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Biomedical subjects

Usha Kiran

Publications and source records attributed to Usha Kiran.

14 recordsLinked to original sources
PubMed2006

Arterial-to-end-tidal carbon dioxide tension difference in children with congenital heart disease.

OBJECTIVES: This study estimated the arterial-to-end-tidal carbon dioxide tension difference (deltaPaCO2-PE'CO2) in children with congenital heart disease; evaluated whether hyperventilation can reduce this difference; and analyzed the relationship between the difference and the oxygen saturation (SaO2) and hemoglobin level. DESIGN: Prospective clinical study. SETTING: Tertiary health care center. PARTICIPANTS: One hundred patients scheduled for correction of their underlying cardiac defect with either right-to-left or left-to-right intracardiac shunts were divided into 4 groups (n = 25 each): (1) N1, cyanotic with severe pulmonary artery hypertension; (2) N2, cyanotic with normal or decreased pulmonary artery pressure (PAP); (3) N3, acyanotic with normal or mild increases in PAP and severe increases in pulmonary blood flow (PBF); and (4) N4, acyanotic with normal PAP and normal or mild increase in PBF. INTERVENTIONS: All the patients received the same anesthetic regimen. The initial settings for tidal volume, respiratory rate, and inspiratory-to-expiratory (I:E) ratio were 10 mL/kg, 15 to 30 breath/min, and inspired time 40% of the total respiratory period with a 10% end-inspiratory pause. After the measurement of oxygen saturation, PO2, Hb, and deltaPaCO2-PE'CO2, all the children were hyperventilated (tidal volume: 14-15 mL/kg, respiratory rate: 5-6 breaths/min more than the initial rate, I:E ratio: same) to observe its effects on the deltaPaCO2-PE'CO2. MEASUREMENTS AND RESULTS: The deltaPaCO2-PE'CO2, when predicted from the oxygen saturation, hemoglobin concentration, and PaO2, was found to be greater than the observed value in the first 3 groups (p < 0.001); whereas in group N4 these 2 values were comparable. It was also found that the gradient was higher when there was a decrease in SaO2 and an increase in the hemoglobin level. After hyperventilation, in groups N1 and N3, deltaPaCO2-PE'CO2 was decreased when compared with their baseline values; this reduction was not as much as predicted (p = 0.363 and 0.236, respectively). However, in groups N2 and N4 posthyperventilation, the deltaPaCO2-PE'27 CO2 was decreased significantly below their baseline measurements. These decreases were as much predicted. CONCLUSION: The deltaPaCO2-end-tidal carbon dioxide (PE'CO2) can be increased both in cyanotic and acyanotic children. Increased PAP is as important as increased PBF or right-to-left shunting in producing disorders in carbon dioxide homeostasis. Hyperventilation is of little use in reducing deltaPaCO2-PE'CO2 in children with high PAPs and pulmonary hyperperfusion.

Blood Gas Analysis↗
PubMed2005

Interruption of aortic arch in adults: surgical experience with extra-anatomic bypass.

We reviewed our 3-year experience in treating interruption of the aorta in adult patients. Clinical profiles, surgical management, and results of early and mid-term follow-up are presented. From August 2001 through June 2003, 7 adult patients underwent an extra-anatomic bypass procedure to repair interruption of the aortic arch. Five patients underwent ventral aortic repair through a mid-sternotomy and an upper midline laparotomy, and 2 patients underwent repair through a left posterolateral thoracotomy. A bovine collagen-impregnated polyester fiber graft was used in 6 patients, and a Gore-Tex graft was interposed in 1 patient. All repairs were performed without cardiopulmonary bypass. Follow-up was complete in all patients. The mean follow-up was 1728 +/- 1 months (range, 9-31 months). No neurologic, renal, or gastrointestinal complications were noted in any patient. There was no in-hospital or late mortality or need for re-intervention. All patients were asymptomatic; however, 5 patients had mild residual hypertension. Graft patency in all the patients was confirmed by computed tomographic angiography. Interruption of the aorta is rare in adults. Ventral aortic repair through a midline approach is our preferred technique for surgical repair of this entity, because it avoids the extensive network of collateral vessels on the chest wall, enables simultaneous treatment of associated lesions, and in all likelihood reduces morbidity and mortality.

Adult↗
PubMed2004

Comparison of epsilon aminocaproic acid and tranexamic acid in pediatric cardiac surgery.

OBJECTIVE: This study compared the efficacy of aminocaproic acid and tranexamic acid in reducing postoperative blood loss, as well as blood and blood product requirements in children with cyanotic congenital heart disease. DESIGN: A prospective randomized study. SETTING: Cardiac center of a tertiary care, referral hospital. PARTICIPANTS: One hundred fifty children in the age group of 2 months to 14.5 years with cyanotic congenital heart disease undergoing corrective surgery on cardiopulmonary bypass (CPB). INTERVENTIONS: Patients were randomized into 3 groups. Group A was given aminocaproic acid in a dose of 100 mg/kg after anesthetic induction, 100 mg/kg on CPB and 100 mg/kg after protamine. Group T was given tranexamic acid, 10 mg/kg, after anesthetic induction, 10 mg/kg on CPB, and 10 mg/kg after protamine. Group C was the control group. MAIN RESULT: Control group had the longest sternal closure time, maximum blood loss at 24 hours, and maximum requirements of blood and blood products. Among the 2 groups given antifibrinolytics, there was no significant difference in postoperative blood loss, blood and product requirement, and reexploration rates. CONCLUSION: Aminocaproic acid and tranexamic acid are equally effective in reducing postoperative blood loss, as well as blood and blood product requirements in children with cyanotic heart disease undergoing corrective surgery as compared with the control group.

Adolescent↗
PubMed2004

Dose comparison of tranexamic acid in pediatric cardiac surgery.

To compare different doses of tranexamic acid, 150 consecutive children with congenital cyanotic heart disease were randomly assigned to one of 5 groups of 30 each. Group A served as a control. Group B received 50 mg.kg(-1) of tranexamic acid at induction of anesthesia. Group C received 10 mg.kg(-1) at induction followed by an infusion of 1 mg.kg(-1).h(-1). Group D had 10 mg.kg(-1) at induction, 10 mg.kg(-1) on bypass, and 10 mg.kg(-1) after protamine. Group E had 20 mg.kg(-1) at induction and again after protamine. The control group had the longest sternal closure time, the greatest blood loss in the first 24 hours, and the highest requirements for blood and blood products. Among the 4 groups given tranexamic acid, group D (triple dose) had the best results, followed by group E (double dose). Group B (single dose) had the worst results among the groups receiving tranexamic acid.

Adolescent↗
PubMed2003

Medicinal and aromatic plant materials as nitrification inhibitors for augmenting yield and nitrogen uptake of Japanese mint (Mentha arvensis L. Var. Piperascens).

Pot experiments were conducted to evaluate the relative performance of medicinal and aromatic plant materials and dicyandiamide (DCD) as nitrification inhibitors to regulate transformation of N from urea. Their effect on the efficiencies of use of N by Japanese mint (Mentha arvensis cv. Hy 77) was tested. Urea was coated with these materials viz., Mentha spicata, Artemisia annua or DCD at the rate of 5% (w/w) of fertilizer urea using an appropriate coating technique. Nimin (tetranortriterpenoids, an ethanol extract of neem (Azadirachta indica Juss) coating was done at the rate of 1% w/w of urea. Fertilizer nitrogen was applied at 100 and 200 mg kg(-1) soil. These natural coating materials significantly increased the herb and essential oil yields of the crop at both rates of fertilizer nitrogen compared to urea alone and were found to be as effective as DCD in retarding NO3- formation in soil. Herb yield increased by 6-81% when compared to uncoated urea. The increase in essential oil yield ranged between 3% and 68% due to coating. The effectiveness of the nitrification-inhibitor--coated urea, however, varied with the soils used and the rate of fertilizer nitrogen applied. The results suggest that the natural products could be potential nitrification inhibitors for increasing fertilizer N use efficiency.

Biological Availability↗