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1.
JAMA ; 323(5): 455-465, 2020 02 04.
Artigo em Inglês | MEDLINE | ID: mdl-32016309

RESUMO

Importance: The association of home noninvasive positive pressure ventilation (NIPPV) with outcomes in chronic obstructive pulmonary disease (COPD) and hypercapnia is uncertain. Objective: To evaluate the association of home NIPPV via bilevel positive airway pressure (BPAP) devices and noninvasive home mechanical ventilator (HMV) devices with clinical outcomes and adverse events in patients with COPD and hypercapnia. Data Sources: Search of MEDLINE, EMBASE, SCOPUS, Cochrane Central Registrar of Controlled Trials, Cochrane Database of Systematic Reviews, National Guideline Clearinghouse, and Scopus for English-language articles published from January 1, 1995, to November 6, 2019. Study Selection: Randomized clinical trials (RCTs) and comparative observational studies that enrolled adults with COPD with hypercapnia who used home NIPPV for more than 1 month were included. Data Extraction and Synthesis: Data extraction was completed by independent pairs of reviewers. Risk of bias was evaluated using the Cochrane Collaboration risk of bias tool for RCTs and select items from the Newcastle-Ottawa Scale for nonrandomized studies. Main Outcomes and Measures: Primary outcomes were mortality, all-cause hospital admissions, need for intubation, and quality of life at the longest follow-up. Results: A total of 21 RCTs and 12 observational studies evaluating 51 085 patients (mean [SD] age, 65.7 [2.1] years; 43% women) were included, among whom there were 434 deaths and 27 patients who underwent intubation. BPAP compared with no device was significantly associated with lower risk of mortality (22.31% vs 28.57%; risk difference [RD], -5.53% [95% CI, -10.29% to -0.76%]; odds ratio [OR], 0.66 [95% CI, 0.51-0.87]; P = .003; 13 studies; 1423 patients; strength of evidence [SOE], moderate), fewer patients with all-cause hospital admissions (39.74% vs 75.00%; RD, -35.26% [95% CI, -49.39% to -21.12%]; OR, 0.22 [95% CI, 0.11-0.43]; P < .001; 1 study; 166 patients; SOE, low), and lower need for intubation (5.34% vs 14.71%; RD, -8.02% [95% CI, -14.77% to -1.28%]; OR, 0.34 [95% CI, 0.14-0.83]; P = .02; 3 studies; 267 patients; SOE, moderate). There was no significant difference in the total number of all-cause hospital admissions (rate ratio, 0.91 [95% CI, 0.71-1.17]; P = .47; 5 studies; 326 patients; SOE, low) or quality of life (standardized mean difference, 0.16 [95% CI, -0.06 to 0.39]; P = .15; 9 studies; 833 patients; SOE, insufficient). Noninvasive HMV use compared with no device was significantly associated with fewer all-cause hospital admissions (rate ratio, 0.50 [95% CI, 0.35-0.71]; P < .001; 1 study; 93 patients; SOE, low), but not mortality (21.84% vs 34.09%; RD, -11.99% [95% CI, -24.77% to 0.79%]; OR, 0.56 [95% CI, 0.29-1.08]; P = .49; 2 studies; 175 patients; SOE, insufficient). There was no statistically significant difference in the total number of adverse events in patients using NIPPV compared with no device (0.18 vs 0.17 per patient; P = .84; 6 studies; 414 patients). Conclusions and Relevance: In this meta-analysis of patients with COPD and hypercapnia, home BPAP, compared with no device, was associated with lower risk of mortality, all-cause hospital admission, and intubation, but no significant difference in quality of life. Noninvasive HMV, compared with no device, was significantly associated with lower risk of hospital admission, but there was no significant difference in mortality risk. However, the evidence was low to moderate in quality, the evidence on quality of life was insufficient, and the analyses for some outcomes were based on small numbers of studies.


Assuntos
Respiração com Pressão Positiva/métodos , Doença Pulmonar Obstrutiva Crônica/terapia , Respiração Artificial/métodos , Serviços de Assistência Domiciliar , Hospitalização , Humanos , Hipercapnia/etiologia , Ventilação não Invasiva/instrumentação , Respiração com Pressão Positiva/instrumentação , Doença Pulmonar Obstrutiva Crônica/complicações , Doença Pulmonar Obstrutiva Crônica/mortalidade , Qualidade de Vida , Respiração Artificial/instrumentação , Resultado do Tratamento
3.
J Neonatal Perinatal Med ; 12(3): 243-248, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30909252

RESUMO

BACKGROUND: Positive pressure ventilation (PPV) is the most important procedure during neonatal resuscitation. Providing effective PPV seems easy. However, performing the procedure correctly is extremely challenging. Airway obstruction and face mask large leaks are common. It is estimated that two-thirds of continued neonatal respiratory depression after the time of birth is caused by ineffective or improperly provided PPV. Finding methods to improve PPV performance are critically needed. Performance coaching is a simple and easy method of improving performing in procedural skills, and has been used previously to optimize compression technique. We performed the simulation-based pilot study to evaluate the impact of PPV coaching during neonatal bag-mask ventilation. METHODS: Randomized cross-over study of nurses performing PPV on a SMART Newborn Resuscitation Training System with, and without, coaching. The PPV coach provided real-time feedback on chest rise, mask hold, and ventilation rate. The SMART system captured data on peak inspiratory pressure (PIP), tidal volume (Vt), mask leak, and ventilation rate. Data were analyzed by a blinded reviewer. RESULTS: PPV coaching resulted in more appropriate PIPs (34 cmH2O, IQR 32-38 vs. 36 cmH2O, IQR 28-37; P < 0.001), lower Vt (4.7 ml/kg, IQR 4-8 vs. 5.5 ml/kg, IQR 4-13; P < 0.001), and less mask leak (39% leak, IQR 21-70 vs. 45%, IQR 22-98; P = 0.005). There was no difference in respiratory rate (P = 0.93). CONCLUSIONS: Coaching improved PPV performance in this simulation-based pilot study. Further research on PPV coaching during neonatal resuscitation is warranted.


Assuntos
Enfermagem Neonatal/educação , Enfermeiras Neonatologistas/educação , Respiração com Pressão Positiva/normas , Ressuscitação/educação , Adulto , Competência Clínica/normas , Estudos Cross-Over , Feminino , Humanos , Recém-Nascido , Máscaras Laríngeas/normas , Masculino , Manequins , Enfermagem Neonatal/normas , Enfermeiras Neonatologistas/normas , Projetos Piloto , Respiração com Pressão Positiva/instrumentação , Respiração com Pressão Positiva/métodos , Transtornos Respiratórios/congênito , Transtornos Respiratórios/terapia , Taxa Respiratória/fisiologia , Treinamento por Simulação/métodos
4.
Can Respir J ; 2019: 9176504, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30774739

RESUMO

Background: The Aerobika® oscillating positive expiratory pressure (OPEP) device is a hand-held, drug-free medical device that has been shown to improve lung function and improve health-related quality of life in patients with chronic obstructive pulmonary disease (COPD). We estimated the cost-effectiveness of this device among postexacerbation COPD patients in the Canadian healthcare system. Methods: We performed a cost-utility analysis using a Markov model to compare both costs and outcome of patients with COPD who had recently experienced an exacerbation between 2 treatment arms: patients who used the Aerobika® device and patients who did not use the Aerobika® device. This cost-utility analysis included costs based on the Alberta healthcare system perspective as these represent Canadian experience. A one-year horizon with 12 monthly cycles was used. Results: For a patient after 1 year, the use of the Aerobika® device would save $694 in healthcare costs and produce 0.04 more in quality-adjusted life years (QALYs) in comparison with no positive expiratory pressure (PEP)/OPEP therapy. In other words, the economic outcome of the device was dominant (i.e., more effective and less costly). The probability for this device to be the dominant strategy was 72%. With a willingness to pay (WTP) threshold of $50,000 per QALY gained, the probability for the Aerobika® device to be cost-effective was 77%. Conclusions: Given one of the major treatment goals in the GOLD guidelines is to minimize the negative impact of exacerbations and prevent re-exacerbations, the Aerobika® OPEP device should be viewed as a potential component of a treatment strategy to improve symptom control and reduce the risk of re-exacerbations in patients with COPD.


Assuntos
Respiração com Pressão Positiva/economia , Respiração com Pressão Positiva/instrumentação , Doença Pulmonar Obstrutiva Crônica/terapia , Canadá , Análise Custo-Benefício , Progressão da Doença , Humanos , Modelos Econômicos , Doença Pulmonar Obstrutiva Crônica/economia
5.
PLoS One ; 14(2): e0212704, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30811470

RESUMO

BACKGROUND: High-quality chest compressions are imperative for Cardio-Pulmonary-Resuscitation (CPR). International CPR guidelines advocate, that chest compressions should not be interrupted for ventilation once a patient's trachea is intubated or a supraglottic-airway-device positioned. Supraglottic-airway-devices offer limited protection against pulmonary aspiration. Simultaneous chest compressions and positive pressure ventilation both increase intrathoracic pressure and potentially enhances the risk of pulmonary aspiration. The hypothesis was, that regurgitation and pulmonary aspiration is more common during continuous versus interrupted chest compressions in human cadavers ventilated with a laryngeal tube airway. METHODS: Twenty suitable cadavers were included, and were positioned supine, the stomach was emptied, 500 ml of methylene-blue-solution instilled and laryngeal tube inserted. Cadavers were randomly assigned to: 1) continuous chest compressions; or, 2) interrupted chest compressions for ventilation breaths. After 14 minutes of the initial designated CPR strategy, pulmonary aspiration was assessed with a flexible bronchoscope. The methylene-blue-solution was replaced by 500 ml barium-sulfate radiopaque suspension. 14 minutes of CPR with the second designated ventilation strategy was performed. Pulmonary aspiration was then assessed with a conventional chest X-ray. RESULTS: Two cadavers were excluded for technical reasons, leaving 18 cadavers for statistical analysis. Pulmonary aspiration was observed in 9 (50%) cadavers with continuous chest compressions, and 7 (39%) with interrupted chest compressions (P = 0.75). CONCLUSION: Our pilot study indicate, that incidence of pulmonary aspiration is generally high in patients undergoing CPR when a laryngeal tube is used for ventilation. Our study was not powered to identify potentially important differences in regurgitation or aspiration between ongoing vs. interrupted chest compression. Our results nonetheless suggest that interrupted chest compressions might better protect against pulmonary aspiration when a laryngeal tube is used for ventilation.


Assuntos
Reanimação Cardiopulmonar/efeitos adversos , Parada Cardíaca/terapia , Refluxo Laringofaríngeo/epidemiologia , Respiração com Pressão Positiva/efeitos adversos , Aspiração Respiratória de Conteúdos Gástricos/epidemiologia , Idoso , Idoso de 80 Anos ou mais , Cadáver , Reanimação Cardiopulmonar/instrumentação , Reanimação Cardiopulmonar/métodos , Estudos Cross-Over , Feminino , Humanos , Incidência , Máscaras Laríngeas/efeitos adversos , Refluxo Laringofaríngeo/etiologia , Masculino , Pessoa de Meia-Idade , Projetos Piloto , Respiração com Pressão Positiva/instrumentação , Distribuição Aleatória , Aspiração Respiratória de Conteúdos Gástricos/diagnóstico por imagem , Aspiração Respiratória de Conteúdos Gástricos/etiologia
7.
Arch Dis Child Fetal Neonatal Ed ; 104(2): F122-F127, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-29728414

RESUMO

BACKGROUND: The T-piece resuscitator (TPR) has seen increased use as a primary resuscitation device with newborns. Traditional TPR design uses a high resistance expiratory valve to produce positive end expiratory pressure (PEEP) or continuous positive airway pressure (CPAP) at resuscitation. A new TPR device that uses a dual flow ratio valve (fluidic flip) to produce PEEP/CPAP is now available (rPAP). We aimed to compare the measured ventilation performance of different TPR devices in a controlled bench test study. DESIGN/METHODS: Single operator provided positive pressure ventilation to an incremental testlung compliance (Crs) model (0.5-5 mL/cmH2O) with five different brands of TPR device (Atom, Neopuff, rPAP, GE Panda warmer and Draeger Resuscitaire). At recommended peak inflation pressure (PIP) 20 cmH2O, PEEP of 5 cmH2O and rate of 60 inflations per minute. RESULTS: 1864 inflations were analysed. Four of the five devices tested demonstrated inadvertent elevations in mean PEEP (5.5-10.3 cmH2O, p<0.001) from set value as Crs was increased, while one device (rPAP) remained at the set value. Measured PIP exceeded the set value in two infant warmer devices (GE and Draeger) with inbuilt TPR at Crs of 0.5 (24.5 and 23.5 cmH2O, p<0.001). Significant differences were seen in tidal volumes across devices particularly at higher Crs (p<0.001). CONCLUSIONS: Results show important variation in delivered ventilation from set values due to inherent TPR device design characteristics with a range of lung compliances expected at birth. Device-generated inadvertent PEEP and overdelivery of PIP may be clinically deleterious for term and preterm newborns or infants with larger Crs during resuscitation.


Assuntos
Reanimação Cardiopulmonar/métodos , Desenho de Equipamento , Cuidado do Lactente/métodos , Respiração com Pressão Positiva/instrumentação , Análise de Variância , Humanos , Recém-Nascido , Respiração com Pressão Positiva/métodos , Volume de Ventilação Pulmonar
8.
Pulmonology ; 25(2): 79-82, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30033339

RESUMO

This case series of five patients with Duchenne muscular dystrophy demonstrates the nutritional advantages of instituting noninvasive intermittent positive pressure ventilatory support via 15mm angled mouthpieces to relieve tachypnea and provide more time to swallow food safely. In each case weight loss was reversed.


Assuntos
Distrofia Muscular de Duchenne/terapia , Ventilação não Invasiva/métodos , Respiração com Pressão Positiva/instrumentação , Perda de Peso/fisiologia , Adolescente , Adulto , Deglutição/fisiologia , Transtornos de Deglutição/fisiopatologia , Evolução Fatal , Humanos , Masculino , Desnutrição/etiologia , Pessoa de Meia-Idade , Distrofia Muscular de Duchenne/complicações , Taquipneia/complicações , Taquipneia/fisiopatologia , Traqueotomia/efeitos adversos , Adulto Jovem
9.
Prehosp Emerg Care ; 23(2): 210-214, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30130437

RESUMO

INTRODUCTION: Emergency Medical Services (EMS) professionals rely on the bag-valve-mask (BVM) to provide life-saving positive-pressure ventilation in the prehospital setting. Multiple emergency medicine and critical care studies have shown that lung-protective ventilation protocols reduce morbidity and mortality. A recent study has shown that the volumes typically delivered by EMS professionals with the adult BVM are often higher than recommended by lung-protective ventilation protocols. Our primary objective was to determine if a group of EMS professionals could reduce the volume delivered by adjusting the way the BVM was held. Secondary objectives included 1) if the adjusted grip allowed for volumes more consistent with lung-protection ventilation strategies and 2) comparing volumes to similar grip strategies used with a smaller BVM. METHODS: A patient simulator of a head and thorax was used to record respiratory rate, tidal volume, peak pressure, and minute volume delivered by participants for 1 minute each across 6 different scenarios: 3 different grips (using the thumb and either 3 fingers, 2 fingers, or one finger) with 2 different sized BVMs (adult and pediatric). Trials were randomized by blindly selecting a paper with the scenario listed. A convenience sample of EMS providers was used based on EMS provider and research staff availability. RESULTS: We enrolled 50 providers from a large, busy, urban hospital-based EMS agency a mean 8.60 (SD = 9.76) years of experience. Median volumes for each scenario were 836.0 mL, 834.5 mL, and 794 mL for the adult BMV (p = 0.003); and 576.0 mL, 571.5 mL, and 547.0 mL for the pediatric BVM (p < 0.001). Across all 3 grips, the pediatric BVM provided more breaths within the recommended volume range for a 70 kg patient (46.4% vs. 0.4%; p < 0.001) with only a 1.1% of breaths below the recommended tidal volume. CONCLUSION: The study suggests that it is possible to alter the volume provided by the BVM by altering the grip on the BVM. The tidal volumes recorded with the pediatric BVM were above recommended range in 2 of the 3 grips. The volumes of the pediatric BVM were overall more consistent with lung-protective ventilation volumes when compared to all 3 finger-grips of the adult BVM.


Assuntos
Serviços Médicos de Emergência , Força da Mão , Respiração com Pressão Positiva/métodos , Volume de Ventilação Pulmonar/fisiologia , Adulto , Criança , Feminino , Humanos , Máscaras Laríngeas , Masculino , Manequins , Simulação de Paciente , Respiração com Pressão Positiva/instrumentação , Taxa Respiratória , Adulto Jovem
10.
J Clin Monit Comput ; 33(3): 419-429, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30073444

RESUMO

Recently, we developed a novel endotracheal catheter with functional cuff (ECFC). Using such an ECFC and a regular ICU ventilator, we were able to generate clinically relevant tidal volume in a lung model and adult human sized animal. This ECFC allows co-axial ventilation without using a jet ventilator. The aim of this study was to determine if ECFC also could generate clinically relevant positive end expiratory pressure (PEEP). The experiment was conducted on a model lung and artificial trachea. Lung model respiratory mechanics were set to simulate those of an adult human being. The tip of the distal end of ECFC 14 or 19 Fr catheter was positioned in the artificial trachea 3 cm above the carina. The proximal end of ECFC was connected to an ordinary ICU ventilator. With 14 Fr catheter at respiratory rate 10 bpm, PEEP 0, 2.9, 8.2, 12.9 cmH2O was generated at preset PEEP 0, 5, 10, 15 cmH2O respectively and tidal volume was up to 393.4 ml. With 19 Fr catheter, PEEP was 0, 2.8, 7.6, 12.3 cmH2O, at preset PEEP 0, 5, 10, 15 cmH2O respectively and the tidal volume was up to 667.3 ml. With 14 Fr catheter at respiratory rate 20 bpm, PEEP was 0, 3.9, 9.6, 14.6 cmH2O at preset PEEP 0, 5, 10, 15 cmH2O respectively and tidal volume was up to 188.8 ml. With 19 Fr catheter, PEEP was 0, 3.6, 8.9, 13 cmH2O, at preset PEEP 0, 5, 10, 15 cmH2O respectively and tidal volume was up to 345.3 ml. ECFC enables clinicians to generate not only adequate tidal volume but also clinically relevant PEEP via co-axial ventilation using an ordinary ICU ventilator.


Assuntos
Respiração com Pressão Positiva/instrumentação , Mecânica Respiratória , Taxa Respiratória , Volume de Ventilação Pulmonar , Ventiladores Mecânicos , Calibragem , Cateterismo , Cuidados Críticos/métodos , Desenho de Equipamento , Humanos , Unidades de Terapia Intensiva , Pulmão/fisiologia , Troca Gasosa Pulmonar , Respiração Artificial , Traqueia/patologia , Traqueia/fisiologia
11.
Arch Dis Child Fetal Neonatal Ed ; 104(4): F403-F408, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-30337333

RESUMO

AIM: A controlled bench test was undertaken to determine the performance variability among a range of neonatal self-inflating bags (SIB) compliant with current International Standards Organisation (ISO). INTRODUCTION: Use of SIB to provide positive pressure ventilation during newborn resuscitation is a common emergency procedure. The United Nations programmes advocate increasing availability of SIB in low-income and middle-income nations and recommend devices compliant with ISO. No systematic study has evaluated variance in different models of neonatal SIB. METHODS: 20 models of SIB were incrementally compressed by an automated robotic device simulating the geometry and force of a human hand across a range of precise distances in a newborn lung model. Significance was calculated using analysis of variance repeated measures to determine the relationship between distance of SIB compression and delivered ventilation. A pass/fail was derived from a composite score comprising: minimum tidal volume; coefficient of variation (across all compression distances); peak pressures generated and functional compression distance. RESULTS: Ten out of the 20 models of SIB failed our testing methodology. Two models could not provide safe minimum tidal volumes (2.5-5 mL); six models exceeded safety inflation pressure limit >45 cm H2O, representing 6% of their inflations; five models had excessive coefficient of variation (>30% averaged across compression distances) and three models did not deliver inflation volumes >2.5 mL until approximately 50% of maximum bag compression distance was reached. The study also found significant intrabatch variability and forward leakage. CONCLUSION: Compliance of SIBs with ISO standards may not guarantee acceptable or safe performance to resuscitate newborn infants.


Assuntos
Cuidado do Lactente/instrumentação , Insuflação/métodos , Respiração com Pressão Positiva/instrumentação , Respiração Artificial/instrumentação , Robótica/instrumentação , Reanimação Cardiopulmonar/instrumentação , Desenho de Equipamento , Segurança de Equipamentos , Humanos , Cuidado do Lactente/métodos , Recém-Nascido , Respiração com Pressão Positiva/métodos , Respiração Artificial/métodos
12.
BMC Anesthesiol ; 18(1): 181, 2018 12 03.
Artigo em Inglês | MEDLINE | ID: mdl-30509183

RESUMO

BACKGROUND: Microaspiration past the tracheal tube cuffs causes ventilator-associated pneumonia. The objective of the current study was to evaluate whether creating negative pressure between the tracheal double cuffs could block the fluid passage past the tracheal tube cuffs. METHODS: A new negative pressure system was devised between the double cuffs through a suction hole in the intercuff space. Blue-dyed water was instilled above the cuff at negative suction pressures of - 54, - 68, - 82, - 95, - 109, - 122, and - 136 cmH2O, and the volume leaked was measured in an underlying water trap after 10 min. Leakage tests were also performed during positive pressure ventilation, and using higher-viscosity materials. The actual negative pressures delivered at the hole of double cuffs were obtained by placing microcatheter tip between the intercuff space and the artificial trachea. RESULTS: No leakage occurred past the double cuff at - 136 cmH2O suction pressure at all tracheal tube cuff pressures. The volume leaked decreased significantly as suction pressure increased. When connected to a mechanical ventilator, no leakage was found at - 54 cmH2suction pressure. Volume of the higher-viscosity materials (dynamic viscosity of 63-108 cP and 370-430 cP) leaked was small compared to that of normal saline (0.9-1.1 cP). The pressures measured in the intercuff space corresponded to 3.8-5.9% of those applied. CONCLUSIONS: A new prototype double cuff with negative pressure in the intercuff space completely prevented water leakage. The negative pressure transmitted to the tracheal inner wall was a small percentage of that applied.


Assuntos
Desenho de Equipamento/instrumentação , Intubação Intratraqueal/instrumentação , Respiração com Pressão Positiva/instrumentação , Aspiração Respiratória/prevenção & controle , Respiradores de Pressão Negativa , Desenho de Equipamento/métodos , Humanos , Intubação Intratraqueal/métodos , Respiração com Pressão Positiva/métodos , Pressão
13.
Biomed Eng Online ; 17(1): 169, 2018 Nov 12.
Artigo em Inglês | MEDLINE | ID: mdl-30419903

RESUMO

BACKGROUND: Mechanical ventilation is an essential therapy to support critically ill respiratory failure patients. Current standards of care consist of generalised approaches, such as the use of positive end expiratory pressure to inspired oxygen fraction (PEEP-FiO2) tables, which fail to account for the inter- and intra-patient variability between and within patients. The benefits of higher or lower tidal volume, PEEP, and other settings are highly debated and no consensus has been reached. Moreover, clinicians implicitly account for patient-specific factors such as disease condition and progression as they manually titrate ventilator settings. Hence, care is highly variable and potentially often non-optimal. These conditions create a situation that could benefit greatly from an engineered approach. The overall goal is a review of ventilation that is accessible to both clinicians and engineers, to bridge the divide between the two fields and enable collaboration to improve patient care and outcomes. This review does not take the form of a typical systematic review. Instead, it defines the standard terminology and introduces key clinical and biomedical measurements before introducing the key clinical studies and their influence in clinical practice which in turn flows into the needs and requirements around how biomedical engineering research can play a role in improving care. Given the significant clinical research to date and its impact on this complex area of care, this review thus provides a tutorial introduction around the review of the state of the art relevant to a biomedical engineering perspective. DISCUSSION: This review presents the significant clinical aspects and variables of ventilation management, the potential risks associated with suboptimal ventilation management, and a review of the major recent attempts to improve ventilation in the context of these variables. The unique aspect of this review is a focus on these key elements relevant to engineering new approaches. In particular, the need for ventilation strategies which consider, and directly account for, the significant differences in patient condition, disease etiology, and progression within patients is demonstrated with the subsequent requirement for optimal ventilation strategies to titrate for patient- and time-specific conditions. CONCLUSION: Engineered, protective lung strategies that can directly account for and manage inter- and intra-patient variability thus offer great potential to improve both individual care, as well as cohort clinical outcomes.


Assuntos
Engenharia Biomédica , Cuidados Críticos , Respiração com Pressão Positiva/instrumentação , Respiração Artificial/instrumentação , Animais , Estado Terminal , Humanos , Pulmão , Lesão Pulmonar/etiologia , Oscilometria , Oxigênio/sangue , Oxigênio/química , Respiração com Pressão Positiva/métodos , Pressão , Respiração Artificial/métodos , Síndrome do Desconforto Respiratório do Adulto/terapia , Risco , Volume de Ventilação Pulmonar , Ventiladores Mecânicos
14.
Fed Regist ; 83(203): 52964-6, 2018 Oct 19.
Artigo em Inglês | MEDLINE | ID: mdl-30358382

RESUMO

The Food and Drug Administration (FDA or we) is classifying the positive airway pressure delivery system into class II (special controls). The special controls that apply to the device type are identified in this order and will be part of the codified language for the positive airway pressure delivery system's classification. We are taking this action because we have determined that classifying the device into class II (special controls) will provide a reasonable assurance of safety and effectiveness of the device. We believe this action will also enhance patients' access to beneficial innovative devices, in part by reducing regulatory burdens.


Assuntos
Respiração com Pressão Positiva/classificação , Anestesiologia/classificação , Anestesiologia/instrumentação , Segurança de Equipamentos , Humanos , Respiração com Pressão Positiva/instrumentação
15.
Zhonghua Wei Zhong Bing Ji Jiu Yi Xue ; 30(9): 900-901, 2018 Sep.
Artigo em Chinês | MEDLINE | ID: mdl-30309419

RESUMO

OBJECTIVE: Positive end-expiratory pressure (PEEP) is a common method to maintain alveolar patency in patients undergoing mechanical ventilation. However, in patients undergoing tracheotomy, alveolar collapse often occurs due to bedridden, aspiration, and other factors. There is currently no effective means to provide PEEP support for such patients. The application of a high-flow oxygen inhalation device with a PEEP valve was designed to provide patients with continuously adjustable PEEP, which helps to improve the patient's oxygenation and maintain the lung's physiological functions.


Assuntos
Oxigenoterapia/instrumentação , Respiração com Pressão Positiva/instrumentação , Desenho de Equipamento , Humanos , Respiração Artificial
16.
Crit Care ; 22(1): 245, 2018 09 29.
Artigo em Inglês | MEDLINE | ID: mdl-30268138

RESUMO

BACKGROUND: Concepts for optimizing mechanical ventilation focus mainly on modifying the inspiratory phase. We propose flow-controlled expiration (FLEX) as an additional means for lung protective ventilation and hypothesize that it is capable of recruiting dependent areas of the lungs. This study investigates potential recruiting effects of FLEX using models of mechanically ventilated pigs before and after induction of lung injury with oleic acid. METHODS: Seven pigs in the supine position were ventilated with tidal volume 8 ml·kg- 1 and positive end-expiratory pressure (PEEP) set to maintain partial pressure of oxygen in arterial blood (paO2) at ≥ 60 mmHg and monitored with electrical impedance tomography (EIT). Two ventilation sequences were recorded - one before and one after induction of lung injury. Each sequence comprised 2 min of conventional volume-controlled ventilation (VCV), 2 min of VCV with FLEX and 1 min again of conventional VCV. Analysis of the EIT recordings comprised global and ventral and dorsal baseline levels of impedance curves, end-expiratory no-flow periods, tidal variation in ventral and dorsal areas, and regional ventilation delay index. RESULTS: With FLEX, the duration of the end-expiratory zero flow intervals was significantly shortened (VCV 1.4 ± 0.3 s; FLEX 0.7 ± 0.1 s, p < 0.001), functional residual capacity was significantly elevated in both conditions of the lungs (global: healthy, increase of 87 ± 12 ml, p < 0.001; injured, increase of 115 ± 44 ml, p < 0.001; ventral: healthy, increase of 64 ± 11 ml, p < 0.001; injured, increase of 83 ± 22 ml, p < 0.001; dorsal: healthy, increase of 23 ± 5 ml, p < 0.001; injured, increase of 32 ± 26 ml, p = 0.02), and ventilation was shifted from ventral to dorsal areas (dorsal increase: healthy, 1 ± 0.5%, p < 0.01; dorsal increase: injured, 6 ± 2%, p < 0.01), compared to conventional VCV. Recruiting effects of FLEX persisted during conventional VCV following FLEX ventilation mostly in the injured but also in the healthy lungs. CONCLUSIONS: FLEX shifts regional ventilation towards dependent lung areas in healthy and in injured pig lungs. The recruiting capabilities of FLEX may be mainly responsible for lung-protective effects observed in an earlier study.


Assuntos
Lesão Pulmonar/complicações , Respiração Artificial/instrumentação , Respiração Artificial/métodos , Ferimentos e Lesões/complicações , Animais , Modelos Animais de Doenças , Impedância Elétrica/uso terapêutico , Expiração/fisiologia , Alemanha , Pulmão/patologia , Pulmão/fisiopatologia , Lesão Pulmonar/fisiopatologia , Ácido Oleico/análise , Ácido Oleico/sangue , Respiração com Pressão Positiva/instrumentação , Respiração com Pressão Positiva/métodos , Decúbito Dorsal/fisiologia , Suínos , Volume de Ventilação Pulmonar/fisiologia , Tomografia Computadorizada por Raios X/métodos , Ferimentos e Lesões/fisiopatologia
17.
Paediatr Anaesth ; 28(9): 788-794, 2018 09.
Artigo em Inglês | MEDLINE | ID: mdl-30175433

RESUMO

BACKGROUND: Positive-pressure ventilation in critically ill patients is commonly administered via a manual resuscitation device or a mechanical ventilator during transport. Our group previously compared delivered ventilation parameters between a self-inflating resuscitator and a flow-inflating resuscitator during simulated in-hospital pediatric transport. However, unequal group access to inline pressure manometry may have biased our results. In this study, we examined the performance of the self-inflating resuscitator and the flow-inflating resuscitator, both equipped with inline manometry, and several mechanical ventilators to deliver prescribed ventilation parameters during simulated pediatric transport. METHODS: Thirty anesthesia providers were randomized to initial resuscitator device used to hand ventilate a test lung. The resuscitators studied were a Jackson-Rees circuit (flow-inflating resuscitator) or a Laerdal pediatric silicone resuscitator (self-inflating resuscitator), both employing manometers. The scenario was repeated using several mechanical transport ventilators (Hamilton-T1, LTV® 1000, and LTV® 1200). The primary outcome was the proportion of total breaths delivered within the predefined target PIP/PEEP range (30 ± 3, 10 ± 3 cm H2 O). RESULTS: The Hamilton-T1 outperformed the other ventilators for breaths in the recommended range (χ2  = 2284, df = 2, P < .001) and with no breaths in the unacceptable range (χ2  = 2333, df = 2, P < .001). Hamilton-T1 also outperformed all human providers in proportion of delivered acceptable and unacceptable breaths (χ2  = 4540, df = 3, P < .001 and χ2  = 639, df = 3, P < .001, respectively). Compared with the flow-inflating resuscitator, the self-inflating resuscitator was associated with greater odds of breaths falling outside the recommended range (Odds ratio (95% CI): 1.81 (1.51-2.17)) or unacceptable (Odds ratio (95% CI): 1.63 (1.48-1.81)). CONCLUSION: This study demonstrates that a majority of breaths delivered by manual resuscitation device fall outside of target range regardless of provider experience or device type. The mechanical ventilator (Hamilton-T1) outperforms the other positive-pressure ventilation methods with respect to delivery of important ventilation parameters. In contrast, 100% of breaths delivered by the LTV 1200 were deemed unacceptable.


Assuntos
Respiração Artificial/instrumentação , Ressuscitação/instrumentação , Transporte de Pacientes/métodos , Ventiladores Mecânicos , Simulação por Computador , Estudos Cross-Over , Desenho de Equipamento , Humanos , Pulmão/fisiologia , Manometria/instrumentação , Respiração com Pressão Positiva/instrumentação , Respiração , Ressuscitação/métodos
18.
Paediatr Anaesth ; 28(9): 780-787, 2018 09.
Artigo em Inglês | MEDLINE | ID: mdl-30004614

RESUMO

BACKGROUND: Over the last decade, cuffed endotracheal tubes are increasingly used in pediatric anesthesia and also in pediatric intensive care. However, the smaller inner diameter of cuffed endotracheal tubes and, implicitly, the increased endotracheal tube resistance is still a matter of debate. AIMS: This in vitro study investigated work of breathing and inspiratory airway pressures in cuffed and uncuffed endotracheal tubes and the impact of pressure support ventilation and automatic tube compensation. METHODS: In 5 simulated neonatal and pediatric lung models, the Active Servo Lung 5000 and an intensive care ventilator were used to quantify the differences in work of breathing under spontaneous breathing (with and without pressure support ventilation and automatic tube compensation) between cuffed and uncuffed endotracheal tubes. Additionally, differences in inspiratory airway pressures, measured either proximal or distal of the endotracheal tube, between cuffed and uncuffed endotracheal tubes under mechanical ventilation were investigated. RESULTS: Work of breathing was overall 10.27% [95% confidence interval 9.01-11.94] higher with cuffed than with uncuffed endotracheal tubes and was dramatically reduced by 34.19% [95% confidence interval 31.61-35.25] with the application of pressure support. Automatic tube compensation almost diminished work of breathing differences between the 2 endotracheal tube types in nearly all pediatric lung models. Peak inspiratory and mean airway pressures measured at the proximal endotracheal tube end revealed significantly higher values in cuffed than in uncuffed endotracheal tubes. However, these differences measured at the distal end of the endotracheal tube became minimal. CONCLUSION: This in vitro study confirmed significant differences in work of breathing and inspiratory pressures between cuffed and uncuffed endotracheal tubes. Work of breathing, however, is almost neutralized by pressure support ventilation with automatic tube compensation and distal inspiratory airway pressures that, from a clinical perspective, are not significantly increased.


Assuntos
Intubação Intratraqueal/instrumentação , Pulmão/fisiologia , Modelos Biológicos , Respiração com Pressão Positiva/instrumentação , Trabalho Respiratório/fisiologia , Resistência das Vias Respiratórias , Criança , Desenho de Equipamento , Humanos , Pulmão/anatomia & histologia , Volume de Ventilação Pulmonar , Ventiladores Mecânicos
19.
Respir Care ; 63(8): 966-980, 2018 08.
Artigo em Inglês | MEDLINE | ID: mdl-30042124

RESUMO

BACKGROUND: A flow-dependent conical positive expiratory pressure (PEP) resistor incorporated into a oronasal mask was developed, which might reduce dyspnea and dynamic hyperinflation and increase exercise endurance for patients with COPD. We reported here the flow-pressure relationships and the safety and suitability of the device when used by healthy young and older subjects. METHODS: The flow-pressure relationships were determined for a range of resistors with different orifice diameters and cone lengths. A 1-cm conical-PEP device with a 6- or 7-mm orifice was used during a cycle exercise test (60% heart rate reserve) in 15 young (mean ± SD, 24.3 ± 3.9 y) and 12 older (mean ± SD, 64.4 ± 3.5 y) adults. Cardiopulmonary function and dyspnea were monitored for up to 10 min of exercise. RESULTS: For a given flow, pressure decreased as the cone length and orifice size increased. A 1-cm cone with a 6 mm orifice generated pressures of 5.24 ± 0.17 cm H2O and 18.29 ± 0.34 cm H2O at flows of 0.5 and 0.9 L/s, while for a 7 mm orifice, pressures were 4.88 ± 0.13 cm H2O and 19.14 ± 0.10 cm H2O at flows of 0.5 and 1.1 L/s, such as might occur during exercise. The choice of orifice size for a subject depended on his or her estimated expiratory flow; larger flows required the larger orifice to generate an expiratory pressure of between 5 and 20 cm H2O. Breathing with the conical-PEP device did not affect exercise time, dyspnea, minute ventilation, heart rate, or blood pressure. The SpO2 was slightly lower and PETCO2 was somewhat higher than during control exercise, but the differences were not significant. There were no adverse physiological consequences. CONCLUSIONS: A conical-PEP device of 1-cm length with an orifice of 6 or 7 mm generates effective expiratory pressure for most subjects during exercise. There were no adverse effects in healthy young and older subjects, and the device is suitable for trials with patients with COPD. (ClinicalTrials.gov registration NCT 02788370.).


Assuntos
Exercício/fisiologia , Respiração com Pressão Positiva/instrumentação , Adulto , Idoso , Pressão do Ar , Pressão Sanguínea , Dispneia/etiologia , Desenho de Equipamento , Teste de Esforço , Tolerância ao Exercício , Expiração , Feminino , Frequência Cardíaca , Humanos , Masculino , Máscaras , Pessoa de Meia-Idade , Respiração com Pressão Positiva/métodos , Ventilação Pulmonar , Adulto Jovem
20.
Respir Care ; 63(7): 865-872, 2018 07.
Artigo em Inglês | MEDLINE | ID: mdl-29895701

RESUMO

BACKGROUND: Sensitive flow or pressure triggers are usually applied to improve ventilator response time. Conversely, too sensitive triggers can incur risk of auto-triggering, a type of asynchrony in which a breath is triggered without inspiratory muscle activity. A frequent cause of auto-triggering is cardiogenic oscillations, characterized by cyclical variations in pressure and flow waveforms caused by cardiac contractions. Our goal was to test trigger performance and capacity to abolish auto-triggering in 5 different ICU ventilators using different simulated levels of cardiogenic oscillations. METHODS: A mechanical breathing simulator was used to test 5 different ICU ventilators' trigger response time and capacity to minimize auto-triggering in conditions with 0, 0.25, 0.5, and 1 cm H2O cardiogenic oscillation. Each ventilator was evaluated until an ideal trigger was found (the most sensitive that abolished auto-triggering). When the least sensitive flow trigger was unable to avoid auto-triggering, a pressure trigger was used. We compared time delay, airway pressure drop until triggering, and work of breathing before each trigger, all at the ideal trigger level for each cardiogenic oscillation amplitude. We also assessed the proportion of auto-triggered breaths in the whole range of trigger levels tested. RESULTS: Larger cardiogenic oscillations were associated with more frequent auto-triggering. To avoid auto-triggering, less sensitive triggers were required (+2.51 L/min per 1 cm H2O increase in cardiogenic oscillation; 95% CI 2.26-2.76, P < .001). Time delay increased with larger cardiogenic oscillations, because less sensitive trigger levels were required to abolish auto-triggering (4.79-ms increase per 1 L/min increment on flow trigger). CONCLUSIONS: More sensitive triggers led to faster ventilator response, but also to more frequent auto-triggering. To avoid auto-triggering, less sensitive triggers were required, with consequent slower trigger response. To compare trigger performance in a scenario that more closely represents clinical practice, evaluation of the tradeoff between time delay and frequency of auto-triggering should be considered.


Assuntos
Falha de Equipamento , Hemodinâmica , Respiração com Pressão Positiva/instrumentação , Mecânica Respiratória , Ventiladores Mecânicos , Simulação por Computador , Coração/fisiopatologia , Humanos , Oscilometria , Tempo de Reação , Trabalho Respiratório/fisiologia
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