The Retrospective Application of a Prediction Model to Patients Who Have Had a Decompressive Craniectomy for Trauma

Development of a Prediction Model for Cranioplasty Implant Survival Following Craniectomy

BACKGROUND

Cranioplasty after craniectomy can result in high rates of postoperative complications. Although determinants of postoperative outcomes have been identified, a prediction model for predicting cranioplasty implant survival does not exist. Thus, we sought to develop a prediction model for cranioplasty implant survival after craniectomy.

METHODS

We performed a retrospective cohort study of patients who underwent cranioplasty following craniectomy between 2014 and 2020. Missing data were imputed using multiple imputation. For model development, multivariable Cox proportional hazards regression analysis was performed. To test whether candidate determinants contributed to the model, we performed backward selection using the Akaike information criterion. We corrected for overfitting using bootstrapping techniques. The performance of the model was assessed using discrimination and calibration.

RESULTS

A total of 182 patients were included (mean age, 43.0 ± 19.7 years). Independent determinants of cranioplasty implant survival included the indication for craniectomy (compared with trauma-vascular disease: hazard ratio [HR], 0.65 [95% confidence interval (CI), 0.36-1.17]; infection: HR, 0.76 [95% CI, 0.32-1.80]; tumor: HR, 1.40 [95% CI, 0.29-6.79]), cranial defect size (HR, 1.01 per cm2 [95% CI, 0.73-1.38]), use of an autologous bone flap (HR, 1.63 [95% CI, 0.82-3.24]), and skin closure using staples (HR, 1.42 [95% CI, 0.79-2.56]). The concordance index of the model was 0.60 (95% CI, 0.47-0.73).

CONCLUSIONS

We have developed the first prediction model for cranioplasty implant survival after craniectomy. The findings from our study require external validation and deserve further exploration in future studies.

Balancing the short-term benefits and long-term outcomes of decompressive craniectomy for severe traumatic brain injury

Introduction: The role of decompressive craniectomy in the management of neurological emergencies remains controversial. There is evidence available that it can reduce intracranial pressure, but it will not reverse the effects of the pathology that precipitated the neurological crisis, so there has always been concern that any reduction in mortality will result in an increase in the number of survivors with severe disability.Areas covered: The results of recent randomised controlled trials investigating the efficacy of the procedure are analyzed in order to determine the degree to which the short-term goals of reducing mortality and the long-term goals of a good functional outcome are achieved.Expert opinion: Given the results of the trials, there needs to be a change in the clinical decision-making paradigm such that decompression is reserved for patients who develop intractable intracranial hypertension and who are thought unlikely to survive without surgical intervention. In these circumstances, a more patient-centered discussion is required regarding the possibility and acceptability or otherwise of survival with severely impaired neurocognitive function.

Prediction of Early TBI Mortality Using a Machine Learning Approach in a LMIC Population

Background: In a time when the incidence of severe traumatic brain injury (TBI) is increasing in low- to middle-income countries (LMICs), it is important to understand the behavior of predictive variables in an LMIC's population. There are few previous attempts to generate prediction models for TBI outcomes from local data in LMICs. Our study aim is to design and compare a series of predictive models for mortality on a new cohort in TBI patients in Brazil using Machine Learning.

Methods: A prospective registry was set in São Paulo, Brazil, enrolling all patients with a diagnosis of TBI that require admission to the intensive care unit. We evaluated the following predictors: gender, age, pupil reactivity at admission, Glasgow Coma Scale (GCS), presence of hypoxia and hypotension, computed tomography findings, trauma severity score, and laboratory results.

Results: Overall mortality at 14 days was 22.8%. Models had a high prediction performance, with the best prediction for overall mortality achieved through Naive Bayes (area under the curve = 0.906). The most significant predictors were the GCS at admission and prehospital GCS, age, and pupil reaction. When predicting the length of stay at the intensive care unit, the Conditional Inference Tree model had the best performance (root mean square error = 1.011), with the most important variable across all models being the GCS at scene.

Conclusions: Models for early mortality and hospital length of stay using Machine Learning can achieve high performance when based on registry data even in LMICs. These models have the potential to inform treatment decisions and counsel family members.

Level of evidence: This observational study provides a level IV evidence on prognosis after TBI.

Prognosis in Moderate and Severe Traumatic Brain Injury: A Systematic Review of Contemporary Models and Validation Studies

Outcome prognostication in traumatic brain injury (TBI) is important but challenging due to heterogeneity of the disease. The aim of this systematic review is to present the current state-of-the-art on prognostic models for outcome after moderate and severe TBI and evidence on their validity. We searched for studies reporting on the development, validation or extension of prognostic models for functional outcome after TBI with Glasgow Coma Scale (GCS) ≤12 published between 2006-2018. Studies with patients age ≥14 years and evaluating a multi-variable prognostic model based on admission characteristics were included. Model discrimination was expressed with the area under the receiver operating characteristic curve (AUC), and model calibration with calibration slope and intercept. We included 58 studies describing 67 different prognostic models, comprising the development of 42 models, 149 external validations of 31 models, and 12 model extensions. The most common predictors were GCS (motor) score (n = 55), age (n = 54), and pupillary reactivity (n = 48). Model discrimination varied substantially between studies. The International Mission for Prognosis and Analysis of Clinical Trials (IMPACT) and Corticoid Randomisation After Significant Head injury (CRASH) models were developed on the largest cohorts (8509 and 10,008 patients, respectively) and were most often externally validated (n = 91), yielding AUCs ranging between 0.65-0.90 and 0.66-1.00, respectively. Model calibration was reported with a calibration intercept and slope for seven models in 53 validations, and was highly variable. In conclusion, the discriminatory validity of the IMPACT and CRASH prognostic models is supported across a range of settings. The variation in calibration, reflecting heterogeneity in reliability of predictions, motivates continuous validation and updating if clinical implementation is pursued.

Functional and aesthetic evaluation after cranial reconstruction with polymethyl methacrylate prostheses using low-cost 3D printing templates in patients with cranial defects secondary to decompressive craniectomies: A prospective study

Background:

Cranial reconstruction surgery is a procedure used as an attempt to reestablish the cranial bone anatomy. This study evaluates the symptomatic and aesthetic improvement of patients with cranial defects secondary to decompressive craniectomies after cranial reconstruction with customized polymethyl methacrylate (PMMA) prostheses. Secondly, we aim to divide our experience in the production of these prostheses with a low-cost method.

Methods:

A prospective study was carried out with patients submitted to cranioplasty at the Hospital da Restauração between 2014 and 2017. A total of 63 cranioplasties were performed using customized PMMA prosthesis produced by 3D impression molds. All patients underwent a functional and aesthetic evaluation questionnaire in the preoperative period and in the sixth postoperative month.

Results:

Sixty-three patients underwent cranioplasty with a mean age of 33 years, ranging from 13 to 58 years, 55 males and 8 females. The mean area of the defect was 147 cm². The mean postoperative follow-up of the patients was 21 months, ranging from 6 to 33 months. Fifty-five patients attended the 6-month postoperative consultation. All patients presented symptomatic improvement after reconstruction of the skull. The infection rate was 3.2%, 4.8% of extrusion, 1.6% of prosthesis fracture, 7.9% of extradural hematoma, 17.4% of reoperation, 5% of wound dehiscence, and 4.8% of removal of the prosthesis.

Conclusion:

Cranioplasty, with a customized PMMA prosthesis, improved the symptoms and aesthetic appearance of all operated patients. The use of prototypes to customize cranial prostheses facilitated the operative technique and allowed the recovery of a cranial contour very close to normal.

Adhesion sutures for seroma reduction in cranial reconstructions with polymethyl methacrylate prosthesis in patients undergoing decompressive craniectomy: A clinical trial

Background:

Cranial reconstruction with polymethyl methacrylate (PMMA) prosthesis is used for calvarial defects secondary to decompressive craniectomies. Seroma is one of the most frequent complications of this procedure and can lead to the dehiscence, extrusion, infection, and loss of the prosthesis. The objective of the study is to analyze the effectiveness of the tacking sutures between the prosthesis and the scalp flap in reducing the seroma.

Methods:

This is a prospective study with 63 patients submitted to cranioplasty between 2014 and 2017 for defects resulting from decompressive craniectomies. All patients were followed up postoperatively for at least 3 months and the diagnosis of seroma was made clinically. In the first 22 patients, the conventional technique was applied and, in the following 41, the technique with tacking sutures was used. The incidence of seroma was collected for both groups.

Results:

The overall incidence of seroma was 65.1%. Compared to the conventional technique, the use of tacking sutures was associated with a statistically significant reduction in the incidence of seroma from 90.9% to 51.2% (P = 0.002).

Conclusion:

The use of the tacking sutures in cranioplasties with PMMA prosthesis reduced the incidence of seroma postoperatively.

Reconsidering the role of decompressive craniectomy for neurological emergencies

OBJECTIVE

There is little doubt that decompressive craniectomy can reduce mortality. However, there is concern that any reduction in mortality comes at an increase in the number of survivors with severe neurological disability.

METHOD

Over the past decade there have been several randomised controlled trials comparing surgical decompression with standard medical therapy in the context of ischaemic stroke and severe traumatic brain injury. The results of each trial are evaluated.

RESULTS

There is now unequivocal evidence that a decompressive craniectomy reduces mortality in the context of "malignant" middle infarction and following severe traumatic brain injury. However, it has only been possible to demonstrate an improvement in outcome by categorizing a mRS of 4 and upper severe disability as favourable outcome. This is contentious and an alternative interpretation is that surgical decompression reduces mortality but exposes a patient to a greater risk of survival with severe disability.

CONCLUSION

It would appear unlikely that further randomised controlled trials will be possible given the significant reduction in mortality achieved by surgical decompression. It may be that observational cohort studies and outcome prediction models may provide data to determine those patients most likely to benefit from surgical decompression.

Predicting long-term neurological outcomes after severe traumatic brain injury requiring decompressive craniectomy: A comparison of the CRASH and IMPACT prognostic models

BACKGROUND

Predicting long-term neurological outcomes after severe traumatic brain (TBI) is important, but which prognostic model in the context of decompressive craniectomy has the best performance remains uncertain.

METHODS

This prospective observational cohort study included all patients who had severe TBI requiring decompressive craniectomy between 2004 and 2014, in the two neurosurgical centres in Perth, Western Australia. Severe disability, vegetative state, or death were defined as unfavourable neurological outcomes. Area under the receiver-operating-characteristic curve (AUROC) and slope and intercept of the calibration curve were used to assess discrimination and calibration of the CRASH (Corticosteroid-Randomisation-After-Significant-Head injury) and IMPACT (International-Mission-For-Prognosis-And-Clinical-Trial) models, respectively.

RESULTS

Of the 319 patients included in the study, 119 (37%) had unfavourable neurological outcomes at 18-month after decompressive craniectomy for severe TBI. Both CRASH (AUROC 0.86, 95% confidence interval 0.81-0.90) and IMPACT full-model (AUROC 0.85, 95% CI 0.80-0.89) were similar in discriminating between favourable and unfavourable neurological outcome at 18-month after surgery (p=0.690 for the difference in AUROC derived from the two models). Although both models tended to over-predict the risks of long-term unfavourable outcome, the IMPACT model had a slightly better calibration than the CRASH model (intercept of the calibration curve=-4.1 vs. -5.7, and log likelihoods -159 vs. -360, respectively), especially when the predicted risks of unfavourable outcome were <80%.

CONCLUSIONS

Both CRASH and IMPACT prognostic models were good in discriminating between favourable and unfavourable long-term neurological outcome for patients with severe TBI requiring decompressive craniectomy, but the calibration of the IMPACT full-model was better than the CRASH model.

Uncertainty, conflict and consent: revisiting the futility debate in neurotrauma

The concept of futility has been debated for many years, and a precise definition remains elusive. This is not entirely unsurprising given the increasingly complex and evolving nature of modern medicine. Progressively more complex decisions are required when considering increasingly sophisticated diagnostic and therapeutic interventions. Allocating resources appropriately amongst a population whose expectations continue to increase raises a number of ethical issues not least of which are the difficulties encountered when consideration is being given to withholding "life-preserving" treatment. In this discussion we have used decompressive craniectomy for severe traumatic brain injury as a clinical example with which to frame an approach to the concept. We have defined those issues that initially lead us to consider futility and thereafter actually provoke a significant discussion. We contend that these issues are uncertainty, conflict and consent. We then examine recent scientific advances in outcome prediction that may address some of the uncertainty and perhaps help achieve consensus amongst stakeholders. Whilst we do not anticipate that this re-framing of the idea of futility is applicable to all medical situations, the approach to specify patient-centred benefit may assist those making such decisions when patients are incompetent to participate.

Long-term survival with unfavourable outcome: a qualitative and ethical analysis

OBJECTIVE

To assess the issue of 'retrospective consent' among a cohort of patients who had survived with unfavourable outcome and to assess attitudes among next of kin regarding their role as surrogate decision makers.

METHODS

Twenty patients who had survived for at least 3 years with an unfavourable outcome following a decompressive craniectomy for severe traumatic brain injury were assessed with their next of kin. During the course of a semistructured interview, participants were asked whether they would have provided consent if they had known their eventual outcome. They were also asked for general comments regarding all aspects of the clinical journey. Eighteen patients had next of kin who were available for interview. For two patients, there was no longer any family involvement.

RESULTS

Of the 20 patients, 13 were able to provide a response and 11 felt that they would have provided consent even if they had known their eventual outcome. Of the 18 next of kin who were able to express an opinion, 10 felt that they would have provided retrospective consent.

CONCLUSIONS

Many patients appeared to have adapted to a level of disability that competent individuals might deem unacceptable. This does not necessarily mean that such outcomes should be regarded as 'favourable', nor that decompressive craniectomy must be performed for patients with predicted poor outcome. Nevertheless, those burdened with the initial clinical decisions and thereafter the long-term care of these patients may draw some support from the knowledge that unfavourable may not necessarily be unacceptable.

Decompressive craniectomy for severe traumatic brain injury: the relationship between surgical complications and the prediction of an unfavourable outcome

OBJECT

To assess the impact that injury severity has on complications in patients who have had a decompressive craniectomy for severe traumatic brain injury (TBI).

METHODS

This prospective observational cohort study included all patients who underwent a decompressive craniectomy following severe TBI at the two major trauma hospitals in Western Australia from 2004 to 2012. All complications were recorded during this period. The clinical and radiological data of the patients on initial presentation were entered into a web-based model prognostic model, the CRASH (Corticosteroid Randomization After Significant Head injury) collaborators prediction model, to obtain the predicted risk of an unfavourable outcome which was used as a measure of injury severity.

RESULTS

Complications after decompressive craniectomy for severe TBI were common. The predicted risk of unfavourable outcome was strongly associated with the development of neurological complications such as herniation of the brain outside the skull bone defects (median predicted risk of unfavourable outcome for herniation 72% vs. 57% without herniation, p=0.001), subdural effusion (median predicted risk of unfavourable outcome 67% with an effusion vs. 57% for those without an effusion, p=0.03), hydrocephalus requiring ventriculo-peritoneal shunt (median predicted risk of unfavourable outcome 86% for those with hydrocephalus vs. 59% for those without hydrocephalus, p=0.001), but not infection (p=0.251) or resorption of bone flap (p=0.697) and seizures (0.987). We did not observe any associations between timing of cranioplasty and risk of infection or resorption of bone flap after cranioplasty.

CONCLUSIONS

Mechanical complications after decompressive craniectomy including herniation of the brain outside the skull bone defects, subdural effusion, and hydrocephalus requiring ventriculo-peritoneal shunt were more common in patients with a more severe form of TBI when quantified by the CRASH predicted risk of unfavourable outcome. The CRASH predicted risk of unfavourable outcome represents a useful baseline characteristic of patients in observational and interventional trials involving patients with severe TBI requiring decompressive craniectomy.

Prognostic significance of blood-brain barrier disruption in patients with severe nonpenetrating traumatic brain injury requiring decompressive craniectomy

OBJECT

The authors assessed the risk factors and outcomes associated with blood-brain barrier (BBB) disruption in patients with severe, nonpenetrating, traumatic brain injury (TBI) requiring decompressive craniectomy.

METHODS

At 2 major neurotrauma centers in Western Australia, a retrospective cohort study was conducted among 97 adult neurotrauma patients who required an external ventricular drain (EVD) and decompressive craniectomy during 2004-2012. Glasgow Outcome Scale scores were used to assess neurological outcomes. Logistic regression was used to identify factors associated with BBB disruption, defined by a ratio of total CSF protein concentrations to total plasma protein concentration > 0.007 in the earliest CSF specimen collected after TBI.

RESULTS

Of the 252 patients who required decompressive craniectomy, 97 (39%) required an EVD to control intracranial pressure, and biochemical evidence of BBB disruption was observed in 43 (44%). Presence of disruption was associated with more severe TBI (median predicted risk for unfavorable outcome 75% vs 63%, respectively; p = 0.001) and with worse outcomes at 6, 12, and 18 months than was absence of BBB disruption (72% vs 37% unfavorable outcomes, respectively; p = 0.015). The only risk factor significantly associated with increased risk for BBB disruption was presence of nonevacuated intracerebral hematoma (> 1 cm diameter) (OR 3.03, 95% CI 1.23-7.50; p = 0.016). Although BBB disruption was associated with more severe TBI and worse long-term outcomes, when combined with the prognostic information contained in the Corticosteroid Randomization after Significant Head Injury (CRASH) prognostic model, it did not seem to add significant prognostic value (area under the receiver operating characteristic curve 0.855 vs 0.864, respectively; p = 0.453).

CONCLUSIONS

Biochemical evidence of BBB disruption after severe nonpenetrating TBI was common, especially among patients with large intracerebral hematomas. Disruption of the BBB was associated with more severe TBI and worse long-term outcomes, but when combined with the prognostic information contained in the CRASH prognostic model, this information did not add significant prognostic value.

Validation of the CRASH model in the prediction of 18-month mortality and unfavorable outcome in severe traumatic brain injury requiring decompressive craniectomy

Object

The goal in this study was to assess the validity of the corticosteroid randomization after significant head injury (CRASH) collaborators prediction model in predicting mortality and unfavorable outcome at 18 months in patients with severe traumatic brain injury (TBI) requiring decompressive craniectomy. In addition, the authors aimed to assess whether this model was well calibrated in predicting outcome across a wide spectrum of severity of TBI requiring decompressive craniectomy.

Methods

This prospective observational cohort study included all patients who underwent a decompressive craniectomy following severe TBI at the two major trauma hospitals in Western Australia between 2004 and 2012 and for whom 18-month follow-up data were available. Clinical and radiological data on initial presentation were entered into the Web-based model and the predicted outcome was compared with the observed outcome. In validating the CRASH model, the authors used area under the receiver operating characteristic curve to assess the ability of the CRASH model to differentiate between favorable and unfavorable outcomes.

Results

The ability of the CRASH 6-month unfavorable prediction model to differentiate between unfavorable and favorable outcomes at 18 months after decompressive craniectomy was good (area under the receiver operating characteristic curve 0.85, 95% CI 0.80–0.90). However, the model's calibration was not perfect. The slope and the intercept of the calibration curve were 1.66 (SE 0.21) and −1.11 (SE 0.14), respectively, suggesting that the predicted risks of unfavorable outcomes were not sufficiently extreme or different across different risk strata and were systematically too high (or overly pessimistic), respectively.

Conclusions

The CRASH collaborators prediction model can be used as a surrogate index of injury severity to stratify patients according to injury severity. However, clinical decisions should not be based solely on the predicted risks derived from the model, because the number of patients in each predicted risk stratum was still relatively small and hence the results were relatively imprecise. Notwithstanding these limitations, the model may add to a clinician's ability to have better-informed conversations with colleagues and patients' relatives about prognosis.

Decompressive craniectomy for management of traumatic brain injury: an update

Decompressive craniectomy (DC) for the management of severe traumatic brain injury (TBI) has a long history but remains controversial. Although DC has been shown to improve both survival and functional outcome in patients with malignant cerebral infarctions, evidence of benefit in patients with TBI is decidedly more mixed. Craniectomy can clearly be life-saving in the presence of medically intractable elevations of intracranial pressure. Craniectomy also has been consistently demonstrated to reduce "therapeutic intensity" in the ICU, to reduce the need for intracranial-pressure-directed and brain-oxygen-directed interventions, and to reduce ICU length of stay. Still, the only randomized trial of DC in TBI failed to demonstrate any benefit. Studies of therapies for TBI, including hemicraniectomy, are challenging owing to the inherent heterogeneity in the pathophysiology observed in this disease. Craniectomy can be life-saving for patients with severe TBI, but many questions remain regarding its ideal application, and the outcome remains highly correlated with the severity of the initial injury.

Decompressive craniectomy for severe traumatic brain injury: is life worth living?

OBJECT

The object of this study was to assess the long-term outcome and quality of life of patients who have survived with severe disability following decompressive craniectomy for severe traumatic brain injury (TBI).

METHODS

The authors assessed outcome beyond 3 years among a cohort of 39 patients who had been adjudged either severely disabled or in vegetative state 18 months after decompressive craniectomy for TBI. Assessments performed included the Extended Glasgow Outcome Scale, modified Barthel Index (mBI), Zarit Burden Interview, and 36-Item Short-Form Health Survey (SF-36). The issue of retrospective consent for surgery was also assessed.

RESULTS

Of the 39 eligible patients, 7 died, 12 were lost to follow-up, and 20 patients or their next of kin consented to participate in the study. Among those 20 patients, 5 in a vegetative state at 18 months remained so beyond 3 years, and the other 15 patients remained severely disabled after a median follow-up of 5 years. The patients' average daily activity per the mBI (Pearson correlation coefficient [r] = -0.661, p = 0.01) and SF-36 physical score (r = -0.543, p = 0.037) were inversely correlated with the severity of TBI. However, the SF-36 mental scores of the patients were reasonably high (median 46, interquartile range 37-52). The majority of patients and their next of kin believed that they would have provided consent for surgical decompression even if they had known the eventual outcome.

CONCLUSIONS

Substantial physical recovery beyond 18 months after decompressive craniectomy for severe TBI was not observed; however, many patients appeared to have recalibrated their expectations regarding what they believed to be an acceptable quality of life.

The influence of clinical evidence on surgical practice

Given the considerable interest in the use of evidence-based medicine to guide clinical practice, it is surprising that the results of a recent randomized controlled trial have been met with such a limited response. The DECompressive CRAniectomy study investigators have recently published the results of a landmark trial in neurosurgery, comparing early decompressive craniectomy with standard medical therapy in patients who developed intracranial hypertension after diffuse closed traumatic brain injury (TBI). This is the first ever randomized controlled trial investigating the surgical management of adult patients with severe TBI. The trial clearly demonstrated that early decompression did not provide clinical benefit; however, rather than having a significant impact on clinical practice, it has been almost uniformly criticized. While there were some problems with randomization and crossover, we feel that the trial has been somewhat misinterpreted and in this article we address some of the key issues.

Use of the CRASH study prognosis calculator in patients with severe traumatic brain injury treated with an intracranial pressure-targeted therapy

Based on the Corticosteroid Randomisation after Significant Head Injury (CRASH) trial database, a prognosis calculator has been developed for the prediction of outcome in an individual patient with a head injury. In 47 patients with severe traumatic brain injury (sTBI) prospectively treated using an intracranial pressure (ICP) targeted therapy, the individual prognosis for mortality at 14 days and unfavourable outcome at 6 months was calculated and compared with the actual outcome. An overestimation of the risk of mortality and unfavourable outcome was found. The mean risk for mortality and unfavourable outcome were estimated to be 44.6±32.5% (95% confidence interval [CI], 35.1-54.2%) and 69.3±23.7% (95% CI, 62.3-76.2%). The actual outcome was 4.3% and 42.6% respectively. The absolute risk reduction (ARR) for mortality was 33.1% and for unfavourable outcome 29.8%. A logistic fit for outcome at 6 months shows a statistically significant difference (p<0.01). A receiver operating characteristic (ROC) curve analysis shows an area under the curve (AUC) of 0.691. The CRASH prognosis calculator overestimates the risk of mortality and unfavourable outcome in patients with sTBI treated with an ICP-targeted therapy based on the Lund concept. We do not advocate the use of the calculator for treatment decisions in individual patients. We further conclude that patients with blunt sTBI admitted within 8 hours of trauma should be treated regardless of their clinical status as long as the initial cerebral perfusion pressure is >10 mmHg.

Preliminary Experience of Assessment of Intracranial Lesions by Ultrasound in Multiple Trauma Patients Undergoing Craniectomy

Objective

To explore the feasibility and reliability of B-mode ultrasound for assessment of intracranial lesions in multiple trauma patients who had undergone craniectomy.

Design

ingle-centre study.

Setting

A 16-bed emergency intensive care unit (ICU) in the emergency department of 2nd Affiliated Hospital of Zhejiang University School of Medicine from July 2006 to June 2010.

Methods

We retrospectively analysed 13 multiple trauma patients with severe head injury admitted to the emergency department of 2nd Affiliated Hospital of Zhejiang University School of Medicine. All 13 patients were admitted to the ICU after craniectomy and received mechanical ventilation. Computed tomography (CT) were conducted when patients' consciousness, pupillary size, light reflex changed apparently, or if the bone window tension and the intracranial pressure increased unexpectedly. Head ultrasonography was performed within 2 hours of CT scanning.

Results

Ultrasonography revealed 18 pathological changes in the 13 patients. CT and a second operation helped to identify 23 pathological changes. The results of B-mode ultrasound were compared with those of CT and the coincidence rate was 78.3%, with no significant difference in the diagnosis of delayed haematoma or midline shift (Kappa=0.898, p<0.05).

Conclusions

Transcranial ultrasonography may be a useful tool for monitoring post-operation intracranial lesions in multiple trauma patients with severe head injury. It is an effective supplement to CT.

Predicting intracranial hemorrhage after traumatic brain injury in low and middle-income countries: a prognostic model based on a large, multi-center, international cohort

Background

Traumatic brain injury (TBI) affects approximately 10 million people annually, of which intracranial hemorrhage is a devastating sequelae, occurring in one-third to half of cases. Patients in low and middle-income countries (LMIC) are twice as likely to die following TBI as compared to those in high-income countries. Diagnostic capabilities and treatment options for intracranial hemorrhage are limited in LMIC as there are fewer computed tomography (CT) scanners and neurosurgeons per patient as in high-income countries.

Methods

The Medical Research Council CRASH-1 trial was utilized to build this model. The study cohort included all patients from LMIC who received a CT scan of the brain (n = 5669). Prognostic variables investigated included age, sex, time from injury to randomization, pupil reactivity, cause of injury, seizure and the presence of major extracranial injury.

Results

There were five predictors that were included in the final model; age, Glasgow Coma Scale, pupil reactivity, the presence of a major extracranial injury and time from injury to presentation. The model demonstrated good discrimination and excellent calibration (c-statistic 0.71). A simplified risk score was created for clinical settings to estimate the percentage risk of intracranial hemorrhage among TBI patients.

Conclusion

Simple prognostic models can be used in LMIC to estimate the risk of intracranial hemorrhage among TBI patients. Combined with clinical judgment this may facilitate risk stratification, rapid transfer to higher levels of care and treatment in resource-poor settings.

An injury awareness education program on outcomes of juvenile justice offenders in Western Australia: an economic analysis

Background

Injury is a major cause of mortality and morbidity of young people and the cost-effectiveness of many injury prevention programs remains uncertain. This study aimed to analyze the costs and benefits of an injury awareness education program, the P.A.R.T.Y. (Prevent Alcohol and Risk-related Trauma in Youth) program, for juvenile justice offenders in Western Australia.

Methods

Costs and benefits analysis based on effectiveness data from a linked-data cohort study on 225 juvenile justice offenders who were referred to the education program and 3434 who were not referred to the program between 2006 and 2011.

Results

During the study period, there were 8869 hospitalizations and 113 deaths due to violence or traffic-related injuries among those aged between 14 and 21 in Western Australia. The mean length of hospital stay was 4.6 days, a total of 320 patients (3.6%) needed an intensive care admission with an average length of stay of 6 days. The annual cost saved due to serious injury was $3,765 and the annual net cost of running this program was $33,735. The estimated cost per offence prevented, cost per serious injury avoided, and cost per undiscounted and discounted life year gained were $3,124, $42,169, $8,268 and $17,910, respectively. Increasing the frequency of the program from once per month to once per week would increase its cost-effectiveness substantially.

Conclusions

The P.A.R.T.Y. injury education program involving real-life trauma scenarios was cost-effective in reducing subsequent risk of committing violence or traffic-related offences, injuries, and death for juvenile justice offenders in Western Australia.

Cerebral microdialysis and PtiO2 to decide unilateral decompressive craniectomy after brain gunshot

Decompressive craniectomy (DC) following brain injury can induce complications (hemorrhage, infection, and hygroma). It is then considered as a last-tier therapy, and can be deleteriously delayed. Focal neuromonitoring (microdialysis and PtiO2) can help clinicians to decide bedside to perform DC in case of intracranial pressure (ICP) around 20 to 25 mmHg despite maximal medical treatment. This was the case of a hunter, brain injured by gunshot. DC was performed at day 6, because of unstable ICP, ischemic trend of PtiO2, and decreased cerebral glucose but normal lactate/pyruvate ratio. His evolution was good despite left hemiplegia due to initial injury.

Predicting early death in patients with traumatic bleeding: development and validation of prognostic model

OBJECTIVE

To develop and validate a prognostic model for early death in patients with traumatic bleeding.

DESIGN

Multivariable logistic regression of a large international cohort of trauma patients.

SETTING

274 hospitals in 40 high, medium, and low income countries

PARTICIPANTS

Prognostic model development: 20,127 trauma patients with, or at risk of, significant bleeding, within 8 hours of injury in the Clinical Randomisation of an Antifibrinolytic in Significant Haemorrhage (CRASH-2) trial. External validation: 14,220 selected trauma patients from the Trauma Audit and Research Network (TARN), which included mainly patients from the UK.

OUTCOMES

In-hospital death within 4 weeks of injury.

RESULTS

3076 (15%) patients died in the CRASH-2 trial and 1765 (12%) in the TARN dataset. Glasgow coma score, age, and systolic blood pressure were the strongest predictors of mortality. Other predictors included in the final model were geographical region (low, middle, or high income country), heart rate, time since injury, and type of injury. Discrimination and calibration were satisfactory, with C statistics above 0.80 in both CRASH-2 and TARN. A simple chart was constructed to readily provide the probability of death at the point of care, and a web based calculator is available for a more detailed risk assessment (http://crash2.lshtm.ac.uk).

CONCLUSIONS

This prognostic model can be used to obtain valid predictions of mortality in patients with traumatic bleeding, assisting in triage and potentially shortening the time to diagnostic and lifesaving procedures (such as imaging, surgery, and tranexamic acid). Age is an important prognostic factor, and this is of particular relevance in high income countries with an aging trauma population.

Access to reliable information about long-term prognosis influences clinical opinion on use of lifesaving intervention

BACKGROUND

Decompressive craniectomy has been traditionally used as a lifesaving rescue treatment in severe traumatic brain injury (TBI). This study assessed whether objective information on long-term prognosis would influence healthcare workers' opinion about using decompressive craniectomy as a lifesaving procedure for patients with severe TBI.

METHOD

A two-part structured interview was used to assess the participants' opinion to perform decompressive craniectomy for three patients who had very severe TBI. Their opinion was assessed before and after knowing the predicted and observed risks of an unfavourable long-term neurological outcome in various scenarios.

RESULTS

Five hundred healthcare workers with a wide variety of clinical backgrounds participated. The participants were significantly more likely to recommend decompressive craniectomy for their patients than for themselves (mean difference in visual analogue scale [VAS] -1.5, 95% confidence interval -1.3 to -1.6), especially when the next of kin of the patients requested intervention. Patients' preferences were more similar to patients who had advance directives. The participants' preferences to perform the procedure for themselves and their patients both significantly reduced after knowing the predicted risks of unfavourable outcomes, and the changes in attitude were consistent across different specialties, amount of experience in caring for similar patients, religious backgrounds, and positions in the specialty of the participants.

CONCLUSIONS

Access to objective information on risk of an unfavourable long-term outcome influenced healthcare workers' decision to recommend decompressive craniectomy, considered as a lifesaving procedure, for patients with very severe TBI.

Effect of an injury awareness education program on risk-taking behaviors and injuries in juvenile justice offenders: a retrospective cohort study

Background

Risk-taking behavior is a leading cause of injury and death amongst young people.

Methodology and Principal Findings

This was a retrospective cohort study on the effectiveness of a 1-day youth injury awareness education program (Prevent Alcohol and Risk-related Trauma in Youth, P.A.R.T.Y.) program in reducing risk taking behaviors and injuries of juvenille justice offenders in Western Australia. Of the 3659 juvenile justice offenders convicted by the court magistrates between 2006 and 2010, 225 were referred to the P.A.R.T.Y. education program. In a before and after survey of these 225 participants, a significant proportion of them stated that they were more receptive to modifying their risk-taking behavior (21% before vs. 57% after). Using data from the Western Australia Police and Department of Health, the incidence of subsequent offences and injuries of all juvenile justice offenders was assessed. The incidence of subsequent traffic or violence-related offences was significantly lower for those who had attended the program compared to those who did not (3.6% vs. 26.8%; absolute risk reduction [ARR] = 23.2%, 95% confidence interval [CI] 19.9%–25.8%; number needed to benefit = 4.3, 95%CI 3.9–5.1; p = 0.001), as were injuries leading to hospitalization (0% vs. 1.6% including 0.2% fatality; ARR = 1.6%, 95%CI 1.2%–2.1%) and alcohol or drug-related offences (0% vs. 2.4%; ARR 2.4%, 95%CI 1.9%–2.9%). In the multivariate analysis, only P.A.R.T.Y. education program attendance (odds ratio [OR] 0.10, 95%CI 0.05–0.21) and a higher socioeconomic background (OR 0.97 per decile increment in Index of Relative Socioeconomic Advantage and Disadvantage, 95%CI 0.93–0.99) were associated with a lower risk of subsequent traffic or violence-related offences.

Significance

Participation in an injury education program involving real-life trauma scenarios was associated with a reduced subsequent risk of committing violence- or traffic-related offences, injuries, and death for juvenille justice offenders.

Cost-effectiveness of decompressive craniectomy as a lifesaving rescue procedure for patients with severe traumatic brain injury

BACKGROUND

Decompressive craniectomy has been traditionally used as a lifesaving rescue procedure for patients with refractory intracranial hypertension after severe traumatic brain injury (TBI), but its cost-effectiveness remains uncertain.

METHODS

Using data on length of stay in hospital, rehabilitation facility, procedural costs, and Glasgow Outcome Scale (GOS) up to 18 months after surgery, the average total hospital costs per life-year and quality-adjusted life-year (QALY) were calculated for patients who had decompressive craniectomy for TBI between 2004 and 2010 in Western Australia. The Corticosteroid Randomisation After Significant Head Injury prediction model was used to quantify the severity of TBI.

RESULTS

Of the 168 patients who had 18-month follow-up data available after the procedure, 70 (42%) achieved a good outcome (GOS-5), 27 (16%) had moderate disability (GOS-4), 34 (20%) had severe disability (GOS-3), 5 (3%) were in vegetative state (GOS-2), and 32 (19%) died (GOS-1). The hospital costs increased with the severity of TBI and peaked when the predicted risk of an unfavorable outcome was about 80%. The average cost per life-year gained (US$671,000 per life-year) and QALY (US$682,000 per QALY) increased substantially and became much more than the usual acceptable cost-effective limit (US$100,000 per QALY) when the predicted risk of an unfavorable outcome was >80%. Changing different underlying assumptions of the analysis did not change the results significantly.

CONCLUSIONS

Severity of TBI had an important effect on cost-effectiveness of decompressive craniectomy. As a lifesaving procedure, decompressive craniectomy was not cost-effective for patients with extremely severe TBI.

The influence of objective prognostic information on the likelihood of informed consent for decompressive craniectomy: a study of Australian anaesthetists

The aim of this study was to assess the influence of detailed prognostic information on the likelihood of informed consent for decompressive craniectomy for severe traumatic brain injury. The study was a simulation exercise, asking anaesthetists to give opinions as if they themselves were the injured party. Anaesthetists were chosen as they represent a distinct group likely to be familiar with the procedure and the decision-making process, but not necessarily aware of the longer-term outcomes. A two-part structured interview was used. Seventy-five anaesthetists were shown three cases of differing severity of traumatic brain injury. A visual analogue scale (1 to 10) was used to assess the strengths of their opinion. Initially they were asked their opinion with no predictive outcome data. They were then shown the prediction of an unfavourable outcome (Glasgow Outcome Scale severely disabled, vegetative state or dead) and the observed outcome at 18-month follow-up from a cohort of 147 patients (who had had a decompressive craniectomy for severe traumatic brain injury in Perth, Western Australia between the years 2004 and 2008). The opinions of the participants before and after seeing the prediction outcome data were compared. The participants' preferences to consent to the procedure changed after being informed of the predicted risks of unfavourable outcomes (P values < 0.01). The changes in attitude appeared to be independent of age group, amount of experience in caring for similar patients and religious background. These findings suggest that access to objective information on risks of unfavourable outcomes may influence opinions in relation to consent for decompressive craniectomy for traumatic brain injury.

Surgical intervention for severe head injury: ethical considerations when performing life-saving but non-restorative surgery

BACKGROUND

The aim of this study was to compare the predicted outcome with observed outcome in those patients who have had a unilateral decompressive craniectomy following evacuation of an intracranial mass lesion and to consider some of the ethical issues that need to be addressed when performing life-saving but non-restorative surgery.

METHODS

By using the web-based outcome prediction model developed by the CRASH trial collaborators predicted and observed outcomes were compared for those patients who had had a unilateral decompression after evacuation of a mass lesion in the two major neurotrauma hospitals in Western Australia between 2004 and 2008. Three cases were selected with differing outcome predictions.

RESULTS

For the three selected cases the predicted risk of an unfavourable outcome at 6 months was 65.8%, 78.9% and 91.3%, respectively. For the 11 patients in this cohort with an outcome prediction between 61% and 70%, the observed outcome at 18 months (GOS) was: 5 had a good outcome, 4 were moderately disabled, and 3 were severely disabled. For the ten patients with an outcome prediction between 90-100%, observed outcome confirmed: one patient was moderately disabled, four patients were severely disabled, one patient was in a permanent vegetative state, and four patients had died.

CONCLUSION

As the index of injury severity (as adjudged by the CRASH outcome prediction model) increases, clinical decision making and discussion with surrogates must reflect the evidence provided by observed outcome, prior to life-saving but potentially non-restorative decompressive surgery.

Incidence and risk factors for fatal pulmonary embolism after major trauma: a nested cohort study

BACKGROUND

Venous thromboembolism is common after major trauma. Strategies to prevent fatal pulmonary embolism (PE) are widely utilized, but the incidence and risk factors for fatal PE are poorly understood.

METHODS

Using linked data from the intensive care unit, trauma registry, Western Australian Death Registry, and post-mortem reports, the incidence and risk factors for fatal PE in a consecutive cohort of major trauma patients, admitted between 1994 and 2002, were assessed. Non-linear relationships between continuous predictors and risk of fatal PE were modelled by logistic regression.

RESULTS

Of the 971 consecutive trauma patients considered in the study, 134 (13.8%) died after their injuries. Fatal PE accounted for 11.9% of all deaths despite unfractionated heparin prophylaxis being used in 44% of these patients. Fatal PE occurred in those who were older (mean age 51- vs 37-yr-old, P=0.01), with more co-morbidities (Charlson's co-morbidity index 1.1 vs 0.2, P=0.01), had a larger BMI (31.8 vs 24.5, P=0.01), and less severe head and systemic injuries when compared with those who died of other causes. Sites of injuries were not significantly related to the risk of fatal PE. Fatal PE occurred much later than deaths from other causes (median 18 vs 2 days, P=0.01), and the estimated attributable mortality of PE was 49% (95% confidence interval 36-62%).

CONCLUSIONS

Fatal PE appeared to be a potential preventable cause of late mortality after major trauma. Severity of injuries, co-morbidity, and BMI were important risk factors for fatal PE after major trauma.

Decompressive craniectomy for neurotrauma: the limitations of applying an outcome prediction model

BACKGROUND

There is currently much interest in the use of decompressive craniectomy for patients with severe head injury. A number of studies have demonstrated that not only can the technique lower intracranial pressure but can also improve outcome. Whilst many patients who would otherwise have died or had a poor outcome now go on to make a good recovery, there is little doubt that complications can have a very significant impact on long term outcome.

METHODS

By using the corticosteroid randomisation after significant head injury (CRASH) collaborators outcome prediction model, three patients were selected who had a similar outcome prediction. All three patients developed intracranial hypertension following trauma and had a decompressive craniectomy.

RESULTS

Despite having a similar outcome prediction only one patient made an uneventful recovery. The remaining two patients suffered significant complications.

CONCLUSIONS

This report illustrates the potential clinical applications and limitations of an outcome prediction model and demonstrates the impact that complications can have on eventual outcome.