Eliza M. Bruce

The promise of wearable activity sensors to define patient recovery

The recent emergence of mobile health--the use of mobile telecommunication and wireless devices to improve health outcomes, services, and research--has inspired a patient-centric approach to monitor health metrics. Sensors embedded in wearable devices are utilized to acquire greater self-knowledge by tracking basic parameters such as blood pressure, heart rate, and body temperature as well as data related to exercise, diet, and psychological state. To that end, recent studies on utilizing wireless fitness activity trackers to monitor and promote functional recovery in patients suggest that collecting up-to-date performance data could help patients regain functional independence and help hospitals determine the appropriate length of stay for a patient. This manuscript examines existing functional assessment scales, discusses the use of activity tracking sensors in evaluating functional independence, and explores the growing application of wireless technology in measuring and promoting functional recovery.

Hematoma volume as the major determinant of outcomes after intracerebral hemorrhage

Intracerebral hemorrhage (ICH) is a leading cause of morbidity and mortality, greatly linked to hematoma volume. Understanding the characteristics and size of hematoma is integral to evaluating severity and prognosis after ICH. Examination of the literature suggests that markers for hematoma size vary, but the key range between 20-30 mL is most widely used as the cut-off for classification of hematoma volume. The role of hematoma volume in episodes of hematoma expansion and re-bleeding further impact outcomes, with increased growth associated with larger hematoma volume. Additionally, many commonly used predictors of ICH outcomes are directly related to hematoma volume, implicating it as an important variable when determining outcomes. In conclusion, hematoma volume is likely the most significant determinant of outcomes in intracerebral hemorrhage.

Preoperative chemotherapy and corticosteroids: independent predictors of cranial surgical-site infections.

OBJECT Preoperative corticosteroids and chemotherapy are frequently prescribed for patients undergoing cranial neurosurgery but may pose a risk of postoperative infection. Postoperative surgical-site infections (SSIs) have significant morbidity and mortality, dramatically increase the length and cost of hospitalization, and are a major cause of 30-day readmission. In patients undergoing cranial neurosurgery, there is a lack of data on the role of patient-specific risk factors in the development of SSIs. The authors of this study sought to determine whether chemotherapy and prolonged steroid use before surgery increase the risk of an SSI at postoperative Day 30. METHODS Using the national prospectively collected American College of Surgeons National Surgical Quality Improvement Program (ACS NSQIP) database for 2006-2012, the authors calculated the rates of superficial, deep-incisional, and organ-space SSIs at postoperative Day 30 for neurosurgery patients who had undergone chemotherapy or had significant steroid use within 30 days before undergoing cranial surgery. Trauma patients, patients younger than 18 years, and patients with a preoperative infection were excluded. Univariate analysis was performed for 25 variables considered risk factors for superficial and organ-space SSIs. To identify independent predictors of SSIs, the authors then conducted a multivariate analysis in which they controlled for duration of operation, wound class, white blood cell count, and other potential confounders that were significant on the univariate analysis. RESULTS A total of 8215 patients who had undergone cranial surgery were identified. There were 158 SSIs at 30 days (frequency 1.92%), of which 52 were superficial, 27 were deep-incisional, and 79 were organ-space infections. Preoperative chemotherapy was an independent predictor of organ-space SSIs in the multivariate model (OR 5.20, 95% CI 2.33-11.62, p < 0.0001), as was corticosteroid use (OR 1.86, 95% CI 1.03-3.37, p = 0.04), but neither was a predictor of superficial or deep-incisional SSIs. Other independent predictors of organ-space SSIs were longer duration of operation (OR 1.16), wound class of ≥ 2 (clean-contaminated and further contaminated) (OR 3.17), and morbid obesity (body mass index ≥ 40 kg/m(2)) (OR 3.05). Among superficial SSIs, wound class of 3 (contaminated) (OR 6.89), operative duration (OR 1.13), and infratentorial surgical approach (OR 2.20) were predictors. CONCLUSIONS Preoperative chemotherapy and corticosteroid use are independent predictors of organ-space SSIs, even when data are controlled for leukopenia. This indicates that the disease process in organ-space SSIs may differ from that in superficial SSIs. In effect, this study provides one of the largest analyses of risk factors for SSIs after cranial surgery. The results suggest that, in certain circumstances, modulation of preoperative chemotherapy or steroid regimens may reduce the risk of organ-space SSIs and should be considered in the preoperative care of this population. Future studies are needed to determine optimal timing and dosing of these medications.

Intraventricular hemorrhage expansion in patients with spontaneous intracerebral hemorrhage

Objective: To evaluate whether delayed appearance of intraventricular hemorrhage (dIVH) represents an independent entity from intraventricular hemorrhage (IVH) present on admission CT or is primarily related to the time interval between symptom onset and admission CT. Methods: A total of 282 spontaneous intracerebral hemorrhage (ICH) patients, admitted February 2009–March 2014 to the neurological intensive care unit of a tertiary care university hospital, were prospectively enrolled in the ICH Outcomes Project. Multivariate logistic regression was used to determine associations with acute mortality and functional long-term outcome (modified Rankin Scale). Results: A cohort of 282 ICH patients was retrospectively studied: 151 (53.5%) had intraventricular hemorrhage on initial CT scan (iIVH). Of the remaining 131 patients, 19 (14.5%) developed IVH after the initial CT scan (dIVH). The median times from symptom onset to admission CT were 1.1, 6.0, and 7.4 hours for the dIVH, iIVH, and no IVH groups (Mann-Whitney U test, dIVH vs iIVH, p < 0.001) and median time from onset to dIVH detection was 7.2 hours. The increase in ICH volume following hospital admission was larger in dIVH than in iIVH and no IVH patients (mean 17.6, 0.2, and 0.4 mL). After controlling for components of the ICH score and hematoma expansion, presence of IVH on initial CT was associated with discharge mortality and poor outcome at 3, 6, and 12 months, but dIVH was not associated with any of the outcome measures. Conclusions: In ICH patients, associated IVH on admission imaging is commonly encountered and is associated with poor long-term outcome. In contrast, dIVH on subsequent scans is far less common and does not appear to portend worse outcome.

Influence on morbidity and mortality of neoadjuvant radiation and chemotherapy among cranial malignancy patients in the postoperative setting.

We sought to assess the impact of neoadjuvant therapy on 30 day mortality and morbidity using data from the American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP). Chemotherapy and radiotherapy are both often indicated for treatment of cranial or systemic malignancy but can have significant adverse effects in the postsurgical setting. Data from 2006 to 2012 were obtained from the national ACS-NSQIP database. A total of 1044 patients were identified who obtained surgery for removal of metastatic brain tumors, of whom 127 received neoadjuvant chemotherapy and 65 neoadjuvant radiotherapy. Our primary outcome was 30 day mortality and secondary outcomes were 30 day surgical and medical morbidities. We selected previously reported preoperative variables to build a univariate and a multivariate model to determine preoperative characteristics most associated with neurosurgical mortality and morbidity. Our study found that neoadjuvant chemotherapy was associated with a 2.4-fold increase in the risk of 30 day mortality compared to the patient cohort who did not receive chemotherapy (p=0.023). Interestingly, there was no statistically significant increase in overall 30 day surgical or medical morbidity for the chemotherapy group. Neoadjuvant radiotherapy was not associated with an increase in 30 day morbidity or mortality. The significant increase in mortality associated with chemotherapy warrants further investigation, particularly to determine how to best personalize neoadjuvant chemotherapy treatment options to improve surgical outcomes. Neoadjuvant radiotherapy may be safer in terms of short-term postoperative morbidity and mortality.

Mobile Phone-Connected Wearable Motion Sensors to Assess Postoperative Mobilization.

Background Early mobilization after surgery reduces the incidence of a wide range of complications. Wearable motion sensors measure movements over time and transmit this data wirelessly, which has the potential to monitor patient recovery and encourages patients to engage in their own rehabilitation. Objective We sought to determine the ability of off-the-shelf activity sensors to remotely monitor patient postoperative mobility. Methods Consecutive subjects were recruited under the Department of Neurosurgery at Columbia University. Patients were enrolled during physical therapy sessions. The total number of steps counted by the two blinded researchers was compared to the steps recorded on four activity sensors positioned at different body locations. Results A total of 148 motion data points were generated. The start time, end time, and duration of each walking session were accurately recorded by the devices and were remotely available for the researchers to analyze. The sensor accuracy was significantly greater when placed over the ankles than over the hips (P<.001). Our multivariate analysis showed that step length was an independent predictor of sensor accuracy. On linear regression, there was a modest positive correlation between increasing step length and increased ankle sensor accuracy (r=.640, r 2=.397) that reached statistical significance on the multivariate model (P=.03). Increased gait speed also correlated with increased ankle sensor accuracy, although less strongly (r=.444, r 2=.197). We did not note an effect of unilateral weakness on the accuracy of left- versus right-sided sensors. Accuracy was also affected by several specific measures of a patient’s level of physical assistance, for which we generated a model to mathematically adjust for systematic underestimation as well as disease severity. Conclusions We provide one of the first assessments of the accuracy and utility of widely available and wirelessly connected activity sensors in a postoperative patient population. Our results show that activity sensors are able to provide invaluable information about a patient’s mobility status and can transmit this data wirelessly, although there is a systematic underestimation bias in more debilitated patients.

Meta-analysis of Telemonitoring to Improve HbA1c Levels: Promises for Stroke Survivors

Background: Diabetes mellitus predisposes to ischemic stroke, a major cause of death in this population, and worsens the post-stroke prognosis. Monitoring glycemic control is useful not only in the primary prevention of stroke in diabetics, but also in the rehabilitation from and secondary prevention of stroke. In an often functionally and neurocognitively impaired population, however, poor compliance to treatment regimens is a major problem. Digital, wireless telemonitoring glucometers offer a solution to the compliance issue—not only do they give patients a dynamic experience of their own glycemic control via digital monitors, but many also have an integrated alert system with healthcare providers and more real-time feedback than traditional self-monitoring methods. Objective: To evaluate effectiveness of telemonitoring technologies in improving long-term glycemic control. Methods: A search on www.clinicaltrials.gov on November 2013, using keywords “telemonitoring” (n=103), “selfcare device” (n=50), and “self management device” (n=210), revealed trials investigating a range of chronic disease including heart disease, diabetes, COPD, asthma, and hypertension. Some of the cardiac-oriented trials utilized varying outcome measurements. Therefore, we only selected published diabetes trials comparing HbA1c levels of a group receiving standard of care to a group receiving a telemonitoring intervention. Using a random effects model of mean difference, a meta-analysis was conducted on five trials that measured differences in HbA1c levels between the two groups at six months follow-up. Results: Five clinical trials were identified. Four of the five studies showed a greater reduction in HbA1c in the intervention group compared to controls at 6 months, although only one was statistically significant. There was considerable heterogeneity between studies (I2= 69.5%, p=0.02). The random effects model estimated the aggregate effect size for mean difference in reduction of HbA1c levels in the treatment group vs. control to be 0.08% [-0.12- 0.28%], which was not statistically significant (p=0.42). Conclusions: The varying results may be due to specific factors in the trials that contributed to their large heterogeneity. Although there is great potential to use telemonitoring in stroke patients, further trials are needed to support its role in improving diabetes management in this population. Nonetheless, in the future telemonitoring may substantially help patients at risk of ischemic stroke and those who require close glucose monitoring.