Table 4. Exploratory analysis of number of attempts and incidence of hematoma.
| Number of attempts | DNTP group (n = 128) | Hematoma, n | Palpation group (n = 128) | Hematoma, n | Total (n = 256) | Hematoma, n |
|---|---|---|---|---|---|---|
| 1 | 110 (85.9) | 0 | 75 (58.6) | 0 | 185 (72.3) | 0 |
| 2 | 11 (8.6) | 3 | 17 (13.3) | 6 | 28 (10.9) | 9 |
| 3 | 6 (4.7) | 5 | 18 (14.1) | 12 | 24 (9.4) | 17 |
| 4 | 0 (0.0) | 0 | 10 (7.8) | 8 | 10 (3.9) | 8 |
| 5 | 1 (0.8) | 1 | 6 (4.7) | 4 | 7 (2.7) | 5 |
| 6 | 0 (0.0) | 0 | 2 (1.6) | 1 | 2 (0.8) | 1 |
| N ≥ 2* | 18 (14.1) | 9 (50) | 53 (41.4) | 31 (58.5) | 71 (27.7) | 40 (56.3) |
Values are presented as number (percentage, %).
DNTP, dynamic needle tip positioning; n, number.
*For cases that required two or more attempts, 40 (56.3%) out of 71 cases developed a hematoma after radial artery cannulation, including 9 (50%) out of 18 cases in the DNTP group and 31 (58.5%) out of 53 cases in the palpation group.