Maria José Carvalho Carmona

Cross-reactivity between a penicillin and a cephalosporin with the same side chain ☆ ☆☆ ★ ★★

BACKGROUND The cross-reactivity between penicillins and cephalosporins can be influenced by different factors, which are not all well known. The chemical structure of the side chain may contribute to the cross-reactivity. OBJECTIVE The study was carried out in allergic subjects who are selectively responsive to amoxicillin to determine allergenic cross-reactivity with a cephalosporin containing a side chain identical to that of amoxicillin, cefadroxil, and one containing a different side chain, cefamandole. METHODS Allergic subjects with a selective response to amoxicillin were chosen according to the following criteria: history of an immediate allergic reaction to amoxicillin, negative skin test responses to benzylpenicilloyl and minor determinant mixture of benzylpenicillin, negative RAST response to benzylpenicilloyl, and good tolerance to benzylpenicillin and phenoxymethyl penicillin challenges. In addition, subjects had to have a positive skin test response to amoxicillin and/or positive RAST response to amoxicilloyl or, if these test results were negative, a positive challenge test response to amoxicillin. In vivo cross-reactivity to cefadroxil was assessed by giving oral cefadroxil at increasing doses from 5 to 500 mg. In vitro cross-reactivity was determined by RAST inhibition studies with amoxicilloyl RAST disks and the following monomeric conjugates in the fluid phase: amoxicillin-butylamine, cefadroxil-butylamine, and the side chain para-hydroxy-phenylglycine. Tolerance to cefamandole was determined by giving 100 mg and then 500 mg parenterally. RESULTS Twenty-one patients with a selective response to amoxicillin were included in the study. Eight subjects (38%) had a positive response to cefadroxil, and none reacted to cefamandole. In vitro RAST inhibition studies indicated that cefadroxil-butylamine monomers cross-reacted with amoxicillin butylamine and the side chain contributed relevantly to the inhibition. CONCLUSIONS These results indicate that the percentage of cross-reactivity between penicillins and cephalosporins with an identical side chain is high and that this critical part of the molecule seems to be an important contributor to these results. The value is higher than previously reported data from similar studies of non-side-chain-related cephalosporins.

The effect of excess fluid balance on the mortality rate of surgical patients: a multicenter prospective study

IntroductionIn some studies including small populations of patients undergoing specific surgery, an intraoperative liberal infusion of fluids was associated with increasing morbidity when compared to restrictive strategies. Therefore, to evaluate the role of excessive fluid infusion in a general population with high-risk surgery is very important. The aim of this study was to evaluate the impact of intraoperative fluid balance on the postoperative organ dysfunction, infection and mortality rate.MethodsWe conducted a prospective cohort study during one year in four ICUs from three tertiary hospitals, which included patients aged 18 years or more who required postoperative ICU after undergoing major surgery. Patients who underwent palliative surgery and whose fluid balance could change in outcome were excluded. The calculation of fluid balance was based on preoperative fasting, insensible losses from surgeries and urine output minus fluid replacement intraoperatively.ResultsThe study included 479 patients. Mean age was 61.2 ± 17.0 years and 8.8% of patients died at the hospital during the study. The median duration of surgery was 4.0 (3.2 to 5.5) h and the value of the Simplified Acute Physiology Score (SAPS) 3 score was 41.8 ± 14.5. Comparing survivors and non-survivors, the intraoperative fluid balance from non-survivors was higher (1,950 (1,400 to 3,400) mL vs. 1,400 (1,000 to 1,600) mL, P <0.001). Patients with fluid balance above 2,000 mL intraoperatively had a longer ICU stay (4.0 (3.0 to 8.0) vs. 3.0 (2.0 to 6.0), P <0.001) and higher incidence of infectious (41.9% vs. 25.9%, P = 0.001), neurological (46.2% vs. 13.2%, P <0.001), cardiovascular (63.2% vs. 39.6%, P <0.001) and respiratory complications (34.3% vs. 11.6%, P <0.001). In multivariate analysis, the fluid balance was an independent factor for death (OR per 100 mL = 1.024; P = 0.006; 95% CI 1.007 to 1.041).ConclusionsPatients with excessive intraoperative fluid balance have more ICU complications and higher hospital mortality.

Prevalence of Atopy in Students from Málaga, Spain

BACKGROUND Epidemiologic studies are necessary to determine the prevalence of allergic diseases. This varies widely depending on allergen preparations and patients studied. OBJECTIVE To investigate the prevalence of atopic disease, skin test reactivity, total and specific IgE to common allergens, and other variables in a sample of students from Málaga, southern Spain. METHODS Three hundred sixty-five students (age 17.9 +/- 1.18) were interviewed by an allergist. Skin prick tests were performed with Dermatophagoides pteronyssinus, Artemisia vulgaris, Plantago lanceolata, Chenopodium album, Olea europaea, Phleum pratense, Parietaria judaica, Cynodon dactylon, Alternaria tenuis, and cat dander. Total and specific IgE to D. pteronyssinus, Olea, and Parietaria were determined. RESULTS Of all subjects studied, 19.9% suffered from rhinoconjunctivitis, 4.1% rhinoconjunctivitis plus asthma, 3.1% asthma alone, and 0.8% atopic dermatitis; 46.4% had a positive skin test to at least one allergen (28.2% to D. pteronyssinus, 20.4% to Olea, 13.8% to Phleum); and 43% had total IgE > 100 kU/L and 44.7% a family history of atopy. Allergic symptoms were strongly associated with skin test positivities and family allergic history. Patients with asthma or skin prick test positive had higher total IgE values than others (P < .01). There was a significant correlation between specific IgE values and wheal size in skin test. CONCLUSIONS Our findings confirm the high prevalence of atopic diseases, and the close relationship of skin tests reactivity (or presence of specific IgE) to allergens with symptoms of asthma and rhinitis. The presence of a family history of allergic diseases influences the development of positive skin tests and atopic illness. Dermatophagoides pteronyssinus and pollen of Olea europaea were found to be the most common allergens.

Aplicabilidade do escore fisiológico agudo simplificado (SAPS 3) em hospitais brasileiros

JUSTIFICATIVA E OBJETIVOS: O sistema prognostico SAPS 3 (Simplified Acute Physiology Score 3) e composto de 20 variaveis, representadas por escore fisiologico agudo e avaliacao do estado previo, visando estabelecer indice preditivo de mortalidade para pacientes admitidos em unidades de terapia intensiva (UTI). O estudo teve objetivo de validar este sistema e verificar o poder discriminatorio deste indice em pacientes cirurgicos do Brasil. METODO: Estudo prospectivo, realizado em duas UTI especializadas em pacientes cirurgicos de dois diferentes hospitais, no periodo de um ano, excluiuse pacientes com idade inferior a 16 anos, que permaneceram tempo inferior a 24 horas na UTI, readmitidos e aqueles admitidos para procedimento dialitico. A habilidade preditiva do indice SAPS 3 em diferenciar sobreviventes e nao sobreviventes foi verificada utilizando curva ROC e a calibracao pelo teste Hosmer-Lemeshow goodness-of-fit. RESULTADOS: Foram incluidos no estudo 1.310 pacientes. Operacoes gastrintestinais foram predominantes (34,9%). O menor valor do indice SAPS 3 foi 18 e o maior 154, media de 48,5 ± 18,1. A mortalidade hospitalar prevista e real foi de 10,3% e de 10,8%, respectivamente, razao de mortalidade padronizada (SMR) foi 1,04 (IC95% = 1,03-1,07). A calibracao pelo metodo Hosmer e Lemeshow mostrou X2 = 10,47 p = 0,234. O valor do escore SAPS 3 que melhor discriminou sobreviventes e nao sobreviventes foi 57, com sensibilidade de 75,8% e especificidade de 86%. Dos pacientes com indice SAPS 3 maior que 57, 73,5% nao sobreviveram versus 26,5% de sobreviventes (OR = 1,32 IC95% 1,23 - 1,42, p < 0,0001). CONCLUSOES: O sistema SAPS 3 e valido na populacao brasileira de pacientes cirurgicos, sendo util para indicar pacientes graves e determinar maiores cuidados neste grupo.

Intolerance to piroxicam in patients with adverse reactions to nonsteroidal antiinflammatory drugs

To evaluate the tolerance to piroxicam in patients with urticaria induced by analgesic and/or nonsteroidal antiinflammatory drugs (NSAIDs), we carried out a 2-year study in an outpatient clinic. All the patients referred to the clinic for study entered a protocol for evaluation of intolerance to one or more drugs. If patients were allergic to at least two different NSAIDs they were allocated to group A, but if patients were allergic to only one they were considered as having selective intolerance (group B). Either piroxicam or placebo was administered under controlled conditions to both groups. In group A, five out of 18 patients had a positive response to piroxicam. In group B, in all the 25 cases studied a good tolerance to piroxicam was shown. These results indicate that in the group with intolerance to NSAIDs piroxicam induced a positive reaction in 27% of the cases, and that this drug should be administered with caution and with a previous controlled challenge in this type of patient. Piroxicam was well tolerated in the group with selective intolerance, indicating that mechanisms other than interference with the prostaglandin synthesis and release of inflammatory mediators participate in allergic reactions to NSAIDs.

Applicability of the simplified acute physiology score (SAPS 3) in brazilian hospitals

BACKGROUND AND OBJECTIVES The SAPS 3 (Simplified Acute Physiology Score 3) prognostic system is composed of 20 parameters, represented by an acute physiology score and assessment of the previous status, aimed at establishing a predictive mortality index for patients admitted to intensive care units (ICU). The objective of this study was to validate this system and determine its discriminatory power in surgical patients in Brazil. METHODS This is a prospective study undertaken in two surgical ICUs of two different hospitals over a one-year period; patients younger than 16 years, who stay at the ICU for less than 24 hours, readmitted to the unit, and those admitted for dialysis were excluded from the study. The predictive ability of the SAPS 3 index to differentiate survivors and non-survivors was determined by the ROC curve and calibration by the Hosmer-Lemeshow goodness-of-fit test. RESULTS One thousand three-hundred and ten patients were included in the study. Gastrointestinal surgeries predominated (34.9%). Eighteen was the lower SAPS 3 index and the highest was 154, with a mean of 48.5 +/- 18.1. The predicted and real hospital mortality was 10.3% and 10.8%, respectively; the standardized mortality ratio (SMR) was 1.04 (95%CI = 1.03-1.07). Calibration by the Hosmer and Lemeshow method showed X(2) = 10.47 p = 0.234. The SAPS 3 score that better discriminated survivors and non-survivors was 57, with sensitivity of 75.8% and specificity 86%. Among the patients with SAPS 3 index higher than 57, 73.5% did not survive versus 26.5% who survived (OR= 1.32, 95%CI 1.23-1.42, p < 0.0001). CONCLUSIONS The SAPS 3 system is valid for the Brazilian population of surgical patients, being a useful indicator of critical patients and to determine greater care in this group.

Atelectasis during anesthesia: pathophysiology and treatment

JUSTIFICATIVA Y OBJETIVOS: El colapso pulmonar intraoperatorio es una complicacion de elevada incidencia en pacientes sometidos a la intervencion quirurgica bajo anestesia general con relajamiento/paralisis de la musculatura. Esta complicacion esta asociada al empeoramiento de los cambios de gas en el intraoperatorio y en algunos casos, necesidad de soporte respiratorio prolongado en el periodo postoperatorio. Los objetivos de este estudio fueron los de revisar los aspectos fisiopatologicos de la formacion de atelectasias durante anestesia general y las posibles maniobras terapeuticas para prevenir y tratar esa complicacion. CONTENIDO: En esta revision, los conceptos sobre la incidencia de atelectasias intraoperatorias, los factores relacionados a su desarrollo, tanto mecanicos como los relacionados al ajuste del respirador durante el procedimiento quirurgico, los aspectos del diagnostico y las estrategias de prevencion y tratamiento fueron abordados de manera sistematica. CONCLUSIONES: La comprension de los mecanismos relacionados al desarrollo del colapso pulmonar durante el periodo intraoperatorio, como tambien su tratamiento, pueden contribuir para la reduccion de la incidencia de complicaciones pulmonares postoperatorias, el tiempo de recuperacion y los costes de las internaciones en los hospitales.BACKGROUND AND METHODS The incidence of intraoperative pulmonary collapse is elevated in patients undergoing surgery under general anesthesia with muscle relaxation/paralysis. This complication is associated with worsening intraoperative gas exchange and, in some cases, the need for prolonged postoperative respiratory support. The objective of this report was to review the pathophysiological aspects of atelectasis during general anesthesia and possible therapeutic maneuvers that could prevent and treat this complication. CONTENTS This review discusses the concepts about the incidence of intraoperative atelectasis, factors that influence their development, both mechanical and those related to mechanical ventilator settings during the surgery, diagnostic criteria, and strategies to prevent and treat this complication. CONCLUSIONS Understanding of the mechanisms related with the development of intraoperative pulmonary collapse, as well as its treatment, can contribute to reduce the incidence of postoperative pulmonary complications, the length of recovery and hospital costs.

Hypoxemia after myocardial revascularization: analysis of risk factors

JUSTIFICATIVA E OBJETIVOS: Hipoxemia grave e uma complicacao frequente no pos-operatorio imediato de revascularizacao do miocardio (RM), promovendo aumento da duracao da ventilacao mecânica, da incidencia de infeccoes pulmonares, dos custos e da mortalidade. O objetivo desse estudo foi identificar fatores preditivos de hipoxemia grave em pacientes submetidos a RM. METODO: Foram estudados 481 pacientes adultos submetidos a RM eletiva entre outubro de 2003 e marco de 2004. Considerou-se hipoxemia grave uma relacao PaO2/FiO2 0,2 para exclusao da variavel do modelo de RL e p < 0,1 como sendo significativo. RESULTADOS: O tempo para extubacao dos pacientes com hipoxemia grave foi maior que nos outros pacientes (p < 0,001). Na analise multivariada, as variaveis idade (p = 0,081), peso (p = 0,001), necessidade de CEC prolongada (p = 0,033) e disfuncao ventricular esquerda (p = 0,082) foram identificadas como preditores independentes para hipoxemia grave. CONCLUSOES: Pacientes com idade e peso elevados, disfuncao ventricular esquerda e necessidade de CEC apresentaram risco aumentado para hipoxemia grave apos RM. Nesses pacientes, o uso de estrategias ventilatorias perioperatoria com pressoes positivas expiratorias mais elevadas e manobra de recrutamento alveolar devem ser consideradas tendo como objetivo a prevencao da disfuncao pulmonar pos-operatoria.BACKGROUND AND OBJECTIVES Severe hypoxemia is complication frequently seen in the immediate postoperative period of myocardial revascularization (MR), increasing the duration of mechanical ventilation, the incidence of pulmonary infections, hospital costs, and mortality. The objective of this study was to identify predictive factors of severe hypoxemia in patients undergoing MR. METHODS Four-hundred and eighty-one adult patients undergoing elective MR between October 2003 and March 2004 were enrolled in this study. Severe hypoxemia was defined as PaO2/FiO2 < 150 upon admission to the ICU. The Chi-square test, Students t or Wilcoxon test, followed by multivariate analysis and logistic regression (LR) for parameters with p < 0.25 in the univariate analysis, were used for the statistical analysis. A p > 0.2 was required to exclude the parameter from the LR model, and a p < 0.1 was considered significant. RESULTS Time for extubation was greater in patients with severe hypoxemia (p < 0.001). Multivariate analysis identified age (p = 0.081), weight (p = 0.001), need of prolonged CBP (p = 0.033), and left ventricular dysfunction (p = 0.082) as independent predictors of severe hypoxemia. CONCLUSIONS Older and overweighted patients, those with left ventricular dysfunction, and those who needed CPB presented an increased risk of severe hypoxemia after MR. In those patients, the use of perioperative ventilatory strategies, with elevated positive expiratory pressures and alveolar recruitment maneuver should be considered to prevent postoperative pulmonary dysfunction.

Hipoxemia após revascularização miocárdica: análise dos fatores de risco

JUSTIFICATIVA E OBJETIVOS: Hipoxemia grave e uma complicacao frequente no pos-operatorio imediato de revascularizacao do miocardio (RM), promovendo aumento da duracao da ventilacao mecânica, da incidencia de infeccoes pulmonares, dos custos e da mortalidade. O objetivo desse estudo foi identificar fatores preditivos de hipoxemia grave em pacientes submetidos a RM. METODO: Foram estudados 481 pacientes adultos submetidos a RM eletiva entre outubro de 2003 e marco de 2004. Considerou-se hipoxemia grave uma relacao PaO2/FiO2 0,2 para exclusao da variavel do modelo de RL e p < 0,1 como sendo significativo. RESULTADOS: O tempo para extubacao dos pacientes com hipoxemia grave foi maior que nos outros pacientes (p < 0,001). Na analise multivariada, as variaveis idade (p = 0,081), peso (p = 0,001), necessidade de CEC prolongada (p = 0,033) e disfuncao ventricular esquerda (p = 0,082) foram identificadas como preditores independentes para hipoxemia grave. CONCLUSOES: Pacientes com idade e peso elevados, disfuncao ventricular esquerda e necessidade de CEC apresentaram risco aumentado para hipoxemia grave apos RM. Nesses pacientes, o uso de estrategias ventilatorias perioperatoria com pressoes positivas expiratorias mais elevadas e manobra de recrutamento alveolar devem ser consideradas tendo como objetivo a prevencao da disfuncao pulmonar pos-operatoria.BACKGROUND AND OBJECTIVES Severe hypoxemia is complication frequently seen in the immediate postoperative period of myocardial revascularization (MR), increasing the duration of mechanical ventilation, the incidence of pulmonary infections, hospital costs, and mortality. The objective of this study was to identify predictive factors of severe hypoxemia in patients undergoing MR. METHODS Four-hundred and eighty-one adult patients undergoing elective MR between October 2003 and March 2004 were enrolled in this study. Severe hypoxemia was defined as PaO2/FiO2 < 150 upon admission to the ICU. The Chi-square test, Students t or Wilcoxon test, followed by multivariate analysis and logistic regression (LR) for parameters with p < 0.25 in the univariate analysis, were used for the statistical analysis. A p > 0.2 was required to exclude the parameter from the LR model, and a p < 0.1 was considered significant. RESULTS Time for extubation was greater in patients with severe hypoxemia (p < 0.001). Multivariate analysis identified age (p = 0.081), weight (p = 0.001), need of prolonged CBP (p = 0.033), and left ventricular dysfunction (p = 0.082) as independent predictors of severe hypoxemia. CONCLUSIONS Older and overweighted patients, those with left ventricular dysfunction, and those who needed CPB presented an increased risk of severe hypoxemia after MR. In those patients, the use of perioperative ventilatory strategies, with elevated positive expiratory pressures and alveolar recruitment maneuver should be considered to prevent postoperative pulmonary dysfunction.

Hyperkalemia accompanies hemorrhagic shock and correlates with mortality

OBJECTIVE: This study was designed to evaluate the effects of terlipressin versus fluid resuscitation with normal saline, hypertonic saline or hypertonic-hyperoncotic hydroxyethyl starch, on hemodynamics, metabolics, blood loss and short-term survival in hemorrhagic shock. METHOD: Twenty-nine pigs were subjected to severe liver injury and treated 30 min later with either: (1) 2 mg terlipressin in a bolus, (2) placebo-treated controls, (3) 4 mL/kg 7.5% hypertonic NaCl, (4) 4 mL/kg 7.2% hypertonic-hyperoncotic hydroxyethyl starch 200/0.5, or (5) normal saline at three times lost blood volume. RESULTS: The overall mortality rate was 69%. Blood loss was significantly higher in the hypertonic-hyperoncotic hydroxyethyl starch and normal saline groups than in the terlipressin, hypertonic NaCl and placebo-treated controls groups (p<0.005). Hyperkalemia (K>5 mmol/L) before any treatment occurred in 66% of the patients (80% among non-survivors vs. 22% among survivors, p=0.019). Post-resuscitation hyperkalemia occurred in 86.66% of non-survivors vs. 0% of survivors (p<0.001). Hyperkalemia was the first sign of an unsuccessful outcome for the usual resuscitative procedure and was not related to arterial acidemia. Successfully resuscitated animals showed a significant decrease in serum potassium levels relative to the baseline value. CONCLUSION: Hyperkalemia accompanies hemorrhagic shock and, in addition to providing an early sign of the acute ischemic insult severity, may be responsible for cardiac arrest related to hemorrhagic shock.