Clostridium difficile in patients undergoing primary hip and knee replacement

Antibiotic prophylaxis is routinely administered during joint replacement surgery and may predispose patients to Clostridium difficile-associated disease (CDAD). The primary aim of this study was to determine the incidence of this following joint replacement, using a cefuroxime-based regimen. Patients developing CDAD were compared with a control group of patients without CDAD. The incidence of the former was 1.7 per 1000 primary joint replacements. Those patients prescribed additional antibiotics had a higher incidence of CDAD (p = 0.047), but there was no difference between the two groups in relation to the use of gastroprotective agents (p = 0.703). A trial of a new prophylaxis regimen would require 43 198 patients in each arm to show a reduction of one case per 1000 procedures. Cefuroxime-based antibiotic prophylaxis is safe in patients undergoing primary elective joint replacement.

Impact of a waiting room videotape message on parent attitudes toward pediatric antibiotic use

OBJECTIVE

To reduce the injudicious use of antibiotics, we developed an educational strategy that focused on parents of pediatric patients and their physicians.

METHODS

This intervention was conducted in 5 pediatric practices in Arkansas during a 9-month period. Baseline data on parent attitudes about antibiotics and physician practice habits were measured by questionnaire. During the following 36 weeks, an educational videotape about the judicious use of antibiotics was played in waiting rooms. The videotape on antibiotics used a standard script based on the recommendations of the American Academy of Pediatrics. The physicians and staff at each site were actors in the videotape. During week 2 and week 36 of videotape use, parent attitudes were measured again. After the baseline week, the physicians and staff in each site were provided a standard in-service review of the American Academy of Pediatrics recommendations for judicious use of antibiotics. A study nurse recruited patients, administered questionnaires, and reviewed charts on-site.

RESULTS

Parents who were exposed to the videotape were significantly less inclined to seek antibiotics for viral infections. Passively provided pamphlets were not read. No significant change in antibiotic prescribing by physicians was seen.

CONCLUSION

Parent-focused passive education tools are effective at changing parent attitudes toward the use of antibiotics. Although physicians have blamed parent attitudes and demands for the overuse of antibiotics, changes in parent attitudes in this study were not associated with changes in prescribing rates. Changes in parent attitudes may be necessary but do not seem sufficient for changes in antimicrobial prescribing patterns.

Elevation of serum interleukin 8 levels in acetaminophen overdose in children and adolescents

BACKGROUND

Elevations of inflammatory cytokines have been reported in animal models of acetaminophen (INN, paracetamol) toxicity. In addition, interleukin 8, a chemokine, has been found to be elevated in toxin-associated hepatic disease (ie, acute alcoholic hepatitis). The purpose of this study was to measure serum cytokine levels in children and adolescents with acetaminophen overdose and to evaluate relationships between cytokine elevation and hepatotoxicity.

METHODS

Serum levels of tumor necrosis factor alpha, interleukin 1beta, interleukin 6, interleukin 8, and interleukin 10 were measured by ELISA in children and adolescents (n = 35) with acetaminophen overdose. Peak cytokine levels were examined relative to biochemical evidence of hepatocellular injury, nomogram risk assessment, and prothrombin time.

RESULTS

Five patients had aspartate aminotransferase or alanine aminotransferase levels >1000 IU/L, and 4 patients had aspartate aminotransferase or alanine aminotransferase levels > or =100 IU/L and < or =1000 IU/L. No elevations of tumor necrosis factor alpha or interleukin 1beta were detected. Peak interleukin 8, but not interleukin 6 or interleukin 10, correlated with hepatotoxicity (Mann-Whitney exact test, P <.001). The peak interleukin 8 level was greater in patients at high risk by the nomogram combined with those presenting at >15 hours, as compared with other patients (Mann-Whitney U test, P <.01). The interleukin 8 level peaked before aspartate aminotransferase or alanine aminotransferase in 5 of the 9 patients with hepatotoxicity. In addition, interleukin 8 concentrations of >20 pg/mL were associated with peak prothrombin time values (Mann-Whitney exact test, P <.015).

CONCLUSIONS

Interleukin 8 elevation in patients with acetaminophen hepatotoxicity corresponds with other common clinical measures that are predictive of hepatocellular injury. Further study is warranted to evaluate possible mechanistic relationships between inflammatory cytokines and acetaminophen hepatotoxicity in children and adults.

Nosocomial infections during extracorporeal membrane oxygenation

OBJECTIVE

To examine trends in nosocomial infection associated with Extracorporeal Membrane Oxygenation (ECMO).

DESIGN

Retrospective review of all patients who underwent ECMO over a 4-year period at our institution; specifically, examining reasons for placement and duration of time on ECMO, as well as nosocomial infections incurred while on or shortly after discontinuation of support. Infections were considered ECMO-related if the organism was recovered on support or within 7 days from decannulation. Analyses were performed utilizing Pearson's chi-square for dichotomous factors and t-tests for continuous factors.

RESULTS

Of 141 patients requiring ECMO support, 90 (64%) survived to hospital discharge. Indication for support included circulatory failure (53%) and non-cardiac (47%). Twenty-six percent of patients developed infections on ECMO. Organisms isolated included: bacterial 20 (54%), fungal 10 (27%), mixed five (14%) and viral two (5%). Infection sites included: blood 13 (35%), urine nine (24%), mixed eight (22%), wound five (14%) and lung two (5%). Seventy-eight percent of infections noted occurred in cardiac patients. Patients with nosocomial infections were supported for a median of 169 h (range, 84-936 h), versus those without nosocomial infection [146 h (range, 50-886 h); P<0.001]. Procedures on ECMO were associated with an increased risk of infection (P<0.001) as was the presence of an open chest (P<0.025).

CONCLUSIONS

The incidence of infection in ECMO patients at our institution has not increased significantly since our previous study. Cardiac patients have increased risk for nosocomial infection while on ECMO, which may be in part due to longer cannulation times, as well as increased likelihood of undergoing major procedures or having an open chest.

Evaluation of occult acetaminophen hepatotoxicity in hospitalized children receiving acetaminophen. Pediatric Pharmacology Research Unit Network

The safety of repeated doses of acetaminophen in ill children with the potential of reduced glutathione stores has been questioned. This study measured hepatic transaminases in children and adolescents (n=100) who received > or = 6 therapeutic doses of acetaminophen over a 48-hour period of hospitalization. Acetaminophen-protein adducts were measured in a cohort of subjects with hepatic transaminase elevation (n=8) and in those (n=10) receiving concurrent drug therapy with agents that induce the cytochrome P450 enzymes involved in acetaminophen metabolism. Acetaminophen-protein adducts were not detected in this cohort of 18 subjects. Based on this pilot study, the routine use of acetaminophen at therapeutic doses in ill, hospitalized children and adolescents appears safe.

Interactions of inflammatory pain and morphine in infant rats: long-term behavioral effects

Neonatal rat pups exposed to repetitive acute pain show decreases in pain threshold and altered behavior during adulthood. A model using prolonged inflammatory pain in neonatal rats may have greater clinical relevance for investigating the long-term behavioral effects of neonatal pain in ex-preterm neonates. Neonatal rat pups were exposed to repeated formalin injections on postnatal (P) days 1-7 (P1-P7), with or without morphine pretreatment, and were compared with untreated controls. Behavioral testing during adulthood assessed pain thresholds using hot-plate (HP) and tail-flick (TF) tests, alcohol preference, and locomotor activity (baseline and postamphetamine). Adult rats exposed to neonatal inflammatory pain exhibited longer HP latencies than controls and male rats had longer HP thresholds compared to females. Male rats exposed to neonatal morphine alone exhibited longer TF latencies than controls. Both neonatal morphine treatment and neonatal inflammatory pain decreased ethanol preference, but their effects were not additive. During adulthood, male rats exposed to neonatal inflammatory pain exhibited less locomotor activity than untreated controls. We conclude that neonatal formalin and morphine treatment have specific patterns of long-term behavioral effects in adulthood, some of which are attenuated when the two treatments are combined.

Variation in therapy and outcome for pediatric head trauma patients

OBJECTIVE

This study was undertaken to examine variation in therapies and outcome for pediatric head trauma patients by patient characteristics and by pediatric intensive care unit. Specifically, the study was designed to examine severity of illness on admission to the pediatric intensive care unit, the therapies used during the pediatric intensive care unit stay, and patient outcomes.

DATA SOURCES AND SETTING

Consecutive admissions from three pediatric intensive care units were recorded prospectively (n = 5,749). For this study, all patients with an admitting diagnosis of head trauma were included (n = 477). Data collection occurred during an 18-month period beginning in June 1996. All of the pediatric intensive care units were located in children's hospitals, had residency and fellowship training programs, and were headed by a pediatric intensivist.

METHODS

Admission severity was measured as the worst recorded physiological derangement during the period <or=6 hrs before pediatric intensive care unit admission. Therapies and resource use were based on the Therapeutic Intervention Scoring System with adaptations for pediatrics. The use of intracranial pressure monitoring was recorded on admission to the unit (within 1 hr) and at any time during the pediatric intensive care unit stay. Outcomes were measured at the time of pediatric intensive care unit discharge by the Pediatric Overall Performance Category scale. Risk factors for mortality were examined by using bivariate analyses with significant predictors as candidate variables in a logistic regression to predict expected mortality. Intracranial pressure monitoring and other therapies were added to the mortality prediction model to test for protective effects. Finally, race and insurance status were added to the model to test for differences in the quality of care.

RESULTS

The overall mortality rate for the entire sample was 7.8%. Mortality rates for children <or=1 yr old were significantly higher than for children >1 yr old (16.1% vs. 6.1%; p = .002). Comparisons by insurance status indicated that observed mortality rates were highest for self-paying patients. However, patient characteristics were not associated with use of therapies or standardized mortality rates after adjustment for patient severity. There was significant variation in the use of paralytic agents, seizure medications, induced hypothermia, and intracranial pressure monitoring on admission across the three pediatric intensive care units. In multivariate models, only the use of seizure medications was associated significantly with reduced mortality risk (odds ratio = 0.17; 95% confidence interval = 0.04-0.70; p = .014).

CONCLUSIONS

Therapies and outcomes vary across pediatric intensive care units that care for children with head injuries. Increased use of seizure medications may be warranted based on data from this observational study. Large randomized controlled trials of seizure prophylaxis in children with head injury have not been conducted and are needed to confirm the findings presented here.

Phenothiazine, butyrophenone, and other psychotropic medication poisonings in children and adolescents

OBJECTIVE

To describe the presentation, epidemiology, management, and outcome of phenothiazine and butyrophenone ingestions in children requiring hospitalization.

METHOD

Retrospective case series in two pediatric hospitals.

RESULTS

Eighty-six cases were identified among 83 patients. The majority (69.7%) of ingestions occurred in children <6 years of age and there was no gender predominance. These ingestions were more common in African Americans (65.1%). They occurred more commonly in the patient's (64.0%) or a relative's (22.1%) home and haloperidol and thioridazine accounted for 58.1% of exposures. Depressed levels of consciousness and dystonia were the most common presenting signs, present in 90.7% and 51.2% of patients, respectively. Miosis occurred in only 13.9% of the patients. Fluid boluses were administered to 28.7% of the patients but about a quarter of these had coingested potentially cardiotoxic drugs. In addition, 2 of the 12 (13.9%) patients with abnormal electrocardiograms had also ingested potentially cardiotoxic drugs. Numerous diagnostic tests were performed in these patients including electrolyte panels (80.2%), complete blood counts (69.8%), liver function tests (31.4%), serum osmolality (20.9%), blood cultures (10.5%), lumbar punctures (17.4%), head computed tomographies (15.1%), and electroencephalograms (3.5%). The median length of hospitalization was 1.78 (range 1-9) days and there were no deaths. Patients presenting with dystonias were more likely to have extensive diagnostic testing for neurologic disease than those presenting without dystonias.

CONCLUSION

The presentation of phenothiazine and butyrophenone ingestions in children and adolescents may be nonspecific and confounded by coingestants. Patients with dystonias had more extensive neurologic testing than patients without dystonias, suggesting that physicians may not recognize dystonias as a clinical finding characteristic of phenothiazine or butyrophenone exposure.

Encouraging physicians to respond to surveys through the use of fax technology

High response rates in surveys of physicians are difficult to achieve. One possible strategy to improve physicians' survey participation is to offer the option of receiving and returning the survey by fax. This study describes the success of the option of fax communication in a survey of general practitioners, family physicians, and pediatricians in Arkansas with regard to pediatric asthma. Eligible physicians were given the choice of receiving the survey by telephone, mail, or fax. In this observational study, physicians' preferences, response rates, and biases for surveys administered by fax were compared with mail and telephone surveys. The overall survey response rate was 59%. For the 96 physicians completing an eligibility screener survey, the largest percentage requested to be surveyed by fax (47%) rather than by telephone (28%) or mail (25%). Faxing may be one strategy to add to the arsenal of tools to increase response rates in surveying physicians.

Volume-outcome relationships in pediatric intensive care units

CONTEXT

Pediatric intensive care units (PICUs) have expanded nationally, yet few studies have examined the potential impact of regionalization and no study has demonstrated whether a relationship between patient volume and outcome exists in these units. Documentation of an inverse relationship between volume and outcome has important implications for regionalization of care.

OBJECTIVES

This study examines relationships between the volume of patients and other unit characteristics on patient outcomes in PICUs. Specifically, we investigate whether an increase in patient volume improves mortality risk and reduces length of stay.

DESIGN AND SETTING

A prospective multicenter cohort design was used with 16 PICUs. All of the units participated in the Pediatric Critical Care Study Group. Participants. Data were collected on 11 106 consecutive admissions to the 16 units over a 12-month period beginning in January 1993.

MAIN OUTCOME MEASURES

Risk-adjusted mortality and length of stay were examined in multivariate analyses. The multivariate models used the Pediatric Risk of Mortality score and other clinical measures as independent variables to risk-adjust for illness severity and case-mix differences.

RESULTS

The average patient volume across the 16 PICUs was 863 with a standard deviation of 341. We found significant effects of patient volume on both risk-adjusted mortality and patient length of stay. A 100-patient increase in PICU volume decreased risk-adjusted mortality (adjusted odds ratio:.95; 95% confidence interval:.91-.99), and reduced length of stay (incident rate ratio:.98; 95% confidence interval:.975-.985). Other PICU characteristics, such as fellowship training program, university hospital affiliation, number of PICU beds, and children's hospital affiliation, had no effect on risk-adjusted mortality or patient length of stay.

CONCLUSIONS

The volume of patients in PICUs is inversely related to risk-adjusted mortality and patient length of stay. A further understanding of this relationship is needed to develop effective regionalization and referral policies for critically ill children.

A randomized comparison of ketorolac tromethamine and morphine for postoperative analgesia in critically ill children

OBJECTIVES

To evaluate the efficacy of a single dose of ketorolac compared with morphine for the relief of pain in children, and to determine the safety of ketorolac.

SETTING

Tertiary pediatric intensive care unit in a university-affiliated hospital.

DESIGN

Prospective, randomized, double-blind, parallel, single-dose, positive control study.

PATIENTS

Children admitted to the intensive care unit with postoperative pain.

INTERVENTIONS

Patients received a single dose of either morphine or ketorolac as the first postoperative analgesic when the pain score indicated significant pain. Blood pressure, heart rate, and urine output were recorded, as well as blood urea nitrogen, creatinine, bleeding time, hematuria or proteinuria, and aspartate aminotransferase. Side effects such as nausea and vomiting were noted. Morphine was used for rescue treatment if the patient continued to have significant pain > or =30 mins after study drug administration.

MEASUREMENTS AND MAIN RESULTS

Of the 102 children studied, 48 received morphine and 54 received ketorolac. The percentage of patients reporting pain relief in the first and second hours after drug administration was not different between groups. Likewise, the proportion of patients who met the criteria for pain relief during the entire evaluation period was not different between groups. There was a trend toward fewer patients who received ketorolac requiring remedication in the first 4 hrs compared with those who received morphine, but this trend did not reach statistical significance. More patients in the morphine group failed to achieve pain relief at any time after the dose compared with those who received ketorolac. There were no differences between the two groups in physiologic or laboratory variables. Vomiting was more common in patients who received ketorolac.

CONCLUSION

Ketorolac is comparable to morphine in relief of postoperative pain in children. A single dose of ketorolac does not result in abnormal postoperative bleeding or alter renal function. However, ketorolac may cause nausea and vomiting in some patients.

The role of transthoracic echocardiography in the diagnosis of infective endocarditis in children

BACKGROUND

Infective endocarditis (IE) is frequently suspected but infrequently diagnosed in children. Clinicians often order echocardiograms to "rule out" IE. In an era of cost constraint, clinically efficient strategies must be developed to eliminate unnecessary tests. We hypothesized that transthoracic echocardiography (TTE) is only useful in children in whom there is a high clinical suspicion of IE based on history, physical examination, and persistently positive blood cultures.

OBJECTIVE

To determine the role of TTE as a screening test for suspected IE in children.

METHODS

Echocardiographic reports and medical records were reviewed retrospectively for 173 consecutive patients who underwent TTE to rule out IE from January 1993 to August 1996.

RESULTS

Persistent fever was the predominant symptom leading to a suspicion of IE (120 patients [69.4%]). Fifty-seven (32.9%) of the 173 patients had congenital heart disease and 95 patients (54.9%) had indwelling venous catheters. Twenty-six patients (15.0%) were diagnosed and treated for IE. Twelve (46.2%) of these 26 patients had vegetations seen on TTE. The conditions of the remaining 14 patients were diagnosed clinically and these patients had persistently positive blood cultures. By univariate analysis, the risk factors associated with the diagnosis of IE were malaise, congestive heart failure, new or changing heart murmur, leukocytosis, hematuria, and the presence of 2 or more positive blood cultures for the same organism. The risk factors associated with positive TTE were malaise, congestive heart failure, new or changing heart murmur, leukocytosis, hematuria, and 2 or more positive blood cultures. The presence of an indwelling catheter or immunocompromised status were not predictive of vegetation or IE.

CONCLUSIONS

Transthoracic echocardiography has poor sensitivity as a screening test for IE in patients with low clinical probability of the disease. A diagnostic algorithm for IE is suggested based on these data.

Ventilation-perfusion scintigraphic evaluation of pulmonary clot burden after percutaneous thrombolysis of clotted hemodialysis access grafts

The objective of this study is to determine, by using rigorous methods, if pulmonary perfusion defects were detectable by ventilation-perfusion scintigraphy after percutaneous thrombolysis of clotted hemodialysis access grafts. Thirteen patients were studied. Four patients underwent pharmacomechanical thrombolysis with urokinase and the remainder had mechanical thrombolysis alone. Pre- and postthrombolysis scintigraphic studies were performed on all patients. Perfusion defects were described as vascular (well-defined borders confined to segmental boundaries) or nonvascular. Vascular defects were graded by severity (0 to 3) and area (0 to 3) for each involved segment. Nonvascular defects were graded by severity (0 to 1) and area (0 to 1). Two experienced readers evaluated the scans blinded to each other's results and all other clinical data, including thrombolysis outcomes. Twelve patients did not have any significant worsening of their perfusion defect scores postthrombolysis. In only one patient did a study show a new nonvascular perfusion defect with a matching ventilation abnormality. The defect was believed to be caused by mucus plugging. The patient had no evidence of pulmonary embolism. Our study suggests emboli that resulted from the pharmacomechanical or mechanical thrombolysis procedure were either small, underwent lysis before impacting the lung, or were below the limit of detection of ventilation-perfusion scintigraphy.

Increased colonic ornithine decarboxylase activity in inflammatory bowel disease in children

The risk of colorectal carcinoma is increased in pediatric-onset inflammatory bowel disease (IBD). There is little information available regarding the colonic mucosal proliferative state in children with IBD. The aim of this study was to assess colonic ornithine decarboxylase (ODC) activity, a marker of cell proliferation, in pediatric IBD patients. ODC activity was assessed in colonic mucosa from 23 children (7 with ulcerative colitis, 9 with Crohn's disease, and 7 controls) undergoing colonoscopic examination. ODC activities were then compared with degree of inflammation of biopsied samples. ODC activities in patients with and without corticosteroid treatment were also analyzed. The mucosal ODC activities of sigmoid colon and rectum were significantly higher (2.5- to 4-fold) in both ulcerative colitis and Crohn's disease. The higher ODC activity was associated with increased mucosal inflammation. Moreover, treatment with corticosteroids decreased the ODC activity. In conclusion, using ODC activities as a marker of cell proliferation, our results suggest that there is a higher colonic mucosal proliferative state in children with IBD. The increased ODC activities were associated with increased colonic mucosal inflammation. Colonic mucosal ODC activity may provide an additional parameter to access the therapeutic efficacy of corticosteroid treatment in pediatric IBD patients.

Antinuclear antibodies as potential markers of lung cancer

There are multiple case reports of antinuclear antibodies (ANAs) in patients with malignancies, yet to date there has not been a systematic survey of ANAs in lung cancer. We have previously reported that autoantibodies to collagen antigens resembling those found in the connective tissue diseases are consistently detected in the sera from lung cancer patients. In this work, we looked for the presence of ANAs in the sera from these same patients. Sera from 64 patients with lung cancer and 64 subjects without a history of cancer were retrospectively tested for reactivity on immunoblots of nuclear extracts of HeLa, small cell carcinoma, squamous cell carcinoma, adenocarcinoma, large cell carcinoma of the lung, and of normal lung cells. Associations were sought between the reactivities on immunoblots and lung cancer cell type, diagnosis, and progression-free survival by the method of classification and regression trees (CARTs). Cross-validated CART analyses indicated that reactivities to certain bands in immunoblots are associated with different types of lung cancer. Some of these autoantibodies were associated with a prolonged survival without disease progression. Our data suggest that autoimmunity is often a prominent feature of lung cancer and that molecular characterization of these antigens may lead to the discovery of proteins with diagnostic and prognostic value.

Syndrome of inappropriate antidiuretic hormone secretion in children following spinal fusion

OBJECTIVES

a) To determine if antidiuretic hormone (ADH) is elevated in patients undergoing spinal fusion, especially in those who have clinical evidence of syndrome of inappropriate antidiuretic hormone (SIADH); b) to evaluate the relationship between ADH secretion and the secretion of atrial natriuretic peptide (ANP).

SETTING

Tertiary care pediatric intensive care unit (ICU) in a university hospital.

DESIGN

A prospective cross-sectional, observational study with factorial design.

PATIENTS

Thirty patients > or = 10 yrs of age undergoing spinal fusion admitted to the ICU for postoperative care.

INTERVENTIONS

Patients underwent anterior, posterior, or both anterior/posterior spinal fusion. Blood was collected for serial measurements of ADH, ANP and serum electrolyte levels. Heart rate, blood pressure and central venous pressure were measured.

MEASUREMENTS AND MAIN RESULTS

Thirty children were studied. Nineteen had idiopathic scoliosis, nine had neuromuscular scoliosis, one had Marfan's disease, and one had congenital scoliosis. Ten (33%) children met clinical criteria of SIADH. There was no difference in duration of surgery, blood loss, volume of iv fluid administration pre- and intraoperatively, or type of scoliosis between those who developed SIADH and those who did not. Hemodynamic variables were similar in both groups. ADH levels increased in both groups immediately postoperatively and at 6 hrs after surgery, but were much more elevated in those patients with SIADH. Patients with SIADH also had significantly higher ADH levels preoperatively. In relation to serum osmolality, ADH was considerably higher in those with SIADH compared with those who did not. Although ANP values tended to be higher in the group with SIADH, this did not reach statistical significance.

CONCLUSION

SIADH occurs in a subset of children who undergo spinal fusion. The diagnosis of SIADH can be made easily using clinical parameters which are well-defined. In the face of SIADH, continued volume expansion may be harmful, and should therefore be avoided.