RESUMO
The effects of reactive oxygen species (ROS) on myocardial antioxidants and on the activity of oxidative mitochondrial enzymes were investigated in the following groups of isolated, perfused rat hearts. I: After stabilization the hearts freeze clamped in liquid nitrogen (n = 7). II: Hearts frozen after stabilization and perfusion for 10 min with xanthine oxidase (XO) (25 U/l) and hypoxanthine (HX) (1 mM) as a ROS-producing system (n = 7). III: Like group II, but recovered for 30 min after perfusion with XO + HX (n = 9). IV: The hearts were perfused and freeze-clamped as in group III, but without XO + HX (n = 7). XO + HX reduced left ventricular developed pressure and coronary flow to approximately 50% of the baseline value. Myocardial content of hydrogen peroxide (H2O2) and malondialdehyde (MDA) increased at the end of XO + HX perfusion, indicating that generation of ROS and lipid peroxidation occurred. Levels of H2O2 and MDA normalized during recovery. Superoxide dismutase, reduced glutathione and alpha-tocopherol were all reduced after ROS-induced injury. ROS did not significantly influence the tissue content of coenzyme Q10 (neither total, oxidized, nor reduced), cytochrome c oxidase, and succinate cytochrome c reductase. The present findings indicate that the reduced contractile function was not correlated to reduced activity of the mitochondrial electron transport chain. ROS depleted the myocardium of antioxidants, leaving the heart more sensitive to the action of oxidative injury.
Assuntos
Antioxidantes/metabolismo , Hipoxantina/metabolismo , Miocárdio/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Xantina Oxidase/metabolismo , Animais , Circulação Coronária/fisiologia , Transporte de Elétrons , Glutationa/metabolismo , Técnicas In Vitro , Masculino , Mitocôndrias Cardíacas/metabolismo , Contração Miocárdica/fisiologia , Perfusão , Ratos , Ratos Wistar , Estatísticas não Paramétricas , Pressão Ventricular/fisiologiaRESUMO
STUDY OBJECTIVES: The aim of the study was to identify risk factors for early onset pneumonia (EOP) in trauma patients, in order to seek possible intervention strategies. STUDY POPULATION: Participants included 124 consecutive trauma patients admitted to a general intensive care unit (ICU) of a university hospital from December 1990 to February 1992 inclusive. DATA COLLECTION: The following data were prospectively collected for each patient: demographics, severity of trauma according to the abbreviated injury scale (AIS), severity of coma according to the Glasgow coma scale (GCS), presence of pneumothorax, pulmonary contusion, rib fractures, hemothorax, and mechanical ventilation. All patients were monitored daily during the ICU stay for the onset of pneumonia, sepsis syndrome, septic shock, and adult respiratory distress syndrome (ARDS). Criteria for the diagnosis of pneumonia were: core temperature of greater than 38.3 degrees C, a WBC count of 10,000 cells/mm3, purulent tracheobronchial secretions, a worsening of pulmonary gas exchange, and persistent pulmonary infiltrates. All patients with suspected pneumonia underwent quantitative bronchoalveolar lavage (BAL) as well as blood cultures; BAL cultures were considered positive when they showed bacterial growth greater than 1 x 10(5) colony-forming unit (cfu)/ml, or less than 10(5), but with the same microorganism isolated in blood cultures. Pneumonia occurring within the first 96 h after trauma was considered EOP. DATA ANALYSIS: A stepwise logistic regression analysis was carried out in order to identify factors independently associated with an increased risk of EOP and late onset pneumonia (LOP). RESULTS: Overall mortality was 43.5 percent: mortality increased by age and AIS score. Forty one patients (33.1 percent) developed pneumonia: 26 (63.4 percent) were EOP and 15 (36.6 percent) were LOP. In the univariate analysis, an age greater than 40 years, the presence of pulmonary contusion, AIS of more than 4 for thorax and of more than 9 for abdomen, and the absence of mechanical ventilation (MV) during the first 4 days of hospitalization or MV lasting less than 24 h were significantly associated with an increased risk of acquiring EOP. Logistic regression analysis showed that the strongest risk factor for EOP was a combined severe abdominal and thoracic trauma, which increased the risk of EOP by 11 times; an age of more than 40 years and MV of less than 24 h during the first 4 days of hospitalization were also independent risk factors for EOP. Factors associated with LOP were an AIS score of more than 4 for abdomen and a length of MV of more than 5 days. CONCLUSION: In a trauma population, a combined severe abdominal and thoracic trauma represents a major risk factor for EOP. Mechanical ventilation administered during the first days after trauma seems to reduce the risk of EOP. As reported in previous studies, mechanical ventilatory support lasting more than 5 days is associated with an increased risk of LOP.
Assuntos
Traumatismo Múltiplo/complicações , Pneumonia/etiologia , Escala Resumida de Ferimentos , Traumatismos Abdominais/complicações , Adulto , Idoso , Infecções Bacterianas/diagnóstico , Líquido da Lavagem Broncoalveolar/química , Líquido da Lavagem Broncoalveolar/microbiologia , Contagem de Colônia Microbiana , Contusões/complicações , Cuidados Críticos , Feminino , Escala de Coma de Glasgow , Humanos , Lesão Pulmonar , Masculino , Pessoa de Meia-Idade , Pneumonia/diagnóstico , Pneumonia/microbiologia , Estudos Prospectivos , Respiração Artificial , Síndrome do Desconforto Respiratório/etiologia , Fatores de Risco , Taxa de Sobrevida , Traumatismos Torácicos/complicaçõesRESUMO
OBJECTIVE: Retrograde pneumoplegia seems to improve early graft function in experimental and clinical lung transplantation. We evaluated the role of retrograde flushing in addition to antegrade pneumoplegia in clinical lung transplantation. METHODS: Fourteen patients undergoing lung transplantation were randomized into 2 groups: in group I we performed antegrade pulmonary artery flushing with alprostadil (prostaglandin E1) and modified Euro-Collins solution at the time of retrieval. In group II additional retrograde flushing through the pulmonary veins was performed at the back table, before reimplantation. Hemodynamic variables, mean airway pressure, and blood gas analysis were monitored at different time points. Postoperative volumetric monitoring was performed to assess extravascular lung water. The reimplantation response was assessed by a radiographic score; extubation time and intensive care unit stay were recorded. RESULTS: During retrograde flushing, blood and clots coming out from the pulmonary artery were observed; 2 lungs harvested from a donor with multiple bone fractures had fat emboli in the retrograde perfusate. Hemodynamic monitoring did not demonstrate any difference between the 2 groups. The ratio of arterial oxygen tension to inspired oxygen fraction, extravascular lung water, duration of intubation, and length of stay in the intensive care unit were improved in group II, but the differences did not reach statistical significance. Intrapulmonary shunt fraction was significantly improved in group II at each time point ( P =.02), as well as indexed alveolar-arterial oxygen tension gradient (P =.04), mean airway pressure (P =.04), and chest x-ray score ( P =.03). CONCLUSIONS: Preimplantation retrograde flushing is not detrimental and helps to improve early graft function.
Assuntos
Alprostadil/administração & dosagem , Soluções Hipertônicas/administração & dosagem , Transplante de Pulmão/métodos , Artéria Pulmonar , Veias Pulmonares , Irrigação Terapêutica/métodos , Vasodilatadores/administração & dosagem , Adulto , Resistência das Vias Respiratórias , Gasometria , Água Extravascular Pulmonar , Hemodinâmica , Humanos , Tempo de Internação/estatística & dados numéricos , Transplante de Pulmão/efeitos adversos , Circulação Pulmonar , Reimplante/métodos , Índice de Gravidade de Doença , Resultado do TratamentoRESUMO
We report a case of hyperinflation induced isorythmic atrio-ventricular dissociation with circulatory failure in a patient with chronic obstructive pulmonary disease. The arrythmia was successfully treated by applying "pressure support ventilation" (PSV: 20 cmH2O) which, by decreasing the respiratory rate and increasing the expiratory time reduced the level of auto-PEEP. In order to explain this result the Authors recorded, in the same patient, the level of auto-PEEP and delta FRC obtained with Intermittent Positive Pressure Ventilation (IPPV), Intermittent Mandatory Ventilation (IMV) and PSV at the same gas exchange values. PSV showed a dramatic reduction of both these parameters. (Auto-PEEP: IPPV 12 cmH2O, IMV 17 cmH2O, PSV 7 cmH2O).
Assuntos
Arritmias Cardíacas/etiologia , Respiração com Pressão Positiva , Respiração Artificial/efeitos adversos , Idoso , Arritmias Cardíacas/terapia , Humanos , Pneumopatias Obstrutivas/complicações , Masculino , Insuficiência Respiratória/etiologia , Insuficiência Respiratória/terapiaRESUMO
OBJECTIVE: To investigate the role played by the endotracheal tube (ETT) in the correct evaluation of respiratory system mechanics with the end inflation occlusion method during constant flow controlled mechanical ventilation. SETTING: General ICU, university of Rome "La Sapienza". PATIENTS: 12 consecutive patients undergoing controlled mechanical ventilation. METHODS: We compared the values of minimal resistance of the respiratory system (i.e. airway resistance) (RRS min) obtained: i) subtracting the theoretical value of ETT resistance from the difference between P max and P1, measured on airway pressure tracings obtained from the distal end of the ETT; ii) directly measuring airway pressure 2 cm below the ETT, thus automatically excluding ETT resistance from the data. RESULTS. The values of RRS min obtained by measuring airway pressure below the ETT were significantly lower than those obtained by measuring airway pressure at the distal end of the ETT and subtracting the theoretical ETT resistance (4.5 +/- 2.8 versus 2.5 +/- 1.6 cm H2O/l/s, p < 0.01). CONCLUSION: When precise measurements of ohmic resistances are required in mechanically ventilated patients, the measurements must be obtained from airways pressure data obtained at tracheal level. The "in vivo" positioning of ETT significantly increases the airflow resistance of the ETT.
Assuntos
Resistência das Vias Respiratórias , Intubação Intratraqueal/instrumentação , Respiração Artificial , Insuficiência Respiratória/fisiopatologia , Insuficiência Respiratória/terapia , Doença Aguda , Adulto , Idoso , Viés , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Monitorização Fisiológica/métodosRESUMO
OBJECTIVE: To evaluate the efficiency of a new device developed to remove obstructions from endotracheal tubes (ETT) in mechanically ventilated patients. DESIGN: Open study in mechanically ventilated sedated and paralyzed ICU patients. SETTING: General ICU and Laboratory of Respiratory Mechanics of the University of Rome "La Sapienza". PATIENTS: 8 consecutive unselected mechanically ventilated, critically ill patients in which a partial obstruction of ETT was suspected on the basis of an increase of the peak inspiratory pressure (> 20%) plus the difficult introduction of a standard suction catheter. INTERVENTIONS: Obstructions to ETT were removed with an experimental "obstruction remover" (OR) MEASUREMENTS: "In vivo" ETT airflow resistance (0.25; 0.5; 0.75; 11/s) was evaluated before and after use of the OR; the work of breathing necessary to overcome ETT resistance (WOBett) was also evaluated before and after OR use. RESULTS: The use of OR significantly reduced in all patients the ETT "in vivo" resistance (From 5.5 +/- 2.3 to 2.9 +/- 0.5 cmH2O/l/s at 0.25 l/s, p < 0.05; from 9 +/- 2.4 to 3.8 +/- 0.8 cmH2O/l/s at 0.5 l/s; from 12.2 +/- 3.5 to 5.7 +/- 1.2 cmH2O/l/s at 0.75 l/s; from 16.9 +/- 6 to 9.3 +/- 3.8 cmH2O/l/s at 1 l/s, p < 0.01 respectively). Also the WOBett was significantly reduced after use of the OR (from 0.66 +/- 0.19 to 0.34 +/- 0.08 J/l; p < 0.05). CONCLUSION: this experimental device can be safely and successfully used to remove obstructions from the ETT lumen, without suspending mechanical ventilation, reducing the need for rapid ETT substitution in emergency and life-threatening situations.
Assuntos
Obstrução das Vias Respiratórias/terapia , Broncoscópios , Intubação Intratraqueal , Respiração Artificial , Adulto , Idoso , Obstrução das Vias Respiratórias/diagnóstico , Resistência das Vias Respiratórias , Feminino , Humanos , Intubação Intratraqueal/efeitos adversos , Masculino , Pessoa de Meia-Idade , Instrumentos Cirúrgicos , Trabalho RespiratórioRESUMO
OBJECTIVE: The present study was intended to evaluate the "in vivo" endotracheal (ET) tube resistance and respiratory mechanics in mechanically ventilated patients with respiratory failure by using fiber optic catheters. DESIGN: Two fiber optic catheters, consisting of a thin probe with a pressure transducer on the tip, were used. The first was placed at the proximal side of the ET tube and the second was positioned distally beyond the end. A low compliant air-filled catheter connected to a traditional pressure transducer was placed close to the proximal fiber optic device to compare the pressure values obtained with both systems. SETTING: The study was performed in the General Intensive Care Unit of Rome "La Sapienza", University Hospital. PATIENTS AND PARTICIPANTS: Seven patients admitted for the management of acute respiratory failure of different etiologies were included in the protocol. All the patients were intubated and mechanically ventilated for at least 48 h prior to the investigation. MEASUREMENTS AND RESULTS: The endotracheal tube resistance was obtained both by the end-inspiratory occlusion method and measuring pressure proximally and distally to the ET tube. The measurement of respiratory mechanics was obtained proximally and distally to the ET tube. Different flows and tidal volume changes were performed. The results showed that the fiber optic device gives an adequate evaluation of airway pressure and the possibility for an easy detection of obstructions and/or deformations of the ET tube. The area described by inspiratory and expiratory pressure recorded at both sides of the ET tube showed a positive relationship between the surface and flows while no surface changes were shown when the tidal volumes were modified. Thoraco-pulmonary compliance measured proximally and distally to the ET tube gave rise to a small and statistically insignificant difference. CONCLUSION: This study confirms that 48 h after the positioning of ET tubes the airflow resistance is significantly higher than might be expected from the "in vitro" data. The presence of the endotracheal tube can interfere with the evaluation of thoraco-pulmonary mechanics, particularly in dynamic conditions. The fiber optic system represents an interesting and simple tool for the evaluation of ET tube resistance and pulmonary mechanics in patients undergoing mechanical ventilation.
Assuntos
Resistência das Vias Respiratórias , Tecnologia de Fibra Óptica/normas , Manometria/normas , Respiração Artificial/normas , Insuficiência Respiratória/fisiopatologia , Adulto , Idoso , Análise de Variância , Estudos de Avaliação como Assunto , Feminino , Tecnologia de Fibra Óptica/instrumentação , Tecnologia de Fibra Óptica/métodos , Humanos , Unidades de Terapia Intensiva , Análise dos Mínimos Quadrados , Modelos Lineares , Complacência Pulmonar , Masculino , Manometria/instrumentação , Manometria/métodos , Pessoa de Meia-Idade , Fibras Ópticas , Respiração Artificial/efeitos adversos , Insuficiência Respiratória/terapia , Mecânica Respiratória , ReologiaRESUMO
In some instances of unilateral acute lung injury (ALI) refractory to conventional ventilatory support, the intact lung is still able to ensure an efficient CO2 washout, the concomitant hypoxaemia being due to the loss of volume of the injured parenchyma. In these cases, the administration of a sufficient selective continuous distending pressure by means of differential continuous positive airway pressure may restore to normal the resting volume and thus the ventilatory performance of the affected lung, contemporarily avoiding the occurrence of pulmonary and systemic barotrauma.
Assuntos
Lesão Pulmonar , Respiração com Pressão Positiva/instrumentação , Ferimentos Penetrantes/terapia , Adulto , Humanos , Hipóxia/prevenção & controle , Pulmão/fisiopatologia , Masculino , Pessoa de Meia-Idade , Troca Gasosa Pulmonar , Ferimentos Penetrantes/fisiopatologiaRESUMO
OBJECTIVE: The aim of this study was to identify risk factors and to describe epidemiological patterns for early-(EOB) and late-onset bacteremias (LOB) after trauma. DESIGN: A prospective study conducted on 141 consecutive trauma patients. SETTING: A general intensive care unit (ICU) of a university hospital. PATIENTS: All multiple trauma patients admitted to our general intensive care unit (ICU) from December 1990 to May 1992 were prospectively enrolled in the study. The following information was collected for each patient and recorded in a computer database: demography, severity of trauma according to the Abbreviated Injury Scale (AIS), severity of coma according to the Glasgow Coma Scale (GCS), presence of pneumothorax, pulmonary contusion, rib fractures, hemothorax, and abdominal trauma, use of mechanical ventilation, and placement of central venous catheters. Bacteremias were defined as EOB when onset occurred within 96 h after trauma, and as LOB when appearing after 96 h from trauma. RESULTS: Thirty-seven patients developed bacteremia during their ICU stay (26%): 11 (29.7%) EOB and 26 (70.3%) LOB. Gram-positive cocci were isolated more frequently in EOB than in LOB (chi 2 = 4.1, P = 0.04). The risk of EOB was significantly increased by the presence of pulmonary contusion [relative risk (RR) 15.0; confidence interval (CI) 1.99-113.25], pneumonia before the onset of bacteremia (RR 3.56; CI 1.17-10.69), AIS score greater than 32 and an abdominal injury score greater than 9 (RR 3.11; CI 1.02-9.49), while intravascular catheters and mechanical ventilation did not represent risk factors for EOB. LOB had a very different pattern and their risk was significantly increased by exposure to intravascular catheters (RR 4.96; CI 1.23-19.94) and to mechanical ventilation lasting more than 7 days (RR 3.6; CI 1.6-8.1). CONCLUSIONS: Scoring with the AIS of the abdominal and thoracic trauma at admission to the ICU appears a useful tool for identifying trauma patients at increased risk of EOB. A rigorous policy of catheter placement and maintenance as a means of reducing late bacteremias in trauma patients is essential.
Assuntos
Bacteriemia/etiologia , Traumatismo Múltiplo/complicações , Traumatismos Abdominais/classificação , Traumatismos Abdominais/complicações , Adulto , Cateterismo/efeitos adversos , Distribuição de Qui-Quadrado , Feminino , Escala de Coma de Glasgow , Humanos , Unidades de Terapia Intensiva , Masculino , Traumatismo Múltiplo/classificação , Pneumonia/complicações , Estudos Prospectivos , Fatores de Risco , Índice de Gravidade de Doença , Traumatismos Torácicos/classificação , Traumatismos Torácicos/complicações , Fatores de TempoRESUMO
OBJECTIVE: To evaluate respiratory mechanics in the early phase of decompensation in a group of seven patients with severe kyphoscoliosis (KS) (Cobb angle > 90 degrees) requiring mechanical ventilatory support. DESIGN: Prospective clinical study with a control group. SETTING: General intensive care unit at University of Rome "La Sapienza". PATIENTS: Seven consecutive patients affected by severe KS in the early phase of acute decompensation and a control group of six ASA (American Society of Anesthesiology) 1 subjects who were mechanically ventilated during minor surgery. MEASUREMENTS AND RESULTS: Respiratory mechanics were evaluated during constant flow-controlled mechanical ventilation at zero end-expiratory pressure with the end-inspiratory and end-expiratory occlusion technique. In five patients who showed increased ohmic resistance (RRSmin), we evaluated the possibility of reversing this increase with a charge dose of 6 mg/kg doxophylline i.v. In four KS patients, in whom a reliable esophageal pressure was confirmed by a positive occlusion test, we separated respiratory system data into lung and chest wall component. All KS patients showed reduced values of respiratory compliance (CRS) and increased respiratory resistance (RRS). The average basal values of CRS were 36 +/- 10 vs 58 +/- 8.5 cmH2O in control patients; RRSmax was 20 +/- 3.1 vs. 4.5 +/- 1.2 cmH2O/1 per s; RRSmin 6.2 +/- 1.2 vs. 2 +/- 0.5 cmH2O/1 per s: delta RRS 14 +/- 2.6 cmH2O vs 2.4 +/- 0.7 cmH2O/1 per s. All KS patients showed low values of intrinsic positive end-expiratory pressure (PEEPi) (1.8 +/- 1.5 cmH2O). Separation of lung and chest-wall mechanics, performed only in four patients, showed a reduction in both lung (66.7 +/- 7.2 ml/cmH2O) and chest wall values (84 +/- 8.2 ml/cmH2O), while both RmaxL and RmaxCW were increased (16.6 +/- 2 and 2.8 +/- 0.4 cmH2O/1 per s, respectively). Infusion of doxophylline did not significantly change respiratory mechanics when evaluated 15, 30, and 45 min after the infusion. CONCLUSIONS: During acute decompensation, both lung and chest-wall compliance are severely reduced in KS patients: conversely, and, contrary to that in patients with chronic obstructive pulmonary disease, increases in airway resistance and PEEPi seem to play only a secondary role.
Assuntos
Cifose/complicações , Respiração com Pressão Positiva , Insuficiência Respiratória/etiologia , Insuficiência Respiratória/fisiopatologia , Mecânica Respiratória/fisiologia , Escoliose/complicações , Resistência das Vias Respiratórias/fisiologia , Análise de Variância , Estudos de Casos e Controles , Progressão da Doença , Feminino , Humanos , Complacência Pulmonar/fisiologia , Masculino , Pessoa de Meia-Idade , Respiração por Pressão Positiva Intrínseca/fisiopatologia , Estudos ProspectivosRESUMO
OBJECTIVE: We conducted a randomized prospective study comparing noninvasive positive pressure ventilation (NPPV) with conventional mechanical ventilation via endotracheal intubation (ETI) in a group of patients with chronic obstructive pulmonary disease who failed standard medical treatment in the emergency ward after initial improvement and met predetermined criteria for ventilatory support. DESIGN AND SETTING: Prospective randomized study in a university hospital 13-bed general ICU. PATIENTS: Forty-nine patients were randomly assigned to receive NPPV (n=23) or conventional ventilation (n=26). RESULTS: both NPPV and conventional ventilation significantly improved gas exchanges. The two groups had similar length of ICU stay, number of days on mechanical ventilation, overall complications, ICU mortality, and hospital mortality. In the NPPV group 11 (48%) patients avoided intubation, survived, and had a shorter duration of ICU stay than intubated patients. One year following hospital discharge the NPPV group had fewer patients readmitted to the hospital (65% vs. 100%) or requiring de novo permanent oxygen supplementation (0% vs. 36%). CONCLUSIONS: The use of NPPV in patients with chronic obstructive pulmonary disease and acute respiratory failure requiring ventilatory support after failure of medical treatment avoided ETI in 48% of the patients, had the same ICU mortality as conventional treatment and, at 1-year follow-up was associated with fewer patients readmitted to the hospital or requiring for long-term oxygen supplementation. An editorial regarding this article can be found in the same issue (http://dx.doi.org/10.1007/s00134-002-1503-3).
Assuntos
Respiração com Pressão Positiva , Doença Pulmonar Obstrutiva Crônica/terapia , Respiração Artificial/métodos , Insuficiência Respiratória/terapia , Idoso , Distribuição de Qui-Quadrado , Feminino , Seguimentos , Humanos , Intubação Intratraqueal , Masculino , Estudos Prospectivos , Doença Pulmonar Obstrutiva Crônica/mortalidade , Insuficiência Respiratória/mortalidade , Resultado do TratamentoRESUMO
We investigated the levels of auto-PEEP and dynamic hyperinflation during high frequency jet ventilation (HFJV) and controlled mechanical ventilation (CMV) in six patients with chronic obstructive pulmonary disease within the first 36 h of acute exacerbation. The comparative evaluation was performed at similar conditions of gas exchange in HFJV and CMV: PaO2 77.6 +/- 11 mmHg vs 80.8 +/- 12 mmHg; PaCO2 46.8 +/- 2.5 mmHg vs 47 +/- 2.8 mmHg; pH 7.38 vs 7.38. In this situation, the values of auto-PEEP and dynamic hyperinflation, expressed as delta over the apneic functional residual capacity (FRC) did not differ: (auto-PEEPHFJV 8.9 +/- 3.8 cmH2O; auto-PEEPCMV 8.8 +/- 4.7 cmH2O; delta FRCHFJV 0.56 +/- 0.19 l; delta FRCCMV 0.54 +/- 0.2 l). This result suggests that, with a suitable machine setting and similar gas exchanges, HFJV produces the same level of auto-PEEP and dynamic hyperinflation as CMV in patients with chronic obstructive pulmonary disease.
Assuntos
Ventilação em Jatos de Alta Frequência/métodos , Pneumopatias Obstrutivas/terapia , Respiração com Pressão Positiva , Idoso , Resistência das Vias Respiratórias , Volume de Reserva Expiratória , Feminino , Capacidade Residual Funcional , Ventilação em Jatos de Alta Frequência/instrumentação , Humanos , Complacência Pulmonar , Pneumopatias Obstrutivas/patologia , Pneumopatias Obstrutivas/fisiopatologia , Masculino , Pessoa de Meia-Idade , Monitorização FisiológicaRESUMO
Six patients with acute myocardial infarction (AMI) complicated by cardiogenic shock were studied in order to compare the haemodynamic tolerance of controlled mechanical ventilation (CMV) and high frequency jet ventilation (HFJV). The comparative analysis of the two techniques was performed with the same levels of PaO2 (CMV: 101 +/- 13 mmHg; HFJV: 104.2 +/- 14 p = ns); and PaCO2 (CMV: 37 +/- 1.7; HFJV: 35.7 +/- 1.4 p = ns). In this situation the values of mean airway pressure (Paw) did not differ significantly (CMV: 13 +/- 3 cm H2O; HFJV: 12.6 +/- 3.8 cm H2O) and no statistically significant difference in haemodynamic values was observed. These results demonstrate that in patients with cardiogenic shock, there is no difference between HFJV and CMV in terms of haemodynamic tolerance. Because of the more difficult clinical management of HFJV, this technique does not seem indicated as ventilatory support in patients with cardiogenic shock states.
Assuntos
Hemodinâmica , Ventilação em Jatos de Alta Frequência , Respiração Artificial , Choque Cardiogênico/terapia , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Infarto do Miocárdio/complicações , Infarto do Miocárdio/fisiopatologia , Infarto do Miocárdio/terapia , Choque Cardiogênico/etiologia , Choque Cardiogênico/fisiopatologiaRESUMO
In recent years the use of devices called Heat and Moisture Exchangers (HME) has become widespread as gas conditioners for ICU patients requiring mechanical ventilation. As an important variation of the resistive properties of the HME, related to flow and duration of use, has recently been pointed out during "in vitro" studies, the use of these devices in COPD patients could increase the levels of auto PEEP and dynamic hyperinflation. In this study we have compared the levels of auto PEEP and difference in functional residual capacity (delta FRC) in a group of COPD patients, requiring controlled mechanical ventilation (CMV), at basal conditions and after the insertion into the circuit of three HMEs (Dar Hygrobac, Pall Ultipor, Engstrom Edith) at random: the results obtained excluded a significant increase of auto PEEP and delta (FRC) both with "new" HMEs and after 12 h of continuous use.
Assuntos
Temperatura Alta , Umidade , Pneumopatias Obstrutivas/fisiopatologia , Pulmão/fisiopatologia , Respiração com Pressão Positiva/instrumentação , Idoso , Feminino , Capacidade Residual Funcional , Hemodinâmica , Humanos , Complacência Pulmonar , Pneumopatias Obstrutivas/terapia , Masculino , Pessoa de Meia-Idade , OximetriaRESUMO
Patients with unilateral acute lung injury (UALI; n = 6) and ARDS (n = 4) were evaluated by bronchoalveolar lavage, as controls we used 5 patients suffering from cerebral hemorrhage and without pulmonary, cardiac or infectious disease who were mechanically ventilated. For each group of patients two independent bronchoalveolar lavages (BAL) were performed. The BAL fluid recovered from the two lungs was immediately analyzed for leukotrienes (LTS) by means of RP-HPLC and stained for cell counts. The BAL from the control group did not show any LTS and the percentage of neutrophils was within the normal range: 1 +/- 0.2% right lung and 1.2 +/- 0.4% left lung. The BAL fluid from UALI patients showed two different patterns, the injured lung showed high levels of LTS (39.1 +/- 8 ng ml-1 LTB4; 25 +/- 6 ng ml-1 LTD4 and 27.8 +/- 8.2 ng ml-1 11-trans LTC4) and an increased percentage of neutrophils (74.2 +/- 7%) compared to controls. Only 2 out of the 6 patients from the UALI group showed small amounts of LTB4 (4 ng ml-1) and LTD4 (3.2 ng ml-1). The BAL obtained from the "healthy lung" in both cases showed values of LTS almost eight fold lower than those present in the injured lung. The percentage of neutrophils from the unaffected lungs (4.3 +/- 7%) was not significantly different from controls. Lavage fluid from ARDS patients showed a similar picture to that of the affected lung from UALI patients.(ABSTRACT TRUNCATED AT 250 WORDS)
Assuntos
Líquido da Lavagem Broncoalveolar/análise , Leucotrienos/análise , Pneumopatias/fisiopatologia , Síndrome do Desconforto Respiratório/fisiopatologia , Adulto , Líquido da Lavagem Broncoalveolar/citologia , Humanos , Leucotrienos/fisiologia , Pneumopatias/etiologia , Pessoa de Meia-Idade , Neutrófilos/análise , Neutrófilos/fisiologia , Síndrome do Desconforto Respiratório/etiologiaRESUMO
Seven patients with the adult respiratory distress syndrome (ARDS) were studied. As a control group we used 6 surgical patients who underwent minor surgical operation (inguinal hernia). For both groups the same sample collection and analysis was used. The presence of leuktorienes (LTs) B4 and C4 and of their isomers 11-trans LTC4 and delta 6-trans-12-epi LTB4 was determined in arterial, mixed venous blood and in bronchoalveolar lavage (BAL) fluid. The samples, analysed by reverse phase high performance liquid chromatography (RP-HPLC), showed a similar chromatographic picture among ARDS patients, while the control group showed no detectable amounts of LTs in BAL or blood. The distribution of these arachidonic acid metabolites in mixed venous blood, arterial blood and BAL seems to suggest pulmonary metabolism and/or inactivation. It is suggested that these mediators act as humoral factors in pathogenesis of the ARDS.
Assuntos
Líquido da Lavagem Broncoalveolar/análise , Leucotrieno B4/sangue , Síndrome do Desconforto Respiratório/diagnóstico , SRS-A/sangue , Adulto , Feminino , Humanos , Leucotrieno B4/análise , Leucotrieno B4/metabolismo , Masculino , Pessoa de Meia-Idade , Síndrome do Desconforto Respiratório/sangue , Síndrome do Desconforto Respiratório/metabolismo , SRS-A/análise , SRS-A/metabolismoRESUMO
OBJECTIVE: To evaluate non-invasive ventilation (NIV) prospectively in a group of patients developing acute respiratory failure (ARF) after bilateral lung transplantation (BLT). SETTING: General intensive care unit (ICU) of Rome "La Sapienza" University. PATIENTS: Twenty-one patients (18 with cystic fibrosis) undergoing BLT. RESULTS: All consecutive patients developing ARF (according to predefined criteria) and requiring ventilatory support, received non-invasive pressure support ventilation through a face-mask (PEEP 5 cmH2O, PSV 14+/-2 cmH2O) for a mean period of 5+/-4 days. Eighteen out of 21 patients avoided intubation and were discharged from the ICU; 3 patients required intubation: 1 of them survived while 2 developed septic shock and died. CONCLUSIONS: NIV administration was well tolerated and avoided intubation in the large majority of patients (86%); in NIV responders the rate of complications was low and ICU mortality nil. NIV should be considered as an interesting alternative to conventional ventilation in patients who require ventilatory support after BLT.
Assuntos
Transplante de Pulmão/efeitos adversos , Máscaras , Respiração com Pressão Positiva/instrumentação , Respiração com Pressão Positiva/métodos , Insuficiência Respiratória/etiologia , Insuficiência Respiratória/terapia , Doença Aguda , Adulto , Gasometria , Cuidados Críticos/métodos , Fibrose Cística/cirurgia , Mortalidade Hospitalar , Humanos , Intubação Intratraqueal , Transplante de Pulmão/métodos , Pessoa de Meia-Idade , Seleção de Pacientes , Respiração com Pressão Positiva/efeitos adversos , Estudos Prospectivos , Doença Pulmonar Obstrutiva Crônica/cirurgia , Troca Gasosa Pulmonar , Insuficiência Respiratória/diagnóstico , Insuficiência Respiratória/metabolismo , Insuficiência Respiratória/mortalidade , Índice de Gravidade de Doença , Fatores de Tempo , Resultado do Tratamento , Deficiência de alfa 1-Antitripsina/cirurgiaRESUMO
OBJECTIVE: To evaluate the separate effects of sedation and paralysis on chest wall and respiratory system mechanics of mechanically ventilated, critically ill patients. SETTING: ICU of the University "La Sapienza" Hospital, Rome. PATIENTS AND PARTICIPANTS: 13 critically ill patients were enrolled in this study. All were affected by disease involving both lungs and chest wall mechanics (ARDS in 4 patients, closed chest trauma without flail chest in 4 patients, cardiogenic pulmonary oedema with fluidic overload in 5 patients). MEASUREMENTS AND RESULTS: Respiratory system and chest wall mechanics were evaluated during constant flow controlled mechanical ventilation in basal conditions (i.e. with the patients under apnoic sedation) and after paralysis with pancuronium bromide. In details, we simultaneously recorded airflow, tracheal pressure, esophageal pressure and tidal volume; with the end-inspiratory and end-expiratory airway occlusion technique we could evaluate respiratory system and chest wall elastance and resistances. Lung mechanics was evaluated by subtracting chest wall from respiratory system data. All data obtained in basal conditions (with the patients sedated with thiopental or propofol) and after muscle paralysis were compared using the Student's t test for paired data. The administration of pancuronium bromide to sedated patients induced a complete muscle paralysis without producing significant modification both to the viscoelastic and to the resistive parameters of chest wall and respiratory system. CONCLUSIONS: This study demonstrates the lack of additive effects of muscle paralysis in mechanically ventilated, sedated patients. Also in view of the possible side effects of muscle paralysis, our results question the usefulness of generalized administration of neuromuscular blocking drugs in mechanically ventilated patients.
Assuntos
Sedação Consciente/métodos , Hipnóticos e Sedativos/farmacologia , Fármacos Neuromusculares não Despolarizantes/uso terapêutico , Pancurônio/uso terapêutico , Propofol/farmacologia , Respiração Artificial , Mecânica Respiratória/efeitos dos fármacos , Tiopental/farmacologia , Adulto , Idoso , Monitoramento de Medicamentos , Quimioterapia Combinada , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Resultado do TratamentoRESUMO
OBJECTIVE: To elucidate the risk factors for the development of acute renal failure (ARF) in severe trauma. DESIGN: Prospective observational study. SETTING: A general intensive care unit (ICU) of a university hospital. PATIENTS: A cohort of 153 consecutive trauma patients admitted to the ICU over a period of 30 months. RESULTS: Forty-eight (31%) patients developed ARF. They were older than the 105 patients without ARF (p = 0.002), had a higher Injury Severity Score (ISS) (p < 0.001), higher mortality (p < 0.001), a more compromised neurological condition (p = 0.007), and their arterial pressure at study entry was lower (p = 0.0015). In the univariate analysis, the risk of ARF increased by age, ISS > 17, the presence of hemoperitoneum, shock, hypotension, or bone fractures, rhabdomyolysis with creatine phosphokinase (CPK) > 10000 IU/l, presence of acute lung injury requiring mechanical ventilation, and Glasgow Coma Score < 10. Sepsis and use of nephrotoxic agents were not associated with an increased risk of ARF. In the logistic model, the need for mechanical ventilation with a positive end-expiratory pressure > 6 cm H2O, rhabdomyolysis with CPK > 10000 IU/l, and hemoperitoneum were the three conditions most strongly associated with ARF. CONCLUSIONS: The identified risk factors for post-traumatic acute renal failure may help the provision of future strategies.
Assuntos
Injúria Renal Aguda/etiologia , Traumatismo Múltiplo/complicações , Adulto , Fatores Etários , Feminino , Humanos , Unidades de Terapia Intensiva/estatística & dados numéricos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Respiração Artificial , Rabdomiólise/complicações , Fatores de Risco , Choque/complicações , Estatística como Assunto , Índices de Gravidade do TraumaRESUMO
Carnitine was administered to a group of patients in shock, and the activities of cytochrome oxidase and succinate cytochrome c reductase in muscle needle biopsies from these patients were compared to those activities present in a non-carnitine treated control group of patients. Carnitine seemingly exerted a significant protective action on cytochrome oxidase activity during the initial phases of shock, but not to such an extent on succinate cytochrome c reductase activities.