 700 µsec (p ≤ 0.05). The coverage increased in a statistically significant way (p < 0.05) from Pw values of 50 µsec to 300 µsec. Good or very good subjective perception was shown at about Pw 300 µsec. CONCLUSIONS: The patient paresthesia coverage was introduced as an extra variable in the chronaxie-rheobase curve, allowing the adjustment of Pw values for optimal programming. The coverage of the patient against the current chronaxie-rheobase formula will be represented on three axes; an extra axis (z) will appear, multiplying each combination of Pw value and amplitude by the percentage of coverage corresponding to those values. Using this new comparison of chronaxie-rheobase curve vs. coverage, maximum Pw values will be obtained different from those obtained by classic methods.

A Cost-Consequence Analysis Examining the Differences Between Non-Rechargeable and Rechargeable Systems.

BACKGROUND: Spinal cord stimulation (SCS) is an effective treatment option to relieve chronic intractable pain, and failed back surgery syndrome (FBSS) is a key indication. OBJECTIVES: The objective of the current study was to analyze the cost consequences of using non-rechargeable (NR)-SCS and rechargeable (R)-SCS. METHODS: Real data taken from a review of 86 patients were used to simulate costs and review which patients might have benefitted more from R-SCS. Calculations were made to see what is the impact from a monetary point of view. RESULTS: On average, NR-SCS devices lasted for 58 months (M). Only 14 patients were not eligible to receive an R-SCS implant. We found that using R-SCS batteries would save up to €56.322 on average over a patient's life expectancy, which means a saving of 43% compared to using NR-SCS systems. In our analysis, we found that if R-SCS implants were used instead of NR-SCS batteries, a saving of €5,735,334.23 over patients' life expectancy would be made, which represented a 63% saving to the public health system. We found that R-SCS was cost-beneficial from second year compared to NR-SCS, saving up to 70% when patients are implanted for 9 years. CONCLUSIONS: This cost-consequences analysis suggests that R-SCS implants are more cost-beneficial than NR-SCS systems in well-selected patient candidates for this type of treatment.

Use of intraoperative neurophysiological monitoring during epiduroscopy as a safety measure.

OBJECTIVE: In this study, we present the first 12 cases of the use of intraoperative neurophysiological monitoring (IONM) during therapeutic epiduroscopy in patients with clinical canal stenosis. METHODS: IESS was performed using two working instruments: an epidural balloon to dilate the epidural space without damaging the nerve structures (Resaloon®) and an element to perform flavotomy of the ligamentum flavum (Resaflex®). The procedure was performed at levels of the greatest stenosis, as detected using preoperative magnetic resonance imaging. RESULTS: Of the 12 cases that used IONM, 2 patients presented neurotonic activity in roots during ligamentum flavum ablation, 1 patient presented neurotonic activity while using Resaloon® in a root contralateral to the level at which the procedure was conducted, and other presented neurotonic activity in a root below the level at which the ligamentum flavum was ablated. In all cases, potentially harmful discharges stopped when the procedure was interrupted momentarily. CONCLUSIONS: Intraoperative neurophysiological monitoring detected alterations in surgical field and roots below and/or contralateral to the field, which disappeared with complete recovery after interrupting the procedure; this can avoid the possible prolonged or even permanent complications postoperatively. SIGNIFICANCE: Intraoperative neurophysiological monitoring during epiduroscopy is safe, thus optimizing surgical outcomes.