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Biomedical subjects

O Dagan

Publications and source records attributed to O Dagan.

At least 19 recordsLinked to original sources
PubMed2003

Nosocomial infections after cardiac surgery in infants and children: incidence and risk factors.

This prospective study was undertaken to determine the spectrum, sites and main risk factors for hospital-acquired infections (HAI) in our paediatric cardiothoracic intensive care unit (PCICU), and to determine the main organisms causing bloodstream infection in this setting. All patients admitted between January and December 1999 were prospectively followed for the development of HAI. To define risk factors, patients were grouped by age, complexity score, length of stay in PCICU, and whether the patient's chest was open or closed postoperatively. Three hundred and thirty-five patients underwent cardiac surgery. Fifty-five patients acquired 69 HAIs (HAI patient rate 16.4%). The most common HAI were bloodstream and surgical wound infection in 10 and 8%, respectively. The main causative organisms were Klebsiella spp.,Enterobacter spp. and Pseudomonas spp. in 22, 17 and 16% of episodes, respectively. Staphylococcus spp. accounted for 16% of episodes. The main risk factors for developing HAI were: neonatal age [P < 0.05, odds ratio (OR): 5.89, 95% confidence interval (CI): 2.96-11.58] prolonged PCICU stay (P < 0.05, OR: 6.82, 95% CI: 3.37-14.48), open chest postoperatively (P < 0.05, OR: 3.44, 95% CI: 1.31-8.52) and high complexity score (P < 0.05, OR: 4.03 95% CI: 1.87-8.43). The main causative organisms of bloodstream infections in children hospitalized in the PCICU differ from those in adult and pediatric general intensive care units (ICUs) and include mainly Gram-negative bacilli. High complexity score, neonatal age, prolonged ICU stay, and open chest postoperatively are risk factors of HAI in this patient population.

Catheterization, Central Venous↗
PubMed2002

Plasma vascular endothelial growth factor level is a predictor of the severity of postoperative capillary leak syndrome in neonates undergoing cardiopulmonary bypass.

Capillary leak syndrome (CLS), characterized by extravascular fluid accumulation and significant organ dysfunction, is a serious complication in children undergoing cardiopulmonary bypass (CPB). We examined the relationship between plasma vascular endothelial growth factor (VEGF) levels and severity of CLS. The kinetics of VEGF in the plasma of 11 neonates and 7 older children undergoing CPB were investigated, correlating plasma VEGF levels and CLS clinical presentation. The degree of postoperative CLS was quantified by measuring parameters of extracellular volume and end-organ dysfunction. A chest-wall soft-tissue-width index (CSTWI) was designed in order to standardize the extracellular fluid accumulation. Most CLS parameters were significantly more prominent in the neonatal patients. Low plasma VEFG levels (>35 pg/ml) were found in 3 neonatal control patients and all but, sample from the older group patient. The neonates had significantly higher preoperative VEGF plasma levels (684.4 +/- 559.1 pg/ml, P = 0.02), which decreased during the operation to levels below 35 pg/ml and increased again 24 h postoperatively to levels significantly higher than in the older patients (484 +/- 270.3 pg/ml, P = 0.001). Multilinear regression analysis found preoperative VEGF levels to independently correlate with CLS as represented by CSTWI (P < 0.01, r = 0.726). Both the occurrence of post-CPB CLS and plasma VEGF levels pre- and postoperatively were thus higher in neonates than in children. Plasma VEGF level is a predictor of the severity of postoperative CLS.

Capillary Leak Syndrome↗
PubMed2001

Beta-chemokine secretion patterns in relation to clinical course and outcome in children after cardiopulmonary bypass: continuing the search to abrogate systemic inflammatory response.

BACKGROUND: Surgery involving cardiopulmonary bypass (CPB) is frequently accompanied by a systemic inflammatory response partly triggered by neutrophils and monocyte-macrophages. Certain cytokines that are powerful leukocyte-chemotactic factors have recently been characterized and shown to be important in evoking inflammatory responses: monocyte chemoattractant protein-1 (MCP-1) has monocyte-macrophage chemotactic activity, and regulated-upon-activation normal T-cell expressed and secreted (RANTES) has a potent chemoattractant activity for mononuclear phagocytes. This prospective cohort study investigated possible roles of these chemokines in the inflammatory response to CPB and relationships between the changes in chemokine levels and the clinical course and outcome. METHODS: Systemic blood of 16 children undergoing CPB was collected after induction of anesthesia (base line); at 15 minutes after bypass onset; at CPB cessation; and at 1, 2, 4, 8, 12, and 24 hours afterward to measure MCP-1 and RANTES. RESULTS: The significant changes of plasma beta chemokine levels following CPB were associated with patient characteristics, operative variables, and postoperative course. Cardiopulmonary bypass of more than 2 hours, longer surgical times, inotropic support, and reoperation were associated with higher MCP-1 levels and lower RANTES levels. CONCLUSIONS: Our results suggest a relation between CPB-induced mediators and clinical effects, implying pathogenic roles for chemokines following CPB. These molecules should be considered as possible targets for therapeutic intervention.

Adolescent↗
PubMed2001

Soluble P-selectin and the postoperative course following cardiopulmonary bypass in children.

BACKGROUND: Cytokine-inducible leucocyte-endothelial adhesion molecules were shown to affect the postoperative inflammatory response following cardiopulmonary bypass (CPB). Soluble P-selectin (sP-selectin) is one of these molecules. We investigated the correlation between plasma sP-selectin levels and the intra- and postoperative course in children undergoing CPB. METHODS: Serial blood samples of 13 patients were collected preoperatively upon initiation of CPB and seven times postoperatively. Plasma was recovered immediately and frozen at - 70 degrees C until use. Circulating soluble selectin molecules were measured with a sandwich enzyme-linked immunoabsorbent assay technique. RESULTS: The significant post-CPB changes in sP-selectins plasma levels were associated with patient characteristics, operative variables and postoperative course. sP-selectin levels correlated significantly with surgery time, aortic cross-clamping time and inotropic support, as well as with the postoperative Pediatric Risk of Mortality score, hypotension and tachycardia. CONCLUSIONS: A relation between CPB-induced mediators and both early and late clinical effects is suggested. The up-regulation and expression of sP-selectin indicate neutrophil activation as a possible mechanism for the increase, and inhibiting it may reduce the inflammatory response associated with CPB.

Cardiopulmonary Bypass↗
PubMed2001

Circulating leptin levels after cardiopulmonary bypass in children.

OBJECTIVE: To characterize the dynamics of circulating leptin in children after cardiac surgery with cardiopulmonary bypass (CPB), which is known to induce a systemic inflammatory response. DESIGN: Investigative study. SETTING: University-affiliated tertiary care hospital. PARTICIPANTS: Eight children (age range, 3 months to 13 years) undergoing CPB to correct congenital heart disease. INTERVENTIONS: The time courses of leptin and cortisol levels were determined. Serial blood samples were collected from the arterial catheter or from the CPB circuit preoperatively; on termination of CPB; and at 2, 4, 8, 12, 18, and 24 hours postoperatively. Plasma was recovered immediately, divided into aliquots, and frozen at -70 degrees C until use. Leptin was measured by a human leptin radioimmunoassay kit. MEASUREMENTS AND MAIN RESULTS: Leptin levels during CPB decreased to 50% of pre-CPB levels (p < 0.01). After termination of CPB, levels increased gradually and peaked at 12 hours postoperatively (10 P.M. to 1 A.M.). Cortisol levels were inversely correlated to leptin levels (p = 0.016). CONCLUSION: CPB is associated with acute changes in circulating leptin levels. These changes parallel those in cortisol, showing an inverse relationship between leptin and cortisol, suggesting a relationship between the neurobiology of these systems that could be important for the neuroendocrine response to CPB. A prognostic role of leptin and its relationship to cortisol after CPB warrant further study.

Adolescent↗
PubMed2001

Circulating leptin and the perioperative neuroendocrinological stress response after pediatric cardiac surgery.

OBJECTIVE: Leptin may be involved in the acute stress response, regulating inflammatory parameters of major importance after cardiopulmonary bypass (CPB) surgery. Critically ill patients demonstrated significant increases in leptin levels in response to stress-related cytokines (tumor necrosis factor, interleukin [IL]-1) and abolishment of the circadian rhythm of leptin secretion. We characterized the pattern of leptin secretion in the acute postoperative period in children undergoing cardiac surgery and compared the changes in leptin levels with concomitantly occurring changes in cortisol levels, IL-8, and clinical parameters. DESIGN: Investigative study. SETTING: University-affiliated tertiary care hospital. PARTICIPANTS AND INTERVENTIONS: Twenty-nine consecutive patients, aged 6 days to 15 yrs, operated upon for the correction of congenital heart defects were studied. Surgery in 20 patients (group 1) involved conventional CPB techniques, and 9 (group 2) underwent closed-heart surgery. The time courses of leptin, cortisol, and IL-8 levels were determined. Serial blood samples were collected preoperatively, on termination of CPB, and at six time points postoperatively. Plasma was recovered immediately, aliquoted, and frozen at -70 degrees C until use. MEASUREMENTS AND MAIN RESULTS: The leptin levels in group 1 decreased during CPB to 51% of baseline (p <.001), then gradually increased, reaching 120% of baseline levels at 12-18 hrs postoperatively (p <.001), returning to baseline levels at 24 hrs (p <.01). In patients undergoing closed-heart surgery (group 2), leptin levels displayed a pattern resembling the first group: they decreased during surgery to 71% of baseline levels (p =.002) and showed a tendency to return to baseline thereafter. All group 1 patients' cortisol levels increased significantly during the first hour of surgery, then decreased, returning to baseline levels at 18-24 hrs postoperatively. There was a significant negative correlation between leptin and cortisol levels (r = -2.8, p <.01). In group 2, cortisol levels increased during and after surgery, peaking 4 hrs postoperatively and decreasing thereafter. IL-8 levels determined in 15 group 1 patients increased significantly during CPB, peaked at the end of surgery, and then decreased but remained slightly elevated even at 48 hrs postoperatively. There was a significant correlation between cortisol and IL-8 levels (r = 2.55, p <.05). Children with leukocytosis, tachycardia, and hypotension had lower leptin levels and less variation over time as opposed to those with an uncomplicated course. CONCLUSIONS: CPB is associated with acute changes in circulating leptin levels. These changes parallel those in cortisol, demonstrating an inverse relationship between leptin and cortisol. Further studies of the prognostic and therapeutic roles of leptin after CPB should be investigated.

Adolescent↗
PubMed2001

Superior vena cava syndrome following neonatal cardiac surgery.

OBJECTIVE: To review the incidence, diagnosis, and management of superior vena cava syndrome (SVCS) after surgery for congenital heart disease. DESIGN: Retrospective clinical review. All patients were computer registered. Our database includes daily follow-up. SETTING: Pediatric cardiac surgery intensive care unit in a university hospital. PATIENTS: A total of 1853 consecutive pediatric cardiac operations performed in 285 neonates and 1568 older children from 1993 to 1999 are reviewed. MEASUREMENTS AND MAIN RESULTS: The diagnosis of SVCS was suspected clinically: Color changes and swelling of the upper part of the body, confirmed by echo-Doppler, showed no or minimal flow in the superior vena cava at the beginning and collateral flow later on. Nine patients developed SVCS (0.5%). All the study patients were neonates. The prevalence of SVCS in our neonatal patients was 3.15% (nine of 285), with no SVCS in older children. Accompanying complications included chylothorax (five), hydrocephalous (four)-three of whom required ventriculoperitoneal shunt during follow-up. Thrombolytic therapy was used in five patients, and thrombectomy was used in one patient. The ventilation period ranged from 4 to 46 days (mean 20.1 days), and the length of hospital stay ranged from 37 to 120 days (mean 61.3 days). No mortality was observed during follow-up. CONCLUSIONS: SVCS is an uncommon, severe complication following neonatal cardiac surgery. It may cause chylothorax, hydrocephalus, and severe respiratory complications leading to high morbidity. Early diagnosis and thrombolytic therapy may prevent the progression of this syndrome to its subsequent sequels.

Journal Article↗
PubMed2000

Pectoralis major muscle flap for deep sternal wound infection in neonates.

BACKGROUND: Deep sternotomy wound infections during the neonatal period, their management utilizing the pectoralis major muscle flap (PMF), and their follow-up are reported. METHODS: Seven hundred-twenty consecutive pediatric cardiac operations performed from 1995 to mid 1998 in 108 neonates and 612 infants are reviewed. Nine children (1.25%), 6 neonates and 3 infants, developed deep sternotomy wound infections and underwent PMF reconstruction. The 6 neonates are reviewed. Their follow-up includes growth and development reports, physical examination, and computerized tomographic scans of the chest. RESULTS: The incidence of sternal wound complications in our neonatal patients (5.5%, 6 of 108) was significantly higher than in the infantile group (0.5%, 3 of 612), (p = 0.0001, odds ratio = 11.94). Five neonates were treated with a unilateral, turnover PMF reconstruction. One patient was treated by a bilateral rotational PMF. All sternal wounds healed successfully, and all patients survived. In a follow-up period, ranging from 6 to 31 months (mean 16.5 months), the growth and development of all operated neonates was as expected for their age. There were no signs of chronic sternal infection in any of them. CONCLUSIONS: Early recognition of sternal wound complications should facilitate surgical treatment. Utilizing the PMF promotes rapid wound healing and preservation of life in these severely ill neonates, with minimal developmental problems.

Adolescent↗
PubMed2000

Plasma-soluble E-selectin after cardiopulmonary bypass in children: is it a marker of the postoperative course?

OBJECTIVE: To investigate the relationship and possible role of soluble adhesion molecule E-selectin in the postoperative course in children undergoing cardiopulmonary bypass (CPB). DESIGN: Prospective cohort study. SETTING: Pediatric intensive care unit of a university hospital. PARTICIPANTS: Thirteen children who were candidates for cardiac surgery. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Serial blood samples of 13 CPB patients were collected from the arterial catheter or from the bypass circuits preoperatively; on initiation of CPB; on termination of CPB; and 1, 2, 4, 8, 12, 18, 24, and 48 hours postoperatively. Plasma was recovered immediately, aliquoted, and frozen at -70 degrees C until use. Circulating soluble selectin molecules were measured with a sandwich enzyme-linked immunosorbent assay technique. There were significant changes in plasma levels of soluble E-selectins in patients after CPB, and these levels were associated with patient characteristics, operative variables, and postoperative course. Soluble E-selectin correlated significantly with inotropic support and the use of anti-inflammatory drugs. There was a significant association between the development of postoperative sepsis and soluble E-selectin levels. No correlation was found between soluble E-selectins and duration of CPB, aortic cross-clamping, or hemodynamic variables, including heart rate and mean systemic arterial pressure. CONCLUSION: These results suggest a relationship between CPB-induced mediators and early and late clinical effects. Although the mechanism for the increase of soluble E-selectin remains to be elucidated, the upregulation of soluble E-selectin indicates neutrophil activation, and its inhibition may represent a target for reducing the inflammatory response associated with CPB.

Cardiopulmonary Bypass↗
PubMed2000

Septic emboli caused by vascular catheters after surgery for congenital heart disease.

OBJECTIVE: To review the incidence, diagnosis, and management of septic emboli caused by vascular catheters after surgery for congenital heart disease. DESIGN: Retrospective clinical review. All patients were computer registered. Our database includes daily follow-up and every sign of infection registered. SETTING: Pediatric cardiac surgery intensive care unit in a university hospital. PATIENTS: A total of 720 consecutive pediatric cardiac operations performed in 108 neonates and 612 older children from 1995 to 1997 are reviewed. MEASUREMENTS AND MAIN RESULTS: Septic emboli were defined as erythematous non-tender papulonodular hemorrhagic lesions restricted to the limb and distal to the monitoring catheter. Four patients (0.55%) with catheter-related septic emboli after congenital heart surgery were identified, three neonates (0.41%) and one older infant (0.14%). The incidence of catheter-related septic emboli in our patients was significantly higher in the neonatal group compared with older infants (p = .0076; odds ratio=17.45). All infants with catheter-associated septic emboli were severely ill and required prolonged intensive care management postoperatively for periods ranging from 27 to 90 days (mean, 50 days). The catheters involved were in place for periods ranging from 5 to 7 days. All patients were treated by catheter removal and intravenous antibiotics without surgical intervention in the vascular access area. The affected limbs healed well without residual damage. CONCLUSIONS: Septic emboli are a rare complication of infected vascular catheters in neonates and small infants undergoing prolonged postoperative intensive care management (0.55%). They may indicate the source of unexplained sepsis involving mainly Gram-negative bacilli. Generally, treatment consists of removal of the offending catheter and antibiotic administration with no need for surgical intervention.

Bacteremia↗
PubMed2000

Increased levels of basic fibroblast growth factor are found in the cross-clamped heart during cardiopulmonary bypass.

BACKGROUND: High concentrations of fibroblast growth factors (FGFs) are found in the heart. Even higher levels are measured during ischemia. Exogenous administration of FGF to ischemic myocardium promotes synthesis of collateral coronary circulation and induces local myocardial hypertrophy. The kinetics and the contribution of the heart and lungs to circulating basic FGF (bFGF) levels during cardiac surgery were characterized. PATIENTS AND METHODS: Plasma bFGF levels were measured in seven adults undergoing coronary artery bypass operations and 11 neonates undergoing congenital cardiac anomaly repair during cardiopulmonary bypass. RESULTS: In both the adult and the neonatal groups, bFGF plasma levels increased significantly immediately after removal of the aortic cross-clamp (adult group 15.43+/-6.3 aorta cross-clamped versus 29+/-4.1 after release, P=0.011; neonatal group 17.09+/-9.43 aorta cross-clamped versus 43.55+/-14.25 after release, P=0.004) and declined thereafter. In the adult group, higher levels of bFGF were recorded in blood recovered from the coronary sinus than in the aortic root during aortic cross-clamping (63.14+/-14.42 versus 43.86+/-12.05, P=0.011), and in both, levels were significantly higher than the peripheral measurements. CONCLUSIONS: Plasma bFGF levels increase during cardiopulmonary bypass. The source of this elevation is the lungs and heart.

Aged↗
PubMed2000

Anomalous origin of the left coronary artery from the pulmonary artery: diagnosis and postoperative follow up.

BACKGROUND: Anomalous origin of the left coronary artery from the pulmonary artery is a rare congenital malformation that presents a diagnostic challenge to the pediatrician and pediatric cardiologist. Although surgical repair is always indicated, the optimal technique has yet to be determined. OBJECTIVES: To review our experience with the diagnosis of children with ALCAPA and to assess short to midterm surgical results. METHODS: Between 1992 and 1998, 13 infants and children (2 months to 15 years) were treated for ALCAPA at our medical center. Eight were diagnosed during the first year of life; all were symptomatic and had severe dysfunction of the left ventricle. The five patients diagnosed at an older age had normal myocardial function. Diagnosis was established by echocardiography alone in seven patients; six required catheterization (one infant and all older patients). Surgery was performed in 12 patients to establish dual coronary artery system: 7 underwent the Takeuchi procedure and 5 had re-implantation of the anomalous left coronary artery. RESULTS: One infant died shortly after diagnosis before surgical repair was attempted, and one died postoperatively. Four patients required additional surgery: three for late complications of the Takeuchi procedure and one valve replacement for mitral insufficiency. Recent evaluation revealed good global left ventricle function in all patients except for one, who is still within the recovery phase and shows gradual improvement. However, most patients who presented with severe myocardial dysfunction upon diagnosis still display abnormal features such as echo-dense papillary muscles or evidence of small akinetic segments. In this group, early repair was associated with faster myocardial recovery. CONCLUSIONS: The diagnosis of ALCAPA remains a clinical challenge to the pediatrician and cardiologist. Diagnosis can be established echocardiographically, and early diagnosis and treatment may lead to faster myocardial recovery. The preferred surgical method appears to be re-implantation of the ALCA. The chance for good recovery of global ventricular function is high even in the sickest patients, nonetheless abnormal myocardial features can be identified even years after surgery.

Adolescent↗
PubMed2000

The Ross operation: initial Israeli experience.

BACKGROUND: The need for aortic valve replacement in children and young adults poses a special problem to cardiologists and surgeons. Replacing the sick aortic valve with the patient's pulmonary valve as described by Ross has proven to be a good option in this special age group. OBJECTIVE: To review our initial experience in order to assess the short-term results. METHODS: From January 1996 to June 1999, 40 patients (age 8 months to 41 years) underwent aortic valve replacement with pulmonary autograft. Indications for surgery were congenital aortic valve disease in 30 patients, bacterial endocarditis in 5, rheumatic fever in 3, and complex left ventricular outflow tract obstruction in 3. Trans-esophageal echocardiography was performed preoperatively and post-bypass in all patients, and transthoracic echocardiography was done prior to discharge and on follow-up. RESULTS: There was no preoperative or late mortality. All patients remain in functional class I (New York Heart Association) and are free of complications and medication. None showed progression of autograft insufficiency or LVOT obstruction. Homograft insufficiency in the pulmonary position has progressed from mild to moderate in one patient, and three developed mild homograft stenosis. CONCLUSIONS: The Ross procedure can be performed with good results in the young population and is considered an elegant surgical alternative to prosthetic values and homografts.

Adolescent↗
PubMed1999

Nosocomial infection following cardiovascular surgery: comparison of two periods, 1987 vs. 1992.

OBJECTIVE: To evaluate whether changes have occurred at our center in the rate of nosocomial infections and in the infectious organisms consequent to changes in policy and procedure as of 1987. SETTING: Multidisciplinary pediatric intensive care unit (PICU) in a major tertiary care center. DESIGN: Prospective comparative study. PATIENTS: Four-hundred and fifty-five consecutive patients who underwent cardiac surgery within a 10-month period. INTERVENTIONS: Changes related to antibiotic use and invasive device management were introduced after the 1987 survey. To determine the effect of these changes, all patients undergoing cardiac surgery between July 1991 and April 1992 were followed daily from PICU admission to 2 months after hospital discharge for signs of infection. Each infectious episode was reviewed by the nosocomial infection control committee. A weighted scoring system was used to determine risk. MEASUREMENTS AND MAIN RESULTS: In the 1987 study, 40 of 310 patients had 78 infections for a nosocomial infection ratio (NIR) of 25.2. Of the 455 patients surveyed in 1992, 72 had 91 episodes of infection. The nosocomially infected patient rate was 15.8 and the NIR was 20. The frequency of wound infection decreased from 7% in 1987 to 4.3% in this study, and no episode of mediastinitis was observed. In the bacteriological spectrum, the absence of candidal infection was significant, and there was a decrease in the proportional frequency of pseudomonas infection from 21% to 15%. CONCLUSION: The comparison between the two time periods demonstrates that an aggressive approach to managing intravascular catheters and urinary catheters and limiting the use of antibiotics probably affects the spectrum of nosocomial infections.

Cardiovascular Surgical Procedures↗