Teresa L. Jacobs

Comparison of accuracy of optic nerve ultrasound for the detection of intracranial hypertension in the setting of acutely fluctuating vs stable intracranial pressure: post-hoc analysis of data from a prospective, blinded single center study

IntroductionOptic nerve sheath diameter (ONSD) measurement with bedside ultrasound has been shown in many studies to accurately detect high intracranial pressure (ICP). The accuracy of point-in-time ONSD measurement in the presence of ongoing fluctuation of ICP between high and normal is not known. Recent laboratory investigation suggests that reversal of optic nerve sheath distension may be impaired following bouts of intracranial hypertension. Our objective was to compare the accuracy of ONSD measurement in the setting of fluctuating versus stable ICP.MethodsThis was a retrospective analysis of data from prospective study comparing ONSD to invasive ICP. Patients with invasive ICP monitors in the ICU underwent ONSD measurement with simultaneous blinded recording of ICP from the invasive monitor. Three measurements were made in each eye. Significant acute ICP fluctuation (SAIF) was defined in two different ways; as the presence of ICP both above and below 20 mmHg within a cluster of six measurements (Definition 1) and as a magnitude of fluctuation >10 mmHg within the cluster (Definition 2). The accuracy of point-in-time ONSD measurements for the detection of concurrent ICP >20 mmHg within clusters fulfilling a specific definition of SAIF was compared to the accuracy of ONSD measurements within clusters not fulfilling the particular definition by comparison of independent receiver operating characteristic (ROC) curves.ResultsA total of 613 concurrent ONSD-ICP measurements in 109 clusters were made in 73 patients. Twenty-three (21%) clusters fulfilled SAIF Definition 1 and 17 (16%) SAIF Definition 2. For Definition 1, the difference in the area under the curve (AUC) of ROC curves for groups with and without fluctuation was 0.10 (P = 0.0001). There was a fall in the specificity from 98% (95% CI 96 to 99%) to 74% (63 to 83%) and in the positive predictive value from 89% (80 to 95%) to 76% (66 to 84%) with fluctuation. For Definition 2, also, there was a significant difference between the AUC of ROC curves of groups with fluctuation-magnitude >10 mmHg and those with fluctuation-magnitude 5 to 10 mmHg (0.06, P = 0.04) as well as <5 mmHg (0.07, P = 0.01).ConclusionsSpecificity and PPV of ONSD for ICP >20 mmHg are substantially decreased in patients demonstrating acute fluctuation of ICP between high and normal. This may be because of delayed reversal of nerve sheath distension.

Low pulsatility index on transcranial Doppler predicts symptomatic large-vessel vasospasm after aneurysmal subarachnoid hemorrhage.

BACKGROUND Elevated mean cerebral blood flow velocity (mCBFV) on transcranial Doppler predicts vasospasm of the large intracranial arteries after aneurysmal subarachnoid hemorrhage (aSAH). The pulsatility index (PI) is a measure of distal vascular resistance, which may be low when there is compensatory distal vasodilatation following hypoperfusion caused by large-vessel vasospasm. OBJECTIVE To study the predictive value of low PI for symptomatic large-vessel vasospasm (SLVVS) after aSAH. METHODS Medical records of patients admitted with aSAH between January 2007 and April 2009 were reviewed. Transcranial color-coded duplex (TCCD) sonography was performed daily between days 2 and 14. Patients with unexplained acute neurological decline underwent catheter- or computed tomography-angiography. The lowest recorded PI and the highest mCBFV on TCCD were correlated to the occurrence of SLVVS, angiographic vasospasm, and delayed cerebral infraction in multivariate analysis by use of logistic regression. Functional outcome was assessed at first follow-up. RESULTS Eighty-one patients met inclusion criteria. Mean lowest PI was 0.71 + 0.19. Median highest mCBFV was 135 cm/s (interquartile range 99-194 cm/s). SLVVS was seen in 21 of 81 (26%) patients, whereas 27 of 55 (49%) patients with repeat angiography had moderate or severe angiographic vasospasm. Following multivariate analysis, only the lowest PI was an independent predictor of SLVVS (P = .03, odds ratio 0.04, 95% confidence interval 0.001-0.54), whereas only the highest mCBFV was an independent predictor of angiographic vasospasm (P = .02, odds ratio 1.01, 95% confidence interval 1.002-1.02). SLVVS was independently associated with functional outcome at follow-up. CONCLUSION Low PI on TCCD is an independent predictor of SLVVS after aSAH, whereas mCBFV is a better predictor of angiographic vasospasm.

Efficacy of antibiotic-impregnated external ventricular drains in reducing ventriculostomy-associated infections

Use of an external ventricular drain (EVD) is essential for managing patients with hydrocephalus or intracranial hypertension. While this procedure is safe and efficacious, ventriculostomy-associated infections (VAI) continue to cause significant morbidity. In this study, we evaluated the efficacy of antibiotic-coated EVD (AC-EVD) in reducing the occurrence of VAI. Between July 2007 and July 2009, 203 patients underwent placement of an EVD. A total of 145 of these patients met the inclusion criteria, with 76 patients (52.4%) receiving AC-EVD and 69 patients (47.6%) receiving uncoated EVD. Ten patients (6.9%) developed VAI, of whom three were in the AC-EVD group and seven were in the uncoated EVD group (p=0.19). The mean duration between catheter insertion and positive cerebrospinal fluid culture was significantly greater in the AC-EVD group versus the uncoated EVD group (15±4days versus 4±2days, respectively; p=0.001). In the uncoated EVD group, 17 of 69 patients (24.6%) were dead at 3years versus 12 of 76 (15.8%) patients in the AC-EVD group (p=0.21). The overall VAI rate was 6.9% with a trend toward lower infection rates in the AC-EVD group compared to the uncoated EVD group (3.9% versus 10.1%, respectively; p>0.05).

Trial of early noninvasive ventilation for ALS: A pilot placebo-controlled study.

Objective: To evaluate the use and tolerability of noninvasive positive pressure ventilation (NIV) in patients with amyotrophic lateral sclerosis (ALS) early in their disease by comparing active NIV and sham NIV in patients not yet eligible for NIV use as recommended by practice guidelines. Methods: This was a single-center, prospective, double-blind, randomized, placebo (sham)–controlled pilot trial. Patients with ALS were randomized to receive either sham NIV or active NIV and underwent active surveillance approximately every 3 months until they reached a forced vital capacity (FVC) <50% or required NIV for clinical symptom management. Results: In total, 54 participants were randomized. The mean NIV use was 2.0 hours (95% confidence interval [CI] 1.1–3.0) per day in the sham NIV treatment group and 3.3 hours (CI 2.0–4.6) per day in the active NIV group, which did not differ by treatment group (p = 0.347). The majority of sham NIV participants (88%) and active NIV participants (73%) reported only mild or no problem with NIV use. Difference of change in FVC through the treatment period by group (0.44 per month) favored active NIV (p = 0.049). Survival and changes in maximal inspiratory or expiratory pressure did not differ between treatment groups. Conclusions: The efficacy of early NIV in ALS should be tested in randomized, placebo-controlled trials. The trial is registered on clinicaltrials.gov (NCT00580593). Classification of evidence: This study provides Class II evidence that for patients with ALS, adherence with NIV and sham NIV are similar.

CT angiography is cost-effective for confirmation of internal carotid artery occlusions.

While sensitive to internal carotid artery (ICA) occlusion, carotid ultrasound can produce false‐positive results. CT angiography (CTA) has a high specificity for ICA occlusion and is safer and cheaper than catheter angiography, although less accurate. We determined the cost‐effectiveness of CTA versus catheter angiography for confirming an ICA occlusion first suggested by carotid ultrasound.

Leadership at the front line: a clinical partnership model on general care inpatient units.

Hospitals strive to provide all their patients with quality care that is safe, timely, efficient, equitable, effective, and patient centered. Although hospitals have developed technology- and industry-based quality improvement models, there remains a need to better engage the frontline health care workers at the site of care to enhance communication and coordination of care. To foster the work environment and relationships in the general acute care units, the authors describe a leadership model that partners a nurse manager with a physician director to build a local clinical care environment that seeks to enhance the whole patient care experience.

Adolescent knowledge and attitudes related to clinical trials.

Background or aims Poor enrollment plagues most clinical trials. Furthermore, despite mandates to improve minority representation in clinical trial participation, little progress has been made. We investigated the knowledge and attitudes of adolescents related to clinical trials and made race/ethnicity comparisons in an attempt to identify a possible educational intervention target. Methods Students aged 13–18 years in southeast Michigan were offered participation through a class at one high school or two academic summer enrichment programs that drew from multiple high schools (73% response). Questionnaires previously validated in adults were administered. Non-Hispanic whites were compared with minorities using Wilcoxon rank-sum tests. Results Of the 82 respondents, the median age was 16 years (interquartile range: 15–17 years); 22 (28%) were white, 41 (51%) were African American, 11 (14%) were multiracial, 2 (2%) were American Indian or Alaska Native, 1 (1%) was Asian, 3 (4%) were Native Hawaiian or other Pacific Islander, and 2 respondents did not report a race (but did report Hispanic ethnicity). Nine (12%) were Hispanic. Only 27 (33%) had ever heard of a clinical trial. On a scale from 1 (most receptive) to 5 (least receptive) for learning more about a clinical trial for a relevant medical condition, the median score was 2 (interquartile range: 1–3) and for participating in a clinical trial for a relevant medical condition was 2 (interquartile range: 2–3). Overall knowledge was poor, with a median of 46% (interquartile range: 23%−62%) of knowledge answers correct. Knowledge was reduced (p = 0.0006) and attitudes were more negative (p = 0.05) in minorities than non-Hispanic whites, while minorities also endorsed more substantial barriers to trial participation (p = 0.0002). Distrust was similar between minority students and non-Hispanic whites (p = 0.15), and self-efficacy was greater in non-Hispanic whites (p = 0.05). Conclusion Educational interventions directed toward adolescents that address knowledge, attitudes, and distrust in order to improve clinical trial awareness and receptivity overall are needed and may represent a tool to address disparities in minority enrollment in clinical trials.

A Propensity Score Analysis of the Impact of Dexamethasone Use on Delayed Cerebral Ischemia and Poor Functional Outcomes After Subarachnoid Hemorrhage

OBJECTIVE An inflammatory response occurs after aneurysmal subarachnoid hemorrhage (aSAH) and predicts poor outcomes. Glucocorticoids suppress inflammation and promote fluid retention. Dexamethasone is often administered after aSAH for postoperative cerebral edema and refractory headache. Our objective was to examine the impact of dexamethasone use on functional outcomes and delayed cerebral ischemia (DCI) after aSAH. METHODS Patients with aSAH admitted between 2010 and 2015 were included; the data source was a single-center subarachnoid hemorrhage registry. The intervention of interest was a dexamethasone taper used <7 days from ictus. The primary outcome was poor discharge functional outcome, with a modified Rankin Scale score >3. Other outcomes included DCI and infection. A propensity score for use of dexamethasone was calculated using a logistic regression model that included potential predictors of dexamethasone use and outcome. The impact of dexamethasone on outcomes of interest was calculated and the propensity score was controlled for. RESULTS A total of 440 patients with subarachnoid hemorrhage were admitted during the study period and 309 met eligibility criteria. Dexamethasone was administered in 101 patients (33%). A total of 127 patients (41%) had a discharge modified Rankin Scale score >3, 105 (34%) developed DCI, and 94 (30%) developed an infection. After propensity score analysis, dexamethasone use was associated with a significant reduction in poor functional outcomes (odds ratio [OR], 0.35; 95% confidence interval [CI], 0.19-0.66) but showed no significant association with DCI (OR, 0.93; 95% CI, 0.53-1.64) or infection (OR, 0.60; 95% CI, 0.34-1.06). CONCLUSIONS Dexamethasone use after aSAH was associated with a reduction in poor functional outcomes at discharge but not DCI, controlling for predictors of dexamethasone use.

Thrombolytic-Enhanced Extracorporeal Cardiopulmonary Resuscitation After Prolonged Cardiac Arrest.

Objective:To investigate the effects of the combination of extracorporeal cardiopulmonary resuscitation and thrombolytic therapy on the recovery of vital organ function after prolonged cardiac arrest. Design:Laboratory investigation. Setting:University laboratory. Subjects:Pigs. Interventions:Animals underwent 30-minute untreated ventricular fibrillation cardiac arrest followed by extracorporeal cardiopulmonary resuscitation for 6 hours. Animals were allocated into two experimental groups: t-extracorporeal cardiopulmonary resuscitation (t-ECPR) group, which received streptokinase 1 million units, and control extracorporeal cardiopulmonary resuscitation (c-ECPR), which did not receive streptokinase. In both groups, the resuscitation protocol included the following physiologic targets: mean arterial pressure greater than 70 mm Hg, cerebral perfusion pressure greater than 50 mm Hg, PaO2 150 ± 50 torr (20 ± 7 kPa), Paco2 40 ± 5 torr (5 ± 1 kPa), and core temperature 33°C ± 1°C. Defibrillation was attempted after 30 minutes of extracorporeal cardiopulmonary resuscitation. Measurements and Main Results:A cardiac resuscitability score was assessed on the basis of success of defibrillation, return of spontaneous heart beat, weanability from extracorporeal cardiopulmonary resuscitation, and left ventricular systolic function after weaning. The addition of thrombolytic to extracorporeal cardiopulmonary resuscitation significantly improved cardiac resuscitability (3.7 ± 1.6 in t-ECPR vs 1.0 ± 1.5 in c-ECPR). Arterial lactate clearance was higher in t-ECPR than in c-ECPR (40% ± 15% vs 18% ± 21%). At the end of the experiment, the intracranial pressure was significantly higher in c-ECPR than in t-ECPR. Recovery of brain electrical activity, as assessed by quantitative analysis of electroencephalogram signal, and ischemic neuronal injury on histopathologic examination did not differ between groups. Animals in t-ECPR group did not have increased bleeding complications, including intracerebral hemorrhages. Conclusions:In a porcine model of prolonged cardiac arrest, t-ECPR improved cardiac resuscitability and reduced brain edema, without increasing bleeding complications. However, early electroencephalogram recovery and ischemic neuronal injury were not improved.

Expiratory Positive Airway Pressure for Sleep Apnea after Stroke: A Randomized, Crossover Trial

STUDY OBJECTIVES Obstructive sleep apnea (OSA) is common after stroke and predicts poor outcomes. Continuous positive airway pressure (CPAP) treats OSA but is generally poorly tolerated by stroke patients. We assessed whether nasal expiratory positive airway pressure (EPAP), an alternative to CPAP, may be an effective option after acute stroke. METHODS We conducted a randomized, controlled, two-period crossover study in which each acute ischemic stroke patient received 1 night of EPAP and 1 night without EPAP while OSA was monitored with a validated device, the Watch-PAT 200. Linear repeated- measures analyses were conducted. Sample size calculations indicated that 18 subjects would be required to detect a 10-point or larger average reduction in the apnea-hypopnea index (AHI, the primary outcome), with use of EPAP, with power ≥ 80% and α = 0.05. RESULTS Among the 19 subjects who completed the protocol, nasal EPAP treatment was associated with a nonsignificant absolute difference in AHI of -5.73 events/h in the primary analysis (p = 0.183, 95% confidence interval -14.4, 2.97) and a nonsignificant absolute difference in AHI of -5.43 events/h in the subgroup of patients who used nasal EPAP for ≥ 3 h (p = 0.314, 95% confidence interval -16.6, 5.76). CONCLUSIONS This study suggests that EPAP is not an effective alternative to CPAP in acute stroke patients with OSA. Further work is needed to identify other more effective alternatives. CLINICAL TRIAL REGISTRATION ClinicalTrials.gov, ID: NCT01703663.