Indicaciones restrictivas y anestesia / Restrictive indications and anesthesia

Anesthesiologists may deal with ethical dilemmas when looking after Not To Be Resuscitated (NTBR) patients. Sometimes the latters are scheduled to undergo surgical procedures that are palliative in nature. With the advent of the cardio pulmonary resuscitation in the 1960s, new problems arose, such as long resuscitations, quality of life impairment and unnecessary protracted agony. Besides the fear to death and suffering, resuscitation’s dread appeared. In the beginning, the decisión to reject the resuscitation was the physician’s responsability. The development of the Patient Self-Determination Act (PSDA) transfered to the patient or to his/her legal surrogates the right to decide about his/her medical treatment, specially at the end of life. This article revised the evolution that allowed to exercise the patient autonomy, as well as the best way to proceed when anesthesia and surgery are necessary to care for a patient with a Do Not Resuscitate Order.

El anestesiólogo puede enfrentar dilemas éticos cuando debe anestesiar pacientes con indicaciones restrictivas (Límite del Esfuerzo Terapéutico, Orden de No Reanimar). Estos pacientes con frecuencia son sometidos a intervenciones destinadas a mejorar su calidad de vida, o para el control de síntomas, a pesar de tener un mal pronóstico evolutivo, y/o deterioro de su condición física. A mediados de la década de 1960, con la RCP (Reanimación Cardiopulmonar) aparecieron nuevos problemas, como reanimaciones reiteradas, deterioro de la calidad de vida, y prolongación de la agonía. Entonces, al miedo a la muerte y al sufrimiento, se sumó el miedo a la reanimación. Inicialmente, el médico responsable del paciente era el único habilitado para rechazar estas medidas de reanimación (NTBR, “not to be resuscitated”), con el subsiguiente debate bioético. Mas tarde, el desarrollo del principio de autonomía, transfirió al paciente y a su entorno más cercano el derecho a tomar decisiones informadas sobre su propio tratamiento médico1. Este artículo revisa los antecedentes relevantes que han permitido el traspaso del poder de decisión a los pacientes, así como la mejor forma de proceder ante la necesidad de administrarles anestesia cuando hay indicaciones restrictivas.

[Measurement of patient safety: a systematic review of the reliability and validity of adverse event detection with record review]. / Dossieronderzoek geschikt voor opsporen zorgschade?

OBJECTIVES: Record review is the most used method to quantify patient safety. We systematically reviewed the reliability and validity of adverse event detection with record review. DESIGN: A systematic review of the literature. METHODS: We searched PubMed, EMBASE, CINAHL, PsycINFO and the Cochrane Library and from their inception through February 2015. We included all studies that aimed to describe the reliability and/or validity of record review. Two reviewers conducted data extraction. We pooled κ values (κ) and analysed the differences in subgroups according to number of reviewers, reviewer experience and training level, adjusted for the prevalence of adverse events. RESULTS: In 25 studies, the psychometric data of the Global Trigger Tool (GTT) and the Harvard Medical Practice Study (HMPS) were reported and 24 studies were included for statistical pooling. The inter-raterreliability of the GTT and HMPS showed a pooled κ of 0.65 and 0.55, respectively. The inter-rater agreement was statistically significantly higher when the group of reviewers within a study consisted of a maximum five reviewers. We found no studies reporting on the validity of the GTT and HMPS. CONCLUSIONS: The reliability of record review is moderate to substantial and improved when a small group of reviewers carried out record review. The validity of the record review method has never been evaluated, while clinical data registries, autopsy or direct observations of patient care are methods that can be used to test concurrent validity.

Roles and Regulation of Epithelial Splicing Regulatory Proteins 1 and 2 in Epithelial-Mesenchymal Transition.

The transformation of polarized epithelial cells into cells with mesenchymal characteristics by the morphogenetic process of epithelial-mesenchymal transition (EMT) is a well-characterized process essential for embryonic development and associated with cancer progression. EMT is a program driven by changes in gene expression induced by several EMT-specific transcription factors, which inhibit the expression of cell-cell adhesion proteins and other epithelial markers, causing a characteristic loss of cell-cell adhesion, a switch to mesenchymal cell morphology, and increased migratory capabilities. Recently, it has become apparent that in addition to these transcriptionally regulated changes, EMT may also be regulated posttranscriptionally, that is, by alternative splicing. Specifically, the epithelial splicing regulatory proteins 1 and 2 (ESRP1 and ESRP2) have been described as epithelial-specific splicing master regulators specifically involved in EMT-associated alternative splicing. Here, we discuss the regulation of ESRP activity, as well as the evidence supporting a causal role of ESRPs in EMT.

Development of a computerised alert system, ADEAS, to identify patients at risk for an adverse drug event.

INTRODUCTION: Adverse drug events (ADEs) are frequent and pose an important risk for patients treated with drugs. Fortunately, a substantial part of ADEs is preventable, and computerised physician order entry with a sophisticated clinical decision support system may be used to reach this goal. OBJECTIVE: To develop a new automated system that could improve the quality of medication surveillance. The system should focus on detecting patients at risk for an ADE by combining data from the hospital information system and computerised physician order entry (drug prescription data, drug-drug interaction alerts, clinical chemical laboratory parameters, demographic features), using clinical rules. METHODS: The clinical rules were formulated in a multidisciplinary team, based on seven risk categories. The new system was composed in a guideline-based decision support framework consisting of both a guideline development module and a decision support module. A total of 121 clinical rules were built into the system. Validation of the system and a proof of principle test were performed. RESULTS: The adverse drug event alerting system (ADEAS) was developed and validated successfully. The proof of principle test showed that ADEAS has potential clinical usefulness. ADEAS generated alerts and detected additional potential risk situations, which were not generated by the conventional medication surveillance. CONCLUSION: We developed a pharmacy decision support system ADEAS that focuses on the detection of situations prone to lead to an ADE and might help clinicians to take timely corrective interventions and thereby can prevent patient harm.

Exploring the causes of adverse events in hospitals and potential prevention strategies.

OBJECTIVES: To examine the causes of adverse events (AEs) and potential prevention strategies to minimise the occurrence of AEs in hospitalised patients. METHODS: For the 744 AEs identified in the patient record review study in 21 Dutch hospitals, trained reviewers were asked to select all causal factors that contributed to the AE. The results were analysed together with data on preventability and consequences of AEs. In addition, the reviewers selected one or more prevention strategies for each preventable AE. The recommended prevention strategies were analysed together with four general causal categories: technical, human, organisational and patient-related factors. RESULTS: Human causes were predominantly involved in the causation of AEs (in 61% of the AEs), 61% of those being preventable and 13% leading to permanent disability. In 39% of the AEs, patient-related factors were involved, in 14% organisational factors and in 4% technical factors. Organisational causes contributed relatively often to preventable AEs (93%) and AEs resulting in permanent disability (20%). Recommended strategies to prevent AEs were quality assurance/peer review, evaluation of safety behaviour, training and procedures. For the AEs with human and patient-related causes, reviewers predominantly recommended quality assurance/peer review. AEs caused by organisational factors were considered preventable by improving procedures. DISCUSSION: Healthcare interventions directed at human causes are recommended because these play a large role in AE causation. In addition, it seems worthwhile to direct interventions on organisational causes because the AEs they cause are nearly always believed to be preventable. Organisational factors are thus relatively easy to tackle. Future research designs should allow researchers to interview healthcare providers that were involved in the event, as an additional source of information on contributing factors.

Adverse events and potentially preventable deaths in Dutch hospitals: results of a retrospective patient record review study.

OBJECTIVE: This study determined the incidence, type, nature, preventability and impact of adverse events (AEs) among hospitalised patients and potentially preventable deaths in Dutch hospitals. METHODS: Using a three-stage retrospective record review process, trained nurses and doctors reviewed 7926 admissions: 3983 admissions of deceased hospital patients and 3943 admissions of discharged patients in 2004, in a random sample of 21 hospitals in the Netherlands (4 university, 6 tertiary teaching and 11 general hospitals). A large sample of deceased patients was included to determine the occurrence of potentially preventable deaths in hospitals more precisely. RESULTS: One or more AEs were found in 5.7% (95% CI 5.1% to 6.4%) of all admissions and a preventable AE in 2.3% (95% CI 1.9% to 2.7%). Of all AEs, 12.8% resulted in permanent disability or contributed to death. The proportion of AEs and their impact increased with age. More than 50% of the AEs were related to surgical procedures. Among deceased hospital patients, 10.7% (95% CI 9.8% to 11.7%) had experienced an AE. Preventable AEs that contributed to death occurred in 4.1% (95% CI 3.5% to 4.8%) of all hospital deaths. Extrapolating to a national level, between 1482 and 2032 potentially preventable deaths occurred in Dutch hospitals in 2004. CONCLUSIONS: The incidence of AEs, preventable AEs and potentially preventable deaths in the Netherlands is substantial and needs to be reduced. Patient safety efforts should focus on surgical procedures and older patients.

Induced expression of Rnd3 is associated with transformation of polarized epithelial cells by the Raf-MEK-extracellular signal-regulated kinase pathway.

Madin-Darby canine kidney (MDCK) epithelial cells transformed by oncogenic Ras and Raf exhibit cell multilayering and alterations in the actin cytoskeleton. The changes in the actin cytoskeleton comprise a loss of actin stress fibers and enhanced cortical actin. Using MDCK cells expressing a conditionally active form of Raf, we have explored the molecular mechanisms that underlie these observations. Raf activation elicited a robust increase in Rac1 activity consistent with the observed increase in cortical actin. Loss of actin stress fibers is indicative of attenuated Rho function, but no change in Rho-GTP levels was detected following Raf activation. However, the loss of actin stress fibers in Raf-transformed cells was preceded by the induced expression of Rnd3, an endogenous inhibitor of Rho protein function. Expression of Rnd3 alone at levels equivalent to those observed following Raf transformation led to a substantial loss of actin stress fibers. Moreover, cells expressing activated RhoA failed to multilayer in response to Raf. Pharmacological inhibition of MEK activation prevented all of the biological and biochemical changes described above. Consequently, the data are consistent with a role for induced Rnd3 expression downstream of the Raf-MEK-extracellular signal-regulated kinase pathway in epithelial oncogenesis.

Mechanisms and functional features of polarized membrane traffic in epithelial and hepatic cells.

Epithelial cells express plasma-membrane polarity in order to meet functional requirements that are imposed by their interaction with different extracellular environments. Thus apical and basolateral membrane domains are distinguished that are separated by tight junctions in order to maintain the specific lipid and protein composition of each domain. In hepatic cells, the plasma membrane is also polarized, containing a sinusoidal (basolateral) and a bile canalicular (apical)-membrane domain. Relevant to the biogenesis of these domains are issues concerning sorting, (co-)transport and regulation of transport of domain-specific membrane components. In epithelial cells, specific proteins and lipids, destined for the apical membrane, are sorted in the trans-Golgi network (TGN), which involves their sequestration into cholesterol/sphingolipid 'rafts', followed by 'direct' transport to the apical membrane. In hepatic cells, a direct apical transport pathway also exists, as revealed by transport of sphingolipids from TGN to the apical membrane. This is remarkable, since in these cells numerous apical membrane proteins are 'indirectly' sorted, i.e. they are first transferred to the basolateral membrane prior to their subsequent transcytosis to the apical membrane. This raises intriguing questions as to the existence of specific lipid rafts in hepatocytes. As demonstrated in studies with HepG2 cells, it has become evident that, in hepatic cells, apical transport pathways can be regulated by protein kinase activity, which in turn modulates cell polarity. Finally, an important physiological function of hepatic cells is their involvement in intracellular transport and secretion of bile-specific lipids. Mechanisms of these transport processes, including the role of multidrug-resistant proteins in lipid translocation, will be discussed in the context of intracellular vesicular transport. Taken together, hepatic cell systems provide an important asset to studies aimed at elucidating mechanisms of sorting and trafficking of lipids (and proteins) in polarized cells in general.

Actin filaments and microtubules are involved in different membrane traffic pathways that transport sphingolipids to the apical surface of polarized HepG2 cells.

In polarized HepG2 hepatoma cells, sphingolipids are transported to the apical, bile canalicular membrane by two different transport routes, as revealed with fluorescently tagged sphingolipid analogs. One route involves direct, transcytosis-independent transport of Golgi-derived glucosylceramide and sphingomyelin, whereas the other involves basolateral to apical transcytosis of both sphingolipids. We show that these distinct routes display a different sensitivity toward nocodazole and cytochalasin D, implying a specific transport dependence on either microtubules or actin filaments, respectively. Thus, nocodazole strongly inhibited the direct route, whereas sphingolipid transport by transcytosis was hardly affected. Moreover, nocodazole blocked "hyperpolarization," i.e., the enlargement of the apical membrane surface, which is induced by treating cells with dibutyryl-cAMP. By contrast, the transcytotic route but not the direct route was inhibited by cytochalasin D. The actin-dependent step during transcytotic lipid transport probably occurs at an early endocytic event at the basolateral plasma membrane, because total lipid uptake and fluid phase endocytosis of horseradish peroxidase from this membrane were inhibited by cytochalasin D as well. In summary, the results show that the two sphingolipid transport pathways to the apical membrane must have a different requirement for cytoskeletal elements.

Functional involvement of proteins, interacting with sphingolipids, in sphingolipid transport to the canalicular membrane in the human hepatocytic cell line, HepG2?

A photoreactive sphingolipid precursor was used to investigate the potential involvement of protein-lipid interactions that may convey specificity to sphingolipid transport in the human hepatoma cell line, HepG2. A 125I-labeled, photoreactive ceramide, 125I-N3-Cer, was incubated with the cells and became incorporated into two sphingolipid products. The major product was photoreactive sphingomyelin (125I-N3-SM) (25% of total radioactivity), while only minor amounts of photoreactive glucosylceramide (125I-N3-GlcCer) were formed (< 2%). After photoactivation, a restricted number of proteins was labeled. Given the absolute amounts of the newly synthesized, photoreactive lipids and their precursor present in the cells, labeling of the proteins can be assumed to be derived from interaction with either ceramide (Cer) or sphingomyelin (SM), or both. To discriminate between these possibilities, photoactivation and protein analysis was performed in cells treated with D-threo-1-phenyl-2-decanoyl amino-3-morpholino-1-propanol (PDMP), an inhibitor of sphingolipid biosynthesis. In treated cells, the radioactive SM pool was reduced by approximately 80%. Concomitantly, labeling of a 60-kd protein, seen in control cells, decreased. Furthermore, the 60-kd protein is membrane-associated and insoluble in detergent at low temperature. Moreover, when cells containing photoreactive sphingolipids after a preincubation with the photoreactive Cer were photoactivated and subsequently incubated with fluorescent sphingolipid analogs, transport of the latter to the bile canalicular membrane, as observed in control cells, was inhibited. Taken together, the data suggest that distinct proteins, among them a 60-kd protein, may play a specific and functional role in sphingolipid transport to the bile canalicular membrane.

Sphingolipid transport to the apical plasma membrane domain in human hepatoma cells is controlled by PKC and PKA activity: a correlation with cell polarity in HepG2 cells.

The regulation of sphingolipid transport to the bile canalicular apical membrane in the well differentiated HepG2 hepatoma cells was studied. By employing fluorescent lipid analogs, trafficking in a transcytosis-dependent pathway and a transcytosis-independent ('direct') route between the trans-Golgi network and the apical membrane were examined. The two lipid transport routes were shown to operate independently, and both were regulated by kinase activity. The kinase inhibitor staurosporine inhibited the direct lipid transport route but slightly stimulated the transcytosis-dependent route. The protein kinase C (PKC) activator phorbol-12 myristate-13 acetate (PMA) inhibited apical lipid transport via both transport routes, while a specific inhibitor of this kinase stimulated apical lipid transport. Activation of protein kinase A (PKA) had opposing effects, in that a stimulation of apical lipid transport via both transport routes was seen. Interestingly, the regulatory effects of either kinase activity in sphingolipid transport correlated with changes in cell polarity. Stimulation of PKC activity resulted in a disappearance of the bile canalicular structures, as evidenced by the redistribution of several apical markers upon PMA treatment, which was accompanied by an inhibition of apical sphingolipid transport. By contrast, activation of PKA resulted in an increase in the number and size of bile canaliculi and a concomitant enhancement of apical sphingolipid transport. Taken together, our data indicate that apical membrane-directed sphingolipid transport in HepG2 cells is regulated by kinases, which could play a role in the biogenesis of the apical plasma membrane domain.

Segregation of glucosylceramide and sphingomyelin occurs in the apical to basolateral transcytotic route in HepG2 cells.

HepG2 cells are highly differentiated hepatoma cells that have retained an apical, bile canalicular (BC) plasma membrane polarity. We investigated the dynamics of two BC-associated sphingolipids, glucosylceramide (GlcCer) and sphingomyelin (SM). For this, the cells were labeled with fluorescent acyl chain-labeled 6-[N-(7-nitrobenz-2-oxa-1,3-diazol-4-yl)-amino]hexanoic acid (C6-NBD) derivatives of either GlcCer (C6-NBD-GlcCer) or SM (C6-NBD-SM). The pool of the fluorescent lipid analogues present in the basolateral plasma membrane domain was subsequently depleted and the apically located C6-NBD-lipid was chased at 37 degrees C. By using fluorescence microscopical analysis and a new assay that allows an accurate estimation of the fluorescent lipid pool in the apical membrane, qualitative and quantitative insight was obtained concerning kinetics, extent and (intra)cellular sites of the redistribution of apically located C6-NBD-GlcCer and C6-NBD-SM. It is demonstrated that both lipids display a preferential localization, C6-NBD-GlcCer in the apical and C6-NBD-SM in the basolateral area. Such a preference is expressed during transcytosis of both sphingolipids from the apical to the basolateral plasma membrane domain, a novel lipid trafficking route in HepG2 cells. Whereas the vast majority of the apically derived C6-NBD-SM was rapidly transcytosed to the basolateral surface, most of the apically internalized C6-NBD-GlcCer was efficiently redirected to the BC. The redirection of C6-NBD-GlcCer did not involve trafficking via the Golgi apparatus. Evidence is provided which suggests the involvement of vesicular compartments, located subjacent to the apical plasma membrane. Interestingly, the observed difference in preferential localization of C6-NBD-GlcCer and C6-NBD-SM was perturbed by treatment of the cells with dibutyryl cAMP, a stable cAMP analogue. While the preferential apical localization of C6-NBD-GlcCer was amplified, dibutyryl cAMP-treatment caused apically retrieved C6-NBD-SM to be processed via a similar pathway as that of C6-NBD-GlcCer. The data unambiguously demonstrate that segregation of GlcCer and SM occurs in the reverse transcytotic route, i.e., during apical to basolateral transport, which results in the preferential localization of GlcCer and SM in the apical and basolateral region of the cells, respectively. A role for non-Golgi-related, sub-apical vesicular compartments in the sorting of GlcCer and SM is proposed.

Use of photoactivatable sphingolipid analogues to monitor lipid transport in mammalian cells.

Photoactivatable derivatives of ceramide, glucosylceramide (GlcCer) and sphingomyelin {3-(p-azido-m-[125I]iodophenyl)propionylceramide, 3-(p-azido-m-[125I]iodophenyl)propionyl-GlcCer and 3-(p-azido-m-[125I]iodophenyl)propionylsphingomyelin} were synthesized in an attempt to identify compartment-specific proteins involved in sphingolipid sorting or metabolism. In HT29 and BHK cells the ceramide analogue entered the cell by monomeric diffusion, as evidenced by the probe's efficient internalization at low temperature (4 degrees C). In contrast, the photoactivatable GlcCer was internalized only at elevated temperatures (37 degrees C), presumably reflecting an endocytic mechanism of uptake. The photoactivatable ceramide was mainly metabolized to the corresponding sphingomyelin analogue, but small amounts of GlcCer and galactosylceramide were also synthesized. The newly synthesized photoreactive sphingomyelin was subsequently transported to the cell surface, a process that was effectively inhibited by the presence of brefeldin A. The incubation of cells with photoactivatable analogues at 4 degrees C, followed by illumination, led to the association of sphingolipid with a specific subset of proteins. The protein labelling pattern of ceramide differed from that of glucosylceramide. A further shift in labelling pattern was apparent when the cells were incubated with the lipid analogues at 37 degrees C. Moreover, most of the proteins labelled by photoreactive sphingomyelin seemed to be detergent-insoluble, which is indicative of a location in sphingolipid-rich microdomains at the plasma membrane. The potential of applying photoactivatable sphingolipids to further define and identify the role of distinct proteins in sphingolipid biosynthesis, transport and sorting, is discussed.

Mechanism of formation of mercapturic acids from (1-bromoethyl)benzene and (2-bromoethyl)benzene in the rat.

1. Three hypotheses have been proposed for the mechanism of metabolism of alkylhalides to hydroxy-alkylmercapturic acids, two of which involve the intermediate step of dehydrohalogenation and formation of an epoxide. 2. After injection of (1-bromoethyl)benzene in rat, the only mercapturic acid appearing in the urine was N-acetyl-S-1-phenylethylcysteine. After injecting (2-bromoethyl)benzene in the rat only N-acetyl-S-2-phenylethylcysteine and N-acetyl-S-(2-phenyl-2-hydroxyethyl)cysteine were found in the urine. 3. Since the principal mercapturic acid formed from both styrene and styrene oxide could not be detected in the urine of rats receiving either 1- or 2-bromoethyl benzene, the intermediate formation of styrene or styrene oxide from the arylalkylhalides does not occur.

Are muscarinic receptors in the central and peripheral nervous system different?

The concentration-dependent binding of atropine-3 H to membrane fractions from bovine tracheal muscle, parotid gland and caudate nucleus, measured by equilibrium dialysis, revealed the presence of virtually identical high affinity binding sites in all three tissues. Sch 1000 and Sch 1178 geometrical isomers of N-isopropylatropine bromide with a large potency ratio as antimuscarinics, inhibited atropine binding identically in all three tissues. Differences in properties of muscarinic receptors in these tissues are either non-existent or too small to be detected by the applied techniques.