Ultrasound-guided saphenous nerve block--within versus distal to the adductor canal: a proof-of-principle randomized trial.

PURPOSE: Reliable saphenous nerve blockade is a desirable complement to popliteal sciatic nerve blockade for foot and ankle surgery. We compared two promising ultrasound-guided techniques, the supine adductor canal (AC) technique and the prone peri-saphenous branch of the descending genicular artery (Peri-SBDGA) technique, using 8 mL of 2% lidocaine with epinephrine 1:400,000. METHODS: Following Research Ethics Board approval, we conducted a randomized single-blinded parallel-group trial in 102 patients undergoing foot and ankle surgery at a single centre. The primary endpoint was saphenous nerve ease of visualization (0 = not visible; 1 = visible with difficulty; and 2 = easily visible). Other endpoints included vascular landmark visualization (0 = not visible; 1= visible with colour flow Doppler; 2 = visible without colour flow Doppler), block success, onset, and complications. RESULTS: Ninety-one patients were eligible for analysis. Saphenous nerve visibility was not different between the groups (visibility score = 2: AC group, n = 24/49 [49%] vs Peri-SBDGA group, 20/42 [48%]; P = 1.00). Vascular landmark visibility was better in the AC group than in the Peri-SBDGA group (visibility score = 2: 41/49 [84%] vs 25/42 [60%], respectively; P = 0.018). Block success rates were similar (AC group, 41/49 [84%] vs Peri-SBDGA group, 34/42 [81%]; P = 0.79), as were median [interquartile range] onset times (AC group, 5 [5-10] min vs Peri-SBDGA group, 8 [5-11] min; P = 0.38). CONCLUSION: In this randomized trial, we found no differences in nerve visibility, block success rate, or onset between the AC and Peri-SBDGA techniques of ultrasound-guided saphenous nerve blockade, although the former technique provided superior vascular landmark visibility. Neither technique produced a sufficiently high success rate to provide reliable surgical anesthesia per se.

Circulating surfactant protein D as a potential lung-specific biomarker of health outcomes in COPD: a pilot study.

BACKGROUND: There is a paucity of surrogate lung-specific biological markers that can be used to track disease progression and predict clinical outcomes in chronic obstructive pulmonary disease (COPD). The principal aim of this pilot study was to determine whether circulating surfactant protein D (SPD) or Clara Cell protein-16 (CC16) levels are associated with lung function or health status in patients with severe COPD. METHODS: We studied 23 patients with advanced COPD. Lung function measurements, Chronic Respiratory Disease Questionnaire (CRQ) scores, and serum levels of SPD, CC16, and C-reactive protein (CRP) were determined at baseline and at 3 months. RESULTS: At baseline, FEV(1) was inversely associated with serum SPD levels (P = 0.045) but not with CC16 (P = 0.675) or CRP levels (P = 0.549). Over a 3 month period, changes in SPD levels correlated significantly with changes in CRQ scores (adjusted P = 0.008) such that patients who had the largest declines in serum SPD levels experienced the largest gains in health status. The association was particularly notable between circulating SPD level and the dyspnea domain of the CRQ score (P = 0.018). Changes in CC16 or CRP levels did not correlate with changes in CRQ scores. CONCLUSION: Changes in serum SPD levels tracked well with changes in health status over a 3 month period in patients with severe COPD. These data suggest that circulating SPD levels may be useful biomarkers to track health outcomes of COPD patients.