RESUMEN

The prevalence of imipenem resistance among Pseudomonas aeruginosa isolates at a 195-bed tertiary care medical center in Cali, Colombia, rose from 2% in 1996 to 28% in 1997 and to over 40% in 2003. Many isolates showed high-level multiresistance, and phenotypic characterization suggested the spread of a predominant strain with minor variants. Sixty-six resistant isolates collected between February 1999 and July 2003 from hospitalized patients (n = 54) and environmental samples (n = 12) were subjected to a fuller analysis. Genetic fingerprints were compared by pulsed-field gel electrophoresis (PFGE) of SpeI-digested genomic DNA, and bla(IMP) and bla(VIM) genes were sought by PCR. PFGE and serotyping indicated that 52 of the 66 isolates belonged to a single strain, with 82% similarity; the PFGE pattern for this organism was designated pattern A. Two further pairs of isolates represented single strains; the remaining nine isolates were unique, and in the case of one isolate, no satisfactory PFGE profile could be obtained. The pattern A isolates were mostly of serotype O12 and were highly resistant to imipenem (MICs, 32 to >256 microg/ml), with this resistance decreased eightfold or more in the presence of EDTA. They yielded amplicons with bla(VIM)-specific primers, and sequencing of DNA from a representative isolate revealed bla(VIM-8), a novel allele with three polymorphisms compared with the sequence of bla(VIM-2). Two of these nucleotide changes were silent, but the third determined a Thr139Ala substitution. Only 4 of 13 resistant isolates (2 clinical isolates and 2 environmental isolates) assigned to other PFGE types carried bla(VIM) alleles, whereas the others were less multiresistant and mostly had lower levels of imipenem resistance (MICs, < or =32 microg/ml) which was not significantly reduced by EDTA. No bla(IMP) alleles were detected. During 2003, when the environmental study was undertaken, serotype O12 isolates with bla(VIM) were recovered from sinks and stethoscopes in the most-affected units, although not from the hands of staff; the problem declined once these reservoirs were disinfected and hygienic precautions were reinforced.

Asunto(s)

RESUMEN

The associated use of permissive hypercapnia (PHY) and high PEEP levels (PEEP(IDEAL)) has been recently indicated as part of a lung-protective-approach (LPA) in acute respiratory distress syndrome (ARDS). However, the net hemodynamic effect produced by this association is not known. We analyzed the temporal hemodynamic effects of this combined strategy in 48 patients (mean age 34 +/- 13 yr) with ARDS, focusing on its immediate (after 1 h), early (first 36 h), and late (2nd-7th d) consequences. Twenty-five patients were submitted to LPA--with the combined use of permissive hypercapnia (PHY), VT < 6 ml/kg, distending pressures above PEEP < 20 cm H2O, and PEEP 2 cm H2O above the lower inflection point on the static inspiratory P-V curve (P(FLEX))- and 23 control patients were submitted to conventional mechanical ventilation. LPA was initiated at once, resulting in an immediate increase in heart rate (p = 0.0002), cardiac output (p = 0.0002), oxygen delivery (DO2l, p = 0.0003), and mixed venous Po2 (p = 0.0006), with a maintained systemic oxygen consumption (p = 0.52). The mean pulmonary arterial pressure markedly increased (mean increment 8.8 mm Hg; p < 0.0001), but the pulmonary vascular resistance did not change (p = 0.32). Cardiac filling pressures increased (p < 0.001) and the systemic vascular resistance fell (p = 0.003). All these alterations were progressively attenuated in the course of the first 36 h, despite persisting hypercapnia. Plasma lactate suffered a progressive decrement along the early period in LPA but not in control patients (p < 0.0001). No hemodynamic consequences of LPA were noticed in the late period and renal function was preserved. A multivariate analysis suggested that these acute hyperdynamic effects were related to respiratory acidosis, with no depressant effects ascribed to high PEEP levels. In contrast, high plateau pressures were associated with cardiovascular depression. Thus, as long as sufficiently low distending pressures are concomitantly applied, the sudden installation of PHY plus PEEP(IDEAL) induces a transitory hyperdynamic state and pulmonary hypertension without harmful consequences to this young ARDS population.

Asunto(s)

RESUMEN

Fang women are known to practice virtually no contraception but for them induced abortion is not an acceptable option. Their reproductive behaviour consequently is governed by the ability to conceive, spontaneous intrauterine mortality and child spacing (due to prolonged breast-feeding and sexual abstinence). In a sample of 587 women from one hospital and one clinic in Nsork, there was a positive correlation between maternal age and the number of pregnancies, resulting in a mean of 5.52 pregnancies per female and one child born every 2.5 years. The reported spontaneous abortion rate was 28.6%.

PIP: Data were collected in the only hospital built in the Nsork district of Equatorial Guinea. Group A comprised deliveries at Nsork Hospital from March 1988 to July 1990 (29 months). Maternal age, number of previous pregnancies, and number of fetal losses from the fourth month of pregnancy were recorded. The total sample comprised 157 women aged 15-40 years who had a total of 555 pregnancies. Group B data were collected from May 1987 to December 1988 (20 months) from the prenatal clinic at a primary health post from a total of 430 pregnant women aged 14-45 years. Group A women represented 15.6% of all women in the district between 15 and 39 years of age; Group B, 36.5% between 15 and 44 years of age. There was a high level of prenatal attendances in Group B; however, only 20.2% of clinic visitors gave birth at the hospital. In Group A, the number of reported pregnancies continued to rise in direct relation to the woman's age (correlation coefficient r = .91). The reproductive age range of this population was 15 to 40 years with a mean of 5.52 pregnancies. The average number of reported abortions per female was .48 for each age group (p .05). The total incidence of fetal loss was 28.3%, 23.9% of which was reported by women with one abortion and 4.4% by women with at least two abortions. Group A had effective child spacing, achieved by a combination of sexual abstinence and prolonged breast feeding. Sexual abstinence was practiced after the seventh month of pregnancy until breast feeding ceased, and breast feeding was continued until the newborn was aged 16-21 months. The pattern of child spacing calculated from the regression between mean number of conceptions per woman and maternal age (r = .91, p .05) was around one pregnancy every 30 months. The data represented a population with close to natural fertility, since their reproduction was not deliberately controlled and there was no cessation of reproduction once the desired family size had been attained.

Asunto(s)