Comparison of bilateral cerebral and somatic tissue oxygenation with near-infrared spectroscopy in cyanotic and acyanotic pediatric patients receiving cardiac surgery.

INTRODUCTION: Compromise of tissue oxygenation during surgery is associated with increased mortality and morbidity in the postoperative period in patients with congenital cardiac disorders. It may be monitored with near-infrared spectroscopy (NIRS). We aimed to evaluate the tissue oxygenation and factors which may affect it by bilateral cerebral and somatic NIRS levels during cardiopulmonary bypass and to compare the NIRS values of cyanotic and acyanotic patient groups. MATERIAL AND METHODS: Two groups of patients with cyanotic and acyanotic congenital heart diseases were included in the study. Each group consisted of 15 patients between 0 and 5 years of age. All data were collected following anesthesia induction (T1), the 10th (T2) and 30th min (T3) of cardiopulmonary bypass (CPB), every 30 min during CPB (T4, T5, T6) and 1 h after (TS). Bilateral and somatic NIRS, blood gases, mean arterial pressure, and temperatures were recorded. RESULTS: Left and right somatic NIRS values in groups at all measurements did not differ significantly. Left and right cerebral NIRS values at T2 and T3 in cyanotic patients were significantly higher than in acyanotic patients. Mean arterial pressure and lactate levels at T1 and T3 measurements were responsible for left cerebral NIRS changes and mean arterial pressure on right cerebral NIRS values. CONCLUSIONS: Monitorization of tissue perfusion has critical importance during CPB of patients with congenital heart defects. Oxygenation may easily and reliably be measured with NIRS. Cerebral and somatic NIRS are more pronounced in cyanotic patients and cerebral NIRS is strongly associated with mean arterial pressure and circulating lactate levels.

Evaluation of Infection Resistance of Biodegradable versus Conventional Annuloplasty Rings in an in vivo Rat Subcutaneous Model.

BACKGROUND: Biodegradable atrioventricular annuloplasty rings are theoretically more infection resistant due to their intra-annular implantation technique and nonporous structures (monofilament of poly-1,4-dioxanone). The aim of this study was to investigate the infection resistance of a biodegradable annuloplasty ring (Kalangos-Bioring®) in a rat subcutaneous implantation model and to compare it with a commonly used conventional annuloplasty ring (Edwards Physio II®). METHODS: This study included 32 Wistar albino rats which were divided into 2 groups according to the implantation of sterile or infected annuloplasty rings as control and study groups. Each animal had 2 implantation pockets (made on the right and left side of the dorsal median line) where 1 cm of the biodegradable annuloplasty ring was implanted into one pocket and 1 cm of the conventional annuloplasty ring was implanted into the other pocket. The infection model was created by topical inoculation of 1 mL Staphylococcus aureus strain (2 × 107 colony-forming units/mL) into the implantation pockets before skin closure. Each group was equally divided into 4 subgroups according to different follow-up schedules. The animals were inspected for local as well as systemic infection signs, and the rings were explanted at weeks 2, 4, 9, and 14 following implantation. Implantation pockets were evaluated macroscopically as well as by histopathological examinations. Microbiological analysis of the explanted implants with surrounding tissue was done by using quantitative sonication method. RESULTS: Conventional ring-implanted pockets showed a more prominent inflammation reaction than the biodegradable ring-implanted pockets, and this characteristic was found to be accentuated with bacterial contamination. The sterile rings did not reveal any positive cultures in either group. The number of positive cultures found in conventional rings contaminated with S. aureus was greater than in the biodegradable ring group (11/16 vs. 2/16 positive cultures, respectively; p = 0.0032). The amounts of growing bacteria in the culture environment were also statistically significantly higher in the conventional ring group (7,175 ± 5,936 vs. 181 ± 130 colony-forming units/mL, respectively; p < 0.0005). CONCLUSIONS: This is the first experimental study confirming the theoretical advantage of the infection resistance of the biodegradable annuloplasty ring (Kalangos-Bioring®) when implanted in an active infectious environment. Large animal models mimicking clinical scenarios and clinical comparative studies are needed to verify our results.

Prevalence of congenital coronary artery anomalies as shown by multi-slice computed tomography coronary angiography: a single-centre study from Turkey.

Objective Coronary artery anomaly (CAA) is a remarkable etiological factor for sudden cardiac death in young adults. The incidence of CAA is unknown, with most reliable data available based on postmortem/angiography investigations. This study aimed to assess the prevalence of different forms of coronary anomalies, and to investigate the relationships between demographic data and occurrence of CAA. Methods A total of 2401 consecutive patients (1805 men; mean age, 56 ± 11.7 years), who were referred between January 2005 and December 2008 for noninvasive multi-slice computed tomography (MSCT) imaging, were retrospectively analysed. Results A total of 225 cases (191 men; mean age, 55.9 ± 12) of CAAs were identified (9.37%). Because 11 patients had multiple muscular bridges of the coronary arteries, 236 coronary artery anomalies were found in these 225 patients. Cases were classified into three groups: group 1, coronary anomalies of origin and distribution (n = 36, 1.5%); group 2, anomalies of intrinsic coronary arterial anatomy (n = 180, 7.49%); and group 3, anomalies of coronary termination (n = 9, 0.4%). Conclusion The prevalence of CAA was 9.37% in our single-centre study, which is consistent with previous research. A minimally invasive tool, such as MSCT angiography, should be used to identify CAA.

Revascularization in patients with severe left ventricular impairment who have ischemic heart disease.

OBJECTIVE: To assess the effect of coronary bypass grafting on left ventricular (LV) function, exercise capacity and symptom profile in patients with LV impairment and retrospectively evaluate the role of the different factors affecting LV. METHODS: A total of 45 patients (33 men, 12 women, mean age 63.49 +/- 7.38 years) with LV ejection fraction of less than 0.32 were admitted to the Istanbul University, Cardiology Institute, Istanbul, Turkey between January 2001 to June 2003 for coronary bypass operation. Preoperative and postoperative wall motion, functional class (New York Heart Association) and risk factors were analyzed. RESULTS: We had one perioperative mortality (2.2%) and 2 early postoperative mortality (4.4%) due to poor cardiac function. There was a significant increase in the mean LV ejection fraction from 26.64 +/- 5.17 to 32.98 +/- 6.38 (p<0.001) postoperatively. In this group the mean New York Heart Association grade improved from 2.07 +/- 0.76 to 1.5 +/- 0.79 (p<0.001). Preoperative functional class, congestive heart failure, arrhythmia, age, pre/postoperative complications were the main predictors of poor outcome following surgical revascularization for ischemic cardiomyopathy. CONCLUSION: In patients with severe LV impairment with myocardial hibernation, coronary artery bypass grafting improves both global and regional LV function and symptom profile. We therefore, recommend a coronary artery bypass grafting as an alternative to orthotopic heart transplantation whenever myocardial viability are documented.

Prospective evaluation of platelets prepared by single and random methods during 5 days of storage: aspects related to quality and quantity.

Platelets, which have an important role in hemostatic mechanisms and which were prepared by single and random methods were investigated to measure quantity, and aggregation response during 5 days of storage. The aggregation response and quantitative values of platelet concentrates (PCs), 60 of which were prepared by a single donor method and 62 by a random method were investigated during the 1st, 3rd, and 5th days of storage. The single donor platelets (SDP) were obtained by using the MCS Plus apheresis device and the random donor platelets (RDP) were obtained by two-phase centrifugation in the Heraeus 8500i centrifuge device (during the first phase, platelet rich plasma was obtained then platelet concentrate was obtained from this product) and were stored at 22 degrees C on a circular agitator. In addition, pH, PO2, PCO2, glucose and lactate values were measured in order to evaluate the effects of storage. The aggregation response was measured using adenosine diphosphate (ADP), epinephrine (EPN), collagen (COLL) and ristocetin (RIST). The cell count in mm3 and the total cell count were also measured. The total cell counts and cells in mm3 of the PCs which were prepared by the single donar method on the 1st, 3rd and 5th days, were: 3.11 x 10(11), 3.09 x 10(11), 3.07 x 10(11) and 292 x 10(3), 290 x 10(3), 289 x 10(3) and of those prepared by the random method were: 5.71 x 10(10), 5.69 x 10(10), 5.66 x 10(10) and 156 x 10(3), 153 x 10(3), 151 x 10(3). The mean aggregation responses of the PCs prepared by the two methods on the 1st, 3rd and 5th days, expressed as a % were: ADP: 94.8-93.2, 81.6-78.7, 44.3-8.2; COLL: 91.7-89.6, 79.2-74.2, 29.8-11.1; EPN: 88.5-91.3, 64.2-62.7, 39.4-4.5 and RIST: 89.4-89.4, 76.5-73.6, 14.4-3.2. Other data related to platelet storage were obtained by measuring the pH, PO2, PCO2, glucose and lactate levels of the PCs. In our study, it was determined that in spite of the optimal storage conditions, the aggregation response of the PCs decreased significantly, whereas, the numerical values changed little during the storage period.

Investigation of various antibiotic combinations using the E-Test method in multiresistant Pseudomonas aeruginosa strains.

BACKGROUND: Antibiotic combinations are frequently used in order to obtain wide-spectrum effects in the treatment of serious infections such as septicemia and endocarditis, and also to produce an in vivo effect against strains which are defined as resistant to the known inhibiting or fatal dose of one antibiotic. The synergistic effects of combinations such as aminoglycoside + beta-lactam, aminoglycoside + quinolone and quinolone + beta-lactam on Pseudomonas aeruginosa have been revealed in different studies. The multiple resistance rate of nosocomial P. aeruginosa strains isolated from intensive care units (ICUs) has been reported as high in many studies. METHODS: In this study, the effects of various combinations of antibiotics (aminoglycoside + beta-lactam and aminoglycoside + quinolone) against 101 multiresistant P. aeruginosa strains which were isolated from the ICUs of three different hospitals in Istanbul were investigated using the E-test method. The combinations for which the highest synergistic effects were determined by the E-test method were also tested with the checkerboard method, i.e. in addition to the E-test method, in 19 of a total of 23 strains. RESULTS: When the synergistic results which were obtained with the combinations of aminoglycoside + beta-lactam were compared with those of the aminoglycoside + quinolone combinations, they were determined to be higher for the two aminoglycosides gentamicin (GM) and tobramycin (TM). We determined the synergistic rates to be 23, 21, 19, 18, 16, 14, 10 and 10% for GM + ceftriaxone (TX), GM + piperacillin (PP), GM + ceftazidime (TZ), TM + PP, TM + TX, TM + TZ, GM + ciprofloxacin (CI) and TM + CI, respectively. The GM + TX combination - for which the highest synergistic effects were determined with the E-test stripes - was also determined as synergistic with the checkerboard method in 19 of a total of 23 strains (23%), and the agreement rate between the two methods was 100% (kappa > 0.7). The highest synergistic effects against strains which were sensitive to both of the antibiotics which constitute the combinations were found for the GM + TX combination, as 50%, whereas for strains which were resistant to both of the antibiotics, this was found for the TM + PP combination, also as 50%. CONCLUSIONS: We consider that the minimal inhibitory concentration values of antibiotics are not sufficient alone in order to constitute a combination for multiresistant strains and it would be advisable to begin a treatment by applying a combination study. The E-test method has been evaluated as a good alternative for combination investigations because of its ease both of application and evaluation and also for its good agreement with the standard checkerboard method.