Correlation of coronary artery bypass surgery-related myonecrosis with grafted vessel calibre: insights from cardiovascular magnetic resonance imaging.
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Adult↗
Biomedical subjects
N Searle
Publications and source records attributed to N Searle.
Reinfusion of mediastinal blood after heart surgery.
BACKGROUND: Several authors studying autotransfusion of shed mediastinal blood in patients undergoing heart operations have published conflicting results regarding reduction of the need for homologous blood transfusion. The effect on coagulation parameters is also unclear. METHODS: In a prospective randomized study, 198 patients who underwent coronary artery bypass grafting or a valvular operation were divided into 2 groups: a group with autotransfusion of shed mediastinal blood after an operation and a control group. Continuous reinfusion of mediastinal blood was done until no drainage was present or for a period of 12 hours after the operation. The amount of blood lost and autotransfused, the number of homologous blood products transfused, and the coagulation parameters were monitored. RESULTS: The number of patients requiring homologous blood transfusion was significantly different between the 2 groups (54/98 [55%] in autotransfused patients vs 73/100 [73%] in the control group, P =.01). The number of re-explorations for excessive bleeding was similar in the 2 groups (7/98 [7.1%] vs 8/100 [8%]), but the amount of blood collected postoperatively was higher in the autotransfused patients compared with control patients (1200 +/- 201 mL vs 758 +/- 152 mL, P =.0007). Coagulation parameters analyzed and complication rates were similar in the 2 groups after the operations. CONCLUSION: Autotransfusion of shed mediastinal blood reduces the need for homologous blood transfusion in patients undergoing various cardiac operations. The cause of increased shed blood in patients undergoing autotransfusion remains unclear.
Analysis of Variance↗
Early versus late extubation after coronary artery bypass grafting: effects on cognitive function.
OBJECTIVE: To compare the effects of a short period of mechanical ventilation and sedation and a longer one on cognitive functioning of patients exposed to cardiopulmonary bypass (CPB). DESIGN: A randomized, prospective study. SETTING: Tertiary-care university hospital. PARTICIPANTS: Forty-eight adult patients with surgical coronary artery disease. INTERVENTION: Elective coronary artery bypass surgery. MEASUREMENT AND MAIN RESULTS: Patients (n = 48; mean age, 60.12+/-9.30 years) were randomized to either group I (mean delay, 3.49+/-2.21 hours) or group II (mean delay, 10.32+/-1.75 hours). Cognitive functioning was evaluated before surgery, postoperatively, and at the 8-week follow-up. Tests included measures of central nervous system integrity, attention/concentration and psychomotor performance, verbal fluency, visual scanning speed, mental flexibility, auditory and visual attention, and verbal memory. Covariance analyses were used for group comparisons. Covariates were age, education, and baseline or postoperative performance. No differences in cognitive functioning were found between the two groups. Globally, performance deteriorated for 34.1% of the patients at the posttest evaluation, whereas 2.3% improved and 63.6% remained unchanged. At follow-up, nearly 40.5% of the patients showed an improvement from baseline, 2.4% still had deficits, and 57.1% had no change. None of the cognitive functions appeared to be more affected than others. CONCLUSION: Early extubation and a shortened period of anesthesia/analgesia do not appear to positively or negatively affect cognitive functioning at 3 to 5 days and 8 weeks postoperatively. Early extubation is suggested because it has no deleterious effect (besides the low risk for reintubation) and it may facilitate patients' care in the intensive care unit.
Adult↗
Post-traumatic thoracic pseudoaneurysm repair with an endoluminal expandable stent.
Recent technological improvement has allowed endoluminal correction of thoracic and abdominal aortic aneurysm through percutaneous insertion of expandable stents. A woman who presented with chronic pseudoaneurysm of the thoracic aorta 10 years after being in a car accident is presented. A Talent stent was introduced through the femoral artery and successfully deployed under fluoroscopic guidance across the aneurysmal defect. Recovery was uneventful, and 12 months later the patient remained asymptomatic.
Accidents, Traffic↗
Beating heart coronary artery bypass grafting: technical aspects and results in 200 patients.
OBJECTIVE: To describe the initial experience of the first 200 patients who underwent coronary artery bypass grafting (CABG) on beating hearts at the Montreal Heart Institute, Montreal. DESIGN: A prospective cohort of 200 patients was analyzed to study immediate and short term (two-year follow-up) results. SETTING: Patients underwent CABG at the Montreal Heart Institute from February 1996 to June 1998. The first 30 patients underwent CABG without the use of a myocardial wall stabilizer (group 1), and a myocardial wall stabilizer was used in the following 170 patients (group 2). PATIENTS: Group 1 patients averaged 60+/-10 years of age compared with 66+/-10 years in group 2 (P=0.002). Twelve patients (40%) in group 1 had unstable angina compared with 107 patients (63%) in group 2 (P=0.03). INTERVENTIONS: Group 1 patients underwent 1.7+/-0.7 CABG per patient compared with 2.4+/-0.8 grafts per patient in group 2 (P=0.001). Sixty-seven patients (39%) in group 2 had an obtuse marginal coronary artery grafted, and 145 patients (73%) of both groups had a complete myocardial revascularization. RESULTS: Ten patients (5%) in both groups were converted to cardiopulmonary bypass during surgery. Seven patients (3.5%) died postoperatively: five from myocardial infarction, one from aortic dissection and rupture, and one from arrhythmia. Seventeen patients (8.5%) suffered a perioperative myocardial infarction. In groups 1 and 2, respectively, actuarial survival was 100% and 95+/-2%, and freedom rate from reoperation, percutaneous balloon dilation and recurrent myocardial infarction averaged 93+/-4% and 97+/-2% 18 months following CABG. CONCLUSION: CABG on beating hearts appears to be an alternative approach to the use of cardiopulmonary bypass in selected patients.
Aged↗
Retrograde replacement of the thoracic aorta under circulatory arrest and retrograde cerebral perfusion.
Single-stage replacement of the ascending, transverse and descending thoracic aorta remains a noteworthy surgical intervention associated with significant morbidity. Aside from the surgical aspects, brain preservation during the circulatory arrest period, which is generally needed to perform the procedure, is a constant preoccupation for the surgeon. A 43-year-old man had an extensive thoracic aneurysm 4 years after an initial type A aortic dissection involving the entire thoracic aorta. The Cooley technique of retrograde replacement of the thoracic aorta was performed along with retrograde cerebral perfusion. The combined sternal and thoracic approach suggested for this technique provided excellent exposure and, despite a circulatory arrest time of 88 minutes, the patient's cognitive abilities were found to be well preserved at follow-up 2 months after the surgery, indicating the efficacy of the cerebral retrograde perfusion. The authors conclude that retrograde replacement of the thoracic aorta combined with cerebral retrograde perfusion are convenient procedures that allow extensive aortic replacement without brain damage.
Adult↗
Induction of the E-selectin promoter by interleukin 1 and tumour necrosis factor alpha, and inhibition by glucocorticoids.
Cytokine-induced expression of the endothelial cell surface adhesion molecule E-selectin is inhibited by glucocorticoids (GCs). To investigate possible mechanisms for steroid inhibition, a reporter gene (ESAP) was constructed, comprising the cytokine responsive region of the E-selectin gene (nt -383 to +81) coupled to alkaline phosphatase (AP). In A549 cells stably transfected with the ESAP gene, AP production was highly responsive to the cytokines interleukin 1beta (IL-1beta) and tumour necrosis factor alpha, with ED50 values of 3 pM and 1000 pM respectively. Furthermore the cytokine-induced AP responses were inhibited by GCs, indicating that both transcriptional activation and GC suppression of the E-selectin gene were mediated via regulatory elements within the same region of the promoter. The relative potencies of GC drugs as inhibitors of IL-1beta (10 pM)-stimulated ESAP-gene activation were fluticasone> beclomethasone>dexamethasone, with IC50 values of 0.13, 1.1 and 2.7 nM respectively. Inhibition by fluticasone was blocked by the GC receptor (GR) antagonist drug mifepristone (Ru486), which is consistent with the suppressive effects of GCs being mediated via the GR. However, because the E-selectin promoter lacks a consensus glucocorticoid responsive element, mechanisms for inhibition independent of GR-DNA binding were investigated. Evidence that GCs also inhibited cytokine activation of a synthetic nuclear factor kappaB (NFkappaB)-driven reporter gene transiently transfected into A549 cells suggested that interference with the activation and/or function of this transcription factor was important for GC inhibition of ESAP. However, in A549-ESAP cells, fluticasone (100 nM) did not affect IL-1beta (10 pM)-induced IkBalpha degradation, NFkappaB-p65 nuclear translocation or the DNA-binding capacity of nuclear NFkappaB complexes, over a period during which cytokine-induced ESAP-gene activation was inhibited. Finally, there was no evidence to suggest that GC enhancement of IkBalpha gene expression contributed to the suppression of the cytokine response. We conclude that interference by GR with the transcriptional activation potential of DNA-bound NFkappaB complexes might contribute to mechanisms underlying the anti-inflammatory effects of GCs.
Androstadienes↗
Glucocorticoid inhibition of cytokine-induced E-selectin promoter activation.
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Androstadienes↗
[Coronary artery bypass grafting without cardiopulmonary bypass: angiographic evaluation of a preliminary experience].
BACKGROUND: Coronary artery bypass grafting (CABG) without cardiopulmonary bypass has been proposed to decrease morbid events related to the circuit and the blood pump. OBJECTIVE: To evaluate quantitatively coronary anastomoses with CABG without cardiopulmonary bypass. SETTING: Between February and December 1996, 19 patients underwent CABG, through a median sternotomy in 12 patients and an anterior minithoracotomy in seven patients. Twenty internal thoracic artery grafts and seven saphenous vein grafts were studied by quantitative angiography in the immediate postoperative period (4 +/- 2 days). Diameters of native coronary arteries and grafts were analyzed by computer. PATIENTS: Patients averaged 57 +/- 8 years of age, with triple vessel coronary disease in three patients, double vessel disease in nine patients and single vessel disease in seven patients. Twelve patients underwent a single thoracic artery graft to the left anterior descending artery and seven patients underwent a double graft to the anterior descending and the right coronary artery. RESULTS: Hospital stay averaged 5 +/- 2 days, operating time averaged 144 +/- 30 mins and ischemic occlusion of the left anterior descending coronary artery averaged 20 +/- 8 mins. Serum creatine kinase MB fraction averaged 11 +/- 7 U/L and 25 +/- 37 U/L, 1 and 24 h, respectively, after surgery. Diameter stenosis of the native coronary artery averaged 19 +/- 26% proximal to the anastomosis, 36 +/- 31% distal to the anastomosis and 27 +/- 32% at the anastomotic site of internal thoracic artery grafts. One native coronary artery distal to the anastomosis was occluded and an occluded anastomosis was reopened by percutaneous angioplasty 72 h after surgery. Saphenous vein grafted to the right coronary artery had only minimal stenosis at anastomotic sites. CONCLUSION: This initial experience with CABG without cardiopulmonary bypass suggests that adequate coronary anastomosis can be performed in selected patients.
Cardiopulmonary Bypass↗
Amrinone, in combination with norepinephrine, is an effective first-line drug for difficult separation from cardiopulmonary bypass.
A crucial element for weaning patients from cardiopulmonary bypass (CPB) rests on the selection of an appropriate therapeutic regimen. Amrinone, a phosphodiesterase III inhibitor, combines inotropic support with pulmonary and systemic vasodilatation, without increasing heart rate (HR) or myocardial oxygen consumption. These characteristics should be useful in the failing heart during weaning from CPB. Nineteen patients were included in this prospective, open-labelled, phase IV study when systolic blood pressure (DPAP) > 15 mmHg or central venous pressure (CVP) > 15 mmHg, during progressive separation from CPB. At that moment, CPB flow was increased to alleviate heart failure and amrinone administered as a bolus (0.75 mg.kg-1) followed by an infusion (10 micrograms.kg-1.min-1). Weaning from CPB was then resumed and haemodynamic variables (SBP, DPAP, CVP and HR) were compared with those measured at CPB flow when failure had first occurred. Failure to wean from CPB occurred at 57 +/- 28% of full pump flow. After the amrinone bolus, DPAP and CVP decreased by 20% and 21% respectively. Subsequently, 16 patients required the infusion of norepinephrine (4-8 micrograms.min-1) to maintain a SBP > 80 mmHg. Heart rate remained unchanged after the bolus of amrinone, after separation from CPB, and no arrhythmias were noted. Successful weaning from CPB was possible 12 +/- 8 min after the amrinone bolus. Weaning resulted in a cardiac index similar to that measured pre-bypass. Amrinone is rapidly effective during weaning from CPB and, in combination with norepinephrine, provides the necessary inotropic support during this unstable period.
Aged↗
The preterm nonstress test: effects of gestational age and length of study.
The application of the nonstress test between 24 and 32 weeks' gestation has been limited by high rates of "false" nonreactivity in normal fetuses, by use of term criteria, and the lack of age-appropriate interpretative standards. To establish such standards, we studied 30 normal fetuses undergoing 90-minute fetal heart rate recordings at 2-week intervals from 24 to 32 weeks' gestational age. Using a specially programmed computer we quantified (1) baseline fetal heart rate, (2) incidence of 10- and 15-beat accelerations, and (3) incidence of fetal heart rate decelerations. With a criterion of three 15-beat accelerations per 30 minutes 91% of tests were reactive within 90 minutes. A criterion of three 10-beat accelerations per 30 minutes was associated with 100% reactivity within 60 minutes. Suitable interpretative criteria may be established for nonstress tests before 32 weeks' gestation by extending the testing time or by decreasing the minimum amplitude required of fetal heart rate accelerations.
Adult↗
The effects of vibratory acoustic stimulation on baseline fetal heart rate in term pregnancy.
Fetal heart rate responses to vibratory acoustic stimulation have been studied in normal and complicated pregnancies. To determine the precise nature of these responses, we studied 50 normal term fetuses with 60 minutes of electronic antepartum fetal heart rate monitoring divided in two 30-minute segments separated by 3 seconds of vibratory acoustic stimulation. All tracings were analyzed by a programmed microcomputer. Comparison of grouped mean 30-minute values before and after vibratory acoustic stimulation showed significant increases in baseline fetal heart rate, fetal heart rate variation, frequency of accelerations exceeding 10 and 15 beats/min, duration of accelerations exceeding 15 beats/min, and frequency of decelerations after vibratory acoustic stimulation. Mean baseline fetal heart rate elevation greater than 10 beats/min occurred within 7.6 +/- 4.4 seconds in 42 of 50 fetuses and lasted for 596 +/- 531 seconds. Reactive tests increased from 35 (70%) to 47 (94%) after vibratory acoustic stimulation. Most healthy term fetuses exhibit fetal heart rate responses after differing in frequency or magnitude from spontaneous fetal heart rate changes. Vibratory acoustic stimulation may be a valid fetal assessment tool but cannot be considered the physiologic equivalent of nonstress testing.
Acoustic Stimulation↗
Effects of maternal hyperoxia on the biophysical assessment of fetuses with suspected intrauterine growth retardation.
Fifty-two third-trimester fetuses with suspected intrauterine growth retardation were studied by means of a computer-assisted biophysical assessment scheme, which used maternal hyperoxia as a diagnostic probe. Biophysical data examined included percentage of time spent in breathing, mean breath rate, and percentage of time spent in body movement during a 90-minute observation: 30-minute baseline, 15-minute hyperoxia, and 45-minute posthyperoxia. Mean baseline movement in fetuses found as neonates to have intrauterine growth retardation (N = 18) was significantly lower than that of normal fetuses (N = 34). Fetal body movements and breathing movements increased significantly after hyperoxia in the intrauterine growth retardation group but not in the normal group. Increases of more than 75% over baseline for fetal breathing and more than 250% over baseline for fetal body movements yielded a sensitivity of 56%, specificity of 94%, positive predicative value of 83%, and negative predicative value of 80%. Maternal hyperoxia during biophysical testing may improve the accuracy of detecting intrauterine growth retardation.
Female↗
Monitoring intrauterine pressure during active labor. A prospective comparison of two methods.
Conventional recording of intrapartum uterine activity uses fluid-filled internal catheter systems requiring periodic maintenance. An intrauterine pressure catheter system, the INTRAN, uses an electronic pressure sensor and theoretically could obtain satisfactory uterine recordings with less maintenance. Simultaneous recordings with the INTRAN and standard fluid-filled systems were made in 40 third-trimester patients using comparably calibrated electronic monitoring systems. Comparisons of the recordings from each patient showed similar mean baseline uterine tone, contraction interval and duration. Mean peak uterine pressures were significantly higher with the INTRAN system (63 vs. 56 mm Hg). Coefficients of correlation for contraction interval, duration, peak intrauterine pressure and resting tone were .99, .87, .84 and .34, respectively. Both systems detected abnormal uterine activity equally well. Major technical failures were equally frequent with both systems; however, the fluid-filled catheters required more frequent readjustment.
Adolescent↗
Prognostic components of computerized fetal biophysical testing.
Fetal biophysical testing with arbitrary scores for fetal heart rate (FHR), breathing movements, body movements, tone, and amniotic fluid volume has not proved to be highly sensitive or significantly better than FHR testing alone. Using a computerized analysis system for simultaneously acquired biophysical variables, we studied 200 high-risk fetuses near term. The dynamic parameters obtained for each fetus were compared with established nomograms, and overall test results correlated with the presence or absence of perinatal mortality, fetal distress, a 5-minute Apgar score less than 7, and intrauterine growth retardation for those delivered within 7 days of the last test. A test was considered abnormal if two or more parameters fell more than 2 standard deviations from the population mean. A decreased incidence of fetal body movements, amniotic fluid volume, and frequency of FHR acceleration were the most common individual test abnormalities. Test sensitivity (86%), specificity (89%), positive predictive value (75%), and negative predictive value (93%) exceeded those of the "standard" scoring approach and correctly identified all fetuses with malformation, perinatal death, and 19 of 22 fetuses with intrauterine growth retardation.
Amniotic Fluid↗
Does the onset of spontaneous labor at term influence fetal biophysical test parameters?
Recent data suggest that fetal breathing movement incidence declines while fetal heart rate (FHR) and body movement incidence do not change within 72 hours of spontaneous term labor. We conducted a retrospective study to determine whether the length of time from testing to spontaneous labor onset could influence these biophysical test parameters. Eighty-one normal term fetuses underwent 60-minute tests 1-40 days before the onset of spontaneous labor: 41 were tested within 7 days of labor (19 within 3 days and 22 within 4-7 days) and 40 were tested more than 7 days before labor. We simultaneously acquired and analyzed FHR baseline, frequency of accelerations between ten to 14 beats per minute and more than 15 beats per minute in amplitude, percent of time spent in breathing and moving, and fetal breath rate. These biophysical parameters were not significantly different between the groups, implying that they may continue to provide clinically useful information in the prelabor period.
Female↗
A prospective comparative study of the extended nonstress test and the nipple stimulation contraction stress test.
The nonstress test and the nipple stimulation contraction stress test were performed at the Medical College of Georgia and the University of Mississippi Medical Center, with the use of common maternal state protocols, minimum criteria for baseline fetal heart rate reactivity, and follow-up of abnormal test results. At the Medical College of Georgia, 656 patients were studied with nonstress tests used as the primary test, whereas at the University of Mississippi Medical Center, 614 patients were managed with the nipple stimulation contraction stress test used as the primary test. Both populations were comparable in regard to pregnancy complications, gestational age, birth weight, perinatal outcomes, cesarean section rates, and the incidence of positive contraction stress tests. Specificity and positive and negative predictive values were similar for both tests. The extended nonstress test had higher sensitivity but also required significantly longer mean duration of testing. The corrected perinatal mortality rate for a reactive nonstress test or negative nipple stimulation contraction stress test was zero within one week of the last test. We conclude that both tests provide excellent primary methods of fetal surveillance and that the decision to use one test rather than the other should be made on the basis of considerations of cost, convenience, time availability, and the presence of specific test contraindications or pregnancy complications.
Breast↗
The effects of long- and short-term maternal caffeine ingestion on human fetal breathing and body movements in term gestations.
The possible effects of long- and short-term maternal ingestion of caffeine during normal human pregnancy on the breathing and body movements of third-trimester fetuses were studied in 14 patients, selected by a dietary questionnaire, and divided into two equal groups: high consumers (greater than 500 mg/day) (group 1) and low consumers (less than 250 mg/day) (group 2). All mothers followed a standard study protocol and underwent overnight fasting; studies began with a 30-minute control period, followed by oral administration of 200 mg caffeine, and a 180-minute subsequent observation period with continued maternal fasting. Blood samples for glucose and caffeine were obtained every 30 minutes and continuous recording of fetal breathing and body movements were entered on a microcomputer for off-line analysis. The two groups were similar for all obstetric outcome features. Plasma glucose levels were similar and constant in both groups whereas caffeine levels increased significantly at 60 minutes after administration; mean plasma caffeine levels were significantly higher in group 1 than in group 2 at all intervals. Fetal breathing rates and body movement incidences were similar in both groups before and after caffeine administration. Fetal breathing movement incidence decreased significantly in group 2 but was sustained at baseline levels in group 1 throughout the study. High long-term ingestion of caffeine during pregnancy is associated with higher maternal plasma caffeine levels and fetal breathing activity when compared with low caffeine ingestion. Short-term administration of 200 mg caffeine does not appear to have a significant physiologic impact on these activities.
Caffeine↗