[In-hospital mortality in surgical patients. Predictive factors]

OBJECTIVE

To analyze the value of patient and surgical variables as predictors of the survival until discharge of hospitalized surgical patients in a tertiary care hospital over the course of 1 year.

MATERIAL AND METHODS

The hospital records for patients admitted for surgery between January 1 and December 31, 2007, were consulted to extract age, sex, ASA physical status classification of the patient, type of admission and surgery (scheduled or emergency), surgical department assigned, and date of discharge or exitus. The data were subjected to multivariate survival analysis using the Cox regression model.

RESULTS

A total of 4184 patients underwent surgery in 2007; the median (25th-75th percentile) patient age was 56 (39-71) years. In 77.5% of the cases (3244 patients) surgery was scheduled; 23.1% of those patients had been admitted by the emergency department. The ASA classification was 1 for 21.8%, 2 for 44.2%, 3 for 28%, and 4 for 6%. Of patients classified as ASA 1-3, a total of 33.2% were aged 65 years or older; in contrast, 78.7% of ASA 4 patients were in that age bracket. Eighty-nine (2.1%) surgical patients died. Cox regression survival analysis showed that variables related to a lower likelihood of survival to discharge were a physical status classification of ASA 4, age 65 years or older, and emergency surgery (P < .0005 for all comparisons).

CONCLUSIONS

Patients over the age of 65 years, in an ASA 4 anesthetic risk category, admitted on an emergency basis for emergency surgery were at higher risk of death. Greater vigilance in the perioperative care of patients with these risk factors is advisable in the interest of reducing mortality.

[Health-care workload and instructional capacity of Spanish hospitals accredited to train residents in anesthesiology]

OBJECTIVES

To describe the health-care workload and instructional capacity of Spanish hospitals accredited to train anesthesiology residents.

METHODS

Survey of supervisors of anesthesiology residents in 2008 to determine caseloads in surgery and obstetrics as well as in pain clinics and critical care units. The results are presented for different Spanish autonomous communities. The maximum theoretical capacity for instruction in accordance with European guidelines is calculated.

RESULTS

The 100 hospitals surveyed train 325 residents per year and could theoretically increase the training opportunities they offer, within certain limits. Given optimal distribution of resources, the system could train 397 residents per year in pediatric surgery in 3-month rotations, 442 residents in neurosurgery in 2-month rotations, and 479 residents in thoracic surgery in 1-month rotations. Some Spanish communities presently have problems giving training in the settings of pediatric, thoracic, and major outpatient surgery. Furthermore, even though anesthesiologists are presently responsible for 41.6% of available critical care beds, 46 hospitals do not have a sufficient number of beds to give training in this setting. This shortage may have negative repercussions on the accreditation of training programs.

CONCLUSIONS

Although certain limitations were found, the survey showed that the training capacity of the system is greater than accreditation suggests. It would therefore be possible to increase the number of residents.

Shuttle walking versus maximal cycle testing: clinical correlates in patients with kyphoscoliosis

A cross-sectional prospective design was used to compare the effectiveness of the shuttle walking test (SWT) and the maximal cycle ergometry test (CET) to assess the functional capacity of patients with chronic hypercapnic respiratory failure due to severe kyphoscoliosis. Twenty-four patients completed both the SWT and CET. Heart rate, blood pressure, leg fatigue, chest pain and dyspnea (Borg's scale) were measured immediately after each test. Correlation coefficients and Bland-Altman analysis were used to compare the two methods. Borg's dyspnea, leg and chest pain after exercise were not significantly different between tests. Only heart rate (SWT 130[20.7] versus CET 116[28.75]; p = 0.048) and diastolic blood pressure (SWT: 85.5[13.75] versus CET 95[17.5]; p = 0.021) were slightly but significantly different between the two protocols. There was a good positive correlation between the distance walked in SWT and maximal oxygen consumption (r = 0.675; p < 0.001). SWT and CET testing elicited similar clinical and hemodynamic responses. SWT is a feasible measure of functional capacity in this patient group.

Development of cytosolic hypoxia and hypoxia-inducible factor stabilization are facilitated by aquaporin-1 expression

O(2) is essential for aerobic life, and the classic view is that it diffuses freely across the plasma membrane. However, measurements of O(2) permeability of lipid bilayers have indicated that it is much lower than previously thought, and therefore, the existence of membrane O(2) channels has been suggested. We hypothesized that, besides its role as a water channel, aquaporin-1 (AQP-1) could also work as an O(2) transporter, because this transmembrane protein appears to be CO(2)-permeable and is highly expressed in cells with rapid O(2) turnover (erythrocytes and microvessel endothelium). Here we show that in mammalian cells overexpressing AQP-1 and exposed to hypoxia, the loss of cytosolic O(2), as well as stabilization of the O(2)-dependent hypoxia-inducible transcription factor and expression of its target genes, is accelerated. In normoxic endothelial cells, knocking down AQP-1 produces induction of hypoxia-inducible genes. Moreover, lung AQP-1 is markedly up-regulated in animals exposed to hypoxia. These data suggest that AQP-1 has O(2) permeability and thus could facilitate O(2) diffusion across the cell membrane.

Prenatal ultrasound diagnosis of vasa praevia and analysis of risk factors

OBJECTIVE

To evaluate the role of ultrasound in prenatal diagnosis of vasa praevia (VP) and to asses the risk of VP associated with different causal factors.

MATERIAL AND METHODS

A retrospective study of the incidence of VP in a series of 12,063 deliveries between January 2000 and March 2005. We also studied the factors that predisposed for VP and the perinatal outcome of pregnancies.

RESULTS

The prevalence of VP in our centre during this period was 0.07% (9 cases). All cases were prenatally diagnosed. The mean gestational age at diagnosis was 26 weeks. Multivariate analysis revealed the following associated factors: IVF pregnancies, bilobate or succenturiate placenta, and second-trimester placenta praevia, with an odds ratio of 7.75, 22.11 and 22.86, respectively.

CONCLUSIONS

In our series, the prenatal diagnosis of all cases of VP achieved during the second-trimester scan allowed us to avoid any prenatal death related to this condition.

Neuroprotection by transgenic expression of glucose-6-phosphate dehydrogenase in dopaminergic nigrostriatal neurons of mice

Oxidative damage to dopaminergic nigrostriatal (DNS) neurons plays a central role in the pathogenesis of Parkinson's disease (PD). Glucose-6-phosphate dehydrogenase (G6PD) is a key cytoprotective enzyme that provides NADPH, the major source of the reducing equivalents of a cell. Mutations of this enzyme are the most common enzymopathies worldwide. We have studied in vivo the role of G6PD overexpressed specifically in the DNS pathway and show that the increase of G6PD activity in the soma and axon terminals of DNS neurons, separately from other neurons or glial cells, protects them from parkinsonism. Analysis of DNS neurons by histological, neurochemical, and functional methods showed that even a moderate increase of G6PD activity rendered transgenic mice more resistant than control littermates to the toxic effects of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP). The neuroprotective action of G6PD was also observed in aged animals despite that they had a greater susceptibility to MPTP. Therefore, overexpression of G6PD in dopaminergic neurons or pharmacological activation of the native enzyme should be considered as potential therapeutic strategies to PD.

Rat adrenal chromaffin cells are neonatal CO2 sensors

We studied the participation of adrenal medulla (AM) chromaffin cells in hypercapnic chemotransduction. Using amperometric recordings, we measured catecholamine (CAT) secretion from cells in AM slices of neonatal and adult rats perfused with solutions bubbled with different concentrations of CO2. The secretory activity augmented from 1.74 +/- 0.19 pC/min at 5% CO2 to 6.36 +/- 0.77 pC/min at 10% CO2. This response to CO2 was dose dependent and appeared without changes in extracellular pH, although it was paralleled by a drop in intracellular pH. Responsiveness to hypercapnia was higher in neonatal than in adult slices. The secretory response to hypercapnia required extracellular Ca2+ influx. Both the CO2-induced internal pH drop and increase in CAT secretion were markedly diminished by methazolamide (2 microm), a membrane-permeant carbonic anhydrase (CA) inhibitor. We detected the presence of two CA isoforms (CAI and CAII) in neonatal AM slices by in situ hybridization and real-time PCR. The expression of these enzymes decreased in adult AM together with the disappearance of responsiveness to CO2. In patch-clamped chromaffin cells, hypercapnia elicited a depolarizing receptor potential, which led to action potential firing, extracellular Ca2+ influx, and CAT secretion. This receptor potential (inhibited by methazolamide) was primarily attributable to activation of a resting cationic conductance. In addition, voltage-gated K+ current amplitude was also decreased by high CO2. The CO2-sensing properties of chromaffin cells may be of physiologic relevance, particularly for the adaptation of neonates to extrauterine life, before complete maturation of peripheral and central chemoreceptors.

Aquaporins in chicken: Localization of ck-AQP5 along the small and large intestine

Aquaporins (AQPS) are transmembrane water channels poorly investigated in birds. Using degenerated primers and RT-PCR, we identified in kidney and gastrointestinal tract of Hubbard chickens (Gallus gallus) three fragments, corresponding to ck-AQP2, ck-AQP4, and ck-AQP5 mRNAs. Comparison of nucleotide ck-AQPs sequences to their rat and human orthologues revealed an overall identity of 75-90%. Expression in the renal and gastrointestinal systems of the three ck-AQPs mRNA was analysed by Northern assays. Transcript of ck-AQP2 was only identified in kidney. ck-AQP4 mRNA was highly expressed in brain, and to a lesser extent in kidney and stomach. ck-AQP5 mRNA was found in jejunum and ileum, and to a lesser extent in colon and lung. In situ hybridisation showed ck-AQP5 mRNA in the crypt cells of jejunum, ileum and colon, whereas it was absent from the cells lining the villi. Levels of ck-AQP5 mRNA (analyzed by Northern and in situ hybridisation assays) and protein (analysed by immunohistochemistry) decreased from the jejunum to the colon. This work confirmed the presence of AQPs in chicken, and showed that chicken and mammalian AQPs share a high degree of similarity in nucleotide sequence and tissue distribution.

Induction of the glucose-6-phosphate dehydrogenase gene expression by chronic hypoxia in PC12 cells

We studied the regulation of glucose-6-phosphate dehydrogenase (G6PD) gene expression by chronic hypoxia. G6PD mRNA level and activity were increased in PC12 cells by hypoxia in a dose- and time-dependent manner. Cobalt chloride and dimethyloxalylglycine, which can mimic hypoxia, also activated G6PD gene expression. Interestingly, hypoxia-induced G6PD expression followed a time course much slower than that of phosphoglycerate kinase 1 (PGK1), a hypoxia-inducible factor (HIF)-dependent glycolytic enzyme. Hypoxic-G6PD induction was almost negligible in non-excitable Buffalo rat liver cells, although in these cells PGK1 was strongly upregulated by low PO(2). Furthermore, G6PD but not PGK1 induction was blocked by the antioxidants glutathione and N-acetylcysteine. These results suggest the dependence of G6PD gene expression on HIF and intracellular redox status and the differential hypoxic regulation of glucose-metabolizing enzymes.

Jugular vein and carotid artery blood flow in fetuses with increased nuchal translucency at 10-14 weeks' gestation

OBJECTIVE

The aim of our study was to obtain measurements of the jugular vein and carotid artery pulsatility index (PI) at 10-14 weeks' gestation in chromosomally normal and abnormal fetuses with or without increased nuchal translucency (NT), in order to explore whether a relationship exists between increased NT and overperfusion of the head.

METHODS

This was a prospective study involving 179 pregnant women at high risk for chromosomal anomalies or structural malformations who were referred for chorionic villus sampling or first-trimester ultrasound examination at 10-14 weeks' gestation, respectively. Color and pulsed Doppler ultrasound were used to obtain jugular vein and carotid artery blood flow velocity waveforms at the level of the mid-neck. All Doppler measurements were obtained by a single investigator. The PIs of the jugular vein and carotid artery were correlated with NT measurement and fetal karyotype.

RESULTS

Doppler measurements of the jugular vein and carotid artery were successfully obtained in 90.5% of the fetuses. The fetal karyotype was abnormal in 13 cases, including three trisomies 21 and two trisomies 18, and normal in 149 cases. In the group with normal karyotype the NT was above the 95th percentile in 22 cases (15%). No correlation between the jugular vein or the carotid artery PI and the thickness of the NT was found. There were no significant differences when comparing the values of the jugular vein and carotid artery PI between the group with normal NT and the group with increased NT, or between the group with a normal karyotype and an abnormal karyotype.

CONCLUSION

Our results suggest that NT is not related to blood flow impedance in either the carotid artery or the jugular vein. Overperfusion and venous congestion of the head do not appear to be a causative pathophysiological mechanism involved in increased NT.

Trophic restoration of the nigrostriatal dopaminergic pathway in long-term carotid body-grafted parkinsonian rats

We studied the mechanisms underlying long-term functional recovery of hemiparkinsonian rats grafted intrastriatally with carotid body (CB) cell aggregates. Amelioration of their motor syndrome is a result of the trophic actions of these grafts on the remaining ipsilateral substantia nigra neurons rather than of the release of dopamine from the CB grafts. The grafts maintain a stable morphological appearance and differentiated cell phenotype for the duration of the life of the host. Adult CB expresses high levels of glial cell line-derived neurotrophic factor (GDNF) and the multicomponent GDNF receptor complex. These properties may contribute to the trophic actions of the CB transplants on nigrostriatal neurons and to their extraordinary longevity. We show that CB glomus cells, although highly dopaminergic, are protected from dopamine-mediated oxidative damage because of the absence of the high-affinity dopamine transporter. Thus, intrastriatal CB grafts are uniquely suited for long-term delivery of trophic factors capable of promoting restoration of the nigrostriatal pathway.

[Influence of bispectral index monitoring on fentanyl requirements during total intravenous anesthesia for major gynecological surgery]

OBJECTIVE

To determine the influence that bispectral index (BIS) monitoring of hypnosis might have on need for analgesia during surgery under total intravenous anesthesia provided by bolus administration of fentanyl.

PATIENTS AND METHOD

Prospective, randomized and partially double-blind study of 40 patients undergoing major gynecological surgery under total intravenous anesthesia with propofol and fentanyl. In the BIS group (n = 20) propofol administration was adjusted to maintain BIS between 40 and 60. In the control group (n = 20) standard doses were given: 10 mg/kg-1/h-1 after anesthetic induction and for 5 minutes, 8 mg/kg-1/h-1 over the next 5 minutes and 6 mg/kg-1/h-1 throughout the rest of the operation. All patients received intravenous bolus administration of 150 or 75 microg of fentanyl to maintain analgesia whenever systolic blood pressure and heart rate increased 20% over baseline. We compared propofol and fentanyl requirements, intraoperative changes in BIS, and awakening from anesthesia.

RESULTS

Patient and surgical characteristics were similar in both groups. BIS monitoring allowed propofol administration to be decreased a mean 24% during maintenance of anesthesia, and this in turn was associated with a significant increase in mean dose of fentanyl (415 microg versus 253 microg in the BIS and control groups, respectively; p = 0.01). Mean values of BIS were higher in the BIS group (46.4 versus 42.2; p = 0.04) and patients in the BIS group awoke sooner (in 7.7 min versus 11.1 min; p = 0.01) and tended to report less pain upon arrival at the postanesthetic recovery room, although the difference was not statistically significant.

CONCLUSIONS

BIS monitoring of depth of hypnosis can influence requirements for fentanyl during total intravenous anesthesia by bolus dosing for maintenance of analgesia. This is probably due to changes in the administration of propofol made possible by BIS monitoring.

[The efficacy and safety of continuous epidural analgesia versus intradural-epidural analgesia during labor]

OBJECTIVE

To determine the efficacy and safety of intradural-epidural analgesia in comparison with continuous epidural analgesia during labor and childbirth.

PATIENTS AND METHOD

Forty-two women whose labor began spontaneously were enrolled and distributed randomly in two groups. The intradural-epidural analgesia group (IEA, n = 21) received 25 microgram of intradural fentanyl with 2.5 mg of isobaric bupivacaine with adrenalin, after which analgesia was maintained with epidural administration of one 8 mL bolus of 0.125% bupivacaine, followed by perfusion of a balanced concentration at a rate of 8 ml/h. Patients in the continuous epidural analgesia group (CEA, n = 21) were given 8 ml of 0.25% bupivacaine with adrenalin; the epidural perfusion of 0.125% bupivacaine and 1 microgram/ml of fentanyl was started at the same rate as in the IEA group. We recorded pain as assessed on a visual analog scale, extension of sensory and motor block, maternal hemodynamic constants, number of boluses of bupivacaine used, total doses of bupivacaine and oxytocin, instruments needed for childbirth, and side effects (pruritus, nausea and vomiting).

RESULTS

Analgesic efficacy during the first 30 minutes was greater in the IEA group. The total dose of bupivacaine, required top-up boluses, and the extension of sensory block at 30 minutes, one hour and two hours were also significantly less in the IEA group. The incidence of pruritus was higher in the IEA group. No significant differences were observed for other variables.

CONCLUSIONS

Intradural-epidural analgesia provides effective analgesia for labor, with rapid onset, reduced extension of sensory block, lower total doses of local anesthetics and few side effects.

The role of ductus venosus blood flow assessment in screening for chromosomal abnormalities at 10-16 weeks of gestation

OBJECTIVE

To evaluate the role of ductus venosus blood flow assessment at 10-16 weeks' gestation in screening for chromosomal abnormalities.

METHODS

Ductus venosus blood flow was prospectively evaluated in 1371 consecutive pregnancies between 10 and 16 weeks of gestation. The pulsatility index for veins was calculated. All cases were screened for chromosomal defects combining maternal age and fetal nuchal translucency thickness.

RESULTS

A chromosomal abnormality was found in 20 cases. The overall detection rate, specificity, positive predictive value, negative predictive value and odds ratio for chromosomal abnormalities were 65%, 95.7%, 18.3%, 99.5% and 41 (95% CI 16-108), respectively, when using the 95th centile pulsatility index as a cut-off.

CONCLUSIONS

These preliminary results suggest that evaluation of the ductus venosus pulsatility index at 10-16 weeks' gestation is a useful second-line screening test for chromosomal defects. A combination of nuchal translucency measurement and ductus venosus assessment might increase specificity while maintaining an optimal detection rate for chromosomal abnormalities. Such a policy could identify 55% of all chromosomal abnormalities and about 69% of autosomal trisomies, reducing the need for invasive testing to less than 1%.

Identification of a new water channel (Rp-MIP) in the Malpighian tubules of the insect Rhodnius prolixus

Malpighian tubules (MT) of Rhodnius prolixus transport fluid at very high rates. To identify whether aquaporins (AQPs) are present in the MT of R. prolixus, total ribonucleic acid (RNA) was isolated from MT and used in a reverse transcription, polymerase chain reaction (RT-PCR), with two degenerate primers to highly conserved regions of the members of the AQPs family. A deoxyribonucleic acid (DNA) fragment of 370 bp was amplified; its sequence revealed a novel protein, representing a new member of the major intrinsic protein (MIP) family. The complementary DNA (cDNA) sequence of this new MIP protein was cloned by using RNA from MT and the rapid amplification of cDNA ends (RACE) technique. The cDNA had 1133 bp and the largest open reading frame coded for a protein of 286 amino acids, named R. prolixus major intrinsic protein (Rp-MIP). The hydrophobicity profile of the amino acid sequence predicts six transmembrane domains. Northern blot analysis of MT RNA showed a single transcript of about 1-1.3 kb for Rp-MIP. RT-PCR of single isolated MT and in situ hybridization analysis showed Rp-MIP transcripts in both proximal and distal segments. Expression of Rp-MIP in Xenopus laevis oocytes doubled the osmotic water permeability Pf, indicating that Rp-MIP may function as an aquaporin protein in the MT of the insect and thus may participate in urine formation in R. prolixus.

Nuchal thickness evolution in trisomy 18 fetuses

OBJECTIVE

To assess the natural evolution of nuchal thickness in trisomy 18 fetuses.

METHODS

Serial measurements of nuchal thickness were performed over a 1- to 5-week period in 17 fetuses with trisomy 18, from the 10th to the 20th week of pregnancy. To avoid a confounding effect due to gestational age, nuchal thickness was also expressed in standard deviations (SD) for the corresponding gestational week. In addition, the changes were assessed in terms of the presence of clinically positive thickening, considered as such when its measurement was above 2.5 SD for the corresponding gestational week.

RESULTS

On the initial nuchal thickness measurement, sensitivity for trisomy 18 decreased from 66% on assessment at 10-13 weeks of gestation to 38% at 14-16 weeks. In serial determinations, a mean increase of 1.3 mm [95% confidence interval (CI), 0.1-2.5] was observed for a mean period of 21 days. When corrected for gestational age, the mean increase of 0.2 SD (95% CI, -1.2 to -1.6) was found to be non-significant. No clinically relevant changes were recorded on re-examination, with nuchal thickening remaining stable in 76% of cases.

CONCLUSION

Nuchal thickening at re-examination was observed in a similar proportion of trisomy 18 fetuses as when initially observed.

Biochemical markers of bone turnover after surgical menopause and hormone replacement therapy

The objective of this study was to evaluate the effect of surgical menopause and hormone replacement therapy (HRT) on the new biochemical markers of bone turnover. Fourteen women who had undergone surgical menopause and began HRT 3 months after surgery were recruited for a 1-year study. Results were compared with a control group of 31 healthy premenopausal women of similar age. Serum samples were obtained to determine total alkaline phosphatase, bone alkaline phosphatase, propeptides carboxy- and amino-terminal of type I procollagen (PICP, PINP), osteocalcin, tartrate-resistant acid phosphatase, and carboxy-terminal telopeptides of type I collagen (ICTP and serum CTX). Urine samples were analyzed for hydroxyproline, pyridinoline, deoxypyridinoline, alpha- and beta-carboxy-terminal telopeptides of type I collagen (alpha-CTX and beta-CTX), and amino-terminal telopeptide of type I collagen (NTX). Determinations were performed after 3 months of surgical menopause and after 3 and 9 months of HRT. All biochemical markers increased after menopause, and most of them normalized after 9 months of HRT. Serum PINP showed the highest proportion of increased values after surgery among bone formation markers (62%), as well as the highest mean percent increase (101%). Among bone resorption markers in postmenopausal women, urinary beta-CTX, alpha-CTX, NTX, and serum CTX showed the highest proportion of increased values (100%, 67%, 58%, 58%, respectively) as well as the greatest mean percent increase. They were also the markers with the most marked response to HRT. In conclusion, serum PINP is the most sensitive marker of bone formation, whereas beta-CTX is the most sensitive marker of bone resorption after surgical menopause. In addition, both markers showed the highest response after HRT.

Differential upregulation of aquaporin-4 mRNA expression in reactive astrocytes after brain injury: potential role in brain edema

Astrocytes and aquaporin-4 (AQP4) play a significant role in brain ion homeostasis. Consequently the regulation of AQP4 mRNA in the CNS after different neurological insults was of interest. A single intrastriatal injection of ringer or quinolinic acid strongly induced AQP4 mRNA in the striatum, specially at the core of the lesion. Colocalization studies demonstrated that AQP4 mRNA induction was restricted to hypertrophic astrocytes. The extent of striatal AQP4 mRNA induction did not correlate with neuronal degeneration, but it did with extravasation of Evans blue dye as a marker of BBB disruption. Distant lesions were additionally induced by either 6-OHDA or a knife cut in the medial forebrain bundle (MFB). The former, but not the latter, induced a high AQP4 mRNA expression in the lesioned substantia nigra. However, axotomy of the MFB induced a high AQP4 mRNA expression at the lesion site. We conclude that the induction of AQP4 mRNA expression is related to disruption of the blood-brain barrier and under brain edema conditions this water channel plays a key role in the reestablishment of the brain osmotic equilibrium.

Localization of aquaporin-3 mRNA and protein along the gastrointestinal tract of Wistar rats

Since specific proteins responsible for water transport (aquaporins, AQPs) have been identified in a great variety of tissues, we decided to study the presence of AQP3 in the gastrointestinal tract (GIT) of Wistar rats. Poly(A+) RNA was purified from the mucosa of the stomach, jejunum, ileum and colon, and gross detection of AQP3 mRNA was done by Northern blot analysis. In situ hybridization studies were carried out to precisely localize the distribution of this transcript. Sections of the different tissues were hybridized with @400-bp [35S]riboprobes. The results presented here demonstrate that AQP3 is expressed throughout the GIT, with its expression in the colon and ileum greater than that in the stomach. Immunohistochemistry experiments, using a polyclonal antibody against AQP3, revealed that AQP3 protein is present at the basolateral membrane of the epithelial cells lining the villus tip of the small intestine and colon. The finding of AQP3 in the intestinal epithelia strongly suggests that this protein functions as a pathway for water transport in this epithelium.

Fetal heart rate and nuchal translucency in detecting chromosomal abnormalities other than Down syndrome

OBJECTIVE

To evaluate whether the combined use of fetal heart rate (FHR) and nuchal translucency measurements would be useful in the prediction of fetal chromosomal abnormalities at 10-13 weeks' gestation.

METHODS

In a prospective study, 1053 (553 reported previously) consecutive singleton pregnancies between 10 and 13 weeks' gestation underwent chorionic villus sampling at our institution. Fetal heart rate and fetal nuchal translucency thickness were measured immediately before the invasive procedure.

RESULTS

Thirty-five abnormal karyotypes were diagnosed, including 17 trisomy 21, seven trisomy 18, one trisomy 13, one trisomy 9, four unbalanced translocation, two Klinefelter syndrome, one Turner syndrome, one deletion of chromosome 18, and one true mosaicism. Using 95% of normal ranges as the cutoff for both measurements, the detection rate for all chromosomal anomalies was 77.1%, with a false-positive rate (1-specificity) of 7.7%, a positive predictive value of 25.7%, and a negative predictive value of 99.2%. Fetal heart rate improved the sensitivity of nuchal thickness in trisomies 21 and 18 (from 62.5% to 75%) and was particularly useful to detect other chromosomal anomalies (from 27.2% to 81.8%).

CONCLUSION

Our findings suggest that there is an added role of FHR in ultrasound screening of chromosomal abnormalities, specifically for those other than trisomy 21 and 18. The value of a single measurement of fetal heart rate for screening purposes needs to be confirmed by further investigation in a low-risk population.

Aquaporins

Aquaporins (AQP) are members of the major intrinsic protein superfamily of integral membrane proteins, which function as specialized water channels to facilitate the passage of water through the cell membrane in animals, plants and bacterias. Ten AQP homologues named from 0 to 9 have been clones so far in mammals. They are widely distributed and more than one AQP could be present in the same cell. Most of the AQPs are only permeable to water and impermeable to small organic and inorganic molecules, except for AQP 3, 7 and 9 which are also permeable to urea and glycerol. From the hydrophobicity profile all AQPs seem to have six transmembrane domains with five connecting loops and with the amino and carboxyl termini in the cytoplasm. They are synthesized as monomers, but there is evidence suggesting that AQPs are formed in the membrane as tetrameric units, each of which has four water pores. The primary amino acid sequence contains putative phosphorylation sites for protein kinasses A and/or C or casein kinase II, and the expression and membrane protein abundance of some AQPs are known to be under hormonal regulation. The human genes for several AQPs have been cloned and an increasing number of disturbances associated to abnormal functioning of these proteins had been identified.

[Explicit and implicit memory during inhalation and intravenous anesthesia]

OBJECTIVE

Patients rarely report memory or knowledge of surgery after general anesthesia. During apparently adequate surgical anesthesia, however, information processing of high level functions, such as language comprehension and learning, can continue unconsciously. Our objective is to assess whether different anesthetic techniques (two inhalational and two intravenous) guarantee the absence of both types of memory.

PATIENTS AND METHOD

One hundred patients were randomly assigned to receive the following anesthetic procedures: desflurane/N2O (group 1), isoflurane/N2O (group 2), fentanyl/N2O (group 3) and total intravenous anesthesia (group 4). A cassette with the same music was played in all cases, and an order requiring a nonverbal response was given to 15 randomly chosen patients in each group. Response was evaluated at a visit 24 to 48 hours after surgery. Fifteen patients, therefore, constituted the study group for each anesthetic procedure, and 10 patients formed the control group. We assessed the presence of explicit memory in a structured interview, and implicit memory by way of the relation between the number of times the nonverbal order was obeyed and the time of the interview.

RESULTS

Explicit memory was absent in all patients. The presence of implicit memory was confirmed, however, in the isoflurane (p = 0.02) group. Significant differences between the isoflurane group and both the desflurane and total intravenous anesthesia groups (p = 0.03) were found.

CONCLUSION

Explicit memory was absent with all four anesthetic techniques used in our study. Implicit memory was more difficult to inhibit, however, with isoflurane/N2O.

[Satisfaction with locoregional anesthesia in women who had undergone cesarean section]

OBJECTIVES

To compare satisfaction with local-regional and general anesthesia in women undergoing cesarean, the possible influence of time of evaluation and recall of the anesthesiologist.

PATIENTS AND METHODS

Retrospective study performed in all women who delivered by cesarean in the 6 first months of 1997. The women were assigned to two groups according to type of anesthesia, local-regional or general. Their satisfaction with anesthesia was evaluated by questionnaire 48 to 72 hours after surgery and two weeks after release. Most items required discrete-point answers, including a satisfaction of a scale of 0 to 10. During the second interview we also evaluated satisfaction with the procedure and hospital in general, as well as recall of the anesthesiologist. Group homogeneity was based on demographic, sociocultural, obstetric and surgical variables.

RESULTS

In a context of high satisfaction with anesthesia, 189 (76%) of the 247 women receiving local-regional anesthesia gave high evaluations to the anesthesia (8.90 +/- 1.5; mean: 10), compared with 58 (24%) of those receiving general anesthesia (8 +/- 2; mean 8.5) (p = 0.001). Both groups were homogeneous except for the distribution of emergencies, which occurred more often in those receiving general anesthesia (p < 0.001). Women who had received local-regional anesthesia expressed greater willingness to repeat or recommend the technique (p < 0.001). The highest score in this group was from women receiving intradural anesthesia along with fentanyl for local anesthesia, with significant differences only in comparison to epidural anesthesia. The differences in responses between the first and second interview were scarce. The hospital received a lower evaluation than did either anesthesia or surgery (p < 0.001). The anesthesiologist, who was less well recognized than the obstetrician was remembered better among women receiving local-regional anesthesia (p = 0.008).

CONCLUSIONS

Local-regional anesthesia can improve levels of satisfaction over that of general anesthesia among women undergoing cesarean surgery, and contributes to maintaining recall of the anesthesiologist. These results may be related to the fact of being conscious during the birth of a child.