Tracheal deviation with phrenic nerve palsy after brachial plexus block.

We present a case of a woman who received a left single-injection supraclavicular brachial plexus block for analgesia to facilitate upper extremity orthopaedic surgery. Before tracheal extubation she desaturated, was noted to have a low tidal volume and reduced left-sided air entry on auscultation of the chest. A chest x-ray taken 1 h following tracheal extubation revealed elevation of the left hemidiaphragm and a rightward shift of the trachea and mediastinal structures, with no evidence of pneumothorax. Findings were in-keeping with phrenic nerve palsy complicating the brachial plexus block performed. The patient was asymptomatic and discharged home the next day following repeat chest x-rays. We believe this is the first report of tracheal deviation contralateral to the side of an elevated hemidiaphragm secondary to phrenic nerve palsy from a brachial plexus block.

The crossed-leg position increases the dimensions within the acoustic target window for neuraxial needle placement in term pregnancy: a prospective observational study.

INTRODUCTION: Neuraxial anesthesia in obstetric patients may be difficult to achieve due to anatomical changes in pregnancy. The crossed-leg position may help in optimizing patient position. We prospectively evaluated the utility of the crossed-leg position compared with a standard position using ultrasound measurements. METHODS: Thirty women with term singleton pregnancy admitted for vaginal delivery were recruited. Women with a history of spinal trauma or surgery, congenital spinal abnormality, advanced first stage of labor or a language barrier were excluded. Two anesthesiologists, blinded to each other's measurements, scanned each subject in the crossed-leg position and standard position. Measurements of the lengths of the posterior longitudinal ligament, ligamentum flavum and interlaminar distance were recorded at the L3-L4 interspace. Comfort level in each position was scored on a Likert Scale. RESULTS: Twenty-nine women completed the study (complete data n=28). Significant increases were observed in the lengths of the posterior longitudinal ligament (mean difference 2.2 mm, 95% CI 1.3 to 3.2; P <0.001), ligamentum flavum (mean difference 1.4 mm, 95% CI 0.7 to 2.1; P <0.001) and interlaminar distance (mean difference 1.4 mm, 95% CI 0.4 to 2.5; P=0.006) in the crossed-leg position. No significant differences in comfort were observed. CONCLUSION: We demonstrated a significant increase in the sonographically measured lengths of the posterior longitudinal ligament, ligamentum flavum and interlaminar distance in the crossed-leg position when compared with the standard position. Both positions were comfortable. Further studies should explore whether these findings translate clinically into easier needle placement in the crossed-leg position.

Efficacy of the Epidural Positioning Device® in optimizing the acoustic target window for neuraxial needle placement in term pregnancy.

BACKGROUND: Neuraxial anesthesia can be challenging in obstetric patients due to the gravid uterus interfering with patient positioning. Ultrasound is commonly used in obstetric anesthesia to facilitate neuraxial needle placement. Some positioning maneuvers facilitate the ultrasound visualization of structures and the placement of neuraxial needles, but the Epidural Positioning Device (EPD) has yet to be evaluated. OBJECTIVES: Our goal was to evaluate whether the use of the EPD increased the acoustic target window in the lumbar area of pregnant patients. We hypothesized that the application of the EPD would increase the measured lengths of the paravertebral longitudinal ligament (PLL), the interlaminar distance (ILD) and the ligamentum flavum (LF). METHODS: Lumbar ultrasonography was performed on 29 pregnant women having an elective cesarean delivery. Two anesthesiologists independently scanned the L3-4 right paramedian space, using a curvilinear ultrasound transducer, in two positions for each patient: traditional sitting with lumbar flexion and sitting with use of the EPD for lumbar flexion. The PLL, ILD and LF lengths were measured using the ultrasound caliper software and recorded, with the anesthesiologists blinded to the results. Patients were asked to rate their comfort in both positions. RESULTS: There were no significant differences between the measured lengths of the PLL, ILD and LF in the two positions. Patient comfort was significantly higher with use of the EPD (OR 10, 95% CI 2.4 to 88). CONCLUSION: Although the application of an EPD did not improve the paramedian acoustic target area in term parturients, greater patient comfort might facilitate needle placement.