Out-of-Hospital AAM and Outcomes in TBI, Hemorrhagic Shock
Out-of-Hospital AAM and Outcomes in TBI, Hemorrhagic Shock
Of 2135 patients who received fluid in the trials, 1644 received AAM, including 1116 TBI (764 out-of-hospital AAM, 352 ED AAM) and 528 haemorrhagic shock (296 out-of-hospital AAM, 232 ED AAM). Most AAM in both settings were endotracheal intubation ( Table 1 ). We excluded 26 patients who died in the field, 444 who did not receive AAM in the out-of-hospital or ED settings, and 21 who had missing key covariates.
In the TBI cohort, patients receiving out-of-hospital AAM tended to be more severely injured ( Table 1 ). Mechanism of injury, systolic blood pressure, heart rate and Glasgow Coma Scale were similar between out-of-hospital and ED AAM patients. A large number of patients received air medical transport in the out-of-hospital AAM group. The distribution of the trial interventions drugs (HS) was similar between airway groups.
In the shock cohort, injury severity was also worse in the out-of-hospital AAM group. A large proportion of patients in the ED AAM group sustained penetrating injury. Initial blood pressure and heart rate were similar between groups, although Glasgow Coma Scale was lower in the out-of-hospital AAM group. Out-of-hospital TBI and shock AAM patients were more likely to receive air medical transport. The distribution of the trial interventions was similar.
Among shock patients receiving AAM, 28-day mortality was 34.3%. After adjustment for confounders, out-of-hospital AAM was associated with increased 28-day mortality (OR 5.14; 95% CI 2.42 to 10.90) (Figure 1, see Online Supplementary Appendix 2).
(Enlarge Image)
Figure 1.
Adjusted association of out-of-hospital advanced airway management with traumatic brain injury outcomes (28-day death, and 6-month neurologic and functional outcome) and haemorrhagic shock outcomes (28-day death). AAM, advanced airway management; DRS, Disability Rating Scale; GOSE, Glasgow Outcome Scale Extended (Full models listed in online supplementary appendices 1 and 2).
Among TBI patients receiving AAM, unadjusted 28-day mortality was 26.8%. After adjusting for confounders, out-of-hospital AAM showed a tendency towards increased 28-day mortality (OR 1.57; 95% CI 0.93 to 2.64), but this association was not statistically significant (Figure 1, seeOnline Supplementary Appendix 1). Mean 6-month GOSE and DRS were 4.0 and 12.4. After adjustment for confounders, out-of-hospital AAM showed a tendency towards poorer 6-month DRS (OR 1.63; 95% CI 1.00 to 2.68), but this association was not statistically significant. Out-of-hospital AAM was associated with poorer 6-month GOSE (OR 1.80; 95% CI 1.09 to 2.96).
Out-of-hospital airway management was not associated with elevated initial ED lactate level in either TBI (OR 0.90; 95% CI 0.48 to 1.71) or shock cohorts (1.25; 0.45, 3.42) (see Online Supplementary Appendix 3).
In a sensitivity analysis, we classified cases receiving any out-of-hospital AAM attempts (successful or failed) as out-of-hospital AAM. The absence of association with TBI mortality persisted. The association with increased shock mortality also persisted (see Online Supplementary Appendix 4). We repeated the analysis including only out-of-hospital endotracheal intubations, again finding no association with TBI mortality, but identifying increased odds of 28-day death in the shock cohort. In the subgroup of TBI patients, we repeated the analyses of neurologic and functional outcomes without multiple imputation; while the models again showed a tendency toward worsened outcomes, the association between 6-month GOSE and out-of-hospital AAM was not statistically significant (Appendix 5). Finally, when repeating the analyses excluding prehospital neuromuscular blockade from the multivariable models, the ORs for the associations with out-of-hospital AAM were attenuated, but the inferences remained the same.
Results
Of 2135 patients who received fluid in the trials, 1644 received AAM, including 1116 TBI (764 out-of-hospital AAM, 352 ED AAM) and 528 haemorrhagic shock (296 out-of-hospital AAM, 232 ED AAM). Most AAM in both settings were endotracheal intubation ( Table 1 ). We excluded 26 patients who died in the field, 444 who did not receive AAM in the out-of-hospital or ED settings, and 21 who had missing key covariates.
In the TBI cohort, patients receiving out-of-hospital AAM tended to be more severely injured ( Table 1 ). Mechanism of injury, systolic blood pressure, heart rate and Glasgow Coma Scale were similar between out-of-hospital and ED AAM patients. A large number of patients received air medical transport in the out-of-hospital AAM group. The distribution of the trial interventions drugs (HS) was similar between airway groups.
In the shock cohort, injury severity was also worse in the out-of-hospital AAM group. A large proportion of patients in the ED AAM group sustained penetrating injury. Initial blood pressure and heart rate were similar between groups, although Glasgow Coma Scale was lower in the out-of-hospital AAM group. Out-of-hospital TBI and shock AAM patients were more likely to receive air medical transport. The distribution of the trial interventions was similar.
Among shock patients receiving AAM, 28-day mortality was 34.3%. After adjustment for confounders, out-of-hospital AAM was associated with increased 28-day mortality (OR 5.14; 95% CI 2.42 to 10.90) (Figure 1, see Online Supplementary Appendix 2).
(Enlarge Image)
Figure 1.
Adjusted association of out-of-hospital advanced airway management with traumatic brain injury outcomes (28-day death, and 6-month neurologic and functional outcome) and haemorrhagic shock outcomes (28-day death). AAM, advanced airway management; DRS, Disability Rating Scale; GOSE, Glasgow Outcome Scale Extended (Full models listed in online supplementary appendices 1 and 2).
Among TBI patients receiving AAM, unadjusted 28-day mortality was 26.8%. After adjusting for confounders, out-of-hospital AAM showed a tendency towards increased 28-day mortality (OR 1.57; 95% CI 0.93 to 2.64), but this association was not statistically significant (Figure 1, seeOnline Supplementary Appendix 1). Mean 6-month GOSE and DRS were 4.0 and 12.4. After adjustment for confounders, out-of-hospital AAM showed a tendency towards poorer 6-month DRS (OR 1.63; 95% CI 1.00 to 2.68), but this association was not statistically significant. Out-of-hospital AAM was associated with poorer 6-month GOSE (OR 1.80; 95% CI 1.09 to 2.96).
Out-of-hospital airway management was not associated with elevated initial ED lactate level in either TBI (OR 0.90; 95% CI 0.48 to 1.71) or shock cohorts (1.25; 0.45, 3.42) (see Online Supplementary Appendix 3).
In a sensitivity analysis, we classified cases receiving any out-of-hospital AAM attempts (successful or failed) as out-of-hospital AAM. The absence of association with TBI mortality persisted. The association with increased shock mortality also persisted (see Online Supplementary Appendix 4). We repeated the analysis including only out-of-hospital endotracheal intubations, again finding no association with TBI mortality, but identifying increased odds of 28-day death in the shock cohort. In the subgroup of TBI patients, we repeated the analyses of neurologic and functional outcomes without multiple imputation; while the models again showed a tendency toward worsened outcomes, the association between 6-month GOSE and out-of-hospital AAM was not statistically significant (Appendix 5). Finally, when repeating the analyses excluding prehospital neuromuscular blockade from the multivariable models, the ORs for the associations with out-of-hospital AAM were attenuated, but the inferences remained the same.
