Survival Analysis of Occipital Nerve Stimulator Leads Placed under Fluoroscopic Guidance with and without Ultrasonography.

BACKGROUND: Electrical stimulation of the greater occipital nerves is performed to treat pain secondary to chronic daily headaches and occipital neuralgia. The use of fluoroscopy alone to guide the surgical placement of electrodes near the greater occipital nerves disregards the impact of tissue planes on lead stability and stimulation efficacy. OBJECTIVE: We hypothesized that occipital neurostimulator (ONS) leads placed with ultrasonography combined with fluoroscopy would demonstrate increased survival rates and times when compared to ONS leads placed with fluoroscopy alone. STUDY DESIGN: A 2-arm retrospective chart review. SETTING: A single academic medical center. METHODS: This retrospective chart review analyzed the procedure notes and demographic data of patients who underwent the permanent implant of an ONS lead between July 2012 and August 2015. Patient data included the diagnosis (reason for implant), smoking tobacco use, disability, and age. ONS lead data included the date of permanent implant, the imaging modality used during permanent implant (fluoroscopy with or without ultrasonography), and, if applicable, the date and reason for lead removal. A total of 21 patients (53 leads) were included for the review. Chi-squared tests, Fishers exact tests, 2-sample t-tests, and Wilcoxon rank-sum tests were used to compare fluoroscopy against combined fluoroscopy and ultrasonography as implant methods with respect to patient demographics. These tests were also used to evaluate the primary aim of this study, which was to compare the survival rates and times of ONS leads placed with combined ultrasonography and fluoroscopy versus those placed with fluoroscopy alone. Survival analysis was used to assess the effect of implant method, adjusted for patient demographics (age, smoking tobacco use, and disability), on the risk of lead explant. RESULTS: Data from 21 patients were collected, including a total of 53 ONS leads. There was no statistically significant difference in the lead survival rate or time, disability, or patient age with respect to the implant method with or without ultrasonography. There was a statistically significant negative effect on the risk of explant with regards to lead removal in smoking patients compared to non-smoking patients (hazard ratio 0.36). There was also a statistically significant difference in smoking tobacco use with respect to the implant method, such that a greater number of patients whose leads were placed with combined fluoroscopy and ultrasonography had a history of smoking (P = 0.048). LIMITATIONS: This study is a retrospective chart review that had statistically significant differences in the patient groups and a small sample size. CONCLUSION: This study assessed the survival rates and times of ONS leads placed with ultrasonography and fluoroscopy versus fluoroscopy alone. We did not observe an effect to suggest that the incremental addition of ultrasound guidance to fluoroscopy as the intraoperative imaging modality used during the permanent implant of ONS leads yields statistically significant differences in lead survival rate or time. Medical comorbidities, including age and smoking status, may play a role in determining the risk of surgical revision and should be considered in future studies. KEY WORDS: Neuromodulation, peripheral nerve stimulation, occipital nerve stimulation, occipital neuralgia, chronic daily headaches, ultrasonography.

Perioperative Ketamine Administration for Thoracotomy Pain.

BACKGROUND: Of all the postsurgical pain conditions, thoracotomy pain poses a particular therapeutic challenge in terms of its prevalence, severity, and ensuing postoperative morbidity. Multiple pain generators contribute to the severity of post-thoracotomy pain, and therefore a multimodal analgesic therapy is considered to be a necessary strategy. Along with opioids, thoracic epidural analgesia, and paravertebral blocks, N-Methyl-D-Aspartate (NMDA) receptor antagonists such as ketamine have been used as adjuvants to improve analgesia. OBJECTIVE: We reviewed the evidence for the efficacy of intravenous and epidural administration of ketamine in acute post-thoracotomy pain management, and its effectiveness in reducing chronic post-thoracotomy pain. STUDY DESIGN: Systematic literature review and an analytic study of a data subset were performed. METHODS: We searched PubMed, Embase, and Cochrane reviews using the key terms "ketamine," "neuropathic pain," "postoperative," and "post-thoracotomy pain syndrome." The search was limited to human trials and included all studies published before January 2015. Data from animal studies, abstracts, and letters were excluded. All studies not available in the English language were excluded. The manuscript bibliographies were reviewed for additional related articles. We included randomized controlled trials and retrospective studies, while excluding individual case reports. RESULTS: This systematic literature search yielded 15 randomized control trials evaluating the efficacy of ketamine in the treatment of acute post-thoracotomy pain; fewer studies assessed its effect on attenuating chronic post-thoracotomy pain. The majority of reviewed studies demonstrated that ketamine has efficacy in reduction of acute pain, but the evidence is limited on the long-term benefits of ketamine to prevent post-thoracotomy pain syndrome, regardless of the route of administration. A nested analytical study found there is a statistically significant reduction in acute post-thoracotomy pain with IV or epidural ketamine. However currently, the evidence for a role of ketamine as a preventative agent for chronic post-thoracotomy pain is insufficient due to the heterogeneity of the studies reviewed with regard to the route of administration, dosage, and outcome measures. LIMITATIONS: The evidence for a role of ketamine as a preventative agent for chronic post-thoracotomy pain is insufficient due to the heterogeneity of the studies reviewed. CONCLUSION: The majority of randomized controlled trials reviewed show no role for ketamine in attenuating or preventing post-thoracotomy pain syndrome at variable follow-up lengths. Therefore, additional research is warranted with consideration of risk factors and long-term follow-up for chronic post-thoracotomy pain though the evidence for benefit appears clear for acute post-thoracotomy pain.Key words: Ketamine, postoperative, thoracotomy pain, post thoracotomy pain syndrome, neuropathic pain.

Twitter-Augmented Journal Club: Educational Engagement and Experience So Far.

Social media is a nascent medical educational technology. The benefits of Twitter include (1) easy adoption; (2) access to experts, peers, and patients across the globe; (3) 24/7 connectivity; (4) creation of virtual, education-based communities using hashtags; and (5) crowdsourcing information using retweets. We report on a novel Twitter-augmented journal club for anesthesia residents: its design, implementation, and impact. Our inaugural anesthesia Twitter-augmented journal club succeeded in engaging the anesthesia community and increasing residents' professional use of Twitter. Notably, our experience suggests that anesthesia residents are willing to use social media for their education.