Relação entre a Complacência Pulmonar Estática e a Falha de Extubação em Pacientes Pós-Operatório de Cirurgia Cardíaca / Relationship between Static Lung Compliance and Extubation Failure in Postoperative Cardiac Surgery Patients

Resumo Fundamento: Pouco explorada na decisão de extubação no pós-operatório de cirurgia cardíaca, a complacência pulmonar estática seriamente afetada no procedimento cirúrgico pode levar à insuficiência respiratória e à falha na extubação. Objetivo: Avaliar a complacência pulmonar estática no pós-operatório de cirurgia cardíaca e relacionar sua possível redução aos casos de falha na extubação dos pacientes submetidos ao método fast-track de extubação. Métodos: Foram incluídos pacientes que realizaram cirurgia cardíaca com uso de circulação extracorpórea (CEC) em um hospital universitário estadual admitidos na UTI sob sedação e bloqueio residual. Tiveram sua complacência pulmonar estática avaliada no ventilador mecânico por meio do software que utiliza o least squares fitting (LSF) para a medição. No período de 48 horas após a extubação os pacientes foram observados respeito à necessidade de reintubação por insuficiência respiratória. O nível de significância adotado para os testes estatísticos foi de 5%, ou seja, p<0,05. Resultados: Obtiveram sucesso na extubação 77 pacientes (75,49%) e falharam 25 (24,51%). Os pacientes que falharam na extubação tiveram a complacência pulmonar estática mais baixa quando comparados aos que tiveram sucesso (p<0,001). Identificamos o ponto de corte para complacência por meio da análise da curva Receiver Operating Characteristic Curve (ROC) sendo o ponto de corte o valor da complacência <41ml/cmH2O associado com maior probabilidade de falha na extubação (p<0,001). Na análise de regressão múltipla, verificou-se a influência da complacência pulmonar (dividida pelo ponto de corte da curva ROC) com risco de falha 9,1 vezes maior para pacientes com complacência <41ml/cmH2O (p< 0,003). Conclusões: A complacência pulmonar estática <41ml/cmH2O é um fator que compromete o sucesso da extubação no pós-operatório de cirurgia cardíaca.

Abstract Background: Static lung compliance, which is seriously affected during surgery, can lead to respiratory failure and extubation failure, which is little explored in the decision to extubate after cardiac surgery. Objective: To evaluate static lung compliance in the postoperative period of cardiac surgery and relate its possible reduction to cases of extubation failure in patients submitted to the fast-track method of extubation. Methods: Patients undergoing cardiac surgery using cardiopulmonary bypass (CPB) at a state university hospital admitted to the ICU under sedation and residual block were included. Their static lung compliance was assessed on the mechanical ventilator using software that uses least squares fitting (LSF) for measurement. Within 48 hours of extubation, the patients were observed for the need for reintubation due to respiratory failure. The level of significance adopted for the statistical tests was 5%, i.e., p<0.05. Results: 77 patients (75.49%) achieved successful extubation and 25 (24.51%) failed extubation. Patients who failed extubation had lower static lung compliance compared to those who succeeded (p<0.001). We identified the cut-off point for compliance through analysis of the Receiver Operating Characteristic Curve (ROC), with the cut-off point being compliance <41ml/cmH2O associated with a higher probability of extubation failure (p<0.001). In the multiple regression analysis, the influence of lung compliance (divided by the ROC curve cut-off point) was found to be 9.1 times greater for patients with compliance <41ml/cmH2O (p< 0.003). Conclusions: Static lung compliance <41ml/cmH2O is a factor that compromises the success of extubation in the postoperative period of cardiac surgery.

O Uso de um Ventilador Mecânico Portátil na Ressuscitação Cardiopulmonar é Viável, Melhora os Parâmetros Respiratórios e Previne a Redução da Complacência Pulmonar Dinâmica / Use of a Portable Mechanical Ventilator during Cardiopulmonary Resuscitation is Feasible, Improves Respiratory Parameters, and Prevents the Decrease of Dynamic Lung Compliance

Resumo Fundamentos Para ventilação prática e protetora durante a ressuscitação cardiopulmonar (RCP), desenvolveu-se um ventilador mecânico (VLP2000E) de 150 gramas que limita o pico de pressão inspiratória (PPI) durante ventilação e compressões torácicas simultâneas. Objetivos Avaliar a viabilidade da ventilação com VLP2000E durante RCP e comparar os parâmetros monitorados versus ventilação com bolsa-válvula. Métodos Estudo experimental randomizado com 10 porcos intubados por grupo. Após sete minutos de fibrilação ventricular, iniciaram-se ciclos de RCP de 2 minutos. Todos os animais foram ventilados com VLP2000E após o retorno da circulação espontânea (RCE). Resultados Os grupos bolsa-válvula e VLP2000E apresentaram taxa de RCE (60% vs. 50%, respectivamente) e saturação arterial de oxigênio similares na maioria dos ciclos de RCP, volume corrente basal diferente [0,764 (0,068) vs. 0,591 (0,123) L, p = 0,0309, respectivamente] e, em 14 ciclos, diferentes PPI [52 (9) vs. 39 (5) cm H2O, respectivamente], volume corrente [0,635 (0,172) vs. 0,306 (0,129) L], ETCO2 [14 (8) vs. 27 (9) mm Hg], e pico de fluxo inspiratório [0,878 (0,234) vs. 0,533 (0,105) L/s], todos p < 0,0001. A complacência pulmonar dinâmica (≥ 0,025 L/cm H2O) diminuiu após o RCE no grupo bolsa-válvula, mas se manteve no grupo VLP2000E [ 0,019 (0,006) vs. 0,024 (0,008) L/cm H2O, p = 0,0003]. Conclusões Ventilação com VLP2000E durante RCP é viável e equivalente a ventilação com bolsa-válvula quanto à taxa de RCE e saturação arterial de oxigênio. Esse ventilador produz melhores parâmetros respiratórios, com pressão das vias aéreas e volume corrente menores. Ventilação com VLP2000E também previne a redução significante da complacência pulmonar dinâmica observada após ventilação com bolsa-válvula. Seria interessante realizar mais estudos pré-clínicos para confirmar esses resultados.

Abstract Background For practical and protective ventilation during cardiopulmonary resuscitation (CPR), a 150-grams mechanical ventilator (VLP2000E) that limits peak inspiratory pressure (PIP) during simultaneous ventilation with chest compressions was developed. Objectives To evaluate the feasibility of VLP2000E ventilation during CPR and to compare monitored parameters versus bag-valve ventilation. Methods A randomized experimental study with 10 intubated pigs per group. After seven minutes of ventricular fibrillation, 2-minute CPR cycles were delivered. All animals were placed on VLP2000E after achieving return of spontaneous circulation (ROSC). Results Bag-valve and VLP2000E groups had similar ROSC rate (60% vs. 50%, respectively) and arterial oxygen saturation in most CPR cycles, different baseline tidal volume [0.764 (0.068) vs. 0.591 (0.123) L, p = 0.0309, respectively] and, in 14 cycles, different PIP [52 (9) vs. 39 (5) cm H2O, respectively], tidal volume [0.635 (0.172) vs. 0.306 (0.129) L], ETCO2[14 (8) vs. 27 (9) mm Hg], and peak inspiratory flow [0.878 (0.234) vs. 0.533 (0.105) L/s], all p < 0.0001. Dynamic lung compliance (≥ 0.025 L/cm H2O) decreased after ROSC in bag-valve group but was maintained in VLP2000E group [0.019 (0.006) vs. 0.024 (0.008) L/cm H2O, p = 0.0003]. Conclusions VLP2000E ventilation during CPR is feasible and equivalent to bag-valve ventilation in ROSC rate and arterial oxygen saturation. It produces better respiratory parameters, with lower airway pressure and tidal volume. VLP2000E ventilation also prevents the significant decrease of dynamic lung compliance observed after bag-valve ventilation. Further preclinical studies confirming these findings would be interesting.

Fisiología respiratoria: fisiología de las enfermedades pulmonares restrictivas / Pathophysiology of pulmonary restrictive diseases

Las enfermedades restrictivas comprenden un grupo heterogéneo de trastornos que se caracterizan por una alteración en la distensibilidad pulmonar, generada por enfermedades del parénquima o intersticio pulmonar o por problemas extrapulmonares (alteraciones de la caja torácica o enfermedades neuromusculares). Presentan un patrón característico en las pruebas de función pulmonar, relación VEF1/ FVC normal o aumentada con CVF disminuida, VEF1 disminuido leve o normal y capacidad pulmonar total disminuida (CPT). Su manejo es complejo debido a la dificultad para establecer el diagnóstico diferencial, por lo que se recomienda una derivación precoz a un especialista en enfermedades respiratorias y el enfrentamiento por un equipo multidisciplinario.

Restrictive diseases comprise a heterogeneous group of disorders characterized by an alteration in lung compliance, generated by diseases of the lung parenchyma or interstitium, as well as by extrapulmonary problems (abnormalities of the rib cage or neuromuscular diseases). They present a characteristic pattern in pulmonary function tests, with decreased FVC (forced vital capacity), slightly decreased or normal FEV1 (forced expiratory volume in 1 second), normal or increased FEV1/FVC ratio, and decreased total lung capacity. Its management is complex due to the difficulty in establishing the differential diagnosis, so early referral to a specialist in respiratory diseases and confrontation by a multidisciplinary team is recommended.

Asociación y valor predictivo del índice poder mecánico-distensibilidad pulmonar con días libres de ventilación mecánica en pacientes con COVID-19 en una unidad de terapia intensiva / Association and predictive value of the mechanical power-lung compliance index with free days off mechanical ventilation in patients with COVID-19 in an intensive care unit / Associação e valor preditivo do índice de potência mecânica/complacência pulmonar com dias livres de ventilação mecânica em pacientes com COVID-19 em unidade de terapia intensiva

Resumen: Introducción: El poder mecánico (PM) se asocia a mortalidad y se debe ajustar a las características pulmonares en pacientes COVID-19. Material y métodos: Estudio observacional, retrospectivo y analítico, de septiembre de 2020 a febrero de 2021. Los parámetros de ventilación y análisis de la curva ROC y modelos de regresión de Poisson para OR. Objetivo primario fue determinar la asociación entre el índice PM/Cest y días libres de ventilación mecánica (DLVM). Resultados: Se incluyeron 43 pacientes. Se dividió en sobrevivientes (n = 25, 58.1%) y no sobrevivientes (n = 18, 41.9%). Se eligió mediana de DLVM con los parámetros de VMI. El índice PM/Cest inicial ABC 0.73 [IC 95% (0.58-0.88), p = 0.008], punto de corte de 0.90 Joules/min/mL/cm H2O. La regresión multivariable de Poisson el índice PM/Cest inicial OR 0.18 [IC 95% (0.03-0.98), p = 0.047]. Discusión: Coppola y colaboradores documentaron que en pacientes con SDRA no COVID-19, el valor de PM absoluto no demostró significancia; al ajustarlo a Cest fue independiente para mortalidad. Conclusiones: El índice PM/Cest al inicio se asoció de forma significativa e independiente con DLVM en COVID-19. Punto de corte de 0.9 J/min/mL/cmH2O con mejor sensibilidad y especificidad para predecir los DLVM y esto podría reducir la mortalidad.

Abstract: Introduction: Mechanical power (MP) is associated with mortality and must be adjusted to the pulmonary characteristics in COVID-19 patients. Material and methods: Observational, retrospective, analytical study from September 2020-February 2021. Ventilation parameters and ROC curve analysis and Poisson regression models for OR. Primary objective was to determine the association between the PM/Cest index and free days of mechanical ventilation (FDMV). Results: 43 patients were included. It was divided into survivors (n = 25, 58.1%) and non-survivors (n = 18, 41.9%). Median FDMV was chosen with the IMV parameters. The initial MP/Cest index ABC 0.73 [95% CI (0.58-0.88), p = 0.008], cut-off point of 0.90 J/min/mL/cmH2O. The multivariate Poisson regression showed the initial MP/Cest index OR 0.18 [95% CI (0.03-0.98), p = 0.047]. Discussion: Coppola et al. documented in patients with non-COVID-19 ARDS, the absolute MP value did not demonstrate significance; when adjusted to Cest, it was independent for mortality. Conclusions: The MP/Cest index at baseline was significantly and independently associated with FDMV in COVID-19. Cut-off point of 0.9 J/min/mL/cmH2O with better sensitivity and specificity to predict FDMV and this could reduce mortality.

Resumo: Introdução: A potência mecânica (PM) está associada à mortalidade e deve ser ajustada para características pulmonares em pacientes com COVID-19. Material e métodos: Estudo observacional, retrospectivo, analítico de setembro de 2020 a fevereiro de 2021. Os parâmetros ventilatórios, análise da curva ROC e modelos de regressão de Poisson para OR. O objetivo primário foi determinar a associação entre o índice PM/Cest e dias livres de ventilação mecânica (DLVM). Resultados: Foram incluídos 43 pacientes. Dividiu-se em sobreviventes (n = 25, 58.1%) e não sobreviventes (n = 18, 41.9%). A mediana do DLVM foi escolhida com os parâmetros do VMI. Índice inicial PM/Cest ABC 0.73 [IC 95% (0.58-0.88), p = 0.008], ponto de corte de 0.90 J/min/mL/cmH2O. Regressão multivariável de Poisson no índice PM/Cest inicial OR 0.18 [IC 95% (0.03-0.98), p = 0.047]. Discussão: Coppola et al. documentaram em pacientes com SDRA não-COVID-19, o valor de PM absoluto não mostrou significância; quando ajustado a Cest, foi independente para mortalidade. Conclusões: O índice PM/Cest ao início se associou de maneira significativa e independentemente com DLVM na COVID-19. Ponto de corte de 0.9 J/min/mL/cmH2O com melhor sensibilidade e especificidade para predizer DLVM e isso poderia reduzir a mortalidade.

Caracterización de parámetros del intercambio gaseoso en la Ciudad de México / Characterization of gas exchange parameters in Mexico City

Introducción: en las grandes altitudes, el intercambio gaseoso suele estar deteriorado; en la altitud moderada de la Ciudad de México esto no está aún plenamente definido. Objetivo: caracterizar el intercambio gaseoso en la altitud moderada de la Ciudad de México. Material y métodos: mediante un estudio transversal analítico se estudiaron sujetos nacidos y habitantes de la Ciudad de México, de ambos géneros, con edades de 20 a 59 años sin enfermedad cardiopulmonar. Se registraron sus variables demográficas, espirometría simple y de gasometría arterial. Las diferencias en las variables se calcularon con ANOVA de una vía para grupos independientes y ajuste de Bonferroni. Una p < 0.05 se aceptó como significativa. Resultados: se estudiaron 335 sujetos, de los cuales 168 (50.15%) fueron hombres, la edad grupal fue de 45 ± 11 años, con índice de masa corporal 22.97 ± 1.54 Kg/m2. La relación volumen espiratorio forzado en el primer segundo/Capacidad vital forzada (VEF1/CVF) de 91.58 ± 12.86%. La presión arterial de oxígeno fue de 66 ± 5.02 mmHg, el bióxido de carbono: 32.07 ± 2.66 mmHg, la saturación arterial de oxígeno: 93.03 ± 1.80% y la hemoglobina: 14.07 ± 1.52 gr/dL. Conclusiones: la presión arterial de oxígeno y del bióxido de carbono están disminuidos a la altura de la Ciudad de México.

Background: At high altitude the gas exchange is impaired, in the moderate altitude of Mexico City they are not yet defined. Objective: To characterize the gas exchange in the moderate altitude of Mexico City. Material and methods: Through an analytical cross-sectional study, subjects born and inhabitants of Mexico City, both genders, aged 20 to 59 years without cardiopulmonary disease, were studied. Their demographic variables, simple spirometry and arterial blood gas were recorded. Differences in variables were calculated with one-way ANOVA for independent groups and Bonferroni adjustment. p < 0.05 was accepted as significant. Results: 335 subjects were studied, 168 (50.15%) men. Group age 45 ± 11 years old, body mass index 22.97 ± 1.54 Kg/m2. Forced expiratory volume ratio in the first second / Forced vital capacity (FEV1/FVC) 91.58 ± 12.86%. The arterial oxygen pressure was: 66 ± 5.02 mmHg, carbon dioxide: 32.07 ± 2.66 mmHg, arterial oxygen saturation: 93.0 3 ± 1.80%, and hemoglobin: 14.07 ± 1.52 gr/dL. Conclusions: The arterial oxygen pressure and carbon dioxide are lowered at the Mexico City altitude.

Comparison of pressure-controlled volume-guaranteed ventilation and volume-controlled ventilation in obese patients during gynecologic laparoscopic surgery in the Trendelenburg position / Comparação entre ventilação garantida por volume controlado por pressão e ventilação controlada por volume em pacientes obesos durante cirurgia laparoscópica ginecológica na posição de Trendelenburg

Abstract Background and objectives: The aim of this study was to investigate the efficacy of the pressure-controlled, volume-guaranteed (PCV-VG) and volume-controlled ventilation (VCV) modes for maintaining adequate airway pressures, lung compliance and oxygenation in obese patients undergoing laparoscopic hysterectomy in the Trendelenburg position. Methods: Patients (104) who underwent laparoscopic gynecologic surgery with a body mass index between 30 and 40 kg.m-2 were randomized to receive either VCV or PCV-VG ventilation. The tidal volume was set at 8 mL.kg-1, with an inspired oxygen concentration of 0.4 with a Positive End-Expiratory Pressure (PEEP) of 5 mmHg. The peak inspiratory pressure, mean inspiratory pressure, plateau pressure, driving pressure, dynamic compliance, respiratory rate, exhaled tidal volume, etCO2, arterial blood gas analysis, heart rate and mean arterial pressure at 5 minutes after induction of anesthesia in the and at 5, 30 and 60 minutes, respectively, after pneumoperitoneum in the Trendelenburg position were recorded. Results: The PCV-VG group had significantly decreased peak inspiratory pressure, mean inspiratory pressur, plateau pressure, driving pressure and increased dynamic compliance compared to the VCV group. Mean PaO2 levels were significantly higher in the PCV-VG group than in the VCV group at every time point after pneumoperitoneum in the Trendelenburg position. Conclusions: The PCV-VG mode of ventilation limited the peak inspiratory pressure, decreased the driving pressure and increased the dynamic compliance compared to VCV in obese patients undergoing laparoscopic hysterectomy. PCV-VG may be a preferable modality to prevent barotrauma during laparoscopic surgeries in obese patients.

Resumo Justificativa e objetivos: O objetivo deste estudo foi investigar a eficácia dos modos de ventilação garantida por volume controlado por pressão (PCV-VG) e ventilação controlada por volume (VCV) para manter pressões adequadas nas vias aéreas, complacência pulmonar e oxigenação em pacientes obesos submetidos à histerectomia laparoscópica na posição de Trendelenburg. Métodos: Cento e quatro pacientes submetidos à cirurgia ginecológica laparoscópica, com índice de massa corporal entre 30 e 40 kg.m-2, foram randomizados para receber ventilação com VCV ou PCV-VG. O volume corrente foi fixado em 8 mL.kg-1, com uma concentração inspirada de oxigênio de 0,4 e pressão positiva expiratória final (PEEP) de 5 mmHg. Registramos os seguintes parâmetros: pressão de pico inspiratório, pressão inspiratória média, pressão de platô, driving pressure, complacência dinâmica, frequência respiratória, volume corrente expirado, etCO2, gasometria arterial, frequência cardíaca e pressão arterial média aos 5, 30 e 60 minutos, respectivamente, após o pneumoperitônio na posição de Trendelenburg. Resultados: O grupo PCV-VG apresentou uma redução significativa da pressão de pico inspiratório, pressão inspiratória média, pressão de platô, driving pressure e aumento da complacência dinâmica comparado ao grupo VCV. Os níveis médios de PaO2 foram significativamente maiores no grupo PCV-VG do que no grupo VCV em todos os momentos após o pneumoperitônio na posição de Trendelenburg. Conclusões: O modo de ventilação PCV-VG limitou a pressão de pico inspiratório, diminuiu a driving pressure e aumentou a complacência dinâmica, comparado ao VCV em pacientes obesas submetidas à histerectomia laparoscópica. O PCV-VG pode ser uma modalidade preferida para prevenir o barotrauma durante cirurgias laparoscópicas em pacientes obesos.

The Effects of Chest Physiotherapy on Applied to Patients Mechanicalventilated: In Patients with Acute Lung Injury / 중환자간호학회지

PURPOSE: The purpose of this study was to examine the effects of two single chest physiotherapies mechanically ventilated patients with acute lung injury.METHOD: Participants were 30 ICU patients depending entirely on ventilators without self-respiration. Each patients received two single chest physiotherapiesvibration palm cup percussion at hour intervals. Data were analyzed one-way ANOVA and Wilcoxon signed-rank test. Statistical significance was accepted at a p value less than .05.RESULTS: ibration therapy, dynamic compliance and statics compliance demonstrated a significant increase immediately and remained increased until 30 minutes after chest physiotherapy. palm cum percussion therapy saturation showed a significant increase immediately chest physiotherapyut there were no significant differences in tidal volume, dynamic compliance and statics compliance.CONCLUSION: In this study, we analyzed the effects of oscillation method and palm cup percussion method separately for each type of chest physiotherapy. Nursing interventions that actively utilize vibration methods should be provided to patients with respiratory diseases.

Comparison of clinical performance of i-gelⓇ and Baska MaskⓇ during laparoscopic cholecystectomy / 대한마취과학회지

BACKGROUND: The supraglottic airway device is an appropriate alternative to tracheal intubation in laparoscopic surgery. We compared the Baska MaskⓇ with i-gelⓇ by measuring the oropharyngeal leak pressure (OLP) and hemodynamic and respiratory parameters during laparoscopic cholecystectomy.METHODS: A total of 97 patients were randomly allocated to either i-gel group (n = 49) or Baska Mask group (n = 48). Insertion time, number of insertion attempts, fiber-optic view of the glottis, and OLP were recorded. Heart rate, mean arterial pressure, peak airway pressure (PAP), lung compliance, and perioperative complications were assessed before, during, and after pneumoperitoneum.RESULTS: There were no significant differences between the two groups regarding demographic data, insertion time, fiber-optic view of the glottis, and the use of airway manipulation. The OLP was higher in the Baska Mask group than in the i-gel group (29.6 ± 6.8 cmH₂O and 26.7 ± 4.5 cmH₂O, respectively; P = 0.014). Heart rate, mean arterial pressure, PAP, and lung compliance were not significantly different between the groups. The incidence of perioperative complications was small and not statistically significant.CONCLUSIONS: Both the i-gel and Baska Mask provided a satisfactory airway during laparoscopic cholecystectomy. Compared with the i-gel, the Baska Mask demonstrated a higher OLP.

Effects of propofol, desflurane, and sevoflurane on respiratory functions following endoscopic endonasal transsphenoidal pituitary surgery: a prospective randomized study / 대한마취과학회지

BACKGROUND: General anesthesia with intravenous or inhalation anesthetics reduces respiratory functions. We investigated the effects of propofol, desflurane, and sevoflurane on postoperative respiratory function tests.METHODS: This single-center randomized controlled study was performed in a university hospital from October 2015 to February 2017. Ninety patients scheduled for endoscopic endonasal transsphenoidal pituitary surgery were randomly categorized into either of these three groups: propofol (n = 30, the Group TIVA), desflurane (n = 30, the Group D) or sevoflurane (n = 30, the Group S). We analyzed the patients before, after, and 24 h following surgery, to identify the following parameters: forced expiratory volume in 1 second (FEV₁) %, forced vital capacity (FVC) %, FEV₁/FVC, and arterial blood gases (ABG). Furthermore, we also recorded the intraoperative dynamic lung compliance and airway resistance values.RESULTS: We did not find any significant differences in FEV₁ values (primary outcome) among the groups (P = 0.336). There was a remarkable reduction in the FEV₁ and FVC values in all groups postoperatively relative to the baseline (P < 0.001). The FVC, FEV₁/FVC, ABG analysis, compliance, and airway resistance were similar among the groups. Intraoperative dynamic compliance values were lower at the 1st and 2nd hours than those immediately after intubation (P < 0.001).CONCLUSIONS: We demonstrated that propofol, desflurane, and sevoflurane reduced FEV₁ and FVC values postoperatively, without any significant differences among the drugs.

Effect of dynamic lung compliance-guided PEEP titration on lung injury in elderly patients undergo-ing robot-assisted radical prostatectomy / 中华麻醉学杂志

Objective To evaluate the effect of dynamic lung compliance ( Cydn)-guided positive end-expiratory pressure (PEEP) titration on lung injury in the patients undergoing robot-assisted radical prostatectomy. Methods Forty American Society of Anesthesiologists physical status Ⅱ or Ⅲ patients, aged 65-80 yr, with body mass index of 19-28 kg∕m2 , scheduled for elective robot-assisted radical prosta-tectomy under general anesthesia, were divided into 2 groups ( n=20 each) using a random number table method: control group (group C) and PEEP group (group P). Mechanical ventilation was performed ac-cording to preset parameters after tracheal intubation in group C, and PEEP was set by a double titration method after tracheal intubation and after pneumoperitoneum in group P. At 4 min after intubation (T1), 4 min, 1 h and 2 h after establishing pneumoperitoneum-Trendelenburg position ( T2-4 ) , and 1 and 30 min after extubation ( T5,6 ) in group C or at 4 min after completing the first PEEP titration ( T1 ) , 4 min, 1 h and 2 h after completing the second PEEP titration (T2-4) and T5,6 in group P, blood samples were collect-ed from the radial artery for determination of club cell protein 16, surfactant protein-D, tumor necrosis fac-tor-alpha and interleukin-6 concentrations in serum ( by enzyme-linked immunosorbent assay) . Results Compared with group C, the serum concentrations of club cell protein 16 at T2-6 and surfactant protein-D, tumor necrosis factor-alpha and interleukin-6 at T3-6 were significantly decreased in group P (P<0. 05). Conclusion Cydn-guided PEEP titration can reduce the lung injury in patients undergoing robot-assisted radical prostatectomy.

Effect of Cdyn-guided PEEP titration on pulmonary function of elderly patients undergoing robotic-assisted radical prostatectomy / 中华麻醉学杂志

Objective To evaluate the effect of dynamic lung compliance (Cdyn)-guided positive end-expiratory pressure (PEEP) titration on the pulmonary function of elderly patients undergoing roboticassisted radical prostatectomy.Methods Forty patients,aged 65-80 yr,with body mass index of 19-28 kg/m2,of American Society of Anesthesiologists physical status Ⅱ or Ⅲ,scheduled for elective robotic-assisted laparoscopic radical prostatectomy,were divided into 2 groups (n=20 each) using a random number table method:control group (group C) and PEEP group (group P).After anesthesia induction and endotracheal intubation,all the patients were mechanically ventilated in pressure-controlled ventilation-volume guaranteed mode,with tidal volume 6-8 ml/kg,respiratory rate 12 breaths/min,fraction of inspired oxygen 50％,and inspiratory/expiratory ratio 1 ∶ 2.Respiratory rate was adjusted after onset of pneumoperitoneum to maintain the end-tidal pressure of carbon dioxide at 30-45 mmHg.Immediately after intubation and immediately after establishing pneumoperitoneum-Trendelenburg position,patients received PEEP titration from the lowest PEEP available in the anesthesia machine,with an increment of 2 cmH2O every 4 min until the maximal Cdyn was achieved in group P.Patients in group C received no PEEP during procedure.At 4 min after completion of the first PEEP titration,4 min and 1 and 2 h after completion of the second PEEP titration,and 1 min after closure of abdominal cavity in group P and at 4 min after the end of intubation,4 min and 1 and 2 h after establishing pneumoperitoneum-Trendelenburg position in group C,blood samples from the radical artery were obtained for blood gas analysis,peak airway pressure was recorded,and oxygenation index,driving pressure,alveolar-arterial oxygen difference,and ratio of physical dead space to tidal volume were calculated.Results Compared with group C,the oxygenation index and partial pressure of arterial oxygen were significantly increased,and driving pressure and alveolar-arterial oxygen difference were decreased at each time point (P＜0.05),and no significant change was found in peak airway pressure,ratio of physical dead space to tidal volume or partial pressure of arterial carbon dioxide in group P (P＞0.05).Conclusion Cdyn-guided PEEP titration can improve pulmonary function of elderly patients undergoing robotic-assisted radical prostatectomy.

Effect of lung strain on breathing mechanics in dogs with acute respiratory distress syndrome / 中华危重病急救医学

Objective To explore the effect of lung strain on breathing mechanics in dogs with acute respiratory distress syndrome (ARDS).Methods Twenty-four healthy male Beagle dogs were recruited to reproduce medium ARDS models with venous injection of 0.18 mL/kg oleic acid, and they were randomly assigned to five groups with random numbers table method. In lung protective ventilation (LPV) group (n = 4), the ventilation was supported for 24 hours with tidal volume (VT) at 6-8 mL/kg, and in lung strain 1.0, 1.5, 2.0, 2.5 groups (S1.0, S1.5, S2.0, S2.5 groups), the VT was calculated from lung strain, the volume recruitment by positive end expiratory pressure (VPEEP) and functional residual capacity (FRC). Five groups were given mechanical ventilation for 24 hours or until reaching the end point of the experiment [when the dosage of norepinephrine was higher than 1.4μg·kg-1·min-1, the blood pressure was still lower than 60 mmHg (1 mmHg = 0.133 kPa) for more than 30 minutes, which was regarded as the end point of the experiment]. Static lung compliance (Cst), airway plateau pressure (Pplat) and lung stress during the experiment were recorded. Linear regression analysis was used to fit the regression equations of lung strain and Cst descending rate,Pplat and lung stress for analyzing their relationships.Results The VT of group LPV was (7.1±0.5) mL/kg. With the increase of lung strain, VT was gradually increased. VT of group S1.0 [(7.3±1.8) mL/kg] was similar to group LPV. VT of groups S1.5, S2.0, S2.5 was significantly higher than that of group LPV (mL/kg: 13.3±5.5, 18.7±5.4, 20.1±7.4 vs. 7.1±0.5, allP < 0.05). Moreover, under the same lung strain, the difference in VT among individuals was large. The Cst of each group was decreased significantly at the end of the experiment as compared with that before model reproduction. With the increase of lung strain, the rate of Cst descending was increased, Cst dropped more significantly in groups S2.0 and S2.5 than that in groups S1.0 and S1.5 [(48.0±15.0)％, (54.4±9.5)％ vs. (25.9±13.7)％, (38.6±8.1)％, all P < 0.05]. Pplat and pulmonary stress at model reproduction in all groups were significantly higher than those before model reproduction, and they increased with the prolongation of ventilation time. Pplat and lung stress at 4 hours of ventilation in group S1.5 were significantly higher than those in group LPV [Pplat (cmH2O, 1 cmH2O = 0.098 kPa):26.2±2.3 vs. 20.2±4.2, lung stress (cmH2O): 20.5±2.0 vs. 16.6±2.5, bothP < 0.05], and they increased with lung strain increasing till to the end of experiment. It was shown by correlation analysis that lung strain was positively related with Cst descending rate, Pplat and lung stress at 4 hours of ventilation (rvalue was 0.716, 0.660, 0.539, respectively, allP < 0.05), which indicated a strong linear correlation. It was shown by fitting linear regression analysis that when lung strain increased by 1, Cst descending rate increased by 19.0％ [95％ confidence interval (95％CI) = 14.6-23.3, P = 0.000], Pplat increased by 10.8 cmH2O (95％CI = 7.9-13.7,P = 0.002), and the lung stress increased by 7.4 cmH2O (95％CI = 4.7-10.2,P = 0.002).Conclusion In animal ARDS models, the larger the lung strain, the higher the Pplat and lung stress during mechanical ventilation, VT originated for lung strain 2.0 and 2.5 may further reduce Cst in ARDS models, when lung strain over 1.5, Pplat and lung stress increased significantly, which exceeded the safe range of LPV (35 cmH2O and 25 cmH2O, respectively), and further aggravated ventilator induced lung injury (VILI).

Effect of Trendelenburg position and artificial pneumoperitoneum on change of respiratory mechanics in-dexes due to change of preset airway pressure in PCV / 实用医学杂志

Objective In pressure controlled ventilation(PCV),a self-control method was used to ob-serve the change of respiration mechanics indexes under Trendelenburg position and pneumoperitoneum versus su-pine position and non-pneumoperitoneum with preset airway pressure.Methods Thirty patients scheduled for lapa-roscopic radical resection of rectal carcinoma were enrolled in this study.ECG,MAP,SpO2,BIS and body temper-ature were routinely detected. After induction of anesthesia,volume controlled ventilation(VCV)was used as ba-sic ventilation,and then switched to PCV after 5 minutes. The airway pressure was the preset airway pressure be-fore pneumoperitoneum,then was lowered 1 cmH2O in proper order,and then restored preset airway pressure and increased 1 cmH2O. 15 minutes after pneumoperitoneum,the airway pressure of PCV was used as preset airway pressure after pneumoperitoneum,and then the above procedure was repeated.The time interval was at least 5 min-utes.The values of MAP,HR,SpO2,VT and Cdyn were recorded at each time;VT,and Cdyn were continuously recorded five times to take the average value. The postoperative recovery in patients was observed. Results After pneumoperitoneum,the values of Cdyn and VT were significantly reduced(P < 0.01),MAP was increased(P <0.05). When the preset airway pressure changed 1 cmH2O,ΔVT was decreased(P < 0.05),and the change of Cdyn was not statistically significant. Conclusions As altering a unit of the preset airway pressure in PCV,the change in VT is significantly reduced but Cdyn does not change markedly in Trendelenburg posture and artificial pneumoperitoneum,as compared with supine position and non-pneumoperitoneum.

The Effect of Pneumoperitoneum and Trendelenburg position on respiratory mechanics under general anesthesia during gynecological laparoscopic surgery / Монголын Анагаах Ухаан

Background@#Gynecological laparoscopic surgery requires pneumoperitoneum(PP) with CO₂ gas insufflation and Trendelenburg position. Pneumoperitoneum and Trendelenburg position may impact intraoperative respiratory mechanics in anesthetic management.The goal of this study was to evaluate the influence of Pneumoperitoneum and Trendelenburg position on respiratory mechanics and ventilation. @*Methods@#Twenty one patients scheduled for elective gynecological laparoscopy were evaluated. The patients had no preexisting lung and heart disease or pathologic lung function. Conventional general anesthesia with thiopental sodium, fentanyl, аtracrium and isoflurane was administered. The peak inspiratory pressure, plateau pressure, and end-tidal CO₂ were compared before after creation of pneumoperitoneum with an intraabdominal pressure of 15 mmH₂O, then after PP10, PP20, PP30 minutes in the 20° Trendelenburg position, and after deflation of pneumoperitoneum. The dynamic lung compliance was calculated.@*Results@#During of pneumoperitoneum, there were a significant increase in peak inspiratory pressure by 6 cmH₂O, plateau pressure by 5 cmH₂O, while dynamic lung compliance decreased by 11 ml/cmH₂O. General, the Trendelenburg position induced no significant hemodynamic and pulmonary changes.@*Conclusion@#The effects of pneumoperitoneum significantly reduced dynamic lung compliance and increased peak inspiratory and plateau pressures. The Tredelenburg position did not change these parameters. The end-tidal CO₂ significantly increased after pneumoperitoneum and CO₂ deflation.

Evaluation of Respiratory Dynamics in an Asymmetric Lung Compliance Model / 대한구급학회지

BACKGROUND: Unilateral lung hyperinflation develops in lungs with asymmetric compliance, which can lead to vital instability. The aim of this study was to investigate the respiratory dynamics and the effect of airway diameter on the distribution of tidal volume during mechanical ventilation in a lung model with asymmetric compliance. METHODS: Three groups of lung models were designed to simulate lungs with a symmetric and asymmetric compliance. The lung model was composed of two test lungs, lung1 and lung2. The static compliance of lung1 in C15, C60, and C120 groups was manipulated to be 15, 60, and 120 ml/cmH₂O, respectively. Meanwhile, the static compliance of lung2 was fixed at 60 ml/cmH₂O. Respiratory variables were measured above (proximal measurement) and below (distal measurement) the model trachea. The lung model was mechanically ventilated, and the airway internal diameter (ID) was changed from 3 to 8 mm in 1-mm increments. RESULTS: The mean ± standard deviation ratio of volumes distributed to each lung (VL1/VL2) in airway ID 3, 4, 5, 6, 7, and 8 were in order, 0.10 ± 0.05, 0.11 ± 0.03, 0.12 ± 0.02, 0.12 ± 0.02, 0.12 ± 0.02, and 0.12 ± 0.02 in the C15 group; 1.05 ± 0.16, 1.01 ± 0.09, 1.00 ± 0.07, 0.97 ± 0.09, 0.96 ± 0.06, and 0.97 ± 0.08 in the C60 group; and 1.46 ± 0.18, 3.06 ± 0.41, 3.72 ± 0.37, 3.78 ± 0.47, 3.77 ± 0.45, and 3.78 ± 0.60 in the C120 group. The positive end-expiratory pressure (PEEP) of lung1 was significantly increased at airway ID 3 mm (1.65 cmH₂O) in the C15 group; at ID 3, 4, and 5 mm (2.21, 1.06, and 0.95 cmH₂O) in the C60 group; and ID 3, 4, and 5 mm (2.92, 1.84, and 1.41 cmH₂O) in the C120 group, compared to ID 8 mm (P < 0.05). CONCLUSIONS: In the C15 and C120 groups, the tidal volume was unevenly distributed to both lungs in a positive relationship with lung compliance. In the C120 group, the uneven distribution of tidal volume was improved when the airway ID was equal to or less than 4 mm, but a significant increase of PEEP was observed.

Evaluation of Respiratory Dynamics in an Asymmetric Lung Compliance Model / 대한중환자의학회지

BACKGROUND: Unilateral lung hyperinflation develops in lungs with asymmetric compliance, which can lead to vital instability. The aim of this study was to investigate the respiratory dynamics and the effect of airway diameter on the distribution of tidal volume during mechanical ventilation in a lung model with asymmetric compliance. METHODS: Three groups of lung models were designed to simulate lungs with a symmetric and asymmetric compliance. The lung model was composed of two test lungs, lung1 and lung2. The static compliance of lung1 in C15, C60, and C120 groups was manipulated to be 15, 60, and 120 ml/cmH₂O, respectively. Meanwhile, the static compliance of lung2 was fixed at 60 ml/cmH₂O. Respiratory variables were measured above (proximal measurement) and below (distal measurement) the model trachea. The lung model was mechanically ventilated, and the airway internal diameter (ID) was changed from 3 to 8 mm in 1-mm increments. RESULTS: The mean ± standard deviation ratio of volumes distributed to each lung (VL1/VL2) in airway ID 3, 4, 5, 6, 7, and 8 were in order, 0.10 ± 0.05, 0.11 ± 0.03, 0.12 ± 0.02, 0.12 ± 0.02, 0.12 ± 0.02, and 0.12 ± 0.02 in the C15 group; 1.05 ± 0.16, 1.01 ± 0.09, 1.00 ± 0.07, 0.97 ± 0.09, 0.96 ± 0.06, and 0.97 ± 0.08 in the C60 group; and 1.46 ± 0.18, 3.06 ± 0.41, 3.72 ± 0.37, 3.78 ± 0.47, 3.77 ± 0.45, and 3.78 ± 0.60 in the C120 group. The positive end-expiratory pressure (PEEP) of lung1 was significantly increased at airway ID 3 mm (1.65 cmH₂O) in the C15 group; at ID 3, 4, and 5 mm (2.21, 1.06, and 0.95 cmH₂O) in the C60 group; and ID 3, 4, and 5 mm (2.92, 1.84, and 1.41 cmH₂O) in the C120 group, compared to ID 8 mm (P < 0.05). CONCLUSIONS: In the C15 and C120 groups, the tidal volume was unevenly distributed to both lungs in a positive relationship with lung compliance. In the C120 group, the uneven distribution of tidal volume was improved when the airway ID was equal to or less than 4 mm, but a significant increase of PEEP was observed.

Effect of sevoflurane preconditioning on lung compliance and oxygenation index during one lung ventilation / 安徽医科大学学报

Objective To investigate the effect of sevoflurane preconditioning on lung compliance and oxygenation index during one lung ventilation( OLV) . Methods In this study, sixty patients, ASAⅠorⅡ, scheduled for pul-monary surgeries were enrolled, and randomly divided into two groups:sevoflurane preconditioning group(n=30) and total intravenous group( n=30 ) . For preconditioning, patients in sevoflurane preconditioning group were ad-ministrated with one minimal alveolar concentration(1MAC) sevoflurane for 30 min after general anesthesia induc-tion and then followed with total intravenous anesthesia. While in total intravenous group, only intravenous anes-thetic agents were administrated for maintenane of anesthesia after induction. The indexes of hemodynamics, pulse oximeter( SpO2 ) , plateau pressure( Pplat) and lung compliance( Cdyn) were recorded at the following time points:before anesthesia( T0 ) , after anesthesia induction at laternal position TLV 30 min( T1 ) ,30 min after OLV( T2 ) , 60 min after OLV( T3 ) and recovering TLV 20 min( T4 ) . Arterial blood samples were taken to measure partial pressure of carbon dioxide( PaCO2 ) , partial pressure of oxygen( PaO2 ) , pH, oxygenation index( PaO2/FiO2 ) at the follow-ing time points: T1 , T2 , T3 , T4 . Results Compared with T1 , the oxygenation index and lung compliance de-creased significantly at T2 ,T3 ( P<0. 05 ); compared with total intravenous group, the lung compliance was obvi-ously higher than that in sevoflurane preconditioning group at T2,T3(P<0. 05). There were no significantly differ-ences in the oxygenation index between total intravenous group and sevoflurane preconditioning group at all time points. Conclusion Compared with total intravenous anesthesia with propofol , sevoflurane preconditioning can im-prove lung compliance, but does not make contribute to improve oxygenation index.

Longitudinal assessment of the lung mechanics of very low birth weight preterm infants with and without bronchopulmonary dysplasia / Avaliação longitudinal da mecânica pulmonar de crianças pré-termo de muito baixo peso com e sem displasia broncopulmonar

ABSTRACT CONTEXT AND OBJECTIVE: Prematurity has been correlated with altered lung mechanics. Some infants develop lung injury as a consequence of lung immaturity, invasive mechanical ventilation and exposure to oxygen, thus resulting in bronchopulmonary dysplasia. The aim here was to compare the lung mechanics of preterm infants with and without bronchopulmonary dysplasia during the first year of life. DESIGN AND SETTING: Prospective cohort study in a tertiary-level hospital. METHODS: This study included premature infants at a public hospital who underwent two pulmonary function tests: one at discharge and the other at the corrected age of 4 to 8 months. Tidal volume, lung compliance and lung resistance were measured. Statistical tests were used for comparisons between infants with and without bronchopulmonary dysplasia. RESULTS: 102 children with mean gestational age of 29 ± 2.0 weeks were studied; 17 with bronchopulmonary dysplasia. Lung compliance (0.84 ± 0.29 versus 1.28 ± 0.46; P < 0.001) and tidal volume (6.1 ± 0.94 versus 7.2 ± 1.43; P < 0.01) at discharge were significant lower in children with bronchopulmonary dysplasia than in those without the disease, but no differences were observed at the second test (compliance: 1.53 ± 0.77 versus 1.94 ± 1.01; P = 0.12; and tidal volume: 6.9 ± 1.4 versus 7.3 ± 1.6; P = 0.42). CONCLUSION: Differences in lung mechanics were observed between infants with and without bronchopulmonary dysplasia at hospital discharge but these differences were no longer detected at the final follow-up. The lung mechanics of all the infants improved over this period of time.

RESUMO CONTEXTO E OBJETIVO: Prematuridade tem sido associada com mecânica pulmonar alterada. Algumas crianças desenvolvem lesão pulmonar como consequência de imaturidade pulmonar, ventilação mecânica invasiva e exposição a oxigênio, resultando em displasia broncopulmonar. O objetivo foi comparar a mecânica pulmonar de prematuros com e sem displasia broncopulmonar durante o primeiro ano de vida. DESENHO DO ESTUDO E LOCAL: Estudo de coorte prospectivo em um hospital terciário. MÉTODOS: O estudo incluiu prematuros, de hospital público, que realizaram duas provas de função pulmonar, uma na alta e outra entre quatro e oito meses de idade corrigida. Foram mensurados o volume corrente, a complacência e a resistência pulmonares. Testes estatísticos foram usados para comparações entre crianças com e sem displasia broncopulmonar. RESULTADOS: Foram estudadas 102 crianças com idade gestacional média de 29 ± 2 semanas; 17 com displasia broncopulmonar. A complacência pulmonar (0,84 ± 0,29versus 1,28 ± 0,46; P < 0.001) e o volume corrente (6,1 ± 0,94 versus 7,2 ± 1,43; P < 0.01) na alta foram significativamente inferiores nas crianças com displasia broncopulmonar comparadas às crianças sem a doença, mas não foram observadas diferenças significativas no segundo teste (complacência: 1.53 ± 0.77versus 1.94 ± 1.01; P = 0.12; e volume corrente: 6.9 ± 1.4 versus 7.3 ± 1.6; P = 0.42). CONCLUSÃO: Diferenças na mecânica pulmonar foram observadas entre crianças com e sem displasia broncopulmonar na alta hospitalar, mas essas diferenças não foram detectadas no seguimento final. A mecânica pulmonar de todas as crianças melhorou no decorrer desse período de tempo.

Lowering Pulmonary Wedge Pressure after Heart Transplant: Pulmonary Compliance and Resistance Effect / Redução da Pressão Capilar Pulmonar após Transplante Cardíaco: Complacência Pulmonar e Efeito Resistência

AbstractBackground:Right ventricular (RV) afterload is an important risk factor for post-heart transplantation (HTx) mortality, and it results from the interaction between pulmonary vascular resistance (PVR) and pulmonary compliance (CPA). Their product, the RC time, is believed to be constant. An exception is observed in pulmonary hypertension because of elevated left ventricular (LV) filling pressures.Objective:Using HTx as a model for chronic lowering of LV filling pressures, our aim was to assess the variations in RV afterload components after transplantation.Methods:We retrospectively studied 159 patients with right heart catheterization before and after HTx. The effect of Htx on hemodynamic variables was assessed.Results:Most of the patients were male (76%), and the mean age was 53 ± 12 years. HTx had a significant effect on the hemodynamics, with normalization of the LV and RV filling pressures and a significant increase in cardiac output and heart rate (HR). The PVR decreased by 56% and CPA increased by 86%. The RC time did not change significantly, instead of increasing secondary to pulmonary wedge pressure (PWP) normalization after HTx as expected. The expected increase in RC time with PWP lowering was offset by the increase in HR (because of autonomic denervation of the heart). This effect was independent from the decrease of PWP.Conclusion:The RC time remained unchanged after HTx, notwithstanding the fact that pulmonary capillary wedge pressure significantly decreased. An increased HR may have an important effect on RC time and RV afterload. Studying these interactions may be of value to the assessment of HTx candidates and explaining early RV failure after HTx.

ResumoFundamento:A pós-carga do ventrículo direito (VD) é um fator de risco importante para avaliar a mortalidade decorrente de transplante cardíaco (HTx) e resulta da interação entre a resistência vascular pulmonar (RVP) e a complacência pulmonar (CPA). Acredita-se que o produto da interação, o RC-time, seja constante. Entretanto, é exceção a hipertensão pulmonar devido às elevadas pressões de preenchimento do ventrículo esquerdo (VE).Objetivos:Ao utilizar o HTx como modelo para redução crônica das pressões de preenchimento do VE, nosso objetivo foi avaliar as variações nos componentes pós-carga do VD após o transplante.Métodos:Foram estudados, retrospectivamente, 159 pacientes com cateterismo cardíaco direito realizado antes e após o HTx. O impacto do HTx nas variáveis hemodinâmicas foi avaliado.Resultados:A maioria dos pacientes foi do sexo masculino (76%) e a média de idade foi 53 ± 12 anos. O HTx teve um efeito significativo na hemodinâmica, com normalização do VE e das pressões de preenchimento de VD e no aumento significativo do débito cardíaco e da freqüência cardíaca (FC). A RVP diminuiu 56% e a CPA aumentou 86%. Em vez de aumentar como era esperado, o RC-time não alterou significativamente e teve papel secundário em relação à normalização da pressão capilar pulmonar (PECP) após o HTx. O aumento esperado no RC timecom PWP reduzido foi atenuado pelo aumento da FC (devido à denervação autonômica do coração). Esse efeito ocorreu independentemente da diminuição da PCPConclusões:O RC-time permaneceu inalterado após HTx, entretanto a PECP diminuiu significativamente. O aumento da FC pode ter impacto importante no RC-time e na pós-carga do VD. O estudo dessas interações pode ser de grande valor para avaliar os candidatos HTx e explicar a falência do VD ocorrida logo após o HTx.

THE EFFECT OF PNEUMOPERITONEUM ON RESPIRATORY MECHANICS UNDER GENERAL ANESTHESIA DURING GYNECOLOGICAL LAPAROSCOPIC SURGERY / Шинэ санаа Шинэ нээлт

Gynecological laparoscopic surgery requires pneumoperitoneum(PP) with CO2 gas insufflation and Trendelenburg position. Pneumoperitoneum and Trendelenburg position may impact intraoperative respiratory mechanics in anesthetic management. This study was conducted to investigate the influence of Pneumoperitoneum and Trendelenburg position on respiratory compliance and ventilation pressure. Twenty one patients scheduled for elective gynecological laparoscopy were evaluated. The patients had no preexisting lung and heart disease or pathologic lung function. Conventional general anesthesia with thiopental sodium, fentanyl, аtracrium and isoflurane was administered. The peak inspiratory pressure, plateau pressure, and end-tidal CO2 were compared before after creation of pneumoperitoneum with an intraabdominal pressure of 15 mmH2O, then after T10, T20, T30 minutes in the 20°Trendelenburg position, and after deflation of pneumoperitoneum. The dynamic lung compliance was calculated.During of pneumoperitoneum, there were a significant increase in peak inspiratory pressure (7 cmH2O), plateau pressure(6 cmH2O), and end-tidal CO2 (6 mmH2O) while dynamic lung compliance decreased by 11 ml/cmH2O. General, the Trendelenburg position induced no significant hemodynamic and pulmonary changes.The effects of pneumoperitoneum significantly reduced dynamic lung compliance and increased peak inspiratory and plateau pressures. The Tredelenburg position did not change these parameters. The end-tidal CO2 significantly increased after pneumoperitoneum and CO2 deflation. Anesthesiologists must be aware of changes in respiratory dynamics and must be ready to respond promptly and adequately according to pneumoperitoneum with Tredelenburg position during laparoscopic surgery.