Aziz S. Alali, Nancy Temkin, Monica S. Vavilala, Abhijit V. Lele, Jason Barber, Sureyya Dikmen and Randall M. Chesnut
The aim of this study was to examine the relationship between early arterial oxygenation thresholds and long-term outcome after severe traumatic brain injury (TBI).
In a post hoc analysis of a randomized trial, adults with severe TBI were classified based on exposure to different levels of arterial oxygenation as measured using the average of arterial partial pressure of oxygen (PaO2) values obtained within 24 hours of admission. Potentially important PaO2 thresholds were defined a priori. The primary outcome was Glasgow Outcome Scale–Extended (GOSE) score at 6 months. Secondary outcomes were cognitive outcomes measured using a battery of 9 neuropsychological tests administered at 6 months, and 6-month mortality.
In adjusted analyses, oxygenation thresholds of 150 and 200 mm Hg were associated with better functional outcome at 6 months (adjusted OR for better functional outcome on GOSE 1.82 [95% CI 1.12–2.94] and 1.59 [95% CI 1.06–2.37], respectively) and improved cognitive outcome at 6 months (adjusted beta coefficients for better cognitive percentile across 9 neuropsychological tests: 6.9 [95% CI 1.3–12.5] and 6.8 [95% CI 2.4–11.3], respectively). There was no significant association between oxygenation level and 6-month mortality except at a PaO2 threshold of 200 mm Hg (OR for death 0.36, 95% CI 0.18–0.71). Higher or lower oxygenation thresholds were not associated with functional or cognitive outcome.
In this observational study, the relationship between early arterial oxygenation and long-term functional and cognitive TBI outcomes appears to be U-shaped. Mild levels of hyperoxemia within the first 24 hours after injury were associated with better long-term functional and cognitive outcomes. These findings highlight the importance of examining balanced oxygen supplementation as a potential strategy to improve TBI outcomes in future research.
Aziz S. Alali, Nancy Temkin, Jason Barber, Jim Pridgeon, Kelley Chaddock, Sureyya Dikmen, Peter Hendrickson, Walter Videtta, Silvia Lujan, Gustavo Petroni, Nahuel Guadagnoli, Zulma Urbina and Randall M. Chesnut
While existing guidelines support the treatment of intracranial hypertension in severe traumatic brain injury (TBI), it is unclear when to suspect and initiate treatment for high intracranial pressure (ICP). The objective of this study was to derive a clinical decision rule that accurately predicts intracranial hypertension.
Using Delphi methods, the authors identified a set of potential predictors of intracranial hypertension and a clinical decision rule a priori by consensus among a group of 43 neurosurgeons and intensivists who have extensive experience managing severe TBI without ICP monitoring. To validate these predictors, the authors used data from a Latin American trial (n = 150; BEST TRIP). To report on the performance of the rule, they calculated sensitivity, specificity, and positive and negative predictive values with 95% confidence intervals. In a secondary analysis, the rule was validated using data from a North American trial (n = 131; COBRIT).
The final predictors and the clinical decision rule were approved by 97% of participants in the consensus working group. The predictors are divided into major and minor criteria. High ICP would be considered suspected in the presence of 1 major or ≥ 2 minor criteria. Major criteria are: compressed cisterns (CT classification of Marshall diffuse injury [DI] III), midline shift > 5 mm (Marshall DI IV), or nonevacuated mass lesion. Minor criteria are: Glasgow Coma Scale (GCS) motor score ≤ 4, pupillary asymmetry, abnormal pupillary reactivity, or Marshall DI II. The area under the curve for the logistic regression model that contains all the predictors was 0.86. When high ICP was defined as > 22 mm Hg, the decision rule performed with a sensitivity of 93.9% (95% CI 85.0%–98.3%), a specificity of 42.3% (95% CI 31.7%–53.6%), a positive predictive value of 55.5% (95% CI 50.7%–60.2%), and a negative predictive value of 90% (95% CI 77.1%–96.0%). The sensitivity of the clinical decision rule improved with higher ICP cutoffs up to a sensitivity of 100% when intracranial hypertension was defined as ICP > 30 mm Hg. Similar results were found in the North American cohort.
A simple clinical decision rule based on a combination of clinical and imaging findings was found to be highly sensitive in distinguishing patients with severe TBI who would suffer intracranial hypertension. It could be used to identify patients who require ICP monitoring in high-resource settings or start ICP-lowering treatment in environments where resource limitations preclude invasive monitoring.
Clinical trial registration no.: NCT02059941 (clinicaltrials.gov).
Isaac Josh Abecassis, John D. Nerva, Jason Barber, Jason Rockhill, Richard G. Ellenbogen, Louis J. Kim and Laligam N. Sekhar
Brain arteriovenous malformations (bAVMs) are rare in pediatric patients but represent the most common cause of hemorrhagic stroke in this population. Pediatric patients demonstrate superior outcomes in comparison with adult patients with similar lesions and presentations. Most studies of clinical outcomes of pediatric bAVMs use the modified Rankin Scale (mRS), despite a lack of validation in pediatric patients.
The authors interviewed the parents of 26 pediatric patients who underwent multimodality bAVM treatment and administered the Pediatric Quality of Life Inventory (PedsQL)—a well-validated tool for pediatric outcomes that quantifies performance in a physical, emotional, social, and school domains. They also reviewed clinical information from the patients' medical charts. Statistical analysis was performed using a log-transformed t-test, the Mann-Whitney exact test, the Kruskal-Wallis test, and Spearman correlation. In addition, the literature was reviewed for prior reports of clinical outcome of pediatric cases of bAVM.
The average PedsQL health-related quality of life score was 71 ± 24, with an average age at diagnosis of 12.5 years and an average follow-up period of 6.8 years. Seventeen patients (65%) presented with hemorrhage and 4 (15%) with seizures. PedsQL scores correlated strongly and at a statistically significant level (p < 0.001) with mRS, Pediatric Overall Performance Category (POPC), Pediatric Cerebral Performance Category (PCPC), and Glasgow Outcome Scale scores. Multivariate modeling validated special education, corrective devices, and cure status as significant predictors of PedsQL scores. Statistically significant risk factors for undergoing placement of a ventriculoperitoneal shunt included lower Glasgow Coma Scale motor scores on admission (p = 0.042), cerebellar location (p = 0.046), and nidus volume (p = 0.017). Neither treatment modality nor location statistically affected clinical outcomes at follow-up.
There have been few studies of long-term clinical outcomes of bAVM in pediatric patients, and previously published studies have used conventional metrics that have been validated in the adult population, such as the mRS. Although these metrics can serve as reasonable surrogates, an accurate understanding of overall health-related quality of life is contingent on utilizing validated toolsets, such as the PedsQL.
Ryan P. Morton, I. Josh Abecassis, Josiah F. Hanson, Jason Barber, John D. Nerva, Samuel N. Emerson, Chibawanye I. Ene, Michelle M. Chowdhary, Michael R. Levitt, Andrew L. Ko, Timothy H. Dellit and Randall M. Chesnut
The authors' aim was to report the largest study on predictors of infection after cranioplasty and to assess the predictive value of intraoperative bone flap cultures before cryopreservation.
They retrospectively examined all cranioplasties performed between March 2004 and November 2014. Throughout this study period, the standard protocol during initial craniectomy was to obtain a culture swab of the extracted autologous bone flap (ABF)—prior to its placement in cytostorage—to screen for microbial contamination. Two consecutive protocols were employed for the use and interpretation of the intraoperative swab culture results: A) From March 2004 through June 2013, any culture-positive ABF (+ABF) was discarded and a custom synthetic prosthesis was implanted at the time of cranioplasty. B) From July 2013 through November 2014, any ABF with a skin flora organism was not discarded. Instead, cryopreservation was maintained and the +ABF was reimplanted after a 10-minute soak in bacitracin irrigation as well as a 3-minute soak in betadine.
Over the 10.75-year period, 754 cranioplasty procedures were performed. The median time from craniectomy to cranioplasty was 123 days. Median follow-up after cranioplasty was 237 days for protocol A and 225 days for protocol B. The overall infection rate after cranioplasty was 6.6% (50 cases) occurring at a median postoperative Day 31. Staphylococcus spp. were involved as the causative organisms in 60% of cases.
Culture swabs taken at the time of initial craniectomy were available for 640 ABFs as 114 ABFs were not salvageable. One hundred twenty-six (20%) were culture positive. Eighty-nine +ABFs occurred during protocol A and were discarded in favor of a synthetic prosthesis at the time of cranioplasty, whereas 37 +ABFs occurred under protocol B and were reimplanted at the time of cranioplasty.
Cranioplasty material did not affect the postcranioplasty infection rate. There was no significant difference in the infection rate among sterile ABFs (7%), +ABFs (8%), and synthetic prostheses (5.5%; p = 0.425). All 3 +ABF infections under protocol B were caused by organisms that differed from those in the original intraoperative bone culture from the initial craniectomy. A cranioplasty procedure ≤ 14 days after initial craniectomy was the only significant predictor of postcranioplasty infection (p = 0.007, HR 3.62).
Cranioplasty procedures should be performed at least 14 days after initial craniectomy to minimize infection risk. Obtaining intraoperative bone cultures at the time of craniectomy in the absence of clinical infection should be discontinued as the culture results were not a useful predictor of postcranioplasty infection and led to the unnecessary use of synthetic prostheses and increased health care costs.
Robert T. Buckley, Tiffany Morgan, Russell P. Saneto, Jason Barber, Richard G. Ellenbogen and Jeffrey G. Ojemann
Functional hemispherectomy is a well-recognized surgical option for the treatment of unihemispheric medically intractable epilepsy. While the resultant motor deficits are a well-known and expected consequence of the procedure, the impact on other cortical functions has been less well defined. As the cortical control of swallowing would appear to be threatened after hemispherectomy, the authors retrospectively studied a pediatric population that underwent functional hemispherectomy for medically intractable epilepsy to characterize the incidence and severity of dysphagia after surgery.
A retrospective cohort (n = 39) of pediatric patients who underwent hemispherectomy at a single institution was identified, and available clinical records were reviewed. Additionally, the authors examined available MR images for integrity of the thalamus and basal ganglia before and after hemispherectomy. Clinical and video fluoroscopic assessments of speech pathology were reviewed, and the presence, type, and duration of pre- and postoperative dysphagia were recorded.
New-onset, transient dysphagia occurred in 26% of patients after hemispherectomy along with worsening of preexisting dysphagia noted in an additional 15%. Clinical symptoms lasted a median of 19 days. Increased duration of symptoms was seen with late (> 14 days postoperative) pharyngeal swallow dysfunction when compared with oral dysphagia alone. Neonatal stroke as a cause for seizures decreased the likelihood of postoperative dysphagia. There was no association with seizure freedom or postoperative hydrocephalus.
New-onset dysphagia is a frequent and clinically significant consequence of hemispherectomy for intractable epilepsy in pediatric patients. This dysphagia was always self-limited except in those patients in whom preexisting dysphagia was noted.