Biomedical subjects

Mary Cheang

Publications and source records attributed to Mary Cheang.

At least 19 recordsLinked to original sources

PubMed2006

Cosmetic outcomes following breast conservation therapy: in search of a reliable scale.

INTRODUCTION: Multiple scales to evaluate breast cosmesis following breast conserving treatment (BCT) have been developed, however reliability is a problem. Panel scores, where scores from two or more individuals are combined, were assessed to examine their effect on reliability for two different cosmetic scales. METHODS: Women, two or more years following BCT, were recruited from a single breast centre. Photographs of each participant were evaluated independently by six health care professionals on two separate occasions. A simple four-point scale and more involved multi-item scale were used to assess cosmetic outcome. Reliability was assessed with the weighted kappa statistic for increasing panel sizes. RESULTS: Ninety-nine women were evaluated. Intra rater reliability increased from 0.73 to 0.83 for the four-point scale, for increasing panel sizes, however 95% confidence intervals generally overlapped. A smaller and more unpredictable effect was seen on the multi-item subscale, range 0.69 to 0.73. Inter rater reliability increased from 0.68 to 0.93 for the four-point scale, and 0.75 to 0.96 for the multi-item scale, for increasing panel sizes; 95% confidence intervals did not overlap. A panel of three for either scale provided almost perfect kappa values with only small improvements with larger panel sizes. CONCLUSIONS: Care should be used in interpreting results where cosmetic outcomes have been obtained from a single evaluator. Panel scores can be used to significantly improve inter-rater, but not intra rater reliability, for the scales studied. Comparable reliability, in combination with simplicity of use and interpretation, would favour the four-point scale for breast cosmetic evaluation over the multi-item scale.

Breast Neoplasms↗

PubMed2006

Duration of hypotension before initiation of effective antimicrobial therapy is the critical determinant of survival in human septic shock.

OBJECTIVE: To determine the prevalence and impact on mortality of delays in initiation of effective antimicrobial therapy from initial onset of recurrent/persistent hypotension of septic shock. DESIGN: A retrospective cohort study performed between July 1989 and June 2004. SETTING: Fourteen intensive care units (four medical, four surgical, six mixed medical/surgical) and ten hospitals (four academic, six community) in Canada and the United States. PATIENTS: Medical records of 2,731 adult patients with septic shock. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: The main outcome measure was survival to hospital discharge. Among the 2,154 septic shock patients (78.9% total) who received effective antimicrobial therapy only after the onset of recurrent or persistent hypotension, a strong relationship between the delay in effective antimicrobial initiation and in-hospital mortality was noted (adjusted odds ratio 1.119 [per hour delay], 95% confidence interval 1.103-1.136, p<.0001). Administration of an antimicrobial effective for isolated or suspected pathogens within the first hour of documented hypotension was associated with a survival rate of 79.9%. Each hour of delay in antimicrobial administration over the ensuing 6 hrs was associated with an average decrease in survival of 7.6%. By the second hour after onset of persistent/recurrent hypotension, in-hospital mortality rate was significantly increased relative to receiving therapy within the first hour (odds ratio 1.67; 95% confidence interval, 1.12-2.48). In multivariate analysis (including Acute Physiology and Chronic Health Evaluation II score and therapeutic variables), time to initiation of effective antimicrobial therapy was the single strongest predictor of outcome. Median time to effective antimicrobial therapy was 6 hrs (25-75th percentile, 2.0-15.0 hrs). CONCLUSIONS: Effective antimicrobial administration within the first hour of documented hypotension was associated with increased survival to hospital discharge in adult patients with septic shock. Despite a progressive increase in mortality rate with increasing delays, only 50% of septic shock patients received effective antimicrobial therapy within 6 hrs of documented hypotension.

Adult↗

PubMed2006

Validity of a prescription claims database to estimate medication adherence in older persons.

BACKGROUND: Prescription claims data have been used to estimate refill medication adherence through calculations of cumulative medication acquisition (CMA) and cumulative medication gap (CMG) values. Few studies have assessed the validity of these calculated rates. OBJECTIVES: We sought to assess the validity of CMA and CMG calculated from the Manitoba prescription claims database (DPIN) against pill count medication adherence, targeting overall medications and angiotensin converting enzyme inhibitors (ACEIs). METHODS: Using a survey of a convenience sample of subjects recruited through community pharmacies, subjects who were eligible for study (ie, 65 years or older, noninstitutionalized, taking 2 or more "discrete" prescribed medications, including an ACEI, and willing to provide informed consent) were studied. Pill counts were conducted on all prescribed medicines during 3 home interviews over the course of 4 months. Ten months of DPIN data also were collected on each subject. RESULTS: The concordance between CMA and pill count for overall medications was 411/522 (79%) and for ACEIs was 89/101 (88%) with no systematic differences (McNemar's P = 0.68 and P = 0.097, respectively). CMG and pill count showed even better concordance of 438/514 (85%) for overall medications and 96/101 (95%) for ACEIs, although systematic differences were noted for overall medications (McNemar's P = 0.0012) but not for ACEIs (McNemar's P = 0.500). Spearman's rank correlations were weak for all comparisons. CONCLUSIONS: The high concordance between prescription claims database and pill counts suggested that the rate with which patients refill their medications usually is consistent with the rate they consume them. DPIN is not accurate for nondiscrete dosage forms or medications prescribed for "as-required" use.

Aged↗

PubMed2006

A population-based case control study of potential risk factors for IBD.

BACKGROUND: We aimed to pursue potential etiological clues to Crohn's disease (CD) and ulcerative colitis (UC) through a population-based case control survey study. METHODS: Cases with CD (n = 364) and UC (n = 217), ages 18-50 yr were drawn from the population-based University of Manitoba IBD Research Registry. Potential control subjects were drawn from the population-based Manitoba Health Registry by age, gender, and geographic residence matching to the cases (n = 433). Subjects were administered a multiitem questionnaire. RESULTS: By univariate analysis, some of the variables predictive of CD included lower likelihood of living on a farm, of having drunk unpasteurized milk or having eaten pork, and UC patients were less likely to have drunk unpasteurized milk and to have eaten pork. On multivariate analysis, variables significantly associated with CD were being Jewish (OR = 4.32, 95% CI 1.10-16.9), having a first degree relative with IBD (OR = 3.07, 95% CI 1.73-5.46), ever having smoked (OR = 1.54, 95% CI, 1.06-2.25), living longer with a smoker (OR = 1.03, 95% CI, 1.01-1.04). Being a first generation Canadian (OR = 0.33, 95% CI, 0.17-0.62), having pet cats before age 5 (OR = 0.66, 95% CI, 0.46-0.96) and having larger families (OR = 0.87, 95% CI, 0.79-0.96) were protective against CD. For UC being Jewish (OR = 7.46, 95% CI, 2.33-23.89), having a relative with IBD (OR = 2.23, 95% CI, 1.27-3.9), and ever smoking (OR = 1.62, 95% CI, 1.14-2.32) were predictive. CONCLUSION: This study reinforced the increased risk associated with family history, being Jewish, and smoking history, however, a number of significant associations with CD and UC on univariate and multivariate analysis may support the "hygiene hypothesis" and warrant further exploration in prospective studies.

Adolescent↗

PubMed2005

Treatment of AIDS-associated Kaposi's sarcoma in Zimbabwe: results of a randomized quality of life focused clinical trial.

Kaposi's sarcoma is currently the most common tumor in Zimbabwe. The purpose of our study is to compare the effectiveness of supportive care vs. 3 intervention approaches, namely oral Etoposide, a 3-drug combination, and radiotherapy using quality of life (QOL) as the primary measure of success. In addition, our study was to determine whether a disease-specific module has greater sensitivity to group differences than a generic QOL questionnaire and to determine the most pragmatic approach to treating epidemic Kaposi's sarcoma (EKS) in Zimbabwe. Histologically confirmed HIV-positive patients with Kaposi's sarcoma were randomized to receive supportive care only or supportive care plus either radiotherapy, oral Etoposide or a 3-drug combination consisting of actinomycin-D, vincristine and bleomycin. No patient received antiretroviral therapy. The primary outcome was QOL measured by the functional living index-cancer (FLI-C) and supplemented by the Kaposi's sarcoma module (KSM). From 1994-1999, 495 EKS patients were accrued, and 470 were evaluable. Of these, 433 are known to be dead, 26 are lost to follow-up and 11 are still alive. The group treated with oral Etoposide had a significantly better QOL than the radiotherapy group for the total FLI-C score (adjusted mean plus standard error at 3-months 89 +/- 3 vs. 76 +/- 3; p = 0.004) and for the hardship (11 +/- 0.4 vs. 9 +/- 0.4; p = 0.001); social (10 +/- 0.4 vs. 8 +/- 0.4; p = 0.001) and nausea (9 +/- 0.4 vs. 8 +/- 0.4; p = 0.002) subscales. In addition, on the physical and psychological subscales, the Etoposide group had a significantly better QOL than the other 3 treatment groups (p < 0.04). The 3-drug combination, supportive care and radiotherapy groups did not differ significantly from each other with respect to the total FLI-C score or its subscales. There were no group differences with respect to survival. Oral Etoposide therapy resulted in better total FLI-C QOL score than radiotherapy. As well, Etoposide resulted in better physical and psychological subscale scores than radiotherapy, 3-drugs and supportive care. Thus, funds permitting, oral Etoposide is a pragmatic approach to treating EKS in an environment where antiretroviral drugs are not universally available. The study underscores the value of undertaking studies in areas of disease prevalence and the necessity of selecting appropriate outcome measures.

Acquired Immunodeficiency Syndrome↗

PubMed2005

Defining the predictors of the placebo response in irritable bowel syndrome.

BACKGROUND AND AIMS: We sought to determine the components of irritable bowel syndrome (IBS) clinical trials that correlate with higher levels of placebo response. METHODS: We performed a systematic review of placebo-controlled trials in patients with IBS to assess which variables correlate with a higher placebo response. Placebo responses for global symptom improvement and for decreased abdominal pain were assessed. Univariate and multiple linear regression analyses were conducted. RESULTS: Higher rates of global improvement correlated with frequency of administration of study intervention ( r = .31, P = .03), duration of the study ( r = .28, P = .04), and overall treatment effect of the active agent being studied ( r = .33, P = .02). Higher rates of decreased abdominal pain correlated with the frequency of intervention ( r = .39, P = .02) and overall treatment effect ( r = .40, P = .01), whereas lower placebo response rates correlated with year of the study ( r = -.36, P = .03), median age ( r = -.38, P = .04), and duration of study run-in period ( r = -.33, P = .04). On multivariate analysis, global improvement in the placebo group was associated significantly with intervention frequency ( P = .0079), overall treatment response ( P = .0031), and parallel study design ( P = .0044). Decreased abdominal pain was associated significantly with frequency of intervention ( P = .0061) and overall treatment response ( P = .0128). CONCLUSIONS: In IBS studies, higher placebo response rates correlated with frequency of the intervention and with overall treatment effect of the active agent being studied. In designing IBS trials, it may be possible to minimize placebo response by less frequent dosing. In treating patients with IBS, it may be possible to harness the placebo response and maximize therapeutic response rates by more frequent dosing.

Clinical Trials as Topic↗

PubMed2005

Cyclin D expression in chronic lymphocytic leukemia.

Although the majority of circulating leukemic cells in chronic lymphocytic leukemia (CLL) are in G0/early G1, recent studies have shown that these cells have undergone multiple cell divisions. In this study, we have determined whether there are abnormalities in cell cycle control in CLL by examining the three cyclin D isoforms in 43 patients and correlating the findings with clinical features. Cyclin D mRNA was measured by a sensitive RNase protection assay and the order of expression in CLL cells was D3 > D2 > D1. The mean cyclin D1 and D3 mRNA levels were 4 to 6-fold higher in CLL cells than in normal peripheral blood B cells. In contrast, the levels of cyclin D2 mRNA were similar in CLL and normal B cells. Expression of the cyclin D isoforms was two- to four-fold greater in normal T cells than B cells, and the order of expression for both cell types was D2 > D3 > D1. The relative overexpressions of cyclins D1 and D3 in CLL were unrelated to gene amplification, as assessed by Southern blotting, but structural changes in the genes were seen in four patients. Both cyclin D1 and D3 mRNA levels correlated positively with lymphocyte doubling time (LDT) and inversely with Rai stage and duration of disease. In addition, a significant correlation was observed between cyclin D mRNA levels and survival, with patients having high levels of cyclin D1, and to a lesser extent cyclin D3, mRNA having the best survival. Thus, cyclin D1 and D3 are relatively overexpressed in CLL cells and patients with higher levels have low stage disease, long LDT and prolonged survival. Further studies should evaluate the predictive value of cyclin D measurements in comparison to other prognostic markers in CLL.

Adult↗

PubMed2005

Interleukin-10 blunts the human inflammatory response to lipopolysaccharide without affecting the cardiovascular response.

OBJECTIVE: The objective of this study was to assess the efficacy of variations in dose and timing of administration of recombinant human IL-10 (rhIL-10) on inflammatory and cardiovascular responses in a human endotoxemia model of sepsis. DESIGN: The authors conducted a randomized, placebo-controlled, double-blind trial. SETTING: The study was conducted in a procedure room of an intensive-care unit. PARTICIPANTS: The study comprised 24 healthy male volunteers. INTERVENTIONS: Interventions consisted of intravenous administration of rhIL-10 at 1, 10, or 25 microg/kg either 2 mins or 2 hrs before Escherichia coli lipopolysaccharide (4 ng/kg) or placebo. MEASUREMENTS AND RESULTS: The placebo group receiving lipopolysaccharide alone demonstrated significant, time-dependent changes in vital signs, white blood cell counts, inflammatory cytokine/cortisol levels, and hemodynamic/cardiovascular (including echocardiographic) parameters over the duration of the study. rhIL-10, administered immediately before (concurrent) lipopolysaccharide resulted in decreased temperature and heart rate responses as well as decreased serum levels of proinflammatory cytokines (tumor necrosis factor-alpha, IL-6), IL-1 receptor antagonist, cortisol, and total leukocytes/neutrophils compared with lipopolysaccharide alone. Dose-dependent effects were absent. In contrast, rhIL-10 administration 2 hrs before endotoxin augmented the endotoxin-induced IL-beta and IL-1 receptor antagonist response. rhIL-10 failed to modulate major cardiovascular responses (cardiac output, stroke volume index, ejection fraction, peak systolic pressure/end-systolic volume ratio) to endotoxin in both study groups as assessed by echocardiography. CONCLUSION: Concurrent administration of rhIL-10 suppresses the human inflammatory/stress response but has no effect on the hemodynamic/cardiovascular response to endotoxin. Early administration of rhIL-10 can potentially augment elements of the cytokine inflammatory response to lipopolysaccharide. These findings suggest significant limitations of rhIL-10 as a potential immunomodulatory therapy for sepsis.

Adolescent↗

PubMed2005

Evaluation of education in palliative care: determining the effects on nurses' knowledge and attitudes.

Our study was an evaluation of a pilot course in palliative nursing care designed to improve practising nurses' knowledge regarding cancer pain management and attitudes toward care of the dying patient. The course involved 12 weeks (36 hours) of systematic classroom instruction for registered nurses, and a one-day observational experience on a designated palliative care unit. A total of 16 nurses participated in the study. A repeated measures design was used to evaluate the effectiveness of the course. Attitudes toward care of the dying patient and his/her family were also evaluated. Results showed that nurses' attitudes improved significantly from Time 1 (first day of course) to Time 2 (last day of course) (p=0.0007), and that this improvement was maintained at Time 3 (three months later) (p=0.064). The observational experience on a palliative care unit held in conjunction with the course was reported to be helpful to students in consolidating theoretical instruction.

Analysis of Variance↗

PubMed2005

Familial seropositive rheumatoid arthritis in North American Native families: effects of shared epitope and cytokine genotypes.

OBJECTIVE: A number of North American native (NAN) populations have high prevalence rates of both rheumatoid arthritis (RA) and the shared epitope (SE). We examined the phenotype and familial incidence of RA in a NAN population, and investigated how the SE and cytokine genes may affect disease risk within affected families. METHODS: NAN patients with seropositive RA or polyarthritis rheumatoid factor (RF) positive juvenile idiopathic arthritis (JIA) were identified from clinical databases. Patients were recruited consecutively as they presented for clinic visits. Family pedigrees were constructed and consenting relatives were interviewed and examined. The risk of RA within families was calculated by multiple logistic regression. Input variables were the SE and cytokine genotypes. Probands and affected relatives were entered as the affected group, and unaffected relatives within families as the unaffected group. Results were confirmed among unrelated subjects, i.e., unrelated patients and unaffected relatives of other probands. RESULTS: The familial prevalence of RA was 0.50 (95% confidence intervals 0.30, 0.70) among 28 families studied. The interleukin 10 (IL-10) promoter -1082 G/A genotype decreased the odds of RA relative to the A/A genotype in affected families (OR 0.247, 95% CI 0.081, 0.751; p = 0.014) and among unrelated subjects (OR 0.203, 95% CI 0.064, 0.640; p = 0.006). The G/G genotype yielded an OR of 0.093 (95% 0.013, 0.676; p = 0.019) among unrelated subjects. The SE had no effect in these calculations. CONCLUSION: There was a high familial prevalence of RA in this NAN cohort. In susceptible NAN families, the risk of RA was reduced by IL-10 genotypes, whereas the SE did not affect risk. Study of healthy NAN controls is required to determine if these conclusions apply to this NAN population as a whole.

Adolescent↗

PubMed2004

Predictors of pain in children with established juvenile rheumatoid arthritis.

OBJECTIVE: To examine demographic and disease-related variables that affect pain in a large cohort of patients with juvenile rheumatoid arthritis (JRA). METHODS: Selection criteria were an onset of JRA >/=5 years prior to study and age >/=8 years at the time of the study. Pain was measured by a self-administered 10-cm visual analog scale. Possible explanatory variables studied included age at study, sex, race, onset subtype, active disease duration, active joint count, and physician's global assessment (PGA). RESULTS: In a multiple regression model, active disease duration, PGA, and age at study were independent predictors explaining 22% of the variation in pain scores. Stratified analyses showed an effect of age in the 8-15-year group, but not in older patients. CONCLUSION: Disease-related factors explain only a small proportion of the variation in pain scores. Age has an effect on pain scores only in younger patients. The role of other factors, including psychosocial factors, needs further study.

Adolescent↗

PubMed2004

Effect of large volume infusion on left ventricular volumes, performance and contractility parameters in normal volunteers.

OBJECTIVE: Characterize the normal human cardiovascular response to large volume infusion of normal saline. DESIGN: Prospective, interventional trial. SETTING: ICU procedure room. PARTICIPANTS: Healthy male volunteers ( n=32). INTERVENTIONS. Volumetric echocardiography during 4-L saline infusion (3 L over 3 h followed by 1 L over 2 h). MEASUREMENTS AND RESULTS: Following 3-L saline infusion, stroke volume and cardiac output increased approximately 10% without a significant change in heart rate or blood pressure. A decrease in end-systolic volume contributed to the increase in stroke volume to an extent similar to that provided by the increase in end-diastolic volume. All contractility indices except end-systolic wall stress/end-systolic volume index were increased at 3 h post-initiation of saline infusion. Stroke volume but not cardiac output remained elevated at 5 h with persistence of ventricular volume responses; only ejection fraction was significantly elevated among the contractility indices. Afterload measures including total peripheral resistance and end-systolic wall stress were significantly decreased after 3-L infusion but were unchanged compared to baseline following infusion of an additional 1 L over 2 h. Modeled blood viscosity studies demonstrate that changes in apparent contractility after 3-L saline infusion can be explained solely by viscosity reduction associated with hypervolemic hemodilution. CONCLUSION: The initial increase in stroke volume associated with high volume saline infusion in normal volunteers is associated with increases of most load-dependent and ostensibly load-independent parameters of left ventricular contractility. This phenomenon is unlikely to represent a true increase in contractility and appears to be caused by reduced afterload as a consequence of decreased blood viscosity. This decrease in blood viscosity may complicate analysis of some previous in vivo studies examining the effect of volume loading on cardiac function using low-viscosity solutions.

Adult↗

PubMed2004

Preload-independent mechanisms contribute to increased stroke volume following large volume saline infusion in normal volunteers: a prospective interventional study.

INTRODUCTION: Resuscitation with saline is a standard initial response to hypotension or shock of almost any cause. Saline resuscitation is thought to generate an increase in cardiac output through a preload-dependent (increased end-diastolic volume) augmentation of stroke volume. We sought to confirm this to be the mechanism by which high-volume saline administration (comparable to that used in resuscitation of shock) results in improved cardiac output in normal healthy volunteers. METHODS: Using a standardized protocol, 24 healthy male (group 1) and 12 healthy mixed sex (group 2) volunteers were infused with 3 l normal (0.9%) saline over 3 hours in a prospective interventional study. Individuals were studied at baseline and following volume infusion using volumetric echocardiography (group 1) or a combination of pulmonary artery catheterization and radionuclide cineangiography (group 2). RESULTS: Saline infusion resulted in minor effects on heart rate and arterial pressures. Stroke volume index increased significantly (by approximately 15-25%; P < 0.0001). Biventricular end-diastolic volumes were only inconsistently increased, whereas end-systolic volumes decreased almost uniformly. Decreased end-systolic volume contributed as much as 40-90% to the stroke volume index response. Indices of ventricular contractility including ejection fraction, ventricular stroke work and peak systolic pressure/end-systolic volume index ratio all increased significantly (minimum P < 0.01). CONCLUSION: The increase in stroke volume associated with high-volume saline infusion into normal individuals is not only mediated by an increase in end-diastolic volume, as standard teaching suggests, but also involves a consistent and substantial decrease in end-systolic volumes and increases in basic indices of cardiac contractility. This phenomenon may be consistent with either an increase in biventricular contractility or a decrease in afterload.

Adolescent↗

PubMed2004

Role of myeloid cell factor-1 (Mcl-1) in chronic lymphocytic leukemia.

The primary abnormality in chronic lymphocytic leukemia (CLL) is a defect in apoptosis, probably related to alterations in the expressions of Bcl-2 family members. In transgenic mice over expressing the anti-apoptotic Bcl-2 family member, myeloid cell factor-1 (Mcl-1), B cell lymphomas occur. Moreover, mice conditional for the loss of Mcl-1 display a profound reduction in B and T lymphocytes. This suggests that Mcl-1 is an essential survival factor in lymphocytes. In the present study, we have evaluated the role of Mcl-1 in CLL. Mcl-1 protein expression was measured by Western blot analysis in the CLL cells of 45 patients and correlated with clinical variables and survival. Mcl-1 levels were similar in 29 patients to normal B and T lymphocytes, were decreased in 8 patients and increased in 12 patients. An inverse correlation was found between Mcl-1 expression and Rai stage (P = 0.001). When assessed by flow cytometry, Mcl-1 expressions were normally distributed among CLL cells in individual patients and the mean levels correlated with those obtained by Western blotting. To evaluate the role of Mcl-1 in drug resistance, Mcl-1 levels were sequentially measured in the leukemic cells of 4 CLL patients during therapy with fludarabine (Flu). The Mcl-1 levels were found to increase in 2 patients while the peripheral blood lymphocyte counts dropped, suggesting that the residual drug-resistant cells had the highest Mcl-1 levels. Primary CLL cells were also treated with chlorambucil (CLB) or Flu in vitro and the Mcl-1 levels decreased correlating with the sensitivity of these cells to undergo apoptosis. Drug sensitivities of the CLL cells to CLB and Flu were also measured by MTT assay and the concentrations of drug required to decrease cell viability by 50% (IC50) varied from 1.9 to 9.27 microM for Flu (median, 9.4 microM) and 10 to 32.5 microM (median, 5.5 microM) for CLB. The sensitivities of the leukemic cells to CLB correlated inversely with Mcl-1 levels (P < 0.05). These results suggest that Mcl-1 may contribute to cell survival in CLL.

Adult↗

PubMed2004

Variable ventilation improves perioperative lung function in patients undergoing abdominal aortic aneurysmectomy.

BACKGROUND: Optimizing perioperative mechanical ventilation remains a significant clinical challenge. Experimental models indicate that "noisy" or variable ventilation (VV)--return of physiologic variability to respiratory rate and tidal volume--improves lung function compared with monotonous control mode ventilation (CV). VV was compared with CV in patients undergoing abdominal aortic aneurysmectomy, a patient group known to be at risk of deteriorating lung function perioperatively. METHODS: After baseline measurements under general anesthesia (CV with a tidal volume of 10 ml/kg and a respiratory rate of 10 breaths/min), patients were randomized to continue CV or switch to VV (computer control of the ventilator at the same minute ventilation but with 376 combinations of respiratory rate and tidal volume). Lung function was measured hourly for the next 6 h during surgery and recovery. RESULTS: Forty-one patients for aneurysmectomy were studied. The characteristics of the patients in the two groups were similar. Repeated-measures analysis of variance (group x time interaction) revealed greater arterial oxygen partial pressure (P = 0.011), lower arterial carbon dioxide partial pressure (P = 0.012), lower dead space ventilation (P = 0.011), increased compliance (P = 0.049), and lower mean peak inspiratory pressure (P = 0.013) with VV. CONCLUSIONS: The VV mode of ventilation significantly improved lung function over CV in patients undergoing abdominal aortic aneurysmectomy.

Aged↗

PubMed2004

Pulmonary artery occlusion pressure and central venous pressure fail to predict ventricular filling volume, cardiac performance, or the response to volume infusion in normal subjects.

OBJECTIVE: Pulmonary artery occlusion pressure and central venous pressure have been considered to be reliable measures of left and right ventricular preload in patients requiring invasive hemodynamic monitoring. Studies in recent years have questioned the correlation between these estimates of ventricular filling pressures and ventricular end-diastolic volumes/cardiac performance variables in specific patient groups, but clinicians have continued to consider the relationship valid in the broader context. The objective of this study was to assess the relationship between pressure estimates of ventricular preload (pulmonary artery occlusion pressure, central venous pressure) and end-diastolic ventricular volumes/cardiac performance in healthy volunteers. DESIGN: Prospective, nonrandomized, nonblinded interventional study. SETTING: Cardiac catheterization and echocardiography laboratories. SUBJECTS: Normal healthy volunteers (n = 12 group 1, n = 32 group 2). INTERVENTIONS: Pulmonary catheterization and radionuclide cineangiography (group 1) and volumetric echocardiography (group 2) during 3 L of normal saline infusion over 3 hrs. MEASUREMENTS AND MAIN RESULTS: In group 1, the initial pulmonary artery occlusion pressure and central venous pressure did not correlate significantly with initial end-diastolic ventricular volume indexes or cardiac performance (cardiac index and stroke volume index). Changes in pulmonary artery occlusion pressure and central venous pressure following saline infusion also did not correlate with changes in end-diastolic ventricular volume indexes or cardiac performance. In contrast, initial end-diastolic ventricular volume indexes and changes in these ventricular volume indexes in response to 3 L of normal saline loading correlated well with initial stroke volume index and changes in stroke volume index, respectively. The relationship between left ventricular end-diastolic volume index and stroke volume index was confirmed in group 2 subjects using mathematically independent techniques to measure these variables. In addition, initial central venous pressure, right ventricular end-diastolic volume index, pulmonary artery occlusion pressure, and left ventricular end-diastolic volume index failed to correlate significantly with changes in cardiac performance in response to saline infusion in group 1 subjects. CONCLUSIONS: Normal healthy volunteers demonstrate a lack of correlation between initial central venous pressure/pulmonary artery occlusion pressure and both end-diastolic ventricular volume indexes and stroke volume index. Similar results are found with respect to changes in these variables following volume infusion. In contrast, initial end-diastolic ventricular volume indexes and changes in end-diastolic ventricular volume indexes in response to saline loading correlate strongly with initial and postsaline loading changes in cardiac performance as measured by stroke volume index. These data suggest that the lack of correlation of these variables in specific patient groups described in other studies represents a more universal phenomenon that includes normal subjects. Neither central venous pressure nor pulmonary artery occlusion pressure appears to be a useful predictor of ventricular preload with respect to optimizing cardiac performance.

Adolescent↗

PubMed2003

Early predictors of longterm outcome in patients with juvenile rheumatoid arthritis: subset-specific correlations.

OBJECTIVE: To determine early predictors of longterm outcome in juvenile rheumatoid arthritis (JRA) in a multicenter cohort. METHODS: Patients were selected if they were > or = 8 years of age; the onset of arthritis occurred > or = 5 years before study; and a diagnosis of JRA was made at a participating center. Outcome variables were scores on self-administered Childhood Health Assessment Questionnaires (CHAQ) and active disease duration. Possible explanatory variables assessed included characteristics present at onset, HLA alleles, in particular the rheumatoid arthritis associated shared epitope (RASE), and radiographic indicators of joint damage within 2 years of onset. Data for 393 patients were available. Multivariate analyses were performed for the total group and for each onset subtype. RESULTS: Male sex correlated with worse disability in systemic onset JRA but less disability in RF negative, and a shorter active disease duration in RF positive polyarticular onset JRA. Positive antinuclear antibody correlated with a longer active disease duration in patients with pauciarticular onset JRA. Younger age at onset predicted longer active disease duration in pauciarticular and RF negative polyarticular, and a shorter active disease duration in systemic onset JRA. Residence on a reserve, rather than native North American race, correlated with worse disability. The RASE correlated with less disability in systemic JRA; but no correlation with outcome was evident for patients with rheumatoid factor positive polyarticular JRA. CONCLUSION: Variables predictive of longterm outcome in JRA are specific for each onset subtype. The most important early predictors were age at onset and sex of the patient. Place of residence may have a greater effect on disability than race. RASE may associate with a more favorable outcome in systemic onset disease.

Adolescent↗

PubMed2003

Radiologic outcome and its relationship to functional disability in juvenile rheumatoid arthritis.

OBJECTIVE: To determine the radiologic outcome in juvenile rheumatoid arthritis (JRA) and the relationship of radiologically detected joint damage to functional disability using multivariate analyses. METHODS: Selection criteria included a diagnosis of JRA made by 1977 American College of Rheumatology criteria, onset of arthritis > or = 5 years prior to study, current age > or = 8 years, a minimum grade 3 reading ability, and the availability of radiographs. Disability was measured by the Childhood Health Assessment Questionnaire (CHAQ) and Steinbrocker classifications. Radiographs taken within 2 years after onset (early) and the most recent radiographs (late) were examined by a single pediatric radiologist blinded to patients' identities, diagnoses, and outcomes. Multiple regression analyses were performed. RESULTS: On late radiographs the frequencies of joint space narrowing were 38, 14, 43, and 79%, respectively, among patients with systemic, pauciarticular, rheumatoid factor (RF) negative polyarticular, and RF positive polyarticular onset; erosions occurred in 63, 25, 39, and 75%, respectively. Early erosions were most frequent in patients with RF+ polyarticular onset, while both joint space narrowing and erosions occurred early in systemic onset. Radiologic signs of joint damage were most frequent at hips and wrists, while knees and ankles were relatively spared. Based on patients who had radiographs performed within one year of clinical study, 17.7% of the variation in CHAQ score was explained by joint space narrowing, 32.4% by pain, and 5% by a severe rating on physician's global estimate of disease activity. The odds of a Steinbrocker class > I were increased by joint space narrowing, pain, systemic onset, and active joint count. CONCLUSION: Differences in the frequencies and patterns of joint damage occur both among JRA onset subtypes and among individual joints. Radiographic damage, especially joint space narrowing, correlates with functional disability. However, pain is the major contributor to variation in CHAQ scores.

Activities of Daily Living↗