Twin Transfusion Syndrome

Twin transfusion syndrome (TTS) is a rare, yet frequently fatal, complication of twin gestations. Recently published data demonstrate a reduction in the perinatal mortality rate associated with TTS from nearly 100% to 20-40%. This article explains the pathophysiology of TTS, newly described treatments, complications, and specific aspects of nursing care for patients with this complication of multiple gestation.     

Comparison of Biphasic and Monophasic Pulses: Does the Advantage of Biphasic Shocks Depend on the Waveshape?

With present implantable defibrillators, the ability to vary the defibrillation technique has been shown to increase the number of patients suitable for transvenous system. As newer waveforms become available, the need for a flexible device may change. In addition, although it has been shown that the option of biphasic waveform may increase the defibrillation efficacy, this may depend upon the shape of the biphasic waveform used. Thirty patients undergoing transvenous defibrillator implant were included in the study. In 20 patients (group I), defibrillation efficacy of simultaneous monophasic, sequential monophasic, and biphasic waveform with 50% tilt was determined randomly. Similarly, in ten patients (group II) testing of simultaneous monophasic shocks and biphasic waveforms with 65% and 80% tilt was performed in random order. The electrode system used consisted of two transvenous leads and a subcutaneous patch in all 30 patients. In group I, 50% tilt biphasic waveform consistently provided similar or better defibrillation efficacy compared to monophasic waveforms (biphasic 7.5 ±5.1 joules vs simultaneous 17 ± 7.8 joules, P < 0.01; and vs sequential 17 ± 8.4 joules, P <0.01). In group II, 65% tilt biphasic pulse required less energy for defibrillation as compared with simultaneous monophasic shocks (9.6 ± 4.5 joulesvs 15.6 ± 5.1 joules, P = 0.04). No significant difference was observed in terms of defibrillation threshold between 80% tilt biphasic shocks and simultaneous monophasic pulses (11.8 ± 6 joules vs 15.6 ±5.1 joules, P = NS). Biphasic shocks with smaller tilt delivered using a triple lead system more uniformly improved defibrillation threshold over standard monophasic waveforms.     

Effect of the Implantable Atrial Defibrillator on the Natural History of Atrial Fibrillation

INTRODUCTION: The purpose of our study was to evaluate the effect of repeated cardioversion with an implantable atrial defibrillator on the clinical outcome of patients with atrial fibrillation. METHODS AND RESULTS: The effects of the implantable atrial defibrillator on the total duration of atrial fibrillation, number of atrial fibrillation recurrences, and left atrial size were evaluated prospectively in 16 patients with atrial fibrillation (13 men and 3 women; mean age 58 +/- 11 years). Seven patients had no cardiovascular disease, 5 patients had hypertension, 3 patients had coronary heart disease, and 1 patient had congenital heart disease. Eight patients had paroxysmal atrial fibrillation for a mean duration of 80 +/- 61 months, and eight patients had persistent atrial fibrillation for a mean duration of 68 +/- 119 months. Except for one patient who received digoxin throughout the study, all patients received the same Class I or III antiarrhythmic agent throughout the study. The implantable atrial defibrillator successfully converted 50 (93%) of 54 spontaneous episodes of atrial fibrillation in 12 patients. During the initial 3 months of clinical follow-up, the atrial defibrillator documented 261 +/- 270 hours of atrial fibrillation compared with 126 +/- 172 hours (P = 0.01) during the subsequent 3 months. The left atrial size decreased from 4.4 +/- 0.7 cm at the time of atrial defibrillator implantation to 4.1 +/- 0.6 cm (P = 0.02) 6 months later. The number of atrial fibrillation recurrences did not change. These findings were observed in the absence of changes in drug therapy. No complications were observed. CONCLUSION: Restoration and maintenance of sinus rhythm in patients with atrial fibrillation by repeated cardioversion with an implantable atrial defibrillator was associated with a reduction in the total arrhythmia duration and a reduction in left atrial size. These results suggest that maintenance of sinus rhythm with the atrial defibrillator may reverse the remodeling process associated with atrial fibrillation.     

Modelling crack cocaine use trends over 10 years in a Canadian setting

Introduction and Aims. Crack cocaine use among illicit drug users is associated with a range of health and community harms. However, long‐term epidemiological data documenting patterns and risk factors for crack use initiation remain limited especially among injection drug users. We investigated longitudinal patterns of crack cocaine use among polydrug users in Vancouver, Canada. Design and Methods. We examined the rate of crack use among injection drug users enrolled in a prospective cohort study in Vancouver, Canada between 1996 and 2005. We also used a Cox proportional hazards regression analysis to identify independent predictors of crack use initiation among this population. Results. In total, 1603 injection drug users were recruited between May 1996 and December 2005. At baseline, 7.4% of participants reported ever using crack and this rate increased to 42.6% by the end of the study period (Mantel trend test P < 0.001). Independent predictors of crack use initiation during the study period included frequent cocaine injection, crystal methamphetamine injection, residency in the city's drug using epicenter and involvement in the sex trade (all P < 0.05). Discussion and Conclusions. These findings demonstrate a massive increase in crack use among injection drug users in a Canadian setting. Our findings also highlight the complex interactions that contribute to the initiation of crack use among injection drug users and suggest that evidence‐based interventions are urgently needed to address crack use initiation and to address harms associated with its ongoing use.[Werb D, DeBeck K, Kerr T, Li K, Montaner J, Wood E. Modelling crack cocaine use trends over 10 years in a Canadian setting. Drug Alcohol Rev 2010]     

Offer of financial incentives for unprotected sex in the context of sex work

Introduction and Aims. Commercial sex workers (CSW) are often portrayed as vectors of disease transmission. However, the role clients play in sexual risk taking and related decision making has not been thoroughly characterised. Design and Methods. Participants were drawn from the Vancouver Injection Drug Users Study, a longitudinal cohort. Analyses were restricted to those who reported selling sex between June 2001 and December 2005. Using multivariate generalised estimating equation, we evaluated the prevalence of and factors associated with being offered money for sex without a condom. Results. A total of 232 CSW were included in the analyses, with 73.7% reporting being offered more money for condom non‐use, and 30.6% of these CSW accepting. Variables independently associated with being offered money for sex without a condom included daily speedball use [adjusted odds ratio (AOR) = 1.21, 95% confidence interval (CI): 0.23–0.62], daily crack smoking (AOR = 1.51, 95% CI: 1.04–2.19), daily heroin injection (AOR = 1.76, 95% CI: 1.27–2.43) and drug use with clients (AOR = 3.22, 95% CI: 2.37–4.37). Human immunodeficiency virus seropositivity was not significant (AOR = 0.98, 95% CI: 0.67–1.44). Discussion and Conclusions. Findings highlight the role clients play in contributing to unprotected sex through economic influence and exploitation of CSW drug use. HIV serostatus has no bearing on whether more money is offered for sex without a condom. Novel interventions should target both CSW and clients. [Johnston CL, Callon C, Li K, Wood E, Kerr T. Offer of financial incentives for unprotected sex in the context of sex work. Drug Alcohol Rev 2009]     

FEEDING PRACTICES INFLUENCE WEIGHT AND HEMOGLOBIN STATUSIN KUWAITI INFANTS

Kuwait, one of the wealthiest countries in the Arabian Gulf and the world, has nutritional problems that vary from undernourishment-related anemia to overnourishment (overweight), associated with health complications such as diabetes, hypertension, and heart diseases (Ministry of Health, 1996 Ministry of Health, Kuwait0. 1996. Kuwait Health Survey  [Google Scholar]). Previous studies reported the prevalence of obesity among Kuwaiti school children as 18 per cent and 27 per cent for boys and girls, respectively (Eid etal., 1986 Eid, N., Al–Hooti, S. and Khalafawi, M. 1986. Nutritional Anthropometry of School Children in Kuwait. Nutrition Reports International, 33(253.) [Google Scholar]), and anemia in about 75 per cent of children aged 1–24 months and 40.7 per cent for those aged 25–60 months (Mostafa and Nuwayhed, 1979 Mousa, M. A., Shaltout, A. A., Nkansa–Dwamena, D., Mourad, M., Alsheikh, N., Agha, N. and Galal, D. O. 1999. Factors Associated with Obesity in Kuwaiti Children. European Journal of Epidemiology, 15: 41–49.  [Google Scholar]). The purpose of this study was to evaluate the influence of infant feeding practices and mothers’ education and occupation on hemoglobin (Hb) levels and obesity among young children in Kuwait. Data previously collected (January through November 2000) by the Department of Food and Nutrition Administration of the Ministry of Health from 254 apparently healthy mothers and their infants (127 boys, 127 girls) aged 2–23 months, in all five Governates was used. The lengths, weights, and Hb levels of infants were measured and mothers were asked about their infant feeding practices, number of pregnancies, educational level, and occupation. The prevalence of anemia among Kuwaiti infants in this study was significantly (p=0.004) higher (29.5%) than that reported for American infants, 18.4 per cent (DHHS 1997 Department of Health and Human Services (DHHS). 1997. “Healthy People 2000”. In National Health Promotion and Disease Prevention Objectives (DHHS Publication No. PHS), DHHS Publication No. PHS 91–50212/G Washington, DC: U.S. Department of Health and Human Services.  [Google Scholar]). Formula-fed Kuwaiti infants were significantly (P<0.001) heavier (9.38±2.35) than the breast and mixed-fed group

(7.98±1.75). Our findings suggest that programs for the prevention and control of obesity and anemia in Kuwait should be a priority on the national nutrition and health agenda.     

The Short- and Long-Term Outcome of Left Internal Mammary Artery Angioplasty

Failure of internal mammary artery (IMA) bypass grafts is uncommon. However, as their use continues to increase, this complication will be encountered more frequently by interventional cardiologists. The purpose of this article is to describe the short- and long-term outcome of patients undergoing IMA angioplasty through a retrospective review of patients undergoing internal mammary angioplasty at two centers from January 1988 to June 1995. Percutaneous recanalization was attempted on 82 lesions either within an IMA or in the ongoing native left anterior descending artery during 74 procedures in 67 patients. The mean time from bypass surgery was 23 months. The lesion success rate was 84%. Dissection of the IMA occurred in 18% of procedures and was the most common cause for procedural failure and unfavorable outcome. Long-term follow-up was available in 82% of patients at a mean follow-up of 45 months postprocedure. Clinical events occurred in 23 patients (34%) with 4 deaths (1 of which occurred during the initial hospitalization and after emergency bypass surgery), 2 repeat coronary bypass operations, and 17 patients with repeat coronary angioplasties. Despite the high repeat revascularization rate, 80% of patients were asymptomatic or had only infrequent angina at follow-up. We conclude that angioplasty of or through an IMA bypass graft can be performed with a satisfactory procedural success rate and long-term symptomatic benefit.     

Central line infection: a review

• ? There is increasing and widespread use of central line catheterization in clinical practice. Nevertheless, there is a growing awareness and concern about the escalating rate of infection related to central lines, especially in those patients receiving total parenteral nutrition.
• ? This paper reviews selected studies which have identified factors contributing to central line infection.
• ? Factors relating to all areas of catheter management, including insertion, maintenance and removal have been implicated in central line infections.
• ? Nurses who are involved to varying degrees in all phases of central line management, play an important role in infection control.
• ? An understanding of infection-related factors is the first step needed to effect changes in procedures and protocols in the care of patients with central lines.