Ventilation Strategy In Patients Research Articles

Analysis of compliance with lung protective mechanical ventilation strategy in patients with acute respiratory distress syndrome

Objective: To assess the compliance with a lung protective ventilation strategy and to evaluate the relationship with prognosis in patients with acute respiratory distress syndrome (ARDS). Methods: In the prospective multicenter cohort study (CHARDS), patients with ARDS undergoing invasive mechanical ventilation were enrolled to collect essential information, mechanical ventilation data, and prognostic data. Compliance was operationally defined as tidal volume ≤7 ml/kg predicted body weight (PBW) or plateau pressure ≤30 cmH2O or driving pressure≤15 cmH2O. Tidal volume data collected 7 days prior to ventilation after ARDS diagnosis were categorized into four groups: standard group (Group A, 100% compliance), non-standard group (Group B, 50%-99% compliance, Group C,1%-49% compliance,and Group D,totally non-compliant). Plateau pressure and drive pressure measurements were recorded on the first day. Stepwise regression, specifically Logistics regression, was used to identify the factors influencing ICU survival. Results: A total of 449 ARDS patients with invasive mechanical ventilation were included; the proportion of mild, moderate, and severe patients was 71 (15.8%), 198 (44.1%) and 180 (40.1%), respectively. During the first 7 days, a total of 2880 tidal volume measurements were recorded with an average tidal volume of (6.89±1.93) ml/kg PBW. Of these measurements, 53.2% were found to be≤7 ml/kg PBW. The rates of compliance with lung protective mechanical ventilation were 29.8% (134/449), 24.5% (110/449), 23.6% (106/449), and 22% (99/449) in groups A, B, C, and D, respectively. In the standard group, the tidal volume for mild ARDS patients was 18.3%(13/71), while it was 81.7%(58/71)in the non-standard group. Similarly, in patients with moderate ARDS, the tidal volume was 25.8% (51/198) in the standard group, while it was 74.2% (147/198) in the non-standard group. Finally, in patients with severe ARDS, the tidal volume was 38.9% (70/180) in the standard group, while it was 61.1% (110/180) in the non-standard group. Notably, the compliance rate was higher in patients with moderate and severe ARDS in group A compared to patients with mild and moderate ARDS (18.3% vs. 25.8% vs. 38.9%, χ2=13.124, P=0.001). Plateau pressure was recorded in 221 patients, 95.9% (212/221) patients with plateau pressure≤30 cmH2O, and driving pressure was recorded in 207 patients, 77.8% (161/207) patients with a driving pressure ≤15 cmH2O.During the first 7 days, the mortality rate in the intensive care unit (ICU) was lower in the tidal volume standard group compared to the non-standard group (34.6% vs. 51.3%, χ2=10.464, P=0.001). In addition, the in-hospital mortality rate was lower in the standard group compared to the non-standard group (39.8% vs. 57%, χ2=11.016, P=0.001).The results of the subgroup analysis showed that the mortality rates of moderate and severe ARDS patients in the standard group were significantly lower than those in the non-standard group, both in the ICU and in the hospital (all P<0.05). However, there was no statistically significant difference in mortality among mild ARDS patients (all P>0.05). Conclusions: There was high compliance with recommended lung protective mechanical ventilation strategies in ARDS patients, with slightly lower compliance in patients with mild ARDS, and high compliance rates for plateau and drive pressures. The tidal volume full compliance group had a lower mortality than the non-compliance group, and showed a similar trend in the moderate-to-severe ARDS subgroup, but there was no significant correlation between compliance and prognosis in patients with mild ARDS subgroup.

Application of prone position ventilation in ventilation strategies for patients with COVID-19.

Patients with coronavirus disease 2019 (COVID-19) have been shown to die mainly due to disease-induced acute respiratory distress syndrome (ARDS). Prone position ventilation (PPV) is an important ventilation strategy in the management of patients with ARDS. To investigate the application of PPV in ventilation strategies for patients with COVID-19. Three hundred patients with COVID-19 admitted to the Intensive Care Unit (ICU) of Shanxi Bethune Hospital from January 2020 to June 2021 were retrospectively collected. Based on body position and conscious state, all patients were divided into three groups: intubation prone position group (n= 110), awake prone position group (n= 90) and supine position group (n= 100); The acute physiology and chronic health evaluation II (APACHE-II) scores, blood gas indicators, complications and other relevant clinical indicators were compared among the three groups. One-way ANOVA was used to compare means between multiple groups for quantitative information that conformed to a normal distribution. Repeated measures ANOVA was used for repeated measures data. Component comparisons were made using the Kruskal-Wallis H rank sum test for non-normally distributed quantitative data. One-way repeated-measures ANOVA main effect analysis showed different effects of different treatments on PaO2 in patients with COVID-19 (F treatment = 256.231, P< 0.05), with the order of awake prone position group > intubation prone position group > supine position group. The effects of the three different treatments on P/F in patients with COVID-19 (F treatment = 311.661, P< 0.05), with the order of awake prone position group > supine position group > intubation prone position group; Moreover, the three treatments had different effects on APACHE II scores in patients with COVID-19 (F treatment = 201.342, P< 0.05), with the order of intubation prone position group > supine position group > awake prone position group. Intubation prone position and awake prone position can improve lung function to some extent in patients with COVID-19, and should be applied as early as possible in patients with COVID-19-induced ARDS.

Lung protection effect of EIT-based individualized protective ventilation strategy in patients with partial pulmonary resection.

This study aimed to evaluate the lung protection effect of an individualized protective ventilation strategy based on lung impedance tomography (EIT) technology in patients with partial pulmonary resection. Eighty patients of any gender, American Society of Anesthesiologists (ASA) classification I-II, age 30-64 years and body mass index (BMI) 18-28 kg/m2 who underwent elective thoracoscopic partial lung resection were selected and divided into 2 groups (n=40) using the random number table method: [positive end-expiratory pressure (PEEP) by electrical impedance tomography (EIT)] PEEPEIT group (experimental group) and control group. The PEEPEIT group used volume-controlled ventilation after one-lung ventilation, setting a tidal volume of 6 ml/kg and titrating the optimal PEEP value by EIT. Group C used volume-controlled ventilation after one-lung ventilation, setting a tidal volume of 6 ml/kg and a PEEP of 5 cm H2O. Clinical data were collected and recorded at 5 min after double lung ventilation (T0), single lung ventilation, 30 min after PEEP setting (T1), 60 min after PEEP setting (T2), the end of surgery, 10 min after resumption of double lung ventilation (T3) and 10 min after removal of the tracheal tube (T4), and serum surface active substance-associated protein-A (SP-A) concentrations were measured at T0, T3 and 1 d after surgery (T5). PEEP values were higher in the PEEPEIT group than in the control group at T1 and T2 (p-value <0.05); oxygenation index (OI) was higher in the PEEPEIT group compared to the control group at T2 and T3 (p-value <0.05); pulmonary dynamic compliance (Cdyn) was higher in the PEEPEIT group compared to the control group at T1 and T2 (p-value <0.05); intrapulmonary shunt rate (Qs/Qt) was lower in the PEEPEIT group compared to the control group at T1, T2 and at T3, the intrapulmonary shunt rate (Qs/Qt) was reduced in the PEEPEIT group compared to group C (p-value <0.05); at T5, the SP-A protein was reduced in the PEEPEIT group compared to group C. There was no statistically significant difference in the incidence of postoperative pulmonary complications between the two groups (p-value >0.05). The EIT-guided individualized protective ventilation strategy has a lung-protective effect in patients undergoing thoracoscopic partial lung resection.

Invasive Mechanical Ventilation in Traumatic Brain Injured Patients with Acute Respiratory Failure.

Patients with severe traumatic brain injury (TBI) need to be admitted to intensive care (ICU) because they require invasive mechanical ventilation (IMV) due to reduced consciousness resulting in loss of protective airway reflexes, reduced ability to cough and altered breathing control. In addition, these patients can be complicated by pneumonia and acute distress syndrome (ARDS). IMV allows these patients to be sedated, decreasing intracranial pressure and ensuring an adequate oxygen delivery and tight control of arterial carbon dioxide tension. However, IMV can also cause dangerous effects on the brain due to its interaction with intrathoracic and intracranial compartments. Moreover, when TBI is complicated by ARDS, the setting of mechanical ventilation can be very difficult as ventilator goals are often different and in conflict with each other. Consequently, close brain and respiratory monitoring is essential to reduce morbidity and mortality in mechanically ventilated patients with severe TBI and ARDS. Recently, recommendations for the setting of mechanical ventilation in patients with acute brain injury (ABI) were issued by the European Society of Intensive Care Medicine (ESICM). However, there is insufficient evidence regarding ventilation strategies for patients with ARDS associated with ABI. The purpose of this paper is to analyze in detail respiratory strategies and targets in patients with TBI associated with ARDS.

Electrical impedance tomography for titration of positive end-expiratory pressure in acute respiratory distress syndrome patients with chronic obstructive pulmonary disease

BackgroundChronic obstructive pulmonary disease (COPD) is one of most common comorbidities in acute respiratory distress syndrome (ARDS). There are few specific studies on the appropriate ventilation strategy for patients with ARDS comorbid with COPD, especially regarding on positive end-expiratory pressure (PEEP) titration.MethodsTo compare the respiratory mechanics in mechanical ventilated ARDS patients with or without COPD and to determine whether titration of PEEP based on electrical impedance tomography (EIT) is superior to the ARDSnet protocol. This is a single center, perspective, repeated measure study. ARDS patients requiring mechanical ventilation who were admitted to the intensive care unit between August 2017 and December 2020 were included. ARDS patients were divided according to whether they had COPD into a COPD group and a non-COPD group. Respiratory mechanics, gas exchange, and hemodynamics during ventilation were compared between the groups according to whether the PEEP level was titrated by EIT or the ARDSnet protocol.ResultsA total of twenty-seven ARDS patients including 14 comorbid with and 13 without COPD who met the study eligibility criteria were recruited. The PEEP levels titrated by EIT and the ARDSnet protocol were lower in the COPD group than in the non-COPD group (6.93 ± 1.69 cm H2O vs. 12.15 ± 2.40 cm H2O, P < 0.001 and 10.43 ± 1.20 cm H2O vs. 14.0 ± 3.0 cm H2O, P < 0.001, respectively). In the COPD group, the PEEP level titrated by EIT was lower than that titrated by the ARDSnet protocol (6.93 ± 1.69 cm H2O vs. 10.43 ± 1.20 cm H2O, P < 0.001), as was the global inhomogeneity (GI) index (0.397 ± 0.040 vs. 0.446 ± 0.052, P = 0.001), plateau airway pressure (16.50 ± 4.35 cm H2O vs. 20.93 ± 5.37 cm H2O, P = 0.001), dead space ventilation ratio (48.29 ± 6.78% vs. 55.14 ± 8.85%, P < 0.001), ventilation ratio (1.63 ± 0.33 vs. 1.87 ± 0.33, P < 0.001), and mechanical power (13.92 ± 2.18 J/min vs. 15.87 ± 2.53 J/min, P < 0.001). The cardiac index was higher when PEEP was treated by EIT than when it was titrated by the ARDSnet protocol (3.41 ± 0.50 L/min/m2 vs. 3.02 ± 0.43 L/min/m2, P < 0.001), as was oxygen delivery (466.40 ± 71.08 mL/min/m2 vs. 411.10 ± 69.71 mL/min/m2, P = 0.001).ConclusionTitrated PEEP levels were lower in patients with ARDS with COPD than in ARDS patients without COPD. In ARDS patient comorbid with COPD, application of PEEP titrated by EIT was lower than those titrated by the ARDSnet protocol, which contributed to improvements in the ventilation ratio, mechanical energy, cardiac index, and oxygen delivery with less of an adverse impact on hemodynamics.

Invasive mechanical ventilation in patients with acute respiratory distress syndrome receiving extracorporeal support: a narrative review of strategies to mitigate lung injury.

Veno-venous extracorporeal membrane oxygenation is indicated in patients with acute respiratory distress syndrome and severely impaired gas exchange despite evidence-based lung protective ventilation, prone positioning and other parts of the standard algorithm for treating such patients. Extracorporeal support can facilitate ultra-lung-protective ventilation, meaning even lower volumes and pressures than standard lung-protective ventilation, by directly removing carbon dioxide in patients needing injurious ventilator settings to maintain sufficient gas exchange. Injurious ventilation results in ventilator-induced lung injury, which is one of the main determinants of mortality in acute respiratory distress syndrome. Marked reductions in the intensity of ventilation to the lowest tolerable levels under extracorporeal support may be achieved and could thereby potentially mitigate ventilator-induced lung injury and theoretically patient self-inflicted lung injury in spontaneously breathing patients with high respiratory drive. However, the benefits of this strategy may be counterbalanced by the use of continuous deep sedation and even neuromuscular blocking drugs, which may impair physical rehabilitation and impact long-term outcomes. There are currently a lack of large-scale prospective data to inform optimal invasive ventilation practices and how to best apply a holistic approach to patients receiving veno-venous extracorporeal membrane oxygenation, while minimising ventilator-induced and patient self-inflicted lung injury. We aimed to review the literature relating to invasive ventilation strategies in patients with acute respiratory distress syndrome receiving extracorporeal support and discuss personalised ventilation approaches and the potential role of adjunctive therapies in facilitating lung protection.

Efficacy of Higher Positive End-Expiratory Pressure Ventilation Strategy in Patients With Acute Respiratory Distress Syndrome: A Systematic Review and Meta-Analysis.

Previous systematic reviews and meta-analyses assessing the pooled effects of higher positive end-expiratory pressure (PEEP) failed to show significantly reduced mortality in patients with acute respiratory distress syndrome (ARDS). Some new randomized controlled trials (RCTs) have been reported and an updated systematic review is needed to evaluate the use of higher PEEP in patients with ARDS.We searched MEDLINE, Cochrane Central Register of Controlled Trials (CENTRAL), EMBASE, Cumulative Index to Nursing and Allied Health Literature (CINAHL), Igaku-Chuo-Zasshi, ICTRP, the National Institute of Health Clinical Trials Register, and the reference list of recent guidelines. We included RCTs to compare the higher PEEP ventilation strategy with the lower strategy in patients with ARDS. Two authors independently assessed the eligibility of the studies and extracted the data. The primary outcomes were 28-day mortality. The GRADE (Grading of Recommendations, Assessment, Development, and Evaluations) methodology was used to evaluate the certainty of the evidence.Among the 6530 screened records, 16 randomized trials involving 4150 patients were included in our meta-analysis. When comparing higher PEEP versus lower PEEP, the pooled risk ratio (RR) for 28-day mortality was 0.85 (15 studies, n=4108, 95% CI 0.72 to 1.00, I2=58%, low certainty of evidence). Subgroup analysis by study participants with a low tidal volume (LTV) strategy showed an interaction (P for interaction, 0.001).Our study showed that in patients with ARDS, the use of higher PEEP did not significantly reduce 28-day mortality compared to the use of lower PEEP.

Usefulness of low tidal volume ventilation strategy for patients with acute respiratory distress syndrome: a systematic review and meta-analysis

The effects of lower tidal volume ventilation (LTV) were controversial for patients with acute respiratory distress syndrome (ARDS). This systematic review and meta-analysis aimed to evaluate the use of LTV strategy in patients with ARDS. We performed a literature search on MEDLINE, CENTRAL, EMBASE, CINAHL, “Igaku-Chuo-Zasshi”, clinical trial registration sites, and the reference of recent guidelines. We included randomized controlled trials (RCTs) to compare the LTV strategy with the higher tidal volume ventilation (HTV) strategy in patients with ARDS. Two authors independently evaluated the eligibility of studies and extracted the data. The primary outcomes were 28-day mortality. We used the GRADE methodology to assess the certainty of evidence. Among the 19,864 records screened, 13 RCTs that recruited 1874 patients were included in our meta-analysis. When comparing LTV (4–8 ml/kg) versus HTV (> 8 ml/kg), the pooled risk ratio for 28-day mortality was 0.79 (11 studies, 95% confidence interval [CI] 0.66–0.94, I2 = 43%, n = 1795, moderate certainty of evidence). Subgroup-analysis by combined high positive end-expiratory pressure with LTV showed interaction (P = 0.01). Our study indicated that ventilation with LTV was associated with reduced risk of mortality in patients with ARDS when compared with HTV.Trial registration: UMIN-CTR (UMIN000041071).

Effects of different positive end-expiratory pressure titration strategies during prone positioning in patients with acute respiratory distress syndrome: a prospective interventional study

BackgroundProne positioning in combination with the application of low tidal volume and adequate positive end-expiratory pressure (PEEP) improves survival in patients with moderate to severe acute respiratory distress syndrome (ARDS). However, the effects of PEEP on end-expiratory transpulmonary pressure (Ptpexp) during prone positioning require clarification. For this purpose, the effects of three different PEEP titration strategies on Ptpexp, respiratory mechanics, mechanical power, gas exchange, and hemodynamics were evaluated comparing supine and prone positioning.MethodsIn forty consecutive patients with moderate to severe ARDS protective ventilation with PEEP titrated according to three different titration strategies was evaluated during supine and prone positioning: (A) ARDS Network recommendations (PEEPARDSNetwork), (B) the lowest static elastance of the respiratory system (PEEPEstat,RS), and (C) targeting a positive Ptpexp (PEEPPtpexp). The primary endpoint was to analyze whether Ptpexp differed significantly according to PEEP titration strategy during supine and prone positioning.ResultsPtpexp increased progressively with prone positioning compared with supine positioning as well as with PEEPEstat,RS and PEEPPtpexp compared with PEEPARDSNetwork (positioning effect p < 0.001, PEEP strategy effect p < 0.001). PEEP was lower during prone positioning with PEEPEstat,RS and PEEPPtpexp (positioning effect p < 0.001, PEEP strategy effect p < 0.001). During supine positioning, mechanical power increased progressively with PEEPEstat,RS and PEEPPtpexp compared with PEEPARDSNetwork, and prone positioning attenuated this effect (positioning effect p < 0.001, PEEP strategy effect p < 0.001). Prone compared with supine positioning significantly improved oxygenation (positioning effect p < 0.001, PEEP strategy effect p < 0.001) while hemodynamics remained stable in both positions.ConclusionsProne positioning increased transpulmonary pressures while improving oxygenation and hemodynamics in patients with moderate to severe ARDS when PEEP was titrated according to the ARDS Network lower PEEP table. This PEEP titration strategy minimized parameters associated with ventilator-induced lung injury induction, such as transpulmonary driving pressure and mechanical power. We propose that a lower PEEP strategy (PEEPARDSNetwork) in combination with prone positioning may be part of a lung protective ventilation strategy in patients with moderate to severe ARDS.Trial registrationGerman Clinical Trials Register (DRKS00017449). Registered June 27, 2019. https://www.drks.de/drks_web/navigate.do?navigationId=trial.HTML&TRIAL_ID=DRKS00017449

Mechanical Ventilation Strategies in Patients with Intra-Abdominal Hypertension and Open Abdomen

Mechanical Ventilation Strategies in Patients with Intra-Abdominal Hypertension and Open Abdomen

High-Frequency Positive Pressure Ventilation as Primary Rescue Strategy for Patients with Congenital Diaphragmatic Hernia: A Comparison to High-Frequency Oscillatory Ventilation.

The aim of this article was to evaluate high-frequency positive pressure ventilation (HFPPV) compared with high-frequency oscillatory ventilation (HFOV) as a rescue ventilation strategy for patients with congenital diaphragmatic hernia (CDH). HFPPV is a pressure-controlled conventional ventilation method utilizing high respiratory rate and low positive end-expiratory pressure. Seventy-seven patients diagnosed with CDH from January 2005 to September 2019 who were treated with stepwise progression from HFPPV to HFOV versus only HFOV were included. Fisher's exact test and the Kruskal-Wallis test were used to compare outcomes. Patients treated with HFPPV + HFOV had higher survival to discharge (80 vs. 50%, p = 0.007) and to surgical intervention (95.6 vs. 68.8%, p = 0.003), with average age at repair 2 days earlier (p = 0.004). Need for extracorporeal membrane oxygenation (p = 0.490), inhaled nitric oxide (p = 0.585), supplemental oxygen (p = 0.341), and pulmonary hypertension medications (p = 0.381) were similar. In CDH patients who fail respiratory support with conventional ventilation, HFPPV may be used as an intermediary mode of rescue ventilation prior to HFOV without adverse effects. · HFPPV may be used as an intermediary mode of rescue ventilation prior to HFOV without adverse effect.. · HFPPV is more widely available and can mitigate the limitations faced when using HFOV.. · HFPPV allows for intra- or interhospital transfer of neonates with CDH..

Laparoscopic Cholecystectomy in a Patient with Glenn Shunt-Aided with Erector Spine Block.

The bidirectional (BD) Glenn shunt or hemi-Fontan procedure has been used to temporarily improve cardiac function in patients with severe structural heart disease which feature single ventricular physiology. Subsequently, more of these patients present for noncardiac surgical interventions, which present as an anaesthetic challenge. Erector spinae block (ESP) is an effective analgesic modality used in various thoraco abdominal surgeries, which can also be given safely in such patients. A case of a 17-year-old female patient with complex congenital heart disease (CHD) who underwent BD Glenn shunting with main pulmonary artery ligation in childhood, presently admitted for laparoscopic cholecystectomy done under general anaesthesia. With detailed preoperative workups, close haemodynamic monitoring and use of ESP for analgesia during perioperative period, the patient had successful outcome. We outline the anaesthetic management and the concerns of laparoscopy in such patients. A comprehensive understanding of physiology of Glenn's shunt and implications of the proposed surgical procedure is necessary to plan the anaesthetic and analgesic agents, cardiovascular drugs and ventilation strategies in patients with CHD with shunt procedure done.

Mechanical ventilation in septic shock

The aim of this study was to review the most recent literature on mechanical ventilation strategies in patients with septic shock. Indirect clinical trial evidence has refined the use of neuromuscular blocking agents, positive end-expiratory pressure (PEEP) and recruitment manoeuvres in septic shock patients with acute respiratory distress syndrome. Weaning strategies and devices have also been recently evaluated. The role of lung protective ventilation in patients with healthy lungs, while recognized, still needs to be further refined. The possible detrimental effects of spontaneous breathing in patients who develop acute respiratory distress syndrome is increasingly recognized, but clinical trial evidence is still lacking to confirm this hypothesis. A new concept of lung and diaphragm protective is emerging in the critical care literature, but its application will need a complex intervention implementation approach to allow adequate scrutiny of this concept and uptake by clinicians. Many advances in the management of the mechanically ventilated patient with sepsis and septic shock have occurred in recent years, but clinical trial evidence is still necessary to translate new hypotheses to the bedside and find the right balance between benefits and risks of these new strategies.

Noninvasive ventilation and high-flow nasal oxygen for acute respiratory failure: is less more?

High-flow nasal oxygen and noninvasive ventilation (NIV) are two strategies representing an alternative to standard oxygen in the management of respiratory failure. Although high-flow nasal oxygen has shown promising results in patients with de-novo acute respiratory failure, further large clinical trials are needed to determine the best oxygenation strategy. As NIV may have deleterious effects, especially in patients generating strong inspiratory efforts, protective NIV using higher levels of positive-end expiratory pressure, more prolonged sessions and additional interfaces such as helmets should be assessed in the future. Whereas NIV is the first-line ventilation strategy in patients with acute exacerbation of chronic lung diseases, high-flow nasal oxygen could be an alternative to NIV after partial reversal of respiratory acidosis. To prevent severe hypoxemia during intubation of hypoxemic patients or to prevent postextubation respiratory failure in patients at high-risk of reintubation, NIV is the best strategy for preoxygenation or immediately after extubation in ICUs. New large-scale clinical trials are needed to compare high-flow nasal oxygen with standard oxygen in patients with de-novo acute respiratory failure to determine the reference treatment. After which, more protective NIV could be assessed among the more severe patients.

Effect of Hematocrit on the CO2 Removal Rate of Artificial Lungs.

Extracorporeal CO2 removal (ECCO2R) can permit lung protective or noninvasive ventilation strategies in patients with chronic obstructive pulmonary disease (COPD) and acute respiratory distress syndrome (ARDS). With evidence supporting ECCO2R growing, investigating factors which affect CO2 removal is necessary. Multiple factors are known to affect the CO2 removal rate (vCO2) which can complicate the interpretation of changes in vCO2; however, the effect of hematocrit on the vCO2 of artificial lungs has not been investigated. This in vitro study evaluates the relationship between hematocrit level and vCO2 within an ECCO2R device. In vitro gas transfer was measured in bovine blood in accordance with the ISO 7199 standard. Plasma and saline were used to hemodilute the blood to hematocrits between 33% and 8%. The vCO2 significantly decreased as the blood was hemodiluted with saline and plasma by 42% and 32%, respectively, between a hematocrit of 33% and 8%. The hemodilution method did not significantly affect the vCO2. In conclusion, the hematocrit level significantly affects vCO2 and should be taken into account when interpreting changes in the vCO2 of an ECCO2R device.

The advances of mechanical ventilation in patients with traumatic brain injury

Mechanical ventilation is regarded as an important respiratory support method for patients with traumatic brain injury (TBI). It′s widely used during the treatment for these patients. However, because of the existence of brain-lung crosstalk, it′s still be controversial about the strategies of mechanical ventilation for patients with TBI. We reviewed and summarized the related research in recent years. We suggested cautiously using large tide volume, hyperventilation and hypercapnia in clinical practice because they do have some negatively influences on cerebral blood flow and intracranial pressure. The use of positive end expiratory pressure (PEEP) and recruitment maneuvers (RMs) can improve the exchange of gas within the pulmonary, but they may have adverse effects on cerebral hemodynamics. It seems safe by taking the strategies of PEEP and RMs when adequate monitors were used for both lung and brain to guarantee stable arterial blood pressure and adequate cerebral oxygen perfusion. However, the best ventilation strategy for patients with TBI still need to be further explored. Key words: Craniocerebral injury; Mechanical ventilation; Positive end expiratory pressure; Recruitment maneuvers

Lung Compliance and Outcomes in Patients With Acute Respiratory Distress Syndrome Receiving ECMO

Limited data are available regarding mechanical ventilation strategies in patients with acute respiratory distress syndrome receiving extracorporeal membrane oxygenation (ECMO). A retrospective analysis of acute respiratory distress syndrome patients on ECMO was conducted in 9 hospitals in Korea. Data on ventilator settings (pre-ECMO and 0, 4, 24, and 48 hours after ECMO) were collected. Based on the effect of the duration and intensity of mechanical ventilator on outcomes, time-weighted average values were calculated for ventilator parameters. The 56 patients included in the study had a mean age of 55.5 years. The hospital and 6-month mortality rates were 48.1% and 54.0%, respectively, with a median ECMO duration of 9.4 days. After initiation of ECMO, peak inspiratory pressure, above positive end-expiratory pressure, tidal volume, and respiration rate were reduced, while lung compliance did not change significantly. Before and during ECMO support, tidal volume and lung compliance were higher in 6-month survivors than in nonsurvivors. In Cox proportional models, both lung compliance (odds ratio, 0.961; 95% confidence interval, 0.928 to 0.995) and time-weighted average-lung compliance (odds ratio, 0.943; 95% confidence interval, 0.903 to 0.986) were significantly associated with 6-month mortality. Kaplan-Meier curves revealed that patients with higher lung compliance before ECMO had a longer survival time at the 6-month follow-up than did those with lower lung compliance. Lung compliance, whether before or during ECMO, may be an important predictor of outcome in acute respiratory distress syndrome patients receiving ECMO. However, this result requires confirmation in larger clinical studies.

Abstract PCCLB-13: DIFFERENTIAL LUNG VENTILATION IN A PEDIATRIC PATIENT ON ECMO USING A BRONCHIAL BLOCKER: A CASE REPORT

Aims & Objectives: Differential lung ventilation (DLV) may be a useful alternative ventilation strategy in patients with disparate lung disease. We describe a patient with respiratory failure post cardiac arrest that was cannulated to VA ECMO. The patient developed right sided interstitial emphysema along with air leak and left sided Hemothorax with secondary atelectasis. The patient was ventilated with DLV using left sided ETT and a right sided bronchial blocker. Methods A fiberoptic bronchoscope was loaded with a 5.5 cuffed ETT and the 7Fr Arndt bronchial blocker was attached to the ETT via the guide loop on the distal end. The bronchoscope was advanced into the right mainstem bronchus and deployed in position releasing the guide loop. The cuff of the bronchial blocker was inflated to ensure complete occlusion of the right mainstem bronchus. The scope was then advanced into the left mainstem and the ETT was placed in good position. ETT and bronchial blockers were noted to be in good position by direct visualization, then attached to 2 separate ventilators.Results The left lung was recruited with PC-SIMV PIP-30, PEEP-12, iTime-3 secs and the right lung rested with CPAP-12, via bronchial blocker; at this pressure level, no air leak was noted. Thirty six hours later, Arndt blocker was removed, the ETT was pulled back into the trachea and the patient transitioned to conventional ventilation strategy. The patient was subsequently decannulated from ECMO and weaned to room air. Conclusions DLV may be performed in patients on ECMO with differential lung disease as an alternative ventilation strategy.

Variable ventilation decreases airway responsiveness and improves ventilation efficiency in a rat model of asthma

The optimal ventilation strategy in patients receiving mechanical ventilation for severe asthma remains unclear. The effect of conventional ventilation (with constant tidal volume and respiratory rate) and variable ventilation (with the same average but variable tidal volume and respiratory rate) on peak airway pressure and airway exacerbation induced by increasing doses of methacholine was compared in a rat model of asthma. The respiratory rate and tidal volume data were obtained from a spontaneously breathing intact rat during immobility using a whole-body plethysmograph. Peak airway pressure and airway responsiveness to cumulative doses of methacholine were significantly affected by ventilation mode and they were lower in variable ventilation group than in the conventional ventilation group. Also, variable ventilation improved oxygen saturation compared to conventional ventilation. Our results indicate that variable ventilation decreases airway responsiveness and enhances ventilation efficiency in a rat model of asthma. We suggest further investigations on beneficial effects of variable ventilation strategy in mechanically ventilated patients with severe asthma.

The effect of an intraoperative, lung-protective ventilation strategy in neurosurgical patients undergoing craniotomy: study protocol for a randomized controlled trial

BackgroundVentilator-induced lung injury is a major cause of postoperative pulmonary complications (PPCs) in patients undergoing neurosurgery after general anesthesia. However, there is no study on the effect of a lung-protective ventilation strategy in patients undergoing neurosurgery.MethodsThis is a single-center, randomized, parallel-group controlled trial which will be carried out at Beijing Tiantan Hospital, Capital Medical University. Three hundred and thirty-four patients undergoing intracranial tumor surgery will be randomly allocated to the control group and the protective-ventilation strategy group. In the control group, tidal volume (VT) will be set at 10–12 ml/kg of predicted body weight but PEEP and recruitment maneuvers will not be used. In the protective group, VT will be set at 6–8 ml/kg of predicted body weight, PEEP at 6–8 cmH2O, and a recruitment maneuver will be used intermittently. The primary outcome is pulmonary complications within 7 days postoperatively. Secondary outcomes include intraoperative brain relaxation, the postoperative complications within 30 days and the cost analysis.DiscussionThis study aims to determine if the protective, pulmonary-ventilation strategy decreases the incidence of PPCs in patients undergoing neurosurgical anesthesia. If our results are positive, the study will indicate whether the protective, pulmonary-ventilation strategy is efficiently and safely used in neurosurgical patients undergoing the craniotomy.Trial registrationClinicalTrials.gov, ID: NCT02386683. Registered on 18 October 2014.