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Cydni Williams, Tamara D. Simon, Jay Riva-Cambrin and Susan L. Bratton

Object

Intracranial neoplasms are the second most common childhood cancer, and lead to significant morbidity and mortality. Hyponatremia is a complication associated with neurosurgical procedures, but children undergoing intracranial tumor resection have not been selectively studied. In this study, the authors aimed to determine the incidence and risk factors associated with hyponatremia among children undergoing intracranial neoplasm resection.

Methods

A retrospective cohort was compiled using the 2006 Kids' Inpatient Database to identify children younger than 21 years of age who underwent intracranial neoplasm resection. Hyponatremia was ascertained by diagnosis codes. Bivariate analyses were conducted using chi-square and Mann-Whitney U-tests. Logistic regression models were developed to evaluate factors associated with hyponatremia in bivariate analyses.

Results

Hyponatremia occurred in 205 (8.7%) of 2343 annual weighted cases, and was independently associated with tumor location in the deep brain structures and ventricles compared with the cortical area (adjusted odds ratio [aOR] 2.4; 95% CI 1.1–5.3). Hyponatremia was also associated with obstructive hydrocephalus (aOR 2.7; 95% CI 1.7–4.3) and emergency department admission (aOR 1.7; 95% CI 1.1–2.4). Hyponatremia was significantly associated with mechanical ventilation, ventriculostomy placement, ventriculoperitoneal shunt placement, and sepsis. Hyponatremia was also associated with a significantly longer average length of stay (24.6 vs 10.2 days), higher average charges ($191,000 vs $92,000), and a higher percentage of discharges to intermediate-care facilities.

Conclusions

Hyponatremia commonly occurs with resection of intracranial malignant tumors, especially for lesions located in the deep brain and in patients with obstructive hydrocephalus. Hyponatremia was associated with higher morbidity. Further research is needed to develop targeted monitoring and intervention strategies to decrease perioperative hyponatremia and to determine if this could decrease the number of complications in this specialized population.

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Matthew R. Test, Kathryn B. Whitlock, Marcie Langley, Jay Riva-Cambrin, John R. W. Kestle and Tamara D. Simon

OBJECTIVE

Infection is a common complication of cerebrospinal fluid (CSF) shunts, occurring in 6%–20% of children. Although studies are limited, Staphylococcus aureus is thought to cause more rapid and aggressive infection than coagulase-negative Staphylococcus (CONS) or gram-negative organisms. The authors’ objective was to evaluate the relationship between the causative organisms of CSF shunt infection and the timing of infection.

METHODS

The authors performed a retrospective cohort study of children who underwent CSF shunt placement at a tertiary care children’s hospital over a 9-year period and subsequently developed a CSF shunt infection. The primary predictor variable was the causative organism recovered from CSF culture, characterized as S. aureus, CONS, or gram-negative organisms. The primary outcome was time to infection, defined as the number of days from most recent shunt intervention to the diagnosis of the infection. The association between causative organism and time to infection was visualized using Kaplan-Meier curves, and statistical comparisons were made using nonparametric Kruskal-Wallis tests.

RESULTS

Among 103 children in whom a CSF shunt infection developed, the causative organism was CONS in 57 (55%), S. aureus in 19 (18%), and gram-negative organisms in 9 (9%). The median time to infection did not differ (p = 0.81) for infections caused by CONS (20 days, IQR 11–40), S. aureus (26 days, IQR 12–95), and gram-negative organisms (23 days, IQR 17–34).

CONCLUSIONS

No significant difference in time to infection based on the causative organism was observed among children with a CSF shunt infection.

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John R. W. Kestle, Jay Riva-Cambrin, John C. Wellons III, Abhaya V. Kulkarni, William E. Whitehead, Marion L. Walker, W. Jerry Oakes, James M. Drake, Thomas G. Luerssen, Tamara D. Simon and Richard Holubkov

Object

Quality improvement techniques are being implemented in many areas of medicine. In an effort to reduce the ventriculoperitoneal shunt infection rate, a standardized protocol was developed and implemented at 4 centers of the Hydrocephalus Clinical Research Network (HCRN).

Methods

The protocol was developed sequentially by HCRN members using the current literature and prior institutional experience until consensus was obtained. The protocol was prospectively applied at each HCRN center to all children undergoing a shunt insertion or revision procedure. Infections were defined on the basis of CSF, wound, or pseudocyst cultures; wound breakdown; abdominal pseudocyst; or positive blood cultures in the presence of a ventriculoatrial shunt. Procedures and infections were measured before and after protocol implementation.

Results

Twenty-one surgeons at 4 centers performed 1571 procedures between June 1, 2007, and February 28, 2009. The minimum follow-up was 6 months. The Network infection rate decreased from 8.8% prior to the protocol to 5.7% while using the protocol (p = 0.0028, absolute risk reduction 3.15%, relative risk reduction 36%). Three of 4 centers lowered their infection rate. Shunt surgery after external ventricular drainage (with or without prior infection) had the highest infection rate. Overall protocol compliance was 74.5% and improved over the course of the observation period. Based on logistic regression analysis, the use of BioGlide catheters (odds ratio [OR] 1.91, 95% CI 1.19–3.05; p = 0.007) and the use of antiseptic cream by any members of the surgical team (instead of a formal surgical scrub by all members of the surgical team; OR 4.53, 95% CI 1.43–14.41; p = 0.01) were associated with an increased risk of infection.

Conclusions

The standardized protocol for shunt surgery significantly reduced shunt infection across the HCRN. Overall protocol compliance was good. The protocol has established a common baseline within the Network, which will facilitate assessment of new treatments. Identification of factors associated with infection will allow further protocol refinement in the future.

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Tamara D. Simon, Kathryn B. Whitlock, Jay Riva-Cambrin, John R. W. Kestle, Margaret Rosenfeld, J. Michael Dean, Richard Holubkov, Marcie Langley and Nicole Mayer-Hamblett

Object

The neurosurgical literature has conflicting findings regarding the association between indications for CSF shunt placement and subsequent shunt surgery. The object of this study was to identify baseline factors at the time of initial CSF shunt placement that are independently associated with subsequent surgery.

Methods

This was a retrospective cohort study of children ages 0–18 years who underwent initial CSF shunt placement between January 1, 1997, and October 12, 2006, at a tertiary care children's hospital. The outcome of interest was CSF shunt surgery (either for revision or infection) within 12 months after initial placement. Associations between subsequent CSF shunt surgery and indication for the initial shunt, adjusting for patient age and surgeon factors at the time of initial placement, were estimated using multivariate logistic regression. Medical and surgical decisions, which varied according to surgeon, were examined separately in a univariate analysis.

Results

Of the 554 children in the study cohort, 233 (42%) underwent subsequent CSF shunt surgery, either for revision (167 patients [30%]) or infection (66 patients [12%]). In multivariate logistic regression modeling, significant risk factors for subsequent CSF shunt surgery included (compared with aqueductal stenosis) intraventricular hemorrhage (IVH) secondary to prematurity (adjusted odds ratio [AOR] 2.2, 95% CI 1.1–4.5) and other unusual indications (AOR 3.7, 95% CI 1.0–13.6). The patient's age at initial CSF shunt placement was not significantly associated with increased odds of subsequent surgery after adjusting for other associated factors.

Conclusions

The occurrence of IVH is associated with increased odds of subsequent CSF shunt surgery within 12 months after shunt placement. Families of and care providers for children with IVH should be attuned to their increased risk of shunt failure.

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Tamara D. Simon, Jay Riva-Cambrin, Raj Srivastava, Susan L. Bratton, J. Michael Dean, John R. W. Kestle and for the Hydrocephalus Clinical Research Network

Object

The aims of this study were to measure inpatient health care for pediatric hydrocephalus in the US; describe patient, hospital, and hospitalization characteristics for pediatric hydrocephalus inpatient care; and determine characteristics associated with death.

Methods

A cross-sectional study was performed using the 1997, 2000, and 2003 Healthcare Cost and Utilization Project Kids' Inpatient Databases (KID), nationally representative weighted data sets of hospital discharges for pediatric patients. A hydrocephalus-related hospitalization was classified as either cerebrospinal fluid (CSF) shunt–related (including initial placements, infections, malfunctions, or other) or non–CSF shunt–related. Patients > 18 years of age were excluded. The KID provided weighted estimates of 6.657, 6.597, and 6.732 million total discharges in the 3 study years.

Results

Each year there were 38,200–39,900 admissions, 391,000–433,000 hospital days, and total hospital charges of $1.4–2.0 billion for pediatric hydrocephalus. Hydrocephalus accounted for 0.6% of all pediatric hospital admissions in the US in 2003, but for 1.8% of all pediatric hospital days and 3.1% of all pediatric hospital charges. Over the study years, children admitted with hydrocephalus were older, had an increase in comorbidities, and were admitted more frequently to teaching hospitals. Compared with children who survived, those who died were more likely to be < 3 months of age and have a birth-related admission, have no insurance, have comorbidities, be transferred, and have a non–CSF shunt–related admission.

Conclusions

Children with hydrocephalus have a chronic illness and use a disproportionate share of hospital days and healthcare dollars in the US. Since 1997 they have increased in age and in number of comorbid conditions. For important changes in morbidity and mortality rates to be made, focused research efforts and funding are necessary.

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Chevis N. Shannon, Tamara D. Simon, Gavin T. Reed, Frank A. Franklin, Russell S. Kirby, Meredith L. Kilgore and John C. Wellons III

Object

Detailed costs to individuals with hydrocephalus and their families as well as to third-party payers have not been previously described. The purpose of this study was to determine the primary caregiver out-of-pocket expenses and the third-party payer reimbursement rate associated with a shunt failure episode.

Methods

A retrospective study of children born between 2000 and 2005 who underwent initial ventriculoperitoneal (VP) shunt placement and who subsequently experienced a shunt failure requiring surgical intervention within 2 years of their initial shunt placement was conducted. Institutional reimbursement and demographic data from Children's Hospital of Alabama (CHA) were augmented with a caregiver survey of any out-of pocket expenses encountered during the shunt failure episode. Institutional reimbursements and caregiver out-of-pocket expenses were then combined to provide the cost for a shunt failure episode at CHA.

Results

For shunt failures, the median reimbursement total was $5008 (interquartile range [IQR] $2068–$17,984), the median caregiver out-of-pocket expenses was $419 (IQR $251–$1112), and the median total cost was $5411 (IQR $2428–$18,582). Private insurance reimbursed at a median rate of $5074 (IQR $2170–$14,852) compared with public insurance, which reimbursed at a median rate of $4800 (IQR $1876–$19,395). Caregivers with private insurance reported a median $963 (IQR $322–$1741) for out-of-pocket expenses, whereas caregivers with public insurance reported a median $391 (IQR $241–$554) for out-of-pocket expenses (p = 0.017).

Conclusions

This study confirmed that private insurance reimbursed at a higher rate, and that although patients had a shorter length of stay as compared with those with public insurance, their out-of-pocket expenses associated with a shunt failure episode were greater. However, it could not be determined if the significant difference in out-of-pocket expenses between those with private and those with public insurance was due directly to the cost of shunt failure. This model does not take into consideration community resources and services available to those with public insurance. These resources and services could offset the out-of-pocket burden, and therefore should be considered in future cost models.

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Tamara D. Simon, Matthew Hall, J. Michael Dean, John R. W. Kestle and Jay Riva-Cambrin

Object

Significant variation exists in the surgical and medical management of CSF shunt infection. The objectives of this study were to determine CSF shunt reinfection rates following initial CSF shunt infection in a large patient cohort and to determine management, patient, hospital, and surgeon factors associated with CSF shunt reinfection.

Methods

This retrospective cohort study included children who were in the Pediatric Health Information System (PHIS) database, who ranged in age from 0 to 18 years, and who underwent uncomplicated initial CSF shunt placement in addition to treatment for initial CSF shunt infection between January 1, 2001, and December 31, 2008. The outcome was CSF shunt reinfection within 6 months. The main predictor variable of interest was surgical approach to treatment of first infection, which was determined for 483 patients. Covariates included patient, hospital, surgeon, and other management factors.

Results

The PHIS database includes 675 children with initial CSF shunt infection. Surgical approach to treatment of the initial CSF shunt infection was determined for 483 children (71.6%). The surgical approach was primarily shunt removal/new shunt placement (in 286 children [59.2%]), but a substantial number underwent externalization (59 children [12.2%]), of whom a subset went on to have the externalized shunt removed and a new shunt placed (17 children [3.5% overall]). Other approaches included nonsurgical management (64 children [13.3%]) and complete shunt removal without shunt replacement (74 children [15.3%]).

The 6-month reinfection rate was 14.8% (100 of 675 patients). The median time from infection to reinfection was 21 days (interquartile range [IQR] 5–58 days). Children with reinfection had less time between shunt placement and initial infection (median 50 vs 79 days, p = 0.06). No differences between those with and without reinfection were seen in patient factors (patient age at either shunt placement or initial infection, sex, race/ethnicity, payer, indication for shunt, number of comorbidities, distal shunt location, and number of shunt revisions at first infection); hospital volume; surgeon volume; or other management factors (for example, duration of intravenous antibiotic use). Nonsurgical management was associated with reinfection, and complete shunt removal was negatively associated with reinfection. However, reinfection rates did not differ between the 2 most common surgical approaches: shunt removal/new shunt placement (44 [15.4%] of 286; 95% CI 11.4%–20.1%) and externalization (total 12 [20.3%] of 59; 95% CI 11.0%–32.8%). Externalization followed by shunt removal/new shunt placement (5 [29.4%] of 17; 95% CI 10.3%–56.0%) and nonsurgical management (15 [23.4%] of 64; 95% CI 13.8%–35.7%) had higher, but nonstatistically significant, reinfection rates. The length of stay was shorter for nonsurgical management.

Conclusions

Surgical approach to treatment of initial CSF shunt infection was not associated with reinfection in this large cohort of patients.

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Jay Riva-Cambrin, Chevis N. Shannon, Richard Holubkov, William E. Whitehead, Abhaya V. Kulkarni, James Drake, Tamara D. Simon, Samuel R. Browd, John R. W. Kestle and John C. Wellons III

Object

There is little consensus regarding the indications for surgical CSF diversion (either with implanted temporizing devices [reservoir or subgaleal shunt] or shunt alone) in preterm infants with posthemorrhagic hydrocephalus. The authors determined clinical and neuroimaging factors associated with the use of surgical CSF diversion among neonates with intraventricular hemorrhage (IVH), and describe variations in practice patterns across 4 large pediatric centers.

Methods

The use of implanted temporizing devices and conversion to permanent shunts was examined in a consecutive sample of 110 neonates surgically treated for IVH related to prematurity from the 4 clinical centers of the Hydrocephalus Clinical Research Network (HCRN). Clinical, neuroimaging, and so-called processes of care factors were analyzed.

Results

Seventy-three (66%) of the patients underwent temporization procedures, including 50 ventricular reservoir and 23 subgaleal shunt placements. Center (p < 0.001), increasing ventricular size (p = 0.04), and bradycardia (p = 0.07) were associated with the use of an implanted temporizing device, whereas apnea, occipitofrontal circumference (OFC), and fontanel assessments were not. Implanted temporizing devices were converted to permanent shunts in 65 (89%) of the 73 neonates. Only a full fontanel (p < 0.001) and increased ventricular size (p = 0.002) were associated with conversion of the temporizing devices to permanent shunts, whereas center, OFCs, and clot characteristics were not.

Conclusions

Considerable center variability exists in neurosurgical approaches to temporization of IVH in prematurity within the HCRN; however, variation between centers is not seen with permanent shunting. Increasing ventricular size—rather than classic clinical findings such as increasing OFCs—represents the threshold for either temporization or shunting of CSF.

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Tamara D. Simon, Matthew Hall, Jay Riva-Cambrin, J. Elaine Albert, Howard E. Jeffries, Bonnie LaFleur, J. Michael Dean, John R. W. Kestle and in collaboration with the Hydrocephalus Clinical Research Network

Object

Reported rates of CSF shunt infection vary widely across studies. The study objective was to determine the CSF shunt infection rates after initial shunt placement at multiple US pediatric hospitals. The authors hypothesized that infection rates between hospitals would vary widely even after adjustment for patient, hospital, and surgeon factors.

Methods

This retrospective cohort study included children 0–18 years of age with uncomplicated initial CSF shunt placement performed between January 1, 2001, and December 31, 2005, and recorded in the Pediatric Health Information System (PHIS) longitudinal administrative database from 41 children's hospitals. For each child with 24 months of follow-up, subsequent CSF shunt infections and procedures were determined.

Results

The PHIS database included 7071 children with uncomplicated initial CSF shunt placement during this time period. During the 24 months of follow-up, these patients had a total of 825 shunt infections and 4434 subsequent shunt procedures. Overall unadjusted 24-month CSF shunt infection rates were 11.7% per patient and 7.2% per procedure. Unadjusted 24-month cumulative incidence rates for each hospital ranged from 4.1 to 20.5% per patient and 2.5–12.3% per procedure. Factors significantly associated with infection (p < 0.05) included young age, female sex, African-American race, public insurance, etiology of intraventricular hemorrhage, respiratory complex chronic condition, subsequent revision procedures, hospital volume, and surgeon case volume. Malignant lesions and trauma as etiologies were protective. Infection rates for each hospital adjusted for these factors decreased to 8.8–12.8% per patient and 1.4–5.3% per procedure.

Conclusions

Infections developed in > 11% of children who underwent uncomplicated initial CSF shunt placements within 24 months. Patient, hospital, and surgeon factors contributed somewhat to the wide variation in CSF shunt infection rates across hospitals. Additional factors may contribute to variation in CSF shunt infection rates between centers, but further study is needed. Benchmarking and future prospective multicenter studies of CSF shunt infection will need to incorporate these and other patient, hospital, and surgeon factors.