Interventional Pain Procedures: A Narrative Review Focusing on Safety and Complications. Part 1 Injections for Spinal Pain.

In recent years, there has been a considerable increase in the number of image-guided interventional procedures performed for the management of acute and chronic pain. Concomitantly, there has also been an increase in the complication rate related to these procedures. The aim of this narrative review is to summarize the primary complications associated with commonly performed image-guided (fluoroscopic- or ultrasound-guided) interventional procedures. We conclude that although complications from interventional pain procedures can be mitigated to a certain degree, they cannot be eliminated altogether. In order to avoid adverse events, patient safety should be given considerable attention and physicians should be constantly aware of the possibility of developing complications.

Interventional Pain Procedures: A Narrative Review Focusing On Safety and Complications. PART 2 Interventional Procedures For Back Pain.

In patients where conservative approaches have failed to relieve from chronic pain, interventional procedures may be an option in well selected patients. In recent years there has been an increase in the use and development of invasive procedures. Concomitantly, there has also been an increase in the complications associated with these procedures. Taken this into consideration, it is important for healthcare providers to take a cautious and vigilant approach, with a focus on patient safety, in order to minimize the risk of adverse events and ensure the best possible outcome for the patient. This may include careful selection of patients for procedures, use of proper techniques and equipment, and close monitoring and follow-up after the procedure. The aim of this narrative review is to summarize the primary complications associated with commonly performed image-guided (fluoroscopy or ultrasound-guided) interventional procedures and provide strategies to reduce the risk of these complications. We conclude that although complications from interventional pain procedures can be mitigated to a certain degree, they cannot be eliminated altogether. In order to avoid adverse events, patient safety should be given considerable attention and physicians should be constantly aware of the possibility of developing complications.

Chronic Pain in the Elderly: Mechanisms and Distinctive Features.

BACKGROUND: Chronic pain is a major issue affecting more than 50% of the older population and up to 80% of nursing homes residents. Research on pain in the elderly focuses mainly on the development of clinical tools to assess pain in patients with dementia and cognitive impairment or on the efficacy and tolerability of medications. In this review, we searched for evidence of specific pain mechanisms or modifications in pain signals processing either at the cellular level or in the central nervous system. METHODS: Narrative review. RESULTS: Investigation on pain sensitivity led to conflicting results, with some studies indicating a modest decrease in age-related pain sensitivity, while other researchers found a reduced pain threshold for pressure stimuli. Areas of the brain involved in pain perception and analgesia are susceptible to pathological changes such as gliosis and neuronal death and the effectiveness of descending pain inhibitory mechanisms, particularly their endogenous opioid component, also appears to deteriorate with advancing age. Hyperalgesia is more common at older age and recovery from peripheral nerve injury appears to be delayed. In addition, peripheral nociceptors may contribute minimally to pain sensation at either acute or chronic time points in aged populations. CONCLUSIONS: Elderly subjects appear to be more susceptible to prolonged pain development, and medications acting on peripheral sensitization are less efficient. Pathologic changes in the central nervous system are responsible for different pain processing and response to treatment. Specific guidelines focusing on specific pathophysiological changes in the elderly are needed to ensure adequate treatment of chronic pain conditions.

Practical Advices for Treating Chronic Pain in the Time of COVID-19: A Narrative Review Focusing on Interventional Techniques.

BACKGROUND: Since the management of chronic pain has become even more challenging secondary to the occurrence of SARS-CoV-2 outbreaks, we developed an exhaustive narrative review of the scientific literature, providing practical advices regarding the management of chronic pain in patients with suspected, presumed, or confirmed SARS-CoV-2 infection. We focused particularly on interventional procedures, where physicians are in closer contact with patients. METHODS: Narrative Review of the most relevant articles published between June and December of 2020 that focused on the treatment of chronic pain in COVID-19 patients. RESULTS: Careful triage of patients is mandatory in order to avoid overcrowding of hospital spaces. Telemedicine could represent a promising tool to replace in-person visits and as a screening tool prior to admitting patients to hospitals. Opioid medications can affect the immune response, and therefore, care should be taken prior to initiating new treatments and increasing dosages. Epidural steroids should be avoided or limited to the lowest effective dose. Non urgent interventional procedures such as spinal cord stimulation and intrathecal pumps should be postponed. The use of personal protective equipment and disinfectants represent an important component of the strategy to prevent viral spread to operators and cross-infection between patients due to the SARS-CoV-2 outbreaks.

Reduction of opioid intake after cooled radiofrequency denervation for sacroiliac joint pain: a retrospective evaluation up to 1 year.

BACKGROUND: Opioids can present intolerable adverse side-effects to patients who use these analgesics to mitigate chronic pain. In this retrospective analysis, cooled radiofrequency (CRF) denervation was evaluated to provide pain and disability relief and reduce opioid use in patients with sacroiliac joint (SIJ) derived low back pain (LBP). METHODS: Twenty-seven patients with pain from SIJ refractory to conservative treatments, and taking opioids chronically (> 3 mo), were included. Numeric rating scale (NRS) and Oswestry disability index (ODI) scores were collected at 1, 6, and 12 months post-procedure. Opioid use between baseline and each follow-up visit was compared for the entire group and for those who experienced successful (pain reduction ≥ 50% of baseline value) or unsuccessful CRF denervation. RESULTS: Severe initial mean pain (NRS score: 7.7 ± 1.0) and disability (ODI score: 50.1 ± 9.0), and median opioid use (morphine equivalent daily dose: 40 ± 37 mg) were significantly reduced up to 12 months post-intervention. CRF denervation was successful in 44.4% of the patients at 12 months. Regardless of procedure success, patients demonstrated similar opioid reductions and changes in opioid use at 12 months. Two patients (7.4%) experienced neuritis following CRF denervation. CONCLUSIONS: CRF denervation of the SIJ can safely elicit pain and disability relief, and reduce opioid use, regardless of intervention success. Future studies may support CRF denervation as a dependable therapy to alleviate opioid use in patients with SIJ-derived LBP and show that opioid use measurements can be a surrogate indicator of pain.

Pulsed Radiofrequency Application on Femoral and Obturator Nerves for Hip Joint Pain: Retrospective Analysis with 12-Month Follow-up Results.

BACKGROUND: Osteoarthritis of the hip joint is a common cause of pain and disability. Patients not responding to conservative management often cannot undergo joint replacement due to the presence of multiple comorbidities, while some other patients prefer to postpone surgery as long as possible. Radiofrequency denervation of articular branches of the femoral and obturator nerves, which supply innervation of the joint, is a novel technique to reduce hip joint pain. Previous studies reported positive results after application of continuous radiofrequency to the target nerves; however, this approach carries the potential risk of neuritis and neuroma formation. Pulsed radiofrequency (PRF) is a safer alternative to continuous radiofrequency not creating necrosis but a complex neuromodulatory effect on target nerves. There is no published evidence of PRF efficacy after 3 month follow-up. OBJECTIVES: This single-center study objective was to evaluate the short and medium term effectiveness of PRF on the femoral articular branches and obturator nerves in patients with chronic hip pain. STUDY DESIGN: Retrospective single-center study. SETTING: Italian National Health Service Public Hospital. METHODS: Retrospective analysis of 14 patients treated with PRF for severe hip joint pain (mean numericAL rating scale (NRS) 7.7 ± 1.2 mean Oxford Hip Score (OHS) 20 ± 8.4). Mean pain and disability scores were evaluated with NRS and OHS respectively at 1, 3, 6 and 12-month follow-up. Mean pain and disability scores were evaluated with NRS and OHS respectively at 1, 3, 6, and 12-month follow-up. All patients were treated with pulsed radiofrequency applied under fluoroscopy on the articular branches of the femoral and obturator nerves for 300 seconds each. RESULTS: Eight patients out of 14 (57%) reported an NRS reduction > 50% at 1 month post procedure. Overall, both pain and disability scores were significantly (P < 0.01) lower at all follow-up until 6 months, mean NRS at 1, 3, and 6 months was 3.6 ± 3; 4.1 ± 3.3; 4.8 ± 2.9 while OHS was 37.6 ± 17.7; 35.8 ± 17.7; 35.8 ± 14 respectively. At 12 months, NRS was 5.8 ± 2.4 while OHS 23.3 ± 12.7, it must be pointed out that even if both scores are significantly (P < 0.01) lower than basal, only 3 patients out of 14 (21%) maintained a NRS reduction > 50% from basal at 12 months post procedure. We reported 2 femoral artery punctures without any significant complication. LIMITATIONS: Retrospective study, small sample size. CONCLUSIONS: Pulsed radiofrequency is a safe and effective modality to treat hip joint pain in the short and medium term. Definition of positive outcome predictors is required to reserve radiofrequency treatment only for those patients who can benefit from this procedure. KEY WORDS: Hip joint pain, pulsed radiofrequency, obturator nerve, femoral nerve, interventional pain management, radiofrequency.

Conventional (Simplicity III) and Cooled (SInergy) Radiofrequency for Sacroiliac Joint Denervation: One-Year Retrospective Study Comparing Two Devices.

OBJECTIVE: To compare two radiofrequency (RF) devices, Simplicity III (conventional RF), and SInergy (cooled RF), which are specifically designed to denervate the sacroiliac joint (SIJ). DESIGN: Retrospective observational study. SETTING: Italian National Health Service Public Hospital. SUBJECTS: Forty-three patients with SIJ-derived pain refractory to conservative treatment; 21 and 22 patients, respectively, received Simplicity III or SInergy to denervate the SIJ. METHODS: Mean numerical rating scale (NRS) and Oswestry Disability Index (ODI) scores were determined for each study group up to 12 months postprocedure. Secondary outcomes included the average amount of time required to complete each RF procedure and the adverse events associated with each technique. RESULTS: Average SInergy group NRS and ODI scores were consistently less than those in the Simplicity III cohort at each post-RF denervation follow-up, and such differences were statistically significant at six and 12 months. The Simplicity III procedure was completed approximately 2.5 times faster than the SInergy procedure, and one minor adverse event was reported in the SInergy group. CONCLUSIONS: The study results suggest that SInergy safely afforded patients with greater and more durable analgesia and disability relief than Simplicity III for SIJ-derived pain. The Simplicity III procedure may be more conducive than SInergy for bilateral procedures and for patients who have limited tolerance to be in an RF procedure-required prone position. Randomized controlled trials are needed to confirm the implication made in this study that SInergy is the preferred RF denervation option for treating SIJ-derived pain and the disability associated with it.

Effect of external PEEP in patients under controlled mechanical ventilation with an auto-PEEP of 5 cmH2O or higher.

BACKGROUND: In some patients with auto-positive end-expiratory pressure (auto-PEEP), application of PEEP lower than auto-PEEP maintains a constant total PEEP, therefore reducing the inspiratory threshold load without detrimental cardiovascular or respiratory effects. We refer to these patients as "complete PEEP-absorbers." Conversely, adverse effects of PEEP application could occur in patients with auto-PEEP when the total PEEP rises as a consequence. From a pathophysiological perspective, all subjects with flow limitation are expected to be "complete PEEP-absorbers," whereas PEEP should increase total PEEP in all other patients. This study aimed to empirically assess the extent to which flow limitation alone explains a "complete PEEP-absorber" behavior (i.e., absence of further hyperinflation with PEEP), and to identify other factors associated with it. METHODS: One hundred patients with auto-PEEP of at least 5 cmH2O at zero end-expiratory pressure (ZEEP) during controlled mechanical ventilation were enrolled. Total PEEP (i.e., end-expiratory plateau pressure) was measured both at ZEEP and after applied PEEP equal to 80 % of auto-PEEP measured at ZEEP. All measurements were repeated three times, and the average value was used for analysis. RESULTS: Forty-seven percent of the patients suffered from chronic pulmonary disease and 52 % from acute pulmonary disease; 61 % showed flow limitation at ZEEP, assessed by manual compression of the abdomen. The mean total PEEP was 7 ± 2 cmH2O at ZEEP and 9 ± 2 cmH2O after the application of PEEP (p < 0.001). Thirty-three percent of the patients were "complete PEEP-absorbers." Multiple logistic regression was used to predict the behavior of "complete PEEP-absorber." The best model included a respiratory rate lower than 20 breaths/min and the presence of flow limitation. The predictive ability of the model was excellent, with an overoptimism-corrected area under the receiver operating characteristics curve of 0.89 (95 % CI 0.80-0.97). CONCLUSIONS: Expiratory flow limitation was associated with both high and complete "PEEP-absorber" behavior, but setting a relatively high respiratory rate on the ventilator can prevent from observing complete "PEEP-absorption." Therefore, the effect of PEEP application in patients with auto-PEEP can be accurately predicted at the bedside by measuring the respiratory rate and observing the flow-volume loop during manual compression of the abdomen.

Assessment of Factors Related to Auto-PEEP.

BACKGROUND: Previous physiological studies have identified factors that are involved in auto-PEEP generation. In our study, we examined how much auto-PEEP is generated from factors that are involved in its development. METHODS: One hundred eighty-six subjects undergoing controlled mechanical ventilation with persistent expiratory flow at the beginning of each inspiration were enrolled in the study. Volume-controlled continuous mandatory ventilation with PEEP of 0 cm H2O was applied while maintaining the ventilator setting as chosen by the attending physician. End-expiratory and end-inspiratory airway occlusion maneuvers were performed to calculate respiratory mechanics, and tidal flow limitation was assessed by a maneuver of manual compression of the abdomen. RESULTS: The variable with the strongest effect on auto-PEEP was flow limitation, which was associated with an increase of 2.4 cm H2O in auto-PEEP values. Moreover, auto-PEEP values were directly related to resistance of the respiratory system and body mass index and inversely related to expiratory time/time constant. Variables that were associated with the breathing pattern (tidal volume, frequency minute ventilation, and expiratory time) did not show any relationship with auto-PEEP values. The risk of auto-PEEP ≥5 cm H2O was increased by flow limitation (adjusted odds ratio 17; 95% CI: 6-56.2), expiratory time/time constant ratio <1.85 (12.6; 4.7-39.6), respiratory system resistance >15 cm H2O/L s (3; 1.3-6.9), age >65 y (2.8; 1.2-6.5), and body mass index >26 kg/m(2) (2.6; 1.1-6.1). CONCLUSIONS: Flow limitation, expiratory time/time constant, resistance of the respiratory system, and obesity are the most important variables that affect auto-PEEP values. Frequency expiratory time, tidal volume, and minute ventilation were not independently associated with auto-PEEP. Therapeutic strategies aimed at reducing auto-PEEP and its adverse effects should be primarily oriented to the variables that mainly affect auto-PEEP values.