Magnetic resonance imaging validation of medial transthyroid ultrasound-guided stellate ganglion block: A pilot study.

OBJECTIVE: Ultrasound-guided stellate ganglion block (usSGB) facilitates improved accuracy of needle position and application of lesser volumes of local anesthetic (LA). Approaches of usSGB, however, have not fully been optimized with respect to efficacy and technical convenience. This pilot study examined the anatomical position and spatial distribution of a small volume of LA injectate dispensed by medial transthyroid usSGB via magnetic resonance imaging (MRI) and assessment of its effect on cervical sympathetic nerves. METHODS: Twelve healthy males were tested in a double-blinded within-subject design. In a total of 37 usSGB, 3 ml of LA and saline 0.9% solution were injected intramuscularly into the longus colli muscle (LCM) preventing uncontrollable spread of LA within cervical structures. Immediately after injection, distribution of injectate was traced by MRI. Twenty-four out of the 37 usSGB-injections with 3 ml ropivacaine 1% (verum) and saline 0.9% (placebo) were compared. Efficacy of usSGB was assessed by the appearance of oculosympathetic paresis and increases in skin temperature. RESULTS: All usSGBs were positioned in the proximity of the LCM muscle belly. Most of the axial injectate was distributed within the transversal plane between the middle section of C5 and the upper section of T1 vertebra. Signs of oculosympathetic paresis and skin temperature increase were found exclusively under verum conditions. CONCLUSION: This pilot study demonstrated the feasibility of medial transthyroid usSGB using an out-of-plane technique and a volume of 3 ml of LA. Further studies are required to establish the relative value and safety of this technique compared to other published approaches.

Multiple prevalent fractures in relation to macroscopic bone architecture in patients with cystic fibrosis.

BACKGROUND: The relative risk for bone fractures in patients with cystic fibrosis (CF) and its relationship to macroscopic bone architecture assessed by pQCT and DXA are incompletely defined. METHODS: In a cross-sectional study of 43 CF patients (age, 17.8±6.2years), rate and location of fractures, bone mass, density, geometry, and strength of the radius as well as forearm muscle size were investigated. RESULTS: The fracture rate in CF was 9.2-fold higher compared to an age-matched German control population. The probability of remaining free of any fracture in CF patients at 25years was reduced to 39.8% compared to 84.6% in controls (P<0.001). Assessment of macroscopic bone architecture by DXA and pQCT allowed the differentiation of patients with multiple prevalent fractures with a high sensitivity (up to 100%) and specificity (up to 94.3%). CONCLUSIONS: Bone densitometry is a useful tool for noninvasive assessment of fracture risk in CF patients.