Remote Ischemic Pre-conditioning in Subarachnoid Hemorrhage: A Prospective Pilot Trial.

BACKGROUND: Cerebral injury from aneurysmal subarachnoid hemorrhage (aSAH) is twofold. The initial hemorrhage causes much of the injury; secondary injury can occur from delayed cerebral ischemia (DCI). Remote ischemic preconditioning (RIPC) is a mechanism of organ protection in response to transient ischemia within a distant organ. This pilot trial sought to apply RIPC in patients with aSAH to evaluate its effect on secondary cerebral injury and resultant outcomes. METHODS: Patients were randomized to the high-pressure occlusion group (HPO) or the low-pressure occlusion group (LPO). Lower extremity RIPC treatment was initiated within 72 h of symptom onset and every other day for 14 days or until Intensive Care Unit (ICU) discharge. In HPO, each treatment consisted of 4 five-minute cycles of manual blood pressure cuff inflation with loss of distal pulses. LPO received cuff inflation with lower pressures while preserving distal pulses. Retrospectively matched controls were also analyzed. Efficacy of treatment was measured by total days spent in vasospasm out of study enrollment days, hospital and ICU length of stay (LOS), cerebral infarction, one and six month modified Rankin score, and mortality. RESULTS: The final analysis included 33 patients with 11 in each group. Patient demographics, aneurysm location, admission airway status, Glasgow Coma Scale (GCS), modified Rankin score, Hunt and Hess score, modified Fisher Score and aneurysm management were not significantly different between groups. Hospital and ICU LOS was shorter in LPO compared to the control (p = 0·0468 and p = 0·0409, respectively). Total vasospasm days/study enrollment days, cerebral infarction, one and six month modified Rankin score, and mortality were not significantly different between the groups. CONCLUSIONS: This pilot trial did demonstrate feasibility and safety. The shortened LOS in the LPO may implicate a protective role of RIPC and warrants future study.

Comparison of Three Point-of-Care Ultrasound Views and MRI Measurements for Optic Nerve Sheath Diameter: A Prospective Validity Study.

INTRODUCTION: Point-of-care ultrasound of the optic nerve sheath diameter (ONSD) to diagnose increased intracranial pressure (ICP) is of great interest in various clinical scenarios. Yet, the lack of examination standardization has made clinical utility difficult. We compare three ultrasound ocular plane views (inferior, sagittal, and transverse), which are currently used in the literature to evaluate their consistency. Comparisons for each view to magnetic resonance imaging (MRI) measurements were also made. METHODS: Fifty-one patients with recent MRI of the brain, but without clinical or radiological signs of elevated ICP, were selected to undergo ocular sonography via three ultrasound planes (inferior, sagittal, and transverse). Optic nerve sheath was measured in each ultrasound view as well with MRI. Image quality scores were assigned for the ultrasound views in different orientations. The three ocular plane views were analyzed for correlation. In addition, correlation of the three ocular ultrasound views with MRI was also performed. RESULTS: Correlation analysis showed a wide variability in the correlation between different ultrasound views with magnitude range of 0.1 to 0.8 and directions being both positive and negative. There was a difference in image quality scores between the ultrasound views. The inferior and transverse orientations were superior to the sagittal orientation in achieving high image quality. Comparison to MRI measurements did not demonstrate a significant correlation. CONCLUSION: Our findings suggest that absolute measurements should not be compared across different ultrasound orientations given the wide variability in the correlation between the ultrasound views used to assess the optic nerve sheath. The inferior and transverse ultrasound views are the most likely to yield high-quality images, although the specific view, for the best image, in an individual patient can vary. We would caution against absolute values of ONSD to indicate increased ICP, as it may be view dependent.

Anesthesiologists as perioperative hospitalists and outcomes in patients undergoing major urologic surgery: a historical prospective, comparative effectiveness study.

BACKGROUND: Perioperative care has been identified as an area of wide variability in quality, with conflicting models, and involving multiple specialties. In 2014, the Loma Linda University Departments of Anesthesiology and Urology implemented a perioperative hospitalist service (PHS), consisting of anesthesiology-trained physicians, to co-manage patients for the entirety of their perioperative period. We hypothesized that implementation of this PHS model would result in an improvement in patient recovery. METHODS: As a quality improvement (QI) initiative, the PHS service was formed of selected anesthesiologists who received training on the core competencies for hospitalist medicine. The service was implemented following a co-management agreement to medically manage patients undergoing major urologic procedures (prostatectomy, cystectomy, and nephrectomy). Impact was assessed by comparisons to data from the year prior to PHS service implementation. Data was compared with and without propensity matching. Primary outcome marker was a reduction in length of stay. Secondary outcome markers included complication rate, return of bowel function, number of consultations, reduction in total direct patient costs, and bed days saved. RESULTS: Significant reductions in length of stay (p <  0.05) were demonstrated for all surgical procedures with propensity matching and were demonstrated for cystectomy and nephrectomy cases without. Significant reductions in complication rates and ileus were also observed for all surgical procedures post-PHS implementation. Additionally, reductions in total direct patient costs and frequency of consultations were also observed. CONCLUSIONS: Anesthesiologists can safely function as perioperative hospitalists, providing appropriate medical management, and significantly improving both patient recovery and throughput.

Crotalus atrox venom preconditioning increases plasma fibrinogen and reduces perioperative hemorrhage in a rat model of surgical brain injury.

Perioperative bleeding is a potentially devastating complication in neurosurgical patients, and plasma fibrinogen concentration has been identified as a potential modifiable risk factor for perioperative bleeding. The aim of this study was to evaluate preconditioning with Crotalus atrox venom (Cv-PC) as potential preventive therapy for reducing perioperative hemorrhage in the rodent model of surgical brain injury (SBI). C. atrox venom contains snake venom metalloproteinases that cleave fibrinogen into fibrin split products without inducing clotting. Separately, fibrinogen split products induce fibrinogen production, thereby elevating plasma fibrinogen levels. Thus, the hypothesis was that preconditioning with C. atrox venom will produce fibrinogen spilt products, thereby upregulating fibrinogen levels, ultimately improving perioperative hemostasis during SBI. We observed that Cv-PC SBI animals had significantly reduced intraoperative hemorrhage and postoperative hematoma volumes compared to those of vehicle preconditioned SBI animals. Cv-PC animals were also found to have higher levels of plasma fibrinogen at the time of surgery, with unchanged prothrombin time. Cv-PC studies with fractions of C. atrox venom suggest that snake venom metalloproteinases are largely responsible for the improved hemostasis by Cv-PC. Our findings indicate that Cv-PC increases plasma fibrinogen levels and may provide a promising therapy for reducing perioperative hemorrhage in elective surgeries.

Beta Blockade and Clinical Outcomes in Aneurysmal Subarachnoid Hemorrhage.

BACKGROUND: Aneurysmal subarachnoid hemorrhages are frequently complicated by hypertension and neurogenic myocardial stunning. Beta blockers may be used for management of these complications. We sought to investigate sympathetic nervous system modulation by beta blockers and their effect on radiographic vasospasm, delayed cerebral infarction, discharge destination and death. METHODS: Retrospective chart review of 218 adults admitted to the ICU between 8/2004 and 9/2010 was performed. Groups were identified relevant to beta blockade: 77 were never beta blocked (No/No), 123 received post-admission beta blockers (No/Yes), and 18 were continued on their home beta blockers (Yes/Yes). Records were analyzed for baseline characteristics and the development of vasospasm, delayed cerebral infarction, discharge destination and death, expressed as adjusted odds ratio. RESULTS: Of the 218 patients 145 patients developed vasospasm, 47 consequently infarcted, and 53 died or required care in a long-term facility. When compared to No/No patients, No/Yes patients had significantly increased vasospasm (OR 2.11 (1.06-4.16)). However, these patients also had significantly fewer deaths or need for long term care (OR 0.17 (0.05-0.64)), with decreased tendency for infarcts (OR 0.70 (0.32-1.55)). When compared to No/No patients, Yes/Yes patients demonstrated a trend toward increased vasospasm (OR 1.61 (0.50-5.29)) that led to infarction (OR 1.51 (0.44-5.13)), but with decreased mortality or need for long term care in a facility (OR 0.13 (0.01-1.30)). CONCLUSION: Post-admission beta blockade in aneurysmal subarachnoid hemorrhage patients was associated with increased incidence of vasospasm. However, despite the increased occurrence of vasospasm, beta blockers were associated with improved discharge characteristics and fewer deaths.