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PubMed1997

The first US National Toxicology Program exercise on the prediction of rodent carcinogenicity: definitive results.

A few years ago, the US National Toxicology Program sponsored an exercise aimed at comparing different prediction approaches for carcinogenicity by challenging them on a common set of chemicals. The exercise was considered to be sufficiently completed when 40 (out of 44) chemicals were actually experimentally tested, and the experimental and estimated carcinogenicity were compared. More recently, the rodent results for the remaining 4 chemicals have been disclosed, making it possible to draw definitive conclusions on the comparative exercise. Having analyzed the first subset of results with multivariate statistical methods, we present here the analysis of the complete set of results. The present analysis also considers aspects (e.g., the complementarity of the different systems in identifying the carcinogens), which had not been investigated previously. The conclusion of this study were: (a) the expansion of the data base from 40 to 44 chemicals did not significantly change the results of the exercise; (b) the structure-activity approaches generated prediction profiles different from those generated by the prediction systems mainly relying on the use of experimental data (in vitro and in vivo); (c) the performance of the predictive systems was generally rather limited; (d) the prediction systems were affected by over sensitivity; they were generally capable of identifying the molecules containing the potentially alerting substructures, but were not so refined as to be able to discriminate between potential and actual carcinogenicity; (e) the combination of the systems into batteries did not permit a significant increase in the performance of the individual methods. The need for, and possible approaches to finely tuning the systems are discussed.

Animals↗
PubMed2005

Immunological patterns identifying disease course and evolution in multiple sclerosis patients.

Reliable, and easy to measure, immunological markers able to denote disease characteristics in multiple sclerosis (MS) patients are still lacking. We applied a multivariate statistical analysis on results obtained by measuring-by real-time RT-PCR-mRNA levels of 25 immunological relevant molecules in PBMCs from 198 MS patients. The combined measurement of mRNA levels of IL-1beta, TNF-alpha, TGF-beta, CCL20 and CCR3 was able to distinguish MS patients from healthy individuals. CXCR5, CCL5, and CCR3 combined mRNA levels identify primary progressive MS patients while TNF-alpha, IL-10, CXCL10 and CCR3 differentiate relapsing MS patients. Our results indicate that multi-parametric analysis of mRNA levels of immunological relevant molecules in PBMCs may represent a successful strategy for the identification of putative peripheral markers of disease state and disease activity in MS patients.

Adult↗
PubMed2005

Synonymous codon usage in adenoviruses: influence of mutation, selection and protein hydropathy.

Trends in synonymous codon usage in adenoviruses have been examined through the multivariate statistical analysis on the annotated protein-coding regions of 22 adenoviral species, for which complete genome sequences are available. One of the major determinants of such trends is the G+C content at third codon positions of the genes, the average value of which varied from one viral genome to other depending on the overall mutational bias of the species. G3S and C3S interacted synergistically along the first principal axis of correspondence analysis on the Relative Synonymous Codon Usage of adenoviral genes, but antagonistically along the second principal axis. The intra-genomic variation in codon usage pattern in adenoviruses is generally influenced by asymmetrical mutational bias in two DNA strands. Other major determinants of the trends are the natural selection, putatively operative at the level of translation and quite interestingly, hydropathy of the encoded proteins. The trends in codon usage, though characterized by distinct virus-specific mutational bias, do not exhibit any sign of host-specificity. Significant variations are observed in synonymous codon choice in structural and nonstructural genes of adenoviruses.

Adenoviridae↗
PubMed1990

Surgery for soft tissue sarcoma in the extremities. A multivariate analysis of the 6-26-year prognosis in 137 patients.

In 137 patients with soft tissue sarcomas in the extremities, the influence of patient and tumor characteristics and surgical procedures on prognosis was studied using a multivariate statistical analysis. The minimum follow-up time was 6 years, and no patient was lost to follow-up. Eighty-nine patients were referred with the tumor intact (primary series), while 48 were referred after biopsy or with local recurrence after previous surgery (secondary series). The frequency of amputation was 15 percent in the primary series and 48 percent in the secondary series. A local, function-preserving operation with a wide margin was performed in 37 patients without biopsy (clinical diagnosis alone). Local control of the disease was obtained in all but one of these patients without any adjunctive treatment. Independent, unfavorable factors concerning local recurrence were advancing age, open biopsy, and marginal surgery. Independent, unfavorable factors concerning survival were advancing age, increasing histologic malignancy grade, and ablative surgery. A tumor-related death was observed in 0, 29, 47, and 67 percent of the patients with tumors of malignancy grades I, II, III, and IV, respectively.

Adolescent↗
PubMed1992

A multivariate analysis of the relations between craniofacial structure and occlusion with DiPaolo's quadrilateral measures.

This study examined the relations between craniofacial structure and occlusion with clinically oriented skeletal measures consistent with Enlow's counterpart principle and a combination of univariate and multivariate statistics. The pretreatment lateral cephalograms and dental casts of 59 white adolescents with natural skeletal and occlusal development were selected to provide a random sampling of various malocclusions. Craniofacial structure was described with DiPaolo's quadrilateral measures. The relations between craniofacial structure and occlusion were analyzed with simple correlation analysis, stepwise multiple regression, and stepwise discriminant analysis. Intratester and intertester reliability were established, and a lack of sexual dimorphism was demonstrated. Three types of relations were identified: anteroposterior relations, vertical relations, and coordinations. A strong association was found between the variation in the anteroposterior measures and the variation in sagittal occlusion. A more modest association was found between the variation in the vertical measures and the variation in vertical occlusion. A combined skeletal measure composed of the variable pair mandibular plane angle and the ratio of anterior lower facial height to anterior upper facial height was found to explain the greatest percent of the variance in vertical occlusion. Several coordinations were found which, when taken together, described an overall pattern of associations.

Adolescent↗
PubMed2003

Combined effect of cooking (grilling and roasting) and chilling storage (with and without air) on lipid and cholesterol oxidation in chicken breast.

The oxidation of the lipid fraction and cholesterol in raw and cooked chicken breast samples stored for 0 and 6 days at 4 degrees C under aerobic conditions and in vacuum packaging was studied. The multivariate statistical analysis showed significant effects of both culinary process and storage conditions on the lipid and cholesterol oxidation process, with a significant interaction between the two variables. Aerobic storage increased thiobarbituric acid reactive substances (TBA) from 0.04 to 0.06 ppm for raw samples, from 0.21 to 1.20 ppm for grilled samples, and from 0.24 to 1.62 ppm for roasted samples. During vacuum storage, only roasted samples showed significant increases in TBA. Levels of total cholesterol oxidation products (COP) remained low (2.88 to 4.35 microg/g of lipid) for all raw samples. Cooking increased COP levels to 12.85 and 11.54 microg/ g of lipid for grilled and roasted samples, respectively. Total COP and all individual COP except for cholestanetriol were significantly correlated with TBA and the peroxide index. However, the most extensive effect was attributable to the aerobic storage of cooked samples, which led to COP levels of 92.35 and 88.60 microg/g of lipid in grilled and roasted samples, respectively. Vacuum packaging did not increase COP levels for cooked samples.

Animals↗
PubMed1998

Is hypertriglyceridaemia an independent risk factor for coronary heart disease? The epidemiological evidence.

There has been considerable controversy over whether elevated levels of triglycerides, or hypertriglyceridaemia, is an independent risk factor in coronary heart disease (CHD). Discrepancies between findings of univariate and multivariate statistical analyses are likely to be due to the strong inverse correlation between plasma triglyceride levels and high density lipoprotein cholesterol. Convincing evidence of a link between elevated triglyceride levels and CHD has been reported in a meta-analysis of patients whose plasma triglyceride levels were measured in the fasting state. Further evidence has come from several angiographic studies that have examined the relationship between plasma triglyceride levels and the progression of coronary artery disease (CAD). It is critical that the threshold of placebo triglyceride, above which hypertriglyceridaemia is recognized, is set at an appropriate level. This will ensure that patients at potential risk of CHD receive appropriate lipid-lowering treatment. In an 18-year follow-up study, incidence and severity of stenosis correlated with plasma triglyceride level. At a triglyceride level of 100 mg. dl-1, which current guidelines would consider to be low risk, patients had a reduced chance of survival from coronary events. These findings suggest that the present classification of triglyceride levels in the assessment of CAD risk may need to be redefined.

Cholesterol, HDL↗
PubMed1991

X-ray microanalysis of cell nuclei.

The principal component analysis, a multivariate statistical analysis of data, has been used to process X-ray microanalytical data from cell nuclei. Sixty-seven measurements from different areas of chromatin, nucleoli of rat follicular cells, and nucleoli of rat oocyte cells in their antral stage have been studied. The variables are the X-ray characteristic signals for P, S, Al, Fe, Cu, and Zn. This method demonstrates four distinct groups, the chromatin area, which is associated with a higher concentration of P; the compact mass of oocyte nucleolus which possesses the highest content in S, Al, and Zn, and two groups of nucleolar areas. The fibrillar component is richer in S, Al, and Zn than the granular component. The high degree of correlation between these three elements proves the chemical affinity of metals for the proteins (S being the signature for proteins). Cryoembedding in Lowicryl resin at even lower temperatures (213 degrees K in K11M) after quick cryofixation and cryosubstitution in the absence of chemical fixatives gives good ultrastructural preservation and the possibility of simultaneously performing X-ray microanalysis and immunocytochemistry.

Animals↗
PubMed1994

Impact of bladder neck preservation during radical prostatectomy on continence and cancer control.

OBJECTIVES: To assess the effect of preservation of the bladder neck and other factors on the rate of postoperative urinary continence and cancer control after radical prostatectomy. METHODS: Prospective analysis of clinical and pathologic findings in 206 consecutive patients undergoing radical prostatectomy with a surgical technique that emphasizes preservation of periurethral supporting tissue, urethral length, incorporation of the posterior periurethral fascia into the vesicourethral anastomosis, and preservation of the bladder neck. RESULTS: Uni- and multivariate statistical analysis demonstrated that patient age (p = 0.033) and vesical neck contracture (p = 0.047) were predictive of incomplete return of urinary control. Preservation of the vesical neck had no impact on return of continence, but was associated with a trend to a lower incidence of vesical neck contractures. A positive bladder neck margin occurred in 6.8% of surgical specimens and was associated with a higher grade, more advanced local stage, and other positive margins in all cases. The rate of local recurrence or prostate-specific antigen (PSA)-only failure was similarly independent of whether the vesical neck was preserved or resected and reconstructed. CONCLUSIONS: Age greater than 65 and occurrence of a vesical neck contracture are adverse predictors for return of urinary continence after radical prostatectomy. Preservation of the bladder neck does not have an impact on return of urinary control but may be associated with a lower risk of vesical neck contracture. Preservation of the bladder neck does not compromise cancer control as assessed by local or PSA-only failure rates.

Adult↗
PubMed2005

Serum PCB profiles in Native Americans from Wisconsin based on region, diet, age, and gender: Implications for epidemiology studies.

BACKGROUND: Different PCB congeners and different mixtures of congeners have been demonstrated to have different biological actions. More complete characterization of congener profiles in exposure sources may assist in predicting health outcomes. METHODS: Thirty-six (36) polychlorinated biphenyl (PCB) congeners were measured by gas chromatography isotope-dilution mass spectrometry (IDMS) in 314 serum samples from Native Americans in Wisconsin, Michigan and Minnesota. Five dietary groups were established based on the quantity and species of fish consumed and the waters from which the fish were caught. Multivariate statistical methods were able to resolve gender and dietary differences in PCB homologue and PCB congener patterns. RESULTS: Females had higher proportions of lower chlorinated homologues, including a consistently higher proportion of pentaCB 118. The relative presence of the very labile and volatile PCB 18, above 1% of the total PCB in females from the minimal fish consumption and "other" groups, suggests possible exposure to PCBs in the atmosphere. The dietary group consuming predatory fishes from Lakes Michigan and Superior had the highest serum concentrations of total PCB (mean of 3.1 ng/ml) and the most distinct congener profile. The two dietary groups least dependent on fishing or fishing mostly from inland lakes (non-Great Lakes) had the lowest total PCB concentrations, both with means of 1.4 ng/ml. CONCLUSIONS: These serum PCB concentrations were less than those found in earlier studies of fish consumers in the Great Lakes region and may reflect the decrease in PCBs in these lakes.

Age Factors↗
PubMedDate not supplied

Ultrasound visibility of needles used for regional nerve block: an in vitro study.

BACKGROUND AND OBJECTIVES: Ultrasound visibility of regional block needles is a critical component for safety and success of regional anesthetic procedures. The aim of the study was to formally assess factors that influence ultrasound visibility of needles used in regional anesthesia. METHODS: Regional block needles between 17- and 22-G diameter were inserted in a tissue equivalent phantom at angles from 0 degrees to 65 degrees relative to the phantom surface. For visibility enhancement, the needles were primed with air or water in combination with stylets and different size guide wires. Ultrasound measurements of needle tips and shafts were performed using transversal and longitudinal imaging with a linear 15-MHz transducer. Univariate and multivariate statistical analyses were performed on 719 visibility measurements. RESULTS: Hustead tip needles exhibited best ultrasound visibility. Ultrasound visibility of the needle tip was increased by insertion of a medium size guide wire. Water or air priming of the needle, insulation, and the insertion of a stylet did not influence needle visibility. Long axis imaging of the needle for shallow insertion angles (<30 degrees in relation to the phantom surface) and short-axis imaging for steep angles (>60 degrees ) provided the best ultrasound visibility of the needle tips. Needle visibility decreased linearly with steeper insertion angles ( P <.001) and smaller needle diameters ( P <.001). CONCLUSIONS: The results of our in-vitro study suggest a number of factors enhancing ultrasound visibility of regional block needles. The use of needles in the largest possible size inserted with a medium-size guide wire provides the best ultrasound visibility. Analysis of the approach angle favors needle insertion parallel to the transducer. The consideration of these factors may improve safety and success of ultrasound-guided regional blocks.

Equipment Design↗
PubMed2000

Trace element levels in harp seal (Pagophilus groenlandicus) and hooded seal (Cystophora cristata) from the Greenland Sea. A multivariate approach.

Concentrations of the essential trace elements, iron, copper, zinc and selenium and the non-essential elements arsenic, cadmium, total mercury and lead, were measured in the meat, liver and kidney of two species of seals, harp seal (Pagophilus groenlandicus) and hooded seal (Cystophora cristata) collected in the Greenland Sea. The spread among the individual seals was considerable. However, multivariate statistics simplified the evaluation of the data. The muscle tissue contained lower levels of the elements than kidney and liver. The kidney and liver tissue were also different, in particular with higher levels of iron in the liver and higher levels of cadmium in the kidney. Species differences were clear in both liver and kidney tissue, with higher levels of most of the elements in the hooded seals, while the harp seals had a higher burden of arsenic in the two tissues. Male hooded seals had higher levels of mercury and selenium than the females in all tissues. For harp seal there was a slight difference between the sexes in the muscle tissue, while no difference was observed in the liver and kidney tissues. The juvenile seals generally had lower levels of the elements in their tissues than the adults, although copper and zinc were higher in the muscles and livers of the juveniles as was iron in the muscles. No correlation between age and trace element levels in the tissues of the adult seals was observed.

Age Factors↗
PubMed2004

Endoscopic third ventriculostomy in the management of obstructive hydrocephalus: an outcome analysis.

OBJECT: The purpose of this paper is to elucidate the safety and efficacy of, and indications and outcome prognosis for endoscopic third ventriculostomy (ETV) in 58 patients with obstructive hydrocephalus. METHODS: Between September 1999 and April 2003, 58 ETVs were performed in 58 patients with obstructive hydrocephalus (36 male and 22 female patients) at the authors' institution. The ages of the patients ranged from 5 to 67 years (mean age 35 years) and the follow-up period ranged from 3 to 41 months (mean duration of follow up 24 months). Patients were divided into four subgroups based on the cause of the obstructive hydrocephalus: 21 with intracranial tumors; 11 with intracranial cysts; 18 with aqueductal stenosis: and eight with intracranial hemorrhage or infection. Both univariate and multivariate statistical analyses were performed to assess the prognostic relevance of the cause of the obstructive hydrocephalus, early postoperative clinical appearance, and neuroimaging findings in predicting the result of the ETV. The survival rate was 87% at the end of the 1st year and 84% at the end of the 2nd year post-ETV. One month after ETV an overall clinical improvement was observed in 45 (77.6%) of 58 patients. If we also consider the successful revision of ETV in two patients, a success rate of 78.3% (47 of 60 patients) was reached. The ETV was successful in 17 (81%) of 21 patients with intracranial tumors, nine (82%) of 11 with cystic lesions, 16 (88.9%) of 18 with aqueductal stenosis, and three (38%) of eight with intracranial hemorrhage or infection. A Kaplan-Meier analysis illustrates that the percentage of functioning ETVs stabilizes between 75 and 80% 1 year after the operation. In a comparison of results 1 year after ETV, the authors found that the aqueductal stenosis subgroup had the highest proportion of functioning ETV (89%). The proportions of the tumor and cyst subgroups were 84 and 82%, respectively, whereas the proportion was only 50% in the ventriculitis/intracranial hemorrhage subgroup (strata log-rank test: chi2 = 7.93, p = 0.0475). In the present study, ETV failed in eight patients (13.8%) and the time to failure after the procedure was a mean of 3.4 months (median 2 months, range 0-8 months). The logistic regression analysis confirmed an early postoperative improvement (within 2 weeks after ETV, significance [Sig] of log likelihood ratio [LLR] < 0.0001) and a patent stoma on cine phase-contrast magnetic resonance (MR) images (Sig of LLR = 0.0002) were significant prognostic factors for a successful ETV. The results demonstrated the multivariate model (B = -53.7309, standard error = 325.1732, Wald = 0.0273, Sig = 0.8688) could predict a correct result in terms of success or failure from ETV surgery in 89.66% of observed cases. The Pearson chi-square test demonstrated that little reliance could be placed on the finding of a reduced size of the lateral ventricle (chi2 = 5.305, p = 0.07) on neuroimaging studies within 2 weeks after ETV, but it became a significant predictive factor at 3 months (chi2 = 8.992, p = 0.011) and 6 months (chi2 = 10.586, p = 0.005) post-ETV. Major complications occurred in seven patients (12.1%), including intraoperative venous bleeding in three, arterial bleeding in one, and occlusion of the stoma in three patients. The overall mortality rate was 10.3% (six patients). One of these patients died of pulmonary infection and another of ventriculitis. Four additional patients died of progression of malignant tumor during the follow-up period. CONCLUSIONS: The results indicate that ETV is a most effective treatment in cases of obstructive hydrocephalus that is caused by aqueductal stenosis and space-occupying lesions. For patients with infections or intraventricular bleeding, ETV has considerable effects in selected cases with confirmed CSF dynamic studies. Early clinical and cine phase-contrast MR imaging findings after the operation play an important role in predicting patient outcomes after ETV. The predictive value of an alteration in ventricle size, especially during the early stage following ETV, is unsatisfactory. Seventy-five percent of ETV failures occur within 6 months after surgery. A repeated ventriculostomy should be considered to be a sufficient treatment option in cases in which stoma dysfunction is suspected.

Adolescent↗
PubMed1999

Glycometabolic state at admission: important risk marker of mortality in conventionally treated patients with diabetes mellitus and acute myocardial infarction: long-term results from the Diabetes and Insulin-Glucose Infusion in Acute Myocardial Infarction (DIGAMI) study.

BACKGROUND: The Diabetes and Insulin-Glucose Infusion in Acute Myocardial Infarction (DIGAMI) study addressed prognostic factors and the effects of concomitant treatment and glycometabolic control in diabetic patients with myocardial infarction (AMI). METHODS AND RESULTS: Of 620 diabetic patients with AMI, 306 were randomly assigned to a >/=24-hour insulin-glucose infusion followed by multidose subcutaneous insulin. Three hundred fourteen patients were randomized as controls, receiving routine antidiabetic therapy. Thrombolysis and beta-blockers were administered when possible. Univariate and multivariate statistical analyses were applied to study predictors of long-term mortality. During an average follow-up of 3.4 years (range, 1.6 to 5.6 years), 102 patients (33%) in the intensive insulin group and 138 (44%) in the control group died (P=0. 011). Old age, previous heart failure, diabetes duration, admission blood glucose, and admission Hb AIc were independent predictors of mortality in the total cohort, whereas previous AMI, hypertension, smoking, or female sex did not add independent predictive value. Metabolic control, mirrored by blood glucose and Hb AIc, improved significantly more in patients on intensive insulin treatment than in the control group. beta-Blockers improved survival in control subjects, whereas thrombolysis was most efficient in the intensive insulin group. CONCLUSIONS: Mortality in diabetic patients with AMI is predicted by age, previous heart failure, and severity of the glycometabolic state at admission but not by conventional risk factors or sex. Intensive insulin treatment reduced long-term mortality despite high admission blood glucose and Hb AIc.

Aged↗
PubMed2005

[Multivariate study of risk factors for developing complications after multinodular goiter surgery].

INTRODUCTION: Multinodular goiter (MG) accounts for a large volume of procedures performed in endocrine surgery departments. However, risk factors for postoperative complications have not been systematically investigated. The aim of the present study was to evaluate surgical outcomes in terms of morbidity and mortality through multivariate statistical analysis with a view to determining risk factors in MG surgery. PATIENTS AND METHOD: A total of 672 patients who underwent surgery for MG were retrospectively reviewed. The variables analyzed were age, sex, prior surgery, disease duration, symptomatology, intrathoracic component, the surgeons experience, surgical technique, identification of structures, associated thyroid carcinoma and thyroid specimen weight. The chi-squared test, Students t-test and logistic regression analysis were performed. RESULTS: Morbidity was 22% (n = 147) and mostly corresponded to hypoparathyroidisms and transitory recurrent lesions. Risk factors for developing these complications were symptomatic disease (p = 0.0131), hyperthyroidism (p = 0.0333), compressive symptoms (p = 0.0158), clinical grade of the goiter (p = 0.0482), surgical technique (p < 0.00001) and thyroid weight (p = 0.0302). Independent risk factors were surgical technique, hyperthyroidism and goiter grade. The definitive complication rate was 2.2% (n = 15), corresponding to six hypoparathyroidisms (0.9%) and 10 recurrent lesions (1.5%). The risk factor for their development was hyperthyroidism (p = 0.0037; RR = 2.8). CONCLUSIONS: The main independent risk factor for complications after MG surgery is hyperthyroidism.

Female↗
PubMed2002

Predicting the stability and growth of acoustic neuromas.

HYPOTHESIS: Acoustic neuroma (AN) growth can be predicted using information gathered at the time the AN is initially diagnosed. BACKGROUND: Knowledge of AN growth is essential for treatment planning. Previous studies have not been able to identify predictors of AN growth. METHODS: A multivariate statistical analysis was carried out using two independent sets of secondary data from the natural histories of ANs. Logit, probit, and censored regression techniques were used to test alternative hypotheses of AN growth between the initial and second measurements, as well as between subsequent measurements. RESULTS: In one data set, AN growth between the first and second measurements varied significantly and inversely with age. It was much greater if the AN was on the left side and if there were more symptoms. It did not depend on initial tumor size or the measurement interval. In the other data set, AN growth was also greater for left-sided tumors and depended on symptoms. However, it varied inversely with tumor size and directly with the measurement interval. There was also some evidence that tumors that were more stable between the initial two measurements were more likely to remain stable between the second and third measurements. However, this did not apply to AN growth between the third and fourth measurements. CONCLUSIONS: AN growth is predictable but the prediction model is not apparently independent of the policy for selecting ANs for conservative management.

Cell Division↗
PubMed2006

Prehospital standardization of medical airway management: incidence and risk factors of difficult airway.

OBJECTIVES: The rate of difficult intubation in prehospital emergency medicine varies greatly among studies already published and depends on several factors. The authors' objective was to determine the rate of difficult intubations and to determine factors associated with prehospital difficult airways when a standard protocol for sedation and intubation was applied. METHODS: This 30-month clinical, observational, prospective study was performed in a suburb of Paris, France (Val de Marne, population 1,300,000) by a prehospital emergency medical unit. Airway management for patients who needed tracheal intubation was standardized. The pharmacological procedure recommended rapid sequence intubation for patients with spontaneous cardiac activity. In cases of difficult, laryngoscopy-assisted intubation, a predefined algorithm was proposed. The Intubation Difficulty Score (IDS) was calculated for all patients requiring tracheal intubation, and factors associated with difficult intubation, defined by IDS of >5, were identified by using multivariate statistical analysis. RESULTS: During the study period, 1,442 patients were included; 640 (44%) were in cardiorespiratory arrest, and 802 had a spontaneous cardiac activity. Deviation from the pharmacological and airway management procedures occurred in 1% of cases. When the predefined difficult airway management algorithm was followed, failure to intubate was encountered twice (0.1%). One hundred six (7.4%) patients had an IDS of >5, and 60 (4.1%) required first (n = 56) then second (n = 4) alternative techniques for tracheal intubation. Semirigid leaders allowed tracheal access in 93% of difficult-intubation patients. One patient required a prehospital cricothyroidotomy. Factors associated with difficult intubation were the following: a history of ear, nose, or throat neoplasia or surgery; obesity; facial trauma; the operator's status; and the operator's position. CONCLUSIONS: If prehospital medical airway management is standardized and performed by trained operators, failure to intubate is rare (0.1%), and the incidence of difficult tracheal intubation is 7.4%, independent of cardiorespiratory status.

Airway Obstruction↗
PubMed2000

[Risk factors and prognosis of nosocomial pneumonia due to gram-negative bacteria in a general hospital].

Nosocomial pneumonia due to Gram-negative bacteria is one of the most important infections because of its high frequency, morbidity and mortality. The objective of this study was to determine the risk factors and prognosis for nosocomial pneumonia caused by Gram-negative bacteria. A group of 50 patients with nosocomial pneumonia due to Gram-negative bacteria were studied in a prospective, consecutive manner and compared with another group of 50 patients with similar characteristics but without infection. The diagnostic criteria, acquisition, previous infections, prognosis of the underlying disease, the initial severity of the clinical situation, presence of complications, type and evolution of antibiotic treatment were adjusted according to the criteria in the literature. Univariate and multivariate statistical analysis of the results was carried out. The risk factors found included the following: male sex, high-risk hospital units, nosocomial acquisition and previous manipulation with intubation and mechanical ventilation, previous pulmonary infections, and the use of wide-spectrum antibiotics in the six weeks prior to the study. The most isolated Gram-negative bacterium was Pseudomonas aeruginosa (32%), followed by polymicrobial flora (18%). Bacteriemia was found in 30% of the cases. Mortality was 24%, with the factors significantly associated with a poor prognosis being a serious underlying disease, a clinically critical situation, previous surgery, complications, Gram-negative bacteria, use of wide-spectrum antibiotics in the six months before the study, and advanced age. The mortality of the group was 8%. It was concluded that knowledge of the risk factors and prognosis of nosocomial pneumonia due to Gram-negative bacteria is of high importance to improve treatment and decrease morbidity and mortality.

Anti-Bacterial Agents↗