Cervical epidural depth: correlation between needle angle, cervical anatomy, and body surface area.

OBJECTIVES: Prior to performing a cervical interlaminar epidural steroid injection (CIESI), knowledge of the depth from lamina to epidural space may assist in preventing cord injury. METHODS: This is a prospective analysis of data including gender, age, weight, height, previous surgery, neck circumference, distances from tip of chin to sternal notch, occiput to C7 vertebral prominence, and ear lobe to tip of shoulder, pain score, angle from C7 vertebral prominence to the back, depth at which the Tuohy needle contacted T1 vertebral lamina and depth at which the epidural space was entered was conducted with 92 subjects, average age (± standard deviation [SD]) 41.3 ± 13.2 years underwent fluoroscopically guided C7-T1 intralaminar epidural steroid injections. RESULTS: Depth to lamina was the best individual predictor with an r value of 0.86. Weight, neck circumference, and body mass index (BMI) positively correlated with depth to epidural space with r values of 0.66, 0.62, and 0.61, respectively. A linear regression model of depth to lamina for predicting depth to epidural space was accurate to within ± 0.5 cm of the actual depth in 69% of subjects. However, when comparing predicted with actual depth to epidural space for individual subjects, the prediction was inaccurate by as much as 1.6 cm deep or 1.7 cm shallow. CONCLUSIONS: While statistically significant correlations do exist between both quantitative external body characteristics and depth to cervical epidural space and T1vertebral lamina to depth of cervical epidural space for fluoroscopically guided interlaminar epidural steroid injections at C7-T1, even the most optimal regression models do not permit clinical confidence in predicted depth to epidural space.

Advances in intrathecal drug delivery.

PURPOSE OF REVIEW: Intrathecal drug delivery (IDD) continues to gain relevance as a beneficial tool for the treatment of cancer pain, spasticity, and chronic nonmalignant pain. This review includes advances in recommendations for the use of IDD for cancer pain, nonmalignant pain, and spasticity, as well as a new study of cerebrospinal fluid kinetics, updates in logistics, and recent reports of complications. RECENT FINDINGS: Consensus-based guidelines support the use of IDD system (IDDS) in the treatment of cancer-related pain. IDDS with opioids in younger age groups may not be as successful as older patients due to tolerance issues. Research in new technologies to monitor and detect catheter breakage and disconnects is promising. There continues to be a need for more research in outcomes and new therapeutics for IDDS. SUMMARY: IDDS continues to play an important role in the management of severe intractable pain. However, the most important areas in need of advancement, outcome studies and new therapeutics, did not have any significant breakthroughs over the past year. There is some interesting preclinical work on new therapeutics but likely the translation into clinical practice will be challenging. More work is also needed on improving technologies that will result in less catheter breaks and disconnects.

Current developments in intraspinal agents for cancer and noncancer pain.

Since the late 1980s, intrathecal (IT) analgesic therapy has improved, and implantable IT drug delivery devices have become increasingly sophisticated. Physicians and patients now have myriad more options for agents and their combination, as well as for refining their delivery. As recently as 2007, The Polyanalgesic Consensus Conference of expert panelists updated its algorithm for drug selection in IT polyanalgesia. We review this algorithm and the emerging therapy included. This article provides an update on newly approved as well as emerging IT agents and the advances in technology for their delivery.