Benjamin P. Rosenbaum

Preoperative anemia and perioperative outcomes in patients who undergo elective spine surgery.

Study Design. Analysis of the prospectively collected American College of Surgeons National Surgical Quality Improvement Program database. Objective. To assess whether preoperative anemia predicted adverse, early, perioperative outcomes in patients undergoing elective spine surgery. Summary of Background Data. Prior studies have assessed the association of anemia with outcomes in various noncardiac surgical procedures. The association between preoperative anemia and 30-day outcomes for spine surgery is unknown. Methods. A total of 24,473 adults, classified as having severe (N = 88), moderate (N = 314), mild (N = 5477), and no anemia. Using propensity scores, patients with severe, mild, and moderate anemia were matched with patients with no anemia. Logistic regression was used to predict adverse postoperative outcomes. Sensitivity analyses were conducted limiting the study sample to patients who did not receive intra- or postoperative transfusion and to patients with and without preoperative cardiovascular comorbidities. Results. Patients with all levels of anemia had significantly higher risk of nearly all adverse outcomes than nonanemic patients in unadjusted and propensity-matched models. Patients with moderate and mild anemia were more likely to have prolonged length of hospitalization, experience 1 or more complications, and expire within 30 days of surgery compared with nonanemic patients. The association between anemia and adverse outcomes was found independently of intra- and postoperative transfusions, and was not more pronounced in patients with preoperative cardiovascular comorbidities. Conclusion. All levels of anemia were significantly associated with prolonged length of hospitalization and poorer operative or 30-day outcomes in patients undergoing elective spine surgery. Our findings, using a large multi-institutional sample of prospectively collected data, suggests that anemia should be regarded as an independent risk factor for perioperative and postoperative complications that deserves attention prior to elective spine surgery. Level of Evidence: 3

Incidence and risk factors associated with in-hospital venous thromboembolism after aneurysmal subarachnoid hemorrhage

Our purpose was to determine the incidence and risk factors associated with in-hospital venous thromboembolism (VTE) in patients with aneurysmal subarachnoid hemorrhage (aSAH). The Nationwide Inpatient Sample database was queried from 2002 to 2010 for hospital admissions for subarachnoid hemorrhage or intracerebral hemorrhage and either aneurysm clipping or coiling. Exclusion criteria were age <18, arteriovenous malformation/fistula diagnosis or repair, or radiosurgery. Primary outcome was VTE (deep vein thrombosis [DVT] or pulmonary embolus [PE]). Multivariate logistic regression was used to assess association between risk factors and VTE. Secondary outcomes were in-hospital mortality, discharge disposition, length of stay and hospital charges. A total of 15,968 hospital admissions were included. Overall rates of VTE (DVT or PE), DVT, and PE were 4.4%, 3.5%, and 1.2%, respectively. On multivariate analysis, the following factors were associated with increased VTE risk: increasing age, black race, male sex, teaching hospital, congestive heart failure, coagulopathy, neurologic disorders, paralysis, fluid and electrolyte disorders, obesity, and weight loss. Patients that underwent clipping versus coiling had similar VTE rates. VTE was associated with pulmonary/cardiac complication (odds ratio [OR] 2.8), infectious complication (OR 2.8), ventriculostomy (OR 1.8), and vasospasm (OR 1.3). Patients with VTE experienced increased non-routine discharge (OR 3.3), and had nearly double the mean length of stay (p<0.001) and total inflation-adjusted hospital charges (p<0.001). To our knowledge, this is the largest study evaluating the incidence and risk factors associated with the development of VTE after aSAH. The presence of one or more of these factors may necessitate more aggressive VTE prophylaxis.

A new Elixhauser-based comorbidity summary measure to predict in-hospital mortality.

Background:Recently, van Walraven developed a weighted summary score (VW) based on the 30 comorbidities from the Elixhauser comorbidity system. One of the 30 comorbidities, cardiac arrhythmia, is currently excluded as a comorbidity indicator in administrative datasets such as the Nationwide Inpatient Sample (NIS), prompting us to examine the validity of the VW score and its use in the NIS. Methods:Using data from the 2009 Maryland State Inpatient Database, we derived weighted summary scores to predict in-hospital mortality based on the full (30) and reduced (29) set of comorbidities and compared model performance of these and other comorbidity summaries in 2009 NIS data. Results:Weights of our derived scores were not sensitive to the exclusion of cardiac arrhythmia. When applied to NIS data, models containing derived summary scores performed nearly identically (c statistics for 30 and 29 variable-derived summary scores: 0.804 and 0.802, respectively) to the model using all 29 comorbidity indicators (c=0.809), and slightly better than the VW score (c=0.793). Each of these models performed substantially better than those based on a simple count of Elixhauser comorbidities (c=0.745) or a categorized count (0, 1, 2, or ≥3 comorbidities; c=0.737). Conclusions:The VW score and our derived scores are valid in the NIS and are statistically superior to summaries using simple comorbidity counts. Researchers wishing to summarize the Elixhauser comorbidities with a single value should use the VW score or those derived in this study.

Effect of smoking on the perioperative outcomes of patients who undergo elective spine surgery.

Study Design. Retrospective analysis of the prospectively collected American College of Surgeons National Surgical Quality Improvement database. Objective. We assessed whether preoperative cigarette smoking and smoking duration predicted adverse, early, perioperative outcomes in patients undergoing elective spine surgery. Summary of Background Data. Prior studies have assessed the association of smoking and long-term outcomes for a number of spine surgery procedures, with conflicting findings. The association between smoking and 30-day outcomes for spine surgery is unknown. Methods. A total 14,500 adults, classified as current (N = 3914), prior (N = 2057), and never smokers. Using propensity scores, current and prior smokers were matched to never smokers. Logistic regression was used to predict adverse postoperative outcomes. The relationship between pack-years and adverse outcomes was tested. Sensitivity analyses were conducted limiting the study sample to patients who underwent spine fusion (N = 4663), and using patient subgroups by procedure. Results. In unadjusted analyses, prior smokers were significantly more likely to have prolonged hospitalization (1.2, 95% confidence interval [CI]: 1.1–1.3) and major complications (1.3, 95% CI: 1.1–1.6) compared with never smokers. No association was found between smoking status and adverse outcomes in adjusted, matched patient models. Current smokers with more than 60 pack-years were more likely to die within 30 days of surgery (3.0, 95% CI, 1.1–7.8), compared with never smokers. Sensitivity analyses confirmed these findings. Conclusion. The large National Surgical Quality Improvement population was carefully matched for a wide range of baseline comorbidities, including 29 variables previously suggested to influence perioperative outcomes. Although previous studies conducted in subgroups of spine surgery patients have suggested a deleterious effect for smoking on long-term outcomes in patients undergoing spine surgery, our analysis did not find smoking to be associated with early (30 d) perioperative morbidity or mortality.

Pseudoarthrosis rates in anterior cervical discectomy and fusion: a meta-analysis

BACKGROUND CONTEXT Anterior cervical discectomy and fusion (ACDF) is a commonly performed procedure for patients presenting with cervical radiculopathy, myelopathy, or deformity. A systematic literature review and meta-analysis of pseudoarthrosis rates associated with ACDF with plate fixation have not been previously performed. PURPOSE The purpose of this study was to identify all prospective studies reporting pseudoarthrosis rates for ACDF with plate fixation. STUDY DESIGN/SETTING This study is based on a systematic review and meta-analysis. PATIENT SAMPLE Studies reporting pseudoarthrosis rates in patients who received one-, two-, or three-level ACDF surgeries were included. OUTCOME MEASURES Outcomes of interest included reported pseudoarthrosis events after ACDF with plate fixation. METHODS We conducted a MEDLINE, SCOPUS, Web of Science, and EMBASE search for studies reporting complications for ACDF with plate fixation. We recorded pseudoarthrosis events from all included studies. A meta-analysis was performed to calculate effect summary mean values, 95% confidence intervals (CIs), Q statistics, and I(2) values. Forest plots were constructed for each analysis group. RESULTS Of the 7,130 retrieved articles, 17 met the inclusion criteria. The overall pseudoarthrosis rate was 2.6% (95% CI: 1.3-3.9). Use of autograft fusion (0.9%, 95% CI: -0.4 to 2.1) resulted in a reduced pseudoarthrosis rate compared with allograft fusion procedures (4.8%, 95% CI: 1.7-7.9). Studies were separated based on the length of follow-up: 12 to 24 and greater than 24 months. These groups reported rates of 3.1% (95% CI: 1.2-5.0) and 2.3% (95% CI: 0.1-4.4), respectively. Studies performing single-level ACDF yielded a rate of 3.7% (95% CI: 1.6-5.7). Additionally, there was a large difference in the rate of pseudoarthrosis in randomized controlled trials (4.8%, 95% CI: 2.6-7.0) versus prospective cohort studies (0.2%, 95% CI: -0.1 to 0.5), indicating that the extent of follow-up criteria affects the rate of pseudoarthrosis. CONCLUSIONS This review represents a comprehensive estimation of the actual incidence of pseudoarthrosis across a heterogeneous group of surgeons, patients, and ACDF techniques. The definition of pseudoarthrosis varied significantly within the literature. To ensure its diagnosis and prevent sequelae, standardized criteria need to be established. This investigation sets the framework for surgeons to understand the impact of surgical techniques on the rate of pseudoarthrosis.

Radio Frequency Identification (RFID) in Health Care: Privacy and Security Concerns Limiting Adoption

Radio frequency identification (RFID) technology has been implemented in a wide variety of industries. Health care is no exception. This article explores implementations and limitations of RFID in several health care domains: authentication, medication safety, patient tracking, and blood transfusion medicine. Each domain has seen increasing utilization of unique applications of RFID technology. Given the importance of protecting patient and data privacy, potential privacy and security concerns in each domain are discussed. Such concerns, some of which are inherent to existing RFID hardware and software technology, may limit ubiquitous adoption. In addition, an apparent lack of security standards within the RFID domain and specifically health care may also hinder the growth and utility of RFID within health care for the foreseeable future. Safeguarding the privacy of patient data may be the most important obstacle to overcome to allow the health care industry to take advantage of the numerous benefits RFID technology affords.

Lumbar microdiscectomy complication rates: a systematic review and meta-analysis

OBJECT Lumbar microdiscectomy and its various minimally invasive surgical techniques are seeing increasing popularity, but a systematic review of their associated complications has yet to be performed. The authors sought to identify all prospective clinical studies reporting complications associated with lumbar open microdiscectomy, microendoscopic discectomy (MED), and percutaneous microdiscectomy. METHODS The authors conducted MEDLINE, Scopus, Web of Science, and Embase database searches for randomized controlled trials and prospective cohort studies reporting complications associated with open, microendoscopic, or percutaneous lumbar microdiscectomy. Studies with fewer than 10 patients and published before 1990 were excluded. Overall and interstudy median complication rates were calculated for each surgical technique. The authors also performed a meta-analysis of the reported complications to assess statistical significance across the various surgical techniques. RESULTS Of 9504 articles retrieved from the databases, 42 met inclusion criteria. Most studies screened were retrospective case series, limiting the number of studies that could be included. A total of 9 complication types were identified in the included studies, and these were analyzed across each of the surgical techniques. The rates of any complication across the included studies were 12.5%, 13.3%, and 10.8% for open, MED, and percutaneous microdiscectomy, respectively. New or worsening neurological deficit arose in 1.3%, 3.0%, and 1.6% of patients, while direct nerve root injury occurred at rates of 2.6%, 0.9%, and 1.1%, respectively. Hematoma was reported at rates of 0.5%, 1.2%, and 0.6%, respectively. Wound complications (infection, dehiscence, orseroma) occurred at rates of 2.1%, 1.2%, and 0.5%, respectively. The rates of recurrent disc complications were 4.4%, 3.1%, and 3.9%, while reoperation was indicated in 7.1%, 3.7%, and 10.2% of operations, respectively. Meta-analysis calculations revealed a statistically significant higher rate of intraoperative nerve root injury following percutaneous procedures relative to MED. No other significant differences were found. CONCLUSIONS This review highlights complication rates among various microdiscectomy techniques, which likely reflect real-world practice and conceptualization of complications among physicians. This investigation sets the framework for further discussions regarding microdiscectomy options and their associated complications during the informed consent process.

Myelomeningocele: surgical trends and predictors of outcome in the United States, 1988–2010

OBJECT Myelomeningocele repair is an uncommonly performed surgical procedure. The volume of operations has been decreasing in the past 2 decades, probably as the result of public health initiatives for folate supplementation. Because of the rarity of myelomeningocele, data on patient or hospital factors that may be associated with outcome are scarce. To determine these factors, the authors investigated the trends in myelomeningocele surgical repair in the United States over a 23-year period and examined patient and hospital characteristics that were associated with outcome. METHODS The Nationwide Inpatient Sample database for 1988-2010 was queried for hospital admissions for myelomeningocele repair. This database reports patient, hospital, and admission characteristics and surgical trends. The authors used univariate and multivariate logistic regression to assess associations between patient and hospital characteristics and in-hospital deaths, nonroutine discharge, long hospital stay, and shunt placement. RESULTS There were 4034 hospitalizations for surgical repair of myelomeningocele. The annual volume decreased since 1988 but plateaued in the last 4 years of the study. The percentages of myelomeningocele patients with low income (30.8%) and Medicaid insurance (48.2%) were disproportionately lower than those for the overall live-born population (p < 0.0001). More operations per 10,000 live births were performed for Hispanic patients (3.2) than for white (2.0) or black (1.5) patients (p < 0.0001). Overall, 56.6% of patients required shunt placement during the same hospital stay as for surgical repair; 95.0% of patients were routinely discharged; and the in-hospital mortality rate was 1.4%. Nonwhite race was associated with increased in-hospital risk for death (OR 2.8, 95% CI 1.2-6.3) independent of socioeconomic or insurance status. CONCLUSIONS Overall, the annual surgical volume of myelomeningocele repairs decreased after public health initiatives were introduced but has more recently plateaued. The most disproportionately represented populations are Hispanic, low-income, and Medicaid patients. Among nonwhite patients, increased risk for in-hospital death may represent a disparity in care or a difference in disease severity.

Ventriculostomy: Frequency, length of stay and in-hospital mortality in the United States of America, 1988-2010

Ventriculostomy is a common neurosurgical procedure. We evaluated a large national sample of data regarding epidemiologic trends in neurosurgical practice relating to ventriculostomy. The USA Nationwide Inpatient Sample (1988 to 2010) provided retrospective data on patients hospitalized who underwent a ventriculostomy procedure. We categorized ventriculostomy procedures as the principal procedure performed for definitive treatment or as any other procedure. We identified 101,577 relevant hospital admissions with an estimated national volume of 507,762 hospital admissions from 1988 to 2010. For all patients, the mean age was 45.0 years and 46.5% were female. The three most common individual principal diagnoses were subarachnoid hemorrhage (19.1%), intracerebral hemorrhage (14.9%), and obstructive hydrocephalus (3.8%). The three most common principal procedures were other excision or destruction of lesion or tissue of brain (16.0%), clipping of aneurysm (13.5%), and temporary tracheostomy (10.8%). Mean length of stay was 20.8 days and in-hospital mortality was 24.5%. In-hospital mortality was associated with emergency admission (multivariate odds ratio 1.98; 95% confidence interval 1.92-2.05), age 45 years or greater (mean of data set) (1.91; 1.85-1.98), multiple ventriculostomies (1.55; 1.44-1.67), and ventriculostomy as a principal procedure (1.39; 1.35-1.44). A total of 32.7% of patients were discharged to home. Most (94.3%) hospitalizations had one, 5.0% had two, and 0.7% multiple (three or more) ventriculostomies performed. Neurosurgeons must be aware of the association of in-hospital mortality, especially during the first days of admission, particularly when ventriculostomy is the principal procedure performed for definitive treatment during the hospitalization.

Neurologic disorders, in-hospital deaths, and years of potential life lost in the USA, 1988-2011

Premature mortality is a public health concern that can be quantified as years of potential life lost (YPLL). Studying premature mortality can help guide hospital initiatives and resource allocation. We investigated the categories of neurologic and neurosurgical conditions associated with in-hospital deaths that account for the highest YPLL and their trends over time. Using the Nationwide Inpatient Sample (NIS), we calculated YPLL for patients hospitalized in the USA from 1988 to 2011. Hospitalizations were categorized by related neurologic principal diagnoses. An estimated 2,355,673 in-hospital deaths accounted for an estimated 25,598,566 YPLL. The traumatic brain injury (TBI) category accounted for the highest annual mean YPLL at 361,748 (33.9% of total neurologic YPLL). Intracerebral hemorrhage, cerebral ischemia, subarachnoid hemorrhage, and anoxic brain damage completed the group of five diagnoses with the highest YPLL. TBI accounted for 12.1% of all inflation adjusted neurologic hospital charges and 22.4% of inflation adjusted charges among neurologic deaths. The in-hospital mortality rate has been stable or decreasing for all of these diagnoses except TBI, which rose from 5.1% in 1988 to 7.8% in 2011. Using YPLL, we provide a framework to compare the burden of premature in-hospital mortality on patients with neurologic disorders, which may prove useful for informing decisions related to allocation of health resources or research funding. Considering premature mortality alone, increased efforts should be focused on TBI, particularly in and related to the hospital setting.