Inappropriate Prehospital Ventilation in Severe Traumatic Brain Injury Increases In-Hospital Mortality

Abstract

In the setting of acute brainstem herniation in traumatic brain injury (TBI), the use of hyperventilation to reduce intracranial pressure may be life-saving. However, undue use of hyperventilation is thought to increase the incidence of secondary brain injury through direct reduction of cerebral blood flow. This is a retrospective review determining the effect of prehospital hyperventilation on in-hospital mortality following severe TBI. All trauma patients admitted directly to a single level 1 trauma center from January 2000 to January 2007 with an initial Glasgow Coma Scale (GCS) score <or=8 were included in the study (n = 77). Patients without documented or with late (>20 min) arterial blood gas at presentation (n = 12) were excluded from the study. The remaining population (n = 65) was sorted into three groups based on the initial partial pressure of carbon dioxide: hypocarbic (Pco(2) < 35 mm Hg), normocarbic (Pco(2) 35-45 mm Hg), and hypercarbic (Pco(2) > 45 mm Hg). Outcome was based on mortality during hospital admission. Survival was found to be related to admission Pco(2) in head trauma patients requiring intubation (p = 0.045). Patients with normocarbia on presenting arterial blood gas testing had in-hospital mortality of 15%, significantly improved over patients presenting with hypocarbia (in-hospital mortality 77%) or hypercarbia (in-hospital mortality 61%). Although there are many reports of the negative impact of prophylactic hyperventilation following severe TBI, this modality is frequently utilized in the prehospital setting. Our results suggest that abnormal Pco(2) on presentation after severe head trauma is correlated with increased in-hospital mortality. We advocate normoventilation in the prehospital setting.

Impact of pre-hospital oxygenation and ventilation status on outcome in patients with isolated severe traumatic brain injury

“…In addition, an increase in cerebral blood flow in the hypoventilated group could raise ICP above the critical threshold and increase mortality. (29) Findings from our study do not support the results from previously mentioned studies. Ventilation status failed to significantly affect survival and functional outcome in patients after isolated TBI.…”

“…The possible detrimental impact of prehospital intubation is associated with the risk of hyperventilation and positive pressure ventilation. Hyperventilation (9) and hypoventilation (28,29) in intubated patients with TBI increase the mortality rate. Only targeted prehospital ventilation is associated with lower mortality rate.…”

Correlation between Arterial Blood Gas Analysis and Outcome in patients with severe head trauma

“…These findings are in line with similar reports. [8,9] Dumont et al [5] studied 65 patients with traumatic brain injury in a retrospective manner to determine the effect of prehospital hyperventilation on in-hospital mortality. According to their findings, survival was related to admission PCO 2 in patients requiring intubation.…”

“…[3,4] The identification of reliable predictors of outcome after head injury is essential to appropriate counseling of family members and employing resources. Some authors believe that arterial PCO 2 at the time of admission is a significant prognostic factor in patients with traumatic head injury, [5] whereas others have denied the parameters of arterial blood gas (ABG) as reliable indicators of short term outcome in these patients. [6] The present prospective study aimed to investigate a possible association between the parameters of ABG and outcome in patients with severe head injury.…”

Ventilación mecánica en el paciente con lesión cerebral aguda

“…En el ambiente pre-hospitalario, la PaCO 2 se correlaciona con mayor mortalidad hospitalaria. Así, pacientes que ingresan con PaCO 2 < 35 mmHg, la mortalidad fue 77%, con hipercapnia 61% y con normocapnia de 15% 22 . En presencia de una disminución del FSC en pacientes con LCA en las primeras horas de evolución, se hace recomendable evitar la hiperventilación.…”