Improvement of postoperative pulmonary function during general anesthesia for open abdominal surgery with lung protective ventilation strategy and alveolar recruitment maneuvers / 中国医师进修杂志

Objective To observe the improvement of postoperative pulmonary function and oxygen partial pressure during general anesthesia for open abdominal surgery with lung protective ventilation strategies and alveolar recruitment maneuvers. Methods Seventy patients who underwent selective open abdominal surgery were selected, and they were divided into standard ventilation group (tidal volume 8 ml/kg) and protective ventilation group (tidal volume 6 ml/kg, 5 cmH2O positive end-expiratory pressure, and alveolar recruitment maneuvers, 1 cmH2O=0.098 kPa) according to the random digits table method with 35 cases each. The airway pressure, blood pressure, pulse oxygen saturation (SpO2), end-tidal partial pressure of carbon dioxide (PETCO2) and adverse reactions were observed. The SpO2, partial pressure of O2 (PaO2) and pulmonary function before surgery and 1, 3, 5 d after surgery were measured. Results The respiratory rate, airway pressure and PETCO2 levels in protective ventilation group were significantly higher than those in standard ventilation group: (12.3 ± 2.1) times/min vs. (10.2 ± 1.0) times/min, (15.1 ± 2.8) cmH2O vs. (13.5 ± 2.3) cmH2O, (34.6 ± 2.1) mmHg (1 mmHg=0.133 kPa) vs. (32.1 ± 1.4) mmHg, and there were statistical differences (P0.05). The SpO2 and PaO2 levels at 1, 3 d after surgery in protective ventilation group were significantly higher than those in standard ventilation group:0.951 ± 0.018 vs. 0.936 ± 0.016 and 0.964 ± 0.018 vs. 0.949 ± 0.018, (74.8 ± 6.8) mmHg vs. (65.0 ± 6.2) mmHg and (79.6 ± 6.0) mmHg vs. (70.6 ± 5.3) mmHg, and there were statistical differences (P<0.05). The forced expiratory volume in 1 s (FEV1), percentage of the estimated value of FEV1, forced vital capacity (FVC) and percentage of the estimated value of FVC at 1, 3 and 5 d after surgery in protective ventilation group were significantly higher than those in standard ventilation group, the FEV1/FVC at 1 d after surgery was significantly higher than that in standard ventilation group, and there were statistical differences (P<0.05). Conclusions The lung protective ventilation strategy and alveolar recruitment maneuvers can improve the postoperative pulmonary function and oxygen partial pressure during general anesthesia for abdominal surgery. Low vital volume, appropriate positive end-expiratory pressure and recruitment maneuvers can protect the lung in general anesthesia patients.

Effects of Alveolar Recruitment and Positive End-Expiratory Pressure on Oxygenation during One-Lung Ventilation in the Supine Position

PURPOSE: Hypoxemia during one-lung ventilation (OLV) remains a serious problem, particularly in the supine position. We investigated the effects of alveolar recruitment (AR) and positive end-expiratory pressure (PEEP) on oxygenation during OLV in the supine position. MATERIALS AND METHODS: Ninety-nine patients were randomly allocated to one of the following three groups: a control group (ventilation with a tidal volume of 8 mL/kg), a PEEP group (the same ventilatory pattern with a PEEP of 8 cm H2O), or an AR group (an AR maneuver immediately before OLV followed by a PEEP of 8 cm H2O). The tidal volume was reduced to 6 mL/kg during OLV in all groups. Blood gas analyses, respiratory variables, and hemodynamic variables were recorded 15 min into TLV (TLVbaseline), 15 and 30 min after OLV (OLV15 and OLV30), and 10 min after re-establishing TLV (TLVend). RESULTS: Ultimately, 92 patients were analyzed. In the AR group, the arterial oxygen tension was higher at TLVend, and the physiologic dead space was lower at OLV15 and TLVend than in the control group. The mean airway pressure and dynamic lung compliance were higher in the PEEP and AR groups than in the control group at OLV15, OLV30, and TLVend. No significant differences in hemodynamic variables were found among the three groups throughout the study period. CONCLUSION: Recruitment of both lungs with subsequent PEEP before OLV improved arterial oxygenation and ventilatory efficiency during video-assisted thoracic surgery requiring OLV in the supine position.

Recrutamento alveolar na Síndrome do desconforto respiratório agudo / Alveolar recruitment in Acute respiratory syndrome of desconfort

Objetivo: revisar conceitos atuais relacionados às técnicas fisioterapêuticas utilizadas para recrutar alvéolos colap-sados na Síndrome do desconforto respiratório agudo, identificando seus possíveis benefícios, riscos e cuidados a serem tomados na aplicação da manobra de recrutamento alveolar Método: realizado levantamento bibliográfico nas seguintes bases de pesquisa: PubMed, Google Acadêmico e SciELO nos últimos 10 anos (2003-2013). Foram incluídos artigos publicados em língua portuguesa e inglesa. Considerações finais: a manobra de recrutamento alveolar ideal será aquela que garantir menores efeitos hemodinâmicos e fisiológicos melhorando o prognóstico de pacientes com síndrome do desconforto respiratório agudo.

Objective: to review current concepts related ace physical therapy techniques used to recruit collapsed alveoli in acute respiratory distress syndrome, identifying its potential benefits, risks and precautions to be taken in the application of recruitment maneuvers. Method: performed bibliographic research on the following bases: PubMed, Google Scholar and SciELO the last 10 years (2003-2013). We included articles published in English and Portuguese. Conclusion: the recruitment maneuver ideal one that will ensure lower hemodynamic and physiologic improving the prognosis of patients with acute respiratory distress syndrome.

Effects of a preemptive alveolar recruitment strategy on arterial oxygenation during one-lung ventilation with different tidal volumes in patients with normal pulmonary function test / 대한마취과학회지

BACKGROUND: Hypoxemia during one-lung ventilation (OLV) remains a major concern. The present study compared the effect of alveolar recruitment strategy (ARS) on arterial oxygenation during OLV at varying tidal volumes (Vt) with or without positive end-expiratory pressure (PEEP). METHODS: In total, 120 patients undergoing wedge resection by video assisted thoracostomy were randomized into four groups comprising 30 patients each: those administered a 10 ml/kg tidal volume with or without preemptive ARS (Group H and Group H-ARS, respectively) and those administered a 6 ml/kg tidal volume and a 8 cmH2O PEEP with or without preemptive ARS (Group L and Group L-ARS, respectively). ARS was performed using pressure-controlled ventilation with a 40 cmH2O plateau airway pressure and a 15 cmH2O PEEP for at least 10 breaths until OLV began. RESULTS: Preemptive ARS significantly improved the PaO2/FiO2 ratio compared to the groups that did not receive ARS (P < 0.05). The H-ARS group showed a highest PaO2/FiO2 ratio during OLV, the L-ARS and H groups showed similarly improved arterial oxygenation, which was significantly higher than in group L (P < 0.05). The plateau airway pressure in group H-ARS was significantly higher than in group L-ARS (P < 0.05). CONCLUSIONS: Preemptive ARS can improve arterial oxygenation during OLV. Furthermore, a 6 ml/kg tidal volume combined with 8 cmH2O PEEP after preemptive ARS may reduce the risk of pulmonary injury caused by high tidal volume during one-lung ventilation in patients with normal pulmonary function.

Recruitment maneuvers in pediatric patients with acute respiratory distress syndrome / 中国小儿急救医学

Recently,alveolar recruitment maneuver is one of effective management of mechanically ventilated patients with acute respiratory distress syndrome.Recruitment maneuvers are widely used in clinical practice to open the lung and prevent lung injury by derecruitment,improving the compliance,increasing PaO2,increasing the PaO2/FiO2 ratio,and reducing the pulmonary shunt fraction,although the evidence is still discussed.This review discussed recruitment maneuvers in pediatric patients with acute respiratory distress syndrome.

Análisis de las maniobras de reclutamiento alveolar aplicadas en siete Unidades de Cuidado Intensivo / Analysis of the alveolar recruitment maneuvers of applications in the intensive care units seven / Análise das manobras de recrutamento alveolar aplicadas em sete unidades de cuidado intensivo

Introducción: En los últimos años las maniobras de reclutamiento alveolar (MR) han despertado un interés creciente por su potencial beneficio en la protección pulmonar y se han ido introduciendo en la práctica clínica. Objetivo: Describir y analizar los conocimientos sobre las MR y su aplicación en siete Unidades de Cuidado Intensivo de la ciudad de Cali - Colombia. Materiales y métodos: Estudio descriptivo de corte transversal, con una muestra intencional de 64 profesionales que laboran en siete Unidades de Cuidado Intensivo de Cali y aplican las MR. La encuesta auto-administrada constaba de trece preguntas y el periodo de aplicación fue de dos meses. Resultados: De los 64 encuestados el 77,8% sigue una guía o protocolo para realizar las MR; el 54,7% utiliza durante la MR un nivel de Presión Positiva al Final de la Espiración (PEEP) ideal que asegure una saturación > de 90% y PaO2 > de 60 mmHg; el 42,1% acepta presiones en la vía aérea entre 35 y 50 cmH2O; el 48,4% realiza las MR con aumento progresivo de la PEEP y bajo volumen corriente. Conclusiones: Se encontró heterogeneidad en las respuestas relacionadas con el conocimiento de las MR. No existe en la actualidad un consenso acerca de cuál es la forma más eficaz y segura de aplicar una MR. Este estudio puede ser el punto de partida para un llamado de atención a la revisión de los conocimientos, competencias y habilidades que se requieren para realizar las MR.

Introduction: For the past years, alveolar recruitment maneuvers (RM) have originated a growing interest due to their beneficial potential in pulmonary protection, and have been introduced in clinical practice. Objective: Describe and analyze the knowledge of the MR and its application in seven intensive care units in the city of Cali, Colombia. Method and materials: Descriptive Cross-Sectional Study with an intentional sample of 64 professionals working in seven intensive care units and apply MR. The self-completed survey was made up of thirteen questions, and the application period was two months. Results: To perform RM, of 64 professionals survey, 77.8% of the healthcare providers that were polled follow a protocol guide, in which 54.7% answered that during RM the ideal Positive end-expiratory pressure (PEEP) is the one which maintains a saturation > 90% and a PaO2 > 60 mmHg; 42.1% tolerates airway pressures between 35 and 50 cmH2O; 48.4% perform RM with a progressive increase of the PEEP and a low tidal volume. Conclusions: Regarding the knowledge related to RM, heterogeneity was found in the answers. There is currently no consensus about which is the most effective and secure way to implement an MR. This study can be the starting point to create awareness towards the revision of knowledge, capacities and abilities that are required to perform RM.

Introdução: Nos últimos anos as manobras de recrutamento alveolar (MR) têm despertado um interesse crescente por seu potencial benéfico na proteção pulmonar e têm-se ido introduzindo na prática clínica. Objetivo: Descrever e analisar os conhecimentos sobre as MR e sua aplicação em sete Unidades de Cuidado Intensivo da cidade de Cali - Colômbia. Materiais e métodos: Estudo descritivo de corte transversal, com uma amostra intencional de 64 profissionais que trabalham em sete Unidades de Cuidado Intensivo de Cali e aplicam as MR. A enquête auto-administrada constava de treze perguntas e o período de aplicação foi de sois meses. Resultados: Dos 64 pesquisados o 77,8% segue uma guia ou protocolo para realizar as MR; o 54,7% utiliza durante a MR um nível de Pressão Expiratória Positiva Final (PEEP) ideal que segure uma saturação > de 90% e PaO2 > de 60 mmHg; o 42,1% aceita pressões na via aérea entre 35 e 50 cmH2O; o 48,4% realiza as MR com aumento progressivo da PEEP e sob o volume corrente. Conclusões: Se encontrou heterogeneidade nas respostas relacionadas com o conhecimento das MR. Não existe na atualidade um consenso acerca de qual é a forma mais eficaz e segura de aplicar uma MR. Este estudo pode ser o ponto de partida para um chamado de atenção à revisão dos conhecimentos, competências e habilidades que se requerem para realizar as MR.

The Effects of Repetitive Alveolar Recruitment on Oxygenation and Compliance in ARDS Patients / 대한마취과학회지

BACKGROUND: If the effects of alveolar recruitment are beneficial, but of short duration, repetitive recruitment maneuvers (RMs) will be necessary to maintain oxygenation. This study was performed to assess the effect of repetitive alveolar recruitment, with high-sustained inflation pressure on oxygenation and compliance of the respiratory system, in patients with acute respiratory distress syndrome. METHODS: Ten adult patients on ventilator support, with controlled mechanical ventilation, received three repetitive RMs with a high-sustained inflation pressure. The time intervals from the first to second RM and from the second to third RM were 8.42 +/- 0.56 hours and 12.43 +/- 1.45 hours, respectively. Recruitment was conducted by setting the ventilator mode to a continuous positive airway pressure of 40 cmH2O for 40 seconds. After each alveolar recruitment, the previous ventilator settings in the pressure control mode were re-established with a high positive end expiratory pressure. The FIO2, PaO2/FIO2 and lung compliance (tidal volume/[plateau pressure-PEEP]) were recorded with reference to the arterial blood gas analysis at both 30 minutes pre and post recruitment. RESULTS: The FIO2 was able to be decreased from 0.9 to 0.5 while maintaining the PaO2 at higher than 80 mmHg after three recruitments. The PaO2/FIO2 improved from 98 to 288 and the compliance of the respiratory system improved from 26 to 41 ml/cmH2O after three recruitments. CONCLUSIONS: Our RESULTS suggest that repetitive recruitment can be used to maintain the beneficial effects of alveolar recruitment in patients with acute respiratory distress syndrome when supported using a lung protective mechanical ventilation strategy.

Improvement of Hypoxemia by Repetitive Alveolar Recruitments in Brain-dead Donor: A case report / 대한마취과학회지

Brain-dead potential donors manifest devastating physiological changes associated with pulmonary edema, profound hemodynamic and metabolic abnormalities. These derangements may be more significant after apnea tests which result in severe hypoxemia and cardiovascular complications. De-recruitment can occur following apnea tests in the brain-dead donor whose ventilator support has been maintained with high positive end-expiratory pressure (PEEP), and recruitment maneuvers are intended to open collapsed lung units. We report a brain-dead potential donor with severe hypoxemia and hemodynamic instability after apnea tests, which improved after multiple alveolar recruitments with adequate vasoactive drugs. Multiple high-pressure recruitment maneuvers will be helpful for expansion of lung collapse with improvement of severe hypoxemia after de-recruitment which could be developed with apnea tests in brain-dead organ donor.

Difference of Short Term Survival in Patients with ARDS According to Responsiveness to Alveolar Recruitment / 결핵

BACKGROUND: Lung protective strategies, using low tidal volume in ARDS, improve survival rate in ARDS. However, low tidal volume ventilation may promote alveolar de-recruitment. Therefore, alveolar recruitment is necessary to maintain arterial oxygenation and to prevent repetitive opening and closure of collapsed alveoli in lung protective strategies. There has been a recent report describing improvement in arterial oxygenation with use of recruitment maneuver. However, impact of recruitment on outcome of ARDS is unknown. We evaluated whether short-term survival difference existed in patients with ARDS, who were performed alveolar recruitment maneuver(ARM) and prone position, according to response of alveolar recruitment or not. METHODS: All patients who were diagnosed with ADRS and received mechanical ventilation were included. ARM were sustained inflation(35-45 cmH2O CPAP for 30-40 sec.) or increasing level of PEEP. If these methods were ineffective, alveolar recruitment with prone position was done for at least 10 hours. PaO2/FiO2(P/F) ratio was determined before and at 0.5 and 2 hours after ARM. We defined a responder if the P/F ratio was increased over 50% of baseline value. We compared 10-days and 30-days survival rate between responders and non-responders. RESULTS: 20 patients(M:F=12:8, 63 +/- 14 age) were included. Among them, 12 patients were responders and 8 patients were non-responders. In responders, P/F ratio was increased from 92 +/- 25 mmHg to 244 +/- 85 mmHg. In non-responders, P/F ratio increased from 138 +/- 37 mmHg to 163 +/- 60 mmHg. Among non-responders, P/F ratio was improved over 50% in 2 patients after prone position. Overall, 14 patients were responders after ARM and prone position. The 10-days and 30-days survival rate in responders was significantly higher than in non-responders(86%, 57% in responders and 33%, 0% in non-responders)(p<0.05). There was no significant difference between responders and non-responders in age(71 +/- 11, 60 +/- 14), lung injury score(2.8 +/- 0.2, 2.9 +/- 0.45), simplified acute physiology score(SAPS) II (35 +/- 4.6, 34 +/- 5.7), positive end-positive pressure level(15.6 +/- 1.9 cmH2O, 14.5 +/- 2.1 cmH2O). CONCLUSION: ARM may improve arterial oxygenation in some patients with ARDS. These responders in patients with ARDS showed significant higher 10-days and 30-days survival rate than non-responders patients with alveolar recruitment.

Tomografia computadorizada na insuficiência respiratória aguda / Computerized tomography in acute respiratory failure

O objetivo do presente trabalho é revisar o uso da tomografia computadorizada (TC) na insuficiência respiratória aguda (IRA) - lesão pulmonar aguda ou acute lung injury (ALI) e síndrome da angústia respiratória aguda (SARA). Foram revisados os principais trabalhos publicados na literatura em língua inglesa e localizados por pesquisa na Medline, que estudaram o uso da TC na IRA. A TC permite, num primeiro momento, uma avaliação qualitativa da morfologia pulmonar buscando a presença de hiperdensidades difusas e/ou localizadas e de outras anormalidades concomitantes (como derrame pleural e pneumotórax). Além disso, permite avaliar os histogramas de densidade pulmonares a partir dos quais podem ser efetuados o cálculo dos volumes pulmonares totais e regionais (volume das regiões ventiladas, parcialmente ventiladas, não ventiladas e de hiperdistensão). Isso possibilita quantificar recrutamento alveolar e hiperdistensão decorrentes de estratégias ventilatórias, como por exemplo do uso de diferentes níveis de pressão expiratória final positiva (PEEP).

The goal of this paper is to review the use of CT scan in acute respiratory failure (ARF), acute lung injury (ALI) and acute respiratory distress syndrome (ARDS). The most important papers studying CT in ARF, published in English language literature, were found in Medline. The use of CT in patients with ARF let allowed the authors to proceed to a qualitative evaluation of lung morphology looking for diffuse an/or localized hyperdensities, and for other concomitant abnormalities (pleural effusion, pneumothorax). It is also possible to evaluate lung density histograms and calculate the gas-tissue ratio within the lungs. Likewise, one can also calculate total and regional lung volumes (aerated, poorly-aerated, non-aerated, and overdistension volumes). Knowing those volumes it is possible to quantify alveolar recruitment and overdistension due to ventilatory strategies as the use of different positive end expiratory pressure (PEEP) levels.