Flecainide

Flecainide. Flecainide is a Class IC antiarrhythmic agent whose primary electrophysiologic effect is a slowing of conduction in a wide range of cardiac tissues. It is well absorbed and effective in suppressing isolated premature ventricular contractions (PVCs) or nonsustained ventricular arrhythmia but has only a modest efficacy when electrophysiologic testing is used as an endpoint. Us adverse effect on mortality in the CAST trial suggested a propensity to proarrhythmia-a phenomenon to which the Class IC agents appear particularly prone. Despite the applicability of the CAST study only to patients with a prior myocardial infarction, there has been a shift away from flecainide in ventricular arrhythmia, but the low noncardiac side effect profile of the agent allows for its continued use in a wide variety of supraventricular arrhythmias. ( J Cardiovasc Electrophysiol, Vol. 5, pp. 964–981. November 1994 )     

Intercostal nerve blockade versus thoracic epidural analgesia for post thoracotomy pain relief

Background Post thoractomy pain is a major source of concern in the postoperative period. The purpose of this study was to evaluate the effectiveness of intraoperative temporary intercostal nerve blockade versus thoracic epidural analgesia for control of post thoracotomy pain. Methods 40 patients undergoing elective pulmonary resection through a postero lateral thoractomy were randomly allocated to receive epidural analgesia using 0.25% bupivicaine (Group A, n=20) or temporary intercostal nerve blockade using 0.25% bupivicaine (Group B, n=20). Adequacy of analgesia was assessed over a period of 24 hours using a visual analogue score and an observer verbal ranking scale. Results Pain scores were similar in both the groups for the first 4 hours after surgery. Thereafter, the pain scores were significantly higher (p<0.05) in Group B as compared to Group A for the remainder of the observation period. There was significantly higher (p<0.01) usage, of nonsteroidal analgesic consumption in Group B. No neurological complications were encountered, in both the study groups. Conclusion We conclude that in the early postoperative period there is no significant difference in pain relief in both the techniques but there after, epidural analgesia significantly reduces post thoracotomy pain.     

Thoracic epidural infusions for post thoracotomy pain relief: a clinical study to compare the efficacy of fentanyl — bupivicaine mixtures versus fentanyl alone

Background: Optimum pain relief following thoracotomy is essential for patient comfort and to reduce the incidence of postoperative pulmonary complications. Methods: A randomized clinical trial was conducted on 90 patients scheduled for pulmonary resection. The patients were randomly divided into three groups. Group 1 received 0.125% bupivicaine with fentanyl 10μg.ml⁻¹, Group 2 received 0.25% bupivicaine with fentanyl 10μg.ml⁻¹ and Group 3 received only fentanyl 10μg.ml⁻¹ in a calculated dose as a continuous thoracic epidural infusion. Adequacy of anglesia was assessed at rest and during movement over 24 hours. Analgesic efficacy was assessed using a visual analogue score and an observer verbal ranking scale. Results: Pain scores were significantly higher in Group 3 during the assessment period. (p<0.01) as compared to the other groups. The use of intraoperative vasopressors was significantly higher (p<0.05) in Group 2 as compared to the other groups. No neurological complications were encountered in any of the study groups. Conclusion: We conclude that in the early postoperative period, the use of 0.125% bupivicaine improves fentanyl epidural analgesia in patients undergoing lung resection.     

Haplotype relative risks: an easy reliable way to construct a proper control sample for risk calculations

An alternative to Woolf's (1955) relative risk (RR) statistic is proposed for use in calculating the risk of disease in the presence of particular antigens or phenotypes. This alternative uses, as the control sample, the parental antigens or haplotypes not present in the affected child. The formulation of a haplotype relative risk (HRR) thus eliminates the problems of sampling from the same homogeneous population to form both the disease sample and an appropriate control.
We show that, in families selected through a single affected individual, where transmission of the four parental haplotypes can be followed unambiguously, the mathematical expectation of the HRR is identical to that of the RR. Since the sample formed from the 'non-affected' parental haplotypes is clearly from the same population as the disease sample, the HRR thus provides a reliable alternative to the RR. A further advantage obtains when family data are being collected as part of a study since the control sample is then automatically contained in the family material.
Data from studies of patients with insulin dependent diabetes mellitus (IDDM) are used to obtain an estimate of the risk to those with HLA antigens or phenotypes associated with IDDM using the HRR statistic. A comparison of the HRR's and RR's for these data is also presented.