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Discussion Of Survival Trends After Vascular Surgery

Trauma is the most common cause of death for those under the age of 45. Traumatic brain injury (TBI) remains the cause of approximately half of the deaths secondary to trauma.1 One of the important early sequelae of TBI is the development of intracranial hematomas. These can be extradural, subdural, intraparenchymal, or a combination thereof. It has long been recognized that acute subdural hematomas (ASDHs) are often associated with intraparenchymal injuries and brain swelling. Hence, outcomes have historically been worse for patients with ASDH with mortality rates as high as 68%. An essay writer is a person whose job is to create articles related to surgical content as well.

Temporal evidence from the 1990s suggested that outcome following head injury had failed to improve to the same degree as other trauma. As a result, the UK National Institute for Health and Care Excellence (NICE) introduced guidelines for the management of head injury in 2003, subsequently revised in January 2014 (NICE CG176). Indeed, a study presenting data from 2003 to 2009 identified a reduction in the odds of death following head injury.7 There was, however, no specific analysis performed for ASDH, the focus of this study. Research utilizing the Nationwide Inpatient Sample in the USA identified an improvement in traumatic subdural hematoma mortality from 16.4% in 1996 to 11.6% in 2006.

 However, the authors did not to distinguish acute vs chronic subdural hematomas, as it was based on International Classification of Diseases, Ninth Revision (ICD)-9 codes. As the pathophysiology, patient populations, management strategies, and outcomes differ significantly between acute and chronic subdural hematomas, the findings of this study cannot be extrapolated to ASDH. The writer assigned to write my essay request about surgical content is qualified to the same academic level or higher than your writing requirements.

Previous retrospective cohort studies have found age, Glasgow Coma Scale (GCS), Injury Severity Scale (ISS), and pupil reactivity as independent prognostic factors. Following research from the 1980s investigating the effect of time to surgery on outcome after ASDH, and studies supporting this finding thereafter, it has been advised that life-saving decompressive surgery must be available within four hours”. However, more recent studies have challenged this conclusion.

The aim of this study therefore was to identify trends in survival for surgical management of ASDH across England and Wales, leveraging multiple logistic regression analysis to control for case mix changes over the last 20 years. Through this, we also sought to identify prognostic factors relating to outcome in ASDH and examine the relationship between time interval from injury to craniotomy and survival. An online essay writing service offers an original surgical content papers crafted by our professional essay writers.


Study Design

This is an observational cohort study with a retrospective analysis of prospectively recorded data. The study is reported in accordance with the STROBE statement for cohort studies. We analyzed anonymized data on all patients with a diagnosis of subdural hematoma from the Trauma Audit and Research Network (TARN) database over a 20-year period (1994 to 2013). A 20-year period starting in 1994 was selected to provide data 10 years before and after the introduction of 2003 NICE head injury guidelines. The TARN database was established in 1989. The objective of TARN is to support trauma service development and inform the research agenda by collecting information on patients admitted with major trauma. The TARN database is now one of the largest trauma registries in Europe, with more than 500,000 cases. Initially covering 13 hospitals, the database now covers 100% of trauma-receiving hospitals in England and Wales.

Outcome was recorded as a dichotomous variable (alive or dead) based on assessment at 30 days or at discharge if the latter happened before 30 days. This will be referred to as 30-day survival for economy of words. No further outcome measures were collected for identification of neurological sequelae or other disability following injury. Cases over the age of 16 who underwent craniotomy within 48 hours of injury were selected, in order to focus on acute operative cases in the adult.

Statistical Analysis

Descriptive statistics were performed on the basis of 5-year intervals (1994 to 1998, 1998 to 2003, 2004 to 2008, 2009 to 2013). We investigated 30-day survival as a dependent variable. Variables hypothesized to be related to survival were modeled using univariate logistic regression, retained as continuous variables where possible to maximize statistical utility. The date of injury was converted to a decimal, such that the exact point in the year in which the injury occurred could be retained. Subdural hematoma severity was coded using the Abbreviated Injury Scale (AIS), ranging from 4 (Severe) to 5 (Critical) in this study. Additional injuries were combined with the subdural hematoma AIS to create the ISS. Other variables analyzed included GCS, age, sex, day of the week of injury, time interval from injury to craniotomy, location of admission, presence of polytrauma, pupil reactivity, and mechanism of injury. Pupil reactivity and GCS were recorded on arrival in the emergency department; the values at the scene of the accident were recorded for patients arriving intubated. This is a commonly employed approach in the TBI literature. Variables were progressed into a multiple logistic regression model. Interaction terms were tested and included if significant. Nonlinear variables in this study were all modeled using restricted cubic splines. Persuasive speech topics should be acute and of real interest for the wide audience so these surgical topics are highlighted in that category.

Following selection of operative cases in adults within 48 hours, where pupil reactivity data were missing but GCS was 14 or 15, we assumed that no significant brainstem compression/uncal herniation would exist and pupils were considered to be both reactive. Multiple imputation was then applied in the updated dataset. Sensitivity was tested under multiple logistic regression analysis in 3 ways, firstly, using an offset ranging between the maximum and minimum of the variable in question, with restrictions such that any imputed data did not exceed the highest and lowest possible values. For example, with an offset of +12 on GCS (ranging from 3 to 15), all imputed values would be 15 regardless of their initial value. Secondly, multiple logistic regression was repeated using only original sites to account for bias as a result of the addition of new sites over time. Finally, we performed propensity score matching as a further sensitivity test of modifiable risk factors found to be significant in the multivariable logistic regression model. Propensity score matching involves the construction of a conditional probability for a patient chosen at random to be exposed to the risk factor in question, after controlling for other known risk factors. This methodology was undertaken to minimize bias as a result of nonrandomization, and was performed through a one-to-one nearest neighbor method matching process.