Cardiac surgery in patients receiving long term hemodialysis. Short and long term results.

AIM: Cardiac surgery carries a high risk in hemodialysis patients and has been questioned for its results; the purpose of this study is to focus on the short and long term results in our institution. METHODS: We retrospectively analyzed the data from 124 hemodialysis patients who underwent cardiac surgery in our unit between January 1980 and December 1998; 14.5% were diabetic; 46% had isolated coronary artery disease (group 1); 29.8% had valvular disease alone (group 2); 14.5% valve and coronary disease (group 3) and 9.6% miscellaneous disease at highest risk (group 4). We analyzed the relationship between several variables (age, sex, hypertension, diabetes, previous myocardial infarction, type of disease, preoperative ejection fraction) and operative mortality (30 days) and late survival. RESULTS: The overall operative mortality was 16.9%. The only risk factor was the type of cardiac disease: operative mortality was higher in groups 3 and 4 combined than in groups 1 and 2 combined (30% versus 12.7%, p=0.07). Ninety-nine patients were followed until January 2002. Late survival rate was 46.6+/-5% at 6 years for all patients, it was significantly better in groups 1 and 2 combined than in groups 3 and 4 combined. The only risk factor for late mortality was arterial hypertension. Fifty-seven patients are still alive, 46 in groups 1 and 2, 11 in groups 3 and 4. Progression of coronary lesions occurred in 6 patients and valvular lesions in 3 patients. The remainder are doing well. CONCLUSION: Cardiac surgery seems to be justified by the severity of the lesions. Its actual results can perhaps, be improved by earlier detection of cardiac disease and better prevention of myocardial hypertrophy and cardiac calcifications.

Is age a risk factor for esophagectomy?

In recent years, the number of elderly patients with esophageal cancer as well as the number submitted for esophageal resection has been increasing. With respect to nutritional and pulmonary evaluations, surgical staging, and mortality, 37 patients over the age of 65 who underwent esophagectomy and simultaneous reconstruction were analyzed. This group was compared statistically with a group of 162 patients younger than 65 to determine whether age was a factor influencing treatment and outcome. There was no statistical difference between the groups relating to the described variables. Age should not be a limiting factor when it comes to offering an aggressive surgical approach for the esophageal cancer patient aged 65 or more. This approach can be performed as safely in older patients as it is in younger patients, with similar incidence of mortality.

Is acute cholecystitis a contraindication for laparoscopic cholecystectomy?

Two-hundred and ninety-four patients underwent laparoscopic cholecystectomy between May 1993 and April 1997 in the Clinical and Surgical Gastrointestinal Unit at Santa Casa Hospital of Porto Alegre. Of all, 47 were operated on for acute cholecystitis (AC). The mean age was 47.1 years, 70.2% were females and 29.8% were males. The mean operative time was 142.8 minutes. Routine intraoperative cholangiography was successfully done in 38 (80.8%) and conversion was necessary in 3 (6.4%). All patients received prophylactic antibiotics for 24 hours. No intraoperative or postoperative complications were detected. The results in this series showed that laparoscopic cholecystectomy is a possible and safe technique for the treatment of the AC.

Active native valve endocarditis: determinants of operative death and late mortality.

BACKGROUND: In this report, we reviewed 247 patients who underwent operation by our team for active native valve endocarditis between January 1979 and December 1993. METHODS: There were 201 male and 46 female patients (mean age, 45.4 +/- 6 years). The aortic valve was involved in 163 cases, the mitral valve in 36 cases, both mitral and aortic valves in 44 cases, and the tricuspid valve alone in 4 cases. The most common microorganisms were streptococci. Univariate Pearson (chi2 test) and multivariate (stepwise logistic regression [BMDPLR]) analyses were used to identify significant predictors of operative mortality, reoperation, and recurrent endocarditis. Cox proportional hazards regression model was used to study late survival. RESULTS: Operative mortality was 7.6% (n = 19). Increased age, cardiogenic shock at the time of operation, insidious illness, and greater thoracic ratio (>0.5) were the predominant risk factors; the length of antibiotic therapy appeared to have no influence. Two hundred thirteen patients were followed up. Median follow-up time was 6 years (range, 2 to 19 years). Overall survival rate (operative mortality excluded) was 71.3% +/- 3.8% at 9 years. Increased age, preoperative neurologic complications, cardiogenic shock at the time of operation, shorter duration of the illness, insidious illness before the operation, and mitral valve endocarditis were the predominant risk factors for late mortality. The probability of freedom from reoperation (operative mortality included) was 73.3% +/- 4.2% at 8 years; risk factors were younger age and aortic valve endocarditis. The rate of prosthetic valve endocarditis was 7%. No significant risk factor was found. CONCLUSIONS: Increased age, insidious illness, and hemodynamic failure are the main risk factors for operative mortality. Long-term survival is good except for patients with preoperative neurologic complications and mitral valve endocarditis.

Toxicology of cupric salts on honeybees. V. Gluconate and sulfate action on gut alkaline and acid phosphatases.

Some aspects of putative nontarget effects of cupric ions systemically fed to honeybees against their parasite mite Varroa jacobsoni have been investigated on the host phosphatases. The alkaline and acid forms extracted from the guts of worker bees exhibited substrate-inhibition features. Upon detailed kinetic analysis, cupric organic salts indicate activation effects at concentrations of about 1 mM. Concentrations up to 10 mM (alkaline form) and 25 mM (acid form) induced no important changes, except a partial quenching of the substrate-inhibition process, characterized by a wide increase in the constant of apparent inhibitory binding of substrate to the enzyme-substrate complex. Partial purification gave a single alkaline form with quite similar kinetic behavior in the absence of natural ions as in crude extracts. Cupric gluconate and sulfate demonstrated similar patterns, except an increase of the apparent Hill coefficient by sulfate only. The substrate constant of acid phosphatases was decreased at high cupric gluconate doses while its maximum velocity was biphasically increased (with observed maximum at 1 mM), resulting in a sustained activation. Chemiluminescence studies revealed that cupric ion activation is counteracted by oxygen radicals generated by cupric ions and also, in vitro, by the artificial substrate para-nitrophenylphosphate. The para-nitrophenol molecules released from the reaction are therefore responsible for biphasic effects selectively observed with gluconate salts. In apicultural practice, neither blockade of activity nor dramatic changes are to be expected at doses administered to bees against the parasite.

Toxicology of cupric salts in honeybees. I. Hormesis effects of organic derivatives on lethality parameters.

Feeding bees with organic cupric salts provides long-term control of the parasite Varroa jacobsoni. A set of new algebraic parameters (M. Bounias C.R. Acad. Sci. 310(3), 65-70, 1990) completely describing the population lethality function has been calculated following chronic administration of cupric gluconate, aspartate, and isoleucinate, with or without dietary pollen. Mortality curves allowed the calculation of LT50 (time for 50% lethality) as well as Hill coefficients (h) of the curves and the LD50 as a function of time. The tangent at the inflexion point of the sigmoidal time/mortality curves (delta i) gave the maximum mortality acceleration as an additional parameter. No toxicity (i.e., no decrease of TL50 vs doses and no LD50 values) was found for cupric gluconate and isoleucinate with pollen, whereas increases in LT50 and decreases in delta indicated hormesis effects. Doses decreasing by half-time LT50, h, or delta were used as objective lethality indexes for comparisons of toxicity in the other cases. Routine acute toxicity at high dosage was also compared with phosalone and lindane effects 24 hr after treatment.

Toxicology of cupric salts on honeybees. IV--Gluconate and sulfate action on hemolymph trehalose activity in vivo and in vitro.

A biphasic increase of hemolymph glucose levels was observed following injection to bees of cupric gluconate or sulfate, both potent agents for the control of Varroa jacobsoni, a parasitic mite of hives. The simultaneous injection to bees of 0.3 microM BAYg5421 (an inhibitor of alpha-glucosidases) quenched the response, suggesting a direct effect of 2 nmol/bee cupric ions on trehaloses' activity. One nanomol of injected cupric gluconate increased the trehalose (Tre) activity by 233% in crude hemolymph extracts at 1 mM trehalose concentration, and exhibited biphasic dose-related effects with a maximum 15% increase at 0.5 mM cupric ion and a stabilized 20% inhibition from 4 mM, regardless of the anionic moiety. Upon partial purification of the enzyme complex, two fractions (FI = 75% and FII = 25% of total activity) were isolated that exhibited, respectively, less and more marked positive cooperatively than crude extract. Form I showed almost no susceptibility to either cupric derivatives, which indicated form II as the most likely target, with 68% and 72% increases with 0.25 mM cupric sulfate and 0.5 mM cupric gluconate, in presence of 16 mM trehalose.

The formamidine amitraz as a hyperglycemic alpha-agonist in worker honeybees (Apis mellifera mellifera L.) in vivo.

Intra-abdominal injection of amitraz (0.25 nmol per honeybee, i.e., approx 2.3 nmol/g) to emerging worker bees, in vivo, led to a significant hypertrehalosemia (300-400%) followed by a hyperglucosemia (approximately equal to 600%). Maxima were reached at 0.5 and 2 h, respectively. A strong negative correlation between glucosemia and trehalosemia appeared after injection of pure phentolamine (1 nmol per bee), suggesting stimulation of trehalase activities. Simultaneous administration of the alpha-blocker at greater than or equal to 0.25 nmol per individual suppressed the hyperglycemic response of amitraz. The formamidine pesticide thus likely acts on the honeybee alpha-aminergic system.

[Toxicology of cupric sulfate in honeybees. I. New algebraic parameters of lethality as alternatives to the LD50]. / Toxicologie du sulfate cuivrique chez l'Abeille. I. Nouveaux paramètres algébriques de létalité comme alternative à la DL50.

A full kinetic study, over the whole life span of individuals, has been performed on the lethality of honeybees receiving by chronic administration: 0; 0.25; 0.5; 1; 2 g.l-1 of cupric sulfate in sucrose syrups. Three algebraic parameters, based on the Hill equation, allow a complete description of the curves: the time corresponding to the death of 50% of the individuals (LT50), the Hill coefficient (nt) and the slope of the tangent at the inflexion point (delta) corresponding to the maximum mortality rate. Studying the variations of the 3 parameters versus administered doses, leads to new relations allowing the calculation of the dose decreasing by half the 50% survival time of controls (dT50), and the doses increasing up to half the maximum, the value of nt(dnt50) and the value of delta (d delta 50). The experimental data gave: dT50 = 0.27 g.l-1; dnt50 = 0.51 g.l-1; d delta 50 = 0.93 g.l-1. These indexes, which represent new objective parameters for the characterization of lethality, should be substituted to the LD50 whose values vary between zero and infinite according to the time arbitrarily chosen for their calculation, and wear only a very restrictive significance.

[Evaluation of the control quality of arterial hypertension over a 10-year period at a hemodialysis center]. / Evaluation de la qualité du contrôle de l'hypertension artérielle pendant dix ans dans un centre d'hémodialyse.

Using the "Diaphane" computed medical record system enables multicentric statistical studies to be conducted. With this system, the quality of arterial hypertension control (supine systolic and diastolic arterial pressure before and after dialysis) was evaluated over a 10-year period in chronic haemodialysis patients in comparison with a multicentric population. A continuous statistical study of the results showed a regular voluntary decrease in arterial pressure. The evaluation of the quality of medical care represented by this comparison contributes to a therapeutic improvement.

[Operative risk in coronary bypass. A multivariate analysis of prognostic factors]. / Le risque opératoire du pontage coronaire. Analyse multivariée des facteurs pronostiques.

In order to determine the predictors of operative risk in coronary bypass surgery, we have studied 2112 consecutive patients who underwent isolated coronary bypass surgery between January 1979 and September 1984. The overall operative mortality (OM) was 4.4 percent (3.5 percent during the last 3 years). OM increases significantly with age (from O before the age of 30 to 12.3 percent after 70), the functional class (FC) of angina, the FC of dyspnea (NYHA), the creatinine blood level (23.5 percent if greater than 200 mumol/l), the left ventricular end-diastolic pressure and in case of reoperation (16.7 percent), as well as in women (11.6 percent). There is a trend toward higher OM in case of past history of ventricular tachycardia or arterial hypertension, atherosclerotic disease of the lower extremities, left ventricular dysfunction or severe stenosis of the left main coronary artery. OM is not increased in patients with multivessel disease, diabetes or with a past history of myocardial infarction, and is even decreased in obese patients. The variables selected by multivariate analysis were: creatinine blood level, then angina FC, sex, dyspnea FC, age, the absence os obesity, left ventricular dysfunction, the year of surgery and finally reoperation. These results, mainly based on simple clinical variables, should facilitate the therapeutic decisions in borderline indications of coronary bypass surgery.

[Incidence of neonatal bacterial infections in intensive care and/or neonatology units. A multicenter study using a computerized data system]. / Fréquence des infections bactériennes néonatales dans les unités de réanimation et/ou néonatologie. Etude multicentrique à l'aide d'un codage commun informatisé.

The authors have studied the incidence and short term prognosis of neonatal bacterial infections among 3,833 newborn babies admitted into 12 intensive care and/or neonatal units of Ile-de-France (Paris region) during 1984. this study was carried out with a computerized data base system. Septicemia was present in 3% of the total population, purulent meningitis in 0/6% and urinary tract infection in 1.4%. The authors have found a great incidence of group B streptococci (26% of septicemia) and e. coli (18% of septicemia). The frequency of use of antibiotics is very different among the units, without evidence of correlation with therapeutic results or with incidence of demonstrated bacterial infections. So, it appears necessary to reevaluate the indications of antibiotherapy, with more objective arguments. The authors emphasize the interest for such studies of computerized epidemiologic multicentric works.