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Biomedical subjects

D M Nicoloff

Publications and source records attributed to D M Nicoloff.

At least 37 records · Page 2Linked to original sources
PubMed1987

The comparative influence of prophylactic antibiotics on the prothrombin response to warfarin in the postoperative prosthetic cardiac valve patient. Cefamandole, cefazolin, vancomycin.

A prospective randomized trial was conducted comparing the effect of three antibiotics: cefamandole (CM), cefazolin (CZ), and vancomycin (V), used as prophylaxis for prosthetic valve surgery, on the prothrombin (PT) response to warfarin (W) on the third day of anticoagulant therapy. Twenty patients, with normal preoperative PTs, were randomized to each antibiotic. Their PTs were not significantly different at 2 hours after operation and the morning before W was begun. The three groups received similar W doses for 2 days, and the PT, as percentage of activity, on the morning of the third day demonstrated that V (51 +/- 18%) was significantly greater (p less than 0.005) than CM (29 +/- 14%) or CZ (38 +/- 18%). CM had a significantly greater percentage of change in PT (64 +/- 14%, p less than 0.0001) from the first to third day than either CZ (51.1 +/- 18%) or V (44.6 +/- 19%). CM also had a greater number of patients (6) with PTs greater than or equal to 30 seconds on day 3 than either CZ (1) or V (1). The antibiotic influence on the PT response to W in this study is ranked as CM greater than CZ greater than V.

Aged↗
PubMed1987

Aortic dissection presenting as pericarditis.

In five patients with aortic dissection, signs and/or symptoms of pericarditis were part of the early manifestations of the aortic disease. Signs of inflammatory pericarditis were noted clinically in four patients and were found at autopsy in one. In the three nonoperated patients who died of aortic rupture leading to fatal hemopericardium, symptoms of pericarditis preceded fatal rupture of the aorta by four to five days. A fourth patient died after surgical repair of aortic dissection 35 days after the onset of pericarditis. In the fifth patient, manifestations of chronic constrictive pericardial disease occurred over a period of seven months after which old aortic dissection was first identified. In each case, the internal tear of classic aortic dissection was located in the ascending aorta. Microscopic evidence of cystic medial necrosis of the aorta was present in each case. In each of two cases, there was a congenital bicuspid aortic valve. The phenomenon observed represents acute aortic dissection in which slow penetration of blood into the pericardial space caused inflammatory pericarditis. The interval between the onset of pericarditis and rupture of the aorta may allow sufficient time for appropriate diagnosis and potentially lifesaving treatment of the aortic disease.

Adult↗
PubMed1985

Combined techniques for double valve replacement in the infant.

A 6-month-old female infant was seen with heart failure secondary to severe aortic and mitral regurgitation. As a neonate the infant had undergone an aortic valvotomy for congenital aortic stenosis. Subsequently the infant had aortic and mitral regurgitation with an infarcted papillary muscle. Double valve replacement was carried out with the St. Jude valve. The first approach was by the Manouguian procedure with extension of the aortotomy out between the left coronary cusp and the noncoronary cusp. The posterior mitral apparatus was resected, and a 19-mm St. Jude aortic valve was sewn into the mitral position. Because the enlarged aortic valve annulus was still inadequate to accommodate a 19-mm St. Jude valve, a Konno procedure was carried out to enlarge the aortic ring anteriorly. Atrial, septal, and aortic repair and right ventricular outflow tract reconstruction were carried out with bovine pericardium. Bypass was carried out with standard techniques of hypothermia, aortic cross-clamping, and cardioplegia. Postoperative anticoagulation therapy was initially with aspirin and dipyridamole (Persantine); however, clotting of the mitral prosthesis necessitated treatment with urokinase and heparin, which completely resolved the clot. Sodium warfarin (Coumadin) therapy was then begun. One year postoperatively, the child is developing normally.

Animals↗
PubMed1985

Six years of experience with the St. Jude Medical valvular prosthesis.

The cases of 680 consecutive patients who underwent valve replacement with the St. Jude Medical prostheses by one group of surgeons from October 1977 through October 1983 were reviewed. The operative mortality for the entire group was 6.6% (3.7% for aortic valve replacement [AVR], 1.6% for AVR and coronary artery bypass [CAB], 14.3% for AVR and miscellaneous procedures; 7.9% for mitral valve replacement [MVR], 15.5% for MVR and CAB, 33% for MVR and miscellaneous procedures; 5% for double valve replacement [DVR], 8.3% for DVR and CAB, and 0% for DVR and miscellaneous procedures). Warfarin (Coumadin) anticoagulation was recommended for all the patients. The mean follow-up of 24 months was completed in 95% of the patients (14,737 patient-months). The overall late mortality was 7.7% (6.2% for AVR, 6.3% for AVR and CAB, 8.3% for AVR and miscellaneous procedures; 7.9% for MVR, 6.7% for MVR and CAB, 33% for MVR and miscellaneous procedures; 15.8% for DVR, 18.2% for DVR and CAB, and 0% for DVR and miscellaneous procedures). There were no cases of mechanical prosthetic failure. Clinically significant hemolysis occurred in only five patients (less than 1%) with paravalvular leak after MVR. Only three patients (less than 0.5%) experienced prosthetic infection. Incidence of embolization was 0.7 per 100 patient-years in the patients who underwent AVR and 2.2 per 100 patient-years in those who underwent MVR.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1984

Atraumatic coronary perfusion cannula.

A coronary perfusion cannula has been developed that allows the administration of cold cardioplegic solution or blood into either the right or left coronary artery without trauma to the coronary ostia or to the proximal portion of the coronary artery.

Cardiac Catheterization↗
PubMed1984

Should valve replacement and related procedures be performed in elderly patients?

The cases of 135 consecutive elderly patients 70 years old or older who had valve replacement and related surgical procedures from October, 1977, through April, 1982, were reviewed. There were 75 men and 60 women. The mean left ventricular ejection fraction was 50.16 +/- 5%. The overall operative mortality was 8% (11 patients). The early operative deaths were related mainly to cardiac failure, low cardiac output, sepsis, and renal and multiorgan failure. To assess the operative risk, these 135 patients were compared with 312 younger patients (less than 70 years old) who had undergone similar procedures during the same period. The operative mortality in this group was 5.2% (16). In-hospital complications included arrhythmia (13%), psychosis (7.4%), respiratory failure (6.7%), renal failure (6.7%), cerebrovascular accident (5.2%), myocardial infarction (4.4%), and reoperation for bleeding (2.2%). Wound dehiscence occurred in 1.5% of the patients, and pulmonary emboli and sepsis developed in 0.7%. Of these complications, only the incidence of cerebrovascular accident appeared to be more common in the elderly group (5.2% versus 2.8%), but it had no statistical significance (p = 0.18). A follow-up of 3,892 patient-months was completed in 98.4% of the survivors. There were 8 late deaths (6.4%). Six were related to the valve or to ongoing cardiovascular disease. Thirty-four patients subsequently required medical attention: 4 had bleeding because of the anticoagulant; 3 required a blood transfusion; and 27 were hospitalized. Six were admitted for related cardiac conditions and 7, for observation of other conditions; 14 underwent surgical procedures not related to the cardiovascular system.(ABSTRACT TRUNCATED AT 250 WORDS)

Age Factors↗
PubMed1984

The influence of prophylactic antibiotics on the warfarin anticoagulation response in the postoperative prosthetic cardiac valve patient. Cefamandole versus vancomycin.

The influence of cefamandole and vancomycin used for prophylaxis on the warfarin anticoagulation response in 60 cardiac valve replacement patients during the postoperative period is presented. Patients were divided into two groups, hyper-responders prothrombin time (PT) greater than or equal to 32 sec, 48 hr after the initial warfarin dose (GrIHR), or normal responders PT less than 32 sec (GrIINR). Fifteen patients (25%) were in GrIHR (PT 44.3 +/- 10.5) and 45 in GrIINR (21 +/- 5). Fourteen of the 15 GrIHR patients received cefamandole and 1 of the 15 GrIHR patients received vancomycin p less than 0.05, as prophylaxis. Warfarin sensitivity was assessed using a warfarin dose index (WDI) calculated in the initial postoperative period (WDIINT) and at discharge (WDIDIS). GrIHR patients had greater WDIINT and WDIDIS compared to GrIINR p less than 0.001. Baseline prothrombin time measured 8 hours prior to start of warfarin therapy (PTBL), was linearly correlated to the WDIINT with r = 0.8, p less than 0.001 in cefamandole patients only. The data suggests that cefamandole increases warfarin sensitivity early in the postoperative course of oral anticoagulation therapy, which may lead to excessively high prothrombin times with the possibility for serious bleeding.

Blood Coagulation↗
PubMed1982

Effect of sodium nitroprusside during the payback period of cardiopulmonary bypass on the incidence of postoperative arrhythmias.

This study was designed to determine whether a sodium nitropruside infusion during the reperfusion (payback) period of cardiopulmonary bypass would minimize arrhythmias during the early postoperative period of coronary artery bypass surgery. A double-blind randomized study was carried out in 38 patients with no previous history of ventricular arrhythmias. Seventeen received 5% dextrose in water (D5W) and 21 received sodium nitroprusside at the rate of 2 microgram per kilogram per minute during the payback period. The pump flow was kept constant at 2.2 liters per square meter per minute, and mean pressure was maintained at greater than 50 mm Hg. There was a statistically significant difference between the two groups in the number of patients who developed ventricular arrhythmias (13 of 17, or 76%, in the D5W group versus 6 of 21, or 29%, in the sodium nitroprusside group; p less than 0.005). Twelve of the 13 patients in the D5W group experienced arrhythmias (6 ventricular tachycardia and 6 ventricular premature depolarization) within the first 24 hours, compared to 5 of 12 patients in the nitroprusside group (3 ventricular tachycardia and 2 ventricular premature depolarization). Only 1 patient in each group developed ventricular arrhythmia after the first postoperative day. One patient in each group experienced atrial arrhythmia during the first 24 hours. After 24 hours, atrial arrhythmias developed in 5 patients in the D5W group (35%) and 3 patients in the sodium nitroprusside group (17%) (p greater than 0.05). The arterial pH ranged from 7.35 to 7.55, with a Po2 greater than 70 torr and a serum potassium of 3.7 +/- 0.36 mEq per liter in the D5W group and 3.4 +/- 0.34 mEq per liter in the nitroprusside group during the period of arrhythmias. Sodium nitroprusside given during the payback period of cardiopulmonary bypass appears to minimize ventricular arrhythmias in the early postoperative period of coronary artery bypass surgery.

Arrhythmias, Cardiac↗
PubMed1981

Influence of aspirin and dipyridamole on patency of coronary artery bypass grafts.

A prospective randomized trial was performed to determine if the administration of inhibitors of platelet function would improve the patency of coronary artery bypass grafts. Patients were operated on for intractable angina with angiographically demonstrable lesions. The left internal mammary artery (IMA) was used for bypass of lesions of the left anterior descending coronary artery (LAD). Saphenous vein grafts were used for the LAD if the IMA was inadequate and for all other vessels. Treated patients received 1,300 mg of aspirin and 100 mg of dipyridamole (Persantine) orally each day. Control patients received neither drug. Patients returned 3 to 6 months after operation for repeat angiography. Results were analyzed by chi-square. One hundred seventy-four patients entered the study from June, 1973, through December, 1975, and 113 were analyzed. In the control group, 66 patients had 27 IMA-LAD grafts and 93 saphenous vein grafts. In the treatment group, 47 patients underwent 18 IMA-LAD grafts and 75 saphenous vein grafts. Ninety-eight of the 120 grafts (82%) were patent in the control group, and 87 of 93 grafts (94%) were patent in the treatment group (x2 = 6.34, p less than 0.02). Of the 45 IMA-LAD grafts in both groups, only 1 was occluded, a patency of 98%. In the control group, 72 of 93 saphenous vein grafts (77%) were patent. In the treatment group, 69 of 75 (92%) were patent (x2 = 6.54, p less than 0.02). The results of the study show a 15% difference between the two groups in the early patency of saphenous vein grafts. We continue to use aspirin and dipyridamole to improve the patency of saphenous vein bypass grafts.

Aspirin↗
PubMed1981

Separation of neointima from Dacron graft causing obstruction. Case following Fontan procedure for tricuspid atresia.

A nine-year-old patient with tricuspid atresia and normally related great vessels underwent a Fontan procedure, in which a porcine valved Dacron conduit was interposed between the right atrium and pulmonary trunk. After death, 6 months postoperatively, pathological examination revealed a thick layer of neointima (peel) lining the conduit. The peel was thicker in the segment of the conduit proximal to the valve, where it measured up to 4.5 mm in thickness. Proximal to the valve, the peel had separated from the wall of the graft and a hematoma had developed between the separated peel and graft. The result was reduction in the caliber of the conduit to about half the original. The patient's final illness was complicated, being associated with acute pancreatitis. Reduction in the caliber of the graft may have contributed to the death.

Acute Disease↗
PubMed1981

Complement activation and neutropenia occurring during cardiopulmonary bypass.

Complement activation and pulmonary leukostasis with neutropenia occur in hemodialysis and filtration leukapheresis, with attendant pulmonary dysfunction. Wondering whether similar phenomena might attend cardiopulmonary bypass (CPB), we studied 34 patients undergoing coronary artery bypass operations. As in the other extracorporeal circulation systems, neutropenia (mean 44.7% +/- 4.3% SEM of prebypass PMN count) occurred during the first half hour of bypass and then a rebound neutrophilia followed. CH50 and C3H50 fell 22% to 25% (p for CH50 less than 0.01) during bypass, but C3 conversion and C5a were not demonstrable in patient plasmas. Nonetheless, polymorphonuclear neutrophils (PMNs) harvested late in bypass showed low adherence to nylon and selective chemotactic and aggregative insensitivity to C5a--functional aberrations which are seen after exposure to activated complement. Furthermore, smaller infusions of activated complement into animals produced neutropenia than were required to achieve a detectable [C5a] in the plasma. We conclude that neutropenia during CPB probably results from complement activation below the threshold of detection; complement-stimulated PMNs deserve study as possible mediators of tissue injury occurring during CPB.

Agranulocytosis↗
PubMed1981

Clinical and hemodynamic results with the St. Jude Medical cardiac valve prosthesis. A three-year experience.

Two hundred thirty-two consecutive patients (October 3, 1977, through December, 31, 1980) underwent aortic (AVR), mitral (MVR), or double (DVR) valve replacement with the St. Jude Medical (SJM) prosthesis. Operative mortality for the entire group was 7.3%. There was 100% follow-up. Warfarin (Coumadin) anticoagulation was recommended for all patients. There were no cases of mechanical failure. The incidence of thromboembolism was 0.6/1,000 patient-months for those with AVR, 3/1,000 patient-months for those with MVR, and 0% for those with DVR. Thrombosis of a prosthesis occurred in two patients with DVR. Clinically significant hemolysis occurred in three patients with paravalvar leaks following MVR. Late postoperative prosthetic infection has not occurred. Postoperative catheterization studies in 33 patients revealed no transvalvular gradient at rest in 21 patients. The remainder of the patients catheterizd had low transvalvular gradients. There was a minimal increase in transvalvular gradient with exercise. The SJM cardiac valve is a viable alternative in the surgical therapy of valvular heart disease.

Adolescent↗
PubMed1980

A comparison of the effects of membrane and bubble oxygenators on platelet counts and platelet size in elective cardiac operations.

To compare the effects of membrane and bubble oxygenators on platelet counts and the size of circulating platelets, serial hematocrits, platelet counts, and platelet sizing were measured in 23 patients undergoing elective cardiac operations. In 10 patients a bubble oxygenator was used and in 13, a SciMed membrane oxygenator. The two groups were statistically similar with respect to age, weight, time on bypass, and mean blood flow rates during bypass. It was found that platelet counts, when corrected for hemodilution, did not fall from control levels during or up to 24 hours after cardiopulmonary bypass in either group. In both groups, the relative number of platelets per gram of hemoglobin increased slightly during and after bypass, and this increase was significant in the bubble oxygenator group. The average size of circulating platelets increased only in the bubble oxygenator group, and then only in the one-day postoperative sample. These findings suggest that the membrane oxygenator offers no advantage with respect to preservation of platelets during cardiopulmonary bypass lasting up to 2 to 3 hours.

Adult↗
PubMed1980

Regional myocardial blood flow and cardiac function in a naturally occurring congestive cardiomyopathy of turkeys.

Round heart disease, a presumed viral myocarditis of turkeys, provides a unique opportunity for the study of congestive cardiomyopathy. Regional myocardial blood flow and cardiac output measurements were made in nine, 19 to 34 day old anaesthetised birds using 141Ce labelled microspheres (15 micron diameter). Atrial, right ventricular and weighted-average left ventricular myocardial blood flow values were similar in control (n = 5) and round heart disease (n = 4) turkeys. The left ventricular subendocardial/subepicardial blood flow ratio of 0.89 +/- 0.02 (mean +/- SE) in round heart disease birds was, however, reduced compared with the value of 1.19 +/- 0.09 in the control birds (P < 0.05). Round heart disease turkeys also had lower systemic pressures and lower cardiac outputs when compared with control birds. M-mode echocardiograms were obtained in 42 unanaesthetised 17 to 37 day old turkeys, 34 control and eight with round heart disease. Echocardiographic evidence of left ventricular dysfunction characterised by left atrial and left ventricular dilation and a markedly reduced left ventricular shortening fraction was found in round heart disease turkeys. Paradoxical motion of the interventricular septum was present in two of eight round heart disease turkeys but in none of the control turkeys. The interventricular septum/left ventricular posterior wall ratio in control and round heart turkeys were similar. Although the body weight of control and round heart disease turkeys were similar, and the diastolic thickness of the left ventricular wall were not substantially different, the ventricular weight/body weight ratio in round heart disease turkeys was increased approximately 52%. The increased ventricular weight was not due to myocardial oedema, as myocardial water content was similar in control and round heart disease turkeys. The features which characterise round heart disease in turkeys: left atrial and left ventricular dilatation, reduced left ventricular shortening fraction, systemic hypotension, low cardiac output, relative subendocardial underperfusion, and an increase in ventricular mass, make it a useful model for congestive cardiomyopathy.

Animals↗
PubMed1980

Myocardial perfusion abnormalities in carbon monoxide poisoned dogs.

The effect of carbon monoxide inhalation on the regional distribution of right and left ventricular myocardial blood flow was studied in 12 closed-chest anesthetized dogs. Dogs were exposed to a nonhypoxic mixture of oxygen (21-40%) and carbon monoxide (1.5-2.0%) for 10 min. Myocardial blood flow was measured (15 micron radionuclide-labeled spheres) during control conditions, and 10 and 60 min following discontinuation of carbon monoxide corresponding to carboxyhemoglobin levels (COHb) of 41.6 +/- 2.8 and 26.5 +/- 1.6% (mean +/- SE), respectively. At COHb level of 26.5%, right and left ventricular blood flows were increased to approximately 1.8-1.9 times the control values (1.06 +/- 0.10 vs 0.64 +/- 0.08 mL/min per gram and 1.72 +/- 0.12 vs. 0.91 +/- 0.07 mL/min per gram, respectively, P less than 0.002). At a COHb level of 41.6%, both right and left ventricular vascular beds were maximally or near maximally dilated as right ventricular and left ventricular myocardial blood flow values were increased approximately fivefold. The right and left ventricular subendocardial-subepicardial flow ratios were reduced at both COHb levels (P less than 0.05). Thus, in addition to the global myocardial hypoxia that occurs following elevation of the COHb level, relative subendocardial underperfusion is a component of carbon monoxide poisoning in the intact dog.

Animals↗