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Factors Influencing the Outcomes in Extradural Haematoma Patients

Kiboi JG, Nganga HK, Kitunguu PK, Mbuthia JM

Department of Neurosurgery, University of Nairobi, Kenya

Correspondence to: Dr. Hudson Kamau. P.O Box 76480-00508 Nairobi, Kenya. Email: hudson.kamau@ gmail.com

 

Abstract

Background: Extradural hematomas are neurosurgical emergencies and are one of the most common causes of mortality and disability after traumatic brain injury. This study aimed at evaluating the current management and factors that influence outcome in patients treated for extradural hematoma in an African setting. Methods: A total of 224 consecutive patients who were admitted to the neurosurgical unit at the Kenyatta National Hospital and diagnosed with extradural hematoma between January 2007 and December 2011 were included in this study. Results: There was a male predominance of 96.9%. The median age was 29 years. The most common cause of injury was assault (45%). Good functional recovery was achieved by 190(86.2%) of the patients in our series, whereas residual disability accounted for 6.7% and mortality for 7.1%. The proportion of patients who achieved functional recovery significantly decreased with increasing age (p=0.011). A lower GCS score at admission was associated with a poorer outcome (p=0.032). The time elapsed from initial trauma to surgery significantly influenced outcome (p=0.007). Conclusion: A longer duration between trauma and decompression, a low preoperative GCS score, pupillary abnormalities and those older than age 61 are poor prognostic indicators.

Key Words: Extradural hematoma, Head injury, Intracranial hematoma, Outcome

Introduction

Extradural hematoma (EDH) is hemorrhage between the inner table of the skull and the dura mater and is a neurosurgical emergency with early diagnosis and intervention being essential for adequate management. Many reported series show great differences in post-operative results between patients operated on when comatose, compared with patients showing no alteration in their level of consciousness up to the time of surgery (1–4). Studies show that mortality may range from 41% in patients with a Glasgow coma scale (GCS) score of 8 or less, to zero in patients who are alert at the time of the operation (5). There have been great improvements in diagnostic and monitoring tools, evacuation and rescue, and early treatment options which have positively influenced the outcome of patients with extradural hematomas especially in Africa. These improvements have included the introduction of the computed tomography (CT), aggressive rescue and

evacuation to specialised centers and introduction of standardised surgical techniques for removal of intracranial haematomas (2). Even with these improvements, studies have shown that the quality of outcome varies dramatically between hospitals (5,6). The aim of this study was to evaluate the clinical pattern and factors that influence outcome in patients treated for extradural hematoma in a single institution in Kenya.

Methods

This retrospective study was conducted in Kenyatta National Hospital (KNH) the largest neurosurgical unit in East and Central Africa after ethical approval by the hospital’s ethics board. Two hundred and twenty four records of patients admitted between January 2007 and December 2011 were retrieved.Data was collected from the patient records using a standardized structured questionnaire. The data variables collected included gender, age, GCS on admission, pupil abnormalities, mechanism of injury, accompanying injuries, loss of consciousness, focal limb weakness, sensory loss, CSF rhinorhea and otorhea. Pre-morbid risk factors, surgical variables such as type of surgery and time elapsed from accident to surgery (time to diagnosis and time to surgery) and outcome at discharge were also documented.

 

The Glasgow Coma Scale (GCS) was used to classify the severity of the injuries. Patients with GCS of ≤8, 9-12 and 13-15 were classified as severe, moderate, mild head injuries respectively. Outcome of these patients was measured using a Glasgow Outcome Scale (GOS) at the point of discharge. GOS 1 indicated death and GOS 2-4 (GOS 2-vegetative state, GOS 3-severe disability, GOS 4-moderate disability) were used to indicate residual disabilities or poor outcomes, whereas GOS scores of 5 (good functional recovery) indicated a favorable outcome. This scale was chosen because it is widely accepted as a standard means of describing outcome in head injury and has established validity and interobserver invariability.

 

The data was coded and analyzed using Statistical Package for Social Sciences (SPSS), version 18.0. Discrete variables were compared using the chi square test while continuous variables were compared using Student’s t test. Logistic and univariate linear regression models were conducted to determine which variables were independently associated with functional recovery and mortality. A value of p < 0.05 was considered significant.

 

Results

A total of 224 (217 male, 7 female) cases of extradural hematoma were retrieved. The mean age was 30.66 years (±12.434), with a range from 1 year to 82 years. There was an uneven age distribution with most of the patients (55.4%) being in the 26-45 year age group (Figure 1).