Brain Injury review

This abstract is taken from Davis et al from the Hoyt lab at the department of emergency at UCSD. The pubmed ID is 16484927

OBJECTIVES: An increase in mortality has been reported with early intubation in severe traumatic brain injury, possibly due to suboptimal ventilation. This analysis explores the impact of early ventilation on outcome in moderate to severe traumatic brain injury.

DESIGN: Retrospective, registry-based analysis.

SETTING: This study was conducted in a large county trauma system that includes urban, suburban, and rural jurisdictions.

PATIENTS: Nonarrest trauma victims with a Head Abbreviated Injury Score of > or =3 were identified from our county trauma registry.

INTERVENTIONS: Intubated patients were stratified into 5 mm Hg arrival PCO(2) increments. Logistic regression was used to calculate odds ratios for each increment, adjusting for age, gender, mechanism of injury, year of injury, preadmission Glasgow Coma Scale score, hypotension, Head Abbreviated Injury Score, Injury Severity Score, PO(2), and base deficit. Increments with the highest relative survival were used to define the optimal PCO(2) range. Outcomes for patients with arrival PCO(2) values inside and outside this optimal range were then explored for both intubated and nonintubated patients, adjusting for the same factors as defined previously. In addition, the independent outcome effect of hyperventilation and hypoventilation was assessed.

MEASUREMENTS AND MAIN RESULTS: A total of 890 intubated and 2,914 nonintubated patients were included. Improved survival was observed for the arrival PCO(2) range 30-49 mm Hg. Patients with arrival PCO(2) values inside this optimal range had improved survival and a higher incidence of good outcomes. Conversely, there was no improvement in outcomes for patients within this optimal PCO(2) range for nonintubated patients after adjusting for all of the factors defined previously. Both hyperventilation and hypoventilation were associated with worse outcomes in intubated but not nonintubated patients. The proportion of arrival PCO(2) values within the optimal range was lower for intubated vs. nonintubated patients.

CONCLUSIONS: Arrival hypercapnia and hypocapnia are common and associated with worse outcomes in intubated but not spontaneously breathing patients with traumatic brain injury.
he full article is availble in the April 2006 edition of critical care medicine, starting at page number 1202.

This abstract is by Shankar, churchill and Deshpande, who work at the Pediatric critical care unit at the children’s hospital in Vanderbilt, Tennessee. The pubmed number is 16614808.

OBJECTIVE: To describe the use of inhaled isoflurane in a series of children with life-threatening asthma.

DESIGN:Retrospective case series.

SETTING: Pediatric intensive care unit of a tertiary-care children’s hospital. Ten children ranging in age from 1 to 16 years with 11 episodes of severe asthma requiring invasive mechanical ventilation in the pediatric intensive care unit over a 5-year period. RESULTS: Isoflurane resulted in an improvement in arterial pH and a reduction in partial pressure of arterial carbon dioxide (PaCO(2)) in all the 11 instances. This effect was sustained in 10 cases and led to clinical improvement and rapid weaning from mechanical ventilation. One child failed to show sustained response and was placed on veno-venous extracorporeal membrane oxygenation. One child died secondary to anoxic brain injury sustained prior to hospitalization. Hypotension was the major side effect, and occurred in 8 children necessitating vasopressor support.

CONCLUSIONS: Isoflurane improves arterial pH and reduces partial pressure of arterial carbon dioxide in mechanically ventilated children with life-threatening status asthmaticus who are not responsive to conventional management.

The full text of the article is available in the April 2006 edition of  Intensive Care Medicine.

This abstract is from Pinto et al from the University of Sao Paulo. It is available in full from the Journal of Trauma, issue number 60, starting on on page number 758.
BACKGROUND

The devastating effects of hypotension on head-trauma-related mortality are well known. This study evaluates the systemic and cerebral hemodynamic responses to volume replacement with 3% hypertonic saline (HSS) or lactated Ringer’s solution (LR), during the acute phase of hemorrhagic shock (HS) associated with traumatic brain injury.

 METHODS

Fifteen dogs were assigned to one of three groups (n = 5, each) according to the volume replacement protocol, infused after traumatic brain injury  (brain fluid percussion, 4 atm) and epidural balloon to an intracranial pressure (ICP) higher than 20 mm Hg and HS, induced by blood removal to a mean arterial pressure (MAP) of 40 mm Hg in 5 minutes: Group HS+traumatic brain injury +HSS (8 mL/kg of 3% HSS), HS+TBI+LR (16 mL/kg LR), and Group HS+TBI (controls, no fluids).

We simulated treatment during prehospital and early hospital admission. Groups HS+ traumatic brain injury  and HS+TBI+LR received shed blood infusion to a target hematocrit of 30%. Measurements included shed blood volume, fluid volume infused to restore MAP, MAP, cardiac output, cerebral perfusion pressure, cerebral and systemic lactate, and oxygen extraction ratios.

RESULTS

Fluid replacement with HSS 3% or LR promoted major hemodynamic benefits over control animals without luids. Cerebral perfusion pressure was higher than controls and similar between treated groups; however, HSS 3% infusion was associated with lower ICP during the “early hospital phase” and a higher serum sodium and osmolarity. CONCLUSION:: In the event of severe head trauma and hemorrhagic shock, the use of HSS 3% and larger volumes of LR promote similar systemic and cerebral hemodynamic benefits. However, a lower ICP was observed after HSS 3% than after LR.

The pubmed number of this article is 16612295