Faculty Bibliography

OBJECTIVE: There are multiple etiologies for failure while weaning an external ventricular drain (EVD) after subarachnoid hemorrhage (SAH), but there is little data on the relationship between etiology of wean failure and ventriculoperitoneal shunt (VPS) placement. METHODS: We performed a retrospective analysis of SAH patients who had an EVD placed between January 2008 and June 2012 at our institution. For each wean step (defined as raising or clamping the EVD), we recorded success or failure. We categorized failure as lowering or opening the EVD due to elevated intracranial pressure (ICP), clinical failure (due to headache or vomiting or altered mental status), leakage from the EVD site, or development of radiographic hydrocephalus. We evaluated the relationship between etiology of wean failure and subsequent need for VPS. RESULTS: Of 116 patients with an EVD placed, 35 required VPS placement (30%). Patients who required VPS placement had a median of 2 (interquartile range (IQR) 1-4) wean failures and those who did not require VPS placement had a median of 1 (IQR 0-1) wean failure (p=0.001). There was no significant relationship between age, sex, Hunt Hess score, Fisher score, Glasgow coma scale, aneurysm location, aneurysm size, aneurysm treatment method, vasospasm and need for VPS. There was a significant relationship between patients with at least one wean failure due to clinical changes or radiographic hydrocephalus and need for VPS (p=0.007 and p=0.029, respectively). After multivariate analysis, there was only a significant relationship between clinical changes and need for VPS (OR 2.76, CI 1.03-7.36, p=0.04). CONCLUSION: There is a significant association between wean failure due to clinical changes and requirement for VPS placement after SAH.

Stroke is one of the leading causes of death. Hyperlipidemia is a major risk factor for stroke. The United States Preventive Service Task Force defines lipid screening guidelines. Treatment options of hyperlipidemia include lifestyle modifications and medical management. Statins have been shown to decrease lipids and exert a pleiotropic effect on intracranial vasculature and inflammatory modulators, leading to neuroprotection. Lower low-density lipoprotein and higher high-density lipoprotein levels are associated with decreased risk of stroke. Despite screening guidelines and evidence of the efficacy of statins, there are numerous barriers to maintaining adequate control of lipids.

In this double-blinded randomized study, we sought to confirm that patients undergoing general anesthesia who were exposed to a hemispheric synchronization (Hemi-Sync) musical recording during surgery had a smaller analgesia requirement, as was suggested in a previous study. Bispectral index monitoring was used to adjust depth of hypnosis, and hemodynamic variables were used to determine analgesia administration. Consented patients underwent either laparoscopic bariatric or one-level lumbar disk surgery. After endotracheal intubation and application of headphones, baseline heart rate and arterial blood pressure were established. Isoflurane was titrated to maintain sedation on the basis of a target bispectral index range of 40-60, and 25-microg increments of fentanyl were administered in response to increases in heart rate and systolic arterial blood pressure. Bariatric patients who listened to Hemi-Sync required one-third less fentanyl than the control group (mean [SD]: 0.015 [0.01] vs 0.024 microg.kg(-1).min(-1) [0.01]) (P = 0.009). It is interesting to note that lumbar patients in the experimental and control groups required similar amounts of fentanyl (0.012 [0.01] vs 0.015 microg.kg(-1).min(-1) [0.01]). End-tidal isoflurane concentration was similar for Hemi-Sync and blank-tape patients (bariatric, 0.74% (0.14) vs 0.77% (0.21); lumbar, 0.36% [0.16] vs 0.39% [0.12]). The bariatric patients in this study demonstrated that Hemi-Sync may be an innovative intraoperative supplement to analgesia. IMPLICATIONS: The purpose of this study was to determine the decrease in analgesia requirement for patients listening to hemispheric synchronization (musical tones) while under general anesthesia. We demonstrated that bariatric patients who listened to hemispheric synchronization had a smaller analgesia requirement than those who listened to a blank tape.