Gregory J. Stoddard

Temporal trends of invasive disease due to Streptococcus pneumoniae among children in the intermountain west : Emergence of nonvaccine serogroups

BACKGROUND Use of the heptavalent pneumococcal conjugate vaccine (PCV-7 [Prevnar]) has been associated with decreased a incidence of invasive pneumococcal disease (IPD) among children in the United States. METHODS Cases of IPD in children < 18 years of age insured by or receiving health care from Intermountain Health Care during 1996-2003 were identified. Isolates of S. pneumoniae from children with IPD treated at Primary Childrens Medical Center (PCMC; Salt Lake City, UT) during 1997-2003 were serogrouped. Temporal trends of IPD, serogroup distribution of pneumococci, and antibiotic resistance among pneumococci were analyzed. RESULTS A total of 1535 cases of IPD were identified. The rate of IPD decreased 27% after the introduction of PCV7. Among children with IPD who were cared for at PCMC, disease in 73% was caused by PCV7 serogroups in 1997-2000, compared with 50% in 2001-2003 (P < .001), and the percentage of isolates resistant to penicillin decreased from 34% in 1997-2000 to 22% in 2001-2003 (P = .04). The percentage of IPD cases that were empyema increased from 16% to 30% (P = .015), and the percentage of severe cases of IPD increased from 57% to 71% (P = .026). Children with IPD due to non-PCV7 serogroups were older, were more likely to have parapneumonic empyema, and had longer hospital stays. CONCLUSIONS The incidence of IPD in the IMW decreased by 27% after the introduction of the PCV7 vaccine. During the postvaccine period (2001-2003), there were significant decreases in the proportion of cases of IPD caused by PCV7 and antibiotic-resistant serogroups. These benefits were accompanied by a significant increase in the proportion of IPD cases due to non-PCV7 serogroups, with increases in the incidence of empyema and severe IPD.

Opioid-Related Adverse Drug Events in Surgical Hospitalizations: Impact on Costs and Length of Stay

Background: Opioid analgesics remain a mainstay in the treatment of pain associated with surgical procedures. Such use is associated with adverse drug events (ADEs). Objective: To investigate the impact of opioid-related ADEs on total hospital costs and length of stay (LOS) in adult surgical patients. Methods: This was a retrospective matched cohort study using data from computerized medical records. ADE cases were prospectively detected using computerized surveillance and verified by pharmacists. Surgical patients treated at LDS Hospital in Salt Lake City from January 1, 1998, to December 31, 2003, were included. The primary outcomes were costs and hospital LOS associated with opioid-related ADEs and the relationship of opioid dose to ADE events. Results: Patients experiencing opioid-related ADEs had significantly increased median total hospital costs (7.4% increase; 95% CI 3.83 to 10.96; p < 0.001) and increased median LOS (10.3% increase; 95% CI 6.5 to 14.2; p < 0.001) compared with matched non-ADE contrals. The increased costs attributable to ADEs, by surgery type, were general surgery (

Acetabular Cartilage Delamination in Femoroacetabular Impingement: Risk Factors and Magnetic Resonance Imaging Diagnosis

676.51; 95% CI 351.50 to 1001.50), orthopedics (

Impact of Timing of Initiation of Dialysis on Mortality

861.50; 95% CI 448.20 to 1274.80), and obstetrics/gynecology (

Low plasma arginine concentrations in children with cerebral malaria and decreased nitric oxide production

540.90; 95% CI 281.40 to 800.40). Similarly, increased LOS attributable to ADEs, by surgery type, were general surgery (0.64 days; 95% CI 0.40 to 0.88), orthopedics (0.52 days; 95% CI 0.33 to 0.71), and obstetrics/gynecology (0.53 days; 95% CI 0.33 to 0.72). Higher doses of opioids were associated with increased risk of experiencing ADEs (OR 1.3; 95% CI 1.07 to 1.60; p = 0.01). Conclusions: Opioid-related ADEs following surgery were associated with significantly increased LOS and hospitalization costs. These ADEs occurred more frequently in patients receiving higher doses of opioids.

Creatinine Production, Nutrition, and Glomerular Filtration Rate Estimation

BACKGROUND Delamination of acetabular articular cartilage is a common abnormality in hips with femoroacetabular impingement. The purpose of the present study was to identify clinical and radiographic factors predisposing to delamination and to assess the diagnostic accuracy of magnetic resonance arthrography for the detection of these lesions. METHODS Following a retrospective review of records, we determined that acetabular cartilage delamination had been present in twenty-eight of sixty-four hips that had undergone a surgical dislocation procedure for the treatment of femoroacetabular impingement. Multivariable logistic regression was performed to assess the correlation of radiographic findings (i.e., magnetic resonance imaging and computerized tomography findings) with the status of delamination. The preoperative interpretations of the magnetic resonance arthrograms for twenty-seven hips that underwent surgical dislocation were reviewed to assess the accuracy of detecting delamination. At the time of surgery, nine of these twenty-seven hips were found to have delamination. Magnetic resonance arthrography interpretations that did not correlate with operative findings were subjected to conspicuity assessment and error analysis. RESULTS The rate of delamination of the acetabular cartilage as noted at the time of surgical dislocation was 44% (twenty-eight of sixty-four). Delamination was strongly associated with male sex and femoral sided signs of impingement; however, it was not associated with acetabular overcoverage (center-edge angle, >40 degrees) (odds ratio = 0.16; p < 0.05). While there was no significant difference in the prevalence of labral lesions between groups, whenever labral and delamination lesions were found in the same hip, they were directly adjacent to one another. Preoperative magnetic resonance arthrography had a low sensitivity for delamination (22%) but had a high specificity (100%). Two-thirds of the delamination lesions were visible on retrospective review of these images when the reader was unblinded to the surgical findings. Delamination could most often be identified on the sagittal T1-weighted image and on the proton-density sequences with fat saturation. DISCUSSION There should be a high level of suspicion for articular cartilage delamination in men and in patients with primarily cam-type femoroacetabular impingement. Acetabular overcoverage may be protective against delamination. Preoperative high-quality magnetic resonance arthrograms should be carefully analyzed for evidence of delamination in this patient population.

Risk Factors for Adverse Drug Events: A 10-Year Analysis

Previous studies showed that sicker patients were initiated on dialysis at higher GFR as estimated by the Modification of Diet in Renal Disease (MDRD) formula. It was previously shown that patients with low creatinine production were malnourished and had low serum creatinine levels and creatinine clearances (CrCl) but high MDRD GFR at initiation of dialysis. Therefore, a propensity score approach was used to examine the associations of MDRD GFR and measured CrCl at the initiation of dialysis with subsequent mortality. Baseline data and outcomes were obtained from the Dialysis Morbidity Mortality Study Wave II. Propensity scores for early initiation derived by logistic regression were used in Cox models to examine mortality. Each 5-ml/min increase in MDRD GFR at initiation of dialysis in the entire cohort was associated with increased hazard of death in multivariable Cox model (hazard ratio [HR] 1.14; P = 0.002). In the subgroup of patients with reported CrCl, higher MDRD GFR was associated with increased risk of death (for each 5-ml/min increase, HR 1.27; P < 0.001) but not CrCl (for each 5-ml/min increase, HR 0.98; P = 0.81). These divergent results might reflect erroneous GFR estimation by the MDRD formula. Furthermore, these data do not support earlier initiation of dialysis. Therefore, for patients without clinical indications for initiation of dialysis, the appropriate GFR level for initiation of dialysis is unknown.

Pulsatility and the Risk of Nonsurgical Bleeding in Patients Supported With the Continuous-Flow Left Ventricular Assist Device HeartMate II

Nitric oxide (NO) production and mononuclear cell NO synthase 2 (NOS2) expression are high in healthy Tanzanian children but low in those with cerebral malaria. Factors that downregulate NOS2 also diminish factors involved in cellular uptake and biosynthesis of L-arginine, the substrate for NO synthesis. We therefore postulated that L-arginine concentrations would be low in individuals with cerebral malaria. We measured concentrations of L-arginine in cryopreserved plasma samples from Tanzanian children with and without malaria. L-arginine concentrations were low in individuals with cerebral malaria (mean 46 micromol/L, SD 14), intermediate in those with uncomplicated malaria (70 micromol/L, 20), and within the normal range in healthy controls (122 micromol/L, 22; p<0.0001). Analysis by logistic regression showed that hypoargininaemia was significantly associated with cerebral malaria case-fatality. Hypoargininaemia may contribute to limited NO production in children with cerebral malaria and to severe disease.

Effects of Platelet-Rich Fibrin Matrix on Repair Integrity of At-Risk Rotator Cuff Tears:

This study examined the validity and clinical implications of the assumption of the Modification of Diet in Renal Disease Study (MDRD) formula that age, gender, race, and BUN account for creatinine production (CP). The relationships of MDRD GFR, CP, and nutrition were examined in 1074 Dialysis Morbidity and Mortality Study Wave II patients with reported measured creatinine clearances at initiation of dialysis. Age, gender, race, BUN, and serum creatinine (Scr) were used to calculate MDRD GFR. The measured 24-h urinary creatinine was used to estimate CP. In linear regression, Scr positively correlated with CP independent of age, gender, race, and BUN. Compared with the highest CP quartile, the lowest CP quartile had lower creatinine clearance (5.8 +/- 2.9 versus 11.3 +/- 3.4 ml/min, P <.01) despite lower Scr (5.8 +/- 2.6 versus 8.6 +/- 3.1 mg%, P <.01). There was an excellent correlation between the reciprocal of Scr and the MDRD GFR (r = 0.90). As a result, the MDRD GFR was higher in the lowest CP quartile (10.9 +/- 4.6 versus 7.6 +/- 2.4 ml/min, P <.01). Malnutrition (48% versus 26%, P <.01) was more common in the lowest CP quartile. Each 5-ml/min increase in MDRD GFR was associated with 21% higher odds of malnutrition (P = 0.046) in a multivariable logistic regression, which was abolished by controlling for CP. The fundamental assumption of the MDRD formula is invalid in patients with advanced renal failure, and the use of this formula in these patients might introduce biases.

Mortality of Late-Preterm (Near-Term) Newborns in Utah

BACKGROUND Many adverse drug events (ADEs) are the result of known pharmacologic properties, and some result from medication errors. However, some are the result of patient-specific risk factors. OBJECTIVE To identify inpatient risk factors for ADEs. METHODS Conditional logistic regression was used to analyze all pharmacist-verified ADEs by therapeutic class of drugs and severity during a 10-year study period. All inpatients ≥18 years of age from a 520-bed tertiary teaching hospital were included. Each case patient was matched with up to 16 control patients. Odds ratios for patient factors associated with ADEs were calculated from different therapeutic classes of drugs. RESULTS Odds ratios for numerous risk factors were identified for 4376 ADEs and were found to vary depending on therapeutic classification. The risk factors for the different classifications were grouped by (1) patient characteristics—female (OR 1.5–1.7), age (0.7–0.9), weight (1.2–1.4), creatinine clearance (0.8–4.7), and number of comorbidities (1.1–12.6); (2) drug administration—dosage (1.2–3.7), administration route (1.4–149.9), and number of concomitant drugs (1.2–2.4); and (3) patient type—service (1.2–4.9), nursing division (1.5–3.8), and diagnosis-related group (1.5–5.7). CONCLUSIONS Some risk factors are consistent for all ADEs and across multiple therapeutic classes of drugs, while others are class specific. High-risk agents should be closely monitored based on patient characteristics (gender, age, weight, creatinine clearance, number of comorbidities) and drug administration (dosage, administration route, number of concomitant drugs).