Search PubMed⌕ Search

Biomedical subjects

V R Conti

Publications and source records attributed to V R Conti.

49 records · Page 3Linked to original sources
PubMed1983

Renal function in children undergoing cardiac operations.

Because we sometimes observed large amounts of uric acid crystals in the urine of infants and children after open-heart operations and since renal insufficiency from any cause can be a serious complication of cardiac procedures, 8 acyanotic and 5 cyanotic children were studied prospectively by comparing several preoperative and postoperative measures of renal function. There were no significant differences between the acyanotic and cyanotic groups in terms of age, time on cardiopulmonary bypass, or other preoperative variables. Postoperatively, children in both groups had a wide range of free water clearances (CH2O), with some values in the range reported to be diagnostic of renal insufficiency in adults. Since none of these children had renal insufficiency by other criteria, CH2O may not be as reliable an indicator of renal insufficiency in children. The major difference between the cyanotic and acyanotic groups was seen in postoperative serum uric acid levels (SUA); the mean SUA levels in the acyanotic and cyanotic groups were 5.3 +/- 0.5 mg/dl (+/- standard error of the mean) and 10.4 +/- 1.7 mg/dl (range, 8.0 to 15.5 mg/dl), respectively. Since the hyperuricemia in the cyanotic children could not be related to increased exogenous administration or decreased renal excretion, it is probably caused by increased endogenous production and may be related to the resolution of the cyanotic state.

Acute Kidney Injury↗
PubMed1983

A technique for cardioplegic infusion and left heart venting during coronary artery bypass grafting.

A method for administering cardioplegia and venting the left heart that utilizes a single cannula in the aortic root and minimizes the risk of air entering the left heart is presented. This technique permits precise control of flow and pressure of the cardioplegic solution. Left heart decompression is accomplished by siphon drainage with controlled negative pressure. This method effectively vents the left heart while preventing aspiration of air around the cannula insertion site or retrograde through an opened coronary artery with a nonocclusive proximal lesion during the construction of the distal anastomoses.

Aorta↗
PubMed1982

Effective use of captopril in postoperative paradoxical hypertension of coarctation of the aorta.

Severe systemic hypertension may complicate the postoperative course of patients undergoing surgical repair for coarctation of the aorta. The sympathetic and the renin-angiotensin systems have been demonstrated as underlying mechanisms for this paradoxical phenomenon (Farrell et al., 1979; Rocchini et al., 1979). We recently utilized captopril, a competitive inhibitor of angiotensin converting enzyme, with success in the management of severe hypertension that developed in a 15-year-old male after successful surgical repair for coarctation of the aorta. To our knowledge, this is the first report on the use of captopril for the treatment of this paradoxical phenomenon.

Adolescent↗
PubMed1982

Anterior spinal artery syndrome with chronic traumatic aortic aneurysm.

Shortly after severe blunt chest trauma, a young man experienced neurological symptoms suggestive of a spinal cord lesion at the lower thoracic level. The symptoms resolved at first, but then recurred 3 years later and progressed slowly. Neurological workup failed to define the cause until a thoracic aortogram showed an aneurysm in the middle portion of the descending aorta in close proximity to a vessel supplying the anterior spinal artery. After the operative repair with precautions taken to avoid further neurological injury, the neurologic deficit resolved partially. Because of the potential for symptomatic spinal cord ischemia resulting from lesions of the aorta, angiographic delineation of the spinal cord blood supply is valuable in planning operative repair.

Adult↗
PubMed1982

Effect of temperature during potassium arrest on myocardial metabolism and function.

Past studies have not established the optimal myocardial temperature range for hyperkalemic arrest but have generated controversy regarding the safety of exposing the myocardium to more profound levels of hypothermia. We therefore used the isolated working rat heart model of ischemic arrest to study the metabolic and functional effects of cardioplegia at the full range of temperatures pertinent clinically. Experimental conditions were designed to reliably control and maintain myocardial temperature during the 60 minute arrest period. We found that nearly full recovery of function occurred when hearts were arrested at or below 16 degrees C. High-energy phosphate levels measured immediately after arrest were better maintained at 4 degrees and 8 degrees C, despite evidence of decreased anaerobic glycolysis. When measured after the recovery period, high-energy phosphate levels returned to somewhat less than control levels in all groups arrested at or below 24 degrees C. Myocardial glucose utilization was best preserved in hearts arrested at or below 12 degrees C. We found no evidence that greater myocardial edema resulted from arrest at colder temperatures. Severe and permanent damage was observed when hearts were arrested at or above 28 degrees C. In this model, therefore, the best overall metabolic and functional protection occurred when hearts were maintained at 12 degrees C or below potassium-induced cardioplegia. Our results support the idea that cold injury to the heart does not occur and that colder temperatures provide better protection from ischemic myocardial injury.

Adenosine Triphosphate↗
PubMed1979

Preparation of cardioplegic solutions.

The manufacturing methods and quality control procedures for two cardioplegic solutions are described. Procedures for preparing individual bottles or batches of two cardioplegic solutions (one with and one without albumin) and a carbonate-bicarbonate buffer solution are described. Final buffered cardioplegic solutions with albumin are stable for seven days. Cardioplegic solutions without albumin and buffer are stable for 30 days. The chemical and physiological factors affecting the content and preparation of cardioplegic solutions used during intracardiac surgery are reviewed. Because consistency is attained more readily, and because control procedures, including quarantining, are applied more readily to batch production of cardioplegic solutions, it is advised that this method be used.

Albumins↗
PubMed1978

Cold cardioplegia versus hypothermia for myocardial protection. Randomized clinical study.

Seventeen of 34 consecutive patients undergoing coronary artery bypass grafting were randomly assigned to one of two methods of myocardial preservation. With the cold cardioplegic method (Group A), a 4 degrees C. asanguineous solution with 30 mEq. of potassium per liter was infused into the aortic root for about 2 minutes immediately after aortic cross-clamping and again after about 45 minutes or when myocardial temperature rose above 19 degrees C. External cardiac cooling was provided by constant infusion of 4 degrees C. Ringer's solution into the pericardium. Seventeen patients were assigned to simple cardiac cooling by hypothermic systemic perfusion before aortic cross-clamping plus external cardiac cooling (Group B). Electromechanical activity ceased within 1 to 2 minutes in Group A but continued throughout the ischemic period in 14 patients in Group B. Myocardial temperature (mean for all observations) during aortic cross-clamping was 17.2 +/- 0.44 degrees C. In Group A and 24.0 +/- 0.70 degrees C. in Group B. Operating conditions were better in Group A. Card-ac function early postoperatively was good in both groups clinically and according to measurements, but only in the cold cardioplegic group (A) was cardiac index not adversely affected by longer cross-clamp time. Myocardial necrosis occurred in both groups but was probably less in the cold cardioplegic group. Thirteen patients (76 percent) in Group A had no electrocardiographic evidence of myocardial injury, compared with eight (47 percent) in Group B (p = 0.08). Eleven (65 percent of Group A had no or short-lived appearance of ceatine phosphokinase isoenzyme (CK-MB), compared with six (35 percent) of Group B (p = 0.08). Time-related CK-MB and SGOT mean levels were consistently lower in Group A.

Cold Temperature↗
PubMedDate not supplied

Comparison of two topical collagen-based hemostatic sponges during cardiothoracic procedures.

The need for topical hemostasis during cardiothoracic procedures continues to fuel the development of additional hemostatic products with a focus on minimizing cost and increasing efficacy. The efficacy of a recently approved collagen-based topical hemostatic agent (Hemostagene, Coletica, S.A., Lyon, France) was tested in a prospective randomized trial of 60 consecutive patients undergoing cardiothoracic surgical procedures. Comparisons to a control collagen sponge (Helistat, Integra Life Sciences, Inc., Plainsboro, NJ) were made and hemostasis was considered successful if bleeding was controlled in 10 min or less. We employed a unique hemorrhage grading scale to more closely assess the relative effectiveness of these different topical agents. Overall, Hemostagene and Helistat achieved a successful hemostasis rate of 75% and 77%, respectively, with no statistically significant difference. The Hemostagene sponge was deemed easier to handle when compared to control. During the study, neither of the products was associated with complications attributable to the topical sponge. In conclusion, Hemostagene had improved handling characteristics yet was equal to Helistat at topical hemostasis, adding an alternative to the topical hemostatic market.

Blood Coagulation↗
PubMedDate not supplied

Reversal of anticoagulation without protamine using a heparin removal device after cardiopulmonary bypass.

Protamine sulfate is routinely administered after cardiopulmonary bypass to reverse systemic heparinization, but may cause a severe hypotensive reaction in as many as 2% of patients. Research Medical, Inc., has developed an extracorporeal venovenous heparin removal device (HRD) for use in patients at high risk for a protamine reaction. Circulation through the HRD removes heparin by hollow fiber plasma separation and selective sorption of anionically charged heparin to a polycationically charged poly-L-lysine ligand coupled to a agarose substrate. The heparin depleted plasma then reenters the whole blood pathway and is returned to the patient through the double lumen catheter in the right atrium. To evaluate the HRD in a clinically relevant model, cardiopulmonary bypass was performed in pigs using RA-Ao cardiopulmonary bypass (120 min) with systemic heparinization (300 IU/kg), a nonpulsatile pump with a membrane oxygenator, and systemic hypothermia (28 degrees C). Group 1 (HEP n = 7) had no intervention to neutralize the heparin; Group 2 (HRD n = 7) used the HRD. After 19.7 +/- 4.2 min of circulation through the HRD, the activated clotting time had returned to baseline, whereas the pigs in the HEP group were still anticoagulated (activated clotting time = 396 +/- 152 sec; time to baseline was 124 +/- 9 min). There were no significant differences between groups with respect to hemodynamics, hematocrit levels, leukocyte profiles, or platelet counts, HRD is an effective heparin removal device in a pig model of cardiopulmonary bypass and awaits a phase I clinical trial in humans.

Animals↗