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V Guru

Publications and source records attributed to V Guru.

11 recordsLinked to original sources
PubMed2004

The role of N-acetylcysteine in preventing radiographic contrast-induced nephropathy.

INTRODUCTION: There have been many small randomized controlled trials evaluating the effectiveness of N-acetylcysteine (NAC) in preventing radiographic contrast-induced nephropathy. Most studies have suggested a beneficial NAC effect. This meta-analysis describes the effect of NAC in the prevention of radiographic contrast-induced nephropathy in the aggregated trial data. METHODS: A search using MEDLINE from 1966 to December 2003 identified all randomized control trials that evaluated NAC in those patients at risk of acute renal failure (ARF) following either angiographic or CT scan contrast exposure. All studies included in the review employed the use of either low-osmolar (n = 9 trials) or iso-osmolar (n = 2 trials) contrast agents. The outcome of interest was ARF as defined by a rise in serum creatinine (Cr > or = 0.5 mg/dl rise or > 25% increase from baseline) after exposure to contrast. The data were aggregated by the methods of Mantel and Haenszel. RESULTS: The overall summary odds ratio estimate of 0.46 (95% confidence interval 0.32 - 0.66) suggests a strong protective effect of NAC in preventing radiographic-induced nephropathy. CONCLUSION: In summary, there is good aggregate trial evidence to suggest that patients who have an elevated serum creatinine level at baseline benefit from receiving periprocedure NAC in the prevention of contrast-induced ARF.

Acetylcysteine↗
PubMed2001

The radial artery versus the saphenous vein graft in contemporary CABG: a case-matched study.

BACKGROUND: Although use of the internal thoracic artery has been shown to improve outcomes after coronary artery bypass grafting, the same cannot be said of alternative arterial conduits. To determine the benefit of radial artery (RA) grafting, a case-matched review was undertaken. METHODS: Between March 1994 and March 1999, 2,847 patients underwent isolated coronary artery bypass grafting with a left internal thoracic artery graft, plus saphenous vein grafts (SVGs). Of these patients, 478 also received an RA graft (RA group). The RA patients were matched at a ratio of 1:2 with patients receiving only SVGs and a left internal thoracic artery graft (SVG group; n = 956) using six prognostic risk factors: age, sex, Canadian Cardiovascular Society class, left ventricular grade, number of diseased vessels, and timing of operation. Target vessels were graded according to quality and graftability and were similar between groups. Outcomes were evaluated by univariate and multivariate analyses. RESULTS: There was a significantly higher prevalence of diabetes, hypertension, and peripheral vascular disease in the RA group (p < 0.05). Although stay in the intensive care unit was shorter in the RA group (RA, 30 +/- 2 hours, and SVG, 37 +/- 2 hours; p = 0.0002), total hospital stay was similar between groups. The incidence of perioperative myocardial infarction was higher in the SVG group (SVG, 31 of 956 or 3.2%, and RA, 6 of 478 or 1.3%; p = 0.02). Multivariate analysis revealed RA grafting to be protective against early mortality and morbidity (odds ratio = 0.58; 95% confidence interval, 0.37 to 0.90; p = 0.015) and late mortality and morbidity including late reintervention (risk ratio = 0.60; 95% confidence interval, 0.37 to 0.93; p = 0.02). Actuarial freedom from events at 36 months postoperatively was greater in the RA group (RA, 95% +/- 2%, and SVG, 86% +/- 4%; p = 0.01). CONCLUSIONS: Despite a higher prevalence of preoperative comorbidity, patients in the RA group demonstrated improved outcomes after coronary artery bypass grafting. The RA is a viable and beneficial conduit for this operation.

Case-Control Studies↗
PubMed2001

Renal dysfunction after cardiac surgery.

OBJECTIVE: To assess the causes and outcomes of patients with postcardiac surgery renal dysfunction. PATIENTS AND METHODS: A large cardiovascular data- base including pre-, peri- and postoperative serum creatinine concentrations from 2214 consecutive cardiac surgery patients was analyzed. RESULTS: Sixty-nine patients developed postoperative renal dysfunction, defined as at least a 15 mL/min decline in the creatinine clearance rate resulting in a value of less than 40 mL/min. These patients were significantly older, and had a higher incidence of previous cardiac surgery, diabetes, obesity, peripheral vascular disease, hypertension and poor ventricular function. Postoperatively, these patients had a higher occurrence of low output syndrome and myocardial infarction. Stepwise logistic regression predictors of postoperative renal dysfunction included the following: postoperative low output syndrome; repeat cardiac surgery; being older than 65 years; having diabetes; having poor left ventricular function; and having had valve surgery. Preoperative renal dysfunction (defined as a creatinine clearance of less than 40 mL/min) was not found to be one of the predictors. The mean creatinine concentrations of patients with mild postoperative renal dysfunction (defined as a creatinine concentration of less than 200 mmol/L on the fourth or fifth postoperative day) decreased significantly at the fifth postoperative day, while that of patients with severe postoperative renal dysfunction rose to a mean of 300 mmol/L six months postoperatively. The incidence of late dialysis (defined as a need for dialysis after postoperative day 10) approached 30% among patients with severe postoperative renal dysfunction and only 2% among patients with mild postoperative renal dysfunction. The early mortality rate (during the first postoperative month) was similar in both groups and approached 30%. CONCLUSIONS: Patients who develop postoperative renal dysfunction have a high mortality rate. Postoperative low cardiac output is the most important cause of postoperative renal dysfunction and, therefore, should be avoided. Patients with creatinine concentrations of less than 200 mmol/L at postoperative day 4 or 5 will probably resume normal renal function. Patients with creatinine concentrations of more than 200 mmol/L at days 4 and 5 have a 30% chance of needing long term dialysis.

Age Distribution↗
PubMed2000

Right and left ventricular systolic function late after repair of tetralogy of Fallot.

Right ventricular (RV) dysfunction has adverse effects on long-term outcome in patients with repaired tetralogy of Fallot (TOF). We employed serial radionuclide angiography (RNA) to examine RV and left ventricular (LV) systolic function in adults late after TOF repair and its relation to clinical outcome. We reviewed 10-year records of 95 patients (53 men) with TOF followed in our clinic (mean age at repair 12.6 +/- 10.5 years, mean age at last follow-up 37.7 +/- 9.8 years) who underwent at least 2 RNAs between 1987 and 1997. Most patients were well by the end of the study (80% were New York Heart Association class I, 17% were class II, and 3% were in class III). Sixteen patients experienced sustained tachyarrhythmias (8 had atrial; 8 patients had ventricular). One patient died suddenly. Fifteen patients underwent RV outflow reoperations (15 underwent pulmonary valve replacement; 7 had relief of RV outflow obstruction); RV systolic function during exercise in these 15 patients was significantly impaired before and returned to similar levels after surgery, compared with the rest of the patients. Overall, RV and LV function remained stable in the whole group at a mean interval of 5.7 +/- 2.2 years between first and last RNA. This group of closely followed adults with TOF remained well over 10 years with a low incidence of sudden death and stable RV and LV systolic function, despite a relatively large number of RV outflow reoperations. Aggressive intervention for right-sided hemodynamic abnormalities may have contributed to this outcome. Preserved ventricular function may herald a favorable long-term outlook in this group.

Adult↗
PubMed2000

Trends in coronary artery bypass surgery results: a recent, 9-year study.

BACKGROUND: The demographics of patients undergoing coronary artery bypass grafting (CABG) have changed over time and may contribute to differing operative mortality and the combination of mortality and morbidity (M + M). In this study, the trends in results are analyzed and causes are suggested. METHODS: Prospectively collected data concerning 4,839 CABG operations was divided into three time cohorts (1990 to 1992, 1993 to 1995, 1996 to 1998) and analyzed by univariate and multivariate techniques. RESULTS: Mean age and female gender frequency increased in the later time cohorts (60.7 +/- 9.0 to 63.4 +/- 9.9 years and 16.5% to 21.4%, respectively). The following comorbidities were more prevalent in the later time cohorts: diabetes (26.7% versus 18.6%), renal failure (8.5% versus 2.2%), peripheral vascular disease (20.7% versus 11.0%), previous cerebrovascular accident (6.7% versus 5.0%), urgent procedures (41.5% versus 26.9%), unstable angina (47.8% versus 31.7%), urgent CABG following myocardial infarction (17.1% versus 7.3%), previous percutaneous transluminal coronary angioplasty (8.0% versus 4.5%), ejection fraction less than 35% (20.5% versus 10.4%), (all p < 0.05). Procedurally, increased utilization of the left internal mammary artery, multiple arterial conduits, and warm blood cardioplegia occurred in the later cohorts (91.2%, 22.2%, and 80.4% versus 78.7%, 3.4%, and 38.0%, respectively). The mortality rate was 2.0% and the M + M rate was 15.6% in all 4,839 patients. The mortality and M + M for the three cohorts were 1.6%, 2.0%, and 2.3% and 18.4%, 17.2% and 12.5%, respectively. The risk-adjusted mortality and M + M decreased from 2.4% and 15.9%, respectively, in 1990 to 1992 to 1.8% and 8.4% in 1996 to 1998 (p < 0.001). The difference in adjusted event rates was minimized when the surgical factors were entered into the model. CONCLUSIONS: Over time, there has been a trend toward operating on older patients with more comorbidities. Though hospital mortality has been stable, risk-adjusted M + M has been in a constant decline. This decline was associated with an increased use of left internal mammary artery grafts, multiple arterial conduits, and warm blood cardioplegia during the later years of the study.

Aged↗
PubMed2000

The patient vs. caregiver perception of acute pain in the emergency department.

The assessment and management of acute pain is an essential part of care received in the emergency department (ED). This study was undertaken to measure how ED caregivers interpret and treat acute pain. A convenience cohort of 71 patients in a tertiary care teaching hospital were asked to rate their pain on arrival to the ED using a visual analog scale (VAS) and numerical rating scale (NRS). These ratings were compared with those given by their nurse and physician. Both physicians and nurses gave statistically significantly lower NRS and VAS pain ratings than those reported by the patients. Nurses' NRS pain ratings were found to be lower than physicians' ratings of the same patients. On chart review, no pain scale assessments were employed, and only one chart noted that a patient's pain had been relieved after treatment. Approximately half the patients (49%, n = 35) felt on discharge from the ED that their pain had not been relieved. Pain assessment and treatment in the ED appears to be inadequate. The integration of pain assessment before and after treatment is essential in monitoring the effectiveness of pain management in the ED.

Acute Disease↗
PubMed1999

Response of paramedics to terminally ill patients with cardiac arrest: an ethical dilemma.

BACKGROUND: In an environment characterized by cuts to health care, hospital closures, increasing reliance on home care and an aging population, more terminally ill patients are choosing to die at home. The authors sought to determine the care received by these patients when paramedics were summoned by a 911 call and to document whether do-not-resuscitate (DNR) requests influenced the care given. METHODS: The records of a large urban emergency medical services system were reviewed to identify consecutive patients with cardiac arrest over the 10-month period November 1996 to August 1997. Data were abstracted from paramedics' ambulance call reports according to a standardized template. The proportion of these patients described as having a terminal illness was determined, as was the proportion of terminally ill patients with a DNR request. The resuscitative efforts of paramedics were compared for patients with and without a DNR request. RESULTS: Of the 1534 cardiac arrests, 144 (9.4%) involved patients described as having a terminal illness. The mean age of the patients was 72.2 (standard deviation 14.8) years. Paramedics encountered a DNR request in 90 (62.5%) of these cases. Current regulations governing paramedic practice were not followed in 34 (23.6%) of the cases. There was no difference in the likelihood that cardiopulmonary resuscitation (CPR) would be initiated between patients with and those without a DNR request (73% v. 83%; p = 0.17). In patients for whom CPR was initiated, paramedics were much more likely to withhold full advanced cardiac life support if there was a DNR request than if there was not (22% v. 68%; p < 0.001). INTERPRETATION: Paramedics are frequently called to attend terminally ill patients with cardiac arrest. Current regulations are a source of conflict between the paramedic's duty to treat and the patient's right to limit resuscitative efforts at the time of death.

Adolescent↗
PubMed1999

Current status of transmyocardial laser revascularization: review of the literature.

BACKGROUND: Transmyocardial laser revascularization (TMLR) is a new procedure for the treatment of angina pectoris in which high power laser energy is used to create channels in ischemic myocardium. OBJECTIVE: To describe in detail the historical, experimental and state-of-the-art studies regarding TMLR. DATA SOURCES: The English-language literature published from 1966 to 1998 was thorougly searched in MEDLINE. Further information regarding unpublished data was obtained on request. STUDY SELECTION: The most important experimental studies and randomized prospective clinical trials were examined. Additional papers were selected to provide a historical perspective and future prospects of TMLR. DATA SYNTHESIS: Although the results of TMLR in terms of angina relief are impressive, the procedure is associated with significant mortality and morbidity, and the results of objective cardiac perfusion measurements such as radionucleic perfusion scans and positron emission tomography are not conclusive. Furthermore, little information is available concerning the effect of this procedure on life expectancy. This article reviews the historical background of TMLR and possible mechanisms by which it may work, and discusses existing evidence for and against the procedure and how it may be applied in the future. CONCLUSIONS: At present, TMLR is potentially indicated for patients with severe angina that is refractory to medical therapy and who have contraindications for the more traditional therapies (coronary artery bypass grafting, percutaneous transluminal coronary angioplasty and transplantation). More data are needed to evaluate fully the indications for this procedure.

Angina Pectoris↗
PubMed1996

Streptococcal toxic shock syndrome in dogs.

OBJECTIVE: To determine the clinical, pathologic, and bacteriologic findings in dogs that developed severe invasive infections with group G streptococci (GGS) over a 6-month period in southern Ontario. DESIGN: Prospective case series. ANIMALS: 7 dogs n southern Ontario with severe streptococcal infection during a 6-month period. PROCEDURE: Using pulsed-field gel electrophoresis, molecular typing of streptococcal isolates was performed. Isolates were examined for the M protein gene emm1.0, pyrogenic exotoxin genes speA, speB, speF, hyaluronic acid synthase genes hasA, hasB, and for C5a peptidase gene scpA by use of DNA probes or polymerase chain reaction. RESULTS: 3 dogs with streptococcal shock without necrotizing fasciitis died or were euthanatized within 48 hours of admission, whereas 4 dogs with streptococcal shock and necrotizing fasciitis survived following surgical debridement, supportive medical treatment, and treatment with antibiotics. Of the 6 Lancefield group G streptococcal isolates available for characterization, 5 were Streptococcus canis and 1 had characteristics of group G streptococcal strains of human origin. Results of molecular typing indicated that isolates were unrelated to each other. Examination of the canine isolates for putative virulence genes found in human group A streptococci resulted in identification of the emm1.0 gene only in 1 of the isolates. The canine isolates otherwise lacked virulence genes associated with human group A streptococcal toxic shock infections. CLINICAL-IMPLICATIONS: The development of severe invasive infection in dogs resulting from GGS indicates that a virulent form of GGS has developed in southern Ontario.

Animals↗
PubMedDate not supplied

Clinical results of endarterectomy of the right and left anterior descending coronary arteries.

In this study, we examined the clinical outcome of coronary endarterectomy. From 1990 to 1998, 4839 patients underwent surgical revascularization. Coronary artery bypass graft surgery (CABG) was performed alone on 4516 patients, was combined with right coronary artery endarterectomy (RCA-E) in 242 patients, and was combined with left anterior descending coronary artery endarterectomy (LAD-E) in 81 patients. An analysis of preoperative variables revealed a higher proportion of males (90.7% vs 80.2%, p < 0.001), of patients with low ejection fraction (< 35%; 4.6% vs 1.7%, p < 0.001), and of three-vessel disease (47.9% vs 36%, p < 0.001) in the RCA-E versus the CABG patients. There was a higher proportion of unstable angina (51.9% vs 40.3%, p = 0.04) in the LAD-E patients. The 30-day mortality rate for CABG was 2% versus 2.5% for RCA-E and 3.7% for LAD-E (p = NS). Perioperative myocardial infarction (MI) rate for CABG was 3.4% versus 7.0% for RCA-E (p < 0.001) and 4.9% for LAD-E patients (p = NS). Postoperative low cardiac output syndrome was recorded in 11.5% of CABG, 18.6% of RCA-E (p = 0.01), and 11.1% of LAD-E (p = NS) patients. Predictors of postoperative bad outcome (death, MI, low cardiac output, cerebrovascular accident) were preoperative intra-aortic balloon pump, repeat operation, ejection fraction of < 35%, renal insufficiency, female gender, RCA-E, and age over 70. Protective factors included the use of internal mammary artery, multiple arterial grafts, and warm cardioplegia. Actuarial analysis at 6, 12, and 24 months showed late mortality rates of 0.8%, 1.3%, and 2.1% for CABG; 1.2%, 3.7%, and 3.7% for RCA-E; and 2.9%, 2.9%, and 2.9% for LAD-E, respectively. Late MI occurrence was 0.4%, 0.4%, and 0.7% for CABG; 1.5%, 1.5%, and 2.7% for RCA-E; and 0% for LAD-E, respectively. Multivariate analysis found renal insufficiency, ejection fraction of < 35%, repeat operation, female gender, New York Heart Association functional class IV, and diabetes to be predictors for late adverse events (recurrence of angina, MI, and cardiac death), and RCA-E was found to be a predictor of late MI. We conclude that the use of coronary endarterectomy to achieve complete revascularization in patients with diffuse distal coronary artery disease is a reasonable option, associated with a minimal addition in complication rates.

Cause of Death↗