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R Chawla

Publications and source records attributed to R Chawla.

63 records · Page 4Linked to original sources
PubMedDate not supplied

Clinical agreement in quantitative measurements.

With advances in medical technology, simpler and safer methods for diagnosis and therapy are increasingly replacing the old ones and it has become important that these be correctly assessed. When a measurement by a new method is the same as that using the old method, one frequently encounters the problem of assessing the agreement. Evidence such as a correlation equal to 1 or equality of means is known to be inadequate. However, two recent approaches--limits of agreement and intraclass correlation coefficient--have gained acceptance but each has its own merits and demerits. To help investigators choose a procedure which is appropriate and to help them use it properly, we provide a description of these two approaches and discuss their advantages and disadvantages, both clinical and statistical, using a real example.

Analysis of Variance↗
PubMedDate not supplied

Transcatheter closure of atrial septal defect using buttoned device--Indian experience.

Transcatheter closure of secundum atrial septal defect (ASD) < 21 mm in diameter with adequate septal margins, assessed by transthoracic echocardiography (TTE) was attempted using Sideris buttoned device under fluoroscopic and TTE guidance in 27 patients (age range 5-35 years). The stretched diameter of ASD estimated by balloon sizing at cardiac catheterization was, on an average, 3 mm larger than assessed on TTE. A 25 to 50 mm second-generation Sideris device could be successfully implanted in 24 patients, with disappearance of left-to-right shunt, assessed by colour flow mapping on TTE in 17 patients. Residual shunt of 0.12-0.54 L/min/m2 was seen on day one in 7 patients which increased on follow-up in 3 patients over a period of 12 months. The maximum shunt in one patient was 1.1 L/min/m2. On follow-up (14.5 +/- 3.8 months), the device was in a stable position in all patients evaluated by fluoroscopy and TTE, and intracardiac ultrasound study in two patients. The procedure was unsuccessful in 3 patients, due to unbuttoning of the device in one and recurrent slippage of the device through the ASD in two patients. Mitral regurgitation was detected in 5 patients on follow-up (mild in 4 and moderate in 1). There was no mortality and none of the patients required any surgical intervention. It is concluded that transcatheter closure of some selected cases of secundum ASD can be safely and effectively done using Sideris buttoned device through a small sheath; however, a centering device is likely to close larger defects with less interference with mitral valve function.

Adolescent↗
PubMedDate not supplied

Methodological variation and agreement in assessing mitral valve orifice area by echo-Doppler methods in mitral stenosis.

Two-dimensional echocardiographic planimetry of the directly observed mitral valve orifice, pressure-half-time methods, continuity equation and the Gorlin formula are commonly used to calculate the mitral valve area. However, there have been few comparisons of the four methods. In this study, the mitral valve orifice area was determined by the above four methods using echo-Doppler data in 49 consecutive patients in sinus rhythm (mean area 0.87 to 1.26 cm2). The valve area estimated by these methods correlated well (r = 0.7 to 0.97) with excellent agreement between the continuity equation and the Gorlin formula (mean difference 0.4 cm2, r = 0.97, SEE = 0.26) and between the planimetric area and the pressure-half-time method (mean difference = 0.06 cm2, r = 0.87, SEE = 0.23). However, the limits of agreement were wide and exceeded 1 cm2 in planimetry versus the Gorlin, planimetry versus the continuity equation and pressure-half-time method versus the Gorlin formula. The standard error of estimate varied from 0.23 to 0.51 cm2 for various comparisons. Use of an empirical constant of 51.6 instead of 37.7 in the Gorlin formula provided excellent correlation between the valve area determined by the continuity equation and the modified hydraulic formula (mean difference 0.07 cm2, r = 0.95, SEE = 0.08). Estimates of the valve orifice area by any of the equations tested should be seen as a guide rather than a precise measure of actual orifice area.

Adolescent↗
PubMedDate not supplied

Efficacy and safety of promethazine hydrochloride as a local anaesthetic agent for inguinal hernia repair: a pilot study.

Promethazine hydrochloride is known to possess properties as a local anaesthetic which scientists have not researched well. Therefore, a prospective, randomised, double-blind clinical study was conducted to evaluate the efficacy of promethazine hydrochloride compared to lignocaine hydrochloride, when used as a local anaesthetic agent. Twenty adult male patients undergoing inguinal hernia repair were included in the study. Regional nerve block technique was employed in all the patients. Efficacy of the agents was assessed on a four-point scale and by recording the pulse and the blood pressure. Promethazine hydrochloride was found to be as effective as lignocaine hydrochloride in terms of the intensity and the duration of regional anaesthesia produced. None of the patients from either group required additional anaesthesia in any form, and no complications were witnessed. To conclude, promethazine hydrochloride appears to be a safe alternative to lignocaine hydrochloride for performing surgery under regional anaesthesia.

Adult↗