The Influence of Body Mass Index on Outcomes in Patients Undergoing Mechanical Thrombectomy for Anterior Circulation Large Vessel Occlusion: Institutional Experience and Meta-analysis.

BACKGROUND: An obesity paradox, whereby patients with higher body mass index (BMI) experience improved outcomes, has been described for ischemic stroke. It is unclear whether this applies to patients undergoing mechanical thrombectomy (MT) for large vessel occlusion (LVO). METHODS: Mechanical thrombectomies for anterior circulation LVO between 2015 and 2021 at a single institution were reviewed. Multivariable logistic regressions were used to determine the association between BMI and favorable functional outcome (90-day modified Rankin Scale 0-2), intracranial hemorrhage, and malignant middle cerebral infarction. A systematic review was performed to identify studies reporting the effect of BMI on outcomes among patients receiving MT for LVO. The data from the systematic review were combined with the institutional data by using a random effects model. RESULTS: The institutional cohort comprised 390 patients with a median BMI of 27 kg/m2. Most patients were obese [36.7% (BMI ≥ 30 kg/m2)], followed by overweight [30.5% (BMI ≥ 25 and < 30 kg/m2)], normal [27.9% (BMI ≥ 18.5 and < 25 kg/m2)], and underweight [4.9% (BMI < 18.5 kg/m2)]. As a continuous variable, BMI was not associated with any of the outcomes. When analyzing BMI ordinally, obesity was associated with lower odds of favorable 90-day modified Rankin Scale (odds ratio 0.42, 95% confidence interval 0.20-0.86). The systematic review identified three eligible studies comprising 1,348 patients for a total of 1,738 patients. In the random effects model, there was no association between obesity and favorable outcome (odds ratio 0.89, 95% confidence interval 0.63-1.24). CONCLUSIONS: Obesity is not associated with favorable outcomes in patients undergoing MT for LVO.

Machine learning prediction of malignant middle cerebral artery infarction after mechanical thrombectomy for anterior circulation large vessel occlusion.

OBJECTIVE: Prediction of malignant middle cerebral artery infarction (MMI) could identify patients for early intervention. We trained and internally validated a ML model that predicts MMI following mechanical thrombectomy (MT) for ACLVO. METHODS: All patients who underwent MT for ACLVO between 2015 - 2021 at a single institution were reviewed. Data was divided into 80% training and 20% test sets. 10 models were evaluated on the training set. The top 3 models underwent hyperparameter tuning using grid search with nested 5-fold CV to optimize the area under the receiver operating curve (AUROC). Tuned models were evaluated on the test set and compared to logistic regression. RESULTS: A total of 381 patients met the inclusion criteria. There were 50 (13.1%) patients who developed MMI. Out of the 10 ML models screened on the training set, the top 3 performing were neural network (median AUROC 0.78, IQR 0.72 - 0.83), support vector machine ([SVM] median AUROC 0.77, IQR 0.72 - 0.83), and random forest (median AUROC 0.75, IQR 0.68 - 0.81). On the test set, random forest (median AUROC 0.78, IQR 0.73 - 0.83) and neural network (median AUROC 0.78, IQR 0.73 - 0.83) were the top performing models, followed by SVM (median AUROC 0.77, IQR 0.70 - 0.83). These scores were significantly better than those for logistic regression (AUROC 0.72, IQR 0.66 - 0.78), individual risk factors, and the Malignant Brain Edema score (p < 0.001 for all). CONCLUSION: ML models predicted MMI with good discriminative ability. They outperformed standard statistical techniques and individual risk factors.

The Obesity Paradox in Spontaneous Intracerebral Hemorrhage: Results from a Retrospective Analysis of the Nationwide Inpatient Sample.

BACKGROUND/OBJECTIVE: Mild obesity is associated with a survival benefit in cardiovascular and cerebrovascular disease. Only a few studies have analyzed the effect of obesity on outcomes after spontaneous intracerebral hemorrhage (ICH), and none have used a national US database. We sought to determine whether or not obesity was associated with outcomes and in-hospital complications following ICH. METHODS: The Nationwide Inpatient Sample was used to identify patients with ICH in the USA who were discharged between 2002 and 2011. The presence of obesity (body mass index [BMI] 30-39.9) or morbid obesity (BMI ≥ 40) was noted. The primary outcome of interest was in-hospital mortality, and secondary outcomes included non-routine discharge disposition, tracheostomy or gastrostomy placement, length of stay (LOS), inflation-adjusted hospital charges, and in-hospital complications. RESULTS: A total of 123,415 patients with ICH met the inclusion criteria, and the 10-year overall incidence of obesity was 4.5%. Between 2002 and 2011, the incidence of obesity increased from 1.9 to 4.4% and the incidence of morbid obesity increased from 0.7 to 3.2%. Both obese (OR 0.62, 95% CI 0.56-0.69) and morbidly obese (OR 0.76, 95% CI 0.66-0.88) patients had lower odds of inpatient mortality. Obese (OR 0.85, 95% CI 0.78-0.93) but not morbidly obese patients had lower odds of non-routine discharge. Morbidly obese patients were twice as likely to require a tracheostomy than non-obese patients (OR 2.07, 95% CI 1.62-2.66). Both obese and morbidly obese patients had higher total hospital charges and rates of pulmonary, renal, and venous thromboembolic complications. There was no difference in LOS according to body habitus. CONCLUSIONS: In patients with spontaneous ICH, obesity is associated with decreased in-hospital mortality but higher rates of in-hospital complications and greater total hospital charges. Non-morbid obesity carries lower odds of non-routine hospital discharge.

A Propensity Score-Matched Comparison of Readmission Rates Associated With Microsurgical Clipping and Endovascular Treatment of Ruptured Intracranial Aneurysms.

BACKGROUND: In the treatment of aneurysmal subarachnoid hemorrhage (aSAH), microsurgical clipping, and endovascular therapy (EVT) with coiling are modalities for securing the ruptured aneurysm. Little data is available regarding associated readmission rates. We sought to determine whether readmission rates differed according to treatment modality for ruptured intracranial aneurysms. METHODS: The Nationwide Readmissions Database (NRD) was used to identify adults who experienced aSAH and underwent clipping or EVT. Primary outcomes of interest were the incidences of 30- and 90-day readmissions (30dRA, 90dRA). Propensity score matching was used to generate matched pairs based on age, comorbidities, hospital volume, and hemorrhage severity. RESULTS: We identified 13,623 and 11,160 patients who were eligible for 30dRA and 90dRA analyses, respectively. Among the patients eligible for 30dRA and 90dRA, we created 4282 and 3518 propensity score-matched pairs, respectively. There was no difference in the incidence of 30dRA (12.4% for clipping versus 11.2% for EVT; P = .094). However, 90dRA occurred more frequently after clipping (22.5%) compared to EVT (19.7%; P = .003). Clipping was associated with poor outcome after 30dRA (odds ratio [OR] = 1.51, 95% confidence interval [CI] 1.21-1.88, P < .001) and after 90dRA (OR = 1.60, 95% CI 1.34-1.91, P = .001). Mean duration to readmission and cost of readmission did not vary, but clipping was associated with longer lengths of stay during readmission. CONCLUSIONS: Microsurgical clipping of ruptured aneurysms is associated with a greater incidence of 90dRA, but not 30dRA, compared to EVT. Poor outcomes after readmission are more common following clipping.

The risk factors, outcomes, and costs associated with venous thromboembolism after traumatic brain injury: a nationwide analysis.

Objective: We sought to identify risk factors for VTE following traumatic brain injury (TBI) and determine how venous thromboembolism (VTE) affects outcomes and costs using a national database.Methods: The Nationwide Inpatient Sample (NIS) was used to identify patients with TBI between 2002 and 2014. VTE was identified as any occurrence of deep venous thrombosis or pulmonary embolism. We investigated putative risk factors for VTE and determined the effect of VTE on outcomes including mortality and disposition.Results: 424,929 patients met the inclusion criteria. There were 16,690 (3.9%) patients who developed a VTE. The annual incidence of VTE increased from 2.2% in 2002 to 5.4% in 2014 (R2 = 0.992, p < .001). Older age, increasing number of comorbidities, craniotomy or craniectomy, and more severe injuries were associated with increased odds of developing VTE (p < .001 for all). Patients with VTE had decreased odds of in-hospital mortality (OR 0.53; 95% CI 0.50-0.57) and increased odds of non-routine disposition (OR 2.05; 95% CI 1.97-2.14), tracheostomy, and gastrostomy.Conclusion: To our knowledge, we provide the largest analysis of VTE in TBI. This entity appears to be increasing in frequency, which may merit new strategies for prevention.

The Incidence of Meningitis in Patients with Traumatic Brain Injury Undergoing External Ventricular Drain Placement: A Nationwide Inpatient Sample Analysis.

BACKGROUND/OBJECTIVE: Infection is the most common complication of external ventricular drain (EVD) placement. National trends in the annual incidence of meningitis among patients with traumatic brain injury (TBI) who have undergone EVD placement have not been reported. METHODS: The Nationwide Inpatient Sample was used to select adults with a primary diagnosis of TBI who underwent EVD placement between 2002 and 2011. Annual rates of meningitis among patients who underwent EVD placement were determined. We also calculated mortality rates and length of stay (LOS). Potential factors associated with meningitis were evaluated in a binary logistic regression analysis. RESULTS: Out of 1,571,927 adult discharges with a primary diagnosis of TBI between 2002 and 2011, 39,029 (2.5%) underwent EVD placement. Of these, 1544 (4.3%) patients developed meningitis. There was no significant trend in the annual incidence of meningitis (p = 0.88), mortality (p = 0.55), or mean LOS (p = 0.13) during the study period. Meningitis and mortality rates remained stable when stratifying patients by hospital volume. In the binary logistic regression, acquired immunodeficiency syndrome, sepsis, and cerebrospinal fluid leak were associated with meningitis. CONCLUSIONS: The incidence of meningitis in patients who underwent EVD placement remained stable between 2002 and 2011. Further prospective studies are needed to identify approaches for preventing these infections.

Development and Internal Validation of Machine Learning Models to Predict Mortality and Disability After Mechanical Thrombectomy for Acute Anterior Circulation Large Vessel Occlusion.

OBJECTIVE: Mechanical thrombectomy (MT) improves outcomes in patients with LVO but many still experience mortality or severe disability. We sought to develop machine learning (ML) models that predict 90-day outcomes after MT for LVO. METHODS: Consecutive patients who underwent MT for LVO between 2015-2021 at a Comprehensive Stroke Center were reviewed. Outcomes included 90-day favorable functional status (mRS 0-2), severe disability (mRS 4-6), and mortality. ML models were trained for each outcome using prethrombectomy data (pre) and with thrombectomy data (post). RESULTS: Three hundred and fifty seven patients met the inclusion criteria. After model screening and hyperparameter tuning the top performing ML model for each outcome and timepoint was random forest (RF). Using only prethrombectomy features, the AUCs for the RFpre models were 0.73 (95% CI 0.62-0.85) for favorable functional status, 0.77 (95% CI 0.65-0.86) for severe disability, and 0.78 (95% CI 0.64-0.88) for mortality. All of these were better than a standard statistical model except for favorable functional status. Each RF model outperformed Pre, SPAN-100, THRIVE, and HIAT scores (P < 0.0001 for all). The most predictive features were premorbid mRS, age, and NIHSS. Incorporating MT data, the AUCs for the RFpost models were 0.80 (95% CI 0.67-0.90) for favorable functional status, 0.82 (95% CI 0.69-0.91) for severe disability, and 0.71 (95% CI 0.55-0.84) for mortality. CONCLUSIONS: RF models accurately predicted 90-day outcomes after MT and performed better than standard statistical and clinical prediction models.

The influence of pre-reperfusion blood pressure on outcomes following mechanical thrombectomy for anterior circulation large vessel occlusion.

BACKGROUND: We evaluated how systolic blood pressure (SBP) and mean arterial pressure (MAP) parameters between presentation and reperfusion influence functional status and intracranial hemorrhage (ICH). METHODS: All patients who underwent MT for LVO at a single institution were reviewed. Independent variables included SBP and MAP measurements obtained on presentation, between presentation and reperfusion (pre-reperfusion), and between groin puncture and reperfusion (thrombectomy). Mean, minimum, maximum, and standard deviations (SD) for SBP and MAP were calculated. Outcomes included 90-day favorable functional status, radiographic ICH (rICH), and symptomatic ICH (sICH). RESULTS: 305 patients were included. Higher pre-reperfusion SBPmax was associated with rICH (OR 1.41, 95% CI 1.08-1.85) and sICH (OR 1.84, 95% CI 1.26-2.72). Higher SBPSD was also associated with rICH (OR 1.38, 95% CI 1.06-1.81) and sICH (OR 1.59, 95% CI 1.12-2.26). Greater SBPmax (OR 0.64, 95% CI 0.47-0.86), MAPmax (OR 0.72, 95% CI 0.52-0.97), SBPSD (OR 0.63, 95% CI 0.46-0.86), and MAPSD (0.63, 95% CI 0.45-0.84) during thrombectomy were associated with lower odds of 90-day favorable functional status. In a subgroup analysis, these associations were primarily limited to patients with intact collateral circulation. Optimal SBPmax cutoffs for predicting rICH were 171 (pre-reperfusion) and 179 mmHg (thrombectomy). Cutoffs for predicting sICH were 178 (pre-reperfusion) and 174 mmHg (thrombectomy). CONCLUSION: Greater maximum BP and variability in BP during the pre-reperfusion period are associated with unfavorable functional status and ICH after MT for anterior circulation LVO.

Outcomes after endovascular embolization for the treatment of nasal and oropharyngeal hemorrhage: safety, efficacy, and rebleeding.

BACKGROUND: Intractable nasal and oropharyngeal hemorrhage may be treated with endovascular embolization, but limited data are available. We sought to evaluate the efficacy, safety, and factors associated with rebleeding. METHODS: A retrospective analysis of consecutive embolizations for nasal and oropharyngeal hemorrhage over a 10-year period at a single institution was performed. Outcomes included procedural success (defined as cessation of hemorrhage in the immediate postoperative period), rebleeding requiring an additional intervention, and procedural complications. RESULTS: A total of 47 embolizations on 39 patients were included. The mean age was 60 years (standard deviation 16.1), 23.1% of patients were women, and 21 (53.8%) patients had a previously diagnosed head/neck malignancy. Bleeding sites were the nose in 20 patients and oropharynx in 21 (two patients presented with both nasal and oral bleeding). Immediate procedural success was achieved in 45 (95.7%) embolizations. Rebleeding requiring an additional intervention occurred after 11 (23.4%) embolizations at a median of one day after the procedure. In the multivariate analysis, preoperative hypotension (odds ratio 4.78, 95% confidence interval 1.04-24.61) and the use of coils (odds ratio 6.09, 95% confidence interval 1.24-46.69) were associated with rebleeding requiring repeat intervention. Complications included two watershed strokes that were anticipated due to occlusion of the internal carotid artery. CONCLUSIONS: In our experience endovascular embolization was a safe and effective treatment option for stopping oral and nasal hemorrhage. However, rebleeding was present after 23.4% of treatments and was associated with preoperative hypotension and the use of coils. Further study in a large multi-institutional cohort is warranted.

Embolization of a Dural Arteriovenous Fistula Using Transcranial Middle Meningeal Artery Access: 2-Dimensional Operative Video.

The transcranial approach for direct middle meningeal artery (MMA) access to embolize dural arteriovenous fistulas (dAVF) has been described, but limited information regarding the setup, equipment, and technique is available. We present the details of this hybrid approach in the setting of a ruptured Cognard grade IV tentorial dAVF (Video 1). The patient was an adult female who presented with nausea, vomiting, and dizziness and was found to have a cerebellar hemorrhage. Catheter angiography revealed a tentorial dAVF fed by bilateral middle meningeal, left posterior meningeal, and left occipital arteries. Attempted transarterial embolizations through each of these were unsuccessful. The left MMA was a primary source of supply, but distal microcatheter placement was not possible due to proximal tortuosity. Therefore transcranial MMA access distal to this tortuosity was pursued. The MMA was localized using roadmap angiography and a temporal craniectomy was completed over the artery. A 4-French sheath was placed, and super selective angiography was performed, demonstrating the fistula. A microcatheter was navigated to the fistula and it was embolized with Onyx. Postoperative angiogram demonstrated fistula occlusion. The patient remained at her neurologic baseline and was discharged home. Transcranial MMA access is a useful technique to overcome tortuosity that cannot be navigated with traditional endovascular techniques.

Management of chronic subdural hematoma with the subdural evacuating port system: Systematic review and meta-analysis.

The subdural evacuating port system (SEPS) is a minimally invasive option for treating chronic subdural hematoma (cSDH). Individual case series have shown it to be safe and effective, but outcomes have not been systematically reviewed. We sought to review the literature in order to determine the safety and efficacy of SEPS as a first line treatment for cSDH. A comprehensive literature search for outcomes following SEPS placement as a primary treatment for cSDH was performed. The primary outcome was treatment success, which was defined as a composite of improvement in presenting symptoms and no need for further treatment in the operating room. Additional outcomes included discharge disposition, length of stay (LOS), hematoma recurrence, and complications. A total of 12 studies comprising 953 patients who underwent SEPS placement met the inclusion criteria. The pooled rate of a successful outcome was 0.79 (95% CI 0.75-0.83). Frequency of delayed hematoma recurrence was 0.15 (95% CI 0.10-0.21). The pooled inpatient mortality rate was 0.02 (95% CI 0.01-0.03). Complications rates included 0.02 (95% CI 0.00-0.03) for any acute hemorrhage, 0.01 (95% CI 0.00-0.01) for acute hemorrhage requiring surgery, and 0.02 (95% CI 0.01-0.03) for seizure. SEPS placement is associated with a success rate of 79% and very low rates of acute hemorrhage and seizure. This data supports its use as a first-line management strategy, although prospective randomized studies are needed.

Prediction of mortality after evacuation of supratentorial intracerebral hemorrhage using NSQIP data.

Spontaneous intracerebral hemorrhage (sICH) is associated with high rates of morbidity and mortality. Neurosurgical clot evacuation is controversial but often a life saving maneuver in the setting of severe mass effect and cerebral herniation. Outcomes from large multicenter databases are sparsely reported. Patients who underwent craniotomy for evacuation of a supratentorial sICH between 2006 and 2017 were systematically extracted from the American College of Surgeons National Surgical Quality Improvement Program Participant Use Files. Our primary outcomes of interest were 30-day mortality, non-routine discharge disposition, and extended length of stay ([eLOS], defined as the top quartile for the cohort). Individual binary logistic regression models were constructed to query the associations between pre- and perioperative variables and each outcome. A total of 751 patients met the inclusion criteria. The 30-day mortality rate was 23.3% and increased from 2011 to 2017 (pooled OR 2.060 [95% CI 1.437 - 2.953]). Older age, morbid obesity, preoperative mechanical ventilation, preoperative systemic inflammatory response syndrome (SIRS) or septic shock, and thrombocytopenia were associated with mortality. Older age, race, and preoperative mechanical ventilation were associated with non-routine discharge. Patients who were mechanically ventilated or were insulin-dependent diabetics had greater odds of experiencing eLOS. A formula for estimating 30-day mortality was developed and found to have a strong linear association with actual mortality rates (R2 = 0.777, p = 0.002). Preoperative mechanical ventilation is a consistent predictor of poor outcomes following surgery for supratentorial sICH. Mortality is also influenced by older age, body habitus, SIRS, septic shock, and thrombocytopenia.

Annual incidences and predictors of 30-day readmissions following spontaneous intracerebral hemorrhage from 2010 to 2014 in the United States: A retrospective Nationwide analysis.

OBJECTIVE: 30-day readmission rate is a quality metric often employed to represent hospital and provider performance. Currently, little is known regarding 30-day readmissions (30dRA) following spontaneous intracerebral hemorrhage (sICH). The purpose of this study was to use a national database to identify risk factors and trends in 30dRAs following sICH. PATIENTS AND METHODS: 64,909 cases with a primary diagnosis of sICH were identified within the Nationwide Readmission Database (NRD) from 2010 through 2014. Charlson Comorbidity Index (CCI) was used to adjust for the severity of each patient's comorbidities. A binary logistic regression model was constructed to identify predictors of 30-day readmission. Cochran-Mantel-Haenszel test was used to generate a pooled odd ratio (OR) describing the likelihood of experiencing a 30dRA according to year. RESULTS: The 30dRA rate following sICH decreased from 13.9% in 2010 to 12.5% in 2014 (pooled OR = 0.90, 95% CI 0.87-0.94). Cerebrovascular and cardiovascular etiologies accounted for the greatest number of admissions (36.1%). Sodium abnormality, healthcare-associated infection, gastrostomy, venous thromboembolism, and ischemic stroke during the index admission were associated with 30-day readmission. Furthermore, patients who underwent ventriculostomy (OR = 1.20, 95% CI 1.03-1.38) and craniotomy (OR = 1.20, 95% CI 1.09-1.31) were more likely to be readmitted within 30 days. Hospital volume, hospital teaching status, mechanical ventilation, and tracheostomy did not affect 30dRAs. Median readmission costs increased from $9,875 in 2012 to $11,028 in 2014 (p = 0.040). CONCLUSION: The overall U.S. 30dRA rate after sICH from 2010 to 2014 was 12.9% and decreased slightly during this time period, but associated costs increased. Prospective studies are required to confirm the risk factors described in this study and to identify methods for preventing readmissions.

Costs and predictors of 30-day readmissions after craniotomy for traumatic brain injury: a nationwide analysis.

OBJECTIVE: There is increasing interest in the use of 30-day readmission (30dRA) as a quality metric to represent hospital and provider performance. Data regarding the incidence and risk factors for 30dRA after traumatic brain injury (TBI) are sparse. The authors sought to characterize these variables using a national database. METHODS: The Nationwide Readmissions Database was used to identify patients with a primary diagnosis of TBI who underwent craniotomy or craniectomy between 2010 and 2014. Our primary outcome of interest was 30dRA. Binary logistic regression was used to identify variables related to patient demographics, comorbidities, and index hospital admission that were associated with 30dRA. RESULTS: A total of 25,354 patients met the inclusion criteria. The 30dRA rate during the entire study period was 15.5%. In 2010 the 30dRA rate was 16.8% and in 2014 it decreased to 15.1% (pooled OR 0.90, 95% CI 0.87-0.94). The mean cost associated with a 30dRA increased slightly but significantly, from $9999 in 2010 to $10,114 in 2014 (p = 0.021). Factors associated with increased odds of 30dRA in the binary logistic regression included increased age, greater comorbidity burden, more severe injury, tracheostomy, gastrostomy, sodium abnormality, and venous thromboembolism. In order of decreasing frequency, the most common causes for 30dRA were neurological, injury/iatrogenic, cardiovascular/cerebrovascular, infectious, and respiratory. CONCLUSIONS: The incidence of 30dRA after craniotomy for TBI decreased slightly from 2010 to 2014. This study identified several variables associated with 30dRA that require confirmation in a prospective study, which could direct attempts to prevent readmissions.

Comparison of Cortical Bone Trajectory Screw Placement Using the Midline Lumbar Fusion Technique to Traditional Pedicle Screws: A Case-Control Study.

BACKGROUND: Cortical bone trajectory (CBT) screws are an alternative to traditional pedicle screws (PS) for lumbar fixation. The proposed benefits of CBT screws include decreased approach-related morbidity and greater cortical bone contact to prevent screw pullout. Relatively little data is published on this technique. Here, we compare the midline lumbar fusion (MIDLF) approach for CBT screw placement to transforaminal lumbar interbody fusion (TLIF) for traditional PS placement. METHODS: A prospectively maintained institutional database was retrospectively reviewed for all patients undergoing lumbar spinal fusion using CBT screws over the past 5 years. Controls were identified from the same database as patients undergoing lumbar spinal fusion with traditional PS placement and matched based on age, sex, and number of levels fused. Exclusion criteria included prior lumbar instrumentation. The electronic health record was retrospectively reviewed for demographic, perioperative, and postoperative data. RESULTS: A total of 23 patients who underwent CBT screw placement and 35 controls who received traditional PS were included in the study. The median follow-up time was 52.5 months. The CBT screw group had significantly less mean estimated blood loss than the PS group (186 mL versus 414 mL respectively; P = .008). Both groups experienced significant improvements in preoperative Oswestry Disability Index (ODI) and visual analog scale (VAS) scores for back and leg pain. However, there was no significant difference between the groups in regard to operative time and amount of improvement in VAS pain score or ODI. The CBT group was associated with a significantly shorter mean length of stay (LOS). There were 2 instances of screw pullout in each group. CONCLUSIONS: The MIDLF approach with CBT screw placement is associated with less intraoperative blood loss and shorter LOS than traditional PS placement. There is no difference between the 2 techniques in regard to improvement in pain or disability.

Effect of Hypernatremia on Outcomes After severe Traumatic Brain Injury: A Nationwide Inpatient Sample analysis.

OBJECTIVE: Induced hypernatremia is frequently used to reduce intracranial pressure in patients with severe traumatic brain injury (TBI). This technique is controversial, and some studies have independently associated hypernatremia with worse outcomes after TBI. We sought to investigate this potential association in a large healthcare database. METHODS: The Nationwide Inpatient Sample was used to obtain data on all adults who had been discharged from 2002 to 2011 with a primary diagnosis of TBI who required mechanical ventilation, intracranial pressure monitoring, or craniotomy/craniectomy. Patients with diabetes insipidus were excluded. The patients with hypernatremia were assigned to the hypernatremia group, and the rest were assigned to the control group. The primary outcome was in-hospital mortality, and the secondary outcomes included the length of stay, nonroutine hospital discharge, total hospital charges, tracheostomy, and gastrostomy placement. RESULTS: A total of 85,579 patients without a diagnosis of hypernatremia (control group) and 4542 patients with a diagnosis of hypernatremia (hypernatremia group) were identified. When controlling for age, comorbidities, gender, and cerebral edema, hypernatremia was associated with an increased rate of in-hospital mortality (odds ratio, 1.51; 95% confidence interval, 1.39-1.65), a longer mean length of stay (23.65 vs. 12.12 days; P < 0.001), an increased rate of nonroutine hospital discharge (odds ratio, 2.58; 95% confidence interval, 2.28-2.92), and greater mean total hospital cost ($227,112 vs. $112,507; P < 0.001). The patients with hypernatremia also had greater rates of tracheostomy and gastrostomy placement. CONCLUSIONS: Hypernatremia was associated with poorer outcomes in patients with severe TBI. This finding warrants further investigation in a prospective, randomized study.