High osmolality feedings do not increase the incidence of thrombophlebitis during peripheral i.v. nutrition

Peripheral i.v. nutrition has been advocated for patients who require short-term i.v. nutrition support to avoid the complications and expense of central venous catheterization. Feeding formulas for peripheral administration have usually been modified by increasing the proportion of lipid, because increasing osmolality is reported to cause thrombophlebitis. The aim of this study was to determine whether standard feeding formulas can be given via the peripheral route and also to establish whether increasing osmolality does increase the incidence of thrombophlebitis under these conditions.

Thirty-six patients requiring parenteral nutrition were randomized to receive either a "high" (1700 mOsmol/L) or "standard" (1200 mOsmol/L) osmolality feeding containing 2000 kcal and 12 g nitrogen via a peripheral line.

Twenty patients (mean age 55.6 years, range 16 to 78) received standard osmolality feedings using 20 peripheral feeding lines for a mean duration of 6.8 days (range 2 to 16) with 10 line failures (8 thrombophlebitis, 2 occlusion). Nineteen patients (mean age 56.1 years, range 27 to 83) received high osmolality feedings via 20 lines for a mean of 6.3 days (range 0 to 18) with five line failures (4 thrombophlebitis, 1 occlusion), one failed insertion, one line removed at the patient's request, and four lines that fell out. Forty lines were inserted overall of which 19 (47.5%) were removed electively, 12 (30%) developed thrombophlebitis, 3 (7.5%) occluded, 4 (10%) fell out, 1 (2.5%) was a failed insertion, and 1 (2.5%) was removed for nonmedical reasons.

Increasing osmolality of total parenteral nutrition did not increase episodes of thrombophlebitis in this trial and did not affect the success rate of the lines. We conclude that standard total parenteral nutrition formulas of higher osmolality than previously thought can be safely given via the peripheral route for short-term feeding and do not increase the risk of thrombophlebitis.