Reliability and validity of the COSMED K5 portable metabolic system during walking.

PURPOSE: Portable methods for assessing energy expenditure outside the laboratory and clinical environments are becoming more widely used. As such, it is important to understand the accuracy of such devices. Therefore, the purpose was to determine the reliability and validity of the COSMED K5 portable metabolic system. METHODS: Reliability and validity were assessed in 27 adults (age: 27 ± 5 years; n = 15 women) using a walking protocol. The protocol consisted of a 5-min walk/2-min rest cycle starting at 1.5 mph and increasing in 0.5-mph increments to 4.0 mph. During visit one, participants wore the K5 to assess oxygen consumption ([Formula: see text]O2), carbon dioxide production ([Formula: see text]CO2), and other metabolic variables. Two to seven days later, the protocol was repeated twice with the COSMED K5 and K4b2 systems in a randomized, counterbalanced order. RESULTS: Intraclass correlation coefficients (ICC) revealed that the K5 reliably measured [Formula: see text]O2 (ICC 0.64-0.85) and [Formula: see text]CO2 across all walking speeds (ICC 0.50-0.80), with stronger reliability at faster walking speeds compared with slower speeds. Moderate-to-strong relationships were observed for measured gases between the K5 and K4b2. Specifically, [Formula: see text]O2 exhibited a moderately high-to-high relationship between devices (r = 0.72-0.82), and a similarly moderately high-to-high relationship was observed for [Formula: see text]CO2 (r = 0.68-0.82). While there were no differences in [Formula: see text]O2 measured between devices (p ≥ 0.10), the K5 provided lower [Formula: see text]CO2 readings than the K4b2 during the 3.0, 3.5, and 4.0 mph walking speeds (p ≤ 0.02). CONCLUSIONS: The K5 provided reliable and valid measures of metabolic variables, with greater reliability and validity at faster walking speeds.

Recurrent brachial artery aneurysm repair in a child managed with Gore-Tex conduit reinforcement.

Pediatric nonaortic arterial aneurysms are uncommon diagnoses and can be affiliated with underlying conditions, which include neurofibromatosis I, Ehlers-Danlos type IV syndrome, Kawasaki disease, Marfan syndrome, and Loeys-Dietz, polyarteritis nodosa, as well as Klippel-Trenauny syndrome. The standard of care has been early surgical excision and arterial reconstruction when indicated. This report details a case of recurrent brachial artery aneurysm in a 2-year-old boy despite multiple attempts at excision and reconstruction. Such recurrences were seen as rapidly as 3 months postoperatively. Ultimately, a Gore-Tex conduit was used to reinforce a reversed saphenous vein graft repair. There has been no evidence of recurrent disease during the 18-month follow-up period.