Table 3.
Baseline procedural characteristics of study cohort stratified by annual hospital volume
| Hospital Annual Volume | p-value | ||||
|---|---|---|---|---|---|
| <150 cases/year n=4,460 | ≥150-300 cases/year n=12,787 | ≥300-500 cases/year n=21,391 | ≥500 cases/year n=17,815 | ||
| Procedure-Type Risk Group--no. (%) | < 0.001 | ||||
| Risk Group 1 | 1,550 (34.8) | 4,590 (35.9) | 8,649 (40.4) | 8,490 (47.7) | |
| Risk Group 2 | 1,883 (42.2) | 4,881 (38.2) | 7,011 (32.8) | 4,562 (25.6) | |
| Risk Group 3 | 766 (17.2) | 2,466 (19.3) | 4,250 (19.9) | 3,391 (19.0) | |
| Risk Group 4 | 261 (5.9) | 850 (6.6) | 1,481 (6.9) | 1,372 (7.7) | |
| Procedure Status--no. (%)* | < 0.001 | ||||
| Elective | 3,906 (87.8) | 11,228 (88.6) | 18,245 (85.8) | 14,797 (83.3) | |
| Urgent | 480 (10.8) | 1,159 (9.1) | 2,355 (11.1) | 2,435 (13.7) | |
| Emergent | 61 (1.4) | 259 (2.0) | 593 (2.8) | 503 (2.8) | |
| Salvage | 2 (0.0) | 26 (0.2) | 64 (0.3) | 27 (0.2) | |
| Procedure Time-- mean ± s.d.† | 100.3 ± 61.6 | 96.5 ± 64.0 | 92.0 ± 64.5 | 84.8 ± 66.4 | < 0.001 |
| Anesthesiologist Present--no. (%)‡ | 3,437 (77.2) | 12,137 (95.1) | 20,247 (94.8) | 15,714 (88.3) | < 0.001 |
| Airway Management--no. (%) | < 0.001 | ||||
| Spontaneous Respirations | 1,153 (25.9) | 1,920 (15.0) | 2,690 (12.6) | 3,147 (17.7) | |
| Bag Mask Ventilation | 3 (0.1) | 165 (1.3) | 19 (0.1) | 28 (0.2) | |
| CPAP | 3 (0.1) | 4 (0.0) | 14 (0.1) | 21 (0.1) | |
| Laryngeal Mask Airway | 144(3.2) | 836 (6.5) | 1,330 (6.2) | 1,361 (7.6) | |
| Elective Intubation at case start | 2,931 (65.7) | 9,193 (71.9) | 15,598 (72.9) | 11,315 (63.5) | |
| Tracheostomy | 45 (1.0) | 165 (1.3) | 223 (1.0) | 335 (1.9) | |
| Previously Intubated | 199 (4.5) | 840 (6.6) | 1,497 (7.0) | 1,632 (9.2) | |
Abbreviations: no., number; s.d., standard deviation; CPAP, continuous positive airway pressure
*
313 patients (11 from small, 115 from medium, 134 from large, 53 from very large volume programs) with missing information for procedure status
†
279 patients (26 from small, 72 from medium, 74 from large, 107 from very large volume programs) with missing information for procedure time
‡
96 patients (7 from small, 27 from medium, 42 from large, 20 from very large volume programs) with missing information for Anesthesiologist present