Effects of hypertonic sodium chloride solution on the electrophysiologic alterations caused by bupivacaine in the dog heart

The effects of various hypertonic solutions on the intraventricular conduction, ventricular repolarization and the arrhythmias caused by the intravenous (iv) injection of bupivacaine (6.5 mg/kg) were studied in sodium pentobarbital-anesthetized mongrel dogs. Hypertonic solutions, given iv 5 min before bupivacaine, were 7.5% (w/v) NaCl, 5.4% (w/v) LiCl, 50% (w/v) glucose (2,400 mOsm/l, 5 ml/kg), or 20% (w/v) mannitol (1,200 mOsm/l, 10 ml/kg). Bupivacaine induced severe arrhythmias and ventricular conduction and repolarization disturbances, as reflected by significant increases in QRS complex duration, HV interval, IV interval and monophasic action potential duration, as well as severe hemodynamic impairment. Significant prevention against ventricular electrophysiologic and hemodynamic disturbances and ventricular arrhythmias was observed with 7.5% NaCl (percent increase in QRS complex duration: 164.4 ± 21.8% in the non-pretreated group vs 74.7 ± 14.1% in the pretreated group, P<0.05; percent increase in HV interval: 131.4 ± 16.1% in the non-pretreated group vs 58.2 ± 7.5% in the pretreated group, P<0.05; percent increase in monophasic action potential duration: 22.7 ± 6.8% in the non-pretreated group vs 9.8 ± 6.3% in the pretreated group, P<0.05; percent decrease in cardiac index: -46 ± 6% in the non-pretreated group vs -28 ± 5% in the pretreated group, P<0.05). The other three hypertonic solutions were ineffective. These findings suggest an involvement of sodium ions in the mechanism of hypertonic protection.

Fuzzy expert system in the prediction of neonatal resuscitation

In view of the importance of anticipating the occurrence of critical situations in medicine, we propose the use of a fuzzy expert system to predict the need for advanced neonatal resuscitation efforts in the delivery room. This system relates the maternal medical, obstetric and neonatal characteristics to the clinical conditions of the newborn, providing a risk measurement of need of advanced neonatal resuscitation measures. It is structured as a fuzzy composition developed on the basis of the subjective perception of danger of nine neonatologists facing 61 antenatal and intrapartum clinical situations which provide a degree of association with the risk of occurrence of perinatal asphyxia. The resulting relational matrix describes the association between clinical factors and risk of perinatal asphyxia. Analyzing the inputs of the presence or absence of all 61 clinical factors, the system returns the rate of risk of perinatal asphyxia as output. A prospectively collected series of 304 cases of perinatal care was analyzed to ascertain system performance. The fuzzy expert system presented a sensitivity of 76.5% and specificity of 94.8% in the identification of the need for advanced neonatal resuscitation measures, considering a cut-off value of 5 on a scale ranging from 0 to 10. The area under the receiver operating characteristic curve was 0.93. The identification of risk situations plays an important role in the planning of health care. These preliminary results encourage us to develop further studies and to refine this model, which is intended to implement an auxiliary system able to help health care staff to make decisions in perinatal care.

Protective effect of bronchial challenge with hypertonic saline on nocturnal asthma

Inhalation of hypertonic saline (HS) causes bronchoconstriction in asthmatic subjects. Repeated inhalation of HS leads to substantially reduced bronchoconstriction, known as the refractory period. Refractoriness due to different stimuli has also been described (cross-refractoriness). Nocturnal asthma is defined as an increase in symptoms, need for medication, airway responsiveness, and/or worsening of lung function that usually occurs from 4 to 6 am. Our objective was to determine the effect of refractoriness on nocturnal asthma. The challenge test consisted of inhalations of 4.5% saline with increasing durations until a reduction of 20% in forced expiratory volume in 1 s (FEV1) (PD20HS) or total time of 15.5 min. Twelve subjects with nocturnal asthma were challenged with HS at 16:00 and 18:00 h and FEV1 was measured at 4:00 h. One to 2 weeks later, FEV1 was determined at 16:00 and 4:00 h. LogPD20HS at 18:00 h was significantly greater than logPD20HS at 16:00 h, 0.51 ± 0.50 and 0.69 ± 0.60 mg, respectively (P = 0.0033). When subjects underwent two HS challenges in the afternoon, mean (± SD) FEV1 reduction was 206 ± 414 mL or 9.81 ± 17.42%. On the control day (without challenge in the afternoon) FEV1 reduction was 523 ± 308 mL or 22.75 ± 15.40% (P = 0.021). Baseline FEV1 values did not differ significantly between the control and study days, 2.48 ± 0.62 and 2.36 ± 0.46 L, respectively. The refractory period following HS challenges reduces the nocturnal worsening of asthma. This new concept may provide beneficial applications to asthmatic patients.

Comparison of the effects of lactated Ringer solution with and without hydroxyethyl starch fluid resuscitation on gut edema during severe splanchnic ischemia

The type of fluid used during resuscitation may have an important impact on tissue edema. We evaluated the impact of two different regimens of fluid resuscitation on hemodynamics and on lung and intestinal edema during splanchnic hypoperfusion in rabbits. The study included 16 female New Zealand rabbits (2.9 to 3.3 kg body weight, aged 8 to 12 months) with splanchnic ischemia induced by ligation of the superior mesenteric artery. The animals were randomized into two experimental groups: group I (N = 9) received 12 mL·kg-1·h-1 lactated Ringer solution and 20 mL/kg 6% hydroxyethyl starch solution; group II (N = 7) received 36 mL·kg-1·h-1 lactated Ringer solution and 20 mL/kg 0.9% saline. A segment from the ileum was isolated to be perfused. A tonometric catheter was placed in a second gut segment. Superior mesenteric artery (Q SMA) and aortic (Qaorta) flows were measured using ultrasonic flow probes. After 4 h of fluid resuscitation, tissue specimens were immediately removed for estimations of gut and lung edema. There were no differences in global and regional perfusion variables, lung wet-to-dry weight ratios and oxygenation indices between groups. Gut wet-to-dry weight ratio was significantly lower in the crystalloid/colloid-treated group (4.9 ± 1.5) than in the crystalloid-treated group (7.3 ± 2.4) (P < 0.05). In this model of intestinal ischemia, fluid resuscitation with crystalloids caused more gut edema than a combination of crystalloids and colloids.

Rabbit model of uncontrolled hemorrhagic shock and hypotensive resuscitation

Clinically relevant animal models capable of simulating traumatic hemorrhagic shock are needed. We developed a hemorrhagic shock model with male New Zealand rabbits (2200-2800 g, 60-70 days old) that simulates the pre-hospital and acute care of a penetrating trauma victim in an urban scenario using current resuscitation strategies. A laparotomy was performed to reproduce tissue trauma and an aortic injury was created using a standardized single puncture to the left side of the infrarenal aorta to induce hemorrhagic shock similar to a penetrating mechanism. A 15-min interval was used to simulate the arrival of pre-hospital care. Fluid resuscitation was then applied using two regimens: normotensive resuscitation to achieve baseline mean arterial blood pressure (MAP, 10 animals) and hypotensive resuscitation at 60% of baseline MAP (10 animals). Another 10 animals were sham operated. The total time of the experiment was 85 min, reproducing scene, transport and emergency room times. Intra-abdominal blood loss was significantly greater in animals that underwent normotensive resuscitation compared to hypotensive resuscitation (17.1 ± 2.0 vs 8.0 ± 1.5 mL/kg). Antithrombin levels decreased significantly in normotensive resuscitated animals compared to baseline (102 ± 2.0 vs 59 ± 4.1%), sham (95 ± 2.8 vs 59 ± 4.1%), and hypotensive resuscitated animals (98 ± 7.8 vs 59 ± 4.1%). Evidence of re-bleeding was also noted in the normotensive resuscitation group. A hypotensive resuscitation regimen resulted in decreased blood loss in a clinically relevant small animal model capable of reproducing hemorrhagic shock caused by a penetrating mechanism.

Increased osmotic sensitivity for antidiuretic response in chronic chagas' disease

The osmotic threshold for attaining the antidiuretic response to hypertonic saline infusion and Progressive dehydration was studied in 31 patients with the chronic form of Chagas' disease and 16 control patients. The chagasic patients exhibited enhanced osmoticsensitivity to the antidiuretic response. This was demonstrated by lower values of the increments in plasma osmolarity sufficient to induce a significant fall in water clearance, without alterations in the osmolar clearance or creatinine excretion. The time needed to attain the antidiuretic response was shorterfor chagasics in relation to normal subjects. The results suggest the existence of a disturbance in the fine control of osmoregulation in the chagasic patients. They are interpreted to be a consequence of the denervation in hypothalamic or extrahypothalamic areas that regulate the secretion of vasopressin in chronic Chagas' disease.

Fatal pulmonary thromboembolism in gastrectomy intraoperative procedures by gastric adenocarcinoma: case report

The case of a patient with gastric adenocarcinoma with indication for gastrectomy is reported. The surgery took place without complications. A palliative, subtotal gastrectomy was performed after para-aortic lymph nodes compromised by neoplasm were found, which was confirmed by pathological exam of frozen sections carried out during the intervention. At the end of the gastroenteroanastomosis procedure, the patient began to show intense bradycardia: 38 beats per minute (bpm), arterial hypotension, changes in the electrocardiogram's waveform (upper unlevelling of segment ST), and cardiac arrest. Resuscitation maneuvers were performed with temporary success. Subsequently, the patient had another circulatory breakdown and again was recovered. Finally, the third cardiac arrest proved to be irreversible, and the intra-operative death occurred. Necropsy showed massive pulmonary embolism. The medical literature has recommended heparinization of patients, in an attempt to avoid pulmonary thromboembolism following major surgical interventions. However, in the present case, heparinization would have been insufficient to prevent death. This case indicates that it is necessary to develop preoperative propedeutics for diagnosing the presence of venous thrombi with potential to migrate, causing pulmonary thromboembolism (PTE). If such thrombi could be detected, preventative measures, such as filter installation in the Cava vein could be undertaken.

Necrotizing fasciitis in a newborn infant: a case report

We report the case of a one-day-old newborn infant, female, birth weight 1900 g, gestational age 36 weeks presenting with necrotizing fasciitis caused by E. coli and Morganella morganii. The newborn was allowed to fall into the toilet bowl during a domestic delivery. The initial lesion was observed at 24 hours of life on the left leg at the site of the venipuncture for the administration of hypertonic glucose solution. Despite early treatment, a rapid progression occurred resulting in a fatal outcome. We call attention to the risk presented by this serious complication in newborns with a contaminated delivery, and highlight the site of the lesion and causal agents.

Ethical aspects in the management of the terminally ill patient in the pediatric intensive care unit

OBJECTIVE: To identify the prevalence of management plans and decision-making processes for terminal care patients in pediatric intensive care units. METHODOLOGY: Evidence-based medicine was done by a systematic review using an electronic data base (LILACS, 1982 through 2000) and (MEDLINE, 1966 through 2000). The key words used are listed and age limits (0 to 18 years) were used. RESULTS: One hundred and eighty two articles were found and after selection according to the exclusion/inclusion criteria and objectives 17 relevant papers were identified. The most common decisions found were do-not-resuscitation orders and withdrawal or withholding life support care. The justifications for these were "imminent death" and "unsatisfatory quality of life". CONCLUSION: Care management was based on ethical principles aiming at improving benefits, avoiding harm, and when possible, respecting the autonomy of the terminally ill patient.

Educação Permanente em SBV e SAVC: impacto no conhecimento dos profissionais de enfermagem

FUNDAMENTO: O conhecimento teórico e as habilidades práticas das equipes de Suporte Básico de Vida (SBV) e Suporte Avançado de Vida (SAV) estão entre os determinantes mais importantes das taxas de sucesso em reanimação cardiopulmonar. OBJETIVO: Avaliar o impacto de um programa permanente de treinamento em SBV e SAV no conhecimento dos profissionais de enfermagem. MÉTODO: Estudo de corte transversal. A população foi composta por profissionais de enfermagem de um hospital de nível terciário. Foram realizadas avaliações antes e após o treinamento. Abordaram-se pontos críticos das diretrizes do International Liaison Committee on Resuscitation (ILCOR). RESULTADOS: Foram avaliados 213 profissionais (76 enfermeiros, 35,7%; 38 auxiliares, 17,8%; e 99 técnicos, 46,7%). As médias na avaliação pré-curso foram estatisticamente diferentes (p<0,001) entre auxiliares (3,25), técnicos (3,96) e enfermeiros (4,69). Os profissionais solteiros e sem filhos apresentaram desempenho significativamente superior ao dos casados e com filhos (p=0,02 e 0,004 respectivamente). O nível de conhecimento pré-treinamento foi inversamente proporcional ao tempo transcorrido desde a conclusão da graduação ou curso técnico. As maiores deficiências foram relacionadas à abordagem inicial das vias aéreas, aos cuidados pós-ressuscitação e à técnica de massagem cardíaca externa. A média geral pós-curso foi 7,26. Os auxiliares alcançaram um desempenho de 131,2%, os técnicos de 78,9% e os enfermeiros de 85%, sem diferença estatisticamente significante (p=0,43). CONCLUSÃO: O programa de treinamento permanente em SBV e SAV resultou em importante incremento no nível de conhecimento dos profissionais de enfermagem.

Teaching Basic Life Support to Students of Public and Private High Schools

Background:Despite being recommended as a compulsory part of the school curriculum, the teaching of basic life support (BLS) has yet to be implemented in high schools in most countries.Objectives:To compare prior knowledge and degree of immediate and delayed learning between students of one public and one private high school after these students received BLS training.Methods:Thirty students from each school initially answered a questionnaire on cardiopulmonary resuscitation (CPR) and use of the automated external defibrillator (AED). They then received theoretical-practical BLS training, after which they were given two theory assessments: one immediately after the course and the other six months later.Results:The overall success rates in the prior, immediate, and delayed assessments were significantly different between groups, with better performance shown overall by private school students than by public school students: 42% ± 14% vs. 30.2% ± 12.2%, p = 0.001; 86% ± 7.8% vs. 62.4% ± 19.6%, p < 0.001; and 65% ± 12.4% vs. 45.6% ± 16%, p < 0.001, respectively. The total odds ratio of the questions showed that the private school students performed the best on all three assessments, respectively: 1.66 (CI95% 1.26-2.18), p < 0.001; 3.56 (CI95% 2.57-4.93), p < 0.001; and 2.21 (CI95% 1.69-2.89), p < 0.001.Conclusions:Before training, most students had insufficient knowledge about CPR and AED; after BLS training a significant immediate and delayed improvement in learning was observed in students, especially in private school students.

Sudden Cardiac Death in Brazil: A Community-Based Autopsy Series (2006-2010)

Background: Sudden cardiac death (SCD) is a sudden unexpected event, from a cardiac cause, that occurs in less than one hour after the symptoms onset, in a person without any previous condition that would seem fatal or who was seen without any symptoms 24 hours before found dead. Although it is a relatively frequent event, there are only few reliable data in underdeveloped countries. Objective: We aimed to describe the features of SCD in Ribeirão Preto, Brazil (600,000 residents) according to Coroners’ Office autopsy reports. Methods: We retrospectively reviewed 4501 autopsy reports between 2006 and 2010, to identify cases of SCD. Specific cause of death as well as demographic information, date, location and time of the event, comorbidities and whether cardiopulmonary resuscitation (CPR) was attempted were collected. Results: We identified 899 cases of SCD (20%); the rate was 30/100000 residents per year. The vast majority of cases of SCD involved a coronary artery disease (CAD) (64%) and occurred in men (67%), between the 6th and the 7th decades of life. Most events occurred during the morning in the home setting (53.3%) and CPR was attempted in almost half of victims (49.7%). The most prevalent comorbidity was systemic hypertension (57.3%). Chagas’ disease was present in 49 cases (5.5%). Conclusion: The majority of victims of SCD were men, in their sixties and seventies and the main cause of death was CAD. Chagas’ disease, an important public health problem in Latin America, was found in about 5.5% of the cases.

Sobre os efeitos vasomotôres exercidos pela agua distilada e pelas soluções anisotonicas de clorêto de sodio

The writer reports experiments done with distilled water and hypotonic and hypertonic salt solutions of definite osmotic concentrations. The experiments were performed according to the Laewen-Trendelenburg technic using the vascular system of the frog's hind legs, and according to the Pissemski-Krawkow method using the capillaries of the rabbit's ear. Both preparations react to distilled water by marked vaso-constriction, the same phenomenon taking place in the case of the hypotonic salt solutions. The lower the concentration pf the hypotonic salt solution the stronger the vaso-constriction obtained. With hypertonic salt solutions was observed a strong but rather transient vaso-dilatation followed by secondary vaso-constriction. The later results were found only in the experiments with the frog's hind legs.

Evaluation of antinociceptive effect of Petiveria alliacea (guiné) in animals

Petiveria alliacea (Phytolaccaceae) is a bush widely distributed in South America including Brazil, where it is popularly known as "guiné", pipi", "tipi" or "erva-de-tipi". Brazilian folk medicine attributes to the hot water infusion of its roots or leaves the following pharmacologicalproperties: antipyretic, antispasmodic, abortifacient, antirrheumatic, diuretic, analgesic and sedative. The present study has evaluated the alleged effects of P. alliacea on central nervous system (CNS), particularly, the sedative and analgesic properties of root crude aqueous extract of this plant in mice and rats. This extract showed an antinociceptive effect in acetic acid - acetylcholine - and hypertonic saline - induced abdominal constrictions, but not in hot-plate and tail flick tests P. alliacea did not produce any CNS depressor effect. Thus its antinociceptive action in animals can be responsible by its poplar use as an analgesic.

Distance education in neonatal nursing scenarios: a systematic review

OBJECTIVE Identify resources that support learning mediated by technology in the field of neonatal nursing. METHOD Systematic review with searches conducted in MEDLINE, LILACS and SciELO. Titles and abstracts were independently evaluated by two experts. RESULTS Of the 2,051 references, 203 full-text articles were analyzed, resulting in the inclusion of nine studies on semiotics and semiology, cardiopulmonary resuscitation, general aspects of neonatal care, diagnostic reasoning and assessment of pain. Only two articles addressed the development of educational strategies and seven papers described the assessment of these strategies by experts and/or users. CONCLUSION Distance education is an important resource for education, and its improvement and updating, and it particularly adds advantages for neonatal nursing by approximating teaching and real-life situations and by minimizing the exposure of newborns for teaching purposes. The lack of educational initiatives mediated by technology suggests the need for the development, evaluation and dissemination of educational resources focused on nursing care of newborns and their families.