Prospective Observational Study of Volatile Sedation with Sevoflurane After Aneurysmal Subarachnoid Hemorrhage Using the Sedaconda Anesthetic Conserving Device.

BACKGROUND: Volatile sedation is still used with caution in patients with acute brain injury because of safety concerns. We analyzed the effects of sevoflurane sedation on systemic and cerebral parameters measured by multimodal neuromonitoring in patients after aneurysmal subarachnoid hemorrhage (aSAH) with normal baseline intracranial pressure (ICP). METHODS: In this prospective observational study, we analyzed a 12-h period before and after the switch from intravenous to volatile sedation with sevoflurane using the Sedaconda Anesthetic Conserving Device with a target Richmond Agitation Sedation Scale score of - 5 to - 4. ICP, cerebral perfusion pressure (CPP), brain tissue oxygenation (PBrO2), metabolic values of cerebral microdialysis, systemic cardiopulmonary parameters, and the administered drugs before and after the sedation switch were analyzed. RESULTS: We included 19 patients with a median age of 61 years (range 46-78 years), 74% of whom presented with World Federation of Neurosurgical Societies grade 4 or 5 aSAH. We observed no significant changes in the mean ICP (9.3 ± 4.2 vs. 9.7 ± 4.2 mm Hg), PBrO2 (31.0 ± 13.2 vs. 32.2 ± 12.4 mm Hg), cerebral lactate (5.0 ± 2.2 vs. 5.0 ± 1.9 mmol/L), pyruvate (136.6 ± 55.9 vs. 134.1 ± 53.6 µmol/L), and lactate/pyruvate ratio (37.4 ± 8.7 vs. 39.8 ± 9.2) after the sedation switch to sevoflurane. We found a significant decrease in mean arterial pressure (MAP) (88.6 ± 7.6 vs. 86.3 ± 5.8 mm Hg) and CPP (78.8 ± 8.5 vs. 76.6 ± 6.6 mm Hg) after the initiation of sevoflurane, but the decrease was still within the physiological range requiring no additional hemodynamic support. CONCLUSIONS: Sevoflurane appears to be a feasible alternative to intravenous sedation in patients with aSAH without intracranial hypertension, as our study did not show negative effects on ICP, cerebral oxygenation, or brain metabolism. Nevertheless, the risk of a decrease of MAP leading to a consecutive CPP decrease should be considered.

Risks of nimodipine dose reduction during the high-risk period for delayed cerebral ischemia after aneurysmal subarachnoid hemorrhage.

Nimodipine dose reduction is recommended in case of high vasopressor demand after aneurysmal subarachnoid hemorrhage (aSAH). The aim of this study was to assess potential adverse effects of nimodipine reduction during the high-risk period for delayed cerebral ischemia (DCI) and cerebral vasospasm (CVS) between days 5 and 10 after hemorrhage. Demographic and clinical data as well as daily nimodipine dose of aSAH patients admitted between 2010 and 2019 were retrospectively analyzed. Univariable and multivariable regression analyses were performed to identify factors associated with DCI, angiographic CVS, DCI-related infarction, and unfavorable outcome. A total of 205 patients were included. Nimodipine dose reduction occurred in 108 (53%) patients ('nimodipine reduction group'), while 97 patients (47%) received the full dose ('no nimodipine reduction group'), Patients in the 'nimodipine reduction group' had significant worse WFNS and Fisher grades and developed significantly more often DCI and angiographic CVS. DCI-related infarction and unfavorable outcome were also significantly increased in the 'nimodipine reduction group.' 'Reduced nimodipine dose' was the only independent predictor for the occurrence of DCI and angiographic CVS in multivariable regression analysis. 'Poor WFNS grade' and 'reduced nimodipine dose' were identified as independent risk factors for DCI-related infarction while 'older age,' 'poor WFNS grade,' and 'reduced nimodipine dose' were associated with unfavorable outcome at 3 months after discharge. Nimodipine dose reduction during the high-risk period of DCI and CVS between days 5 and 10 after hemorrhage might abrogate the positive prognostic effects of nimodipine and should be critically evaluated.

Limitations of prone positioning in patients with aneurysmal subarachnoid hemorrhage and concomitant respiratory failure.

OBJECTIVE: Prone positioning (PP) is an established treatment modality for respiratory failure. After aneurysmal subarachnoid hemorrhage (aSAH), PP is rarely performed considering the risk of intracranial hypertension. The aim of this study was to analyze the effects of PP on intracranial pressure (ICP), cerebral perfusion pressure (CPP) and cerebral oxygenation following aSAH. PATIENTS AND METHODS: Demographic and clinical data of aSAH patients admitted over a 6-year period and treated with PP due to respiratory insufficiency were retrospectively analyzed. ICP, CPP, brain tissue oxygenation (pBrO2), respiratory parameters and ventilator settings were analyzed before and during PP. RESULTS: Thirty patients receiving invasive multimodal neuromonitoring were included. Overall, 97 PP sessions were performed. Mean arterial oxygenation and pBrO2 increased significantly during PP. We found a significant increase in median ICP compared to the baseline level in supine position. No significant changes in CPP were observed. Five PP sessions had to be terminated early due to medically refractory ICP-crisis. The affected patients were younger (p = 0.02) with significantly higher baseline ICP values (p = 0.009). Baseline ICP correlates significantly (p < 0.001) with ICP 1 h (R: 0.57) and 4 h (R: 0.55) after onset of PP. CONCLUSION: PP in aSAH patients with respiratory insufficiency is an effective therapeutic option improving arterial and global cerebral oxygenation without compromising CPP. The significant increase in ICP was moderate in most sessions. However, as some patients experience intolerable ICP crises during PP, continuous ICP-Monitoring is considered mandatory. Patients with elevated baseline ICP and reduced intracranial compliance should not be considered for PP.

Volatile Sedation With Isoflurane in Neurocritical Care Patients After Poor-grade Aneurysmal Subarachnoid Hemorrhage.

OBJECTIVE: Volatile sedation after aneurysmal subarachnoid hemorrhage (aSAH) promises several advantages, but there are still concerns regarding intracranial hypertension due to vasodilatory effects. We prospectively analyzed cerebral parameters during the switch from intravenous to volatile sedation with isoflurane in patients with poor-grade (World Federation of Neurosurgical Societies grade 4-5) aSAH. METHODS: Eleven patients were included in this prospective observational study. Between day 3 and 5 after admission, intravenous sedation was switched to isoflurane using the Sedaconda Anesthetic Conserving Device (Sedana Medical, Danderyd, Sweden). Intracranial pressure (ICP), cerebral perfusion pressure (CPP), brain tissue oxygenation (PBrO2), cerebral mean flow velocities (MFVs; transcranial Doppler ultrasound) and regional cerebral oxygen saturation (rSO2, near-infrared spectroscopy monitoring), as well as cardiopulmonary parameters were assessed before and after the sedation switch (-12 to +12 hours). Additionally, perfusion computed tomography data during intravenous and volatile sedation were analyzed retrospectively for changes in cerebral blood flow. RESULTS: There were no significant changes in mean ICP, CPP, and PBrO2 after the sedation switch to isoflurane. Mean rSO2 showed a non-significant trend towards higher values, and mean MFV in the middle cerebral arteries increased significantly after the initiation of volatile sedation. Isoflurane sedation resulted in a significantly increased norepinephrine administration. Despite an increase in mean inspiratory pressure, we observed a significant increase in mean partial arterial pressure of carbon dioxide. CONCLUSIONS: Isoflurane sedation does not compromise ICP or cerebral oxygenation in poor-grade aSAH patients, but the significant depression of CPP could limit the use of volatiles in case of hemodynamic instability or high vasopressor demand.

Analysis of Angiographic Treatment Response to Intra-Arterial Nimodipine Bolus Injection in Patients with Medically Refractory Cerebral Vasospasm After Spontaneous Subarachnoid Hemorrhage.

BACKGROUND: Intra-arterial nimodipine (IAN) injections are performed in refractory delayed cerebral ischemia (DCI) related to cerebral vasospasm (CVS) after spontaneous subarachnoid hemorrhage (sSAH), but the clinical benefits are inconclusive and angiographic treatment failure is observed. We analyzed angiographic IAN response in a detailed vessel-specific manner and examined the impact of poor angiographic response on the further clinical course. METHODS: Clinical data were retrospectively assessed in patients with spontaneous subarachnoid hemorrhage with symptomatic CVS receiving IAN bolus treatment. Clinical and angiographic predictors for poor angiographic response, DCI-related infarction, and unfavorable outcome were analyzed. RESULTS: Eighty-nine patients were included and 356 treated vessel segments, mainly located in the anterior circulation (93%), were analyzed. Angiographic response was good in 77% of the treated segments. Older age, poor World Federation of Neurosurgical Societies (WFNS) grade 4-5 and early onset of CVS were independently associated with poor angiographic response. The factors short-segment, distal, and bilateral CVS as well as treatment of multiple vessel segments, WFNS grade 4-5, and early onset of CVS were significantly associated with an increased risk of DCI-related infarction. Clinical outcome was significantly influenced by poor WFNS grade and early onset of CVS, whereas poor angiographic response was not related to DCI-related infarction or unfavorable outcome. CONCLUSIONS: The risk of angiographic treatment failure is significantly increased in older patients and those with poor WFNS grade as in cases of early-onset CVS. Although the extent of angiographic CVS significantly affected the development of DCI-related infarction, poor angiographic response had no impact on cerebral infarction and clinical outcome.

The "Shiny and Thick High Heel Sign" : A novel radiologic sign for detecting intracranial dural arteriovenous fistulas with time-of-flight magnetic resonance angiography.

PURPOSE: Together with the foramen ovale, the middle meningeal artery (MMA) looks like a high heel shoe print on axial time-of-flight magnetic resonance angiography (TOF-MRA) images, with the MMA resembling the heel. Cranial dural arteriovenous fistulas (DAVF) are often fed by the MMA, which can lead to an increase of signal intensity and diameter of this vessel, resulting in a more "shiny" and "thick" high heel print appearance than on the contralateral side. We describe this finding as a novel radiologic sign and provide cut-off values for the ratios of MMA signal intensities and diameters for predicting the presence of a DAVF. METHODS: A total of 84 TOF-MRA examinations of 44 patients with DAVFs (40 with unilateral MMA feeders, 4 with bilateral feeders) and of 40 patients without DAVFs were included. Diameters and signal intensities of both MMAs were measured by two raters and evaluated using receiver operating characteristic analysis. RESULTS: The diameters of feeding and non-feeding MMAs differed significantly, as did the ratios of signal intensities and of diameters of DAVF and control patients (P < 0.0001). Cut-off values were 1.25 for average signal intensity ratio (shiny high heel sign) and 1.21 for diameter ratio (thick high heel sign). The combination of the "shiny" and the "thick" high heel sign resulted in the highest sensitivity (92.5%) and positive predictive value (95%). CONCLUSION: The described sign seems promising for the detection of DAVFs with noncontrast-enhanced MRI. The TOF-MRA source images should be reviewed with special attention to the MMA.

Paraneoplastic encephalomyeloradiculits with multiple autoantibodies against ITPR-1, GFAP and MOG: case report and literature review.

BACKGROUND: Recently, antibodies against the alpha isoform of the glial-fibrillary-acidic-protein (GFAPα) were identified in a small series of patients with encephalomyelitis. Coexisting autoantibodies (NMDA receptor, GAD65 antibodies) have been described in a few of these patients. We describe a patient with rapidly progressive encephalomyeloradiculitis and a combination of anti-ITPR1, anti-GFAP and anti-MOG antibodies. CASE PRESENTATION AND LITERATURE REVIEW: A 44-year old caucasian woman with a flu-like prodrome presented with meningism, progressive cerebellar signs and autonomic symptoms, areflexia, quadriplegia and respiratory insufficiency. MRI showed diffuse bilateral T2w-hyperintense brain lesions in the cortex, white matter, the corpus callosum as well as a longitudinal lesion of the medulla oblongata and the entire spinal cord. Anti-ITPR1, anti-GFAP and anti-MOG antibodies were detected in cerebrospinal fluid along with lymphocytic pleocytosis. Borderline tumor of the ovary was diagnosed. Thus, the disease of the patient was deemed to be paraneoplastic. The patient was treated by surgical removal of tumor, steroids, immunoglobulins, plasma exchange and rituximab. Four months after presentation, the patient was still tetraplegic, reacted with mimic expressions to pain or touch and could phonate solitary vowels. An extensive literature research was performed. CONCLUSION: Our case and the literature review illustrate that multiple glial and neuronal autoantibodies can co-occur, that points to a paraneoplastic etiology, above all ovarian teratoma or thymoma. Clinical manifestation can be a mixture of typically associated syndromes, e.g. ataxia associated with anti-ITPR1 antibodies, encephalomyelitis with anti-GFAPα antibodies and longitudinal extensive myelitis with anti-MOG antibodies.

Effects of post-interventional antiplatelet therapy on angiographic vasospasm, delayed cerebral ischemia, and clinical outcome after aneurysmal subarachnoid hemorrhage: a single-center experience.

Platelet activation has been postulated to be involved in the pathogenesis of delayed cerebral ischemia (DCI) and cerebral vasospasm (CVS) after aneurysmal subarachnoid hemorrhage (aSAH). The aim of this study was to investigate potentially beneficial effects of antiplatelet therapy (APT) on angiographic CVS, DCI-related infarction and functional outcome in endovascularly treated aSAH patients. Retrospective single-center analysis of aSAH patients treated by endovascular aneurysm obliteration. Based on the post-interventional medical regime, patients were assigned to either an APT group or a control group not receiving APT. A subgroup analysis separately investigated those APT patients with aspirin monotherapy (MAPT) and those receiving dual treatment (aspirin plus clopidogrel, DAPT). Clinical and radiological characteristics were compared between groups. Possible predictors for angiographic CVS, DCI-related infarction, and an unfavorable functional outcome (modified Rankin scale ≥ 3) were analyzed. Of 160 patients, 85 (53%) had received APT (n = 29 MAPT, n = 56 DAPT). APT was independently associated with a lower incidence of an unfavorable functional outcome (OR 0.40 [0.19-0.87], P = 0.021) after 3 months. APT did not reduce the incidence of angiographic CVS or DCI-related infarction. The pattern of angiographic CVS or DCI-related infarction as well as the rate of intracranial hemorrhage did not differ between groups. However, the lesion volume of DCI-related infarctions was significantly reduced in the DAPT subgroup (P = 0.011). Post-interventional APT in endovascularly treated aSAH patients is associated with better functional outcome at 3 months. The beneficial effect of APT might be mediated by reduction of the size of DCI-related infarctions.

Routine use of perfusion computed tomography for the detection of delayed cerebral ischemia in unconscious patients after aneurysmal subarachnoid hemorrhage.

BACKGROUND: Delayed cerebral ischemia (DCI) after aneurysmal subarachnoid hemorrhage (aSAH) is difficult to diagnose in unconscious patients, but it is essential for the prognosis. We analyzed the diagnostic value of routinely performed perfusion computed tomography (rPCT) to detect DCI-related hypoperfusion in this subgroup of patients. METHODS: Retrospective analysis of unconscious aSAH patients who underwent rPCT according to a predefined protocol. We exclusively analyzed PCT examinations in patients who were clinically and functionally asymptomatic with regard to transcranial Doppler ultrasound (TCD) and invasive neuromonitoring at the time of the PCT examination. The perfusion maps were quantitatively evaluated to detect DCI-related hypoperfusion. Possible clinical risk factors for the occurrence of DCI-related hypoperfusion in rPCT imaging were analyzed by multivariate analyses. RESULTS: One hundred thirty-six rPCTs were performed in 55 patients. New onset of DCI-related hypoperfusion was observed in 18% of rPCTs. The positive predictive value of rPCT to detect angiographic CVS was 0.80. Between examination days 6 and 10, the rate of DCI-related hypoperfusion was increased significantly (p < 0.05). After rPCT imaging with proof of DCI-related hypoperfusion, short-term follow-up showed secondary cerebral infarction (SCI) in 38%, compared with 5% for patients with normal perfusion on rPCT. The parameters "high risk phase (examination days 6-10)" and "new onset of DCI-related SCI" were significantly associated with the occurrence of DCI-related hypoperfusion in rPCT. CONCLUSIONS: In unconscious and asymptomatic aSAH patients, rPCT identifies DCI-related hypoperfusion in a relevant number of examinations. However, despite timely endovascular rescue therapy, a significant proportion of secondary infarction still occurs in this subgroup.

Non-compliant and compliant balloons for endovascular rescue therapy of cerebral vasospasm after spontaneous subarachnoid haemorrhage: experiences of a single-centre institution with radiological follow-up of the treated vessel segments.

BACKGROUND: For endovascular rescue therapy (ERT) of cerebral vasospasm (CVS) due to spontaneous subarachnoid haemorrhage (sSAH), non-compliant (NCB) and compliant (CB) balloons are used with both balloon types bearing the risk of vessel injury due to specific mechanical properties. Although severe delayed arterial narrowing after transluminal balloon angioplasty (TBA) for CVS has sporadically been described, valid data concerning incidence and relevance are missing. Our aim was to analyse the radiological follow-up (RFU) of differently TBA-treated arteries (CB or NCB). METHODS: Twelve patients with utilisation of either NCB or CB for CVS were retrospectively analysed for clinical characteristics, ERT, functional outcome after 3 months and RFU. Compared with the initial angiogram, we classified delayed arterial narrowing as mild, moderate and severe (<30%, 30%-60%, respectively >60% calibre reduction). RESULTS: Twenty-three arteries were treated with CB, seven with NCB. The median first RFU was 11 months after TBA with CB and 10 after NCB. RFU was performed with catheter angiography in 18 arteries (78%) treated with CB and in five (71%) after NCB; magnetic resonance angiography was acquired in five vessels (22%) treated with CB and in two (29%) after NCB. Mild arterial narrowing was detected in three arteries (13%) after CB and in one (14%) after NCB. Moderate or severe findings were neither detected after use of CB nor NCB. CONCLUSION: We found no relevant delayed arterial narrowing after TBA for CVS after sSAH. Despite previous assumptions that CB provides for more dilatation in segments adjacent to CVS, we observed no disadvantages concerning long-term adverse effects. Our data support TBA as a low-risk treatment option.

Cerebral Vasospasm After Spontaneous Subarachnoid Hemorrhage: Angiographic Pattern and Its Impact on the Clinical Course.

OBJECTIVE: To analyze angiographic characteristics of cerebral vasospasm (CVS) after spontaneous subarachnoid hemorrhage (sSAH) and their potential impact on secondary infarction and functional outcome. METHODS: Demographic, clinical, and imaging data of sSAH patients with angiographic CVS admitted over a 6-year period were retrospectively analyzed. RESULTS: A total of 85 patients were included in the final analysis. A total of 311 arterial territories in 85 angiographies demonstrated angiographic CVS. The anterior cerebral artery (ACA) was the most common site of angiographic CVS (42.1%), followed by the middle cerebral artery (MCA) (26.7%). In 29 angiographies (34%) CVS was found in more than 3 vessels and a bilateral pattern was identified in 53 cases (62%). Older age (OR 3.24 [95% CI 1.30-8.07], P = 0.012) was identified as the only significant risk factor for CVS-related infarction (OR 22.67, P = 0.015). Unfavorable outcome was associated with older age (OR 3.24, P = 0.023) and poor World Federation of Neurosurgical Societies grade (OR 3.64, P = 0.015). Analyses of angiographic characteristics did not reveal any risk factors for unfavorable outcome. We identified distal CVS as a significant risk factor for CVS-related infarction (OR 2.89, P = 0.026). CONCLUSIONS: Angiographic CVS after sSAH shows a specific distribution pattern in favor of ACA and MCA and in most cases 2-3 affected vessels are affected, often bilaterally. Patients exhibiting distal CVS have a higher risk for CVS-related infarction and should be observed closely. Nonetheless, the majority of angiographic characteristics did not allow conclusions about functional outcome nor the occurrence of CVS-related infarction in sSAH patients.

Cerebral effects of resuscitation with either epinephrine or vasopressin in an animal model of hemorrhagic shock.

PURPOSE: The use of epinephrine (EN) or vasopressin (VP) in hemorrhagic shock is well established. Due to its specific neurovascular effects, VP might be superior in concern to brain tissue integrity. The aim of this study was to evaluate cerebral effects of either EN or VP resuscitation after hemorrhagic shock. METHODS: After shock induction fourteen pigs were randomly assigned to two treatment groups. After 60 min of shock, resuscitation with either EN or VP was performed. Hemodynamics, arterial blood gases as well as cerebral perfusion pressure (CPP) and brain tissue oxygenation (PtiO2) were recorded. Interstitial lactate, pyruvate, glycerol and glutamate were assessed by cerebral and subcutaneous microdialysis. Treatment-related effects were compared using one-way ANOVA with post hoc Bonferroni adjustment (p < 0.05) for repeated measures. RESULTS: Induction of hemorrhagic shock led to a significant (p < 0.05) decrease of mean arterial pressure (MAP), cardiac output (CO) and CPP. Administration of both VP and EN sufficiently restored MAP and CPP and maintained physiological PtiO2 levels. Brain tissue metabolism was not altered significantly during shock and subsequent treatment with VP or EN. Concerning the excess of glycerol and glutamate, we found a significant EN-related release in the subcutaneous tissue, while brain tissue values remained stable during EN treatment. VP treatment resulted in a non-significant increase of cerebral glycerol and glutamate. CONCLUSIONS: Both vasopressors were effective in restoring hemodynamics and CPP and in maintaining brain oxygenation. With regards to the cerebral metabolism, we cannot support beneficial effects of VP in this model of hemorrhagic shock.

Symptomatic Cerebral Vasospasm after Spontaneous Subarachnoid Hemorrhage: Comparison of Single and Multiple Intra-arterial Treatment with Respect to the Functional Outcome.

OBJECTIVE: In cases of spontaneous subarachnoid hemorrhage (sSAH) and symptomatic cerebral vasospasm (sCVS), multiple intra-arterial treatments (IATs) can be potentially useful for the functional outcome, even if the prognosis is initially poor. But the actual influence of the number of IATs has yet to be clarified. We wanted to assess if there are differences in the functional outcome between patients with a singular IAT and multiple IATs for sCVS after sSAH. METHODS: In a single-center study, 405 consecutive patients with nontraumatic SAH were analyzed retrospectively. A total of 126 developed sCVS, and 86 received IAT (32 singular and 54 multiple, i.e., more than one) with nimodipine with or without percutaneous transluminal angioplasty (PTA). Both groups were compared for demographic data, initial treatment (clipping or endovascular), and initial grading (World Federation of Neurosurgical Societies/Fisher classification, intraventricular hemorrhage, and intracerebral hemorrhage). The modified Rankin Scale (mRS) was used to assess functional outcome at the time of discharge and after 3 and 6 months. The development of CVS-associated infarction was assessed by computed tomography (CT). Categorical variables of the patient groups were analyzed in contingency tables using the Fisher exact test, chi-square test, and the Mann-Whitney U test. Statistical significance was accepted at p < 0.05. RESULTS: Patient groups with singular and multiple IATs were comparable concerning demographic data and initial grading. At the end of follow-up after 6 months, both groups showed comparable functional outcomes. A favorable outcome (mRS: 0-3) was observed in 14 of 26 patients (53.9%) with a single IAT and for 29 of 49 patients (59.2%) with multiple IATs. An unfavorable outcome (mRS: 4-6) occurred in 12 of 26 patients (46.1%) with a single IAT and for 20 of 49 patients (40.8%) with multiple IATs (p = 0.420). In the group with a single IAT, 22 of 32 patients (68.8%) developed CVS-associated infarction; 32 of 54 patients (59.3%) showed brain infarcts after multiple IATs (p = 0.259). CONCLUSION: For patients with sCVS after sSAH, multiple IATs (nimodipine with or without additional PTA) can be applied safely because no significant differences in functional outcome were observed compared with a singular IAT. We conclude that patients should be treated repeatedly if vasospasm reoccurs.

Transluminal balloon angioplasty for cerebral vasospasm after spontaneous subarachnoid hemorrhage: A single-center experience.

OBJECTIVES: After spontaneous subarachnoid hemorrhage (sSAH), cerebral vasospasm (CVS) is a common complication, potentially resulting in infarction mainly responsible for a poor outcome. Intra-arterial vasodilators lead to transient increase of brain perfusion, but only transluminal balloon angioplasty (TBA) promises longer-lasting effects, though it poses the risk of severe complications. Until now, the precise impact of TBA on the course of CVS is not yet finally clarified. Thus we aimed to identify risk factors of recurrent CVS and vasospasm-related infarction following TBA. PATIENTS AND METHODS: We analyzed 35 patients with CVS after sSAH who received TBA (41 procedures, 99 vessel segments). Gender, age, WFNS grade and Fisher scale, occurrence of intraventricular and intracerebral hemorrhage, localization of the aneurysm and the initial treatment modality were obtained. We assessed functional outcome after 3 months and in-hospital mortality. TBA was analyzed concerning time point, localization, technique, complications and angiographic response. Furthermore, recurrence of CVS and vasospasm-related infarction after TBA were described and risk factors were identified with logistic regression analyses. RESULTS: In 7 of 35 patients (20%) and in 16 of 99 vessel segments (16%) previously treated with TBA, we found recurrent CVS. Vasospasm-related infarction occurred in 18 cases (18%) in the arterial territories of the TBA-treated vessel segments. The angiographic effect after TBA was mostly classified as good (87%), good response was negatively associated with recurrent CVS (p = 0.004) and vasospasm-related infarction (p = 0.001). We identified only the male gender as a risk factor for vasospasm-related infarction after TBA (p = 0.040). In connection with TBA, only one complication occurred (intracranial dissection). CONCLUSION: Our data support TBA as a safe and effective therapy for CVS. Nevertheless, recurrent CVS and vasospasm-related infarction were common after TBA and not predictable by clinical conditions on admission or the localization of CVS. A moderate or poor angiographic response after TBA was identified as a risk factor for both, recurrent CVS and vasospasm-related infarction, while male gender was associated with a higher risk of vasospasm-related infarction. Our results augment the still sparse evidence concerning optimal patient selection for this method and provide new aspects for individual therapy decisions.

Management of tracheostomized patients after poor grade subarachnoid hemorrhage: Disease related and pulmonary risk factors for failed and delayed decannulation.

OBJECTIVE: Tracheostomy is often indicated in patients with spontaneous subarachnoid hemorrhage (sSAH). Decannulation is a major goal of neurorehabilitation, but cannot be achieved in all patients. The aim of this study was to describe the course of decannulation and to identify associated risk factors in a single-center collective. PATIENTS AND METHODS: We retrospectively reviewed 87 sSAH patients with WFNS (World Federation of Neurosurgical Societies) grade III-IV, who received tracheostomy. Decannulation events and the time from tracheostomy to decannulation were recorded in a 200-days follow-up. Variables analyzed were: age, sex, WFNS grade, Fisher grade, the presence of intracerebral or intraventricular hematoma, acute hydrocephalus, aneurysm location, aneurysm obliteration (surgical vs. endovascular), treatment related complications, decompressive craniectomy, symptomatic cerebral vasospasm, vasospasm-related infarction and timing of tracheostomy. Further risk factors analyzed were preexisting chronic lung disease and pneumonia. Functional outcome was assessed by the modified Rankin Scale (mRS). RESULTS: The rate of successful decannulation was 84% after a median of 47 days. A higher WFNS grade and pneumonia were associated with both a prolonged time to decannulation (TTD) and decannulation failure (DF). Older age (> 60 years) and necessity for decompressive craniectomy were only associated with prolonged TTD. Outcome analysis revealed that patients with DF show a significantly (p < 0.01) higher rate of unfavorable outcome (mRS 3-6). CONCLUSION: Successful decannulation is possible in the majority of sSAH patients and particularly, in all patients with WFNS grade III. WFNS grading, age, the necessity for decompressive craniectomy and pneumonia are significantly associated with the TTD. WFNS grade and pneumonia are significantly associated with DF. The mean cannulation time of sSAH patients is shorter in relation to stroke patients.

The Impact of Intrahospital Transports on Brain Tissue Metabolism in Patients with Acute Brain Injury.

BACKGROUND: Patients with severe acute brain injury (ABI) often require intrahospital transports (IHTs) for repeated computed tomography (CT) scans. IHTs are associated with serious adverse events (AE) that might pose a risk for secondary brain injury. The goal of this study was to assess IHT-related alterations of cerebral metabolism in ABI patients. METHODS: We included mechanically ventilated patients with ABI who had continuous multimodality neuromonitoring during an 8-h period before and after routine IHT. Intracranial pressure (ICP), cerebral perfusion pressure (CPP), brain tissue oxygenation (PtiO2) as well as cerebral and subcutaneous microdialysis parameters (lactate, pyruvate, glycerol, and glutamate) were recorded. Values were compared between an 8-h period before (pre-IHT) and after (post-IHT) the IHT. RESULTS: A total of 23 IHT for head CT scans in 18 patients were analyzed. Traumatic brain injury (n = 7) was the leading cause of ABI, followed by subarachnoid hemorrhage (n = 6) and intracerebral hemorrhage (n = 5). The analyzed microdialysis parameters in the brain tissue as in the subcutaneous tissue did not show significant changes between the pre-IHT and post-IHT period. In addition, we observed no significant increase in ICP or decrease in CPP and PtiO2 in the 8-h period after IHT. CONCLUSIONS: While the occurrence of AE during IHT is a known risk factor for ABI patients, our results demonstrate that IHTs do not alter the brain tissue chemistry in a significant manner. This fact may help assess the risk for routine IHT more accurately.

The Impact of Extubation Failure in Patients with Good-Grade Subarachnoid Hemorrhage.

OBJECTIVE: To analyze the clinical impact of extubation failure (EF) in patients with good-grade subarachnoid hemorrhage (SAH), in whom a good clinical course usually is expected. PATIENTS AND METHODS: We reviewed the clinical data from 141 patients with SAH and 1) initial Hunt & Hess grade 1-3; 2) induction of general anesthesia for intervention; and 3) the presence of data about the functional outcome. Patients were divided into 3 groups: 1) primary tracheotomized patients (PT); 2) patients with successful extubation (ES); and 3) patients with EF (reintubation within 48 hours). RESULTS: EF occurred with a rate of 0.12. The leading cause of EF was respiratory insufficiency (n = 7), followed by impaired consciousness (n = 5). Multivariate logistic regression did not show any neurologic predictor of EF. Patients with ES showed an excellent outcome after 6 months (favorable outcome: 95.7%), whereas the outcome of patients with EF and PT was significantly (P < 0.05) poorer. The case fatality rate was nonsignificantly greater in the EF group (0.15 vs. 0.03). Hospitalization was significantly reduced for patients with ES, whereas the occurrence of symptomatic cerebral vasospasms and vasospastic cerebral infarction was similar between patients with EF, ES, or PT. CONCLUSIONS: We showed that EF is a frequent condition in good grade-SAH but is not predictable using common neurologic parameters. Regarding the functional outcome, we were able to show that the result of an extubation trial clearly delineates the patients in 2 distinct groups, in which ES predicts an excellent outcome.

Repeated Endovascular Treatments in Patients with Recurrent Cerebral Vasospasms After Subarachnoid Hemorrhage: A Worthwhile Strategy?

OBJECTIVE: Endovascular interventions in patients with subarachnoid hemorrhage (SAH) and symptomatic cerebral vasospasm (sCVS) are commonly performed, but the potential benefits of repeated interventions have not been proven. The aim of this study was to show the potential burden and opportunities of repeated endovascular interventions in cases of recurrent sCVS. METHODS: We reviewed 15 patients with SAH who underwent more than 2 endovascular treatments of recurrent sCVS (CVS group) regarding the radiation doses, their clinical course, and their functional outcome. A case-control group of SAH patients without sCVS individually matched for age, World Federation of Neurosurgical Societies score, Fisher grade, and treatment modality was used as control group (non-CVS group). RESULTS: A total of 70 endovascular treatments were performed in the CVS group. CVS group patients received longer mechanical ventilation (585 days vs. 439 days) and showed a higher rate of tracheostomy (12/15 vs. 7/15) and shunt-dependent hydrocephalus (6/15 vs. 2/15) than did the non-CVS patients. Moreover, patients from the CVS group underwent significantly (P < 0.001) more angiographies (median, 5 vs. 2) and CTP/CTA scans (median, 4 vs. 1) and consequently received significantly (P < 0.001) higher radiation doses. The rate of unfavorable outcomes (mRS 3-6) after 3 months was nonsignificantly higher in the CVS group (6/15 vs. 2/15), but after 6 months at least 5/14 patients from the CVS group showed a favorable outcome. CONCLUSION: Repeated endovascular treatments of SAH patients with recurrent CVS are complex and expose the patients to high radiation doses. Nevertheless, favorable results could be achieved in patients in otherwise poor condition.

Safety of Percutaneous Dilatational Tracheostomy in Patients with Acute Brain Injury and Reduced PaO2/FiO2 Ratio-Retrospective Analysis of 54 Patients.

OBJECTIVE: Percutaneous dilatational tracheostomy (PDT) is a commonly performed method in neurocritical care, and its safety has been proven in numerous studies. Nevertheless, data regarding the application in patients with acute brain injury and poor respiratory function are poor. The purpose of this study was to evaluate the incidence of hypoxemia and hypercapnia during PDT in those patients. METHODS: In a retrospective analysis, we acquired data from 54 patients with an acute brain injury (ABI) and a reduced PaO2/FiO2 ratio (PaO2/FiO2 < 300 mm Hg). In all cases, blood gas analyses before, during, and approximately 12 hours after PDT were available. We reviewed the patients' ventilator settings, results of gas exchange, and radiographic signs of acute respiratory distress syndrome (ARDS). Patients with ARDS were defined using the Berlin criteria. RESULTS: We observed 2 cases (3.6%) of intraoperative hypoxemia (PaO2 < 60 mm Hg) and 4 cases (7.4%) of intraoperative hypercapnia (PaCO2 > 55 mm Hg). Twenty patients fulfilled the Berlin criteria for ARDS. While mean PaO2 did not differ significantly between ARDS and non-ARDS patients, intraoperative hypoxemia only occurred in the ARDS group (2/20). Mean PaCO2 was similar in the ARDS and non-ARDS groups, and cases of hypercapnia were apparent in both groups. The mean PaO2/FiO2 ratio of all patients improved from 229.1 mm Hg before PDT to 255.3 mm Hg. CONCLUSIONS: Regarding the intraoperative gas exchange, indication of PDT in patients with ABI and ARDS should be considered carefully. However, PDT in ABI patients with reduced PaO2/FiO2 ratio alone appears to be a safe procedure.

Analysis of extracellular brain chemistry during percutaneous dilational tracheostomy: A retrospective study of 19 patients.

OBJECTIVE: The purpose of this study was to analyze changes in brain tissue chemistry around percutaneous dilational tracheostomy (PDT) in patients with acute brain injury (ABI) in a retrospective single-center analysis. PATIENTS AND METHODS: We included 19 patients who had continuous monitoring of brain tissue chemistry and intracranial pressure (ICP) during a 20h period before and after PDT. Different microdialysis parameters (lactate, pyruvate, lactate pyruvate ratio (LPR), glycerol and glutamate) and values of ICP, cerebral perfusion pressure (CPP) and brain tissue oxygenation (PBrO2) were recorded per hour. Mean values were compared between a 10h period before PDT (prePDT) and after PDT (postPDT). RESULTS: Mean values of cerebral lactate, pyruvate, LPR, glycerol and glutamate did not differ significantly between prePDT and postPDT. In addition, the rate of patients, which exceeded the known threshold was similar between prePDT and postPDT. Only one patient showed a strong increase of cerebral glycerol during the postPDT period, but analysis of subcutaneous glycerol could exclude an intracerebral event. ICP, CPP and PBrO2 did not exhibit significant changes. CONCLUSIONS: We could exclude the occurrence of cerebral metabolic crisis and the excess release of cerebral glutamate and glycerol in a series of 19 patients. Our results support the safety of PDT in patients with ABI.