Mark Angle

Milrinone and Homeostasis to Treat Cerebral Vasospasm Associated with Subarachnoid Hemorrhage: The Montreal Neurological Hospital Protocol

IntroductionFor the treatment of cerebral vasospasm, current therapies have focused on increasing blood flow through blood pressure augmentation, hypervolemia, the use of intra-arterial vasodilators, and angioplasty of proximal cerebral vessels. Through a large case series, we present our experience of treating cerebral vasospasm with a protocol based on maintenance of homeostasis (correction of electrolyte and glucose disturbances, prevention and treatment of hyperthermia, replacement of fluid losses), and the use of intravenous milrinone to improve microcirculation (the Montreal Neurological Hospital protocol). Our objective is to describe the use milrinone in our practice and the neurological outcomes associated with this approach.MethodsLarge case series based on the review of all patients diagnosed with delayed ischemic neurologic deficits after aneurysmal subarachnoid hemorrhage between April 1999 and April 2006.Results88 patients were followed for a mean time of 44.6xa0months. An intravenous milrinone infusion was used for a mean of 9.8xa0days without any significant side effects. No medical complications associated with this protocol were observed. There were five deaths; of the surviving patients, 48.9xa0% were able to go back to their previous baseline and 75xa0% had a good functional outcome (modified Rankin scalexa0≤2).ConclusionA protocol using intravenous milrinone, and the maintenance of homeostasis is simple to use and requires less intensive monitoring and resources than the standard triple H therapy. Despite the obvious limitations of this study’s design, we believe that it would be now appropriate to proceed with formal prospective studies of this protocol.

Lumbar Drainage for the Treatment of Severe Bacterial Meningitis

ObjectiveTo assess the safety and effectiveness of lumbar drains as adjuvant therapy in severe bacterial meningitis, and compare it to standard treatment.DesignA retrospective cohort study of all patients above the age of 18xa0years with bacterial meningitis and altered mental status admitted to the Montreal Neurological Hospital Intensive Care Unit from January 2000 to December 2010.PatientsThirty-seven patients were identified using clinical and cerebrospinal fluid criteria. Patients were divided into lumbar drain (LD) (nxa0=xa011) and conventional therapy (no LD) (nxa0=xa026) groups.MeasurementsOutcomes were assessed using meningitis-related mortality and the Glasgow Outcome Scale (GOS) at 1 and 3xa0months.OutcomesAll patients received broad-spectrum antibiotic therapy, 84xa0% received steroids. There was no significant difference in mean age, type of bacteria, or time from arrival in ER to initiation of therapy. There was significantly less co-morbidity (24xa0% healthy vs. 18.1xa0%) and coma (GCSxa0<xa08 34.6 vs. 54.5xa0%) in the conventional therapy group, as well as a longer duration of symptoms prior to admission (mean 1.34xa0±xa01.24 vs. 2.19xa0±xa02.34xa0days). The mean opening pressure was high in all patients (20–55xa0cm H2O in the LD and 12–60xa0cm H2O in the no LD). Mean time from arrival in ER to insertion of the lumbar drain was 37xa0h. Lumbar drains were set for a maximum drainage of 10xa0cc/h and an ICP below 10xa0mmHg. Despite greater clinical severity, the LD group had 0xa0% mortality and 91xa0% of the patients achieved a GOS of 4–5. The non-LD group had 15.4xa0% mortality and only 60xa0% achieved a GOS of 4–5. No adverse events were associated with LD therapy.ConclusionsIn this study, the use of lumbar drainage in adult patients with severe bacterial meningitis was safe, and likely contributed to the low mortality and morbidity.

Healthcare-associated infections in the neurological intensive care unit: Results of a 6-year surveillance study at a major tertiary care center

HighlightsNeuro‐ICU HAIs are associated with an increase in length of stay.VAP remains most prevalent in high‐risk neurocritical care categories.Infection prevention and control strategies kept rates of infection and resistance organisms very low.Daily consideration of indwelling devices in the Neuro‐ICU is strongly warranted. Background: Healthcare‐associated infections (HAIs) occur frequently in neurological intensive care units (neuro‐ICUs); however, data differentiating associations with various diagnostic categories and resulting burdens are limited. This prospective cohort study reported incidence rates, pathogen distribution, and patient‐related outcomes of HAIs in a neuro‐ICU population from April 2010 to March 2016. Methods: Laboratory results and specific clinical indicators were used to categorize infections as per National Healthcare Safety Network nosocomial infection surveillance definitions. Patient outcomes studied included length of stay and mortality. Results: There were 6,033 neuro‐ICU admissions resulting in 20,800 neuro‐ICU days over the 6‐year study period. A total of 227 HAIs were identified for a rate of 10.9/1,000 ICU days. Device‐associated infections accounted for 80.6% of HAIs, with incidence rates (per 1,000 device days) being 18.4 for ventilator‐associated pneumonia; 4.9 for catheter‐associated urinary tract infections (CAUTIs); 4.0 for ventriculostomy‐associated infections; and 0.6 for central line‐associated blood stream infections (CLABSIs). Of the various diagnostic categories, subdural hematoma and intracerebral/intraventricular hemorrhage were associated with the highest pooled HAIs, with incidence rates of 21.3 and 21.1 per 1,000 neuro‐ICU days, respectively. Prolonged neuro‐ICU length of stay was strongly associated with all HAIs. Conclusions: This large‐scale surveillance study provides estimates of the risk of common HAIs in neurocritical care patients and their effect on hospitalization. Preventive strategies kept rates of infection very low, in particular CAUTI, CLABSI, and Clostridium difficile infections, and inhibited the emergence of resistant organisms.

Early abnormal transient hyperemic response test can predict delayed ischemic neurologic deficit in subarachnoid hemorrhage

BackgroundEarly detection of vasospasm is crucial to prevent significant delayed ischemic neurological deficit post subarachnoid hemorrhage. The standard methods of detection, including cerebral angiogram and computed tomography are invasive and not safe to be repeated, as is very often indicated clinically. Transient hyperemic response test has been previously used to predict autoregulation failure in traumatic brain injury and subarachnoid hemorrhage.AimsWe investigate the usability of transient hyperemic response test as a predictor of clinical vasospasm in a cohort of patients with aneurismal subarachnoid hemorrhage.MethodsA retrospective review of all THRT examinations done between January 2011 and July 2012 conducted at Montreal Neurological Institute and Hospital and the Montreal General Hospital. Patients diagnosed with aSAH in which the THRT was performed within the first 24–48xa0h of admission were included in the study. Two-dimensional transcranial Doppler images were obtained and velocities were recorded. A positive response was one in which the velocity was increased by more than 9% of the baseline systolic velocity, indicating an intact cerebral autoregulation. Lindegaard ratioxa0>xa03 is considered abnormal and in the context of elevated systolic velocity of the MCA, is highly suggestive of DIND.ResultsFifteen patients met the inclusion criteria. A total of 6 patients developed clinical and radiological vasospasm. Out of these 6 patients, 5 (83%) had an abnormal THRT in the initial TCD assessment (pxa0=xa00.0406). We found that abnormal transient hyperemic response test readings are predictive of subsequent vasospasm development.ConclusionsThe results of this small retrospective study support the notion that transient hyperemic response test has predictive value in vasospasm development and may prove useful in patient monitoring and successful clinical management.

Mortality after Spontaneous Subarachnoid Hemorrhage: Causality and Validation of a Prediction Model

OBJECTIVEnTo evaluate primary causes of death after spontaneous subarachnoid hemorrhage (SAH) and externally validate the HAIR score, a prognostication tool, in a single academic institution.nnnMETHODSnWe reviewed all patients with SAH admitted to our neuro-intensive care unit between 2010 and 2016. Univariate and multivariate logistic regressions were performed to identify predictors of in-hospital mortality. The HAIR score predictors were Hunt and Hess grade at treatment decision, age, intraventricular hemorrhage, and rebleeding within 24 hours. Validation of the HAIR score was characterized with the receiver operating curve, the area under the curve, and a calibration plot.nnnRESULTSnAmong 434 patients with SAH, in-hospital mortality was 14.1%. Of the 61 mortalities, 54 (88.5%) had a neurologic cause of death or withdrawal of care and 7 (11.5%) had cardiac death. Median time from SAH to death was 6 days. The main causes of death were effect of the initial hemorrhage (26.2%), rebleeding (23%) and refractory cerebral edema (19.7%). Factors significantly associated with in-hospital mortality in the multivariate analysis were age, Hunt and Hess grade, and intracerebral hemorrhage. Maximum lumen size was also a significant risk factor after aneurysmal SAH. The HAIR score had a satisfactory discriminative ability, with an area under the curve of 0.89.nnnCONCLUSIONSnThe in-hospital mortality is lower than in previous reports, attesting to the continuing improvement of our institutional SAH care. The major causes are the same as in previous reports. Despite a different therapeutic protocol, the HAIR score showed good discrimination and could be a useful tool for predicting mortality.

Health Care–Associated Infections after Subarachnoid Hemorrhage

OBJECTIVEnHealth care-associated infections (HAIs) after subarachnoid hemorrhage (SAH) are prevalent; however, data describing epidemiology of infection are limited. This study reports incidence rates, risk factors, and the resulting SAH patient-related outcomes.nnnMETHODSnWe studied the incidence of HAIs acquired in the intensive care unit (ICU) over a 6-year period. We used Bayesian Model Averaging to identify risk factors associated with an increased risk of HAIs, particularly urinary tract infections (UTI), pneumonia, and ventriculostomy-associated infections (VAI). We also examined the impact of HAIs on risk of vasospasm, ICU and hospital length of stay, and discharge disposition and adjusted for other risk factors.nnnRESULTSnOf 419 patients with SAH, 66 (15.8%) developed 79 HAI episodes. Mean HAI incidence rates (per 1000 ICU-days) were UTI, 7.1; pneumonia, 4.3; and VAI, 2.4. The admission characteristic associated with increased risk of overall HAI, UTI, and VAI was diabetes mellitus. Hunt and Hess grades III-V were associated with increased risk of overall HAI and VAI. Male gender, intraventricular hemorrhage, and blood glucose level (>10) were associated with increased risk of pneumonia, whereas the incidence was lower in the presence of steroids. HAI was associated with increased length of stay of 10 ICU-days and 22 hospital-days, but not vasospasm or poor discharge disposition.nnnCONCLUSIONSnHAIs are serious complications after SAH associated with prolonged ICU and hospital length of stay. Additional rigorous infection control measures aimed at patients with identifiable risk factors should trigger prevention, and early detection of nosocomial infections is warranted to further reduce the prevalence of HAIs.

Intra-operative Video Characterization of Carotid Artery Pulsation Patterns in Case Series with Post-endarterectomy Hypertension and Hyperperfusion Syndrome

Cerebral hyperperfusion syndrome (CHS) is a complication that can occur after carotid endarterectomy (CEA), the treatment of choice to decrease the subsequent risk of fatal or disabling stroke for patients with symptomatic severe stenosis of the carotid artery. Because of its rarity and complexity, the mechanism of the condition is still unclear, making its prevention via prediction and monitoring challenging. This is especially true during surgery, when multiple factors can induce physiological changes, including blood pressure and baroreceptor functions, which are crucial factors for post-CEA hypertension and CHS. Thus, with intra-operative videos taken by surgical microscopes, we employed a new video processing technique to magnify ordinarily invisible carotid artery pulsation patterns as rhythmic color fluctuations. We applied the technique for three CEA cases, two of which developed CHS with post-CEA hypertension. For those with CHS, abnormal pulsation patterns were detected at the site of the baroreceptors. The results suggested that intra-operative baroreceptor dysfunction can potentially be linked with post-operative hypertension, as well as the occurrence of CHS. Guided by the preliminary discovery, further investigation may help establish the introduced technique as a simple and contactless technique to help predict post-CEA hypertension and CHS in order to facilitate the management and understanding of the condition and improve the care of CEA.

CT Perfusion to Guide Placement of Invasive Cerebral Perfusion Monitor in Subarachnoid Hemorrhage Induced Vasospasm

Background Vasospasm is a challenging component of the subarachnoid hemorrhage “syndrome” that is unpredictable and very difficult to monitor using noninvasive or invasive monitoring technologies in neurocritical units. Methods We describe the novel use of computerized tomography perfusion (CTP) imaging to choose proper targets for invasive cerebral blood flow monitors. Results A total of 3 patients are included in this report. CTP parameters were used to generate points of interest to target using invasive cerebral monitoring of the cerebral blood flow and initiate vasodilator therapy and subsequently guide its weaning. Conclusions CTP can be useful in localizing a specific anatomical target for invasive monitoring in subarachnoid hemorrhage patients suffering from vasospasm.

Aneurysmal subarachnoid hemorrhage prognostic decision-making algorithm using classification and regression tree analysis

Background: Classification and regression tree analysis involves the creation of a decision tree by recursive partitioning of a dataset into more homogeneous subgroups. Thus far, there is scarce literature on using this technique to create clinical prediction tools for aneurysmal subarachnoid hemorrhage (SAH). Methods: The classification and regression tree analysis technique was applied to the multicenter Tirilazad database (3551 patients) in order to create the decision-making algorithm. In order to elucidate prognostic subgroups in aneurysmal SAH, neurologic, systemic, and demographic factors were taken into account. The dependent variable used for analysis was the dichotomized Glasgow Outcome Score at 3 months. Results: Classification and regression tree analysis revealed seven prognostic subgroups. Neurological grade, occurrence of post-admission stroke, occurrence of post-admission fever, and age represented the explanatory nodes of this decision tree. Split sample validation revealed classification accuracy of 79% for the training dataset and 77% for the testing dataset. In addition, the occurrence of fever at 1-week post-aneurysmal SAH is associated with increased odds of post-admission stroke (odds ratio: 1.83, 95% confidence interval: 1.56–2.45, P < 0.01). Conclusions: A clinically useful classification tree was generated, which serves as a prediction tool to guide bedside prognostication and clinical treatment decision making. This prognostic decision-making algorithm also shed light on the complex interactions between a number of risk factors in determining outcome after aneurysmal SAH.

Clinical outcome prediction in aneurysmal subarachnoid hemorrhage - Alterations in brain-body interface.

Background: Brain–body associations are essential in influencing outcome in patients with ruptured brain aneurysms. Thus far, there is scarce literature on such important relationships. Methods: The multicenter Tirilazad database (3551 patients) was used to create this clinical outcome prediction model in order to elucidate significant brain–body associations. Traditional binary logistic regression models were used. Results: Binary logistic regression main effects model included four statistically significant single prognostic variables, namely, neurological grade, age, stroke, and time to surgery. Logistic regression models demonstrated the significance of hypertension and liver disease in development of brain swelling, as well as the negative consequences of seizures in patients with a history of myocardial infarction and post-admission fever worsening neurological outcome. Conclusions: Using the aforementioned results generated from binary logistic regression models, we can identify potential patients who are in the high risk group of neurological deterioration. Specific therapies can be tailored to prevent these detriments, including treatment of hypertension, seizures, early detection and treatment of myocardial infarction, and prevention of hepatic encephalopathy.