Validation of an International Classification of Disease, Ninth Revision coding algorithm to identify decompressive craniectomy for stroke

Background: Although International Classification of Disease, Ninth Revision, Clinical Modification (ICD9-CM) coding is the basis of administrative claims data, no study has validated an ICD9-CM algorithm to identify patients undergoing decompressive craniectomy for space-occupying supratentorial infarction. Methods: Patients who underwent decompressive craniectomy for stroke at our institution were retrospectively identified and their associated ICD9-CM codes were extracted from billing data. An ICD9-CM algorithm was generated and its accuracy compared against physician review. Results: A total of 10,925 neurosurgical operations were performed from December 2008 to March 2015, of which 46 (0.4%) were decompressive craniectomy for space-occupying stroke. The ICD9-CM procedure code for craniectomy (01.25) was only encoded in 67.4% of patients, while craniotomy (01.24) was used in 19.6% and lobectomy (01.39, 01.53, 01.59) in 13.1%. The ICD-9-CM algorithm included patients with a diagnosis codes for cerebral infarction (433.11, 434.01, 434.11, and 434.91) and a procedure code for craniotomy, craniectomy, or lobectomy. Patients were excluded with an ICD9-CM diagnosis code for brain tumor, intracranial abscess, subarachnoid hemorrhage, vertebrobasilar infarction, intracranial aneurysm, Moyamoya disease, intracranial venous sinus thrombosis, vertebral artery dissection, congenital cerebrovascular anomaly, head trauma or an ICD9-CM procedure code for laminectomy. This algorithm had a sensitivity of 97.8%, specificity of 99.9%, positive predictive value of 88.2%, and negative predictive value of 99.9%. The majority of false-positive results were patients who underwent evacuation of a primary intracerebral hematoma. Conclusion: An ICD-9-CM algorithm based on diagnosis and procedure codes can effectively identify patients undergoing decompressive craniectomy for supratentorial stroke

Recent Research on EMF and Health Risk, Twelfth report from SSM's Scientific Council on Electromagnetic Fields, 2017

Background: The Swedish Radiation Safety Authority's (SSM) Scientific Council on Electromagnetic Fields monitors current research on potential health risks with a correlation to exposure to electromagnetic fields, and provides the Authority with advice on assessing possible health risks. The Council gives guidance when the Authority must give an opinion on policy matters when scientific testing is necessary. The Council is required to submit a written report each year on the current research and knowledge situation. Objective: The report has the objective of covering the previous year's research in the area of electromagnetic fields (EMF). The report gives the Swedish Radiation Safety Authority an overview and provides an important basis for risk assessment. Results: The present annual report is the twelfth in this series and covers studies published from October 2015 up to and including March 2017. The report covers different areas of EMF (static, low frequency, intermediate, and radio frequency fields) and different types of studies such as biological, human and epidemiological studies. No new health risks have been identified. Whether mobile phone use causes brain tumours or not was mainly addressed using time trends studies in the last two years. The results were not entirely consistent but mainly point towards a lack of association. Some cell and animal studies indicate that EMF exposure may cause oxidative stress even at low exposure levels. It is unclear what relevance this may have when it comes to direct health effects in humans. A striking result was that some studies showed a stronger association between memory functions and radio wave exposure than other usage variables. The annual report also has a section covering other relevant scientific reports published recently

Decline in subarachnoid haemorrhage volumes associated with the first wave of the COVID-19 pandemic

BACKGROUND: During the COVID-19 pandemic, decreased volumes of stroke admissions and mechanical thrombectomy were reported. The study\u27s objective was to examine whether subarachnoid haemorrhage (SAH) hospitalisations and ruptured aneurysm coiling interventions demonstrated similar declines. METHODS: We conducted a cross-sectional, retrospective, observational study across 6 continents, 37 countries and 140 comprehensive stroke centres. Patients with the diagnosis of SAH, aneurysmal SAH, ruptured aneurysm coiling interventions and COVID-19 were identified by prospective aneurysm databases or by International Classification of Diseases, 10th Revision, codes. The 3-month cumulative volume, monthly volumes for SAH hospitalisations and ruptured aneurysm coiling procedures were compared for the period before (1 year and immediately before) and during the pandemic, defined as 1 March-31 May 2020. The prior 1-year control period (1 March-31 May 2019) was obtained to account for seasonal variation. FINDINGS: There was a significant decline in SAH hospitalisations, with 2044 admissions in the 3 months immediately before and 1585 admissions during the pandemic, representing a relative decline of 22.5% (95% CI -24.3% to -20.7%, p\u3c0.0001). Embolisation of ruptured aneurysms declined with 1170-1035 procedures, respectively, representing an 11.5% (95%CI -13.5% to -9.8%, p=0.002) relative drop. Subgroup analysis was noted for aneurysmal SAH hospitalisation decline from 834 to 626 hospitalisations, a 24.9% relative decline (95% CI -28.0% to -22.1%, p\u3c0.0001). A relative increase in ruptured aneurysm coiling was noted in low coiling volume hospitals of 41.1% (95% CI 32.3% to 50.6%, p=0.008) despite a decrease in SAH admissions in this tertile. INTERPRETATION: There was a relative decrease in the volume of SAH hospitalisations, aneurysmal SAH hospitalisations and ruptured aneurysm embolisations during the COVID-19 pandemic. These findings in SAH are consistent with a decrease in other emergencies, such as stroke and myocardial infarction

Lung tumor induction upon long-term low-level inhalation of crystalline silica

F-344 rats were exposed 6 hours/day, 5 days/week for up to 24 months to 1mg/cubicmeter SiO2 or 5 mg/cubicmeter TiO2. A third group of rats inhaled filtered air. No treatment-related effects on life span or causes of deaths were observed. The final sacrifices started 6 weeks after the end of the exposure interval. The lung weight of the silica-exposed animals doubled, while the TiO2-treated animals had lung weights similar to those of the control group. An incidence of 18 % of lung tumors was observed in the silica exposed animals. Tumors were first observed after 21 months in the study. The incidence of lung tumors in the control and TiO2-exposed groups was 2-3%. The significance of the results is that the silica-induced tumors were detected after a relatively low exposure level. The small particle size with corresponding large surface area of the silica used may be one factor for the increased tumor rate observed

O-007 An analysis of stroke thrombectomy interhospital transportation modality

Objective Expeditious interhospital transport of patients with potential large-vessel occlusions is key in the hub and spoke model, where patients are first taken to a local primary hospital to be evaluated for intravenous thrombolysis, and then subsequently transferred to an endovascular capable stroke center. The decision on transport modality—air versus ground transportation—may be multifactorial, dependent upon dispatch times, availability, and cost. This study aims to evaluate and quantify the presumed reduction in time to thrombectomy with air compared to ground transport. Methods Patients undergoing mechanical thrombectomy for carotid circulation occlusion within 6 hours at an urban, comprehensive stroke center were retrospectively analyzed. Multivariable linear regression evaluated the relationship between transport modality and the time from last known well to groin puncture after adjusting for distance from the comprehensive stroke center. Results From January 2015 to March 2018, 133 mechanical thrombectomy interhospital transfers were identified; transportation modality was air in 30.8% (n=41) and ground in 69.2% (n=92). The mean inter-hospital distance was 24.1 (standard deviation 16.4, range 0–62) miles. Among patients travelling greater than 10 miles, the use of air transport was associated with a significantly shorter time between last known well and groin puncture when compared to ground (by 26.3 minutes, 95% CI: 1.1–51.9 minutes, p=0.04). The benefit of air transport was greater with increasing distances, with a significantly shorter time to thrombectomy of 35.1 minutes (p=0.02) if an inter-hospital distance of greater than 20 miles, and of 42.2 minutes (p=0.03) if greater than 30 miles. Within 10 miles however, all patients were transported by ground. Conclusions In this single-center analysis, helicopter emergency medical service lead to a shorter time to thrombectomy compared with ground transport. Given the known benefit to earlier revascularization on stroke outcomes, these data support the use of emergency aeromedical services when logistically feasible for stroke thrombectomy interhospital transfers greater than 10 miles. Disclosures H. Dasenbrock: None. A. Beer-Furlan: None. A. Vargas: None. J. Connors: None. R. Crowley: None. M. Chen: 2; C; Genentech, Pneumbra, Stryker, Medtronic

Role of blood-brain barrier P-glycoprotein in limiting brain accumulation and sedative side-effects of asimadoline, a peripherally acting analgaesic drug

1 Studies with knockout mice lacking mdrla P-glycoprotein (P-gp) have previously shown that blood-brain barrier P-gp is important in preventing the accumulation of several drugs in the brain. 2 Asimadoline (EMD 61753) is a peripherally selective kappa-opioid receptor agonist which is under development as a therapeutic analgaesic. From the structural characteristics of this drug and its peripheral selectivity, we hypothesized that it is transported by P-gp. 3 Using a pig-kidney polarized epithelial cell line transfected with mdr cDNAs, we demonstrate that asimadoline is transported by the mouse mdrla P-gp and the human MDRI P-gp. 4 Furthermore, we show that in mdr 1a/1b double knockout mice, the absence of P-gp leads to a 9 fold increased accumulation of asimadoline in the brain. In line with this accumulation difference, mdr 1a/1b (-/-) mice are at least 8 fold more sensitive to the sedative effect of asimadoline than wild-type mice. 5 Interestingly, the oral uptake of asimadoline was not substantially altered in mdr 1a/1b (-/-) mice. 6 Our results demonstrate that for some drugs, P-gp in the blood-brain barrier can have a therapeutically beneficial effect by limiting brain penetration, whereas at the same time intestinal P-gp is not a significant impediment to oral uptake of the drug