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 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.

Postural Control in Bilateral Vestibular Failure: Its Relation to Visual, Proprioceptive, Vestibular, and Cognitive Input.

Patients with bilateral vestibular failure (BVF) suffer from postural and gait unsteadiness with an increased risk of falls. The aim of this study was to elucidate the differential role of otolith, semicircular canal (SSC), visual, proprioceptive, and cognitive influences on the postural stability of BVF patients. Center-of-pressure displacements were recorded by posturography under six conditions: target visibility; tonic head positions in the pitch plane; horizontal head shaking; sensory deprivation; dual task; and tandem stance. Between-group analysis revealed larger postural sway in BVF patients on eye closure; but with the eyes open, BVF did not differ from healthy controls (HCs). Head tilts and horizontal head shaking increased sway but did not differ between groups. In the dual task condition, BVF patients maintained posture indistinguishable from controls. On foam and tandem stance, postural sway was larger in BVF, even with the eyes open. The best predictor for the severity of bilateral vestibulopathy was standing on foam with eyes closed. Postural control of our BVF was indistinguishable from HCs once visual and proprioceptive feedback is provided. This distinguishes them from patients with vestibulo-cerebellar disorders or functional dizziness. It confirms previous reports and explains that postural unsteadiness of BVF patients can be missed easily if not examined by conditions of visual and/or proprioceptive deprivation. In fact, the best predictor for vestibular hypofunction (VOR gain) was examining patients standing on foam with the eyes closed. Postural sway in that condition increased with the severity of vestibular impairment but not with disease duration. In the absence of visual control, impaired otolith input destabilizes BVF with head retroflexion. Stimulating deficient SSC does not distinguish patients from controls possibly reflecting a shift of intersensory weighing toward proprioceptive-guided postural control. Accordingly, proprioceptive deprivation heavily destabilizes BVF, even when visual control is provided.

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.

Hippocampal gray matter volume in bilateral vestibular failure.

Bilateral vestibular failure (BVF) is a severe chronic disorder of the labyrinth or the eighth cranial nerve characterized by unsteadiness of gait and disabling oscillopsia during head movements. According to animal data, vestibular input to the hippocampus is proposed to contribute to spatial memory and spatial navigation. Except for one seminal study showing the association of impaired spatial navigation and hippocampal atrophy, patient data in BVF are lacking. Therefore, we performed a voxel-wise comparison of the hippocampal gray matter volume (GMV) in a clinically representative sample of 27 patients with incomplete BVF and 29 age- and gender-matched healthy controls to test the hypothesis of hippocampal atrophy in BVF. Although the two groups did not generally differ in their hippocampal GMV, a reduction of GMV in the bilateral hippocampal CA3 region was significantly correlated with increased vestibulopathy-related clinical impairment. We propose that GMV reduction in the hippocampus of BVF patients is related to the severity of vestibular-induced disability which is in line with combined hippocampal atrophy and disorders of spatial navigation in complete vestibular deafferentation due to bilateral nerve section. Clinically, however, the most frequent etiologies of BVF cause incomplete lesions. Accordingly, hippocampus atrophy and deficits in spatial navigation occur possibly less frequently than previously suspected. Hum Brain Mapp 37:1998-2006, 2016. © 2016 Wiley Periodicals, Inc.

Altered resting-state functional connectivity in patients with chronic bilateral vestibular failure.

Patients with bilateral vestibular failure (BVF) suffer from gait unsteadiness, oscillopsia and impaired spatial orientation. Brain imaging studies applying caloric irrigation to patients with BVF have shown altered neural activity of cortical visual-vestibular interaction: decreased bilateral neural activity in the posterior insula and parietal operculum and decreased deactivations in the visual cortex. It is unknown how this affects functional connectivity in the resting brain and how changes in connectivity are related to vestibular impairment. We applied a novel data driven approach based on graph theory to investigate altered whole-brain resting-state functional connectivity in BVF patients (n= 22) compared to age- and gender-matched healthy controls (n= 25) using resting-state fMRI. Changes in functional connectivity were related to subjective (vestibular scores) and objective functional parameters of vestibular impairment, specifically, the adaptive changes during active (self-guided) and passive (investigator driven) head impulse test (HIT) which reflects the integrity of the vestibulo-ocular reflex (VOR). BVF patients showed lower bilateral connectivity in the posterior insula and parietal operculum but higher connectivity in the posterior cerebellum compared to controls. Seed-based analysis revealed stronger connectivity from the right posterior insula to the precuneus, anterior insula, anterior cingulate cortex and the middle frontal gyrus. Excitingly, functional connectivity in the supramarginal gyrus (SMG) of the inferior parietal lobe and posterior cerebellum correlated with the increase of VOR gain during active as compared to passive HIT, i.e., the larger the adaptive VOR changes the larger was the increase in regional functional connectivity. Using whole brain resting-state connectivity analysis in BVF patients we show that enduring bilateral deficient or missing vestibular input leads to changes in resting-state connectivity of the brain. These changes in the resting brain are robust and task-independent as they were found in the absence of sensory stimulation and without a region-related a priori hypothesis. Therefore they may indicate a fundamental disease-related change in the resting brain. They may account for the patients' persistent deficits in visuo-spatial attention, spatial orientation and unsteadiness. The relation of increasing connectivity in the inferior parietal lobe, specifically SMG, to improvement of VOR during active head movements reflects cortical plasticity in BVF and may play a clinical role in vestibular rehabilitation.