Table 4.
Negative binomial regression model exploring the risk factors for the four types of asynchronies.
| Variables | RR for IEE (95% CI) | p | RR for DT (95% CI) | p | RR for SC (95% CI) | p | RR for PC (95% CI) | p |
|---|---|---|---|---|---|---|---|---|
| Day hours (night as reference)* | 1.063 (1.026, 1.101) | <0.001 | 0.994 (0.964, 1.024) | 0.666 | 0.963 (0.923, 1.006) | 0.084 | 1.243 (1.196, 1.293) | <0.001 |
| Ventilation mode (PCV as reference) | 1.186 (1.111, 1.267) | <0.001 | 0.402 (0.381, 0.424) | <0.001 | 1.388 (1.285, 1.499) | <0.001 | 4.398 (4.103, 4.715) | <0.001 |
| TV (<6 ml/kg as reference) | ||||||||
| 6–8 ml/kg | 0.654 (0.612, 0.699) | <0.001 | 0.718 (0.684, 0.753) | <0.001 | 1.139 (1.06, 1.223) | <0.001 | 1.43 (1.339, 1.526) | <0.001 |
| 8–10 ml/kg | 0.425 (0.392, 0.46) | <0.001 | 0.541 (0.511, 0.573) | <0.001 | 1.47 (1.349, 1.6) | <0.001 | 1.87 (1.725, 2.026) | <0.001 |
| >10 ml/kg | 0.239 (0.215, 0.267) | <0.001 | 0.419 (0.387, 0.454) | <0.001 | 1.519 (1.346, 1.715) | <0.001 | 5.159 (4.575, 5.818) | <0.001 |
| WOB (<10 J/ml/kg as reference) | ||||||||
| 10–15 J/ml/kg | 1.26 (1.182, 1.343) | <0.001 | 0.948 (0.904, 0.995) | 0.04 | 0.473 (0.442, 0.506) | <0.001 | 0.415 (0.388, 0.444) | <0.001 |
| 15–20 J/ml/kg | 1.167 (1.068, 1.275) | <0.001 | 1.239 (1.162, 1.322) | <0.001 | 0.556 (0.507, 0.61) | <0.001 | 0.216 (0.197, 0.237) | <0.001 |
| >20 J/ml/kg | 0.867 (0.776, 0.969) | 0.008 | 2.114 (1.949, 2.292) | <0.001 | 1.206 (1.067, 1.364) | 0.003 | 0.154 (0.136, 0.174) | <0.001 |
| PEEP (≤5 cm H2O as reference) | ||||||||
| 5–10 cm H2O | 0.638 (0.61, 0.668) | <0.001 | 1.236 (1.191, 1.282) | <0.001 | 1.218 (1.155, 1.286) | <0.001 | 1.443 (1.369, 1.521) | <0.001 |
| >10 cm H2O | 1.063 (0.94, 1.205) | 0.313 | 2.018 (1.823, 2.238) | <0.001 | 6.702 (5.722, 7.869) | <0.001 | 4.446 (3.875, 5.116) | <0.001 |
| Plateau pressure (<20 cm H2O as reference) | ||||||||
| 20–30 cm H2O | 1.39 (1.317, 1.467) | <0.001 | 0.64 (0.613, 0.668) | <0.001 | 0.538 (0.506, 0.571) | <0.001 | 1.354 (1.271, 1.441) | <0.001 |
| >30 cm H2O | 0.768 (0.703, 0.838) | <0.001 | 0.318 (0.296, 0.341) | <0.001 | 0.079 (0.071, 0.088) | <0.001 | 0.96 (0.87, 1.06) | 0.401 |
RR, relative risk; CI, confidence interval; DT, double triggering; IEE, ineffective effort; SC, short cycling; PC, prolonged cycling; PEEP, positive end expiratory pressure; WOB, work of breathing; VCV, volume control ventilation; PCV, pressure control ventilation; VC+, volume control plus; APRV, airway pressure release ventilation; PSV, pressure support ventilation; CPAP, continuous positive airway pressure; TV, tidal volume. Four negative binomial regression models were built by using each type of asynchrony as the dependent variable. All variables in the table were entered into the models to adjust for confounding effects.
Day hours were categorized by visually inspecting the asynchrony–day hour trend curve.