Vacuum-assisted apical suction devices induce passive electrical changes consistent with myocardial ischemia during off-pump coronary artery bypass graft surgery

Objective: Off-pump coronary artery bypass graft surgery is common therapy to completely revascularize diseased hearts. In order to graft posterior arteries in this procedure, the heart must be lifted from the chest cavity and manipulated to expose the surgical field using an apical suction device. This suction device may cause unwanted myocardial ischemia. Methods: In this observational study, we measured myocardial electrical impedance, a parameter that responds to myocardial ischemia, as well as ST-segment changes during off-pump coronary artery bypass graft surgery in 12 patients with two-vessel coronary artery disease undergoing revascularisation of the left anterior descending and the posterior descending coronary arteries. During the posterior descending artery revascularisation phase of the procedure the apical suction device was oriented over the electrodes used to measure myocardial electrical impedance, thus allowing us the opportunity to assess myocardial ischemia in this region of the heart. Results: In these 12 patients, myocardial electrical impedance progressively increased under the suction device during posterior coronary artery revascularisation, suggesting that myocardial ischemia developed in this region of the myocardium. ST-segment changes were negligible while the heart was vertically displaced (and the suction device attached), but increased immediately when the heart was returned to the neutral anatomical position. Conclusion: Our data suggest that the apical suction device may cause ischemia while the heart is vertically displaced and electrically disconnected from the body. Under these conditions, ST-segment changes may not detect myocardial ischemia. Myocardial electrical impedance has the potential to reliably detect intraoperative myocardial ischemia under these circumstances.     

UK study of intrapartum care for low risk primigravidas: a survey of interventions

STUDY OBJECTIVE: To determine the extent of intrapartum intervention received by primigravidas. DESIGN: Cross sectional survey of NHS hospitals in the UK. SETTING: One hundred and one randomly selected hospital maternity units. PARTICIPANTS: Forty consecutive primigravid women, judged to be at low risk at the start of labour, in each hospital. MAIN OUTCOME MEASURES: Seven groups of interventions or monitoring procedures were identified from the first, second, and third stages of labour: fetal monitoring, vaginal examinations, artificial rupture of membranes, augmentation of labour, pain relief, type of delivery, and episiotomy. Data were collected during 1993. MAIN RESULTS: Ninety eight hospitals took part in the study and data were collected on 3160 low risk primigravidas. Seventy four per cent of these women had continuous cardiotocography. The proportion of women having restrictive or invasive fetal monitoring showed appreciable geographical variation for both the first and second stages of labour. Using the criterion of a vaginal examination every four hours and allowing for the length of each woman's labour, 72% had more vaginal examinations than expected; there was a significant geographical variation in the number of women receiving more than five examinations. Fifty three per cent had artificial rupture of membranes; the procedure was performed over a wide range of cervical dilatations (0 cm-10 cm). Thirty eight per cent of labours were augmented, most commonly by intravenous syntocinon; the procedure showed significant geographical variation. Twenty eight per cent had a spinal block or epidural analgesia for the relief of pain; this intervention varied by geographical region only for the second stage of labour. Over one quarter of the women required instrumental delivery. Forty six per cent had an episiotomy; the frequency of this intervention varied substantially by region. There were no infant deaths. Twelve babies were recorded at birth as having a congenital anomaly. CONCLUSIONS: The rates of several interventions seem high for this low risk group and there was substantial geographical variation in the use of six interventions. Clinical trials are needed to evaluate the optimum criteria for using these interventions from which guidelines should be drawn up by local groups and the Royal College.     

Health knowledge of children in Bangladesh: an exploratory study

This article explores the relationship between selected socio-economic factors and health knowledge of children in Bangladesh. Data was generated from a representative sample survey of 2520 children aged 11–12 y and resident throughout the country. A total of six health knowledge items, all of which are very relevant to Bangladesh, were assessed in this study. Both bivariate and multivariate analysis were used for this purpose. Analysis revealed that the urban/rural residence of the child, the length of the child's schooling in years, the parental level of education and the economic status of the household was associated with the level of health knowledge of the children. To achieve the required improvement in health knowledge of Bangladeshi children this study concluded that adequate schooling of all children must be ensured by removing social barriers to this. Greater educational investment as well as quality education related to everyday life should be provided in rural areas.     

Association of vasculitic glomerulonephritis with membranous nephropathy: a report of 10 cases

Background. The concomitant occurrence of a vasculitic glomerulonephritis and membranous nephropathy in the same patient is unusual. We report data on 10 patients with this unusual combination. Methods. Ten patients (nine males/one female; median age 63.5 years, range 30-70 years) presented between 1981 and 1995 with: acute renal failure (n = 3), nephrotic syndrome (n = 4), non-nephrotic range proteinuria and renal insufficiency (n = 3). The median serum creatinine at presentation was 296 &mgr;mol/l (range 65-1749 mgr;mol/l). One patient had a vasculitic transformation from membranous nephropathy 5 years after the original presentation, coincident with an acute deterioration of renal function requiring dialysis; in all other patients the two glomerular disorders were seen together at presentation. Treatment was with oral prednisolone and cyclophosphamide (eight patients), of whom one also had plasma exchange; and oral prednisolone and azathioprine (one patient). Specific immunosuppressive treatment was withheld in one patient with histological evidence of chronic renal damage. Sera from four patients out of nine tested were positive for ANCA. Results. After a median follow-up of 3.5 years (range 2 months - 10 years), renal function had improved in three patients and remained stable in two. Two patients required renal replacement therapy. Three patients had died: one was ANCA-negative and died of a systemic vasculitis, and the other two died of sepsis. Conclusion. Membranous nephropathy complicated by a vasculitic glomerulonephritis: (1) has a more aggressive clinical course than membranous nephropathy alone, (2) appears to have an association with ANCA, (3) should be considered in those patients with an accelerated decline in renal function, and (4) may respond to treatment with immunosuppressive drugs.     

Renal histopathology in fatal cases of diarrhoea-associated haemolytic uraemic syndrome

 Autopsy material was examined from British children dying early in the course of haemolytic uraemic syndrome (HUS). These presented after 1983, the period in which verocytotoxin-producing Escherichia coli (VTEC) infection was confirmed as the leading cause of diarrhoea-associated (D+HUS) in the United Kingdom. Of 18 cases referred for this study, 3 were found on review to have no history of a diarrhoeal prodrome (D-HUS). In the D+ patients, the median duration from onset of diarrhoea to death was 8 days (range 4–42 days). VTEC infection was confirmed in 6 cases. All had neutrophilia at presentation (median 21, range 15–49.8 × 10⁹/l). The 15 cases had uniform pathological features, consisting of glomerular thromboses and congested rather than ischaemic glomeruli. Arteriolar thromboses were common at the hilum of glomeruli and were sometimes also seen proximally, including in interlobular arteries. There were cortical infarcts in 5 cases with extensive thrombosis. Cases were demonstrated to have significantly greater numbers of neutrophils expressed per 100 glomeruli than controls, when counted using immunohistological stains to neutrophil elastase and CD15. This study showed uniformity of the renal changes in D+ HUS and gave further evidence of the importance of neutrophils in the pathogenesis of the disease. Received November 15, 1996; received in revised form February 25, 1997; accepted February 27, 1997     

Endocytotic uptake of small unilamellar liposomes by human trophoblast cells in culture

We evaluated the mechanism of uptake of carboxyfluorescein-containing small unilamellar liposomes of different surface charge by trophoblast cells in culture. Carboxyfluorescein-encapsulated neutral liposomes were prepared by using equimolar concentrations of lecithin and cholesterol. Anionic and cationic liposomes were prepared by adding dicetylphosphate and stearylamine. Trophoblast cells from human term placenta were cultured and incubated on the first day at 37 degrees C with liposome-encapsulated carboxyfluorescein or 500 nM of free carboxyfluorescein. The mechanism of uptake was determined by pre- treating the cells with metabolic inhibitors: 2 mM of sodium azide and 25 mM of deoxyglucose for 30 min. The uptake of liposomes was also evaluated both qualitatively under fluorescent microscope and quantitatively by measuring carboxyfluorescein fluorometrically. The uptake of free carboxyfluorescein and cationic liposomes was comparable. The anionic liposomes were taken up by the trophoblast cells more avidly than the neutral (13.2 +/- 1.6 versus 9.5 +/- 1.4%; P <0.01), cationic (2.9 +/- 0.4%; P <0.001) and the free carboxyfluorescein (2.1 +/- 0.9%; P <0.01). When cells were pre-treated with metabolic inhibitors, the uptake of anionic (5.9 +/- 1.8%; P <0.001) and neutral liposomes (4.0 +/- 0.8%; P <0.01) was significantly reduced, whereas uptake of cationic and free carboxyfluorescein remained unaltered. This study indicates that small unilamellar liposomes are internalized by the trophoblast cells in culture by an energy-dependent pathway; most probably by endocytosis. The neutral and anionic liposomes are internalized more avidly than cationic liposomes.