Table 3.
Univariate analysis of factors associated with failed anesthesia (N = 440).
| Factors | Failed spinal anesthesia (n = 110) | Control (n = 330) | P value | Crude OR (95% CI) |
|---|---|---|---|---|
| Age | ||||
| ≤30 yr | 49 (44.5) | 123 (37.3) | .176 | 1.4 (0.9–2.1) |
| > 30 yr | 61 (55.5) | 207 (62.7) | 1 | |
| BMI | ||||
| ≤29.5 kg/m2 | 82 (74.5) | 203 (41.5) | .013 | |
| >29.5 kg/m2 | 28 (25.5) | 127 (38.5) | 1.8 (1.1–2.9) | |
| History of cesarean delivery | .909 | |||
| Yes | 40 (63.6) | 122(37) | 1 | |
| No | 70 (36.4) | 208(63) | 1.1 (0.7–1.6) | |
| Twin | ||||
| Yes | 5 (4.5) | 13 (3.9) | .783 | 1.2 (0.4–3.3) |
| No | 105 (95.5) | 137 (96.1) | 1 | |
| Emergency cesarean delivery | ||||
| Yes | 66 (60) | 166 (50.3) | .078 | 1.5 (0.9–2.3) |
| No | 44 (40) | 164 (49.7) | 1 | |
| Out of office hours | ||||
| Yes | 53 (48.2) | 149 (45.2) | .581 | 1.1 (0.7–1.7) |
| No | 57 (51.8) | 181(54.8) | 1 | |
| Anesthesiologist | ||||
| First- and second-year resident | 45 (40.9) | 202 (61.2) | <.001 | 1 |
| Third-year resident | 64 (58.2) | 124 (38.6) | 2.3 (1.5–3.6) | |
| Consultant | 1 (0.9) | 4 (1.2) | 1.1 (0.1–10.3) | |
| Needle type | ||||
| Whitacre no. 25 | 10 (9.1) | 46 (13.9) | .413 | 1 |
| Quincke no. 26 | 9 (8.2) | 27 (8.2) | 1.5 (0.6–4.2) | |
| Quincke no. 27 | 91 (82.7) | 257 (77.9) | 1.6 (0.8–3.4) | |
| Tubal sterilization | ||||
| Yes | 31 (28.2) | 81 (24.5) | .448 | 1 |
| No | 79 (71.8) | 249 (75.4) | 1.2 (0.7–1.9) |
The cutpoint of patient age and BMI used receiver operating characteristic curve (ROC curve).
BMI = body mass index, CI = confidence interval, OR = odd ratio, ROC = receiver operating characteristic.