prehospital intubation ( phi ) is an essential component of advanced life support for the initial management of severely injured trauma patients .
the primary goal of phi is to stabilize the patient and prevent physiological and hemodynamic deterioration .
though , on - scene airway - management decisions are mostly controversial in marginal cases .
several studies have reported an increased failure rates and severe complications in trauma patients who underwent phi .
many factors are thought to explain in part the high risk of worse outcomes in phi such as severe head injury , malpositioning of the endotracheal tube , direct blocking of the respiratory system , and aspiration of gastric contents .
in addition , herff et al . , observed suboptimal airway management training and inexperience of the prehospital emergency medical services ( emss ) team associated with high failure and complication rates in phi . on the contrary , sise et al . , advocated early intubation to be safe and effective in trauma patients .
worldwide , blunt trauma constitutes a significant cause of morbidity and mortality among young population .
qatar , a rapidly developing middle eastern country , is also experiencing high incidence of blunt trauma due to road traffic crashes and work - related accidents . despite great improvement in trauma care ,
qatar still has one of the highest rates of road traffic- related death in the region with death rate of 19 per 100,000 populations . in order to provide superior trauma services , a dedicated trauma system has been established in qatar late in 2007 with advanced ems department .
a world health organization report in 2011 stated that according to quality indicators , the length of stay in the hospital for trauma patients has also got reduced from an average of 12 days in 2007 to 8 days in 2011 .
trauma center has achieved a 50% reduction in the number of deaths of patients admitted to the hospital with serious traumatic injury in five years .
the impact of scene intubation in improving outcome of severely injured patients has not been adequately evaluated in the arab middle east .
so , the present study aims to analyze the patterns and outcome of phi compared with the emergency room intubation ( eri ) over a 2-year period in qatar .
this study was approved by the medical research center at hamad medical corporation , qatar ( irb # 12238 ) .
medical records of all trauma patients who required intubation between january 2010 and december 2011cwere retrospectively reviewed .
the study specifically analyzed and compared posttraumatic phi to eri at hamad general hospital ; the only level i trauma center in the state of qatar .
patients were classified according to the site of intubation into two groups ; group-1(phi ) and group-2 ( eri ) .
inclusion criteria included any traumatic injury that required intubation [ i.e. low glasgow coma scale ( gcs ) , and desaturation ] .
intubation was carried on either at the location of injury on the scene ( phi ) or on arrival to the er . exclusion criteria included patients who died at the scene before intubation , patients with incomplete data , and patients who were intubated during the hospital course ( surgical wards , intensive care unit , or operating room ) .
data such as age , gender , mechanism of injury , mode of transportation , activation , response , and transportation intervals , total ems and scene time , injury severity scoring ( iss ) , abbreviated injury score ( ais ) , type of injuries , hospital length of stay ( los ) , intensive care unit ( icu ) los , morbidity , and mortality were analyzed .
our ems service is following up - to - date evidence - based standard treatment protocols and is staffed by critical care paramedics as well as emergency medical technicians .
recently , helicopter ems ( hems ) staffed by critical care paramedics has been launched in qatar .
the training program includes rapid sequence intubation ( rsi ) and the application of a comprehensive critical care medication formulary and the management of critical care patients during transfer .
dispatch records of the emergency room were utilized to calculate the ems intervals , which were based on standard ems definitions .
it included activation interval ( time of 999 call received at dispatch to alarm activation at ems first response agency ) , response interval ( time from alarm activation to arrival of first responding vehicle on scene ) , on - scene interval ( time arrival of first ems responding vehicle on scene until leaving the scene ) , and transport interval ( time leaving the scene to vehicle arrival at the receiving hospital ) .
the total ems interval is considered as time from call received to arrival at the receiving hospital .
further , categorical versions of total ems time ( 60 versus > 60 min ) and response interval ( < 4 , 4 - 8 , and > 8 min ) were also evaluated as described previously by newgard et al .
data were presented as proportions , mean  standard deviation ( sd ) or median as appropriate .
baseline demographic characteristics , clinical presentation , and outcomes were compared according to site of intubation , scene time , and ems time using the student - t test for continuous variables and pearson 's chi - square ( x ) test was used for categorical variables .
a significant difference was considered when the two - tailed p value was less than 0.05 .
data analysis was carried out using the statistical package for social sciences version 18 ( spss inc .
it included activation interval ( time of 999 call received at dispatch to alarm activation at ems first response agency ) , response interval ( time from alarm activation to arrival of first responding vehicle on scene ) , on - scene interval ( time arrival of first ems responding vehicle on scene until leaving the scene ) , and transport interval ( time leaving the scene to vehicle arrival at the receiving hospital ) .
the total ems interval is considered as time from call received to arrival at the receiving hospital .
further , categorical versions of total ems time ( 60 versus > 60 min ) and response interval ( < 4 , 4 - 8 , and > 8 min ) were also evaluated as described previously by newgard et al .
data were presented as proportions , mean  standard deviation ( sd ) or median as appropriate .
baseline demographic characteristics , clinical presentation , and outcomes were compared according to site of intubation , scene time , and ems time using the student - t test for continuous variables and pearson 's chi - square ( x ) test was used for categorical variables .
a significant difference was considered when the two - tailed p value was less than 0.05 .
data analysis was carried out using the statistical package for social sciences version 18 ( spss inc .
between january 2010 and december 2011 , a total of 570 trauma patients were intubated ; of them 239 and 243 patients were intubated at the scene ( phi ) and in the er , respectively .
there were 88 patients excluded from the analysis ( 80 patients were intubated during hospital course and eight patients had missing relevant data .
the mean age was 32  14.6 ( median 29 ; range 1 - 92 ) years with 94% males .
study design and outcome blunt trauma ( 96% ) was the major cause of injury which included motor vehicle crash ( 42% ) , pedestrians hit by vehicle ( 21% ) , fall from height ( 20% ) , and fall of heavy objects ( 4% ) .
[ table 1 ] shows the demographic characteristics , presentation , and outcomes of trauma patients according to the site of intubation i.e. phi ( group-1 ) vs eri ( group-2 ) .
the majority of patients ( 80% ) were transported by ground ems in group 1 and 2 .
hems use was more frequent in group 1 , whereas private transportation was observed only in group 2 .
higher number of patients in group-1 were shifted to the hospital by hems ( 20% vs 11% ; p = 0.001 ) .
number of patients shifted to the operating room ( 25% vs. 13% ) and icu ( 70% vs. 54% ; p = 0.001 ) were significantly higher in group-2 .
the rates of head injury ( 74% vs. 61% ; 0.003 ) and multiple trauma ( 81% vs 69.5% ; p = 0.004 ) were significantly greater in group-1 whereas , solid organ injuries ( 33% vs 23% ; p = 0.02 ) occurred more often in group-2 .
demographics , presentation , and injury type according to site of intubation for all the patients [ table 2 ] shows the clinical profile and outcome based on the mode of transportation .
patients who were transported by hems comprised only 14% of the study population and had greater rate of head injury and multiple trauma in comparison to other mode of transportation . [ table 3 ] shows the prehospital intervals and outcome for trauma patients according to the location of intubation .
patients in group-1 had significantly longer activation , response , scene , and total ems times in comparison to group 2 patients .
moreover , response time ( > 8 min ) was also higher in group-1 patients ( 75% vs. 59% ; p = 0.01 ) .
greater mean injury severity scoring and head ais and lower gcs were observed in group-1 whereas ; patients in group-2 had higher chest ais .
clinical profile and mortality based on the mode of transportation prehospital time intervals and outcome based on the location of intubation there were 180 ( out of 570 ) deaths ( 31.6% ) during the study period .
this mortality rate increased to 35.5% ( 171 out of 482 ) after excluding those who were intubated during hospitalization and who had incomplete data .
the mortality was higher in group-1 in comparison to group-2 ( 53% vs. 18.5% , p = 0.001 ) [ figure 1 ] .
moreover , mortality rate ( 24% vs. 9% , p = 0.02 ) was significantly higher in patients who experienced prolonged scene time ( 20 min ) [ table 4 ] .
mechanism of injury and outcome according to scene time univariate analysis demonstrated that phi , head injury ; higher iss , lower initial gcs and prolonged scene time were associated with high mortality .
however , in multivariate logistic regression analysis , only initial gcs [ odds ratio ( or ) 0.78 , p = 0.005 ] and iss ( or 1.12 , p = 0.001 ) were independent predictors of mortality [ table 5 ] .
there were 180 ( out of 570 ) deaths ( 31.6% ) during the study period .
this mortality rate increased to 35.5% ( 171 out of 482 ) after excluding those who were intubated during hospitalization and who had incomplete data .
the mortality was higher in group-1 in comparison to group-2 ( 53% vs. 18.5% , p = 0.001 ) [ figure 1 ] .
moreover , mortality rate ( 24% vs. 9% , p = 0.02 ) was significantly higher in patients who experienced prolonged scene time ( 20 min ) [ table 4 ] .
univariate analysis demonstrated that phi , head injury ; higher iss , lower initial gcs and prolonged scene time were associated with high mortality .
however , in multivariate logistic regression analysis , only initial gcs [ odds ratio ( or ) 0.78 , p = 0.005 ] and iss ( or 1.12 , p = 0.001 ) were independent predictors of mortality [ table 5 ] .
to the best of our knowledge , there is no similar study from the arab middle east that analyzes prehospital intervals , mode of transportation , and outcomes among patients sustained trauma based on the location of intubation ( phi vs. eri ) .
our data found that apart from mortality , total hospital and intensive care unit length of stay and ventilator days were nonsignificantly higher in phi group .
mort and schwartz et al . , also demonstrated increased procedure related complication rates in phi . besides complications
, phi affects other resuscitation efforts and eventually delayed definitive care at the same time is life saving .
the present study also shows increased scene time and total ems time in patients intubated at the scene .
although , ground ems was the main mean of transportation in both groups , hems frequently served group-1 patients .
ringburg et al . , demonstrated increased prehospital time with higher frequency use of hems .
an earlier study showed greater iss in patients with phi compared to the patients with eri . in our study , compared to eri , the mortality rate was significantly higher in phi group .
the current findings corroborate with earlier studies showing increased risk of mortality for phi in head injury patients .
further , sen and nichani showed that phi was associated with adverse neurological outcome and a fourfold increased risk of mortality .
mortality rate did not differ significantly with either mode of ems transportation in our study .
talving et al . , observed more number of patients transported by hems had severe injuries and need on - scene intubation .
moreover , the overall adjusted survival benefit post trauma remains unaffected in patients transported by hems .
the possible explanation for increased mortality in phi group is that these patients had significantly higher incidence of head injuries , polytrauma , and greater iss .
however , in order to analyze the safety of phi in comparison to eri , prospective studies are needed
. in general , improvement in the transportation methods in addition to advanced training for ems personnel would lead to significant reduction of the interval between the point in time of injury to the time of receiving the appropriate management .
however , it is noteworthy that the initial 60 min posttraumatic injury ( golden hour ) is the most effective time period for reducing complications and severity of injuries . in order to analyze the exact duration in various events involved in prehospital care , investigators have classified  golden hour  into different time intervals .
these time intervals are useful in assessing the performance of ems for the delivery of best possible care for critically ill patients .
the overall prehospital time intervals in the current study are consistent with the earlier published reports [ table 6 ] .
we reported prolonged out - of - hospital time in patients with phi compared with patients with eri .
this finding is consistent with earlier studies that have reported increased overall prehospital time for definitive care due to prehospital interventions involving advanced life support in severely injured patients . in our analysis
, the majority of patients in group-1 were located in rural areas , whereas group-2 patients were mainly transported from urban areas .
this observation may explain in part the shorter activation and response intervals in group 2 .
comparison of emergency medical services intervals among trauma patients from diff erent countries it remains unclear whether there is a correlation between the on - scene time and outcomes in trauma patients .
the observed increased mortality rate was analyzed and has been found to be significantly higher in patients who experienced increased scene time ( 20 min ) . a recent study from netherlands analyzed relationship between mobile medical team ( mmt ) involvement with on - scene time and mortality .
they have reported that an increased mortality observed in trauma patients managed by mmt , but after adjustment of major confounders the mortality was not independently associated with mmt involvement .
earlier reports have demonstrated that on - scene time is influenced by injury severity and ems interventions . over a 17-year period , wyen et al .
, reported 16 variables that had significant impact on the on - scene - treatment time .
of these variables ; intubation , car occupant , hems , volume administration , sedation , open fracture and establishing chest tubes were important determinants of on - scene - treatment time .
the present study attempted to analyze the association between total ems time and outcome in adult trauma patients .
our findings are consistent with earlier reports which have observed lack of association between total prehospital time and outcome in traumatic injury patients .
the main limitation of this study is the retrospective nature and availability of a preexisting dataset .
as the data were studied retrospectively , missing data points or erroneous data entry may have skewed the present data mainly for the prehospital time intervals .
the skewed prehospital time intervals may be attributed to the airfield restrictions or natural and structural barriers for hems , whereas ground ems also suffers traffic congestion at peak hours .
the study finding shows that phi and prolonged scene time is associated with high mortality in qatar .
can not be ruled out in this study , phi needs critical assessment and evaluation before on - site management decision .
 background : the impact of prehospital intubation ( phi ) in improving outcome of trauma patients has not been adequately evaluated in the developing countries.aims:the present study analyzed the outcome of phi versus emergency room intubation ( eri ) among trauma patients in qatar.materials and methods : data were retrospectively reviewed for all intubated trauma patients between 2010 and 2011 . 
 patients were classified according to location of intubation ( phi : group-1 versus eri : group-2 ) . 
 data were analyzed and compared.results:out of 570 intubated patients ; 482 patients ( 239 in group-1 and 243 in group-2 ) met the inclusion criteria with a mean age of 32  14.6 years head injury ( p = 0.003 ) and multiple trauma ( p = 0.004 ) were more prevalent in group-1 , whereas solid organ injury predominated in group-2 ( p = 0.02 ) . 
 group-1 had significantly higher mean injury severity scoring ( iss ) , lower glasgow coma scale ( gcs ) , greater head abbreviated injury score and longer activation , response , scene and total emergency medical services times . 
 the mortality was higher in group-1 ( 53% vs. 18.5% ; p = 0.001 ) . 
 multivariate analysis showed that gcs [ odds ratio ( or ) 0.78 , p = 0.005 ) and iss ( or 1.12 , p = 0.001 ) were independent predictors of mortality.conclusions:phi is associated with high mortality when compared with eri . 
 however , selection bias can not be ruled out and therefore , phi needs further critical assessment in qatar . 
Introduction
Materials and Methods
Definitions
Statistical analysis
Results
Mortality
Univariate and multivariate analysis
Discussion
Conclusion