Acute Effects of Ketamine on Intracranial Pressure in Children With Severe Traumatic Brain Injury.

OBJECTIVES: The acute cerebral physiologic effects of ketamine in children have been incompletely described. We assessed the acute effects of ketamine on intracranial pressure (ICP) and cerebral perfusion pressure (CPP) in children with severe traumatic brain injury (TBI). DESIGN: In this retrospective observational study, patients received bolus doses of ketamine for sedation or as a treatment for ICP crisis (ICP > 20 mm Hg for > 5 min). Administration times were synchronized with ICP and CPP recordings at 1-minute intervals logged in an automated database within the electronic health record. ICP and CPP were each averaged in epochs following drug administration and compared with baseline values. Age-based CPP thresholds were subtracted from CPP recordings and compared with baseline values. Trends in ICP and CPP over time were assessed using generalized least squares regression. SETTING: A 30-bed tertiary care children's hospital PICU. PATIENTS: Children with severe TBI who underwent ICP monitoring. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: We analyzed data from 33 patients, ages 1 month to 16 years, 22 of whom received bolus doses of ketamine, with 127 doses analyzed. Demographics, patient, and injury characteristics were similar between patients who did versus did not receive ketamine boluses. In analysis of the subset of ketamine doses used only for sedation, there was no significant difference in ICP or CPP from baseline. Eighteen ketamine doses were given during ICP crises in 11 patients. ICP decreased following these doses and threshold-subtracted CPP rose. CONCLUSIONS: In this retrospective, exploratory study, ICP did not increase following ketamine administration. In the setting of a guidelines-based protocol, ketamine was associated with a reduction in ICP during ICP crises. If these findings are reproduced in a larger study, ketamine may warrant consideration as a treatment for intracranial hypertension in children with severe TBI.

Stent-Graft Length Is Associated with Decreased Patency in Treatment of Central Venous Stenosis in Hemodialysis Patients.

BACKGROUND: Central venous occlusion may occur in hemodialysis patients, resulting in arm or facial swelling and failure of dialysis access. Endovascular management with balloon angioplasty or stenting has been described, but there are minimal data on the use of covered stents in this pathology. We sought to review a single institution's experience with the use of covered stents for central venous occlusive disease in hemodialysis patients. METHODS: A retrospective review of all patients undergoing placement of covered stents between April 2014 and December 2016 for central venous occlusive disease to preserve a failing dialysis access was performed. Patients' records were reviewed to identify demographics, medical comorbidities, operative variables, primary patency rates, and secondary interventions. RESULTS: A total of 29 patients were included in the analysis. Viabahn (W.L. Gore and Associates, Flagstaff, AZ) stent grafts were exclusively used in all patients. Technical success rate was 100%. The patients were predominantly female (65.5%), with a mean age of 67.9 ± 12.1 and medical comorbidities of hypertension (86%), diabetes (76%), and tobacco use (7%). The majority (86%) had prior angioplasty and 17 of 29 (59%) patients had previous central venous catheters. The right brachiocephalic vein was the most commonly stented vessel (28%). The median stent length and diameter used were 50 millimeters (range 25-100 millimeters) and 13 millimeters (range: 9-13 millimeters), respectively. The majority of patients (83%) received a single stent, with only 2 patients requiring more than one. Median follow-up was 24 months (range: 6-41 months). Four of 29 (13.8%) patients developed symptomatic stent restenosis requiring secondary intervention, all of which occurred in patients with primary stenosis between 50% and 75%. When compared to the patients without restenosis, longer stents were found to be significantly associated with restenosis (62.5 centimeters, interquartile range [IQR]: 0] vs. 50 centimeter, IQR: 0, P = 0.002). Primary patency rates were 92.9%, 91.7%, and 80.0% at 6, 12, and 24 months respectively. Secondary patency rates were 96.4%, 95.8%, and 93.3% at 6 months, 12 months, and 24 months, respectively. The overall primary patency rate was estimated at 86.2% using Kaplan-Meier analysis at 30.5 months (95% confidence interval: 26.5-34.5 months). CONCLUSIONS: Covered stent grafts have reasonable primary patency and excellent secondary patency when used for central venous stenosis in dialysis patients. Stent-graft length is associated with poorer long-term patency rates.

Multimodal Neurologic Monitoring in Children With Acute Brain Injury.

Children with acute neurologic illness are at high risk of mortality and long-term neurologic disability. Severe traumatic brain injury, cardiac arrest, stroke, and central nervous system infection are often complicated by cerebral hypoxia, hypoperfusion, and edema, leading to secondary neurologic injury and worse outcome. Owing to the paucity of targeted neuroprotective therapies for these conditions, management emphasizes close physiologic monitoring and supportive care. In this review, we will discuss advanced neurologic monitoring strategies in pediatric acute neurologic illness, emphasizing the physiologic concepts underlying each tool. We will also highlight recent innovations including novel monitoring modalities, and the application of neurologic monitoring in critically ill patients at risk of developing neurologic sequelae.