Incidence and etiology of postoperative neurological symptoms after peripheral nerve block: a retrospective cohort study.

BACKGROUND: Nerve injury from peripheral nerve block (PNB) is an uncommon but potentially serious complication. We present a retrospective cohort study to evaluate the incidence and etiology of new postoperative neurological symptoms after surgery and regional anesthesia. METHODS: We performed a retrospective cohort study of all PNBs performed on elective orthopedic and plastic surgical patients over 6 years (2011-2017). We collected patient and surgical data, results of neurophysiological and imaging tests, neurology and chronic pain consultations, etiology and outcome for patients with prolonged neurological symptoms (lasting ≥10 days). RESULTS: A total of 26 251 PNBs were performed in 19 219 patients during the study period. Transient postoperative neurological symptoms (<10 days) were reported by 14.4% (95% CI 13.1% to 15.7%) of patients who were reached by telephone follow-up. Prolonged postoperative neurological symptoms (≥10 days) were identified and investigated in 20 cases (1:1000, 95% CI 0.6 to 1.6). Of these 20 cases, three (0.2:1000, 95% CI 0.04 to 0.5) were deemed to be block related, seven related to surgical causes, three due to musculoskeletal causes or pain syndromes, one was suspected of having an inflammatory etiology and six remained of undetermined etiology. Of those who completed follow-up, 56% had full recovery of their symptoms with the remaining having partial recovery. CONCLUSION: This retrospective review of 19 219 patients receiving PNBs for anesthesia or analgesia suggests that determining the etiology and causative factors of postoperative neurological symptoms is a complex, often challenging process that requires a multidisciplinary approach. We suggest a classification of cases based on the etiology. A most likely cause was identified in 70% of cases. This type of classification system can help broaden the differential diagnosis, help consider non-regional anesthesia and non-surgical causes and may be useful for clinical and research purposes.

Comparison of two ultrasound-guided techniques for greater occipital nerve injections in chronic migraine: a double-blind, randomized, controlled trial.

BACKGROUND AND OBJECTIVES: Two ultrasound (US)-guided techniques for greater occipital nerve (GON) block have been described for the management of headache disorders: a "proximal or central" technique targeting the GON at the level of the second cervical vertebra and a "distal or peripheral" technique targeting the GON at the level of the superior nuchal line. In this multicenter, prospective, randomized control trial, we compared accuracy, effectiveness, and safety of these two techniques in patients with chronic migraines (CMs). METHODS: Forty patients with refractory CMs were randomized to receive either a proximal or distal US-guided GON block with bupivacaine and methylprednisolone acetate. The primary outcome was the difference in Numerical Rating Score (NRS) for headache intensity at 1 month. Secondary outcomes were effectiveness, performance, and safety-related. Effectiveness-related outcomes included NRS for headache intensity, number of headache days per week, patient satisfaction, quality of life, assessment of sleep quality, and sleep interruption. Performance-related outcomes included procedure time, accuracy of block, and patient discomfort. Safety-related outcomes included an assessment for adverse effects. RESULTS: NRS pain scores were significantly reduced at 24 hours and at 1 week postprocedure in both cohorts and at 1 and 3 months in the proximal group as compared with the baseline. There was no significant difference in NRS pain scores between the two cohorts at any of the follow-up time points. There was a significant reduction in number of headache days per week at 1 month in both groups, and a significant improvement in sleep interruption at 1 week in both groups. There were no significant adverse effects. CONCLUSIONS: This study was designed to compare two different US-guided approaches for blocking the GON. Our results demonstrate that both distal and proximal techniques can provide a short-term improvement in headache intensity, reduction in number of headache days per week, and an improvement in sleep interruption. The proximal GON technique may confer more sustained analgesic benefit compared with the distal approach in patients with CM headaches. TRIAL REGISTRATION NUMBER: NCT02031822.

The Parable of the Errant Chest Drain in the Heart: Is There Only 1 Option?

Accidental intraventricular placement of a pericardiocentesis catheter is a rare but well-recognized complication. Failure to achieve adequate hemostasis in the ventricular wall on removal of the catheter can potentially result in fatal consequences. Here we describe a case in which a chest drain (10.2F) accidentally entered into the right ventricle while attempting to drain pleural fluid, and the entry site was sealed using an Amplatzer VSD occluder device (St. Jude Medical, St. Paul, MN).

Ultrasound-Guided Interventional Procedures in Pain Medicine: A Review of Anatomy, Sonoanatomy, and Procedures: Part VI: Ankle Joint.

Ultrasound-guided injections in pain medicine are emerging as a popular technique for pain interventions. Ultrasound can be applied for procedures of the ankle joint and surrounding structures. This review describes the anatomy and sonoanatomy of the ankle joint, subtalar joint, and surrounding extra-articular structures relevant for intra-articular injection. Second, it reviews injection techniques and the accuracy and efficacy of these intra-articular ankle injections.

Comparison of Fluoroscopy and Ultrasound Guidance for Sacroiliac Joint Injection in Patients with Chronic Low Back Pain.

BACKGROUND AND OBJECTIVES: Sacroiliac joint (SIJ) arthritis is a common cause of chronic mechanical low back pain (LBP) that is often treated with injection of local anesthetic and steroids. Ultrasound (US) has emerged as a viable alternative to fluoroscopy (FL) to guide SIJ injections; however, few studies have compared these modalities. In this prospective randomized, controlled trial, we compared both accuracy and efficacy of US and FL guidance for SIJ injections. METHODS: Forty patients with chronic moderate-to-severe LBP secondary to SIJ arthritis were randomized to receive US- or FL-guided unilateral SIJ injections. Primary outcomes included pain at 1 month measured by numerical rating scale (NRS) scores. Secondary outcomes included NRS scores at 24 hours, 72 hours, 1 week, and 3 months after injection, physical functioning at 1 month after the procedure, procedure time, incidence of intra-articular and peri-articular needle placement, patient discomfort, overall patient satisfaction, and daily opioid consumption. RESULTS: There was no significant difference in NRS pain scores between the 2 groups at 1 month or at any other follow-up points. A significant reduction from baseline mean NRS scores was observed in both groups at 1 month after injection (US 22.7%, P = 0.025; FL 37.3%, P < 0.001). There was no significant difference in procedure-related variables, physical functioning, discomfort, opioid utilization, and patient satisfaction between the 2 groups. CONCLUSIONS: Ultrasound-guided SIJ injection with fluoroscopic confirmation has similar accuracy and efficacy to fluoroscopy alone for SIJ injections in patients with chronic low back pain secondary to SIJ arthritis.

Rates and risk factors for prolonged opioid use after major surgery: population based cohort study.

OBJECTIVE: To describe rates and risk factors for prolonged postoperative use of opioids in patients who had not previously used opioids and undergoing major elective surgery. DESIGN: Population based retrospective cohort study. SETTING: Acute care hospitals in Ontario, Canada, between 1 April 2003 and 31 March 2010. PARTICIPANTS: 39,140 opioid naïve patients aged 66 years or older who had major elective surgery, including cardiac, intrathoracic, intra-abdominal, and pelvic procedures. MAIN OUTCOME MEASURE: Prolonged opioid use after discharge, as defined by ongoing outpatient prescriptions for opioids for more than 90 days after surgery. RESULTS: Of the 39,140 patients in the entire cohort, 49.2% (n=19,256) were discharged from hospital with an opioid prescription, and 3.1% (n=1229) continued to receive opioids for more than 90 days after surgery. Following risk adjustment with multivariable logistic regression modelling, patient related factors associated with significantly higher risks of prolonged opioid use included younger age, lower household income, specific comorbidities (diabetes, heart failure, pulmonary disease), and use of specific drugs preoperatively (benzodiazepines, selective serotonin reuptake inhibitors, angiotensin converting enzyme inhibitors). The type of surgical procedure was also highly associated with prolonged opioid use. Compared with open radical prostatectomies, both open and minimally invasive thoracic procedures were associated with significantly higher risks (odds ratio 2.58, 95% confidence interval 2.03 to 3.28 and 1.95 1.36 to 2.78, respectively). Conversely, open and minimally invasive major gynaecological procedures were associated with significantly lower risks (0.73, 0.55 to 0.98 and 0.45, 0.33 to 0.62, respectively). CONCLUSIONS: Approximately 3% of previously opioid naïve patients continued to use opioids for more than 90 days after major elective surgery. Specific patient and surgical characteristics were associated with the development of prolonged postoperative use of opioids. Our findings can help better inform understanding about the long term risks of opioid treatment for acute postoperative pain and define patient subgroups that warrant interventions to prevent progression to prolonged postoperative opioid use.

Ultrasound-guided pain interventions - a review of techniques for peripheral nerves.

Ultrasound has emerged to become a commonly used modality in the performance of chronic pain interventions. It allows direct visualization of tissue structure while allowing real time guidance of needle placement and medication administration. Ultrasound is a relatively affordable imaging tool and does not subject the practitioner or patient to radiation exposure. This review focuses on the anatomy and sonoanatomy of peripheral non-axial structures commonly involved in chronic pain conditions including the stellate ganglion, suprascapular, ilioinguinal, iliohypogastric, genitofemoral and lateral femoral cutaneous nerves. Additionally, the review discusses ultrasound guided intervention techniques applicable to these structures.