Introduction: Aneurysmal subarachnoid hemorrhage (aSAH) may result in abnormal respiratory and swallowing dysfunction such as dysphagia, dyspnea, apnea, hyperventilation and systems-wide hypoxemia3. The mechanism underlying this relationship is poorly understood, though they may depend on hemorrhagic severity or the size of the subarachnoid clot4. Posterior circulation aneurysms, particularly those with mass effect and deformation of the medulla, may have a higher risk of neurogenic pulmonary edema (NPE) due to proximity to respiratory control centers1,2,5. However, there are few reports of the factors that influence long-term respiratory and swallowing function in this population.

Methods: We retrospectively reviewed all aSAH patients from January 2011 through June 2014. We identified 400 patients (full analysis pending), and completed data analysis for 77 patients. We recorded the location of the aneurysm, the incidence of vestibular symptoms and respiratory indices on arrival, in-hospital adverse respiratory events and the need for tracheostomy (for respiratory failure) or percutaneous endoscopic gastrostomy (PEG) tube (for prolonged dysphagia). Respiratory and swallowing function was also reviewed at 1 year and at most recent clinical follow-up.

Results: There were 56 (73%) anterior circulation and 21 (27%) posterior circulation aneurysms identified in 77 aSAH patients. Vestibular symptoms (vertigo, dizziness, nystagmus) were significantly more likely to occur in patients with posterior circulation aneurysms (p=0.006). There was no difference in oxygen saturation or PaO2:FiO2 ratio on arrival, pneumonia, acute respiratory distress syndrome, NPE, or rates of tracheostomy or PEG tube placement between anterior and posterior circulation aneurysms. A subgroup analysis of 4 basilar artery aneurysms also revealed no differences in these outcomes compared to anterior circulation aneurysms. There ws a 3.9% rate of tracheostomy, and 15.6% rate of PEG placement. There was 1 year follow up information for 30 patients; 0 patients had any respiratory issues, and 1 patient (with a posterior circulation aneurysm) had improving dysphagia with PEG tube feeds.

Conclusions: Anterior and posterior circulation aneurysms have similar rates of in-hospital and long-term respiratory and swallowing dysfunction. Vestibular symptoms were more frequently observed on presentation in posterior circulation aneurysms.

Patient Care: The findings of our study help to elucidate a specific and important outcome for patients with subarachnoid hemorrhage, namely respiratory and swallowing function. Using prognostic information can help guide discussions with families on presentation, as well as implementation of supportive therapies (i.e. speech therapy, pulmonary hygiene).

Learning Objectives: (1) To review the respiratory and swallowing outcomes in aneurysmal subarachnoid hemorrhage to help guide family discussions for expectations, (2) to determine if there are clinical variables underlying differences in outcomes, potentially shedding light on a mechanism for breathing/swallowing disturbances in aSAH

References: 1. Gekka M, Yamaguchi S, Kazumata K, Kobayashi H, Motegi H, Terasaka S, Houkin K: Hemorrhagic onset of hemangioblastoma located in the dorsal medulla oblongata presenting with tako-tsubo cardiomyopathy and neurogenic pulmonary edema: a case report. Case Rep Neurol 6: 68-73, 2014 2. Ochiai, H., Yamakawa, Y., & Kubota, E.: Deformation of the ventrolateral medulla oblongata by subarachnoid hemorrhage from ruptured vertebral artery aneurysms causes neurogenic pulmonary edema. Neurol Med Chir (Tokyo) 41: 529-534; discussion 534-525, 2001 3. Rothberg C, Weir B, Overton T, Grace M: Responses to experimental subarachnoid hemorrhage in the spontaneously breathing primate. J Neurosurg 52: 302-308, 1980 4. Watanabe, T., Sekiguchi, K., Inoue, A., Taniguchi, Y., & Sato, S.: [Clinical evaluation of neurogenic pulmonary edema following acute stage of subarachnoid hemorrhage]. No Shinkei Geka 20: 417-422, 1992 5. Yan, Y., Chen, J. X., Lu, Y. C., Hu, G. H., Sun, K. H., Ding, X. H., et al.: [Surgical treatment of hemangioblastoma in medulla oblongata:a report of 12 cases]. Zhonghua Yi Xue Za Zhi 93: 2799-2802, 2013