Generation of a bank of clinical-grade, HLA-homozygous iPSC lines with high coverage of the Spanish population

BACKGROUND

Induced pluripotent stem cell (iPSC)-derived cell therapies are an interesting new area in the field of regenerative medicine. One of the approaches to decrease the costs of iPSC-derived therapies is the use of allogenic homozygous human leukocyte antigen (HLA)-matched donors to generate iPSC lines and to build a clinical-grade iPSC bank covering a high percentage of the Spanish population.

METHODS

The Spanish Stem Cell Transplantation Registry was screened for cord blood units (CBUs) homozygous for the most common HLA-A, HLA-B and HLA-DRB1 haplotypes. Seven donors were selected with haplotypes covering 21.37% of the haplotypes of the Spanish population. CD34-positive hematopoietic progenitors were isolated from the mononuclear cell fraction of frozen cord blood units from each donor by density gradient centrifugation and further by immune magnetic labeling and separation using purification columns. Purified CD34 + cells were reprogrammed to iPSCs by transduction with the CTS CytoTune-iPS 2.1 Sendai Reprogramming Kit.

RESULTS

The iPSCs generated from the 7 donors were expanded, characterized, banked and registered. Master cell banks (MCBs) and working cell banks (WCBs) from the iPSCs of each donor were produced under GMP conditions in qualified clean rooms.

CONCLUSIONS

Here, we present the first clinical-grade, iPSC haplobank in Spain made from CD34 + cells from seven cord blood units homozygous for the most common HLA-A, HLA-B and HLA-DRB1 haplotypes within the Spanish population. We describe their generation by transduction with Sendai viral vectors and their GMP-compliant expansion and banking. These haplolines will constitute starting materials for advanced therapy medicinal product development (ATMP).

Effect of nopal mucilage addition on physical, barrier and mechanical properties of citric pectin-based films

This study considered the effect of the nopal mucilage (NM) fraction on the physical, barrier and mechanical properties of citric pectin-based (CP) films. Pectin aqueous dispersion 75 mL (2.0 g/100 g water) were mixed with 5 mL of glycerol and 20 mL of NM aqueous dispersions at different concentrations; namely, 5, 10, 12, 14 16, 18 and 20 g/100 g water. Films containing the highest NM content (20 g/100 g water) exhibited improved thermal stability. The addition of NM at relatively low concentration (0-10 g/100 g water) led to important modifications of mechanical properties, including elongation to break, tensile strength, and elasticity. Microstructural analysis showed that films containing between 14 and 20 g/100 g water of NM presented rough and fractured surfaces. As mucilage concentration in films was increased, the vapor water permeability decreased as result of better internal cohesiveness of components. The modification of the physical properties in CP films resulted from molecular and physical interaction of its components. In general, the combination of NM and CP for forming edible films led to enhanced thermal stability and higher water vapor permeability, which are prescribed properties for applications as food packaging.

Thermodynamic sorption analysis and glass transition temperature of faba bean (Vicia faba L.) protein

Freeze-dried faba bean (Vicia faba L.) protein adsorption isotherms were determined at 25, 35 and 40 °C and fitted with the Guggenheim-Anderson-de Boer model. The pore radius of protein was in the range of 0.87-6.44 nm, so that they were considered as micropores and mesopores. The minimum integral entropy ranged between 4.33 and 4.44 kg H₂O/100 kg d.s., was regarded as the point of maximum of stability. The glass transition temperature of the protein equilibrated at the different conditions of storage was determined, showing that the protein remained in glassy state for all cases. The protein showed compact and rigid structures, evidenced by microscopy analysis.

Familial isolated pituitary adenoma caused by a Aip gene mutation not described before in a family context

The cause of familial isolated pituitary adenomas (FIPA) remains unknown in a high percentage of cases, but the AIP gene plays an important role in the etiology. The aim of the study is to describe a family with FIPA syndrome and the results of genomic studies. A 16-year-old man had a giant prolactinoma resistant tomedical treatment with delayed growth and pubertal development. His mother had been previously diagnosed with a nonfunctioning pituitary macroadenoma. Transsphenoidal endoscopic resection was performed and a genetic study revealed a heterozygous mutation in exon 6: 974G>A (p.Arg325Gln). Because the AIP gene is a tumor suppressor gene, we searched for loss of heterozygosity within the AIP gene by amplifying exon 6 from tumor tissue of the patient. In the electropherogram, only the A allele was amplified (hemizygous state), indicating loss of the normal allele. We report a Spanish family with FIPA in whom a mutation in the AIP gene previously unreported in a familiar context was identified.

[Hypertension and anesthesia: consensus statement of the Catalan Associations of Anesthesiology and Hypertension]

The prevalence of hypertension is high in the surgical population. Differing practices and the absence of consensus among physicians involved in caring for hypertensive patients has made it one of the most frequent reasons for cancelling scheduled surgery. The aim of this consensus statement is to outline a practical approach to managing the hypertensive surgical patient. Hypertension is associated with increased risk of perioperative complications, particularly those related to systemic effects and notable fluctuations in blood pressure during surgery. Preoperative assessment should center on a search for signs and symptoms of target organ damage. The anesthesiologist should seek to reduce perioperative fluctuations in arterial pressure, particularly guarding against sustained hypotension. After surgery, antihypertensive medication should be resumed as soon as possible.

[Effects of supply with glutamine on antioxidant system and lipid peroxidation in patients with parenteral nutrition]

INTRODUCTION

In the critically ill patient, there is a continuous production of reactive oxygen species (ROS) that need to be neutralized to prevent oxidative stress (OS). Quantitatively speaking, the glutathione system (GSH) is the most important anti-oxidant endogenous defense. To increase it, glutamine supplementation has been shown to be effective by protecting against the oxidative damage and reducing the morbimortality.

OBJECTIVE

To assess the effect of adding an alanylglutamine dipeptide to PN on lipid peroxidation lipidica and glutathione metabolism, as well as its relationship with morbidity in critically ill patients.

METHODS

Determination through spectrophotometry techniques of glutathione peroxidase, glutathione reductase, total glutathione, and maloniladdehyde at admission adn after seven days of hospitalization at the Intensive Care Unit (ICU) in 20 patients older than 18 years on parenteral nutrition therapy.

RESULTS

The group of patients receiving parenteral nutrition with glutamine supplementation had significant increases in total glutathione (42.35+/-13 vs 55.29+/-12 micromol/l; p<0.05) and the enzymatic activity of glutathione peroxidasa (470+/-195 vs 705+/-214 micromol/l; p<0.05) within one week of nutritional therapy, whereas the group on conventional parenteral nutrition did not show significant changes of any of the parameters studied (p>0.05). However, both mortality and ICU stay were not different between the study group, whereas the severity (assessed by the SOFA score) was lower in the group of patients receiving glutamine (SOFA 5+/-2 vs 8+/-1.8; p<0.05).

CONCLUSIONS

Glutamine intake in critically ill patients improves the antioxidant defenses, which leads to lower lipid peroxidation and lower morbidity during admission at the ICU.

Simple genotyping of functional polymorphisms of the human immunoglobulin G receptors CD16A and CD32A: a reference cell panel

The Fcgamma receptors CD16A and CD32A connect the innate and the adaptive immune responses by transmitting activating signals to natural killer lymphocytes and myeloid cells upon recognition of antigen-immunoglobulin G (IgG) complexes. Two allelic dimorphisms of these receptors, valine/phenylalanine-158 of CD16A and histidine/arginine-131 of CD32A, modulate their affinity for certain human IgG subclasses. Furthermore, these polymorphisms are clinically relevant because they modify the susceptibility, the clinical course and the response to therapy of several human diseases. Genotyping of CD16A and CD32A alleles, encoded by FCGR3A and FCGR2A, respectively, is complicated by the fact that they both belong to families of highly homologous genes. In this study, we present an original method for genotyping the FCGR3A and FCGR2A dimorphisms based on the technique of polymerase chain reaction with confronting two-pair primers. The new method simplifies the analysis of FCGR3A and FCGR2A because the two alleles of each gene are detected simultaneously in a single reaction and separated, with no further manipulations, by their different electrophoretic mobilities in regular agarose gels. We also present the CD16A and CD32A genotypes of cells from the Tenth International Histocompatibility Workshop, which can serve as a reference cell panel for investigating the influence of CD16A and CD32A polymorphisms on human health.

[Incidence in Catalonia of spinal cord compression due to spinal hematoma secondary to neuraxial anesthesia]

OBJECTIVE

To study the incidence in Catalonia of spinal cord compression due to spinal hematoma secondary to neuraxial anesthesia.

METHODS

The incidence of hematoma was based on published cases (MEDLINE, the Spanish Medical Index [Indice Medico Español], and Google) or cases reported at medical meetings or conferences by anesthesiologists from Catalan hospitals from 1996 to 2005, inclusive. The annual number of neuraxial anesthesias (spinal, epidural, and combined) was estimated based on the ANESCAT 2003 survey and the total number of anesthesias was calculated using the ANESCAT 2003 survey in conjunction with the surgical reports of Catalan hospitals.

RESULTS

A total of 11 cases of spinal hematoma after neuraxial anesthesia (7 after spinal anesthesia and 4 after epidural anesthesia) were reported or published from 1996 to 2005, inclusive. A total of 194 154 neuraxial anesthesias were performed in 2003 (126 560 spinal anesthesias and 5926 combined spinal-epidural anesthesias) and it was estimated that somewhat over 1 700 000 neuraxial anesthesias were performed over the 10 years reviewed. The incidence (95% confidence interval [CI]) of hematoma was 0.6 (95% CI, 0.3-1.2) per 100 000 neuraxial anesthesias, 0.6 (95% CI, 0.3-1.3) per 100 000 spinal anesthesias, and 0.7 (95% CI, 0.2-1.9) per 100 000 epidural anesthesias.

CONCLUSIONS

The incidence of spinal hematoma after neuraxial anesthesia is slightly more than 1 per 150 000 anesthesias-a similar finding to that of other epidemiological studies. The incidence is slightly higher in epidural anesthesia. These data imply a risk of approximately 1 spinal hematoma per year in Catalonia.

Facilitation of KIR genotyping by a PCR-SSP method that amplifies short DNA fragments

Detection of killer-cell immunoglobulin-like receptors (KIR) genes by polymerase chain reaction with sequence-specific primers (PCR-SSP) led in 1997 to the discovery that human genomes diverge largely in the KIR they encode. While only a few KIR genes are conserved in all humans, most individuals lack several those genes, which tend to associate in diverse haplotypic combinations. The PCR-SSP technique, updated to detect the more recently identified KIR genes and alleles, is still used widely to analyze the diversity of human populations, and to study the influence of KIR-gene variability on human health. Several published PCR-SSP methods for KIR genotyping, although simple and robust, have the drawback of relying on the amplification of DNA fragments spanning 0.5-2.0 kbp, which tends to fail in low-quality DNAs. Valuable collections of DNAs often include such poor quality samples, which lead to loss of data and resources. Even worse, undetected falsely negative or positive reactions may result in erroneous gene frequencies and in odd gene combinations. To address those problems, we have redesigned our previously published KIR genotyping method so that it produces short amplicons (less than 200 bp for most genes). This modification minimizes amplification failures, thus conferring greater consistency and reliability to KIR genotyping. In addition, the new PCR-SSP method detects recently described alleles of several KIR genes, and allows for discrimination between the major structural variants of KIR2DS4 and KIR3DP1 without increasing the number of reactions.

Formulation in tablets of a cholera whole cells inactivated vaccine candidate

Licensed as well as candidate cholera vaccines available at the present requires the dose preparation (included buffer) at the moment of application. The aim of this work was to evaluate the presentation in oral tablets of an inactivated cholera vaccine to avoid that inconveniences during application. We have therefore compared inactivated cultures of Vibrio cholerae with tablets formulation vaccine. We obtained that antigenic activity (ELISA) and immunogenicity in animal model (ELISA and vibriocidal tests) of V. cholerae inactivated cell remained unaltered in the final tablet formulation. The results suggest that the oral tablet formulation could be a useful pharmaceutical form in order to produce a new and affordable cholera vaccine.

[Spinal cord compression caused by hematoma related to neuroaxial anesthesia in Spain]

OBJECTIVES

Spinal cord compression from a hematoma is a rare serious complication of neuroaxial anesthesia. Our objective was to investigate cases reported and published by Spanish authors.

MATERIAL AND METHODS

Cases of spinal cord compression related to neuroaxial hematomas (epidural, subarachnoid, or both) reported at congreses and meetings in Spain or published in Medline-indexed journals from 1989 through December 2002 were reviewed. The clinical characteristics, risk factors, treatments, and outcomes were described for each case.

RESULTS

Since 1996, when the first cases were reported, 20 cases in all have appeared: 8 related to sub-arachnoid anesthesia, 8 to epidural anesthesia, 1 to a combination, and 1 to diagnostic lumbar puncture. In 2 cases, the neuroaxial technique used was poorly defined. Factors that might have caused the complication could be identified in 11 cases, among which there were 7 cases of anesthetic puncture or manipulation of an epidural catheter during a period of hemorrhagic risk because of antithrombotic therapy. The hematoma was evacuated surgically in 11 cases, and medical treatment was provided in 9 cases. The neurologic outcome was satisfactory in 14 cases.

CONCLUSIONS

The number of compressive spinal hematomas reported or published by Spanish authors is fairly high, and there are cases related to both sub-arachnoid and epidural anesthesia. Nonsurgical treatment was provided in 45% of the cases and the outcome was satisfactory in 70%. Risk factors were identified in over half of the reported cases.

[Neurobiological bases of language and its disorders]

AIMS

The purpose of this study is to offer an update on the anatomofunctional bases of language and the theories that explain its normal and pathological development.

METHOD

Language is a clear example of one of the higher functions of the brain, the development of which is carried out, on the one hand, in a genetically determined anatomofunctional structure and, on the other hand, by the verbal stimulus provided by the environment. Several systems and subsystems are at play within the anatomofunctional structure and these operate in series and in parallel. A large amount of the knowledge we have about the neurophysiological bases of language come from observations carried out in adult patients with circumscribed lesions and their clinical consequences (aphasias). Findings from recent studies involving functional imaging in volunteers submitted to linguistic tests have added more data. According to Damasio, three functional systems are at work in language: 1. The instrumental system, which corresponds to the perisylvian region of the dominant hemisphere where phonological processing takes place; 2. The mediation system, which includes temporal, frontal and parietal areas that surround the anterior region and are where lexical items are organised in a modular fashion, in terms of categories, actions and functional or connecting words; 3. The semantic system, which includes extensive areas of the cortex in both hemispheres and is the seat of concepts and meanings. Throughout a child s development, the evolution he or she follows to reach the neurolinguistic organisation of the adult brain requires the integrity and proper functioning of these structures that are for the most part located in the dominant hemisphere. We review the different theories that appear in the specialised literature concerning the causes and fisiopathogenic mechanisms behind dysphasias in early childhood.

CONCLUSIONS

Among the numerous functions that take part in the complex language system, some are essential for its normal development. From the work of Tallal et al. it has been seen that the sequential and fast phonological processing of consonant vowel shifts is altered in dysphasic and dyslexic children. This finding is related with the disorders in the normal asymmetry of the temporal planum (the left is larger than the right) that has been observed in these patients and with the neuropathological findings of Galaburda et al. in dyslexic patients who had previously been dysphasic, in whom cytoarchitectural anomalies (heterotopias) were found, above all in the left perisylvian region. Obviously not all forms of dysphasia are the result of this alteration. According to Chevrie Muller s classical chart adapted by us in accordance with Damasio s scheme it is possible to locate the dysphasic syndromes in different loci and distinguish a different physiopathological mechanism for each of them.

Robust relational parsing over biomedical literature: extracting inhibit relations

We describe the design of a robust parser for identifying and extracting biomolecular relations from the biomedical literature. Separate automata over distinct syntactic domains were developed for extraction of nominal-based relational information versus verbal-based relations. This allowed us to optimize the grammars separately for each module, regardless of any specific relation resulting in significantly better performance. A unique feature of this system is the use of text-based anaphora resolution to enhance the results of argument binding in relational extraction. We demonstrate the performance of our system on inhibition-relations, and present our initial results measured against an annotated text used as a gold standard for evaluation purposes. The results represent a significant improvement over previously published results on extracting such relations from Medline: Precision was 90%, Recall 57%, and Partial Recall 22%. These results demonstrate the effectiveness of a corpus-based linguistic approach to information extraction over Medline.

[Neuronal plasticity and the scientific bases of neurohabilitation]

INTRODUCTION

The validity of methods of neurological habilitation and rehabilitation has long been questioned by a large proportion of the medical profession. This sceptical attitude was partly due to lack of scientific confirmation of the theories on which methods of habilitation-rehabilitation were based, and the absence of reliable studies of the follow-up of such treatment, designed on strict statistical criteria.

DEVELOPMENT

Advances in recent years in understanding neuronal plasticity have permitted better understanding of the mechanisms which come into action following brain damage and the factors which help or hinder recovery, and the various possible patterns involved in the reorganization of neuronal circuits. A review of studies of animal experiments, and recently in humans (using techniques of functional imaging and magnetic exploration) show that by sensory stimulation and exercise it is possible to modify the structure and function of the brain, after its somatotopical organization, increase synaptic connections, influence the orientation of the dendrites, number of receptors etc. There are critical periods in development during which these plastic properties of the brain become fully developed and subsequently the possibility of recovery is considerably less.

CONCLUSIONS

The findings of neurobiological investigation show that there are good prospects for the recovery of a damaged nervous system by means of embryonic neurone implantation, axon bridges, transference of genes producing trophic factor, enzymes, neurotransmitters etc. In any case, therapeutic intervention and rehabilitation teaching continue to be useful for the functional recovery of these patients.

[Clinical forms of infantile dysphasias]

INTRODUCTION

By 'Dysphasias' we mean disorders of language development in children, as opposed to Aphasias which is the term used for loss of previously acquired language as a consequence of focal cerebral lesions. The definition of Dysphasia refers to alteration in the expression or comprehension of language which cannot be explained by deafness, motor deficit, mental retardation, brain damage, emotional disorders or insufficient exposure to language (DSM IV). Even within this definition there is room for different criteria for inclusion. This is shown by the lack of homogeneity in the populations studied by different authors, depending to some degree on the age of the children studied (the symptoms and signs of dysphagia are not the same in a 3 year old child as in one of school age) and the intellectual level required to rule out mental deficiency. Once the differential diagnosis with other conditions has been established, we should try to situate the dysphasia as being due to faulty reception, emission or both. Allen and Rapin have defined 4 categories of Dysphasia with subtypes which permit more specific classification within the two spheres mentioned above (reception and emission). In the sphere of emission, with characteristics of lack of fluency of speech and better comprehension than elocution are: syntactic phonological deficit syndrome, phonological programming deficit syndrome, verbal dyspraxia and lexical syntactic deficit syndrome. In the sphere of reception, with comprehension more affected than elocution are: verbal auditory agnosia and pragmatic semantic syndrome. Although the work of Allen and Rafin was done on a population of English-speaking children, this classification has also been shown to be useful in the Spanish language. We give a detailed description of these syndromes, illustrating them with video recordings of clinical cases.

[The contribution of neuropsychology to the diagnosis and treatment of learning disorders]

INTRODUCTION

In its broadest sense, the basic concept of Neuropsychology is that all behaviour originates in the brain; according to Luria, it depends on functional systems constituted by different areas of the brain which are inter related. Each area deals with a particular function which is part of the whole (for example, the cortical area for vision deals with reading). Which cortical areas make up the functional system depends on how the person acquired a certain type of behaviour.

DEVELOPMENT

The neuropsychological model, when applied to learning disorders, assumes that they are the expression of specific cerebral dysfunction due to genetic or environmental factors which have altered the development of the nervous system. Pennington recognizes five functional systems or nodules related to intellectual function. Each of these corresponds to a clearly defined zone of the cerebrum and impaired function of any zone causes specific learning disorders. Thus, the left perisylvan region deals with neurolinguistic function and disorders of this causes dyslexia. The hippocampal area of both hemispheres is related to memory and changes in this lead to disorders of memory. Right hemisphere dysfunction causes dyscalculia (posterior right hemisphere) and behaviour disorders (anterior right hemisphere) which may present together or separately. The dysexecutive syndrome is due to frontal lobe changes and is characterized by attention deficit, poor planning and anticipation, defective abstraction and other behaviour disorders. Although these are the best defined and most commonly seen syndromes in clinical practice, it would be logical to expect that there may be as many types of disorder as there are neural systems or subsystems involved in particular types of learning or behaviour, which may be altered. In support of these concepts we report four clinical cases seen by us in the Italian Hospital, Buenos Aires.

Automatic extraction of acronym-meaning pairs from MEDLINE databases

Acronyms are widely used in biomedical and other technical texts. Understanding their meaning constitutes an important problem in the automatic extraction and mining of information from text. Here we present a system called ACROMED that is part of a set of Information Extraction tools designed for processing and extracting information from abstracts in the Medline database. In this paper, we present the results of two strategies for finding the long forms for acronyms in biomedical texts. These strategies differ from previous automated acronym extraction methods by being tuned to the complex phrase structures of the biomedical lexicon and by incorporating shallow parsing of the text into the acronym recognition algorithm. The performance of our system was tested with several data sets obtaining a performance of 72 % recall with 97 % precision. These results are found to be better for biomedical texts than the performance of other acronym extraction systems designed for unrestricted text.

[Remifentanil or propofol for sedation in subarachnoid anesthesia. Effects on ventilation, hemodynamic stability and bispectral index]

OBJECTIVES

To compare depth of sedation, hemodynamic and respiratory effects, and bispectral index (BIS) in surgical patients under subarachnoid anesthesia with intravenous perfusion of 1 mg/kg/h of propofol or 3 microgram/kg/h of remifentanil or placebo.

PATIENTS AND METHOD

Fifty-one elective surgery patients were randomly assigned to one of 3 groups: propofol (n = 17), remifentanil (n = 17) or placebo (n = 17). We monitored ECG, blood pressure (BP), respiratory frequency (RF), oxygen saturation by pulse oximetry (SpO2), nasal end tidal carbon dioxide pressure (PETCO2), BIS and sedation on the Observer's Assessment of Alertness/Sedation scale (OAA/S). Five minutes after starting subarachnoid anesthesia, we initiated the assigned intravenous perfusion. Measurement of hemodynamic variables, BIS, PETCO2, RF and OAA/S score occurred at baseline, every 5 minutes during surgery and after withdrawal of sedation at intervals until recovery of baseline values.

RESULTS

Patient data and SpO2 were similar in the 3 groups. PETCO2, FR and OAA/S did not change significantly from baseline in the placebo group but were significantly different in the other groups. BIS was significantly lower in the propofol group than in either the remifentanil or the control group. Times to recovery were similar in the two sedation groups. Slight complications were observed in 35.3% patients in the propofol group, 53.3% in the remifentanil group and 7.7% in the placebo group; complications were mainly nausea, pruritus and hypoventilation in the remifentanil group and venous pain in the propofol group.

CONCLUSIONS

The sedation regimens used were safe and adequate. Propofol is associated with fewer complications than remifentanil.

[Drug allergy in a population of surgical patients]

OBJECTIVES

To determine the prevalence of drug allergies in a population of surgical patients. To establish a clinical classification of events as being very or not very likely to be allergic reactions. To detect which drug groups are associated with greater incidence of anaphylactic reaction and to analyze the severity of such reactions.

PATIENTS AND METHODS

Epidemiological study. During a preoperative interview, patients were asked if they were aware of the existence of any episode of allergy to drugs. If a patient answered yes, a specific data collection questionnaire on allergies was completed. Based on signs and symptoms described by the patient, reactions were classified as indicating high likelihood of allergy, low likelihood of allergy, or as being of unknown origin.

RESULTS

We questioned 1,218 patients (754 women/464 men), of whom 159 (13.05%) reported being allergic to drugs. The total number of drugs employed was 212 (1.34 drugs/patient). Antibiotics (54.7%), nonsteroidal anti-inflammatory drugs (NSAIDs) (19.3%), radiological contrast media (6.1%) and local anesthetics (4.7%) were the substance groups most often mentioned. We classified 74.5% of the reactions as indicating high likelihood of allergy, 19.8% as indicating low likelihood, and 5.6% to be of unknown origin. The skin was involved in 72.1% of the reactions that were highly likely to have been caused by allergy; 6.9% of these reactions involved the respiratory tract, 4.4% the circulatory system, 12% the skin plus respiratory tract, and 4.4% the skin plus respiratory and circulatory systems. The most severe reactions (16.4%) were associated with radiological contrast media (36.4%), NSAIDs (33.3%) and intravenous administration (38.1%). Signs of latex allergy were seen in 0.4% and signs of allergy to hair dyes in 0.9%. All allergy tests were negative in all these patients.

CONCLUSIONS

Drug allergy is reported by 13% of patients. It is highly likely that 74.5% of reactions are due to allergy. Antibiotics are the most frequently implicated drugs, followed by NSAIDs. The most serious reactions are caused by radiological contrast media and NSAIDs. Intravenous administration causes the most serious reactions.

[Potential and real drug interactions in critical care patients]

OBJECTIVES

To detect potential drug interactions occurring during treatment of critically ill patients and to evaluate the real clinical and analytical repercussions of such interactions.

PATIENTS AND METHODS

Seventy consecutive patients in a six-bed medical-surgical intensive care unit (ICU) were studied prospectively over a period of five months. The pharmacological department of the hospital provided the drugs through a computerized unit dosing system, using a program that gave warnings of possible drug interactions as each patient's treatment was entered. Interactions were cataloged according to clinical importance following the criteria of Hansten. The repercussions were evaluated by clinical and analytical monitoring.

RESULTS

On hundred two potential interactions were detected in 44.3% of patients (1.5 interactions per patient). In 6 patients (19.3%) analytical alterations were observed but only 2 (6.4%) of them presented clinical manifestations. Most of the interactions were cataloged as being of moderate clinical importance. Digoxin was the most frequently implicated drug. The number of drugs administered per patient was 14.7 and patients receiving the most drugs were the most likely to experience and interaction. We found a significant correlation (p < 0.05) between the number of interactions and age, APACHE III score, length of ICU stay and number of drugs administered.

CONCLUSIONS

The frequently of drug interactions in critically ill patients can be high, given the large number of drugs they receive. Although the real clinical repercussions of interactions are few, physicians should watch for them and the act appropriately.

[Efficacy of ondansetron in the prevention of nausea and vomiting after laparoscopic cholecystectomy]

To assess the efficacy of 4 mg of intravenous ondansetron versus placebo for the prevention of postoperative nausea and vomiting (PONV) in cholecystectomy, a type of surgery that is highly emetic. A random, double blind, placebo controlled study of 40 women over 18 years of age who were scheduled for non urgent laparoscopic cholecystectomy under general anesthesia. The patients were assigned to two groups to receive ondansetron (n = 23) or placebo (n = 17). Premedication and anesthesia were similar for all. The severity of PONV in the first 24 hours after surgery was recorded. There were no significant differences between the two groups with respect to biological characteristics or other factors that might influence the presentation or severity of PONV. The percentage of PONV-free patients was significantly higher in the ondansetron group than in the control group (73.91 and 11.76%, respectively; p < 0.001). Intravenous administration of 4 mg ondansetron is significantly superior to placebo for PONV prophylaxis after laparoscopic cholecystectomy.

[Succinylcholine induces hyperpotassemia in patients in critically ill patients]

OBJECTIVE

To study changes in kalemia caused by succinylcholine administration to patients in critical care, and the possible association of succinylcholine with clinical and analytical data, severity-of-disease classification, duration of stay in the intensive care unit (ICU) and immobility.

PATIENTS AND METHODS

Twenty-three patients admitted to the ICU, none of whom suffered burns, polytrauma or neuromuscular disease, and who had received 1.5 mg/kg succinylcholine on 28 occasions, usually to facilitate tracheal intubation. Kalemia was analyzed before neuromuscular relaxation and 5 and 30 min afterwards. Electrocardiographic II and V5 derivations and invasive arterial pressure were monitored in all patients. The increase in kalemia at 5 min correlated with age, sex, weight, APACHE II score, days in ICU, current and accumulated immobility, and analytical parameters such as glycemia, creatinine, GOT, bilirubinemia, pH and creatine kinase. The kalemia of these patients was compared with that of 15 patients in acceptable general state who had undergone scheduled surgery.

RESULTS

Kalemia increased significantly from a mean baseline level of 4.2 (0.9) mEq/l to 5.5 (1.4) at 5 min and 4.6 (0.9) at 30 min in ICU patients. In the non ICU patients there were no statistically significant changes. Kalemia at 5 min was correlated with baseline (r = 0.84; p < 0.0001), days in the ICU (r = 0.39; p < 0.05) and weight (r = 0.46; p < 0.05). The mean increase in kalemia at 5 min was 0.5 mEq/l in patients who stayed less than 10 days, 1.8 mEq/l in those whose stay was from 10 to 30 days and 1.4 mEq/l in patients who stayed longer than 30 days. The percent increase in kalemia correlated directly (r = 0.7; p < 0.001) with days in the ICU and with accumulated immobility in patients whose ICU stay was less than 30 days. For ICU stays longer than 30 days the correlation was negative (r = -0.98; p = 0.03). Electrocardiographic changes were recorded in 2 patients with brief sinus bradycardia having no hemodynamic repercussions.

CONCLUSIONS

The use of succinylcholine in critically ill patients causes a brief but significant increase in kalemia, with slight and rare electrocardiographic changes. The effect varies according to the length of time spent in the ICU and the degree of immobility, with maximum increases seen when the ICU stay is between 10 and 30 days. Patient immobility may play an important pathophysiological role. The indications for use of succinylcholine in critically ill patients should be very strict, particularly during the period of greatest sensitivity.

[Usefulness of the preoperative electrocardiogram in elective surgery]

OBJECTIVES

To assess the prevalence of abnormal electrocardiograms (ECG) recorded routinely in patients undergoing elective surgery as well as the prevalence of ECG abnormalities that could not be predicted by the patient's medical history. To determine the influence of ECG results on patient care. To identify patient groups at high risk for abnormal ECG.

PATIENTS AND METHODS

Retrospective study of 2,146 patients scheduled for non cardio-thoracic surgery requiring anesthesia. Two physicians reviewed the preoperative ECG reports in consultation with a cardiologist. The reports were considered normal, abnormal but expected or abnormal and unexpected based on agreement or not with the patient's medical history.

RESULTS

The 161 (7.4%) patients for whom data was missing were excluded. Preoperative ECGs were performed in 1,898 (95.6%) cases. Abnormal ECG results were reported for 351 (18.5%), most often for men, patients over 45 years of age, those classified ASA III-V, those with cardiovascular disease, kidney failure and diabetes mellitus. Two hundred seventy unexpected abnormalities were found in 234 (12.3%) patients. Of these, 117 (43.3%) were considered major. The unexpected abnormalities motivated changes of attitude toward 4 (1.7%) patients, but new treatment was established for only 2 (0.8%) of them. The prevalence of unexpected abnormalities was higher in men, patients over 45 years of age and those classified as ASA III-V.

CONCLUSIONS

The prevalence of unexpected preoperative ECG abnormalities among non cardio-thoracic surgical patients is high but the influence of such results is minimal. The sensitivity and specificity of preoperative ECG for detecting electrocardiographic abnormalities are low. We suggest that performance of ECG before surgery is useful in patients over 45 years of age or in those with cardiovascular disease, chronic kidney failure, diabetes mellitus, physical state ASA III-V and those for whom it has not been possible to obtain an adequate medical history or perform a complete physical.

[Cardio-circulatory response to laryngoscopy. Comparative study between Macintosh and McCoy laryngoscopes]

To assess the cardiocirculatory repercussions of laryngoscopy performed with the Macintosh or McCoy laryngoscopes, we studied 20 patients randomly divided into 2 groups of 10 to undergo laryngoscopy with one or the other of the aforementioned instruments. All patients were in good health overall (ASA I or II) and presented no criteria for difficult intubation (Mallampati I or II, distance between the thyroid and the menton greater than 7 cm and maximum distance between the incisors greater than 3.5 cm). The McCoy laryngoscope was associated with significantly lower systolic arterial pressure and heart rate.

The efficacy and optimum time of administration of ranitidine in the prevention of the acid aspiration syndrome

In order to evaluate the efficacy of a single oral dose of ranitidine 150 mg and the optimum time for its administration, we studied pH and volume measurements in 138 surgical patients, who formed six groups according to the time elapsed from ranitidine administration to gastric fluid aspiration as follows: group A: no ranitidine, group B: 60-90 min, group C: 91-120 min, group D: 121-150 min, group E: 151-180 min and group F: > 180 min. The patients from groups B, C, D, E and F had a significant increase in gastric pH and a significant decrease in gastric fluid volume when compared to the patients from group A. 33.3% (95% CI 16.63-53.22%) of patients in group A were deemed 'at risk' of acid aspiration compared to 0.9% (95% CI 0.02-4.90%) in the other groups. No significant differences were found between the patients receiving ranitidine after 60 min with respect to risk of acid aspiration. It is concluded that a single oral dose of ranitidine 150 mg is effective against the acid aspiration syndrome 60 min after administration.

[Prevalence of viral hepatitis in candidates for orthopedic surgery]

OBJECTIVES

To study the prevalence of positive serology results for hepatitis B and C viruses among patients scheduled for elective orthopedic surgery, to establish risk groups and to assess the economic cost involved in testing patients in such groups.

PATIENTS AND METHODS

We performed a retrospective study of 1090 preoperative charts for patients awaiting elective orthopedic surgery between November 1993 and January 1995. Variables recorded were age, sex, physical status, history of alcoholism or addiction to injected drugs, associated disease (liver disease, chronic kidney failure and hemodialysis, and coagulation disorders), history of blood products transfusion, preoperative liver enzymes and blood levels of AcVHC and AgVHB as determined by enzyme immunoassay.

RESULTS

Mean age was 51.8 (SD 17.5). Women predominated, accounting for 60.6% of the sample. ASA I and ASA II patients accounted for 84.9%, 72 (6.61%) had had previous transfusions, 51 (4.6%) suffered liver disease, 4 (0.36%) had coagulation disorder, 5 (0.45%) were receiving hemodialysis for chronic kidney failure, and 5 (0.45%) admitted having injected drugs. We discovered alterations in preoperative liver enzyme levels in 116 (10.6%) cases. Sixty-five (5.96%) were positive for AcVHC and 13 (1.19%) were positive for AgVHB. Factors that predicted positive results for hepatitis C and B were liver disease, previous administration of blood products, chronic kidney failure requiring hemodialysis, drug addiction and high preoperative liver enzyme levels. Serologic testing for viruses performed on patients in this risk group would have detected 76.6% of the positive cases, resulting in savings of 90% of the cost of indiscriminate testing.

CONCLUSIONS

We believe that patients with histories of liver disease, blood product transfusion, chronic kidney failure with hemodialysis or drug addiction, or with high liver enzyme levels should be tested for hepatitis B and C before surgery.

[Prolonged sedation with midazolam in critically ill patients undergoing artificial ventilation]

OBJECTIVES

To analyze the dose of midazolam needed for induction and maintenance of sedation, as well as its hemodynamic repercussions in critically ill patients requiring mechanical ventilation.

PATIENTS AND METHODS

We studied 20 adult patients requiring mechanical ventilation for respiratory failure in the intensive care unit. An induction dose of 1 mg/min midazolam was given until the patient became drowsy (eyes closed but opened again) and this level of sedation was maintained by continuous intravenous perfusion. We calculated induction dose, maintenance dose and their correlation with age, weight, general state (APACHE-II index), liver function, hematocrit and blood chemistry.

RESULTS

The induction dose was 4.76 +/- 3.4 mg and correlated with weight and plasma albumin levels. The maintenance dose of 6.4 +/- 3.97 mg/h did not correlate with any of the parameters studied. A statistically significant reduction in arterial pressure was observed.

CONCLUSIONS

The sedation dose of midazolam in critically ill patients is related to weight and plasma albumin levels. Recovery time is related to mean maintenance dose.

[Usefulness of preoperative chest radiography in elective surgery]

OBJECTIVES

To study the prevalence of abnormalities in preoperative chest X-rays taken of patients undergoing elective surgery; to determine radiological abnormalities not expected based on the patient's case history and their influence on treatment; and to identify patients with high risk of presenting abnormal radiographs.

PATIENTS AND METHODS

This retrospective study included 2,146 consecutive patients entering the hospital over a period of one year for non-cardiopulmonary surgery requiring anesthesia. Two physicians reviewed the radiodiagnostic reports on routine preoperative chest X-rays requested by surgeons. The reviewers classified the results as normal, expected abnormal and unexpected abnormal based on concordance or not between the patient's case history and the radiologist's report.

RESULTS

Of the original 2,146 patients, 160 (7.4%) were excluded from the study because of incomplete case histories and/or physical exams. X-rays were taken of 1,880 (94.6%) of the 1,986 patients remaining in the study. Abnormalities were found in 508 (27%), most often in men, patients over 45, those classified as ASA III-V and those with a history of cardiovascular or lung disease, or smokers of more than 20 cigarettes/day. In 254 (13.5%), the abnormalities were not expected based on the patient's history; the physician's attitude changed toward 11 of these (4.3%), 5 of whom had cancer. Unexpected abnormalities were detected in 2 patients (0.8%) during physical examination and the real index of unexpected attitude changes based on case history and physical examination was 9 (3.5%). A new treatment based on unexpected radiological abnormalities was chosen for only 2 (0.8%) patients. The prevalence of unexpected radiological abnormalities was higher in men, in those over 45 years old and in those classified as ASA III-V.

CONCLUSIONS

The prevalence of unexpected abnormalities in routine preoperative chest X-rays taken before non-cardiothoracic elective surgery is high, but the influence of their detection on patient management is minimal. The results of our study suggest that X-rays should be recommended for patients over 45; those with a history of cardiovascular or lung disease, or of cancer; smokers of more than 20 cigarettes/day; those classified as ASA III-V; and those with incomplete case histories or physical examinations.

Effects of omeprazole, ranitidine, famotidine and placebo on gastric secretion in patients undergoing elective surgery

We have compared the effects of omeprazole, ranitidine, famotidine and placebo on gastric secretion in a double-blind study in 110 patients undergoing elective surgery. Three hours before operation, the patients received, orally, omeprazole 40 mg, ranitidine 150 mg, famotidine 40 mg or placebo. Gastric volume and pH were measured immediately after induction of anaesthesia. Omeprazole, ranitidine and famotidine produced a significant increase in gastric pH and a significant decrease in gastric volume compared with placebo. When the effects of omeprazole on gastric volume were compared with those of ranitidine and famotidine, no significant difference was found, but omeprazole was significantly less effective in increasing gastric pH. The number of patients having a pH less than 2.5 and a volume greater than 0.4 ml kg-1 were: none in the ranitidine group, one (3%) in the famotidine group, four (15%) in the omeprazole group and six (23%) in the placebo group. We conclude that omeprazole 40 mg given 2-4 h before surgery does not afford adequate prophylaxis for the acid aspiration syndrome.

[Respiratory distress in adults and disseminated intravascular coagulation after administration of iodinated contrast]

We report a patient with urinary sepsis who, during intravenous urography with iodinated contrast (70 mg Na, Ca diatrizoate and meglumine) developed dyspnea, tachypnea, sinus tachycardia and moderate hypoxemia (pO2: 72 with FiO2 of 0.21). She subsequently developed adult respiratory distress syndrome (ARDS) with refractory hypoxemia (pO2: 40 mmHg with FiO2 of 0.5) and disseminated intravascular coagulation (DIC) (prothrombin index: 5%, platelets: 20,000/mm3, APTT: 102/37 min, FDP: 80 ng/ml, and fibrinogen: 120 mg %). The patient required mechanical ventilation and treatment with inotropic drugs, antibiotics, corticosteroids, plasma, platelets and erythrocytes. The outcome was favorable, and she could be discharged from the Reanimation Service 7 days after admission. In severe systemic reactions to iodinated contrasts (SRIC), ARDS and DIC are common. In our patient, the close temporal association between the administration of iodinated contrast and the development of the clinical picture made us suspect their possible causal relation. A higher predisposition to SRIC in patients with sepsis has been reported. We review the SRIC in which the anesthesiologist may play a role for reanimation.

Comparison of the effects of famotidine and ranitidine on gastric secretion in patients undergoing elective surgery

A randomised double-blind comparison of oral famotidine and ranitidine given 2 hours before induction, on gastric secretion (volume and pH) was carried out on 93 patients undergoing elective surgery. Gastric contents were aspirated immediately after tracheal intubation. Famotidine significantly reduced the gastric volume, compared with the other groups, including ranitidine. Both famotidine and ranitidine significantly elevated gastric pH towards neutral, compared with the other groups. There was no significant difference between ranitidine and famotidine in respect of the pH. The patients premedicated with famotidine and ranitidine were well protected against Mendelson's syndrome, whereas 38% of patients from the other groups remained at risk.