Effect of intraoperative ventilation modes on postoperative pulmonary complications after cardiac surgery under cardiopulmonary bypass: A retrospective cohort study / 中国胸心血管外科临床杂志

@#Objective    To evaluate the association of intraoperative ventilation modes with postoperative pulmonary complications (PPCs) in adult patients undergoing selective cardiac surgery under cardiopulmonary bypass (CPB). Methods    The clinical data of 604 patients who underwent selective cardiac surgical procedures under CPB in the West China Hospital, Sichuan University from June to December 2020 were retrospectively analyzed. There were 293 males and 311 females with an average age of 52.0±13.0 years. The patients were divided into 3 groups according to the ventilation modes, including a pressure-controlled ventilation-volume guarantee (PCV-VG) group (n=201), a pressure-controlled ventilation (PCV) group (n=200) and a volume-controlled ventilation (VCV) group (n=203). The association between intraoperative ventilation modes and PPCs (defined as composite of pneumonia, respiratory failure, atelectasis, pleural effusion and pneumothorax within 7 days after surgery) was analyzed using modified poisson regression. Results    The PPCs were found in a total of 246 (40.7%) patients, including 86 (42.8%) in the PCV-VG group, 75 (37.5%) in the PCV group and 85 (41.9%) in the VCV group. In the multivariable analysis, there was no statistical difference in PPCs risk associated with the use of either PCV-VG mode (aRR=0.951, 95%CI 0.749-1.209, P=0.683) or PCV mode (aRR= 0.827, 95%CI 0.645-1.060, P=0.133) compared with VCV mode. Conclusion    Among adults receiving selective cardiac surgery, PPCs risk does not differ significantly by using different intraoperative ventilation modes.

Comparison of volume-controlled and pressure-controlled ventilation on respiratory mechanics in laparoscopic bariatric surgery: randomized clinical trial / Comparação das ventilações controlada por volume e controlada por pressão na mecânica respiratória em cirurgia bariátrica laparoscópica: estudo clínico randômico

Abstract Background: It is not clear which mechanical ventilation mode should be used in bariatric surgery, one of the treatment options for patients with obesity. Objectives: To compare volume-controlled ventilation and pressure-controlled ventilation in terms of respiratory mechanics and arterial blood gas values in patients undergoing laparoscopic bariatric surgery. Methods: Sixty-two patients with morbid obesity scheduled for gastric bypass were included in this study. Their ideal body weights were calculated during preoperative visits, and patients were divided into two groups, volume-controlled ventilation and pressure-controlled ventilation. The patients were ventilated in accordance with a previously determined algorithm. Mechanical ventilation parameters and arterial blood gas analysis were recorded 5minutes after induction, 30minutes after pneumoperitoneum, and at the end of surgery. Also, the dynamic compliance, inspired O2 pressure/fractional O2 ratio, and alveolar-arterial oxygen gradient pressure were calculated. Results: Peak airway pressures were lower in patients ventilated in pressure-controlled ventilation mode at the end of surgery (p = 0.011). Otherwise, there was no difference between groups in terms of intraoperative respiratory parameters and arterial blood gas analyses. Conclusions: Pressure-controlled ventilation mode is not superior to volume-controlled ventilation mode in patients with laparoscopic bariatric surgery.

Resumo Justificativa: O modo de ventilação mecânica que deve ser usado em cirurgia bariátrica, uma das opções de tratamento para pacientes com obesidade, ainda não foi definido. Objetivos: Comparar as ventilações controladas por volume e por pressão em termos de mecânica respiratória e dos valores da gasometria arterial em pacientes submetidos à cirurgia bariátrica laparoscópica. Métodos: Foram incluídos neste estudo 62 pacientes com obesidade mórbida programados para bypass gástrico. Seus pesos corporais ideais foram calculados durante as consultas pré-operatórias e os pacientes foram divididos em dois grupos: ventilação controlada por volume e ventilação controlada por pressão. Os pacientes foram ventilados de acordo com um algoritmo previamente determinado. Os parâmetros da ventilação mecânica e as análises da gasometria arterial foram registrados 5 minutos após a indução, 30 minutos após o pneumoperitônio e ao final da cirurgia. Além disso, a complacência dinâmica, a pressão e a fração de oxigênio inspirado e a pressão do gradiente alvéolo-arterial de oxigênio foram calculados. Resultados: As pressões de pico das vias aéreas foram menores nos pacientes ventilados no modo de ventilação controlada por pressão ao final da cirurgia (p = 0,011). Exceto por esse aspecto, não houve diferença entre os grupos quanto aos parâmetros respiratórios intraoperatórios e às gasometrias arteriais. Conclusões: O modo de ventilação controlada por pressão não é superior ao modo de ventilação controlada por volume em pacientes de cirurgia bariátrica laparoscópica.

Ventilación controlada por volumen y por presión en pacientes con enfermedades respiratorias crónicas intervenidos quirúrgicamente / Volume- and pressure-controlled ventilation in surgically intervened patients with chronic respiratory diseases

Fundamento: Existe una alta frecuencia en nuestro medio de pacientes con enfermedad pulmonar obstructiva crónica y asma bronquial que requieren intervenciones quirúrgicas electivas y precisan de anestesia general con ventilación mecánica controlada por volumen y por presión. Objetivo: Comparar ambos métodos de ventilación controlada en los pacientes con enfermedades respiratorias crónicas intervenidos quirúrgicamente de forma electiva en el Hospital Universitario Manuel Ascunce Domenech de Camagüey. Métodos: Estudio observacional analítico. El universo comprendió 83 pacientes y la muestra por 40 pacientes. Se conformaron dos grupos de estudio: grupo I, en el cual se utilizó la ventilación controlada por volumen y se prefijó el volumen tidal a 7 mL/kg, con frecuencia respiratoria de 10-12 respiraciones por minuto, índice de inspiración-espiración 1:2 y FiO2 de 20,5 por ciento, y grupo II, en el cual se empleó la ventilación controlada por presión y se prefijó la presión inspiratoria pico ideal para garantizar el volumen minuto adecuado en el paciente, con frecuencia respiratoria de 10-12 respiraciones por minuto, índice de inspiración-espiración 1:2 y FiO2 0,5 por ciento. En ambos grupos se calculó la compliance dinámica y se determinó la relación presión arterial de oxígeno y fracción inspirada de oxígeno. Resultados: Se encontraron cifras mayores de la relación PO2/FiO 2, cifras de PIP más bajas y una mejor compliance dinámica en el grupo II. Conclusiones: La ventilación controlada por presión es una modalidad ventilatoria que ofrece al paciente adecuada oxigenación con mejor compliance y control de la presión inspiratoria pico(AU)

Background: Our scenario presents high frequency of patients with chronic obstructive pulmonary disease and bronchial asthma and who require elective surgery and general anesthesia with volume- and pressure-controlled mechanical ventilation. Objective: To compare both methods of controlled ventilation in patients with chronic respiratory diseases electively operated at Manuel Ascunce Domenech University Hospital in Camagüey. Methods: Analytical, observational study. The universe comprised 83 patients and the sample comprised 40 patients. Study group I, in which volume-controlled ventilation was used, and volume was adjusted to 7 mL/kg, with respiratory rate of 10-12 breaths per minute, inspiratory-expiration ratio 1:2, and FiO 2 at 20.5 percent; and group II, in which pressure-controlled ventilation was used and the ideal peak inspiratory pressure was set to ensure the patient's adequate volume per minute, respiratory rate of 10-12 breaths per minute, inspiratory-expiration index 1:2, and FiO2 at 0.5 percent. Dynamic compliance was calculated in both groups and the relationship between oxygen arterial pressure and inspired oxygen fraction was determined. Results: We found higher numbers of the PO2/FiO2 ratio, lower PIP numbers and better dynamic compliance in group II. Conclusions : Pressure-controlled ventilation is a ventilation modality that offers the patient adequate oxygenation with better compliance and control of peak inspiratory pressure(AU)

Comparison of Effects of Pressure Controlled Ventilation and Volume Controlled Ventilation on Perioperative Blood Loss of Patients with Posterior Lumbar Interbody Fusion / 医学研究杂志

Objective To compare the effects of pressure controlled ventilation and volume controlled ventilation on perioperative blood loss of patients with posterior lumbar interbody fusion (PLIF).Methods According to the random number table method,a total of 88 patients scheduled to PLIF were allocated into two groups,44 cases per groups.Patients received respectively pressure controlled ventilation and volume controlled ventilation in pressure controlled ventilation group (PCV group) and volume controlled ventilation group (VCV group).Mean arterial blood pressure (MAP),heart rate (HR) and central venous pressure (CVP) were continuously monitored at anesthesia induction immediately (T0),10min after supine position to prone position (T1),skin suture immediately (T2),10min after prone position to supine position (T3) and when tracheal extubation (T4).Hemoglobin (Hb) and hematokrit (HCT) were tested from T0 to T4 in the two groups.Respiratory parameters were recorded from T0 to T3 in the two groups.Intraoperative blood loss and blood loss at 96h after operation patients were recorded.Allogeneic blood transfusion,volume of fluid input and the rate of secondary surgery to stop th bleeding were recorded in the two groups.Results Compared to VCV group,peak inspimtory pressure (PIP) from T1 to T3 were all significantly lower (P ＜0.05) in PCV group.There was no statistical significance (P ＞ 0.05) in MAP,HR,tidal volume,respiratory rate (RR),PaO2/FiO2 and PaCO2 between the two groups.There was no statistical significance (P ＞ 0.05) in Hb and Hct at different time points between the two groups.Compared to VCV group,intraoperative blood loss,plasma infusions and red blood cell infusions were al significantly lower (P ＜ 0.05) in PCV group.Conclusion PCV can decrease intraoperative blood loss of patients with PLIF,which may be related to lower PIP during operation.

Application of pressure-controlled ventilation-volume guaranteed in obese patients with obstructive sleep apnea syndrome / 实用医学杂志

Objective To explore the clinical effectiveness of pressure-controlled ventilation-volume guar-anteed(PCV-VG)in obese patients with obstructive sleep apnea syndrome(OSAS)during uvulopalatopharyngo-plasty. Methods 40 obese patients(BMI≥30 kg/m2)with OSAS scheduled for uvulopalatopharyngoplasty under general anesthesia were randomly divided into two groups of volume-controlled ventilation(group V,n = 20)and pressure-controlled ventilation-volume guaranteed(group P,n=20). The heart rate(HR),mean arterial pressure (MAP),arterial partial pressure of oxygen(PaO2)and arterial partial pressure of carbondioxide(PaCO2)were recorded before induction of anesthesia without oxygen inhalation(T0),30 min(T1)and 1 h(T2)after tracheal intubation,and 30 min after extubation(T3). The peak airway pressure(Ppeak),airway resistance(Raw),thoracic compliance (CL),oxygenation index (OI) and respiratory index (RI) were also calculated at T1 and T2 under observation of recovery. Results There were no obvious differences between the two groups of patients before anesthesia and after recovery. Compared with the group V ,PaCO2 ,PPEAK ,Raw at T1 ,T2 and RI at T1 ~ T3 of the group P decreased(P<0.05),while CL at T1,T2 and PaO2,OI at T1~T3 increased(P<0.05). There were no sig-nificant differences in HR ,MAP at the above time points. Conclusions Compared with volume-controlled venti-lation,PCV-VG can effectively enhance thoracic compliance,lower inspiratory pressure and airway resistance ,and decrease intrapulmonary shunt ,which is conductive to improve arterial oxygenation and gas exchange in obese patients with OSAS.

Effects of Different Ventilation Modes on Respiration and Circulation in Elderly Patients Undergoing Thoracic Surgery / 昆明医科大学学报

Objective The aim of this study was to explore the effects of volume controlled ventilation (VCV),pressure controlled ventilation(PCV)and pressure controlled ventilation-volume guaranteed (PCV-VG)on respiration and circulation in elderly patients undergoing thoracic surgery. Methods Thirty-six elderly patients who underwent thoracic surgery were enrolled in our study. Patients were divided into VCV,PCV and PCV-VG groups according to randomized design. The hemodynamic and respiratory data and the arterial blood gases had been recorded in the pre-operation,20 min,40 min,60 min after OLV and 20 min after the resumption of two lung ventilation. Results Compared with VCV group,Ppeak value was significantly lower in PCV and PCV-VG groups(P 0.05). Conclusion Compared with VCV,the use of PCV and PCV-VG have significant advantages in the operative oxygenation and airway pressure for elderly patients undergoing OLV.

Application of PRVC ventilation mode in one-lung ventilation during pulmonary lobectomy / 中国癌症杂志

Background and purpose:Obvious pulmonary dysfunction may exsist preoperatively in part of the patients undergoing pulmonary lobectomy. Volume-controlled ventilation (VC) during one-lung ventilation (OLV) may lead to lung injury in lung cancer patients with preoperative pulmonary dysfunction. However, pressure-regulated volume-controlled (PRVC) ventilation mode is a new type of ventilation mode, and can alleviate ventilation-induced lung injury. This study explored the effect of PRVC on respiratory mechanics, oxygenation index, pulmonary inlfam-matory response, and clinical outcomes in patients undergoing pulmonary lobectomy during OLV compared with VC mode.Methods:Forty ASAⅡ-Ⅲ patients with moderate to severe pulmonary dysfunction undergoing pulmonary lobectomy were randomly divided into group VC and group PRVC (n=20).PRVC ventilation mode was performed for patients in group VC during the ifrst 5 minutes after OLV, and then ventilation mode was switched to VC ventilation mode till the end of surgery. In the other group, ventilation modes were performed in reverse order. Ventilation settings remained unchanged when ventilation mode was switched. Respiratory mechanics, static lung compliance, hemody-namic parameters and arterial blood gas were obtained during the surgery. Blood samples and bronchoalveolar lavage (BALF) in ventilated lung were collected to determine the level of TNF-α, IL-1β, IL-6 and IL-8 at the end of surgery.Results:Both the peak expiratory pressure and static lung compliance in group PRVC were signiifcantly lower than those in group VC (P<0.01). However, there were no statistical difference in hemodynamic parameters (heart rate and blood pressure) and arterial blood gas analysis (pH,paO2andpaCO2) between the two groups during OLV, as well as postoperative pulmonary complications and length of hospital stay. The levels of TNF-α, IL-1β and IL-6 in BALF in group PRVC were signiifcantly lower than those in group VC (P<0.05), while there was no difference in blood sample. Conclusion:PRVC mode during OLV may relieve the extravagant airway pressure and then reduce the release of inlfammatory factors in ventilation lung, which might prevent acute lung injury induced by lung barotraumas, especially for those patients with pulmonary dysfunction preoperatively. Therefore, PRVC mode is a safe and effective ventilation mode for high-risk patients undergoing pulmonary lobectomy.

Evaluation of tidal volume delivered by ventilators during volume-controlled ventilation / 中华危重病急救医学

Objective To study the ways which ensure the delivery of enough tidal volume to patients under various conditions close to the demand of the physician. Methods The volume control ventilation model was chosen,and the simulation lung type was active servo lung ASL 5000 or Michigan lung 1601. The air resistance,air compliance and lung type in simulation lungs were set. The tidal volume was obtained from flow analyzer PF 300. At the same tidal volume,the displaying values of tidal volume of E5,Servo i,Evital 4,and Evital XL ventilators with different lung types of patient,compliance of gas piping,leakage,gas types,etc. were evaluated. Results With the same setting tidal volume of a same ventilator,the tidal volume delivered to patients was different with different lung types of patient,compliance of gas piping,leakage,gas types,etc. Reducing compliance and increasing resistance of the patient lungs caused high peak airway pressure,the tidal volume was lost in gas piping,and the tidal volume be delivered to the patient lungs was decreased. If the ventilator did not compensate to leakage,the tidal volume delivered to the patient lungs was decreased. When the setting gas type of ventilator did not coincide with that applying to the patient,the tidal volume be delivered to the patient lungs might be different with the setting tidal volume of ventilator. Conclusion To ensure the delivery of enough tidal volume to patients close to the demand of the physician, containable factors such as the compliance of gas piping,leakage,and gas types should be controlled.

Comparison of volume-controlled and pressure-controlled ventilation using a laryngeal mask airway during gynecological laparoscopy / 대한마취과학회지

BACKGROUND: Several publications have reported the successful, safe use of Laryngeal Mask Airway (LMA)-Classic devices in patients undergoing laparoscopic surgery. However, there have been no studies that have examined the application of volume-controlled ventilation (VCV) or pressure-controlled ventilation (PCV) using a LMA during gynecological laparoscopy. The aim of this study is to compare how the VCV and PCV modes and using a LMA affect the pulmonary mechanics, the gas exchange and the cardiovascular responses in patients who are undergoing gynecological laparoscopy. METHODS: Sixty female patients were randomly allocated to one of two groups, (the VCV or PCV groups). In the VCV group, baseline ventilation of the lung was performed with volume-controlled ventilation and a tidal volume of 10 ml/kg ideal body weight (IBW). In the PCV group, baseline ventilation of the lung using pressure-controlled ventilation was initiated with a peak airway pressure that provided a tidal volume of 10 ml/kg IBW and an upper limit of 35 cmH2O. The end-tidal CO2, the peak airway pressures (Ppeak), the compliance, the airway resistance and the arterial oxygen saturation were recorded at T1: 5 minutes after insertion of the laryngeal airway, and at T2 and T3: 5 and 15 minutes, respectively, after CO2 insufflation. RESULTS: The Ppeak at 5 minutes and 15 minutes after CO2 insufflation were significantly increased compared to the baseline values in both groups. Also, at 5 minutes and 15 minutes after CO2 insufflation, there were significant differences of the Ppeak between the two groups. The compliance decreased in both groups after creating the pneumopertoneim (P < 0.05). CONCLUSIONS: Our results demonstrate that PCV may be an effective method of ventilation during gynecological laparoscopy, and it ensures oxygenation while minimizing the increases of the peak airway pressure after CO2 insufflation.

Ventilación por presión en cirugía torácica / Pressure ventilation in thoracic surgery

Introducción: La ventilación controlada por presión es un modo de ventilación ampliamente utilizado en el fallo respiratorio severo, donde ha demostrado que mejora la oxigenación arterial. Objetivo: Comparar la ventilación controlada por volumen comúnmente utilizado durante la ventilación unipulmonar con tres estrategias ventilatorias de ventilación controlada por presión. Método: Se realizó un estudio comparativo y prospectivo de 100 pacientes tratados por cirugía torácica divididos en cuatro grupos según modo ventilatorio utilizado. Grupo I VCV, con volumen minuto 100 mL/kg. Grupo II VCP con Vot de 10 mL/kg, Grupo III VCP con Vot de 8 mL/kg, y Grupo IV VCP con 5cm de H2O de PEEP y un Vot de 8 mL/kg. Se comparó PaO2, SatO2, Shunt Intrapulmonar, Presión Pico y Meseta a los 30 minutos de la ventilación unipulmonar y los episodios de desaturación arterial. Se utilizó Chi Cuadrado y ANOVA para el análisis estadístico. Resultados: La PaO2 presentó valores similares en los Grupos I y II, 148,28 ± 68,21 y 146,8 ± 67,8 mmHg, respectivamente, disminuyó en el Grupo III a 117,2 ± 51,0 mmHg y aumentó significativamente en el Grupo IV 189,0 ± 49,2 mmHg. La SatO2 se incrementó y el shunt intrapulmonar disminuyó con significación estadística en el Grupo IV. Las presiones en la vía aérea fueron menores durante la VCP. Conclusión: La ventilación controlada por presión "per se" no mejoró las variables de oxigenación durante la ventilación unipulmonar, pero sí, permite alcanzar menores presiones en la vía aérea. La administración de PEEP durante la ventilación controlada por presión evidenció mejoría significativa de la oxigenación.

Introduction: Pressure controlled ventilation is a very used way of ventilation in severe respiratory failure, where it has been showed that it improves arterial oxygenation. Objective: To compare volume controlled ventilation commonly used during unipulmonar ventilation with three ventilator strategies of pressure controlled ventilation. Method: We made a comparative and prospective study of 100 patients undergoing thoracic surgery divided into 4 groups by ventilator mode used: group I VCV with a minute volume 100 mL/kg, group II VCP with Vot of 10 mL/kg, group III VCP with Vot of 8 mL/kg, and group IV VCP with 5 cm of H2O of PEEP, and a Vot of 8 mL/kg. We compared PaO2, SatO2, intrapulmonary shunt, peak and plateau pressures at 30 minutes of unipulmonar ventilation, and the arterial desaturation episodes. We used Chi2 and ANOVA for statistical analysis. Results: The PaO2 yields similar values in Groups I and II, 148,28 ± 68,21 and 146,8 ± 67,8 mmHg, respectively, it decreased in Group III to 117,2 ± 51,0 mmHg, and then increased significantly in group IV 189,0 ± 49,2 mmHg. The SatO2 increased and intrapulmonary shunt decreased with statistical significance in group IV. Airway pressures were low during VCP. Conclusion: Pressure controlled ventilation "per se" not improved oxygenation variables during unipulmonar ventilation, but allowing lower pressures in airway. Administration of PEEP during pressure controlled evidenced a significant improvement of oxygenation.

Three ventilation modes during laparoscopic operations in obese patients / 中国微创外科杂志

Objective To observe oxygenation status when different modes of mechanical ventilation were actualized during laparoscopic operations in obese patients. Methods Sixty obese patients for laparoscopy were divided into three groups with 20 patients in each group, receiving volume controlled ventilation (VCV Group), or pressure controlled ventilation (PCV Group), or pressure controlled ventilation with positive end-expiratory pressure (PCV+PEEP Group). Levels of pH value, PCO_2, PO_2/FiO_2, and Qs/Qt were measured at 30 min after pneumoperitoneum (T1), 60 min after pneumoperitoneum (T2), 30 min after extubation (T3), and 60 min after extubation (T4), respectively. Results The oxygenation index was significantly higher in the PCV+PEEP Group at T1 (429.35?51.88) and T4 (231.87?20.47) than in the VCV Group at T1 (346.15?54.48; q=6.771, P

Difference in Patient's Work of Breathing Between Pressure-Controlled Ventilation with Deccelerating Flow and Volume-Controlled Ventilation with Constant Flow during Assited Ventilation / 결핵

BACKGROUND: The patient's work of breathing(WOBp) during assisted ventilation may vary according to many factors including ventilatory demand of the patients and applied ventilatory setting by the physician. Pressure-controlled ventilation(PCV) which delivers gas with decelerating flow may better meet patients' demand to improve patientventilator synchrony compared with volume-controlled ventilation(VCV) with constant flow. This study was conducted to compare the difference in WOBp in two assisted modes of ventilation, PCV and VCV with constant flow. METHODS: Ten patients with respiratory failure were included in this study. Initially, the patients were placed on VCV with constant flow at low tidal volume(VT,LOW)(6-8 ml/kg) or high tidal volume(VT,HIGH)(10-12 ml/kg). After a 15 minute stabilization period, VCV with constant flow was switched to PCV and pressure was adjusted to maintain the same tidal volume(VT) received on VCV. Other ventilator settings were kept constant. Before changing the ventilatory mode, WOBp, VT, minute ventilation(VE), respiratory rate(RR), peak airway pressure (Ppeak), peak inspiratory flow rate(PIFR) and pressure-time product(PTP) were measured. RESULTS: The mean VE and RR were not different between PCV and VCV during study period. The Ppeak was significantly lower in PCV than in VCV during VT,HIGH ventilation(p<0.05). PIFR was significantly higher in PCV than in VCV at both VT (p<0.05). During VT,LOW ventilation, WOBp and PTP in PCV(0.80?0.37 J/min, 164.5?74.4 cmH2O.S) were significantly lower than in VCV(1.06+/-0.39J /min, 256.4+/-107.5 cmH2O.S)(p<0.05). During VT,HIGH ventilation, WOBp and PTP in PCV(0.33+/-0.14 J/min, 65.7+/-26.3 cmH2O.S) were also significantly lower than in VCV(0.40+/-0.14 J/min, 83.4+/-35.1 cmH2O.S)(p<0.05). CONCLUSION: During assisted ventilation, PCV with deccelerating flow was more effective in reducing WOBp than VCV with constant flow. But since individual variability was shown, further studies are needed to confirm these results.