Table 2.
Post Hoc Comparison of Outcomes Stratified by Duration of Peripheral Norepinephrine Infusion
| Variable | ≤ 24 h (n = 508) | > 24 h (n = 127) | Effect Estimate (95% CI) |
|---|---|---|---|
| Infusion duration, h | 3.8 (1.5-9.7) | 42.4 (32.4-66.1) | a |
| Maximum dose, μg/min | 10 (5-15) | 10 (7-15) | –1.2 (–2.9 to 0.6)b |
| Extravasation events | 24 (4.7) | 11 (8.7) | 3.9 (–0.4 to 10.3)c |
| Extravasation incidence, per 1,000 d of peripheral infusion (95% CI) | 176.4 (113.1-262.5) | 33.8 (16.9-60.4) | 0.19 (0.09-0.39)d |
| Highest infiltration gradee | 8.0 (–23.3 to 39.1)f | ||
| 0 | 5 (20.8) | 0 (0) | |
| 1 | 10 (41.7) | 6 (54.5) | |
| 2 | 8 (33.3) | 5 (45.5) | |
| 3 | 0 (0) | 0 (0) | |
| 4 | 1 (4.2) | 0 (0) |
Data are presented as No. (%) or median (interquartile range), unless otherwise indicated. Effect estimates with 95% CIs compare the effect in the group of patients receiving peripheral norepinephrine for > 24 h with the effect in the group of patients receiving peripheral norepinephrine for ≤ 24 h.
Only descriptive statistics for the groups without an effect estimate are reported because of the expected between-group difference resulting from how the cohorts were generated.
Mean difference.
Absolute percentage difference.
Incidence rate ratio.
Evaluated only in the 35 patients experiencing an extravasation event (n = 24 and n = 11, respectively). One patient was graded as showing infiltration grade 4 by the bedside nurse, but was transitioned to comfort care measures and died before being evaluated by the study team. Study site policy suggests marking all vasopressor extravasations as infiltration grade 4 in the electronic medical record initially regardless of degree of tissue injury, so it is unclear whether this truly constituted significant tissue damage.
Absolute percentage difference for highest infiltration grade ≥ 2.