***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
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    Input: BACKGROUND Although early intubation to prevent the mortality that accompanies hypoxia is considered the st and ard of care for severe traumatic brain injury ( TBI ) , the efficacy of this approach remains unproven . METHODS Patients with moderate to severe TBI ( Head/Neck Abbreviated Injury Scale [ AIS ] score 3 + ) were identified from our county trauma registry .  Logistic regression was used to explore the impact of prehospital intubation on outcome , controlling for age , gender , mechanism , Glasgow Coma Scale score , Head/Neck AIS score , Injury Severity Score , and hypotension . Neural network analysis was performed to identify patients predicted to benefit from prehospital intubation . RESULTS A total of 13,625 patients from five trauma centers were included ;  overall mortality was 22.9 % , and 19.3 % underwent prehospital intubation . Logistic regression revealed an increase in mortality with prehospital intubation ( odds ratio , 0.36 ; 95 % confidence interval , 0.32 - 0.42 ; p < 0.001 ) . This was true for all patients , for those with severe TBI ( Head/Neck AIS score 4 + and /or Glasgow Coma Scale score of 3 - 8 ) , and with exclusion of patients transported by aeromedical crews . Patients intubated in the field versus the emergency department had worse outcomes . Neural network analysis identified a subgroup of patients with more significant injuries as potentially benefiting from prehospital intubation . CONCLUSION Prehospital intubation is associated with a decrease in survival among patients with moderate-to-severe TBI . More critically injured patients may benefit from prehospital intubation but may be difficult to identify prospect ively BACKGROUND Prehospital intubation and airway control is routinely performed by paramedics in critically injured patients . Despite the advantages provided by this procedure , numerous potential risks exist when this is performed in the field . We review ed the outcome of patients with severe head injury , to determine whether prehospital intubation is associated with an improved outcome . METHODS A retrospective review of registry data of patients admitted to an urban trauma center with severe head injury ( field Glasgow Coma Scale score of < or = 8 and head Abbreviated Injury Scale score of > or =3 ) was performed . Patients were stratified by methods of airway control performed by prehospital personnel : not intubated , intubated , or unsuccessful intubation .  Mortality was determined for each group . To control for significant variables between these population s , matching and multivariate analysis were performed . RESULTS Patients requiring prehospital intubation or in whom intubation was attempted had an increased mortality ( 81 % and 77 % , respectively ) when compared with nonintubated patients ( 43 % ) . The mortality for patients who had prehospital intubation performed did not demonstrate an improved survival using matching . In fact , intubated patients had a significantly higher relative risk ( RR ) of mortality when compared with nonintubation ( RR = 1.74,p < 0.001 ) and unsuccessful intubation patients ( RR = 1.53 , p = 0.008 ) CONCLUSION For patients with severe head injury , prehospital intubation did not demonstrate an improvement in survival . Further prospect i ve r and omized trials are necessary to confirm these results The value of advanced prehospital life support for patients with severe trauma — for example , endotracheal intubation by ambulance staff — is unclear . Only one r and omised controlled trial was found among 2034 papers in a Cochrane review , concluding that advanced trauma life support by ambulance crews should be initiated only as part of rigorously conducted trials.1 A critical review also failed to show benefit and reported success rates for endotracheal intubation  from 57 % to 92%.2 The review question ed whether prehospital staff could master the required skills . These review s focus on paramedic based systems . The helicopter emergency medical services in London is staffed by doctors ; the service studied 486 trauma patients OBJECTIVE To quantify the occurrence of arterial hypotension and arterial oxygen desaturation in a series of patients with head trauma rescued by helicopter .  DESIGN Prospect i ve , observational study . MATERIAL S AND METHODS  Arterial HbO2 was measured before tracheal intubation at the accident scene in 49 consecutive patients with head injuries .  Arterial pressure  was measured using a sphygmomanometer . MAIN RESULTS Mean arterial saturation was 81 % ( SD 24.24 ) ; mean arterial systolic pressure was 112 mm Hg ( SD 37.25 ) . Airway obstruction was detected in 22 cases . Twenty-seven patients showed an arterial saturation lower than 90 % on the scene , and 12 had a systolic arterial pressure of less than 100 mm Hg . The outcome was significantly worse in cases of hypotension , desaturation , or both . CONCLUSIONS Hypoxemia and shock are frequent findings on patients at the accident scene . Hypoxemia is more frequently detected and promptly corrected , white arterial hypotension is more difficult to control . Both insults may have a significant impact on outcome CONTEXT Endotracheal intubation ( ETI ) is widely used for airway management of children in the out-of-hospital setting , despite a lack of controlled trials demonstrating a positive effect on survival or neurological outcome . OBJECTIVE To compare the survival and neurological outcomes of pediatric patients treated with bag-valve-mask ventilation ( BVM )  with those of patients treated with BVM followed by ETI .  DESIGN Controlled clinical trial , in which patients were assigned to interventions by calendar day from March 15 , 1994 , through January 1 , 1997 . SETTING Two large , urban , rapid-transport emergency medical services ( EMS ) systems . PARTICIPANTS A total of 830 consecutive patients aged 12 years or younger or estimated to weigh less than 40 kg who required airway management ; 820 were available for follow-up . INTERVENTIONS Patients were assigned to receive either BVM ( odd days ; n = 410 ) or BVM followed by ETI ( even days ; n = 420 ) . MAIN OUTCOME MEASURES Survival to hospital discharge and neurological status at discharge from an acute care hospital compared by treatment group . RESULTS There was no significant difference in survival between the BVM group ( 123/404 [ 30 % ] ) and the ETI group ( 110/416 [ 26 % ] ) ( odds ratio [ OR ] , 0.82 ; 95 % confidence interval [ CI ] , 0.61 - 1.11 ) or in the rate of achieving a good neurological outcome  ( BVM , 92/404 [ 23 % ] vs ETI , 85/416 [ 20 % ] ) ( OR , 0.87 ; 95 % CI , 0.62 - 1.22 ) . CONCLUSION These results indicate that the addition of out-of-hospital ETI to a paramedic scope of practice that already includes BVM did not improve survival or neurological outcome of pediatric patients treated in an urban EMS system As triage and resuscitation protocol s evolve , it is critical to determine the major extracranial variables influencing outcome in the setting of severe head injury . We prospect ively studied the outcome from severe head injury ( GCS score < or = 8) in 717 cases in the Traumatic Coma Data Bank . We investigated the impact on outcome of  hypotension  ( SBP < 90 mm Hg ) and  hypoxia  ( Pao2 < or = 60 mm Hg or apnea or cyanosis in the field ) as secondary brain insults , occurring from injury through resuscitation .  Hypoxia and hypotension were independently associated with significant increases in morbidity and mortality from severe head injury . Hypotension was profoundly detrimental , occurring in 34.6 % of these patients and associated with a 150 % increase in mortality . The increased morbidity and mortality related to severe trauma to an extracranial organ system appeared primarily attributable to associated hypotension . Improvements in trauma care delivery over the past decade have not markedly altered the adverse influence of hypotension . Hypoxia and hypotension are common and detrimental secondary brain insults .  Hypotension  , particularly , is a major determinant of outcome from severe head injury . Resuscitation protocol s for brain injured patients should assiduously avoid hypovolemic shock on an absolute basis OBJECTIVE Determine whether prehospital advanced life support ( ALS ) improves the survival of major trauma patients and whether it is associated with longer on-scene times . METHODS A 36-month retrospective study of all major trauma patients who received either prehospital bag-valve-mask ( BVM ) or endotracheal intubation ( ETI ) and were transported by paramedics to our Level I trauma center . Logistic regression analysis determined the association of prehospital ALS with patient survival . RESULTS Of 9,451 major trauma patients , 496 ( 5.3 % ) had either BVM or ETI . Eighty-one percent received BVM , with a mean Injury Severity Score of 29 and a mortality rate of 67 % ; 93 patients ( 19 % ) underwent successful ETI , with a mean Injury Severity Score of 35 and a mortality rate of 93 % . Adjusted survival for patients who had BVM was 5.3 times more likely than for patients who had ETI ( 95 % confidence interval , 2.3 - 14.2 , p = 0.00 ) . Survival among patients who received intravenous fluids was 3.9 times more likely than those who did not ( p = not significant ) . Average on-scene times for patients who had ETI or intravenous fluids were not significantly longer than those who had BVM or no intravenous fluids . CONCLUSION ALS procedures can be performed by paramedics on major trauma patients without prolonging on-scene time , but they do not seem to improve survival BACKGROUND Pre-hospital endotracheal intubation for the purpose of controlled ventilation may prevent secondary brain injury in patients with severe head injury . In view of the limited monitoring devices utilized in the pre-hospital setting , little is known about the ' quality ' of controlled ventilation initiated in the pre-hospital setting . METHODS Included in this prospect i ve study were 122 trauma patients with severe head injury ( abbreviated injury scale score > or = 3 ) . In all cases , the pre-hospital treatment included endotracheal intubation in the field . Upon hospital admission , and maintaining the same ventilation mode and setting initiated in the pre-hospital setting , arterial blood gas sample s were taken . RESULTS ' Optimal ' oxygenation ( PaO2 > 100 mm Hg ) was achieved in 85.2 % and ' adequate ' ventilation ( PaCO2 35 - 45 mm Hg ) in 42.6 % of the patients upon hospital admission . ' Optimal ' oxygenation as well as ' adequate ' ventilation was achieved in 37.7 % of the study population . Hypoxaemia ( PaO2 < 60 mm Hg ) was observed in 2.5 % , hypercapnia ( PaCO2 > 45 mm Hg ) in 16.4 % , and hypocapnia ( PaCO2 < 35 mm Hg ) in 40.9 % of the study patients . The incidence of hypocapnia was significantly more frequent in polytraumatized patients .  Hypocapnia as well as hypercapnia was significantly more frequent in patients with associated pulmonary contusion . CONCLUSIONS Endotracheal intubation and controlled ventilation of the lungs initiated in the pre-hospital setting do not guarantee optimal oxygenaton and ventilation in patients with severe head injury STUDY OBJECTIVE We evaluate the ability of paramedic rapid sequence intubation ( RSI ) to facilitate intubation of patients with severe head injuries in an urban out-of-hospital system . METHODS Adult patients with head injuries were prospect ively enrolled over a 1-year period by using the following inclusion criteria : Glasgow Coma Scale score of 3 to 8 , transport time of greater than 10 minutes , and inability to intubate without RSI .  Midazolam and succinylcholine were administered before laryngoscopy , and rocuronium was given after tube placement was confirmed by means of capnometry , syringe aspiration , and pulse oximetry . The Combitube was used as a salvage airway device . Outcome measures included intubation success rates , preintubation and postintubation oxygen saturation values , arrival arterial blood gas values , and total out-of-hospital times for patients intubated en route versus on scene . RESULTS Of 114 enrolled patients , 96 ( 84.2 % ) underwent successful endotracheal intubation , and 17 ( 14.9 % ) underwent Combitube intubation , with only 1 ( 0.9 % ) airway failure . There were no unrecognized esophageal intubations . On arrival at the trauma center , median oxygen saturation was 99 % , mean arrival PO2 was 307 mm Hg , and mean arrival PCO2 was 35.8 mm Hg . Total out-of-hospital times were higher when RSI was performed on scene ( 26 versus 13 minutes ) . CONCLUSION Paramedics can use RSI protocol s that include neuromuscular blocking and sedative agents to facilitate intubation of patients with head injuries OBJECTIVE To evaluate the effect of paramedic rapid sequence intubation ( RSI ) on outcome in patients with severe traumatic brain injury . METHODS Adult major trauma victims were prospect ively enrolled over two years using the following inclusion criteria : Glasgow Coma Scale ( GCS 
    Output:
    
CONCLUSIONS Overall , the available evidence did not support any benefit from pre-hospital intubation and mechanical ventilation after TBI .