RESUMO
OBJECTIVES: Despite protocols incorporating spontaneous breathing trials, 31% of ICU patients experience difficult or prolonged weaning from mechanical ventilation. Nonfatiguing modes such as pressure support ventilation are recommended. Proportional assist ventilation provides assistance in proportion to patient effort, which may optimize weaning. However, it is not known how proportional assist ventilation performs relative to pressure support ventilation over a prolonged period in the complex ICU setting. The purpose of this study was to compare the physiologic and clinical performance (failure rate), safety, and feasibility of protocols using daily spontaneous breathing trial plus pressure support ventilation versus proportional assist ventilation until ventilation discontinuation. DESIGN: Single-center, unblinded pilot randomized controlled trial. SETTING: Medical-surgical ICU of a tertiary-care hospital. PATIENTS: Adult patients intubated greater than 36 hours were randomized if they met eligibility criteria for partial ventilatory support, tolerated pressure support ventilation greater than or equal to 30 minutes, and either failed or did not meet criteria for a spontaneous breathing trial. INTERVENTIONS: Patients were randomized to the pressure support ventilation or proportional assist ventilation protocol (PAV+, Puritan Bennett 840; Covidien, Boulder, CO). Both protocols used progressive decreases in level of assistance as tolerated, coupled with daily assessment for spontaneous breathing trials. MEASUREMENTS AND MAIN RESULTS: Of 54 patients randomized, outcome data are available for 50 patients; 27 were randomized to receive proportional assist ventilation and 23 to receive pressure support ventilation. There were no adverse events linked to the study interventions, and protocol violations were infrequent. Recruitment was slower than projected (1.3 patients per month). The median (interquartile range) time from randomization to successful extubation was 3.9 days (2.8-8.4 d) on proportional assist ventilation versus 4.9 days (2.9-26.3 d) on pressure support ventilation (p = 0.39). Time to live ICU discharge was 7.3 days (5.2-11.4 d) on proportional assist ventilation versus 12.4 days (7.5-30.8 d) on pressure support ventilation (p = 0.03). CONCLUSION: This pilot study demonstrates the utility, safety, and feasibility of the weaning protocols and provides important information to guide the design of a future randomized controlled trial comparing weaning from mechanical ventilation on pressure support ventilation versus proportional assist ventilation.
Assuntos
Suporte Ventilatório Interativo , Respiração com Pressão Positiva Intermitente , Desmame do Respirador/métodos , Idoso , Extubação , Antipsicóticos/administração & dosagem , Feminino , Humanos , Hipnóticos e Sedativos/administração & dosagem , Unidades de Terapia Intensiva , Suporte Ventilatório Interativo/efeitos adversos , Respiração com Pressão Positiva Intermitente/efeitos adversos , Tempo de Internação , Masculino , Pressões Respiratórias Máximas , Pessoa de Meia-Idade , Entorpecentes/administração & dosagem , Projetos Piloto , Estudos Prospectivos , Volume de Ventilação Pulmonar , Fatores de TempoRESUMO
OBJECTIVE: To compare the effect of the use of intermittent and continuous positive airway pressure in postoperative patients undergoing coronary artery bypass grafting. METHODS: This study included forty patients divided into two groups: one undergoing continuous positive airway pressure (CPAP Group), and the other undergoing intermittent pressure (Müller Resuscitator Group). The patients were evaluated in relation to the several study variables at the following time points: preoperative, 3rd, 24th, and 48th hours. RESULTS: The patient groups were homogeneous in relation to the several demographic and clinical variables. The values of pO2, pCO2 and sO2 were within normal limits and no significant differences were found between the groups. Regarding respirometry, the groups showed significant differences in the tidal volume and respiratory rate at the 48th postoperative hour. Dyspnea and use of accessory muscle in postoperative assessments were found with a significantly higher frequency in patients undergoing CPAP. Patients undergoing Müller Resuscitator had a normal chest radiograph more frequently than did patients undergoing CPAP. CONCLUSION: Both devices were shown to be able to keep pO2, pCO2, and sO2 values within normal limits. However, when the objective was pulmonary reexpansion with less imposed workload, the Müller Resuscitator was more effective because of its prompter action and consequently lower levels of dyspnea, respiratory rate (RR) and use of accessory muscle were observed.
Assuntos
Pressão Positiva Contínua nas Vias Aéreas/normas , Ponte de Artéria Coronária , Respiração com Pressão Positiva Intermitente/normas , Desmame do Respirador/normas , Pressão Positiva Contínua nas Vias Aéreas/efeitos adversos , Feminino , Humanos , Concentração de Íons de Hidrogênio , Respiração com Pressão Positiva Intermitente/efeitos adversos , Masculino , Pessoa de Meia-Idade , Período Pós-Operatório , Estudos Prospectivos , Estatísticas não Paramétricas , Volume de Ventilação Pulmonar , Fatores de TempoRESUMO
This analysis of asthma mortality has emphasized the roles played in its pathogenesis by different modes of therapy as reported in the literature. In addition attention was directed towards yet another potentially lethal therapeutic modality, IPPB, the efficacy and potential benefits of which are critically questioned. IPPB treatments were related to every fatal episode of asthma which made up the entire asthma mortality experience during a 12 month period at Morrisania Hospital. The adverse consequences of IPPB therapy were reviewed and it was further suggested that its use in acute asthma attacks was related to lethal episodes of hypoxia and pneumothorax. The patient must, in order to trigger an IPPB apparatus, create a pre-determined negative pressure to initiate inflation. The machine may, therefore, be ineffective in a patient with severe obstruction and greatly increased airway resistance either because of the inability to trigger it or with adequate triggering the subsequent delivery of an inadequate tidal volume at the pressure limitation set. Thus, severe hypercapnia and hypoxia may result especially if oxygen enriched gas mixtures are not used. This may occur even with the delivery of an adequate tidal volume since its distribution within the lungs is poor resulting in a worsening of ventilation-perfusion relationships as evidenced by an increase in the measured physiologic dead space. This experience and review of the literature suggests that IPPB treatment in asthma, especially during an acute attack, should always be administered with small doses of nebulized bronchodilators and oxygen with careful monitoring of arterial blood gases. This will allow for the detection of the adverse effects of this mode of therapy which may exceed the hoped for benefits, the most important being bronchodilatation and subsequent mobilization of secretions with continued treatment.
Assuntos
Asma/mortalidade , Adulto , Aminofilina/uso terapêutico , Asma/terapia , Criança , Epinefrina/uso terapêutico , Feminino , Humanos , Hidrocortisona/uso terapêutico , Respiração com Pressão Positiva Intermitente/efeitos adversos , Isoproterenol/uso terapêutico , Masculino , Pessoa de Meia-Idade , Cidade de Nova Iorque , Estados UnidosRESUMO
Thoracic gas volume, airway resistance (Raw), and dynamic lung compliance (CL) were measured in 48 infants surviving after hyaline membrane disease. Some infants were found to have a small reduction in CL after recovery from the acute phase of the illness but no other abnormalities were detected, irrespective of the type of treatment received. When studied again between the ages of 4 and 10 months, CL had returned to normal, but all infants who had been treated with intermittent positive pressure ventilation (IPPV) during the neonatal period were found to have developed a raised Raw. In contrast, all nonventilated infants, including those who had received up to five days of oxygen therapy in concentrations above 80%, had normal lung function. We conclude that IPPV, and not the increased inspired oxygen concentration, damaged the airways and interfered with their growth.
Assuntos
Resistência das Vias Respiratórias , Doença da Membrana Hialina/fisiopatologia , Oxigenoterapia , Humanos , Doença da Membrana Hialina/terapia , Lactente , Recém-Nascido , Respiração com Pressão Positiva Intermitente/efeitos adversos , Complacência Pulmonar , Respiração com Pressão Positiva , Testes de Função RespiratóriaRESUMO
Chronic lung disease in the form of stage III or IV bronchopulmonary dysplasia (BPD) was found to occur among nine of 188 infants receiving intermittent positive-pressure ventilation for respiratory insufficiency. None occurred in infants ventilated with a mask alone. The duration of endotracheal intubation was not significantly longer in patients developing BPD; however, the duration of exposure to inspired oxygen greater than 60 percent was significantly longer in that group (mean, 141 hours). A previously undescribed form of chronic lung disease was found to occur among nine of 150 infants ventilated because of underlying idiopathic respiratory distress syndrome. A radiographic appearance of diffuse haziness with loss of identifiable lung markings occurred at 5 to 15 days of age and was not associated with clinical signs or symptoms or increased oxygen needs. These changes disappeared in one to five days.
Assuntos
Doenças do Recém-Nascido/etiologia , Respiração com Pressão Positiva Intermitente/efeitos adversos , Pneumopatias/etiologia , Respiração com Pressão Positiva/efeitos adversos , Peso ao Nascer , Doença Crônica , Feminino , Idade Gestacional , Humanos , Recém-Nascido , Intubação Intratraqueal/efeitos adversos , Pneumopatias/diagnóstico por imagem , Pneumopatias/mortalidade , Oxigenoterapia/efeitos adversos , Pneumonia/etiologia , Gravidez , Radiografia , Fatores de Tempo , Estenose Traqueal/etiologiaRESUMO
Noninvasive nasal ventilation is an effective but underutilized method of chronic respiratory support for patients with respiratory insufficiency due to neuromuscular disease. Noninvasive nasal ventilation corrects nocturnal hypoxia and hypercapnia, resolving symptoms of chronic alveolar hypoventilation. Noninvasive nasal ventilation can allow selected patients with acute respiratory failure to avoid intubation and it can facilitate endotracheal extubation. Practical guidelines and the rationale for pediatric noninvasive nasal ventilation therapy will be discussed in this review.
Assuntos
Respiração com Pressão Positiva Intermitente/métodos , Doenças Neuromusculares/complicações , Insuficiência Respiratória/terapia , Adolescente , Criança , Contraindicações , Humanos , Lactente , Respiração com Pressão Positiva Intermitente/efeitos adversos , Insuficiência Respiratória/etiologia , Desmame do Respirador/métodosRESUMO
There are relatively few valid indications for the use of intermittent positive-pressure breathing (IPPB). It is of limited or no value as prophylaxis of postoperative pulmonary problems (pneumonia, atelectasis) or as a means of delivering aerosol medications or treating stable chronic obstructive pulmonary disease. In these situations, IPPB has few if any advantages over voluntary hyperventilation or deep breathing.
Assuntos
Respiração com Pressão Positiva Intermitente , Respiração com Pressão Positiva , Aerossóis , Doença Crônica , Custos e Análise de Custo , Humanos , Respiração com Pressão Positiva Intermitente/efeitos adversos , Respiração com Pressão Positiva Intermitente/estatística & dados numéricos , Pneumopatias/prevenção & controle , Pneumopatias Obstrutivas/terapia , Respiração com Pressão Positiva/estatística & dados numéricos , Complicações Pós-Operatórias/prevenção & controle , Respiração , Estados UnidosRESUMO
The authors describe a case of fatal air embolism in a patient with an endovenous catheter introduced into the subclavian vein through a supraclavicular way. The opening of pleura caused by the needle during the thrusting of the needle caused a subcutaneous supraclavicular and laterocervical emphysema during ventilation with intermittent positive pressure (IPPV). The authors suggest that IPPV, in the postoperative period following kidney removal, was the main ancillary reason of the air embolism since opening of pleura, in a patient who breathes spontaneously, only induces pneumothorax according to the majority of the authors.
Assuntos
Cateterismo/efeitos adversos , Embolia Aérea/etiologia , Veia Subclávia , Adulto , Pressão Sanguínea , Frequência Cardíaca , Humanos , Respiração com Pressão Positiva Intermitente/efeitos adversos , Transplante de Rim , Masculino , Pneumotórax/etiologia , Complicações Pós-OperatóriasRESUMO
Whether or not intermittent positive pressure breathing (IPPB) is beneficial in the treatment of asthma has been controversial for 30 years. IPPB is expensive and has been associated with pulmonary infection, pneumomediastinum, pneumothorax, and death. The exact factors involved in the observed effectiveness of IPPB remain undetermined. With evidence from a literature review, it is concluded that in cases of severe asthma failing to respond to other methods of beta-agonist inhalation, there is sufficient evidence for the use of IPPB.
Assuntos
Asma/terapia , Respiração com Pressão Positiva Intermitente , Respiração com Pressão Positiva , Doença Aguda , Adolescente , Agonistas Adrenérgicos beta/administração & dosagem , Asma/tratamento farmacológico , Feminino , Humanos , Respiração com Pressão Positiva Intermitente/efeitos adversos , Enfisema Mediastínico/etiologia , Pneumotórax/etiologia , Respiração com Pressão Positiva/efeitos adversosRESUMO
BACKGROUND: In the absence of endotracheal intubation, the manual bag-valve-mask (BVM) is the most frequently used ventilation technique during resuscitation. The efficiency of other devices has been poorly studied. The bench-test study described here was designed to evaluate the effectiveness of an automatic, manually triggered system, and to compare it with manual BVM ventilation. METHODS: A respiratory system bench model was assembled using a lung simulator connected to a manikin to simulate a patient with unprotected airways. Fifty health-care providers from different professional groups (emergency physicians, residents, advanced paramedics, nurses, and paramedics; n = 10 per group) evaluated manual BVM ventilation, and compared it with an automatic manually triggered device (EasyCPR). Three pathological situations were simulated (restrictive, obstructive, normal). Standard ventilation parameters were recorded; the ergonomics of the system were assessed by the health-care professionals using a standard numerical scale once the recordings were completed. RESULTS: The tidal volume fell within the standard range (400-600 mL) for 25.6% of breaths (0.6-45 breaths) using manual BVM ventilation, and for 28.6% of breaths (0.3-80 breaths) using the automatic manually triggered device (EasyCPR) (P < .0002). Peak inspiratory airway pressure was lower using the automatic manually triggered device (EasyCPR) (10.6 ± 5 vs 15.9 ± 10 cm H2O, P < .001). The ventilation rate fell consistently within the guidelines, in the case of the automatic manually triggered device (EasyCPR) only (10.3 ± 2 vs 17.6 ± 6, P < .001). Significant pulmonary overdistention was observed when using the manual BVM device during the normal and obstructive sequences. The nurses and paramedics considered the ergonomics of the automatic manually triggered device (EasyCPR) to be better than those of the manual device. CONCLUSIONS: The use of an automatic manually triggered device may improve ventilation efficiency and decrease the risk of pulmonary overdistention, while decreasing the ventilation rate.
Assuntos
Atitude do Pessoal de Saúde , Reanimação Cardiopulmonar/instrumentação , Respiração com Pressão Positiva Intermitente/instrumentação , Reanimação Cardiopulmonar/efeitos adversos , Reanimação Cardiopulmonar/métodos , Desenho de Equipamento , Ergonomia , Humanos , Respiração com Pressão Positiva Intermitente/efeitos adversos , Respiração com Pressão Positiva Intermitente/métodos , Manequins , Volume Residual , Taxa Respiratória , Volume de Ventilação PulmonarAssuntos
Ensaios Clínicos como Assunto/métodos , Insuficiência Cardíaca/complicações , Respiração com Pressão Positiva Intermitente/métodos , Apneia do Sono Tipo Central/terapia , Insuficiência Cardíaca/mortalidade , Humanos , Respiração com Pressão Positiva Intermitente/efeitos adversos , Projetos de Pesquisa , Apneia do Sono Tipo Central/complicações , Taxa de SobrevidaAssuntos
Síndrome do Desconforto Respiratório do Recém-Nascido/terapia , Gasometria , Feminino , Humanos , Cuidado do Lactente , Recém-Nascido , Respiração com Pressão Positiva Intermitente/efeitos adversos , Respiração com Pressão Positiva Intermitente/métodos , Pulmão/fisiopatologia , Trabalho de Parto Prematuro/prevenção & controle , Oxigênio/administração & dosagem , Respiração com Pressão Positiva/instrumentação , Respiração com Pressão Positiva/métodos , Gravidez , Síndrome do Desconforto Respiratório do Recém-Nascido/diagnóstico , Síndrome do Desconforto Respiratório do Recém-Nascido/fisiopatologiaAssuntos
Respiração Artificial/efeitos adversos , Colorado , Humanos , Hiperventilação/etiologia , Hipotensão/etiologia , Hipoventilação/etiologia , Infarto/etiologia , Respiração com Pressão Positiva Intermitente/efeitos adversos , Intubação Intratraqueal/efeitos adversos , Pulmão/irrigação sanguínea , Monitorização Fisiológica/normas , Oxigênio/intoxicação , Pneumonia/etiologia , Pneumotórax/etiologia , Estudos Prospectivos , Atelectasia Pulmonar/etiologia , Infecções Respiratórias/etiologia , TraqueotomiaAssuntos
Terapia Intensiva Neonatal/métodos , Respiração com Pressão Positiva Intermitente/mortalidade , Síndrome do Desconforto Respiratório do Recém-Nascido/terapia , Feminino , Idade Gestacional , Humanos , Índia , Recém-Nascido , Unidades de Terapia Intensiva Neonatal/estatística & dados numéricos , Respiração com Pressão Positiva Intermitente/efeitos adversos , Masculino , Estudos Retrospectivos , Taxa de SobrevidaAssuntos
Respiração com Pressão Positiva Intermitente , Respiração com Pressão Positiva , Humanos , Respiração com Pressão Positiva Intermitente/efeitos adversos , Respiração com Pressão Positiva Intermitente/instrumentação , Pneumopatias Obstrutivas/terapia , Respiração com Pressão Positiva/instrumentaçãoRESUMO
The occurrence of massive air embolism in a neonate during treatment with intermittent positive-pressure respiration and positive end expiratory pressure is reported as a note of caution. It is possible that this complication may indeed be more common. Careful post-mortem examinations (including radiological examinations) are advocated in order that the true incidence of this devastating event shall be known.
Assuntos
Embolia Aérea/etiologia , Doenças do Recém-Nascido/etiologia , Respiração com Pressão Positiva/efeitos adversos , Síndrome do Desconforto Respiratório do Recém-Nascido/terapia , Humanos , Recém-Nascido , Respiração com Pressão Positiva Intermitente/efeitos adversos , MasculinoRESUMO
2 patients developing acute alveolar hypoventilation following IPPB therapy are presented. The hypoventilation occurred insidiously following therapy. It is hypothesized that respiratory center depression from excessive oxygen administration caused the hypoventilation. When the IPPB machines were driven by compressed air instead of oxygen, this complication was revealed in 1 of the patients.
Assuntos
Hipoventilação/etiologia , Respiração com Pressão Positiva Intermitente/efeitos adversos , Respiração com Pressão Positiva/efeitos adversos , Alvéolos Pulmonares/fisiopatologia , Doença Aguda , Idoso , Dispneia/terapia , Humanos , MasculinoRESUMO
Two cases are presented in which injury to the stomach occurred in association with laparoscopy under general anaesthesia. The common aetiological factor was gastric inflation resulting from I.P.P.V. via mask. Precautionary measures in the anaesthetic induction technique are described.
Assuntos
Anestesia Geral/efeitos adversos , Laparoscopia/efeitos adversos , Estômago/lesões , Adulto , Anestesia Endotraqueal/efeitos adversos , Feminino , Humanos , Respiração com Pressão Positiva Intermitente/efeitos adversosRESUMO
We compared the histopathologic changes in the airways of premature baboons treated with conventional positive-pressure ventilation (PPV) with those seen after high-frequency oscillatory ventilation (HFOV) and high-frequency flow interruption (HFFI). Twenty-six animals were treated with ventilation for 24 hours (five PPV, 10 HFOV, 11 HFFI), and 18 were treated with ventilation for 96 hours (six PPV, six HFOV, six HFFI). A semiquantitative scoring system was used to grade tissue changes in the trachea, carina, and both main-stem bronchi. Alterations were produced by all forms of mechanical ventilation. The degree of injury was similar and relatively mild for the PPV- and HFOV-treated animals at both 24 and 96 hours. Eleven of 17 baboons treated with HFFI ventilation (8/11 at 24 hours; 3/6 at 96 hours) had severe airway damage characterized by diffuse submucosal necrosis, extensive hemorrhage, dense polymorphonuclear leukocyte infiltration, sloughed epithelium, focal basophilia, and intraluminal debris. HFOV resulted in no greater degree of airway damage than did PPV. The use of HFFI, with the particular strategy we employed, resulted in a far greater degree of damage than either PPV (P less than 0.01) or HFOV.