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Biomedical subjects

T Ryan

Publications and source records attributed to T Ryan.

At least 55 records · Page 3Linked to original sources
PubMed1998

Perioperative determinants of morbidity and mortality in elderly patients undergoing cardiac surgery.

OBJECTIVE: To determine perioperative predictors of morbidity and mortality in patients > or =75 yrs of age after cardiac surgery. DESIGN: Inception cohort study. SETTING: A tertiary care, 54-bed cardiothoracic intensive care unit (ICU). PATIENTS: All patients aged > or =75 yrs admitted over a 30-month period for cardiac surgery. INTERVENTION: Collection of data on preoperative factors, operative factors, postoperative hemodynamics, and laboratory data obtained on admission and during the ICU stay. MEASUREMENTS AND MAIN RESULTS: Postoperative death, frequency rate of organ dysfunction, nosocomial infections, length of mechanical ventilation, and ICU stay were recorded. During the study period, 1,157 (14%) of 8,501 patients > or =75 yrs of age had a morbidity rate of 54% (625 of 1,157 patients) and a mortality rate of 8% (90 of 1,157 patients) after cardiac surgery. Predictors of postoperative morbidity included preoperative intraaortic balloon counterpulsation, preoperative serum bilirubin of >1.0 mg/dL, blood transfusion requirement of >10 units of red blood cells, cardiopulmonary bypass time of >120 mins (aortic cross-clamp time of >80 mins), return to operating room for surgical exploration, heart rate of >120 beats/min, requirement for inotropes and vasopressors after surgery and on admission to the ICU, and anemia beyond the second postoperative day. Predictors of postoperative mortality included preoperative cardiac shock, serum albumin of <4.0 g/dL, systemic oxygen delivery of <320 mL/ min/m2 before surgery, blood transfusion requirement of >10 units of red blood cells, cardiopulmonary bypass time of >140 mins (aortic cross-clamp time of >120 mins), subsequent return to the operating room for surgical exploration, mean arterial pressure of <60 mm Hg, heart rate of >120 beats/min, central venous pressure of >15 mm Hg, stroke volume index of <30 mL/min/m2, requirement for inotropes, arterial bicarbonate of <20 mmol/L, plasma glucose of >300 mg/dL after surgery, and anemia beyond the second postoperative day. During the study period, the study cohort used 6,859 (21.5%) ICU patient-days out of a total 31,867 ICU patient-days. Nonsurvivors used 2,023 (30%) ICU patient-days and patients with morbidity used 5,903 (86%) ICU patient-days. CONCLUSIONS: Severe underlying cardiac disease (including shock, requirement for mechanical circulatory support, hypoalbuminemia, and hepatic dysfunction), intraoperative blood loss, surgical reexploration, long ischemic times, immediate postoperative cardiovascular dysfunction, global ischemia and metabolic dysfunction, and anemia beyond the second postoperative day predicted poor outcome in the elderly after cardiac surgery. Postoperative morbidity and mortality disproportionately increased the utilization of intensive care resources in elderly patients. Future efforts should focus on preoperative selection criteria, improvement in surgical techniques, perioperative therapy to ameliorate splanchnic and global ischemia, and avoidance of anemia to improve the outcome in the elderly after cardiac surgery.

Aged↗
PubMed1998

Perioperative predictors of acute cholecystitis after cardiovascular surgery.

OBJECTIVE: To determine the incidence, diagnostic features, and perioperative predictors of acute cholecystitis after cardiovascular surgery. DESIGN: Inception cohort study. SETTING: A tertiary care 54-bed cardiothoracic ICU. PATIENTS: All patients admitted to an ICU after cardiovascular surgery during a 42-month period. INTERVENTION: Collection of relevant preoperative, operative, and ICU data from a database and medical charts. PRIMARY OUTCOME: Postoperative acute cholecystitis (AC). RESULTS: Out of 11,330 admissions, 876 patients stayed in the ICU more than 7 days and 30 of them (3%) developed postoperative AC. AC was diagnosed a median of 26 days after cardiovascular surgery (interquartile range, 11 to 41 days). All patients with AC developed at least two criteria of the systemic inflammatory response syndrome (SIRS), and 16 of them (53%) were vasopressor-dependent on the day of diagnosis. Trends in biochemical testing of liver function were not diagnostic for AC. Death occurred in seven of 17 patients (41%) who underwent cholecystectomy, three of nine patients (33%) treated with percutaneous cholecystostomy, and one of four patients (25%) treated conservatively (p=not significant). Specific earlier predictors of AC were arterial vascular disease, preoperative oxygen delivery less than 430 mL/min x m2, longer times on cardiopulmonary bypass, surgical re-exploration, ICU course complicated by cardiac arrhythmia, mechanical ventilation > or = 3 days, bacteremia, and nosocomial infections. CONCLUSION: The incidence of AC is low after cardiovascular surgery. Although SIRS and hemodynamic instability were common at the time of diagnosis, the delayed occurrence and lack of specificity of these features for AC limited their utility for early diagnosis. Specific predictors of AC should be sought in the ICU setting to identify patients who are at risk for AC after cardiovascular surgery. When identified, such predictors can prompt earlier diagnosis and treatment. Further evaluation of the selection criteria for different treatment options is needed in order to decrease the morbidity and mortality associated with AC.

Acute Disease↗
PubMed1998

The effects of preoperative therapy with angiotensin-converting enzyme inhibitors on clinical outcome after cardiovascular surgery.

OBJECTIVE: To determine the effect of preoperative therapy with angiotensin-converting enzyme (ACE) inhibitors on clinical outcome after cardiovascular surgery. STUDY: Inception cohort. SETTING: A tertiary care 54-bed cardiothoracic ICU. PATIENTS: All admissions to an ICU over a 42-month period after cardiovascular surgery. INTERVENTION: Extraction of preoperative, operative, and ICU data from a database. OUTCOME MEASURES: Incidence of acute organ dysfunction, length of mechanical ventilation, ICU stay, and death after cardiovascular surgery. RESULTS: The study cohort consisted of four groups: normal or moderately impaired left ventricular function control (group A, n=6,400); normal or moderately impaired left ventricular function treated with ACE inhibitors (group B, n=1,375); severe left ventricular dysfunction control (group C, n=1,905); and severe left ventricular dysfunction treated with ACE inhibitors (group D, n=1,650). The incidence of three or more organ dysfunction was similar on comparison of group A vs group B (5% vs 6%) or group C vs group D (15% vs 13%). There were no differences in the total duration of mechanical ventilation or length of stay in the ICU in group A vs group B or group C vs group D. Death occurred in 2% of groups A and B, and at 6% in groups C and D. Preoperative severe left ventricular dysfunction in both groups C and D was associated with an increased incidence of three or more organ dysfunction, duration of mechanical ventilation, length of stay in ICU, and death after surgery. Multivariate analysis indicated that therapy with ACE inhibitors did not affect the clinical outcome after cardiovascular surgery. CONCLUSION: Preoperative therapy with ACE inhibitors did not influence the clinical outcome after cardiac surgery. It is unlikely that therapy with ACE inhibitors can alter the clinical sequelae of cardiopulmonary bypass and cardiac surgical procedures performed in high-risk patients because of underlying severe left ventricular dysfunction.

Aged↗
PubMed1997

Cognitive function 5 years after randomization to coronary angioplasty or coronary artery bypass graft surgery.

BACKGROUND: Coronary bypass surgery often leads to short-term cognitive dysfunction, whereas coronary angioplasty does not. Perioperative cognitive dysfunction usually resolves, although a subgroup of surgical patients may continue to exhibit long-term cognitive dysfunction. The purpose of this study was to compare cognitive function 5 years after randomization to a strategy of either initial coronary surgery or initial angioplasty. METHODS AND RESULTS: Five centers in the Bypass Angioplasty Revascularization Investigation participated in this ancillary study. Patients with multivessel coronary disease randomized to angioplasty or surgery were eligible at the time of their 5-year clinic visit. A battery of five measures previously shown to be sensitive to perioperative changes in cognitive function was administered, including the Logical and Figural Memory Scales from the Wechsler Memory Scale, the Digit Symbol and Digit Span subtests from the Wechsler Adult Intelligence Scale, and Part B of the Reitan Trail Making Test. The 125 study patients were generally similar to the 133 patients who were eligible but did not participate, although study participants were significantly younger (P=.003). The 64 patients randomly assigned to angioplasty had baseline characteristics similar to those of 61 patients randomly assigned to surgery. Cognitive function scores were not significantly different between angioplasty or surgery patients in an intention-to-treat analysis (P=.57). There also was no difference in cognitive function scores when the data were analyzed according to whether the patient had ever undergone bypass surgery (P=.59). CONCLUSIONS: Long-term cognitive function is similar after coronary bypass surgery and coronary angioplasty in the majority of patients.

Adult↗
PubMed1997

Functional expression of Fasciola hepatica cathepsin L1 in Saccharomyces cerevisiae.

A cDNA encoding the complete precursor of a Fasciola hepatica cathepsin L protease was isolated and sequenced. Functionally active enzyme was expressed and secreted by Saccharomyces cerevisiae transformed with a plasmid carrying the complete gene. Experiments with temperature-sensitive yeast mutants showed that the enzyme is trafficked through the yeast secretory pathway. Yeast transformed with a truncated gene, which lacked the pre-peptide-encoding and most of the pro-peptide-encoding sequences, did not express funtionally active enzyme. The yeast-expressed enzyme exhibited physicochemical properties in common with the native enzyme including, pH optimum for activity, stability at 37 degrees C and ability to cleave gelatin and immunoglobulin. Enzyme kinetic data showed that the native and yeast-expressed cathepsin L1 have similar specificities for substrates with hydrophobic residues in the P2 position. This is the first report of the functional expression of a cathepsin L proteinase in S. cerevisiae that did not require the use of yeast secretory signal sequences.

Animals↗
PubMed1997

Medical care costs and quality of life after randomization to coronary angioplasty or coronary bypass surgery. Bypass Angioplasty Revascularization Investigation (BARI) Investigators.

BACKGROUND: Randomized trials comparing coronary angioplasty with bypass surgery in patients with multivessel coronary disease have shown no significant differences in overall rates of death and myocardial infarction. We compared quality of life, employment, and medical care costs during five years of follow-up among patients treated with angioplasty or bypass surgery. METHODS: A total of 934 of the 1829 patients enrolled in the randomized Bypass Angioplasty Revascularization Investigation participated in this study. Detailed data on quality of life were collected annually, and economic data were collected quarterly. RESULTS: During the first three years of follow-up, functional-status scores on the Duke Activity Status Index, which measures the ability to perform common activities of daily living, improved more in patients assigned to surgery than in those assigned to angioplasty (P<0.05). Other measures of quality of life improved equally in both groups throughout the follow-up period. Patients in the angioplasty group returned to work five weeks sooner than did patients in the surgery group (P<0.001). The initial mean cost of angioplasty was 65 percent that of surgery ($21,113 vs. $32,347, P<0.001), but after five years the total medical cost of angioplasty was 95 percent that of surgery ($56,225 vs. $58,889), a difference of $2,664 (P = 0.047). The five-year cost of angioplasty was significantly lower than that of surgery among patients with two-vessel disease ($52,930 vs. $58,498, P<0.05), but not among patients with three-vessel disease ($60,918 vs. $59,430). After five years of follow-up, surgery had an overall cost-effectiveness ratio of $26,117 per year of life added, but unacceptable ratios of $100,000 or more per year of life added could not be excluded (P=0.13). Surgery appeared particularly cost effective in treating diabetic patients because of their significantly improved survival. CONCLUSIONS: In patients with multivessel coronary disease, coronary-artery bypass surgery is associated with a better quality of life for three years than coronary angioplasty, after the initial morbidity caused by the procedure. Coronary angioplasty has a lower five-year cost than bypass surgery only in patients with two-vessel coronary disease.

Angioplasty, Balloon, Coronary↗
PubMed1997

Isolation of a cDNA encoding Fasciola hepatica cathepsin L2 and functional expression in Saccharomyces cerevisiae.

Cathepsin L2 is a major cysteine proteinase secreted by adult Fasciola hepatica. The enzyme differs from other reported cathepsin Ls in that it can cleave peptide substrates that contain proline in the P2 position. A cDNA was isolated from an expression library by immunoscreening with antiserum prepared against purified native cathepsin L2. This cDNA was sequenced and shown to encode a complete preprocathepsin L proteinase. Functionally active recombinant cathepsin L proteinase was expressed and secreted by Saccharomyces cerevisiae transformed with the cDNA. The recombinant enzyme was purified from large-scale fermentation broths using ultrafiltration and gel filtration chromatography on Sephacryl S200 HR columns. NH2-terminal amino acid sequencing showed that the cleavage point for activation of the recombinant pro-enzyme is identical to that of the F. hepatica-produced cathepsin L2. The mature active recombinant proteinase behaved similarly to the native enzyme when analysed by SDS-PAGE, immunoblotting and zymography and also cleaved peptides containing proline in the P2 position. Finally, the recombinant cathepsin L2 cleaved fibrinogen to form a fibrin clot, a property we described for F. hepatica cathepsin L2.

Animals↗
PubMed1997

Evaluation of patterns of perfusion and metabolism in dobutamine-responsive myocardium.

OBJECTIVES: We investigated the patterns of perfusion and metabolism in dysfunctional myocardium whose contractility improved with dobutamine. BACKGROUND: Clinical studies have suggested that dobutamine echocardiography can identify hibernating myocardium, but laboratory studies suggest that reduced perfusion limits the response to dobutamine. METHODS: Twenty-five patients with coronary disease and ventricular dysfunction underwent low (5 and 10 micrograms/kg body weight per min) and high dose (maximum of 50 micrograms/kg per min) dobutamine echocardiography and positron emission tomography (PET) using nitrogen-13 (N-13) ammonia and fluorine-18 fluorodeoxyglucose (FDG) for imaging of perfusion and metabolism. Wall motion and tracer uptake were scored in 16 left ventricular segments. RESULTS: Perfusion and metabolism were normal in 56.4%, mildly reduced in 29.1% and mismatched (reduced perfusion, preserved FDG uptake) in 14.5% of dysfunctional segments viable on PET. Wall motion improved with dobutamine in 89 dysfunctional segments (62 at low dose, 27 only at peak dose), and 86 of these (97%) were viable on PET. Improvement in wall motion with dobutamine was more common in segments with normal perfusion and metabolism (56.5%) than in those with mildly reduced tracer uptake (28.5%, p < 0.001) and those with mismatch (32%, p = 0.03). All the segments with a biphasic response were supplied by vessels with > or = 70% stenosis, and 88% had normal perfusion and metabolism. CONCLUSIONS: The majority of viable segments with rest dysfunction had normal perfusion and metabolism, suggesting that myocardial stunning was common. Improvement of wall motion at low and high doses of dobutamine was highly correlated with myocardial viability on PET and was more common in myocardium with normal perfusion. A biphasic response to dobutamine identified segments with normal perfusion and metabolism supplied by severely diseased vessels.

Ammonia↗
PubMed1997

Improvement in inducible ischemia during dobutamine stress echocardiography after transmyocardial laser revascularization in patients with refractory angina pectoris.

OBJECTIVES: The purpose of this ongoing study is to determine whether transmyocardial laser revascularization (TMLR) can lessen inducible ischemia and improve contractile reserve in patients with refractory angina pectoris. BACKGROUND: TMLR is an emerging surgical technique for the treatment of myocardial ischemia and angina pectoris not amenable to conventional percutaneous or surgical revascularization. Objective data documentating a reduction in ischemia during noninvasive stress testing after TMLR are rare. METHODS: Fifteen patients with severe coronary artery disease unsuitable for treatment with standard revascularization techniques were studied with dobutamine stress echocardiography (DSE) before TMLR. Of the 12 patients who underwent TMLR, DSE was repeated at 3 months postoperatively in 11 patients and at 6 months in 9 patients. Stress echocardiograms were analyzed for inducible ischemia, with calculation of the wall motion score index (WMSI). Heart rate and dobutamine dose achieved at peak stress were also assessed as indexes of stress tolerance. RESULTS: Compared with that before TMLR, wall motion at rest for all myocardial segments did not change significantly after TMLR, although there was a mild improvement in the WMSI of the lased myocardial regions ([mean +/- SD] 1.64 +/- 0.34 after vs. 1.78 +/- 0.34 before TMLR, p < 0.05). Overall WMSI at peak stress improved markedly after TMLR (1.70 +/- 0.30 after vs. 2.06 +/- 0.31 before TMLR, p < 0.002), with the improvement in WMSI limited to the lased segments only (1.47 +/- 0.31 after vs. 2.15 +/- 0.34 before TMLR, p < 0.0004). The improvement in WMSI with stress resulted primarily from a decrease in the percentage of ischemic segments (47% before vs. 23% after TMLR, p < 0.0008), with no change in the percentage of infarcted segments (23% before vs. 26% after TMLR). Heart rate (83 +/- 5 beats/min before vs. 102 +/- 21 beats/min after TMLR, p = 0.01) and dobutamine infusion rate (26 +/- 9 micrograms/kg body weight per min before vs. 34 +/- 9 micrograms/kg per min after TMLR) achieved at peak stress also increased postoperatively, consistent with improved stress tolerance. The reduction in ischemic wall motion abnormalities and improved stress tolerance persisted at 6 months, without evidence of further improvement or deterioration of function over time. CONCLUSIONS: TMLR performed in patients with refractory angina pectoris reduces ischemic wall motion abnormalities and improves stress-induced tolerance during dobutamine echocardiography. These beneficial effects persist up to 6 months postoperatively.

Aged↗
PubMed1997

Role of echocardiography in evaluation of patients with Staphylococcus aureus bacteremia: experience in 103 patients.

OBJECTIVES: The purpose of this prospective study was to examine the role of echocardiography in patients with Staphylococcus aureus bacteremia (SAB). BACKGROUND: The reported incidence of infective endocarditis (IE) among patients with SAB varies widely. Distinguishing patients with uncomplicated bacteremia from those with IE is therapeutically and prognostically important, but often difficult. METHODS: One hundred-three consecutive patients undergoing both transthoracic (TTE) echocardiography and transesophageal (TEE) echocardiography were prospectively evaluated. All patients presented with fever and > or = 1 positive blood culture and were followed up for 12 weeks. RESULTS: Although predisposing heart disease was present in 42 patients (41%), clinical evidence of infective endocarditis (IE) was rare (7%). TTE revealed anatomic abnormalities in 33 patients, but vegetations in only 7 (7%), and was considered indeterminate in 19 (18%). TEE identified vegetations in 22 patients (aortic valve in 5, mitral valve in 9, tricuspid valve in 4, catheter in 2 and pacemaker in 2, abscesses in 2, valve perforation in 1 and new severe regurgitation in 1; 26 total [25%]). Using Duke criteria for the diagnosis of IE, definite IE was present in 26 patients (25%). Clinical findings and predisposing heart disease did not distinguish between patients with and without IE. The sensitivity of TTE for detecting IE was 32%, and the specificity was 100%. The addition of TEE increased the sensitivity to 100%, but resulted in one false positive result (specificity 99%). TEE detected evidence of IE in 19% of patients with a negative TTE and 21% of patients with an indeterminate TTE. At follow-up, cure of staphylococcal infection occurred in a similar percentage of patients with and without IE (77% and 75%, respectively). However, death due to sepsis was significantly more likely among patients with IE (4 of 26 [15%]) than among those without IE (2 of 77 [3%]) (p = 0.03). CONCLUSIONS: Our results suggest that IE is common among patients admitted to the hospital with SAB and is associated with an increased risk of death due to sepsis. TEE is essential to establish the diagnosis and to detect associated complications. Therefore, the test should be considered part of the early evaluation of patients with SAB.

Aged↗
PubMed1997

Preoperative therapy with amiodarone and the incidence of acute organ dysfunction after cardiac surgery.

UNLABELLED: We examined the influence of preoperative therapy with amiodarone on the incidence of acute organ dysfunction after cardiac surgery in a matched case-control study. There were 220 case-control pairs matched by day of surgery, source of admission, demographic characteristics, placement of intraaortic balloon pump before surgery, repeat operations, emergency surgery, thoracic aorta surgery and other surgical procedures. History of congestive heart failure was more prevalent in the amiodarone group than in the control group before surgery (60% vs 38%, P < 0.0001). The incidence of acute organ dysfunction, duration of mechanical ventilation, and death was similar in both groups after surgery. The requirement for inotropes (26% vs 17%, P = 0.03) and vasopressors (66% vs 55%, P = 0.02) and the incidence of postoperative nosocomial infections (12% vs 6%, P = 0.04) was greater in the amiodarone group. However, the difference was not significant after adjustment for congestive heart failure (Cochran-Mantel-Haenszel test P = 0.15, P = 0.25, P = 0.16, respectively). Amiodarone did not increase the incidence of acute organ dysfunction or death after cardiac surgery. The requirement for inotropes and vasopressors and the incidence of nosocomial infections were related to the severity of the underlying cardiac disease. The practice of discontinuing amiodarone treatment before surgery to reduce the incidence of postoperative organ dysfunction should be critically reevaluated. IMPLICATIONS: Amiodarone is often used for the treatment of life-threatening rhythm disorder. Amiodarone has been blamed for causing organ injury after cardiac surgery. In a study of 220 patients, amiodarone did not increase the risk of organ injury or death after cardiac surgery when compared with control patients. There was no evidence to support the practice of stopping amiodarone before cardiac surgery to avoid serious complications.

Acute Disease↗
PubMed1997

Early onset of acute pulmonary dysfunction after cardiovascular surgery: risk factors and clinical outcome.

OBJECTIVE: To define the incidence, risk factors, and clinical outcome of early pulmonary dysfunction after cardiovascular surgery for adults. STUDY: Inception cohort. SETTING: Adult cardiovascular intensive care unit (ICU). PATIENTS: All adult admissions after cardiovascular surgery without preoperative pulmonary parenchyma or vascular disease over a period of 12 consecutive months. INTERVENTION: Collection of data on demographics, preoperative organ insufficiency, emergency surgery, type of surgical procedure, cardiopulmonary bypass time, transfusion of blood products, postoperative arterial blood gases, and systemic hemodynamics on admission to the cardiovascular ICU. MEASUREMENTS AND MAIN RESULTS: Early postoperative pulmonary dysfunction was defined by mechanical ventilation with a PaO2/FIO2 ratio of < or = 150 torr (< or = 20 kPa) and chest radiography on admission to the cardiovascular ICU. Secondary outcome included postoperative renal and neurologic dysfunction, nosocomial infections, length of mechanical ventilation, hospitalization, and death. A total of 3,122 patients were evaluated and 1,461 patients satisfied the entry criteria of the study. Early postoperative pulmonary dysfunction was present in 180 (12%) patients on admission to the cardiovascular ICU. Preoperative variables: age of > or = 75 yrs (odds ratio 1.69, 95% confidence interval [CI] 1.06 to 2.65), body mass index of > or = 30 kg/m2 (odds ratio 1.60, 95% CI 1.09 to 2.32), mean pulmonary arterial pressure of > or = 20 mm Hg (odds ratio 1.60, 95% CI 1.13 to 2.28), stroke volume index of < or = 30 mL/m2 (odds ratio 1.57, 95% CI 1.08 to 2.26), serum albumin (odds ratio 0.71, 95% CI 0.49 to 0.97), history of cerebral vascular disease (odds ratio 1.81; 95% CI 1.08 to 2.96); operative variables: emergency surgery (odds ratio 2.12, 95% CI 1.01 to 4.51), total cardiopulmonary bypass time of > or = 140 mins (odds ratio 1.54, 95% CI 1.0 to 2.34); and postoperative variables (on admission to cardiovascular ICU): hematocrit of > or = 30% (odds ratio 2.46, 95% CI 1.71 to 3.56), systemic mean arterial pressure of > or = 90 mm Hg (odds ratio 1.67, 95% CI 1.13 to 2.42), and cardiac index of > or = 3.0 L/min/m2 (odds ratio 2.09, 95% CI 1.44 to 3.01) were predictors of early postoperative pulmonary dysfunction. Pulmonary dysfunction was associated with a postoperative increase of serum creatinine (1.36 +/- 0.4 vs. 1.24 +/- 0.4 mg/dL, p < .02), neurologic complications (3% vs. 1.6%, p < .001), nosocomial infections (3% vs. 1.6%, p < .001), prolonged mechanical ventilation (2.2 +/- 5.9 vs. 1.7 +/- 5.6 days, p < .001), length of stay in the cardiovascular ICU (4.4 +/- 12.2 vs. 2.6 +/- 6.2 days, p < .001) and hospital (14.8 +/- 13.1 vs. 10.5 +/- 8.0 days, p < .001), and death (4.4% vs. 1.6%, p < .001). CONCLUSIONS: The incidence of early postoperative pulmonary dysfunction is uncommon; however, once developed, it is associated with increased morbidity and mortality after cardiovascular surgery. Advanced age, large body mass index, preoperative increased pulmonary arterial pressure, low stroke volume index, hypoalbuminemia, history of cerebral vascular disease, emergency surgery, and prolonged cardiopulmonary bypass time are risk factors for early onset of severe pulmonary dysfunction after surgery. Postoperative hematocrit and systemic hemodynamics suggest that early postoperative pulmonary dysfunction can be a component of a generalized inflammatory reaction to cardiovascular surgery.

Aged↗
PubMed1997

Early bloodstream infection after cardiopulmonary bypass: frequency rate, risk factors, and implications.

OBJECTIVE: To determine the incidence, predisposing factors, and outcome of early bloodstream infection after cardiopulmonary bypass. DESIGN: A case control study. SETTING: A 54-bed cardiac surgical intensive care in a tertiary referral center. PATIENTS: Patients from a 30-month period with preoperative hospital stay of <48 hrs and subsequent bloodstream infection within 96 hrs of cardiopulmonary bypass were included in a case group. The control group consisted of patients who had cardiac surgery on the same day as the case group. MEASUREMENTS AND MAIN RESULTS: Patient demographics, history of comorbidity, preoperative laboratory testing, details of surgery, transfusion requirement, inotropic infusions, hemodynamics, and arterial blood gases on admission to intensive care were compared in the two groups. Measures of outcome were duration of mechanical ventilation and intensive care stay, serum creatinine on the first postoperative day, highest creatinine and bilirubin concentrations, and hospital mortality. During the study period, 7,928 patients had cardiac surgery. Sixteen (0.2%) patients had early bloodstream infection; the control group consisted of 95 patients. Thirteen of the patients with bloodstream infection had Gram-negative bacilli on blood culture, two had Candida species, and two had Gram-positive bacteria. On multivariate logistic regression analysis, greater prevalence of preoperative pulmonary hypertension (odds ratio 9; 95% confidence interval 2 to 41.8; p = .004), diabetes (odds ratio 4.6; 95% confidence interval 1.4 to 15.8; p = .01), number of blood products transfused (odds ratio 1.09; 95% confidence interval 1.04 to 1.17; p = .005), and infusion of inotropes (odds ratio 4.7; 95% confidence interval 1.3 to 16.4; p = .02) or vasopressors (odds ratio 4.1; 95% confidence interval 1.3 to 15.6; p = .02) were associated with postoperative bloodstream infection. Early bloodstream infection was associated with significantly prolonged duration of mechanical ventilation (117.2 +/- 21.5 vs. 18 +/- 8.8 hrs; p = .0001), intensive care stay (213 +/- 27.5 vs. 53 +/- 11.3 hrs; p < .0001), greater creatinine concentrations on the first postoperative day (1.6 +/- 0.1 vs. 1.2 +/- 0.04 mg/dL; p = .0002), greater maximum creatinine concentration (2.4 +/- 0.2 vs. 1.3 +/- 0.1 mg/dL; p < .0001), and greater maximum bilirubin concentration (4.7 +/- 0.6 vs. 1.3 +/- 0.2 mg/dL; p < .0001) when compared with the control group. Five (32%) of 16 bacteremic patients died vs. none of the 95 control patients (p < .0001). CONCLUSIONS: Early bloodstream infection after cardiac surgery is uncommon and involves predominantly Gram-negative bacteria. The risk factors associated with bloodstream infection were preoperative morbidity and more complex surgery. Bloodstream infection was associated with a significantly adverse impact on outcome after cardiac surgery.

Analysis of Variance↗
PubMed1997

The relationship between the supply of cardiac catheterization laboratories, cardiologists and the use of invasive cardiac procedures in northern New England.

OBJECTIVES: Utilization rates of coronary angiography and cardiac revascularization have been found to vary between areas. This study addresses the relationship between resource supply and procedure rates. METHODS: We compared the association of per capita catheterization laboratories, per capita cardiologists and multi-provider markets (where more than one hospital offers coronary angiography services) with the utilization rates for angiography and cardiac revascularization in northern New England, USA. Administrative data were used to capture invasive cardiac procedures. Small area analyses were used to create coronary angiography service areas. Linear regression methods were used to measure associations between the resource supply and utilization rates. RESULTS: Variation in the use of invasive cardiac procedures was strongly associated with the population-based availability of catheterization facilities and multi-provider markets and unrelated to cardiologist supply or need (as reflected in the hospitalization rates for myocardial infarction). In the multivariate model, an increase of 1 catheterization laboratory per 100,000 population was associated with an increase in the angiography rate of 1.62 per 1000 population; those service areas with multi-provider markets were associated with an additional increase in the angiography rate of 1.27 per 1000 population (R2 = 0.84, P = 0.0006). There was a moderately strong relationship between the catheterization laboratories per capita and the revascularization rates (R2 = 0.43, P = 0.029). Angiography rates were highly associated with cardiac revascularization rates: an increase in the angiography rate of 1 per 1000 population was associated with a 0.46 per 1000 increase in the cardiac revascularization rate (R2 = 0.85, P = 0.0001). CONCLUSIONS: Our work suggests that current efforts to address variation in cardiac procedures through activities such as appropriateness criteria, guidelines and utilization review are misdirected and should be redirected towards capacity, in this case the supply of catheterization facilities.

Cardiac Catheterization↗
PubMed1996

Evaluation using dobutamine stress echocardiography in patients with insulin-dependent diabetes mellitus before kidney and/or pancreas transplantation.

The purpose of this study was to examine the ability of dobutamine stress echocardiography to stratify patients with juvenile onset, insulin-dependent diabetes mellitus who are being considered for kidney and/or pancreas transplantation, into high-or low-risk groups for future cardiac events. Fifty-three such patients underwent dobutamine stress echocardiography before kidney and/or pancreas transplantation. Cardiac events, including cardiac death, nonfatal myocardial infarction, unstable angina, pulmonary edema, and need for coronary revascularization, occurring between the time of the dobutamine stress echocardiogram and the last patient follow-up contact were retrospectively identified. Twenty patients 938%) had an abnormal dobutamine stress echocardiogram. Eleven patients had 15 cardiac events over a mean (+/- SD) follow-up period of 418 +/- 269 days. Event rates were 45% among those with an abnormal, versus 6% among those with a normal dobutamine stress echocardiogram (p = 0.002). The result of the dobutamine stress test independently predicted prognosis in a multivariate analysis (p = 0.003, odds ratio = 12.7). We conclude that dobutamine stress echocardiography accurately stratifies patients with juvenile onset, insulin-dependent diabetes being considered for kidney and/or pancreas transplantation for risk of future cardiac events.

Adult↗