RESUMO
BACKGROUND: Because few studies have addressed postoperative hypoalbuminaemia in relation to hospital mortality, we evaluated this association and the prognostic value of increased procalcitonin (PCT) after cardiopulmonary bypass (CPB) surgery. METHODS: In 454 consecutive patients undergoing CPB, minimal serum albumin, colloid osmotic pressure (COP) and maximal PCT were retrospectively obtained from the 2nd to 10th postoperative day. Receiver operating characteristic (ROC) and multiple regression analyses determined independent predictive strength for 28-day mortality from preoperative albumin, Euroscore, postoperative minimal albumin and COP, and maximal PCT. Cut-off points for the four strongest predictors were calculated by the area under the curve (AUC) in the ROC for the 28-day mortality. RESULTS: Maximal PCT showed the largest AUC (0.85; 95% CI 0.79-0.90) and the highest relative risk (RR 12.17; 95%CI 5.26-28.16; P < 0.001), compared with postoperative albumin (AUC 0.72; 95% CI 0.62-0.81; RR 5.35; 95%CI 2.99-9.56; P < 0.001) and EuroSCORE (AUC 0.73; 95%CI 0.63-0.83; RR 4.48; 95%CI: 1.78-11.28; P < 0.01). By logistic regression, postoperative albumin was the strongest predictor of mortality (odds ratio 0.86; 95% CI 0.84-0.89). Cut-off values for predicting 28-day mortality were found for postoperative albumin and PCT at 17.8 g l(-1) and 2.5 ng l(-1), respectively. A slight but significant inverse correlation between PCT and albumin was found. Patients with albumin less than the cut-off showed significantly higher median values for PCT levels (2.5 vs. 1.0 g l-1), a higher 28-day mortality rate (20.8% vs. 4.5%), and a longer ICU stay (6 vs. 3 days) in comparison with patients with minimal albumin greater than 18 g l(-1). CONCLUSIONS: Post-operative serum albumin <18 g l(-1) and PCT >2.5 ng l(-1) are predictive for a higher 28-day mortality rate in cardiosurgical patients. Both peak PCT and minimal albumin were better outcome predictors than the Euroscore, which better represents the preoperative condition of the patient.
Assuntos
Calcitonina/sangue , Ponte de Artéria Coronária/mortalidade , Hipoalbuminemia/etiologia , Complicações Pós-Operatórias , Precursores de Proteínas/sangue , Idoso , Peptídeo Relacionado com Gene de Calcitonina , Feminino , Humanos , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Pressão Osmótica , Prognóstico , Curva ROC , Estudos Retrospectivos , Fatores de Risco , Taxa de SobrevidaRESUMO
Tissue hypoxia, especially in the splanchnic area, is still considered to be an important cofactor in the pathogenesis of multiple organ failure. Therefore, the specific effects of the various therapeutic interventions on splanchnic perfusion and oxygenation are of particular interest. Restoring and maintaining oxygen transport and tissue oxygenation is the most important step in the supportive treatment of patients with sepsis and impaired gut perfusion. Therefore, supportive treatment should be focused on an adequate volume resuscitation and appropriate use of vasoactive drugs. Adequate volume loading may be the most important step in the treatment of patients with septic shock. An elevated oxygen delivery may be beneficial in some patients, but the increase of oxygen delivery should be guided by the measurement of parameters assessing global and regional oxygenation. Forcing an elevation in oxygen delivery by the use of very high dosages of catecholamines can be harmful. Vasopressors should be used for achieving an adequate perfusion pressure. For norepinephrine, no negative effects on gut perfusion have been demonstrated. Epinephrine and dopamine should be avoided because they seem to redistribute blood flow away from the splanchnic region. There are no convincing data yet to support the routine use of low-dose dopamine or dopexamine to improve an impaired gut perfusion. There is even evidence that low-dose dopamine may reduce the mucosal perfusion in the gut in some patients. It has been suggested that dopexamine can improve splanchnic perfusion, but because these effects remain somewhat controversial, a general recommendation for dopexamine to improve gut perfusion is not justified.
Assuntos
Infecções Bacterianas/complicações , Enteropatias/microbiologia , Enteropatias/terapia , Humanos , Enteropatias/prevenção & controleRESUMO
OBJECTIVE: To assess the effects of dopexamine on splanchnic blood flow and splanchnic oxygen uptake in septic patients. DESIGN: A prospective, controlled trial. SETTING: A ten-bed intensive care unit (ICU) in a university hospital. PATIENTS: Twelve patients with severe sepsis (according to the criteria of the 1992 American College of Chest Physicians/Society of Critical Care Medicine consensus conference) being stabilized by volume loading and treated to an elevated oxygen delivery by dobutamine infusion. INTERVENTIONS: Infusion of increasing dosages of dopexamine (0.5, 1.0, 2.0, and 4.0 microg/kg/min). MEASUREMENTS AND MAIN RESULTS: Systemic and splanchnic hemodynamic and oxygen transport parameters as well as gastric mucosal pH (pHi) were measured. A hepatic venous catheter technique with indocyanine green dye dilution was used to determine splanchnic blood flow. Dopexamine increased global and splanchnic oxygen delivery without affecting oxygen consumption (VO2). Splanchnic blood flow increased proportionally to cardiac output, indicating that there was no selective effect of dopexamine on the splanchnic flow. Dopexamine decreased pHi in a dose-dependent fashion in all 12 patients. CONCLUSIONS: In hemodynamically stable, hyperdynamic septic patients being treated with dobutamine, dopexamine has no selective effect on splanchnic blood flow. In fact, a decreased pHi suggests a harmful effect on gastric mucosal perfusion.
Assuntos
Cardiotônicos/uso terapêutico , Dobutamina/uso terapêutico , Agonistas de Dopamina/administração & dosagem , Dopamina/análogos & derivados , Mucosa Gástrica/efeitos dos fármacos , Sepse/tratamento farmacológico , Circulação Esplâncnica/efeitos dos fármacos , Adulto , Idoso , Velocidade do Fluxo Sanguíneo/efeitos dos fármacos , Cardiotônicos/administração & dosagem , Dobutamina/administração & dosagem , Dopamina/administração & dosagem , Feminino , Mucosa Gástrica/irrigação sanguínea , Hospitais Universitários , Humanos , Concentração de Íons de Hidrogênio , Infusões Intravenosas , Unidades de Terapia Intensiva , Masculino , Microcirculação/efeitos dos fármacos , Pessoa de Meia-Idade , Consumo de Oxigênio , Estudos Prospectivos , Sepse/metabolismo , Sepse/fisiopatologia , Resultado do TratamentoRESUMO
PURPOSE: The purpose of this study was to analyze three different variables of cardiac preload; central venous pressure (CVP), pulmonary artery occlusion pressure (PAOP), and intrathoracic blood volume index (ITBVI) that served as the best indicator of cardiac function, that is, cardiac index (C1) or stroke index (SI). MATERIALS AND METHODS: This was a prospective study in 57 critically ill patients with sepsis or septic shock in whom 581 hemodynamic profiles were analyzed. One patient was included a second time after a period of 6 weeks. All patients were sedated and mechanically ventilated. Each patient had a 7.5-Frfive-lumen pulmonary artery catheter (PAC) and a 4-Fr catheter with an integrated thermistor and fiberoptic that was advanced into the descending aorta via a femoral artery sheath. The study was performed in the surgical intensive care unit of a university hospital. RESULTS: Linear regression analysis of the first profile for each case (n = 58) revealed a significant correlation between ITBVI and SI (r = 0.66). For comparison, correlations for PAOP/SI (r = 0.06) and CVP/SI (r = 0.10) were poor. The analysis of all second profiles showed that only the change in ITBVI reflected the change in SI (r = 0.67), whereas PAOP (r = 0.07) and CVP (r = 0.05) failed. Furthermore, a positive change in SI (n = 265) was most often associated with an increase in ITBVI (n = 189, 71.3%), less for PAOP (n = 122, 46.0%) and CVP (n = 137, 51.7%). A reduction in SI (n = 256) was accompanied by a decrease in ITBVI (n = 176, 68.8%), PAOP (n = 119, 46.5%), and CVP (n = 118, 46.1%). An increase in ITBVI (n = 269) was accompanied by an increase in SI in 189 cases (70.3%). In these, PAOP increased only in 91 (48.1%) and CVP in 101 cases (53.4%), respectively. Accordingly, a positive change in PAOP (n = 218) was associated with an increase in SI in 122 cases (56.0%). ITBVI increased in 91 (74.6%) and CVP in 84 (68.9%) of these cases. A decrease in ITBVI (n = 250) was associated with a decrease in SI in 176 cases (70.4%). Decreases in PAOP (n = 89, 50.6%) and CVP (n = 91, 51.7%) did not reflect these changes. However, when PAOP (n = 229) and SI decreased (n = 119, 52.0%), ITBVI decreased in 89 (74.8%) and CVP in 73 cases (61.3%). CONCLUSIONS: In comparison with cardiac filling pressures, ITBVI seems to be the more reliable indicator of cardiac preload in patients with sepsis or septic shock.
Assuntos
Volume Sanguíneo , Pressão Venosa Central , Hemodinâmica , Pressão Propulsora Pulmonar , Sepse/fisiopatologia , Choque Séptico/fisiopatologia , Volume Sistólico , Tórax/irrigação sanguínea , Adulto , Idoso , Idoso de 80 Anos ou mais , Cateterismo de Swan-Ganz , Feminino , Humanos , Modelos Lineares , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Estudos Prospectivos , Reprodutibilidade dos TestesAssuntos
Corticosteroides/efeitos adversos , Dermatite de Contato/etiologia , Fármacos Dermatológicos/efeitos adversos , Excipientes/efeitos adversos , Ceras/efeitos adversos , Corticosteroides/imunologia , Reações Cruzadas , Dermatite de Contato/tratamento farmacológico , Dermatite de Contato/imunologia , Fármacos Dermatológicos/imunologia , Humanos , Masculino , Pessoa de Meia-Idade , Testes do Emplastro , Sapatos/efeitos adversosRESUMO
OBJECTIVE: To make clinically relevant recommendations for electrocardiogram (ECG) testing among psychiatric patients, the study examined the practice of ordering ECGs for this population. METHODS: The records of 4,045 patients consecutively admitted for psychiatric care to seven community teaching hospitals over one year were examined. The frequency of ECG orders was documented, and abnormal ECG results were grouped into two categories: relevant to psychiatric treatment (ischemia or conduction defects) and incidental to treatment (minor abnormalities and screening abnormalities). For those with abnormalities, additional cardiac follow-up data were recorded. Associations between ECG results and patients' characteristics were analyzed. RESULTS: ECGs were performed for 2,857 (71 percent) of first admissions, of which 2,225 (78 percent) showed neither relevant nor screening abnormalities. Eighteen percent of those tested had relevant abnormalities, most commonly a first-degree atrioventricular block or some evidence of a myocardial infarction. ECG screening abnormalities were found for another 4 percent, primarily left ventricular hypertrophy (3 percent), but no follow-up occurred for 46 percent of these patients. Among patients under 40 years of age, 8 percent had relevant abnormalities, and 3 percent had screening abnormalities. Among patients without apparent cardiac risk, 10 percent had relevant and 3 percent had screening abnormalities. More than half the patients who had a second or third admission during the year had a repeat ECG, even when previous ECGs were normal. CONCLUSIONS: Routine ECG is not an effective treatment or screening tool in this population, and substantial cost savings could result from more selective testing, particularly among young patients, those at low risk, and those with repeat admissions.
Assuntos
Arritmias Cardíacas/epidemiologia , Testes Diagnósticos de Rotina/estatística & dados numéricos , Eletrocardiografia/estatística & dados numéricos , Transtornos Mentais/epidemiologia , Isquemia Miocárdica/epidemiologia , Admissão do Paciente/estatística & dados numéricos , Adulto , Idoso , Arritmias Cardíacas/diagnóstico , Arritmias Cardíacas/etiologia , Comorbidade , Redução de Custos , Diagnóstico Duplo (Psiquiatria) , Testes Diagnósticos de Rotina/economia , Eletrocardiografia/economia , Feminino , Humanos , Masculino , Transtornos Mentais/diagnóstico , Transtornos Mentais/reabilitação , Pessoa de Meia-Idade , Isquemia Miocárdica/diagnóstico , Isquemia Miocárdica/etiologia , Admissão do Paciente/economia , Sensibilidade e Especificidade , Resultado do TratamentoAssuntos
Anestesia Local , Anestésicos Locais/administração & dosagem , Procedimentos Cirúrgicos Dermatológicos , Epinefrina/administração & dosagem , Vasoconstritores/administração & dosagem , Antagonistas Adrenérgicos beta/uso terapêutico , Idoso , Anti-Hipertensivos/uso terapêutico , Pressão Sanguínea/efeitos dos fármacos , Epinefrina/efeitos adversos , Humanos , Hipertensão/tratamento farmacológico , Injeções Subcutâneas , Propranolol/uso terapêutico , Vasoconstritores/efeitos adversosRESUMO
OBJECTIVE: Qualitative and quantitative evaluation of leukocyte activation in septic patients in comparison to two control groups. DESIGN: A prospective clinical study in which the leukocyte oxidative output of whole blood was measured in three groups of patients. Two chemiluminescence markers (luminol or lucigenin), indicative of either total oxidant output or superoxide production, and three stimuli (opsonized zymosan, formyl-methionyl-leucyl-phenylalanine (fMLP), phorbol myristate acetate) (PMA), representing different pathways of leukocyte activation, were used. Tumor necrosis factor, interleukin-6 and C-reactive protein (TNF, IL-6, and CRP) were determined to evaluate the severity of the inflammatory process. SETTING: Intensive care and surgical units of a university hospital. PATIENTS: Seventy-four healthy patients, ten ICU patients without signs of sepsis or systemic inflammatory response syndrome and 19 septic patients were studied. MEASUREMENT AND MAIN RESULTS: With all three stimuli, whole blood total oxidative output and superoxide production were generally increased in septic patients. This was most likely due to the increased leukocyte numbers in these patients. When the chemiluminescence values were normalized per phagocyte (granulocytes and monocytes), the total oxidative output of septic phagocytes decreased with opsonin and fMLP but increased with PMA, while superoxide output decreased regardless of the stimuli used. TNF, IL-6 and CRP, although increased in septic patients as compared to ICU controls, correlated weakly with oxidant output. CONCLUSIONS: The oxidative output of whole blood was increased in septic patients compared to controls because of elevated leukocyte numbers. However, oxidant output normalized for phagocyte numbers generally decreases during sepsis for most stimuli. Cytokines and CRP do not appear to be associated with the extent of oxidant output during sepsis.
Assuntos
Proteína C-Reativa/metabolismo , Interleucina-6/sangue , Ativação de Neutrófilo , Explosão Respiratória , Sepse/imunologia , Sepse/metabolismo , Fator de Necrose Tumoral alfa/metabolismo , Adulto , Idoso , Estudos de Casos e Controles , Feminino , Humanos , Contagem de Leucócitos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Índice de Gravidade de DoençaRESUMO
Inadvertent drug substitution occurred in several instances in our practices due to the combination of the physician's illegible handwriting on prescriptions and the pharmacist's misinterpretation of subtle clues, which might have prevented the errors. The literature on the legibility of physician handwriting is reviewed. Our specific recommendations include using preprinted prescription pads, training staff assistants who write prescriptions, printing complete directions on each prescription, and aggressively educating each patient about the name and purpose of all drugs being prescribed. Patients are encouraged to bring their medications to each office visit to identify potential errors.
Assuntos
Escrita Manual , Erros de Medicação , Humanos , Relações InterprofissionaisRESUMO
BACKGROUND: Despite anecdotal evidence of a possibility of decreased effectiveness of oral contraceptives (OCs) with some antibiotics, it is not known whether antibiotic use in dermatologic practices engenders any increased risk of accidental pregnancy. OBJECTIVE: Our purpose was to examine the effect of commonly prescribed oral antibiotics (tetracyclines, penicillins, cephalosporins) on the failure rate of OCs. METHODS: The records from three dermatology practices were reviewed, and 356 patients with a history of combined oral antibiotic/OC use were surveyed retrospectively. Of these patients, 263 also provided "control" data (during the times they used OCs alone). An additional 162 patients provided control data only. RESULTS: Five pregnancies occurred in 311 woman-years of combined antibiotic/OC exposure (1.6% per year failure rate) compared with 12 pregnancies in 1245 woman-years of exposure (0.96% per year) for the 425 control patients. This difference was not significant (p = 0.4), and the 95% confidence interval on the difference (-0.81, 2.1) ruled out a substantial difference (> 2.1% per year). There was also no significant difference between OC failure rates for the women who provided data under both conditions, nor between the two control groups. All our data groups had failure rates below the 3% or higher per year, which are typically found in the United States. CONCLUSION: The difference in failure rates of OCs when taken concurrently with antibiotics commonly used in dermatology versus OC use alone suggests that these antibiotics do not increase the risk of pregnancy. Physicians and patients need to recognize that the expected OC failure rate, regardless of antibiotic use, is at least 1% per year and it is not yet possible to predict in whom OCs may fail.
PIP: Although some antibiotics are assumed to compromise the effectiveness of oral contraceptives (OCs), it is unknown whether the antibiotics used in dermatologic practice are associated with such a risk. To address this issue, a review was conducted in three US dermatologic practices of the records of 356 patients with a history of combined oral antibiotic/OC use in 1990-95 who responded to a follow-up questionnaire. 263 of these patients provided control data during the times they used OCs alone and an additional 162 patients were controls only. There were five pregnancies in 311 woman-years of combined antibiotic/OC exposure (1.6% annual failure rate) compared with 12 pregnancies in 1245 woman-years of exposure among controls (0.96% annual failure rate)--a nonsignificant difference. In addition, there were no significant differences between OC failure rates among women who served as both cases and controls or between the two control groups. All five cases who became pregnant had been taking an antibiotic (microcycline or a cephalosporin) for at least 3 months. Side effects potentially linked to reduced OC effectiveness (e.g., diarrhea, breakthrough menstrual bleeding) were not reported by the women who became pregnant. It is presumed that inter-individual differences in steroid plasma levels are a more important cause of OC failure than concomitant antibiotic therapy.
Assuntos
Antibacterianos/administração & dosagem , Anticoncepcionais Orais Combinados , Gravidez , Administração Oral , Adolescente , Adulto , Antibacterianos/efeitos adversos , Dermatologia , Interações Medicamentosas , Feminino , Humanos , Estudos RetrospectivosRESUMO
OBJECTIVE: To assess the effects of epinephrine on splanchnic perfusion and splanchnic oxygen uptake in patients with septic shock. DESIGN: Prospective, controlled trial. SETTING: University hospital intensive care unit (ICU). PATIENTS: Eight patients with septic shock, according to the criteria of the 1992 American College of Chest Physicians/Society of Critical Care Medicine Consensus Conference, requiring treatment with vasopressors. INTERVENTIONS: We compared in crossover design a 2-hr infusion of epinephrine with dobutamine plus norepinephrine in eight ICU patients with septic shock. Systemic and splanchnic hemodynamics and oxygen transport were measured before and during treatment with epinephrine. MEASUREMENTS AND MAIN RESULTS: There was essentially no effect of epinephrine on the global parameters, except for increased lactate concentrations. There were marked effects on the regional variables; epinephrine caused lower splanchnic flow and oxygen uptake, lower mucosal pH, and higher hepatic vein lactate. CONCLUSION: We conclude that undesirable splanchnic effects on patients in whom that region is particularly fragile should be considered when using epinephrine for septic shock treatment.
Assuntos
Dobutamina/uso terapêutico , Epinefrina/uso terapêutico , Norepinefrina/uso terapêutico , Choque Séptico/tratamento farmacológico , Circulação Esplâncnica/efeitos dos fármacos , Simpatomiméticos/uso terapêutico , Vasoconstritores/uso terapêutico , Adulto , Idoso , Estudos Cross-Over , Quimioterapia Combinada , Feminino , Hemodinâmica/efeitos dos fármacos , Humanos , Masculino , Pessoa de Meia-Idade , Consumo de Oxigênio/efeitos dos fármacos , Estudos Prospectivos , Choque Séptico/fisiopatologiaRESUMO
OBJECTIVE: To assess the effects of low-dose dopamine on splanchnic blood flow and splanchnic oxygen uptake in patients with septic shock. DESIGN: Prospective, controlled trial. SETTING: University hospital intensive care unit. PATIENTS: 11 patients with septic shock, diagnosed according the criteria of the 1992 American College of Chest Physicians/Society of Critical Care Medicine consensus conference, who required treatment with norepinephrine. MEASUREMENTS AND MAIN RESULTS: Systemic and splanchnic hemodynamics and oxygen transport were measured before and during addition of low-dose dopamine (3 micrograms/kg per min). Low-dose dopamine and a marked effect on total body hemodynamics and oxygen transport. The fractional splanchnic flow at baseline ranged from 0.15 to 0.57. In 7 patients with a fractional splanchnic flow less than 0.30, low-dose dopamine increased splanchnic flow and splanchnic oxygen delivery and oxygen consumption. In 4 patients with a fractional splanchnic flow above 0.30, low-dose dopamine did not appear to change splanchnic blood flow. CONCLUSION: Low-dose dopamine has a potential beneficial effect on splanchnic blood flow and oxygen consumption in patients with septic shock, provided the fractional splanchnic flow is not already high before treatment.
Assuntos
Dopamina/uso terapêutico , Consumo de Oxigênio/efeitos dos fármacos , Choque Séptico/tratamento farmacológico , Circulação Esplâncnica/efeitos dos fármacos , Adulto , Idoso , Gasometria , Dopamina/administração & dosagem , Feminino , Hemodinâmica/efeitos dos fármacos , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Análise de Regressão , Choque Séptico/metabolismo , Choque Séptico/fisiopatologia , Estatísticas não Paramétricas , Análise de SobrevidaRESUMO
OBJECTIVE: To assess global and splanchnic blood flow and oxygen transport in patients with sepsis with and without norepinephrine treatment. DESIGN: Prospective, clinical study. SETTING: University hospital intensive care unit. PATIENTS: A convenience sample of 15 septic shock patients treated with norepinephrine and 13 patients with severe sepsis who did not receive norepinephrine. MEASUREMENTS AND MAIN RESULTS: There were no differences between the two groups in global haemodynamics and oxygen transport. Splanchnic blood flow and oxygen delivery (splanchnic DO2 303 +/- 43 ml/min per m2) and consumption (splanchnic VO2 100 +/- 13 ml/min per m2) were much higher in the septic shock group compared with the severe sepsis group (splanchnic DO2 175 +/- 19 ml/min per m2, splanchnic VO2 61 +/- 6 ml/min per m2). Gastric mucosal pH was subnormal in both groups (septic shock 7.29 +/- 0.02, severe sepsis 7.25 +/- 0.02) with no significant difference. No significant differences between groups were detected in lactate values. CONCLUSION: These data confirm a redistribution of blood flow to the splanchnic region in sepsis that is even more pronounced in patients with septic shock requiring norepinephrine. However, subnormal gastric mucosal pH suggested inadequate oxygenation in parts of the splanchnic region due to factors other than splanchnic hypoperfusion. Progress in this area will depend on techniques that address not only total splanchnic blood flow, but also inter-organ flow distribution, intra-organ distribution, and other microcirculatory or metabolic malfunctions.
Assuntos
Norepinefrina/uso terapêutico , Sepse/tratamento farmacológico , Choque Séptico/tratamento farmacológico , Circulação Esplâncnica/efeitos dos fármacos , Vasoconstritores/uso terapêutico , APACHE , Adulto , Idoso , Gasometria , Feminino , Hemodinâmica/efeitos dos fármacos , Humanos , Masculino , Pessoa de Meia-Idade , Consumo de Oxigênio/efeitos dos fármacos , Estudos Prospectivos , Sepse/fisiopatologia , Choque Séptico/fisiopatologiaRESUMO
Although stroke volume during exercise is affected by aging and posture, few studies have carefully examined the heart rate, blood pressure, and peak oxygen uptake (VO2) responses of older subjects to supine exercise. The present study examined these responses during graded supine cycling in younger (21-30 yr) and older (51-62 yr) untrained (Treadmill VO2max = 47.0 vs 32.3 ml.kg-1.min-1) and endurance-trained (66.3 vs 52.7 ml.kg-1.min-1) men (N = 6/group). All subjects had lower (P < 0.05) peak VO2 (ml.min-1) and peak heart rate responses during supine cycling compared with treadmill exercise. Additionally, the age-related reduction in peak VO2 (approximately 20-30%) was similar for supine compared with treadmill testing, even when normalized to fat-free leg volume and fat-free mass, respectively. However, at given absolute intensities (VO2) of supine exercise, heart rates were 10-15 beats.min-1 less (P < 0.05) in both older groups. Across relative supine work intensities (% of peak), systolic pressure increased most rapidly in the younger trained and older untrained groups. These findings suggest that the effects of aging on peak VO2 are similar during treadmill and supine exercise in both endurance-trained and untrained men. These data also indicate that the heart rate response to supine exercise is attenuated in healthy older men and contributes to their reduced peak VO2.
Assuntos
Envelhecimento/fisiologia , Pressão Sanguínea , Exercício Físico/fisiologia , Frequência Cardíaca , Consumo de Oxigênio , Educação Física e Treinamento/métodos , Adulto , Composição Corporal , Humanos , Masculino , Pessoa de Meia-Idade , Decúbito DorsalRESUMO
OBJECTIVE: To test whether dopexamine hydrochloride, by its beta 2-adrenoreceptor and dopaminergic 1 (DA1) and dopaminergic 2 (DA2) agonistic properties, can improve oxygen consumption (VO2) in hyperdynamic patients with septic shock. DESIGN: Prospective, single-cohort study. SETTING: ICU, university hospital. PATIENTS: Twenty-nine postoperative, hemodynamically stabilized, hyperdynamic patients with septic shock. INTERVENTIONS: Short-term application (30 min) of dopexamine hydrochloride at a dose of 2 microgram/kg/min. MEASUREMENTS: Complete hemodynamic profile with O2 transport-related variables at baseline, 30 min after starting the dopexamine infusion, and 30 min after stopping the infusion. MAIN RESULTS: The dopexamine infusion resulted in significant increases in cardiac index (17%) (p<0.001) and O2 delivery (DO2) (16%) (p<0.001). VO2 increased slightly but significantly about 4% (p<0.001) by respiratory gas exchange measurements and 9% (p<0.001) by cardiovascular Fick calculations. The O2 extraction ratio decreased about 8% (0.001). CONCLUSIONS: The addition of dopexamine hydrochloride at a dose of 2 microgram/kg/min resulted in significant increases of DO2 and to a lesser extent VO2. Much of the global DO2 increase was not utilized, because O2 extraction ratio decreased. Direct calorigenic effects of dopexamine and an increase in myocardial VO2 likely account for a large portion of the increase in global VO2. Whether any of the VO2 increase reflects improvement in regions of jeopardized tissue oxygenation remains to be clarified before the definite value of this drug in septic shock can be established.
Assuntos
Agonistas Adrenérgicos beta/farmacologia , Agonistas de Dopamina/farmacologia , Dopamina/análogos & derivados , Consumo de Oxigênio/efeitos dos fármacos , Choque Séptico/fisiopatologia , APACHE , Agonistas Adrenérgicos beta/uso terapêutico , Adulto , Dopamina/farmacologia , Dopamina/uso terapêutico , Agonistas de Dopamina/uso terapêutico , Feminino , Hemodinâmica/efeitos dos fármacos , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Choque Séptico/tratamento farmacológicoRESUMO
Hypertonic saline with or without colloidal solution has been successfully used for treating hemorrhagic shock in animal experiments and clinical studies. Due to its various effects at systemic, organ, and microcirculatory levels, the substance appears to be a promising candidate for improving tissue oxygenation in sepsis. We therefore investigated the hypothesis that infusion of hypertonic saline would further improve O2 delivery, O2 extraction, and O2 uptake in hyperdynamic septic shock patients already stabilized by adequate volume and catecholamine infusion. Twenty-one patients received 2-4 mL/kg body weight of hypertonic saline in hydroxyethyl starch within 15 min. This hypertonic saline infusion caused a rapid significant increase in O2 delivery by 14% but only a marginal increase in O2 consumption (7% by cardiovascular Fick [p < .05], 4% by respiratory gases [n.s.]). Hypertonic saline increased the already elevated cardiac output by 24%. The pulmonary capillary wedge pressure increased from 14 +/- 3 to 23 +/ 3 mmHg and pulmonary shunt fraction increased 15%, but arterial PO2 did not fall. Except for the increase in pulmonary capillary wedge pressure, none of the cardiovascular changes lasted longer than 60 min. Plasma sodium levels increased from 138 +/- 25 to 163 +/- 38 mmol/L and normalized within 24 h. In these hyperdynamic septic patients, hypertonic saline infusion produced a transient increase in circulation, but no evidence of a substantial increase in O2 consumption. Either there was no significant O2 debt due to the already elevated O2 delivery levels at baseline (700 mL/min/m2) or the global O2 measurements we used were not able to detect discrete regional hypoxia.
Assuntos
Solução Salina Hipertônica/administração & dosagem , Choque Séptico/terapia , Adulto , Idoso , Idoso de 80 Anos ou mais , Gasometria , Feminino , Hemodinâmica/efeitos dos fármacos , Humanos , Infusões Intravenosas , Lactatos/sangue , Ácido Láctico , Masculino , Pessoa de Meia-Idade , Consumo de Oxigênio , Estudos Prospectivos , Choque Séptico/metabolismo , Choque Séptico/fisiopatologia , Sódio/sangueRESUMO
OBJECTIVES: To test whether dopamine infusion improves oxygen delivery (Do2) and oxygen uptake (VO2) in hyperdynamic septic shock patients stabilized by adequate volume and dobutamine alone, or by the combination of dobutamine and norepinephrine. DESIGN: Prospective clinical trial of two patient groups. Group 1 (n = 15) was stabilized with dobutamine, and group 2 (n = 10) was stabilized with dobutamine and norepinephrine. SETTING: Intensive care unit in a university hospital. PATIENTS: Twenty-five postoperative, hyperdynamic septic shock patients. INTERVENTIONS: The stabilizing catecholamine infusion was replaced in a stepwise manner by dopamine to achieve a similar mean arterial pressure (dopamine doses: group 1, mean 22 +/- 15 micrograms/kg/min [range 6 to 52]; and group 2, mean 57 +/- 41 micrograms/kg/min [range 15 to 130]). MEASUREMENTS AND MAIN RESULTS: A complete hemodynamic profile was performed with oxygen transport-related variables at baseline, after replacement by dopamine, and after resetting to the original catecholamine infusion. The change to dopamine resulted in increases in cardiac index (group 1: 20% [p < .01]; group 2: 33% [p < .01]), and DO2 (group 1: 19% [p < .01]; group 2: 27% [p < .01]). However, VO2, whether directly measured from the respiratory gases or calculated by the cardiovascular Fick principle, did not change in both groups with dopamine, while the oxygen extraction ratio decreased significantly in both groups with dopamine. Heart rate, pulmonary artery occlusion pressure, and pulmonary shunt fraction all increased with dopamine. PaO2 decreased, but oxygen saturation remained stable in both groups with dopamine. CONCLUSIONS: Short-term dopamine infusion in hyperdynamic septic shock patients, despite producing higher global DO2, was not superior to dobutamine or the combination of dobutamine and norepinephrine infusion.
Assuntos
Cardiotônicos/administração & dosagem , Dobutamina/administração & dosagem , Dopamina/uso terapêutico , Norepinefrina/administração & dosagem , Consumo de Oxigênio/efeitos dos fármacos , Choque Séptico/tratamento farmacológico , Adulto , Idoso , Idoso de 80 Anos ou mais , Pressão Sanguínea/efeitos dos fármacos , Quimioterapia Combinada , Feminino , Hemodinâmica/efeitos dos fármacos , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Choque Séptico/fisiopatologiaRESUMO
Hyperoxic ventilation, used to prevent hypoxemia during potential periods of hypoventilation, has been reported to paradoxically decrease whole body oxygen consumption (VO2). Reduction in nutritive blood flow due to oxygen radical production is one possible mechanism. We investigated whether pretreatment with the sulfhydryl group donor and O2 radical scavenger N-acetylcysteine (NAC) would preserve whole body VO2 and prevent deterioration of oxygenation in gastric mucosal tissue during hyperoxia. Thirty-eight patients, requiring hemodynamic monitoring (radial and pulmonary artery catheters) due to sepsis syndrome, were included in this randomized experiment. All patients exhibited stable clinical conditions (hemodynamics, body temperature, hemoglobin, FIO2 < 0.5). A gastric tonometer was placed to measure the gastric intramucosal pH (pHi), which indirectly assesses nutritive blood flow to the mucosa. Cardiac output was determined by thermodilution and VO2 by cardiovascular Fick. After baseline measurements, patients randomly received either 150 mg.kg-1 NAC (n = 19) or placebo (n = 19) in 250 ml 5% dextrose intravenously over a period of 15 min. Measurements were repeated 30 min after starting NAC or placebo infusion, 30 min after starting hyperoxia (FIO2 = 1.0), and 60 min after resetting the original FIO2. There were no significant differences between groups in any of the measurements before treatment and after the return to baseline FIO2 at the end of the study. NAC, but not placebo infusion, caused a slight but significant increase in cardiac output and decrease in systemic vascular resistance.(ABSTRACT TRUNCATED AT 250 WORDS)