Cardiopulmonary bypass considerations for pediatric patients on the ketogenic diet.

BACKGROUND: There is a population of children with epilepsy that is refractory to anti-epileptic drugs. The ketogenic diet, a high-fat, low-carbohydrate regimen, is one alternative treatment to decrease seizure activity. Special considerations are required for patients on the ketogenic diet undergoing cardiopulmonary bypass (CPB) to prevent exposure to glucose substrates that could alter ketosis, increasing the risk of recurrent seizures. CASE STUDY: A 2-year-old, 9 kilogram male with a history of infantile spasms with intractable epilepsy, trisomy 21 status post tetralogy of Fallot repair, presented to the cardiac operating room for closure of a residual atrial septal defect. All disciplines of the surgical case minimized the use of carbohydrate-containing and contraindicated medications. Changes to the standard protocol and metabolic monitoring ensured the patient maintained ketosis. DISCUSSION: All disciplines within cardiac surgery need to be cognizant of patients on the ketogenic diet and prepare a modified protocol. Future monitoring considerations include thromboelastography, electroencephalography and continuous glucose measurement. Key areas of focus with this patient population in the cardiac surgical theater are to maintain a multidisciplinary approach, alter the required CPB prime components, address cardiac pharmacological concerns and limit any abnormal hematological occurrences.

Evaluation of the Maquet Neonatal and Pediatric Quadrox I with an integrated arterial line filter during cardiopulmonary bypass.

BACKGROUND: Perfusion equipment has evolved since its introduction into clinical practice more than fifty years ago to include smaller cardiopulmonary bypass (CPB) circuits and components. Perfusionists are now exploring the function of new oxygenators with an integrated arterial line filter (IALF). The purpose of this trial was to examine the Maquet Quadrox-I Neonatal and Pediatric oxygenators with IALF in a clinical setting, with respect to gas transfer, heat exchange co-efficiency (HEC), trans-membrane pressure (TMP) gradient and clinical experience. METHODS: The Maquet Quadrox-I Neonatal oxygenator was used on 30 patients ranging from 2.2-13.1 kg. The Maquet Quadrox-I Pediatric oxygenator was used on 15 patients ranging from 12.7-24.5 kg. Arterial and venous blood gases were taken once the patient was stable on CPB and, subsequently, every 30 minutes afterwards, as per institution protocol. The values for gas transfer rates, HEC and TMP gradient were stratified into three main categories with each oxygenator: normothermia, cooling and re-warming. RESULTS: During all conditions, the gas transfer rate with both oxygenators was efficient. The HEC values showed efficient heat exchanger performance during all conditions with both oxygenators. While maintaining CPB flow within the manufacturer's recommended flow rate for each oxygenator, the TMP gradient range for the Neonatal Quadrox-I was 10-40 mmHg and the Pediatric Quadrox-I was 10-60 mmHg. During the clinical trial, foam was shown to break through the cardiotomy on several occasions when high sucker return was required. CONCLUSION: This new line of oxygenators performed well with regards to gas transfer, HEC and TMP gradient, but there were clinical experiences that did not meet expectations. There were repeated incidences with the venous reservoir which ultimately cast a negative light on the design of this new product from Maquet. In the future, the authors would like to evaluate updated versions of this product from Maquet and any other pediatric perfusion devices that could help the patient in the clinical arena.

A systematic evaluation of the core communication skills expected of a perfusionist.

BACKGROUND: The objective of this systematic evaluation was to identify the sentinel standards necessary to obtain a core level of communication required of a clinical perfusionist during cardiopulmonary bypass (CPB). Once these sentinel standards were identified and a core level of communication was established (via four simulated case scenarios), a team of cardiac healthcare professionals was assembled to interpret both the accuracy of response and the speed of response encountered in each case scenario. METHODS: Four simulated case scenarios were utilized in order to replicate the typical patterns of verbal exchange that occur during surgeries using extracorporeal technology. The simulated case scenarios included CPB interactions associated with preparation, initiation, maintenance, termination and post CPB. For all CPB interactions, two variables were measured: accuracy of the perfusionist's response and speed of the perfusionist's response. The cases took place in a controlled setting within an empty operating room at The Children's Hospital of Philadelphia. Four clinical perfusionists each represented the role of the "perfusionist" in all simulated case scenarios. RESULTS: When analyzing the accuracy and speed of the responses, each clinical perfusionist recorded an average score of 96.3% or higher with all case scenarios. Since the clinical perfusionists who participated in the scenarios were primarily pediatric perfusionists, the scores were best during the pediatric case scenario, 99.3% (Case Scenario #4). The lowest scores were captured during Case Scenario #3 (96.3%) which involved a more intense adult patient scenario. CONCLUSION: The systematic evaluation of both response accuracy and response time (presented in various adult and pediatric patient case scenarios) can be beneficial within the realm of perfusion education. Students will be introduced to core communication concepts within the clinical realm. This study supports the idea that simulation and evaluation may ease the transition for students from the didactic to clinical realm in terms of communication. Further studies need to be developed in order to define "standard" CPB communication guidelines for perfusion students.

TNF-like weak inducer of apoptosis inhibits proinflammatory TNF receptor-1 signaling.

Soluble TNF-like weak inducer of apoptosis (TWEAK) trimers induce, in a variety of cell lines, translocation of cytosolic tumor necrosis factor (TNF) receptor-associated factor-2 (TRAF2) to a triton X-100-insoluble compartment without changes in the total cellular TRAF2 content. TWEAK-induced TRAF2 translocation is paralleled by a strong increase in nuclear factor kappaB 2 (NFkappaB2)/p100 processing to p52, indicating that TRAF2 redistribution is sufficient for activation of the alternative NFkappaB pathway. In accordance with the crucial role of TRAF2 in proinflammatory, anti-apoptotic TNF receptor-1 (TNFR1) signaling, we observed that TWEAK-primed cells have a reduced capacity to activate the classical NFkappaB pathway or JNK (cJun N-terminal kinase) in response to TNF. Furthermore, TWEAK-primed cells are sensitized for the TNFR1-mediated induction of apoptotic and necrotic cell death. Notably, the expression of the NFkappaB-regulated, TRAF2-interacting TRAF1 protein can attenuate TWEAK-induced depletion of the triton X-100-soluble TRAF2 fraction and improve TNFR1-induced NFkappaB signaling in TWEAK-primed cells. Taken together, we demonstrate that soluble TWEAK desensitizes cells for proinflammatory TNFR1 signaling and thus identify TWEAK as a modifier of TNF signaling.

Angiotensin inhibition and malignancies: a review.

After an early report that patients treated with angiotensin-converting enzyme (ACE) inhibitors had a lower than expected incidence of cancers, there was a large number of publications investigating the possible pathophysiological mechanism mediating this effect, as well as population studies comparing the incidence of cancers in patients treated with agents inhibiting the renin-angiotensin system with their incidence in the general population. Several mechanisms are proposed to explain a potential anti-tumour activity of such agents in vitro in experimental animal models. However, the population studies are mostly inconclusive, although they do suggest a possible interaction between ACE genotypes and susceptibility to altered behaviour of certain tumours.

Synapsin-like immunoreactivity is present in hair cells and efferent terminals of the toadfish crista ampullaris.

The synapsins are presynaptic membrane-associated proteins involved in neurotransmitter release. They are differentially expressed in tissues and cells of the central and peripheral nervous system. In vestibular end organs of mammals, synapsin I-like immunoreactivity has been reported in efferent and afferent terminals and in afferent nerve calyces surrounding type I hair cells. In addition, synapsin I has recently been described in several non-neural cell lines. The present study was conducted to locate synapsin-like immunoreactivity in the neuronal and non-neuronal cells of the fish crista ampullaris, to examine the possibility that the non-neuronal sensory receptor cells express synapsins in vivo. Synapsin-like immunostaining was visualized by immunofluorescence detection in wholemounts of the toadfish crista ampullaris using multiphoton laser scanning microscopy and by electron microscopic visualization of post-embedding immunogold labeling. The results demonstrate that synapsin-like immunoreactivity is present in vestibular hair cells and efferent boutons of the toadfish crista ampullaris. Afferent endings are not labeled. Staining in hair cells is not associated with the synaptic ribbons, suggesting that there is an additional, non-synaptic role for the synapsins in some non-neuronal cells of vertebrates. Moreover, while the cristae of amniote and anamniote species share many functional attributes, differences in their synaptic vesicle-associated protein profiles appear to reflect their disparate hair cell populations.

A multimodal assessment of driving performance in HIV infection.

OBJECTIVE: To examine if HIV-seropositive (HIV+) individuals are at risk for impaired driving. METHODS: Sixty licensed drivers (40 HIV+, 20 HIV-) completed a neuropsychological (NP) test battery and driving assessments. Eleven HIV+ subjects were NP-impaired. Driving-related skills were assessed using 1) two driving simulations (examining accident avoidance and navigational abilities), 2) the Useful Field of View (UFOV) test, and 3) an on-road evaluation. RESULTS: HIV+ NP-impaired subjects had greater difficulty than cognitively intact subjects on all driving measures, whereas the HIV- and HIV+ NP-normal groups performed similarly. On the UFOV, the HIV+ NP-impaired group had worse performance on Visual Processing and Divided Attention tasks but not in overall risk classification. They also had a higher number of simulator accidents (1.3 vs 2.0; p = 0.03), were less efficient at completing the navigation task (3.2 vs 9.2 blocks; p = 0.001), and were more likely to fail the on-road evaluation (6 vs 36%; p = 0.02). Impairment in Executive Functioning was the strongest NP predictor of failing the on-road drive test. NP performance and both simulations independently contributed to a model predicting 48% of the variance in on-road performance. CONCLUSION: HIV+ NP-impaired individuals are at increased risk for on-road driving impairments, whereas HIV+ individuals with normal cognition are not at a significantly higher risk than HIV- subjects. Executive Functioning is most strongly associated with impaired on-road performance. Cognitive and simulator testing may each provide data in identifying driving-impaired individuals.

The effect of antihypertensive drugs on the fetus.

A critical review of the literature on the effects of antihypertensive drugs on the fetus in pregnant women is presented. The survey covers the alpha-adrenergic receptor agonists, beta-blockers including topical eye medications, alpha-beta blockers, calcium antagonists, diuretics, and angiotensin-converting enzyme (ACE) inhibitors. The lack of data on angiotensin II receptor blockers is noted although effects are considered to be similar to those reported with ACE inhibitors and therefore to be avoided. Analysis of the literature underscores that some antihypertensive drugs can be used safely at certain stages of pregnancy, while others are suspect and to be avoided at all costs. The lack of placebo-controlled studies on the treatment of severe hypertension in pregnancy due to ethical considerations is discussed against the background of the pressing need to treat these women despite the possible deleterious effects of antihypertensive drugs.

The effects of allicin and enalapril in fructose-induced hyperinsulinemic hyperlipidemic hypertensive rats.

The effects of a synthetic preparation of an active constituent of garlic, allicin, were studied on blood pressure (BP), triglycerides, and insulin levels in Sprague-Dawley rats in which high fructose feeding elicited hyperinsulinemia, hypertension, and hypertriglyceridemia. Results were compared with those of the antihypertensive drug enalapril. Three groups of male Sprague-Dawley rats were fed a fructose-enriched diet for 5 weeks. During the last 2 weeks 10 animals received only fructose, 10 received allicin, and 10 received enalapril. Blood pressure, insulin level, and triglyceride levels were measured at the beginning of the experiment and after 3 and 5 weeks on the fructose diet, fructose/allicin diet, or fructose/enalapril diet. Allicin lowered BP from the maximal level (after 3 weeks of fructose) of 153.4 +/- 8 mm Hg to 139.7 +/- 12 mm Hg after 2 weeks on allicin; insulin from 11.7 +/- 3.7 ng/mL on fructose diet to 6.92 +/- 3.3 ng/mL on allicin; and triglycerides from 132.8 +/- 18 mg/dL on fructose to 59.6 +/- 27 mg/dL on allicin. The similar effect of allicin and enalapril on BP, insulin, and triglycerides reinforces the trend toward combining the nonpharmacologic approach with drug therapy.

Nitric oxide does not participate in the metabolic effects of exogenous bradykinin in fructose-fed rats.

The study was carried out to demonstrate the effects of bradykinin (BK) on hypertension, hyperinsulinemia, and hypertriglyceridemia in fructose-fed rats, and to determine whether these actions are mediated through nitric-oxide (NO) formation. Eighteen rats, rendered hypertensive, hyperinsulinemic, and hypertriglyceridemic by a fructose-enriched diet, were studied. BK (0.2 mg/day) was infused intravenously using osmotic pumps attached by a catheter to the jugular vein of 12 rats for 12 days. BK was administered either alone (n = 6) or with concomitant inhibition of NO synthase (n = 6). Six untreated rats served as control. Measurements of systolic blood pressure (indirect method) and levels of insulin and triglyceride in serum were taken every second day. BK infused chronically, induced a marked fall in all parameters as early as the second day of infusion: in blood pressure from 152+/-7 to 126+/-12 mmHg, in insulin from 8.7+/-2.9 to 4.6+/-5.4 pg/mL, and in triglyceride from 308+/-94 to 76+/-19 mg/dL. No such reduction was seen in untreated animals. When BK was administered concurrently with NO synthase inhibitor, blood pressure rose significantly, reaching very high values at the end of treatment. However, the reduction in insulin and triglyceride levels induced by BK was not affected. The capacity of BK to enhance reduction in hyperinsulinemia and hypertriglyceridemia in the fructose-fed rats is not mediated by NO formation. Whether this action of BK is related to a direct effect of this peptide remains to be determined.

Device-guided breathing exercises reduce blood pressure: ambulatory and home measurements.

Slow breathing practiced routinely using an interactive device has demonstrated a sustained reduction in high blood pressure (BP). We reevaluated the BP response of hypertensives (n = 13) to this daily treatment for 8 weeks using 24-h ambulatory, home, and office BP measurements. A clinically significant BP reduction of similar magnitude was observed in all BP monitoring modalities during the daytime. Greater BP reductions were found for older patients and higher baseline BP. The results provide additional support for the efficacy of the device as an adjunctive lifestyle modification for treating hypertension.

Dietary electrolytes and hypertension in the elderly.

The effect of age on older hypertensive patient's blood pressure response to increased sodium intake is well known. Salt sensitivity which does increase with age and the decrease in renal function limiting the ability of aged kidney to excrete sodium load are major factors, responsible for rise in blood pressure during Na consumption in the elderly. Clinical studies encourage salt reduction with and without weight loss. Although potassium consumption is highly recommended, one should be aware of potassium overload in the elderly.

Outcomes of rural training tracks: a review.

Rural training tracks (RTTs) have developed as a strategy to encourage family medicine resident entrance into rural practice. Because most programs are small (two to four residents), data must be aggregated to determine RTT impact on practice preparation and location. Several studies over the last decade reveal that 76 percent of RTT graduates are practicing in rural America and that graduates describe themselves as prepared for rural practice. Sixty-five percent are providing obstetrical services, and half are performing cesarean sections. From 1989 to 1999, there were a total of 107 graduates of rural training programs, making it unlikely that, without significant investment, this model could supply an adequate quantity of family physicians for rural America.

Hypertension in women.

Hypertension in women has received less attention than hypertension in men, and the major controlled trials of antihypertensive therapy have been carried out in populations made up predominantly of and have emphasised outcomes in men. Recently it has been recognised that women develop high blood pressure, particularly systolic hypertension, at an increased rate as they age, and that this age-related blood pressure increase is exaggerated by the menopause. The age-related rise in blood pressure, particularly systolic blood pressure and pulse pressure, contributes substantially to the age-related increase in risk of heart attack, heart failure, and stroke in middle-aged and elderly women. This article reviews aspects of hypertension epidemiology, pathophysiology, diagnosis and treatment that are important to women's health with particular emphasis on important concomitant cardiovascular disease risk factors such as type 2 diabetes and the menopause. The role of ovarian hormones and their withdrawal in the pathogenesis of hypertension and related target organ damage is considered, as are the results of drug treatment of high blood pressure in women. Blood pressure in pregnancy is discussed in a separate article by Broughton-Pipkin and Roberts.

End-tidal carbon monoxide measurements in women with pregnancy-induced hypertension and preeclampsia.

OBJECTIVE: We sought to compare the end-tidal carbon monoxide breath levels in pregnant women with and without pregnancy-induced hypertension and preeclampsia. STUDY DESIGN: We prospectively performed end-tidal carbon monoxide measurements corrected for ambient carbon monoxide in nonsmoking women during late gestation (>31 weeks). The study group included 22 women with pregnancy-induced hypertension or symptoms of preeclampsia and a control group of 20 normotensive pregnant women. RESULTS: The carbon monoxide measurements corrected for ambient carbon monoxide (mean +/- SD) were significantly lower (P <.01) in the hypertensive group than in the control group (1.17 +/- 0.35 vs 1.70 +/- 0.54 ppm). The study group had a significantly higher number of low (<1.2 ppm) end-tidal carbon monoxide measurements corrected for ambient carbon monoxide (13 [59.1%] vs 1 [5.0%]; P <.001). The end-tidal carbon monoxide measurements corrected for ambient carbon monoxide remained significantly lower in comparison with those found in the control group when the study group was divided into women with pregnancy-induced hypertension only (n = 11) and those with preeclampsia (n = 11) (1.19 +/- 0.37 ppm; P <.01; and 1.15 +/- 0.41 ppm; P <.01; respectively). CONCLUSIONS: Our findings suggest that carbon monoxide formation may be significantly lower in women with pregnancy-induced hypertension and preeclampsia. These data suggest that carbon monoxide could have a contributory role in the apparent paradox of the seemingly protective effect of smoking to decrease the risk of preeclampsia.

Morbidity and mortality in patients randomised to double-blind treatment with a long-acting calcium-channel blocker or diuretic in the International Nifedipine GITS study: Intervention as a Goal in Hypertension Treatment (INSIGHT).

BACKGROUND: The efficacy of antihypertensive drugs newer than diuretics and beta-blockers has not been established. We compared the effects of the calcium-channel blocker nifedipine once daily with the diuretic combination co-amilozide on cardiovascular mortality and morbidity in high-risk patients with hypertension. METHODS: We did a prospective, randomised, double-blind trial in Europe and Israel in 6321 patients aged 55-80 years with hypertension (blood pressure > or = 150/95 mm Hg, or > or = 160 mm Hg systolic). Patients had at least one additional cardiovascular risk factor. We randomly assigned patients nifedipine 30 mg in a long-acting gastrointestinal-transport-system (GITS) formulation (n=3157), or co-amilozide (hydrochlorothiazide 25 mg [corrected] plus amiloride 2.5 mg; n=3164). Dose titration was by dose doubling, and addition of atenolol 25-50 mg or enalapril 5-10 mg. The primary outcome was cardiovascular death, myocardial infarction, heart failure, or stroke. Analysis was done by intention to treat. FINDINGS: Primary outcomes occurred in 200 (6.3%) patients in the nifedipine group and in 182 (5.8%) in the co-amilozide group (18.2 vs 16.5 events per 1000 patient-years; relative risk 1.10 [95% CI 0.91-1.34], p=0.35). Overall mean blood pressure fell from 173/99 mm Hg (SD 14/8) to 138/82 mm Hg (12/7). There was an 8% excess of withdrawals from the nifedipine group because of peripheral oedema (725 vs 518, p<0.0001), but serious adverse events were more frequent in the co-amilozide group (880 vs 796, p=0.02). Deaths were mainly non-vascular (nifedipine 176 vs co-amilozide 172; p=0.81). 80% of the primary events occurred in patients receiving randomised treatment (157 nifedipine, 147 co-amilozide, difference 0.33% [-0.7 to 1.4]). INTERPRETATION: Nifedipine once daily and co-amilozide were equally effective in preventing overall cardiovascular or cerebrovascular complications. The choice of drug can be decided by tolerability and blood-pressure response rather than long-term safety or efficacy.