Patient population
TBI patients undergoing DC from January 2008 to December 2013 were selected from The First Affiliated Hospital of Guangxi Medical University database. A total of 105 patients were enrolled to take the 37-itemed QOLIBRI instrument. At completion, 50 participants were willing to be re-interviewed after 2 weeks for the test-retest analysis.
Inclusion criteria
Criteria for applying QOLIBRI instrument: Patients must be adults (age 16 years or older) and 17–68 years at recruitment to the study; 6 to 96 months after injury, capacity to give informed consent; adequate cognitive and behavioral functioning to understand, answer and cooperate. Criteria for DC: appearance of definite unilateral or bilateral brain swelling and a midline shift of at least 5 mm on the computed tomography (CT) scan with poor initial Glasgow coma scale (GCS) score (≤8); neurological worsening (a worsening of GCS score ≥2 points) and aggravation of pupillary response to light during initial medical therapy; bilateral fixed pupils with an intact brain stem reflex; a swollen brain despite hematoma evaluation.
Exclusion criteria
Pre-injury or current cognitive disability interfering with assessments; spinal cord injury; severe psychiatric diseases; ongoing severe drug addiction; previously diagnosed with hypertension; a diagnosed terminal illness; multiple severe trauma and burns.
Treatment plan and operative procedures
All patients underwent CT scanning of the brain in the emergency room on presentation. The mainstay for TBI patient management is medical. Our hospital operates on a protocol that includes head elevation, adequate oxygenation, fluid resuscitation, mild hyperventilation to reduce cerebral blood volume and osmotic diuretics. When non-invasive methods tend to fail, we assess the patient for ventriculostomy, craniotomy for hematoma removal or craniectomy to convert the ‘closed’ intracranial compartment into an ‘open’ one. DC reduces ICP and enhances blood flow, it has been shown that the larger the craniectomy, the greater the reduction of ICP. It has been shown that a 10 cm diameter bone flap with durotomy provides an additional volume of around 50 ml. 70 % of volume expansion of a DC is achieved through wide dural opening and 30 % by bone removal only. Usually a bone flap of 12 cm is recommended [9, 22].
Decompressive craniectomy was performed by removing large portion of frontotemporoparietal cranium (>12 cm) for lesions confined to one cerebral hemisphere. Patients with bifrontal or anterior cranial fossa lesions underwent bilateral frontal craniectomy. The reference points used for bone flaps were at the pterion of frontal bone, the parietal eminence and in the temporal squamous areas. Temporal squama was rongered out until the floor of the middle cranial fossa was exposed. For patients with bilateral decompression, a frontal median segment of the bone, measuring about 3–4 cm in width along the sagittal sinus was saved to prevent damage to the sagittal sinus and to serve as a framework for later cranioplasty. Radial dural incisions are usually preferred over circumferential incisions giving adequate exposure to the hematoma. After craniectomy, epidural hematoma (EDH) and subdural hematoma (SDH) were evacuated when present. Brain parenchymal hemorrhagic contusions were removed in cases with persistent and significant brain swelling after craniectomy and hematoma evacuation. Artificial dura was used in majority of the patients and was secured with several sutures. Other duroplasty were done by harvesting the fascia overlying the temporal muscle. All patients underwent duroplasty to prevent cortical adhesions. Thin large gel-foam (roughly 0.5 cm thickness and 4×5cm size) pieces were placed between the dura and muscle layer for post-operative bleeding control and prevention of adherence between the dura and temporalis muscle. This gel-foam layer also facilitated the dissection plane for later cranioplasty.
Postoperative management and additional operation
After the decompression surgery propofol infusion is usually stopped, patient return to the neurosurgery intensive care unit (NICU) and conventional medical management, including hyperosmotic agents, neuroprotective drugs and antibiotics are used. Patients are ventilated until they regain consciousness and GCS is evaluated. A decision to extubated the patient or to continue with elective ventilation is taken. The next morning, all patients undergo a CT scan to evaluate the patient post-operatively. All patients (with exception to 2 patients in whom the bone defect healed itself), titanium cranioplasty using 3-D computer modelling of skull defects were carried out after 3–6 months after craniectomy. A ventriculo-peritoneal shunt was performed if the diagnosis of hydrocephalus was confirmed.
Data collection
After ethics clearance was obtained, data collection was performed retrospectively from review of medical charts and database of First Affiliated Hospital of Guangxi Medical University. Patients were recruited from the database on the basis of the coding of surgical procedures and diagnoses, allowing access to all patients undergoing DC in our institution. After receiving the informed consent of the patients, demographic data of patients, e.g. age, gender, previous medical history, the mode of injury and level of education were recorded. Level of education was divided as high and low: fewer than 10 years of education was considered low and greater than 10 years of education as high. When possible and often the case, missing data for education were imputed based on the type of work. For example, a participant whose occupation was listed as “farmer” was categorized as low education. Prehospital and hospital data of patients e.g. the lowest GCS score post-injury, presence of unilateral or bilateral dilated pupils, presence of a corneal reflex in the case of bilateral dilated pupils, whether patients performed reconstructive cranioplasty or not, blood pressure, patient temperature, midline shift on CT scan, fasting blood glucose, whether patients performed rehabilitation therapy, days of use of mannitol and barbiturates sedation were recorded.
The QOLIBRI instrument was the outcome measure in the present study. The first part taps on the responder’s satisfaction with their HRQOL in 4 domains comprising cognition, self, daily life and autonomy and social relationships. The second part relates to how bothered the responders rate themselves after TBI in 2 domains concerning emotions and physical problems. Each item (37 in total) is scored on a 5-point scale, from 1 (not-at-all satisfied) to 5 (very satisfied), with reverse scoring on the bothered subscales. The QOLIBRI was scored according to an algorithm published by von Steinbuchel et al. [14]. Missing item scores on each subscale were imputed by the scale mean if less than one third of the responses were missing. Raw scores were transformed into a score range of 0 (lowest) to 100 (highest). Individual subscale scores and a total score were calculated. The interviewer determined if the participant was able to respond to the self-report questionnaire independently. If yes, the questionnaires were completed in the clinic. If no, questionnaire was completed by telephone or in a face to face interview.
Statistical analysis
Data analysis was carried out in SPSS 16.0 for windows (SPSS, Inc., Chicago, IL, USA). Item scores on the QOLIBRI “bothered” scales were reversed to match the “satisfaction” questions. Means were calculated for each QOLIBRI scale, prorated if no more than one-third of items were missing. A total QOLIBRI score was also calculated as the mean of all individual items, using prorating if necessary. Results are reported as the number (and percentage) of patients or mean ± standard deviation unless otherwise specified. A difference with a p value of ≤0.05 was regarded as statistically significant (two tailed test).
Skewness was present in the reported data and seems to be common in response to clinical scales. Extreme skewness can however create problems for analysis using correlations, reducing the probability that a scale will show strong relationships with other measures, and its reliability (or precision of measurement) of a scale. Skewness was checked but, however, some moderately skewed items were included, to capture a range of impairments [19]. Multivariate regression analyses were performed for the influence of sex, age, educational level, TBI to DC time, Worst GCS score, pupillary response, TBI to questionnaire time, whether performed cranioplasty, systolic blood pressure, diastolic blood pressure, temperature of patient, midline shift on computed tomography scan, fasting blood glucose, whether or not treated in a rehabilitation center, days of use of mannitol and use of barbiturate sedation to the 6 different QOLIBRI domain scores and total score.
For the internal consistency of the scales, which reflects their reliability, was assessed using the Cronbach’s α, and the fit of individual items to each scale was examined by correlating the item with the total for the other items in the scale. Cronbach’s α and corrected item-total correlations (CITCs) were calculated. Test-retest reliability is one of the most important measures of reliability for questionnaires. The test-retest reliability of the QOLIBRI scales was assessed using the intra-class correlation coefficient (ICC), calculated between the scale means on two occasions (retested on average 14 days after initial testing). The conventional interpretation of the ICC is that values of 0.40–0.75 are fair to good and values over 0.75 are excellent [19].
