PubMed Health⌕ Search

Biomedical subjects

O N Okike

Publications and source records attributed to O N Okike.

15 recordsLinked to original sources
PubMed1996

Reduction of bleeding after heart operations through the prophylactic use of epsilon-aminocaproic acid.

UNLABELLED: Excessive postoperative bleeding after heart operations continues to be a source of morbidity. This prospective double-blind study evaluated epsilon-aminocaproic acid as an agent to reduce postoperative bleeding and investigated its mode of action. One hundred three patients were randomly assigned to receive either 30 gm epsilon-aminocaproic acid (51 patients) or an equivalent volume of placebo (52 patients). In a subset of these patients (14 epsilon-aminocaproic acid, 12 placebo), tests of platelet function and fibrinolysis were performed. RESULTS: By multivariate analysis, three factors were associated with decreased blood loss in the first 24 hours after operation: epsilon-aminocaproic acid versus placebo (647 ml versus 839 ml, p = 0.004), surgeon 1 versus all other surgeons (582 ml versus 978 ml, p = 0.002), and no intraaortic balloon versus intraaortic balloon pump use (664 ml versus 1410 ml, p = 0.02). No significant differences in platelet function could be demonstrated between the two groups. Inhibited fibrinolysis, as reflected by less depression of the euglobulin clot lysis and no rise in D-dimer levels, was significant in the epsilon-aminocaproic acid group compared with the placebo group. CONCLUSION: The intraoperative use of epsilon-aminocaproic acid reduces postoperative cardiac surgical bleeding.

Aminocaproic Acid↗
PubMed1993

Prolonged bradyarrhythmias after isolated coronary artery bypass graft surgery.

To evaluate clinical and electrocardiographic (ECG) characteristics that may predict the occurrence of bradyarrhythmias after isolated coronary artery bypass graft (CABG) surgery, 1614 consecutive patients who had this procedure performed at our institution from January 1988 to December 1990 were reviewed. Thirteen (0.8%, 7 males and 6 females) patients had prolonged (mean 10.5 +/- 6.5 days) postoperative bradyarrhythmias and required insertion of a permanent pacemaker. Complete heart block occurred in eight patients and sinus node dysfunction in five. These 13 patients (group A) were compared with a group of 490 arbitrarily selected CABG patients (group B) without bradyarrhythmias whose preoperative ECGs were reviewed. Patients in group A were older (mean 69.2 vs 62.8 years; p = 0.0004) and had concomitant left ventricular (LV) aneurysmectomy more frequently (p = 0.02) and internal mammary graft revascularization less frequently (p = 0.022) than group B patients. Review of preoperative ECGs revealed a higher occurrence of complete left bundle branch block (LBBB) (5 of 13 vs 6 of 490; p < 0.0001) and a borderline, more leftward frontal plane QRS axis (-5.3 vs 13.1 degrees, p = 0.068) in group A patients. There were no differences between the groups with respect to gender, number of bypass grafts, location of prior myocardial infarction, and preoperative ECG intervals (PR, QRS, QTc). Multivariate analysis identified the presence of a preoperative LBBB, concomitant LV aneurysmectomy and age > 64 years as independent predictors of severe and prolonged postoperative bradyarrhythmias, mainly complete heart block.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1990

Free and total lidocaine levels in cardiac surgical patients.

A lidocaine bolus of 2 mg/kg has been shown to decrease the incidence of ventricular fibrillation in cardiac surgical patients during reperfusion following aortic cross-clamp release (CCR). In an effort to extend this effect into the immediate postoperative period, many centers routinely administer a prophylactic lidocaine infusion for the first 12 to 24 hours after surgery. Sequential total serum lidocaine levels were measured over 6 hours in 28 adult cardiac surgical patients without liver, kidney, or respiratory disease, and free serum lidocaine levels were measured in 15 of these patients. In addition, pharmacokinetic data were collected and analyzed in 8 of these patients. Each patient received a lidocaine bolus of 1.5 mg/kg and an infusion at 2 mg/min immediately before CCR. Serum levels were determined just before CCR, and at 10, 20, 30, 60, 120, 240, and 480 minutes after CCR. More than 50% of patients had subtherapeutic total serum lidocaine levels from 20 to 120 minutes after CCR, but free lidocaine levels remained within the therapeutic range. No patient showed malignant ventricular dysrhythmias during the study. The results suggest that (1) it may be misleading to estimate free lidocaine concentration based on total lidocaine levels; and (2) free drug is the moiety responsible for lidocaine's antiarrhythmic effect.

Adrenergic beta-Antagonists↗
PubMed1989

Internal mammary artery grafts: the shortest route to the coronary arteries.

Inadequate length can limit the use of the internal mammary artery (IMA) for coronary revascularization. By following the shortest route from its origin to the recipient coronary artery, IMA use can be maximized. Seven cadavers were studied to determine that shortest route for the left and right IMAs. The shortest route for the left IMA to the left anterior descending coronary, diagonal, and circumflex coronary arteries was through the pericardium (p less than or equal to 0.01). For the right IMA, the significantly shortest routes were across the anterior heart for the left anterior descending and diagonal arteries, through the right pericardium for the right coronary artery or posterior descending artery, and through the pericardium and transverse sinus for the circumflex artery. Thus, any coronary artery can be reached with an in situ IMA, and the route through the pericardium is markedly shorter to ipsilateral coronary arteries.

Coronary Vessels↗
PubMed1989

Reduction of sternal infection by application of topical vancomycin.

Sternal or mediastinal infection after heart operations occurs infrequently but carries a high cost in money, morbidity, and mortality. At our hospital, Staphylococcus nonaureus causes most of these infections and is uniformly sensitive to vancomycin. In a prospective study of 416 patients having cardiac operations, randomized by hospital record number, topical vancomycin was applied to the cut sternal edges in 223 patients (group V) and was omitted in the control group (C) of 193 patients. The vancomycin was applied in a hemostatic paste of topical thrombin and powdered absorbable gelatin; in the control group only the hemostatic paste was applied. All patients received prophylactic systemic antibiotics for 2 days. Sternal infection occurred in one patient in group V (0.45%) and in seven patients in group C (3.6%) (p = 0.02). Infection also correlated with longer operative times (p = 0.027). By multivariate testing, vancomycin (p = 0.013) and shorter operative times (p = 0.014) independently predicted reduced infection rates. In the one patient with an infection in group V, Staphylococcus aureus was cultured; this organism was also cultured in two patients in group C, with Staphylococcus nonaureus being the culprit in the other five patients with sternal infections in group C. Topical vancomycin applied to the cut sternal edges reduces the risk of postoperative sternal infection.

Administration, Topical↗
PubMed1988

The role of epsilon-aminocaproic acid in reducing bleeding after cardiac operation: a double-blind randomized study.

Sixty patients scheduled for elective coronary artery bypass graft operations were randomly assigned to receive epsilon-aminocaproic acid or placebo to test whether antifibrinolytic therapy would decrease postoperative bleeding. A small but significant decrease in bleeding was observed in the treated group without complications resulting from treatment with epsilon-aminocaproic acid.

Aminocaproates↗
PubMed1987

Efficacy of nadolol in preventing supraventricular tachycardia after coronary artery bypass grafting.

To investigate the efficacy of nadolol in the prevention of supraventricular arrhythmias after coronary artery bypass graft (CABG) surgery, 148 patients undergoing elective CABG were randomized in double-blind, placebo-controlled fashion to receive either nadolol or placebo. The test medication was started on the first postoperative morning and maintained as a single daily dose for 6 weeks. Aside from routine daily clinical evaluation and postoperative electrocardiographic monitoring, patients underwent 24-hour Holter recording once preoperatively and 3 times postoperatively. Seven patients were excluded from the evaluation of efficacy analysis because of insufficient postoperative data. There were no significant differences between the patients receiving nadolol (n = 67) and those receiving placebo (n = 74) with respect to age, preoperative heart rate, previous medications (including beta blockers), incidence of previous myocardial infarction, frequency of preoperative ventricular and supraventricular arrhythmias, concomitant valvular heart disease, mean cardiopulmonary bypass time, mean aortic cross-clamp time, use of blood and crystalloid cardioplegia, mean number of bypass grafts placed, postoperative use of inotropic agents and catecholamines and incidence of perioperative myocardial infarction. Analysis of postoperative Holter recordings showed that the heart rate was consistently and significantly higher in the placebo group throughout the period of the study (p less than 0.001). The average number of premature atrial contractions was significantly smaller in the nadolol group (p less than 0.05), and nadolol patients had fewer ventricular premature complexes, couplets and non-sustained ventricular tachycardias during the first week postoperatively.(ABSTRACT TRUNCATED AT 250 WORDS)

Coronary Artery Bypass↗
PubMed1986

Prevention of postoperative pericardial adhesions. An animal study.

Following heart operations, adhesions uniformly form between the epicardium and surrounding structures such as the pericardium, mediastinal fat, pleura, and sternum. These adhesions make reoperations both difficult and hazardous. Three groups of 15 dogs each were studied to assess the effectiveness of pharmacologic manipulation in reducing the adhesions. In the control group, adhesions were created by allowing epicardial/pericardial surfaces to dry, and then adding cotton fibers and blood before closing the pericardium. In the methylprednisolone group, 500 mg of methylprednisolone was given intravenously at the time of operation, followed by 0.3 mg/kg orally three times a day for one week. In the ibuprofen group, 12.5 mg/kg of ibuprofen was given intravenously at operation and then orally three times in one day, followed by 5 mg/kg orally three times a day for six days. Dogs were killed at three to four weeks and the adhesions between pericardium and epicardium were graded. In the control group, none were adhesion-free and none had filmy adhesions; three dogs had dense patchy adhesions and 12 had dense diffuse adhesions. In the methylprednisolone group, 14 dogs had no adhesions; one had filmy adhesions; and none had dense patchy or dense diffuse adhesions. In the ibuprofen group, none were adhesion-free; one dog had filmy adhesions; four had dense patchy adhesions; and ten had dense diffuse adhesions. The near-total elimination of pericardial/epicardial adhesions utilizing methylprednisolone, if also achievable in humans, would markedly reduce the difficulty and increase the safety of cardiac reoperations.

Animals↗
PubMed1986

Preliminary experience with synchronized coronary sinus retroperfusion in humans.

Synchronized coronary sinus retroperfusion (SCSR) with arterial blood has been extensively tested in animals. This intervention offers temporary support to areas of ischemic myocardium while a method of definitive revascularization is being sought. The feasibility and safety of this procedure for patients with unstable angina was therefore tested. A No. 7F autoinflatable retroperfusion balloon catheter (USCI) was inserted percutaneously into the coronary sinus of the study patients. Arterial blood was obtained through a No. 8F catheter placed in the femoral artery. Arterial blood was infused in a retrograde fashion into the coronary venous system during cardiac diastole by means of a piston-driven pump that was electrocardiographically synchronized with the drainage of the venous system during systole. This procedure was performed in five patients with unstable angina refractory to maximum medical therapy. SCSR significantly decreased the frequency of anginal episodes and the requirement for antianginal medications. SCSR also provided time for patient stabilization before diagnostic cardiac catheterization or therapeutic intervention. This preliminary experience suggests that synchronized coronary sinus retroperfusion is a feasible and safe procedure. It can be performed at the bedside with no apparent adverse effects to the patient. Retroperfusion also appears to be effective in relieving ischemic symptoms as assessed by clinical parameters. Based on our preliminary experience, further delineation of its clinical applications is warranted.

Adult↗
PubMed1983

Surgical versus percutaneous removal of the intra-aortic balloon.

In order to determine the best method for removal of the percutaneous intra-aortic balloon (IAB), we divided 38 patients into two groups. The IAB was removed percutaneously in Group I and surgically in Group II. There were two hemorrhagic and four thrombotic complications sufficiently severe to necessitate vascular surgical intervention in Group I. There were no vascular complications in Group II (p less than 0.1). Among the 19 patients in Group II, eight were found to have acute thrombosis of the superficial or deep femoral artery at the time of operation. It is concluded that thrombus development at the site of IAB insertion is a common event and often leads to acute ischemia. Surgical removal of a percutaneously placed IAB is recommended because it provides an opportunity for the detection and removal of thrombotic material, as well as careful closure of the puncture site.

Assisted Circulation↗
PubMed1982

Improved myocardial preservation by improved distribution of cardioplegic solutions.

Two groups of elective coronary artery bypass graft (CABG) patients were compared with respect to a single variable: method of cardioplegia administration. All patients had saphenous vein grafts and all distal anastomoses were done with continuous aortic occlusion and intermittent administration of a 4 degrees C cardioplegic solution. One hundred patients in Group I had the distal anastomoses performed before the proximal anastomoses with cardioplegic solution administered only via the aortic root. One hundred patients in Group II had the proximal anastomoses performed first so that cardioplegic solution also perfused beyond coronary obstructions as each subsequent distal anastomosis was completed. Aortic occlusion averaged 6 minutes longer in Group II (46.5 minutes) than in Group I (40.3 minutes) (p less than 0.01). Mortality from cardiac causes was six times greater in Group I than in Group II (6% versus 1% p = 0.027) and overall mortality was eight times greater in Group I than in Group II (8% versus 1%; p = 0.008). We conclude that earlier cardioplegic perfusion of myocardium beyond obstructed coronary arteries substantially improves myocardial protection.

Albumins↗
PubMed1982

Brachial plexus injury following median sternotomy. Part II.

Brachial plexus injury may be a consequence of median sternotomy. In a previous study, we documented that median sternotomy can cause first rib fractures and that the first rib fractures may be associated with brachial plexus injury. In the current study, two groups of patients were compared for the incidence of brachial plexus injury and first rib fracture. In Group A, an Ankeney retractor was used with the crossbar placed caudal to the incision: in Group C, a Cooley sternal retractor was used with the crossbar placed cephalad to the incision. The major effective difference between these two retractors was the more caudal placement of the retractor blades with the Cooley retractor than with the Ankeney retractor. Our previous study showed that first rib fractures were caused by high placement of the sternal retractor and that they could be avoided by placing the retractor at a lower position. In the present study, 33% in Group A and 14% in Group C sustained first rib fractures (p = 0.024). Signs of brachial plexus injury occurred in 18% of Group A and 12% of Group C (p = 0.52). We found no correlation between the presence of rib fracture and the presence of neurologic symptoms, but all patients who had both neurologic symptoms and a rib fracture had the symptoms only on the same side as the rib fracture. We also found that standard chest x-ray films identified only 15% of the rib fractures seen on special first rib views. The study demonstrates that the incidence of first rib fractures following median sternotomy is reduced when the sternal retractor is placed at a lower position and that the incidence of brachial plexus injury may also thereby be reduced.

Age Factors↗